An ANOVA approach for statistical comparisons of brain networks.

PubMed

Fraiman, Daniel; Fraiman, Ricardo

2018-03-16

The study of brain networks has developed extensively over the last couple of decades. By contrast, techniques for the statistical analysis of these networks are less developed. In this paper, we focus on the statistical comparison of brain networks in a nonparametric framework and discuss the associated detection and identification problems. We tested network differences between groups with an analysis of variance (ANOVA) test we developed specifically for networks. We also propose and analyse the behaviour of a new statistical procedure designed to identify different subnetworks. As an example, we show the application of this tool in resting-state fMRI data obtained from the Human Connectome Project. We identify, among other variables, that the amount of sleep the days before the scan is a relevant variable that must be controlled. Finally, we discuss the potential bias in neuroimaging findings that is generated by some behavioural and brain structure variables. Our method can also be applied to other kind of networks such as protein interaction networks, gene networks or social networks.

An Analysis of Research Methods and Statistical Techniques Used by Doctoral Dissertation at the Education Sciences in Turkey

ERIC Educational Resources Information Center

Karadag, Engin

2010-01-01

To assess research methods and analysis of statistical techniques employed by educational researchers, this study surveyed unpublished doctoral dissertation from 2003 to 2007. Frequently used research methods consisted of experimental research; a survey; a correlational study; and a case study. Descriptive statistics, t-test, ANOVA, factor…

A Statistical Analysis Plan to Support the Joint Forward Area Air Defense Test.

DTIC Science & Technology

1984-08-02

hy estahlishing a specific significance level prior to performing the statistical test (traditionally a levels are set at .01 or .05). What is often...undesirable increase in 8. For constant a levels , the power (I - 8) of a statistical test can he increased by Increasing the sample size of the test. fRef...ANOVA Iparison Test on MOP I=--ferences Exist AmongF "Upon MOP "A" Factor I "A" Factor I 1MOP " A " Levels ? I . I I I _ _ ________ IPerform k-Sample Com- I

Increasing the Efficiency on Producing Radiology Reports for Breast Cancer Diagnosis by Means of Structured Reports. A Comparative Study.

PubMed

Segrelles, J Damian; Medina, Rosana; Blanquer, Ignacio; Martí-Bonmatí, Luis

2017-05-18

Radiology reports are commonly written on free-text using voice recognition devices. Structured reports (SR) have a high potential but they are usually considered more difficult to fill-in so their adoption in clinical practice leads to a lower efficiency. However, some studies have demonstrated that in some cases, producing SRs may require shorter time than plain-text ones. This work focuses on the definition and demonstration of a methodology to evaluate the productivity of software tools for producing radiology reports. A set of SRs for breast cancer diagnosis based on BI-RADS have been developed using this method. An analysis of their efficiency with respect to free-text reports has been performed. The methodology proposed compares the Elapsed Time (ET) on a set of radiological reports. Free-text reports are produced with the speech recognition devices used in the clinical practice. Structured reports are generated using a web application generated with TRENCADIS framework. A team of six radiologists with three different levels of experience in the breast cancer diagnosis was recruited. These radiologists performed the evaluation, each one introducing 50 reports for mammography, 50 for ultrasound scan and 50 for MRI using both approaches. Also, the Relative Efficiency (REF) was computed for each report, dividing the ET of both methods. We applied the T-Student (T-S) test to compare the ETs and the ANOVA test to compare the REFs. Both tests were computed using the SPSS software. The study produced three DICOM-SR templates for Breast Cancer Diagnosis on mammography, ultrasound and MRI, using RADLEX terms based on BIRADs 5th edition. The T-S test on radiologists with high or intermediate profile, showed that the difference between the ET was only statistically significant for mammography and ultrasound. The ANOVA test performed grouping the REF by modalities, indicated that there were no significant differences between mammograms and ultrasound scans, but both have significant statistical differences with MRI. The ANOVA test of the REF for each modality, indicated that there were only significant differences in Mammography (ANOVA p = 0.024) and Ultrasound (ANOVA p = 0.008). The ANOVA test for each radiologist profile, indicated that there were significant differences on the high profile (ANOVA p = 0.028) and medium (ANOVA p = 0.045). In this work, we have defined and demonstrated a methodology to evaluate the productivity of software tools for producing radiology reports in Breast Cancer. We have evaluated that adopting Structured Reporting in mammography and ultrasound studies in breast cancer diagnosis improves the performance in producing reports.

Statistical inference methods for sparse biological time series data.

PubMed

Ndukum, Juliet; Fonseca, Luís L; Santos, Helena; Voit, Eberhard O; Datta, Susmita

2011-04-25

Comparing metabolic profiles under different biological perturbations has become a powerful approach to investigating the functioning of cells. The profiles can be taken as single snapshots of a system, but more information is gained if they are measured longitudinally over time. The results are short time series consisting of relatively sparse data that cannot be analyzed effectively with standard time series techniques, such as autocorrelation and frequency domain methods. In this work, we study longitudinal time series profiles of glucose consumption in the yeast Saccharomyces cerevisiae under different temperatures and preconditioning regimens, which we obtained with methods of in vivo nuclear magnetic resonance (NMR) spectroscopy. For the statistical analysis we first fit several nonlinear mixed effect regression models to the longitudinal profiles and then used an ANOVA likelihood ratio method in order to test for significant differences between the profiles. The proposed methods are capable of distinguishing metabolic time trends resulting from different treatments and associate significance levels to these differences. Among several nonlinear mixed-effects regression models tested, a three-parameter logistic function represents the data with highest accuracy. ANOVA and likelihood ratio tests suggest that there are significant differences between the glucose consumption rate profiles for cells that had been--or had not been--preconditioned by heat during growth. Furthermore, pair-wise t-tests reveal significant differences in the longitudinal profiles for glucose consumption rates between optimal conditions and heat stress, optimal and recovery conditions, and heat stress and recovery conditions (p-values <0.0001). We have developed a nonlinear mixed effects model that is appropriate for the analysis of sparse metabolic and physiological time profiles. The model permits sound statistical inference procedures, based on ANOVA likelihood ratio tests, for testing the significance of differences between short time course data under different biological perturbations.

Content and Method in the Teaching of Marketing Research Revisited

ERIC Educational Resources Information Center

Wilson, Holt; Neeley, Concha; Niedzwiecki, Kelly

2009-01-01

This paper presents the findings from a survey of marketing research faculty. The study finds SPSS is the most used statistical software, that cross tabulation, single, independent, and dependent t-tests, and ANOVA are among the most important statistical tools according to respondents. Bivariate and multiple regression are also considered…

Biostatistics Series Module 3: Comparing Groups: Numerical Variables.

PubMed

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.

Two Methods of Automatic Evaluation of Speech Signal Enhancement Recorded in the Open-Air MRI Environment

NASA Astrophysics Data System (ADS)

Přibil, Jiří; Přibilová, Anna; Frollo, Ivan

2017-12-01

The paper focuses on two methods of evaluation of successfulness of speech signal enhancement recorded in the open-air magnetic resonance imager during phonation for the 3D human vocal tract modeling. The first approach enables to obtain a comparison based on statistical analysis by ANOVA and hypothesis tests. The second method is based on classification by Gaussian mixture models (GMM). The performed experiments have confirmed that the proposed ANOVA and GMM classifiers for automatic evaluation of the speech quality are functional and produce fully comparable results with the standard evaluation based on the listening test method.

Classical Statistics and Statistical Learning in Imaging Neuroscience

PubMed Central

Bzdok, Danilo

2017-01-01

Brain-imaging research has predominantly generated insight by means of classical statistics, including regression-type analyses and null-hypothesis testing using t-test and ANOVA. Throughout recent years, statistical learning methods enjoy increasing popularity especially for applications in rich and complex data, including cross-validated out-of-sample prediction using pattern classification and sparsity-inducing regression. This concept paper discusses the implications of inferential justifications and algorithmic methodologies in common data analysis scenarios in neuroimaging. It is retraced how classical statistics and statistical learning originated from different historical contexts, build on different theoretical foundations, make different assumptions, and evaluate different outcome metrics to permit differently nuanced conclusions. The present considerations should help reduce current confusion between model-driven classical hypothesis testing and data-driven learning algorithms for investigating the brain with imaging techniques. PMID:29056896

Bootstrapping in Applied Linguistics: Assessing Its Potential Using Shared Data

ERIC Educational Resources Information Center

Plonsky, Luke; Egbert, Jesse; Laflair, Geoffrey T.

2015-01-01

Parametric analyses such as t tests and ANOVAs are the norm--if not the default--statistical tests found in quantitative applied linguistics research (Gass 2009). Applied statisticians and one applied linguist (Larson-Hall 2010, 2012; Larson-Hall and Herrington 2010), however, have argued that this approach may not be appropriate for small samples…

The Influence of Ability Grouping on Math Achievement in a Rural Middle School

ERIC Educational Resources Information Center

Pritchard, Robert R.

2012-01-01

The researcher examined the academic performance of low-tracked students (n = 156) using standardized math test scores to determine whether there is a statistically significant difference in achievement depending on academic environment, tracked or nontracked. An analysis of variance (ANOVA) was calculated, using a paired samples t-test for a…

Goodness-Of-Fit Test for Nonparametric Regression Models: Smoothing Spline ANOVA Models as Example.

PubMed

Teran Hidalgo, Sebastian J; Wu, Michael C; Engel, Stephanie M; Kosorok, Michael R

2018-06-01

Nonparametric regression models do not require the specification of the functional form between the outcome and the covariates. Despite their popularity, the amount of diagnostic statistics, in comparison to their parametric counter-parts, is small. We propose a goodness-of-fit test for nonparametric regression models with linear smoother form. In particular, we apply this testing framework to smoothing spline ANOVA models. The test can consider two sources of lack-of-fit: whether covariates that are not currently in the model need to be included, and whether the current model fits the data well. The proposed method derives estimated residuals from the model. Then, statistical dependence is assessed between the estimated residuals and the covariates using the HSIC. If dependence exists, the model does not capture all the variability in the outcome associated with the covariates, otherwise the model fits the data well. The bootstrap is used to obtain p-values. Application of the method is demonstrated with a neonatal mental development data analysis. We demonstrate correct type I error as well as power performance through simulations.

Retentive force and microleakage of stainless steel crowns cemented with three different luting agents.

PubMed

Yilmaz, Yucel; Dalmis, Anya; Gurbuz, Taskin; Simsek, Sera

2004-12-01

The aim of this investigation was to compare the tensile strength, microleakage, and Scanning Electron Microscope (SEM) evaluations of SSCs cemented using different adhesive cements on primary molars. Sixty-three extracted primary first molars were used. Tooth preparations were done. Crowns were altered and adapted for investigation purpose, and then cemented using glass ionomer cement (Aqua Meron), resin modified cement (RelyX Luting), and resin cement (Panavia F) on the prepared teeth. Samples were divided into two groups of 30 samples each for tensile strength and microleakage tests. The remaining three samples were used for SEM evaluation. Data were analyzed with one-way ANOVA and Tukey test. The statistical analysis of ANOVA revealed significant differences among the groups for both tensile strength and microleakage tests (p < 0.05). Tukey test showed statistically significant difference between Panavia F and RelyX Luting (p < 0.05), but none between the others (p > 0.05). This study showed that the higher the retentive force a crown possessed, the lower would be the possibility of microleakage.

Shear Bond Strengths and Morphological Evaluation of Filled and Unfilled Adhesive Interfaces to Enamel and Dentine

PubMed Central

Mortazavi, Vajihesadat; Fathi, Mohammadhosein; Ataei, Ebrahim; Khodaeian, Niloufar; Askari, Navid

2012-01-01

In this laboratory study shear bond strengths of three filled and one unfilled adhesive systems to enamel and dentine were compared. Forty-eight extracted intact noncarious human mandibular molars were randomly assigned to two groups of 24 one for bonding to enamel and the other for bonding to dentine. Buccal and lingual surfaces of each tooth were randomly assigned for application of each one of filled (Prime & Bond NT (PBNT), Optibond Solo Plus (OBSP), and Clearfil SE Bond (CSEB)) and unfilled (Single Bond (SB)) adhesive systems (n = 12). A universal resin composite was placed into the translucent plastic cylinders (3 mm in diameter and 2 mm in length) and seated against the enamel and dentine surfaces and polymerized for 40 seconds. Shear bond strength was determined using a universal testing machine, and the results were statistically analyzed using two-way ANOVA, one-way ANOVA, t-test, and Tukey HSD post hoc test with a 5% level of significance.There were no statistically significant differences in bond strength between the adhesive systems in enamel, but CSEB and SB exhibited significantly higher and lower bond strength to dentine, respectively, than the other tested adhesive systems while there were no statistically significant differences between PBNT and OBSP. PMID:23209471

Demineralization of resin-sealed enamel by soft drinks in a clinically relevant pH cycling model.

PubMed

Bartels, Agata A; Evans, Carla A; Viana, Grace; Bedran-Russo, Ana K

2016-04-01

To compare the in vitro protective effect of orthodontic sealants on the enamel demineralization under a soft drink-induced erosive challenge. The facial surfaces of bovine incisors were sectioned into 5 mm x 4 mm x 4 mm enamel blocks. Specimens were randomly assigned to three surface protection measures: control (exposed enamel), coating with Transbond XT (unfilled resin primer), or coating with Opal Seal (filled and fluoride releasing primer). Thermocycling was used to simulate aging. The specimens were pH cycled through an acidic buffer, test beverage and a neutral buffer for a total of 7 days. Test beverages included water, Diet Mountain Dew, and Coke Classic. Quantitative light-induced fluorescence (QLF) images were taken at baseline and after aging. Final QLF images were taken to evaluate the demineralization of enamel. Data were analyzed statistically using a two-way ANOVA to compare the interaction between enamel surface protection and beverages as well as one-way ANOVA to compare surface protection and the test beverage levels. A statistically significant interaction was found between the surface protected groups and the test beverage groups (P < 0.05). Statistically significant differences were found among the test beverage groups (P < 0.05) and among the surface protection groups (P < 0.05). Coke Classic went through the sealant layer resulting in high enamel demineralization. Enamel coating with Opal Seal significantly reduced the erosive attack of beverages.

Tools for Basic Statistical Analysis

NASA Technical Reports Server (NTRS)

Luz, Paul L.

2005-01-01

Statistical Analysis Toolset is a collection of eight Microsoft Excel spreadsheet programs, each of which performs calculations pertaining to an aspect of statistical analysis. These programs present input and output data in user-friendly, menu-driven formats, with automatic execution. The following types of calculations are performed: Descriptive statistics are computed for a set of data x(i) (i = 1, 2, 3 . . . ) entered by the user. Normal Distribution Estimates will calculate the statistical value that corresponds to cumulative probability values, given a sample mean and standard deviation of the normal distribution. Normal Distribution from two Data Points will extend and generate a cumulative normal distribution for the user, given two data points and their associated probability values. Two programs perform two-way analysis of variance (ANOVA) with no replication or generalized ANOVA for two factors with four levels and three repetitions. Linear Regression-ANOVA will curvefit data to the linear equation y=f(x) and will do an ANOVA to check its significance.

The Design and Development of a Context-Rich, Photo-Based Online Testing to Assess Students' Science Learning

ERIC Educational Resources Information Center

Lin, Min-Jin; Guo, Chorng-Jee; Hsu, Chia-Er

2011-01-01

This study designed and developed a CP-MCT (content-rich, photo-based multiple choice online test) to assess whether college students can apply the basic light concept to interpret daily light phenomena. One hundred college students volunteered to take the CP-MCT, and the results were statistically analyzed by applying t-test or ANOVA (Analysis of…

Association Between Selenium and Malondialdehyde as an Efficient Biomarker of Oxidative Stress in Infantile Cardiac Surgery.

PubMed

de Oliveira Ulbrecht, Marlice Oliveira; Gonçalves, Daniel Araujo; Zanoni, Lourdes Zélia Garcia; do Nascimento, Valter Aragão

2018-05-12

The present work describes a method to quantify the level of oxidative stress in infantile cardiac surgery. Fifteen patients, 6 girls and 9 boys, aged between 3 months and 16 years were divided into three groups. The first group sought to quantify the oxidative stress from differing concentrations of selenium. The second group used malondialdehyde as an indicator of oxidative stress. Finally, the third group quantified oxidative stress by normalizing the selenium concentration via malondialdehyde. Blood aliquots of 1.50 ml, drawn from the radial artery, were collected and centrifuged for quantification of Se and MDA in plasma. The statistical method ANOVA was used with a 95% confidence interval to indicate significant statistical differences between the post- and pre-operative stage for each group. The concentrations of malondialdehyde were measured by using UV-Vis following the thiobarbituric acid reaction method. For quantification of selenium, the samples were submitted to assisted microwave digestion and measured by ICP OES. In the first two groups, it was not possible to affirm that selenium and malondialdehyde could be biomarkers of oxidative stress, so a statistic test (ANOVA) was performed. However, the selenium/malondialdehyde ratios in the pre-operative and post-operative stage were 2.10 ± 0.70 and 3.20 ± 0.40, respectively. The ANOVA test confirmed a statistically significant difference between the pre- and post-operative stages with p value = 0.004. Here, the ratio of selenium concentration by malondialdehyde was confirmed to be an effective parameter for demonstration and quantification of oxidative stress activity at the post-operative stage.

Variable criteria sequential stopping rule: Validity and power with repeated measures ANOVA, multiple correlation, MANOVA and relation to Chi-square distribution.

PubMed

Fitts, Douglas A

2017-09-21

The variable criteria sequential stopping rule (vcSSR) is an efficient way to add sample size to planned ANOVA tests while holding the observed rate of Type I errors, α o , constant. The only difference from regular null hypothesis testing is that criteria for stopping the experiment are obtained from a table based on the desired power, rate of Type I errors, and beginning sample size. The vcSSR was developed using between-subjects ANOVAs, but it should work with p values from any type of F test. In the present study, the α o remained constant at the nominal level when using the previously published table of criteria with repeated measures designs with various numbers of treatments per subject, Type I error rates, values of ρ, and four different sample size models. New power curves allow researchers to select the optimal sample size model for a repeated measures experiment. The criteria held α o constant either when used with a multiple correlation that varied the sample size model and the number of predictor variables, or when used with MANOVA with multiple groups and two levels of a within-subject variable at various levels of ρ. Although not recommended for use with χ 2 tests such as the Friedman rank ANOVA test, the vcSSR produces predictable results based on the relation between F and χ 2 . Together, the data confirm the view that the vcSSR can be used to control Type I errors during sequential sampling with any t- or F-statistic rather than being restricted to certain ANOVA designs.

Subtle Cognitive Effects of Moderate Hypoxia

DTIC Science & Technology

2009-08-01

using SPSS® 13.0 with significance set at an alpha level of .05 for all statistical tests. A repeated measures analysis of variance (ANOVA) was...there was not statistically significant change in reaction time (p=.781), accuracy (p=.152), or throughout (p=.967) with increasing altitude. The...results indicate that healthy individuals aged 19 to 45 years do not experience significant cognitive deficit, as measured by the CogScreen®-HE, when

Recognizing the Signs and Symptoms of Youth and Adolescents That Experience Mental Health Problems and/or Crises

ERIC Educational Resources Information Center

Pritchett, Tierra M.

2017-01-01

Health First Aid at the Philadelphia Red Cross completed a survey with information pertaining to knowledge and confidence in recognizing the signs and symptoms of youth/adolescents that may be experiencing a mental health problem and or crisis. Descriptive statistics, independent t-tests, ANOVA, and Tukey tests were conducted to investigate the…

A SAS macro for testing differences among three or more independent groups using Kruskal-Wallis and Nemenyi tests.

PubMed

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.

Modeling the low-velocity impact characteristics of woven glass epoxy composite laminates using artificial neural networks

NASA Astrophysics Data System (ADS)

Mathivanan, N. Rajesh; Mouli, Chandra

2012-12-01

In this work, a new methodology based on artificial neural networks (ANN) has been developed to study the low-velocity impact characteristics of woven glass epoxy laminates of EP3 grade. To train and test the networks, multiple impact cases have been generated using statistical analysis of variance (ANOVA). Experimental tests were performed using an instrumented falling-weight impact-testing machine. Different impact velocities and impact energies on different thicknesses of laminates were considered as the input parameters of the ANN model. This model is a feed-forward back-propagation neural network. Using the input/output data of the experiments, the model was trained and tested. Further, the effects of the low-velocity impact response of the laminates at different energy levels were investigated by studying the cause-effect relationship among the influential factors using response surface methodology. The most significant parameter is determined from the other input variables through ANOVA.

Lower incisor inclination regarding different reference planes.

PubMed

Zataráin, Brenda; Avila, Josué; Moyaho, Angeles; Carrasco, Rosendo; Velasco, Carmen

2016-09-01

The purpose of this study was to assess the degree of lower incisor inclination with respect to different reference planes. It was an observational, analytical, longitudinal, prospective study conducted on 100 lateral cephalograms which were corrected according to the photograph in natural head position in order to draw the true vertical plane (TVP). The incisor mandibular plane angle (IMPA) was compensated to eliminate the variation of the mandibular plane growth type with the formula "FMApx.- 25 (FMA) + IMPApx. = compensated IMPA (IMPACOM)". As the data followed normal distribution determined by the KolmogorovSmirnov test, parametric tests were used for the statistical analysis, Ttest, ANOVA and Pearson coefficient correlation test. Statistical analysis was performed using a statistical significance of p <0.05. There is correlation between TVP and NB line (NB) (0.8614), Frankfort mandibular incisor angle (FMIA) (0.8894), IMPA (0.6351), Apo line (Apo) (0.609), IMPACOM (0.8895) and McHorris angle (MH) (0.7769). ANOVA showed statistically significant differences between the means for the 7 variables with 95% confidence level, P=0.0001. The multiple range test showed no significant difference among means: APoNB (0.88), IMPAMH (0.36), IMPANB (0.65), FMIAIMPACOM (0.01), FMIATVP (0.18), TVPIMPACOM (0.17). There was correlation among all reference planes. There were statistically significant differences among the means of the planes measured, except for IMPACOM, FMIA and TVP. The IMPA differed significantly from the IMPACOM. The compensated IMPA and the FMIA did not differ significantly from the TVP. The true horizontal plane was mismatched with Frankfort plane in 84% of the sample with a range of 19°. The true vertical plane is adequate for measuring lower incisor inclination. Sociedad Argentina de Investigación Odontológica.

A Didactic Experience of Statistical Analysis for the Determination of Glycine in a Nonaqueous Medium Using ANOVA and a Computer Program

ERIC Educational Resources Information Center

Santos-Delgado, M. J.; Larrea-Tarruella, L.

2004-01-01

The back-titration methods are compared statistically to establish glycine in a nonaqueous medium of acetic acid. Important variations in the mean values of glycine are observed due to the interaction effects between the analysis of variance (ANOVA) technique and a statistical study through a computer software.

Academic Motivations of Pre-Service English Language Teachers

ERIC Educational Resources Information Center

Ariogul, Sibel

2009-01-01

This study examines the academic motivation, in a Turkish context, of Turkish pre-service English teachers to contribute field research. Students (n=287) completed the Academic Motivation Scale (AMS) and a demographic questionnaire. Data were analyzed using descriptive statistics, a one-way ANOVA, independent sample t-test, and Pearson product…

Quality of reporting statistics in two Indian pharmacology journals.

PubMed

Jaykaran; Yadav, Preeti

2011-04-01

To evaluate the reporting of the statistical methods in articles published in two Indian pharmacology journals. All original articles published since 2002 were downloaded from the journals' (Indian Journal of Pharmacology (IJP) and Indian Journal of Physiology and Pharmacology (IJPP)) website. These articles were evaluated on the basis of appropriateness of descriptive statistics and inferential statistics. Descriptive statistics was evaluated on the basis of reporting of method of description and central tendencies. Inferential statistics was evaluated on the basis of fulfilling of assumption of statistical methods and appropriateness of statistical tests. Values are described as frequencies, percentage, and 95% confidence interval (CI) around the percentages. Inappropriate descriptive statistics was observed in 150 (78.1%, 95% CI 71.7-83.3%) articles. Most common reason for this inappropriate descriptive statistics was use of mean ± SEM at the place of "mean (SD)" or "mean ± SD." Most common statistical method used was one-way ANOVA (58.4%). Information regarding checking of assumption of statistical test was mentioned in only two articles. Inappropriate statistical test was observed in 61 (31.7%, 95% CI 25.6-38.6%) articles. Most common reason for inappropriate statistical test was the use of two group test for three or more groups. Articles published in two Indian pharmacology journals are not devoid of statistical errors.

Effect of cefuroxime and moxifloxacin on Staphylococcus epidermidis adherence to intraocular lenses.

PubMed

Karadağ, Serhat; Ozkan, Berna; Karabaş, V Levent; Alintaş, Ozgül; Yumuk, Zeki; Cağlar, Yusuf

2009-12-01

To investigate and compare the effect of cefuroxime and moxifloxacin on adhesion of Staphylococcus epidermidis to intraocular lenses (IOLs). Experimental study. The 3-pieced hydrophobic acrylic lenses were contaminated with S. epidermidis (American Type Culture Collection 35983) solutions containing 108 colony-forming units. IOLs were inoculated into test tubes containing tryptic soy broth after being held in antibiotic solutions for 15 minutes. Sonication and vortex procedures were performed in order to remove all the remaining bacteria. From each tube 10 microL and 100 microL was taken and inoculated into sheep blood agar. The colonies were counted overnight. The statistical analyses were made using one-way ANOVA, Turkey Honestly Significant Differences test (HSD) and independent t tests, and a p value less than 0.05 was considered statistically significant. Overall, the mean numbers of colony-forming units on the lenses that were held in control, cefuroxime, moxifloxacin 0.5 mg/0.1 mL and moxifloxacin 0.1 mg/0.1 mL solutions were 1398 (SE 10.01 x 10(3)), 29.9 (SE 1.16 x 10(3)), 0.23 (SD 0.04 x 10(3)), and 0.41 (SD 0.05 x 10(3)), respectively. The evaluation using one-way ANOVA and Turkey HSD tests revealed significant statistical differences among the groups (p = 0.000). The evaluation using independent t tests revealed significant statistical differences between the 2 moxifloxacin groups (p < 0.05). Our results suggest that moxifloxacin and cefuroxime significantly inhibit bacterial adherence to IOLs. The effect of moxifloxacin on inhibition of bacterial adherence was significantly greater than that of cefuroxime. For this reason moxifloxacin might be considered as a better prophylactic agent.

Formative Use of Intuitive Analysis of Variance

ERIC Educational Resources Information Center

Trumpower, David L.

2013-01-01

Students' informal inferential reasoning (IIR) is often inconsistent with the normative logic underlying formal statistical methods such as Analysis of Variance (ANOVA), even after instruction. In two experiments reported here, student's IIR was assessed using an intuitive ANOVA task at the beginning and end of a statistics course. In both…

[Analysis of variance of repeated data measured by water maze with SPSS].

PubMed

Qiu, Hong; Jin, Guo-qin; Jin, Ru-feng; Zhao, Wei-kang

2007-01-01

To introduce the method of analyzing repeated data measured by water maze with SPSS 11.0, and offer a reference statistical method to clinical and basic medicine researchers who take the design of repeated measures. Using repeated measures and multivariate analysis of variance (ANOVA) process of the general linear model in SPSS and giving comparison among different groups and different measure time pairwise. Firstly, Mauchly's test of sphericity should be used to judge whether there were relations among the repeatedly measured data. If any (P

Using Performance Methods to Enhance Students' Reading Fluency

ERIC Educational Resources Information Center

Young, Chase; Valadez, Corinne; Gandara, Cori

2016-01-01

The quasi-experimental study examined the effects of pairing Rock and Read with Readers Theater and only Rock and Read on second grade students' reading fluency scores. The 51 subjects were pre- and post-tested on five different reading fluency measures. A series of 3 × 2 repeated measures ANOVAs revealed statistically significant interaction…

Robust Optimum Invariant Tests for Random MANOVA Models.

DTIC Science & Technology

1986-10-01

are assumed to be independent normal with zero mean and dispersion o2 and o72 respectively, Roy and Gnanadesikan (1959) considered the prob- 2 2 lem of...Part II: The multivariate case. Ann. Math. Statist. 31, 939-968. [7] Roy, S.N. and Gnanadesikan , R. (1959). Some contributions to ANOVA in one or more

Local and systemic effect of transfection-reagent formulated DNA vectors on equine melanoma.

PubMed

Mählmann, Kathrin; Feige, Karsten; Juhls, Christiane; Endmann, Anne; Schuberth, Hans-Joachim; Oswald, Detlef; Hellige, Mareu; Doherr, Marcus; Cavalleri, Jessika-M V

2015-05-14

Equine melanoma has a high incidence in grey horses. Xenogenic DNA vaccination may represent a promising therapeutic approach against equine melanoma as it successfully induced an immunological response in other species suffering from melanoma and in healthy horses. In a clinical study, twenty-seven, grey, melanoma-bearing, horses were assigned to three groups (n = 9) and vaccinated on days 1, 22, and 78 with DNA vectors encoding for equine (eq) IL-12 and IL-18 alone or in combination with either human glycoprotein (hgp) 100 or human tyrosinase (htyr). Horses were vaccinated intramuscularly, and one selected melanoma was locally treated by intradermal peritumoral injection. Prior to each injection and on day 120, the sizes of up to nine melanoma lesions per horse were measured by caliper and ultrasound. Specific serum antibodies against hgp100 and htyr were measured using cell based flow-cytometric assays. An Analysis of Variance (ANOVA) for repeated measurements was performed to identify statistically significant influences on the relative tumor volume. For post-hoc testing a Tukey-Kramer Multiple-Comparison Test was performed to compare the relative volumes on the different examination days. An ANOVA for repeated measurements was performed to analyse changes in body temperature over time. A one-way ANOVA was used to evaluate differences in body temperature between the groups. A p-value < 0.05 was considered significant for all statistical tests applied. In all groups, the relative tumor volume decreased significantly to 79.1 ± 26.91% by day 120 (p < 0.0001, Tukey-Kramer Multiple-Comparison Test). Affiliation to treatment group, local treatment and examination modality had no significant influence on the results (ANOVA for repeated measurements). Neither a cellular nor a humoral immune response directed against htyr or hgp100 was detected. Horses had an increased body temperature on the day after vaccination. This is the first clinical report on a systemic effect against equine melanoma following treatment with DNA vectors encoding eqIL12 and eqIL18 and formulated with a transfection reagent. Addition of DNA vectors encoding hgp100 respectively htyr did not potentiate this effect.

Local and systemic effect of transfection-reagent formulated DNA vectors on equine melanoma.

PubMed

Mählmann, Kathrin; Feige, Karsten; Juhls, Christiane; Endmann, Anne; Schuberth, Hans-Joachim; Oswald, Detlef; Hellige, Maren; Doherr, Marcus; Cavalleri, Jessika-M V

2015-06-11

Equine melanoma has a high incidence in grey horses. Xenogenic DNA vaccination may represent a promising therapeutic approach against equine melanoma as it successfully induced an immunological response in other species suffering from melanoma and in healthy horses. In a clinical study, twenty-seven, grey, melanoma-bearing, horses were assigned to three groups (n = 9) and vaccinated on days 1, 22, and 78 with DNA vectors encoding for equine (eq) IL-12 and IL-18 alone or in combination with either human glycoprotein (hgp) 100 or human tyrosinase (htyr). Horses were vaccinated intramuscularly, and one selected melanoma was locally treated by intradermal peritumoral injection. Prior to each injection and on day 120, the sizes of up to nine melanoma lesions per horse were measured by caliper and ultrasound. Specific serum antibodies against hgp100 and htyr were measured using cell based flow-cytometric assays. An Analysis of Variance (ANOVA) for repeated measurements was performed to identify statistically significant influences on the relative tumor volume. For post-hoc testing a Tukey-Kramer Multiple-Comparison Test was performed to compare the relative volumes on the different examination days. An ANOVA for repeated measurements was performed to analyse changes in body temperature over time. A one-way ANOVA was used to evaluate differences in body temperature between the groups. A p-value < 0.05 was considered significant for all statistical tests applied. In all groups, the relative tumor volume decreased significantly to 79.1 ± 26.91% by day 120 (p < 0.0001, Tukey-Kramer Multiple-Comparison Test). Affiliation to treatment group, local treatment and examination modality had no significant influence on the results (ANOVA for repeated measurements). Neither a cellular nor a humoral immune response directed against htyr or hgp100 was detected. Horses had an increased body temperature on the day after vaccination. This is the first clinical report on a systemic effect against equine melanoma following treatment with DNA vectors encoding eqIL12 and eqIL18 and formulated with a transfection reagent. Addition of DNA vectors encoding hgp100 respectively htyr did not potentiate this effect.

Effects of metacognitive instruction on the academic achievement of students in the secondary sciences

NASA Astrophysics Data System (ADS)

Bianchi, Gregory A.

The purpose of this study was to investigate the effects of reflective assessment in the form of situated metacognitive prompts on student achievement in the secondary sciences. A second goal was to determine whether specific gender differences existed in terms of student responsiveness to the metacognitive interventions. Participants in the study consisted of a convenience sample from a population of ninth-grade honors biology students in a large suburban school district located near Seattle, Washington. Beyond answering the specific research questions raised in this study, an additional aim was to broaden the growing body of research pertaining to the effect of metacognition on student achievement. A quasi-experimental, non-equivalent control group design was employed in this study. Descriptive and inferential statistics were computed to address the specific research questions raised. Specifically, a three-way repeated-measures ANOVA was performed. For this purpose, a single within-subjects factor, termed Testing, was defined. Three levels were allocated to this factor, and quantitative data from the Pretest, Posttest, and Retention Test were assigned to the levels, respectively. Group and Gender were defined as between-subjects factors, and both were allocated two levels; the two Group levels were Reflective and Non-Reflective. The effects of Group and Gender on each of the three quantitative measures were examined singly and in interaction with each other. Tests of statistical significance were analyzed at the .05 level. There was a statistically significant effect for Group (Reflective, Non-Reflective) by Testing (Pretest, Posttest, Retention Test). A three-way repeated-measures ANOVA procedure revealed that students in the Reflective group outperformed students in the Non-Reflective group (F = 10.258, p = .002, Partial eta 2 = .088). According to the effect size estimate, almost 9% of variance in the Testing variable was attributable to the Group variable. There was not a significant interaction effect for Gender. A three-way repeated-measures ANOVA procedure revealed that Testing X Group X Gender did not yield a statistically significant F ratio (F = 1.471, p = .228, Partial eta2 = .014). Students in the Reflective group outperformed students in the Non-Reflective group, regardless of gender. The findings of this study offer modest evidence that reflective assessment in the form of situated metacognitive prompts may improve student academic outcomes at the secondary level. This study failed to provide a significant finding regarding gender-related variation in a metacognitive learning cycle.

Quality of reporting statistics in two Indian pharmacology journals

PubMed Central

Jaykaran; Yadav, Preeti

2011-01-01

Objective: To evaluate the reporting of the statistical methods in articles published in two Indian pharmacology journals. Materials and Methods: All original articles published since 2002 were downloaded from the journals’ (Indian Journal of Pharmacology (IJP) and Indian Journal of Physiology and Pharmacology (IJPP)) website. These articles were evaluated on the basis of appropriateness of descriptive statistics and inferential statistics. Descriptive statistics was evaluated on the basis of reporting of method of description and central tendencies. Inferential statistics was evaluated on the basis of fulfilling of assumption of statistical methods and appropriateness of statistical tests. Values are described as frequencies, percentage, and 95% confidence interval (CI) around the percentages. Results: Inappropriate descriptive statistics was observed in 150 (78.1%, 95% CI 71.7–83.3%) articles. Most common reason for this inappropriate descriptive statistics was use of mean ± SEM at the place of “mean (SD)” or “mean ± SD.” Most common statistical method used was one-way ANOVA (58.4%). Information regarding checking of assumption of statistical test was mentioned in only two articles. Inappropriate statistical test was observed in 61 (31.7%, 95% CI 25.6–38.6%) articles. Most common reason for inappropriate statistical test was the use of two group test for three or more groups. Conclusion: Articles published in two Indian pharmacology journals are not devoid of statistical errors. PMID:21772766

The effects of academic grouping on student performance in science

NASA Astrophysics Data System (ADS)

Scoggins, Sally Smykla

The current action research study explored how student placement in heterogeneous or homogeneous classes in seventh-grade science affected students' eighth-grade Science State of Texas Assessment of Academic Readiness (STAAR) scores, and how ability grouping affected students' scores based on race and socioeconomic status. The population included all eighth-grade students in the target district who took the regular eighth-grade science STAAR over four academic school years. The researcher ran three statistical tests: a t-test for independent samples, a one-way between subjects analysis of variance (ANOVA) and a two-way between subjects ANOVA. The results showed no statistically significant difference between eighth-grade Pre-AP students from seventh-grade Pre-AP classes and eighth-grade Pre-AP students from heterogeneous seventh-grade classes and no statistically significant difference between Pre-AP students' scores based on socioeconomic status. There was no statistically significant interaction between socioeconomic status and the seventh-grade science classes. The scores between regular eighth-grade students who were in heterogeneous seventh-grade classes were statistically significantly higher than the scores of regular eighth-grade students who were in regular seventh-grade classes. The results also revealed that the scores of students who were White were statistically significantly higher than the scores of students who were Black and Hispanic. Black and Hispanic scores did not differ significantly. Further results indicated that the STAAR Level II and Level III scores were statistically significantly higher for the Pre-AP eighth-grade students who were in heterogeneous seventh-grade classes than the STAAR Level II and Level III scores of Pre-AP eighth-grade students who were in Pre-AP seventh-grade classes.

Early Childhood Inservice and Preservice Teachers' Perceived Levels of Preparedness to Handle Stress in Their Students

ERIC Educational Resources Information Center

Onchwari, Jacqueline

2010-01-01

This article reports a study that investigated preservice and inservice early childhood teachers' perceived levels of preparedness to handle stress in early childhood and elementary education students. A survey that included vignettes was used to collect data. Data were analyzed both qualitatively and statistically, using one-way ANOVA, "t"-test,…

Stability of Playfulness across Environmental Settings: A Pilot Study

ERIC Educational Resources Information Center

Rigby, Patricia; Gaik, Sandy

2007-01-01

The Test of Playfulness (ToP) was used in this pilot study to examine the stability of playfulness of 16 children with cerebral palsy (CP), aged 4-8 years, across three environmental settings: home, community, and school. Each videotaped play segment was scored using the ToP. The ANOVA statistic demonstrated a significant variance (p less than…

Effects of measurement errors on psychometric measurements in ergonomics studies: Implications for correlations, ANOVA, linear regression, factor analysis, and linear discriminant analysis.

PubMed

Liu, Yan; Salvendy, Gavriel

2009-05-01

This paper aims to demonstrate the effects of measurement errors on psychometric measurements in ergonomics studies. A variety of sources can cause random measurement errors in ergonomics studies and these errors can distort virtually every statistic computed and lead investigators to erroneous conclusions. The effects of measurement errors on five most widely used statistical analysis tools have been discussed and illustrated: correlation; ANOVA; linear regression; factor analysis; linear discriminant analysis. It has been shown that measurement errors can greatly attenuate correlations between variables, reduce statistical power of ANOVA, distort (overestimate, underestimate or even change the sign of) regression coefficients, underrate the explanation contributions of the most important factors in factor analysis and depreciate the significance of discriminant function and discrimination abilities of individual variables in discrimination analysis. The discussions will be restricted to subjective scales and survey methods and their reliability estimates. Other methods applied in ergonomics research, such as physical and electrophysiological measurements and chemical and biomedical analysis methods, also have issues of measurement errors, but they are beyond the scope of this paper. As there has been increasing interest in the development and testing of theories in ergonomics research, it has become very important for ergonomics researchers to understand the effects of measurement errors on their experiment results, which the authors believe is very critical to research progress in theory development and cumulative knowledge in the ergonomics field.

Which statistics should tropical biologists learn?

PubMed

Loaiza Velásquez, Natalia; González Lutz, María Isabel; Monge-Nájera, Julián

2011-09-01

Tropical biologists study the richest and most endangered biodiversity in the planet, and in these times of climate change and mega-extinctions, the need for efficient, good quality research is more pressing than in the past. However, the statistical component in research published by tropical authors sometimes suffers from poor quality in data collection; mediocre or bad experimental design and a rigid and outdated view of data analysis. To suggest improvements in their statistical education, we listed all the statistical tests and other quantitative analyses used in two leading tropical journals, the Revista de Biología Tropical and Biotropica, during a year. The 12 most frequent tests in the articles were: Analysis of Variance (ANOVA), Chi-Square Test, Student's T Test, Linear Regression, Pearson's Correlation Coefficient, Mann-Whitney U Test, Kruskal-Wallis Test, Shannon's Diversity Index, Tukey's Test, Cluster Analysis, Spearman's Rank Correlation Test and Principal Component Analysis. We conclude that statistical education for tropical biologists must abandon the old syllabus based on the mathematical side of statistics and concentrate on the correct selection of these and other procedures and tests, on their biological interpretation and on the use of reliable and friendly freeware. We think that their time will be better spent understanding and protecting tropical ecosystems than trying to learn the mathematical foundations of statistics: in most cases, a well designed one-semester course should be enough for their basic requirements.

Analysis of Variance in Statistical Image Processing

NASA Astrophysics Data System (ADS)

Kurz, Ludwik; Hafed Benteftifa, M.

1997-04-01

A key problem in practical image processing is the detection of specific features in a noisy image. Analysis of variance (ANOVA) techniques can be very effective in such situations, and this book gives a detailed account of the use of ANOVA in statistical image processing. The book begins by describing the statistical representation of images in the various ANOVA models. The authors present a number of computationally efficient algorithms and techniques to deal with such problems as line, edge, and object detection, as well as image restoration and enhancement. By describing the basic principles of these techniques, and showing their use in specific situations, the book will facilitate the design of new algorithms for particular applications. It will be of great interest to graduate students and engineers in the field of image processing and pattern recognition.

Effect of Dentin Wetness on the Bond Strength of Universal Adhesives.

PubMed

Choi, An-Na; Lee, Ji-Hye; Son, Sung-Ae; Jung, Kyoung-Hwa; Kwon, Yong Hoon; Park, Jeong-Kil

2017-10-25

The effects of dentin wetness on the bond strength and adhesive interface morphology of universal adhesives have been investigated using micro-tensile bond strength (μTBS) testing and confocal laser scanning microscopy (CLSM). Seventy-two human third molars were wet ground to expose flat dentin surfaces. They were divided into three groups according to the air-drying time of the dentin surfaces: 0 (without air drying), 5, and 10 s. The dentin surfaces were then treated with three universal adhesives: G-Premio Bond, Single Bond Universal, and All-Bond Universal in self-etch or etch-and-rinse mode. After composite build up, a μTBS test was performed. One additional tooth was prepared for each group by staining the adhesives with 0.01 wt % of Rhodamine B fluorescent dye for CLSM analysis. The data were analyzed statistically using ANOVA and Tukey's post hoc tests (α = 0.05). Two-way ANOVA showed significant differences among the adhesive systems and dentin moisture conditions. An interaction effect was also observed ( p < 0.05). One-way ANOVA showed that All-Bond Universal was the only material influenced by the wetness of the dentin surfaces. Wetness of the dentin surface is a factor influencing the micro-tensile bond strength of universal adhesives.

Effect of Dentin Wetness on the Bond Strength of Universal Adhesives

PubMed Central

Lee, Ji-Hye; Son, Sung-Ae; Jung, Kyoung-Hwa; Kwon, Yong Hoon

2017-01-01

The effects of dentin wetness on the bond strength and adhesive interface morphology of universal adhesives have been investigated using micro-tensile bond strength (μTBS) testing and confocal laser scanning microscopy (CLSM). Seventy-two human third molars were wet ground to expose flat dentin surfaces. They were divided into three groups according to the air-drying time of the dentin surfaces: 0 (without air drying), 5, and 10 s. The dentin surfaces were then treated with three universal adhesives: G-Premio Bond, Single Bond Universal, and All-Bond Universal in self-etch or etch-and-rinse mode. After composite build up, a μTBS test was performed. One additional tooth was prepared for each group by staining the adhesives with 0.01 wt % of Rhodamine B fluorescent dye for CLSM analysis. The data were analyzed statistically using ANOVA and Tukey’s post hoc tests (α = 0.05). Two-way ANOVA showed significant differences among the adhesive systems and dentin moisture conditions. An interaction effect was also observed (p < 0.05). One-way ANOVA showed that All-Bond Universal was the only material influenced by the wetness of the dentin surfaces. Wetness of the dentin surface is a factor influencing the micro-tensile bond strength of universal adhesives. PMID:29068404

Eta- and Partial Eta-Squared in L2 Research: A Cautionary Review and Guide to More Appropriate Usage

ERIC Educational Resources Information Center

Norouzian, Reza; Plonsky, Luke

2018-01-01

Eta-squared (?[superscript 2]) and partial eta-squared (?[subscript p][superscript 2]) are effect sizes that express the amount of variance accounted for by one or more independent variables. These indices are generally used in conjunction with ANOVA, the most commonly used statistical test in second language (L2) research (Plonsky, 2013).…

The Perceptions of Principals and Teachers Regarding Mental Health Providers' Impact on Student Achievement in High Poverty Schools

ERIC Educational Resources Information Center

Perry, Teresa

2012-01-01

This study examined the perceptions of principals and teachers regarding mental health provider's impact on student achievement and behavior in high poverty schools using descriptive statistics, t-test, and two-way ANOVA. Respondents in this study shared similar views concerning principal and teacher satisfaction and levels of support for the…

The effect of Kinesio Taping on postural control in subjects with non-specific chronic low back pain.

PubMed

Abbasi, Soheila; Rojhani-Shirazi, Zahra; Shokri, Esmaeil; García-Muro San José, Francisco

2018-04-01

The aim of this study was to investigate the possible alterations in postural control during upright standing in subjects with non-specific chronic low back pain and the effect of Kinesio taping on the postural control. Twenty subjects with non-specific chronic low back pain and twenty healthy subjects participated in this study. The center of pressure excursion was evaluated before the intervention for both groups, and immediately after intervention for the low back pain group. Independent sample t-test, Mann-Whitney test and repeated measure ANOVA were used for the statistical analysis of the data. There were significant differences in the center of pressure excursion between the low back pain group versus the healthy group. The results of the ANOVA demonstrated a statistically significant difference in the mean COP displacement and velocity before Kinesio Taping, immediately after, and 24 h after in the low back pain group. There are poor postural control mechanisms in subjects with non-specific chronic low back pain. Kinesio taping seems to change postural control immediately and have lasting effects until the day after. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reporting Practices and Use of Quantitative Methods in Canadian Journal Articles in Psychology.

PubMed

Counsell, Alyssa; Harlow, Lisa L

2017-05-01

With recent focus on the state of research in psychology, it is essential to assess the nature of the statistical methods and analyses used and reported by psychological researchers. To that end, we investigated the prevalence of different statistical procedures and the nature of statistical reporting practices in recent articles from the four major Canadian psychology journals. The majority of authors evaluated their research hypotheses through the use of analysis of variance (ANOVA), t -tests, and multiple regression. Multivariate approaches were less common. Null hypothesis significance testing remains a popular strategy, but the majority of authors reported a standardized or unstandardized effect size measure alongside their significance test results. Confidence intervals on effect sizes were infrequently employed. Many authors provided minimal details about their statistical analyses and less than a third of the articles presented on data complications such as missing data and violations of statistical assumptions. Strengths of and areas needing improvement for reporting quantitative results are highlighted. The paper concludes with recommendations for how researchers and reviewers can improve comprehension and transparency in statistical reporting.

Morphometric analysis of root canal cleaning after rotary instrumentation with or without laser irradiation

NASA Astrophysics Data System (ADS)

Marchesan, Melissa A.; Geurisoli, Danilo M. Z.; Brugnera, Aldo, Jr.; Barbin, Eduardo L.; Pecora, Jesus D.

2002-06-01

The present study examined root canal cleaning, using the optic microscope, after rotary instrumentation with ProFile.04 with or without laser application with different output energies. Cleaning and shaping can be accomplished manually, with ultra-sonic and sub-sonic devices, with rotary instruments and recently, increasing development in laser radiation has shown promising results for disinfection and smear layer removal. In this study, 30 palatal maxillary molar roots were examined using an optic microscope after rotary instrumentation with ProFile .04 with or without Er:YAG laser application (KaVo KeyLaser II, Germany) with different output energies (2940 nm, 15 Hz, 300 pulses, 500 milli-sec duration, 42 J, 140 mJ showed on the display- input, 61 mJ at fiberoptic tip-output and 140 mJ showed on the display-input and 51 mJ at fiberoptic tip-output). Statistical analysis showed no statistical differences between the tested treatments (ANOVA, p>0.05). ANOVA also showed a statistically significant difference (p<0.01) between the root canal thirds, indicating that the middle third had less debris than the apical third. We conclude that: 1) none of the tested treatments led to totally cleaned root canals; 2) all treatments removed debris similarly, 3) the middle third had less debris than the apical third; 4) variation in output energy did not increase cleaning.

An evaluation of shear bond strength of self-etch adhesive on pre-etched enamel: an in vitro study.

PubMed

Rao, Bhadra; Reddy, Satti Narayana; Mujeeb, Abdul; Mehta, Kanchan; Saritha, G

2013-11-01

To determine the shear bond strength of self-etch adhesive G-bond on pre-etched enamel. Thirty caries free human mandibular premolars extracted for orthodontic purpose were used for the study. Occlusal surfaces of all the teeth were flattened with diamond bur and a silicon carbide paper was used for surface smoothening. The thirty samples were randomly grouped into three groups. Three different etch systems were used for the composite build up: group 1 (G-bond self-etch adhesive system), group 2 (G-bond) and group 3 (Adper single bond). Light cured was applied for 10 seconds with a LED unit for composite buildup on the occlusal surface of each tooth with 8 millimeters (mm) in diameter and 3 mm in thickness. The specimens in each group were tested in shear mode using a knife-edge testing apparatus in a universal testing machine across head speed of 1 mm/ minute. Shear bond strength values in Mpa were calculated from the peak load at failure divided by the specimen surface area. The mean shear bond strength of all the groups were calculated and statistical analysis was carried out using one-way Analysis of Variance (ANOVA). The mean bond strength of group 1 is 15.5 Mpa, group 2 is 19.5 Mpa and group 3 is 20.1 Mpa. Statistical analysis was carried out between the groups using one-way ANOVA. Group 1 showed statistically significant lower bond strength when compared to groups 2 and 3. No statistical significant difference between groups 2 and 3 (p < 0.05). Self-etch adhesive G-bond showed increase in shear bond strength on pre-etched enamel.

One-dimensional statistical parametric mapping in Python.

PubMed

Pataky, Todd C

2012-01-01

Statistical parametric mapping (SPM) is a topological methodology for detecting field changes in smooth n-dimensional continua. Many classes of biomechanical data are smooth and contained within discrete bounds and as such are well suited to SPM analyses. The current paper accompanies release of 'SPM1D', a free and open-source Python package for conducting SPM analyses on a set of registered 1D curves. Three example applications are presented: (i) kinematics, (ii) ground reaction forces and (iii) contact pressure distribution in probabilistic finite element modelling. In addition to offering a high-level interface to a variety of common statistical tests like t tests, regression and ANOVA, SPM1D also emphasises fundamental concepts of SPM theory through stand-alone example scripts. Source code and documentation are available at: www.tpataky.net/spm1d/.

Measurement Consistency from Magnetic Resonance Images

PubMed Central

Chung, Dongjun; Chung, Moo K.; Durtschi, Reid B.; Lindell, R. Gentry; Vorperian, Houri K.

2010-01-01

Rationale and Objectives In quantifying medical images, length-based measurements are still obtained manually. Due to possible human error, a measurement protocol is required to guarantee the consistency of measurements. In this paper, we review various statistical techniques that can be used in determining measurement consistency. The focus is on detecting a possible measurement bias and determining the robustness of the procedures to outliers. Materials and Methods We review correlation analysis, linear regression, Bland-Altman method, paired t-test, and analysis of variance (ANOVA). These techniques were applied to measurements, obtained by two raters, of head and neck structures from magnetic resonance images (MRI). Results The correlation analysis and the linear regression were shown to be insufficient for detecting measurement inconsistency. They are also very sensitive to outliers. The widely used Bland-Altman method is a visualization technique so it lacks the numerical quantification. The paired t-test tends to be sensitive to small measurement bias. On the other hand, ANOVA performs well even under small measurement bias. Conclusion In almost all cases, using only one method is insufficient and it is recommended to use several methods simultaneously. In general, ANOVA performs the best. PMID:18790405

Analysis of tribological behaviour of zirconia reinforced Al-SiC hybrid composites using statistical and artificial neural network technique

NASA Astrophysics Data System (ADS)

Arif, Sajjad; Tanwir Alam, Md; Ansari, Akhter H.; Bilal Naim Shaikh, Mohd; Arif Siddiqui, M.

2018-05-01

The tribological performance of aluminium hybrid composites reinforced with micro SiC (5 wt%) and nano zirconia (0, 3, 6 and 9 wt%) fabricated through powder metallurgy technique were investigated using statistical and artificial neural network (ANN) approach. The influence of zirconia reinforcement, sliding distance and applied load were analyzed with test based on full factorial design of experiments. Analysis of variance (ANOVA) was used to evaluate the percentage contribution of each process parameters on wear loss. ANOVA approach suggested that wear loss be mainly influenced by sliding distance followed by zirconia reinforcement and applied load. Further, a feed forward back propagation neural network was applied on input/output date for predicting and analyzing the wear behaviour of fabricated composite. A very close correlation between experimental and ANN output were achieved by implementing the model. Finally, ANN model was effectively used to find the influence of various control factors on wear behaviour of hybrid composites.

An investigation of thermal changes of various permanent dental cements.

PubMed

Duymus, Zeynep Yesil; Yilmaz, Baykal; Karaalioglu, F Osman

2009-05-01

The aim of this study was to investigate and compare the temperature rises which occurred during the setting reactions of different permanent cements used to lute fixed partial prosthodontics. In this study, four cements were used. They were mixed in three different proportions: according to manufacturers' recommendations, at doubled powder ratio, and at doubled liquid ratio. With a thermocouple, the temperature rises which occurred during the setting reactions were measured. For each proportion, the measurement was repeated five times such that a total of 60 measurements were done for the four different cements. Data were analyzed using analysis of variance (ANOVA). ANOVA results showed that cement type and the interaction between cement type and the powder-liquid ratio were statistically significant factors (p<0.001). Similarly, the powder-liquid ratio was a statistically significant (p<0.01) factor. Among the dental cements tested, zinc phosphate cement showed the highest temperature rise during setting reaction, whereas glass ionomer cement showed the lowest.

One-way ANOVA based on interval information

NASA Astrophysics Data System (ADS)

Hesamian, Gholamreza

2016-08-01

This paper deals with extending the one-way analysis of variance (ANOVA) to the case where the observed data are represented by closed intervals rather than real numbers. In this approach, first a notion of interval random variable is introduced. Especially, a normal distribution with interval parameters is introduced to investigate hypotheses about the equality of interval means or test the homogeneity of interval variances assumption. Moreover, the least significant difference (LSD method) for investigating multiple comparison of interval means is developed when the null hypothesis about the equality of means is rejected. Then, at a given interval significance level, an index is applied to compare the interval test statistic and the related interval critical value as a criterion to accept or reject the null interval hypothesis of interest. Finally, the method of decision-making leads to some degrees to accept or reject the interval hypotheses. An applied example will be used to show the performance of this method.

Evaluating the efficacy of a chemistry video game

NASA Astrophysics Data System (ADS)

Shapiro, Marina

A quasi-experimental design pre-test/post-test intervention study utilizing a within group analysis was conducted with 45 undergraduate college chemistry students that investigated the effect of implementing a game-based learning environment into an undergraduate college chemistry course in order to learn if serious educational games (SEGs) can be used to achieve knowledge gains of complex chemistry concepts and to achieve increase in students' positive attitude toward chemistry. To evaluate if students learn chemistry concepts by participating in a chemistry game-based learning environment, a one-way repeated measures analysis of variance (ANOVA) was conducted across three time points (pre-test, post-test, delayed post-test which were chemistry content exams). Results showed that there was an increase in exam scores over time. The results of the ANOVA indicated a statistically significant time effect. To evaluate if students' attitude towards chemistry increased as a result of participating in a chemistry game-based learning environment a paired samples t-test was conducted using a chemistry attitudinal survey by Mahdi (2014) as the pre- and post-test. Results of the paired-samples t-test indicated that there was no significant difference in pre-attitudinal scores and post-attitudinal scores.

Evaluation of the three-dimensional accuracy of implant impression techniques in two simulated clinical conditions by optical scanning.

PubMed

Sabouhi, Mahmoud; Bajoghli, Farshad; Abolhasani, Majid

2015-01-01

The success of an implant-supported prosthesis is dependent on the passive fit of its framework fabricated on a precise cast. The aim of this in vitro study was to digitally compare the three-dimensional accuracy of implant impression techniques in partially and completely edentulous conditions. The master model simulated two clinical conditions. The first condition was a partially edentulous mandibular arch with an anterior edentulous space (D condition). Two implant analogs were inserted in bilateral canine sites. After elimination of the teeth, the model was converted to a completely edentulous condition (E condition). Three different impression techniques were performed (open splinted [OS], open unsplinted [OU], closed [C]) for each condition. Six groups of casts (DOS, DOU, DC, EOS, EOU, EC) (n = 8), totaling 48 casts, were made. Two scan bodies were secured onto the master edentulous model and onto each test cast and digitized by an optical scanning system. The related scans were superimposed, and the mean discrepancy for each cast was determined. The statistical analysis showed no significant difference in the accuracy of casts as a function of model status (P = .78, analysis of variance [ANOVA] test), impression technique (P = .57, ANOVA test), or as the combination of both (P = .29, ANOVA test). The distribution of data was normal (Kolmogorov-Smirnov test). Model status (dentate or edentulous) and impression technique did not influence the precision of the casts. There is no difference among any of the impression techniques in either simulated clinical condition.

A prospective study of cognitive fluency and originality in children exposed in utero to carbamazepine, lamotrigine, or valproate monotherapy.

PubMed

McVearry, Kelly M; Gaillard, William D; VanMeter, John; Meador, Kimford J

2009-12-01

To investigate the differential effects of fetal exposure to antiepileptic drugs (AEDs) on cognitive fluency and flexibility in a prospective sample of children. This substudy of the Neurodevelopmental Effects of Antiepileptic Drugs investigation enrolled pregnant women with epilepsy on AED monotherapy (carbamazepine, lamotrigine, and valproate). Blinded to drug exposure, 54 children were tested for ability to generate ideas in terms of quantity (fluency/flexibility) and quality (originality). Forty-two children met inclusion criteria (mean age=4.2 years, SD=0.5) for statistical analyses of drug exposure group differences. Fluency was lower in the valproate group (mean=76.3, SD=7.53) versus the lamotrigine (mean=93.76, SD=13.5, ANOVA P<0.0015) and carbamazepine (mean=95.5, SD=18.1, ANOVA P<0.003) groups. Originality was lower in the valproate group (mean=84.2, SD=3.23) versus the lamotrigine (mean=103.1, SD=14.8, ANOVA P<0.002) and carbamazepine (mean=99.4, SD=17.1, ANOVA P<0.01) groups. These results were not explained by factors other than AED exposure. Children prenatally exposed to valproate demonstrate impaired fluency and originality compared with children exposed to lamotrigine and carbamazepine.

Precipitation-snowmelt timing and snowmelt augmentation of large peak flow events, western Cascades, Oregon

Treesearch

Keith Jennings; Julia A. Jones

2015-01-01

This study tested multiple hydrologic mechanisms to explain snowpack dynamics in extreme rain-on-snow floods, which occur widely in the temperate and polar regions. We examined 26, 10 day large storm events over the period 1992–2012 in the H.J. Andrews Experimental Forest in western Oregon, using statistical analyses (regression, ANOVA, and wavelet coherence) of hourly...

Effect of at-home bleaching with different thickeners and aging on physical properties of a nanocomposite.

PubMed

Gouveia, Thayla Hellen Nunes; Públio, Juliana do Carmo; Ambrosano, Glaucia Maria Bovi; Paulillo, Luís Alexandre Maffei Sartini; Aguiar, Flávio Henrique Baggio; Lima, Débora Alves Nunes Leite

2016-01-01

To evaluate the influence of 16% carbamide peroxide (CP) containing different thickeners on the physical characteristics of a nanocomposite resin submitted or not to accelerated artificial aging (AAA). One hundred samples were randomly distributed into two groups (n = 50) according to AAA. Each group was divided into 5 subgroups (n = 10) depending on the bleaching/thickener treatment: CP + carbopol, CP + natrosol, carbopol, natrosol, and no treatment (control). The physical properties tested were color (ΔE), gloss (GU), mean roughness (Ra), and Knoop microhardness (KHN). The resin surface was performed with atomic force microscopy (AFM). The color (variable Δ E) was assessed with two-way analysis of variance (ANOVA) and additionally with Tukey's and Dunnett's tests, the roughness values were submitted to Kruskal-Wallis, Dunn's, and Mann-Whitney's tests. Data on gloss and KHN were submitted to two-way ANOVA and Tukey's test (α = 0.05). Among the physical properties evaluated, CP + carbopol promoted a reduction in composite microhardness only, thus differing statistically from the controls. As for CP + natrosol, such a change was not observed. The aging process reduced all the physical properties, thus differing statistically from the nonaging group. CP + carbopol increased the roughness and decreased the gloss of aged resins, whereas natrosol reduced gloss only, which differed statistically from the controls. AFM showed evidence of the loss of organic matrix and exposure to load particles in the aged samples. Therefore, the replacement of carbopol with natrosol provided maintenance of the composite microhardness following bleaching. The aging process reduced the physical properties evaluated, and some changes were enhanced by the application of bleaching.

Effect of a Trampoline Exercise on the Anthropometric Measures and Motor Performance of Adolescent Students

PubMed Central

Aalizadeh, Bahman; Mohammadzadeh, Hassan; Khazani, Ali; Dadras, Ali

2016-01-01

Background: Physical exercises can influence some anthropometric and fitness components differently. The aim of present study was to evaluate how a relatively long-term training program in 11-14-year-old male Iranian students affects their anthropometric and motor performance measures. Methods: Measurements were conducted on the anthropometric and fitness components of participants (n = 28) prior to and following the program. They trained 20 weeks, 1.5 h/session with 10 min rest, in 4 times trampoline training programs per week. Motor performance of all participants was assessed using standing long jump and vertical jump based on Eurofit Test Battery. Results: The analysis of variance (ANOVA) repeated measurement test showed a statistically significant main effect of time in calf girth P = 0.001, fat% P = 0.01, vertical jump P = 0.001, and long jump P = 0.001. The ANOVA repeated measurement test revealed a statistically significant main effect of group in fat% P = 0.001. Post hoc paired t-tests indicated statistical significant differences in trampoline group between the two measurements about calf girth (t = −4.35, P = 0.001), fat% (t = 5.87, P = 0.001), vertical jump (t = −5.53, P = 0.001), and long jump (t = −10.00, P = 0.001). Conclusions: We can conclude that 20-week trampoline training with four physical activity sessions/week in 11–14-year-old students seems to have a significant effect on body fat% reduction and effective results in terms of anaerobic physical fitness. Therefore, it is suggested that different training model approach such as trampoline exercises can help students to promote the level of health and motor performance. PMID:27512557

Effect of a Trampoline Exercise on the Anthropometric Measures and Motor Performance of Adolescent Students.

PubMed

Aalizadeh, Bahman; Mohammadzadeh, Hassan; Khazani, Ali; Dadras, Ali

2016-01-01

Physical exercises can influence some anthropometric and fitness components differently. The aim of present study was to evaluate how a relatively long-term training program in 11-14-year-old male Iranian students affects their anthropometric and motor performance measures. Measurements were conducted on the anthropometric and fitness components of participants (n = 28) prior to and following the program. They trained 20 weeks, 1.5 h/session with 10 min rest, in 4 times trampoline training programs per week. Motor performance of all participants was assessed using standing long jump and vertical jump based on Eurofit Test Battery. The analysis of variance (ANOVA) repeated measurement test showed a statistically significant main effect of time in calf girth P = 0.001, fat% P = 0.01, vertical jump P = 0.001, and long jump P = 0.001. The ANOVA repeated measurement test revealed a statistically significant main effect of group in fat% P = 0.001. Post hoc paired t-tests indicated statistical significant differences in trampoline group between the two measurements about calf girth (t = -4.35, P = 0.001), fat% (t = 5.87, P = 0.001), vertical jump (t = -5.53, P = 0.001), and long jump (t = -10.00, P = 0.001). We can conclude that 20-week trampoline training with four physical activity sessions/week in 11-14-year-old students seems to have a significant effect on body fat% reduction and effective results in terms of anaerobic physical fitness. Therefore, it is suggested that different training model approach such as trampoline exercises can help students to promote the level of health and motor performance.

Spectral transmittance of UV-blocking soft contact lenses: a comparative study.

PubMed

Rahmani, Saeed; Mohammadi Nia, Mohadeseh; Akbarzadeh Baghban, Alireza; Nazari, Mohammad Reza; Ghassemi-Broumand, Mohammad

2014-12-01

Three major parts of sunlight consist of visible, ultraviolet and infrared radiation. Exposure to ultraviolet radiation (UVR) can result in a spectrum of skin and ocular diseases. UV-blocking contact lenses help provide protection against harmful UV radiation. We studied the ultraviolet and visible light rays transmission in some soft UV-blocking contact lenses. Four available tinted soft lenses (Acuvue Moist, Zeiss CONTACT Day 30 Air spheric, Pretty Eyes and Sauflon 56 UV) have been evaluated for UV and visible transmission. One-way ANOVA testing was performed to establish is there a statistically significant difference between the UV regions and visible spectra means for the contact lenses (α=0.05). Pretty Eyes, Zeiss CONTACT, Acuvue Moist and Sauflon 56 UV showed UV-B transmittance value of 0.65%, 10.69%, 1.22%, and 5.78%, respectively. Pretty Eyes and Acuvue Moist had UV-A transmittance values of 32% and 34%, Sauflon 56 UV and Zeiss CONTACT had transmittance values of 48% and 43%, respectively. All of the studied lenses transmitted at least 94.6% on the visible spectrum. The results of the one-way ANOVA statistical analysis show that a statistically significant difference exists within the group of contact lenses tested for the visible (p<0.001), UV-B (p<0.001) and UV-A (p<0.001) portions of the spectrum (α=0.05). Acuvue Moist has the best UV-blocking property and also visible transmission between other tested contact lenses in this study. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Dental hygiene students' perceptions of distance learning: do they change over time?

PubMed

Sledge, Rhonda; Vuk, Jasna; Long, Susan

2014-02-01

The University of Arkansas for Medical Sciences dental hygiene program established a distant site where the didactic curriculum was broadcast via interactive video from the main campus to the distant site, supplemented with on-line learning via Blackboard. This study compared the perceptions of students towards distance learning as they progressed through the 21 month curriculum. Specifically, the study sought to answer the following questions: Is there a difference in the initial perceptions of students on the main campus and at the distant site toward distance learning? Do students' perceptions change over time with exposure to synchronous distance learning over the course of the curriculum? All 39 subjects were women between the ages of 20 and 35 years. Of the 39 subjects, 37 were Caucasian and 2 were African-American. A 15-question Likert scale survey was administered at 4 different periods during the 21 month program to compare changes in perceptions toward distance learning as students progressed through the program. An independent sample t-test and ANOVA were utilized for statistical analysis. At the beginning of the program, independent samples t-test revealed that students at the main campus (n=34) perceived statistically significantly higher effectiveness of distance learning than students at the distant site (n=5). Repeated measures of ANOVA revealed that perceptions of students at the main campus on effectiveness and advantages of distance learning statistically significantly decreased whereas perceptions of students at distant site statistically significantly increased over time. Distance learning in the dental hygiene program was discussed, and replication of the study with larger samples of students was recommended.

The Global Error Assessment (GEA) model for the selection of differentially expressed genes in microarray data.

PubMed

Mansourian, Robert; Mutch, David M; Antille, Nicolas; Aubert, Jerome; Fogel, Paul; Le Goff, Jean-Marc; Moulin, Julie; Petrov, Anton; Rytz, Andreas; Voegel, Johannes J; Roberts, Matthew-Alan

2004-11-01

Microarray technology has become a powerful research tool in many fields of study; however, the cost of microarrays often results in the use of a low number of replicates (k). Under circumstances where k is low, it becomes difficult to perform standard statistical tests to extract the most biologically significant experimental results. Other more advanced statistical tests have been developed; however, their use and interpretation often remain difficult to implement in routine biological research. The present work outlines a method that achieves sufficient statistical power for selecting differentially expressed genes under conditions of low k, while remaining as an intuitive and computationally efficient procedure. The present study describes a Global Error Assessment (GEA) methodology to select differentially expressed genes in microarray datasets, and was developed using an in vitro experiment that compared control and interferon-gamma treated skin cells. In this experiment, up to nine replicates were used to confidently estimate error, thereby enabling methods of different statistical power to be compared. Gene expression results of a similar absolute expression are binned, so as to enable a highly accurate local estimate of the mean squared error within conditions. The model then relates variability of gene expression in each bin to absolute expression levels and uses this in a test derived from the classical ANOVA. The GEA selection method is compared with both the classical and permutational ANOVA tests, and demonstrates an increased stability, robustness and confidence in gene selection. A subset of the selected genes were validated by real-time reverse transcription-polymerase chain reaction (RT-PCR). All these results suggest that GEA methodology is (i) suitable for selection of differentially expressed genes in microarray data, (ii) intuitive and computationally efficient and (iii) especially advantageous under conditions of low k. The GEA code for R software is freely available upon request to authors.

Effect of saliva contamination on cementation of orthodontic brackets using different adhesive systems.

PubMed

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.

Laser and plasma dental soldering techniques applied to Ti-6Al-4V alloy: ultimate tensile strength and finite element analysis.

PubMed

Castro, Morgana G; Araújo, Cleudmar A; Menegaz, Gabriela L; Silva, João Paulo L; Nóbilo, Mauro Antônio A; Simamoto Júnior, Paulo Cézar

2015-05-01

The literature provides limited information regarding the performance of Ti-6Al-4V laser and plasma joints welded in prefabricated bars in dental applications. The purpose of this study was to evaluate the mechanical strength of different diameters of Ti-6Al-4V alloy welded with laser and plasma techniques. Forty-five dumbbell-shaped rods were created from Ti-6Al-4V and divided into 9 groups (n=5): a control group with 3-mm and intact bars; groups PL2.5, PL3, PL4, and PL5 (specimens with 2.5-, 3-, 4-, and 5-mm diameters welded with plasma); and groups L2.5, L3, L4, and L5 (specimens with 2.5-, 3-, 4-, and 5-mm diameters welded with laser). The specimens were tested for ultimate tensile strength (UTS), and elongation percentages (EP) were obtained. Fractured specimens were analyzed by stereomicroscopy, and welded area percentages (WAP) were calculated. Images were made with scanning electron microscopy. In the initial analysis, the data were analyzed with a 2-way ANOVA (2×4) and the Tukey Honestly Significant Difference (HSD) test. In the second analysis, the UTS and EP data were analyzed with 1-way ANOVA, and the Dunnett test was used to compare the 4 experimental groups with the control group (α=.05). The Pearson and Spearman correlation coefficient tests were applied to correlate the study factors. Finite element models were developed in a workbench environment with boundary conditions simulating those of a tensile test. The 2-way ANOVA showed that the factors welding type and diameter were significant for the UTS and WAP values. However, the interaction between them was not significant. The 1-way ANOVA showed statistically significant differences among the groups for UTS, WAP, and EP values. The Dunnett test showed that all the tested groups had lower UTS and EP values than the control group. The 2.5- and 3-mm diameter groups showed higher values for UTS and WAP than the other test groups. A positive correlation was found between welded area percentage and UTS and a negative correlation between these parameters and the diameters of the specimens. No statistically significant difference was found between the weld techniques. Under the experimental conditions described, diameters of 2.5 and 3 mm resulted in higher UTS and WAP for both laser and plasma welding and appear to be the best option for joining prefabricated rods in this kind of union. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Effectiveness of probiotic, chlorhexidine and fluoride mouthwash against Streptococcus mutans – Randomized, single-blind, in vivo study

PubMed Central

Jothika, Mohan; Vanajassun, P. Pranav; Someshwar, Battu

2015-01-01

Aim: To determine the short-term efficiency of probiotic, chlorhexidine, and fluoride mouthwashes on plaque Streptococcus mutans level at four periodic intervals. Materials and Methods: This was a single-blind, randomized control study in which each subject was tested with only one mouthwash regimen. Fifty-two healthy qualified adult patients were selected randomly for the study and were divided into the following groups: group 1- 10 ml of distilled water, group 2- 10 ml of 0.2% chlorhexidine mouthwash, group 3- 10 ml of 500 ppm F/400 ml sodium fluoride mouthwash, and group 4- 10 ml of probiotic mouthwash. Plaque samples were collected from the buccal surface of premolars and molars in the maxillary quadrant. Sampling procedure was carried out by a single examiner after 7 days, 14 days, and 30 days, respectively, after the use of the mouthwash. All the samples were subjected to microbiological analysis and statistically analyzed with one-way analysis of variance (ANOVA) and post-hoc test. Results: One-way ANOVA comparison among groups 2, 3, and 4 showed no statistical significance, whereas group 1 showed statistically significant difference when compared with groups 2, 3, and 4 at 7th, 14th, and 30th day. Conclusion: Chlorhexidine, sodium fluoride, and probiotic mouthwashes reduce plaque S. mutans levels. Probiotic mouthwash is effective and equivalent to chlorhexidine and sodium fluoride mouthwashes. Thus, probiotic mouthwash can also be considered as an effective oral hygiene regimen. PMID:25984467

Anteroposterior condylar position: a comparative study between subjects with normal occlusion and patients with Class I, Class II Division 1, and Class III malocclusions.

PubMed

Fraga, Marcelo Reis; Rodrigues, Andréia Fialho; Ribeiro, Luiz Claudio; Campos, Marcio José da Silva; Vitral, Robert Willer Farinazzo

2013-10-29

The present study aimed to determine and compare the anteroposterior position of the condyle in the mandibular fossa between groups of asymptomatic subjects with normal occlusion and asymptomatic subjects with Class I, Class II Division 1, and Class III malocclusions. Thirty persons with normal occlusion, 30 with Class I malocclusion, 30 with Class II Division 1, and 30 with Class III had computed tomography scans of their temporomandibular joints. The anterior joint space/posterior joint space (AJS/PJS) ratio was determined for the right and left joints. The paired t test was used to analyze the AJS/PJS ratio between both sides for each group. The ANOVA test was applied to verify the differences between the groups for the measurements of the right and left sides. In case the ANOVA test confirmed significance, the Dunnett's t test was performed to compare the groups of malocclusion with that of normal occlusion. The paired t test between the AJS/PJS relationships in the right and left sides showed the following p values: Class I (0.168), Class II Division 1 (0.662), Class III (0.991), and normal occlusion (0.390). The ANOVA test showed a p value of 0.445 for the comparisons of the right side and 0.040 for the left side. The Dunnett's t test demonstrated a statistically significant difference between the Class II group and the normal occlusion group (p value of 0.026) in the joints of the left side. Bilateral symmetry and lack of condyle centralization were common characteristics among all groups. The greatest condylar decentralization was observed in the Class II group, whereas the least condylar decentralization was found in the normal occlusion group.

Electric Field Stimulation Enhances Healing of Post-Traumatic Osteoarthritic Cartilage

DTIC Science & Technology

2017-10-01

expected. Statistics: Comparisons were analyzed using ANOVA with Tukey’s post -hoc test (pɘ.05). RESULTS: In study 1, a proportion of synovial...AWARD NUMBER: W81XWH-14-1-0591 TITLE: Electric Field Stimulation Enhances Healing of Post -Traumatic Osteoarthritic Cartilage PRINCIPAL...2016 – 29 Sep 2017 4. TITLE AND SUBTITLE Cartilage 5a. CONTRACT NUMBER Electric Field Stimulation Enhances Healing of Post -Traumatic Osteoarthritic

Mental and Reproductive Health Correlates of Academic Performance among Debre Berhan University Female Students, Ethiopia: The Case of Premenstrual Dysphoric Disorder.

PubMed

Alemu, Sisay Mulugeta; Habtewold, Tesfa Dejenie; Haile, Yohannes Gebreegziabhere

2017-01-01

Globally 3 to 8% of reproductive age women are suffering from premenstrual dysphoric disorder (PMDD). Several mental and reproductive health-related factors cause low academic achievement during university education. However, limited data exist in Ethiopia. The aim of the study was to investigate mental and reproductive health correlates of academic performance. Institution based cross-sectional study was conducted with 667 Debre Berhan University female students from April to June 2015. Academic performance was the outcome variable. Mental and reproductive health characteristics were explanatory variables. Two-way analysis of variance (ANOVA) test of association was applied to examine group difference in academic performance. Among 529 students who participated, 49.3% reported mild premenstrual syndrome (PMS), 36.9% reported moderate/severe PMS, and 13.8% fulfilled PMDD diagnostic criteria. The ANOVA test of association revealed that there was no significant difference in academic performance between students with different level of PMS experience ( F -statistic = 0.08, p value = 0.93). Nevertheless, there was a significant difference in academic performance between students with different length of menses ( F -statistic = 5.15, p value = 0.006). There was no significant association between PMS experience and academic performance, but on the other hand, the length of menses significantly associated with academic performance.

Self esteem and organizational commitment among health information management staff in tertiary care hospitals in Tehran.

PubMed

Sadoughi, Farahnaz; Ebrahimi, Kamal

2014-12-12

Self esteem (SE) and organizational commitment (OC)? have significant impact on the quality of work life. This study aims to gain a better understanding of the relationships between SE and OC among health information management staff in tertiary care hospitals in Tehran (Iran). This was a descriptive correlational and cross sectional study conducted on the health information management staff of tertiary care hospitals in Tehran, Iran. A total of 155 participants were randomly selected from 400 staff. Data were collected by two standard questionnaires. The SE and OC was measured using Eysenck SE scale and Meyer and Allen's three component model, respectively. The collected data were analyzed with the SPSS (version 16) using statistical tests of of independent T-test, Pearson Correlation coefficient, one way ANOVA and F tests. The OC and SE of the employees' were 67.8?, out of 120 (weak) and 21.0 out of 30 (moderate), respectively. The values for affective commitment, normative commitment, and continuance commitment were respectively 21.3 out of 40 (moderate), 23.9 out of 40 (moderate), and 22.7 out of 40 (moderate). The Pearson correlation coefficient test showed a significant OC and SE was statistically significant (P<0.05). The one way ANOVA test (P<0.05) did not show any significant difference between educational degree and work experience with SE and OC. This research showed that SE and OC ?are moderate. SE and OC have strong correlation with turnover, critical thinking, job satisfaction, and individual and organizational improvement. Therefore, applying appropriate human resource policies is crucial to reinforce these measures.

Bias, precision and statistical power of analysis of covariance in the analysis of randomized trials with baseline imbalance: a simulation study.

PubMed

Egbewale, Bolaji E; Lewis, Martyn; Sim, Julius

2014-04-09

Analysis of variance (ANOVA), change-score analysis (CSA) and analysis of covariance (ANCOVA) respond differently to baseline imbalance in randomized controlled trials. However, no empirical studies appear to have quantified the differential bias and precision of estimates derived from these methods of analysis, and their relative statistical power, in relation to combinations of levels of key trial characteristics. This simulation study therefore examined the relative bias, precision and statistical power of these three analyses using simulated trial data. 126 hypothetical trial scenarios were evaluated (126,000 datasets), each with continuous data simulated by using a combination of levels of: treatment effect; pretest-posttest correlation; direction and magnitude of baseline imbalance. The bias, precision and power of each method of analysis were calculated for each scenario. Compared to the unbiased estimates produced by ANCOVA, both ANOVA and CSA are subject to bias, in relation to pretest-posttest correlation and the direction of baseline imbalance. Additionally, ANOVA and CSA are less precise than ANCOVA, especially when pretest-posttest correlation ≥ 0.3. When groups are balanced at baseline, ANCOVA is at least as powerful as the other analyses. Apparently greater power of ANOVA and CSA at certain imbalances is achieved in respect of a biased treatment effect. Across a range of correlations between pre- and post-treatment scores and at varying levels and direction of baseline imbalance, ANCOVA remains the optimum statistical method for the analysis of continuous outcomes in RCTs, in terms of bias, precision and statistical power.

Bias, precision and statistical power of analysis of covariance in the analysis of randomized trials with baseline imbalance: a simulation study

PubMed Central

2014-01-01

Background Analysis of variance (ANOVA), change-score analysis (CSA) and analysis of covariance (ANCOVA) respond differently to baseline imbalance in randomized controlled trials. However, no empirical studies appear to have quantified the differential bias and precision of estimates derived from these methods of analysis, and their relative statistical power, in relation to combinations of levels of key trial characteristics. This simulation study therefore examined the relative bias, precision and statistical power of these three analyses using simulated trial data. Methods 126 hypothetical trial scenarios were evaluated (126 000 datasets), each with continuous data simulated by using a combination of levels of: treatment effect; pretest-posttest correlation; direction and magnitude of baseline imbalance. The bias, precision and power of each method of analysis were calculated for each scenario. Results Compared to the unbiased estimates produced by ANCOVA, both ANOVA and CSA are subject to bias, in relation to pretest-posttest correlation and the direction of baseline imbalance. Additionally, ANOVA and CSA are less precise than ANCOVA, especially when pretest-posttest correlation ≥ 0.3. When groups are balanced at baseline, ANCOVA is at least as powerful as the other analyses. Apparently greater power of ANOVA and CSA at certain imbalances is achieved in respect of a biased treatment effect. Conclusions Across a range of correlations between pre- and post-treatment scores and at varying levels and direction of baseline imbalance, ANCOVA remains the optimum statistical method for the analysis of continuous outcomes in RCTs, in terms of bias, precision and statistical power. PMID:24712304

Correlation Between University Students' Kinematic Achievement and Learning Styles

NASA Astrophysics Data System (ADS)

Çirkinoǧlu, A. G.; Dem&ircidot, N.

2007-04-01

In the literature, some researches on kinematics revealed that students have many difficulties in connecting graphs and physics. Also some researches showed that the method used in classroom affects students' further learning. In this study the correlation between university students' kinematics achieve and learning style are investigated. In this purpose Kinematics Achievement Test and Learning Style Inventory were applied to 573 students enrolled in general physics 1 courses at Balikesir University in the fall semester of 2005-2006. Kinematics Test, consists of 12 multiple choose and 6 open ended questions, was developed by researchers to assess students' understanding, interpreting, and drawing graphs. Learning Style Inventory, a 24 items test including visual, auditory, and kinesthetic learning styles, was developed and used by Barsch. The data obtained from in this study were analyzed necessary statistical calculations (T-test, correlation, ANOVA, etc.) by using SPSS statistical program. Based on the research findings, the tentative recommendations are made.

An experiment with spectral analysis of emotional speech affected by orthodontic appliances

NASA Astrophysics Data System (ADS)

Přibil, Jiří; Přibilová, Anna; Ďuračková, Daniela

2012-11-01

The contribution describes the effect of the fixed and removable orthodontic appliances on spectral properties of emotional speech. Spectral changes were analyzed and evaluated by spectrograms and mean Welch’s periodograms. This alternative approach to the standard listening test enables to obtain objective comparison based on statistical analysis by ANOVA and hypothesis tests. Obtained results of analysis performed on short sentences of a female speaker in four emotional states (joyous, sad, angry, and neutral) show that, first of all, the removable orthodontic appliance affects the spectrograms of produced speech.

Extraction of coffee silverskin to convert waste into a source of antioxidant

NASA Astrophysics Data System (ADS)

Tangguh, Patrick; Kusumocahyo, Samuel P.

2017-01-01

Coffee silverskin (CS) is a thin layer of coffee bean, and is regarded as a waste during coffee roasting process. In this work, coffee silverskin was extracted by three types of method: conventional extraction (CE) with agitation, conventional extraction (CE) without agitation and ultrasound-assisted extraction (UAE). The total phenolic content, the total flavonoid content and the antioxidant activity of the extract were analyzed. It was found that the type of extraction method, the extraction time and the extraction temperature strongly influenced the total phenolic content, the total flavonoid content and the antioxidant activity of the extract. Comparison between conventional extraction (CE) and ultrasound-assisted extraction (UAE) were statistically analyzed using 3-way ANOVA test. The optimum extraction time and temperature for each method were analyzed using 2-way ANOVA test. It was found that the optimum condition to obtain a high antioxidant activity of 68.9% was by using CE with agitation with the extraction time and temperature of 60 minutes and 60˚C, respectively.

E-WOM Review Adoption: Consumers’ Demographic Profile Influence on Green Purchase Intention

NASA Astrophysics Data System (ADS)

Rahim, Roslin Abdul; Sulaiman, Zuraidah; Chin, Thoo Ai; Arif, Mohd Shoki Mohd; Hamid, Mohd Hakim Abdul

2017-06-01

Nowadays, green products are getting popular in their acceptance by the Malaysian consumers. Due to the advancement of the Internet technologies and the wide spread of electronic word of mouth (E-WOM), consumers seem to be more influenced in purchasing the green products. In this study, consumers’ demographic profiles, such as age, gender, income, education background, and occupation are being explored to investigate their influences on consumers’ green product purchase intention. The purpose of this paper is to showcase the results of the differences between several demographic profile groups on green product purchase intention using descriptive analysis, ANOVA and independent sample T-Test. T-test results showed that there is a statistically significant difference between gender on consumers’ green product purchase intention. Meanwhile, the results generated by ANOVA indicated that there are no significant differences between age, income, education background and occupation on consumers’ green product purchase intention. These results shed light on the potential market segment that should be targeted by marketers and producers of green products in Malaysia.

The effect of a family-based intervention with a cognitive-behavioral approach on elder abuse.

PubMed

Khanlary, Zahra; Maarefvand, Masoomeh; Biglarian, Akbar; Heravi-Karimooi, Majideh

2016-01-01

Elder abuse may become a health issue in developing countries, including Iran. The purpose of this investigation was to study the effectiveness of Family-Based Cognitive-Behavioral Social Work (FBCBSW) in reducing elder abuse. In a randomized clinical trial in Iran, 27 elders participated in intervention and control groups. The intervention groups received a five-session FBCBSW intervention and completed the Domestic-Elder-Abuse-Questionnaire (DEAQ), which evaluates elder abuse at baseline and follow-ups. Repeated measures of analysis of variance (ANOVA) and the Wilcoxon test were used to analyze the data. The repeated measures ANOVA revealed that FBCBSW was successful in reducing elder abuse. The Wilcoxon test indicated that emotional neglect, care neglect, financial neglect, curtailment of personal autonomy, psychological abuse, and financial abuse significantly decreased over time, but there was no statistically significant difference in physical abuse before and after the intervention. The findings from this study suggest that FBCBSW is a promising approach to reducing elder abuse and warrants further study with larger samples.

A Comparison of Live Classroom Instruction and Internet-Based Lessons for a Preparatory Training Course Delivered to 4th Year Pharmacy Students

NASA Astrophysics Data System (ADS)

Nuffer, Wesley; Duke, Jodi

2013-08-01

To compare the effectiveness of an internet-based training series with a traditional live classroom session in preparing pharmacy students to oversee a diabetes management program in community settings. Two cohorts of students were identified that prepared by utilizing a recorded online training exclusively, and two separate cohorts of students prepared by receiving only live classroom instruction. All students in the four cohorts were given a survey to evaluate the training sessions, and results were analyzed using the analysis of variance statistical test (ANOVA). Preceptors at the sites who interacted with students in all four cohorts were surveyed to evaluate which students appeared more prepared; these data were compared using paired t tests. Final assessment data for students in all four cohorts were analyzed using ANOVA. There were statistical differences between the two live training groups, with the second group finding the training to be more beneficial for preparing them, feeling the training length was appropriate and preferring the live modality for delivery. The two internet training cohorts were similar except for perceptions regarding the length of the online training. Comparing responses from those students who received live training with those receiving internet instruction demonstrated a statistical difference with the live groups rating the trainings as more helpful in preparing them for the clinics, rating the training as necessary, and rating their confidence higher in seeing patients. Preceptors rated the live training statistically higher than online training in preparing students. There was no difference between groups on their final site assessments. Live classroom training appears to be superior to the recorded internet training in preparing pharmacy students to oversee a diabetes management program in community settings.

Surface hardness evaluation of different composite resin materials: influence of sports and energy drinks immersion after a short-term period

PubMed Central

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

Statistic analyses of the color experience according to the age of the observer.

PubMed

Hunjet, Anica; Parac-Osterman, Durdica; Vucaj, Edita

2013-04-01

Psychological experience of color is a real state of the communication between the environment and color, and it will depend on the source of the light, angle of the view, and particular on the observer and his health condition. Hering's theory or a theory of the opponent processes supposes that cones, which are situated in the retina of the eye, are not sensible on the three chromatic domains (areas, fields, zones) (red, green and purple-blue), but they produce a signal based on the principle of the opposed pairs of colors. A reason of this theory depends on the fact that certain disorders of the color eyesight, which include blindness to certain colors, cause blindness to pairs of opponent colors. This paper presents a demonstration of the experience of blue and yellow tone according to the age of the observer. For the testing of the statistically significant differences in the omission in the color experience according to the color of the background we use following statistical tests: Mann-Whitnney U Test, Kruskal-Wallis ANOVA and Median test. It was proven that the differences are statistically significant in the elderly persons (older than 35 years).

Analysis of Variance: Variably Complex

ERIC Educational Resources Information Center

Drummond, Gordon B.; Vowler, Sarah L.

2012-01-01

These authors have previously described how to use the "t" test to compare two groups. In this article, they describe the use of a different test, analysis of variance (ANOVA) to compare more than two groups. ANOVA is a test of group differences: do at least two of the means differ from each other? ANOVA assumes (1) normal distribution…

The impact of environmental and demographic factors on nursing job satisfaction.

PubMed

Rahnavard, Farnaz; Sadati, Ahmad Kalateh; Hemmati, Sorror; Ebrahimzade, Najmeh; Sarikhani, Yaser; Heydari, Seyed Taghi; Lankarani, Kamran Bagheri

2018-04-01

This study aims to evaluate all aspects of job satisfaction in registered nurses working in different hospitals in Shiraz, Iran. This cross-sectional study was performed during February to August 2015 in Shiraz, Iran. It comprised of 371 registered nurses working in government and private hospitals using multi-stage cluster sampling. Job satisfaction was evaluated using 5 items of the Job Descriptive Index (JDI) consisting of 63 questions developed by Smith, Kendall, and Hulin (1969). Statistical tests including independent sample t test and one-way analysis of variance (ANOVA) were used in order to identify the relation between job satisfaction, and demographic features and work environment. Data were analyzed by SPSS version 15.0, using descriptive statistics, independent-samples t-test, and ANOVA. Our findings showed no relationship between demographic variables and job satisfaction. However, a significant association was observed between environmental aspects such as work rotation (fixed versus rotating) nurse's status (staff vs. supervisors), type of hospitals (governmental vs. private) and work (p<0.01), promotion (p<0.02) and pay (p<0.01) items respectively; however, type of hospital was deemed exempt regarding promotion. Also regarding the number of shifts per week, nurses with more than eight shifts present a lower mean score of satisfaction about pay significantly (p=0.03). The results concerning younger nurses have different types of satisfaction based on several environmental factors. Nurses' policy makers must pay more attention to nurses' satisfaction and focus on reducing the various inequalities.

Tips and Tricks for Successful Application of Statistical Methods to Biological Data.

PubMed

Schlenker, Evelyn

2016-01-01

This chapter discusses experimental design and use of statistics to describe characteristics of data (descriptive statistics) and inferential statistics that test the hypothesis posed by the investigator. Inferential statistics, based on probability distributions, depend upon the type and distribution of the data. For data that are continuous, randomly and independently selected, as well as normally distributed more powerful parametric tests such as Student's t test and analysis of variance (ANOVA) can be used. For non-normally distributed or skewed data, transformation of the data (using logarithms) may normalize the data allowing use of parametric tests. Alternatively, with skewed data nonparametric tests can be utilized, some of which rely on data that are ranked prior to statistical analysis. Experimental designs and analyses need to balance between committing type 1 errors (false positives) and type 2 errors (false negatives). For a variety of clinical studies that determine risk or benefit, relative risk ratios (random clinical trials and cohort studies) or odds ratios (case-control studies) are utilized. Although both use 2 × 2 tables, their premise and calculations differ. Finally, special statistical methods are applied to microarray and proteomics data, since the large number of genes or proteins evaluated increase the likelihood of false discoveries. Additional studies in separate samples are used to verify microarray and proteomic data. Examples in this chapter and references are available to help continued investigation of experimental designs and appropriate data analysis.

Adaptation and Assessment of Reliability and Validity of the Greek Version of the Ohkuma Questionnaire for Dysphagia Screening

PubMed Central

Papadopoulou, Soultana L.; Exarchakos, Georgios; Christodoulou, Dimitrios; Theodorou, Stavroula; Beris, Alexandre; Ploumis, Avraam

2016-01-01

Introduction The Ohkuma questionnaire is a validated screening tool originally used to detect dysphagia among patients hospitalized in Japanese nursing facilities. Objective The purpose of this study is to evaluate the reliability and validity of the adapted Greek version of the Ohkuma questionnaire. Methods Following the steps for cross-cultural adaptation, we delivered the validated Ohkuma questionnaire to 70 patients (53 men, 17 women) who were either suffering from dysphagia or not. All of them completed the questionnaire a second time within a month. For all of them, we performed a bedside and VFSS study of dysphagia and asked participants to undergo a second VFSS screening, with the exception of nine individuals. Statistical analysis included measurement of internal consistency with Cronbach's α coefficient, reliability with Cohen's Kappa, Pearson's correlation coefficient and construct validity with categorical components, and One-Way Anova test. Results According to Cronbach's α coefficient (0.976) for total score, there was high internal consistency for the Ohkuma Dysphagia questionnaire. Test-retest reliability (Cohen's Kappa) ranged from 0.586 to 1.00, exhibiting acceptable stability. We also estimated the Pearson's correlation coefficient for the test-retest total score, which reached high levels (0.952; p = 0.000). The One-Way Anova test in the two measurement times showed statistically significant correlation in both measurements (p = 0.02 and p = 0.016). Conclusion The adapted Greek version of the questionnaire is valid and reliable and can be used for the screening of dysphagia in the Greek-speaking patients. PMID:28050209

Adaptation and Assessment of Reliability and Validity of the Greek Version of the Ohkuma Questionnaire for Dysphagia Screening.

PubMed

Papadopoulou, Soultana L; Exarchakos, Georgios; Christodoulou, Dimitrios; Theodorou, Stavroula; Beris, Alexandre; Ploumis, Avraam

2017-01-01

Introduction  The Ohkuma questionnaire is a validated screening tool originally used to detect dysphagia among patients hospitalized in Japanese nursing facilities. Objective  The purpose of this study is to evaluate the reliability and validity of the adapted Greek version of the Ohkuma questionnaire. Methods  Following the steps for cross-cultural adaptation, we delivered the validated Ohkuma questionnaire to 70 patients (53 men, 17 women) who were either suffering from dysphagia or not. All of them completed the questionnaire a second time within a month. For all of them, we performed a bedside and VFSS study of dysphagia and asked participants to undergo a second VFSS screening, with the exception of nine individuals. Statistical analysis included measurement of internal consistency with Cronbach's α coefficient, reliability with Cohen's Kappa, Pearson's correlation coefficient and construct validity with categorical components, and One-Way Anova test. Results  According to Cronbach's α coefficient (0.976) for total score, there was high internal consistency for the Ohkuma Dysphagia questionnaire. Test-retest reliability (Cohen's Kappa) ranged from 0.586 to 1.00, exhibiting acceptable stability. We also estimated the Pearson's correlation coefficient for the test-retest total score, which reached high levels (0.952; p  = 0.000). The One-Way Anova test in the two measurement times showed statistically significant correlation in both measurements ( p  = 0.02 and p  = 0.016). Conclusion  The adapted Greek version of the questionnaire is valid and reliable and can be used for the screening of dysphagia in the Greek-speaking patients.

Linearised and non-linearised isotherm models optimization analysis by error functions and statistical means

PubMed Central

2014-01-01

In adsorption study, to describe sorption process and evaluation of best-fitting isotherm model is a key analysis to investigate the theoretical hypothesis. Hence, numerous statistically analysis have been extensively used to estimate validity of the experimental equilibrium adsorption values with the predicted equilibrium values. Several statistical error analysis were carried out. In the present study, the following statistical analysis were carried out to evaluate the adsorption isotherm model fitness, like the Pearson correlation, the coefficient of determination and the Chi-square test, have been used. The ANOVA test was carried out for evaluating significance of various error functions and also coefficient of dispersion were evaluated for linearised and non-linearised models. The adsorption of phenol onto natural soil (Local name Kalathur soil) was carried out, in batch mode at 30 ± 20 C. For estimating the isotherm parameters, to get a holistic view of the analysis the models were compared between linear and non-linear isotherm models. The result reveled that, among above mentioned error functions and statistical functions were designed to determine the best fitting isotherm. PMID:25018878

Use of a Self-Instructional Radiographic Anatomy Module for Dental Hygiene Faculty Calibration.

PubMed

Brame, Jennifer L; AlGheithy, Demah Salem; Platin, Enrique; Mitchell, Shannon H

2017-06-01

Purpose: Dental hygiene educators often provide inconsistent instruction in clinical settings and various attempts to address the lack of consistency have been reported in the literature. The purpose of this pilot study was to determine if the use of a use of a self-instructional, radiographic anatomy (SIRA) module improved DH faculty calibration regarding the identifica-tion of normal intraoral and extraoral radiographic anatomy and whether its effect could be sustained over a period of four months. Methods: A convenience sample consisting of all dental hygiene faculty members involved in clinical instruction (N=23) at the University of North Carolina (UNC) was invited to complete the four parts of this online pilot study: a pre-test, review of the SIRA module, an immediate post-test, and a four-month follow-up post-test. Descriptive analyses, the Friedman's ANOVA, and the exact form of the Wilcoxon-Signed-Rank test were used to an-alyze the data. Level of significance was set at 0.05. Participants who did not complete all parts of the study were omitted from data analysis comparing the pre to post-test performance. Results: The pre-test response rate was 73.9% (N=17), and 88.2% (N=15) of those initial participants completed both the immediate and follow-up post-tests. Faculty completing all parts of the study consisted of: 5 full-time faculty, 5 part-time faculty, and 5 graduate teaching assistants. The Friedman's ANOVA revealed no statistically significant difference (P=0.179) in percentages of correct responses between the three tests (pre, post and follow-up). The exact form of the Wilcoxon-Signed-Rank test revealed marginal significance when comparing percent of correct responses at pre-test and immediate post-test (P=0.054), and no statistically significant difference when comparing percent of correct responses at immediate post-test and the follow-up post-test four months later (P=0.106). Conclusions: Use of a SIRA module did not significantly affect DH faculty test performance. Lack of statistical significance in the percentages of correct responses between the three tests may have been affected by the small number of participants completing all four parts of the study (N=15). Additional research is needed to identify and improve methods for faculty calibration. Copyright © 2017 The American Dental Hygienists’ Association.

Effects of chocolate intake on Perceived Stress; a Controlled Clinical Study

PubMed Central

Al Sunni, Ahmed; Latif, Rabia

2014-01-01

Background Cocoa polyphenols have been shown to reduce stress in highly stressed, as well as normal healthy individuals, we wondered whether commercially available chocolate could reduce perceived stress in medical students or not, so we decided to conduct this study. Methods Sixty students were divided into 3 groups (10 males + 10 females/group): i) Dark chocolate (DC) ii) Milk chocolate (MC) iii) White chocolate (WC). Subjects answered a PSS-10 (Perceived Stress Scale) questionnaire at baseline and after consumption of chocolate (40 g/day) for 2 weeks. Data were analyzed by using Microsoft Excel and SPSS version 20. Descriptive analyses were conducted. Means were compared across the study groups by One-Way ANOVA and within the same group by paired ‘t’ test. Results Mean stress scores compared between the groups by ANOVA revealed statistically not significant differences before (F =0.505; P=0.606) and after chocolate consumption (F=0.188; P=0.829). Paired ‘t’ test compared stress scores means before and after chocolate supplementation within the same group and exhibited statistically significant decrease in DC (t = 2.341; p value = 0.03) and MC (t = 3.302; p value = 0.004) groups. Mean stress scores decreased, on average, by approximately 2 and 3 points in DC and MC groups, respectively, at 95% Confidence Interval. The difference was more evident and statistically significant in female students as compared to the males. Conclusion Consumption of 40 g of Dark and Milk chocolate daily during a period of 2 weeks appear to be an effective way to reduce perceived stress in females. PMID:25780358

Effects of chocolate intake on Perceived Stress; a Controlled Clinical Study.

PubMed

Al Sunni, Ahmed; Latif, Rabia

2014-10-01

Cocoa polyphenols have been shown to reduce stress in highly stressed, as well as normal healthy individuals, we wondered whether commercially available chocolate could reduce perceived stress in medical students or not, so we decided to conduct this study. Sixty students were divided into 3 groups (10 males + 10 females/group): i) Dark chocolate (DC) ii) Milk chocolate (MC) iii) White chocolate (WC). Subjects answered a PSS-10 (Perceived Stress Scale) questionnaire at baseline and after consumption of chocolate (40 g/day) for 2 weeks. Data were analyzed by using Microsoft Excel and SPSS version 20. Descriptive analyses were conducted. Means were compared across the study groups by One-Way ANOVA and within the same group by paired 't' test. Mean stress scores compared between the groups by ANOVA revealed statistically not significant differences before (F =0.505; P=0.606) and after chocolate consumption (F=0.188; P=0.829). Paired 't' test compared stress scores means before and after chocolate supplementation within the same group and exhibited statistically significant decrease in DC (t = 2.341; p value = 0.03) and MC (t = 3.302; p value = 0.004) groups. Mean stress scores decreased, on average, by approximately 2 and 3 points in DC and MC groups, respectively, at 95% Confidence Interval. The difference was more evident and statistically significant in female students as compared to the males. Consumption of 40 g of Dark and Milk chocolate daily during a period of 2 weeks appear to be an effective way to reduce perceived stress in females.

The Role of Gender in Neuropsychological Assessment in Healthy Adolescents.

PubMed

Mormile, Megan Elizabeth Evelyn; Langdon, Jody L; Hunt, Tamerah Nicole

2018-01-01

Research in college athletes has revealed significant gender differences in areas of verbal memory, visual memory, and reaction time. Additionally, research has focused on differences in neuropsychological components and gender in college populations; however, such differences in gender have not been documented in healthy adolescent populations. To identify potential differences between males and females using different components of a common computerized neuropsychological test. A computerized neuropsychological test battery (ImPACT®) was administered to 662 high-school age adolescent athletes (male: n = 451 female: n = 262). Differences between genders were calculated using a 1-way ANOVA. All statistical analyses were conducted using SPSS 23.0. Significance levels were set a priori at P < .05. A 1-way ANOVA revealed statistically significant differences between males and females for composite reaction time (F 1,660  = 10.68, P = .001) and total symptom score (F 1,660  = 81.20, P < .001). However, no statistically significant differences were found between males and females in composite verbal memory, visual memory, visual motor, or impulse control (P > .05). Significant differences between males and females were discovered for composite reaction time and total symptom scores, with females reporting more symptoms and slower reaction times at a baseline assessment. Increased symptom reporting by females may be attributed to both hormonal differences and increased honesty. Quicker reaction times in males may support theories that repetition of activities and quicker muscle contraction are gender dependent. However, additional research is necessary to understand gender differences in adolescent athletes during periods of cognitive and physical maturation.

Sample Size and Statistical Conclusions from Tests of Fit to the Rasch Model According to the Rasch Unidimensional Measurement Model (Rumm) Program in Health Outcome Measurement.

PubMed

Hagell, Peter; Westergren, Albert

Sample size is a major factor in statistical null hypothesis testing, which is the basis for many approaches to testing Rasch model fit. Few sample size recommendations for testing fit to the Rasch model concern the Rasch Unidimensional Measurement Models (RUMM) software, which features chi-square and ANOVA/F-ratio based fit statistics, including Bonferroni and algebraic sample size adjustments. This paper explores the occurrence of Type I errors with RUMM fit statistics, and the effects of algebraic sample size adjustments. Data with simulated Rasch model fitting 25-item dichotomous scales and sample sizes ranging from N = 50 to N = 2500 were analysed with and without algebraically adjusted sample sizes. Results suggest the occurrence of Type I errors with N less then or equal to 500, and that Bonferroni correction as well as downward algebraic sample size adjustment are useful to avoid such errors, whereas upward adjustment of smaller samples falsely signal misfit. Our observations suggest that sample sizes around N = 250 to N = 500 may provide a good balance for the statistical interpretation of the RUMM fit statistics studied here with respect to Type I errors and under the assumption of Rasch model fit within the examined frame of reference (i.e., about 25 item parameters well targeted to the sample).

Application of one-way ANOVA in completely randomized experiments

NASA Astrophysics Data System (ADS)

Wahid, Zaharah; Izwan Latiff, Ahmad; Ahmad, Kartini

2017-12-01

This paper describes an application of a statistical technique one-way ANOVA in completely randomized experiments with three replicates. This technique was employed to a single factor with four levels and multiple observations at each level. The aim of this study is to investigate the relationship between chemical oxygen demand index and location on-sites. Two different approaches are employed for the analyses; critical value and p-value. It also presents key assumptions of the technique to be satisfied by the data in order to obtain valid results. Pairwise comparisons by Turkey method are also considered and discussed to determine where the significant differences among the means is after the ANOVA has been performed. The results revealed that there are statistically significant relationship exist between the chemical oxygen demand index and the location on-sites.

Self Esteem and Organizational Commitment Among Health Information Management Staff in Tertiary Care Hospitals in Tehran

PubMed Central

Sadoughi, Farahnaz; Ebrahimi, Kamal

2015-01-01

Background: Self esteem (SE) and organizational commitment (OC) have significant impact on the quality of work life. Aim: This study aims to gain a better understanding of the relationships between SE and OC among health information management staff in tertiary care hospitals in Tehran (Iran). Methods: This was a descriptive correlational and cross sectional study conducted on the health information management staff of tertiary care hospitals in Tehran, Iran. A total of 155 participants were randomly selected from 400 staff. Data were collected by two standard questionnaires. The SE and OC was measured using Eysenck SE scale and Meyer and Allen’s three component model, respectively. The collected data were analyzed with the SPSS (version 16) using statistical tests of of independent T-test, Pearson Correlation coefficient, one way ANOVA and F tests. Results: The OC and SE of the employees’ were 67.8, out of 120 (weak and 21.0 out of 30 (moderate), respectively. The values for affective commitment, normative commitment, and continuance commitment were respectively 21.3 out of 40 (moderate), 23.9 out of 40 (moderate), and 22.7 out of 40 (moderate). The Pearson correlation coefficient test showed a significant OC and SE was statistically significant (P<0.05). The one way ANOVA test (P<0.05) did not show any significant difference between educational degree and work experience with SE and OC. Conclusion: This research showed that SE and OC are moderate. SE and OC have strong correlation with turnover, critical thinking, job satisfaction, and individual and organizational improvement. Therefore, applying appropriate human resource policies is crucial to reinforce these measures. PMID:25716374

Digital versus conventional techniques for pattern fabrication of implant-supported frameworks

PubMed Central

Alikhasi, Marzieh; Rohanian, Ahmad; Ghodsi, Safoura; Kolde, Amin Mohammadpour

2018-01-01

Objective: The aim of this experimental study was to compare retention of frameworks cast from wax patterns fabricated by three different methods. Materials and Methods: Thirty-six implant analogs connected to one-piece abutments were divided randomly into three groups according to the wax pattern fabrication method (n = 12). Computer-aided design/computer-aided manufacturing (CAD/CAM) milling machine, three-dimensional printer, and conventional technique were used for fabrication of waxing patterns. All laboratory procedures were performed by an expert-reliable technician to eliminate intra-operator bias. The wax patterns were cast, finished, and seated on related abutment analogs. The number of adjustment times was recorded and analyzed by Kruskal–Wallis test. Frameworks were cemented on the corresponding analogs with zinc phosphate cement and tensile resistance test was used to measure retention value. Statistical Analysis Used: One-way analysis of variance (ANOVA) and post hoc Tukey tests were used for statistical analysis. Level of significance was set at P < 0.05. Results: The mean retentive values of 680.36 ± 21.93 N, 440.48 ± 85.98 N, and 407.23 ± 67.48 N were recorded for CAD/CAM, rapid prototyping, and conventional group, respectively. One-way ANOVA test revealed significant differences among the three groups (P < 0.001). The post hoc Tukey test showed significantly higher retention for CAD/CAM group (P < 0.001), while there was no significant difference between the two other groups (P = 0.54). CAD/CAM group required significantly more adjustments (P < 0.001). Conclusions: CAD/CAM-fabricated wax patterns showed significantly higher retention for implant-supported cement-retained frameworks; this could be a valuable help when there are limitations in the retention of single-unit implant restorations. PMID:29657528

Mass univariate analysis of event-related brain potentials/fields I: a critical tutorial review.

PubMed

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.

Fracture load and failure analysis of zirconia single crowns veneered with pressed and layered ceramics after chewing simulation.

PubMed

Stawarczyk, Bogna; Ozcan, Mutlu; Roos, Malgorzata; Trottmann, Albert; Hämmerle, Christoph H F

2011-01-01

This study determined the fracture load of zirconia crowns veneered with four overpressed and four layered ceramics after chewing simulation. The veneered zirconia crowns were cemented and subjected to chewing cycling. Subsequently, the specimens were loaded at an angle of 45° in a Universal Testing Machine to determine the fracture load. One-way ANOVA, followed by a post-hoc Scheffé test, t-test and Weibull statistic were performed. Overpressed crowns showed significantly lower fracture load (543-577 N) compared to layered ones (805-1067 N). No statistical difference was found between the fracture loads within the overpressed group. Within the layered groups, LV (1067 N) presented significantly higher results compared to LC (805 N). The mean values of all other groups were not significantly different. Single zirconia crowns veneered with overpressed ceramics exhibited lower fracture load than those of the layered ones after chewing simulation.

Study of long term structural and functional changes in medically controlled glaucoma

PubMed Central

Pandey, Achyut N; Sujata, S

2014-01-01

AIM Prospectively analyze the long term structural and functional changes in patients of primary open angle glaucoma (POAG) receiving medical therapy (beta blockers and non beta blockers). In this study an attempt has been made to evaluate whether medical reduction of IOP prevents or delays the progression of glaucomatous visual field loss and/or optic nerve damage in patients with open angle glaucoma. METHODS Study conducted over a period of 27 months, at a tertiary eye care hospital including both eyes of 40 patients with POAG. Group 1 (20 patients, 40 eyes) received beta-blockers, and Group 2 (20 patients, 40 eyes) received non-beta-blockers. Each patient underwent intraocular pressure measurement, best corrected visual acuity, slit-lamp, fundus examination, gonioscopy, central corneal thickness, visual field assessment by Humphrey automated perimetry and retinal nerve fibre layer thickness by Stratus optical coherence tomography at baseline and at two subsequent visits. The average time interval between each visit was 10-11 months. The statistical analysis was done using one-way analysis of variance (ANOVA). Post-hoc test, using tukey' method were adopted. Probablity (P) value of 0.05 or less was considered to be statistically significant. RESULTS A total of 80 eyes of 40 patients of POAG were enrolled, 24 males, 16 females, age group 50-80 years. In both beta and non beta blocker group, reduction (improvement) in mean IOP from initial levels to the levels achieved at the 2nd and 3rd visits was statistically significant. One way ANOVA (df=2), fisher f value=11.64, P=0.000, one way ANOVA (df=3), fisher f value=35.61, P=0.000. Both mean deviation (MD) and pattern standard deviation (PSD) in both beta and non beta blockers at different visits were not statistically significant. Retinal nerve fibre layer thickness (RNFL) -only mean inferior retinal nerve fibre layer, the difference between the mean value in beta and non beta blocker groupwere statistically significant. [unpaired t test value (df=78) =2.27, P=0.03]. Side effects with beta blocker were conjunctival hyperemia (10%), burning (5%), and conjunctival hyperemia (5%) in non beta blockers. CONCLUSION Non-beta-blockers are as effective as beta-blockers in bringing about a significant lowering of intraocular pressure to the normal range, and in preventing progressive damage to the visual fields and retinal nerve fibre layer. The absence of systemic side effects and superior IOP lowering efficacy has made non beta-blockers attractive for first line therapy for the treatment of glaucoma worldwide. PMID:24634878

Study of long term structural and functional changes in medically controlled glaucoma.

PubMed

Pandey, Achyut N; Sujata, S

2014-01-01

Prospectively analyze the long term structural and functional changes in patients of primary open angle glaucoma (POAG) receiving medical therapy (beta blockers and non beta blockers). In this study an attempt has been made to evaluate whether medical reduction of IOP prevents or delays the progression of glaucomatous visual field loss and/or optic nerve damage in patients with open angle glaucoma. Study conducted over a period of 27 months, at a tertiary eye care hospital including both eyes of 40 patients with POAG. Group 1 (20 patients, 40 eyes) received beta-blockers, and Group 2 (20 patients, 40 eyes) received non-beta-blockers. Each patient underwent intraocular pressure measurement, best corrected visual acuity, slit-lamp, fundus examination, gonioscopy, central corneal thickness, visual field assessment by Humphrey automated perimetry and retinal nerve fibre layer thickness by Stratus optical coherence tomography at baseline and at two subsequent visits. The average time interval between each visit was 10-11 months. The statistical analysis was done using one-way analysis of variance (ANOVA). Post-hoc test, using tukey' method were adopted. Probablity (P) value of 0.05 or less was considered to be statistically significant. A total of 80 eyes of 40 patients of POAG were enrolled, 24 males, 16 females, age group 50-80 years. In both beta and non beta blocker group, reduction (improvement) in mean IOP from initial levels to the levels achieved at the 2nd and 3rd visits was statistically significant. One way ANOVA (df=2), fisher f value=11.64, P=0.000, one way ANOVA (df=3), fisher f value=35.61, P=0.000. Both mean deviation (MD) and pattern standard deviation (PSD) in both beta and non beta blockers at different visits were not statistically significant. Retinal nerve fibre layer thickness (RNFL) -only mean inferior retinal nerve fibre layer, the difference between the mean value in beta and non beta blocker groupwere statistically significant. [unpaired t test value (df=78) =2.27, P=0.03]. Side effects with beta blocker were conjunctival hyperemia (10%), burning (5%), and conjunctival hyperemia (5%) in non beta blockers. Non-beta-blockers are as effective as beta-blockers in bringing about a significant lowering of intraocular pressure to the normal range, and in preventing progressive damage to the visual fields and retinal nerve fibre layer. The absence of systemic side effects and superior IOP lowering efficacy has made non beta-blockers attractive for first line therapy for the treatment of glaucoma worldwide.

Modeling neuroendocrine stress reactivity in salivary cortisol: adjusting for peak latency variability.

PubMed

Lopez-Duran, Nestor L; Mayer, Stefanie E; Abelson, James L

2014-07-01

In this report, we present growth curve modeling (GCM) with landmark registration as an alternative statistical approach for the analysis of time series cortisol data. This approach addresses an often-ignored but critical source of variability in salivary cortisol analyses: individual and group differences in the time latency of post-stress peak concentrations. It allows for the simultaneous examination of cortisol changes before and after the peak while controlling for timing differences, and thus provides additional information that can help elucidate group differences in the underlying biological processes (e.g., intensity of response, regulatory capacity). We tested whether GCM with landmark registration is more sensitive than traditional statistical approaches (e.g., repeated measures ANOVA--rANOVA) in identifying sex differences in salivary cortisol responses to a psychosocial stressor (Trier Social Stress Test--TSST) in healthy adults (mean age 23). We used plasma ACTH measures as our "standard" and show that the new approach confirms in salivary cortisol the ACTH finding that males had longer peak latencies, higher post-stress peaks but a more intense post-peak decline. This finding would have been missed if only saliva cortisol was available and only more traditional analytic methods were used. This new approach may provide neuroendocrine researchers with a highly sensitive complementary tool to examine the dynamics of the cortisol response in a way that reduces risk of false negative findings when blood samples are not feasible.

Impact of pictorial warning labels on tobacco products among patients attending outpatient department of a dental college in Bangalore city: A cross-sectional study.

PubMed

Vanishree, N; Narayan, R R; Naveen, N; Bullapa, D; Vignesh, D; P Raveendran, N M

2017-01-01

The aim of this study is to assess the knowledge, attitude, and impact of pictorial warnings present on tobacco packets among patients attending outpatient department of a dental college of Bangalore city. A cross-sectional study was conducted among 419 patients through convenience sampling, using a structured close-ended questionnaire containing 35 questions. The participants were approached and invited to participate voluntarily. The data obtained were analyzed using descriptive statistics, Chi-square test and ANOVA. Mean age of the participants was 28.1 ± 7.06 years. Out of total 419 participants, 62.8% were tobacco users. About 40.6% of the participants had average knowledge and only 22.9% had positive attitude regarding the pictorial warnings. Nearly 77.9% of tobacco users had previously attempted decreased frequency of tobacco use and 63.7% had tried quitting the habit. The difference was statistically significant (P < 0.05 Chi-square test and ANOVA). The present study revealed that most of study participants have noticed the warnings on tobacco products, and most of them believe that they could understand warning labels. This study also showed that most of study participants believed that pictorial health warnings create awareness about probable health hazards of tobacco use and that these pictorial presentations on tobacco packs positively assist in reducing or quitting tobacco smoking.

Mental and Reproductive Health Correlates of Academic Performance among Debre Berhan University Female Students, Ethiopia: The Case of Premenstrual Dysphoric Disorder

PubMed Central

Alemu, Sisay Mulugeta; Haile, Yohannes Gebreegziabhere

2017-01-01

Background Globally 3 to 8% of reproductive age women are suffering from premenstrual dysphoric disorder (PMDD). Several mental and reproductive health-related factors cause low academic achievement during university education. However, limited data exist in Ethiopia. The aim of the study was to investigate mental and reproductive health correlates of academic performance. Methods Institution based cross-sectional study was conducted with 667 Debre Berhan University female students from April to June 2015. Academic performance was the outcome variable. Mental and reproductive health characteristics were explanatory variables. Two-way analysis of variance (ANOVA) test of association was applied to examine group difference in academic performance. Result Among 529 students who participated, 49.3% reported mild premenstrual syndrome (PMS), 36.9% reported moderate/severe PMS, and 13.8% fulfilled PMDD diagnostic criteria. The ANOVA test of association revealed that there was no significant difference in academic performance between students with different level of PMS experience (F-statistic = 0.08, p value = 0.93). Nevertheless, there was a significant difference in academic performance between students with different length of menses (F-statistic = 5.15, p value = 0.006). Conclusion There was no significant association between PMS experience and academic performance, but on the other hand, the length of menses significantly associated with academic performance. PMID:28630874

Why we should use simpler models if the data allow this: relevance for ANOVA designs in experimental biology.

PubMed

Lazic, Stanley E

2008-07-21

Analysis of variance (ANOVA) is a common statistical technique in physiological research, and often one or more of the independent/predictor variables such as dose, time, or age, can be treated as a continuous, rather than a categorical variable during analysis - even if subjects were randomly assigned to treatment groups. While this is not common, there are a number of advantages of such an approach, including greater statistical power due to increased precision, a simpler and more informative interpretation of the results, greater parsimony, and transformation of the predictor variable is possible. An example is given from an experiment where rats were randomly assigned to receive either 0, 60, 180, or 240 mg/L of fluoxetine in their drinking water, with performance on the forced swim test as the outcome measure. Dose was treated as either a categorical or continuous variable during analysis, with the latter analysis leading to a more powerful test (p = 0.021 vs. p = 0.159). This will be true in general, and the reasons for this are discussed. There are many advantages to treating variables as continuous numeric variables if the data allow this, and this should be employed more often in experimental biology. Failure to use the optimal analysis runs the risk of missing significant effects or relationships.

A Search for Factors Causing Training Costs to Rise by Examining the U. S. Navy’s AT, AW, and AX Ratings during their First Enlistment Period

DTIC Science & Technology

1986-09-01

HYPOTHESIS TEST .................... 20 III. TIME TO GET RATED TWO FACTOR ANOVA RESULTS ......... 23 IV. TIME TO GET RATED TUKEY’S PAIRED COvfl’PARISON... TEST RESULTS A ............................................ 24 V. TIME TO GET RATED TUKEY’S PAIRED COMPARISON TEST RESULTS B...25 VI. SINGLE FACTOR ANOVA HYPOTHESIS TEST #I............... 27 VII. AT: TIME TO GET RATED ANOVA TEST RESULTS ............. 30

Effects of Laser Treatment on the Bond Strength of Differently Sintered Zirconia Ceramics.

PubMed

Dede, Doğu Ömür; Yenisey, Murat; Rona, Nergiz; Öngöz Dede, Figen

2016-07-01

The purpose of this study was to investigate the effects of carbon dioxide (CO2) and Erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiations on the shear bond strength (SBS) of differently sintered zirconia ceramics to resin cement. Eighty zirconia specimens were prepared, sintered in two different periods (short = Ss, long = Ls), and divided into four treatment groups (n = 10 each). These groups were (a) untreated (control), (b) Er:YAG laser irradiated with 6 W power for 5 sec, (c) CO2 laser with 2 W power for 10 sec, (d) CO2 laser with 4 W power for 10 sec. Scanning electron microscope (SEM) images were recorded for each of the eight groups. Eighty composite resin discs (3 × 3 mm) were fabricated and cemented with an adhesive resin cement to ceramic specimens. The SBS test was performed after specimens were stored in water for 24 h by an universal testing machine at a crosshead speed of 1 mm/min. Data were statistically analyzed with two way analysis of variance (ANOVA) and Tukey honest significant difference (HSD) test (α = 0.05). According to the ANOVA, the sintering time, surface treatments and their interaction were statistically significant (p < 0.05). Although each of the laser-irradiated groups were significantly higher than the control groups, there was no statistically significant difference among them (p > 0.05). Variation in sintering time from 2.5 to 5.0 h may have influenced the SBS of Yttrium-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramics. Although CO2 and Er:YAG laser irradiation techniques may increase the SBS values of both tested zirconia ceramics, they are recommended for clinicians as an alternative pretreatment method.

Ethiopian health care professionals' knowledge, attitude, and interests toward pharmacogenomics.

PubMed

Abdela, Ousman Abubeker; Bhagavathula, Akshaya Srikanth; Gebreyohannes, Eyob Alemayehu; Tegegn, Henok Getachew

2017-01-01

Pharmacogenomics is a field of science which studies the impact of inheritance on individual variation in medication therapy response. We assessed healthcare professionals' knowledge, attitude, and interest toward pharmacogenomics. A cross-sectional survey was conducted using a 32-item questionnaire among physicians, nurses, and pharmacists who were working at the University of Gondar Referral and Teaching Hospital in northwest Ethiopia. Descriptive statistics was applied, and the categorical variables were summarized as frequency and percentages. An analysis of variance (ANOVA) test was performed to compare mean scores among health professionals. A p -value of <0.05 was considered as statistically significant. Of 292 health professionals who responded, the majority were male (60%) and the mean age of study participants was 27.00 (±4.85 SD) years. The mean knowledge scores of all participants, pharmacists, physicians, and nurses were 2.343±1.109, 2.671±1.059, 2.375±1.093, and 2.173±1.110, respectively. Based on the ANOVA test, a statistically significant difference was noted in mean knowledge score between pharmacists and nurses ( p =0.002). More than two-thirds (67.33%) of nurses, 42.86% of pharmacists, and 40.27% of physicians who participated did not know that genetic variations can account for as much as 95% of the variability in drug disposition and effects. The ability to accurately apply their knowledge to drug therapy selection, dosing, or monitoring parameter was reported by 35.3% of the participants. More than two-thirds (69.2%) of participants thought that pharmacogenomic testing will allow the identification of the right drug with less side effects. Most of the participants (83.2%) also requested to have training on pharmacogenomics. Participants showed limited knowledge, but they had positive attitude toward pharmacogenomics. Educational programs focusing on pharmacogenomic testing and its clinical application need to be emphasized.

An investigative comparison of purging and non-purging groundwater sampling methods in Karoo aquifer monitoring wells

NASA Astrophysics Data System (ADS)

Gomo, M.; Vermeulen, D.

2015-03-01

An investigation was conducted to statistically compare the influence of non-purging and purging groundwater sampling methods on analysed inorganic chemistry parameters and calculated saturation indices. Groundwater samples were collected from 15 monitoring wells drilled in Karoo aquifers before and after purging for the comparative study. For the non-purging method, samples were collected from groundwater flow zones located in the wells using electrical conductivity (EC) profiling. The two data sets of non-purged and purged groundwater samples were analysed for inorganic chemistry parameters at the Institute of Groundwater Studies (IGS) laboratory of the Free University in South Africa. Saturation indices for mineral phases that were found in the data base of PHREEQC hydrogeochemical model were calculated for each data set. Four one-way ANOVA tests were conducted using Microsoft excel 2007 to investigate if there is any statistically significant difference between: (1) all inorganic chemistry parameters measured in the non-purged and purged groundwater samples per each specific well, (2) all mineral saturation indices calculated for the non-purged and purged groundwater samples per each specific well, (3) individual inorganic chemistry parameters measured in the non-purged and purged groundwater samples across all wells and (4) Individual mineral saturation indices calculated for non-purged and purged groundwater samples across all wells. For all the ANOVA tests conducted, the calculated alpha values (p) are greater than 0.05 (significance level) and test statistic (F) is less than the critical value (Fcrit) (F < Fcrit). The results imply that there was no statistically significant difference between the two data sets. With a 95% confidence, it was therefore concluded that the variance between groups was rather due to random chance and not to the influence of the sampling methods (tested factor). It is therefore be possible that in some hydrogeologic conditions, non-purged groundwater samples might be just as representative as the purged ones. The findings of this study can provide an important platform for future evidence oriented research investigations to establish the necessity of purging prior to groundwater sampling in different aquifer systems.

Bayesian inference for psychology. Part II: Example applications with JASP.

PubMed

Wagenmakers, Eric-Jan; Love, Jonathon; Marsman, Maarten; Jamil, Tahira; Ly, Alexander; Verhagen, Josine; Selker, Ravi; Gronau, Quentin F; Dropmann, Damian; Boutin, Bruno; Meerhoff, Frans; Knight, Patrick; Raj, Akash; van Kesteren, Erik-Jan; van Doorn, Johnny; Šmíra, Martin; Epskamp, Sacha; Etz, Alexander; Matzke, Dora; de Jong, Tim; van den Bergh, Don; Sarafoglou, Alexandra; Steingroever, Helen; Derks, Koen; Rouder, Jeffrey N; Morey, Richard D

2018-02-01

Bayesian hypothesis testing presents an attractive alternative to p value hypothesis testing. Part I of this series outlined several advantages of Bayesian hypothesis testing, including the ability to quantify evidence and the ability to monitor and update this evidence as data come in, without the need to know the intention with which the data were collected. Despite these and other practical advantages, Bayesian hypothesis tests are still reported relatively rarely. An important impediment to the widespread adoption of Bayesian tests is arguably the lack of user-friendly software for the run-of-the-mill statistical problems that confront psychologists for the analysis of almost every experiment: the t-test, ANOVA, correlation, regression, and contingency tables. In Part II of this series we introduce JASP ( http://www.jasp-stats.org ), an open-source, cross-platform, user-friendly graphical software package that allows users to carry out Bayesian hypothesis tests for standard statistical problems. JASP is based in part on the Bayesian analyses implemented in Morey and Rouder's BayesFactor package for R. Armed with JASP, the practical advantages of Bayesian hypothesis testing are only a mouse click away.

Fracture strength of lithium disilicate crowns compared to polymer-infiltrated ceramic-network and zirconia reinforced lithium silicate crowns.

PubMed

Sieper, Kim; Wille, Sebastian; Kern, Matthias

2017-10-01

The aim of this study was to evaluate the fracture strength of crowns made from current CAD/CAM materials. In addition the influence of crown thickness and chewing simulation on the fracture strength was evaluated. Crowns were fabricated from lithium disilicate, zirconia reinforced lithium silicate (ZLS-ceramic) and a polymer-infiltrated ceramic-network (PICN) with an occlusal thickness of 1.0mm or 1.5mm, respectively (n=16). Crowns were cemented on composite dies. Subgroups of eight specimens were loaded with 5kg in a chewing simulator for 1,200,000 cycles with thermal cycling. Finally, all specimens were loaded until fracture in a universal testing machine. Three-way ANOVA was used to detect statistical interaction. Differences regarding the materials were tested with two-way ANOVA, following one-way ANOVA and a post-hoc Tukey's-Test. All crowns survived the chewing simulation. The material had a significant influence on the fracture resistance (p≤0.05). Lithium disilicate achieved the highest values of fracture strength in almost all groups followed by ZLS-ceramic. PICN achieved the lowest values of fracture strength. Chewing simulation increased the fracture strength of thick lithium disilicate crown significantly. Greater occlusal thickness of all crown materials resulted in higher crown fracture strength before chewing simulation. After chewing simulation occlusal thickness of lithium disilicate and PICN crowns had no significant influence on the fracture strength. All crowns revealed fracture strength above the clinically expected loading forces. Therefore the durability of the tested CAD/CAM materials seems promising also in an occlusal thickness of 1.0mm. Copyright © 2017 Elsevier Ltd. All rights reserved.

Eta Squared, Partial Eta Squared, and Misreporting of Effect Size in Communication Research.

ERIC Educational Resources Information Center

Levine, Timothy R.; Hullett, Craig R.

2002-01-01

Alerts communication researchers to potential errors stemming from the use of SPSS (Statistical Package for the Social Sciences) to obtain estimates of eta squared in analysis of variance (ANOVA). Strives to clarify issues concerning the development and appropriate use of eta squared and partial eta squared in ANOVA. Discusses the reporting of…

Quantitative Comparison of Three Standardization Methods Using a One-Way ANOVA for Multiple Mean Comparisons

ERIC Educational Resources Information Center

Barrows, Russell D.

2007-01-01

A one-way ANOVA experiment is performed to determine whether or not the three standardization methods are statistically different in determining the concentration of the three paraffin analytes. The laboratory exercise asks students to combine the three methods in a single analytical procedure of their own design to determine the concentration of…

The comet assay for the evaluation of genotoxic potential of landfill leachate.

PubMed

Widziewicz, Kamila; Kalka, Joanna; Skonieczna, Magdalena; Madej, Paweł

2012-01-01

Genotoxic assessment of landfill leachate before and after biological treatment was conducted with two human cell lines (Me45 and NHDF) and Daphnia magna somatic cells. The alkali version of comet assay was used to examine genotoxicity of leachate by DNA strand breaks analysis and its repair dynamics. The leachate samples were collected from Zabrze landfill, situated in the Upper Silesian Industrial District, Poland. Statistically significant differences (Kruskal-Wallice ANOVA rank model) were observed between DNA strand breaks in cells incubated with leachate before and after treatment (P < 0.001). Nonparametric Friedman ANOVA confirmed time-reliable and concentration-reliable cells response to leachate concentration. Examinations of chemical properties showed a marked decrease in leachate parameters after treatment which correlate to reduced genotoxicity towards tested cells. Obtained results demonstrate that biological cotreatment of leachate together with municipal wastewater is an efficient method for its genotoxic potential reduction; however, treated leachate still possessed genotoxic character.

The Comet Assay for the Evaluation of Genotoxic Potential of Landfill Leachate

PubMed Central

Widziewicz, Kamila; Kalka, Joanna; Skonieczna, Magdalena; Madej, Paweł

2012-01-01

Genotoxic assessment of landfill leachate before and after biological treatment was conducted with two human cell lines (Me45 and NHDF) and Daphnia magna somatic cells. The alkali version of comet assay was used to examine genotoxicity of leachate by DNA strand breaks analysis and its repair dynamics. The leachate samples were collected from Zabrze landfill, situated in the Upper Silesian Industrial District, Poland. Statistically significant differences (Kruskal-Wallice ANOVA rank model) were observed between DNA strand breaks in cells incubated with leachate before and after treatment (P < 0.001). Nonparametric Friedman ANOVA confirmed time-reliable and concentration-reliable cells response to leachate concentration. Examinations of chemical properties showed a marked decrease in leachate parameters after treatment which correlate to reduced genotoxicity towards tested cells. Obtained results demonstrate that biological cotreatment of leachate together with municipal wastewater is an efficient method for its genotoxic potential reduction; however, treated leachate still possessed genotoxic character. PMID:22666120

A comparison of the wear resistance and hardness of indirect composite resins.

PubMed

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.

The Statistical Power of Planned Comparisons.

ERIC Educational Resources Information Center

Benton, Roberta L.

Basic principles underlying statistical power are examined; and issues pertaining to effect size, sample size, error variance, and significance level are highlighted via the use of specific hypothetical examples. Analysis of variance (ANOVA) and related methods remain popular, although other procedures sometimes have more statistical power against…

Effect of Time on Gypsum-Impression Material Compatibility

NASA Astrophysics Data System (ADS)

Won, John Boram

The purpose of this study was to evaluate the compatibility of dental gypsum with three recently introduced irreversible hydrocolloid (alginate) alternatives. The test materials were Alginot® (Kerr™), Position Penta Quick® (3M ESPE™) and Silgimix ® (Sultan Dental™). The irreversible hydrocolloid impression material, Jeltrate Plus antimicrobial® (Dentsply Caulk™) served as the control. Materials and Methods: Testing of materials was conducted in accordance with ANSI/ADA Specification No. 18 for Alginate Impression Materials. Statistical Analysis: The 3-Way ANOVA test was used to analyze measurements between different time points at a significance level of (p < 0.05). Outcome: It was found that there was greater compatibility between gypsum and the alternative materials over time than the traditional irreversible hydrocolloid material that was tested. A statistically significant amount of surface change/incompatibility was found over time with the combination of the dental gypsum products and the control impression material (Jeltrate Plus antimicrobial®).

Different modes of data processing and statistical testing applied to the same set of pharmaco-EEG recordings: effects on the evaluation of a selective and reversible MAO A inhibitor (brofaromine).

PubMed

Reimann, I W; Jobert, M; Gleiter, C H; Turri, M; Bieck, P R; Herrmann, W M

1996-01-01

The comparison of two different modes of data processing and two different approaches to statistical testing both applied to the same set of EEG recordings was the main objective of this pharmacological study. Brofaromine (CGP 11,305 A), a new selective and reversible monoamine oxidase type A inhibitor was used as an example for investigating a potentially antidepressant drug in clinical development. The two modes of pharmaco-EEG (PEEG) data processing differed mainly in the sampling frequency and definition of spectral parameters. Patterns of significant changes were noted in terms of descriptive data analysis using either a nonparametric Wilcoxon signed-rank test or an ANOVA of transformed data, as suggested by Conover and Iman. These data clearly demonstrate that slight discrepancies in the results may simply arise from differences in data processing and statistical approach applied. In spite of these discrepancies, the pattern of brofaromine-induced PEEG changes was very similar regardless of the mode of data handling used.

Effect of structural parameters on burning behavior of polyester fabrics having flame retardancy property

NASA Astrophysics Data System (ADS)

Çeven, E. K.; Günaydın, G. K.

2017-10-01

The aim of this study is filling the gap in the literature about investigating the effect of yarn and fabric structural parameters on burning behavior of polyester fabrics. According to the experimental design three different fabric types, three different weft densities and two different weave types were selected and a total of eighteen different polyester drapery fabrics were produced. All statistical procedures were conducted using the SPSS Statistical software package. The results of the Analysis of Variance (ANOVA) tests indicated that; there were statistically significant (5% significance level) differences between the mass loss ratios (%) in weft and mass loss ratios (%) in warp direction of different fabrics calculated after the flammability test. The Student-Newman-Keuls (SNK) results for mass loss ratios (%) both in weft and warp directions revealed that the mass loss ratios (%) of fabrics containing Trevira CS type polyester were lower than the mass loss ratios of polyester fabrics subjected to washing treatment and flame retardancy treatment.

Rank-based permutation approaches for non-parametric factorial designs.

PubMed

Umlauft, Maria; Konietschke, Frank; Pauly, Markus

2017-11-01

Inference methods for null hypotheses formulated in terms of distribution functions in general non-parametric factorial designs are studied. The methods can be applied to continuous, ordinal or even ordered categorical data in a unified way, and are based only on ranks. In this set-up Wald-type statistics and ANOVA-type statistics are the current state of the art. The first method is asymptotically exact but a rather liberal statistical testing procedure for small to moderate sample size, while the latter is only an approximation which does not possess the correct asymptotic α level under the null. To bridge these gaps, a novel permutation approach is proposed which can be seen as a flexible generalization of the Kruskal-Wallis test to all kinds of factorial designs with independent observations. It is proven that the permutation principle is asymptotically correct while keeping its finite exactness property when data are exchangeable. The results of extensive simulation studies foster these theoretical findings. A real data set exemplifies its applicability. © 2017 The British Psychological Society.

A Comparative Study of Shaping Ability of four Rotary Systems.

PubMed

Rubio, Jorge; Zarzosa, José Ignacio; Pallarés, Antonio

2015-12-01

This study compared the cutting area, instrumentation time, root canal anatomy preservation and non-instrumented areas obtained by F360(®), Mtwo(®), RaCe(®) and Hyflex(®) files with ISO size 35. 120 teeth with a single straight root and root canal were divided into 4 groups. Working length was calculated by using X-rays. The teeth were sectioned with a handpiece and a diamond disc, and the sections were observed with Nikon SMZ-2T stereoscopic microscope and an Intralux 4000-1 light source. The groups were adjusted with a preoperative analysis with AutoCAD. The teeth were reconstructed by a #10 K-File and epoxy glue. Each group was instrumented with one of the four file systems. The instrumentation time was calculated with a 1/100 second chronometer. The area of the thirds and root canal anatomy preservation were analyzed with AutoCAD 2013 and the non-instrumented areas with AutoCAD 2013 and SMZ-2T stereoscopic microscope. The statistical analysis was made with Levene's Test, ANOVA, Bonferroni Test and Pearson´s Chi-square. Equal variances were shown by Levene's Test (P > 0.05). ANOVA (P > 0.05) showed the absence of significant differences. There were significant differences in the instrumentation time (P < 0.05). For root canal anatomy preservation and non-instrumented areas, there were no significant differences between all systems (P > 0.05). The 4 different rotary systems produced similar cutting area, root canal anatomy preservation and non-instrumented areas. Regarding instrumentation time, F360(®) was the fastest system statistically.

A Comparative Study of Shaping Ability of four Rotary Systems

PubMed Central

Zarzosa, José Ignacio; Pallarés, Antonio

2015-01-01

Purpose This study compared the cutting area, instrumentation time, root canal anatomy preservation and non-instrumented areas obtained by F360®, Mtwo®, RaCe® and Hyflex® files with ISO size 35. Material and Methods 120 teeth with a single straight root and root canal were divided into 4 groups. Working length was calculated by using X-rays. The teeth were sectioned with a handpiece and a diamond disc, and the sections were observed with Nikon SMZ-2T stereoscopic microscope and an Intralux 4000-1 light source. The groups were adjusted with a preoperative analysis with AutoCAD. The teeth were reconstructed by a #10 K-File and epoxy glue. Each group was instrumented with one of the four file systems. The instrumentation time was calculated with a 1/100 second chronometer. The area of the thirds and root canal anatomy preservation were analyzed with AutoCAD 2013 and the non-instrumented areas with AutoCAD 2013 and SMZ-2T stereoscopic microscope. The statistical analysis was made with Levene’s Test, ANOVA, Bonferroni Test and Pearson´s Chi-square. Results Equal variances were shown by Levene’s Test (P > 0.05). ANOVA (P > 0.05) showed the absence of significant differences. There were significant differences in the instrumentation time (P < 0.05). For root canal anatomy preservation and non-instrumented areas, there were no significant differences between all systems (P > 0.05). Conclusions The 4 different rotary systems produced similar cutting area, root canal anatomy preservation and non-instrumented areas. Regarding instrumentation time, F360® was the fastest system statistically. PMID:27688412

The effect of prolonged storage and disinfection on the dimensional stability of 5 vinyl polyether silicone impression materials.

PubMed

Nassar, Usama; Flores-Mir, Carlos; Heo, Giseon; Torrealba, Ysidora

2017-06-01

Vinyl polyether silicone (VPES) has a different composition from other elastomeric impression materials as it combines vinyl polysiloxane (VPS) and polyether (PE). Therefore, it is important to study its properties and behavior under different test conditions. This study investigated the dimensional stability of 5 VPES consistencies when stored for up to 2 weeks, with and without using a standard disinfection procedure. 40 discs of each VPES consistency (total 200) were made using a stainless steel die and ring as described by ANSI /ADA specification No. 19. 20 discs of each material were immersed in a 2.5% buffered glutaraldehyde solution for 30 minutes. Dimensional stability measurements were calculated immediately after fabrication and repeated on the same discs after 7 and 14 days of storage. The data was analyzed using two-way ANOVA with a significance level set at α = 0.05. The discs mean contraction was below 0.5% at all test times ranging from 0.200 ± 0.014 to 0.325 ± 0.007. Repeated measures ANOVA showed a statistically significant difference after 2-week storage between the disinfected and non-disinfected groups ( P < .001). Although there was no statistically significant difference between the materials at the time of fabrication, the contraction of the materials increased with storage for 1 and 2 weeks. The dimensional changes of VPES impression discs after disinfection and prolonged storage complied with ANSI/ADA standard. The tested VPES impression materials were dimensionally stable for clinical use after disinfection for 30 minutes in glutaraldehyde and storage for up to 2 weeks.

Color stability comparison of silicone facial prostheses following disinfection.

PubMed

Goiato, Marcelo Coelho; Pesqueira, Aldiéris Alves; dos Santos, Daniela Micheline; Zavanelli, Adriana Cristina; Ribeiro, Paula do Prado

2009-04-01

The purpose of this study was to evaluate the color stability of two silicones for use in facial prostheses, under the influence of chemical disinfection and storage time. Twenty-eight specimens were obtained half made from Silastic MDX 4-4210 silicone and the other half from Silastic 732 RTV silicone. The specimens were divided into four groups: Silastic 732 RTV and MDX 4-4210 with disinfection three times a week with Efferdent and Sliastic 732 RTV and MDX 4-4210 disinfected with neutral soap. Color stability was analyzed by spectrophotometry, immediately and 2 months after making the specimens. After obtaining the results, ANOVA and Tukey test with 1% reliability were used for statistical analysis. Statistical differences between mean color values were observed. Disinfection with Efferdent did not statistically influence the mean color values. The factors of storage time and disinfection statistically influenced color stability; disinfection acts as a bleaching agent in silicone materials.

A study on the compatibility between one-bottle dentin adhesives and composite resins using micro-shear bond strength.

PubMed

Song, Minju; Shin, Yooseok; Park, Jeong-Won; Roh, Byoung-Duck

2015-02-01

This study was performed to determine whether the combined use of one-bottle self-etch adhesives and composite resins from same manufacturers have better bond strengths than combinations of adhesive and resins from different manufacturers. 25 experimental micro-shear bond test groups were made from combinations of five dentin adhesives and five composite resins with extracted human molars stored in saline for 24 hr. Testing was performed using the wire-loop method and a universal testing machine. Bond strength data was statistically analyzed using two way analysis of variance (ANOVA) and Tukey's post hoc test. Two way ANOVA revealed significant differences for the factors of dentin adhesives and composite resins, and significant interaction effect (p < 0.001). All combinations with Xeno V (Dentsply De Trey) and Clearfil S(3) Bond (Kuraray Dental) adhesives showed no significant differences in micro-shear bond strength, but other adhesives showed significant differences depending on the composite resin (p < 0.05). Contrary to the other adhesives, Xeno V and BondForce (Tokuyama Dental) had higher bond strengths with the same manufacturer's composite resin than other manufacturer's composite resin. Not all combinations of adhesive and composite resin by same manufacturers failed to show significantly higher bond strengths than mixed manufacturer combinations.

Influence of Various Acidic Beverages on Tooth Erosion. Evaluation by a New Method

PubMed Central

Zimmer, Stefan; Kirchner, Georg; Bizhang, Mozhgan; Benedix, Mathias

2015-01-01

Material & Methods We have analyzed the loss of enamel and dentine after exposure to different non-alcoholic drinks with a simple new method using bovine teeth. 100 enamel and 100 dentine specimens from freshly extracted bovine incisors were randomly attributed to 10 groups (n=10 for enamel and dentine each). Prior to the start of the experiment all specimens were weighed using a precision balance. The mean initial masses (SD) were 35.8 mg (7.2) for enamel and 24.7 mg (7.0) for dentine. No statistically significant differences were found between groups for initial masses (p>0.05, ANOVA with Bonferroni post hoc test). Thereafter, all specimens of one group were simultaneously placed in 200 ml of the following fluids: Coca-Cola, Coca-Cola light, Sprite, apple juice, Red Bull, orange juice, Bonaqua Fruits (Mango-Acai), tap water, chlorinated swimming pool water, and lemon juice. Fluids were continuously ventilated at 37° C for 7 days. Thereafter the specimens were weighed again and the mean mass loss was calculated. Results The values were (enamel/dentine): Coca-Cola 7.5 mg/6.6 mg; Coca-Cola light 5.2 mg/3.5 mg, Sprite 26.1 mg/17.7 mg, apple juice 27.1 mg/15.2 mg, Red Bull 16.6 mg/17.0 mg, orange juice 24.3 mg/20.2 mg, Bonaqua Fruits (Mango-Acai) 17.8 mg/16.2 mg, tap water -0.2 mg/-0.3 mg, swimming pool water -0.3 mg/-0.2 mg, and lemon juice 32.0 mg/28.3 mg. From all drinks, Cola and Cola light showed the least erosivity (p<0.001, ANOVA with Bonferroni post hoc test) whereas lemon juice showed statistically significant higher erosivity than all other drinks except Sprite and apple juice (p<0.01, ANOVA with Bonferroni post hoc test). Conclusions In conclusion, erosivity of common non-alcoholic drinks varies widely. For example, Sprite, apple juice, and orange juice are about five times more erosive than Coca-Cola light. The findings from the present study should be taken into account in choosing a diet that provides satisfactory nutrition while minimizing tooth erosion. PMID:26035729

Influence of various acidic beverages on tooth erosion. Evaluation by a new method.

PubMed

Zimmer, Stefan; Kirchner, Georg; Bizhang, Mozhgan; Benedix, Mathias

2015-01-01

We have analyzed the loss of enamel and dentine after exposure to different non-alcoholic drinks with a simple new method using bovine teeth. 100 enamel and 100 dentine specimens from freshly extracted bovine incisors were randomly attributed to 10 groups (n=10 for enamel and dentine each). Prior to the start of the experiment all specimens were weighed using a precision balance. The mean initial masses (SD) were 35.8 mg (7.2) for enamel and 24.7 mg (7.0) for dentine. No statistically significant differences were found between groups for initial masses (p>0.05, ANOVA with Bonferroni post hoc test). Thereafter, all specimens of one group were simultaneously placed in 200 ml of the following fluids: Coca-Cola, Coca-Cola light, Sprite, apple juice, Red Bull, orange juice, Bonaqua Fruits (Mango-Acai), tap water, chlorinated swimming pool water, and lemon juice. Fluids were continuously ventilated at 37° C for 7 days. Thereafter the specimens were weighed again and the mean mass loss was calculated. The values were (enamel/dentine): Coca-Cola 7.5 mg/6.6 mg; Coca-Cola light 5.2 mg/3.5 mg, Sprite 26.1 mg/17.7 mg, apple juice 27.1 mg/15.2 mg, Red Bull 16.6 mg/17.0 mg, orange juice 24.3 mg/20.2 mg, Bonaqua Fruits (Mango-Acai) 17.8 mg/16.2 mg, tap water -0.2 mg/-0.3 mg, swimming pool water -0.3 mg/-0.2 mg, and lemon juice 32.0 mg/28.3 mg. From all drinks, Cola and Cola light showed the least erosivity (p<0.001, ANOVA with Bonferroni post hoc test) whereas lemon juice showed statistically significant higher erosivity than all other drinks except Sprite and apple juice (p<0.01, ANOVA with Bonferroni post hoc test). In conclusion, erosivity of common non-alcoholic drinks varies widely. For example, Sprite, apple juice, and orange juice are about five times more erosive than Coca-Cola light. The findings from the present study should be taken into account in choosing a diet that provides satisfactory nutrition while minimizing tooth erosion.

SOCR Analyses - an Instructional Java Web-based Statistical Analysis Toolkit.

PubMed

Chu, Annie; Cui, Jenny; Dinov, Ivo D

2009-03-01

The Statistical Online Computational Resource (SOCR) designs web-based tools for educational use in a variety of undergraduate courses (Dinov 2006). Several studies have demonstrated that these resources significantly improve students' motivation and learning experiences (Dinov et al. 2008). SOCR Analyses is a new component that concentrates on data modeling and analysis using parametric and non-parametric techniques supported with graphical model diagnostics. Currently implemented analyses include commonly used models in undergraduate statistics courses like linear models (Simple Linear Regression, Multiple Linear Regression, One-Way and Two-Way ANOVA). In addition, we implemented tests for sample comparisons, such as t-test in the parametric category; and Wilcoxon rank sum test, Kruskal-Wallis test, Friedman's test, in the non-parametric category. SOCR Analyses also include several hypothesis test models, such as Contingency tables, Friedman's test and Fisher's exact test.The code itself is open source (http://socr.googlecode.com/), hoping to contribute to the efforts of the statistical computing community. The code includes functionality for each specific analysis model and it has general utilities that can be applied in various statistical computing tasks. For example, concrete methods with API (Application Programming Interface) have been implemented in statistical summary, least square solutions of general linear models, rank calculations, etc. HTML interfaces, tutorials, source code, activities, and data are freely available via the web (www.SOCR.ucla.edu). Code examples for developers and demos for educators are provided on the SOCR Wiki website.In this article, the pedagogical utilization of the SOCR Analyses is discussed, as well as the underlying design framework. As the SOCR project is on-going and more functions and tools are being added to it, these resources are constantly improved. The reader is strongly encouraged to check the SOCR site for most updated information and newly added models.

Augmented effects of EMG biofeedback interfaced with virtual reality on neuromuscular control and movement coordination during reaching in children with cerebral palsy.

PubMed

Yoo, Ji Won; Lee, Dong Ryul; Cha, Young Joo; You, Sung Hyun

2017-01-01

The purpose of the present study was to compare therapeutic effects of an electromyography (EMG) biofeedback augmented by virtual reality (VR) and EMG biofeedback alone on the triceps and biceps (T:B) muscle activity imbalance and elbow joint movement coordination during a reaching motor taskOBJECTIVE: To compare therapeutic effects of an electromyography (EMG) biofeedback augmented by virtual reality (VR) and EMG biofeedback alone on the triceps and biceps muscle activity imbalance and elbow joint movement coordination during a reaching motor task in normal children and children with spastic cerebral palsy (CP). 18 children with spastic CP (2 females; mean±standard deviation = 9.5 ± 1.96 years) and 8 normal children (3 females; mean ± standard deviation = 9.75 ± 2.55 years) were recruited from a local community center. All children with CP first underwent one intensive session of EMG feedback (30 minutes), followed by one session of the EMG-VR feedback (30 minutes) after a 1-week washout period. Clinical tests included elbow extension range of motion (ROM), biceps muscle strength, and box and block test. EMG triceps and biceps (T:B) muscle activity imbalance and reaching movement acceleration coordination were concurrently determined by EMG and 3-axis accelerometer measurements respectively. Independent t-test and one-way repeated analysis of variance (ANOVA) were performed at p < 0.05. The one-way repeated ANOVA was revealed to be significantly effective in elbow extension ROM (p = 0.01), biceps muscle strength (p = 0.01), and box and block test (p = 0.03). The one-way repeated ANOVA also revealed to be significantly effective in the peak triceps muscle activity (p = 0.01). However, one-way repeated ANOVA produced no statistical significance in the composite 3-dimensional movement acceleration coordination data (p = 0.12). The present study is a first clinical trial that demonstrated the superior benefits of the EMG biofeedback when augmented by virtual reality exercise games in children with spastic CP. The augmented EMG and VR feedback produced better neuromuscular balance control in the elbow joint than the EMG biofeedback alone.

Differences in Empathy Levels of Medical Students Based on Gender, Year of Medical School and Career Choice.

PubMed

Tariq, Nabia; Tayyab, Ali; Jaffery, Tara

2018-04-01

To measure mean empathy scores of Pakistani medical students and to explore any association of empathy scores with gender, medical school year and future career choice. Cross-sectional survey. Shifa College of Medicine, Shifa Tameer-e-Millat University, during the academic year 2015-2016. The student version of Jefferson Scale of Physician Empathy (JSPE) was distributed to the students electronically via the student portal. Response that were completed in full were included in the study. Descriptive statistics was used to analyse student demographic data. The student score on the JSPE was reported as the mean (out of 7) of each item. Independent samples t-test was employed to check the significant differences between genders. Empathy score with advancing year of study was investigated using ANOVA. ANOVA with post-hoc Tukey's test was used to study the relationship between career choice and empathy score. The response rate was 70.94%. The mean score was 4.51 ±0.69. Females obtained greater, but statistically insignificant (p=0.08) empathy score (4.58) as compared to the male students (4.45). No statistically significant difference was seen between scores on the survey across the five academic years (F=0.88, p=0.47). Students who selected medicine and allied as career choice showed a significantly higher empathy score than those who opted for surgery. The internal consistency reliability (Cronbach's alpha) was 0.78. There were low levels of empathy in Pakistani medical students. Students with interest in medicine and allied showed higher empathy scores compared to surgical or technical specialties. No association of empathy scores with gender and medical school year was observed.

Roles of frequency, attitudes, and multiple intelligence modality surrounding Electricity Content-Based Reader's Theatre

NASA Astrophysics Data System (ADS)

Hosier, Julie Winchester

Integration of subjects is something elementary teachers must do to insure required objectives are covered. Science-based Reader's Theatre is one way to weave reading into science. This study examined the roles of frequency, attitudes, and Multiple Intelligence modalities surrounding Electricity Content-Based Reader's Theatre. This study used quasi-experimental, repeated measures ANOVA with time as a factor design. A convenience sample of two fifth-grade classrooms participated in the study for eighteen weeks. Five Electricity Achievement Tests were given throughout the study to assess students' growth. A Student Reader's Theatre Attitudinal Survey revealed students' attitudes before and after Electricity Content-Based Reader's Theatre treatment. The Multiple Intelligence Inventory for Kids (Faris, 2007) examined whether Multiple Intelligence modality played a role in achievement on Electricity Test 4, the post-treatment test. Analysis using repeated measures ANOVA and an independent t-test found that students in the experimental group, which practiced its student-created Electricity Content-Based Reader's Theatre skits ten times versus two times for the for control group, did significantly better on Electricity Achievement Test 4, t(76) = 3.018, p = 0.003. Dependent t-tests did not find statistically significant differences between students' attitudes about Electricity Content-Based Reader's Theatre before and after treatment. A Kruskal-Wallis test found no statistically significant difference between the various Multiple Intelligence modalities score mean ranks (x2 = 5.57, df = 2, alpha = .062). Qualitative data do, however, indicate students had strong positive feelings about Electricity Content-Based Reader's Theatre after treatment. Students indicated it to be motivating, confidence-building, and a fun way to learn about science; however, they disliked writing their own scripts. Examining the frequency, attitudes, and Multiple Intelligence modalities lead to the conclusion that the role of frequency had the greatest impact on the success of Electricity Content-Based Reader's Theatre. The participating teachers, students, and research found integrating science and reading through Electricity Content-Based Reader's Theatre beneficial.

A LISREL Model for the Analysis of Repeated Measures with a Patterned Covariance Matrix.

ERIC Educational Resources Information Center

Rovine, Michael J.; Molenaar, Peter C. M.

1998-01-01

Presents a LISREL model for the estimation of the repeated measures analysis of variance (ANOVA) with a patterned covariance matrix. The model is demonstrated for a 5 x 2 (Time x Group) ANOVA in which the data are assumed to be serially correlated. Similarities with the Statistical Analysis System PROC MIXED model are discussed. (SLD)

Comparison of central corneal thickness measurements using ultrasound pachymetry, ultrasound biomicroscopy, and the Artemis-2 VHF scanner in normal eyes

PubMed Central

Al-Farhan, Haya M; Al-Otaibi, Wafa’a Majed

2012-01-01

Purpose To compare the precision of central corneal thickness (CCT) measurements taken with the handheld ultrasound pachymeter (USP), ultrasound biomicroscopy (UBM), and the Artemis-2 very high frequency ultrasound scanner (VHFUS) on normal subjects. Design Prospective study. Methods One eye from each of 61 normal subjects was randomly selected for this study. The measurements of the CCT were taken with the USP, VHFUS, and UBM. Results were compared statistically using repeated-measures analysis of variance (ANOVA), Pearson’s correlation coefficient, and limits of agreement. Results The average CCT (± standard deviation) was 530.1 ± 30.5 μm, 554.9 ± 31.7 μm, and 559.5 ± 30.7 μm for UBM, VHFUS, and USP respectively. The intraobserver repeatability analyses of variance are not significant for USP, UBM, and VHFUS. P-values were 0.17, 0.19, and 0.37 respectively. Repeated-measures ANOVA showed a significant difference between the three different methods of measuring CCT (P = 0.0001). The ANOVA test revealed no statistically significant difference between USP and VHFUS (P > 0.05), yet statistical significant differences with UBM versus USP and UBM versus VHFUS (P < 0.001). There were high correlations between the three instruments (P < 0.0001). The mean differences (and upper/lower limits of agreement) for CCT measurements were 29.4 ± 14.3 (2.7/56), 4.6 ± 8.6 (−14.7/23.8), and −24.8 ± 13.1 (−50.4/0.8) for USP versus UBM, USP versus VHFUS, and UBM versus VHFUS, respectively. Conclusion The UBM produces CCT measurements that vary significantly from those returned by the USP and the VHFUS, suggesting that the UBM may not be used interchangeably with either equipment for monitoring the CCT in the clinical setting. PMID:22848145

The Applicability of Standard Error of Measurement and Minimal Detectable Change to Motor Learning Research-A Behavioral Study.

PubMed

Furlan, Leonardo; Sterr, Annette

2018-01-01

Motor learning studies face the challenge of differentiating between real changes in performance and random measurement error. While the traditional p -value-based analyses of difference (e.g., t -tests, ANOVAs) provide information on the statistical significance of a reported change in performance scores, they do not inform as to the likely cause or origin of that change, that is, the contribution of both real modifications in performance and random measurement error to the reported change. One way of differentiating between real change and random measurement error is through the utilization of the statistics of standard error of measurement (SEM) and minimal detectable change (MDC). SEM is estimated from the standard deviation of a sample of scores at baseline and a test-retest reliability index of the measurement instrument or test employed. MDC, in turn, is estimated from SEM and a degree of confidence, usually 95%. The MDC value might be regarded as the minimum amount of change that needs to be observed for it to be considered a real change, or a change to which the contribution of real modifications in performance is likely to be greater than that of random measurement error. A computer-based motor task was designed to illustrate the applicability of SEM and MDC to motor learning research. Two studies were conducted with healthy participants. Study 1 assessed the test-retest reliability of the task and Study 2 consisted in a typical motor learning study, where participants practiced the task for five consecutive days. In Study 2, the data were analyzed with a traditional p -value-based analysis of difference (ANOVA) and also with SEM and MDC. The findings showed good test-retest reliability for the task and that the p -value-based analysis alone identified statistically significant improvements in performance over time even when the observed changes could in fact have been smaller than the MDC and thereby caused mostly by random measurement error, as opposed to by learning. We suggest therefore that motor learning studies could complement their p -value-based analyses of difference with statistics such as SEM and MDC in order to inform as to the likely cause or origin of any reported changes in performance.

Silica coating on alumina ceramic: comparison of three chairside air-abrasion devices working for different times and distances.

PubMed

Pestana Passos, S; Dias Vanderlei, A; Ozcan, M; Felipe Valandro, L F; Felipe Valandro, L

2011-03-01

This study evaluated, by scanning electron microscope (SEM) and EDS, the effect of different strategies for silica coating (sandblasters, time and distance) of a glass-infiltrated ceramic (In-Ceram Alumina). Forty-one ceramic blocks were produced. For comparison of the three air-abrasion devices, 15 ceramic samples were divided in three groups (N.=5): Bioart, Microetcher and Ronvig (air-abrasion parameters: 20 s at a distance of 10 mm). For evaluation of the time and distance factors, ceramic samples (N.=5) were allocated in groups considering three applied times (5 s, 13 s and 20 s) and two distances (10 mm and 20 mm), using the Ronvig device. In a control sample, no surface treatment was performed. After that, the micro-morphologic analyzes of the ceramic surfaces were made using SEM. EDS analyzes were carried out to detect the % of silica on representative ceramic surface. ANOVA and Tukey tests were used to analyze the results. One-way ANOVA showed the silica deposition was different for different devices (P=0.0054). The Ronvig device promoted the highest silica coating compared to the other devices (Tukey test). Two-way ANOVA showed the distance and time factors did not affect significantly the silica deposition (application time and distance showed no statistical difference). The Ronvig device provided the most effective silica deposition on glass-infiltrated alumina ceramic surface and the studied time and distance for air-abrasion did not affect the silica coating.

Influence of Immediate Dentin Sealing on the Shear Bond Strength of Pressed Ceramic Luted to Dentin with Self-Etch Resin Cement

PubMed Central

Dalby, Robert; Ellakwa, Ayman; Millar, Brian; Martin, F. Elizabeth

2012-01-01

Objectives. To examine the effect of immediate dentin sealing (IDS), with dentin bonding agents (DBAs) applied to freshly cut dentin, on the shear bond strength of etched pressed ceramic luted to dentin with RelyX Unicem (RXU) cement. Method. Eighty extracted noncarious third molars were ground flat to expose the occlusal dentin surfaces. The teeth were randomly allocated to five groups (A to E) of sixteen teeth each. Groups A to D were allocated a dentin bonding agent (Optibond FL, One Coat Bond, Single Bond, or Go!) that was applied to the dentin surface to mimic the clinical procedure of IDS. These specimen groups then had etched glass ceramic discs (Authentic) luted to the sealed dentin surface using RXU. Group E (control) had etched glass ceramic discs luted to the dentin surface (without a dentin bonding agent) using RXU following the manufacturer's instructions. All specimens were stored for one week in distilled water at room temperature and then shear stressed at a constant cross-head speed of 1 mm per minute until failure. Statistical analysis was performed by ANOVA followed by post hoc Tukey HSD method (P < 0.05) applied for multiple paired comparisons. Results. The shear bond strength results for group A to E ranged from 6.94 ± 1.53 to 10.03 ± 3.50 MPa. One-way ANOVA demonstrated a difference (P < 0.05) between the groups tested and the Tukey HSD demonstrated a significant (P < 0.05) difference between the shear bond strength (SBS) of Optibond FL (Group A) and Go! (Group D). There was no statistical difference (P > 0.05) in the SBS between the test groups (A–D) or the control (group E). Conclusion. IDS using the dentin bonding agents tested does not statistically (P > 0.05) affect the shear bond strength of etched pressed ceramic luted to dentin with RXU when compared to the control. PMID:22287963

Evaluation of the flexural strength and microhardness of provisional crown and bridge materials fabricated by different methods

PubMed Central

Digholkar, Shruti; Madhav, V. N. V.; Palaskar, Jayant

2016-01-01

Purpose: The purpose of this study was to evaluate and compare the flexural strength and microhardness of provisional restorative materials fabricated utilizing rapid prototyping (RP), Computer Assisted Designing and Computer Assisted Milling (CAD-CAM) and conventional method. Materials and Methods: Twenty specimens of dimensions 25 mm × 2 mm × 2 mm (ADA-ANSI specification #27) were fabricated each using: (1) Three dimensional (3D) printed light-cured micro-hybrid filled composite by RP resin group, (2) a milled polymethyl methacrylate (CH) using CAD-CAM (CC resin group), and (3) a conventionally fabricated heat activated polymerized CH resin group. Flexural strength and microhardness were measured and values obtained were evaluated. Results: The measured mean flexural strength values (MegaPascals) were 79.54 (RP resin group), 104.20 (CC resin group), and 95.58 (CH resin group). The measured mean microhardness values (Knoop hardness number) were 32.77 (RP resin group), 25.33 (CC resin group), and 27.36 (CH resin group). The analysis of variance (ANOVA) test shows that there is statistically significant difference in the flexural strength values of the three groups (P < 0.05). According to the pairwise comparison of Tukey's honest significant difference (HSD) test, flexural strength values of CC resin group and CH resin group were higher and statistically significant than those of the RP resin group (P < 0.05). However, there was no significant difference between flexural strength values of CC resin and CH resin group (P = 0.64). The difference in microhardness values of the three groups was statistically significant according to ANOVA as well as the intergroup comparison done using the Tukey's HSD (post hoc) test (P < 0.05). Conclusions: CC-based CH had the highest flexural strength whereas RP-based 3D printed and light cured micro-hybrid filled composite had the highest microhardness. PMID:27746595

Cervical and Incisal Marginal Discrepancy in Ceramic Laminate Veneering Materials: A SEM Analysis

PubMed Central

Ranganathan, Hemalatha; Ganapathy, Dhanraj M.; Jain, Ashish R.

2017-01-01

Context: Marginal discrepancy influenced by the choice of processing material used for the ceramic laminate veneers needs to be explored further for better clinical application. Aims: This study aimed to evaluate the amount of cervical and incisal marginal discrepancy associated with different ceramic laminate veneering materials. Settings and Design: This was an experimental, single-blinded, in vitro trial. Subjects and Methods: Ten central incisors were prepared for laminate veneers with 2 mm uniform reduction and heavy chamfer finish line. Ceramic laminate veneers fabricated over the prepared teeth using four different processing materials were categorized into four groups as Group I - aluminous porcelain veneers, Group II - lithium disilicate ceramic veneers, Group III - lithium disilicate-leucite-based veneers, Group IV - zirconia-based ceramic veneers. The cervical and incisal marginal discrepancy was measured using a scanning electron microscope. Statistical Analysis Used: ANOVA and post hoc Tukey honest significant difference (HSD) tests were used for statistical analysis. Results: The cervical and incisal marginal discrepancy for four groups was Group I - 114.6 ± 4.3 μm, 132.5 ± 6.5 μm, Group II - 86.1 ± 6.3 μm, 105.4 ± 5.3 μm, Group III - 71.4 ± 4.4 μm, 91.3 ± 4.7 μm, and Group IV - 123.1 ± 4.1 μm, 142.0 ± 5.4 μm. ANOVA and post hoc Tukey HSD tests observed a statistically significant difference between the four test specimens with regard to cervical marginal discrepancy. The cervical and incisal marginal discrepancy scored F = 243.408, P < 0.001 and F = 180.844, P < 0.001, respectively. Conclusion: This study concluded veneers fabricated using leucite reinforced lithium disilicate exhibited the least marginal discrepancy followed by lithium disilicate ceramic, aluminous porcelain, and zirconia-based ceramics. The marginal discrepancy was more in the incisal region than in the cervical region in all the groups. PMID:28839415

Academic dishonesty among nursing students: a descriptive study.

PubMed

Keçeci, Ayla; Bulduk, Serap; Oruç, Deniz; Çelik, Serpil

2011-09-01

This descriptive and cross-sectional study aims to evaluate academic dishonesty among university nursing students in Turkey. The study's sample included 196 students. Two instruments were used for gathering data. The first instrument, a questionnaire, which included some socio-demographic variables (age, class, gender, education, family structure, parents' attitude and educators' attitude) formed the first part. The second part included the Academic Dishonesty Tendency Scale developed by Eminoğlu and Nartgün. The data were analyzed using descriptive statistics and Kruskall Wallis, One-way Anova, t- test and Mann-Whitney U test. It was found that academic dishonesty was at medium-level (2.60-3.39) in nursing students.

EFFECT OF LIGHT-CURING UNITS AND ACTIVATION MODE ON POLYMERIZATION SHRINKAGE AND SHRINKAGE STRESS OF COMPOSITE RESINS

PubMed Central

Lopes, Lawrence Gonzaga; Franco, Eduardo Batista; Pereira, José Carlos; Mondelli, Rafael Francisco Lia

2008-01-01

The aim of this study was to evaluate the polymerization shrinkage and shrinkage stress of composites polymerized with a LED and a quartz tungsten halogen (QTH) light sources. The LED was used in a conventional mode (CM) and the QTH was used in both conventional and pulse-delay modes (PD). The composite resins used were Z100, A110, SureFil and Bisfil 2B (chemical-cured). Composite deformation upon polymerization was measured by the strain gauge method. The shrinkage stress was measured by photoelastic analysis. The polymerization shrinkage data were analyzed statistically using two-way ANOVA and Tukey test (p≤0.05), and the stress data were analyzed by one-way ANOVA and Tukey's test (p≤0.05). Shrinkage and stress means of Bisfil 2B were statistically significant lower than those of Z100, A110 and SureFil. In general, the PD mode reduced the contraction and the stress values when compared to CM. LED generated the same stress as QTH in conventional mode. Regardless of the activation mode, SureFil produced lower contraction and stress values than the other light-cured resins. Conversely, Z100 and A110 produced the greatest contraction and stress values. As expected, the chemically cured resin generated lower shrinkage and stress than the light-cured resins. In conclusion, The PD mode effectively decreased contraction stress for Z100 and A110. Development of stress in light-cured resins depended on the shrinkage value. PMID:19089287

A Comparison of Face to Face and Video-Based Self Care Education on Quality of Life of Hemodialysis Patients

PubMed Central

Hemmati Maslakpak, Masumeh; Shams, Shadi

2015-01-01

Background End stage renal disease negatively affects the patients’ quality of life. There are different educational methods to help these patients. This study was performed to compare the effectiveness of self-care education in two methods, face to face and video educational, on the quality of life in patients under treatment by hemodialysis in education-medical centers in Urmia. Methods In this quasi-experimental study, 120 hemodialysis patients were selected randomly; they were then randomly allocated to three groups: the control, face to face education and video education. For face to face group, education was given individually in two sessions of 35 to 45 minutes. For video educational group, CD was shown. Kidney Disease Quality Of Life- Short Form (KDQOL-SF) questionnaire was filled out before and two months after the intervention. Data analysis was performed in SPSS software by using one-way ANOVA. Results ANOVA test showed a statistically significant difference in the quality of life scores among the three groups after the intervention (P=0.024). After the intervention, Tukey’s post-hoc test showed a statistically significant difference between the two groups of video and face to face education regarding the quality of life (P>0.05). Conclusion Implementation of the face to face and video education methods improves the quality of life in hemodialysis patients. So, it is suggested that video educational should be used along with face to face education. PMID:26171412

Statistical inference for classification of RRIM clone series using near IR reflectance properties

NASA Astrophysics Data System (ADS)

Ismail, Faridatul Aima; Madzhi, Nina Korlina; Hashim, Hadzli; Abdullah, Noor Ezan; Khairuzzaman, Noor Aishah; Azmi, Azrie Faris Mohd; Sampian, Ahmad Faiz Mohd; Harun, Muhammad Hafiz

2015-08-01

RRIM clone is a rubber breeding series produced by RRIM (Rubber Research Institute of Malaysia) through "rubber breeding program" to improve latex yield and producing clones attractive to farmers. The objective of this work is to analyse measurement of optical sensing device on latex of selected clone series. The device using transmitting NIR properties and its reflectance is converted in terms of voltage. The obtained reflectance index value via voltage was analyzed using statistical technique in order to find out the discrimination among the clones. From the statistical results using error plots and one-way ANOVA test, there is an overwhelming evidence showing discrimination of RRIM 2002, RRIM 2007 and RRIM 3001 clone series with p value = 0.000. RRIM 2008 cannot be discriminated with RRIM 2014; however both of these groups are distinct from the other clones.

MANCOVA for one way classification with homogeneity of regression coefficient vectors

NASA Astrophysics Data System (ADS)

Mokesh Rayalu, G.; Ravisankar, J.; Mythili, G. Y.

2017-11-01

The MANOVA and MANCOVA are the extensions of the univariate ANOVA and ANCOVA techniques to multidimensional or vector valued observations. The assumption of a Gaussian distribution has been replaced with the Multivariate Gaussian distribution for the vectors data and residual term variables in the statistical models of these techniques. The objective of MANCOVA is to determine if there are statistically reliable mean differences that can be demonstrated between groups later modifying the newly created variable. When randomization assignment of samples or subjects to groups is not possible, multivariate analysis of covariance (MANCOVA) provides statistical matching of groups by adjusting dependent variables as if all subjects scored the same on the covariates. In this research article, an extension has been made to the MANCOVA technique with more number of covariates and homogeneity of regression coefficient vectors is also tested.

Factors influencing medical informatics examination grade--can biorhythm, astrological sign, seasonal aspect, or bad statistics predict outcome?

PubMed

Petrovecki, Mladen; Rahelić, Dario; Bilić-Zulle, Lidija; Jelec, Vjekoslav

2003-02-01

To investigate whether and to what extent various parameters, such as individual characteristics, computer habits, situational factors, and pseudoscientific variables, influence Medical Informatics examination grade, and how inadequate statistical analysis can lead to wrong conclusions. The study included a total of 382 second-year undergraduate students at the Rijeka University School of Medicine in the period from 1996/97 to 2000/01 academic year. After passing the Medical Informatics exam, students filled out an anonymous questionnaire about their attitude toward learning medical informatics. They were asked to grade the course organization and curriculum content, and provide their date of birth; sex; study year; high school grades; Medical Informatics examination grade, type, and term; and describe their computer habits. From these data, we determined their zodiac signs and biorhythm. Data were compared by the use of t-test, one-way ANOVA with Tukey's honest significance difference test, and randomized complete block design ANOVA. Out of 21 variables analyzed, only 10 correlated with the average grade. Students taking Medical Informatics examination in the 1998/99 academic year earned lower average grade than any other generation. Significantly higher Medical Informatics exam grade was earned by students who finished a grammar high school; owned and regularly used a computer, Internet, and e-mail (p< or =0.002 for all items); passed an oral exam without taking a written test (p=0.004), or did not repeat the exam (p<0.001). Better high-school students and students with better grades from high-school informatics course also scored significantly better (p=0.032 and p<0.001, respectively). Grade in high-school mathematics, student's sex, and time of year when the examination was taken were not related to the grade, and neither were pseudoscientific parameters, such as student zodiac sign, zodiac sign quality, or biorhythm cycles, except when intentionally inadequate statistics was used for data analysis. Medical Informatics examination grades correlated with general learning capacity and computer habits of students, but showed no relation to other investigated parameters, such as examination term or pseudoscientific parameters. Inadequate statistical analysis can always confirm false conclusions.

Effect of in-office bleaching agents on physical properties of dental composite resins.

PubMed

Mourouzis, Petros; Koulaouzidou, Elisabeth A; Helvatjoglu-Antoniades, Maria

2013-04-01

The physical properties of dental restorative materials have a crucial effect on the longevity of restorations and moreover on the esthetic demands of patients, but they may be compromised by bleaching treatments. The purpose of this study was to evaluate the effects of in-office bleaching agents on the physical properties of three composite resin restorative materials. The bleaching agents used were hydrogen peroxide and carbamide peroxide at high concentrations. Specimens of each material were prepared, cured, and polished. Measurements of color difference, microhardness, and surface roughness were recorded before and after bleaching and data were examined statistically by analysis of variance (ANOVA) and Tukey HSD post-hoc test at P < .05. The measurements showed that hue and chroma of silorane-based composite resin altered after the bleaching procedure (P < .05). No statistically significant differences were found when testing the microhardness and surface roughness of composite resins tested (P > .05). The silorane-based composite resin tested showed some color alteration after bleaching procedures. The bleaching procedure did not alter the microhardness and the surface roughness of all composite resins tested.

Statistical testing of the full-range leadership theory in nursing.

PubMed

Kanste, Outi; Kääriäinen, Maria; Kyngäs, Helvi

2009-12-01

The aim of this study is to test statistically the structure of the full-range leadership theory in nursing. The data were gathered by postal questionnaires from nurses and nurse leaders working in healthcare organizations in Finland. A follow-up study was performed 1 year later. The sample consisted of 601 nurses and nurse leaders, and the follow-up study had 78 respondents. Theory was tested through structural equation modelling, standard regression analysis and two-way anova. Rewarding transformational leadership seems to promote and passive laissez-faire leadership to reduce willingness to exert extra effort, perceptions of leader effectiveness and satisfaction with the leader. Active management-by-exception seems to reduce willingness to exert extra effort and perception of leader effectiveness. Rewarding transformational leadership remained as a strong explanatory factor of all outcome variables measured 1 year later. The data supported the main structure of the full-range leadership theory, lending support to the universal nature of the theory.

Evaluation of setting time and flow properties of self-synthesize alginate impressions

NASA Astrophysics Data System (ADS)

Halim, Calista; Cahyanto, Arief; Sriwidodo, Harsatiningsih, Zulia

2018-02-01

Alginate is an elastic hydrocolloid dental impression materials to obtain negative reproduction of oral mucosa such as to record soft-tissue and occlusal relationships. The aim of the present study was to synthesize alginate and to determine the setting time and flow properties. There were five groups of alginate consisted of fifty samples self-synthesize alginate and commercial alginate impression product. Fifty samples were divided according to two tests, each twenty-five samples for setting time and flow test. Setting time test was recorded in the s unit, meanwhile, flow test was recorded in the mm2 unit. The fastest setting time result was in the group three (148.8 s) and the latest was group fours). The highest flow test result was in the group three (69.70 mm2) and the lowest was group one (58.34 mm2). Results were analyzed statistically by one way ANOVA (α= 0.05), showed that there was a statistical significance of setting time while no statistical significance of flow properties between self-synthesize alginate and alginate impression product. In conclusion, the alginate impression was successfully self-synthesized and variation composition gives influence toward setting time and flow properties. The most resemble setting time of control group is group three. The most resemble flow of control group is group four.

Teaching Principles of Inference with ANOVA

ERIC Educational Resources Information Center

Tarlow, Kevin R.

2016-01-01

Analysis of variance (ANOVA) is a test of "mean" differences, but the reference to "variances" in the name is often overlooked. Classroom activities are presented to illustrate how ANOVA works with emphasis on how to think critically about inferential reasoning.

The use of reinforced composite resin cement as compensation for reduced post length.

PubMed

Nissan, J; Dmitry, Y; Assif, D

2001-09-01

Cements that yield high retentive values are believed to allow use of shorter posts. This study investigated the use of reinforced composite resin cement as compensation for reduced dowel length. The retention values of stainless steel posts (parallel-sided ParaPost and tapered Dentatus in 5-, 8-, and 10-mm lengths) luted with Flexi-Flow titanium-reinforced composite resin and zinc phosphate cements were evaluated. Single-rooted extracted human teeth with crowns (n = 120), removed at the cementoenamel junction, were randomly divided into 4 groups of 30 samples each. Different post lengths were luted with either Flexi-Flow or zinc phosphate. Each sample was placed into a specialized jig and on a tensile testing machine with a crosshead speed of 2 mm/min, applied until failure. The effect of different posts and cements on the force required to dislodge the dowels was evaluated with multiple analyses of variance (ANOVA). One-way ANOVA with Scheffé contrast was applied to determine the effect of different post lengths on the retentive failure of posts luted with the 2 agents. Flexi-Flow reinforced composite resin cement significantly increased retention of ParaPost and Dentatus dowels (P<.001) compared with zinc phosphate. One-way ANOVA revealed no statistically significant difference (P>.05) between mean retention of both dowels luted with Flexi-Flow for all posts length used (5 mm = 8 mm = 10 mm). Mean retention values of the groups luted with zinc phosphate showed a statistically significant difference (P<.001) for the different post lengths (10 > 8 > 5 mm). Parallel-sided ParaPost dowels demonstrated a higher mean retention than tapered Dentatus dowels (P<.001). In this study, Flexi-Flow reinforced composite resin cement compensated for the reduced length of shorter parallel-sided ParaPost and tapered Dentatus dowels.

The Short-Term Effects of Lying, Sitting and Standing on Energy Expenditure in Women

PubMed Central

POPP, COLLIN J.; BRIDGES, WILLIAM C.; JESCH, ELLIOT D.

2018-01-01

The deleterious health effects of too much sitting have been associated with an increased risk for overweight and obesity. Replacing sitting with standing is the proposed intervention to increase daily energy expenditure (EE). The purpose of this study was to determine the short-term effects of lying, sitting, and standing postures on EE, and determine the magnitude of the effect each posture has on EE using indirect calorimetry (IC). Twenty-eight healthy females performed three separate positions (lying, sitting, standing) in random order. Inspired and expired gases were collected for 45-minutes (15 minutes for each position) using breath-by-breath indirect calorimetry. Oxygen consumption (VO2) and carbon dioxide production (VCO2) were measured to estimate EE. Statistical analyses used repeat measures ANOVA to analyze all variables and post hoc t-tests. Based on the ANOVA the individual, time period and order term did not result in a statistically significant difference. Lying EE and sitting EE were not different from each other (P = 0.56). However, standing EE (kcal/min) was 9.0 % greater than lying EE (kcal/min) (P = 0.003), and 7.1% greater than sitting EE (kcal/min) (P = 0.02). The energetic cost of standing was higher compared to lying and sitting. While this is statistically significant, the magnitude of the effect of standing when compared to sitting was small (Cohen’s d = 0.31). Short-term standing does not offer an energetic advantage when compared to sitting.

Influence of hydrostatic pulpal pressure on the microtensile bond strength of all-in-one self-etching adhesives.

PubMed

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.

[Divisibility of warfarin and fluindione tablets tested in elderly patients and their family circle].

PubMed

Pautas, Eric; Despres, Jérémie; Peyron, Isabelle; Golmard, Jean-Louis; Grange, Jennifer; Koenig, Nelly; Gouronnec, Adeline; Mitha, Nathalie; Siguret, Virginie; Gouin-Thibault, Isabelle

2011-06-01

Vitamin K antagonist tablets are often split to fractionate the dose by elderly patients. We performed a study in order to assess the divisibility of one dosage strength of score-lined warfarin and of score-lined fluindione. Due to a recent change in the pharmaceutical form of fluindione in order to improve the divisibility, the study was performed over 2 different periods (with the « old » and with the « new » pharmaceutical form). In each period, 10 patients mean aged 82 years, 10 relatives, 10 nurses, 10 medical doctors) were asked to split in half warfarin tablets (W2 1(st) period et W2 2(d) period) and fluindione tablets (F2 et F'2), and to split fluindione tablets into 4 fragments (F4 et F'4). The first end-point was the accuracy of splitting estimated by the difference between the real and the expected weight of fragmented tablets. The statistical analysis was performed using an ANOVA test with 2 variables, subject and drug. The difference between the 2 periods were analyzed using an ANOVA test with 2 variables, subject and period. Over the 2 periods, the differences between real and expected weight were of 4.65% for W2 1(st) phase, 9.48% for F2, 15.35% for F4, 5.56% for W2 2(d )period, 4.30% for F'2, and 6.98% for F'4. The quality of splitting was statistically poorer in the elderly patient group compared to other subjects. This study was not design to assess the clinical relevance (bleeding or thromboembolism) or the anticoagulation control of the variations in drug mass due to inappropriate splitting of tablets. However, split form of drugs should be prescribe with caution to elderly patients.

The Effect of Different Chemical Surface Treatments of Denture Teeth on Shear Bond Strength: A Comparative Study

PubMed Central

Palekar, Umesh; Awinashe, Vaibav; Mishra, Sunil Kumar; Kawadkar, Abhishek; Rahangdale, Tripti

2014-01-01

Background: The development of better cross linked acrylic resin teeth has solved the problems related to wearing and discoloration of acrylic teeth. The same cross linking at ridge lap region acts as a double edge sword as it weakens the bond between denture base and tooth. Aim of Study: The purpose of study was to evaluate the effect of surface treatment on the bond strength of resin teeth to denture base resin using monomethyl methacrylate monomer and dichloromethane with no surface treatment acting as control. Settings and Design:Denture base cylinder samples in wax (n=180) were made with maxillary central incisor attached at 450 (JIST 6506). These samples were randomly and equally divided into three groups of 60 each. These specimens were then flasked, dewaxed as per the standard protocol. Materials and Methods: Before acrylization, ridge lap area was treated as follows: Group A- no surface treatment act as control, Group B treated with monomethyl methacrylate monomer, Group C treated with dichloromethane. Digitally controlled acryliser was used for acrylization as per manufacturer’s instructions and shear bond strength was tested on Universal Testing Machine (Servo Hydraulic, 50kN High Strain, BISS Research). Statistical Analysis used: Result was statistically analyzed with One-way analysis of variance (ANOVA) and Post-hoc ANOVA Tukey’s HSD test at 5% level of significance. Results: The application of dichloromethane showed increased bond strength between cross linked acrylic resin teeth and heat cure denture base resin followed by monomethyl methacrylate monomer and control group. Conclusion: The application of dichloromethane on the ridge lap surface of the resin teeth before packing of the dough into the mold significantly increased the bond strength between cross linked acrylic resin teeth and heat cure denture base resin. PMID:25121057

The effect of prolonged storage and disinfection on the dimensional stability of 5 vinyl polyether silicone impression materials

PubMed Central

Flores-Mir, Carlos; Heo, Giseon; Torrealba, Ysidora

2017-01-01

PURPOSE Vinyl polyether silicone (VPES) has a different composition from other elastomeric impression materials as it combines vinyl polysiloxane (VPS) and polyether (PE). Therefore, it is important to study its properties and behavior under different test conditions. This study investigated the dimensional stability of 5 VPES consistencies when stored for up to 2 weeks, with and without using a standard disinfection procedure. MATERIALS AND METHODS 40 discs of each VPES consistency (total 200) were made using a stainless steel die and ring as described by ANSI /ADA specification No. 19. 20 discs of each material were immersed in a 2.5% buffered glutaraldehyde solution for 30 minutes. Dimensional stability measurements were calculated immediately after fabrication and repeated on the same discs after 7 and 14 days of storage. The data was analyzed using two-way ANOVA with a significance level set at α = 0.05. RESULTS The discs mean contraction was below 0.5% at all test times ranging from 0.200 ± 0.014 to 0.325 ± 0.007. Repeated measures ANOVA showed a statistically significant difference after 2-week storage between the disinfected and non-disinfected groups (P < .001). Although there was no statistically significant difference between the materials at the time of fabrication, the contraction of the materials increased with storage for 1 and 2 weeks. CONCLUSION The dimensional changes of VPES impression discs after disinfection and prolonged storage complied with ANSI/ADA standard. The tested VPES impression materials were dimensionally stable for clinical use after disinfection for 30 minutes in glutaraldehyde and storage for up to 2 weeks. PMID:28680549

Steroid-induced osteoporosis monitored by Raman spectroscopy

NASA Astrophysics Data System (ADS)

Maher, Jason R.; Takahata, Masahiko; Awad, Hani A.; Berger, Andrew J.

2011-03-01

Glucocorticoids are frequently used to treat inflammatory disorders such as rheumatoid arthritis. Unfortunately, extended exposure to this steroid is the leading cause of physician-induced osteoporosis, leaving patients susceptible to fractures at rates of 30-50%. In this presentation, we report correlations between Raman spectra and biomechanical strength tests on bones of glucocorticoid- and placebo- treated mice. Both wild-type mice and a transgenic model of rheumatoid arthritis have been studied. A two-way ANOVA model reveals statistically significant spectral differences as influenced by glucocorticoid treatment and mouse type.

The impact of teacher preparation on student achievement in rural secondary schools

NASA Astrophysics Data System (ADS)

Barnes, Shontier Prescott

The primary purpose of this study was to examine significant differences, if any, in student achievement in the area of math and science of students taught by traditionally certified teachers and alternatively certified teachers. This study examined alternatively certified teachers, as identified from through the Georgia TAPP (Teacher Alternative Preparation Program), and traditionally certified teachers in rural high schools in the Central Savannah River Area of Georgia. Student achievement was measured by student scores on the Algebra I and Physical Science End-Of-Course Test, a criterion-referenced test aligned with state adopted curriculum standards. The study utilized frequency distributions, correlations, descriptive statistics, and univariate analysis of variance (ANOVA) to examine the data. Univariate tests were done to find individual differences for each dependent variable. The ANOVA was used for the single dependent (student achievement) and formed comparisons and tracked the effect of the independent variable (teacher preparation), each of which (traditional and alternative) may have a number of levels and may interact to affect the dependent variable. The covariates, the independent variables not manipulated, but still affecting the response, are students' ethnicity, gender, and school socioeconomic status were also analyzed to predict student achievement. KEY WORDS. Teacher Preparation, Student Achievement, Math, Science, Traditionally certified teachers, Alternatively certified teachers, Georgia TAPP (Teacher Alternative Preparation Program), End-Of-Course Test (EOCT), Performance standard.

Salivary protein concentration, flow rate, buffer capacity and pH estimation: A comparative study among young and elderly subjects, both normal and with gingivitis and periodontitis.

PubMed

Shaila, Mulki; Pai, G Prakash; Shetty, Pushparaj

2013-01-01

To evaluate the salivary protein concentration in gingivitis and periodontitis patients and compare the parameters like salivary total protein, salivary albumin, salivary flow rate, pH, buffer capacity and flow rate in both young and elderly patients with simple methods. One hundred and twenty subjects were grouped based on their age as young and elderly. Each group was subgrouped (20 subjects) as controls, gingivitis and periodontitis. Unstimulated whole saliva was collected from patients and flow rate was noted down during collection of the sample. Salivary protein estimation was done using the Biuret method and salivary albumin was assessed using the Bromocresol green method. pH was estimated with a pHmeter and buffering capacity was analyzed with the titration method. Student's t-test, Fisher's test (ANOVA) and Tukey HSD (ANOVA) tests were used for statistical analysis. A very highly significant rise in the salivary total protein and albumin concentration was noted in gingivitis and periodontitis subjects of both young and elderly. An overall decrease in salivary flow rate was observed among the elderly, and also the salivary flow rate of women was significantly lower than that of men. Significant associations between salivary total protein and albumin in gingivitis and periodontitis were found with simple biochemical tests. A decrease in salivary flow rate among elderly and among women was noted.

Facilitating the Transition from Bright to Dim Environments

DTIC Science & Technology

2016-03-04

For the parametric data, a multivariate ANOVA was used in determining the systematic presence of any statistically significant performance differences...performed. All significance levels were p < 0.05, and statistical analyses were performed with the Statistical Package for Social Sciences ( SPSS ...1950. Age changes in rate and level of visual dark adaptation. Journal of Applied Physiology, 2, 407–411. Field, A. 2009. Discovering statistics

TSP Symposium 2012 Proceedings

DTIC Science & Technology

2012-11-01

and Statistical Model 78 7.3 Analysis and Results 79 7.4 Threats to Validity and Limitations 85 7.5 Conclusions 86 7.6 Acknowledgments 87 7.7...Table 12: Overall Statistics of the Experiment 32 Table 13: Results of Pairwise ANOVA Analysis, Highlighting Statistically Significant Differences...we calculated the percentage of defects injected. The distribution statistics are shown in Table 2. Table 2: Mean Lower, Upper Confidence Interval

[Effectiveness of the Military Mental Health Promotion Program].

PubMed

Woo, Chung Hee; Kim, Sun Ah

2014-12-01

This study was done to evaluate the Military Mental Health Promotion Program. The program was an email based cognitive behavioral intervention. The research design was a quasi-experimental study with a non-equivalent control group pretest-posttest design. Participants were 32 soldiers who agreed to participate in the program. Data were collected at three different times from January 2012 to March 2012; pre-test, post-test, and a one-month follow-up test. The data were statistically analyzed using SPSS 18.0. The effectiveness of the program was tested by repeated measures ANOVA. The first hypothesis that the level of depression in the experimental group who participated in the program would decrease compared to the control group was not supported in that the difference in group-time interaction was not statistically significant (F=2.19, p=.121). The second and third hypothesis related to anxiety and self-esteem were supported in group-time interaction, respectively (F=7.41, p=.001, F=11.67, p<.001). Results indicate that the program is effective in improving soldiers' mental health status in areas of anxiety and self-esteem.

Force Relaxation Characteristics of Medium Force Orthodontic Latex Elastics: A Pilot Study

PubMed Central

Fernandes, Daniel J.; Abrahão, Gisele M.; Elias, Carlos N.; Mendes, Alvaro M.

2011-01-01

To evaluate force extension relaxation of different brands and diameters of latex elastics subjected to static tensile testing under an apparatus designed to simulate oral environments, sample sizes of 5 elastics from American Orthodontics (AO), Tp, and Morelli Orthodontics (Mo) of equivalent medium force, (3/16, 1/4, and 5/16 inch size) were tested. The forces were read after 1-, 3-, 6-, 12- and 24-hour periods in Emic testing machine with 30 mm/min cross-head speed and load cell of 20 N. Two-way ANOVA and Bonferroni tests were used to identify statistical significance. There were statistically differences among different manufacturers at all observation intervals (P < 0.0001). The relationships among loads at 24-hour time period were as follows: Morelli>AO>Tp for 3/16, 1/4, and 5/16 elastics. The force decay pattern showed a notable drop-off of forces until 3 hours, a slight increase in some groups from 3–6 hours and a more homogeneous force pattern over 6–24 hours. PMID:21991478

Influence of translucence/opacity and shade in the flexural strength of lithium disilicate ceramics

PubMed Central

Santos, Mila Oliveira; do Amaral, Flávia Lucisano Botelho; França, Fabiana Mantovani Gomes; Basting, Roberta Tarkany

2015-01-01

Background: Lithium disilicate ceramic system consists of glass ceramic ingots with different grades of translucence which may influence its flexural strength. Aims: To assess the three-point flexural strength of the different lithium disilicate-based ceramic ingots (IPS e.max Press/Ivoclar Vivadent) with different levels of translucence and shade. Materials and Methods: Six groups of ceramic ingots were selected to represent different levels of translucence and shade (HTA1, HTBL2, LTA2, LTB2, MO2, and HO). They measured 25 mm × 5 mm × 2 mm (n = 10), according to ISO 6872 specifications, and tested on a universal test machine (EMIC). Statistical Analysis Used: A one-way analysis of variance (ANOVA) was used (α = 0.05). Results: The results (in MPa) were: HTA1 = 392.98; HTBL2 = 390.74; LTA2 = 390.46; LTB2 = 389.92; MO2 = 390.43; HO = 391.96. ANOVA showed no significant difference among groups (P = 0.1528). Conclusions: Different levels of translucence, opacity and shade of ingots did not affect their mechanical strength, and the use of these ceramics should be guided by the esthetic demands of each clinical situation. PMID:26430304

Effect of Erythrinamu lungu on anxiety during extraction of third molars.

PubMed

Silveira-Souto, Maria-Luisa; São-Mateus, Carla-Rocha; de Almeida-Souza, Liane-Maciel; Groppo, Francisco-Carlos

2014-09-01

The aim of the present study was to evaluate the effect of Erythrinamu lungu on the control of dental anxiety in patients who had under gone bilateral extraction of asymptomatic, impacted mandibular third molars. In a randomized, double-blind, crossover study, 30 healthy volunteers (5 men and 25 women, over 18 years of age), received either 500mg of E.mulungu (MulunguMatusa®) or 500 mg of placebo, p.o., one hour before surgical procedure. The level ofanxiety was assessed through questionnaire sand physical parameters, such as blood pressure, heart rate andoxygen saturation. Data were analyzed by Chi-square test, ANOVA (Tukey test) and Friedman with significance level of 5%. A higher preference (Chi-square, p = 0.0062) for E. mulungu was observed for both genders. Volunteers with higher anxiety levels tended to to prefer E. mulungu. No statistically significant differences were verified in blood pressure (one-way ANOVA, p = 0.1259), heart rate (Friedman, p> 0.05) and oxygen saturation (Friedman, p = 0.7664) among periods and types of treatments. E. mulungu showed an anxiolytic effect without significant changes in physiological parameters. It could be considered as an alternative to control the anxiety in adult patients undergoing mandibular thirdmolars surgery.

Comparison of the effect of three autogenous bone harvesting methods on cell viability in rabbits

PubMed Central

Moradi Haghgoo, Janet; Arabi, Seyed Reza; Hosseinipanah, Seyyed Mohammad; Solgi, Ghasem; Rastegarfard, Neda; Farhadian, Maryam

2017-01-01

Background. This study was designed to compare the viability of autogenous bone grafts, harvested using different methods, in order to determine the best harvesting technique with respect to more viable cells. Methods. In this animal experimental study, three harvesting methods, including manual instrument (chisel), rotary device and piezosurgery, were used for harvesting bone grafts from the lateral body of the mandible on the left and right sides of 10 rabbits. In each group, 20 bone samples were collected and their viability was assessed using MTS kit. Statistical analyses, including ANOVA and post hoc Tukey tests, were used for evaluating significant differences between the groups. Results. One-way ANOVA showed significant differences between all the groups (P=0.000). Data analysis using post hoc Tukey tests indicated that manual instrument and piezosurgery had no significant differences with regard to cell viability (P=0.749) and the cell viability in both groups was higher than that with the use of a rotary instrument (P=0.000). Conclusion. Autogenous bone grafts harvested with a manual instrument and piezosurgery had more viable cells in comparison to the bone chips harvested with a rotary device. PMID:28748046

A Comparison of Analytical and Data Preprocessing Methods for Spectral Fingerprinting

PubMed Central

LUTHRIA, DEVANAND L.; MUKHOPADHYAY, SUDARSAN; LIN, LONG-ZE; HARNLY, JAMES M.

2013-01-01

Spectral fingerprinting, as a method of discriminating between plant cultivars and growing treatments for a common set of broccoli samples, was compared for six analytical instruments. Spectra were acquired for finely powdered solid samples using Fourier transform infrared (FT-IR) and Fourier transform near-infrared (NIR) spectrometry. Spectra were also acquired for unfractionated aqueous methanol extracts of the powders using molecular absorption in the ultraviolet (UV) and visible (VIS) regions and mass spectrometry with negative (MS−) and positive (MS+) ionization. The spectra were analyzed using nested one-way analysis of variance (ANOVA) and principal component analysis (PCA) to statistically evaluate the quality of discrimination. All six methods showed statistically significant differences between the cultivars and treatments. The significance of the statistical tests was improved by the judicious selection of spectral regions (IR and NIR), masses (MS+ and MS−), and derivatives (IR, NIR, UV, and VIS). PMID:21352644

A Tutorial for the Student Edition (Release 1.1) of Minitab.

ERIC Educational Resources Information Center

MacFarland, Thomas W.; Hou, Cheng-I

This guide for using Minitab requires DOS version 2.0 or greater, 512K RAM memory, two double-sided diskette drives, and a graphics monitor. Topics covered in the tutorial are Getting started; Installation; Making a data diskette; Entering data; Central tendency and dispersion; t-test; Chi-square test; Oneway ANOVA test; Twoway ANOVA test; and…

Comparison of soymilk, powdered milk, Hank's balanced salt solution and tap water on periodontal ligament cell survival.

PubMed

Moazami, Fariborz; Mirhadi, Hosein; Geramizadeh, Bita; Sahebi, Safoura

2012-04-01

The purpose of this study was to evaluate the ability of soymilk, powdered milk, and Hank's balanced salt solution (HBSS) to maintain human periodontal ligament (PDL) cell viability in vitro. PDL cells were obtained from extracted healthy third molars and cultured in Dulbecco's modified Eagles medium (DMEM). The cultures were exposed for 1, 2, 4, and 8 h to experimental solutions (tap water served as negative control and DMEM as positive control) at 37°C. The viable cells were then counted using the trypan blue exclusion technique. Data were analyzed by using one-way anova, post hoc Scheffe and two-way anova test. Statistical analysis showed that HBSS, powdered baby formula, and soymilk maintain cell viability equally well in different periods of times. Tap water cannot keep cells viable as well as other solutions. Soymilk and powdered baby formula can be recommended as suitable storage media for avulsed teeth for up to 8 h. © 2011 John Wiley & Sons A/S.

Split-plot microarray experiments: issues of design, power and sample size.

PubMed

Tsai, Pi-Wen; Lee, Mei-Ling Ting

2005-01-01

This article focuses on microarray experiments with two or more factors in which treatment combinations of the factors corresponding to the samples paired together onto arrays are not completely random. A main effect of one (or more) factor(s) is confounded with arrays (the experimental blocks). This is called a split-plot microarray experiment. We utilise an analysis of variance (ANOVA) model to assess differentially expressed genes for between-array and within-array comparisons that are generic under a split-plot microarray experiment. Instead of standard t- or F-test statistics that rely on mean square errors of the ANOVA model, we use a robust method, referred to as 'a pooled percentile estimator', to identify genes that are differentially expressed across different treatment conditions. We illustrate the design and analysis of split-plot microarray experiments based on a case application described by Jin et al. A brief discussion of power and sample size for split-plot microarray experiments is also presented.

Halogen and LED light curing of composite: temperature increase and Knoop hardness.

PubMed

Schneider, L F; Consani, S; Correr-Sobrinho, L; Correr, A B; Sinhoreti, M A

2006-03-01

This study assessed the Knoop hardness and temperature increase provided by three light curing units when using (1) the manufacturers' recommended times of photo-activation and (2) standardizing total energy density. One halogen--XL2500 (3M/ESPE)--and two light-emitting diode (LED) curing units--Freelight (3M/ESPE) and Ultrablue IS (DMC)--were used. A type-K thermocouple registered the temperature change produced by the composite photo-activation in a mold. Twenty-four hours after the photo-activation procedures, the composite specimens were submitted to a hardness test. Both temperature increase and hardness data were submitted to ANOVA and Tukey's test (5% significance). Using the first set of photo-activation conditions, the halogen unit produced a statistically higher temperature increase than did both LED units, and the Freelight LED resulted in a lower hardness than did the other curing units. When applying the second set of photo-activation conditions, the two LED units produced statistically greater temperature increase than did the halogen unit, whereas there were no statistical differences in hardness among the curing units.

Marginal Adaptation and Quality of Interfaces in Lithium Disilicate Crowns - Influence of Manufacturing and Cementation Techniques.

PubMed

Melo Freire, C A; Borges, G A; Caldas, Dbm; Santos, R S; Ignácio, S A; Mazur, R F

To evaluate the cement line thickness and the interface quality in milled or injected lithium disilicate ceramic restorations and their influence on marginal adaptation using different cement types and different adhesive cementation techniques. Sixty-four bovine teeth were prepared for full crown restoration (7.0±0.5 mm in height, 8.0 mm in cervical diameter, and 4.2 mm in incisal diameter) and were divided into two groups: CAD/CAM automation technology, IPS e.max CAD (CAD), and isostatic injection by heat technology, IPS e.max Press (PRESS). RelyX ARC (ARC) and RelyX U200 resin cements were used as luting agents in two activation methods: initial self-activation and light pre-activation for one second (tack-cure). Next, the specimens were stored in distilled water at 23°C ± 2°C for 72 hours. The cement line thickness was measured in micrometers, and the interface quality received scores according to the characteristics and sealing aspects. The evaluations were performed with an optical microscope, and scanning electron microscope images were presented to demonstrate the various features found in the cement line. For the cement line thickness, data were analyzed with three-way analysis of variance (ANOVA) and the Games-Howell test (α=0.05). For the variable interface quality, the data were analyzed with the Mann-Whitney U-test, the Kruskal-Wallis test, and multiple comparisons nonparametric Dunn test (α=0.05). The ANOVA presented statistical differences among the ceramic restoration manufacturing methods as well as a significant interaction between the manufacturing methods and types of cement (p<0.05). The U200 presented lower cement line thickness values when compared to the ARC with both cementation techniques (p<0.05). With regard to the interface quality, the Mann-Whitney U-test and the Kruskal-Wallis test demonstrated statistical differences between the ceramic restoration manufacturing methods and cementation techniques. The PRESS ceramics obtained lower scores than did the CAD ceramics when using ARC cement (p<0.05). Milled restorations cemented with self-adhesive resin cement resulted in a thinner cement line that is statistically different from that of CAD or pressed ceramics cemented with resin cement with adhesive application. No difference between one-second tack-cure and self-activation was noted.

Functional vs. Traditional Analysis in Biomechanical Gait Data: An Alternative Statistical Approach

PubMed Central

Seeley, Matthew K.; Francom, Devin; Reese, C. Shane; Hopkins, J. Ty

2017-01-01

Abstract In human motion studies, discrete points such as peak or average kinematic values are commonly selected to test hypotheses. The purpose of this study was to describe a functional data analysis and describe the advantages of using functional data analyses when compared with a traditional analysis of variance (ANOVA) approach. Nineteen healthy participants (age: 22 ± 2 yrs, body height: 1.7 ± 0.1 m, body mass: 73 ± 16 kg) walked under two different conditions: control and pain+effusion. Pain+effusion was induced by injection of sterile saline into the joint capsule and hypertonic saline into the infrapatellar fat pad. Sagittal-plane ankle, knee, and hip joint kinematics were recorded and compared following injections using 2×2 mixed model ANOVAs and FANOVAs. The results of ANOVAs detected a condition × time interaction for the peak ankle (F1,18 = 8.56, p = 0.01) and hip joint angle (F1,18 = 5.77, p = 0.03), but did not for the knee joint angle (F1,18 = 0.36, p = 0.56). The functional data analysis, however, found several differences at initial contact (ankle and knee joint), in the mid-stance (each joint) and at toe off (ankle). Although a traditional ANOVA is often appropriate for discrete or summary data, in biomechanical applications, the functional data analysis could be a beneficial alternative. When using the functional data analysis approach, a researcher can (1) evaluate the entire data as a function, and (2) detect the location and magnitude of differences within the evaluated function. PMID:29339984

Functional vs. Traditional Analysis in Biomechanical Gait Data: An Alternative Statistical Approach.

PubMed

Park, Jihong; Seeley, Matthew K; Francom, Devin; Reese, C Shane; Hopkins, J Ty

2017-12-01

In human motion studies, discrete points such as peak or average kinematic values are commonly selected to test hypotheses. The purpose of this study was to describe a functional data analysis and describe the advantages of using functional data analyses when compared with a traditional analysis of variance (ANOVA) approach. Nineteen healthy participants (age: 22 ± 2 yrs, body height: 1.7 ± 0.1 m, body mass: 73 ± 16 kg) walked under two different conditions: control and pain+effusion. Pain+effusion was induced by injection of sterile saline into the joint capsule and hypertonic saline into the infrapatellar fat pad. Sagittal-plane ankle, knee, and hip joint kinematics were recorded and compared following injections using 2×2 mixed model ANOVAs and FANOVAs. The results of ANOVAs detected a condition × time interaction for the peak ankle (F1,18 = 8.56, p = 0.01) and hip joint angle (F1,18 = 5.77, p = 0.03), but did not for the knee joint angle (F1,18 = 0.36, p = 0.56). The functional data analysis, however, found several differences at initial contact (ankle and knee joint), in the mid-stance (each joint) and at toe off (ankle). Although a traditional ANOVA is often appropriate for discrete or summary data, in biomechanical applications, the functional data analysis could be a beneficial alternative. When using the functional data analysis approach, a researcher can (1) evaluate the entire data as a function, and (2) detect the location and magnitude of differences within the evaluated function.

Functional vs. Traditional Analysis in Biomechanical Gait Data: An Alternative Statistical Approach

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

Park, Jihong; Seeley, Matthew K.; Francom, Devin

In human motion studies, discrete points such as peak or average kinematic values are commonly selected to test hypotheses. The purpose of this study was to describe a functional data analysis and describe the advantages of using functional data analyses when compared with a traditional analysis of variance (ANOVA) approach. Nineteen healthy participants (age: 22 ± 2 yrs, body height: 1.7 ± 0.1 m, body mass: 73 ± 16 kg) walked under two different conditions: control and pain+effusion. Pain+effusion was induced by injection of sterile saline into the joint capsule and hypertonic saline into the infrapatellar fat pad. Sagittal-plane ankle,more » knee, and hip joint kinematics were recorded and compared following injections using 2×2 mixed model ANOVAs and FANOVAs. The results of ANOVAs detected a condition × time interaction for the peak ankle (F1,18 = 8.56, p = 0.01) and hip joint angle (F1,18 = 5.77, p = 0.03), but did not for the knee joint angle (F1,18 = 0.36, p = 0.56). The functional data analysis, however, found several differences at initial contact (ankle and knee joint), in the mid-stance (each joint) and at toe off (ankle). Although a traditional ANOVA is often appropriate for discrete or summary data, in biomechanical applications, the functional data analysis could be a beneficial alternative. Thus when using the functional data analysis approach, a researcher can (1) evaluate the entire data as a function, and (2) detect the location and magnitude of differences within the evaluated function.« less

Functional vs. Traditional Analysis in Biomechanical Gait Data: An Alternative Statistical Approach

DOE PAGES

Park, Jihong; Seeley, Matthew K.; Francom, Devin; ...

2017-12-28

In human motion studies, discrete points such as peak or average kinematic values are commonly selected to test hypotheses. The purpose of this study was to describe a functional data analysis and describe the advantages of using functional data analyses when compared with a traditional analysis of variance (ANOVA) approach. Nineteen healthy participants (age: 22 ± 2 yrs, body height: 1.7 ± 0.1 m, body mass: 73 ± 16 kg) walked under two different conditions: control and pain+effusion. Pain+effusion was induced by injection of sterile saline into the joint capsule and hypertonic saline into the infrapatellar fat pad. Sagittal-plane ankle,more » knee, and hip joint kinematics were recorded and compared following injections using 2×2 mixed model ANOVAs and FANOVAs. The results of ANOVAs detected a condition × time interaction for the peak ankle (F1,18 = 8.56, p = 0.01) and hip joint angle (F1,18 = 5.77, p = 0.03), but did not for the knee joint angle (F1,18 = 0.36, p = 0.56). The functional data analysis, however, found several differences at initial contact (ankle and knee joint), in the mid-stance (each joint) and at toe off (ankle). Although a traditional ANOVA is often appropriate for discrete or summary data, in biomechanical applications, the functional data analysis could be a beneficial alternative. Thus when using the functional data analysis approach, a researcher can (1) evaluate the entire data as a function, and (2) detect the location and magnitude of differences within the evaluated function.« less

Salt preference: age and sex related variability.

PubMed

Verma, Punam; Mittal, Sunita; Ghildiyal, Archana; Chaudhary, Lalita; Mahajan, K K

2007-01-01

Salt preference was assessed in 60 adults of 18-21 yrs of age (30 males and 30 females) and in 60 children of 7-12 yrs of age (30 boys and 30 girls). Subjects rated the preference on Likert scale for popcorns of five salt concentrations (OM, 1M, 2M, 3M and +3M). Statistical analysis using Two way ANOVA revealed statistically significant effect of age and sex on salt preference (F4,100 = 15.027, P < 0.01) and One Way ANOVA revealed statistically significant sex difference in salt preference of adults (F4,50 = 16.26, P < 0.01) but no statistically significant sex difference in salt preference of children (F4,50 = 4.08, P > 0.05). Dietary experiences during development and more physical activity in children may be responsible for higher salt preference in children while finding no sex variability in children favours the role of sex hormones in salt preference of male and females.

Light transmittance of zirconia as a function of thickness and microhardness of resin cements under different thicknesses of zirconia

PubMed Central

Egilmez, Ferhan; Ergun, Gulfem; Kaya, Bekir M.

2013-01-01

Objective: The objective of this study was to compare microhardness of resin cements under different thicknesses of zirconia and the light transmittance of zirconia as a function of thickness. Study design: A total of 126 disc-shaped specimens (2 mm in height and 5 mm in diameter) were prepared from dual-cured resin cements (RelyX Unicem, Panavia F and Clearfil SA cement). Photoactivation was performed by using quartz tungsten halogen and light emitting diode light curing units under different thicknesses of zirconia. Then the specimens (n=7/per group) were stored in dry conditions in total dark at 37°C for 24 h. The Vicker’s hardness test was performed on the resin cement layer with a microhardness tester. Statistical significance was determined using multifactorial analysis of variance (ANOVA) (alpha=.05). Light transmittance of different thicknesses of zirconia (0.3, 0.5 and 0.8 mm) was measured using a hand-held radiometer (Demetron, Kerr). Data were analyzed using one-way ANOVA test (alpha=.05). Results: ANOVA revealed that resin cement and light curing unit had significant effects on microhardness (p < 0.001). Additionally, greater zirconia thickness resulted in lower transmittance. There was no correlation between the amount of light transmitted and microhardness of dual-cured resin cements (r = 0.073, p = 0.295). Conclusion: Although different zirconia thicknesses might result in insufficient light transmission, dual-cured resin cements under zirconia restorations could have adequate microhardness. Key words:Zirconia, microhardness, light transmittance, resin cement. PMID:23385497

CASPASE-12 and rheumatoid arthritis in African-Americans

PubMed Central

Marshall, Laura; Obaidullah, Mohammad; Fuchs, Trista; Fineberg, Naomi S.; Brinkley, Garland; Mikuls, Ted R.; Bridges, S. Louis; Hermel, Evan

2014-01-01

CASPASE-12 (CASP12) has a down-regulatory function during infection, and thus may protect against inflammatory disease. We investigated the distribution of CASP12 alleles (#rs497116) in African-Americans (AA) with rheumatoid arthritis (RA). CASP12 alleles were genotyped in 953 RA patients and 342 controls. Statistical analyses comparing genotype groups were performed using Kruskal-Wallis non-parametric ANOVA with Mann-Whitney U tests and chi-square tests. There was no significant difference in the overall distribution of CASP12 genotypes within AA with RA, but CASP12 homozygous patients had lower baseline joint narrowing scores. CASP12 homozygosity appears to be a subtle protective factor for some aspects of RA in AA patients. PMID:24515649

Testing Interaction Effects without Discarding Variance.

ERIC Educational Resources Information Center

Lopez, Kay A.

Analysis of variance (ANOVA) and multiple regression are two of the most commonly used methods of data analysis in behavioral science research. Although ANOVA was intended for use with experimental designs, educational researchers have used ANOVA extensively in aptitude-treatment interaction (ATI) research. This practice tends to make researchers…

A method for age-matched OCT angiography deviation mapping in the assessment of disease- related changes to the radial peripapillary capillaries.

PubMed

Pinhas, Alexander; Linderman, Rachel; Mo, Shelley; Krawitz, Brian D; Geyman, Lawrence S; Carroll, Joseph; Rosen, Richard B; Chui, Toco Y

2018-01-01

To present a method for age-matched deviation mapping in the assessment of disease-related changes to the radial peripapillary capillaries (RPCs). We reviewed 4.5x4.5mm en face peripapillary OCT-A scans of 133 healthy control eyes (133 subjects, mean 41.5 yrs, range 11-82 yrs) and 4 eyes with distinct retinal pathologies, obtained using spectral-domain optical coherence tomography angiography. Statistical analysis was performed to evaluate the impact of age on RPC perfusion densities. RPC density group mean and standard deviation maps were generated for each decade of life. Deviation maps were created for the diseased eyes based on these maps. Large peripapillary vessel (LPV; noncapillary vessel) perfusion density was also studied for impact of age. Average healthy RPC density was 42.5±1.47%. ANOVA and pairwise Tukey-Kramer tests showed that RPC density in the ≥60yr group was significantly lower compared to RPC density in all younger decades of life (p<0.01). Average healthy LPV density was 21.5±3.07%. Linear regression models indicated that LPV density decreased with age, however ANOVA and pairwise Tukey-Kramer tests did not reach statistical significance. Deviation mapping enabled us to quantitatively and visually elucidate the significance of RPC density changes in disease. It is important to consider changes that occur with aging when analyzing RPC and LPV density changes in disease. RPC density, coupled with age-matched deviation mapping techniques, represents a potentially clinically useful method in detecting changes to peripapillary perfusion in disease.

Planned Comparisons as Better Alternatives to ANOVA Omnibus Tests.

ERIC Educational Resources Information Center

Benton, Roberta L.

Analyses of data are presented to illustrate the advantages of using a priori or planned comparisons rather than omnibus analysis of variance (ANOVA) tests followed by post hoc or posteriori testing. The two types of planned comparisons considered are planned orthogonal non-trend coding contrasts and orthogonal polynomial or trend contrast coding.…

Use of "t"-Test and ANOVA in Career-Technical Education Research

ERIC Educational Resources Information Center

Rojewski, Jay W.; Lee, In Heok; Gemici, Sinan

2012-01-01

Use of t-tests and analysis of variance (ANOVA) procedures in published research from three scholarly journals in career and technical education (CTE) during a recent 5-year period was examined. Information on post hoc analyses, reporting of effect size, alpha adjustments to account for multiple tests, power, and examination of assumptions…

SOCR Analyses – an Instructional Java Web-based Statistical Analysis Toolkit

PubMed Central

Chu, Annie; Cui, Jenny; Dinov, Ivo D.

2011-01-01

The Statistical Online Computational Resource (SOCR) designs web-based tools for educational use in a variety of undergraduate courses (Dinov 2006). Several studies have demonstrated that these resources significantly improve students' motivation and learning experiences (Dinov et al. 2008). SOCR Analyses is a new component that concentrates on data modeling and analysis using parametric and non-parametric techniques supported with graphical model diagnostics. Currently implemented analyses include commonly used models in undergraduate statistics courses like linear models (Simple Linear Regression, Multiple Linear Regression, One-Way and Two-Way ANOVA). In addition, we implemented tests for sample comparisons, such as t-test in the parametric category; and Wilcoxon rank sum test, Kruskal-Wallis test, Friedman's test, in the non-parametric category. SOCR Analyses also include several hypothesis test models, such as Contingency tables, Friedman's test and Fisher's exact test. The code itself is open source (http://socr.googlecode.com/), hoping to contribute to the efforts of the statistical computing community. The code includes functionality for each specific analysis model and it has general utilities that can be applied in various statistical computing tasks. For example, concrete methods with API (Application Programming Interface) have been implemented in statistical summary, least square solutions of general linear models, rank calculations, etc. HTML interfaces, tutorials, source code, activities, and data are freely available via the web (www.SOCR.ucla.edu). Code examples for developers and demos for educators are provided on the SOCR Wiki website. In this article, the pedagogical utilization of the SOCR Analyses is discussed, as well as the underlying design framework. As the SOCR project is on-going and more functions and tools are being added to it, these resources are constantly improved. The reader is strongly encouraged to check the SOCR site for most updated information and newly added models. PMID:21546994

SU-F-T-386: Analysis of Three QA Methods for Predicting Dose Deviation Pass Percentage for Lung SBRT VMAT Plans

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

Hardin, M; To, D; Giaddui, T

2016-06-15

Purpose: To investigate the significance of using pinpoint ionization chambers (IC) and RadCalc (RC) in determining the quality of lung SBRT VMAT plans with low dose deviation pass percentage (DDPP) as reported by ScandiDos Delta4 (D4). To quantify the relationship between DDPP and point dose deviations determined by IC (ICDD), RadCalc (RCDD), and median dose deviation reported by D4 (D4DD). Methods: Point dose deviations and D4 DDPP were compiled for 45 SBRT VMAT plans. Eighteen patients were treated on Varian Truebeam linear accelerators (linacs); the remaining 27 were treated on Elekta Synergy linacs with Agility collimators. A one-way analysis ofmore » variance (ANOVA) was performed to determine if there were any statistically significant differences between D4DD, ICDD, and RCDD. Tukey’s test was used to determine which pair of means was statistically different from each other. Multiple regression analysis was performed to determine if D4DD, ICDD, or RCDD are statistically significant predictors of DDPP. Results: Median DDPP, D4DD, ICDD, and RCDD were 80.5% (47.6%–99.2%), −0.3% (−2.0%–1.6%), 0.2% (−7.5%–6.3%), and 2.9% (−4.0%–19.7%), respectively. The ANOVA showed a statistically significant difference between D4DD, ICDD, and RCDD for a 95% confidence interval (p < 0.001). Tukey’s test revealed a statistically significant difference between two pairs of groups, RCDD-D4DD and RCDD-ICDD (p < 0.001), but no difference between ICDD-D4DD (p = 0.485). Multiple regression analysis revealed that ICDD (p = 0.04) and D4DD (p = 0.03) are statistically significant predictors of DDPP with an adjusted r{sup 2} of 0.115. Conclusion: This study shows ICDD predicts trends in D4 DDPP; however this trend is highly variable as shown by our low r{sup 2}. This work suggests that ICDD can be used as a method to verify DDPP in delivery of lung SBRT VMAT plans. RCDD may not validate low DDPP discovered in D4 QA for small field SBRT treatments.« less

Three-dimensional analysis of enamel surface alteration resulting from orthodontic clean-up -comparison of three different tools.

PubMed

Janiszewska-Olszowska, Joanna; Tandecka, Katarzyna; Szatkiewicz, Tomasz; Stępień, Piotr; Sporniak-Tutak, Katarzyna; Grocholewicz, Katarzyna

2015-11-18

The present study aimed at 3D analysis of adhesive remnants and enamel loss following the debonding of orthodontic molar tubes and orthodontic clean-up to assess the effectiveness and safety of One-Step Finisher and Polisher and Adhesive Residue Remover in comparison to tungsten carbide bur. Thirty human molars were bonded with chemical-cure orthodontic adhesive (Unite, 3M, USA), stored 24 h in 0.9 % saline solution, debonded and cleaned using three methods (Three groups of ten): tungsten carbide bur (Dentaurum, Pforzheim, Germany), one-step finisher and polisher (One gloss, Shofu Dental, Kyoto, Japan) and Adhesive Residue Remover (Dentaurum, Pforzheim, Germany). Direct 3D scanning in blue-light technology to the nearest 2 μm was performed before etching and after adhesive removal. Adhesive remnant height and volume as well as enamel loss depth and volume were calculated. An index of effectiveness and safety was proposed and calculated for every tool; adhesive remnant volume and duplicated enamel lost volume were divided by a sum of multiplicands. Comparisons using parametric ANOVA or nonparametric ANOVA rank Kruskal-Wallis tests were used to compare between tools for adhesive remnant height and volume, enamel loss depth and volume as well as for the proposed index. No statistically significant differences in the volume (p = 0.35) or mean height (p = 0.24) of adhesive remnants were found (ANOVA rank Kruskal-Wallis test) between the groups of teeth cleaned using different tools. Mean volume of enamel loss was 2.159 mm(3) for tungsten carbide bur, 1.366 mm(3) for Shofu One Gloss and 0.659 mm(3) for Adhesive Residue Remover - (F = 2.816, p = 0.0078). A comparison of the proposed new index between tools revealed highly statistically significant differences (p = 0.0081), supporting the best value for Adhesive Residue Remover and the worst - for tungsten carbide bur. The evaluated tools were all characterized by similar effectiveness. The most destructive tool with regards to enamel was the tungsten carbide bur, and the least was Adhesive Residue Removal.

The best motivator priorities parents choose via analytical hierarchy process

NASA Astrophysics Data System (ADS)

Farah, R. N.; Latha, P.

2015-05-01

Motivation is probably the most important factor that educators can target in order to improve learning. Numerous cross-disciplinary theories have been postulated to explain motivation. While each of these theories has some truth, no single theory seems to adequately explain all human motivation. The fact is that human beings in general and pupils in particular are complex creatures with complex needs and desires. In this paper, Analytic Hierarchy Process (AHP) has been proposed as an emerging solution to move towards too large, dynamic and complex real world multi-criteria decision making problems in selecting the most suitable motivator when choosing school for their children. Data were analyzed using SPSS 17.0 ("Statistical Package for Social Science") software. Statistic testing used are descriptive and inferential statistic. Descriptive statistic used to identify respondent pupils and parents demographic factors. The statistical testing used to determine the pupils and parents highest motivator priorities and parents' best priorities using AHP to determine the criteria chosen by parents such as school principals, teachers, pupils and parents. The moderating factors are selected schools based on "Standard Kualiti Pendidikan Malaysia" (SKPM) in Ampang. Inferential statistics such as One-way ANOVA used to get the significant and data used to calculate the weightage of AHP. School principals is found to be the best motivator for parents in choosing school for their pupils followed by teachers, parents and pupils.

Analysis of Statistical Methods Currently used in Toxicology Journals

PubMed Central

Na, Jihye; Yang, Hyeri

2014-01-01

Statistical methods are frequently used in toxicology, yet it is not clear whether the methods employed by the studies are used consistently and conducted based on sound statistical grounds. The purpose of this paper is to describe statistical methods used in top toxicology journals. More specifically, we sampled 30 papers published in 2014 from Toxicology and Applied Pharmacology, Archives of Toxicology, and Toxicological Science and described methodologies used to provide descriptive and inferential statistics. One hundred thirteen endpoints were observed in those 30 papers, and most studies had sample size less than 10, with the median and the mode being 6 and 3 & 6, respectively. Mean (105/113, 93%) was dominantly used to measure central tendency, and standard error of the mean (64/113, 57%) and standard deviation (39/113, 34%) were used to measure dispersion, while few studies provide justifications regarding why the methods being selected. Inferential statistics were frequently conducted (93/113, 82%), with one-way ANOVA being most popular (52/93, 56%), yet few studies conducted either normality or equal variance test. These results suggest that more consistent and appropriate use of statistical method is necessary which may enhance the role of toxicology in public health. PMID:25343012

Analysis of Statistical Methods Currently used in Toxicology Journals.

PubMed

Na, Jihye; Yang, Hyeri; Bae, SeungJin; Lim, Kyung-Min

2014-09-01

Statistical methods are frequently used in toxicology, yet it is not clear whether the methods employed by the studies are used consistently and conducted based on sound statistical grounds. The purpose of this paper is to describe statistical methods used in top toxicology journals. More specifically, we sampled 30 papers published in 2014 from Toxicology and Applied Pharmacology, Archives of Toxicology, and Toxicological Science and described methodologies used to provide descriptive and inferential statistics. One hundred thirteen endpoints were observed in those 30 papers, and most studies had sample size less than 10, with the median and the mode being 6 and 3 & 6, respectively. Mean (105/113, 93%) was dominantly used to measure central tendency, and standard error of the mean (64/113, 57%) and standard deviation (39/113, 34%) were used to measure dispersion, while few studies provide justifications regarding why the methods being selected. Inferential statistics were frequently conducted (93/113, 82%), with one-way ANOVA being most popular (52/93, 56%), yet few studies conducted either normality or equal variance test. These results suggest that more consistent and appropriate use of statistical method is necessary which may enhance the role of toxicology in public health.

The use of statistical tools in field testing of putative effects of genetically modified plants on nontarget organisms

PubMed Central

Semenov, Alexander V; Elsas, Jan Dirk; Glandorf, Debora C M; Schilthuizen, Menno; Boer, Willem F

2013-01-01

Abstract To fulfill existing guidelines, applicants that aim to place their genetically modified (GM) insect-resistant crop plants on the market are required to provide data from field experiments that address the potential impacts of the GM plants on nontarget organisms (NTO's). Such data may be based on varied experimental designs. The recent EFSA guidance document for environmental risk assessment (2010) does not provide clear and structured suggestions that address the statistics of field trials on effects on NTO's. This review examines existing practices in GM plant field testing such as the way of randomization, replication, and pseudoreplication. Emphasis is placed on the importance of design features used for the field trials in which effects on NTO's are assessed. The importance of statistical power and the positive and negative aspects of various statistical models are discussed. Equivalence and difference testing are compared, and the importance of checking the distribution of experimental data is stressed to decide on the selection of the proper statistical model. While for continuous data (e.g., pH and temperature) classical statistical approaches – for example, analysis of variance (ANOVA) – are appropriate, for discontinuous data (counts) only generalized linear models (GLM) are shown to be efficient. There is no golden rule as to which statistical test is the most appropriate for any experimental situation. In particular, in experiments in which block designs are used and covariates play a role GLMs should be used. Generic advice is offered that will help in both the setting up of field testing and the interpretation and data analysis of the data obtained in this testing. The combination of decision trees and a checklist for field trials, which are provided, will help in the interpretation of the statistical analyses of field trials and to assess whether such analyses were correctly applied. We offer generic advice to risk assessors and applicants that will help in both the setting up of field testing and the interpretation and data analysis of the data obtained in field testing. PMID:24567836

The use of statistical tools in field testing of putative effects of genetically modified plants on nontarget organisms.

PubMed

Semenov, Alexander V; Elsas, Jan Dirk; Glandorf, Debora C M; Schilthuizen, Menno; Boer, Willem F

2013-08-01

To fulfill existing guidelines, applicants that aim to place their genetically modified (GM) insect-resistant crop plants on the market are required to provide data from field experiments that address the potential impacts of the GM plants on nontarget organisms (NTO's). Such data may be based on varied experimental designs. The recent EFSA guidance document for environmental risk assessment (2010) does not provide clear and structured suggestions that address the statistics of field trials on effects on NTO's. This review examines existing practices in GM plant field testing such as the way of randomization, replication, and pseudoreplication. Emphasis is placed on the importance of design features used for the field trials in which effects on NTO's are assessed. The importance of statistical power and the positive and negative aspects of various statistical models are discussed. Equivalence and difference testing are compared, and the importance of checking the distribution of experimental data is stressed to decide on the selection of the proper statistical model. While for continuous data (e.g., pH and temperature) classical statistical approaches - for example, analysis of variance (ANOVA) - are appropriate, for discontinuous data (counts) only generalized linear models (GLM) are shown to be efficient. There is no golden rule as to which statistical test is the most appropriate for any experimental situation. In particular, in experiments in which block designs are used and covariates play a role GLMs should be used. Generic advice is offered that will help in both the setting up of field testing and the interpretation and data analysis of the data obtained in this testing. The combination of decision trees and a checklist for field trials, which are provided, will help in the interpretation of the statistical analyses of field trials and to assess whether such analyses were correctly applied. We offer generic advice to risk assessors and applicants that will help in both the setting up of field testing and the interpretation and data analysis of the data obtained in field testing.

A spreadsheet template compatible with Microsoft Excel and iWork Numbers that returns the simultaneous confidence intervals for all pairwise differences between multiple sample means.

PubMed

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.

Effect of the statin therapy on biochemical laboratory tests--a chemometrics study.

PubMed

Durceková, Tatiana; Mocák, Ján; Boronová, Katarína; Balla, Ján

2011-01-05

Statins are the first-line choice for lowering total and LDL cholesterol levels and very important medicaments for reducing the risk of coronary artery disease. The aim of this study is therefore assessment of the results of biochemical tests characterizing the condition of 172 patients before and after administration of statins. For this purpose, several chemometric tools, namely principal component analysis, cluster analysis, discriminant analysis, logistic regression, KNN classification, ROC analysis, descriptive statistics and ANOVA were used. Mutual relations of 11 biochemical laboratory tests, the patient's age and gender were investigated in detail. Achieved results enable to evaluate the extent of the statin treatment in each individual case. They may also help in monitoring the dynamic progression of the disease. Copyright © 2010 Elsevier B.V. All rights reserved.

Comparision of Immunohistochemical Expression of CD10 in Odontogenic Cysts

PubMed Central

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

Normal Distribution of CD8+ T-Cell-Derived ELISPOT Counts within Replicates Justifies the Reliance on Parametric Statistics for Identifying Positive Responses.

PubMed

Karulin, Alexey Y; Caspell, Richard; Dittrich, Marcus; Lehmann, Paul V

2015-03-02

Accurate assessment of positive ELISPOT responses for low frequencies of antigen-specific T-cells is controversial. In particular, it is still unknown whether ELISPOT counts within replicate wells follow a theoretical distribution function, and thus whether high power parametric statistics can be used to discriminate between positive and negative wells. We studied experimental distributions of spot counts for up to 120 replicate wells of IFN-γ production by CD8+ T-cell responding to EBV LMP2A (426 - 434) peptide in human PBMC. The cells were tested in serial dilutions covering a wide range of average spot counts per condition, from just a few to hundreds of spots per well. Statistical analysis of the data using diagnostic Q-Q plots and the Shapiro-Wilk normality test showed that in the entire dynamic range of ELISPOT spot counts within replicate wells followed a normal distribution. This result implies that the Student t-Test and ANOVA are suited to identify positive responses. We also show experimentally that borderline responses can be reliably detected by involving more replicate wells, plating higher numbers of PBMC, addition of IL-7, or a combination of these. Furthermore, we have experimentally verified that the number of replicates needed for detection of weak responses can be calculated using parametric statistics.

Chlorine dioxide water disinfection: a prospective epidemiology study

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

Michael, G.E.; Miday, R.K.; Bercz, J.P.

An epidemiologic study of 198 persons exposed for 3 months to drinking water disinfected with chlorine dioxide was conducted in a rural village. A control population of 118 nonexposed persons was also studied. Pre-exposure hematologic and serum chemical parameters were compared with test results after 115 days of exposure. Chlorite ion levels in the water averaged approximately 5 ppM during the study period. Statistical analysis (ANOVA) of the data failed to identify any significant exposure-related effects. This study suggests that future evaluations of chlorine dioxide disinfection should be directed toward populations with potentially increased sensitivity to hemolytic agents.

Fracture resistance of Kevlar-reinforced poly(methyl methacrylate) resin: a preliminary study.

PubMed

Berrong, J M; Weed, R M; Young, J M

1990-01-01

The reinforcing effect of Kevlar fibers incorporated in processed poly(methyl methacrylate) resin samples was studied using 0% (controls), 0.5%, 1%, and 2% by weight of the added fibers. The samples were subjected to impact testing to determine fracture resistance, and sample groups were statistically compared using an ANOVA. Each reinforced sample had significantly greater fracture resistance (P less than 0.05) than the control, and no difference was found either within or between control groups. The use of reinforcing Kevlar fibers appears to enhance the fracture resistance of acrylic resin denture base materials.

The Effect of Personality Traits of Managers/Supervisor on Job Satisfaction of Medical Sciences University Staffs.

PubMed

Abedi, G; Molazadeh-Mahali, Q A; Mirzaian, B; Nadi-Ghara, A; Heidari-Gorji, A M

2016-01-01

Todays people are spending most of their time life in their workplace therefore investigation for job satisfaction related factors is necessities of researches. The purpose of this research was to analyze the effect of manager's personality traits on employee job satisfaction. The present study is a descriptive and causative-comparative one utilized on a statistical sample of 44 managers and 119 employees. It was examined and analyzed through descriptive and inferential statistics of Student's t -test (independent T), one-way ANOVA, and Kolmogorov-Smirnov test. Findings showed that the managers and supervisors with personality traits of extraversion, eagerness to new experiences, adaptability, and dutifulness had higher subordinate employee job satisfaction. However, in the neurotic trait, the result was different. The results showed that job satisfaction was low in the aspect of neurosis. Based on this, it is suggested that, before any selection in managerial and supervisory positions, candidates receive a personality test and in case an individual has a neurotic trait, appropriate interference takes place both in this group and the employees' one.

The Effect of Personality Traits of Managers/Supervisor on Job Satisfaction of Medical Sciences University Staffs

PubMed Central

Abedi, G; Molazadeh-Mahali, QA; Mirzaian, B; Nadi-Ghara, A; Heidari-Gorji, AM

2016-01-01

Background: Todays people are spending most of their time life in their workplace therefore investigation for job satisfaction related factors is necessities of researches. Aim: The purpose of this research was to analyze the effect of manager's personality traits on employee job satisfaction. Subjects and Methods: The present study is a descriptive and causative-comparative one utilized on a statistical sample of 44 managers and 119 employees. It was examined and analyzed through descriptive and inferential statistics of Student's t-test (independent T), one-way ANOVA, and Kolmogorov–Smirnov test. Results: Findings showed that the managers and supervisors with personality traits of extraversion, eagerness to new experiences, adaptability, and dutifulness had higher subordinate employee job satisfaction. However, in the neurotic trait, the result was different. Conclusion: The results showed that job satisfaction was low in the aspect of neurosis. Based on this, it is suggested that, before any selection in managerial and supervisory positions, candidates receive a personality test and in case an individual has a neurotic trait, appropriate interference takes place both in this group and the employees' one. PMID:28480099

Effect of light aging on silicone-resin bond strength in maxillofacial prostheses.

PubMed

Polyzois, Gregory; Pantopoulos, Antonis; Papadopoulos, Triantafillos; Hatamleh, Muhanad

2015-04-01

The aim of this study was to investigate the effect of accelerated light aging on bond strength of a silicone elastomer to three types of denture resin. A total of 60 single lap joint specimens were fabricated with auto-, heat-, and photopolymerized (n = 20) resins. An addition-type silicone elastomer (Episil-E) was bonded to resins treated with the same primer (A330-G). Thirty specimens served as controls and were tested after 24 hours, and the remaining were aged under accelerated exposure to daylight for 546 hours (irradiance 765 W/m(2) ). Lap shear joint tests were performed to evaluate bond strength at 50 mm/min crosshead speed. Two-way ANOVA and Tukey's test were carried out to detect statistical significance (p < 0.05). ANOVA showed that the main effect of light aging was the most important factor determining the shear bond strength. The mean bond strength values ranged from 0.096 to 0.136 MPa. The highest values were recorded for auto- (0.131 MPa) and photopolymerized (0.136 MPa) resins after aging. Accelerated light aging for 546 hours affects the bond strength of an addition-type silicone elastomer to three different denture resins. The bond strength significantly increased after aging for photo- and autopolymerized resins. All the bonds failed adhesively. © 2014 by the American College of Prosthodontists.

Measurement of air contamination in different wards of public sector hospital, Sukkur.

PubMed

Memon, Badaruddin AllahDino; Bhutto, Gul Hassan; Rizvi, Wajid Hussain

2016-11-01

The aim of this study was to evaluate and assess the index of bacterial contamination in different wards of the Public Sector Hospital of Sukkur (Teaching) Pakistan; whether or not the air contamination was statistically different from the acceptable level using active and passive sampling. In addition to this main hypothesis, other investigations included: occurrence of the most common bacteria, whether or not the bacterial contamination in the wards was a persistent problem and identification of the effective antibiotics against the indentified bacteria. The evidence sought based on the One Sample T test suggests that there is a (statistically) significant difference between the observed (higher) than the acceptance level (p<0.01), the result based on One-Way ANOVA suggests that the contamination problem was persistent as there was no significant difference among observed contamination of all three visits at (p>0.01) and the result of antibiotic susceptibility test highlights sensitivity and resistance level of antibiotics for the indentified bacteria.

A study of tensile test on open-cell aluminum foam sandwich

NASA Astrophysics Data System (ADS)

Ibrahim, N. A.; Hazza, M. H. F. Al; Adesta, E. Y. T.; Abdullah Sidek, Atiah Bt.; Endut, N. A.

2018-01-01

Aluminum foam sandwich (AFS) panels are one of the growing materials in the various industries because of its lightweight behavior. AFS also known for having excellent stiffness to weight ratio and high-energy absorption. Due to their advantages, many researchers’ shows an interest in aluminum foam material for expanding the use of foam structure. However, there is still a gap need to be fill in order to develop reliable data on mechanical behavior of AFS with different parameters and analysis method approach. Least of researcher focusing on open-cell aluminum foam and statistical analysis. Thus, this research conducted by using open-cell aluminum foam core grade 6101 with aluminum sheets skin tested under tension. The data is analyzed using full factorial in JMP statistical analysis software (version 11). ANOVA result show a significant value of the model which less than 0.500. While scatter diagram and 3D plot surface profiler found that skins thickness gives a significant impact to stress/strain value compared to core thickness.

Effect of repeated cycles of chemical disinfection on the roughness and hardness of hard reline acrylic resins.

PubMed

Pinto, Luciana de Rezende; Acosta, Emílio José T Rodríguez; Távora, Flora Freitas Fernandes; da Silva, Paulo Maurício Batista; Porto, Vinícius Carvalho

2010-06-01

The aim of this study was to assess the effect of repeated cycles of five chemical disinfectant solutions on the roughness and hardness of three hard chairside reliners. A total of 180 circular specimens (30 mm x 6 mm) were fabricated using three hard chairside reliners (Jet; n = 60, Kooliner; n = 60, Tokuyama Rebase II Fast; n = 60), which were immersed in deionised water (control), and five disinfectant solutions (1%, 2%, 5.25% sodium hypochlorite; 2% glutaraldehyde; 4% chlorhexidine gluconate). They were tested for Knoop hardness (KHN) and surface roughness (microm), before and after 30 simulated disinfecting cycles. Data was analysed by the factorial scheme (6 x 2), two-way analysis of variance (anova), followed by Tukey's test. For Jet (from 18.74 to 13.86 KHN), Kooliner (from 14.09 to 8.72 KHN), Tokuyama (from 12.57 to 8.28 KHN) a significant decrease in hardness was observed irrespective of the solution used on all materials. For Jet (from 0.09 to 0.11 microm) there was a statistically significant increase in roughness. Kooliner (from 0.36 to 0.26 microm) presented a statistically significant decrease in roughness and Tokuyama (from 0.15 to 0.11 microm) presented no statistically significant difference after 30 days. This study showed that all disinfectant solutions promoted a statistically significant decrease in hardness, whereas with roughness, the materials tested showed a statistically significant increase, except for Tokuyama. Although statistically significant values were registered, these results could not be considered clinically significant.

Multi-Reader ROC studies with Split-Plot Designs: A Comparison of Statistical Methods

PubMed Central

Obuchowski, Nancy A.; Gallas, Brandon D.; Hillis, Stephen L.

2012-01-01

Rationale and Objectives Multi-reader imaging trials often use a factorial design, where study patients undergo testing with all imaging modalities and readers interpret the results of all tests for all patients. A drawback of the design is the large number of interpretations required of each reader. Split-plot designs have been proposed as an alternative, in which one or a subset of readers interprets all images of a sample of patients, while other readers interpret the images of other samples of patients. In this paper we compare three methods of analysis for the split-plot design. Materials and Methods Three statistical methods are presented: Obuchowski-Rockette method modified for the split-plot design, a newly proposed marginal-mean ANOVA approach, and an extension of the three-sample U-statistic method. A simulation study using the Roe-Metz model was performed to compare the type I error rate, power and confidence interval coverage of the three test statistics. Results The type I error rates for all three methods are close to the nominal level but tend to be slightly conservative. The statistical power is nearly identical for the three methods. The coverage of 95% CIs fall close to the nominal coverage for small and large sample sizes. Conclusions The split-plot MRMC study design can be statistically efficient compared with the factorial design, reducing the number of interpretations required per reader. Three methods of analysis, shown to have nominal type I error rate, similar power, and nominal CI coverage, are available for this study design. PMID:23122570

Retention of veneered stainless steel crowns on replicated typodont primary incisors: an in vitro study.

PubMed

Guelmann, Marcio; Gehring, Daren F; Turner, Clara

2003-01-01

The purpose of this in vitro study was to determine the effect of crimping and cementation on retention of veneered stainless steel crowns. One hundred twenty crowns, 90 from 3 commercially available brands of veneered stainless steel crowns (Dura Crown, Kinder Krown, and NuSmile Primary Crown) and 30 (plain) Unitek stainless steel crowns were assessed for retention. An orthodontic wire was soldered perpendicular to the incisal edge of the crowns; the crowns were fitted to acrylic replicas of ideal crown preparations and were divided equally into 3 test groups: group 1--crowns were crimped only (no cement used); group 2--crowns were cemented only; and group 3--crowns were crimped and cemented to the acrylic replicas. An Instron machine recorded the amount of force necessary to dislodge the crowns and the results were statistically analyzed using 2-way ANOVA and Tukey honestly significant difference (HSD) test. Group 3 was statistically more retentive than groups 1 and 2. Group 2 was statistically more retentive than group 1 (P < .001). In group 1, Unitek crowns were statistically more retentive than the veneered crowns (P < .05). In group 2, NuSmile crowns showed statistically less retention values than all other crowns (P < .05). In group 3,Kinder Krown crowns showed statistically better retention rates than all other brands (P < .05). Significantly higher retention values were obtained for all brands tested when crimping and cement were combined. The crowns with veneer facings were significantly more retentive than the nonveneered ones when cement and crimping were combined.

The platelet activating factor acetyl hydrolase, oxidized low-density lipoprotein, paraoxonase 1 and arylesterase levels in treated and untreated patients with polycystic ovary syndrome.

PubMed

Carlioglu, Ayse; Kaygusuz, Ikbal; Karakurt, Feridun; Gumus, Ilknur Inegol; Uysal, Aysel; Kasapoglu, Benan; Armutcu, Ferah; Uysal, Sema; Keskin, Esra Aktepe; Koca, Cemile

2014-11-01

To evaluate the platelet activating factor acetyl hydrolyze (PAF-AH), oxidized low-density lipoprotein (ox-LDL), paraoxonase 1 (PON1), arylesterase (ARE) levels and the effects of metformin and Diane-35 (ethinyl oestradiol + cyproterone acetate) therapies on these parameters and to determine the PON1 polymorphisms among PCOS patients. Ninety patients with PCOS, age 30, and body mass index-matched healthy controls were included in the study. Patients were divided into three groups: metformin treatment, Diane-35 treatment and no medication groups. The treatment with metformin or Diane-35 was continued for 6 months and all subjects were evaluated with clinical and biochemical parameters 6 months later. One-way Anova test, t test and non-parametric Mann-Whitney U tests were used for statistical analysis. PAF-AH and ox-LDL levels were statistically significantly higher in untreated PCOS patients than controls, and they were statistically significantly lower in patients treated with metformin or Diane-35 than untreated PCOS patients. In contrast, there were lower PON1 (not statistically significant) and ARE (statistically significant) levels in untreated PCOS patients than the control group and they significantly increased after metformin and Diane-35 treatments. In PCOS patients serum PON1 levels for QQ, QR and RR phenotypes were statistically significantly lower than the control group. In patients with PCOS, proatherogenic markers increase. The treatment of PCOS with metformin or Diane-35 had positive effects on lipid profile, increased PON1 level, which is a protector from atherosclerosis and decreased the proatherogenic PAF-AH and ox-LDL levels.

Effect of chlorhexidine pretreatment on bond strength durability of caries-affected dentin over 2-year aging in artificial saliva and under simulated intrapulpal pressure.

PubMed

Mobarak, E H

2011-01-01

To evaluate the influence of 2% and 5% chlorhexidine (CHX) pretreatment on bond durability of a self-etching adhesive to normal (ND) and caries-affected (AD) dentin after 2-years of aging in artificial saliva and under simulated intrapulpal pressure (IPP). One hundred twenty freshly extracted carious teeth were ground to expose ND and AD. Specimens were distributed into three equal groups (n=40) according to whether the dentin substrates were pretreated with 2% or 5% CHX or with water (control). Clearfil SE Bond (Kuraray) was applied to both substrates and composite cylinders (0.9 mm diameter and 0.7 mm height) were formed. Pretreatment and bonding were done while the specimens were subjected to 15 mm Hg IPP. After curing, specimens were aged in artificial saliva at 37°C and under IPP at 20 mm Hg until being tested after 24 hours or 2 years (n=20/group). Microshear bond strength was evaluated. Failure modes were determined using a scanning electron microscope (SEM) at 400× magnification. Data were statistically analyzed using three-way analysis of variance (ANOVA); one-way ANOVA tests, and t-test (p<0.05). Additional specimens (n=5/group) were prepared to evaluate interfacial silver precipitation. For the 24-hour groups, there were no significant differences among the ND groups and AD groups. For ND aged specimens, the 5% CHX group had the highest value followed by the 2% CHX and control groups, although the difference was statistically insignificant. For AD aged specimens, the 5% CHX group revealed statistically higher bond values compared to the 2% CHX and control groups. Fracture modes were predominately adhesive and mixed. Different interfacial silver depositions were recorded. Two percent or 5% CHX pretreatment has no adverse effect on the 24-hour bonding to ND and AD. Five percent CHX was able to diminish the loss in bonding to AD after 2years of aging in artificial saliva and under simulated IPP.

Practical statistics in pain research.

PubMed

Kim, Tae Kyun

2017-10-01

Pain is subjective, while statistics related to pain research are objective. This review was written to help researchers involved in pain research make statistical decisions. The main issues are related with the level of scales that are often used in pain research, the choice of statistical methods between parametric or nonparametric statistics, and problems which arise from repeated measurements. In the field of pain research, parametric statistics used to be applied in an erroneous way. This is closely related with the scales of data and repeated measurements. The level of scales includes nominal, ordinal, interval, and ratio scales. The level of scales affects the choice of statistics between parametric or non-parametric methods. In the field of pain research, the most frequently used pain assessment scale is the ordinal scale, which would include the visual analogue scale (VAS). There used to be another view, however, which considered the VAS to be an interval or ratio scale, so that the usage of parametric statistics would be accepted practically in some cases. Repeated measurements of the same subjects always complicates statistics. It means that measurements inevitably have correlations between each other, and would preclude the application of one-way ANOVA in which independence between the measurements is necessary. Repeated measures of ANOVA (RMANOVA), however, would permit the comparison between the correlated measurements as long as the condition of sphericity assumption is satisfied. Conclusively, parametric statistical methods should be used only when the assumptions of parametric statistics, such as normality and sphericity, are established.

The interdisciplinary effect of hands-on science as measured by the Tennessee Comprehensive Assessment Program (TCAP)

NASA Astrophysics Data System (ADS)

Cherry, Elvis H.

This study examined the difference in scale scores from Tennessee's standardized test the Tennessee Comprehensive Assessment Program (TCAP). Archival data from the years 2002 and 2005 were compared using ANOVA tests at < .01 and < .05 levels. TCAP/NCE Scale Scores for academic subjects of Science, Math, Social Studies and Reading were used. 3922 student test results were divided into groups based on the number of years the student had a trained hands-on science teacher. Trained hands-on science teachers were identified from Metropolitan Nashville Public Schools (MNPS) Science Department inservice records, which gave information on the teacher's participation in The Hands-on Science Initiative, Biology Gateway and Physical Science training. This information included not only that the teacher had be trained but also the dates of training. The study revealed 1600 students who attended MNPS between the years 2002 and 2005; in grades five through seven that never had a hands-on science trained teacher. About 1600 students in those same years had a hands-on science teacher for only one year, and 588 students had a hands-on science teacher for two of the three years. Lastly of the 3922 students in the study there were 44 students who had a hands-on science teacher for all three years. The results of the ANOVA test showed statistically significant gains in science, math and social studies but not in reading for students who had trained hands-on science teachers for at least one year.

Effect of Various Sugary Beverages on Salivary pH, Flow Rate, and Oral Clearance Rate amongst Adults.

PubMed

Hans, Rinki; Thomas, Susan; Garla, Bharat; Dagli, Rushabh J; Hans, Manoj Kumar

2016-01-01

Introduction. Diet is a major aetiological factor for dental caries and enamel erosion. This study was undertaken with the aim of assessing the effect of selected locally available beverages on salivary pH, flow rate, and oral clearance rate amongst adults. Materials and Method. This clinical trial comprised 120 subjects. Test beverages undertaken were pepsi, fruit drink, coffee, and sweetened milk. Statistical analysis was carried out using SPSS version 17. Descriptive statistics, one-way ANOVA, and post hoc Tukey's test were applied in the statistical tests. Results. It was found that salivary pH decreased for all the beverages immediately after consumption and the salivary flow rate increased after their consumption. The oral clearance rate of sweetened milk was found to be the least at 6.5 minutes and that of pepsi was found to be 13 minutes. However, the oral clearance rates of fruit drink and coffee were found to be equal at 15 minutes. Conclusion. Although it was found out that liquids cleared rapidly from the oral cavity, they had a significant cariogenic and erosive potential. Hence, it is always advised to minimise the consumption of beverages, especially amongst children and young adults to maintain a good oral health.

Effect of Various Sugary Beverages on Salivary pH, Flow Rate, and Oral Clearance Rate amongst Adults

PubMed Central

Hans, Rinki; Thomas, Susan; Garla, Bharat; Dagli, Rushabh J.

2016-01-01

Introduction. Diet is a major aetiological factor for dental caries and enamel erosion. This study was undertaken with the aim of assessing the effect of selected locally available beverages on salivary pH, flow rate, and oral clearance rate amongst adults. Materials and Method. This clinical trial comprised 120 subjects. Test beverages undertaken were pepsi, fruit drink, coffee, and sweetened milk. Statistical analysis was carried out using SPSS version 17. Descriptive statistics, one-way ANOVA, and post hoc Tukey's test were applied in the statistical tests. Results. It was found that salivary pH decreased for all the beverages immediately after consumption and the salivary flow rate increased after their consumption. The oral clearance rate of sweetened milk was found to be the least at 6.5 minutes and that of pepsi was found to be 13 minutes. However, the oral clearance rates of fruit drink and coffee were found to be equal at 15 minutes. Conclusion. Although it was found out that liquids cleared rapidly from the oral cavity, they had a significant cariogenic and erosive potential. Hence, it is always advised to minimise the consumption of beverages, especially amongst children and young adults to maintain a good oral health. PMID:27051556

Antimicrobial and anti-adherence activity of various combinations of coffee-chicory solutions on Streptococcus mutans: An in-vitro study

PubMed Central

Sharma, Rama; Reddy, Vamsi Krishna L; Prashant, GM; Ojha, Vivek; Kumar, Naveen PG

2014-01-01

Context: Several studies have demonstrated the activity of natural plants on the dental biofilm and caries development. But few studies on the antimicrobial activity of coffee-based solutions were found in the literature. Further there was no study available to check the antimicrobial effect of coffee solutions with different percentages of chicory in it. Aims: To evaluate the antimicrobial activity of different combinations of coffee-chicory solutions and their anti-adherence effect on Streptococcus mutans to glass surface. Materials and Methods: Test solutions were prepared. For antimicrobial activity testing, tubes containing test solution and culture medium were inoculated with a suspension of S. mutans followed by plating on Brain Heart Infusion (BHI) agar. S. mutans adherence to glass in presence of the different test solutions was also tested. The number of adhered bacteria (CFU/mL) was determined by plating method. Statistical Analysis: Statistical significance was measured using one way ANOVA followed by Tukey's post hoc test. P value < 0.05 was considered statistically significant. Results: Pure chicory had shown significantly less bacterial count compared to all other groups. Groups IV and V had shown significant reduction in bacterial counts over the period of 4 hrs. Regarding anti-adherence effect, group I-IV had shown significantly less adherence of bacteria to glass surface. Conclusions: Chicory exerted antibacterial effect against S. mutans while coffee reduced significantly the adherence of S. mutans to the glass surface. PMID:25328299

Normality of raw data in general linear models: The most widespread myth in statistics

USGS Publications Warehouse

Kery, Marc; Hatfield, Jeff S.

2003-01-01

In years of statistical consulting for ecologists and wildlife biologists, by far the most common misconception we have come across has been the one about normality in general linear models. These comprise a very large part of the statistical models used in ecology and include t tests, simple and multiple linear regression, polynomial regression, and analysis of variance (ANOVA) and covariance (ANCOVA). There is a widely held belief that the normality assumption pertains to the raw data rather than to the model residuals. We suspect that this error may also occur in countless published studies, whenever the normality assumption is tested prior to analysis. This may lead to the use of nonparametric alternatives (if there are any), when parametric tests would indeed be appropriate, or to use of transformations of raw data, which may introduce hidden assumptions such as multiplicative effects on the natural scale in the case of log-transformed data. Our aim here is to dispel this myth. We very briefly describe relevant theory for two cases of general linear models to show that the residuals need to be normally distributed if tests requiring normality are to be used, such as t and F tests. We then give two examples demonstrating that the distribution of the response variable may be nonnormal, and yet the residuals are well behaved. We do not go into the issue of how to test normality; instead we display the distributions of response variables and residuals graphically.

Color and opacity of composites protected with surface sealants and submitted to artificial accelerated aging.

PubMed

Aguilar, Fabiano Gamero; Roberti Garcia, Lucas da Fonseca; Cruvinel, Diogo Rodrigues; Sousa, Ana Beatriz Silva; de Carvalho Panzeri Pires-de-Souza, Fernanda

2012-01-01

To evaluate the color similarity, stability and opacity of composites (TPH, Charisma, and Concept, shade A2) protected with surface sealants (Fortify Plus and Biscover) and cyanoacrylate (Super Bonder). Forty specimens of each composite were made and separated into 4 groups (n=10) according to the surface protection: GI - without sealant; GII - cyanoacrylate; GIII - Fortify Plus; GIV - Biscover. Color and opacity readings were taken before and after Artificial Acelerated Aging (AAA) and the values obtained for color stability were submitted to statistical analysis by 2-way ANOVA and Bonferroni's test (P<.05). The values acquired for color similarity were submitted to 1-way ANOVA and Tukey's test (P<.05). The specimen sufaces were compared before and after AAA using Scanning Electronic Microscopy (SEM). Studied composites did not present the same values for the coordinates L*, a* and b * before AAA, indicating that there was no color similarity among them. All composites presented color alteration after AAA with clinically unacceptable values. Protected groups presented lower opacity variation after AAA, in comparison with the control goup. SEM evaluation demonstrated that AAA increased the surface irregularities in all of the studied groups. Surface sealants were not effective in maintaining composite color, but were able to maintain opacity.

Effectiveness of Massage Therapy and Abdominal Hypopressive Gymnastics in Nonspecific Chronic Low Back Pain: A Randomized Controlled Pilot Study

PubMed Central

Jiménez-Rejano, J. J.; Chillón-Martínez, R.; Gómez-Benítez, M. A.; De-La-Casa-Almeida, M.

2018-01-01

Background There are a great number of interventions in physiotherapy, but with little evidence of their effectiveness in chronic low back pain. Therefore, this study assesses effectiveness of Massage Therapy and Abdominal Hypopressive Gymnastics and the combination of both to decrease pain and lumbar disability while increasing joint mobility and quality of life in patients with chronic nonspecific low back pain. Methods A randomized, single-blinded, controlled, clinical trial with sample (n = 27) was comprised of patients between 20 and 65 years, diagnosed with pain of mechanical origin characterized by having a duration of at least 12 weeks and no serious complications. Each group received 8 interventions of 30 minutes. Results Friedman ANOVA test obtained statistically significant differences of Oswestry, NRS, and Schober variables (p < 0.05) in the three measurements (pretest, posttest 1, and posttest 2), in each individual group. ANOVA Kruskal-Wallis test was used for comparison between groups, and Oswestry Disability values were significantly higher (p = 0.024) in the group receiving both treatments. Conclusion Both individual groups reduce pain levels, improve disability, and increase the flexibility of the lumbar spine. The combination therapy provides greater benefits in terms of lumbar disability. This study is registered on March 8, 2016, with NCT02721914. PMID:29681973

Effectiveness of Massage Therapy and Abdominal Hypopressive Gymnastics in Nonspecific Chronic Low Back Pain: A Randomized Controlled Pilot Study.

PubMed

Bellido-Fernández, L; Jiménez-Rejano, J J; Chillón-Martínez, R; Gómez-Benítez, M A; De-La-Casa-Almeida, M; Rebollo-Salas, M

2018-01-01

There are a great number of interventions in physiotherapy, but with little evidence of their effectiveness in chronic low back pain. Therefore, this study assesses effectiveness of Massage Therapy and Abdominal Hypopressive Gymnastics and the combination of both to decrease pain and lumbar disability while increasing joint mobility and quality of life in patients with chronic nonspecific low back pain. A randomized, single-blinded, controlled, clinical trial with sample ( n = 27) was comprised of patients between 20 and 65 years, diagnosed with pain of mechanical origin characterized by having a duration of at least 12 weeks and no serious complications. Each group received 8 interventions of 30 minutes. Friedman ANOVA test obtained statistically significant differences of Oswestry, NRS, and Schober variables ( p < 0.05) in the three measurements (pretest, posttest 1, and posttest 2), in each individual group. ANOVA Kruskal-Wallis test was used for comparison between groups, and Oswestry Disability values were significantly higher ( p = 0.024) in the group receiving both treatments. Both individual groups reduce pain levels, improve disability, and increase the flexibility of the lumbar spine. The combination therapy provides greater benefits in terms of lumbar disability. This study is registered on March 8, 2016, with NCT02721914.

Statistical analysis of fNIRS data: a comprehensive review.

PubMed

Tak, Sungho; Ye, Jong Chul

2014-01-15

Functional near-infrared spectroscopy (fNIRS) is a non-invasive method to measure brain activities using the changes of optical absorption in the brain through the intact skull. fNIRS has many advantages over other neuroimaging modalities such as positron emission tomography (PET), functional magnetic resonance imaging (fMRI), or magnetoencephalography (MEG), since it can directly measure blood oxygenation level changes related to neural activation with high temporal resolution. However, fNIRS signals are highly corrupted by measurement noises and physiology-based systemic interference. Careful statistical analyses are therefore required to extract neuronal activity-related signals from fNIRS data. In this paper, we provide an extensive review of historical developments of statistical analyses of fNIRS signal, which include motion artifact correction, short source-detector separation correction, principal component analysis (PCA)/independent component analysis (ICA), false discovery rate (FDR), serially-correlated errors, as well as inference techniques such as the standard t-test, F-test, analysis of variance (ANOVA), and statistical parameter mapping (SPM) framework. In addition, to provide a unified view of various existing inference techniques, we explain a linear mixed effect model with restricted maximum likelihood (ReML) variance estimation, and show that most of the existing inference methods for fNIRS analysis can be derived as special cases. Some of the open issues in statistical analysis are also described. Copyright © 2013 Elsevier Inc. All rights reserved.

Factors affecting the distribution and prevalence of oral mucosal lesions in complete denture wearers.

PubMed

Mandali, Gamze; Sener, Işıl Damla; Turker, Sebnem Begum; Ulgen, Hasan

2011-06-01

To determine the frequency of the oral lesions related to gender, age, the length of time of denture usage, education level and economic status. The 153 patients with old complete dentures (CD) were asked to participate in the investigation. The subjects (76 male and 77 female) were 37-85 years of age with a mean age of 61.8 ± 9.8 years. Education, economic status and age factors were estimated in subgroups. The data obtained were evaluated by one-way anova, Mann-Whitney U-test, Kruskal-Wallis test, Student's t-test and chi-squared test. The level of statistical significance was set at p<0.05. The patients who had denture stomatitis and traumatic ulcers were statistically significantly older than the ones who did not have these lesions (p<0.05). Based on the length of denture usage, patients who had a flabby ridge, fibrous inflammatory hyperplasia, traumatic ulcers (p<0.01) and denture stomatitis (p<0.05) were using their dentures statistically significantly longer than the ones who had healthy tissues. The CD wearers should be advised to visit their dentist regularly to prevent oral mucosal lesions due to the changing supporting tissues during the length of denture usage and to improve their quality of life. © 2010 The Gerodontology Society and John Wiley & Sons A/S.

Empirical study of alginate impression materials by customized proportioning system

PubMed Central

2016-01-01

PURPOSE Alginate mixers available in the market do not have the automatic proportioning unit. In this study, an automatic proportioning unit for the alginate mixer and controller software were designed and produced for a new automatic proportioning unit. With this device, it was ensured that proportioning operation could arrange weight-based alginate impression materials. MATERIALS AND METHODS The variation of coefficient in the tested groups was compared with the manual proportioning. Compression tension and tear tests were conducted to determine the mechanical properties of alginate impression materials. The experimental data were statistically analyzed using one way ANOVA and Tukey test at the 0.05 level of significance. RESULTS No statistically significant differences in modulus of elastisity (P>0.3), tensional/compresional strength (P>0.3), resilience (P>0.2), strain in failure (P>0.4), and tear energy (P>0.7) of alginate impression materials were seen. However, a decrease in the standard deviation of tested groups was observed when the customized machine was used. To verify the efficiency of the system, powder and powder/water mixing were weighed and significant decrease was observed. CONCLUSION It was possible to obtain more mechanically stable alginate impression materials by using the custom-made proportioning unit. PMID:27826387

Comparing the Performance of Approaches for Testing the Homogeneity of Variance Assumption in One-Factor ANOVA Models

ERIC Educational Resources Information Center

Wang, Yan; Rodríguez de Gil, Patricia; Chen, Yi-Hsin; Kromrey, Jeffrey D.; Kim, Eun Sook; Pham, Thanh; Nguyen, Diep; Romano, Jeanine L.

2017-01-01

Various tests to check the homogeneity of variance assumption have been proposed in the literature, yet there is no consensus as to their robustness when the assumption of normality does not hold. This simulation study evaluated the performance of 14 tests for the homogeneity of variance assumption in one-way ANOVA models in terms of Type I error…

Comparative study of dental cephalometric patterns of Japanese-Brazilian, Caucasian and Mongoloid patients

PubMed Central

Sathler, Renata; Pinzan, Arnaldo; Fernandes, Thais Maria Freire; de Almeida, Renato Rodrigues; Henriques, José Fernando Castanha

2014-01-01

Introduction The objective of this study was to identify the patterns of dental variables of adolescent Japanese-Brazilian descents with normal occlusion, and also to compare them with a similar Caucasian and Mongoloid sample. Methods Lateral cephalometric radiographs were used to compare the groups: Caucasian (n = 40), Japanese-Brazilian (n = 32) and Mongoloid (n = 33). The statistical tests used were one-way ANOVA and ANCOVA. The cephalometric measurements used followed the analyses of Steiner, Tweed and McNamara Jr. Results Statistical differences (P < 0.05) indicated a smaller interincisal angle and overbite for the Japanese-Brazilian sample, when compared to the Caucasian sample, although with similar values to the Mongoloid group. Conclusion The dental patterns found for the Japanese-Brazilian descents were, in general, more similar to those of the Mongoloid sample. PMID:25279521

Assessment of Adolescent Perceptions on Parental Attitudes on Different Variables

ERIC Educational Resources Information Center

Ersoy, Evren

2015-01-01

The purpose of this study is to examine secondary school student perceptions of parental attitudes with regards to specific variables. Independent samples t test for parametric distributions and one-way variance analysis (ANOVA) was used for analyzing the data, when the ANOVA analyses were significant Scheffe test was conducted on homogeneous…

Clinical Performance of Viscous Glass Ionomer Cement in Posterior Cavities over Two Years

PubMed Central

Frankenberger, Roland; Garcia-Godoy, Franklin; Krämer, Norbert

2009-01-01

In this controlled prospective clinical study the highly viscous glass ionomer cement Ketac Molar was clinically assessed in Class I and Class II cavities. Forty-nine subjects (mean age 32.3 years) received 108 restorations placed by six operators in conventional Black I and II type cavities with undercuts after excavating primary lesions or after removing insufficient restorations. At baseline, and after 6, 12, and 24 months, restorations were assessed by two independent investigators according to modified USPHS codes and criteria. Impressions of the restorations were taken and epoxy replicas were made. Between the baseline and the 24-month recall, 51 representative samples were analyzed at 130 × magnification by use of a stereo light microscope (SLM). Recall rates were 83% after 6 months, 50% after 12 months, and 24% after 24 months. Failure rates after 24 months were 8% for Class I and 40% for Class II fillings, mainly due to bulk fracture at occlusally loaded areas (Kaplan Meier survival analysis). Significant changes over time were found for the criteria “surface roughness”, “marginal integrity”, “restoration integrity”, and “overall judgement” (P < .05; Friedman test). SLM analysis revealed statistically significant differences for the following criteria over time (baseline/6 months/12 months (in % of entire evaluable margin length); P < .05; Friedman 2-way ANOVA): perfect margin 37/19/11, negative step formation 26/49/57, gap formation 2/7/9, and overhang 24/11/8. Replicas exhibited mainly negative step formation as main finding due to apparently inferior wear resistance (P < .05). Gap formations were more frequently observed in Class II restorations than in Class I (12% versus 3% after 12 months; P < .05, Mann-Whitney-U test). The evaluated margin lengths were not statistically different (P > .05, Friedman 2-way ANOVA). PMID:20339470

Marginal fit of all-ceramic crowns fabricated using two extraoral CAD/CAM systems in comparison with the conventional technique.

PubMed

Alqahtani, Fawaz

2017-01-01

The purpose of this study was to determine the effect of two extraoral computer-aided design (CAD) and computer-aided manufacturing (CAM) systems, in comparison with conventional techniques, on the marginal fit of monolithic CAD/CAM lithium disilicate ceramic crowns. This is an in vitro interventional study. The study was carried out at the Department of Prosthodontics, School of Dentistry, Prince Sattam Bin Abdul-Aziz University, Saudi Arabia, from December 2015 to April 2016. A marginal gap of 60 lithium disilicate crowns was evaluated by scanning electron microscopy. In total, 20 pressable lithium disilicate (IPS e.max Press [Ivoclar Vivadent]) ceramic crowns were fabricated using the conventional lost-wax technique as a control group. The experimental all-ceramic crowns were produced based on a scan stone model and milled using two extraoral CAD/CAM systems: the Cerec group was fabricated using the Cerec CAD/CAM system, and the Trios group was fabricated using Trios CAD and milled using Wieland Zenotec CAM. One-way analysis of variance (ANOVA) and the Scheffe post hoc test were used for statistical comparison of the groups (α=0.05). The mean (±standard deviation) of the marginal gap of each group was as follows: the Control group was 91.15 (±15.35) µm, the Cerec group was 111.07 (±6.33) µm, and the Trios group was 60.17 (±11.09) µm. One-way ANOVA and the Scheffe post hoc test showed a statistically significant difference in the marginal gap between all groups. It can be concluded from the current study that all-ceramic crowns, fabricated using the CAD/CAM system, show a marginal accuracy that is acceptable in clinical environments. The Trios CAD group displayed the smallest marginal gap.

Translucency of zirconia-based pressable ceramics with different core and veneer thicknesses.

PubMed

Jeong, Il-Do; Bae, So-Yeon; Kim, Dong-Yeon; Kim, Ji-Hwan; Kim, Woong-Chul

2016-06-01

Little information is available on the translucency of zirconia-based pressable ceramic restorations with a pressed ceramic veneer and zirconia core in various thickness combinations. The purpose of this in vitro study was to assess the translucency of 3 types of zirconia-based pressable ceramics for different core-veneer thickness combinations. A bilayered ceramic specimen was prepared with a pressable ceramic (IPS e.max Zirpress, Initial IQ, Rosetta UltraPress) veneer over a zirconia core (Zenostar Zr). Three groups of specimens (n=7) were formed with the following core+veneer thicknesses: 1 +0.5 mm, 0.7 +0.8 mm, and 0.5 +1 mm. To obtain consistent thickness and high translucency, all specimens were subjected to surface grinding with a grinding machine. To eliminate the effect of differences in roughness on the translucency, the surface roughness of the ground specimens was measured with a scanning profiler, and the consistency of these measured values was verified through statistical analysis. The luminous transmittance of the specimens was measured with a spectrophotometer. The effects of the pressable ceramic type and core-veneer thickness combination on transmittance were assessed using a 2-way ANOVA (α=.05). The consistency of the surface roughness among the tested specimens was confirmed using a 1-way ANOVA and the Tukey HSD post hoc test (P<.05). The luminous transmittance exhibited a statistically significant dependence on both the type of pressable ceramic and the core-veneer thickness combination (P<.05). The type of pressable ceramic and core-veneer thickness combination affected the translucency of the restoration. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Effect of surface treatments on the bond strength between resin cement and differently sintered zirconium-oxide ceramics.

PubMed

Yenisey, Murat; Dede, Doğu Ömür; Rona, Nergiz

2016-01-01

This study investigated the effects of surface treatments on bond strength between resin cement and differently sintered zirconium-oxide ceramics. 220 zirconium-oxide ceramic (Ceramill ZI) specimens were prepared, sintered in two different period (Short=Ss, Long=Ls) and divided into ten treatment groups as: GC, no treatment; GSil, silanized (ESPE-Sil); GSilPen, silane flame treatment (Silano-Pen); GSb, sandblasted; GSbSil, sandblasted+silanized; GSbCoSil, sandblasted+silica coated (CoJet)+silanized; GSbRoSil, sandblasted+silica coated (Rocatech-Plus)+silanized; GSbDSil, sandblasted+diamond particle abraded (Micron MDA)+silanized; GSbSilPen, sandblasted+silane flame treatment+silanized; GSbLSil, sandblasted+Er:Yag (Asclepion-MCL30) laser treated+silanized. The composite resin (Filtek Z-250) cylinders were cemented to the treated ceramic surfaces with a resin cement (Panavia F2.0). Shear bond strength test was performed after specimens were stored in water for 24h and thermo-cycled for 6000 cycles (5-55 °C). Data were statistically analyzed with two-way analysis of variance (ANOVA) and Tamhane's multiple comparison test (α=0.05). According to the ANOVA, sintering time, surface treatments and their interaction were statistically significant (p<0.05). The highest bond strengths were obtained in GSbCoSil (Ss=13.36/Ls=11.19MPa) and lowest values were obtained in GC (Ss=4.70/Ls=4.62 MPa) for both sinter groups. Sintering time may be effective on the bond strength and 30 μm silica coating (Cojet) with silane coupling application technique increased the bond strength between resin cement and differently sintered zirconium-oxide ceramics. Copyright © 2015 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Drooling, saliva production, and swallowing in cerebral palsy.

PubMed

Senner, Jill E; Logemann, Jerilyn; Zecker, Steven; Gaebler-Spira, Deborah

2004-12-01

Fourteen participants (six females, eight males) ranging in age from 7 years 11 months to 18 years 2 months (mean 11y 7mo) with a confirmed diagnosis of spastic cerebral palsy (CP) were included in the study. Participants included those who drooled (CP+, n=14); age- and sex-matched children with spastic CP who were dry to mild and never to infrequent droolers (CP-, n=14) as well as typically developing peers (CTRL, n=14) served as controls. Frequency of swallowing was measured by using simultaneous cervical ausculation and videotaping of the head and neck. Saliva production was measured with the Saxon test, a simple gauze-chewing procedure. In addition, Pediatric Evaluation of Disability Inventory (PEDI), Test of Nonverbal Intelligence-3 (TONI-3), dysarthria severity scale, and Gross Motor Function Classification System (GMFCS) scores were obtained for each participant. Both groups of participants with CP tended to swallow less frequently than typically developing participants and tended to produce less saliva than typically developing controls; however, these differences were not statistically significant. No correlation was found between amount of saliva produced and amount drooled (r=0.245). An analysis of variance (ANOVA) conducted on the PEDI functional skills mean scores indicated significant differences between the three groups (F(2,39)=23.522,p<0.0001). Likewise, an ANOVA conducted on the TONI-3 scores revealed statistically significant differences between the three groups (F(2,39)=31.761, p<0.0001). A Spearman's rho correlation indicated that GMFCS scores were not significantly correlated with drooling severity (Spearman's rho correlation=0.3951,p=0.037). Drooling severity was found to be positively correlated with dysarthria severity (Spearman's rho correlation=0.82,p<0.0001). These findings suggest that drooling in patients with CP is related to swallowing difficulties rather than hypersalivation.

kruX: matrix-based non-parametric eQTL discovery.

PubMed

Qi, Jianlong; Asl, Hassan Foroughi; Björkegren, Johan; Michoel, Tom

2014-01-14

The Kruskal-Wallis test is a popular non-parametric statistical test for identifying expression quantitative trait loci (eQTLs) from genome-wide data due to its robustness against variations in the underlying genetic model and expression trait distribution, but testing billions of marker-trait combinations one-by-one can become computationally prohibitive. We developed kruX, an algorithm implemented in Matlab, Python and R that uses matrix multiplications to simultaneously calculate the Kruskal-Wallis test statistic for several millions of marker-trait combinations at once. KruX is more than ten thousand times faster than computing associations one-by-one on a typical human dataset. We used kruX and a dataset of more than 500k SNPs and 20k expression traits measured in 102 human blood samples to compare eQTLs detected by the Kruskal-Wallis test to eQTLs detected by the parametric ANOVA and linear model methods. We found that the Kruskal-Wallis test is more robust against data outliers and heterogeneous genotype group sizes and detects a higher proportion of non-linear associations, but is more conservative for calling additive linear associations. kruX enables the use of robust non-parametric methods for massive eQTL mapping without the need for a high-performance computing infrastructure and is freely available from http://krux.googlecode.com.

Evaluation of Resilient Modulus of Subgrade and Base Materials in Indiana and Its Implementation in MEPDG

PubMed Central

Siddiki, Nayyarzia; Nantung, Tommy; Kim, Daehyeon

2014-01-01

In order to implement MEPDG hierarchical inputs for unbound and subgrade soil, a database containing subgrade M R, index properties, standard proctor, and laboratory M R for 140 undisturbed roadbed soil samples from six different districts in Indiana was created. The M R data were categorized in accordance with the AASHTO soil classifications and divided into several groups. Based on each group, this study develops statistical analysis and evaluation datasets to validate these models. Stress-based regression models were evaluated using a statistical tool (analysis of variance (ANOVA)) and Z-test, and pertinent material constants (k 1, k 2 and k 3) were determined for different soil types. The reasonably good correlations of material constants along with M R with routine soil properties were established. Furthermore, FWD tests were conducted on several Indiana highways in different seasons, and laboratory resilient modulus tests were performed on the subgrade soils that were collected from the falling weight deflectometer (FWD) test sites. A comparison was made of the resilient moduli obtained from the laboratory resilient modulus tests with those from the FWD tests. Correlations between the laboratory resilient modulus and the FWD modulus were developed and are discussed in this paper. PMID:24701162

Comparative study between EDXRF and ASTM E572 methods using two-way ANOVA

NASA Astrophysics Data System (ADS)

Krummenauer, A.; Veit, H. M.; Zoppas-Ferreira, J.

2018-03-01

Comparison with reference method is one of the necessary requirements for the validation of non-standard methods. This comparison was made using the experiment planning technique with two-way ANOVA. In ANOVA, the results obtained using the EDXRF method, to be validated, were compared with the results obtained using the ASTM E572-13 standard test method. Fisher's tests (F-test) were used to comparative study between of the elements: molybdenum, niobium, copper, nickel, manganese, chromium and vanadium. All F-tests of the elements indicate that the null hypothesis (Ho) has not been rejected. As a result, there is no significant difference between the methods compared. Therefore, according to this study, it is concluded that the EDXRF method was approved in this method comparison requirement.

Gauging Skills of Hospital Security Personnel: a Statistically-driven, Questionnaire-based Approach.

PubMed

Rinkoo, Arvind Vashishta; Mishra, Shubhra; Rahesuddin; Nabi, Tauqeer; Chandra, Vidha; Chandra, Hem

2013-01-01

This study aims to gauge the technical and soft skills of the hospital security personnel so as to enable prioritization of their training needs. A cross sectional questionnaire based study was conducted in December 2011. Two separate predesigned and pretested questionnaires were used for gauging soft skills and technical skills of the security personnel. Extensive statistical analysis, including Multivariate Analysis (Pillai-Bartlett trace along with Multi-factorial ANOVA) and Post-hoc Tests (Bonferroni Test) was applied. The 143 participants performed better on the soft skills front with an average score of 6.43 and standard deviation of 1.40. The average technical skills score was 5.09 with a standard deviation of 1.44. The study avowed a need for formal hands on training with greater emphasis on technical skills. Multivariate analysis of the available data further helped in identifying 20 security personnel who should be prioritized for soft skills training and a group of 36 security personnel who should receive maximum attention during technical skills training. This statistically driven approach can be used as a prototype by healthcare delivery institutions worldwide, after situation specific customizations, to identify the training needs of any category of healthcare staff.

Gauging Skills of Hospital Security Personnel: a Statistically-driven, Questionnaire-based Approach

PubMed Central

Rinkoo, Arvind Vashishta; Mishra, Shubhra; Rahesuddin; Nabi, Tauqeer; Chandra, Vidha; Chandra, Hem

2013-01-01

Objectives This study aims to gauge the technical and soft skills of the hospital security personnel so as to enable prioritization of their training needs. Methodology A cross sectional questionnaire based study was conducted in December 2011. Two separate predesigned and pretested questionnaires were used for gauging soft skills and technical skills of the security personnel. Extensive statistical analysis, including Multivariate Analysis (Pillai-Bartlett trace along with Multi-factorial ANOVA) and Post-hoc Tests (Bonferroni Test) was applied. Results The 143 participants performed better on the soft skills front with an average score of 6.43 and standard deviation of 1.40. The average technical skills score was 5.09 with a standard deviation of 1.44. The study avowed a need for formal hands on training with greater emphasis on technical skills. Multivariate analysis of the available data further helped in identifying 20 security personnel who should be prioritized for soft skills training and a group of 36 security personnel who should receive maximum attention during technical skills training. Conclusion This statistically driven approach can be used as a prototype by healthcare delivery institutions worldwide, after situation specific customizations, to identify the training needs of any category of healthcare staff. PMID:23559904

Erratum to: Application of addition-cured silicone denture relining materials to adjust mouthguards.

PubMed

Fukasawa, Shintaro; Churei, Hiroshi; Chowdhury, Ruman Uddin; Shirako, Takahiro; Shahrin, Sharika; Shrestha, Abhishekhi; Wada, Takahiro; Uo, Motohiro; Takahashi, Hidekazu; Ueno, Toshiaki

2016-01-01

The purposes of this study were to examine the shock absorption capability of addition-cured silicone denture relining materials and the bonding strength of addition-cured silicone denture relining materials and a commercial mouthguard material to determine its applicability to mouthguard adjustment. Two addition-cured silicone denture relining materials were selected as test materials. The impact test was applied by a free-falling steel ball. On the other hand, bonding strength was determined by a delamination test. After prepared surface treatments using acrylic resin on MG sheet surface, 2 types of addition-cured silicone denture relining materials were glued to MG surface. The peak intensity, the time to peak intensity from the onset of the transmitted force and bonding strength were statistically analyzed using ANOVA and Tukey's honest significant difference post hoc test (p<0.05). These results suggest that the silicone denture relining materials could be clinically applicable as a mouthguard adjustment material.

In vitro evaluation of marginal adaptation in five ceramic restoration fabricating techniques.

PubMed

Ural, Cağri; Burgaz, Yavuz; Saraç, Duygu

2010-01-01

To compare in vitro the marginal adaptation of crowns manufactured using ceramic restoration fabricating techniques. Fifty standardized master steel dies simulating molars were produced and divided into five groups, each containing 10 specimens. Test specimens were fabricated with CAD/CAM, heat-press, glass-infiltration, and conventional lost-wax techniques according to manufacturer instructions. Marginal adaptation of the test specimens was measured vertically before and after cementation using SEM. Data were statistically analyzed by one-way ANOVA with Tukey HSD tests (a = .05). Marginal adaptation of ceramic crowns was affected by fabrication technique and cementation process (P < .001). The lowest marginal opening values were obtained with Cerec-3 crowns before and after cementation (P < .001). The highest marginal discrepancy values were obtained with PFM crowns before and after cementation. Marginal adaptation values obtained in the compared systems were within clinically acceptable limits. Cementation causes a significant increase in the vertical marginal discrepancies of the test specimens.

A hybrid approach to select features and classify diseases based on medical data

NASA Astrophysics Data System (ADS)

AbdelLatif, Hisham; Luo, Jiawei

2018-03-01

Feature selection is popular problem in the classification of diseases in clinical medicine. Here, we developing a hybrid methodology to classify diseases, based on three medical datasets, Arrhythmia, Breast cancer, and Hepatitis datasets. This methodology called k-means ANOVA Support Vector Machine (K-ANOVA-SVM) uses K-means cluster with ANOVA statistical to preprocessing data and selection the significant features, and Support Vector Machines in the classification process. To compare and evaluate the performance, we choice three classification algorithms, decision tree Naïve Bayes, Support Vector Machines and applied the medical datasets direct to these algorithms. Our methodology was a much better classification accuracy is given of 98% in Arrhythmia datasets, 92% in Breast cancer datasets and 88% in Hepatitis datasets, Compare to use the medical data directly with decision tree Naïve Bayes, and Support Vector Machines. Also, the ROC curve and precision with (K-ANOVA-SVM) Achieved best results than other algorithms

Coping, stress, and personality in Spanish nursing students: A longitudinal study.

PubMed

Fornés-Vives, Joana; Garcia-Banda, Gloria; Frias-Navarro, Dolores; Rosales-Viladrich, Gerard

2016-01-01

The purpose of this study was to examine the dominant stress coping style in nursing students, its relationships with stressful life events and personality traits, and the students' changes during their academic training. A non-experimental two-wave longitudinal design was carried out in 199 nursing students recruited from three Spanish nursing schools. The Stressful Life Events Scale, NEO-FFI, and COPE questionnaire were administered at the beginning (T1) and end (T2) of their nursing studies. Descriptive statistics, Anova(s), NPar tests, and Pearson correlations were carried out. Results show that nursing students' dominant coping style was emotion-focused coping, both at T1 and T2. Highly significant correlations between emotional coping and the neuroticism trait were found. Coping, stress, and personality changed positively during the training program. At T2, the use of problem-focused strategies increased, and participants became more extroverted, agreeable, and conscientious. Coping and personality changes experienced by nursing students throughout their degree program seem to mirror the professional competences needed by future licensed nurses. Copyright © 2015 Elsevier Ltd. All rights reserved.

GAPD and tubulin are suitable internal controls for qPCR analysis of oral squamous cell carcinoma cell lines.

PubMed

Campos, M S; Rodini, C O; Pinto-Júnior, D S; Nunes, F D

2009-02-01

The selection of housekeeping genes is critical for gene expression studies. To address this issue, four candidate housekeeping genes, including several commonly used ones, were investigated in oral squamous cell carcinoma cell lines. A simple quantitative RT-PCR approach was employed by comparing relative expression of the four candidate genes within two cancerous cell lines (HN6 and HN31) and one noncancerous cell line (HaCaT) treated or not with EGF and TGF-beta1. Data were analyzed using ANOVA followed by the NormFinder software program. On this basis, stability of the candidate housekeeping genes was ranked and non statistical differences were found using ANOVA test. On the other hand, the NormFinder was able to show that GAPD and TUBB presented the less variable results, representing appropriated housekeeping genes for the samples and conditions analyzed. In conclusion, this study suggests that the GAPD and the TUBB represent adequate normalizers for gene profiling studies in OSCC cell lines, covering, respectively, high and low expression levels genes.

Terrestrial gamma radiation dose (TGRD) levels in northern zone of Jos Plateau, Nigeria: Statistical relationship between dose rates and geological formations

NASA Astrophysics Data System (ADS)

Abba, Habu Tela; Hassan, Wan Muhamad Saridan Wan; Saleh, Muneer Aziz; Aliyu, Abubakar Sadiq; Ramli, Ahmad Termizi

2017-11-01

In- situ measurement of terrestrial gamma radiation dose rates (TGRD) was conducted in northern zone of Jos Plateau and a statistical relationship between the TGRD and the underlying geological formations was investigated. The TGRD rates in all the measurements ranged from 40 to 1265 nGy h-1 with a mean value of 250 nGy h-1. The maximum TGDR was recorded on geological type G8 (Younger Granites) at Bisitchi, and the lowest TGDR was recorded on G6 (Basaltic rocks) at Gabia. One way analysis of variance (ANOVA) statistical test was used to compared the data. Significantly, the results of this study inferred a strong relationship between TGRD levels with geological structures of a place. An isodose map was plotted to represent exposure rates due to TGRD. The results of this investigation could be useful for multiple public interest such as evaluating public dose for the area.

A Study of relationship between frailty and physical performance in elderly women.

PubMed

Jeoung, Bog Ja; Lee, Yang Chool

2015-08-01

Frailty is a disorder of multiple inter-related physiological systems. It is unclear whether the level of physical performance factors can serve as markers of frailty and a sign. The purpose of this study was to examine the relationship between frailty and physical performance in elderly women. One hundred fourteen elderly women participated in this study, their aged was from 65 to 80. We were measured 6-min walk test, grip-strength, 30-sec arm curl test, 30-sec chair stand test, 8 foot Up- and Go, Back scratch, chair sit and reach, unipedal stance, BMI, and the frailty with questionnaire. The collected data were analyzed by descriptive statistics, frequencies, correlation analysis, ANOVA, and simple liner regression using the IBM 21. SPSS program. In results, statistic tests showed that there were significant differences between frailty and 6-min walk test, 30-sec arm curl test, 30-sec chair stand test, grip-strength, Back scratch, and BMI. However, we did not find significant differences between frailty and 8 foot Up- and Go, unipedal stance. When the subjects were divided into five groups according to physical performance level, subjects with high 6-min walk, 30-sec arm curl test, chair sit and reach test, and high grip strength had low score frailty. Physical performance factors were strongly associated with decreased frailty, suggesting that physical performance improvements play an important role in preventing or reducing the frailty.

Testing the effectiveness of an aquatic hazing device on waterbirds in the San Francisco Bay estuary of California

USGS Publications Warehouse

Whisson, Desley A.; Takekawa, John Y.

2000-01-01

Aquatic hazing devices recently have been developed as a possible means of deterring waterbirds from oil spills, thereby reducing casualties. However, the effectiveness of these devices has not been examined with rigorous statistical tests. We conducted a study in the San Francisco Bay estuary to develop a design for testing the effectiveness of an aquatic hazing device on waterbirds in open water. Transects marked with poles at 100-m inter- vals up to 800 m from the hazing device were established at two sites separated by three km in the north bay. Alter- nating two-day test and control periods were conducted at each site. Observers in over-water blinds counted the number, species and behavior (swimming, diving, or preening) of birds on transects each day. Aerial surveys of birds within four km of the device were conducted at the beginning of each test. For both aerial and ground surveys, a three-way mixed model analysis of variance test was used to examine trial, distance from the device, and treatment (device on or off) fixed effects, and site as a random effect on numbers of Greater and Lesser scaup (Aythya affinis and A. marila), Surf Scoter (Melanitta perspicillata), and all other waterbirds. We could not detect a significant deter- rent effect of the hazing device in either aerial surveys of all ducks or scaup (all ducks, F,283 = 1.1; Scaup, F28,230 = 0.9, all n.s.; 3-factor ANOVA), or ground surveys for all ducks or scaup (all ducks, F28,23 = 1.0; scaup, F2s,230 = 0.9, all n.s.; 3-factor ANOVA). There was a significant trial-by-treatment interaction for Surf Scoters (F4,9 = 5.4, P = 0.02; 3-factor ANOVA), but Surf Scoter numbers fluctuated greatly among trials so the effect of the device on this species was not clear. Birds did not alter their behavior when the device was active. In general, although aquatic hazing devices have potential to reduce waterbird mortality in oil spills, the tested device was not effective as a deterrent for waterfowl in experimental trials on the estuary. Received 27 September 1999, accepted 3January 2000.

Laparoscopic skills training using a webcam trainer.

PubMed

Chung, Steve Y; Landsittel, Douglas; Chon, Chris H; Ng, Christopher S; Fuchs, Gerhard J

2005-01-01

Many sophisticated and expensive trainers have been developed to assist surgeons in learning basic laparoscopic skills. We developed an inexpensive trainer and evaluated its effectiveness. The webcam laparoscopic training device is composed of a webcam, cardboard box, desk lamp and home computer. This homemade trainer was evaluated against 2 commercially available systems, namely the video Pelvitrainer (Karl Storz Endoscopy, Culver City, California) and the dual mirror Simuview (Simulab Corp., Seattle, Washington). The Pelvitrainer consists of a fiberglass box, single lens optic laparoscope, fiberoptic light source, endoscopic camera and video monitor, while the Simuview trainer uses 2 offset, facing mirrors and an uncovered plastic box. A total of 42 participants without prior laparoscopic training were enrolled in the study and asked to execute 2 tasks, that is peg transfer and pattern cutting. Participants were randomly assigned to 6 groups with each group representing a different permutation of trainers to be used. The time required for participants to complete each task was recorded and differences in performance were calculated. Paired t tests, the Wilcoxon signed rank test and ANOVA were performed to analyze the statistical difference in performance times for all conditions. Statistical analyses of the 2 tasks showed no significant difference for the video and webcam trainers. However, the mirror trainer gave significantly higher outcome values for tasks 1 and 2 compared to the video (p = 0.01 and <0.01) and webcam (p = 0.04 and <0.01, respectively) methods. ANOVA indicated no overall difference for tasks 1 and 2 across the orderings (p = 0.36 and 0.99, respectively). However, by attempt 3 the time required to complete the skill tests decreased significantly for all 3 trainers (each p <0.01). Our homemade webcam system is comparable in function to the more elaborate video trainer but superior to the dual mirror trainer. For novice laparoscopists we believe that the webcam system is an inexpensive and effective laparoscopic training device. Furthermore, the webcam system also allows instant recording and review of techniques.

Cervical and Incisal Marginal Discrepancy in Ceramic Laminate Veneering Materials: A SEM Analysis.

PubMed

Ranganathan, Hemalatha; Ganapathy, Dhanraj M; Jain, Ashish R

2017-01-01

Marginal discrepancy influenced by the choice of processing material used for the ceramic laminate veneers needs to be explored further for better clinical application. This study aimed to evaluate the amount of cervical and incisal marginal discrepancy associated with different ceramic laminate veneering materials. This was an experimental, single-blinded, in vitro trial. Ten central incisors were prepared for laminate veneers with 2 mm uniform reduction and heavy chamfer finish line. Ceramic laminate veneers fabricated over the prepared teeth using four different processing materials were categorized into four groups as Group I - aluminous porcelain veneers, Group II - lithium disilicate ceramic veneers, Group III - lithium disilicate-leucite-based veneers, Group IV - zirconia-based ceramic veneers. The cervical and incisal marginal discrepancy was measured using a scanning electron microscope. ANOVA and post hoc Tukey honest significant difference (HSD) tests were used for statistical analysis. The cervical and incisal marginal discrepancy for four groups was Group I - 114.6 ± 4.3 μm, 132.5 ± 6.5 μm, Group II - 86.1 ± 6.3 μm, 105.4 ± 5.3 μm, Group III - 71.4 ± 4.4 μm, 91.3 ± 4.7 μm, and Group IV - 123.1 ± 4.1 μm, 142.0 ± 5.4 μm. ANOVA and post hoc Tukey HSD tests observed a statistically significant difference between the four test specimens with regard to cervical marginal discrepancy. The cervical and incisal marginal discrepancy scored F = 243.408, P < 0.001 and F = 180.844, P < 0.001, respectively. This study concluded veneers fabricated using leucite reinforced lithium disilicate exhibited the least marginal discrepancy followed by lithium disilicate ceramic, aluminous porcelain, and zirconia-based ceramics. The marginal discrepancy was more in the incisal region than in the cervical region in all the groups.

Role strain among male RNs in the critical care setting: Perceptions of an unfriendly workplace.

PubMed

Carte, Nicholas S; Williams, Collette

2017-12-01

Traditionally, nursing has been a female-dominated profession. Men employed as registered nurses have been in the minority and little is known about the experiences of this demographic. The purpose of this descriptive, quantitative study was to understand the relationship between the variables of demographics and causes of role strain among male nurses in critical care settings. The Sherrod Role Strain Scale assesses role strain within the context of role conflict, role overload, role ambiguity and role incongruity. Data analysis of the results included descriptive and inferential statistics. Inferential statistics involved the use of repeated measures ANOVA testing for significant difference in the causes of role strain between male nurses employed in critical care settings and a post hoc comparison of specific demographic data using multivariate analyses of variance (MANOVAs). Data from 37 male nurses in critical care settings from the northeast of the United States were used to calculate descriptive statistics standard deviation, mean of the data analysis and results of the repeated ANOVA and the post hoc secondary MANOVA analysis. The descriptive data showed that all participants worked full-time. There was an even split from those participants who worked day shift (46%) vs. night shift (43%), most the participants indicated they had 15 years or more experience as an registered nurse (54%). Significant findings of this study include two causes of role strain in male nurses employed in critical care settings which are: role ambiguity and role overload based on ethnicity. Consistent with previous research findings, the results of this study suggest that male registered nurses employed in critical care settings do experience role strain. The two main causes of role strain in male nurses are role ambiguity and role overload. Copyright © 2017. Published by Elsevier Ltd.

Effect of denture cleaning on abrasion resistance and surface topography of polymerized CAD CAM acrylic resin denture base

PubMed Central

Shinawi, Lana Ahmed

2017-01-01

Background The application of computer-aided design computer-aided manufacturing (CAD CAM) technology in the fabrication of complete dentures, offers numerous advantages as it provides optimum fit and eliminates polymerization shrinkage of the acrylic base. Additionally, the porosity and surface roughness of CAD CAM resins is less compared to conventionally processed resins which leads to a decrease in the adhesion of bacteria on the denture base, which is associated with many conditions including halitosis and aspiration pneumonia in elderly denture wearers. Aim To evaluate the influence of tooth brushing with dentifrices on CAD CAM resin blocks in terms of abrasion resistance, surface roughness and scanning electron photomicrography. Methods This experimental study was carried out at the Faculty of Dentistry of King Abdulaziz University during 2016. A total of 40 rectangular shaped polymerized CAD CAM resin samples were subjected to 40.000 and 60.000 brushing strokes under a 200-gram vertical load simulating three years of tooth brushing strokes using commercially available denture cleaning dentifrice. Data were analyzed by SPSS version 20, using descriptive statistics and ANOVA. Results ANOVA test revealed a statistical significant weight loss of CAD CAM acrylic resin denture base specimens following 40.000 and 60.000 brushing strokes as well as a statistical significant change (p=0.0.5) in the surface roughness following brushing. The CAD CAM resin samples SEM baseline imaging revealed a relatively smooth homogenous surface, but following 40,000 and 60,000 brushing strokes, imaging displayed the presence of small scratches on the surface. Conclusion CAD CAM resin displayed a homogenous surface initially with low surface roughness that was significantly affected following simulating three years of manual brushing, but despite the significant weight loss, the findings are within the clinically acceptable limits. PMID:28713496

Effect of denture cleaning on abrasion resistance and surface topography of polymerized CAD CAM acrylic resin denture base.

PubMed

Shinawi, Lana Ahmed

2017-05-01

The application of computer-aided design computer-aided manufacturing (CAD CAM) technology in the fabrication of complete dentures, offers numerous advantages as it provides optimum fit and eliminates polymerization shrinkage of the acrylic base. Additionally, the porosity and surface roughness of CAD CAM resins is less compared to conventionally processed resins which leads to a decrease in the adhesion of bacteria on the denture base, which is associated with many conditions including halitosis and aspiration pneumonia in elderly denture wearers. To evaluate the influence of tooth brushing with dentifrices on CAD CAM resin blocks in terms of abrasion resistance, surface roughness and scanning electron photomicrography. This experimental study was carried out at the Faculty of Dentistry of King Abdulaziz University during 2016. A total of 40 rectangular shaped polymerized CAD CAM resin samples were subjected to 40.000 and 60.000 brushing strokes under a 200-gram vertical load simulating three years of tooth brushing strokes using commercially available denture cleaning dentifrice. Data were analyzed by SPSS version 20, using descriptive statistics and ANOVA. ANOVA test revealed a statistical significant weight loss of CAD CAM acrylic resin denture base specimens following 40.000 and 60.000 brushing strokes as well as a statistical significant change (p=0.0.5) in the surface roughness following brushing. The CAD CAM resin samples SEM baseline imaging revealed a relatively smooth homogenous surface, but following 40,000 and 60,000 brushing strokes, imaging displayed the presence of small scratches on the surface. CAD CAM resin displayed a homogenous surface initially with low surface roughness that was significantly affected following simulating three years of manual brushing, but despite the significant weight loss, the findings are within the clinically acceptable limits.

Relationship of long-term highly active antiretroviral therapy on salivary flow rate and CD4 Count among HIV-infected patients.

PubMed

Kumar, J Vijay; Baghirath, P Venkat; Naishadham, P Parameswar; Suneetha, Sujai; Suneetha, Lavanya; Sreedevi, P

2015-01-01

To determine if long-term highly active antiretroviral therapy (HAART) therapy alters salivary flow rate and also to compare its relation of CD4 count with unstimulated and stimulated whole saliva. A cross-sectional study was performed on 150 individuals divided into three groups. Group I (50 human immunodeficiency virus (HIV) seropositive patients, but not on HAART therapy), Group II (50 HIV-infected subjects and on HAART for less than 3 years called short-term HAART), Group III (50 HIV-infected subjects and on HAART for more than or equal to 3 years called long-term HAART). Spitting method proposed by Navazesh and Kumar was used for the measurement of unstimulated and stimulated salivary flow rate. Chi-square test and analysis of variance (ANOVA) were used for statistical analysis. The mean CD4 count was 424.78 ± 187.03, 497.82 ± 206.11 and 537.6 ± 264.00 in the respective groups. Majority of the patients in all the groups had a CD4 count between 401 and 600. Both unstimulated and stimulated whole salivary (UWS and SWS) flow rates in Group I was found to be significantly higher than in Group II (P < 0.05). Unstimulated salivary flow rate between Group II and III subjects were also found to be statistically significant (P < 0.05). ANOVA performed between CD4 count and unstimulated and stimulated whole saliva in each group demonstrated a statistically significant relationship in Group II (P < 0.05). There were no significant results found between CD4 count and stimulated whole saliva in each groups. The reduction in CD4 cell counts were significantly associated with salivary flow rates of HIV-infected individuals who are on long-term HAART.

Comparison of immediate complete denture, tooth and implant-supported overdenture on vertical dimension and muscle activity

PubMed Central

Shah, Farhan Khalid; Gebreel, Ashraf; Elshokouki, Ali hamed; Habib, Ahmed Ali

2012-01-01

PURPOSE To compare the changes in the occlusal vertical dimension, activity of masseter muscles and biting force after insertion of immediate denture constructed with conventional, tooth-supported and Implant-supported immediate mandibular complete denture. MATERIALS AND METHODS Patients were selected and treatment was carried out with all the three different concepts i.e, immediate denture constructed with conventional (Group A), tooth-supported (Group B) and Implant-supported (Group C) immediate mandibular complete dentures. Parameters of evaluation and comparison were occlusal vertical dimension measured by radiograph (at three different time intervals), Masseter muscle electromyographic (EMG) measurement by EMG analysis (at three different positions of jaws) and bite force measured by force transducer (at two different time intervals). The obtained data were statistically analyzed by using ANOVA-F test at 5% level of significance. If the F test was significant, Least Significant Difference test was performed to test further significant differences between variables. RESULTS Comparison between mean differences in occlusal vertical dimension for tested groups showed that it was only statistically significant at 1 year after immediate dentures insertion. Comparison between mean differences in wavelet packet coefficients of the electromyographic signals of masseter muscles for tested groups was not significant at rest position, but significant at initial contact position and maximum voluntary clench position. Comparison between mean differences in maximum biting force for tested groups was not statistically significant at 5% level of significance. CONCLUSION Immediate complete overdentures whether tooth or implant supported prosthesis is recommended than totally mucosal supported prosthesis. PMID:22737309

A Comparison of implant impression precision: Different materials and techniques

PubMed Central

Tabesh, Mahtab; Alikhasi, Marzieh

2018-01-01

Background Precision of implant impressions is a prerequisite for long-term success of implant supported prostheses. Impression materials and impression techniques are two important factors that impression precision relies on. Material and Methods A model of edentulous maxilla containing four implants inserted by All-on-4 guide was constructed. Seventy two impressions using polyether (PE), polyvinyl siloxane (PVS), and vinyl siloxanether (VSE) materials with direct and indirect techniques were made (n=12). Coordinates of implants in casts were measured using coordinate measuring machine (CMM). Data were analyzed with ANOVA; t-test and Tukey test were used for post hoc. Results With two-way ANOVA, mean values of linear displacements of implants were significantly different among materials and techniques. One-way ANOVA and Tukey showed significant difference between PE and VSE (P=0.019), PE and PVS (P=0.002) in direct technique, and between PVS and PE (P<0.001), PVS and VSE (P<0.001) in indirect technique. One-way ANOVA and t-test showed significant difference between the two techniques in PVS groups (P<0.001) and in PE groups (P=0.02). Two-way ANOVA showed mean values of rotational displacement of implants were significantly different among materials. One-way ANOVA and Tukey test showed significant difference between PVS and PE (P=0.001) and between PVS and VSE (P=0.012) in indirect groups. Conclusions On the basis of the results, when deciding on the material to make an impression of implants, PE is recommended for direct technique while PE and VSE are recommended for indirect technique. Recommended technique for VSE is either direct or indirect; and for PE and PVS is direct. Key words:Polyvinyl siloxane, polyether, vinyl siloxanether, direct technique, indirect technique, All-on-4, coordinate measuring machine. PMID:29670733

Biomechanical influence of crown-to-implant ratio on stress distribution over internal hexagon short implant: 3-D finite element analysis with statistical test.

PubMed

Ramos Verri, Fellippo; Santiago Junior, Joel Ferreira; de Faria Almeida, Daniel Augusto; de Oliveira, Guilherme Bérgamo Brandão; de Souza Batista, Victor Eduardo; Marques Honório, Heitor; Noritomi, Pedro Yoshito; Pellizzer, Eduardo Piza

2015-01-02

The study of short implants is relevant to the biomechanics of dental implants, and research on crown increase has implications for the daily clinic. The aim of this study was to analyze the biomechanical interactions of a singular implant-supported prosthesis of different crown heights under vertical and oblique force, using the 3-D finite element method. Six 3-D models were designed with Invesalius 3.0, Rhinoceros 3D 4.0, and Solidworks 2010 software. Each model was constructed with a mandibular segment of bone block, including an implant supporting a screwed metal-ceramic crown. The crown height was set at 10, 12.5, and 15 mm. The applied force was 200 N (axial) and 100 N (oblique). We performed an ANOVA statistical test and Tukey tests; p<0.05 was considered statistically significant. The increase of crown height did not influence the stress distribution on screw prosthetic (p>0.05) under axial load. However, crown heights of 12.5 and 15 mm caused statistically significant damage to the stress distribution of screws and to the cortical bone (p<0.001) under oblique load. High crown to implant (C/I) ratio harmed microstrain distribution on bone tissue under axial and oblique loads (p<0.001). Crown increase was a possible deleterious factor to the screws and to the different regions of bone tissue. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluating resin-enamel bonds by microshear and microtensile bond strength tests: effects of composite resin

PubMed Central

de ANDRADE, Andrea Mello; MOURA, Sandra Kiss; REIS, Alessandra; LOGUERCIO, Alessandro Dourado; GARCIA, Eugenio Jose; GRANDE, Rosa Helena Miranda

2010-01-01

Objectives The aims of this study were to evaluate the effect of resin composite (Filtek Z250 and Filtek Flow Z350) and adhesive system [(Solobond Plus, Futurabond NR (VOCO) and Adper Single Bond (3M ESPE)] on the microtensile (µTBS) and microshear bond strength (µSBS) tests on enamel, and to correlate the bond strength means between them. Material and methods Thirty-six extracted human molars were sectioned to obtain two tooth halves: one for µTBS and the other one for µSBS. Adhesive systems and resin composites were applied to the enamel ground surfaces and light-cured. After storage (37ºC/24 h) specimens were stressed (0.5 mm/ min). Fracture modes were analyzed under scanning electron microscopy. The data were analyzed using two-way ANOVA and Tukey's test (α=0.05). Results The correlation between tests was estimated with Pearson's product-moment correlation statistics (α =0.05). For both tests only the main factor resin composite was statistically significant (p<0.05). The correlation test detected a positive (r=0.91) and significant (p=0.01) correlation between the tests. Conclusions The results were more influenced by the resin type than by the adhesives. Both microbond tests seem to be positive and linearly correlated and can therefore lead to similar conclusions. PMID:21308290

Assessment of surface hardness of acrylic resins submitted to accelerated artificial aging.

PubMed

Tornavoi, D C; Agnelli, J A M; Lepri, C P; Mazzetto, M O; Botelho, A L; Soares, R G; Dos Reis, A C

2012-06-01

The aim of this study was to assess the influence of accelerated artificial aging (AAA) on the surface hardness of acrylic resins. The following three commercial brands of acrylic resins were tested: Vipi Flash (autopolymerized resin), Vipi Wave (microwave heat-polymerized resin) and Vipi Cril (conventional heat-polymerized resin). To perform the tests, 21 test specimens (65x10x3 mm) were made, 7 for each resin. Three surface hardness readings were performed for each test specimen, before and after AAA, and the means were submitted to the following tests: Kolmogorov-Smirnov (P>0.05), Levene Statistic, Two-way ANOVA, Tukey Post Hoc (P<0.05) with the SPSS Statistical Software 17.0. The analysis of the factors showed significant differences in the hardness values (P<0.05). Before aging, the autopolymerized acrylic resin Vipi Flash showed lower hardness values when compared with the heat-polymerized resin Vipi Cril (P=0.001). After aging, the 3 materials showed similar performance when compared among them. The Vipi Cril was the only one affected by AAA and showed lower hardness values after this procedure (Pp=0.003). It may be concluded that accelerated artificial aging influenced surface hardness of heat-polymerized acrylic resin Vipi Cril.

Determination of elemental composition of substance lost following wear of all-ceramic materials.

PubMed

Dündar, Mine; Artunç, Celal; Toksavul, Suna; Ozmen, Dilek; Turgan, Nevbahar

2003-01-01

The aim of this study was to test the possible elemental release of four different all-ceramic materials in a wear machine to predict results about their long-term behavior in the oral environment. Four different all-ceramic materials with different chemical compositions were selected for the wear testing. A total of 20 cylindric samples, five for each ceramic group, were prepared according to the manufacturers' instructions. These were subjected to two-body wear testing in an artificial saliva medium under a covered unit with a computer-operated wear machine. The artificial saliva solutions for each material were analyzed for the determination of amounts of sodium, potassium, calcium, magnesium, and lithium elements released from the glass-ceramic materials. The differences between and within groups were statistically analyzed with a one-way ANOVA, followed by Duncan tests. The statistical analyses revealed no significant differences among Na, K, Ca, or Mg levels (P > .05) released from the leucite-reinforced groups, while there was a significant (P < .05) increase in Li release from the lithium disilicate group. Considerable element release to the artifical saliva medium was demonstrated in short-term wear testing. The lithia-based ceramic was more prone to Li release when compared with other elements and materials.

Fulfilling the law of a single independent variable and improving the result of mathematical educational research

NASA Astrophysics Data System (ADS)

Pardimin, H.; Arcana, N.

2018-01-01

Many types of research in the field of mathematics education apply the Quasi-Experimental method and statistical analysis use t-test. Quasi-experiment has a weakness that is difficult to fulfil “the law of a single independent variable”. T-test also has a weakness that is a generalization of the conclusions obtained is less powerful. This research aimed to find ways to reduce the weaknesses of the Quasi-experimental method and improved the generalization of the research results. The method applied in the research was a non-interactive qualitative method, and the type was concept analysis. Concepts analysed are the concept of statistics, research methods of education, and research reports. The result represented a way to overcome the weaknesses of quasi-Experiments and T-test. In addition, the way was to apply a combination of Factorial Design and Balanced Design, which the authors refer to as Factorial-Balanced Design. The advantages of this design are: (1) almost fulfilling “the low of single independent variable” so no need to test the similarity of the academic ability, (2) the sample size of the experimental group and the control group became larger and equal; so it becomes robust to deal with violations of the assumptions of the ANOVA test.

Neuro-evolutionary computing paradigm for Painlevé equation-II in nonlinear optics

NASA Astrophysics Data System (ADS)

Ahmad, Iftikhar; Ahmad, Sufyan; Awais, Muhammad; Ul Islam Ahmad, Siraj; Asif Zahoor Raja, Muhammad

2018-05-01

The aim of this study is to investigate the numerical treatment of the Painlevé equation-II arising in physical models of nonlinear optics through artificial intelligence procedures by incorporating a single layer structure of neural networks optimized with genetic algorithms, sequential quadratic programming and active set techniques. We constructed a mathematical model for the nonlinear Painlevé equation-II with the help of networks by defining an error-based cost function in mean square sense. The performance of the proposed technique is validated through statistical analyses by means of the one-way ANOVA test conducted on a dataset generated by a large number of independent runs.

Physique and Performance of Young Wheelchair Basketball Players in Relation with Classification

PubMed Central

Zancanaro, Carlo

2015-01-01

The relationships among physical characteristics, performance, and functional ability classification of younger wheelchair basketball players have been barely investigated to date. The purpose of this work was to assess anthropometry, body composition, and performance in sport-specific field tests in a national sample of Italian younger wheelchair basketball players as well as to evaluate the association of these variables with the players’ functional ability classification and game-related statistics. Several anthropometric measurements were obtained for 52 out of 91 eligible players nationwide. Performance was assessed in seven sport-specific field tests (5m sprint, 20m sprint with ball, suicide, maximal pass, pass for accuracy, spot shot and lay-ups) and game-related statistics (free-throw points scored per match, two- and three-point field-goals scored per match, and their sum). Association between variables, and predictivity was assessed by correlation and regression analysis, respectively. Players were grouped into four Classes of increasing functional ability (A-D). One-way ANOVA with Bonferroni’s correction for multiple comparisons was used to assess differences between Classes. Sitting height and functional ability Class especially correlated with performance outcomes, but wheelchair basketball experience and skinfolds did not. Game-related statistics and sport-specific field-test scores all showed significant correlation with each other. Upper arm circumference and/or maximal pass and lay-ups test scores were able to explain 42 to 59% of variance in game-related statistics (P<0.001). A clear difference in performance was only found for functional ability Class A and D. Conclusion: In younger wheelchair basketball players, sitting height positively contributes to performance. The maximal pass and lay-ups test should be carefully considered in younger wheelchair basketball training plans. Functional ability Class reflects to a limited extent the actual differences in performance. PMID:26606681

Effect of monomer composition of polymer matrix on flexural properties of glass fibre-reinforced orthodontic archwire.

PubMed

Ohtonen, J; Vallittu, P K; Lassila, L V J

2013-02-01

To compare force levels obtained from glass fibre-reinforced composite (FRC) archwires. Specifically, FRC wires were compared with polymer matrices having different dimethacrylate monomer compositions. FRC material (E-glass provided by Stick Tech Ltd, Turku, Finland) with continuous unidirectional glass fibres and four different types of dimethacrylate monomer compositions for the resin matrix were tested. Cross-sectionally round FRC archwires fitting into the 0.3 mm slot of a bracket were divided into 16 groups with six specimens in each group. Glass fibres were impregnated by the manufacturer, and they were initially light-cured by hand light-curing unit or additionally post-cured in light-curing oven. The FRC archwire specimens were tested at 37°C according to a three-point bending test in dry and wet conditions using a span length of 10 mm and a crosshead speed of 1.0 mm/minute. The wires were loaded until final failure. The data were statistically analysed using analysis of variance (ANOVA). The dry FRC archwire specimens revealed higher load values than water stored ones, regardless of the polymer matrix. A majority of the FRC archwires showed higher load values after being post-cured. ANOVA revealed that the polymer matrix, curing method, and water storage had a significant effect (P < 0.05) on the flexural behaviour of the FRC archwire. Polymer matrix composition, curing method, and water storage affected the flexural properties and thus, force level and working range which could be obtained from the FRC archwire.

Improved Statistical Methods Enable Greater Sensitivity in Rhythm Detection for Genome-Wide Data

PubMed Central

Hutchison, Alan L.; Maienschein-Cline, Mark; Chiang, Andrew H.; Tabei, S. M. Ali; Gudjonson, Herman; Bahroos, Neil; Allada, Ravi; Dinner, Aaron R.

2015-01-01

Robust methods for identifying patterns of expression in genome-wide data are important for generating hypotheses regarding gene function. To this end, several analytic methods have been developed for detecting periodic patterns. We improve one such method, JTK_CYCLE, by explicitly calculating the null distribution such that it accounts for multiple hypothesis testing and by including non-sinusoidal reference waveforms. We term this method empirical JTK_CYCLE with asymmetry search, and we compare its performance to JTK_CYCLE with Bonferroni and Benjamini-Hochberg multiple hypothesis testing correction, as well as to five other methods: cyclohedron test, address reduction, stable persistence, ANOVA, and F24. We find that ANOVA, F24, and JTK_CYCLE consistently outperform the other three methods when data are limited and noisy; empirical JTK_CYCLE with asymmetry search gives the greatest sensitivity while controlling for the false discovery rate. Our analysis also provides insight into experimental design and we find that, for a fixed number of samples, better sensitivity and specificity are achieved with higher numbers of replicates than with higher sampling density. Application of the methods to detecting circadian rhythms in a metadataset of microarrays that quantify time-dependent gene expression in whole heads of Drosophila melanogaster reveals annotations that are enriched among genes with highly asymmetric waveforms. These include a wide range of oxidation reduction and metabolic genes, as well as genes with transcripts that have multiple splice forms. PMID:25793520

Comparing preseason frontal and sagittal plane plyometric programs on vertical jump height in high-school basketball players.

PubMed

King, Jeffrey A; Cipriani, Daniel J

2010-08-01

The primary purpose of this study was to evaluate whether frontal plane (FP) plyometrics, which are defined as plyometrics dominated with a lateral component, would produce similar increases in vertical jump height (VJH) compared to sagittal plane (SP) Plyometrics. Thirty-two junior varsity and varsity high-school basketball players participated in 6 weeks of plyometric training. Players participated in either FP or SP plyometrics for the entire study. Vertical jump height was measured on 3 occasions: preintervention (baseline), at week 3 of preparatory training, and at week 6 of training. Descriptive statistics were calculated for VJH. A 2-way analysis of variance (ANOVA) with repeated measures was used to test the difference in mean vertical jump scores using FP and SP training modalities. Results showed a significant effect over time for vertical jump (p < 0.001). Moreover, a significant time by protocol interaction was noted (p < 0.032). A 1-way ANOVA demonstrated that only the SP group demonstrated improvements over time, in VJH, p < 0.05. The FP group did not improve statistically. The data from this study suggest that FP plyometric training did not have a significant effect on VJH and significant improvement in VJH was seen in subjects participating in SP plyometrics thus reinforcing the specificity principle of training. However, coaches should implement both types of plyometrics because both training modalities can improve power and quickness among basketball players.

Analysis of half diallel mating designs I: a practical analysis procedure for ANOVA approximation.

Treesearch

G.R. Johnson; J.N. King

1998-01-01

Procedures to analyze half-diallel mating designs using the SAS statistical package are presented. The procedure requires two runs of PROC and VARCOMP and results in estimates of additive and non-additive genetic variation. The procedures described can be modified to work on most statistical software packages which can compute variance component estimates. The...

Fracture resistance of aluminium oxide and lithium disilicate-based crowns using different luting cements: an in vitro study.

PubMed

Al-Wahadni, Ahed M; Hussey, David L; Grey, Nicholas; Hatamleh, Muhanad M

2009-03-01

The aim of this study was to investigate the fracture resistance of two types of ceramic crowns cemented with two different cements. Forty premolar crowns were fabricated using lithium-disilicate (IPS Empress-2) and glass-infiltrated aluminium-oxide (In-Ceram) ceramic systems. The crowns were divided into four groups (n=10) with Group 1 (IPS Empress-2) and Group 2 (In-Ceram) cemented with glass ionomer cement. Group 3 (IPS Empress-2) and Group 4 (In-Ceram) were cemented with resin cement. Crowns were tested in a universal testing machine at a compressive-load speed of 10 mm/min. Fracture modes were grouped into five categories. One way analysis of variance (ANOVA) and Bonferroni post-hoc tests were used to detect statistical significances (p<0.05). The mean (SD) fracture resistance (Newtons) for Groups 1 to 4 were: 245.35 (82.69), 390.48 (67.03), 269.69 (10.33), and 418.36 (26.24). The cement type had no statistical significant effect (p>0.05) on fracture resistance within each ceramic system tested. In-Ceram crowns cemented with either glass ionomer or resin cements exhibited a statistically significantly higher fracture-resistance than IPS Empress-2 crowns (p<0.05). Minimal fracture in the test crowns was the common mode exhibited. Fracture resistance of IPS Empress-2 and In-Ceram crowns was not affected by the type of cement used for luting. Both In-Ceram and IPS Empress-2 crowns can be successfully luted with the cements tested with In-Ceram exhibiting higher fracture resistance than IPS Empress-2.

Predictive capacity of a non-radioisotopic local lymph node assay using flow cytometry, LLNA:BrdU-FCM: Comparison of a cutoff approach and inferential statistics.

PubMed

Kim, Da-Eun; Yang, Hyeri; Jang, Won-Hee; Jung, Kyoung-Mi; Park, Miyoung; Choi, Jin Kyu; Jung, Mi-Sook; Jeon, Eun-Young; Heo, Yong; Yeo, Kyung-Wook; Jo, Ji-Hoon; Park, Jung Eun; Sohn, Soo Jung; Kim, Tae Sung; Ahn, Il Young; Jeong, Tae-Cheon; Lim, Kyung-Min; Bae, SeungJin

2016-01-01

In order for a novel test method to be applied for regulatory purposes, its reliability and relevance, i.e., reproducibility and predictive capacity, must be demonstrated. Here, we examine the predictive capacity of a novel non-radioisotopic local lymph node assay, LLNA:BrdU-FCM (5-bromo-2'-deoxyuridine-flow cytometry), with a cutoff approach and inferential statistics as a prediction model. 22 reference substances in OECD TG429 were tested with a concurrent positive control, hexylcinnamaldehyde 25%(PC), and the stimulation index (SI) representing the fold increase in lymph node cells over the vehicle control was obtained. The optimal cutoff SI (2.7≤cutoff <3.5), with respect to predictive capacity, was obtained by a receiver operating characteristic curve, which produced 90.9% accuracy for the 22 substances. To address the inter-test variability in responsiveness, SI values standardized with PC were employed to obtain the optimal percentage cutoff (42.6≤cutoff <57.3% of PC), which produced 86.4% accuracy. A test substance may be diagnosed as a sensitizer if a statistically significant increase in SI is elicited. The parametric one-sided t-test and non-parametric Wilcoxon rank-sum test produced 77.3% accuracy. Similarly, a test substance could be defined as a sensitizer if the SI means of the vehicle control, and of the low, middle, and high concentrations were statistically significantly different, which was tested using ANOVA or Kruskal-Wallis, with post hoc analysis, Dunnett, or DSCF (Dwass-Steel-Critchlow-Fligner), respectively, depending on the equal variance test, producing 81.8% accuracy. The absolute SI-based cutoff approach produced the best predictive capacity, however the discordant decisions between prediction models need to be examined further. Copyright © 2015 Elsevier Inc. All rights reserved.

Trend-surface analysis of morphometric parameters: A case study in southeastern Brazil

NASA Astrophysics Data System (ADS)

Grohmann, Carlos Henrique

2005-10-01

Trend-surface analysis was carried out on data from morphometric parameters isobase and hydraulic gradient. The study area, located in the eastern border of Quadrilátero Ferrífero, southeastern Brazil, presents four main geomorphological units, one characterized by fluvial dissection, two of mountainous relief, with a scarp of hundreds of meters of fall between them, and a flat plateau in the central portion of the fluvially dissected terrains. Morphometric maps were evaluated in GRASS-GIS and statistics were made on R statistical language, using the spatial package. Analysis of variance (ANOVA) was made to test the significance of each surface and the significance of increasing polynomial degree. The best results were achieved with sixth-order surface for isobase and second-order surface for hydraulic gradient. Shape and orientation of residual maps contours for selected trends were compared with structures inferred from several morphometric maps, and a good correlation is present.

Correlation of cardiorespiratory fitness with risk factors for cardiovascular disease in children with type 1 diabetes mellitus.

PubMed

Miculis, Cristiane P; de Campos, Wagner; Gasparotto, Guilherme S; Silva, Michael P; Mascarenhas, Luis P; Boguszewski, Margaret C S

2012-01-01

The objective of this study was to correlate CRF with cardiovascular risk factors in T1DM children. Fifty children and adolescents aged between 9 and 17 years with no diabetes complications and a mean diabetes duration of 4.6 years were selected. Antropometric, sexual maturation and blood pressure data were evaluated. CRF level was assessed with a 20-m shuttle run test. Laboratory tests were performed to verify fasting lipids and glycated hemoglobin. Statistical analyses were made with Pearson partial correlation, t test, and one-way ANOVA, with p≤0.05. After adjustment for body adiposity and sexual maturity, inverse correlations among CRF and TC, TG, TC/HDL-C, TG/HDL-C, non-HDL-C, and SBP were statistically significant. Variables differing by sex included weight Z score, BMI Z score, skinfold thickness, percentage of body fat, and DBP. Boys had higher CRF compared to girls. CRF and TC differed significantly by sexual maturation status. An inverse and significant relationship between CRF and most lipid profile's components and SBP in poor controlled T1DM children and adolescents was found, independently of body adiposity. Copyright © 2012 Elsevier Inc. All rights reserved.

Effectiveness of Conceptual Change Text-oriented Instruction on Students' Understanding of Energy in Chemical Reactions

NASA Astrophysics Data System (ADS)

Taştan, Özgecan; Yalçınkaya, Eylem; Boz, Yezdan

2008-10-01

The aim of this study is to compare the effectiveness of conceptual change text instruction (CCT) in the context of energy in chemical reactions. The subjects of the study were 60, 10th grade students at a high school, who were in two different classes and taught by the same teacher. One of the classes was randomly selected as the experimental group in which CCT instruction was applied, and the other as the control group in which traditional teaching method was used. The data were obtained through the use of Energy Concept Test (ECT), the Attitude Scale towards Chemistry (ASC) and Science Process Skill Test (SPST). In order to find out the effect of the conceptual change text on students' learning of energy concept, independent sample t-tests, ANCOVA (analysis of covariance) and ANOVA (analysis of variance) were used. Results revealed that there was a statistically significant mean difference between the experimental and control group in terms of students' ECT total mean scores; however, there was no statistically significant difference between the experimental and control group in terms of students' attitude towards chemistry. These findings suggest that conceptual change text instruction enhances the understanding and achievement.

Physical fitness profile of professional Italian firefighters: differences among age groups.

PubMed

Perroni, Fabrizio; Cignitti, Lamberto; Cortis, Cristina; Capranica, Laura

2014-05-01

Firefighters perform many tasks which require a high level of fitness and their personal safety may be compromised by the physiological aging process. The aim of the study was to evaluate strength (bench-press), power (countermovement jump), sprint (20 m) and endurance (with and without Self Contained Breathing Apparatus - S.C.B.A.) of 161 Italian firefighters recruits in relation to age groups (<25 yr; 26-30 yr; 31-35 yr; 36-40 yr; 41-42 yr). Descriptive statistics and an ANOVA were calculated to provide the physical fitness profile for each parameter and to assess differences (p < 0.05) among age groups. Anthropometric values showed an age-effect for height and BMI, while performances values showed statistical differences for strength, power, sprint tests and endurance test with S.C.B.A. Wearing the S.C.B.A., 14% of all recruits failed to complete the endurance test. We propose that the firefighters should participate in an assessment of work capacity and specific fitness programs aimed to maintain an optimal fitness level for all ages. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Fracture loads of all-ceramic crowns under wet and dry fatigue conditions.

PubMed

Borges, Gilberto A; Caldas, Danilo; Taskonak, Burak; Yan, Jiahau; Sobrinho, Lourenco Correr; de Oliveira, Wildomar José

2009-12-01

The aim of this study was to test the hypothesis that fracture loads of fatigued dental ceramic crowns are affected by testing environment and luting cement. One hundred and eighty crowns were prepared from bovine teeth using a lathe. Ceramic crowns were prepared from three types of ceramic systems: an alumina-infiltrated ceramic, a lithia-disilicate-based glass ceramic, and a leucite-reinforced ceramic. For each ceramic system, 30 crowns were cemented with a composite resin cement, and the remaining 30 with a resin-modified glass ionomer cement. For each ceramic system and cement, ten specimens were loaded to fracture without fatiguing. A second group (n = 10) was subjected to cyclic fatigue and fracture tested in a dry environment, and a third group (n = 10) was fatigued and fractured in distilled water. The results were statistically analyzed using one-way ANOVA and Tukey HSD test. The fracture loads of ceramic crowns decreased significantly after cyclic fatigue loading (p

Estimation and correlation of salivary thiocyanate levels in periodontally healthy subjects, smokers, nonsmokers, and gutka-chewers with chronic periodontitis.

PubMed

Hegde, Shashikanth; Chatterjee, Elashri; Rajesh, K S; Kumar, M S Arun

2016-01-01

This study was conducted to estimate and correlate salivary thiocyanate (SCN) levels in periodontally healthy subjects, smokers, nonsmokers, and gutka-chewers with chronic periodontitis. The study population consisted of 40 systemically healthy subjects in the age group of 18-55 years that was further divided into four groups: Control, smokers, nonsmokers, and gutka-chewers with chronic periodontitis. Gingival index (GI) (Loe and Silness-1963), probing depth (PD), clinical attachment loss was assessed. Estimation of SCN was performed by ultraviolet spectrophotometer at 447 nm wavelength. Statistical analysis was performed using the one-way ANOVAs Welch test and Pearson's correlation test using SPSS version 17 software. Results showed statistically significant increase in SCN levels in smokers as compared to gutka-chewers with chronic periodontitis, control, and nonsmokers with chronic periodontitis subjects. Significantly higher PD and loss of attachment were seen in smokers group compared with other groups. A negative correlation observed between the GI and thiocyanate levels. The present study revealed a significant increase in SCN levels in smokers with periodontitis as compared to nonsmokers.

Effect of overglazed and polished surface finishes on the compressive fracture strength of machinable ceramic materials.

PubMed

Asai, Tetsuya; Kazama, Ryunosuke; Fukushima, Masayoshi; Okiji, Takashi

2010-11-01

Controversy prevails over the effect of overglazing on the fracture strength of ceramic materials. Therefore, the effects of different surface finishes on the compressive fracture strength of machinable ceramic materials were investigated in this study. Plates prepared from four commercial brands of ceramic materials were either surface-polished or overglazed (n=10 per ceramic material for each surface finish), and bonded to flat surfaces of human dentin using a resin cement. Loads at failure were determined and statistically analyzed using two-way ANOVA and Bonferroni test. Although no statistical differences in load value were detected between polished and overglazed groups (p>0.05), the fracture load of Vita Mark II was significantly lower than those of ProCAD and IPS Empress CAD, whereas that of IPS e.max CAD was significantly higher than the latter two ceramic materials (p<0.05). It was concluded that overglazed and polished surfaces produced similar compressive fracture strengths irrespective of the machinable ceramic material tested, and that fracture strength was material-dependent.

Comparison of mesiodistal tooth widths in Caucasian, African and Japanese individuals with Brazilian ancestry and normal occlusion.

PubMed

Fernandes, Thais Maria Freire; Sathler, Renata; Natalício, Gabriela Letícia; Henriques, José Fernando Castanha; Pinzan, Arnaldo

2013-01-01

To observe the presence of sexual dimorphism and compare the mesiodistal width of the teeth in Caucasian, African and Japanese individuals with Brazilian ancestry not orthodontically treated and with normal occlusion. One hundred pairs of dental casts were used. It was measured, from first molar to first molar in both arches, the teeth's mesiodistal widths, using a digital caliper. For the statistical analysis of results Kolmogorov-Smirnov, t test, ANOVA and Tukey's test (p < 0.05) were used. Sexual dimorphism occurred on the three evaluated groups, and the highest mesiodistal widths were found in males. There was statistically significant difference between racial groups in all evaluated teeth in males. However, in females, this same difference was found only on upper lateral incisor and first molar; and lower lateral incisor, canine, first premolar and first molar. Most of mesiodistal measures present particular characteristics in relation to gender, with higher values for males, and to race, with a tendency for African to present greater mesiodistal distance of the teeth, followed by Japanese and Caucasians, respectively, important for the correct diagnosis and orthodontic planning.

Diametral tensile strength and film thickness of an experimental dental luting agent derived from castor oil.

PubMed

Carmello, Juliana Cabrini; Fais, Laiza Maria Grassi; Ribeiro, Lígia Nunes de Moraes; Claro Neto, Salvador; Guaglianoni, Dalton Geraldo; Pinelli, Lígia Antunes Pereira

2012-02-01

The need to develop new dental luting agents in order to improve the success of treatments has greatly motivated research. The aim of this study was to evaluate the diametral tensile strength (DTS) and film thickness (FT) of an experimental dental luting agent derived from castor oil (COP) with or without addition of different quantities of filler (calcium carbonate - CaCO3). Eighty specimens were manufactured (DTS N=40; FT N=40) and divided into 4 groups: Pure COP; COP 10%; COP 50% and zinc phosphate (control). The cements were mixed according to the manufacturers' recommendations and submitted to the tests. The DTS test was performed in the MTS 810 testing machine (10 KN, 0.5 mm/min). For FT test, the cements were sandwiched between two glass plates (2 cm²) and a load of 15 kg was applied vertically on the top of the specimen for 10 min. The data were analyzed by means of one-way ANOVA and Tukey's test (α=0.05). The values of DTS (MPa) were: Pure COP- 10.94 ± 1.30; COP 10%- 30.06 ± 0.64; COP 50%- 29.87 ± 0.27; zinc phosphate- 4.88 ± 0.96. The values of FT (µm) were: Pure COP- 31.09 ± 3.16; COP 10%- 17.05 ± 4.83; COP 50%- 13.03 ± 4.83; Zinc Phosphate- 20.00 ± 0.12. One-way ANOVA showed statistically significant differences among the groups (DTS - p=1.01E-40; FT - p=2.4E-10). The experimental dental luting agent with 50% of filler showed the best diametral tensile strength and film thickness.

Diametral tensile strength and film thickness of an experimental dental luting agent derived from castor oil

PubMed Central

CARMELLO, Juliana Cabrini; FAIS, Laiza Maria Grassi; RIBEIRO, Lígia Nunes de Moraes; CLARO NETO, Salvador; GUAGLIANONI, Dalton Geraldo; PINELLI, Lígia Antunes Pereira

2012-01-01

The need to develop new dental luting agents in order to improve the success of treatments has greatly motivated research. Objective The aim of this study was to evaluate the diametral tensile strength (DTS) and film thickness (FT) of an experimental dental luting agent derived from castor oil (COP) with or without addition of different quantities of filler (calcium carbonate - CaCO3). Material and Methods Eighty specimens were manufactured (DTS N=40; FT N=40) and divided into 4 groups: Pure COP; COP 10%; COP 50% and zinc phosphate (control). The cements were mixed according to the manufacturers' recommendations and submitted to the tests. The DTS test was performed in the MTS 810 testing machine (10 KN, 0.5 mm/min). For FT test, the cements were sandwiched between two glass plates (2 cm2) and a load of 15 kg was applied vertically on the top of the specimen for 10 min. The data were analyzed by means of one-way ANOVA and Tukey's test (α=0.05). Results The values of DTS (MPa) were: Pure COP- 10.94±1.30; COP 10%- 30.06±0.64; COP 50%- 29.87±0.27; zinc phosphate- 4.88±0.96. The values of FT (µm) were: Pure COP- 31.09±3.16; COP 10%- 17.05±4.83; COP 50%- 13.03±4.83; Zinc Phosphate- 20.00±0.12. One-way ANOVA showed statistically significant differences among the groups (DTS - p=1.01E-40; FT - p=2.4E-10). Conclusion The experimental dental luting agent with 50% of filler showed the best diametral tensile strength and film thickness. PMID:22437672

Digital versus conventional techniques for pattern fabrication of implant-supported frameworks.

PubMed

Alikhasi, Marzieh; Rohanian, Ahmad; Ghodsi, Safoura; Kolde, Amin Mohammadpour

2018-01-01

The aim of this experimental study was to compare retention of frameworks cast from wax patterns fabricated by three different methods. Thirty-six implant analogs connected to one-piece abutments were divided randomly into three groups according to the wax pattern fabrication method ( n = 12). Computer-aided design/computer-aided manufacturing (CAD/CAM) milling machine, three-dimensional printer, and conventional technique were used for fabrication of waxing patterns. All laboratory procedures were performed by an expert-reliable technician to eliminate intra-operator bias. The wax patterns were cast, finished, and seated on related abutment analogs. The number of adjustment times was recorded and analyzed by Kruskal-Wallis test. Frameworks were cemented on the corresponding analogs with zinc phosphate cement and tensile resistance test was used to measure retention value. One-way analysis of variance (ANOVA) and post hoc Tukey tests were used for statistical analysis. Level of significance was set at P < 0.05. The mean retentive values of 680.36 ± 21.93 N, 440.48 ± 85.98 N, and 407.23 ± 67.48 N were recorded for CAD/CAM, rapid prototyping, and conventional group, respectively. One-way ANOVA test revealed significant differences among the three groups ( P < 0.001). The post hoc Tukey test showed significantly higher retention for CAD/CAM group ( P < 0.001), while there was no significant difference between the two other groups ( P = 0.54). CAD/CAM group required significantly more adjustments ( P < 0.001). CAD/CAM-fabricated wax patterns showed significantly higher retention for implant-supported cement-retained frameworks; this could be a valuable help when there are limitations in the retention of single-unit implant restorations.

Statistics in the pharmacy literature.

PubMed

Lee, Charlene M; Soin, Herpreet K; Einarson, Thomas R

2004-09-01

Research in statistical methods is essential for maintenance of high quality of the published literature. To update previous reports of the types and frequencies of statistical terms and procedures in research studies of selected professional pharmacy journals. We obtained all research articles published in 2001 in 6 journals: American Journal of Health-System Pharmacy, The Annals of Pharmacotherapy, Canadian Journal of Hospital Pharmacy, Formulary, Hospital Pharmacy, and Journal of the American Pharmaceutical Association. Two independent reviewers identified and recorded descriptive and inferential statistical terms/procedures found in the methods, results, and discussion sections of each article. Results were determined by tallying the total number of times, as well as the percentage, that each statistical term or procedure appeared in the articles. One hundred forty-four articles were included. Ninety-eight percent employed descriptive statistics; of these, 28% used only descriptive statistics. The most common descriptive statistical terms were percentage (90%), mean (74%), standard deviation (58%), and range (46%). Sixty-nine percent of the articles used inferential statistics, the most frequent being chi(2) (33%), Student's t-test (26%), Pearson's correlation coefficient r (18%), ANOVA (14%), and logistic regression (11%). Statistical terms and procedures were found in nearly all of the research articles published in pharmacy journals. Thus, pharmacy education should aim to provide current and future pharmacists with an understanding of the common statistical terms and procedures identified to facilitate the appropriate appraisal and consequential utilization of the information available in research articles.

A quantitative study of the summer slide in science of elementary school students

NASA Astrophysics Data System (ADS)

Donovan, Giovanna Guadagno

Concerned parents and educators agree children learn best when the rhythm of instruction is continuous with practice and application of skills. Long summer breaks may interrupt the flow of formal school learning leading some students to forget previous instruction. A review of the previous school work is generally required in the fall upon return from the summer vacation. Investigating summer vacation and equity issues, Jamar (1994) noted that more affluent students may "return to school in the fall with a considerable educational advantage over their less advantaged peers as a result of either additional school-related learning, or lower levels of forgetting, over the summer months (p. 1)". The population of 402 fifth grade students from a suburban New England school district participated in this study. The district administered the science subtest of the TerraNova 2 (TN2) assessment in late May 2007 (pre-test data) and in September 2007 (post-test data). These archived data, including gender and student socioeconomic status (SES) levels (as referenced by free or reduced lunch status), were analyzed for an ex-post facto causal comparison study to identify the phenomenon of summer slide in science of fifth graders enrolled in six elementary schools. The ANOVA statistical model was used calculating the repeated measures factor of time (pre/post summer vacation) on the science content area. Subsequent two-way ANOVAS, with one repeated-measures factor (time of testing) explored the existence of similar/different patterns by gender and by SES levels. Two questions guided this study. First, does the summer slide phenomenon exist in science education? Second, if the summer slide in science phenomenon exists in science education, then does SES impact it? Does the summer slide in science phenomenon differ between genders? Findings suggest that the summer slide phenomenon exists in science; SES and gender does not affect the overall science test scores. However, SES impacts the summer slide phenomenon in science but gender does not impact summer slide in science. Furthermore, the school does not statistically impact the summer slide phenomenon in science and the impact of school does not differ across SES and genders.

Management of Chronic Periodontitis Using Chlorhexidine Chip and Diode Laser-A Clinical Study

PubMed Central

Ambooken, Majo; Mathew, Jayan Jacob; Issac, Annie Valayil; Kunju, Ajithkumar Parachalil; Parameshwaran, Renjith Athirkandathil

2016-01-01

Introduction The use of adjuncts like chlorhexidine local delivery and diode laser decontamination have been found to improve the clinical outcomes of scaling and root planing in non-surgical periodontal therapy in patients with chronic periodontitis. Aim To evaluate the effects of diode laser and chlorhexidine chip as adjuncts to scaling and root planing in the management of chronic periodontitis. The objective is to evaluate the outcome of chlorhexidine chip and diode laser as adjuncts to scaling and root planing on clinical parameters like Plaque Index, Gingival Index, probing pocket depth and clinical attachment level. Study and Design Department of Periodontics. Randomized clinical trial with split mouth design. Materials and Methods Fifteen chronic periodontitis patients having a probing pocket depth of 5mm-7mm on at least one interproximal site in each quadrant of the mouth were included in the study. After initial treatment, four sites in each patient were randomly subjected to scaling and root planing (control), chlorhexidine chip application (CHX chip group), diode laser (810 nm) decontamination (Diode laser group) or combination of both (Diode laser and chip group). Plaque Index (PI), Gingival Index (GI), probing pocket depth (PPD) and clinical attachment level (CAL) were assessed at baseline, one month and three months. Statistical analysis Results were statistically analysed using paired T test, one-way ANOVA, Tukey’s HSD test and repeated measure ANOVA. Results Post-treatment, the test and control sites showed a statistically significant reduction in PI, GI, PPD, and CAL. After three months, a mean PPD reduction of 1.47±0.52 mm in control group, 1.40±0.83 mm in diode laser group, 2.67±0.62 mm in CHX group, and 2.80± 0.77 mm in combination group was seen. The mean gain in CAL were 1.47±0.52 mm in the control group, 1.40±0.83 mm in diode laser group, 2.67± 0.49 mm in CHX group and 2.67± 0.82 mm in combination group respectively. The differences in PPD reduction and CAL gain between control group and CHX chip and combination groups were statistically significant (p<0.05) at three months, whereas, the diode laser group did not show any significant difference from the control group. Conclusion Chlorhexidine local delivery alone or in combination with diode laser decontamination is effective in reducing probing pocket depth and improving clinical attachment levels when used as adjuncts to scaling and root planing in non-surgical periodontal therapy of patients with chronic periodontitis. PMID:27190958

Psychometrics of a brief measure of emotional self-efficacy among adolescents from the United States.

PubMed

Valois, Robert F; Zullig, Keith J

2013-10-01

Preliminary data were collected to evaluate the psychometric properties of an emotional self-efficacy (ESE) measure in a sample of 3836 public high school adolescents who completed the Centers for Disease Control and Prevention (CDC) Youth Risk Behavior Survey in South Carolina. Principal axis factor analysis was followed by a 4-way between-groups analysis of variance (ANOVA) testing for differences in total score means on selected demographic estimates and their interactions. Relationships between total score and selected risk behaviors were examined through a series of 1-way ANOVA procedures and subsequent Tukey Honest Significant Difference (HSD) tests. Factor analysis results suggested that a 1-factor model best explained factor structure of the scale items (factor loadings .64 to .71, eigenvalue = 3.24, h(2)  = .46). Girls reported a significantly higher mean total ESE rating than boys; White students reported a significantly higher mean total ESE rating than Black students. Statistically significant lower mean total ESE ratings were also noted for those who reported physical fighting, lifetime alcohol use, and sexual intercourse. This 7-item scale is a reliable measure and could aid school health researchers and mental health practitioners in psychosocial screening and as an outcome of social and emotional learning as a brief measure of adolescent ESE. © 2013, American School Health Association.

Effect of clearfil protect bond and transbond plus self-etch primer on shear bond strength of orthodontic brackets

PubMed Central

Raji, S. Hamid; Ghorbanipour, Reza; Majdzade, Fateme

2011-01-01

Background: The aim of this study was to evaluate the shear bond strength of an antimicrobial and fluoride-releasing self-etch primer (clearfil protect bond) and compare it with transbond plus self-etch primer and conventional acid etching and priming system. Materials and Methods: Forty-eight extracted human premolars were divided randomly to three groups. In group 1, the teeth were bonded with conventional acid etching and priming method. In group 2, the teeth were bonded with clearfil protect bond self-etch primer, and transbond plus self-etch primer was used to bond the teeth in group 3. The samples were stored in 37°C distilled water and thermocycled. Then, the SBS of the sample was evaluated with Zwick testing machine. Descriptive statistics and the analysis of variances (ANOVA) and Tukey's test and Kruskal-Wallis were used to analyze the data. Results: The results of the ANOVA showed that the mean of group 3 was significantly lower than that of other groups. Most of the sample showed a pattern of failure within the adhesive resin. Conclusion: The shear bond strength of clearfil protect bond and transbond plus self-etch primer was enough for bonding the orthodontic brackets. The mode of failure of bonded brackets with these two self-etch primers is safe for enamel. PMID:23372605

Enrichment with Wood Blocks Does Not Affect Toxicity Assessment in an Exploratory Toxicology Model Using Sprague–Dawley Rats

PubMed Central

Ditewig, Amy C; Bratcher, Natalie A; Davila, Donna R; Dayton, Brian D; Ebert, Paige; Lesuisse, Philippe; Liguori, Michael J; Wetter, Jill M; Yang, Hyuna; Buck, Wayne R

2014-01-01

Environmental enrichment in rodents may improve animal well-being but can affect neurologic development, immune system function, and aging. We tested the hypothesis that wood block enrichment affects the interpretation of traditional and transcriptomic endpoints in an exploratory toxicology testing model using a well-characterized reference compound, cyclophosphamide. ANOVA was performed to distinguish effects of wood block enrichment separate from effects of 40 mg/kg cyclophosphamide treatment. Biologically relevant and statistically significant effects of wood block enrichment occurred only for body weight gain. ANOVA demonstrated the expected effects of cyclophosphamide on food consumption, spleen weight, and hematology. According to transcriptomic endpoints, cyclophosphamide induced fewer changes in gene expression in liver than in spleen. Splenic transcriptomic pathways affected by cyclophosphamide included: iron hemostasis; vascular tissue angiotensin system; hepatic stellate cell activation and fibrosis; complement activation; TGFβ-induced hypertrophy and fibrosis; monocytes, macrophages, and atherosclerosis; and platelet activation. Changes in these pathways due to cyclophosphamide treatment were consistent with bone marrow toxicity regardless of enrichment. In a second study, neither enrichment nor type of cage flooring altered body weight or food consumption over a 28-d period after the first week. In conclusion, wood block enrichment did not interfere with a typical exploratory toxicology study; the effects of ingested wood on drug level kinetics may require further consideration. PMID:24827566

Comparative Evaluation of Shear Bond Strength of Three Commercially Available Glass Ionomer Cements in Primary Teeth

PubMed Central

Murthy, S Srinivasa; Murthy, Gargi S

2015-01-01

Background: This study aims to comparatively evaluate the shear bond strength (SBS) of three commercially available glass ionomer cements - Miracle Mix (MM) (GC America Inc., Alsip, USA), Ketac Molar (KM) (3M Corp., Minnesota, USA) and amalgomer CR (AM) (Advanced Healthcare Ltd., Kent, England) in primary teeth and later examine the mode of the adhesive failure at the interface. Materials and Methods: Totally, 90 extracted sound primary molars were selected, and dentin on the buccal surface of crowns was exposed. Specimens were randomly assigned into three groups according to the restorative materials being tested. SBS tests were performed, and the obtained values were statistically analyzed using ANOVA and Tukey tests (P < 0.05). SBS mean values on were recorded in megapascals (MPa) and the mode of failure was assessed using a scanning electron microscope. Results: SBS (in MPa) was - MM-5.39, KM-4.84, AM-6.38. The predominant failure mode was cohesive. Conclusion: Amalgomer CR exhibited statistically significant higher SBS of 6.38 MPa to primary teeth and has better adhesion to the primary teeth compared to the other test materials and can be considered as a restorative material in pediatric dentistry. However, the results of this study should be corroborated with further investigation to reach a definitive conclusion. PMID:26464550

Analysis of residual stress and hardness in regions of pre-manufactured and manual bends in fixation plates for maxillary advancement.

PubMed

Araújo, Marcelo Marotta; Lauria, Andrezza; Mendes, Marcelo Breno Meneses; Claro, Ana Paula Rosifini Alves; Claro, Cristiane Aparecida de Assis; Moreira, Roger William Fernandes

2015-12-01

The aim of this study was to analyze, through Vickers hardness test and photoelasticity analysis, pre-bent areas, manually bent areas, and areas without bends of 10-mm advancement pre-bent titanium plates (Leibinger system). The work was divided into three groups: group I-region without bend, group II-region of 90° manual bend, and group III-region of 90° pre-fabricated bends. All the materials were evaluated through hardness analysis by the Vickers hardness test, stress analysis by residual images obtained in a polariscope, and photoelastic analysis by reflection during the manual bending. The data obtained from the hardness tests were statistically analyzed using ANOVA and Tukey's tests at a significance level of 5 %. The pre-bent plate (group III) showed hardness means statistically significantly higher (P < 0.05) than those of the other groups (I-region without bends, II-90° manually bent region). Through the study of photoelastic reflection, it was possible to identify that the stress gradually increased, reaching a pink color (1.81 δ / λ), as the bending was performed. A general analysis of the results showed that the bent plate region of pre-bent titanium presented the best results.

kruX: matrix-based non-parametric eQTL discovery

PubMed Central

2014-01-01

Background The Kruskal-Wallis test is a popular non-parametric statistical test for identifying expression quantitative trait loci (eQTLs) from genome-wide data due to its robustness against variations in the underlying genetic model and expression trait distribution, but testing billions of marker-trait combinations one-by-one can become computationally prohibitive. Results We developed kruX, an algorithm implemented in Matlab, Python and R that uses matrix multiplications to simultaneously calculate the Kruskal-Wallis test statistic for several millions of marker-trait combinations at once. KruX is more than ten thousand times faster than computing associations one-by-one on a typical human dataset. We used kruX and a dataset of more than 500k SNPs and 20k expression traits measured in 102 human blood samples to compare eQTLs detected by the Kruskal-Wallis test to eQTLs detected by the parametric ANOVA and linear model methods. We found that the Kruskal-Wallis test is more robust against data outliers and heterogeneous genotype group sizes and detects a higher proportion of non-linear associations, but is more conservative for calling additive linear associations. Conclusion kruX enables the use of robust non-parametric methods for massive eQTL mapping without the need for a high-performance computing infrastructure and is freely available from http://krux.googlecode.com. PMID:24423115

Quantitative knowledge acquisition for expert systems

NASA Technical Reports Server (NTRS)

Belkin, Brenda L.; Stengel, Robert F.

1991-01-01

A common problem in the design of expert systems is the definition of rules from data obtained in system operation or simulation. While it is relatively easy to collect data and to log the comments of human operators engaged in experiments, generalizing such information to a set of rules has not previously been a direct task. A statistical method is presented for generating rule bases from numerical data, motivated by an example based on aircraft navigation with multiple sensors. The specific objective is to design an expert system that selects a satisfactory suite of measurements from a dissimilar, redundant set, given an arbitrary navigation geometry and possible sensor failures. The systematic development is described of a Navigation Sensor Management (NSM) Expert System from Kalman Filter convariance data. The method invokes two statistical techniques: Analysis of Variance (ANOVA) and the ID3 Algorithm. The ANOVA technique indicates whether variations of problem parameters give statistically different covariance results, and the ID3 algorithms identifies the relationships between the problem parameters using probabilistic knowledge extracted from a simulation example set. Both are detailed.

Comparison of diffusion-weighted MRI acquisition techniques for normal pancreas at 3.0 Tesla.

PubMed

Yao, Xiu-Zhong; Kuang, Tiantao; Wu, Li; Feng, Hao; Liu, Hao; Cheng, Wei-Zhong; Rao, Sheng-Xiang; Wang, He; Zeng, Meng-Su

2014-01-01

We aimed to optimize diffusion-weighted imaging (DWI) acquisitions for normal pancreas at 3.0 Tesla. Thirty healthy volunteers were examined using four DWI acquisition techniques with b values of 0 and 600 s/mm2 at 3.0 Tesla, including breath-hold DWI, respiratory-triggered DWI, respiratory-triggered DWI with inversion recovery (IR), and free-breathing DWI with IR. Artifacts, signal-to-noise ratio (SNR) and apparent diffusion coefficient (ADC) of normal pancreas were statistically evaluated among different DWI acquisitions. Statistical differences were noticed in artifacts, SNR, and ADC values of normal pancreas among different DWI acquisitions by ANOVA (P <0.001). Normal pancreas imaging had the lowest artifact in respiratory-triggered DWI with IR, the highest SNR in respiratory-triggered DWI, and the highest ADC value in free-breathing DWI with IR. The head, body, and tail of normal pancreas had statistically different ADC values on each DWI acquisition by ANOVA (P < 0.05). The highest image quality for normal pancreas was obtained using respiratory-triggered DWI with IR. Normal pancreas displayed inhomogeneous ADC values along the head, body, and tail structures.

T2 relaxation time is related to liver fibrosis severity

PubMed Central

Siqueira, Luiz; Uppal, Ritika; Alford, Jamu; Fuchs, Bryan C.; Yamada, Suguru; Tanabe, Kenneth; Chung, Raymond T.; Lauwers, Gregory; Chew, Michael L.; Boland, Giles W.; Sahani, Duhyant V.; Vangel, Mark; Hahn, Peter F.; Caravan, Peter

2016-01-01

Background The grading of liver fibrosis relies on liver biopsy. Imaging techniques, including elastography and relaxometric, techniques have had varying success in diagnosing moderate fibrosis. The goal of this study was to determine if there is a relationship between the T2-relaxation time of hepatic parenchyma and the histologic grade of liver fibrosis in patients with hepatitis C undergoing both routine, liver MRI and liver biopsy, and to validate our methodology with phantoms and in a rat model of liver fibrosis. Methods This study is composed of three parts: (I) 123 patients who underwent both routine, clinical liver MRI and biopsy within a 6-month period, between July 1999 and January 2010 were enrolled in a retrospective study. MR imaging was performed at 1.5 T using dual-echo turbo-spin echo equivalent pulse sequence. T2 relaxation time of liver parenchyma in patients was calculated by mono-exponential fit of a region of interest (ROI) within the right lobe correlating to histopathologic grading (Ishak 0–6) and routine serum liver inflammation [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)]. Statistical comparison was performed using ordinary logistic and ordinal logistic regression and ANOVA comparing T2 to Ishak fibrosis without and using AST and ALT as covariates; (II) a phantom was prepared using serial dilutions of dextran coated magnetic iron oxide nanoparticles. T2 weighed imaging was performed by comparing a dual echo fast spin echo sequence to a Carr-Purcell-Meigboom-Gill (CPMG) multi-echo sequence at 1.5 T. Statistical comparison was performed using a paired t-test; (III) male Wistar rats receiving weekly intraperitoneal injections of phosphate buffer solution (PBS) control (n=4 rats); diethylnitrosamine (DEN) for either 5 (n=5 rats) or 8 weeks (n=4 rats) were MR imaged on a Bruker Pharmascan 4.7 T magnet with a home-built bird-cage coil. T2 was quantified by using a mono-exponential fitting algorithm on multi-slice multi echo T2 weighted data. Statistical comparison was performed using ANOVA. Results (I) Histopathologic evaluation of both rat and human livers demonstrated no evidence of steatosis or hemochromatosis There was a monotonic increase in mean T2 value with increasing degree of fibrosis (control 65.4±2.9 ms, n=6 patients); mild (Ishak 1–2) 66.7±1.9 ms (n=30); moderate (Ishak 3–4) 71.6±1.7 ms (n=26); severe (Ishak 5–6) 72.4±1.4 ms (n=61); with relatively low standard error (~2.9 ms). There was a statistically significant difference between degrees of mild (Ishak <4) vs. moderate to severe fibrosis (Ishak >4) (P=0.03) based on logistic regression of T2 and Ishak, which became insignificant (P=0.07) when using inflammatory markers as covariates. Expanding on this model using ordinal logistic regression, there was significance amongst all 4 groups comparing T2 to Ishak (P=0.01), with significance using inflammation as a covariate (P=0.03) and approaching statistical significance amongst all groups by ANOVA (P=0.07); (II) there was a monotonic increase in T2 and statistical significance (ANOVA P<0.0001) between each rat subgroup [phosphate buffer solution (PBS) 25.2±0.8, DEN 5-week (31.1±1.5), and DEN 9-week (49.4±0.4) ms]; (III) the phantoms that had T2 values within the relevant range for the human liver (e.g., 20–100 ms), demonstrated no statistical difference between two point fits on turbo spin echo (TSE) data and multi-echo CPMG data (P=0.9). Conclusions The finding of increased T2 with liver fibrosis may relate to inflammation that may be an alternative or adjunct to other noninvasive MR imaging based approaches for assessing liver fibrosis. PMID:27190762

An In Vitro Comparison of the Marginal Adaptation Accuracy of CAD/CAM Restorations Using Different Impression Systems.

PubMed

Shembesh, Marwa; Ali, Ala; Finkelman, Matthew; Weber, Hans-Peter; Zandparsa, Roya

2017-10-01

To compare the marginal adaptation of 3-unit zirconia fixed dental prostheses (FDPs) obtained from intraoral digital scanners (Lava True Definition, Cadent iTero), scanning of a conventional silicone impression, and the resulting master cast with an extraoral scanner (3Shape lab scanner). One reference model was fabricated from intact, non-carious, unrestored human mandibular left first premolar and first molar teeth (teeth #19 and 21), prepared for a three-unit all-ceramic FDP. Impressions of the reference model were obtained using four impression systems (n = 10), group 1 (PVS impression scan), group 2 (stone cast scan), group 3 (Cadent iTero), and group 4 (Lava True Defintion). Then the three-unit zirconia FDPs were milled. Marginal adaptation of the zirconia FDPs was evaluated using an optical comparator at four points on each abutment. The mean (SD) was reported for each group. One-way ANOVA was used to assess the statistical significance of the results, with post hoc tests conducted via Tukey's HSD. p < 0.05 was considered statistically significant. All analyses were done using SPSS 22.0. The mean (SD) marginal gaps for the recorded data from highest to lowest were silicone impression scans 81.4 μm (6.8), Cadent iTero scan 62.4 μm (5.0), master cast scan 50.2 μm (6.1), and Lava True definition scan 26.6 μm (4.7). One-way ANOVA revealed significant differences (p < 0.001) in the mean marginal gap among the groups. The Tukey's HSD tests demonstrated that the differences between all groups (silicone impression scan, master cast scan, Lava True definition scan, iTero Cadent scan) were statistically significant (all p < 0.001). On the basis of the criterion of 120 μm as the limit of clinical acceptance, all marginal discrepancy values of all groups were clinically acceptable. Within the confines of this in vitro study, it can be concluded that the marginal gap of all impression techniques was within the acceptable clinical limit (120 μm). Group 4 (Lava True Defintion) showed the lowest average gap among all groups followed by group 2 (stone cast scan), group 3 (Cadent iTero), and group 1 (PVS impression scan); these differences were statistically significant. © 2016 by the American College of Prosthodontists.

The High Cost of Complexity in Experimental Design and Data Analysis: Type I and Type II Error Rates in Multiway ANOVA.

ERIC Educational Resources Information Center

Smith, Rachel A.; Levine, Timothy R.; Lachlan, Kenneth A.; Fediuk, Thomas A.

2002-01-01

Notes that the availability of statistical software packages has led to a sharp increase in use of complex research designs and complex statistical analyses in communication research. Reports a series of Monte Carlo simulations which demonstrate that this complexity may come at a heavier cost than many communication researchers realize. Warns…

Statistical analysis of regulatory ecotoxicity tests.

PubMed

Isnard, P; Flammarion, P; Roman, G; Babut, M; Bastien, P; Bintein, S; Esserméant, L; Férard, J F; Gallotti-Schmitt, S; Saouter, E; Saroli, M; Thiébaud, H; Tomassone, R; Vindimian, E

2001-11-01

ANOVA-type data analysis, i.e.. determination of lowest-observed-effect concentrations (LOECs), and no-observed-effect concentrations (NOECs), has been widely used for statistical analysis of chronic ecotoxicity data. However, it is more and more criticised for several reasons, among which the most important is probably the fact that the NOEC depends on the choice of test concentrations and number of replications and rewards poor experiments, i.e., high variability, with high NOEC values. Thus, a recent OECD workshop concluded that the use of the NOEC should be phased out and that a regression-based estimation procedure should be used. Following this workshop, a working group was established at the French level between government, academia and industry representatives. Twenty-seven sets of chronic data (algae, daphnia, fish) were collected and analysed by ANOVA and regression procedures. Several regression models were compared and relations between NOECs and ECx, for different values of x, were established in order to find an alternative summary parameter to the NOEC. Biological arguments are scarce to help in defining a negligible level of effect x for the ECx. With regard to their use in the risk assessment procedures, a convenient methodology would be to choose x so that ECx are on average similar to the present NOEC. This would lead to no major change in the risk assessment procedure. However, experimental data show that the ECx depend on the regression models and that their accuracy decreases in the low effect zone. This disadvantage could probably be reduced by adapting existing experimental protocols but it could mean more experimental effort and higher cost. ECx (derived with existing test guidelines, e.g., regarding the number of replicates) whose lowest bounds of the confidence interval are on average similar to present NOEC would improve this approach by a priori encouraging more precise experiments. However, narrow confidence intervals are not only linked to good experimental practices, but also depend on the distance between the best model fit and experimental data. At least, these approaches still use the NOEC as a reference although this reference is statistically not correct. On the contrary, EC50 are the most precise values to estimate on a concentration response curve, but they are clearly different from the NOEC and their use would require a modification of existing assessment factors.

Evaluating the statistical performance of less applied algorithms in classification of worldview-3 imagery data in an urbanized landscape

NASA Astrophysics Data System (ADS)

Ranaie, Mehrdad; Soffianian, Alireza; Pourmanafi, Saeid; Mirghaffari, Noorollah; Tarkesh, Mostafa

2018-03-01

In recent decade, analyzing the remotely sensed imagery is considered as one of the most common and widely used procedures in the environmental studies. In this case, supervised image classification techniques play a central role. Hence, taking a high resolution Worldview-3 over a mixed urbanized landscape in Iran, three less applied image classification methods including Bagged CART, Stochastic gradient boosting model and Neural network with feature extraction were tested and compared with two prevalent methods: random forest and support vector machine with linear kernel. To do so, each method was run ten time and three validation techniques was used to estimate the accuracy statistics consist of cross validation, independent validation and validation with total of train data. Moreover, using ANOVA and Tukey test, statistical difference significance between the classification methods was significantly surveyed. In general, the results showed that random forest with marginal difference compared to Bagged CART and stochastic gradient boosting model is the best performing method whilst based on independent validation there was no significant difference between the performances of classification methods. It should be finally noted that neural network with feature extraction and linear support vector machine had better processing speed than other.

Virtual and stereoscopic anatomy: when virtual reality meets medical education.

PubMed

de Faria, Jose Weber Vieira; Teixeira, Manoel Jacobsen; de Moura Sousa Júnior, Leonardo; Otoch, Jose Pinhata; Figueiredo, Eberval Gadelha

2016-11-01

OBJECTIVE The authors sought to construct, implement, and evaluate an interactive and stereoscopic resource for teaching neuroanatomy, accessible from personal computers. METHODS Forty fresh brains (80 hemispheres) were dissected. Images of areas of interest were captured using a manual turntable and processed and stored in a 5337-image database. Pedagogic evaluation was performed in 84 graduate medical students, divided into 3 groups: 1 (conventional method), 2 (interactive nonstereoscopic), and 3 (interactive and stereoscopic). The method was evaluated through a written theory test and a lab practicum. RESULTS Groups 2 and 3 showed the highest mean scores in pedagogic evaluations and differed significantly from Group 1 (p < 0.05). Group 2 did not differ statistically from Group 3 (p > 0.05). Size effects, measured as differences in scores before and after lectures, indicate the effectiveness of the method. ANOVA results showed significant difference (p < 0.05) between groups, and the Tukey test showed statistical differences between Group 1 and the other 2 groups (p < 0.05). No statistical differences between Groups 2 and 3 were found in the practicum. However, there were significant differences when Groups 2 and 3 were compared with Group 1 (p < 0.05). CONCLUSIONS The authors conclude that this method promoted further improvement in knowledge for students and fostered significantly higher learning when compared with traditional teaching resources.

Dentascan – Is the Investment Worth the Hype ???

PubMed Central

Shah, Monali A; Shah, Sneha S; Dave, Deepak

2013-01-01

Background: Open Bone Measurement (OBM) and Bone Sounding (BS) are most reliable but invasive clinical methods for Alveolar Bone Level (ABL) assessment, causing discomfort to the patient. Routinely, IOPAs & OPGs are the commonest radiographic techniques used, which tend to underestimate bone loss and obscure buccal/lingual defects. Novel technique like dentascan (CBCT) eliminates this limitation by giving images in 3 planes – sagittal, coronal and axial. Aim: To compare & correlate non-invasive 3D radiographic technique of Dentascan with BS & OBM, and IOPA and OPG, in assessing the ABL. Settings and Design: Cross-sectional diagnostic study. Material and Methods: Two hundred and five sites were subjected to clinical and radiographic diagnostic techniques. Relative distance between the alveolar bone crest and reference wire was measured. All the measurements were compared and tested against the OBM. Statistical Analysis: Student’s t-test, ANOVA, Pearson correlation coefficient. Results: There is statistically significant difference between dentascan and OBM, only BS showed agreement with OBM (p < 0.05). Dentascan weakly correlated with OBM & BS lingually.Rest all techniques showed statistically significant difference between them (p= 0.00). Conclusion: Within the limitations of this study, only BS seems to be comparable with OBM with no superior result of Dentascan over the conventional techniques, except for lingual measurements. PMID:24551722

Wear behavior of AA 5083/SiC nano-particle metal matrix composite: Statistical analysis

NASA Astrophysics Data System (ADS)

Hussain Idrisi, Amir; Ismail Mourad, Abdel-Hamid; Thekkuden, Dinu Thomas; Christy, John Victor

2018-03-01

This paper reports study on statistical analysis of the wear characteristics of AA5083/SiC nanocomposite. The aluminum matrix composites with different wt % (0%, 1% and 2%) of SiC nanoparticles were fabricated by using stir casting route. The developed composites were used in the manufacturing of spur gears on which the study was conducted. A specially designed test rig was used in testing the wear performance of the gears. The wear was investigated under different conditions of applied load (10N, 20N, and 30N) and operation time (30 mins, 60 mins, 90 mins, and 120mins). The analysis carried out at room temperature under constant speed of 1450 rpm. The wear parameters were optimized by using Taguchi’s method. During this statistical approach, L27 Orthogonal array was selected for the analysis of output. Furthermore, analysis of variance (ANOVA) was used to investigate the influence of applied load, operation time and SiC wt. % on wear behaviour. The wear resistance was analyzed by selecting “smaller is better” characteristics as the objective of the model. From this research, it is observed that experiment time and SiC wt % have the most significant effect on the wear performance followed by the applied load.

A Study of relationship between frailty and physical performance in elderly women

PubMed Central

Jeoung, Bog Ja; Lee, Yang Chool

2015-01-01

Frailty is a disorder of multiple inter-related physiological systems. It is unclear whether the level of physical performance factors can serve as markers of frailty and a sign. The purpose of this study was to examine the relationship between frailty and physical performance in elderly women. One hundred fourteen elderly women participated in this study, their aged was from 65 to 80. We were measured 6-min walk test, grip-strength, 30-sec arm curl test, 30-sec chair stand test, 8 foot Up- and Go, Back scratch, chair sit and reach, unipedal stance, BMI, and the frailty with questionnaire. The collected data were analyzed by descriptive statistics, frequencies, correlation analysis, ANOVA, and simple liner regression using the IBM 21. SPSS program. In results, statistic tests showed that there were significant differences between frailty and 6-min walk test, 30-sec arm curl test, 30-sec chair stand test, grip-strength, Back scratch, and BMI. However, we did not find significant differences between frailty and 8 foot Up- and Go, unipedal stance. When the subjects were divided into five groups according to physical performance level, subjects with high 6-min walk, 30-sec arm curl test, chair sit and reach test, and high grip strength had low score frailty. Physical performance factors were strongly associated with decreased frailty, suggesting that physical performance improvements play an important role in preventing or reducing the frailty. PMID:26331137

In vitro shear bond strength of cementing agents to fixed prosthodontic restorative materials.

PubMed

Piwowarczyk, Andree; Lauer, Hans-Christoph; Sorensen, John A

2004-09-01

Durable bonding to fixed prosthodontic restorations is desirable; however, little information is available on the strength of the bond between different cements and fixed prosthodontic restorative materials. This study determined the shear-bond strength of cementing agents to high-gold-content alloy castings and different dental ceramics: high-strength aluminum oxide (Procera AllCeram), leucite-reinforced (IPS Empress), and lithium disilicate glass-ceramic (IPS Empress 2). Prepolymerized resin composite cylinders (5.5 mm internal diameter, n=20) were bonded to the pretreated surfaces of prosthodontic materials. High-gold-content alloy and high-strength aluminum oxide surfaces were airborne-particle-abraded, and pressable ceramics were hydrofluoric acid-etched and silanized prior to cementing. The cementing agents tested were a zinc-phosphate cement (Fleck's zinc cement), glass ionomer cements (Fuji I, Ketac-Cem), resin-modified glass ionomer cements (Fuji Plus, Fuji Cem, RelyX Luting), resin cements (RelyX ARC, Panavia F, Variolink II, Compolute), and a self-adhesive universal resin cement (RelyX Unicem). Half the specimens (n=10) were tested after 30 minutes; the other half (n=10) were stored in distilled water at 37 degrees C for 14 days and then thermal cycled 1000 times between 5 degrees C and 55 degrees C prior to testing. Shear-bond strength tests were performed using a universal testing machine at a constant crosshead speed of 0.5 mm/min. Statistical analysis was performed by multifactorial analysis of variance taking interactions between effects into account. For multiple paired comparisons, the Tukey method was used (alpha=.05). In a 3-way ANOVA model, the main factors substrate, cement, time, and all corresponding interactions were statistically significant (all P <.0001). In subsequent separate 1-way or 2-way ANOVA models for each substrate type, significant differences between cement types and polymerizing modes were found (all P <.001). None of the cement types provided the highest bonding values with all substrate types. After 14 days of water storage followed by thermal cycling, only the self-adhesive universal resin cement (RelyX Unicem) and 2 of the resin cements (Panavia F and Compolute) exhibited strong bond strengths to specific prosthodontic materials. In contrast, zinc-phosphate, glass ionomer, and resin-modified glass ionomer cements showed the lowest values of all tested cementing agents after 14 days of water storage followed by thermal cycling.

Adhesive retention of experimental fiber-reinforced composite, orthodontic acrylic resin, and aliphatic urethane acrylate to silicone elastomer for maxillofacial prostheses.

PubMed

Kosor, Begüm Yerci; Artunç, Celal; Şahan, Heval

2015-07-01

A key factor of an implant-retained facial prosthesis is the success of the bonding between the substructure and the silicone elastomer. Little has been reported on the bonding of fiber reinforced composite (FRC) to silicone elastomers. Experimental FRC could be a solution for facial prostheses supported by light-activated aliphatic urethane acrylate, orthodontic acrylic resin, or commercially available FRCs. The purpose of this study was to evaluate the bonding of the experimental FRC, orthodontic acrylic resin, and light-activated aliphatic urethane acrylate to a commercially available high-temperature vulcanizing silicone elastomer. Shear and 180-degree peel bond strengths of 3 different substructures (experimental FRC, orthodontic acrylic resin, light-activated aliphatic urethane acrylate) (n=15) to a high-temperature vulcanizing maxillofacial silicone elastomer (M511) with a primer (G611) were assessed after 200 hours of accelerated artificial light-aging. The specimens were tested in a universal testing machine at a cross-head speed of 10 mm/min. Data were collected and statistically analyzed by 1-way ANOVA, followed by the Bonferroni correction and the Dunnett post hoc test (α=.05). Modes of failure were visually determined and categorized as adhesive, cohesive, or mixed and were statistically analyzed with the chi-squared goodness-of-fit test (α=.05). As the mean shear bond strength values were evaluated statistically, no difference was found among the experimental FRC, aliphatic urethane acrylate, and orthodontic acrylic resin subgroups (P>.05). The mean peel bond strengths of experimental fiber reinforced composite and aliphatic urethane acrylate were not found to be statistically different (P>.05). The mean value of the orthodontic acrylic resin subgroup peel bond strength was found to be statistically lower (P<.05). Shear test failure types were found to be statistically different (P<.05), whereas 180-degree peel test failure types were not found to be statistically significant (P>.05). Shear forces predominantly exhibited cohesive failure (64.4%), whereas peel forces predominantly exhibited adhesive failure (93.3%). The mean shear bond strengths of the experimental FRC and aliphatic urethane acrylate groups were not found to be statistically different (P>.05). The mean value of the 180-degree peel strength of the orthodontic acrylic resin group was found to be lower (P<.05). Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

LED traffic signal replacement schedules : facilitating smooth freight flows.

DOT National Transportation Integrated Search

2011-11-01

This research details a field study of LED traffic signals in Missouri and develops a replacement schedule based on key findings. : Rates of degradation were statistically analyzed using Analysis of Variance (ANOVA). Results of this research will pro...

Cytocompatibility, cytotoxicity and genotoxicity analysis of dental implants

NASA Astrophysics Data System (ADS)

Reigosa, M.; Labarta, V.; Molinari, G.; Bernales, D.

2007-11-01

Several types of materials are frequently used for dental prostheses in dental medicine. Different treatments with titanium are the most used. The aim of the present study was to analyze by means of cytotoxicity and cytocompatibility techniques the capacity of dental implants to integrate to the bone tissue. Cultures of UMR 106 cell line derived from an osteosarcoma were used for bioassays mainly because they show many of the properties of osteoblasts. Dental implant samples provided by B&W company were compared with others of recognized trademarks. The first ones contain ASTM titanium (8348 GR2) with acid printing. Cytotoxicity was analyzed by means of lysosome activity, using the neutral red technique and alkaline phosphatase enzyme activity. Cell variability was determined by means of the acridine ethidium-orange bromide technique. One-way ANOVA and Bonferroni and Duncan post-ANOVA tests were used for the statistical analysis. The assays did not show significant differences among the dental implants analyzed. Our findings show that the dental prostheses studied present high biocompatibility, quantified by the bioassays performed. The techniques employed revealed that they can be a useful tool for the analysis of other materials for dental medicine use.

Genetic variance of tolerance and the toxicant threshold model.

PubMed

Tanaka, Yoshinari; Mano, Hiroyuki; Tatsuta, Haruki

2012-04-01

A statistical genetics method is presented for estimating the genetic variance (heritability) of tolerance to pollutants on the basis of a standard acute toxicity test conducted on several isofemale lines of cladoceran species. To analyze the genetic variance of tolerance in the case when the response is measured as a few discrete states (quantal endpoints), the authors attempted to apply the threshold character model in quantitative genetics to the threshold model separately developed in ecotoxicology. The integrated threshold model (toxicant threshold model) assumes that the response of a particular individual occurs at a threshold toxicant concentration and that the individual tolerance characterized by the individual's threshold value is determined by genetic and environmental factors. As a case study, the heritability of tolerance to p-nonylphenol in the cladoceran species Daphnia galeata was estimated by using the maximum likelihood method and nested analysis of variance (ANOVA). Broad-sense heritability was estimated to be 0.199 ± 0.112 by the maximum likelihood method and 0.184 ± 0.089 by ANOVA; both results implied that the species examined had the potential to acquire tolerance to this substance by evolutionary change. Copyright © 2012 SETAC.

Influence of Glide Path Preparation on the Canal Shaping Times of WaveOne Gold in Curved Mandibular Molar Canals.

PubMed

Vorster, Martin; van der Vyver, Peet J; Paleker, Farzana

2018-05-01

The aim of this study was to compare the glide path preparation times of stainless steel hand files, PathFiles (Dentsply Sirona, Ballaigues, Switzerland), and the WaveOne Gold Glider (Dentsply Sirona). The preparation times for final root canal shaping with the Primary WaveOne Gold instrument in extracted human molar teeth with and without prior glide path preparation were also recorded and compared. Mesiobuccal canals of 60 extracted human mandibular molars (curvature angles between 25° and 35° and radii <10 mm) were selected and randomly divided into 4 groups with 15 canals each. Canals were negotiated to patency with a #8 K-file. Canal preparations were performed by a single operator using precurved #10-15-20 stainless steel manual K-files (the K-file group), a #10 stainless steel manual K-file followed by PathFiles #1-3 (the PathFile group), a #10 stainless steel manual K-file followed by WaveOne Gold Glider (the WaveOne Gold Glider group), or no further glide path preparation. Final canal preparation of all 60 canals was performed with the Primary WaveOne Gold instrument. Glide path and final preparation times were recorded. Glide path enlargement was statistically significantly fastest in the WaveOne Gold Glider group (19.7 ± 5.6 seconds) followed by the PathFile group (41.0 ± 6.8 seconds) and then the K-file group (81.2 ± 26.3 seconds) using analysis of variance (ANOVA) and Kruskal-Wallis tests (P < .0001). No statistically significant difference in the mean final preparation times was found among the WaveOne Gold Glider (23.1 ± 6.0 seconds), PathFile (24.4 ± 4.9 seconds), and K-file groups (27.2 ± 9.5 seconds). All 3 groups were statistically significantly faster than the no glide path preparation group (35.4 ± 10.2 seconds) using ANOVA (P = .0004) and Kruskal-Wallis tests (P = .0010). Preparation time with the Primary WaveOne Gold file was statistically significantly reduced when the file was used in combination with any of the glide path preparation techniques. The WaveOne Gold Glider performed statistically significantly faster in glide path preparation time than the other glide path preparation techniques. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The effects of guided inquiry instruction on student achievement in high school biology

NASA Astrophysics Data System (ADS)

Vass, Laszlo

The purpose of this quantitative, quasi-experimental study was to measure the effect of a student-centered instructional method called guided inquiry on the achievement of students in a unit of study in high school biology. The study used a non-random sample of 109 students, the control group of 55 students enrolled in high school one, received teacher centered instruction while the experimental group of 54 students enrolled at high school two received student-centered, guided inquiry instruction. The pretest-posttest design of the study analyzed scores using an independent t-test, a dependent t-test (p = <.001), an ANCOVA (p = .007), mixed method ANOVA (p = .024) and hierarchical linear regression (p = <.001). The experimental group that received guided inquiry instruction had statistically significantly higher achievement than the control group.

Variation of Reaction Time in Different Phases of Menstrual Cycle

PubMed Central

Kumar, Sunil; Mufti, Mehak; Kisan, Ravikiran

2013-01-01

Objective: To evaluate the influence of menstrual cycle on auditory and visual reaction times. Method: This study was conducted on thirty, healthy, regularly menstruating female subjects who were in the age group of 18-25 years. Influence of different phases of menstrual cycle on Auditory Reaction Time (ART) and Visual Reaction Time (VRT) was evaluated by using a portable audiovisual reaction time apparatus. Result: The statistical tests which were used were ANOVA and Students ‘t’ test, which showed that there were significant increases in ART and VRT during luteal phase, as compared to those in follicular phase. Conclusion: Changes in ART and VRT during different phases of menstrual cycle could be due to changes in the levels of female sex hormones, which in turn may lead to salt and water retention. PMID:24086851

The relationship investigation between factors affecting demand for broadband and the level of satisfaction among broadband customers in the South East Coast of Sabah, Malaysia

NASA Astrophysics Data System (ADS)

Hashim, S. H. A.; Hamid, F. A.; Kiram, J. J.; Sulaiman, J.

2017-09-01

This paper aims to investigate the relationship between factors that affecting the demand for broadband and the level of satisfaction. Previous researchers have found that the adoption of broadband is greatly influenced by many factors. Thus, in this study, a self-administered questionnaire was developed to obtain the factors affecting demand for broadband among broadband customers as well as their level of satisfaction. Pearson correlation, one-way analysis of variance (ANOVA) and t-test were used for statistical interpretation of the relationship. This study shows that there are better relationships between several factors over demand for broadband and satisfaction level.

Comparison between Growth Patterns and Pharyngeal Widths in Different Skeletal Malocclusions in South Indian Population.

PubMed

Lakshmi, K Bhagya; Yelchuru, Sri Harsha; Chandrika, V; Lakshmikar, O G; Sagar, V Lakshmi; Reddy, G Vivek

2018-01-01

The main aim is to determine whether growth pattern had an effect on the upper airway by comparing different craniofacial patterns with pharyngeal widths and its importance during the clinical examination. Sixty lateral cephalograms of patients aged between 16 and 24 years with no pharyngeal pathology or nasal obstruction were selected for the study. These were divided into skeletal Class I ( n = 30) and skeletal Class II ( n = 30) using ANB angle subdivided into normodivergent, hyperdivergent, and hypodivergent facial patterns based on SN-GoGn angle. McNamara's airway analysis was used to determine the upper- and lower-airway dimensions. One-way ANOVA was used to do the intergroup comparisons and the Tukey's test as the secondary statistical analysis. Statistically significant difference exists between the upper-airway dimensions in both the skeletal malocclusions with hyperdivergent growth patterns when compared to other growth patterns. In both the skeletal malocclusions, vertical growers showed a significant decrease in the airway size than the horizontal and normal growers. There is no statistical significance between the lower airway and craniofacial growth pattern.

Effects of perceived parental attitudes on children's views of smoking.

PubMed

Ozturk, Candan; Kahraman, Seniha; Bektas, Murat

2013-01-01

The aim of this study was to examine the effects of perceived parental attitudes on children's discernment of cigarettes. The study sample consisted of 250 children attending grades 6, 7 and 8. Data were collected via a socio-demographic survey questionnaire, the Parental Attitude Scale (PAS) and the Decisional Balance Scale (DBS). Data analysis covered percentages, medians, one-way analysis of variance (ANOVA) and post-hoc tests using a statistical package. There were 250 participants; 117 were male, 133 were female. The mean age was 13.1 ± 0.98 for the females and 13.3 ± 0.88 for the males. A statistically significant difference was found in the children's mean scores for 'pros' subscale on the Decisional Balance Scale (DBS) according to perceived parental attitudes (F=3.172, p=0.025). There were no statistically significant differences in the DBS 'cons' subscale scores by perceived parental attitudes. It was determined that while perceived parental attitudes affect children's views on advantages of smoking, they have no effect on children's views on its disadvantages.

A study on Korean nursing students' educational outcomes

PubMed Central

Oh, Kasil; Lee, Hyang-Yeon; Lee, Sook-Ja; Kim, In-Ja; Choi, Kyung-Sook; Ko, Myung-Sook

2011-01-01

The purpose of this study was to describe outcome indicators of nursing education including critical thinking, professionalism, leadership, and communication and to evaluate differences among nursing programs and academic years. A descriptive research design was employed. A total of 454 students from four year baccalaureate (BS) nursing programs and two three-year associate degree (AD) programs consented to complete self-administered questionnaires. The variables were critical thinking, professionalism, leadership and communication. Descriptive statistics, χ2-test, t-tests, ANOVA, and the Tukey test were utilized for the data analysis. All the mean scores of the variables were above average for the test instruments utilized. Among the BS students, those in the upper classes tended to attain higher scores, but this tendency was not identified in AD students. There were significant differences between BS students and AD students for the mean scores of leadership and communication. These findings suggested the need for further research to define properties of nursing educational outcomes, and to develop standardized instruments for research replication and verification. PMID:21602914

Application of addition-cured silicone denture relining materials to adjust mouthguards.

PubMed

Fukasawa, Shintaro; Churei, Hiroshi; Chowdhury, Ruman Uddin; Shirako, Takahiro; Shahrin, Sharika; Shrestha, Abhishekhi; Wada, Takahiro; Uo, Motohiro; Takahashi, Hidekazu; Ueno, Toshiaki

2016-01-01

The purposes of this study were to examine the shock absorption capability of addition-cured silicone denture relining materials and the bonding strength of addition-cured silicone denture relining materials and a commercial mouthguard material to determine its applicability to mouthguard adjustment. Two addition-cured silicone denture relining materials and eleven commercial mouthguard materials were selected as test materials. The impact test was applied by a free-falling steel ball. On the other hand, bonding strength was determined by a delamination test. After prepared surface treatments using acrylic resin on MG sheet surface, 2 types of addition-cured silicone denture relining materials were glued to MG surface. The peak intensity, the time to peak intensity from the onset of the transmitted force and bonding strength were statistically analyzed using ANOVA and Tukey's honest significant difference post hoc test (p<0.05). These results suggest that the silicone denture relining materials could be clinically applicable as a mouthguard adjustment material.

Measurement uncertainty of the EU methods for microbiological examination of red meat.

PubMed

Corry, Janet E L; Hedges, Alan J; Jarvis, Basil

2007-09-01

Three parallel trials were made of EU methods proposed for the microbiological examination of red meat using two analysts in each of seven laboratories within the UK. The methods involved determination of aerobic colony count (ACC) and Enterobacteriaceae colony count (ECC) using simulated methods and a freeze-dried standardised culture preparation. Trial A was based on a simulated swab test, Trial B a simulated meat excision test and Trial C was a reference test on reconstituted inoculum. Statistical analysis (ANOVA) was carried out before and after rejection of outlying data. Expanded uncertainty values (relative standard deviation x2) for repeatability and reproducibility, based on the log10 cfu/ml, on the ACC ranged from +/-2.1% to +/-2.7% and from +/-5.5% to +/-10.5%, respectively, depending upon the test procedure. Similarly for the ECC, expanded uncertainty estimates for repeatability and reproducibility ranged from +/-4.6% to +/-16.9% and from +/-21.6% to +/-23.5%, respectively. The results are discussed in relation to the potential application of the methods.

Role of enamel deminerlization and remineralization on microtensile bond strength of resin composite.

PubMed

Rizvi, Abbas; Zafar, Muhammad S; Al-Wasifi, Yasser; Fareed, Wamiq; Khurshid, Zohaib

2016-01-01

This study is aimed to establish the microtensile bond strength of enamel following exposure to an aerated drink at various time intervals with/without application of remineralization agent. In addition, degree of remineralization and demineralization of tooth enamel has been assessed using polarized light microscopy. Seventy extracted human incisors split into two halves were immersed in aerated beverage (cola drink) for 5 min and stored in saliva until the time of microtensile bond testing. Prepared specimens were divided randomly into two study groups; remineralizing group (n = 70): specimens were treated for remineralization using casein phosphopeptides and amorphous calcium phosphate (CPP-ACP) remineralization agent (Recaldent™; GC Europe) and control group (n = 70): no remineralization treatment; specimens were kept in artificial saliva. All specimens were tested for microtensile bond strength at regular intervals (1 h, 1 days, 2 days, 1 week, and 2 weeks) using a universal testing machine. The results statistically analyzed (P = 0.05) using two-way ANOVA test. Results showed statistically significant increase in bond strength in CPP-ACP tested group (P < 0.05) at all-time intervals. The bond strength of remineralizing group samples at 2 days (~13.64 megapascals [MPa]) is comparable to that of control group after 1 week (~12.44 MPa). CPP-ACP treatment of teeth exposed to an aerated drink provided significant increase in bond strength at a shorter interval compared to teeth exposed to saliva alone.

Antimicrobial activity of root canal irrigants against biofilm forming pathogens- An in vitro study

PubMed Central

Ghivari, Sheetal Basavraj; Bhattacharya, Haimanti; Bhat, Kishore G.; Pujar, Madhu A.

2017-01-01

Aims: The aim of the study was to check the antimicrobial activity of the 5% Sodium hypochlorite, 2% Chlorhexidine, 0.10% Octenidine (OCT), and 2% Silver Zeolite (SZ) at different time intervals against a single species biofilm of Enterococcus faecalis, Staphylococcus aureus, and Candida albicans model prepared on a nitrocellulose membrane. Settings and Design: In vitro nitrocellulose biofilm model was used to check antibacterial efficacy of root canal irrigants. Materials and Methods: The in vitro nitrocellulose biofilm model was used to check the antibacterial activity of root canal irrigants. Single species biofilms were suspended into 96-well microtiter plate and treated with root canal irrigants for 1, 5, 10, 15, 30, and 60 s, respectively. The remaining microbial load in the form of colony-forming unit/ml after antimicrobial treatment was tabulated and data were statistically analyzed. Statistical Analysis: SPSS version 17, Kruskal–Wallis ANOVA, Mann–Whitney U-test, and Wilcoxon matched pair test (P < 0.05) were used. Results: All tested microorganisms were eliminated within 30 s by all the antimicrobial substances tested except normal saline. 2% chlorhexidine and 0.10% OCT were equally effective against C. albicans at 30 s. Conclusion: The newly tested irrigants have shown considerable antibacterial activity against selected single species biofilm. OCT (0.10%) can be used as an alternative endodontic irrigant. PMID:29279615

Gene set differential analysis of time course expression profiles via sparse estimation in functional logistic model with application to time-dependent biomarker detection.

PubMed

Kayano, Mitsunori; Matsui, Hidetoshi; Yamaguchi, Rui; Imoto, Seiya; Miyano, Satoru

2016-04-01

High-throughput time course expression profiles have been available in the last decade due to developments in measurement techniques and devices. Functional data analysis, which treats smoothed curves instead of originally observed discrete data, is effective for the time course expression profiles in terms of dimension reduction, robustness, and applicability to data measured at small and irregularly spaced time points. However, the statistical method of differential analysis for time course expression profiles has not been well established. We propose a functional logistic model based on elastic net regularization (F-Logistic) in order to identify the genes with dynamic alterations in case/control study. We employ a mixed model as a smoothing method to obtain functional data; then F-Logistic is applied to time course profiles measured at small and irregularly spaced time points. We evaluate the performance of F-Logistic in comparison with another functional data approach, i.e. functional ANOVA test (F-ANOVA), by applying the methods to real and synthetic time course data sets. The real data sets consist of the time course gene expression profiles for long-term effects of recombinant interferon β on disease progression in multiple sclerosis. F-Logistic distinguishes dynamic alterations, which cannot be found by competitive approaches such as F-ANOVA, in case/control study based on time course expression profiles. F-Logistic is effective for time-dependent biomarker detection, diagnosis, and therapy. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Are Assumptions of Well-Known Statistical Techniques Checked, and Why (Not)?

PubMed Central

Hoekstra, Rink; Kiers, Henk A. L.; Johnson, Addie

2012-01-01

A valid interpretation of most statistical techniques requires that one or more assumptions be met. In published articles, however, little information tends to be reported on whether the data satisfy the assumptions underlying the statistical techniques used. This could be due to self-selection: Only manuscripts with data fulfilling the assumptions are submitted. Another explanation could be that violations of assumptions are rarely checked for in the first place. We studied whether and how 30 researchers checked fictitious data for violations of assumptions in their own working environment. Participants were asked to analyze the data as they would their own data, for which often used and well-known techniques such as the t-procedure, ANOVA and regression (or non-parametric alternatives) were required. It was found that the assumptions of the techniques were rarely checked, and that if they were, it was regularly by means of a statistical test. Interviews afterward revealed a general lack of knowledge about assumptions, the robustness of the techniques with regards to the assumptions, and how (or whether) assumptions should be checked. These data suggest that checking for violations of assumptions is not a well-considered choice, and that the use of statistics can be described as opportunistic. PMID:22593746

Effect of nanofillers' size on surface properties after toothbrush abrasion.

PubMed

Cavalcante, Larissa M; Masouras, Konstantinos; Watts, David C; Pimenta, Luiz A; Silikas, Nick

2009-02-01

To investigate the effect of filler-particle size of experimental and commercial resin composites, undergoing toothbrush abrasion, on three surface properties: surface roughness (SR), surface gloss (G) and color stability (CS). Four model (Ivoclar/Vivadent) and one commercial resin composite (Tokuyama) with varying filler-size from 100-1000 nm were examined. Six discs (10 mm x 2 mm) from each product were prepared and mechanically polished. The samples were then submitted to 20,000 brushing strokes in a toothbrush abrasion machine. SR parameters (Ra, Rt and RSm), G, and CS were measured before and after toothbrush abrasion. Changes in SR and G were analyzed by 2-way ANOVA, with Bonferroni post hoc test. CS values were submitted to one-way ANOVA and Bonferroni post hoc test (alpha=0.05). Initial G values ranged between 73-87 gloss units (GU) and were reduced after toothbrush abrasion to a range of 8-64 GU. Toothbrush abrasion resulted in significant modifications in SR and G amongst the materials tested, attributed to filler sizes. There was statistically significant difference in color (delta E* ranged from 0.38-0.88). Filler size did not affect color stability. Toothbrush abrasion resulted in rougher and matte surfaces for all materials tested. Although the individual differences in surface roughness among filler sizes were not always significant, the correlation showed a trend that larger filler sizes resulted in higher surface roughness after abrasion for the SR parameters Ra and Rt (r = 0.95; r = 0.93, respectively). RSm showed an increase after toothbrush abrasion for all resin composites, however no significant correlation was detected (r = 0.21).There was a significant correlation between G and Ra ratios (r = - 0.95).

Relationship between career motivation and perceived spiritual leadership in health professional educators: a correlational study in Iran.

PubMed

Sadeghifar, Jamil; Bahadori, Mohammadkarim; Baldacchino, Donia; Raadabadi, Mehdi; Jafari, Mehdi

2013-12-20

Career motivation in university educators through efficient ways and appropriate with the educational system, is considered one of the important factors affecting education of students and their competence. This study aimed to determine the relationship between career motivation and spiritual leadership among a university of medical sciences in the west, Iran. This descriptive, cross-sectional correlation study was conducted among the university educators of medical sciences in the west, Iran in 2012. All of the educators (N=230) were selected and recruited according to census method. The data were collected by two established self-completed questionnaires on spiritual leadership (SL) and career motivation. Data were analyzed statistically by parametric tests: Pearson correlation, independent student t-test and one-way analysis of variance (ANOVA). The Pearson correlation test identified a significant relationship between educators' career motivation and vision, altruistic love, hope/faith, meaning/calling and membership dimensions of spiritual leadership (p<0.05). The independent t-test detected a significant relationship between the 'hope/faith' (p=0.04) and organizational commitment (p=0.004) dimensions and the gender of educators. ANOVA revealed significant differences in educators' years of work experience and their overall career motivation (p=0.003) and the dimension of 'membership' (p<0.04). A significant relationship was found in 'altruistic love' and 'Hope/faith', and the educators' academic rank place in the university (p=0.03). Also a significant relationship was found in 'vision' (p=0.03) and 'altruistic love' (p=0.002) and 'membership' (p=0.04) dimensions, and the type of faculty. The results indicate that the dimensions of existence of spiritual leadership may have a positive relationship with educators' career motivation.

Relationship between Career Motivation and Perceived Spiritual Leadership in Health Professional Educators: A Correlational Study in Iran

PubMed Central

Sadeghifar, Jamil; Bahadori, Mohammadkarim; Baldacchino, Donia; Raadabadi, Mehdi; Jafari, Mehdi

2014-01-01

Background and Aims: Career motivation in university educators through efficient ways and appropriate with the educational system, is considered one of the important factors affecting education of students and their competence. This study aimed to determine the relationship between career motivation and spiritual leadership among a university of medical sciences in the west, Iran. Methods: This descriptive, cross-sectional correlation study was conducted among the university educators of medical sciences in the west, Iran in 2012. All of the educators (N=230) were selected and recruited according to census method. The data were collected by two established self-completed questionnaires on spiritual leadership (SL) and career motivation. Data were analyzed statistically by parametric tests: Pearson correlation, independent student t-test and one-way analysis of variance (ANOVA). Results: The Pearson correlation test identified a significant relationship between educators’ career motivation and vision, altruistic love, hope/faith, meaning/calling and membership dimensions of spiritual leadership (p<0.05). The independent t-test detected a significant relationship between the ‘hope/faith’ (p=0.04) and organizational commitment (p=0.004) dimensions and the gender of educators. ANOVA revealed significant differences in educators’ years of work experience and their overall career motivation (p=0.003) and the dimension of ‘membership’ (p<0.04). A significant relationship was found in ‘altruistic love’ and ‘Hope/faith’, and the educators’ academic rank place in the university (p=0.03). Also a significant relationship was found in ‘vision’ (p=0.03) and ‘altruistic love’ (p=0.002) and ‘membership’ (p=0.04) dimensions, and the type of faculty. Conclusion: The results indicate that the dimensions of existence of spiritual leadership may have a positive relationship with educators’ career motivation. PMID:24576374

Toxicity testing of restorative dental materials using brine shrimp larvae (Artemia salina).

PubMed

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.

Fiber post cementation strategies: effect of mechanical cycling on push-out bond strength and cement polymerization stress.

PubMed

Bergoli, Cesar Dalmolin; Amaral, Marina; Boaro, Leticia Cristina; Braga, Roberto Ruggiero; Valandro, Luiz Felipe

2012-08-01

To evaluate the effect of mechanical cycling and cementation strategies on the push-out bond strength between fiber posts and root dentin and the polymerization stresses produced using three resin cements. Eighty bovine mandibular teeth were sectioned to a length of 16 mm, prepared to 12 mm, and embedded in self-curing acrylic resin. The specimens were then distributed into 8 groups (n = 10): Gr1 - Scotchbond Multi Purpose + RelyX ARC; Gr2 - Scotchbond Multi Purpose + RelyX ARC + mechanical cycling; Gr3 - AdheSE + Multilink Automix; Gr4 - AdheSE + Multilink Automix + mechanical cycling; Gr5 - phosphoric acid + RelyX U100 (self-adhesive cement); Gr6 - phosphoric acid+ RelyX U100 + mechanical cycling; Gr7 - RelyX U100; Gr8 - RelyX U100 + mechanical cycling. The values obtained from the push-out bond strength test were submitted to two-way ANOVA and Tukey's test (p = 0.05), while the values obtained from the polymerization stress test were subjected to one-way ANOVA and Tukey's test (α = 0.05). Mechanical cycling did not affect the bond strength values (p = 0.236), while cementation strategies affected the push-out bond strength (p < 0.001). Luting with RelyX U100 and Scotch Bond Multi Purpose + RelyX ARC yielded higher push-out bond strength values. The polymerization stress results were affected by the factor "cement" (p = 0.0104): the self-adhesive cement RelyX U100 exhibited the lowest values, RelyX ARC resulted in the highest values, while Multilink Automix presented values statistically similar to the other two cements. The self-adhesive cement appears to be a good alternative for luting fiber posts due to the high push-out bond strengths and lower polymerization stress values.

The effect of zinc oxide nanoparticles deposition for friction reduction on orthodontic wires

PubMed Central

Kachoei, Mojghan; Eskandarinejad, Faranak; Divband, Baharak; Khatamian, Masumeh

2013-01-01

Background: In the sliding technique, the reduced frictional forces are associated with rapid tooth movements and better control of the anchorage. Recently, wire coating with different nanoparticles has been proposed to decrease frictional forces. This in vitro study was carried out to coat stainless steel (SS) wires with zinc oxide (ZnO) nanoparticles in order to determine the effect of this coating on friction between wires and orthodontic brackets. Materials and Methods: Eighty 0.016 inch and 0.019 inch × 0.025 inch SS wires with and without ZnO nanoparticles were used in 80 orthodontic brackets (0.018 and 0.022 systems). The coated wires were analyzed by SEM and X-Ray diffraction (XRD) observations. Kinetic friction between the wires and orthodontic brackets were calculated using a universal testing machine. Frictional forces were statistically analyzed using three-way ANOVA, one-way ANOVA, Student's t-test and Tukey multiple comparison tests. Results: Coating with ZnO nanoparticles significantly influenced frictional force values (P < 0.0001). In 0.019 inch × 0.025 inch wires, the frictional forces were 1.6912 ± 0.18868 and 3.4485 ± 0.32389 N in the coated and uncoated wires respectively, (51% reductions). In the 0.016 inch wires, the friction values were estimated to be 1.5668 ± 0.10703 and 2.56 ± 0.34008 N in the coated and uncoated conditions, respectively, (39% reductions). Conclusion: Due to the positive effects of ZnO nanoparticle coating on decreasing frictional forces, these nanoparticles might offer a novel opportunity to significantly reduce friction during tooth movement. PMID:24130586

Effect of an adhesive resin luting agent on the dowel-head retention of three different core materials.

PubMed

Aksoy, Gokhan; Cotert, H Serdar; Korkut, Levent

2005-05-01

A dowel-and-core restoration may fail due to failure at either the dowel-tooth or dowel head-core material interface. Long-term clinical success of a dowel-and-core restoration depends on retention of both the dowel to the tooth and the dowel head to the core material. Thus, strengthening of the dowel head-core interface is important. This study evaluated the retention between a prefabricated dowel and 3 different core materials with or without a dual-polymerized adhesive resin luting agent. Sixty prefabricated dowels (Gold Plated Anchorage Post) were divided into 3 groups (n=20) consisting of 1 of 3 core materials, amalgam (Standalloy F), light-polymerized resin composite (Clearfil Ray), or glass ionomer (Chelon-Silver). Each core group was divided into 2 subgroups (n=10), and a dual-polymerized adhesive resin luting agent (Panavia F) was applied to the dowel heads of 1 of these subgroups before application of the core material. The manufacturing procedure was standardized by using a plastic index (4.5-mm internal diameter and 5-mm height) and a custom-made dowel holder, which held the dowel head. Prepared specimens were stored in water at room temperature for 3 months and then loaded to fracture in a universal testing machine with a crosshead speed of 0.05 mm/min until failure. Bond strengths were recorded (MPa). Data were analyzed with 2-way analysis of variance (ANOVA) in a 2 x 3 factorial randomized design (alpha=.05). Afterward, core material differences were computed with 1-way ANOVA for both of the bonded and nonbonded groups. Post hoc multiple comparisons were made with the Dunnett C multiple range test. Dowel-head retention values (MPa) of the tested core materials (mean +/- SD) from the highest to the lowest were as follows: bonded amalgam core, 296.1 +/- 108; bonded composite core, 284.3 +/- 38.3; nonbonded composite core, 177.0 +/- 53.7; nonbonded amalgam core, 128.5 +/- 35.0; bonded glass-ionomer core (GIC), 128.0 +/- 24.5; nonbonded GIC, 61.8 +/- 13.3. Two-way ANOVA revealed significant differences between the core material groups and between the bonded and nonbonded groups (P <.001). The interaction between the core material and bond variables was also significant (P =.018). One-way ANOVA revealed statistically significant differences between the bonded (P <.001) and also between the nonbonded core material groups (P <.001). Post hoc multiple comparisons showed that the dowel-head retention of the GIC was significantly weaker than the post-head retention for amalgam and resin composite, whether bonded or not. Within the limitations of this study, the adhesive resin luting agent tested appeared to have a significant strengthening effect on the dowel-head retention of the core materials.

Evaluating Intervention Programs with a Pretest-Posttest Design: A Structural Equation Modeling Approach

PubMed Central

Alessandri, Guido; Zuffianò, Antonio; Perinelli, Enrico

2017-01-01

A common situation in the evaluation of intervention programs is the researcher's possibility to rely on two waves of data only (i.e., pretest and posttest), which profoundly impacts on his/her choice about the possible statistical analyses to be conducted. Indeed, the evaluation of intervention programs based on a pretest-posttest design has been usually carried out by using classic statistical tests, such as family-wise ANOVA analyses, which are strongly limited by exclusively analyzing the intervention effects at the group level. In this article, we showed how second order multiple group latent curve modeling (SO-MG-LCM) could represent a useful methodological tool to have a more realistic and informative assessment of intervention programs with two waves of data. We offered a practical step-by-step guide to properly implement this methodology, and we outlined the advantages of the LCM approach over classic ANOVA analyses. Furthermore, we also provided a real-data example by re-analyzing the implementation of the Young Prosocial Animation, a universal intervention program aimed at promoting prosociality among youth. In conclusion, albeit there are previous studies that pointed to the usefulness of MG-LCM to evaluate intervention programs (Muthén and Curran, 1997; Curran and Muthén, 1999), no previous study showed that it is possible to use this approach even in pretest-posttest (i.e., with only two time points) designs. Given the advantages of latent variable analyses in examining differences in interindividual and intraindividual changes (McArdle, 2009), the methodological and substantive implications of our proposed approach are discussed. PMID:28303110

Evaluating Intervention Programs with a Pretest-Posttest Design: A Structural Equation Modeling Approach.

PubMed

Alessandri, Guido; Zuffianò, Antonio; Perinelli, Enrico

2017-01-01

A common situation in the evaluation of intervention programs is the researcher's possibility to rely on two waves of data only (i.e., pretest and posttest), which profoundly impacts on his/her choice about the possible statistical analyses to be conducted. Indeed, the evaluation of intervention programs based on a pretest-posttest design has been usually carried out by using classic statistical tests, such as family-wise ANOVA analyses, which are strongly limited by exclusively analyzing the intervention effects at the group level. In this article, we showed how second order multiple group latent curve modeling (SO-MG-LCM) could represent a useful methodological tool to have a more realistic and informative assessment of intervention programs with two waves of data. We offered a practical step-by-step guide to properly implement this methodology, and we outlined the advantages of the LCM approach over classic ANOVA analyses. Furthermore, we also provided a real-data example by re-analyzing the implementation of the Young Prosocial Animation, a universal intervention program aimed at promoting prosociality among youth. In conclusion, albeit there are previous studies that pointed to the usefulness of MG-LCM to evaluate intervention programs (Muthén and Curran, 1997; Curran and Muthén, 1999), no previous study showed that it is possible to use this approach even in pretest-posttest (i.e., with only two time points) designs. Given the advantages of latent variable analyses in examining differences in interindividual and intraindividual changes (McArdle, 2009), the methodological and substantive implications of our proposed approach are discussed.

The effect of yoga in stress reduction for dental students performing their first periodontal surgery: A randomized controlled study

PubMed Central

Shankarapillai, Rajesh; Nair, Manju Anathakrishnan; George, Roy

2012-01-01

Context: The dental students experience a lot of stress, which increase when they perform their first surgical procedure. Yoga as an anxiolytic tool in anxiety reduction has been practiced over centuries in India. Aim: To assess the efficacy of yoga in reducing the state trait anxiety of dental students before their first periodontal surgery performance. Settings and Design: A randomized controlled study using a two-way split plot design (pre-post-test) was conducted in the department of periodontics, Pacific Dental College, Udaipur, India. Materials and Methods: One hundred clinical dental students who were ready to perform their first periodontal surgery were selected. Students were randomly assigned to two groups and were given a 60-min session on stress reduction. Group A, yogic intervention group, were instructed to do yoga and their performances were monitored for a period of one week and Group B, control group, were given a lecture on stress reduction without any yoga instructions. The investigator who was unaware of the groups had taken the state trait anxiety score of the students three times a) before assigning them to each group, b) prior to the surgical procedure and c) immediately after the performance of surgery. Statistical Analysis Used: Analyses of variance (ANOVA) by SPSS V.16. Results: The statistical results showed a significant reduction in the VAS and state trait anxiety of Group A compared to Group B (ANOVA; P<0.001). Conclusions: This study concludes that Yogic breathing has a significant effect on the reduction of state trait anxiety level of dental students. PMID:22346066

Statistical Assessment of a Paired-site Approach for Verification of Carbon and Nitrogen Sequestration on CRP Land

NASA Astrophysics Data System (ADS)

Kucharik, C.; Roth, J.

2002-12-01

The threat of global climate change has provoked policy-makers to consider plausible strategies to slow the accumulation of greenhouse gases, especially carbon dioxide, in the atmosphere. One such idea involves the sequestration of atmospheric carbon (C) in degraded agricultural soils as part of the Conservation Reserve Program (CRP). While the potential for significant C sequestration in CRP grassland ecosystems has been demonstrated, the paired-site sampling approach traditionally used to quantify soil C changes has not been evaluated with robust statistical analysis. In this study, 14 paired CRP (> 8 years old) and cropland sites in Dane County, Wisconsin (WI) were used to assess whether a paired-site sampling design could detect statistically significant differences (ANOVA) in mean soil organic C and total nitrogen (N) storage. We compared surface (0 to 10 cm) bulk density, and sampled soils (0 to 5, 5 to 10, and 10 to 25 cm) for textural differences and chemical analysis of organic matter (OM), soil organic C (SOC), total N, and pH. The CRP contributed to lowering soil bulk density by 13% (p < 0.0001) and increased SOC and OM storage (kg m-2) by 13 to 17% in the 0 to 5 cm layer (p = 0.1). We tested the statistical power associated with ANOVA for measured soil properties, and calculated minimum detectable differences (MDD). We concluded that 40 to 65 paired sites and soil sampling in 5 cm increments near the surface were needed to achieve an 80% confidence level (α = 0.05; β = 0.20) in soil C and N sequestration rates. Because soil C and total N storage was highly variable among these sites (CVs > 20%), only a 23 to 29% change in existing total organic C and N pools could be reliably detected. While C and N sequestration (247 kg C ha{-1 } yr-1 and 17 kg N ha-1 yr-1) may be occurring and confined to the surface 5 cm as part of the WI CRP, our sampling design did not statistically support the desired 80% confidence level. We conclude that usage of statistical power analysis is essential to insure a high level of confidence in soil C and N sequestration rates that are quantified using paired plots.

Median mandibular flexure at different mouth opening and its relation to different facial types: A prospective clinical study

PubMed Central

Prasad, Mandava; Hussain, Mohammed Z.; Shetty, Sharath K.; Kumar, T. Ashok; Khaur, Mohit; George, Suja A.; Dalwai, Sameen

2013-01-01

Objective: To measure the arch width and Median mandibular flexure (MMF) values at relative rest and maximum jaw opening in young adults with Dolichofacial, Mesofacial, and Brachyfacial types and tested whether the variation in the facial pattern is related to the MMF values in South Indian population. Materials and Methods: This Prospective clinical study consisted of sample of 60 young adults. The subjects were grouped into 3 groups: Group 1: Brachyfacial, Group 2: Mesofacial and types, Group 3: Dolichofacial. Impressions were taken for all the 60 subjects and the casts were scanned and digitized. The intermolar width was measured for Dolichofacial, Mesofacial, and Brachyfacial subjects at relative rest (R) and maximum opening (O). Results: The statistical analysis of the observations included Descriptive and Inferential statistics. The statistical analysis was executed by means of Sigma graph pad prism software, USA Version-4. Kruskal wallis (ANOVA) followed by Dunns post hoc test was performed. Mann Whitney U-test was performed to assess the difference in MMF values between Males and Females of the three groups. The Mean (SD) Mandibular flexure in individuals with Brachyfacial type was 1.12 (0.09), Mesofacial type was 0.69 (0.21), and Dolichofacial type was 0.39 (0.08). Conclusions: The Mean intermolar width was maximum in Brachyfacial type and minimum in Dolichofacial type. MMF was maximum at the maximum mouth opening position and was maximum in individuals with Brachyfacial type. PMID:24082745

Evaluation of long-term stability of mesiodistal axial inclinations of maxillary molars through panoramic radiographs in subjects treated with Pendulum appliance.

PubMed

Rocha, Caroline Andrade; Almeida, Renato Rodrigues de; Henriques, José Fernando Castanha; Flores-Mir, Carlos; Almeida, Marcio Rodrigues de

2016-01-01

To evaluate the stability of mesiodistal inclination of maxillary molars produced by a pendulum appliance, five years after completion of orthodontic treatment. Angulation changes were compared to an untreated sample. The sample consisted of 20 patients (14 females and 6 males) with Class II, Division 1 malocclusion that was treated through molar distalization with a pendulum appliance followed by cervical headgear and full fixed appliances. Maxillary molar inclination was evaluated through panoramic radiograph. The mean age at pretreatment was 14.3 ± 1.6 years, whereas at immediate post-treatment it was 18.6 ± 1.8 years, and at long-term post-treatment it was 23.8 ± 2.0 years. A control group of 16 untreated individuals with untreated normocclusion ranging in age from 12 to 17 years old were used as comparison group. Data were statistically analyzed with independent t-tests and ANOVA test followed by Tukey post-hoc tests. Statistically significant differences were found between T1(94.50) and T2 (98.80) as well as between T2 and T3 (94.70) for maxillary first molars. Maxillary second molars did not show any statistically significant positional changes during the evaluated time periods T1 (107.50), T2 (109.30) and T3 (106.90). Although maxillary first molars underwent distal crown inclination immediately after treatment, approximately five years thereafter their roots tended to upright close to the pretreatment positions.

Wear of two pit and fissure sealants in contact with primary teeth

PubMed Central

Galo, Rodrigo; Contente, Marta Maria Martins Giamatei; Borsatto, Maria Cristina

2014-01-01

Objectives: Wear simulations may provide an indication of the clinical performance of pit-and-fissure sealants when associated with primary teeth as counterbody, restricting the involved variables. The aim of this study was to evaluate wear of dental materials used as pit-and-fissure sealants in contact with primary teeth. Materials and Methods: A resinous sealant (Fluroshield®) and a resin-modified glass ionomer cement (Vitremer®) were selected in a post-plate design, using as counterbody primary tooth pins (4 × 4 × 2 mm) at 3 and 10 N vertical load, 1 Hz frequency, 900 wear cycles in artificial saliva (n = 15). Attrition coefficient values were obtained and the material and primary tooth volumes were analyzed. Data were analyzed statistically by ANOVA and Duncan's test (P < 0.05). Results: Fluroshield® presented the highest attrition coefficient values for the 3 N but these values decreased significantly for the 10 N load. The means for volume loss (3 mm) of the different samples after the wear test were not statistically different for the materials. The volume loss values for the primary teeth were statistically different and there was an increase in volume loss with the increase of the load applied in the wear tests. Conclusions: Differences were also observed with regard to the surface deformation characteristics. The wear rates of primary tooth enamel vary according to the type of material and the load applied during mastication. PMID:24966777

Marginal fit of all-ceramic crowns fabricated using two extraoral CAD/CAM systems in comparison with the conventional technique

PubMed Central

Alqahtani, Fawaz

2017-01-01

Objective The purpose of this study was to determine the effect of two extraoral computer-aided design (CAD) and computer-aided manufacturing (CAM) systems, in comparison with conventional techniques, on the marginal fit of monolithic CAD/CAM lithium disilicate ceramic crowns. Study design This is an in vitro interventional study. Place and duration of study The study was carried out at the Department of Prosthodontics, School of Dentistry, Prince Sattam Bin Abdul-Aziz University, Saudi Arabia, from December 2015 to April 2016. Methodology A marginal gap of 60 lithium disilicate crowns was evaluated by scanning electron microscopy. In total, 20 pressable lithium disilicate (IPS e.max Press [Ivoclar Vivadent]) ceramic crowns were fabricated using the conventional lost-wax technique as a control group. The experimental all-ceramic crowns were produced based on a scan stone model and milled using two extraoral CAD/CAM systems: the Cerec group was fabricated using the Cerec CAD/CAM system, and the Trios group was fabricated using Trios CAD and milled using Wieland Zenotec CAM. One-way analysis of variance (ANOVA) and the Scheffe post hoc test were used for statistical comparison of the groups (α=0.05). Results The mean (±standard deviation) of the marginal gap of each group was as follows: the Control group was 91.15 (±15.35) µm, the Cerec group was 111.07 (±6.33) µm, and the Trios group was 60.17 (±11.09) µm. One-way ANOVA and the Scheffe post hoc test showed a statistically significant difference in the marginal gap between all groups. Conclusion It can be concluded from the current study that all-ceramic crowns, fabricated using the CAD/CAM system, show a marginal accuracy that is acceptable in clinical environments. The Trios CAD group displayed the smallest marginal gap. PMID:28352204

Lifestyle Change Plus Dental Care (LCDC) program improves knowledge, attitude, and practice (KAP) toward oral health and diabetes mellitus among the elderly with type 2 diabetes.

PubMed

Saengtipbovorn, Saruta; Taneepanichskul, Surasak

2015-03-01

Currently, there is an increased prevalence of diabetes mellitus among the elderly. Chronic inflammation from diabetes mellitus effects glycemic control and increases risk of diabetes complications. To assess the effectiveness of a Lifestyle Change plus Dental Care (LCDC) program by improved knowledge, attitude, and practice (KAP) toward oral health and diabetes mellitus among the elderly with type 2 diabetes. A quasi-experimental study was conducted in two Health Centers (HC 54 intervention and HC 59 control) between October 2013 and April 2014. Sixty-six diabetic patients per health center were recruited. At baseline, the intervention group attended a 20-minute lifestyle and oral health education program, individual lifestyle counseling using motivational interviewing, application of self-regulation manual, and individual oral hygiene instruction. At 3-month follow-up, the intervention group received individual lifestyle counseling and oral hygiene instruction. The intervention group received booster education every visit by viewing a 15-minute educational video. The control group received the routine program. Participants were assessed at baseline, 3-month, and 6-month follow-up for knowledge, attitude, and practice (KAP) toward oral health and diabetes mellitus. Data was analyzed by using descriptive statistic, Chi-square test, Fisher's exact test, and repeated measure ANOVA. After the 6-month follow-up, repeated measure ANOVA analysis showed that participants in the intervention group had significantly higher knowledge and attitude toward oral health and diabetes mellitus. The participants in the intervention group were more likely to exercise, modify diet, have foot examinations, always wear covered shoes, participate in self-feet screening, use dental floss, and use inter-proximal brush than the control group with statistically significant differences. The combination of lifestyle change and dental care in one program improved knowledge, attitude, andpractice (KAP) toward oral health and diabetes mellitus in the elderly with type 2 diabetes. Trial registration: ClinicalTrials.in.th: TCTR20140602001.

The Health, Enlightenment, Awareness, and Living (HEAL) Intervention: Outcome of an HIV and Hepatitis B and C Risk Reduction Intervention

PubMed Central

Henry-Akintobi, Tabia; Laster, Nastassia; Trotter, Jennie; Jacobs, DeBran; Johnson, Tarita; King Gordon, Tandeca; Miller, Assia

2016-01-01

African American women have among the highest HIV/AIDS and hepatitis B and C incidence rates in the United States, especially among those homeless or incarcerated. The objective of this study was to evaluate the Health Enlightenment, Awareness and Living Intervention, designed to decrease HIV/AIDS, hepatitis and related risky behaviors. The thirteen-session intervention was implemented among homeless and formerly incarcerated low-income African American women, ages 18 to 55, in Atlanta, Georgia from 2006 to 2010. A single group repeated measures study design was employed and consisted of a pre-test (n = 355) group, an immediate post-test (n = 228) group with a response rate of 64%, and a six-month follow up (n = 110) group with response rate of 48%, completing a 135-item survey. Paired-sample t-tests, McNemar tests, and repeated measures ANOVA were applied to compare survey results. Participants demonstrated statistically significant increases in hepatitis B and C knowledge over time (p < 0.001). Statistically significant decreases were also reported for unprotected sex in exchange for money, drugs or shelter (p = 0.008), and sex under the influence of drugs or alcohol (p < 0.001). Reported substance use decreased with statistical significance for alcohol (p = 0.011), marijuana (p = 0.011), illegal drugs (p = 0.002), and crack/cocaine (p = 0.003). Findings broaden the evidence base related to the effectiveness of HIV/AIDS and hepatitis risk reduction interventions designed for homeless and previously incarcerated African American women. PMID:27669284

Environmental monitoring study of linear alkylbenzene sulfonates and insoluble soap in Spanish sewage sludge samples.

PubMed

Cantarero, Samuel; Zafra-Gómez, Alberto; Ballesteros, Oscar; Navalón, Alberto; Reis, Marco S; Saraiva, Pedro M; Vílchez, José L

2011-01-01

In this work we present a monitoring study of linear alkylbenzene sulfonates (LAS) and insoluble soap performed on Spanish sewage sludge samples. This work focuses on finding statistical relations between LAS concentrations and insoluble soap in sewage sludge samples and variables related to wastewater treatment plants such as water hardness, population and treatment type. It is worth to mention that 38 samples, collected from different Spanish regions, were studied. The statistical tool we used was Principal Component Analysis (PC), in order to reduce the number of response variables. The analysis of variance (ANOVA) test and a non-parametric test such as the Kruskal-Wallis test were also studied through the estimation of the p-value (probability of obtaining a test statistic at least as extreme as the one that was actually observed, assuming that the null hypothesis is true) in order to study possible relations between the concentration of both analytes and the rest of variables. We also compared LAS and insoluble soap behaviors. In addition, the results obtained for LAS (mean value) were compared with the limit value proposed by the future Directive entitled "Working Document on Sludge". According to the results, the mean obtained for soap and LAS was 26.49 g kg(-1) and 6.15 g kg(-1) respectively. It is worth noting that LAS mean was significantly higher than the limit value (2.6 g kg(-1)). In addition, LAS and soap concentrations depend largely on water hardness. However, only LAS concentration depends on treatment type.

Life expectancy evaluation and development of a replacement schedule for LED traffic signals.

DOT National Transportation Integrated Search

2011-03-01

This research details a field study of LED traffic signals in Missouri and develops a replacement schedule : based on key findings. Rates of degradation were statistically analyzed using Analysis of Variance : (ANOVA). Results of this research will p...

Iron Activation of Cellular Oxidases: Modulation of NeuronalViability (In Vitro).

DTIC Science & Technology

2018-04-06

Findings related to each specific aim of the study or project, answering each research or study questions, and/or hypothesis: The experimentation ...significant (NS) differences between groups when normalized to GAPDH. All groups were compared using one-way ANOVA with Tukey’s post -hoc test . Western...pɘ.0001. All groups were compared using one-way ANOVA with Tukey’s post -hoc test . All graphs represent n=6. Bars represent mean +/- SEM. It is

Wheat crown rot pathogens Fusarium graminearum and F. pseudograminearum lack specialization.

PubMed

Chakraborty, Sukumar; Obanor, Friday; Westecott, Rhyannyn; Abeywickrama, Krishanthi

2010-10-01

This article reports a lack of pathogenic specialization among Australian Fusarium graminearum and F. pseudograminearum causing crown rot (CR) of wheat using analysis of variance (ANOVA), principal component and biplot analysis, Kendall's coefficient of concordance (W), and κ statistics. Overall, F. pseudograminearum was more aggressive than F. graminearum, supporting earlier delineation of the crown-infecting group as a new species. Although significant wheat line-pathogen isolate interaction in ANOVA suggested putative specialization when seedlings of 60 wheat lines were inoculated with 4 pathogen isolates or 26 wheat lines were inoculated with 10 isolates, significant W and κ showed agreement in rank order of wheat lines, indicating a lack of specialization. The first principal component representing nondifferential aggressiveness explained a large part (up to 65%) of the variation in CR severity. The differential components were small and more pronounced in seedlings than in adult plants. By maximizing variance on the first two principal components, biplots were useful for highlighting the association between isolates and wheat lines. A key finding of this work is that a range of analytical tools are needed to explore pathogenic specialization, and a statistically significant interaction in an ANOVA cannot be taken as conclusive evidence of specialization. With no highly resistant wheat cultivars, Fusarium isolates mostly differ in aggressiveness; however, specialization may appear as more resistant cultivars become widespread.

Cognitive-enhancing and antioxidant activities of the aqueous extract from Markhamia tomentosa (Benth.) K. Schum. stem bark in a rat model of scopolamine.

PubMed

Ionita, Radu; Postu, Paula Alexandra; Beppe, Galba Jean; Mihasan, Marius; Petre, Brindusa Alina; Hancianu, Monica; Cioanca, Oana; Hritcu, Lucian

2017-03-28

Plants of the genus Markhamia have been traditionally used by different tribes in various parts of West African countries, including Cameroun. Markhamia tomentosa (Benth.) K. Schum. (Bignoniaceae) is used as an antimalarial, anti-inflammatory, analgesic, antioxidant and anti-Alzheimer agent. The current study was undertaken in order to investigate its anti-amnesic and antioxidant potential on scopolamine-induced cognitive impairment and to determine its possible mechanism of action. Rats were pretreated with the aqueous extract (50 and 200 mg/kg, p.o.), for 10 days, and received a single injection of scopolamine (0.7 mg/kg, i.p.) before training in Y-maze and radial arm-maze tests. The biochemical parameters in the rat hippocampus were also assessed to explore oxidative status. Statistical analyses were performed using two-way ANOVA followed by Tukey's post hoc test. F values for which p < 0.05 were regarded as statistically significant. In the scopolamine-treated rats, the aqueous extract improved memory in behavioral tests and decreased the oxidative stress in the rat hippocampus. Also, the aqueous extract exhibited anti-acetylcholinesterase activity. These results suggest that the aqueous extract ameliorates scopolamine-induced spatial memory impairment by attenuation of the oxidative stress in the rat hippocampus.

A comparative evaluation of propolis and 5.0% potassium nitrate as a dentine desensitizer: A clinical study

PubMed Central

Purra, Aamir Rashid; Mushtaq, Mubashir; Acharya, Shashi Rashmi; Saraswati, Vidya

2014-01-01

Aim: The purpose of this clinical study was to evaluate the efficacy of saturated ethanolic solution of Propolis for the treatment of dentin hypersensitivity. Materials and Methods: Ten patients aged 20-40 years with 156 hypersensitive teeth were selected for a 3-month study. Each patient was subjected to treatment with saturated ethanolic solution of Propolis, 5% potassium nitrate and distilled water. The patients were recalled at seventh day, 2 weeks and 4 weeks for the application of the agent and re-evaluation. The final re-evaluation of the patients was done after 3 months from the first application. The responses of the patients to the test temperatures were converted to a ranking and data was statistically analyzed. A statistical analysis was done using ANOVA and Bonferroni test and Tukey HSD test for multicomparison. Results: The results between the Propolis group and the potassium nitrate group showed no significant difference in the immediate post-treatment period; however, the results were significant at the end of first week and second week. At 4 weeks and 3 months period, a comparison between the groups again showed no significant difference. Conclusion: It was concluded that Propolis was more effective than 5% potassium nitrate in relieving dentinal hypersensitivity and had an immediate and sustained effect. PMID:25210261

Effect of lidocaine- and prilocaine-based topical anesthetics on the inflammatory exudates in subcutaneous tissue of rats.

PubMed

Pochapski, Márcia Thaís; Neto, José Laufer; Jassen, Jocélia Lago; Farago, Paulo Vitor; Santos, Fábio André

2012-01-01

The aim of this present study was to evaluate the irritative potential of 2 topical anesthetics used in intrapocket anesthesia for periodontal scaling/root planing when applied in subcutaneous tissue of rats. Sixty animals were divided into 4 groups: group 1, saline solution (control); group 2, poloxamer gel (thermosetting vehicle); group 3, lidocaine and prilocaine poloxamer thermosetting gel; group 4: EMLA, a lidocaine and prilocaine dermatological cream. Injections of 2% Evans blue were administrated intravenously into the lateral caudal vein. In order to analyze vascular permeability, the tested substances were injected intradermally. The rats were sacrificed 3, 6, and 9 hours after injection of the substances. The dorsal skin was dissected and removed. The vascular permeability was evaluated by the measurement of area of dye extravasation and the dye was subsequently extracted after immersion in formamide. Statistical analyses were made by ANOVA with Bonferroni's post hoc test and Pearson correlation. The 2 methods to analyze the exudative phase of the inflammatory process showed statistically significant difference among the groups and periods of evaluation (P < .05). Both methods had a significant correlation (P < .0001). Under the tested conditions, the anesthetic agents showed mild initial inflammatory response when implanted in subcutaneous connective tissue.

Effect of Lidocaine- and Prilocaine-Based Topical Anesthetics on the Inflammatory Exudates in Subcutaneous Tissue of Rats

PubMed Central

Pochapski, Márcia Thaís; Neto, José Laufer; Jassen, Jocélia Lago; Farago, Paulo Vitor; Santos, Fábio André

2012-01-01

The aim of this present study was to evaluate the irritative potential of 2 topical anesthetics used in intrapocket anesthesia for periodontal scaling/root planing when applied in subcutaneous tissue of rats. Sixty animals were divided into 4 groups: group 1, saline solution (control); group 2, poloxamer gel (thermosetting vehicle); group 3, lidocaine and prilocaine poloxamer thermosetting gel; group 4: EMLA, a lidocaine and prilocaine dermatological cream. Injections of 2% Evans blue were administrated intravenously into the lateral caudal vein. In order to analyze vascular permeability, the tested substances were injected intradermally. The rats were sacrificed 3, 6, and 9 hours after injection of the substances. The dorsal skin was dissected and removed. The vascular permeability was evaluated by the measurement of area of dye extravasation and the dye was subsequently extracted after immersion in formamide. Statistical analyses were made by ANOVA with Bonferroni's post hoc test and Pearson correlation. The 2 methods to analyze the exudative phase of the inflammatory process showed statistically significant difference among the groups and periods of evaluation (P < .05). Both methods had a significant correlation (P < .0001). Under the tested conditions, the anesthetic agents showed mild initial inflammatory response when implanted in subcutaneous connective tissue. PMID:22822991

Eating Attitudes and Related Factors in Turkish Nursing Students

PubMed Central

Celik, Sevim; Ugur, Bayram Ali; Aykurt, Fethi Ahmet; Bektas, Muammer

2015-01-01

Background: Changing eating behaviors might trigger obesity, deficiency, anorexia nervosa, bulimia nervosa, and reactive eating disorders. Objectives: This study aimed to determine eating attitudes of nursing students in the western Black-Sea region of Turkey as well as to examine the effects of demographic features, self-esteem, body image, income level, and family structure on their eating attitudes. Materials and Methods: This cross-sectional study was conducted on 310 nursing students between January and February 2014. Data were collected using the personal information form, Eating Attitudes Test (EAT), Rosenberg Self-Esteem Scale (RSES), Beck Depression Scale (BDS), Body-Cathexis Scale (BCS), and Body Mass Index (BMI). Data were evaluated by descriptive statistics, independent samples t-test, one-way ANOVA, Kruskal-Wallis test, and Pearson correlation analysis. Results: About 30.0% of Turkish nursing students had negative eating attitudes. There was a significant positive correlation between the BDS and EAT scores (P < 0.001). There was a significant negative correlation between RSES scores and EAT scores of nursing students (P < 0.001). A statistically significant difference was found between the father’s occupation (P < 0.05) and mother’s working condition (P < 0.05), and the students’ eating attitudes. Conclusions: Psychological status, self-esteem, economic level, and place of residence of nursing students may be the potential factors for eating disorders. PMID:26339662

The value of thyroid shielding in intraoral radiography

PubMed Central

Hazenoot, Bart; Sanderink, Gerard C H; Berkhout, W Erwin R

2016-01-01

Objectives: To evaluate the utility of the application of a thyroid shield in intraoral radiography when using rectangular collimation. Methods: Experimental data were obtained by measuring the absorbed dose at the position of the thyroid gland in a RANDO® (The Phantom Laboratory, Salem, NY) male phantom with a dosemeter. Four protocols were tested: round collimation and rectangular collimation, both with and without thyroid shield. Five exposure positions were deployed: upper incisor (Isup), upper canine (Csup), upper premolar (Psup), upper molar (Msup) and posterior bitewing (BW). Exposures were made with 70 kV and 7 mA and were repeated 10 times. The exposure times were as recommended for the exposure positions for the respective collimator type by the manufacturer for digital imaging. The data were statistically analyzed with a three-way ANOVA test. Significance was set at p < 0.01. Results: The ANOVA test revealed that the differences between mean doses of all protocols and geometries were statistically significant, p < 0.001. For the Isup, thyroid dose levels were comparable with both collimators at a level indicating primary beam exposure. Thyroid shield reduced this dose with circa 75%. For the Csup position, round collimation also revealed primary beam exposure, and thyroid shield yield was 70%. In Csup with rectangular collimation, the thyroid dose was reduced with a factor 4 compared with round collimation and thyroid shield yielded an additional 42% dose reduction. The thyroid dose levels for the Csup, Psup, Msup and BW exposures were lower with rectangular collimation without thyroid shield than with round collimation with thyroid shield. With rectangular collimation, the thyroid shield in Psup, Msup and BW reduced the dose 10% or less, where dose levels were already low, implying no clinical significance. Conclusions: For the exposures in the upper anterior region, thyroid shield results in an important dose reduction for the thyroid. For the other exposures, thyroid shield augments little to the reduction achieved by rectangular collimation. The use of thyroid shield is to be advised, when performing upper anterior radiography. PMID:27008105

Challenges of using Hospital Information Systems by nurses: comparing academic and non-academic hospitals.

PubMed

Ahmadian, Leila; Dorosti, Nafise; Khajouei, Reza; Gohari, Sadrieh Hajesmaeel

2017-06-01

Hospital Information Systems (HIS) are used for easy access to information, improvement of documentation and reducing errors. Nonetheless, using these systems is faced with some barriers and obstacles. This study identifies the challenges and the obstacles of using these systems in the academic and non-academic hospitals in Kerman. This is a cross-sectional study which was carried out in 2015. The statistical population in this study consisted of the nurses who had been working in the academic and non-academic hospitals in Kerman. A questionnaire consisting of two sections was used. The first section consisted of the demographic information of the participants and the second section comprised 34 questions about the challenges of HIS use. Data were analyzed by the descriptive and statistical analysis (t-test, and ANOVA) using SPSS 19 software. The most common and important challenges in the academic hospitals were about human environment factors, particularly "negative attitude of society toward using HIS". In the non-academic hospitals, the most common and important challenges were related to human factors, and among them, "no incentive to use system" was the main factor. The results of the t-test method revealed that there was a significant relationship between gender and the mean score of challenges related to the organizational environment category in the academic hospitals and between familiarity with HIS and mean score of human environment factors (p<0.05). The results of the ANOVA test also revealed that the educational degree and work experience in the healthcare environment (years) in the academic hospitals have a significant relationship with the mean score related to the hardware challenges, as well, experience with HIS has a significant relationship, with the mean score related to the human challenges (p<0.05). The most important challenges in using the information systems are the factors related to the human environment and the human factors. The results of this study can bring a good perspective to the policy makers and the managers regarding obstacles of using HISs from the nurses' perspective, so that they can solve their problems and can successfully implement these systems.

Physiological Efficacy of a Lightweight Ambient Air Cooling Unit for Various Applications

DTIC Science & Technology

1993-10-01

Acei 10. Mean skin temperature during continuous work . N*TIS. CRjI DTIC TAB 11. Thermal comfort rate during continuous work. . U nagnounf. 4...perceived exertion (RPE) and thermal comfort (TC) were taken every 10 min. Statistical analysis using a 3-way analysis of variance (ANOVA) was conducted...may account for the fact that no statistically significant differences were seen for thermal comfort and ratings of perceived exertion between the IC

A new device to test cutting efficiency of mechanical endodontic instruments.

PubMed

Giansiracusa Rubini, Alessio; Plotino, Gianluca; Al-Sudani, Dina; Grande, Nicola M; Sonnino, Gianpaolo; Putorti, Ermanno; Cotti, Elisabetta; Testarelli, Luca; Gambarini, Gianluca

2014-03-06

The purpose of the present study was to introduce a new device specifically designed to evaluate the cutting efficiency of mechanically driven endodontic instruments. Twenty new Reciproc R25 (VDW, Munich, Germany) files were used to be investigated in the new device developed to test the cutting ability of endodontic instruments. The device consists of a main frame to which a mobile plastic support for the hand-piece is connected and a stainless-steel block containing a Plexiglas block against which the cutting efficiency of the instruments was tested. The length of the block cut in 1 minute was measured in a computerized program with a precision of 0.1mm. The instruments were activated by using a torque-controlled motor (Silver Reciproc; VDW, Munich, Germany) in a reciprocating movement by the "Reciproc ALL" program (Group 1) and in counter-clockwise rotation at 300 rpm (Group 2). Mean and standard deviations of each group were calculated and data were statistically analyzed with a one-way ANOVA test (P<0.05). Reciproc in reciprocation (Group 1) mean cut in the Plexiglas block was 8.6 mm (SD=0.6 mm), while Reciproc in rotation mean cut was 8.9 mm (SD=0.7 mm). There was no statistically significant difference between the 2 groups investigated (P>0.05). The cutting testing device evaluated in the present study was reliable and easy to use and may be effectively used to test cutting efficiency of both rotary and reciprocating mechanical endodontic instruments.

The effect on the flexural strength, flexural modulus and compressive strength of fibre reinforced acrylic with that of plain unfilled acrylic resin - an in vitro study.

PubMed

Thomas, Tony C; K, Aswini Kumar; Mohamed, Shamaz; Krishnan, Vinod; Mathew, Anil; V, Manju

2015-03-01

The aim of this in vitro study was to compare the flexural strength, the flexural modulus and compressive strength of the acrylic polymer reinforced with glass, carbon, polyethylene and Kevlar fibres with that of plain unfilled resin. A total of 50 specimens were prepared and divided into 10 specimens each under 5 groups namely group 1- control group without any fibres, group 2 - carbon fibres, group 3- glass fibres, group 4 - polyethylene, group 5- Kevlar. Universal testing machine (Tinius olsen, USA) was used for the testing of these specimens. Out of each group, 5 specimens were randomly selected and testing was done for flexural strength using a three point deflection test and three point bending test for compressive strength and the modulus was plotted using a graphical method. Statistical analysis was done using statistical software. The respective mean values for samples in regard to their flexural strength for PMMA plain, PMMA+ glass fibre, PMMA+ carbon, PMMA+ polyethylene and PMMA+ Kevlar were 90.64, 100.79, 102.58, 94.13 and 96.43 respectively. Scheffes post hoc test clearly indicated that only mean flexural strength values of PMMA + Carbon, has the highest mean value. One-way ANOVA revealed a non-significant difference among the groups in regard to their compressive strength. The study concludes that carbon fibre reinforced samples has the greatest flexural strength and greatest flexural modulus, however the compressive strength remains unchanged.

Occupational Safety and Health Measures in Micro-scale Enterprises (MSEs) in Shiraz, Iran.

PubMed

Jahangiri, Mehdi; Rostamabadi, Akbar; Malekzadeh, Gholamreza; Sadi, Amin Fahandej; Hamzavi, Golnar; Rasooli, Javad; Momeni, Zahra; Ghaem, Haleh

2016-05-25

This study aimed to determine the extent of implementation of occupational safety and health measures in micro-scale enterprises (MSEs) and to assess the prevalence of occupational injuries and accidents and its relationship with occupational safety and health measures provided in the MSEs. A cross-sectional study was conducted among 595 of MSEs. An index called the Safety and Health Requirement Index (SHRI) was created and used to calculate the percentage of provided occupational safety and health measures. The relationship between the SHRI and the occurrence of occupational accidents and injuries was investigated with the independent samples t-test and one-way ANOVA. The mean SHRI score was 60.43%, which was categorized into moderate level. Of the 30.9% of enterprises that had experienced accidents and injuries, the most common types of injuries were musculoskeletal disorders and cuts, and the least common types were pulmonary and hearing problems. Results of one-way ANOVA revealed a statistically significant relationship between the mean SHRI score and industrial branch, enterprise size, and type of accident and injury. The independent samples t-test showed that the occurrence of occupational accidents and injuries was not significantly influenced by provided health and safety measures in MSEs. Given the high percentage of enterprises with very poor to poor levels for the SHRI and the high prevalence of occupational accidents and injuries among the studied MSEs, feasible protective strategies and job safety training programs are required to promote occupational health and safety in the studied MSEs.

Effects of structured written feedback by cards on medical students' performance at Mini Clinical Evaluation Exercise (Mini-CEX) in an outpatient clinic.

PubMed

Haghani, Fariba; Hatef Khorami, Mohammad; Fakhari, Mohammad

2016-07-01

Feedback cards are recommended as a feasible tool for structured written feedback delivery in clinical education while effectiveness of this tool on the medical students' performance is still questionable.  The purpose of this study was to compare the effects of structured written feedback by cards as well as verbal feedback versus verbal feedback alone on the clinical performance of medical students at the Mini Clinical Evaluation Exercise (Mini-CEX) test in an outpatient clinic. This is a quasi-experimental study with pre- and post-test comprising four groups in two terms of medical students' externship. The students' performance was assessed through the Mini-Clinical Evaluation Exercise (Mini-CEX) as a clinical performance evaluation tool. Structured written feedbacks were given to two experimental groups by designed feedback cards as well as verbal feedback, while in the two control groups feedback was delivered verbally as a routine approach in clinical education. By consecutive sampling method, 62 externship students were enrolled in this study and seven students were excluded from the final analysis due to their absence for three days. According to the ANOVA analysis and Post Hoc Tukey test,  no statistically significant difference was observed among the four groups at the pre-test, whereas a statistically significant difference was observed between the experimental and control groups at the post-test  (F = 4.023, p =0.012). The effect size of the structured written feedbacks on clinical performance was 0.19. Structured written feedback by cards could improve the performance of medical students in a statistical sense. Further studies must be conducted in other clinical courses with longer durations.

Heterogeneity Between Ducts of the Same Nuclear Grade Involved by Duct Carcinoma In Situ (DCIS) of the Breast

PubMed Central

Miller, Naomi A.; Chapman, Judith-Anne W.; Qian, Jin; Christens-Barry, William A.; Fu, Yuejiao; Yuan, Yan; Lickley, H. Lavina A.; Axelrod, David E.

2010-01-01

Purpose Nuclear grade of breast DCIS is considered during patient management decision-making although it may have only a modest prognostic association with therapeutic outcome. We hypothesized that visual inspection may miss substantive differences in nuclei classified as having the same nuclear grade. To test this hypothesis, we measured subvisual nuclear features by quantitative image cytometry for nuclei with the same grade, and tested for statistical differences in these features. Experimental design and statistical analysis Thirty-nine nuclear digital image features of about 100 nuclei were measured in digital images of H&E stained slides of 81 breast biopsy specimens. One field with at least 5 ducts was evaluated for each patient. We compared features of nuclei with the same grade in multiple ducts of the same patient with ANOVA (or Welch test), and compared features of nuclei with the same grade in two ducts of different patients using 2-sided t-tests (P ≤ 0.05). Also, we compared image features for nuclei in patients with single grade to those with the same grade in patients with multiple grades using t-tests. Results Statistically significant differences were detected in nuclear features between ducts with the same nuclear grade, both in different ducts of the same patient, and between ducts in different patients with DCIS of more than one grade. Conclusion Nuclei in ducts visually described as having the same nuclear grade had significantly different subvisual digital image features. These subvisual differences may be considered additional manifestations of heterogeneity over and above differences that can be observed microscopically. This heterogeneity may explain the inconsistency of nuclear grading as a prognostic factor. PMID:20981137

Power of mental health nursing research: a statistical analysis of studies in the International Journal of Mental Health Nursing.

PubMed

Gaskin, Cadeyrn J; Happell, Brenda

2013-02-01

Having sufficient power to detect effect sizes of an expected magnitude is a core consideration when designing studies in which inferential statistics will be used. The main aim of this study was to investigate the statistical power in studies published in the International Journal of Mental Health Nursing. From volumes 19 (2010) and 20 (2011) of the journal, studies were analysed for their power to detect small, medium, and large effect sizes, according to Cohen's guidelines. The power of the 23 studies included in this review to detect small, medium, and large effects was 0.34, 0.79, and 0.94, respectively. In 90% of papers, no adjustments for experiment-wise error were reported. With a median of nine inferential tests per paper, the mean experiment-wise error rate was 0.51. A priori power analyses were only reported in 17% of studies. Although effect sizes for correlations and regressions were routinely reported, effect sizes for other tests (χ(2)-tests, t-tests, ANOVA/MANOVA) were largely absent from the papers. All types of effect sizes were infrequently interpreted. Researchers are strongly encouraged to conduct power analyses when designing studies, and to avoid scattergun approaches to data analysis (i.e. undertaking large numbers of tests in the hope of finding 'significant' results). Because reviewing effect sizes is essential for determining the clinical significance of study findings, researchers would better serve the field of mental health nursing if they reported and interpreted effect sizes. © 2012 The Authors. International Journal of Mental Health Nursing © 2012 Australian College of Mental Health Nurses Inc.

Colorectal cancer screening patient education materials-how effective is online health information?

PubMed

John, Elizabeth Sheena; John, Ann M; Hansberry, David R; Thomas, Prashant J; Agarwal, Prateek; Deitch, Christopher; Chokhavatia, Sita

2016-12-01

Patients screened for colorectal cancer (CRC) frequently turn to the Internet to improve their understanding of tests used for detection, including colonoscopy, flexible sigmoidoscopy, fecal occult blood test (FOBT), and CT colonography. It was of interest to determine the quality and readability levels of online health information. The screening tools were googled, and the top 20 results of each test were analyzed for readability, accessibility, usability, and reliability. The 80 articles excluded scientific literature and blogs. We used ten validated readability scales to measure grade levels, and one-way ANOVA and Tukey's honestly statistical different (HSD) post hoc analyses to determine any statistically significant differences among the four diagnostic tests. The LIDA tool assessed overall quality by measuring accessibility, usability, and reliability. The 80 articles were written at an 11.7 grade level, with CT colonography articles written at significantly higher levels than FOBT articles, F(3, 75) = 3.07, p = 0.033. LIDA showed moderate percentages in accessibility (83.9 %), usability (73.0 %), and reliability (75.9 %). Online health information about CRC screening tools are written at higher levels than the National Institute of Health (NIH) and American Medical Association (AMA) recommended third to seventh grade levels. More patients could benefit from this modality of information if it were written at a level and quality that would better facilitate understanding.

Neuronal Function in Male Sprague Dawley Rats During Normal Ageing.

PubMed

Idowu, A J; Olatunji-Bello, I I; Olagunju, J A

2017-03-06

During normal ageing, there are physiological changes especially in high energy demanding tissues including the brain and skeletal muscles. Ageing may disrupt homeostasis and allow tissue vulnerability to disease. To establish an appropriate animal model which is readily available and will be useful to test therapeutic strategies during normal ageing, we applied behavioral approaches to study age-related changes in memory and motor function as a basis for neuronal function in ageing in male Sprague Dawley rats. 3 months, n=5; 6 months, n=5 and 18 months, n=5 male Sprague Dawley Rats were tested using the Novel Object Recognition Task (NORT) and the Elevated plus Maze (EPM) Test. Data was analyzed by ANOVA and the Newman-Keuls post hoc test. The results showed an age-related gradual decline in exploratory behavior and locomotor activity with increasing age in 3 months, 6 months and 18 months old rats, although the values were not statistically significant, but grooming activity significantly increased with increasing age. Importantly, we established a novel finding that the minimum distance from the novel object was statistically significant between 3 months and 18 months old rats and this may be an index for age-related memory impairment in the NORT. Altogether, we conclude that the male Sprague Dawley rat show age-related changes in neuronal function and may be a useful model for carrying out investigations into the mechanisms involved in normal ageing.

Effect of 10% Strontium Chloride and 5% Potassium Nitrate with Fluoride on Bleached Bovine Enamel.

PubMed

Alencar, Cristiane de Melo; Pedrinha, Victor Feliz; Araújo, Jesuína Lamartine Nogueira; Esteves, Renata Antunes; Silva da Silveira, Ana Daniela; Silva, Cecy Martins

2017-01-01

Dental whitening has been increasingly sought out to improve dental aesthetics, but may cause chemical and morphological changes in dental enamel surfaces. This study evaluated in vitro the effect of 10% strontium chloride and 5% potassium nitrate with fluoride on bovine enamel, through tristimulus colorimetry, Knoop microhardness (KHN), and roughness after bleaching with 35% hydrogen peroxide (HP). The specimens were divided into three groups (n=15): GControl received bleaching treatment with 35% HP; GNitrate received bleaching with 35% HP followed by the application of 5% potassium nitrate with 2% sodium fluoride; and GStrontium received bleaching with 35% HP followed by the application of 10% strontium chloride on the enamel. Next, five specimens of each experimental group were subjected to KHN and tristimulus colorimetry tests, and 10 specimens were subjected to surface roughness (SR) tests. The values obtained for the different groups were compared through analysis of variance (ANOVA) followed by a post-hoc Tukey-Kramer test in addition to Student's T-test for paired data. In the intergroup comparison, KHN final differed statistically ( p <0.05). The mean SR final of the experimental groups differed statistically from the GControl group ( p <0.05). In addition, the groups did not differ in color variation ( p >0.05). 10% strontium chloride and 5% potassium nitrate combined with 2% fluoride downplayed morphological changes to the enamel, without interfering with the effectiveness of the bleaching process.

Friction and Wear Behavior of Selected Dental Ceramics

NASA Astrophysics Data System (ADS)

Park, Jongee; Pekkan, Gurel; Ozturk, Abdullah

The purpose of this study was to determine the friction coefficients and wear rates of six commercially available dental ceramics including IPS Empress 2 (E2), Cergo Pressable Ceramic (CPC), Cercon Ceram (CCS) and Super porcelain EX-3 (SPE). Bovine enamel (BE) was also tested as a reference material for comparison purposes. Samples of the dental ceramics were prepared according to the instructions described by the manufacturers in disk-shape with nominal dimensions of 12 mm × 2 mm. The wear tests were performed by means of a pin-on-disk type tribometer. The friction coefficients and specific wear rates of the materials were determined at a load of 10 N and rotating speed of 0.25 cm/s without lubrication. Surface morphology of the wear tracks was examined using a scanning electron microscope. Statistical analyses were made using one-way ANOVA and Turkey's HSD (P < 0.05).

Preservice Teachers' Memories of Their Secondary Science Education Experiences

ERIC Educational Resources Information Center

Hudson, Peter; Usak, Muhammet; Fancovicova, Jana; Erdogan, Mehmet; Prokop, Pavol

2010-01-01

Understanding preservice teachers' memories of their education may aid towards articulating high-impact teaching practices. This study describes 246 preservice teachers' perceptions of their secondary science education experiences through a questionnaire and 28-item survey. ANOVA was statistically significant about participants' memories of…

[Development and evaluation of a program to promote self management in patients with chronic hepatitis B].

PubMed

Yang, Jin-Hyang

2012-04-01

The purpose of this study was to identify the effects of the program to promote self management for patients with chronic hepatitis B. The research was a quasi-experimental design using a non-equivalent control group pre-post test. The participants were 61 patients, 29 in the experimental group and 32 in the control group. A pretest and 2 posttests were conducted to measure main variables. For the experimental group, the self-management program, consisting of counseling-centered activities in small groups, was given for 6 weeks. Data were analyzed using χ², t-test, and repeated measures ANOVA with PASW statistics program. There were statistically significant increases in knowledge, self-efficacy, active ways of coping, and self-management compliance but not in passive ways of coping in the experimental group compared to the control group over two different times. The results of this study indicate that the self-management program is effective in increasing knowledge, self-efficacy, active ways of coping, and self-management compliance among patients with chronic hepatitis B. Therefore, it can be usefully utilized in the field of nursing for patients with chronic disease as a nursing intervention for people with chronic hepatitis B.

Effect of laser welding on the titanium composite tensile bond strength.

PubMed

Galo, Rodrigo; Ribeiro, Ricardo Faria; Rodrigues, Renata Cristina Silveira; Pagnano, Valéria de Oliveira; de Mattos, Maria da Glória Chiarello

2009-01-01

The aim of this study was to analyze the shear bond strength between commercially pure titanium, with and without laser welding, after airbone-particle abrasion (Al(2)O(3)) and 2 indirect composites. Sixty-four specimens were cast and divided into 2 groups with and without laser welding. Each group was divided in 4 subgroups, related to Al(2)O(3) grain size: A - 250 microm; B - 180 microm; C- 110 microm; and D - 50 microm. Composite rings were formed around the rods and light polymerized using UniXS unit. Specimens were invested and their shear bond strength at failure was measured with a universal testing machine at a crosshead speed of 2.0 mm/min. Statistical analysis was carried out with ANOVA and Tukey's test (alpha=0.05). The highest bond strength means were recorded in 250 microm group without laser welding. The lowest shear bond strength means were recorded in 50 microm group with laser welding. Statistically significant differences (p<0.05) were found between all groups. In conclusion, airborne particle abrasion yielded significantly lower bond strength as the Al(2)O(3) particle size decreased. Shear bond strength decreased in the laser welded specimens.

[Bonding agent influence on shear bond strength of titanium/polyglass interface].

PubMed

Oyafuso, Denise Kanashiro; Bottino, Marco Antonio; Itinoche, Marcos Koiti; Nasraui, Anna Paula; Costa, Elza Maria Valadares da

2003-09-01

There is little information regarding bond strengths of polyglass to metal alloys. This study evaluated the influence of bonding system on shear bond strength of a composite resin (Artglass/Heraeus Kulzer) to cast titanium (Ti). Twenty metallic structures (4mm in diameter, 5mm thick) of titanium grade I were cast shaped and abraded with 250mm aluminum oxide and separated into two groups. For each group was applied one bonding system (Siloc or Retention Flow) before opaque and dentin polymer superposition. This procedure was managed using teflon matrices. They were manipulated and polymerized according to the manufacturer's recommendations. The samples were stored in distilled water for 24 hours at 37º and thermocycled (5º and 55ºC/500 cycles). Shear bond strength tests were performed by using an Instron Universal testing machine at a crosshead speed of 5mm/min. Results were analyzed statistically with one-way ANOVA (a=0,5) and they indicated that the Retention Flow system was statistically better than Siloc (20.74 MPa and 11.65 MPa , respectively). It was possible to conclude that the bonding agent influenced the adhesion between polymer and cast titanium.

Enhancement of CFD validation exercise along the roof profile of a low-rise building

NASA Astrophysics Data System (ADS)

Deraman, S. N. C.; Majid, T. A.; Zaini, S. S.; Yahya, W. N. W.; Abdullah, J.; Ismail, M. A.

2018-04-01

The aim of this study is to enhance the validation of CFD exercise along the roof profile of a low-rise building. An isolated gabled-roof house having 26.6° roof pitch was simulated to obtain the pressure coefficient around the house. Validation of CFD analysis with experimental data requires many input parameters. This study performed CFD simulation based on the data from a previous study. Where the input parameters were not clearly stated, new input parameters were established from the open literatures. The numerical simulations were performed in FLUENT 14.0 by applying the Computational Fluid Dynamics (CFD) approach based on steady RANS equation together with RNG k-ɛ model. Hence, the result from CFD was analysed by using quantitative test (statistical analysis) and compared with CFD results from the previous study. The statistical analysis results from ANOVA test and error measure showed that the CFD results from the current study produced good agreement and exhibited the closest error compared to the previous study. All the input data used in this study can be extended to other types of CFD simulation involving wind flow over an isolated single storey house.

Bond Strength of Gold Alloys Laser Welded to Cobalt-Chromium Alloy

PubMed Central

Watanabe, Ikuya; Wallace, Cameron

2008-01-01

The objective of this study was to investigate the joint properties between cast gold alloys and Co-Cr alloy laser-welded by Nd:YAG laser. Cast plates were fabricated from three types of gold alloys (Type IV, Type II and low-gold) and a Co-Cr alloy. Each gold alloy was laser-welded to Co-Cr using a dental laser-welding machine. Homogeneously-welded and non-welded control specimens were also prepared. Tensile testing was conducted and data were statistically analyzed using ANOVA. The homogeneously-welded groups showed inferior fracture load compared to corresponding control groups, except for Co-Cr. In the specimens welded heterogeneously to Co-Cr, Type IV was the greatest, followed by low-gold and Type II. There was no statistical difference (P<0.05) in fracture load between Type II control and that welded to Co-Cr. Higher elongations were obtained for Type II in all conditions, whereas the lowest elongation occurred for low-gold welded to Co-Cr. This study indicated that, of the three gold alloys tested, the Type IV gold alloy was the most suitable alloy for laser-welding to Co-Cr. PMID:19088892

Comparative effects of conjugated linoleic acid (CLA) and linoleic acid (LA) on the oxidoreduction status in THP-1 macrophages.

PubMed

Rybicka, Marta; Stachowska, Ewa; Gutowska, Izabela; Parczewski, Miłosz; Baśkiewicz, Magdalena; Machaliński, Bogusław; Boroń-Kaczmarska, Anna; Chlubek, Dariusz

2011-04-27

The aim of this study was to investigate the effect of conjugated linoleic acids (CLAs) on macrophage reactive oxygen species synthesis and the activity and expression of antioxidant enzymes, catalase (Cat), glutathione peroxidase (GPx), and superoxide dismutase (SOD). The macrophages were obtained from the THP-1 monocytic cell line. Cells were incubated with the addition of cis-9,trans-11 CLA or trans-10,cis-12 CLA or linoleic acid. Reactive oxygen species (ROS) formation was estimated by flow cytometry. Enzymes activity was measured spectrophotometrically. The antioxidant enzyme mRNA expression was estimated by real-time reverse transcriptase polymerase chain reaction (RT-PCR). Statistical analysis was based on nonparametric statistical tests [Friedman analysis of variation (ANOVA) and Wilcoxon signed-rank test]. cis-9,trans-11 CLA significantly increased the activity of Cat, while trans-10,cis-12 CLA notably influenced GPx activity. Both isomers significantly decreased mRNA expression for Cat. Only trans-10,cis-12 significantly influenced mRNA for SOD-2 expression. The CLAs activate processes of the ROS formation in macrophages. Adverse metabolic effects of each isomer action were observed.

Consumer knowledge and attitudes toward nutritional labels.

PubMed

Cannoosamy, Komeela; Pugo-Gunsam, Prity; Jeewon, Rajesh

2014-01-01

To determine Mauritian consumers' attitudes toward nutritional labels based on the Kano model and to identify determinants of the use and understanding of nutrition labels. The researchers also used a Kano model questionnaire to determine consumers' attitudes toward nutrition labeling. Four hundred consumers residing in Mauritius. Information was elicited via a questionnaire that assessed nutritional knowledge and information about the use and understanding of nutritional labels and demographic factors. Nutritional label use and understanding, nutrition knowledge, and association of demographic factors with label use. Statistical tests performed included 1-way ANOVA and independent samples t tests. Statistically significant relationships (P < .05) were found for nutritional knowledge and nutritional label usage with demographic factors. All demographic factors with the exception of gender were significantly associated (P < .05) with nutritional label understanding. Based on the outcome of the Kano survey, calorie content, trans fat content, protein content, and cholesterol content were found to be must-be attributes: that is, attributes that, when not present, result in consumer dissatisfaction. Age, education, income, household size, and nutrition knowledge had an impact on nutritional label use. Health promoters should aim to increase the use of nutritional labels. Copyright © 2014 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Efficacy of cevimeline vs. pilocarpine in the secretion of saliva: a pilot study.

PubMed

Brimhall, Jae; Jhaveri, Malhar A; Yepes, Juan F

2013-01-01

To determine the efficacy and compare the side-effects of cevimeline and pilocarpine in the secretion of saliva in patients with xerostomia. A randomized, cross-over, double blind study was designed. Fifteen patients with diagnosis of xerostomia were assigned to take either 5 mg of pilocarpine or 30 mg of cevimeline three times a day for four weeks. Salivary flow rates were measured during the initial baseline, first and second month appointments. Statistical analysis was carried out with ANOVA and post hoc t-tests. Twelve patients completed both medication treatments. Although both medications proved to increase salivary secretion, there was no significant difference between pilocarpine and cevimeline. Also, the perceived side-effects between the two medications were similar. Both medications increased the secretion of saliva at the end of four weeks. However, there was a slightly higher increment in saliva with pilocarpine. However, the difference was not statistically significant. ©2013 Special Care Dentistry Association and Wiley Periodicals, Inc.

[Teaching performance assessment in Public Health employing three different strategies].

PubMed

Martínez-González, Adrián; Moreno-Altamirano, Laura; Ponce-Rosas, Efrén Raúl; Martínez-Franco, Adrián Israel; Urrutia-Aguilar, María Esther

2011-01-01

The educational system depends upon the quality and performance of their faculty and should therefore be process of continuous improvement. To assess the teaching performance of the Public Health professors, at the Faculty of Medicine, UNAM through three strategies. Justification study. The evaluation was conducted under a mediational model through three strategies: students' opinion assessment, self-assessment and students' academic achievement. We applied descriptive statistics, Student t test, ANOVA and Pearson correlation. Twenty professors were evaluated from the Public Health department, representing 57% of all them who teach the subject. The professor's performance was highly valued self-assessment compared with assessment of student opinion, was confirmed by statistical analysis the difference was significant. The difference amongst the three evaluation strategies became more evident between self-assessment and the scores obtained by students in their academic achievement. The integration of these three strategies offers a more complete view of the teacher's performance quality. Academic achievement appears to be a more objective strategy for teaching performance assessment than students' opinion and self-assessment.

Leptin to adiponectin ratio in preeclampsia.

PubMed

Khosrowbeygi, A; Ahmadvand, H

2013-04-01

The aim of the present study was to assess leptin/adiponectin ratio in preeclamptic patients compared with normal pregnant women. A cross-sectional study was designed. The study population consisted of 30 preeclamptic patients and 30 healthy pregnant women. Serum levels of total leptin and adiponectin were assessed using commercially available enzyme-linked immunosorbent assay methods. The one-way ANOVA and Student's t tests and Pearson's correlation analysis were used for statistical calculations. Levels of leptin and adiponectin were also adjusted for BMI. A p-value < 0.05 was considered statistically significant. The leptin/adiponectin ratio was increased significantly in preeclamptic patients. The leptin/adiponectin ratio was significantly higher in severe preeclamptic patient than in mild preeclampsia. Adjusted leptin/adiponectin ratio was also significantly increased in preeclamptic patients than in normal pregnant women. The findings of the present study suggest that the leptin/adiponectin ratio was increased in preeclamsia and imbalance between the adipocytokines could be involved in the pathogenesis of preeclampsia.

Evaluation of implant osseointegration with different regeneration techniques in the treatment of bone defects around implants: an experimental study in a rabbit model.

PubMed

Guerra, Isabel; Morais Branco, Fernando; Vasconcelos, Mário; Afonso, Américo; Figueiral, Helena; Zita, Raquel

2011-03-01

The aim of this study was to evaluate the osseointegration of implants placed in areas with artificially created bone defects, using three bone regeneration techniques. The experimental model was the rabbit femur (16), where bone defects were created and implants were placed. The peri-implant bone defects were filled with a deproteinized bovine bone mineral, NuOss™ (N), NuOss™ combined with plasma rich in growth factors (PRGF) (N+PRGF), NuOss™ covered by an RCM(6) membrane (N+M), or remained unfilled (control group [C]). After 4 and 8 weeks, the animals were euthanized and bone tissue blocks with the implants and the surrounding bone tissue were removed and processed according to a histological protocol for hard tissues on non-decalcified ground sections. The samples were studied by light and electron scanning microscopy, histometric analysis was performed to assess the percentage of bone in direct contact with the implant surface and a statistical analysis of the results was performed. In the samples analyzed 4 weeks after implantation, the percentage of bone tissue in direct contact with the implant surface for the four groups were 57.66±24.39% (N), 58.62±20.37% (N+PRGF), 70.82±20.34 % (N+M) and 33.07±5.49% (C). In the samples with 8 weeks of implantation time, the percentage of bone in direct contact was 63.35±27.69% (N), 58.42±24.77% (N+PRGF), 78.02±15.13% (N+M) and 40.28±27.32% (C). In terms of the percentage of bone contact, groups N and N+M presented statistically significant differences from group C in the 4-week trial test (P<0.05; ANOVA). For the 8-week results, only group N+M showed statistically significant differences when compared with group C (P<0.05; ANOVA). In conclusion, the NuOss™ granules/RCM(6) membrane combination presented a percentage of bone contact with the implant surface statistically greater than in the other groups. © 2010 John Wiley & Sons A/S.

Shear bond strength of orthodontic brackets and disinclusion buttons: effect of water and saliva contamination.

PubMed

Sfondrini, Maria Francesca; Fraticelli, Danilo; Gandini, Paola; Scribante, Andrea

2013-01-01

The aim of this study was to assess the effect of water and saliva contamination on the shear bond strength and failure site of orthodontic brackets and lingual buttons. 120 bovine permanent mandibular incisors were randomly divided into 6 groups of 20 specimens each. Both orthodontic brackets and disinclusion buttons were tested under three different enamel surface conditions: (a) dry, (b) water contamination, and (c) saliva contamination. Brackets and buttons were bonded to the teeth and subsequently tested using a Instron universal testing machine. Shear bond strength values and adhesive failure rate were recorded. Statistical analysis was performed using ANOVA and Tukey tests (strength values) and Chi squared test (ARI Scores). Noncontaminated enamel surfaces showed the highest bond strengths for both brackets and buttons. Under water and saliva contamination orthodontic brackets groups showed significantly lower shear strengths than disinclusion buttons groups. Significant differences in debond locations were found among the groups under the various enamel surface conditions. Water and saliva contamination of enamel during the bonding procedure lowers bond strength values, more with orthodontic brackets than with disinclusion buttons.

In vitro wear of new indirect resin composites.

PubMed

Jain, V; Platt, J A; Moore, B K; Borges, G A

2009-01-01

This in vitro study evaluated the toothbrush abrasion wear, three-body Alabama wear and two-body pin-on-disc wear of four commercial indirect resin composites. Enamel shades of Radica (R), Sculpture Plus (S), Belleglass-NG (B) and Gradia Indirect (G) were used. For measuring wear due to toothbrush abrasion, six specimens of each group were fabricated, then brushed in a toothbrush abrasion machine for 20,000 cycles. Material loss was determined by weighing and conversion to volume loss. Three-body wear was measured on six samples for each group using an Alabama-type wear testing machine for 400,000 cycles. Wear depth was measured with a contact profilometer. For two-body wear, five disc specimens were prepared and tested in a two-body wear-testing machine against hydroxypatite sliders for 25,000 cycles. Data were analyzed with one-way analysis of variance (ANOVA) and Tukey test (alpha=0.05). Wear was the highest in Sculpture Plus by all three methods tested and the lowest wear was observed in Belleglass-NG. No statistical difference in wear was noted from Radica.

Relationship between Omnibus and Post-hoc Tests: An Investigation of performance of the F test in ANOVA.

PubMed

Chen, Tian; Xu, Manfei; Tu, Justin; Wang, Hongyue; Niu, Xiaohui

2018-02-25

Comparison of groups is a common statistical test in many biomedical and psychosocial research studies. When there are more than two groups, one first performs an omnibus test for an overall difference across the groups. If this null is rejected, one then proceeds to the next step of post-hoc pairwise group comparisons to determine sources of difference. Otherwise, one stops and declares no group difference. A common belief is that if the omnibus test is significant, there must exist at least two groups that are significantly different and vice versa. Thus, when the omnibus test is significant, but no post-hoc between-group comparison shows significant difference, one is bewildered at what is going on and wondering how to interpret the results. At the end of the spectrum, when the omnibus test is not significant, one wonders if all post-hoc tests will be non-significant as well so that stopping after a nonsignificant omnibus test will not lead to any missed opportunity of finding group difference. In this report, we investigate this perplexing phenomenon and discuss how to interpret such results.

Prevalence of orthorexia nervosa in resident medical doctors in the faculty of medicine (Ankara, Turkey).

PubMed

Bağci Bosi, A Tülay; Camur, Derya; Güler, Cağatay

2007-11-01

This study has been carried out to "identify highly sensitive behavior on healthy nutrition (orthorexia nervosa-ON)" in residence medical doctors (MD) in the Faculty of Medicine. Diagnoses of ON was based on the presence of a disorder with obsessive-compulsive personality. The study is a cross-sectional research, which reached out to the entire 318 MD. The ORTO-15 test was used to propose a diagnostic proceeding and to try verify the prevalence of ON. Those subjects who were classified below 40 from the ORTO-15 test are accepted to have ON. Chi-square test, ANOVA (univariate) analysis and logistic regression were used for analyses of the data. Mean score of the participants from the ORTO-15 test is 39.8+/-0.22, and there is no statistical difference between women and men. A total of 45.5% of the residence MD involved in the research scored below 40 in the ORTO-15 test. Those who do their food shopping themselves, skip a meal with a salad/fruit, care about the quality of the things they eat, think that eating outside is healthy, look at the content of what they eat and the content of food is important in selection of a product score lower in their average marks in ORTO-15 and the difference among the groups is statistically significant. Food selection of 20.1% of the male participants and 38.9% of the female participants among the residence MD is influenced by the programs on nutrition/health in mass-media. The difference between the groups is statistically significant (p<0.05). Female medical doctors are more careful than men of their physical appearance and weight control and consume less caloric food, which is statistically significant. Since those who exhibit "healthy fanatic" eating habits may have a risk of ON in the future, it would be useful to conduct studies that identify the prevalence of ON in the public.

The correlation between effective factors of e-learning and demographic variables in a post-graduate program of virtual medical education in Tehran University of Medical Sciences.

PubMed

Golband, Farnoosh; Hosseini, Agha Fatemeh; Mojtahedzadeh, Rita; Mirhosseini, Fakhrossadat; Bigdeli, Shoaleh

2014-01-01

E-learning as an educational approach has been adopted by diverse educational and academic centers worldwide as it facilitates learning in facing the challenges of the new era in education. Considering the significance of virtual education and its growing practice, it is of vital importance to examine its components for promoting and maintaining success. This analytical cross-sectional study was an attempt to determine the relationship between four factors of content, educator, learner and system, and effective e-learning in terms of demographic variables, including age, gender, educational background, and marital status of postgraduate master's students (MSc) studying at virtual faculty of Tehran University of Medical Sciences. The sample was selected by census (n=60); a demographic data gathering tool and a researcher-made questionnaire were used to collect data. The face and content validity of both tools were confirmed and the results were analyzed by descriptive statistics (frequency, percentile, standard deviation and mean) and inferential statistics (independent t-test, Scheffe's test, one-way ANOVA and Pearson correlation test) by using SPSS (V.16). The present study revealed that There was no statistically significant relationship between age and marital status and effective e-learning (P>0.05); whereas, there was a statistically significant difference between gender and educational background with effective e-learning (P<0.05). Knowing the extent to which these factors can influence effective e-learning can help managers and designers to make the right decisions about educational components of e-learning, i.e. content, educator, system and learner and improve them to create a more productive learning environment for learners.

Effect of Different Anti-Oxidants on Shear Bond Strength of Composite Resins to Bleached Human Enamel

PubMed Central

Saladi, Hari Krishna; Bollu, Indira Priyadarshini; Burla, Devipriya; Ballullaya, Srinidhi Vishnu; Devalla, Srihari; Maroli, Sohani; Jayaprakash, Thumu

2015-01-01

Introduction The bond strength of the composite to the bleached enamel plays a very important role in the success and longevity of an aesthetic restoration. Aim The aim of this study was to compare and evaluate the effect of Aloe Vera with 10% Sodium Ascorbate on the Shear bond strength of composite resin to bleached human enamel. Materials and Methods Fifty freshly extracted human maxillary central incisors were selected and divided into 5 groups. Group I and V are unbleached and bleached controls groups respectively. Group II, III, IV served as experimental groups. The labial surfaces of groups II, III, IV, V were treated with 35% Carbamide Peroxide for 30mins. Group II specimens were subjected to delayed composite bonding. Group III and IV specimens were subjected to application of 10% Sodium Ascorbate and leaf extract of Aloe Vera following the Carbamide Peroxide bleaching respectively. Specimens were subjected to shear bond strength using universal testing machine and the results were statistically analysed using ANOVA test. Tukey (HSD) Honest Significant Difference test was used to comparatively analyse statistical differences between the groups. A p-value <0.05 is taken as statistically significant. Results The mean shear bond strength values of Group V showed significantly lower bond strengths than Groups I, II, III, IV (p-value <0.05). There was no statistically significant difference between the shear bond strength values of groups I, II, III, IV. Conclusion Treatment of the bleached enamel surface with Aloe Vera and 10% Sodium Ascorbate provided consistently better bond strength. Aloe Vera may be used as an alternative to 10% Sodium Ascorbate. PMID:26674656

Influence of different iodinated contrast media on the induction of DNA double-strand breaks after in vitro X-ray irradiation.

PubMed

Deinzer, Christoph K W; Danova, Daniela; Kleb, Beate; Klose, Klaus J; Heverhagen, Johannes T

2014-01-01

The objective of this work was to examine differences in DNA double-strand break induction in peripheral blood lymphocytes after in vitro X-ray irradiation between iodinated contrast agents. Four different iodinated X-ray contrast agents--three of them with two different iodine concentrations--and mannitol (negative control; concentration of 150 mg mannitol per ml blood) were pipetted into blood samples so that there was a concentration of 0, 7.5 or 15 mg of iodine per ml blood in the samples. Negative controls without contrast medium (0 mg of iodine per ml blood) were also processed for every irradiation dose. The tubes were exposed to 0, 20 or 500 mGy in vitro X-ray irradiation. After that, the lymphocytes were separated by using density-gradient centrifugation. Fluorescence microscopy was applied to determine the average number of γH2AX-foci per lymphocyte in the presence or absence of different contrast media or mannitol. Differences in the number of γH2AX-foci were statistically analysed by one-way ANOVA and post-hoc Tukey's honestly significant difference test. Iodinated contrast agents led to a statistically significant increase in DNA double-strand breaks after in vitro irradiation. This effect increased statistically significant with rising radiation dose and appeared independent of the contrast agent used (iopromid, iodixanol, iomeprol, iopamidol). A statistically significant difference in DNA damage between the different tested contrast agents was not found. Therefore, the increase in DNA double-strand breaks depends solely on the amount of iodine applied. For evaluation of clinical consequences, our findings could be tested in further animal studies. Copyright © 2014 John Wiley & Sons, Ltd.

The investigation of the some body parameters of obese and (obese+diabetes) patients with using bioelectrical impedance analysis techniques

NASA Astrophysics Data System (ADS)

Yerlikaya, Emrah; Karageçili, Hasan; Aydin, Ruken Zeynep

2016-04-01

Obesity is a key risk for the development of hyperglycemia, hypertension, hyperlipidemia, insulin resistance and is totally referred to as the metabolic disorders. Diabetes mellitus, a metabolic disorder, is related with hyperglycemia, altered metabolism of lipids, carbohydrates and proteins. The minimum defining characteristic feature to identify diabetes mellitus is chronic and substantiated elevation of circulating glucose concentration. In this study, it is aimed to determine the body composition analyze of obese and (obese+diabetes) patients.We studied the datas taken from three independent groups with the body composition analyzer instrument. The body composition analyzer calculates body parameters, such as body fat ratio, body fat mass, fat free mass, estimated muscle mass, and base metabolic rate on the basis of data obtained by Dual Energy X-ray Absorptiometry using Bioelectrical Impedance Analysis. All patients and healthy subjects applied to Siirt University Medico and their datas were taken. The Statistical Package for Social Sciences version 21 was used for descriptive data analysis. When we compared and analyzed three groups datas, we found statistically significant difference between obese, (obese+diabetes) and control groups values. Anova test and tukey test are used to analyze the difference between groups and to do multiple comparisons. T test is also used to analyze the difference between genders. We observed the statistically significant difference in age and mineral amount p<0.00 between (diabetes+obese) and obese groups. Besides, when these patient groups and control group were analyzed, there were significant difference between most parameters. In terms of education level among the illiterate and university graduates; fat mass kg, fat percentage, internal lubrication, body mass index, water percentage, protein mass percentage, mineral percentage p<0.05, significant statistically difference were observed. This difference especially may result of a sedentary lifestyle.

Surface hardness of different restorative materials after long-term immersion in sports and energy drinks.

PubMed

Erdemir, Ugur; Yildiz, Esra; Eren, Meltem Mert; Ozel, Sevda

2012-01-01

The purpose of this study was to evaluate the effect of sports and energy drinks on the surface hardness of different restorative materials over a 6-month period. Forty-two disk-shaped specimens were prepared for each of the four restorative materials tested: Compoglass F, Filtek Z250, Filtek Supreme, and Premise. Specimens were immersed for 2 min daily, up to 6 months, in six storage solutions (n=7 per material for each solution): distilled water, Powerade, Gatorade, X-IR, Burn, and Red Bull. Surface hardness was measured at baseline, after 1 week, 1 month, and 6 months. Data were analyzed statistically using repeated measures ANOVA followed by the Bonferroni test for multiple comparisons (α=0.05). Surface hardness of the restorative materials was significantly affected by both immersion solution and immersion period (p<0.001). All tested solutions induced significant reduction in surface hardness of the restorative materials over a 6-month immersion period.

Mechanical Properties Analysis of 4340 Steel Specimen Heat Treated in Oven and Quenching in Three Different Fluids

NASA Astrophysics Data System (ADS)

Fakir, Rachid; Barka, Noureddine; Brousseau, Jean

2018-03-01

This paper proposes a statistical approach to analyze the mechanical properties of a standard test specimen, of cylindrical geometry and in steel 4340, with a diameter of 6 mm, heat-treated and quenched in three different fluids. Samples were evaluated in standard tensile test to access their characteristic quantities: hardness, modulus of elasticity, yield strength, tensile strength and ultimate deformation. The proposed approach is gradually being built (a) by a presentation of the experimental device, (b) a presentation of the experimental plan and the results of the mechanical tests, (c) anova analysis of variance and a representation of the output responses using the RSM response surface method, and (d) an analysis of the results and discussion. The feasibility and effectiveness of the proposed approach leads to a precise and reliable model capable of predicting the variation of mechanical properties, depending on the tempering temperature, the tempering time and the cooling capacity of the quenching medium.

Acute effects of The Stick on strength, power, and flexibility.

PubMed

Mikesky, Alan E; Bahamonde, Rafael E; Stanton, Katie; Alvey, Thurman; Fitton, Tom

2002-08-01

The Stick is a muscle massage device used by athletes, particularly track athletes, to improve performance. The purpose of this project was to assess the acute effects of The Stick on muscle strength, power, and flexibility. Thirty collegiate athletes consented to participate in a 4-week, double-blind study, which consisted of 4 testing sessions (1 familiarization and 3 data collection) scheduled 1 week apart. During each testing session subjects performed 4 measures in the following sequence: hamstring flexibility, vertical jump, flying-start 20-yard dash, and isokinetic knee extension at 90 degrees x s(-1). Two minutes of randomly assigned intervention treatment (visualization [control], mock insensible electrical stimulation [placebo], or massage using The Stick [experimental]) was performed immediately prior to each performance measure. Statistical analyses involved single-factor repeated measures analysis of variance (ANOVA) with Fisher's Least Significant Difference post-hoc test. None of the variables measured showed an acute improvement (p < or = 0.05) immediately following treatment with The Stick.

Mechanical evaluation of quad-helix appliance made of low-nickel stainless steel wire.

PubMed

dos Santos, Rogério Lacerda; Pithon, Matheus Melo

2013-01-01

The objective of this study was to test the hypothesis that there is no difference between stainless steel and low-nickel stainless steel wires as regards mechanical behavior. Force, resilience, and elastic modulus produced by Quad-helix appliances made of 0.032-inch and 0.036-inch wires were evaluated. Sixty Quad-helix appliances were made, thirty for each type of alloy, being fifteen for each wire thickness, 0.032-in and 0.036-in. All the archwires were submitted to mechanical compression test using an EMIC DL-10000 machine simulating activations of 4, 6, 9, and 12 mm. Analysis of variance (ANOVA) with multiple comparisons and Tukey's test were used (p < 0.05) to assess force, resilience, and elastic modulus. Statistically significant difference in the forces generated, resilience and elastic modulus were found between the 0.032-in and 0.036-in thicknesses (p < 0.05). Appliances made of low-nickel stainless steel alloy had force, resilience, and elastic modulus similar to those made of stainless steel alloy.

Pregnancy- and delivery-induced biomechanical changes in rat vagina persist postpartum

PubMed Central

Alperin, Marianna; Feola, Andrew; Duerr, Robert; Moalli, Pamela; Abramowitch, Steven

2010-01-01

Introduction and hypothesis We sought to define changes in vaginal distensibility (VD) induced by pregnancy and vaginal delivery using a novel in vivo biomechanical testing protocol. Methods Under sedation, a balloon was inserted into the vagina of 27 virgin, pregnant and 4-week postpartum Long–Evans rats and incrementally distended. Pressure–volume curves were generated with slopes characterizing VD (higher slope = less distensible). One-way ANOVA with a Bonferroni post-hoc test were used for statistical analyses. Results Mean pressures at an infusion volume of 1 cc were lower in pregnant and postpartum rats than in virgins (P<0.001). VD was increased in pregnant vs. virgin rats (P<0.001) and did not recover to virgin levels post partum (P<0.001). Conclusions We have developed a test that measures VD in vivo under clinically relevant loading conditions. The increased VD in the late postpartum period defines a persistent change in biomechanical behavior of the vagina related to pregnancy and vaginal delivery. PMID:20424824

Effects of various final irrigants on the shear bond strength of resin-based sealer to dentin.

PubMed

Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu; Arathi, Ganesh; Roohi, Riaz; Anand, Suresh

2011-01-01

This study has been designed to evaluate the effect of strong (MTAD) or soft (1- hydroxyethylidene - 1, 1-bisphosphonate (HEBP) final irrigating solution on the shear bond strength of AH plus sealer to coronal dentin. 17% EDTA was used as the reference. Forty freshly extracted human maxillary first premolars were prepared using different irrigation protocols (n=10). All the test groups had 1.3% NaOCl as initial rinse and followed by specific final rinse for each group: G1 - distilled water(control), G2 - 17% EDTA, G3- 18% HEBP and G4 - MTAD. Sections of polyethylene tubes that are 3mm long were filled with freshly mixed sealer and placed on the dentin surfaces. The bonding between the sealer and dentine surface was evaluated using shear bond testing. The values were statistically evaluated using one-way ANOVA followed by Tukey's test. Significant difference was found among the irrigating regimes. EDTA showed highest bond strength followed by HEBP and MTAD.

Data and material of the Safe-Range-Inventory: An assistance tool helping to improve the charging infrastructure for electric vehicles.

PubMed

Carbon, Claus-Christian; Gebauer, Fabian

2017-10-01

The Safe-Range-Inventory (SRI) was constructed in order to help public authorities to improve the charging infrastructures for electric vehicles [1; 10.1016/j.trf.2017.04.011]. Specifically, the impact of fast (vs slow) charging stations on people's range anxiety was examined. Ninety-seven electric vehicle users from Germany (81 male; M age =46.3 years, SD =12.1) were recruited to participate in the experimental design. Statistical analyses were conducted using ANOVA for repeated measures to test for interaction effects of available charging stations and remaining range with the dependent variable range anxiety . The full data set is publicly available via https://osf.io/bveyw/ (Carbon and Gebauer, 2017) [2].

Blood lead levels and risk factors in pregnant women from Durango, Mexico.

PubMed

La-Llave-León, Osmel; Estrada-Martínez, Sergio; Manuel Salas-Pacheco, José; Peña-Elósegui, Rocío; Duarte-Sustaita, Jaime; Candelas Rangel, Jorge-Luís; García Vargas, Gonzalo

2011-01-01

In this cross-sectional study the authors determined blood lead levels (BLLs) and some risk factors for lead exposure in pregnant women. Two hundred ninety-nine pregnant women receiving medical attention by the Secretary of Health, State of Durango, Mexico, participated in this study between 2007 and 2008. BLLs were evaluated with graphite furnace atomic absorption spectrometry. The authors used Student t test, 1-way analysis of variance (ANOVA), and linear regression as statistical treatments. BLLs ranged from 0.36 to 23.6 μg/dL (mean = 2.79 μg/dL, standard deviation = 2.14). Multivariate analysis showed that the main predictors of BLLs were working in a place where lead is used, using lead glazed pottery, and eating soil.

Effect of components and surface treatments of fiber-reinforced composite posts on bond strength to composite resin.

PubMed

Asakawa, Yuya; Takahashi, Hidekazu; Kobayashi, Masahiro; Iwasaki, Naohiko

2013-10-01

The aim of this study was to clarify the effect of the components and surface treatments of fiber-reinforced composite (FRC) posts on the durable bonding to core build-up resin evaluated using the pull-out and microtensile tests. Four types of experimental FRC posts, combinations of two types of matrix resins (polymethyl methacrylate and urethane dimethacrylate) and two types of fiberglass (E-glass and zirconia-containing glass) were examined. The FRC posts were subjected to one of three surface treatments (cleaned with ethanol, dichloromethane, or sandblasting). The bond strength between the FRC posts and core build-up resin were measured using the pull-out and microtensile tests before and after thermal cycling. The bond strengths obtained by each test before and after thermal cycling were statistically analyzed by three-way ANOVA and Tukey's multiple comparisons test (p<0.05). The bond strengths except for UDMA by the pull-out test decreased after thermal cycling. Regardless the test method and thermal cycling, matrix resins, the surface treatment and their interaction were statistically significant, but fiberglass did not. Dichloromethane treatment was effective for the PMMA-based FRC posts by the pull-out test, but not by the microtensile test. Sandblasting was effective for both PMMA- and UDMA-based FRC posts, regardless of the test method. The bond strengths were influenced by the matrix resin of the FRC post and the surface treatment. The bond strengths of the pull-out test showed a similar tendency of those of the microtensile test, but the value obtained by these test were different. Copyright © 2013 Elsevier Ltd. All rights reserved.

Role of enamel deminerlization and remineralization on microtensile bond strength of resin composite

PubMed Central

Rizvi, Abbas; Zafar, Muhammad S.; Al-Wasifi, Yasser; Fareed, Wamiq; Khurshid, Zohaib

2016-01-01

Objective: This study is aimed to establish the microtensile bond strength of enamel following exposure to an aerated drink at various time intervals with/without application of remineralization agent. In addition, degree of remineralization and demineralization of tooth enamel has been assessed using polarized light microscopy. Materials and Methods: Seventy extracted human incisors split into two halves were immersed in aerated beverage (cola drink) for 5 min and stored in saliva until the time of microtensile bond testing. Prepared specimens were divided randomly into two study groups; remineralizing group (n = 70): specimens were treated for remineralization using casein phosphopeptides and amorphous calcium phosphate (CPP-ACP) remineralization agent (Recaldent™; GC Europe) and control group (n = 70): no remineralization treatment; specimens were kept in artificial saliva. All specimens were tested for microtensile bond strength at regular intervals (1 h, 1 days, 2 days, 1 week, and 2 weeks) using a universal testing machine. The results statistically analyzed (P = 0.05) using two-way ANOVA test. Results: Results showed statistically significant increase in bond strength in CPP-ACP tested group (P < 0.05) at all-time intervals. The bond strength of remineralizing group samples at 2 days (~13.64 megapascals [MPa]) is comparable to that of control group after 1 week (~12.44 MPa). Conclusions: CPP-ACP treatment of teeth exposed to an aerated drink provided significant increase in bond strength at a shorter interval compared to teeth exposed to saliva alone. PMID:27403057

In vitro cytotoxicity evaluation of elemental ions released from different prosthodontic materials.

PubMed

Elshahawy, Waleed M; Watanabe, Ikuya; Kramer, Phillip

2009-12-01

This study investigated the cytotoxicity of elemental ions contained in four fixed prosthodontic materials (gold, nickel-chromium, stainless-steel alloys and CAD-CAM ceramics). According to the determination of elements released from prosthodontic materials by using inductively coupled plasma mass spectroscopy, similar amounts of elements Pd, Ag, Zn, Cu, Ni, Cr, Mo, Be, Fe, Al, and K were prepared as salt solutions. Wells with a tenfold higher concentration of the tested elements were used as positive controls, while a well without any tested element was used as a negative control. These salt solutions were tested for cytotoxicity by culturing mouse L-929 fibroblasts in the salt solutions for a 7-day period of incubation. Then, the percentage of viable cells for each element was measured using trypan blue exclusion assay. The data (n=5) were statistically analyzed by ANOVA/Tukey test (p<0.05). The results showed a statistically significant difference for the cytotoxic effect of the tested elements salt solutions. For the released element concentrations the lowest percentage of viable cells (mean+/-SD) was evident with Zn, Cu or Ni indicating that they are the highly toxic elements. Be and Ag were found to be intermediate in cytotoxic effect. Fe, Cr, Mo, Al, Pd or K were found to be the least cytotoxic elements. Zn and Cu released from gold alloys, and Ni released from nickel-chromium alloys, which are commonly used as fixed prosthodontic restorations, show evidence of a high cytotoxic effect on fibroblast cell cultures.

The impact of science notebook writing on ELL and low-SES students' science language development and conceptual understanding

NASA Astrophysics Data System (ADS)

Huerta, Margarita

This quantitative study explored the impact of literacy integration in a science inquiry classroom involving the use of science notebooks on the academic language development and conceptual understanding of students from diverse (i.e., English Language Learners, or ELLs) and low socio-economic status (low-SES) backgrounds. The study derived from a randomized, longitudinal, field-based NSF funded research project (NSF Award No. DRL - 0822343) targeting ELL and non-ELL students from low-SES backgrounds in a large urban school district in Southeast Texas. The study used a scoring rubric (modified and tested for validity and reliability) to analyze fifth-grade school students' science notebook entries. Scores for academic language quality (or, for brevity, language ) were used to compare language growth over time across three time points (i.e., beginning, middle, and end of the school year) and to compare students across categories (ELL, former ELL, non-ELL, and gender) using descriptive statistics and mixed between-within subjects analysis of variance (ANOVA). Scores for conceptual understanding (or, for brevity, concept) were used to compare students across categories (ELL, former ELL, non-ELL, and gender) in three domains using descriptive statistics and ANOVA. A correlational analysis was conducted to explore the relationship, if any, between language scores and concept scores for each group. Students demonstrated statistically significant growth over time in their academic language as reflected by science notebook scores. While ELL students scored lower than former ELL and non-ELL students at the first two time points, they caught up to their peers by the third time point. Similarly, females outperformed males in language scores in the first two time points, but males caught up to females in the third time point. In analyzing conceptual scores, ELLs had statistically significant lower scores than former-ELL and non-ELL students, and females outperformed males in the first two domains. These differences, however, were not statistically significant in the last domain. Last, correlations between language and concept scores were overall, positive, large, and significant across domains and groups. The study presents a rubric useful for quantifying diverse students' science notebook entries, and findings add to the sparse research on the impact of writing in diverse students' language development and conceptual understanding in science.

The role of service-learning in college students' environmental literacy: Content knowledge, attitudes, and behaviors

NASA Astrophysics Data System (ADS)

Singletary, Joanna Lynn Bush

This study evaluated the relationship of environmental service-learning on environmental literacy in undergraduates. The subjects were 36 undergraduates at a small liberal arts university enrolled in an environmental biology course. To determine the role of environmental service-learning on college students' environmental knowledge, attitudes, behaviors, and environmental literacy, this study utilized concurrent mixed methods approach for qualitative and quantitative analysis. A quasi-experimental repeated measures approach was the design of the quantitative component of the study. Data were collected on attitude, behavior, and content knowledge aspects of environmental literacy as measured by the Environmental Literacy Survey (Kibert, 2000). Hypotheses were tested by independent samples ttests and repeated measures ANOVA. Repeated measures ANOVA conducted on participants' three subscales scores for the Environmental Literacy Survey (attitude, behavior, and knowledge) indicated that students who participated in environmental service-learning scored statistically significantly higher than those that did not initially participate in service-learning. Qualitative data collected in the form of journal reflections and portfolios were evaluated for themes of environmental attitudes or affective statements, environmentally positive behaviors and skills, and ecological content. Quantitative and qualitative data support the positive role of environmental service-learning in the development of environmental literacy in undergraduate students.

Morphometric assessment of the red stripe weevils, Rhynchophorus vulneratus (Coleoptera: Curculionidae) from several localities in Malaysia

NASA Astrophysics Data System (ADS)

Sazali, Siti Nurlydia; Hazmi, Izfa Riza; Rahim, Faszly; Abang, Fatimah; Jemain, Abdul Aziz

2018-04-01

The recognition of intraspecific variation could enhance knowledge and understanding on the population divergence that might be resulted from different geographical areas. To study the possible effect derived from different locations, a morphometric study of the red stripe weevils, Rhynchophorus vulneratus from different localities in Malaysia was conducted using field and voucher specimens. A total of twenty-three morphological characters were examined from 108 individuals of R. vulneratus representing population of Kota Samarahan, Mukah and central of Peninsular Malaysia. The data were subjected to univariate one-way single factor analysis of variance (ANOVA) and analysed in factor analysis using SPSS version 22.0 software. Univariate ANOVA showed that all tested variables were significantly different (p<0.05) except for mesocoxal distance (MSD), meanwhile from the factor analysis, the first three factors with eigenvalues greater than 1.0 were successfully extracted, resulting in a high variation of 82.687%. For factor 1, 39.213% of total variation was recorded, factor 2 accounted for 34.096% and factor 3 contributing to 9.377%, respectively. The mixed plotting among the twenty-three morphological characters suggests a strong correlation among the parameters examined and further statistical analysis should be conducted to include environmental factors such as habitat types, food availability and predation effect.

Effect of silver nano particles on flexural strength of acrylic resins.

PubMed

Sodagar, Ahmad; Kassaee, Mohammad Zaman; Akhavan, Azam; Javadi, Negar; Arab, Sepideh; Kharazifard, Mohammad Javad

2012-04-01

Poly(methyl methacrylate), PMMA, is widely used for fabrication of removable orthodontic appliances. Silver nano particles (AgNps) have been added to PMMA because of their antimicrobial properties. The aim of this study is to investigate the effect of AgNps on the flexural strength of PMMA. Acrylic liquid containing 0.05% and 0.2% AgNps was prepared for two kinds of acrylic resins: Rapid Repair &Selecta Plus. Two groups without AgNps were used as control groups. For each one, flexural strength was investigated via Three Point Bending method for the 15 acrylic blocks. Two-way ANOVA, one way ANOVA and Tukey tests were used for statistical analysis. Rapid Repair without AgNps showed the highest flexural strength. Addition of 0.05% AgNps to Rapid Repair, significantly decreased its flexural strength while, continuing the addition up to 0.2% increased it nearly up to its primary level. In contrast, addition of AgNps to Selecta Plus increased its flexural strength but addition of 0.05% nano particles was more effective than 0.2%. The effect of AgNps on flexural strength of PMMA depends on several factors including the type of acrylics and the concentrations of nano particles. Copyright © 2011 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Friction Forces during Sliding of Various Brackets for Malaligned Teeth: An In Vitro Study

PubMed Central

Crincoli, Vito; Di Bisceglie, Maria Beatrice; Balsamo, Antonio; Serpico, Vitaliano; Chiatante, Francesco; Pappalettere, Carmine; Boccaccio, Antonio

2013-01-01

Aims. To measure the friction force generated during sliding mechanics with conventional, self-ligating (Damon 3 mx, Smart Clip, and Time 3) and low-friction (Synergy) brackets using different archwire diameters and ligating systems in the presence of apical and buccal malalignments of the canine. Methods. An experimental setup reproducing the right buccal segment of the maxillary arch was designed to measure the friction force generated at the bracket/wire and wire/ligature interfaces of different brackets. A complete factorial plan was drawn up and a three-way analysis of variance (ANOVA) was carried out to investigate whether the following factors affect the values of friction force: (i) degree of malalignment, (ii) diameter of the orthodontic wire, and (iii) bracket/ligature combination. Tukey post hoc test was also conducted to evaluate any statistically significant differences between the bracket/ligature combinations analyzed. Results. ANOVA showed that all the above factors affect the friction force values. The friction force released during sliding mechanics with conventional brackets is about 5-6times higher than that released with the other investigated brackets. A quasilinear increase of the frictional forces was observed for increasing amounts of apical and buccal malalignments. Conclusion. The Synergy bracket with silicone ligature placed around the inner tie-wings appears to yield the best performance. PMID:23533364

An Enhanced Engineering Perspective of Global Climate Systems and Statistical Formulation of Terrestrial CO2 Exchanges

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

Dai, Yuanshun; Baek, Seung H.; Garcia-Diza, Alberto

2012-01-01

This paper designs a comprehensive approach based on the engineering machine/system concept, to model, analyze, and assess the level of CO2 exchange between the atmosphere and terrestrial ecosystems, which is an important factor in understanding changes in global climate. The focus of this article is on spatial patterns and on the correlation between levels of CO2 fluxes and a variety of influencing factors in eco-environments. The engineering/machine concept used is a system protocol that includes the sequential activities of design, test, observe, and model. This concept is applied to explicitly include various influencing factors and interactions associated with CO2 fluxes.more » To formulate effective models of a large and complex climate system, this article introduces a modeling technique that will be referred to as Stochastic Filtering Analysis of Variance (SFANOVA). The CO2 flux data observed from some sites of AmeriFlux are used to illustrate and validate the analysis, prediction and globalization capabilities of the proposed engineering approach and the SF-ANOVA technology. The SF-ANOVA modeling approach was compared to stepwise regression, ridge regression, and neural networks. The comparison indicated that the proposed approach is a valid and effective tool with similar accuracy and less complexity than the other procedures.« less

Syllabic patterns in typical and atypical phonological development: ultrasonographic analysis.

PubMed

Vassoler, Aline Mara de Oliveira; Berti, Larissa Cristina

2018-01-01

Objective The present study aims to compare the production of syllabic patterns of the CVC and CV types performed by Brazilian children with typical and atypical phonological development through ultrasonography of tongue. Methods Ten children (five with typical and with five atypical phonological development) recorded nine pairs of words from the syllables: CCV and CV. The images and audios were captured simultaneously by the Articulate Assistant Advanced software. The data were submitted to perceptive analysis and ultrasonographic articulatory analysis (the area between the tip and the blade of the tongue). The area measurements were submitted to one-way repeated measures ANOVA. Results ANOVA demonstrated a significant effect for the clinical condition (typical and atypical), (F (1.8) = 172.48, p> 0.000) forthe area measurements. In both syllabic patterns (CCV and CV) the atypical children showed greater values ​​of the area between the tip and the blade of the tongue. Regarding the syllabic patterns analyzed, the statistical test showed no significant effect (F (1.8)=0.19, p>0.658). Conclusion The use of a greater area of ​​the tongue by children with atypical phonological development suggests the non-differentiation of the tip and the anterior body gestures of the tongue in the production of CV and CCV.

Analysis and classification of optical tomographic images of rheumatoid fingers with ANOVA and discriminate analysis

NASA Astrophysics Data System (ADS)

Montejo, Ludguier D.; Kim, Hyun K.; Häme, Yrjö; Jia, Jingfei; Montejo, Julio D.; Netz, Uwe J.; Blaschke, Sabine; Zwaka, Paul; Müeller, Gerhard A.; Beuthan, Jürgen; Hielscher, Andreas H.

2011-03-01

We present a study on the effectiveness of computer-aided diagnosis (CAD) of rheumatoid arthritis (RA) from frequency-domain diffuse optical tomographic (FDOT) images. FDOT is used to obtain the distribution of tissue optical properties. Subsequently, the non-parametric Kruskal-Wallis ANOVA test is employed to verify statistically significant differences between the optical parameters of patients affected by RA and healthy volunteers. Furthermore, quadratic discriminate analysis (QDA) of the absorption (μa) and scattering (μa or μ's) distributions is used to classify subjects as affected or not affected by RA. We evaluate the classification efficiency by determining the sensitivity (Se), specificity (Sp), and the Youden index (Y). We find that combining features extracted from μa and μa or μ's images allows for more accurate classification than when μa or μa or μ's features are considered individually on their own. Combining μa and μa or μ's features yields values of up to Y = 0.75 (Se = 0.84 and Sp = 0.91). The best results when μa or μ's features are considered individually are Y = 0.65 (Se = 0.85 and Sp = 0.80) and Y = 0.70 (Se = 0.80 and Sp = 0.90), respectively.

Comparative evaluation of low cost materials as constructed wetland filling media

NASA Astrophysics Data System (ADS)

Pinho, Henrique J. O.; Vaz, Mafalda M.; Mateus, Dina M. R.

2017-11-01

Three waste materials from civil construction activities were assessed as low cost alternative filling materials used in Constructed Wetlands (CW). CW are green processes for wastewater treatment, whose design includes an appropriate selection of vegetation and filling material. The sustainability of such processes may be incremented using recovered wastes as filling materials. The abilities of the materials to support plant growth and to contribute to pollutants removal from wastewater were assessed and compared to expanded clay, a filling usually used in CW design. Statistical analysis, using one-way ANOVA and Welch's ANOVA, demonstrate that limestone fragments are a better choice of filling material than brick fragments and basalt gravel.

Comparison of the frictional characteristics of aesthetic orthodontic brackets measured using a modified in vitro technique

PubMed Central

Arici, Nursel

2015-01-01

Objective The coefficients of friction (COFs) of aesthetic ceramic and stainless steel brackets used in conjunction with stainless steel archwires were investigated using a modified linear tribometer and special computer software, and the effects of the bracket slot size (0.018 inches [in] or 0.022 in) and materials (ceramic or metal) on the COF were determined. Methods Four types of ceramic (one with a stainless steel slot) and one conventional stainless steel bracket were tested with two types of archwire sizes: a 0.017 × 0.025-in wire in the 0.018-in slots and a 0.019 × 0.025-in wire in the 0.022-in slot brackets. For pairwise comparisons between the 0.018-in and 0.022-in slot sizes in the same bracket, an independent sample t-test was used. One-way and two-way analysis of variance (ANOVA) and Tukey's post-hoc test at the 95% confidence level (α = 0.05) were also used for statistical analyses. Results There were significant differences between the 0.022-in and 0.018-in slot sizes for the same brand of bracket. ANOVA also showed that both slot size and bracket slot material had significant effects on COF values (p < 0.001). The ceramic bracket with a 0.022-in stainless steel slot showed the lowest mean COF (µ = 0.18), followed by the conventional stainless steel bracket with a 0.022-in slot (µ = 0.21). The monocrystalline alumina ceramic bracket with a 0.018-in slot had the highest COF (µ = 0.85). Conclusions Brackets with stainless steel slots exhibit lower COFs than ceramic slot brackets. All brackets show lower COFs as the slot size increases. PMID:25667915

Comparison of fracture resistance between cast, CAD/CAM milling, and direct metal laser sintering metal post systems.

PubMed

Bilgin, Mehmet Selim; Erdem, Ali; Dilber, Erhan; Ersoy, İbrahim

2016-01-01

The purpose of this study was to compare the fracture resistance of Co-Cr post-cores fabricated with 3 different techniques: traditional casting (TC), computer-aided design and manufacturing (CAD/CAM) milling (CCM) and direct metal laser sintering (DMLS). Forty intact human mandibular premolar were endodontically treated. The roots were then randomly divided into four groups according to the post systems: the control group was only filled with gutta percha. Co-Cr metal posts were fabricated with TC, CCM and DMLS in the other three groups. The posts were luted with a resin cement and subjected to compression test at a crosshead speed of 1mm/min. The statistical analysis of the data was performed using one-way analysis of variance (ANOVA) and multiple comparison post hoc Tukey tests (α=.05). The samples were examined under a stereomicroscope with ×20 magnification for the evaluation of the fracture types. The mean fracture loads were 432.69 N for control, 608.89 N for TC, 689.40 N for DMLS and 959.26 N for CCM. One-way ANOVA revealed significant difference between the groups (p<0.01). In the post hoc Tukey test, there were significant differences between groups except DMLS and TC. While Co-Cr posts fabricated by TC and DMLS systems performed similarly in terms of fracture resistance, posts fabricated by CCM techniques showed higher fracture resistance values. Co-Cr metal posts fabricated by CCM and DMLS could be an alternative to TC processing in daily clinical application. Copyright © 2015 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Transcranial direct current stimulation (tDCS) neuromodulatory effects on mechanical hyperalgesia and cortical BDNF levels in ovariectomized rats.

PubMed

da Silva Moreira, Sônia Fátima; Medeiros, Liciane Fernandes; de Souza, Andressa; de Oliveira, Carla; Scarabelot, Vanessa Leal; Fregni, Felipe; Caumo, Wolnei; Torres, Iraci L S

2016-01-15

Epidemiological studies show that painful disorders are more prevalent in women than in men, and the transcranial direct current stimulation (tDCS) technique has been tested in chronic pain states. We explored the effect of tDCS on pain behavior and brain-derived neurotrophic factor (BDNF) levels in ovariectomized rats. Forty-five female Wistar adult rats were distributed into five groups: control (CT), ovariectomy + tDCS (OT), ovariectomy + sham tDCS (OS), sham ovariectomy + tDCS (ST), and sham ovariectomy+shamtDCS (SS). The rats were subjected to cathodal tDCS. The vaginal cytology and the estradiol levels confirmed the hormonal status. In addition, nociceptive behavior was evaluated using the tail-flick, von Frey, and hot-plate tests, as well as the BDNF levels in the serum, hypothalamus, hippocampus, spinal cord, and cerebral cortex. One-way analysis of variance (ANOVA) or two-way ANOVA was used for statistical analysis, followed by the Bonferroni, and P-value b 0.05 was considered significant. The ovariectomized animals presented a hypersensitivity response in the hot-plate (P b 0.01) and von Frey (P b 0.05) tests, as well as increased serum BDNF (P b 0.05) and decreased hypothalamic BDNF (P b 0.01) levels. The OT, OS, ST, and SS groups showed decreased hippocampal BDNF levels as compared with the control group (P b 0.001). The interaction between tDCS and ovariectomy on the cortical BDNF levels (P b 0.01) was observed. The ovariectomy induced nociceptive hypersensitivity and altered serum and hypothalamic BDNF levels. The cathodal tDCS partially reversed nociceptive hypersensitivity.

Impact of Intentional Overload on Joint Stability of Internal Implant-Abutment Connection System with Different Diameter.

PubMed

Lee, Ji-Hye; Lee, Won; Huh, Yoon-Hyuk; Park, Chan-Jin; Cho, Lee-Ra

2017-09-05

To evaluate the axial displacement of the implant-abutment assembly of different implant diameter after static and cyclic loading of overload condition. An internal conical connection system with three diameters (Ø 4.0, 4.5, and 5.0) applying identical abutment dimension and the same abutment screw was evaluated. Axial displacement of abutment and reverse torque loss of abutment screw were evaluated under static and cyclic loading conditions. Static loading test groups were subjected to vertical static loading of 250, 400, 500, 600, 700, and 800 N consecutively. Cyclic loading test groups were subjected to 500 N cyclic loading to evaluate the effect of excessive masticatory loading. After abutment screw tightening for 30 Ncm, axial displacement was measured upon 1, 3, 10, and 1,000,000 cyclic loadings of 500 N. Repeated-measure ANOVA and 2-way ANOVA were used for statistical analysis (α = 0.05). The increasing magnitude of vertical load and thinner wall thickness of implant increased axial displacement of abutment and reverse torque loss of abutment screw (p < 0.05). Implants in the Ø 5.0 diameter group demonstrated significantly low axial displacement, and reverse torque loss after static loading than Ø 4.0 and Ø 4.5 diameter groups (p < 0.05). In the cyclic loading test, all diameter groups of implant showed significant axial displacement after 1 cycle of loading of 500 N (p < 0.05). There was no significant axial displacement after 3, 10, or 1,000,000 cycles of loading (p = 0.603). Implants with Ø 5.0 diameter demonstrated significantly low axial displacement and reverse torque loss after the cyclic and static loading of overload condition. © 2017 by the American College of Prosthodontists.

Does Kinesiology tape counter exercise-related impairments of balance in the elderly?

PubMed

Hosp, Simona; Csapo, Robert; Heinrich, Dieter; Hasler, Michael; Nachbauer, Werner

2018-05-01

Maintaining balance is an essential requirement for the performance of daily tasks and sporting activities, particularly in older adults to prevent falls and associated injuries. Kinesiology tape has gained great popularity in sports and is frequently used as a tool for performance enhancement. However, there is little research investigating its influence on balance. The purpose of this study was to evaluate the effect of Kinesiology tape on dynamic balance, postural stability and knee proprioception after physical activity in healthy, older adults. Twelve physically active, healthy men aged 63-77 years performed the test on two separate days, with and without Kinesiology tape at the knee joint (prospective intervention with cross-over design). Dynamic balance during an obstacle-crossing task, postural stability in a single-leg stance test, and knee joint position sense as a measure of proprioception were examined before and after 30 min of downhill walking on a treadmill. The influences of taping condition and physical activity on all parameters were statistically tested using factorial ANOVAs. Factorial ANOVA revealed significant time × taping condition interaction effects on all performance parameters (p < 0.05), indicating that the exercise-related changes in dynamic balance, postural stability and knee proprioception differed between the two taping conditions. The deterioration of performance was always greater when no tape was used. This study demonstrated that physical exercise significantly deteriorated dynamic balance, postural stability and knee proprioception in older men. These effects can be attenuated through the usage of Kinesiology tape. By preventing exercise-related impairments of balance, Kinesiology tape might help reduce the risk of sports-associated falls and associated injuries. Copyright © 2018 Elsevier B.V. All rights reserved.

Management of Chronic Periodontitis Using Chlorhexidine Chip and Diode Laser-A Clinical Study.

PubMed

Jose, Kachapilly Arun; Ambooken, Majo; Mathew, Jayan Jacob; Issac, Annie Valayil; Kunju, Ajithkumar Parachalil; Parameshwaran, Renjith Athirkandathil

2016-04-01

The use of adjuncts like chlorhexidine local delivery and diode laser decontamination have been found to improve the clinical outcomes of scaling and root planing in non-surgical periodontal therapy in patients with chronic periodontitis. To evaluate the effects of diode laser and chlorhexidine chip as adjuncts to scaling and root planing in the management of chronic periodontitis. The objective is to evaluate the outcome of chlorhexidine chip and diode laser as adjuncts to scaling and root planing on clinical parameters like Plaque Index, Gingival Index, probing pocket depth and clinical attachment level. Department of Periodontics. Randomized clinical trial with split mouth design. Fifteen chronic periodontitis patients having a probing pocket depth of 5mm-7mm on at least one interproximal site in each quadrant of the mouth were included in the study. After initial treatment, four sites in each patient were randomly subjected to scaling and root planing (control), chlorhexidine chip application (CHX chip group), diode laser (810 nm) decontamination (Diode laser group) or combination of both (Diode laser and chip group). Plaque Index (PI), Gingival Index (GI), probing pocket depth (PPD) and clinical attachment level (CAL) were assessed at baseline, one month and three months. Results were statistically analysed using paired T test, one-way ANOVA, Tukey's HSD test and repeated measure ANOVA. Post-treatment, the test and control sites showed a statistically significant reduction in PI, GI, PPD, and CAL. After three months, a mean PPD reduction of 1.47±0.52 mm in control group, 1.40±0.83 mm in diode laser group, 2.67±0.62 mm in CHX group, and 2.80± 0.77 mm in combination group was seen. The mean gain in CAL were 1.47±0.52 mm in the control group, 1.40±0.83 mm in diode laser group, 2.67± 0.49 mm in CHX group and 2.67± 0.82 mm in combination group respectively. The differences in PPD reduction and CAL gain between control group and CHX chip and combination groups were statistically significant (p<0.05) at three months, whereas, the diode laser group did not show any significant difference from the control group. Chlorhexidine local delivery alone or in combination with diode laser decontamination is effective in reducing probing pocket depth and improving clinical attachment levels when used as adjuncts to scaling and root planing in non-surgical periodontal therapy of patients with chronic periodontitis.

Innovative Instrumentation and Analysis of the Temperature Measurement for High Temperature Gasification

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

Seong W. Lee

The project entitled, ''Innovative Instrumentation and Analysis of the Temperature Measurement for High Temperature Gasification'', was successfully completed by the Principal Investigator, Dr. S. Lee and his research team in the Center for Advanced Energy Systems and Environmental Control Technologies at Morgan State University. The major results and outcomes were presented in semi-annual progress reports and annual project review meetings/presentations. Specifically, the literature survey including the gasifier temperature measurement, the ultrasonic application in cleaning application, and spray coating process and the gasifier simulator (cold model) testing has been successfully conducted during the first year. The results show that four factorsmore » (blower voltage, ultrasonic application, injection time intervals, particle weight) were considered as significant factors that affect the temperature measurement. Then the gasifier simulator (hot model) design and the fabrication as well as the systematic tests on hot model were completed to test the significant factors on temperature measurement in the second year. The advanced Industrial analytic methods such as statistics-based experimental design, analysis of variance (ANOVA) and regression methods were applied in the hot model tests. The results show that operational parameters (i.e. air flow rate, water flow rate, fine dust particle amount, ammonia addition) presented significant impact on the temperature measurement inside the gasifier simulator. The experimental design and ANOVA are very efficient way to design and analyze the experiments. The results show that the air flow rate and fine dust particle amount are statistically significant to the temperature measurement. The regression model provided the functional relation between the temperature and these factors with substantial accuracy. In the last year of the project period, the ultrasonic and subsonic cleaning methods and coating materials were tested/applied on the thermocouple cleaning according to the proposed approach. Different frequency, application time and power of the ultrasonic/subsonic output were tested. The results show that the ultrasonic approach is one of the best methods to clean the thermocouple tips during the routine operation of the gasifier. In addition, the real time data acquisition system was also designed and applied in the experiments. This advanced instrumentation provided the efficient and accurate data acquisition for this project. In summary, the accomplishment of the project provided useful information of the ultrasonic cleaning method applied in thermocouple tip cleaning. The temperature measurement could be much improved both in accuracy and duration provided that the proposed approach is widely used in the gasification facilities.« less

Oxygen uptake of overweight and obese children at different stages of a progressive treadmill test

PubMed Central

Meléndez-Ortega, Agustín; Lucy Davis, Catherine; Barbeau, Paule; Boyle, Colleen Ann

2010-01-01

Introduction Maximal oxygen uptake (VO2 max) is associated with cardiovascular and metabolic risks but it is difficult to assess in obese children. The objective of this study was to develop an equation to estimate VO2 (mL/kg/min) and to check the % of tests that were maximal according to recommended criteria. Methods Stress tests were analyzed of 222 subjects (94 male and 128 female with a BMI above the 85 percentile for age and sex), and repeated 4 months later. Mean age was 9.4 ± 1.1 years and weighed 52.4 ± 13.3 kg. Body fat % (40.5 + 6.2) was determined by DXA (Hologic QDR 4500W). The protocol on the treadmill started with a warm up at 2.5 and 3 mph with a slope of 0% and 2%. The speed was kept at 3 mph for all the stages and the slope was increased 2% every 2 minutes. Statistical analysis (descriptive, t-test and ANOVAS 2×2×2) was done with SPSS 15.0. Results Only 35% of the tests were maximal. The equation calculates was Y = 2.6x + 22.3 (x = protocol stage). Data pre and post treatment were not statistically different Discussion Increments in VO2 were consistent despite subject diversity (sex, % body fat, physical fitness, treatment). Conclusion To be able to estimate VO2 at the different stages of the test without complex equipment or specialized staff, will facilitate the performance of stress tests on a daily basis. PMID:21218170

Does Vitamin D Supplementation Enhance Musculoskeletal Performance in Individuals Identified as Vitamin D Deficient through Blood Spot Testing?

NASA Astrophysics Data System (ADS)

Murphy, Kellie A.

This thesis investigated possible changes in performance after one month of vitamin D supplementation in individuals found to be vitamin D deficient or insufficient through blood spot testing. Thirty-two males, ages 18-32, participated. Each subject visited the lab three times in one-month, completing four performance tests each session, including an isometric mid-thigh pull and a vertical jump on a force plate, a isometric 90-degree elbow flexion test using a load cell, and a psychomotor vigilance test on a palm pilot. The initial lab included blood spot tests to find vitamin D levels. In a single blind manner, 16 subjects were assigned vitamin D and 16 the placebo. Repeated measures ANOVA analysis did not reveal any main effects for time (F=2.626, p=0.364), treatment (vitamin D3 vs placebo; F=1.282, p=0.999), or interaction effects for treatment by time (F=0.304, p=0.999) for maximum force production during an isometric mid-thigh pull. Repeated measures ANOVA analysis did not reveal any main effects for time (F=1.323, p=0.999), treatment (vitamin D3 vs placebo; F=0.510, p=0.999), or interaction effects for treatment by time (F= 1.625, p=0.860) for rate of force production during a vertical jump. Repeated measures ANOVA analysis did not reveal any main effects for time (F=0.194, p=0.999), treatment (vitamin D3 vs placebo; F=2.452, p=0.513), or interaction effects for treatment by time (F= 1.179, p=0.999) for maximal force production during a 90-degree isometric elbow flexion. Repeated measures ANOVA analysis did not reveal any main effects for time (F=1.710, p=0.804), treatment (vitamin D3 vs placebo; F=1.471, p=0.94), or interaction effects for treatment by time (F= 0.293, p=0.999) for mean reaction time to random stimuli during the psychomotor vigilance test. Repeated measures ANOVA analysis did not reveal any main effects for time (F=0.530, p=0.999), treatment (vitamin D3 vs placebo; F=0.141, p=0.999), or interaction effects for treatment by time (F=0.784 p=0.999) for incidence of minor lapses during the psychomotor vigilance test.

Assessing the Relationship between Airlines' Maintenance Outsourcing and Aviation Professionals' Job Satisfaction

NASA Astrophysics Data System (ADS)

McCamey, Rotorua

The current economic and security challenges placed an additional burden on U.S. airlines to provide optimum service at reasonable costs to the flying public. In efforts to stay competitive, U.S. airlines increased foreign-based outsourcing of aircraft major repair and overhaul (MRO) mainly to reduce labor costs and conserve capital. This concentrated focus on outsourcing and restructuring, ignored job dissatisfaction among remaining employees which could reduce and or eliminate an airline's competitiveness. The purpose of this quantitative study was (a) to assess the relationship between increased levels of foreign-based MRO outsourcing and aviation professionals' job satisfaction (Y1); (b) to assess the influence of increased levels of foreign-based outsourcing on MRO control (Y2), MRO error rate (Y3), and MRO technical punctuality (Y4) as perceived by aviation professionals; and (c) to assess the influence of increased levels of foreign-based MRO outsourcing on technical skills (Y5) and morale ( Y6) as perceived by aviation professionals. The survey instrument was utilized based on Paul Spector's Job Satisfaction Questionnaire and MRO specific questions. A random sample of 300 U.S. airline participants was requested via MarketTools to meet required sample size of 110 as determined through a priori power analysis. Study data rendered 198 useable surveys of 213 total responses, and correlation, multiple regression, and ANOVA methods were used to test study hypotheses. The Spearman's rho for (Y 1) was statistically significant, p = .010 and multiple regression was statistically significant, p < .001. A one-way ANOVA indicated participants differed in their opinions of (Y2) through (Y6), Recommendations for future research include contrasting domestic and global MRO providers, and examining global aircraft parts suppliers and aviation technical training.

Effects of growth hormone and testosterone therapy on aerobic and anaerobic fitness, body composition and lipoprotein profile in middle-aged men.

PubMed

Zając, Adam; Wilk, Michał; Socha, Teresa; Maszczyk, Adam; Chycki, Jakub

2014-01-01

Andropause and aging are associated with neuroendocrine dysfunctions. Growth hormone and testosterone play a significant role in several processes affecting adaptation and thereby also everyday functioning. The aim of this research project was to evaluate the effects of recombinant human growth hormone and testosterone enanthate injections on body mass and body composition, aerobic and anaerobic fitness and lipid profile in middle-aged men. The research group was comprised of 14 men aged 45 - 60 years. Two series of laboratory analyses were performed. Independent tests were carried out at baseline and after 12 weeks of the experiment. The data were analyzed using Statistica 9.1 software. A two-way repeated measures ANOVA revealed a statistically significant effect of the intervention programme on fat-free mass (η(2)=0.34), total body fat (η(2)=0.79), total cholesterol (η(2)=0.30), high-density lipoprotein cholesterol (η(2)=0.31), low-density lipoprotein cholesterol (η(2)=0.42), triglyceride (η(2)=0.28), testosterone (η(2)=0.52), insulin-like growth factor 1 (η(2)=0.47) and growth hormone (η(2)=0.63). Furthermore, ANOVA revealed a statistically significant effect of the rhGH and T treatment on maximal oxygen uptake (η(2)=0.63), anaerobic threshold (η(2)=0.61) and maximal work rate (η(2)=0.53). It should be emphasized that the lipid profile was affected not only by rhGH+T replacement therapy, but also by the prescribed physical activity programme. The strength and endurance fitness programme alone did not cause significant changes in body mass and composition, nor the anaerobic and aerobic capacity. On the other hand, the rhGH=T treatment stimulated these changes significantly.

Volume analysis of heat-induced cracks in human molars: A preliminary study

PubMed Central

Sandholzer, Michael A.; Baron, Katharina; Heimel, Patrick; Metscher, Brian D.

2014-01-01

Context: Only a few methods have been published dealing with the visualization of heat-induced cracks inside bones and teeth. Aims: As a novel approach this study used nondestructive X-ray microtomography (micro-CT) for volume analysis of heat-induced cracks to observe the reaction of human molars to various levels of thermal stress. Materials and Methods: Eighteen clinically extracted third molars were rehydrated and burned under controlled temperatures (400, 650, and 800°C) using an electric furnace adjusted with a 25°C increase/min. The subsequent high-resolution scans (voxel-size 17.7 μm) were made with a compact micro-CT scanner (SkyScan 1174). In total, 14 scans were automatically segmented with Definiens XD Developer 1.2 and three-dimensional (3D) models were computed with Visage Imaging Amira 5.2.2. The results of the automated segmentation were analyzed with an analysis of variance (ANOVA) and uncorrected post hoc least significant difference (LSD) tests using Statistical Package for Social Sciences (SPSS) 17. A probability level of P < 0.05 was used as an index of statistical significance. Results: A temperature-dependent increase of heat-induced cracks was observed between the three temperature groups (P < 0.05, ANOVA post hoc LSD). In addition, the distributions and shape of the heat-induced changes could be classified using the computed 3D models. Conclusion: The macroscopic heat-induced changes observed in this preliminary study correspond with previous observations of unrestored human teeth, yet the current observations also take into account the entire microscopic 3D expansions of heat-induced cracks within the dental hard tissues. Using the same experimental conditions proposed in the literature, this study confirms previous results, adds new observations, and offers new perspectives in the investigation of forensic evidence. PMID:25125923

Findings regarding the relationships between sociodemographic, psychological, comorbidity factors, and functional status, in geriatric inpatients.

PubMed

Capisizu, Ana; Aurelian, Sorina; Zamfirescu, Andreea; Omer, Ioana; Haras, Monica; Ciobotaru, Camelia; Onose, Liliana; Spircu, Tiberiu; Onose, Gelu

2015-01-01

To assess the impact of socio-demographic and comorbidity factors, and quantified depressive symptoms on disability in inpatients. Observational cross-sectional study, including a number of 80 elderly (16 men, 64 women; mean age 72.48 years; standard deviation 9.95 years) admitted in the Geriatrics Clinic of "St. Luca" Hospital, Bucharest, between May-July, 2012. We used the Functional Independence Measure, Geriatric Depression Scale and an array of socio-demographic and poly-pathology parameters. Statistical analysis included Wilcoxon and Kruskal-Wallis tests for ordinal variables, linear bivariate correlations, general linear model analysis, ANOVA. FIM scores were negatively correlated with age (R=-0.301; 95%CI=-0.439 -0.163; p=0.007); GDS scores had a statistically significant negative correlation (R=-0.322; 95% CI=-0.324 -0.052; p=0.004) with FIM scores. A general linear model, including other variables (gender, age, provenance, matrimonial state, living conditions, education, respectively number of chronic illnesses) as factors, found living conditions (p=0.027) and the combination of matrimonial state and gender (p=0.004) to significantly influence FIM scores. ANOVA showed significant differences in FIM scores stratified by the number of chronic diseases (p=0.035). Our study objectified the negative impact of depression on functional status; interestingly, education had no influence on FIM scores; living conditions and a combination of matrimonial state and gender had an important impact: patients with living spouses showed better functional scores than divorced/widowers; the number of chronic diseases also affected the FIM scores: lower in patients with significant polypathology. These findings should be considered when designing geriatric rehabilitation programs, especially for home--including skilled--cares.

Effect of surface treatments on shear bond strength of resin composite bonded to CAD/CAM resin-ceramic hybrid materials

PubMed Central

Güngör, Merve Bankoğlu; Bal, Bilge Turhan; Ünver, Senem; Doğan, Aylin

2016-01-01

PURPOSE The purpose of this study was to assess the effect of surface treatments on shear bond strength of resin composite bonded to thermocycled and non-thermocycled CAD/CAM resin-ceramic hybrid materials. MATERIALS AND METHODS 120 specimens (10×10×2 mm) from each material were divided into 12 groups according to different surface treatments in combination with thermal aging procedures. Surface treatment methods were airborne-particle abrasion (abraded with 50 micron alumina particles), dry grinding (grinded with 125 µm grain size bur), and hydrofluoric acid (9%) and silane application. According to the thermocycling procedure, the groups were assigned as non-thermocycled, thermocycled after packing composites, and thermocycled before packing composites. The average surface roughness of the non-thermocycled specimens were measured after surface treatments. After packing composites and thermocycling procedures, shear bond strength (SBS) of the specimens were tested. The results of surface roughness were statistically analyzed by 2-way Analysis of Variance (ANOVA), and SBS results were statistically analyzed by 3-way ANOVA. RESULTS Surface roughness of GC were significantly lower than that of LU and VE (P<.05). The highest surface roughness was observed for dry grinding group, followed by airborne particle abraded group (P<.05). Comparing the materials within the same surface treatment method revealed that untreated surfaces generally showed lower SBS values. The values of untreated LU specimens showed significantly different SBS values compared to those of other surface treatment groups (P<.05). CONCLUSION SBS was affected by surface treatments. Thermocycling did not have any effect on the SBS of the materials except acid and silane applied GC specimens, which were subjected to thermocycling before packing of the composite resin. PMID:27555894

A study of the relationships between "highly qualified" status, instructional practices, and students' science achievement in three high poverty Louisiana school systems

NASA Astrophysics Data System (ADS)

Clayton, Michelle

Using a mixed methods research design, the author examined the relationships between "highly qualified" status, instructional practices, and students' science achievement for six third grade teachers in three high poverty Louisiana school systems. The study analyzed qualitative and quantitative data for three science classes taught by "highly qualified" teachers and three science classes taught by "non-highly qualified" teachers. The qualitative portion of the study was conducted through classroom observations, teacher interviews, and lesson plan reviews. The qualitative data was coded and triangulated to determine whether the instructional practices of each teacher were more "teacher-centered" or "student-centered." The qualitative data analysis indicated various patterns and consistencies in the instructional practices used by the "highly qualified" and "non-highly qualified" teachers selected for this study. The quantitative portion of the study involved analysis of the students' science achievement data for the six third grade science teachers selected for the study. Science achievement was measured by the third grade Integrated Louisiana Education Assessment Program (iLEAP) scores. A two-way ANOVA indicated that there were statistically significant differences in the mean scores of the three high poverty Louisiana school systems as well as the students taught by "highly qualified" and "non-highly qualified" teachers and the interactions between the two: F(2, 123) = 46.99, p < 0.01; F(1, 123) = 4.54, p = 0.035; F(2, 123) = 3.73, p = 0.027. A separate one-way ANOVA indicated that statistically significant differences existed between the six participating teachers in the study: F (5, 123) = 20.386, p < 0.01). Tukey's HSD post-hoc tests and homogeneous subset analyses were conducted in order to determine which teachers' scores significantly differed from each other.

Evaluation of five CAD/CAM materials by microstructural characterization and mechanical tests: a comparative in vitro study.

PubMed

Sonmez, Nesrin; Gultekin, Pinar; Turp, Volkan; Akgungor, Gokhan; Sen, Deniz; Mijiritsky, Eitan

2018-01-08

Polymer infiltrated ceramics and nano-ceramic resins are the new restorative materials which have been developed in order to enhance the adverse properties of glass-matrix ceramics and resin composites. The aim of the present in vitro study was to evaluate the characteristics of various CAD/CAM materials through mechanical, microstructural, and SEM analysis. Five test groups (n = 22) were formed by using the indicated CAD/CAM blocks: VITA Enamic (VITA Zahnfabrik), Lava Ultimate (3 M ESPE), IPS e.max CAD (Ivoclar Vivadent), IPS Empress CAD (Ivoclar Vivadent), and VITA Mark II (VITA Zahnfabrik). Two specimens from each test group were used for XRD and EDS analysis. Remaining samples were divided into two subgroups (n = 10). One subgroup specimens were thermocycled (5 °C to 55 °C, 30s, 10,000 cycles) whereas the other were not. All of the specimens were evaluated in terms of flexural strength, Vickers hardness, and fracture toughness. Results were statistically analyzed using two-way ANOVA, one-way ANOVA, Tukey's HSD, and Student's t tests (α = .05). Fractured specimens were evaluated using SEM. The highest Vickers microhardness value was found for VITA Mark II (p < .001), however flexural strength and fracture toughness results were lowest conversely (p < .05). IPS e.max CAD was found to have the highest flexural strength (p < .001). Fracture toughness of IPS e.max CAD was also higher than other tested block materials (p < .001). Lava Ultimate and VITA Enamic's mechanical properties were affected negatively from thermocycling (p < .05). Microhardness, flexural strength, and fracture toughness values of Lava Ultimate and VITA Enamic were found to be similar to VITA Mark II and IPS Empress CAD groups. It should be realised that simulated aging process seem to affect ceramic-polymer composite materials more significantly than glass ceramics.

Evaluation of the safety and durability of low-cost nonprogrammable electric powered wheelchairs.

PubMed

Pearlman, Jonathan L; Cooper, Rory A; Karnawat, Jaideep; Cooper, Rosemarie; Boninger, Michael L

2005-12-01

To evaluate whether a selection of low-cost, nonprogrammable electric-powered wheelchairs (EPWs) meets the American National Standards Institute (ANSI)/Rehabilitation Engineering and Assistive Technology Society of North America (RESNA) Wheelchair Standards requirements. Objective comparison tests of various aspects of power wheelchair design and performance of 4 EPW types. Three of each of the following EPWs: Pride Mobility Jet 10 (Pride), Invacare Pronto M50 (Invacare), Electric Mobility Rascal 250PC (Electric Mobility), and the Golden Technologies Alanté GP-201-F (Golden). Rehabilitation engineering research center. Not applicable. Static tipping angle; dynamic tipping score; braking distance; energy consumption; climatic conditioning; power and control systems integrity and safety; and static, impact, and fatigue life (equivalent cycles). Static tipping angle and dynamic tipping score were significantly different across manufacturers for each tipping direction (range, 6.6 degrees-35.6 degrees). Braking distances were significantly different across manufacturers (range, 7.4-117.3 cm). Significant differences among groups were found with analysis of variance (ANOVA). Energy consumption results show that all EPWs can travel over 17 km before the battery is expected to be exhausted under idealized conditions (range, 18.2-32.0 km). Significant differences among groups were found with ANOVA. All EPWs passed the climatic conditioning tests. Several adverse responses were found during the power and control systems testing, including motors smoking during the stalling condition (Electric Mobility), charger safety issues (Electric Mobility, Invacare), and controller failures (Golden). All EPWs passed static and impact testing; 9 of 12 failed fatigue testing (3 Invacare, 3 Golden, 1 Electric Mobility, 2 Pride). Equivalent cycles did not differ statistically across manufacturers (range, 9759-824,628 cycles). Large variability in the results, especially with respect to static tipping, power and control system failures, and fatigue life suggest design improvements must be made to make these low-cost, nonprogrammable EPWs safe and reliable for the consumer. Based on our results, these EPWs do not, in general, meet the ANSI/RESNA Wheelchair Standards requirements.

Comparative assessment of efficacy of two different pretreatment single oral doses of betamethasone on inter-appointment and postoperative discomfort: An in vivo clinical evaluation.

PubMed

Gyanani, Hitesh; Chhabra, Naveen; Parmar, Ghanshyam R

2016-01-01

Study aimed to evaluate the efficacy of two different pretreatment single oral doses of betamethasone on the incidence of inter-appointment flare up and postoperative discomfort. Fifty-four patients aged 18-59 years requiring endodontic treatment were selected and randomly assigned to three groups; single pretreatment oral dose of placebo or betamethasone in two different oral doses of 0.5 mg and 1 mg, respectively. Endodontic therapy was completed in two visits using triple antibiotic paste as intracanal medicament. Patients were given a questionnaire to record their pain at 1, 2, 3, and 7 days after treatment. In the second visit, obturation was done, and the patients were again instructed to record their pain scores after treatment and discharged. The verbal rating scale was used for recording the pain scores. Statistical analysis was done using ANOVA and the Friedman test. 0.5 mg betamethasone group showed least mean pain scores among all experimental groups; however, there was no statistically significant difference between any of the groups ( P > 0.05). Pretreatment single oral dose of betamethasone is an effective in managing endodontic flare-ups; however, the results were statistically insignificant.

Reproducibility of ZrO2-based freeze casting for biomaterials.

PubMed

Naleway, Steven E; Fickas, Kate C; Maker, Yajur N; Meyers, Marc A; McKittrick, Joanna

2016-04-01

The processing technique of freeze casting has been intensely researched for its potential to create porous scaffold and infiltrated composite materials for biomedical implants and structural materials. However, in order for this technique to be employed medically or commercially, it must be able to reliably produce materials in great quantities with similar microstructures and properties. Here we investigate the reproducibility of the freeze casting process by independently fabricating three sets of eight ZrO2-epoxy composite scaffolds with the same processing conditions but varying solid loading (10, 15 and 20 vol.%). Statistical analyses (One-way ANOVA and Tukey's HSD tests) run upon measurements of the microstructural dimensions of these composite scaffold sets show that, while the majority of microstructures are similar, in all cases the composite scaffolds display statistically significant variability. In addition, composite scaffolds where mechanically compressed and statistically analyzed. Similar to the microstructures, almost all of their resultant properties displayed significant variability though most composite scaffolds were similar. These results suggest that additional research to improve control of the freeze casting technique is required before scaffolds and composite scaffolds can reliably be reproduced for commercial or medical applications. Copyright © 2015 Elsevier B.V. All rights reserved.

Retrospective Evaluation of the Impact of a Geriatric Trauma Institute on Fragility Hip Fracture Patient Outcomes.

PubMed

Katrancha, Elizabeth D; Zipf, Jami; Abrahams, Nancy; Schroeder, Richard

Fragility hip fractures occur in the older than 65-year population at an alarming rate. It is estimated that 260,000 hip fractures occur annually. Patient outcomes following hip fractures are devastating. One of every 5 patients dies within 1 year of injury, and 1 of 3 remains in a nursing home for years after the injury. Published literature recommends an interdisciplinary approach to caring for hip-fractured patients and expediting surgery to improve outcomes. The purpose of this study was to retrospectively evaluate the impact of the Geriatric Trauma Institute (GTI) on fragility hip fracture patient outcomes. Specific outcomes included length of stay (LOS), length of time from emergency department (ED) arrival to operating room (OR), complication rate, and discharge destination. This study is a single-center pre- and post-retrospective chart review. Data were collected using database queries within the hospital system. Pre-GTI (n = 326) patients older than 65 years with International Classification of Disease, Ninth Revision (ICD-9) codes 820.0-820.9 (hip fractures) admitted to either a primary care physician or orthopaedic surgeon service between April 1, 2011, and April 1, 2013, were compared with post-GTI (n = 245) patients older than 65 years with ICD-9 codes 820.0-820.9 (hip fractures) admitted to trauma services (GTI) between May 1, 2013, and May 1, 2015. Descriptive statistics including demographic data (age, sex) and comparison of outcomes (LOS, ED to OR time, complications, and disposition) across the groups using standard analysis of variance (ANOVA) and correlation techniques. No statistical difference was found between groups for age, sex, or time from ED to OR pre- versus post-time period using one-way ANOVA, F(1,569) = 1.08, p = .30. The complication rate was calculated pre- and post-GTI and compared using the 2-proportion z-test. The difference between the pre-GTI group (16.6%; 54 of 326 patients) and the post-GTI group (9.4%; 23 of 245 patients) was statistically significant, p = .013. Mean LOS was statistically significantly higher in the pre-GTI group (M = 5) than in the post-GTI group (M = 5.2), U = 33,55, z = -3.32, p = .001. No statistical significance was found between pre- and postdischarge destination, χ(4) = .4.82, p = .307; likelihood ratio test, χ(4) = .5.19, p = .269. This retrospective pre- and post-GTI chart review demonstrates the effectiveness of a multidisciplinary team approach in decreasing complications and LOS for fragility hip-fractured patients. A team approach to the care of these patients improves outcomes and quality of life.

Factors Influencing Stress, Burnout, and Retention of Secondary Teachers

ERIC Educational Resources Information Center

Fisher, Molly H.

2011-01-01

This study examines the stress, burnout, satisfaction, and preventive coping skills of nearly 400 secondary teachers to determine variables contributing to these major factors influencing teachers. Analysis of Variance (ANOVA) statistics were conducted that found the burnout levels between new and experienced teachers are significantly different,…

Understanding Non-Suicidal Self-Injury: Perceptions of School Counselors

ERIC Educational Resources Information Center

Simpson, Chris; Armstrong, Stephen A.; Couch, Lisa; Bore, Samuel K.

2010-01-01

This national exploratory study examined the perceptions of secondary school counselors' (n = 81) understanding of non-suicidal self-injury (NSSI). Two one-way ANOVAs revealed no statistically significant differences between middle and high school counselors on their perceptions of the prevalence of NSSI. Descriptive analyses revealed that a…

Determining Sample Sizes for Precise Contrast Analysis with Heterogeneous Variances

ERIC Educational Resources Information Center

Jan, Show-Li; Shieh, Gwowen

2014-01-01

The analysis of variance (ANOVA) is one of the most frequently used statistical analyses in practical applications. Accordingly, the single and multiple comparison procedures are frequently applied to assess the differences among mean effects. However, the underlying assumption of homogeneous variances may not always be tenable. This study…

Child Sustained Attention in Preschool-Age Children

ERIC Educational Resources Information Center

DiCarlo, Cynthia F.; Baumgartner, Jennifer J.; Ota, Carrie; Geary, Kelly

2016-01-01

This study examined the mean duration of child attention across three teaching conditions (child choice, adult choice, or adult presentation) of 63 preschool-age children. A repeated-measures ANOVA was used to compare the means across the three teaching conditions, indicating a statistically significant difference between the teaching conditions.…

Analyzing Randomized Controlled Interventions: Three Notes for Applied Linguists

ERIC Educational Resources Information Center

Vanhove, Jan

2015-01-01

I discuss three common practices that obfuscate or invalidate the statistical analysis of randomized controlled interventions in applied linguistics. These are (a) checking whether randomization produced groups that are balanced on a number of possibly relevant covariates, (b) using repeated measures ANOVA to analyze pretest-posttest designs, and…

Identifying the Factors That Influence Change in SEBD Using Logistic Regression Analysis

ERIC Educational Resources Information Center

Camilleri, Liberato; Cefai, Carmel

2013-01-01

Multiple linear regression and ANOVA models are widely used in applications since they provide effective statistical tools for assessing the relationship between a continuous dependent variable and several predictors. However these models rely heavily on linearity and normality assumptions and they do not accommodate categorical dependent…

Analysis of the color alteration and radiopacity promoted by bismuth oxide in calcium silicate cement.

PubMed

Marciano, Marina Angélica; Estrela, Carlos; Mondelli, Rafael Francisco Lia; Ordinola-Zapata, Ronald; Duarte, Marco Antonio Hungaro

2013-01-01

The aim of the study was to determine if the increase in radiopacity provided by bismuth oxide is related to the color alteration of calcium silicate-based cement. Calcium silicate cement (CSC) was mixed with 0%, 15%, 20%, 30% and 50% of bismuth oxide (BO), determined by weight. Mineral trioxide aggregate (MTA) was the control group. The radiopacity test was performed according to ISO 6876/2001. The color was evaluated using the CIE system. The assessments were performed after 24 hours, 7 and 30 days of setting time, using a spectrophotometer to obtain the ΔE, Δa, Δb and ΔL values. The statistical analyses were performed using the Kruskal-Wallis/Dunn and ANOVA/Tukey tests (p<0.05). The cements in which bismuth oxide was added showed radiopacity corresponding to the ISO recommendations (>3 mm equivalent of Al). The MTA group was statistically similar to the CSC/30% BO group (p>0.05). In regard to color, the increase of bismuth oxide resulted in a decrease in the ΔE value of the calcium silicate cement. The CSC group presented statistically higher ΔE values than the CSC/50% BO group (p<0.05). The comparison between 24 hours and 7 days showed higher ΔE for the MTA group, with statistical differences for the CSC/15% BO and CSC/50% BO groups (p<0.05). After 30 days, CSC showed statistically higher ΔE values than CSC/30% BO and CSC/50% BO (p<0.05). In conclusion, the increase in radiopacity provided by bismuth oxide has no relation to the color alteration of calcium silicate-based cements.

Evaluation of anxiety, depression and suicidal intent in undergraduate dental students: A cross-sectional study.

PubMed

Bathla, Manish; Singh, Manpreet; Kulhara, Paramanand; Chandna, Shalu; Aneja, Jitender

2015-01-01

There is an increasing amount of stress in undergraduate dental students leading to anxiety, depression, and suicidal attempts/suicide. This study aims to evaluate anxiety, depression and suicidal intent in undergraduate dental students and to find out the various areas of stress. A cross-sectional study was conducted using a semi-structured questionnaire (to assess academic and nonacademic areas of stress) and three scales-Hamilton scale for anxiety (HAM-A); Hamilton depression rating scale (HDRS) and Beck's Suicide Intent Scale (BSI). Descriptive statistics; Pearson's Chi-square test; Multiple ANOVA; Kruskal-Wallis test and Mann-Whitney test were used to analyze the data at the significant level of P ≤ 0.05. In a total of 258 dental undergraduate students, academic areas of stress that were found to be statistically significant were long teaching hours (P = 0.002); high workload (P ≤ 0.001); frequency of tests (P ≤ 0.001) and competition/fear of failure (P = 0.009). Lack of interest in the profession was a statistically significant nonacademic area for stress (P ≤ 0.001). The students of first and final year reported higher anxiety (HAM-A 13.93 ± 6.908 and 16.44 ± 7.637 respectively) and depression (HDRS 14.29 ± 6.302 and 14.22 ± 5.422); whereas suicidal intent was reported almost the same throughout the study sample (BSI 5.65 ± 5.465). An increasing level of anxiety, depression and suicidal intent due to various stressors in undergraduate dental students indicate a need to modify current education system and timely help to have psychological healthy dental professionals in future.

DESENSITIZING BIOACTIVE AGENTS IMPROVES BOND STRENGTH OF INDIRECT RESIN-CEMENTED RESTORATIONS: PRELIMINARY RESULTS

PubMed Central

Pires-De-Souza, Fernanda de Carvalho Panzeri; de Marco, Fabíola Fiorezi; Casemiro, Luciana Assirati; Panzeri, Heitor

2007-01-01

Objective: The aim of this study was to assess the bond strength of indirect composite restorations cemented with a resin-based cement associated with etch-and-rinse and self-etching primer adhesive systems to dentin treated or not with a bioactive material. Materials and Method: Twenty bovine incisor crowns had the buccal enamel removed and the dentin ground flat. The teeth were assigned to 4 groups (n=5): Group I: acid etching + Prime & Bond NT (Dentsply); Group II: application of a bioactive glass (Biosilicato®)+ acid etching + Prime & Bond NT; Group III: One-up Bond F (J Morita); Group IV: Biosilicato® + One-up Bond F. Indirect composite resin (Artglass, Kulzer) cylinders (6x10mm) were fabricated and cemented to the teeth with a dualcure resin-based cement (Enforce, Dentsply). After cementation, the specimens were stored in artificial saliva at 37oC for 30 days and thereafter tested in tensile strength in a universal testing machine (EMIC) with 50 kgf load cell at a crosshead speed of 1 mm/min. Failure modes were assessed under scanning electron microscopy. Data were analyzed statistically by ANOVA and Tukey's test (95% level of confidence). Results: Groups I, II and III had statistically similar results (p>0.05). Group IV had statistically significant higher bond strength means (p<0.05) than the other groups. The analysis of the debonded surfaces showed a predominance of adhesive failure mode for Group III and mixed failure mode for the other groups. Conclusion: The use of desensitizing agent did not affect negatively the bonding of the indirect composite restorations to dentin, independently of the tested adhesive systems. PMID:19089114

Evaluation of the fracture resistance of computer-aided design/computer-aided manufacturing monolithic crowns prepared in different cement thicknesses.

PubMed

Sagsoz, N Polat; Yanıkoglu, N

2018-04-01

The purpose of this study was to evaluate the fracture resistance of monolithic computer-aided design/computer-aided manufacturing (CAD/CAM) crowns that are prepared with different cement thickness. For this investigation, a human maxillary premolar tooth was selected. Master model preparation was performed with a demand bur under water spray. Master die was taken to fabricate 105 epoxy resin replicas. The crowns were milled using a CEREC 4 CAD/CAM system (Software Version, 4.2.0.57192). CAD/CAM crowns were made using resin nanoceramic, feldspathic glass ceramic, lithium disilicate, and leucite-reinforced ceramics. Each group was subdivided into three groups in accordance with three different cement thicknesses (30, 90, and 150 μm). Crowns milled out. Then RelyX ™ U200 was used as a luting agent to bond the crowns to the prepared samples. After one hour cementations, the specimens were stored in water bath at 37°C for 1 week before testing. Seven unprepared and unrestored teeth were kept and tested as a control group. A universal test machine was used to assume the fracture resistance of all specimens. The compressive load (N) that caused fracture was recorded for each specimen. Fracture resistance data were statistically analyzed by one-way ANOVA and two-factor interaction modeling test (α = 0.001). There are statistically significant differences between fracture resistances of CAD/CAM monolithic crown materials (P < 0.001). It is seen that cement thickness is not statistically significant for fracture resistance of CAD/CAM monolithic crowns (P > 0.001). CAD/CAM monolithic crown materials affected fracture resistance. Cement thickness (30, 90, and 150 μm) was not effective on fracture resistance of CAD/CAM monolithic crowns.

Tensile bond strength of veneering resins to PEEK: impact of different adhesives.

PubMed

Stawarczyk, Bogna; Keul, Christine; Beuer, Florian; Roos, Malgorzata; Schmidlin, Patrick R

2013-01-01

This study tested tensile bond strength (TBS) between veneering resins and polyetheretherketone (PEEK) after pre-treatment with adhesive systems. Five-hundred-seventy-six PEEK disks were fabricated, air-abraded and divided into six pre-treatment groups (n=96/group): Z-Prime Plus, Ambarino P60, Monobond Plus, Visio.link, Signum PEEK Bond, and control group without pre-treatment. Each group was divided into three subgroups of different veneering resins (n=32): Sinfony, GC Gradia and VITA VM LC. After specimen preparation with a bond area of 6.6 mm(2), half of each subgroup (n=16) was tested initially, and the other half was thermo-cycled. TBS measurements were analysed by three-way and one-way ANOVA, t-test and Weibull statistics. Groups without pre-treatment and groups pre-treated by Z-Prime Plus and Ambarino P60 showed no TBS. Pre-treatment with Monobond Plus increased the TBS values. The highest TBS before and after thermo-cycling between PEEK and all tested veneering resins was observed for groups pre-treated with Visio.link and Signum PEEK Bond.

Demographic features of subjects with congenital glaucoma

PubMed Central

Tamçelik, Nevbahar; Atalay, Eray; Bolukbasi, Selim; Çapar, Olgu; Ozkok, Ahmet

2014-01-01

Context: Congenital glaucoma is a potentially blinding ocular disease of the childhood. Identification of the possible associated risk factors and may be helpful for prevention or early detection of this public health problem. Aims: To demonstrate the demographic features of congenital glaucoma subjects. Setting and Design: The charts of congenital glaucoma patients referred to Tamcelik Glaucoma Center were retrospectively reviewed through the dates of 2000 and 2013. Materials and Methods: Analyzed data included diagnosis, age at first presentation, symptoms at first presentation, laterality of the disease, sex, presence of consanguinity, family history of congenital glaucoma, maturity of the fetus at delivery, and maternal age at conception. Statistical Analysis Used: Statistical Package for Social Sciences (SPSS) version 19.0 by IBM (SPSS Inc, Chicago, Illinois, USA) was used to compare the mean of continuous variables with Student's t-test and analysis of variance (ANOVA) and χ2 test was used to test differences in proportions of categorical variables. Results: The data of 600 eyes of 311 patients were analyzed. The distribution of primary and secondary congenital glaucoma among the patients were 63.3% (n = 197) and 36.7% (n = 114), respectively. Of the 311 patients, 57.2% (n = 178) were male and 42.8% (n = 133) were female. The overall frequency of bilateral disease was 92.3% (n = 287). Overall rate of consanguinity and positive family history was 45.3% (n = 141) and 21.2% (n = 66), respectively. Conclusions: Bilateral disease in this study was more common than previously reported studies. Positive family history was more frequent in primary congenital glaucoma although not statistically significant. PMID:24881602

Effect of eugenol-based endodontic sealer on the adhesion of intraradicular posts cemented after different periods.

PubMed

Dias, Larissa Lustosa Lima; Giovani, Alessandro Rogério; Silva Sousa, Yara Teresinha Corrêa; Vansan, Luiz Pascoal; Alfredo, Edson; Sousa-Neto, Manoel Damião; Paulino, Silvana Maria

2009-01-01

This study evaluated in vitro the influence of an eugenol-based sealer (EndoFill) on the retention of stainless steel prefabricated posts cemented with zinc phosphate and resin-based (Panavia F) cements after different periods of root canal obturation, using the pull-out test. Sixty upper canines were decoronated and the roots were embedded in resin blocks. The specimens were distributed into 3 groups, according to the period elapsed between canal obturation and post cementation: Group I - immediately; Group II - 72 h and Group III - 4 months. The groups were subdivided according to the type of cement used for post cementation: A - zinc phosphate and B - Panavia F. Following the experimental periods, specimens were subjected to pullout test in an Instron machine with application of tensile force at a crosshead speed of 0.5 mm/min until post dislodgement. The maximum forces required for post removal were recorded (kN) and means were subjected to statistical analysis by 2-way ANOVA and Tukey-Kramer test (alpha=0.001) There were statistically significant differences (p<0.01) between the posts cemented with zinc phosphate cement (0.2112 kN) and Panavia F (0.0501 kN). However, no statistically significant differences (p>0.05) were found between the three post cementation periods, regardless of the cement. It was concluded that the eugenol-based sealer influenced the tensile strength of the posts cemented with the resin cement, but had no influence on the time waited between root canal obturation and post space preparation/post cementation.

EFFECT OF EUGENOL-BASED ENDODONTIC SEALER ON THE ADHESION OF INTRARADICULAR POSTS CEMENTED AFTER DIFFERENT PERIODS

PubMed Central

Dias, Larissa Lustosa Lima; Giovani, Alessandro Rogério; Sousa, Yara Teresinha Corrêa Silva; Vansan, Luiz Pascoal; Alfredo, Edson; Sousa-Neto, Manoel Damião; Paulino, Silvana Maria

2009-01-01

Objective: This study evaluated in vitro the influence of an eugenol-based sealer (EndoFill) on the retention of stainless steel prefabricated posts cemented with zinc phosphate and resin-based (Panavia F) cements after different periods of root canal obturation, using the pull-out test. Material and methods: Sixty upper canines were decoronated and the roots were embedded in resin blocks. The specimens were distributed into 3 groups, according to the period elapsed between canal obturation and post cementation: Group I - immediately; Group II - 72 h and Group III - 4 months. The groups were subdivided according to the type of cement used for post cementation: A - zinc phosphate and B - Panavia F. Following the experimental periods, specimens were subjected to pull- out test in an Instron machine with application of tensile force at a crosshead speed of 0.5 mm/min until post dislodgement. The maximum forces required for post removal were recorded (kN) and means were subjected to statistical analysis by 2-way ANOVA and Tukey-Kramer test (α=0.001) Results: There were statistically significant differences (p<0.01) between the posts cemented with zinc phosphate cement (0.2112 kN) and Panavia F (0.0501 kN). However, no statistically significant differences (p>0.05) were found between the three post cementation periods, regardless of the cement. Conclusions: It was concluded that the eugenol-based sealer influenced the tensile strength of the posts cemented with the resin cement, but had no influence on the time waited between root canal obturation and post space preparation/post cementation. PMID:20027430

Comparison of chewing ability, oral health related quality of life and nutritional status before and after insertion of complete denture amongst edentulous patients in a Dental College of Pune.

PubMed

Madhuri, Sonawane; Hegde, Shetiya Sahana; Ravi, Shirahatti; Deepti, Agarwal; Simpy, Mahuli

2014-07-01

The relationship between tooth loss and nutritional intake is important. As people age, their diminished physical capacity and decreased income adversely affect their ability to maintain their teeth. The aim of the study was to assess and compare the chewing ability, oral health related quality of life and nutritional status before and after fabrication and insertion of complete denture amongst edentulous participants in a dental college. Non Randomized Intervention study. The study population consisted of 42 participants (16 females and 26 males), aged 50 years and above. Prior to commencement of the study, informed consent was obtained and validation and reliability test of the questionnaire were done. The data for chewing ability, GOHAI and nutritional status assessment was recorded at baseline, 3(rd), 6(th) and 12(th) month after denture fabrication and insertion. The statistical comparisons were performed by repeated measure ANOVA and Chi-square test. P value<0.05 was considered as statistically significant. Chewing ability, GOHAI, BMI (Body Mass Index) and data from Food-intake questionnaire showed statistically significant improvement from baseline to 6(th) month but no statistically significant improvement was observed from 6(th) month to 12(th) month. Nutritive value of food (protein, energy and fat) showed no significant difference over a period of 12 months (p<0.05). Thus, it was concluded that the intervention (denture insertion) was effective in increasing the chewing ability, body weight, food-intake, and oral health related quality of life.

Optical properties of mice skin for optical therapy relevant wavelengths: influence of gender and pigmentation

NASA Astrophysics Data System (ADS)

Sabino, C. P.; Deana, A. M.; Silva, D. F. T.; França, C. M.; Yoshimura, T. M.; Ribeiro, M. S.

2015-03-01

Red and near-infrared light have been widely employed in optical therapies. Skin is the most common optical barrier in non-invasive techniques and in many cases it is the target tissue itself. Consequently, to optimize the outcomes brought by lightbased therapies, the optical properties of skin tissue must be very well elucidated. In the present study, we evaluated the dorsal skin optical properties of albino (BALB/c) and pigmented (C57BL/6) mice using the Kubelka-Munk photon transport model. We evaluated samples from male and female young mice of both strains. Analysis was performed for wavelengths at 630, 660, 780, 810 and 905 nm due to their prevalent use in optical therapies, such as low-level light (or laser) and photodynamic therapies. Spectrophotometric measurements of diffuse transmittance and reflectance were performed using a single integrating sphere coupled to a proper spectrophotometer. Statistic analysis was made by two-way ANOVA, with Tukey as post-test and Levenne and Shapiro-Wilks as pre-tests. Statistical significance was considered when p<0.05. Our results show only a slight transmittance increment (<10 %) as wavelengths are increased from 630 to 905 nm, and no statistical significance was observed. Albino male mice present reduced transmittance levels for all wavelengths. The organization and abundance of skin composing tissues significantly influence its scattering optical properties although absorption remains constant. We conclude that factors such as subcutaneous adiposity and connective tissue structure can have statistically significant influence on mice skin optical properties and these factors have relevant variations among different gender and strains.

Using Plates and Trays with MyPlate Images to Encourage Healthy Food Choices: A Pilot Study at Military Dining Facilities

DTIC Science & Technology

dairy consumption . Future research should investigate the effectiveness of the MyPlate intervention for improving diet quality and nutrition knowledge in larger military dining facilities at different locations....introduced the new food labeling system. Dietary intake of facility patrons was measured during 12 lunch meals using the food photography method. Repeated...measures ANOVA, one-way ANOVA, paired t-test, and McNemars test were used. Results: Dairy consumption increased from baseline to intervention (0.50.4

Bond strength to root dentin and fluid filtration test of AH Plus/gutta-percha, EndoREZ and RealSeal systems

PubMed Central

MAHDI, Alaa Abdul; BOLAÑOS-CARMONA, Victoria; GONZALEZ-LOPEZ, Santiago

2013-01-01

Objectives To investigate the bond strength and seal ability produced by AH Plus/gutta-percha, EndoREZ and RealSeal systems to root canal dentin. Material and Methods Sixty extracted single-root human teeth, instrumented manually to size 40, were divided into three groups (n=20) according to the sealer used; G1: AH Plus, G2: EndoREZ, and G3: RealSeal sealers. After filling using the lateral condensation technique, each sealer group was randomly divided into two subgroups according to the tests applied (n=10 for µPush-out test and n=10 for fluid filtration test). A fluid filtration method was used for quantitative evaluation of apical leakage. Four 1-mm-thick slices (cervical and medium level) were obtained from each root sample and a µPush-out test was performed. Failure modes were examined under microscopy at 40x, and a one-way ANOVA was applied to analyze the permeability. Non-parametrical statistics for related (Friedman's and Wilcoxon's rank tests) or unrelated samples (Kruskal-Wallis' and Mann-Whitney's tests) allowed for comparisons of µPush-out strength values among materials at the different levels. Statistical significance was accepted for p values <.05. Results There are no significant differences among fluid filtration of the three sealers. The sealer/core material does not significantly influence the µPush-out bond strength values (F=2.49; p=0.10), although statistically significant differences were detected with regard to root level (Chi2=23.93; p<0.001). AH Plus and RealSeal obtained higher bond strength to intraradicular dentin in the medium root slices. Conclusions There are no significant differences between the permeability and global µPush-out bond strength to root canal dentin achieved by AH Plus/gutta-percha, EndoREZ and RealSeal systems. PMID:24037078

GLIMMPSE Lite: Calculating Power and Sample Size on Smartphone Devices

PubMed Central

Munjal, Aarti; Sakhadeo, Uttara R.; Muller, Keith E.; Glueck, Deborah H.; Kreidler, Sarah M.

2014-01-01

Researchers seeking to develop complex statistical applications for mobile devices face a common set of difficult implementation issues. In this work, we discuss general solutions to the design challenges. We demonstrate the utility of the solutions for a free mobile application designed to provide power and sample size calculations for univariate, one-way analysis of variance (ANOVA), GLIMMPSE Lite. Our design decisions provide a guide for other scientists seeking to produce statistical software for mobile platforms. PMID:25541688

Physical Fitness For Futsal Referee Of Football Association In Thailand

NASA Astrophysics Data System (ADS)

Thaweesub Koeipakvaen Acting Sub L., t.

2018-01-01

The purpose of the research to study physical fitness for futsal Referee of Football Association in Thailand and Compare of the Physical Fitness for first level, second and third futsal Referee of Football Association in Thailand. The population of first level, second and third level futsal Referee of Football Association in Thailand 107 person. The sample were futsal Referee of Football Association in Thailand 97 person. First level futsal Referee 22 person. Second level futsal Referee 11 person. Third level futsal Referee 64 person. The instrument used was futsal physical fitness test of Football Association in Thailand. Endurance Test (1,000 meter), Speed Test (4x10 meter) 2 time, and Agility Test (80 meter) 2 time. The statistic for data analysis were one way Anova, Percentage, Mean, Standard Deviation and F-test. The results were as the follow: (1) the result comparing F-test first level futsal referee with level second and first level futsal referee with third level. the statically significant different at the 0.05 level, and the result comparing Endurance as the follow the Physical Fitness for first level, second and third futsal Referee. the statically significant different at the 0.05 level.

Evaluation of the strength and radiopacity of Portland cement with varying additions of bismuth oxide.

PubMed

Saliba, E; Abbassi-Ghadi, S; Vowles, R; Camilleri, J; Hooper, S; Camilleri, J

2009-04-01

To study the effect of addition of various proportions of bismuth oxide on compressive strength and radiopacity of Portland cement. The compressive strength of white Portland cement and cement replaced with 10, 15, 20, 25 and 30% bismuth oxide was evaluated by testing cylinders 6 mm in diameter and 12 mm high. Twelve cylinders were tested for each material under study. The radiopacity of the cements tested was evaluated using an aluminium step-wedge and densitometer. The optical density was compared with the relevant thickness of aluminium (Al). Statistical analysis was performed using Analysis of Variance (ANOVA) with P = 0.05 and Tukey test to perform multiple comparison tests. Various additions of bismuth oxide had no significant effect on the strength of the material when compared with the unmodified Portland cement (P > 0.05). The radiopacity of the cements tested ranged from 2.02 mm Al for Portland cement to 9.79 mm Al for the highest bismuth replacement. Addition of bismuth oxide did not affect the compressive strength of Portland cement. All the bismuth oxide cement mixtures had radio-opacities higher than 3 mm thickness of aluminium.

A new device to test cutting efficiency of mechanical endodontic instruments

PubMed Central

Rubini, Alessio Giansiracusa; Plotino, Gianluca; Al-Sudani, Dina; Grande, Nicola M.; Putorti, Ermanno; Sonnino, GianPaolo; Cotti, Elisabetta; Testarelli, Luca; Gambarini, Gianluca

2014-01-01

Background The purpose of the present study was to introduce a new device specifically designed to evaluate the cutting efficiency of mechanically driven endodontic instruments. Material/Methods Twenty new Reciproc R25 (VDW, Munich, Germany) files were used to be investigated in the new device developed to test the cutting ability of endodontic instruments. The device consists of a main frame to which a mobile plastic support for the hand-piece is connected and a stainless-steel block containing a Plexiglas block against which the cutting efficiency of the instruments was tested. The length of the block cut in 1 minute was measured in a computerized program with a precision of 0.1mm. The instruments were activated by using a torque-controlled motor (Silver Reciproc; VDW, Munich, Germany) in a reciprocating movement by the “Reciproc ALL” program (Group 1) and in counter-clockwise rotation at 300 rpm (Group 2). Mean and standard deviations of each group were calculated and data were statistically analyzed with a one-way ANOVA test (P<0.05). Results Reciproc in reciprocation (Group 1) mean cut in the Plexiglas block was 8.6 mm (SD=0.6 mm), while Reciproc in rotation mean cut was 8.9 mm (SD=0.7 mm). There was no statistically significant difference between the 2 groups investigated (P>0.05). Conclusions The cutting testing device evaluated in the present study was reliable and easy to use and may be effectively used to test cutting efficiency of both rotary and reciprocating mechanical endodontic instruments. PMID:24603777

The Effect on the Flexural Strength, Flexural Modulus and Compressive Strength of Fibre Reinforced Acrylic with That of Plain Unfilled Acrylic Resin – An in Vitro Study

PubMed Central

Thomas, Tony C; K, Aswini Kumar; Krishnan, Vinod; Mathew, Anil; V, Manju

2015-01-01

Aim: The aim of this in vitro study was to compare the flexural strength, the flexural modulus and compressive strength of the acrylic polymer reinforced with glass, carbon, polyethylene and Kevlar fibres with that of plain unfilled resin. Materials and Methods: A total of 50 specimens were prepared and divided into 10 specimens each under 5 groups namely group 1- control group without any fibres, group 2 – carbon fibres, group 3- glass fibres, group 4 – polyethylene, group 5- Kevlar. Universal testing machine (Tinius olsen, USA) was used for the testing of these specimens. Out of each group, 5 specimens were randomly selected and testing was done for flexural strength using a three point deflection test and three point bending test for compressive strength and the modulus was plotted using a graphical method. Statistical analysis was done using statistical software. Results: The respective mean values for samples in regard to their flexural strength for PMMA plain, PMMA+ glass fibre, PMMA+ carbon, PMMA+ polyethylene and PMMA+ Kevlar were 90.64, 100.79, 102.58, 94.13 and 96.43 respectively. Scheffes post hoc test clearly indicated that only mean flexural strength values of PMMA + Carbon, has the highest mean value. One-way ANOVA revealed a non-significant difference among the groups in regard to their compressive strength. Conclusion: The study concludes that carbon fibre reinforced samples has the greatest flexural strength and greatest flexural modulus, however the compressive strength remains unchanged. PMID:25954696

Passive fit and accuracy of three dental implant impression techniques.

PubMed

Al Quran, Firas A; Rashdan, Bashar A; Zomar, AbdelRahman A Abu; Weiner, Saul

2012-02-01

To reassess the accuracy of three impression techniques relative to the passive fit of the prosthesis. An edentulous maxillary cast was fabricated in epoxy resin with four dental implants embedded and secured with heat-cured acrylic resin. Three techniques were tested: closed tray, open tray nonsplinted, and open tray splinted. One light-cured custom acrylic tray was fabricated for each impression technique, and transfer copings were attached to the implants. Fifteen impressions for each technique were prepared with medium-bodied consistency polyether. Subsequently, the impressions were poured in type IV die stone. The distances between the implants were measured using a digital micrometer. The statistical analysis of the data was performed with ANOVA and a one-sample t test at a 95% confidence interval. The lowest mean difference in dimensional accuracy was found within the direct (open tray) splinted technique. Also, the one-sample t test showed that the direct splinted technique has the least statistical significant difference from direct nonsplinted and indirect (closed tray) techniques. All discrepancies were less than 100 Μm. Within the limitations of this study, the best accuracy of the definitive prosthesis was achieved when the impression copings were splinted with autopolymerized acrylic resin, sectioned, and rejoined. However, the errors associated with all of these techniques were less than 100 Μm, and based on the current definitions of passive fit, they all would be clinically acceptable.

Cutting efficiency of instruments with different movements: a comparative study.

PubMed

Tocci, Luigi; Plotino, Gianluca; Al-Sudani, Dina; Rubini, Alessio Giansiracusa; Sannino, Gianpaolo; Piasecki, Lucila; Putortì, Ermanno; Testarelli, Luca; Gambarini, Gianluca

2015-01-01

The aim of the present study was to evaluate the cutting efficiency of two new reciprocating instruments, Twisted File Adaptive and WaveOne Primary. 10 new Twisted File Adaptive (TF Adaptive) (SybronEndo, Glendora, CA, USA) and 10 new WaveOne Primary files (Dentsply Maillefer, Ballaigues, Switzerland) were activated using a torque-controlled motor, respectively TFA motor (SybronEndo, Glendora, CA, USA) and Silver motor (VDW, Munich, Germany). The device used for the cutting test consisted on a mainframe to which a mobile plastic support for the hand-piece is connected and a stainless-steel block containing a Plexiglas block against which the cutting efficiency of the instruments was tested. The length of the block cut in 1 minute was measured in a computerized program with a precision of 0.1 mm. Mean and standard deviations of each group were calculated and data were statistically analyzed with one-way ANOVA and Bonferroni t test (P < 0.05). TF Adaptive displayed significantly greater maximum penetration depth than WaveOne Primary (P < 0.05). In fact, TF Adaptive instruments (Group 1) cut the Plexiglas block to a mean depth of 8.7 (SD 0.5) mm, while WaveOne Primary instruments cut the Plexiglas block to a mean depth of 6.4 (SD 0.3) mm. Twisted File Adaptive instruments demonstrated statistically higher cutting efficiency than WaveOne instruments.

Influence of Adhesives and Methods of Enamel Pretreatment on the Shear Bond Strength of Orthodontic Brackets.

PubMed

Jurišić, Sanja; Jurišić, Gordan; Jurić, Hrvoje

2015-12-01

The objective of present study was to examine influence of adhesives and methods of enamel pretreatment on the shear bond strength (SBS) of orthodontic brackets. The adhesives used were resin-reinforced glass ionomer cements-GIC (Fuji Ortho LC) and composite resin (Transbond XT). The experimental sample consisted of 80 extracted human first premolars. The sample was divided into four equal groups, and the metal brackets were bonded with different enamel pretreatments by using two adhesives: group A-10% polyacrylic acid; Fuji Ortho LC, group B-37% phosphoric acid; Fuji Ortho LC, group C-self etching primer; Transbond XT, group D-37% phosphoric acid, primer; Transbond XT. SBS of brackets was measured. After debonding of brackets, the adhesive remnant index (ARI) was evaluated. After the statistical analysis of the collected data was performed (ANOVA; Sheffe post-hoc test), the results showed that significantly lower SBS of the group B was found in relation to the groups C (p=0.031) and D (p=0.026). The results of ARI were similar in all testing groups and it was not possible to determine any statistically significant difference of the ARI (Chi- square test) between all four experimental groups. The conclusion is that the use of composite resins material with appropriate enamel pretreatment according to manufacturer's recommendation is the "gold standard" for brackets bonding for fixed orthodontic appliances.

Cutting Efficiency of Instruments with Different Movements: a Comparative Study

PubMed Central

Plotino, Gianluca; Al-Sudani, Dina; Rubini, Alessio Giansiracusa; Sannino, Gianpaolo; Piasecki, Lucila; Putortì, Ermanno; Testarelli, Luca; Gambarini, Gianluca

2015-01-01

ABSTRACT Objectives The aim of the present study was to evaluate the cutting efficiency of two new reciprocating instruments, Twisted File Adaptive and WaveOne Primary. Material and Methods 10 new Twisted File Adaptive (TF Adaptive) (SybronEndo, Glendora, CA, USA) and 10 new WaveOne Primary files (Dentsply Maillefer, Ballaigues, Switzerland) were activated using a torque-controlled motor, respectively TFA motor (SybronEndo, Glendora, CA, USA) and Silver motor (VDW, Munich, Germany). The device used for the cutting test consisted on a mainframe to which a mobile plastic support for the hand-piece is connected and a stainless-steel block containing a Plexiglas block against which the cutting efficiency of the instruments was tested. The length of the block cut in 1 minute was measured in a computerized program with a precision of 0.1 mm. Mean and standard deviations of each group were calculated and data were statistically analyzed with one-way ANOVA and Bonferroni t test (P < 0.05). Results TF Adaptive displayed significantly greater maximum penetration depth than WaveOne Primary (P < 0.05). In fact, TF Adaptive instruments (Group 1) cut the Plexiglas block to a mean depth of 8.7 (SD 0.5) mm, while WaveOne Primary instruments cut the Plexiglas block to a mean depth of 6.4 (SD 0.3) mm. Conclusions Twisted File Adaptive instruments demonstrated statistically higher cutting efficiency than WaveOne instruments. PMID:25937877

The Effect of Multiple Firings on the Shear Bond Strength of Porcelain to a New Millable Alloy and a Conventional Casting Alloy

PubMed Central

Farzin, Mitra; Giti, Rashin; Asalforush-Rezaiye, Amin

2018-01-01

This study compared the effect of multiple firings on the shear bond strength (SBS) of porcelain to the new millable alloy (Ceramill Sintron) and a conventional casting alloy (4-all). Thirty-six cylindrical cores (6.8 × 9 mm) were made of millable and castable alloy through CAD/CAM and casting techniques, respectively (n = 18). In the center of each bar, a 4 × 4 × 2-mm shot of porcelain was fused. Having divided each group into 3 subgroups based on the number of firing cycles (3, 5, 7), the specimens were fixed in a universal testing machine and underwent a shear force test (1.5 mm/min crosshead speed) until fractured. Then the SBS values (MPa) were calculated, and the failure patterns were microscopically characterized as adhesive, cohesive, or mixed. Two-way ANOVA statistical test revealed that the number of porcelain firings had no significant effect on the SBS of any of the metal groups (p = 0.1); however, it was statistically higher in the millable group than the castable group (p < 0.05). Moreover, detecting the mixed failure pattern in all the specimens implied that the multiple firings had no significant effect on the failure pattern. The multiple porcelain firings had no significant effect on the SBS of porcelain to neither the millable nor castable alloys. PMID:29565827

Indentation fracture toughness and dynamic elastic moduli for commercial feldspathic dental porcelain materials.

PubMed

Rizkalla, Amin S; Jones, Derek W

2004-02-01

The purpose of this study was to evaluate and compare the indentation fracture toughness, true hardness and dynamic elastic moduli for 14 commercial dental porcelain materials. The specimens were fired according to manufacturer instructions. The density of the specimens (n=3) was measured by means of the water displacement technique. Dynamic Young's shear and bulk moduli and Poisson's ratio (n=3) were measured using a non-destructive ultrasonic technique using 10 MHz lithium niobate crystals. The true hardness (n=3) was measured using a Knoop indenter and the fracture toughness (n=3) was determined using a Vickers indenter and a Tukon hardness tester. Statistical analysis of the data was conducted using ANOVA and a Student-Newman-Keuls (SNK) rank order multiple comparative test. The SNK rank test analysis for the mean dynamic Young's modulus and fracture toughness was able to separate 14 dental porcelain materials into seven and nine groups, respectively, at p=0.05. The elastic moduli, true hardness and indentation fracture toughness for opaque porcelains were significantly higher than incisal; and body materials at p=0.05. The indentation fracture toughness and the ultrasonic test methods exhibit lower coefficient of variation compared to conventional methods and have considerable advantage for ceramic dental materials in that only small specimens are required to produce an acceptable number of data for statistical analysis.

Evaluation of the effects of sildenafil citrate (viagra) on vertebral artery blood flow in patients with vertebro-basilar insufficiency.

PubMed

Bozgeyik, Zulkif; Berilgen, Sait; Ozdemir, Huseyin; Tekatas, Aslan; Ogur, Erkin

2008-01-01

To investigate the effects of sildenafil citrate (Viagra) on the vertebral artery blood flow of patients with vertebro-basilar insufficiency (VBI) using color duplex sonography (CDS). The study included 21 patients with VBI (aged 31-76; mean 61.0 +/- 10.5 yrs). We administered a 50 mg oral dose of sildenafil citrate to all patients. Next, we measured the peak systolic velocity (Vmax), end diastolic velocity (Vmin), resistive index (RI), pulsatility index (PI), diameter, area, and flow volume (FV) of vertebral arteries using CDS before the administration of sildenafil citrate; 45 minutes after, and 75 minutes after administration. Statistical testing was performed using SPSS for windows version 11.0. The statistical test used to determine the outcome of the analysis was the repeated measures analysis of variance (ANOVA) test. Compared to the baseline values, the vertebral artery diameter, area, and FV increased significantly following the administration of sildenafil citrate. The diameter, area and FV increased from 3.39 mm at 45 minutes to 3.64 mm at 75 minutes, 9.43 cm(2) to 10.80 cm(2) at 45 minutes and 10.81 cm(2) at 75 minutes, as well as from 0.07 L/min at baseline to 0.09 L/min at 45 minutes and unchanged at 75 minutes, respectively. Sildenafil citrate elicited a significant effect on vertebral artery diameter, area and FVs.

Role of Saccharomyces boulardii in Reduction of Neonatal Hyperbilirubinemia

PubMed Central

Suganthi, V.

2016-01-01

Introduction Probiotics are known to reduce the severity of hyperbilirubinemia. Aim This study was done to evaluate the effect of probiotic on neonatal hyperbilirubinemia in term neonates. Materials and Methods A total of 181 healthy term neonates after birth were divided into a control group (n=95) and a treatment group (n=86) randomly and treated with placebo and probiotic (Saccharomyces boulardii) respectively. A total of two doses were given orally in the first two consecutive days. The serum bilirubin levels were detected on day three of life. Babies were exclusively breastfed, clinical outcome was recorded. Comparison between groups was made by the non-parametric Mann-Whitney test. Analysis of Variance (ANOVA) was used to assess the quantitative variables. A p-value of <0.05 using a two-tailed test was taken as being of significance for all statistical tests. Results On day 3, mean total serum bilirubin in control group among patient who has not developed clinical jaundice is 6.5mg% and in the treatment group is 5mg%. In patient with clinical jaundice, it is 13.6mg% in control group and 10.7mg% in the treatment group. The p-value was found to be <0.05 which is statistically significant. No obvious adverse reactions noted in either group. Conclusion Probiotics lowered the serum bilirubin level of healthy neonate with jaundice safely and significantly without any adverse reaction. PMID:28050461

Role of Saccharomyces boulardii in Reduction of Neonatal Hyperbilirubinemia.

PubMed

Suganthi, V; Das, A Gokul

2016-11-01

Probiotics are known to reduce the severity of hyperbilirubinemia. This study was done to evaluate the effect of probiotic on neonatal hyperbilirubinemia in term neonates. A total of 181 healthy term neonates after birth were divided into a control group (n=95) and a treatment group (n=86) randomly and treated with placebo and probiotic ( Saccharomyces boulardii ) respectively. A total of two doses were given orally in the first two consecutive days. The serum bilirubin levels were detected on day three of life. Babies were exclusively breastfed, clinical outcome was recorded. Comparison between groups was made by the non-parametric Mann-Whitney test. Analysis of Variance (ANOVA) was used to assess the quantitative variables. A p-value of <0.05 using a two-tailed test was taken as being of significance for all statistical tests. On day 3, mean total serum bilirubin in control group among patient who has not developed clinical jaundice is 6.5mg% and in the treatment group is 5mg%. In patient with clinical jaundice, it is 13.6mg% in control group and 10.7mg% in the treatment group. The p-value was found to be <0.05 which is statistically significant. No obvious adverse reactions noted in either group. Probiotics lowered the serum bilirubin level of healthy neonate with jaundice safely and significantly without any adverse reaction.

Bond strengths of custom cast and prefabricated posts luted with two cements.

PubMed

Aleisa, Khalil Ibrahim

2011-02-01

This in vitro study evaluated the bond strength of custom cast and prefabricated posts luted with resin or zinc phosphate cements into unobturated canals of extracted teeth. Forty-eight custom cast and prefabricated posts were placed into extracted single-rooted human teeth. Post-cavity preparation was 1.5 mm in diameter and 10 mm in depth. Specimens were randomly divided into 4 groups of 12 each. Two of the groups were then luted with resin cement, while the other two groups were luted with zinc phosphate cement. A pull-out bond strength evaluation was performed using a universal testing machine. The Kolmogorov-Smirnov test was used to prove normal distribution. Data were statistically analyzed using two-way ANOVA and the Student t test (alpha = .05). For both luting agents, the prefabricated posts group exhibited significantly less bond strength than the custom cast posts group (P = .0001). There were statistically significant differences in mean bond strength for the prefabricated posts group luted with resin cement vs the group cemented with zinc phosphate cement (P = .002). There was no significant difference between the mean bond strength values of custom cast posts luted with resin cement or zinc phosphate cement. Custom cast posts showed significantly greater bond strength than prefabricated posts when luted with either resin or zinc phosphate cements. The type of cement had less significance on the retention of custom cast posts.

Debris Evaluation after Root Canal Shaping with Rotating and Reciprocating Single-File Systems

PubMed Central

Dagna, Alberto; Gastaldo, Giulia; Beltrami, Riccardo; Poggio, Claudio

2016-01-01

This study evaluated the root canal dentine surface by scanning electron microscope (SEM) after shaping with two reciprocating single-file NiTi systems and two rotating single-file NiTi systems, in order to verify the presence/absence of the smear layer and the presence/absence of open tubules along the walls of each sample; Forty-eight single-rooted teeth were divided into four groups and shaped with OneShape (OS), F6 SkyTaper (F6), WaveOne (WO) and Reciproc and irrigated using 5.25% NaOCl and 17% EDTA. Root canal walls were analyzed by SEM at a standard magnification of 2500×. The presence/absence of the smear layer and the presence/absence of open tubules at the coronal, middle, and apical third of each canal were estimated using a five-step scale for scores. Numeric data were analyzed using Kruskal-Wallis and Mann-Whitney U statistical tests and significance was predetermined at P < 0.05; The Kruskal-Wallis ANOVA for debris score showed significant differences among the NiTi systems (P < 0.05). The Mann-Whitney test confirmed that reciprocating systems presented significantly higher score values than rotating files. The same results were assessed considering the smear layer scores. ANOVA confirmed that the apical third of the canal maintained a higher quantity of debris and smear layer after preparation of all the samples; Single-use NiTi systems used in continuous rotation appeared to be more effective than reciprocating instruments in leaving clean walls. The reciprocating systems produced more debris and smear layer than rotating instruments. PMID:27763503

Who pays for the health benefits of exclusive breastfeeding? An analysis of maternal time costs.

PubMed

Smith, J P; Forrester, Robert

2013-11-01

The benefits of exclusive breastfeeding, including public health cost savings, are widely recognized, but breastfeeding requires maternal time investments. This study investigates the time taken to exclusively breastfeed at 6 months compared with not exclusively breastfeeding. Time use data were examined from an Australian survey of new mothers conducted during 2005-2006. Data from 139 mothers with infants age 6 months were analyzed using chi-square tests of independence to examine socioeconomic and demographic characteristics and 2-sided t tests to compare average weekly hours spent on milk feeding, feeding solids, preparing feeds, and the total of these. The comparison was of exclusively breastfeeding mothers with other mothers. We also compared exclusively breastfeeding with partially breastfeeding and formula feeding mothers using a 1-way between-groups analysis of variance (ANOVA). The exclusively breastfeeding (vs other) mothers spent 7 hours extra weekly on milk feeding their infants but 2 hours less feeding solids. These differences were statistically significant. ANOVA revealed significant differences between exclusively breastfeeding mothers, breastfeeding mothers who had introduced solids, and mothers who fed any formula, in time spent feeding milk, and solids, and preparing feeds. Exclusive breastfeeding is time intensive, which is economically costly to women. This may contribute to premature weaning for women who are time-stressed, lack household help from family, or cannot afford paid help. Gaining public health benefits of exclusive breastfeeding requires strategies to share maternal lactation costs more widely, such as additional help with housework or caring for children, enhanced leave, and workplace lactation breaks and suitable child care.

A thermographic study on eyes affected by Age-related Macular Degeneration: Comparison among various forms of the pathology and analysis of risk factors

NASA Astrophysics Data System (ADS)

Matteoli, Sara; Finocchio, Lucia; Biagini, Ilaria; Giacomelli, Giovanni; Sodi, Andrea; Corvi, Andrea; Virgili, Gianni; Rizzo, Stanislao

2016-05-01

The aims of this study are to investigate (1) the ocular thermographic profiles in eyes affected by Age related Macular Degeneration (AMD) and age-matched controls to detect possible hemodynamic abnormalities that could be involved in the pathogenesis of the disease, (2) whether any risk factors associated with the disease could affect the development of a form of AMD rather than another. Thirty-four eyes with Age-Related Maculopathy (ARM), 41 eyes with dry AMD, 60 eyes affected by wet AMD, and 74 eyes with fibrotic AMD were included in the study. The control group consisted of 48 healthy eyes. Exclusion criteria were represented by any other ocular diseases other than AMD, tear film abnormalities, systemic cardiovascular abnormalities, systemic diseases and a body temperature higher than 37.5 °C. A total of 210 eyes without pupil dilation were investigated by infrared thermography (FLIR A320). The Ocular Surface Temperature (OST) of five ocular areas was calculated by means of an image processing technique from the infrared images. Two-sample t-test, one-way ANOVA test and multivariate analysis were used for statistical analyses. ANOVA analyses showed no significant differences among AMD groups (P-value > 0.05), however, OST in AMD patients was significantly lower than in controls (P-value < 0.0001). Smokers showed higher possibility (P-value = 0.012) of developing wet AMD instead of dry AMD. Infrared thermography may be a helpful, non-invasive and not time-consuming method to be used in the management of patients with this common degenerative maculopathy.

The effect of hydrogen peroxide concentration on metal ion release from dental casting alloys.

PubMed

Al-Salehi, S K; Hatton, P V; Johnson, A; Cox, A G; McLeod, C

2008-04-01

There are concerns that tooth bleaching agents may adversely affect dental materials. The aim of this study was to test the hypothesis that increasing concentrations of hydrogen peroxide (HP) are more effective than water at increasing metal ion release from two typical dental casting alloys during bleaching. Discs (n = 28 for each alloy) were prepared by casting and heat treated to simulate a typical porcelain-firing cycle. Discs (n = 7) of each alloy were immersed in either 0%, 3%, 10% or 30% (w/v) HP solutions for 24 h at 37 degrees C. Samples were taken for metal ion release determination using inductively coupled plasma-mass spectrometry and the data analysed using a two-way anova followed by a one-way anova. The surface roughness of each disc was measured using a Talysurf contact profilometer before and after bleaching and the data analysed using a paired t-test. With the exception of gold, the differences in metal ion concentration after treatment with 0% (control) and each of 3%, 10% and 30% HP (w/v) were statistically significant (P < 0.05). Metal ion release from the two alloys increased with increasing HP concentrations (over 3000% increase in Ni and 1400% increase in Pd ions were recorded when HP concentration increased from 0% to 30%). Surface roughness values of the samples before and after bleaching were not significantly different (P > 0.05) Exposure of the two dental casting alloys to HP solutions increased metal ion release of all the elements except gold.

Occupational Safety and Health Measures in Micro-scale Enterprises (MSEs) in Shiraz, Iran

PubMed Central

Jahangiri, Mehdi; Rostamabadi, Akbar; Malekzadeh, Gholamreza; Sadi, Amin Fahandej; Hamzavi, Golnar; Rasooli, Javad; Momeni, Zahra; Ghaem, Haleh

2016-01-01

Objectives: This study aimed to determine the extent of implementation of occupational safety and health measures in micro-scale enterprises (MSEs) and to assess the prevalence of occupational injuries and accidents and its relationship with occupational safety and health measures provided in the MSEs. Method: A cross-sectional study was conducted among 595 of MSEs. An index called the Safety and Health Requirement Index (SHRI) was created and used to calculate the percentage of provided occupational safety and health measures. The relationship between the SHRI and the occurrence of occupational accidents and injuries was investigated with the independent samples t-test and one-way ANOVA. Results: The mean SHRI score was 60.43%, which was categorized into moderate level. Of the 30.9% of enterprises that had experienced accidents and injuries, the most common types of injuries were musculoskeletal disorders and cuts, and the least common types were pulmonary and hearing problems. Results of one-way ANOVA revealed a statistically significant relationship between the mean SHRI score and industrial branch, enterprise size, and type of accident and injury. The independent samples t-test showed that the occurrence of occupational accidents and injuries was not significantly influenced by provided health and safety measures in MSEs. Conclusion: Given the high percentage of enterprises with very poor to poor levels for the SHRI and the high prevalence of occupational accidents and injuries among the studied MSEs, feasible protective strategies and job safety training programs are required to promote occupational health and safety in the studied MSEs. PMID:27010083

Image quality evaluation for smart-phone displays at lighting levels of indoor and outdoor conditions

NASA Astrophysics Data System (ADS)

Gong, Rui; Xu, Haisong; Wang, Binyu; Luo, Ming Ronnier

2012-08-01

The image quality of two active matrix organic light emitting diode (AMOLED) smart-phone displays and two in-plane switching (IPS) ones was visually assessed at two levels of ambient lighting conditions corresponding to indoor and outdoor applications, respectively. Naturalness, colorfulness, brightness, contrast, sharpness, and overall image quality were evaluated via psychophysical experiment by categorical judgment method using test images selected from different application categories. The experimental results show that the AMOLED displays perform better on colorfulness because of their wide color gamut, while the high pixel resolution and high peak luminance of the IPS panels help the perception of brightness, contrast, and sharpness. Further statistical analysis of ANOVA indicates that ambient lighting levels have significant influences on the attributes of brightness and contrast.

Does actually mean chromosome number increase with latitude in vascular plants? An answer from the comparison of Italian, Slovak and Polish floras.

PubMed

Peruzzi, Lorenzo; Góralski, Grzegorz; Joachimiak, Andrzej J; Bedini, Gianni

2012-01-01

WE COMPARED CHROMOSOME NUMBER (CN) VARIATION AMONG VASCULAR FLORAS OF THREE DIFFERENT COUNTRIES WITH INCREASING LATITUDE IN THE BOREAL HEMISPHERE: Italy, Slovakia, Poland. Aim of the study was to verify whether the patterns of CN variation parallel the differences in latitudinal ranges. The three datasets comprised 3426 (Italy), 3493 (Slovakia) and 1870 (Poland) distinct cytotypes. Standard statistics (ANOVA, Kruskal-Wallis tests) evidenced significant differences among the three countries, mean CN increasing together with latitude. On the contrary, an inverse relation (r = -1) was evidenced among the frequency of odd CNs and latitude. Our results show that the hypothesis of a polyploid increase proportional with distance from the Equator seems to be confirmed, when territories from the same hemisphere are compared.

Definition of simulated driving tests for the evaluation of drivers' reactions and responses.

PubMed

Bartolozzi, Riccardo; Frendo, Francesco

2014-01-01

This article aims at identifying the most significant measures in 2 perception-response (PR) tests performed at a driving simulator: a braking test and a lateral skid test, which were developed in this work. Forty-eight subjects (26 females and 22 males) with a mean age of 24.9 ± 3.0 years were enrolled for this study. They were asked to perform a drive on the driving simulator at the University of Pisa (Italy) following a specific test protocol, including 8-10 braking tests and 8-10 lateral skid tests. Driver input signals and vehicle model signals were recorded during the drives and analyzed to extract measures such as the reaction time, first response time, etc. Following a statistical procedure (based on analysis of variance [ANOVA] and post hoc tests), all test measures (3 for the braking test and 8 for the lateral skid test) were analyzed in terms of statistically significant differences among different drivers. The presented procedure allows evaluation of the capability of a given test to distinguish among different drivers. In the braking test, the reaction time showed a high dispersion among single drivers, leading to just 4.8 percent of statistically significant driver pairs (using the Games-Howell post hoc test), whereas the pedal transition time scored 31.9 percent. In the lateral skid test, 28.5 percent of the 2 × 2 comparisons showed significantly different reaction times, 19.5 percent had different response times, 35.2 percent had a different second peak of the steering wheel signal, and 33 percent showed different values of the integral of the steering wheel signal. For the braking test, which has been widely employed in similar forms in the literature, it was shown how the reaction time, with respect to the pedal transition time, can have a higher dispersion due to the influence of external factors. For the lateral skid test, the following measures were identified as the most significant for application studies: the reaction time for the reaction phase, the second peak of the steering wheel angle for the first instinctive response, and the integral of the steering wheel angle for the complete response. The methodology used to analyze the test measures was founded on statistically based and objective evaluation criteria and could be applied to other tests. Even if obtained with a fixed-base simulator, the obtained results represent useful information for applications of the presented PR tests in experimental campaigns with driving simulators.

Influence of Photoinitiator on Accelerated Artificial Aging and Bond Strength of Experimental Resin Cements.

PubMed

Righi, Helouise; Costa, Ana Rosa; Oliveira, Dayane Carvalho Ramos Salles de; Abuna, Gabriel Flores; Sinhoreti, Mario Alexandre Coelho; Naufel, Fabiana Scarparo

2018-01-01

The goal of this study was to evaluate in vitro the effect of the photoinitiator phenylpropanedione (PPD), alone or combined with camphorquinone (CQ), on color stability of photoactivated resin cements and their bond strength to ceramics using a micro-shear test. Four resin cements were used: a commercial brand cement (RelyX Veneer®) and 3 experimental cements with different types and concentration of photoinitiators. For color analysis, ceramic discs were cemented on bovine dentin specimens to simulate indirect restorations (n=8) and were exposed to UV for 120 h and tested for color alteration using a reflectance spectrophotometer and the CIEL*a*b* system. Data were analyzed by Anova and Tukey's test at 5% significance level. The color test results did not present statistically significant difference for the ∆E for all the studied cements, neither for ∆L, ∆a and ∆b. For the bond strength, all the studied cements showed statistically significant differences to each other, with the highest result for the RelyX Veneer® (29.07 MPa) cement, followed by the cement with CQ (21.74 MPa) and CQ+PPD (19.09 MPa) cement; the lowest result was obtained by the cement using only PPD as a photoinitiator (13.99 MPa). So, based on the studied parameters, PPD was not advantageous as photoinitiator of resin cements, because it showed a low value of bond strength to the ceramics and no superior color stability.

Effect of 10% Strontium Chloride and 5% Potassium Nitrate with Fluoride on Bleached Bovine Enamel

PubMed Central

Alencar, Cristiane de Melo; Pedrinha, Victor Feliz; Araújo, Jesuína Lamartine Nogueira; Esteves, Renata Antunes; Silva da Silveira, Ana Daniela; Silva, Cecy Martins

2017-01-01

Background: Dental whitening has been increasingly sought out to improve dental aesthetics, but may cause chemical and morphological changes in dental enamel surfaces. Objective: This study evaluated in vitro the effect of 10% strontium chloride and 5% potassium nitrate with fluoride on bovine enamel, through tristimulus colorimetry, Knoop microhardness (KHN), and roughness after bleaching with 35% hydrogen peroxide (HP). Methods: The specimens were divided into three groups (n=15): GControl received bleaching treatment with 35% HP; GNitrate received bleaching with 35% HP followed by the application of 5% potassium nitrate with 2% sodium fluoride; and GStrontium received bleaching with 35% HP followed by the application of 10% strontium chloride on the enamel. Next, five specimens of each experimental group were subjected to KHN and tristimulus colorimetry tests, and 10 specimens were subjected to surface roughness (SR) tests. The values obtained for the different groups were compared through analysis of variance (ANOVA) followed by a post-hoc Tukey-Kramer test in addition to Student’s T-test for paired data. Results: In the intergroup comparison, KHN final differed statistically (p<0.05). The mean SR final of the experimental groups differed statistically from the GControl group (p<0.05). In addition, the groups did not differ in color variation (p>0.05). Conclusion: 10% strontium chloride and 5% potassium nitrate combined with 2% fluoride downplayed morphological changes to the enamel, without interfering with the effectiveness of the bleaching process. PMID:28979576

[Laboratory exams necessity for patients admitted to an university hospital intensive care unity].

PubMed

Machado, Fernando Osni; Silva, Flávia Solano Patrício da; Argente, Juliana Sonego; Moritz, Rachel Duarte

2006-12-01

The progressive increasing diagnostic resources had influenced the quality and quantity of laboratory exams. It is not clear if the amount of exams performed influence the morbidity and mortality in the ICU patients. The purpose of this study was to appraise the frequency of the most ordering tests in the ICU of HU-UFSC and to check if there was connection between them and the age, the destiny until the ICU discharge and the estimate severity of their diseases. Prospective cohort study with qualitative approach. The blood samples of admitted patients were analyzed, from July to December 2005. Clinical and demographic features were collected and the most frequently blood-samples were quantified per day. In the sequence the daily rate of exams were calculated during all the admission period. The patients were analyzed according to three criterions: age, destiny until the ICU discharge and estimate severity according to APACHE II index. Data were analyzed using Fisher Exact, Chi-square and ANOVA tests. One hundred and thirteen patients were enrolled to this study. The average test-ordering was 11.50 per day. These numbers didn't have statistical difference when they were compared between survivor and non-survivor patients, and between those whose the death estimated tax was bigger or smaller than 50 per cent. The test-ordering didn't show clinical and prognostic relation to its request. There were no statistic relation between the patient's age, ICU discharge and the estimate severity.

Biaxial Flexural Strength of High-Viscosity Glass-Ionomer Cements Heat-Cured with an LED Lamp during Setting

PubMed Central

Fabián Molina, Gustavo; Cabral, Ricardo Juan; Mazzola, Ignacio; Brain Lascano, Laura; Frencken, Jo E.

2013-01-01

Adding heat to glass ionomers during setting might improve mechanical properties. The aim was to compare the biaxial flexural strength (BFS) between and within four glass ionomers, by time of exposure to a high-intensity LED light-curing unit. Materials and methods. Samples of Fuji 9 Gold Label, Ketac Molar Easymix, ChemFil Rock, and the EQUIA system were divided into three treatment groups (n = 30): without heating (Group 1), heated with LED lamp of 1400 mW/cm2 for 30 s while setting (Group 2), and heated with LED lamp of 1400 mW/cm2 for 60 s while setting (Group 3). Samples were stored for 48 hours in distilled water at 37°C until tested. BFS was tested, using a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed, using ANOVA test with the Bonferroni correction (α = 0.05). Heating the glass-ionomer cements with an LED curing light of 1400 mW/cm2 during setting for 30 s increased the BFS value of all GICs. No statistically significant difference in mean BFS scores was found between the EQUIA system and ChemFil Rock at 30 s and 60 s. The mean BFS value was statistically significantly higher for the EQUIA system and ChemFil Rock than for Fuji 9 Gold Label and Ketac Molar Easymix at all exposure times. PMID:23841095

Biaxial flexural strength of high-viscosity glass-ionomer cements heat-cured with an LED lamp during setting.

PubMed

Fabián Molina, Gustavo; Cabral, Ricardo Juan; Mazzola, Ignacio; Brain Lascano, Laura; Frencken, Jo E

2013-01-01

Adding heat to glass ionomers during setting might improve mechanical properties. The aim was to compare the biaxial flexural strength (BFS) between and within four glass ionomers, by time of exposure to a high-intensity LED light-curing unit. Materials and methods. Samples of Fuji 9 Gold Label, Ketac Molar Easymix, ChemFil Rock, and the EQUIA system were divided into three treatment groups (n = 30): without heating (Group 1), heated with LED lamp of 1400 mW/cm(2) for 30 s while setting (Group 2), and heated with LED lamp of 1400 mW/cm(2) for 60 s while setting (Group 3). Samples were stored for 48 hours in distilled water at 37°C until tested. BFS was tested, using a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed, using ANOVA test with the Bonferroni correction (α = 0.05). Heating the glass-ionomer cements with an LED curing light of 1400 mW/cm(2) during setting for 30 s increased the BFS value of all GICs. No statistically significant difference in mean BFS scores was found between the EQUIA system and ChemFil Rock at 30 s and 60 s. The mean BFS value was statistically significantly higher for the EQUIA system and ChemFil Rock than for Fuji 9 Gold Label and Ketac Molar Easymix at all exposure times.

Gender differences in learning physical science concepts: Does computer animation help equalize them?

NASA Astrophysics Data System (ADS)

Jacek, Laura Lee

This dissertation details an experiment designed to identify gender differences in learning using three experimental treatments: animation, static graphics, and verbal instruction alone. Three learning presentations were used in testing of 332 university students. Statistical analysis was performed using ANOVA, binomial tests for differences of proportion, and descriptive statistics. Results showed that animation significantly improved women's long-term learning over static graphics (p = 0.067), but didn't significantly improve men's long-term learning over static graphics. In all cases, women's scores improved with animation over both other forms of instruction for long-term testing, indicating that future research should not abandon the study of animation as a tool that may promote gender equity in science. Short-term test differences were smaller, and not statistically significant. Variation present in short-term scores was related more to presentation topic than treatment. This research also details characteristics of each of the three presentations, to identify variables (e.g. level of abstraction in presentation) affecting score differences within treatments. Differences between men's and women's scores were non-standard between presentations, but these differences were not statistically significant (long-term p = 0.2961, short-term p = 0.2893). In future research, experiments might be better designed to test these presentational variables in isolation, possibly yielding more distinctive differences between presentational scores. Differences in confidence interval overlaps between presentations suggested that treatment superiority may be somewhat dependent on the design or topic of the learning presentation. Confidence intervals greatly overlap in all situations. This undercut, to some degree, the surety of conclusions indicating superiority of one treatment type over the others. However, confidence intervals for animation were smaller, overlapped nearly completely for men and women (there was less overlap between the genders for the other two treatments), and centered around slightly higher means, lending further support to the conclusion that animation helped equalize men's and women's learning. The most important conclusion identified in this research is that gender is an important variable experimental populations testing animation as a learning device. Averages indicated that both men and women prefer to work with animation over either static graphics or verbal instruction alone.

Exploring Preferences of Mentoring Activities among Generational Groups of Registered Nurses in Florida

ERIC Educational Resources Information Center

Posey-Goodwin, Patricia Ann

2013-01-01

The purpose of this study was to explore differences in perceptions of mentoring activities from four generations of registered nurses in Florida, using the Alleman Mentoring Activities Questionnaire ® (AMAQ ®). Statistical procedures of analysis of variance (ANOVA) were employed to explore differences among 65 registered nurses in Florida from…

Inquiring the Most Critical Teacher's Technology Education Competences in the Highest Efficient Technology Education Learning Organization

ERIC Educational Resources Information Center

Yung-Kuan, Chan; Hsieh, Ming-Yuan; Lee, Chin-Feng; Huang, Chih-Cheng; Ho, Li-Chih

2017-01-01

Under the hyper-dynamic education situation, this research, in order to comprehensively explore the interplays between Teacher Competence Demands (TCD) and Learning Organization Requests (LOR), cross-employs the data refined method of Descriptive Statistics (DS) method and Analysis of Variance (ANOVA) and Principal Components Analysis (PCA)…

Time Spent on the Internet by Multicultural Adolescents in Korea

ERIC Educational Resources Information Center

Lim, Yangmi; Nam, Su-Jung

2017-01-01

This study analysed "The 8th Online Survey of Adolescent Health and Behaviour in 2012", which is a government-approved statistical survey of Internet use and patterns in Korea. We conducted a propensity score matching (PSM) to control for economic status differences between monocultural and multicultural families and an ANOVA to estimate…

On statistical analysis of factors affecting anthocyanin extraction from Ixora siamensis

NASA Astrophysics Data System (ADS)

Mat Nor, N. A.; Arof, A. K.

2016-10-01

This study focused on designing an experimental model in order to evaluate the influence of operative extraction parameters employed for anthocyanin extraction from Ixora siamensis on CIE color measurements (a*, b* and color saturation). Extractions were conducted at temperatures of 30, 55 and 80°C, soaking time of 60, 120 and 180 min using acidified methanol solvent with different trifluoroacetic acid (TFA) contents of 0.5, 1.75 and 3% (v/v). The statistical evaluation was performed by running analysis of variance (ANOVA) and regression calculation to investigate the significance of the generated model. Results show that the generated regression models adequately explain the data variation and significantly represented the actual relationship between the independent variables and the responses. Analysis of variance (ANOVA) showed high coefficient determination values (R2) of 0.9687 for a*, 0.9621 for b* and 0.9758 for color saturation, thus ensuring a satisfactory fit of the developed models with the experimental data. Interaction between TFA content and extraction temperature exhibited to the highest significant influence on CIE color parameter.

Improvement of Olfactory Function With High Frequency Non-invasive Auricular Electrostimulation in Healthy Humans

PubMed Central

Maharjan, Ashim; Wang, Eunice; Peng, Mei; Cakmak, Yusuf O.

2018-01-01

In past literature on animal models, invasive vagal nerve stimulation using high frequencies has shown to be effective at modulating the activity of the olfactory bulb (OB). Recent advances in invasive vagal nerve stimulation in humans, despite previous findings in animal models, used low frequency stimulation and found no effect on the olfactory functioning. The present article aimed to test potential effects of non-invasive, high and low frequency vagal nerve stimulation in humans, with supplementary exploration of the orbitofrontal cortex using near-infrared spectroscopy (NIRS). Healthy, male adult participants (n = 18) performed two olfactory tests [odor threshold test (OTT) and supra-threshold test (STT)] before and after receiving high-, low frequency vagal nerve stimulation and placebo (no stimulation). Participant's olfactory functioning was monitored using NIRS, and assessed with two behavioral olfactory tests. NIRS data of separate stimulation parameters were statistically analyzed using repeated-measures ANOVA across different stages. Data from olfactory tests were analyzed using paired parametric and non-parametric statistical tests. Only high frequency, non-invasive vagal nerve stimulation was able to positively modulate the performance of the healthy participants in the STT (p = 0.021, Wilcoxon sign-ranked test), with significant differences in NIRS (p = 0.014, post-hoc with Bonferroni correction) recordings of the right hemispheric, orbitofrontal cortex. The results from the current article implore further exploration of the neurocircuitry involved under vagal nerve stimulation and the effects of non-invasive, high frequency, vagal nerve stimulation toward olfactory dysfunction which showcase in Parkinson's and Alzheimer's Diseases. Despite the sufficient effect size (moderate effect, correlation coefficient (r): 0.39 for the STT) of the current study, future research should replicate the current findings with a larger cohort. PMID:29740266

Critical shear stress measurement of cohesive soils in streams: identifying device-dependent variability using an in-situ jet test device and conduit flume

NASA Astrophysics Data System (ADS)

Mahalder, B.; Schwartz, J. S.; Palomino, A.; Papanicolaou, T.

2016-12-01

Cohesive soil erodibility and threshold shear stress for stream bed and bank are dependent on both soil physical and geochemical properties in association with the channel vegetative conditions. These properties can be spatially variable therefore making critical shear stress measurement in cohesive soil challenging and leads to a need for a more comprehensive understanding of the erosional processes in streams. Several in-situ and flume-type test devices for estimating critical shear stress have been introduced by different researchers; however reported shear stress estimates per device vary widely in orders of magnitude. Advantages and disadvantages exist between these devices. Development of in-situ test devices leave the bed and/or bank material relatively undisturbed and can capture the variable nature of field soil conditions. However, laboratory flumes provide a means to control environmental conditions that can be quantify and tested. This study was conducted to observe differences in critical shear stress using jet tester and a well-controlled conduit flume. Soil samples were collected from the jet test locations and tested in a pressurized flume following standard operational procedure to calculate the critical shear stress. The results were compared using statistical data analysis (mean-separation ANOVA procedure) to identify possible differences. In addition to the device comparison, the mini jet device was used to measure critical shear stress across geologically diverse regions of Tennessee, USA. Statistical correlation between critical shear stress and the soil physical, and geochemical properties were completed identifying that geological origin plays a significant role in critical shear stress prediction for cohesive soils. Finally, the critical shear stress prediction equations using the jet test data were examined with possible suggestions to modify based on the flume test results.

Improvement of Olfactory Function With High Frequency Non-invasive Auricular Electrostimulation in Healthy Humans.

PubMed

Maharjan, Ashim; Wang, Eunice; Peng, Mei; Cakmak, Yusuf O

2018-01-01

In past literature on animal models, invasive vagal nerve stimulation using high frequencies has shown to be effective at modulating the activity of the olfactory bulb (OB). Recent advances in invasive vagal nerve stimulation in humans, despite previous findings in animal models, used low frequency stimulation and found no effect on the olfactory functioning. The present article aimed to test potential effects of non-invasive, high and low frequency vagal nerve stimulation in humans, with supplementary exploration of the orbitofrontal cortex using near-infrared spectroscopy (NIRS). Healthy, male adult participants ( n = 18) performed two olfactory tests [odor threshold test (OTT) and supra-threshold test (STT)] before and after receiving high-, low frequency vagal nerve stimulation and placebo (no stimulation). Participant's olfactory functioning was monitored using NIRS, and assessed with two behavioral olfactory tests. NIRS data of separate stimulation parameters were statistically analyzed using repeated-measures ANOVA across different stages. Data from olfactory tests were analyzed using paired parametric and non-parametric statistical tests. Only high frequency, non-invasive vagal nerve stimulation was able to positively modulate the performance of the healthy participants in the STT ( p = 0.021, Wilcoxon sign-ranked test), with significant differences in NIRS ( p = 0.014, post-hoc with Bonferroni correction ) recordings of the right hemispheric, orbitofrontal cortex. The results from the current article implore further exploration of the neurocircuitry involved under vagal nerve stimulation and the effects of non-invasive, high frequency, vagal nerve stimulation toward olfactory dysfunction which showcase in Parkinson's and Alzheimer's Diseases. Despite the sufficient effect size (moderate effect, correlation coefficient (r): 0.39 for the STT) of the current study, future research should replicate the current findings with a larger cohort.

Evaluation of the color stability of two techniques for reproducing artificial irides after microwave polymerization

PubMed Central

GOIATO, Marcelo Coelho; dos SANTOS, Daniela Micheline; MORENO, Amália; GENNARI-FILHO, Humberto; PELLIZZER, Eduardo Piza

2011-01-01

The use of ocular prostheses for ophthalmic patients aims to rebuild facial aesthetics and provide an artificial substitute to the visual organ. Natural intemperate conditions promote discoloration of artificial irides and many studies have attempted to produce irides with greater chromatic paint durability using different paint materials. Objectives The present study evaluated the color stability of artificial irides obtained with two techniques (oil painting and digital image) and submitted to microwave polymerization. Material and Methods Forty samples were fabricated simulating ocular prostheses. Each sample was constituted by one disc of acrylic resin N1 and one disc of colorless acrylic resin with the iris interposed between the discs. The irides in brown and blue color were obtained by oil painting or digital image. The color stability was determined by a reflection spectrophotometer and measurements were taken before and after microwave polymerization. Statistical analysis of the techniques for reproducing artificial irides was performed by applying the normal data distribution test followed by 2-way ANOVA and Tukey HSD test (α=.05). Results Chromatic alterations occurred in all specimens and statistically significant differences were observed between the oil-painted samples and those obtained by digital imaging. There was no statistical difference between the brown and blue colors. Independently of technique, all samples suffered color alterations after microwave polymerization. Conclusion The digital imaging technique for reproducing irides presented better color stability after microwave polymerization. PMID:21625733

Effect of the infrastructure material on the failure behavior of prosthetic crowns.

PubMed

Sonza, Queli Nunes; Della Bona, Alvaro; Borba, Márcia

2014-05-01

To evaluate the effect of infrastructure (IS) material on the fracture behavior of prosthetic crowns. Restorations were fabricated using a metal die simulating a prepared tooth. Four groups were evaluated: YZ-C, Y-TZP (In-Ceram YZ, Vita) IS produced by CAD-CAM; IZ-C, In-Ceram Zirconia (Vita) IS produced by CAD-CAM; IZ-S, In-Ceram Zirconia (Vita) IS produced by slip-cast; MC, metal IS (control). The IS were veneered with porcelain and resin cemented to fiber-reinforced composite dies. Specimens were loaded in compression to failure using a universal testing machine. The 30° angle load was applied by a spherical piston, in 37°C distilled water. Fractography was performed using stereomicroscope and SEM. Data were statistically analyzed with Anova and Student-Newman-Keuls tests (α=0.05). Significant differences were found between groups (p=0.022). MC showed the highest mean failure load, statistically similar to YZ-C. There was no statistical difference between YZ-C, IZ-C and IZ-S. MC and YZ-C showed no catastrophic failure. IZ-C and IZ-S showed chipping and catastrophic failures. The fracture behavior is similar to reported clinical failures. Considering the ceramic systems evaluated, YZ-C and MC crowns present greater fracture load and a more favorable failure mode than In-Ceram Zirconia crowns, regardless of the fabrication type (CAD-CAM or slip-cast). Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

In Vitro Wear Resistance of Nano-Hybrid Composite Denture Teeth.

PubMed

Munshi, Nabeel; Rosenblum, Marc; Jiang, Shuying; Flinton, Robert

2017-04-01

To evaluate the wear resistance of nano-hybrid composite denture teeth as compared to two commonly used denture teeth: interpenetrating polymer network (IPN) and double crosslinking polymethylmethacrylate (PMMA) denture teeth. 18 styli and 18 disk specimens were prepared from the three denture tooth materials: nano-hybrid composite, IPN, and double crosslinking PMMA. The specimens were mounted in a two-body wear testing machine to simulate chewing in the complete denture. The amount of wear from the styli specimens were measured before and after using a digital micrometer, and the depth of the wear track from the disk specimens was measured using a noncontact 3D optical profilometer. The total wear from each denture tooth group was compared using one-way ANOVA with a 0.05 significance level. A Tukey post hoc test was used to determine differences between the three groups. The mean total wear in the nano-hybrid composite teeth group was 1.16 mm, SD = 0.5 mm, statistically significantly higher (p ≤ 0.0001) than the IPN (mean = 0.13 mm, SD = 0.05) and double crosslinking PMMA tooth groups (mean = 0.31 mm, SD = 0.19). There was no statistically significant difference between IPN denture teeth and double crosslinking PMMA denture teeth in the amount of wear. Nano-hybrid composite denture teeth exhibited statistically significantly more wear than the IPN and double crosslinking PMMA denture teeth. © 2015 by the American College of Prosthodontists.

TOXICITY TESTING OF RESTORATIVE DENTAL MATERIALS USING BRINE SHRIMP LARVAE (ARTEMIA SALINA)

PubMed Central

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 (α =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 (α = 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. PMID:19089264

Histological analysis of effects of 24% EDTA gel for nonsurgical treatment of periodontal tissues.

PubMed

de Vasconcellos, Luana Marotta Reis; Ricardo, Lucilene Hernandes; Balducci, Ivan; de Vasconcellos, Luis Gustavo Oliveira; Carvalho, Yasmin Rodarte

2006-12-01

The aim of this study was to investigate, by means of histological and histomorphometric analysis, the effects of 24% ethylenediaminetetraacetic acid (EDTA) gel in periodontal tissue when used in combination with conventional periodontal treatment. Periodontitis was induced in the 2nd upper left permanent molars of 45 male Wistar rats by means of ligature. After 5 weeks, this was removed and debridement was performed. The animals were then randomly divided into 3 groups; group 1: mechanical treatment, group 2: mechanical treatment and EDTA gel application for 2 min, and group 3: mechanical treatment and placebo gel application for 2 min. After the treatment, rinsing was done with 0.9% saline solution for 1 min in all cases, followed by root notching in the deepest part of the pocket. After 4, 10, and 28 days the animals were sacrificed. The averages obtained were evaluated by means of test two-way analysis of variance (ANOVA) and Tukey statistical tests (P < 0.05). The results showed that with respect to the type of treatment employed, there were no statistically significant differences in the vitality of the periodontal tissue. It was concluded that 24% EDTA gel did not interfere with periodontal tissue repair when used in combination with conventional periodontal treatment.

Reliability of third molar development for age estimation in Gujarati population: A comparative study.

PubMed

Gandhi, Neha; Jain, Sandeep; Kumar, Manish; Rupakar, Pratik; Choyal, Kanaram; Prajapati, Seema

2015-01-01

Age assessment may be a crucial step in postmortem profiling leading to confirmative identification. In children, Demirjian's method based on eight developmental stages was developed to determine maturity scores as a function of age and polynomial functions to determine age as a function of score. Of this study was to evaluate the reliability of age estimation using Demirjian's eight teeth method following the French maturity scores and Indian-specific formula from developmental stages of third molar with the help of orthopantomograms using the Demirjian method. Dental panoramic tomograms from 30 subjects each of known chronological age and sex were collected and were evaluated according to Demirjian's criteria. Age calculations were performed using Demirjian's formula and Indian formula. Statistical analysis used was Chi-square test and ANOVA test and the P values obtained were statistically significant. There was an average underestimation of age with both Indian and Demirjian's formulas. The mean absolute error was lower using Indian formula hence it can be applied for age estimation in present Gujarati population. Also, females were ahead of achieving dental maturity than males thus completion of dental development is attained earlier in females. Greater accuracy can be obtained if population-specific formulas considering the ethnic and environmental variation are derived performing the regression analysis.

The impact of length of stay on recovery measures in faith-based addiction treatment.

PubMed

Lashley, Mary

2018-03-30

To determine the impact of length of stay among homeless men in faith-based residential addictions recovery on physical activity, depression, self-esteem, and nicotine dependence. A time series design was utilized to measure changes in the four quality measures at program entry and at 3, 6, and 9 months following admission. The sample consisted of 175 homeless residents enrolled in a faith-based residential recovery program. Paired t tests were used to determine the change in average instrument response from admission to each follow-up period. Analysis of variance (ANOVA) and Tukey posthoc tests were used to assess for differences in length of stay between demographic variables. Statistically significant improvements were noted in self-esteem and depressive symptomatology at 3 and 6 months following admission and in physical activity levels at 3 months following admission. Nicotine dependence scores declined at 3 and 6 months but were not statistically significant. Time spent in this faith-based spiritual recovery program had a significant impact on depression, self-esteem, and physical activity. Recommendations for future study include conducting research to analyze the relationship between distinct program elements and quality indicators and comparing faith-based programs to other similar programs and to publicly funded secular recovery programs. © 2018 Wiley Periodicals, Inc.

[Review of meta-analysis research on exercise in South Korea].

PubMed

Song, Youngshin; Gang, Moonhee; Kim, Sun Ae; Shin, In Soo

2014-10-01

The purpose of this study was to evaluate the quality of meta-analysis regarding exercise using Assessment of Multiple Systematic Reviews (AMSTAR) as well as to compare effect size according to outcomes. Electronic databases including the Korean Studies Information Service System (KISS), the National Assembly Library and the DBpia, HAKJISA and RISS4U for the dates 1990 to January 2014 were searched for 'meta-analysis' and 'exercise' in the fields of medical, nursing, physical therapy and physical exercise in Korea. AMSTAR was scored for quality assessment of the 33 articles included in the study. Data were analyzed using descriptive statistics, t-test, ANOVA and χ²-test. The mean score for AMSTAR evaluations was 4.18 (SD=1.78) and about 67% were classified at the low-quality level and 30% at the moderate-quality level. The scores of quality were statistically different by field of research, number of participants, number of databases, financial support and approval by IRB. The effect size that presented in individual studies were different by type of exercise in the applied intervention. This critical appraisal of meta-analysis published in various field that focused on exercise indicates that a guideline such as the PRISMA checklist should be strongly recommended for optimum reporting of meta-analysis across research fields.

Evaluation of degree of conversion and hardness of dental composites photo-activated with different light guide tips.

PubMed

Galvão, Marília Regalado; Caldas, Sergei Godeiro Fernandes Rabelo; Bagnato, Vanderlei Salvador; de Souza Rastelli, Alessandra Nara; de Andrade, Marcelo Ferrarezi

2013-01-01

The aim of this study was to evaluate the degree of conversion and hardness of different composite resins, photo-activated for 40 s with two different light guide tips, fiber optic and polymer. Five specimens were made for each group evaluated. The percentage of unreacted carbon double bonds (% C═C) was determined from the ratio of absorbance intensities of aliphatic C═C (peak at 1637 cm(-1)) against internal standard before and after curing of the specimen: aromatic C-C (peak at 1610 cm(-1)). The Vickers hardness measurements were performed in a universal testing machine. A 50 gf load was used and the indenter with a dwell time of 30 seconds. The degree of conversion and hardness mean values were analyzed separately by ANOVA and Tukey's test, with a significance level set at 5%. The mean values of degree of conversion for the polymer and fiber optic light guide tip were statistically different (P<.001). The hardness mean values were statistically different among the light guide tips (P<.001), but also there was difference between top and bottom surfaces (P<.001). The results showed that the resins photo-activated with the fiber optic light guide tip promoted higher values for degree of conversion and hardness.

Evaluation of degree of conversion and hardness of dental composites photo-activated with different light guide tips

PubMed Central

Galvão, Marília Regalado; Caldas, Sergei Godeiro Fernandes Rabelo; Bagnato, Vanderlei Salvador; de Souza Rastelli, Alessandra Nara; de Andrade, Marcelo Ferrarezi

2013-01-01

Objective: The aim of this study was to evaluate the degree of conversion and hardness of different composite resins, photo-activated for 40 s with two different light guide tips, fiber optic and polymer. Methods: Five specimens were made for each group evaluated. The percentage of unreacted carbon double bonds (% C═C) was determined from the ratio of absorbance intensities of aliphatic C═C (peak at 1637 cm−1) against internal standard before and after curing of the specimen: aromatic C-C (peak at 1610 cm−1). The Vickers hardness measurements were performed in a universal testing machine. A 50 gf load was used and the indenter with a dwell time of 30 seconds. The degree of conversion and hardness mean values were analyzed separately by ANOVA and Tukey’s test, with a significance level set at 5%. Results: The mean values of degree of conversion for the polymer and fiber optic light guide tip were statistically different (P<.001). The hardness mean values were statistically different among the light guide tips (P<.001), but also there was difference between top and bottom surfaces (P<.001). Conclusions: The results showed that the resins photo-activated with the fiber optic light guide tip promoted higher values for degree of conversion and hardness. PMID:23407620

Communication partner training for health care professionals in an inpatient rehabilitation setting: A parallel randomised trial.

PubMed

Heard, Renee; O'Halloran, Robyn; McKinley, Kathryn

2017-06-01

The purpose of this study is to determine if the E-Learning Plus communication partner training (CPT) programme is as effective as the Supported Conversation for Adults with Aphasia (SCA TM ) CPT programme in improving healthcare professionals' confidence and knowledge communicating with patients with aphasia. Forty-eight healthcare professionals working in inpatient rehabilitation participated. Participants were randomised to one of the CPT programmes. The three outcome measures were self-rating of confidence, self-rating of knowledge and a test of knowledge of aphasia. Measures were taken pre-, immediately post- and 3-4 months post-training. Data were analysed using mixed between within ANOVAs. Homogeneity of variance was adequate for self-rating of confidence and test of knowledge of aphasia data to continue analysis. There was a statistically significant difference in self-rating of confidence and knowledge of aphasia for both interventions across time. No statistically significant difference was found between the two interventions. Both CPT interventions were associated with an increase in health care professionals' confidence and knowledge of aphasia, but neither programme was superior. As the E-Learning Plus CPT programme is more accessible and sustainable in the Australian healthcare context, further work will continue on this CPT programme.

Characterising the disintegration properties of tablets in opaque media using texture analysis.

PubMed

Scheuerle, Rebekah L; Gerrard, Stephen E; Kendall, Richard A; Tuleu, Catherine; Slater, Nigel K H; Mahbubani, Krishnaa T

2015-01-01

Tablet disintegration characterisation is used in pharmaceutical research, development, and quality control. Standard methods used to characterise tablet disintegration are often dependent on visual observation in measurement of disintegration times. This presents a challenge for disintegration studies of tablets in opaque, physiologically relevant media that could be useful for tablet formulation optimisation. This study has explored an application of texture analysis disintegration testing, a non-visual, quantitative means of determining tablet disintegration end point, by analysing the disintegration behaviour of two tablet formulations in opaque media. In this study, the disintegration behaviour of one tablet formulation manufactured in-house, and Sybedia Flashtab placebo tablets in water, bovine, and human milk were characterised. A novel method is presented to characterise the disintegration process and to quantify the disintegration end points of the tablets in various media using load data generated by a texture analyser probe. The disintegration times in the different media were found to be statistically different (P<0.0001) from one another for both tablet formulations using one-way ANOVA. Using the Tukey post-hoc test, the Sybedia Flashtab placebo tablets were found not to have statistically significant disintegration times from each other in human versus bovine milk (adjusted P value 0.1685). Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of physical activity on musculoskeletal discomforts among handicraft workers

PubMed Central

Shakerian, Mahnaz; Rismanchian, Masoud; Khalili, Pejman; Torki, Akram

2016-01-01

Introduction: Handicrafts seems to be one of the high-risk jobs regarding work-related musculoskeletal disorders (WMSDs) which necessitate the implementation of different corrective intervention like regular physical activities. This study aimed to investigate the impact of physical activity on WMSDs among craftsmen. Methods: This cross-sectional study was an analytical – descriptive study carried out on 100 craftsmen working in Isfahan, Iran, in 2013. The sampling method was census, and all workshops involved with this job were included. Information on demographic parameters and physical activity was collected by demographic forms. The data related to worker's musculoskeletal discomforts were conducted using Cornell Musculoskeletal Discomfort Questionnaire. The data were analyzed using statistical tests including independent t-test, Chi-square, and ANOVA. The statistical analysis was performed using SPSS 18. Results: The highest percentages of complaints related to severe musculoskeletal discomfort were reported in right shoulder (%36), right wrist (%26), neck (%25), and upper right arm (%24), respectively. A significant relationship was observed between physical activity and musculoskeletal discomforts of left wrist (P = 0.012), lower back (P = 0.016), and neck (P = 0.006). Discussion and Conclusion: Based on the study results, it can be inferred that regular but not too heavy physical activity can have a positive impact on decreasing the musculoskeletal discomforts. PMID:27512700

Application of scl - pbl method to increase quality learning of industrial statistics course in department of industrial engineering pancasila university

NASA Astrophysics Data System (ADS)

Darmawan, M.; Hidayah, N. Y.

2017-12-01

Currently, there has been a change of new paradigm in the learning model in college, ie from Teacher Centered Learning (TCL) model to Student Centered Learing (SCL). It is generally assumed that the SCL model is better than the TCL model. The Courses of 2nd Industrial Statistics in the Department Industrial Engineering Pancasila University is the subject that belongs to the Basic Engineering group. So far, the applied learning model refers more to the TCL model, and field facts show that the learning outcomes are less satisfactory. Of the three consecutive semesters, ie even semester 2013/2014, 2014/2015, and 2015/2016 obtained grade average is equal to 56.0; 61.1, and 60.5. In the even semester of 2016/2017, Classroom Action Research (CAR) is conducted for this course through the implementation of SCL model with Problem Based Learning (PBL) methods. The hypothesis proposed is that the SCL-PBL model will be able to improve the final grade of the course. The results shows that the average grade of the course can be increased to 73.27. This value was then tested using the ANOVA and the test results concluded that the average grade was significantly different from the average grade value in the previous three semesters.

Evaluation of the attractive force of different types of new-generation magnetic attachment systems.

PubMed

Akin, Hakan; Coskun, M Emre; Akin, E Gulsah; Ozdemir, A Kemal

2011-03-01

Rare earth magnets have been used in prosthodontics, but their tendency for corrosion in the oral cavity and insufficient attractive forces limit long-term clinical application. The purpose of this study was to evaluate the attractive force of different types of new-generation magnetic attachment systems. The attractive force of the neodymium-iron-boron (Nd-Fe-B) and samarium-cobalt (Sm-Co) magnetic attachment systems, including closed-field (Hilop and Hicorex) and open-field (Dyna and Steco) systems, was measured in a universal testing machine (n=5). The data were statistically evaluated with 1-way ANOVA and post hoc Tukey-Kramer multiple comparison test (α=.05). The closed-field systems exhibited greater (P<.001) attractive force than the open-field systems. Moreover, there was a statistically significant difference in attractive force between Nd-Fe-B and Sm-Co magnets (P<.001). The strongest attractive force was found with the Hilop system (9.2 N), and the lowest force was found with the Steco system (2.3 N). The new generation of Nd-Fe-B closed-field magnets, along with improved technology, provides sufficient denture retention for clinical application. Copyright © 2011 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Investigation of improving MEMS-type VOA reliability

NASA Astrophysics Data System (ADS)

Hong, Seok K.; Lee, Yeong G.; Park, Moo Y.

2003-12-01

MEMS technologies have been applied to a lot of areas, such as optical communications, Gyroscopes and Bio-medical components and so on. In terms of the applications in the optical communication field, MEMS technologies are essential, especially, in multi dimensional optical switches and Variable Optical Attenuators(VOAs). This paper describes the process for the development of MEMS type VOAs with good optical performance and improved reliability. Generally, MEMS VOAs have been fabricated by silicon micro-machining process, precise fibre alignment and sophisticated packaging process. Because, it is composed of many structures with various materials, it is difficult to make devices reliable. We have developed MEMS type VOSs with many failure mode considerations (FMEA: Failure Mode Effect Analysis) in the initial design step, predicted critical failure factors and revised the design, and confirmed the reliability by preliminary test. These predicted failure factors were moisture, bonding strength of the wire, which wired between the MEMS chip and TO-CAN and instability of supplied signals. Statistical quality control tools (ANOVA, T-test and so on) were used to control these potential failure factors and produce optimum manufacturing conditions. To sum up, we have successfully developed reliable MEMS type VOAs with good optical performances by controlling potential failure factors and using statistical quality control tools. As a result, developed VOAs passed international reliability standards (Telcodia GR-1221-CORE).

Investigation of improving MEMS-type VOA reliability

NASA Astrophysics Data System (ADS)

Hong, Seok K.; Lee, Yeong G.; Park, Moo Y.

2004-01-01

MEMS technologies have been applied to a lot of areas, such as optical communications, Gyroscopes and Bio-medical components and so on. In terms of the applications in the optical communication field, MEMS technologies are essential, especially, in multi dimensional optical switches and Variable Optical Attenuators(VOAs). This paper describes the process for the development of MEMS type VOAs with good optical performance and improved reliability. Generally, MEMS VOAs have been fabricated by silicon micro-machining process, precise fibre alignment and sophisticated packaging process. Because, it is composed of many structures with various materials, it is difficult to make devices reliable. We have developed MEMS type VOSs with many failure mode considerations (FMEA: Failure Mode Effect Analysis) in the initial design step, predicted critical failure factors and revised the design, and confirmed the reliability by preliminary test. These predicted failure factors were moisture, bonding strength of the wire, which wired between the MEMS chip and TO-CAN and instability of supplied signals. Statistical quality control tools (ANOVA, T-test and so on) were used to control these potential failure factors and produce optimum manufacturing conditions. To sum up, we have successfully developed reliable MEMS type VOAs with good optical performances by controlling potential failure factors and using statistical quality control tools. As a result, developed VOAs passed international reliability standards (Telcodia GR-1221-CORE).

Shear Bond Strength of Orthodontic Brackets and Disinclusion Buttons: Effect of Water and Saliva Contamination

PubMed Central

Sfondrini, Maria Francesca; Fraticelli, Danilo; Gandini, Paola

2013-01-01

Purpose. The aim of this study was to assess the effect of water and saliva contamination on the shear bond strength and failure site of orthodontic brackets and lingual buttons. Materials and Methods. 120 bovine permanent mandibular incisors were randomly divided into 6 groups of 20 specimens each. Both orthodontic brackets and disinclusion buttons were tested under three different enamel surface conditions: (a) dry, (b) water contamination, and (c) saliva contamination. Brackets and buttons were bonded to the teeth and subsequently tested using a Instron universal testing machine. Shear bond strength values and adhesive failure rate were recorded. Statistical analysis was performed using ANOVA and Tukey tests (strength values) and Chi squared test (ARI Scores). Results. Noncontaminated enamel surfaces showed the highest bond strengths for both brackets and buttons. Under water and saliva contamination orthodontic brackets groups showed significantly lower shear strengths than disinclusion buttons groups. Significant differences in debond locations were found among the groups under the various enamel surface conditions. Conclusions. Water and saliva contamination of enamel during the bonding procedure lowers bond strength values, more with orthodontic brackets than with disinclusion buttons. PMID:23762825

Effects of topical benzocaine and lignocaine on upper airway reflex sensitivity.

PubMed

Raphael, J H; Stanley, G D; Langton, J A

1996-02-01

We studied the degree and duration of effect on upper airway reflex sensitivity of oral benzocaine lozenges, nebulised lignocaine and lignocaine sprayed onto the vocal cords under direct vision, using low concentrations of ammonia as a stimulus to upper airway receptors. Ten minutes after the administration of oral benzocaine 20 mg the threshold response of the upper airway to ammonia (NH3TR) had risen significantly from baseline mean (SEM) of 680 (95) to 975 (109) ppm of ammonia with a return to baseline values after 25 min (n = 8, p < 0.05, repeated measures of ANOVA; p < 0.001, t-test). A direct spray of lignocaine 100 mg onto the vocal cords resulted in a significant elevation in NH3TR from a baseline mean (SEM) of 665 (81) to a maximum of 1600 (88) ppm of ammonia with a significant elevation in the threshold persisting for 100 min (n = 7, p < 0.001, repeated measures of ANOVA; p < 0.05, t-test). The application of 4% nebulised lignocaine 4 ml significantly increased NH3TR from a baseline mean (SEM) of 770 (56) to a maximum of 1190 (63) ppm of ammonia with a significant elevation in the threshold persisting for 30 min (n = 8, p < 0.001, repeated measures of ANOVA; p < 0.05, t-test). The maximum elevations in NH3TR with the two methods of lignocaine delivery were significantly different (p < 0.01, 2-way ANOVA).