scholarly journals Gaze Behavior in Basketball Free Throws Developed in Constant and Variable Practice

2019 ◽  
Vol 16 (20) ◽  
pp. 3875 ◽  
Author(s):  
Stanisław H. Czyż ◽  
Martin Zvonař ◽  
Zbigniew Borysiuk ◽  
Jiří Nykodým ◽  
Piotr Oleśniewicz
Keyword(s):  
Effect Size ◽  
Fixation Duration ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Test Group ◽  
Repeated Measure ◽  
Gaze Behavior ◽  
Total Fixation ◽  
Variable Practice ◽  
Constant Practice

There are a limited number of studies focusing on the mechanisms explaining why variable practice gives an advantage in a novel situation and constant practice in performance in trained conditions. We hypothesized that this may be due to the different gaze behavior that is developed under different conditions. Twenty participants, randomly assigned to two different groups, practiced basketball free throws for three consecutive days, performing 100 throws per day. The constant group (n = 10) practiced at a free throw distance (4.57 m) only. The variable practice group (n = 10) randomly performed 20 shots per five throw distances (3.35, 3.96, 4.57, 5.18, and 5.79 m) on each day, also accumulating 100 shots per day. We analyzed the total gaze fixation duration, a number of fixations, and the average fixation duration on a basketball rim in a pretest and posttest at the 4.57 m distance. We computed a linear mixed model with test (pretest–posttest), group (constant–variable), and test × group interaction in order to analyze the total fixation duration and number of fixations. The average fixation duration was analyzed with a repeated measure two-way ANOVA, with practice conditions as a between-participants factor and test type as a within-participants factor. We found that the total fixation duration increased significantly in the posttest, regardless of the practice conditions (p < 0.001, effect size = 0.504). The number of fixations also increased significantly in the posttest (p = 0.037, effect size = 0.246). The average fixation duration increased in both groups; however, insignificantly. We also did not find any significant differences between groups. Our results suggest that variable and constant practice conditions may lead to the development of similar gaze behavior.

Appetite-stimulating effect of gabapentin vs mirtazapine in healthy cats post-ovariectomy

2020 ◽  
Vol 22 (12) ◽  
pp. 1176-1183
Author(s):  
Marco Fantinati ◽  
Julien Trnka ◽  
Amélia Signor ◽  
Séverine Dumond ◽  
Géraldine Jourdan ◽  
...  
Keyword(s):  
Placebo Group ◽  
Food Intake ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Repeated Measure ◽  
Mixed Model Analysis ◽  
Treatment Groups ◽  
Significant Difference ◽  
Post Hoc ◽  
Difference Test

Objectives The aim of the study was to evaluate the appetite-stimulating effect of gabapentin by comparing it with mirtazapine in healthy cats in the first 8 h after ovariectomy surgery. Methods This double-masked, placebo-controlled, prospective clinical trial included 60 healthy cats presented to the hospital for ovariectomy: 20 received gabapentin, 21 received mirtazapine and 19 received a placebo immediately before and 6 h after surgery. Food was offered at 2, 4, 6 and 8 h post-ovariectomy. After each meal, food intake was measured. Data were analysed using repeated-measure ANOVA and a linear mixed-model analysis. Post-hoc Tukey’s honest significant difference test was performed for multiple comparisons. Results Food intake increased in both treatment groups vs placebo. No statistically significant difference was found between cats treated with gabapentin or mirtazapine. Conclusions and relevance Cats receiving gabapentin ate more than cats in the placebo group. Thirty percent of cats in the gabapentin group covered their resting energy requirements, while none of the cats in the placebo group did. Gabapentin and mirtazapine produced similar effects on food intake.

Effect of dietary magnesium supplementation in alleviating stress associated with road transportation in weaned lambs

2015 ◽  
Vol 55 (2) ◽  
pp. 219 ◽  
Author(s):  
J. L. Pye ◽  
R. E. Doyle ◽  
M. A. Friend ◽  
M. S. Bhanugopan
Keyword(s):  
Feed Intake ◽  
Stress Responses ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Average Daily Gain ◽  
Basal Diet ◽  
Serum Cortisol ◽  
Repeated Measure ◽  
Control Group ◽  
Road Transportation

Magnesium (Mg) supplementation has shown to modulate the stress responses to transport in other species. An experiment was designed to evaluate the effect of Mg for alleviating stress associated with road transportation in lambs. Two groups (n = 18 each) of 4-month old male crossbred lambs (24 ± 4.5 kg) were fed a basal diet comprising oaten hay, pellets and barley, that contained 0.17% Mg. One group was supplemented with magnesium oxide, such that dietary Mg was 0.41%. At the end of the 2-week supplementation period, the lambs were transported by road for 8 h. Blood samples were collected before supplementation, 1 h before transport, within 0.5 h post-transport, at 2 h post-transport and 5 days post-transport. Data were analysed using a repeated-measure analysis of variance and linear mixed model with treatment within time interaction. Supplementation with dietary Mg in the form of MgO increased serum Mg concentrations (1.16 mmol/L ± 0.012, compared with 1.09 mmol/L ± 0.013 in the control group; P < 0.05), but had no effect on alleviating stress during transportation. Transport resulted in a significant increase in serum cortisol, which returned to pre-transport levels 2 h after transport. The serum β-hydroxybutyrate was significantly higher 5 days after transport. The post-transport average feed intake and the average daily gain were significantly lower than pre-transport values, suggesting that the stress of transportation resulted in a decrease in feed intake post-transport, which could have implications on liveweight gain of animals after transportation.

Estimation of Genetic Variance Contributed by a Quantitative Trait Locus — Correcting the Bias Associated with Significance Tests

Genetics ◽  
2021 ◽  
Author(s):  
Fangjie Xie ◽  
Shibo Wang ◽  
William D Beavis ◽  
Shizhong Xu
Keyword(s):  
Qtl Mapping ◽  
Effect Size ◽  
Bias Correction ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Association Studies ◽  
Chromosome 9 ◽  
Genome Wide Association Studies ◽  
Test Statistic ◽  
Chi Square

Abstract The Beavis effect in QTL mapping describes a phenomenon that the estimated effect size of a statistically significant QTL (measured by the QTL variance) is greater than the true effect size of the QTL if the sample size is not sufficiently large. This is a typical example of the Winners’ curse applied to molecular quantitative genetics. Theoretical evaluation and correction for the Winners’ curse have been studied for interval mapping. However, similar technologies have not been available for current models of QTL mapping and genome-wide association studies where a polygene is often included in the linear mixed models to control the genetic background effect. In this study, we developed the theory of the Beavis effect in a linear mixed model using a truncated non-central Chi-square distribution. We equated the observed Wald test statistic of a significant QTL to the expectation of a truncated non-central Chi-square distribution to obtain a bias-corrected estimate of the QTL variance. The results are validated from replicated Monte Carlo simulation experiments. We applied the new method to the grain width (GW) trait of a rice population consisting of 524 homozygous varieties with over 300k single nucleotide polymorphism (SNPs) markers. Two loci were identified and the estimated QTL heritability were corrected for the Beavis effect. Bias correction for the larger QTL on chromosome 5 (GW5) with an estimated heritability of 12% did not change the QTL heritability due to the extremely large test score and estimated QTL effect. The smaller QTL on chromosome 9 (GW9) had an estimated QTL heritability of 9% reduced to 6% after the bias-correction.

scholarly journals The impact of studies with no events in both arms on meta-analysis of rare events: a simulation study using generalized linear mixed model

2021 ◽  
Author(s):  
Chang Xu ◽  
Lifeng Lin
Keyword(s):  
Effect Size ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Mean Squared Error ◽  
Meta Analysis ◽  
Unbiased Estimation ◽  
Double Zero ◽  
Squared Error ◽  
Meta Analyses ◽  
The Impact

AbstractObjectiveThe common approach to meta-analysis with double-zero studies is to remove such studies. Our previous work has confirmed that exclusion of these studies may impact the results. In this study, we undertook extensive simulations to investigate how the results of meta-analyses would be impacted in relation to the proportion of such studies.MethodsTwo standard generalized linear mixed models (GLMMs) were employed for the meta-analysis. The statistical properties of the two GLMMs were first examined in terms of percentage bias, mean squared error, and coverage. We then repeated all the meta-analyses after excluding double-zero studies. Direction of estimated effects and p-values for including against excluding double-zero studies were compared in nine ascending groups classified by the proportion of double-zero studies within a meta-analysis.ResultsBased on 50,000 simulated meta-analyses, the two GLMMs almost achieved unbiased estimation and reasonable coverage in most of the situations. When excluding double-zero studies, 0.00% to 4.47% of the meta-analyses changed the direction of effect size, and 0.61% to 8.78% changed direction of the significance of p-value. When the proportion of double-zero studies increased in a meta-analysis, the probability of the effect size changed the direction increased; when the proportion was about 40% to 60%, it has the largest impact on the change of p-values.ConclusionDouble-zero studies can impact the results of meta-analysis and excluding them may be problematic. The impact of such studies on meta-analysis varies by the proportion of such studies within a meta-analysis.

scholarly journals Application of Multivariate Generalized Linear Mixed Model to Identify Effect of Dialysate Temperature on Physiologic Indicators among Hemodialysis Patients

2021 ◽  
Author(s):  
Omid Hamidi ◽  
Seyed Reza Borzu ◽  
Saman Maroufizadeh ◽  
Payam Amini
Keyword(s):  
Blood Pressure ◽  
Pulse Rate ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Repeated Measure ◽  
Longitudinal Models ◽  
Multivariate Statistical ◽  
Measure Analysis ◽  
Repeated Measure Analysis ◽  
Dialysate Temperature

Introduction: One of the complications of hemodialysis treatment is hypotension, which can increase morbidity and mortality and compromise dialysis efficacy. Dialysate temperature is an important factor that contributes to hemodynamic stability during hemodialysis. This study investigated the effect of dialysate temperature on the patients' blood pressure and pulse rate. Model-based approaches were used to produce more reliable results compared with traditional methods. Methods: A total of 30 patients were studied during 9 dialysis sessions. Dialysate temperatures were 37° C, 36° C and 35° C. A joint longitudinal model was used to analyze both responses of blood pressure and pulse rate, simultaneously. Results: The results showed that low-dialysate temperature was not significantly associated with higher systolic blood pressure (p>0.05) or a higher pulse rate (p>0.05) either during or after dialysis. Pulse rate and blood pressure were higher for women during dialysate (p<0.001). However, increasing age was associated with higher blood pressure and a lower pulse rate (p<0.001). Conclusion: Using several separate, repeated measure analysis of variances may produce misleading results, when there is more than one response variable measured over time, Multivariate statistical methods (including joint longitudinal models), should be used.  

scholarly journals How Users’ Gaze Behavior Is Related to Their Quality Evaluation of a Health Website Based on HONcode Principles?

2020 ◽  
Vol 5 (1) ◽  
pp. 75-85
Author(s):  
Qin Qin ◽  
Qing Ke ◽  
Jia Tina Du ◽  
Yushan Xie
Keyword(s):  
Health Information ◽  
Fixation Duration ◽  
Quality Evaluation ◽  
Critical Issue ◽  
Self Report ◽  
Website Design ◽  
Gaze Behavior ◽  
Website Quality ◽  
Evaluation Approach ◽  
Total Fixation

AbstractWhile the health website is an easily accessible source for patients to use when seeking health information, the quality of online health information has been a critical issue that concerns all stakeholders in healthcare. The aim of this research was to examine the relationship between users’ evaluation of the health website quality and their gaze behavior on the web pages. Eye tracking and a self-report questionnaire based on the HONcode principles were used to address the objective. We found that (1) the evaluations of authority, privacy, financial disclosure, and advertising policy are positively correlated with the fixation count and total fixation duration toward corresponding page components, while the evaluations of complementarity and attribution are negatively correlated with the fixation count and total fixation duration to corresponding page components; and (2) the fixation count and total fixation duration toward health information sources are negatively related to the evaluation of health website quality, while the fixation count and total fixation duration to site owner are positively related to the quality evaluation. Users’ attention to page components is closely related to the evaluation of principles, and also has a certain impact on the overall quality evaluation of a health website. Based on the findings, our research may serve to improve the health website design and be a foundation to develop an automatic evaluation approach of the health website quality.

scholarly journals Effect of visual searching task on the postural stability of children

2021 ◽  
Vol 15 (2) ◽  
pp. 79-90
Author(s):  
Carina L. Moreira ◽  
Leandro F. Oliveira ◽  
Matheus B. Brito ◽  
Sérgio T. Rodrigues ◽  
Paula F. Polastri
Keyword(s):  
Young Adults ◽  
Postural Stability ◽  
Fixation Duration ◽  
Force Plate ◽  
Gaze Behavior ◽  
Cognitive Demands ◽  
Free Viewing ◽  
Total Fixation ◽  
Visual Tasks ◽  
The Relationship

BACKGROUND: The relationship between gaze behavior and postural stability under distinct cognitive loads is still unclear in children. AIM: This study focuses on eye movements' effect on the children's postural stability by varying the visual tasks' attentional/cognitive demands. METHOD: Twenty young adults (23.4 years-old, ± 2.1) and sixteen children (10.3 years-old, ± 0.4) stand in semi- tandem position on a force plate, wearing a head-mounted eye-tracking while performing three 40 second-trials in the following order: stationary gaze task; free-viewing task; and visual searching task. RESULTS: Children showed a higher number of fixations during the stationary gaze task (p<0.0001), but this number was lower during free-viewing (p<0.004) and visual searching tasks (p<0.0001) when compared to young adults. Total fixation duration was lower in children than in young adults (p<0.0001) and higher during stationary gaze task than free-viewing (p<0.0001) and visual searching tasks (p<0.0001) for both groups. CONCLUSION: These results indicate that the performance of the visual searching task during the maintenance of a challenging stance may deteriorate children’s postural stability suggesting that the relationship between gaze behavior and postural control is not well developed around the age of 10 years.

Analyzing discontinuities in longitudinal count data: A multilevel generalized linear mixed model.

2020 ◽  
Author(s):  
James L. Peugh ◽  
Sarah J. Beal ◽  
Meghan E. McGrady ◽  
Michael D. Toland ◽  
Constance Mara
Keyword(s):  
Count Data ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Generalized Linear Mixed Model ◽  
Longitudinal Count Data

Predicting bycatch hotspots based on suitable habitat derived from fishery-independent data

2020 ◽  
Vol 641 ◽  
pp. 159-175
Author(s):  
J Runnebaum ◽  
KR Tanaka ◽  
L Guan ◽  
J Cao ◽  
L O’Brien ◽  
...  
Keyword(s):  
Habitat Suitability ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Gulf Of Maine ◽  
Homarus Americanus ◽  
Management Tool ◽  
American Lobster ◽  
Suitable Habitat ◽  
Climate Conditions ◽  
Suitability Index

Bycatch remains a global problem in managing sustainable fisheries. A critical aspect of management is understanding the timing and spatial extent of bycatch. Fisheries management often relies on observed bycatch data, which are not always available due to a lack of reporting or observer coverage. Alternatively, analyzing the overlap in suitable habitat for the target and non-target species can provide a spatial management tool to understand where bycatch interactions are likely to occur. Potential bycatch hotspots based on suitable habitat were predicted for cusk Brosme brosme incidentally caught in the Gulf of Maine American lobster Homarus americanus fishery. Data from multiple fisheries-independent surveys were combined in a delta-generalized linear mixed model to generate spatially explicit density estimates for use in an independent habitat suitability index. The habitat suitability indices for American lobster and cusk were then compared to predict potential bycatch hotspot locations. Suitable habitat for American lobster has increased between 1980 and 2013 while suitable habitat for cusk decreased throughout most of the Gulf of Maine, except for Georges Basin and the Great South Channel. The proportion of overlap in suitable habitat varied interannually but decreased slightly in the spring and remained relatively stable in the fall over the time series. As Gulf of Maine temperatures continue to increase, the interactions between American lobster and cusk are predicted to decline as cusk habitat continues to constrict. This framework can contribute to fisheries managers’ understanding of changes in habitat overlap as climate conditions continue to change and alter where bycatch interactions could occur.

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