Multiple Comparison Methods Research Articles

Development of a novel computational model for the Balloon Analogue Risk Task: The exponential-weight mean–variance model

The Balloon Analogue Risk Task (BART) is a popular task used to measure risk-taking behavior. To identify cognitive processes associated with choice behavior on the BART, a few computational models have been proposed. However, the extant models either fail to capture choice patterns on the BART or show poor parameter recovery performance. Here, we propose a novel computational model, the exponential-weight mean–variance (EWMV) model, which addresses the limitations of existing models. By using multiple model comparison methods, including post hoc model fits criterion and parameter recovery, we showed that the EWMV model outperforms the existing models. In addition, we applied the EWMV model to BART data from healthy controls and substance-using populations (patients with past opiate and stimulant dependence). The results suggest that (1) the EWMV model addresses the limitations of existing models and (2) heroin-dependent individuals show reduced risk preference than other groups, which may have significant clinical implications.

CHANGES IN GAUSSIAN MODELING PARAMETERS OF PPG PULSE DURING HEALTHY PREGNANCY

We used Gaussian modeling to depict the changes in finger photoplethysmographic (PPG) pulse during pregnancy in healthy women. We enrolled 70 healthy pregnant women and recorded their PPG pulses in 11–13 gestational weeks, 20–22 gestational weeks, and 37–39 gestational weeks. Three independent positive Gaussian functions were utilized to decompose the pulses, and each Gaussian function extracted three key parameters: the peak amplitude ([Formula: see text]), the peak position ([Formula: see text]), and the half-width ([Formula: see text]). The method of ANOVA and post-hoc multiple comparisons of mathematical statistics were utilized to study the differences of these parameters between the three trimesters. We found that in the first trimester [Formula: see text] increased significantly ([Formula: see text]: [Formula: see text] versus [Formula: see text], [Formula: see text]). [Formula: see text] and [Formula: see text] increased in the first trimester ([Formula: see text]: [Formula: see text] versus [Formula: see text], [Formula: see text]; [Formula: see text]: [Formula: see text] versus [Formula: see text], [Formula: see text]), then decreased significantly ([Formula: see text]: [Formula: see text] versus [Formula: see text], [Formula: see text]: [Formula: see text] versus [Formula: see text], [Formula: see text]). [Formula: see text] is associated with cardiac output, and [Formula: see text] and [Formula: see text] are associated with peripheral vascular resistance. The results of this study were consistent with the conclusion that healthy pregnant women exhibited high flow state of the cardiovascular system and their peripheral vascular resistance decreased first and then gradually recovered during pregnancy. This study indicated that PPG pulse could also reflect the changes in the maternal cardiovascular system during pregnancy.

Психологические предпосылки мотивации просоциальной активности студенческой молодежи

The article presents the results of a study of the motives of prosocial activity of students. The study was conducted on a sample of students of Russian universities (Moscow, St. Petersburg, the Republics of Buryatia, Mordovia, Karachay-Cherkessia, Moscow, Nizhny Novgorod, Ivanovo, and Astrakhan regions). We used the methodology for assessing the level of prosociality on the altruism scale (F. Rushton), modification of the portrait value questionnaire of Schwartz, the method “Measurement of prosocial tendencies” (G. Carlo and B.A. Randall), as well as the author’s method of multiple comparison of variables (M.M. Basimov). The study revealed comparative psychograms of groups based on the studied quantitative psychological parameters of prosocial tendencies, altruism and values of the student youth

Multiple Comparison Methods in Zero-dose Control Trials

In this paper, the problem of determining which treatments are statistically significant when compared with a zero-dose or placebo control in a dose-response study is considered. Nonparametric meth- ods developed for the commonly used multiple comparison problem whenever the Jonckheere trend test (JT) is appropriate is extended to the multiple comparisons to control problem. We present four closed testing methods, of which two use an AUC regression model approach for determining the treatment arms that are statistically different from the zero-dose control. A simulation study is performed to compare the proposed methods with two existing rank-based nonparametric mul- tiple comparison procedures. The method is further illustrated using a problem from a clinical setting.

Assessment of Phytochemical Contents and Total Antioxidant Capacity of Five Medicinal Plants with Cosmetic Potential under Three Different Drying Methods

Drying allows the quick conservation of medicinal properties of herbal materials. However, the instability of bioactive compounds in medicinal plants which exhibit potent antioxidant activity and wide range of pharmacological properties may indicate a sensitivity to different drying treatments. Therefore, the objective of the present study was to determine the effect of shade drying, solar drying and oven drying on bioactive ingredients of five cosmetic potential plant leaves. Leaves of Centella asiatica (L.) Urb., Senna alata (L.) Roxb., Justicia adhatoda L., Ocimum tenuiflorum L., Hibiscus rosa-sinensis L. were dried to a constant weight using shade drier at 30-35 °C, solar drier at 30-40 °C and oven at 40 °C. Aluminum chloride colorimetric assay, Folin- Ciocalteau method, and Phosphomolybdate assay were employed to analyse the total flavonoid content (TFC), total phenolic content (TPC) and total antioxidant capacity (TAC) of ethanolic extracts of leaves respectively. All assays were performed in triplicate. Data was analyzed using one -way ANOVA and Tukey’s multiple comparison method. Results showed that significantly higher TFC, TPC and TAC of solar dried leaves of O. tenuiflorum (758.81±2.05 mg RE/100g DW, 3.54±0.71 mg GAE/100g DW and 22.56±0.38 mg AAE/100g DW respectively) and leaves of H. rosa-sinensis (89.72±1.38 mg RE/100g DW, 23.9±0.06 mg GAE/100g DW and 8.53±0.73 mg AAE/100g DW respectively). Solar dried C. asiatica and S. alata leaves showed high TFC and TAC while the TPC was high in oven dried leaves of C. asiatica and shade dried leaves of S. alata respectively. In contrast, J. adhatoda showed the maximum TFC in shade dried samples, the highest TPC in solar dried leaves and the maximum TAC in oven dried leaves. Moreover, there were no significant differences (p > 0.05) among drying methods in terms of antioxidant capacity and phenolic content of J. adhatoda. and antioxidant capacity of C. asiatica. Thus, it can be concluded that, solar drying of medicinal plant materials using solar drier would be an economical, efficient, and effective drying method for preserving bioactive compounds present in leaves of above-mentioned plants.

Evolutionary analysis for Phragmites ecotypes based on full-length plastomes

Abstract Phragmites australis, a Poaceae species distributed worldwide, has strong environmental adaptability and easily forms ecotypes. To study the process of ecotypic evolution of P. australis, we used two sympatric ecotypes with obvious phenotypic differences—Swamp Reed (SR) and Desert-dune Reed (DR) from the Hexi corridor of China as materials, and estimated divergence times derived from chloroplast genome sequencing. Their plastomes were very similar, with a sizes of 137,660 bp (SR) and 137,647 bp (DR). The results of multiple comparison methods revealed only 13 differences between them, most of which were in non-coding regions. A Poaceae chronogram was reconstructed from Bayesian inference using five fossil records. We optimized this analysis by exploring the input datasets, the fossil records, and the test model to get an estimated ecotypic divergence time of 73 Kya. Two main branches in the evolution of P. australis were outstanding: the American lineage and the European lineage. SR/DR came from the late expansion of the European lineage and separated during the Last glacial period (11.5–80 kya). The intense environmental changes in Quaternary likely caused genetic diversity accumulation, which became the driving force for the DR formation. Our estimated divergence time approach for Phragmites ecotypes will help to explore the phylogenetic status and environmental adaption process of polyploid taxa within Poaceae.

AMRmap – antibiotic resistance surveillance system in Russia

Objective. To review the basic principles and functionality of the AMRmap online resource. Materials and Methods. The AMRmap platform was developed using the R programming language and various downloadable modules – packages. The current annually updated version of EUCAST clinical breakpoints was applied for determination of categories of susceptibility to antimicrobial agents. Descriptive analysis includes calculation of absolute and relative frequencies, median values, and confidence intervals using the Wilson method. Categorical variables are compared using Fisher’s exact test and Holm correction method for multiple comparisons. The algorithms are used to visualize multiple comparisons, kernel regression for trend analysis, and algorithms for finding associative rules. Results. The developed surveillance system includes modules for filtering, analyzing and visualizing antibiotic resistance data. The filters allow creating a sample of data with a specific list of parameters. A tab-based separation of analysis and visualization options ensure efficient stepwise evaluation of results. Data saving and sharing functions are also provided. Conclusions. This web-based informatics system provides a convenient way to AMR data from prospective microbiological surveillance studies in Russia. AMRmap can be accessed at https://amrmap.ru.

Reproducibility and Validity of a Semiquantitative Food Frequency Questionnaire in Men Assessed by Multiple Methods.

Among 626 participants of the Men's Lifestyle Validation Study (2011-2013), we evaluated the validity and reproducibility of a self-administered 152-item semiquantitative food frequency questionnaire (SFFQ) using two 7-day dietary records (7DDRs), 4 Automated Self-Administered 24-hour dietary recalls (ASA24s), four 24-hour urine samples, 1 doubly labeled water measurement (repeated in 104 participants), and 2 fasting blood samples, collected over 15 months. Compared with 7DDRs, SFFQs underestimated energy intake, macronutrients, and sodium intake but overestimated some micronutrients. The mean of the Spearman correlation coefficients was 0.66 (range, 0.38-0.88) between 46 energy-adjusted nutrients estimated from 7DDRs and the final SFFQ, deattenuated for within-person variation in the 7DDRs. These deattenuated correlations were similar using ASA24s as the comparison. Relative to biomarkers, SFFQs underestimated energy, sodium, and protein intakes, as well as the sodium:potassium ratio. The energy-adjusted correlations between the final SFFQ and the biomarkers were slightly lower than the correlations between the SFFQ and 7DDRs. Using the method of triads to calculate validity coefficients, the median validity coefficient between SFFQ and true intake was 0.65 and 0.69 using 7DDRs and ASA24s, respectively, as the third method. These data indicate that this SFFQ provided reasonably valid estimates for a wide range of nutrients when evaluated by multiple comparison methods.

Not Just for Joints: The Associations of Moderate-to-Vigorous Physical Activity and Sedentary Behavior with Brain Cortical Thickness.

Cortical thinning is associated with aging; however, lifestyle factors can moderate this relationship. Two distinct lifestyle behaviors associated with brain health are regular moderate-to-vigorous physical activity (MVPA) and limited sedentary behavior (SB). However, it is unclear whether MVPA and SB levels contribute to cortical thickness independent of each other. We therefore investigated the independent relationships of MVPA and SB with cortical thickness using baseline data from a randomized controlled trial. At baseline, we measured MVPA and SB for 7 d using the SenseWear Mini. A subset of the randomized controlled trial participants (n = 30) underwent a 3T magnetic resonance imaging scan, wherein region-specific cortical surface morphometric analyses were performed using T1-weighted structural magnetic resonance imaging. We conducted regression analyses using a surface-based cluster size exclusion method for multiple comparisons within FreeSurfer neuroimaging software to determine if MVPA and SB are independently correlated with region-specific cortical thickness. This subset of participants had a mean age of 61 yr (SD = 9 yr), and 80% were female. Higher MVPA was associated with greater cortical thickness in the temporal pole (cluster size, 855 mm; cortical thickness range, 2.59-3.72 mm; P < 0.05) and superior frontal gyrus (cluster size, 1204 mm; cortical thickness range, 2.41-3.15 mm; P < 0.05) of the left hemisphere, independent of SB. Sedentary behavior was not associated with greater cortical thickness in any region, independent of MVPA. Our results indicate that adults with greater MVPA-independent of SB-are associated with greater cortical thickness in regions, which are susceptible to age-associated atrophy.

Likelihood Ratio Test Method for Multiple Medical Devices Comparison Using Multiple-Site Data with Continuous Outcomes.

With a record number of medical devices approved or cleared, it is important to understand the performance of devices once they are on the market. Using data from multiple medical devices and multiple sites, the problem of interest in this article is to detect if a device is a signal; that is, if a device performs significantly different from other devices of the same class, when the outcome of interest is a continuous variable. We develop a normal likelihood ratio test (LRT) method, henceforth referred to as normal-LRT, by incorporating sample size information into the methodological framework, to detect device signals using multi-site and multi-device data. It is shown via extensive simulation that the proposed method controls the type-I error and false discovery rate (FDR), while having good power and sensitivity. This method is applied to a hypothetical case study, in which 6 medical devices of the same class are compared. The normal-LRT method can be considered as a tool for device signal detection using data from multi-site and multi-device when the outcome of interest is a continuous measurement.

Thalamic pulvinar metabolism, sleep disturbances, and hallucinations in dementia with Lewy bodies: Positron emission tomography and actigraphy study.

Although sleep disturbances are prevalent among patients with dementia with Lewy bodies (DLB), their neural substrates remain unclear. We aimed to clarify the neural substrates of sleep disturbances in patients with DLB. We evaluated sleep disturbances, neuropsychiatric symptoms, and brain glucose metabolism in 22 patients with probable DLB using actigraphy, the Neuropsychiatric Inventory (NPI), and 18 F-fluorodeoxyglucose (FDG) positron emission tomography, respectively. Total sleep time (TST) and average activity count per minute (AAC) during sleep were calculated for seven consecutive days via actigraphy. We investigated associations between FDG uptake and the actigraphy parameters using Statistical Parametric Mapping version 12b. Spearman's rank correlation coefficients were used to investigate associations among TST, AAC, and clinical symptoms. The level of statistical significance was set at P < .05. P values were adjusted using the Benjamini-Hochberg method for multiple comparisons. This study was registered with ClinicalTrials.gov (NCT00776347). TST exhibited a significant positive association with FDG uptake in the bilateral orbitofrontal cortex and left thalamus, while AAC exhibited a significant negative association with FDG uptake in the left thalamus and the left parieto-occipital region. FDG uptake in the left pulvinar was associated with both TST and AAC. In addition, TST exhibited a significant negative association with the NPI hallucinations score (r = -0.66, P = .001), while AAC exhibited significant positive associations with the NPI delusions (r = 0.70, P < .001) and hallucinations (r = 0.63, P = .002) scores. TST and bodily activity during sleep are associated with dysfunction of the left pulvinar and the severity of hallucinations in patients with DLB.

Compbdt: an R program to compare two binary diagnostic tests subject to a paired design

BackgroundThe comparison of the performance of two binary diagnostic tests is an important topic in Clinical Medicine. The most frequent type of sample design to compare two binary diagnostic tests is the paired design. This design consists of applying the two binary diagnostic tests to all of the individuals in a random sample, where the disease status of each individual is known through the application of a gold standard. This article presents an R program to compare parameters of two binary tests subject to a paired design.ResultsThe “compbdt” program estimates the sensitivity and the specificity, the likelihood ratios and the predictive values of each diagnostic test applying the confidence intervals with the best asymptotic performance. The program compares the sensitivities and specificities of the two diagnostic tests simultaneously, as well as the likelihood ratios and the predictive values, applying the global hypothesis tests with the best performance in terms of type I error and power. When the global hypothesis test is significant, the causes of the significance are investigated solving the individual hypothesis tests and applying the multiple comparison method of Holm. The most optimal confidence intervals are also calculated for the difference or ratio between the respective parameters. Based on the data observed in the sample, the program also estimates the probability of making a type II error if the null hypothesis is not rejected, or estimates the power if the if the alternative hypothesis is accepted. The “compbdt” program provides all the necessary results so that the researcher can easily interpret them. The estimation of the probability of making a type II error allows the researcher to decide about the reliability of the null hypothesis when this hypothesis is not rejected. The “compbdt” program has been applied to a real example on the diagnosis of coronary artery disease.ConclusionsThe “compbdt” program is one which is easy to use and allows the researcher to compare the most important parameters of two binary tests subject to a paired design. The “compbdt” program is available as supplementary material.

Automatic detection of tuberculosis related abnormalities in Chest X-ray images using hierarchical feature extraction scheme

Machine learning techniques have been widely used for abnormality detection in medical images. Chest X-ray images (CXR) are among the non-invasive diagnostic tools used to detect various disease pathologies. The ambiguous anatomical structure of soft tissues is one of the major challenges for segregating normal and abnormal images. The main objective of this study is to mimic the expert radiologist’s interpretation procedure in computer-aided diagnosis (CAD) systems. We propose an automatic technique for detection of abnormal CXR images containing one or more pathologies like pleural effusion, infiltration, fibrosis, hila enlargement, dense consolidation, etc. due to tuberculosis (TB). The proposed abnormality detection technique is based on the hierarchical feature extraction scheme in which the features are used in two-level of hierarchy to categorize healthy and unhealthy groups. In level one the handcrafted geometrical features like shape, size, eccentricity, perimeter, etc. and in level 2 traditional first order statistical feature along with texture features like energy, entropy, contrast, correlation, etc. are extracted from segmented lung-fields. Further, a supervised classification approach is employed on the extracted features to detect normal and abnormal CXR images. The performance of the algorithm is validated on a total of 800 CXR images from two public datasets, namely the Montgomery set and Shenzhen set. The obtained results (accuracy = 95.60 ± 5.07% and area under curve (AUC) = 0.95 ± 0.06 for Montgomery collection, and accuracy = 99.40 ± 1.05% and AUC = 0.99 ± 0.01 for Shenzhen collection) shows the promising performance of the proposed technique for TB detection compared to the existing state of the art approaches. Further, the obtained results are statistically validated using Friedman post-hoc multiple comparison methods, which confirms the significance of the proposed method.

The Effects of Initial Procalcitonin Levels on Mortality Rates in Geriatric Patients Undergoing Surgery

IntroductionThe aim of the current study is to investigate the relationship between mortality rate in geriatric patients undergoing surgery with preoperative serum levels of procalcitonin, C-reactive protein, and erythrocyte sedimentation rate.MethodsThis was a single-center retrospective study, including three groups with 101 patients, who are older than 65 years of age. A retrospective investigation was carried out from the laboratory information system for all groups from January to December 2018. Group 1 included patients who had surgery and then mortality within 30 days after surgery. Group 2 included hospitalized patients who had surgery and no mortality within 30 days after surgery. Group 3 included outpatient patients, who had suspicion for a bacterial infection and then no surgery or no mortality within 30 days.ResultsWhen three group comparisons were made for procalcitonin, C-reactive protein, and erythrocyte sedimentation rate values, the p-value of one-way analysis of variance (ANOVA) was higher than 0.05 for procalcitonin and lower than 0.05 for C-reactive protein and erythrocyte sedimentation rate, suggesting that one or more groups were significantly different. When post-hoc multiple comparison methods were applied, there were statistically significant differences between Groups 1 and 3 for C-reactive protein and erythrocyte sedimentation rate.ConclusionsProcalcitonin levels do not predict mortality following surgery. C-reactive protein and erythrocyte sedimentation rate are more useful biomarkers predicting mortality in geriatric patients undergoing surgery.

Concurrent training after photobiomodulation in patients with knee osteoarthritis

Concurrent training after photobiomodulation in patients with knee osteoarthritis

Diversity of butterflies in different habitat types of Seethawaka wet zone botanic gardens and Indikadamukalana forest reserve of Sri Lanka

Botanic gardens, forest reserves and other protected areas are established to conserve biodiversity. The present study was conducted to assess the butterfly diversity in a recently established botanic garden of Sri Lanka, the Seethawaka Wet Zone Botanic Gardens (SWZBG) and Indikadamukalana Forest Reserve (IMFR) adjacent to the garden. Three different habitat types within the botanic gardens, the undisturbed forest habitat within the forest reserve and the buffer zone between the Botanic Gardens and Forest Reserve were investigated for butterflies. Butterfly species richness, diversity, endemic species, family composition in different habitats and effects of habitat parameters on butterfly distribution were assessed. Butterflies were collected from five habitats – grassland, shrub, disturbed forest, undisturbed forest, buffer zone, of the SWZBG and IMFR using transect line method with hand netting and fruit baited traps. Collected butterflies were identified using published field guides. Climate and soil parameters of each habitat were measured using standard methods and equipment. Differences of habitat parameters between habitats were estimated using One-Way Analysis of Variance and Tukey’s Multiple Comparison method and butterfly diversity and evenness in different habitat types were assessed using Shannon-Weiner diversity index. The study revealed seventy-nine butterfly species from SWZBG and IMFR highlighting the importance of the sites for safeguarding and conservation of butterflies. Species richness and diversity of butterflies was highest in the buffer zone and lowest in the grassland habitat. The most common butterfly family in the study sites was family Nymphalidae. Endemic species were high in the forest habitat types. Significant differences were evident in habitat parameters between habitat types indicating their effect on butterfly species richness and diversity. The study revealed SWZBG and IMFR as important areas for butterfly occurrence when compared with similar botanic gardens and forest reserves elsewhere in the world.

Color Shift, Color Stability, and Post-Polishing Surface Roughness of Esthetic Resin Composites.

The aim of this study was to compare color shift, color stability, and post-polishing surface roughness of esthetic restorative materials. Twenty-five disc-shaped specimens (10 mm in diameter and 2 mm in thickness) from five esthetic resin materials (Z250XT, IPS Empress-Direct, G-ænial, Vit-l-escence, and Ceram.X) were fabricated. Color shift before and immediately after light-curing (∆E0) then color stability after immersion in tea, coffee, berry juice, and distilled water were measured using a spectrophotometer. Color changes were measured after 2 (ΔE2), 4 (ΔE4), 6 (ΔE6), and 8 weeks (ΔE8). Surface roughness values (Rq) were determined using an optical profilometer after polishing using a rotary polishing system. Data were analyzed using ANOVA and multiple comparison methods at 0.05 significance level. There were no significant differences between the tested materials regarding color shift except between Vit-l-escence and Ceram.X (p = 0.033). There was no significant difference between coffee and tea solutions (p = 1.0) and between berry juice and distilled water (p = 0.15). There was no difference between the tested materials regarding Rq (p = 0.057). Ceram.X was associated with the lowest ΔE8 values overall. Tested materials were comparable regarding color shift and post-polishing surface roughness. Susceptibility to staining was dependent on the material.

A prospective clinical trial of the effects produced by the Connecticut intrusion arch on the maxillary dental arch.

To assess and compare the effects produced in the maxillary dental arch by means of Connecticut intrusion arch (CIA) with or without a cinch back on the distal end of the tube of the first molars. This study included 44 patients with a mean age of 13.1 ± 1.8 years treated for deep bite with a CIA randomly divided into two groups: group 1 (G1), 22 patients with initial mean age of 12.72 ± 1.74 years treated with the CIA in the upper arch without a cinch back on the distal surface of the tube of the first molars, and group 2 (G2), 22 patients with an initial mean age of 13.67 ± 2.03 years treated with the CIA with a cinch back. Lateral cephalograms were available before treatment (T1) and after intrusion of maxillary incisors (T2). The mean treatment period was 5.5 ± 1.45 months. Intragroup and intergroup changes in the maxillary incisor and molar positions were analyzed by paired and independent t-tests associated with the Holm-Bonferroni correction method for multiple comparisons (P < .05). There were significant differences between groups in terms of maxillary incisor displacement. The maxillary incisors flared labially (2.17°) and proclined (1.68 mm) in group 1, whereas a palatal inclination (-1.99°) and retroclination (-1.13 mm) was observed in group 2. No significant differences were found for the molar positions between the groups. The presence or absence of a distal bend in CIA affects incisor tipping and proclination during intrusion mechanics.

STUDENTS' ATTITUDES TO SELECTED SUBJECTS IN SECONDARY ECONOMIC EDUCATION

Students’ motivation is one of the key factors that determine their school success. It is closely linked to their attitudes toward individual school subjects. This research analyzes four crucial dimensions of students’ subject-related attitudes (practical importance, difficulty, popularity and curriculum contents attractiveness) in the secondary economic education in the Czech Republic and Slovakia in the international context. The research focused on the four dimensions of students’ attitudes (n = 573) toward four major school subjects (economics, accounting, mathematics and the mother tongue) at business academies. It analyzes the data from the questionnaires using the Spearman Correlation Coefficient, the non-parametric Kruskal-Wallis test and the modification of Tukey’s method for multiple comparisons. The results show that the popularity of a school subject significantly correlates with its curriculum contents attractiveness and practical importance. However, the difficulty of school subjects did not influence their popularity in a negative way, which opens several questions for further research in the area. Keywords: economic education; students’ attitudes; motivation in economic school subjects; school subject popularity; school subject difficulty.

Modified testing procedures and multiple comparison methods for ANOVA with AR(1) correlated errors

Modified testing procedures and multiple comparison methods for ANOVA with AR(1) correlated errors