Two-way Analysis Of Variance Model Research Articles

A Study on the Effects of Selected Micronutrients, Locations, and Their Interaction on Cassava Yield Based on the Two-Way ANOVA Model with Interaction

<p dir="ltr"><span>The paper investigated the effects of fertilizer (Zinc, Iron and Manganese), location of farm land and their interaction on cassava yield. The secondary data used for the study were collected from the National Cereal Research Institute of Nigeria Outstanding Farm, Nung Udo, Uyo, Akwa Ibom State. The data comprised of cassava yield (Hectares) for 2016 planting season, five separate farms where three types of fertilizer were applied. The two-way analysis of variance (ANOVA) technique with interaction was used in the analysis of the data. Furthermore, the Tukey HSD test was conducted to compare the treatment means. The result of the study showed that there is significant mean difference in the yield of cassava based on the three types of fertilizer applied. On the basis of farm locations, the result shows that there is no significant mean difference in cassava yield while the interaction between fertilizer and farm location affects cassava yield significantly at 5% level of significance.</span></p><p dir="ltr"><span>Keywords: </span><span>two-way analysis of variance with interaction; Tukey test; fertilizer; cassava yield; farm location</span></p><div><span><br /></span></div>

Different MRI-based methods for the diagnosis of neurovascular compression in trigeminal neuralgia or hemifacial spasm: A network meta-analysis

BackgroundAccurate preoperative diagnosis of neurovascular compression (NVC) is crucial in the treatment of trigeminal neuralgia (TN) or hemifacial spasm (HFS). At present, there are many magnetic resonance imaging (MRI)-based methods for diagnosing NVC in clinical practice. This network meta-analysis (NMA) aimed to evaluate the diagnostic performance of different MRI-based imaging methods for NVC in patients with TN and HFS. Materials and methodsRelated studies based on a search of PubMed, Embase, Web of Science and the Cochrane Library were retrieved. A two-way analysis of variance model was constructed for the Bayesian NMA to compare the performance of different diagnostic imaging methods. ResultsOur search identified 595 articles, of which 26 studies (including 2085 patients) related to 4 diagnostic imaging methods (3D time-of-flight magnetic resonance angiography (3D TOF MRA), high resolution T2-weighted imaging (HR T2WI), 3D TOF MRA combined with HR T2WI, and 3D multimodal image fusion (MIF) based on 3D TOF MRA combined with HR T2WI) were included in this NMA. The results showed that 3D MIF based on 3D TOF MRA combined with HR T2WI had the highest related sensitivity, the highest superiority index and the largest area under the receiver operating characteristic curve among all the methods. Conclusions3D MIF based on 3D TOF MRA combined with HR T2WI had better diagnostic performance for detecting NVC in patients with TN or HSF than other MRI-based imaging methods. This method can be used as an effective tool for preoperative evaluation of MVD.

Sentiment Analysis on the Performance of Engineering Students in University Examination: A Non-parametric Approach Using Two-way Analysis of Variance Model

Higher Education System in India has undergone a rapid change after the year 2000 in India. The Government of India has initiated to start more number of higher learning institutes for the growth of the education sector. In the early years of 2000 a number of engineering colleges / universities were opened for strengthening engineering education by the government and by private management. The engineering educational authorities in particular have formulated a number of guidelines for improving quality of engineering education. The improvements were made in respect of integration of different courses and different streams of engineering disciplines. In this article an attempt is made to study the effects of such integrated efforts based on Sentiment Analysis. The aspects of diversified course structures and the engineering streams are identified with respect to pass percentage of students in university examinations. Friedman Two-way analysis of variance model is used for the analysis of the sampled data. Inferences based on the hypotheses tested are presented.

How to use statistics to claim antagonism and synergism from binary mixture experiments.

We review statistical approaches applicable for the analysis of data from binary mixture experiments, which are commonly used in pesticide science for evaluating antagonistic or synergistic effects. Specifically, two different situations are reviewed, one where every pesticide is only available at a single dose level and a mixture simply combines these doses, and one where the pesticides and their mixture are used at increasing doses. The former corresponds to using factorial designs whereas the latter corresponds to fixed-ratio designs. We consider dose addition and independent action as references for lack of antagonistic and synergistic effects. Data from factorial designs should be analyzed using two-way analysis of variance models whereas data from fixed-ratio designs should be analyzed using non-linear dose-response analysis. In most cases, independent action seems the more natural choice for factorial designs. In contrast, dose addition is more appropriate for fixed-ratio designs although dose addition is not equally compatible with all types of dose-response data. Fixed-ratio designs should be preferred as they allow validation of the assumed dose-response relationship and, consequently, provide much stronger claims about antagonistic and synergistic effects than factorial designs. Finally, it should be noted that, in any case, simple ways of summarizing pesticide mixture effects may come at the price of more or less restrictive modeling assumptions. © 2021 Society of Chemical Industry.

Hearing Disabilities and the Effectiveness of Rehabilitation in Different Age Groups.

To assess differences in hearing disabilities between different age groups and the effectiveness of rehabilitation with hearing aids. Retrospective chart review. First line hearing aid dispensers. First-time hearing aid users divided in a younger group aged 18 to 65 years (119 subjects) and an elderly group aged 70 years and older (213 subjects). Rehabilitative. Weighted pure tone averages (PTA) were calculated using the binaural impairment model. The patient-reported outcome measures (PROMs) Amsterdam Questionnaire for Auditory Disabilities (AVAB), and client oriented scale of improvement (COSI) were collected pre- and post-fitting. To analyze whether age group, weighted PTA, and type of auditory dimension influences AVAB, linear regression and two-way ANalysis Of VAriance models were used. The weighted PTA of the young group was significantly lower than of the elderly group. In the regression model differences between age groups were found to be significant for pre-AVAB and for AVAB benefit. The two-way ANalysis Of VAriance showed that the effect of age on pre- and post-AVAB scores was not influenced by PTA or the type of auditory dimension. Younger first-time hearing aid users experience more auditory disabilities, despite better hearing levels than their elderly counterparts. Their disabilities are rehabilitated more effectively by hearing aids.

Do somatic symptoms relate to PTSD and gender after earthquake exposure? A cross-sectional study on young adult survivors in Italy.

Increasing evidence confirms a strict relationship between mental disorders and physical health. Particularly, stressful life events and post-traumatic stress disorder (PTSD) have been closely correlated with various physical disorders and somatic symptoms, such as chronic pain, gastrointestinal disorders, and headaches. The aim of this study was to investigate the emergence of somatic symptoms in a sample of young adult survivors 21months after exposure to the L'Aquila 2009 earthquake, with particular attention to PTSD and gender impact. Four hundred and fifty high-school senior students (253 male and 197 female) exposed to the 2009 L'Aquila earthquake, 21months earlier, were enrolled and evaluated by the Trauma and Loss Spectrum Self-Report (TALS-SR), for symptomatological PTSD, and the Mood Spectrum Self-Report-Lifetime Version (MOODS-SR) "rhythmicity and vegetative functions" domain, for somatic symptoms. Significantly higher rates of endorsement of the MOODS-SR somatic symptoms emerged in survivors with PTSD compared to those without. Females reported higher rates of endorsement of at least one MOODS-SR somatic symptom compared to males; however, a Decision Tree model and a two-way analysis of variance model confirmed a significant effect of PTSD only. A multivariate logistical regression showed a significant association between the presence of at least one MOOD-SR somatic symptom and re-experiencing and maladaptive coping TALS-SR domains. This study corroborates a relevant impact of symptomatological PTSD, across both the genders, on somatic symptoms occurring in young adults after months from exposure to a massive earthquake.

Growth and Extracellular Enzyme Activity Responses of a Multi-enzymic Strain of Serratia sp. in a Simulated Diesel-contaminated System

Aim: The present study was aimed at elucidating the alternative metabolic preferences of Serratia sp. strain DW2 that permitted its survival in a diesel-contaminated environment.
 Study Design: We adopted a 4 x 4 x 3 completely randomized design of a full-factorial experiment for the study.
 Place and Duration of Study: The study was conducted at the Department of Microbiology, University of Calabar, Nigeria, during the months of March and June, 2019.
 Methodology: In this study, Serratia sp. strain DW2 was isolated from Douglas Creek water of the Qua Iboe Estuary, along the Qua Iboe terminal at Ibeno, Nigeria, as a significant biological contributor to the decontamination process through inherent ability to utilize diesel oil hydrocarbons. This paper elucidated the growth and responses of the bacterial lipase, caseinase and gelatinase activities to diesel-oil hydrocarbon contamination.
 Results: Range finding test results showed that the bacterium could grow in the presence of water soluble fraction of diesel (wsf-D) concentration between .0042 and .0335 µg/mL, albeit with increasing lag time and decreasing specific growth rate when compared with growth in glucose-Bushnell-Haas broth. Lag time changes were not significantly influenced by exposure time but changes in specific growth rate were. Gelatinase activity was most susceptible to toxicant onslaught but was least affected by exposure time. Conversely, lipase activity was the most affected by exposure time. Toxicant concentration/exposure time interaction of a two-way analysis of variance model for caseinase activity was not significant (P > .05) but those for lipase and gelatinase activities were.
 Conclusion: The bacterium survived diesel toxicity by exploiting its lipase and gelatinase activities for provision of alternative sources of carbon, energy and nitrogen to drive ecosystem decontamination in the event of refined petroleum contamination.

Bayesian Generalized Two-way ANOVA Modeling for Functional Data Using INLA

Functional analysis of variance (ANOVA) modeling has been proved particularly useful to investigate the dynamic changes of functional data according to certain categorical factors and their interactions. The current existing methods often encounter difficulties when the functional data are high-dimensional, non-Gaussian, and/or exhibit certain shape characteristics that vary with spatial locations. In this paper, we investigate the functional two-way ANOVA models from a novel Bayesian perspective. A class of highly flexible Gaussian Markov random fields (GMRF) are taken as priors on the functions in the model, which allows us to model various types of functional effects, such as (discrete or continuous) temporal effects and (point-level or areal) spatial effects. The resulting posterior distributions are obtained by an efficient computational tool based on integrated nested Laplace approximations (INLA) Rue, Martino and Chopin (2009). We then employ the excursion method introduced by Bolin and Lindgren (2015) to build simultaneous credible intervals of functional effects and test their significance from a Bayesian point of view. A simulation study and multiple data examples are presented to demonstrate the merits of our method.

Mixtures of g-Priors for Analysis of Variance Models with a Diverging Number of Parameters

We consider Bayesian approaches for the hypothesis testing problem in the analysis-of-variance (ANOVA) models. With the aid of the singular value decomposition of the centered designed matrix, we reparameterize the ANOVA models with linear constraints for uniqueness into a standard linear regression model without any constraint. We derive the Bayes factors based on mixtures of g-priors and study their consistency properties with a growing number of parameters. It is shown that two commonly used hyper-priors on g (the Zellner-Siow prior and the beta-prime prior) yield inconsistent Bayes factors due to the presence of an inconsistency region around the null model. We propose a new class of hyper-priors to avoid this inconsistency problem. Simulation studies on the two-way ANOVA models are conducted to compare the performance of the proposed procedures with that of some existing ones in the literature.

Hyperdynamic left ventricle on radionuclide myocardial perfusion imaging (RNMPI): A marker of diastolic dysfunction in patients presenting with dyspnea on exertion

BackgroundWe hypothesized that among patients presenting with dyspnea on exertion (DOE), those who were found to have hyperdynamic left ventricle (i.e. LVEF≥70%) on stress radionuclide myocardial perfusion imaging (RNMPI), are more likely to have features of diastolic dysfunction on transthoracic echocardiography. MethodsMedical records of 1892 consecutive patients who presented between February 2011 and September 2012 with the chief complaint of DOE and were referred to stress RNMPI were reviewed. Among these, patients who had no evidence of reversible ischemia and had hyperdynamic left ventricle on perfusion imaging, were selected and their recent echocardiograms were reviewed for evidence of diastolic dysfunction. Logistic regression analysis was used to develop an equation to predict diastolic dysfunction with the ejection fraction as the predictor. A two-way analysis of variance model was used to detect differential patterns of ejection fraction across diastolic dysfunction and gender. ResultsA hyperdynamic left ventricle identified on stress RNMPI was found to be a significant predictor of diastolic dysfunction on echocardiography in logistic regression analysis (odds ratio=1.24, 95% CI=1.13–1.35, p<0.0001). A hyperdynamic left ventricle on stress RNMPI has a specificity of 96.77% (CI 83.24–99.46%) and a positive predictor value of 97.83% (CI 88.43–99.64%) in identifying diastolic dysfunction. ConclusionIn patients presenting with DOE who have no evidence of reversible ischemia on radionuclide stress testing but have hyperdynamic left ventricle, a search should be made for alternate cardiac etiology for this complaint such as diastolic dysfunction and heart failure with preserved ejection fraction.

Generalized F Test and Generalized Deviance Test in Two-Way ANOVA Models for Randomized Trials

We consider the problem of detecting treatment effects in a randomized trial in the presence of an additional covariate. By reexpressing a two-way analysis of variance (ANOVA) model in a logistic regression framework, we derive generalized F tests and generalized deviance tests, which provide better power in detecting common location-scale changes of treatment outcomes than the classical F test. The null distributions of the test statistics are independent of the nuisance parameters in the models, so the critical values can be easily determined by Monte Carlo methods. We use simulation studies to demonstrate how the proposed tests perform compared with the classical F test. We also use data from a clinical study to illustrate possible savings in sample sizes.

Prediction of gene expression in human using rat in vivo gene expression in Japanese Toxicogenomics Project

The Japanese Toxicogenomics Project (TGP) provides large amount of data for the toxicology and safety framework. We focus on gene expression data of rat in vivo and human in vitro. We consider two different analyses for the TGP data. The first analysis is based on two-way analysis of variance model and the goal is to detect genes with significant dose-response relationship in both humans and rats. The second analysis consists of a trend analysis at each time point and the goal is to detect genes in the rat in order to predict gene expression in humans. The first analysis leads us to conclusions about the heterogeneity of the compound set and will suggest how to address this issue to improve future analyses. In the second part, we identify, for particular compounds, groups of genes that are translatable from rats to humans, so they can be used for prediction of human in vitro data based on rat in vivo data.

Effects of the sintering conditions of dental zirconia ceramics on the grain size and translucency

PURPOSEThis study aimed to identify the effects of the sintering conditions of dental zirconia on the grain size and translucency.MATERIALS AND METHODSTen specimens of each of two commercial brands of zirconia (Lava and KaVo) were made and sintered under five different conditions. Microwave sintering (MS) and conventional sintering (CS) methods were used to fabricate zirconia specimens. The dwelling time was 20 minutes for MS and 20 minutes, 2, 10, and 40 hours for CS. The density and the grain size of the sintered zirconia blocks were measured. Total transmission measurements were taken using a spectrophotometer. Two-way analysis of variance model was used for the analysis and performed at a type-one error rate of 0.05.RESULTSThere was no significant difference in density between brands and sintering conditions. The mean grain size increased according to sintering conditions as follows: MS-20 min, CS-20 min, CS-2 hr, CS-10 hr, and CS-40 hr for both brands. The mean grain size ranged from 347-1,512 nm for Lava and 373-1,481 nm for KaVo. The mean light transmittance values of Lava and KaVo were 28.39-34.48% and 28.09-30.50%, respectively.CONCLUSIONDifferent sintering conditions resulted in differences in grain size and light transmittance. To obtain more translucent dental zirconia restorations, shorter sintering times should be considered.

On Testing an Unspecified Function Through a Linear Mixed Effects Model with Multiple Variance Components

We examine a generalized F-test of a nonparametric function through penalized splines and a linear mixed effects model representation. With a mixed effects model representation of penalized splines, we imbed the test of an unspecified function into a test of some fixed effects and a variance component in a linear mixed effects model with nuisance variance components under the null. The procedure can be used to test a nonparametric function or varying-coefficient with clustered data, compare two spline functions, test the significance of an unspecified function in an additive model with multiple components, and test a row or a column effect in a two-way analysis of variance model. Through a spectral decomposition of the residual sum of squares, we provide a fast algorithm for computing the null distribution of the test, which significantly improves the computational efficiency over bootstrap. The spectral representation reveals a connection between the likelihood ratio test (LRT) in a multiple variance components model and a single component model. We examine our methods through simulations, where we show that the power of the generalized F-test may be higher than the LRT, depending on the hypothesis of interest and the true model under the alternative. We apply these methods to compute the genome-wide critical value and p-value of a genetic association test in a genome-wide association study (GWAS), where the usual bootstrap is computationally intensive (up to 10(8) simulations) and asymptotic approximation may be unreliable and conservative.

Elevated Circulating Levels of Tissue Factor in Polycystic Ovary Syndrome

Women with polycystic ovary syndrome (PCOS) have coagulation disturbances and inflammation, which increases the risk of atherothrombosis. We evaluated the status of circulating tissue factor (TF), the receptor for coagulation factor VII involved in atherothrombosis, in women with PCOS and weight-matched controls. Two-way analysis of variance models were fit to evaluate the effect of PCOS status and weight class on TF and other parameters. The TF levels were significantly higher in lean women with PCOS compared to lean controls. Plasminogen activator inhibitor 1 (PAI-1) levels were significantly higher in obese participants compared to lean participants after controlling for PCOS status. The TF levels directly correlated with percentage of truncal fat and plasma levels of PAI-1, testosterone, androstendione, and dehydroepiandrosterone-sulfate; and inversely correlated with insulin sensitivity index-OGTT(IS(OGTT)). Circulating TF is elevated in PCOS independent of obesity, but both PCOS and obesity contribute to a prothrombotic state. In PCOS, abdominal adiposity and hyperandrogenism may exacerbate the risk of atherothrombosis.

Testing normality in mixed models using a transformation method

Statistical inference often assumes the normality of the variables involved in the model under study. The existing tests are for independent observations and may not be readily extended to handle the case with correlated ones. In this paper, a transformation method is recommended for normality checking in the two-way analysis of variance model. Its sampling properties are investigated. Simulation studies are carried out to examine the performance of the proposed methodology.

Statistics at the bench: A step‐by‐step handbook for biologists

Statistics at the bench: A step‐by‐step handbook for biologists

Effect of Bioactive Ceramic and Recombinant Human Transforming Growth Factor-Beta (rhTGF-beta) on Regeneration of Parietal Bone Defects in Rat

The purpose of this study was to evaluate the regenerative response of parietal bone defects in rats to bioactive ceramic and TGF-beta 1. Sixty mature adult rats with initial weights of 300 g to 324 g were used. The diameter of each defect was 3 mm. The animals were divided into four study groups consisting of 15 rats per group. Groups 1 and 3 (control groups) received 30 μg bioceramic per surgical defect site. Groups 2 and 4 (experimental groups) received 30 μg bioceramic combined with 10 μL of reconstituted TGF-beta 1 (200 ng). Animals of Groups 1 and 3 were euthanized at 18 days; Group 2 and 4 animals were terminated at 49 days after surgery. Each of the outcomes was analyzed via two-way analysis of variance model (ANOVA). Histologic reactions to the implants were similar with no significant difference between bioceramic and bioceramic + TGF-beta 1 specimens. In the 18-day specimens, the percentage of ceramic was marginally higher than the 49-day specimens. No significant difference was noted in the percentage of bone in 18-day and 49-day specimens. Based on the findings of this study, it was concluded that TGF-beta 1 promoted no significant increase in new bone when compared to bioactive ceramic alone.

Elevated circulating levels of macrophage migration inhibitory factor in polycystic ovary syndrome

Women with polycystic ovary syndrome (PCOS) have chronic low level inflammation which can increase the risk of atherogenesis. We evaluated the status of circulating macrophage migration inhibitory factor (MIF), a proinflammatory cytokine involved in atherogenesis, in women with PCOS and weight-matched controls. Two-way analysis of variance models adjusted for age were fit to evaluate the effect of PCOS status (PCOS vs. controls) and weight-class (obese vs. lean) on MIF and other parameters. MIF levels were significantly ( p < 0.001) higher in women with PCOS (lean: 37.7 ± 10.6 ng/ml; obese: 54.6 ± 15.2 ng/ml) compared to controls (lean: 4.8 ± 0.6 ng/ml; obese: 17.5 ± 8.0 ng/ml) regardless of weight-class. CRP levels were significantly ( p < 0.001) higher in obese subjects (PCOS: 6.2 ± 1.9 mg/l; controls: 6.7 ± 1.4 mg/l) compared to lean subjects (PCOS: 0.9 ± 0.4 mg/l; controls: 0.2 ± 01 mg/l) after controlling for PCOS status. MIF levels directly correlated with % truncal fat ( r = 0.41, p < 0.05), and plasma levels of CRP ( r = 0.42, p = 0.05), LH ( r = 0.45, p = 0.04), testosterone ( r = 0.53, p < 0.008), androstendione ( r = 0.58, p < 0.005). IS OGTT inversely correlated with plasma levels of MIF ( r = −0.51, p < 0.02) and CRP ( r = -0.73, p < 0.001). Circulating MIF is elevated in PCOS independent of obesity, but both PCOS and obesity contribute to a proatherogenic state. In PCOS, abdominal adiposity and hyperandrogenism may exacerbate the risk of atherosclerosis.

Alignment control exercise changes lower extremity movement during stop movements in female basketball players

This study was intended to evaluate a short-term intervention designed to improve the lower extremity alignment with neutral position during stop movements of female basketball players when performing a quick-stop jump shot. In this study, 20 healthy female college basketball players (mean age 20.5 years) participated. The authors monitored two groups for 4 weeks: one which trained ( n = 10) and one which did not train ( n = 10). The exercise program emphasized the neutral position of lower extremities for dynamic alignment control; the players avoided the valgus position with their knees. Kinematics analysis with a lower extremity angle in the stop action was performed using three digital video cameras and analyzed using software. Following the intervention exercise program, each subject was re-evaluated at two and four weeks to determine changes in movement patterns during the “sink shot” task. Two-way analysis of variance models were used to determine differences at pre-intervention, at mid-term, and post-intervention. After the 2-week intervention, the trained athletes group made basketball shots with greater change of the lower extremity motion pattern during the stop action than did non-trained athletes ( p < 0.05). However, no significant differences were found between other data of the 2-week and 4-week intervention groups. Results of this study show that two weeks of training can improve the dynamic alignment control of the lower extremities, as measured using the alignment angle of the coronal plane and the torsion angle of horizontal plane during a stop action.