Comparing Neighborhood Effects Across Tasks Using Repeated-Measures Polynomial Regression

Abstract This chapter covers the methods for obtaining and expressing these mathematical equations and their confidence bands. The methodology is linear regression analysis. Four types of regression analysis are presented, including: simple linear regression with no repeated measures or replication; simple linear regression with repeated measures; simple linear regression with replication; and polynomial regression. The effects of nitrogen rate on crop yield were presented as example.

Download Full-text

Inter- and Intra-Individual Differences in EMG and MMG during Maximal, Bilateral, Dynamic Leg Extensions

Sports ◽

10.3390/sports7070175 ◽

2019 ◽

Vol 7 (7) ◽

pp. 175 ◽

Cited By ~ 5

Author(s):

John Paul V. Anders ◽

Cory M. Smith ◽

Joshua L. Keller ◽

Ethan C. Hill ◽

Terry J. Housh ◽

...

Keyword(s):

Individual Differences ◽

Repeated Measures ◽

Polynomial Regression ◽

Vastus Lateralis ◽

Regression Analyses ◽

Mean Power ◽

Mean Power Frequency ◽

Leg Extension ◽

Neuromuscular Responses ◽

Muscle Actions

The purpose of this study was to compare the composite, inter-individual, and intra-individual differences in the patterns of responses for electromyographic (EMG) and mechanomyographic (MMG) amplitude (AMP) and mean power frequency (MPF) during fatiguing, maximal, bilateral, and isokinetic leg extension muscle actions. Thirteen recreationally active men (age = 21.7 ± 2.6 years; body mass = 79.8 ± 11.5 kg; height = 174.2 ± 12.7 cm) performed maximal, bilateral leg extensions at 180°·s−1 until the torque values dropped to 50% of peak torque for two consecutive repetitions. The EMG and MMG signals from the vastus lateralis (VL) muscles of both limbs were recorded. Four 2(Leg) × 19(time) repeated measures ANOVAs were conducted to examine mean differences for EMG AMP, EMG MPF, MMG AMP, and MMG MPF between limbs, and polynomial regression analyses were performed to identify the patterns of neuromuscular responses. The results indicated no significant differences between limbs for EMG AMP (p = 0.44), EMG MPF (p = 0.33), MMG AMP (p = 0.89), or MMG MPF (p = 0.52). Polynomial regression analyses demonstrated substantial inter-individual variability. Inferences made regarding the patterns of neuromuscular responses to fatiguing and bilateral muscle actions should be considered on a subject-by-subject basis.

Download Full-text

Metabolic parameters for ramp versus step incremental cycle ergometer tests

Applied Physiology Nutrition and Metabolism ◽

10.1139/h2012-098 ◽

2012 ◽

Vol 37 (6) ◽

pp. 1110-1117 ◽

Cited By ~ 7

Author(s):

Jorge M. Zuniga ◽

Terry J. Housh ◽

Clayton L. Camic ◽

Haley C Bergstrom ◽

Daniel A. Traylor ◽

...

Keyword(s):

Repeated Measures ◽

Perceived Exertion ◽

Polynomial Regression ◽

Cycle Ergometer ◽

Rating Of Perceived Exertion ◽

Total Work ◽

Regression Analyses ◽

Mean Values ◽

The Common ◽

Power Outputs

The purpose of this study was to examine mean differences and the patterns of responses for oxygen uptake ([Formula: see text]O2), heart rate (HR), and rating of perceived exertion (RPE) for ramp (15 W·min–1) versus step (30 W increments every 2 min) incremental cycle ergometer tests. Fourteen subjects (age and body mass of 23.2 ± 3.1 (mean ± SD ) years and 71.1 ± 10.1 kg, respectively) visited the laboratory on separate occasions. Two-way repeated measures ANOVAs with appropriate follow-up procedures, as well as paired t tests, were used to analyze the data. In addition, polynomial regression analyses were used to determine the patterns of responses for each dependent variable for the ramp and step tests. The ramp protocol resulted in lower mean [Formula: see text]O2 and HR values at the common power outputs than the step protocol with no differences in RPE. The increased amount of work performed during the step (total work = 75.83 kJ) versus ramp (total work = 65.60 kJ) tests at the common power outputs may have contributed to the greater [Formula: see text]O2 and HR values. The polynomial regression analyses showed that most subjects had the same patterns of responses for the ramp and step incremental tests for HR (86%) and RPE (93%) but different patterns for [Formula: see text]O2 (71%). The findings from the present study suggested that the protocol selection for an incremental cycle ergometer test can affect the mean values for [Formula: see text]O2 and HR, as well as the [Formula: see text]O2 – power output relationship.

Download Full-text

Dynamic filling parameters in patients with atrial fibrillation: differentiating rhythm induced from ventilation-induced variations in pulse pressure

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00712.2015 ◽

2016 ◽

Vol 310 (9) ◽

pp. H1194-H1200

Author(s):

Piet A. H. Wyffels ◽

Frederic Van Heuverswyn ◽

Stefan De Hert ◽

Patrick F. Wouters

Keyword(s):

Atrial Fibrillation ◽

Pulse Pressure ◽

Repeated Measures ◽

Polynomial Regression ◽

Mean Bias Error ◽

Bias Error ◽

Best Fitting ◽

Induced Changes ◽

Quadratic Models ◽

Fitting Model

In patients with sinus rhythm, the magnitude of mechanical ventilation (MV)-induced changes in pulse pressure (PP) is known to predict the effect of fluid loading on cardiac output. This approach, however, is not applicable in patients with atrial fibrillation (AF). We propose a method to isolate this effect of MV from the rhythm-induced chaotic changes in PP in patients with AF. In 10 patients undergoing pulmonary vein ablation for treatment of AF under general anesthesia, ECG and PP waveforms were analyzed during apnea (T1) and during MV at tidal volumes of 8 ml/kg (T2) and 12 ml/kg (T3), respectively. In a first step, three mathematical models were compared in their ability to predict individual PP at T1. The best-fitting model was then selected as the reference to quantify the effects of MV on PP in these patients. A local polynomial regression model based on two preceding RR intervals (LOC2) was found to be superior over the quadratic models to predict PP. LOC2 was therefore selected to quantify variations in PP induced by MV. During T2 and T3, magnitude of PP deviations was related with the amplitude of tidal volume [mean bias error (SD) of −5 (6) and −8 (7) mmHg for T2 and T3, respectively; P = 0.003 repeated-measures ANOVA]. We conclude that LOC2 most accurately predicted rhythm-induced variations in PP. MV-induced deviations in PP can be quantified and may therefore provide a method to study cardiopulmonary interactions in the presence of arrhythmia.

Download Full-text

Velocity-Dependent Changes in Electrical Efficiency of the Leg Extensors during Eccentric Isokinetic Muscle Actions

International Journal of Sports Medicine ◽

10.1055/s-0043-124368 ◽

2018 ◽

Vol 39 (04) ◽

pp. 264-269

Author(s):

Ethan Hill ◽

Terry Housh ◽

Clayton Camic ◽

Cory Smith ◽

Richard Schmidt ◽

...

Keyword(s):

Range Of Motion ◽

Repeated Measures ◽

Polynomial Regression ◽

Regression Analyses ◽

Electrical Efficiency ◽

Slow Velocity ◽

Isokinetic Muscle Actions ◽

Leg Extensors ◽

Muscle Actions

AbstractThe mechanisms underlying velocity-specific decreases in torque production during eccentric muscle actions remain unclear. Therefore, the purpose of the present study was to examine electrical efficiency at 60 and 180°·s −1 during fatiguing, maximal eccentric isokinetic muscle actions of the leg extensors. Thirteen men visited the lab on two occasions and randomly performed 30 repeated maximal eccentric isokinetic muscle actions of the leg extensors at 60 and 180°·s − ¹ through a 90° range of motion. Polynomial regression analyses and separate repeated measures ANOVAs were used to examine the composite patterns of responses for electromyographic amplitude, eccentric torque, and electrical efficiency across the 60 and 180°·s − ¹ protocols. Eccentric torque remained unchanged across the 30 maximal eccentric muscle actions performed at 60 and 180°·s −1. Electromyographic amplitude and electrical efficiency, however, increased linearly across the 180°·s −1 protocol, but there were no changes for either electromyographic amplitude or electrical efficiency during the 60°·s −1 fatiguing protocol. These findings indicated that performing eccentric muscle actions at a fast velocity (i. e., 180°·s −1) was characterized by greater efficiency (i. e., decreased electrical efficiency) compared to eccentric muscle actions performed at a slow velocity (i. e., 60°·s −1). Thus, it is possible that eccentric muscle actions performed at fast velocities are more robust to fatigue due, in part, to greater efficiency compared to slow-velocity eccentric muscle actions.

Download Full-text

Heart Rate Dynamics During Acute Recovery From Maximal Aerobic Exercise in Young Adults

Frontiers in Physiology ◽

10.3389/fphys.2021.627320 ◽

2021 ◽

Vol 12 ◽

Author(s):

Nathaniel T. Berry ◽

Emily Bechke ◽

Lenka H. Shriver ◽

Susan D. Calkins ◽

Susan P. Keane ◽

...

Keyword(s):

Heart Rate ◽

Young Adults ◽

Root Mean Square ◽

Repeated Measures ◽

Polynomial Regression ◽

Complexity Analysis ◽

Statistical Significance ◽

Analysis Of Covariance ◽

Mean Square ◽

Rr Intervals

IntroductionResting heart rate (HRrest), heart rate variability (HRV), and HR recovery (HRR) from exercise provide valuable information about cardiac autonomic control. RR-intervals during acute recovery from exercise (RRrec) are commonly excluded from HRV analyses due to issues of non-stationarity. However, the variability and complexity within these trends may provide valuable information about changes in HR dynamics.PurposeAssess the complexity of RRrec and determine what physiologic and demographic information are associated with differences in these indices in young adults.MethodsRR-intervals were collected throughout maximal treadmill exercise and recovery in young adults (n = 92). The first 5 min of RRrec were (1) analyzed with previously reported methods that use 3-interval lengths for comparison and (2) detrended using both differencing(diff) and polynomial regression(res). The standard deviation of the normal interval (SDNN), root mean square of successive differences (rMSSD), root mean square (RMS) of the residual of regression, and sample entropy (SampEn) were calculated. Repeated measures analysis of covariance (ANCOVA) tested for differences in these indices for each of the methodological approaches, controlling for race, body fat, peak oxygen uptake (VO2peak), and resting HR (HRrest). Statistical significance was set at p < 0.05.ResultsVO2peak and HRrest were significantly correlated with traditional measures of HRR and the variability surrounding RRrec. SampEndiff and SampEnres were correlated with VO2peak but not HRrest or HRR. The residual-method provided a significantly (p = 0.04) lower mean standard error (MSE) (0.064 ± 0.042) compared to the differencing-method (0.100 ± 0.033).ConclusionsComplexity analysis of RRrec provides unique information about cardiac autonomic regulation immediately following the cessation of exercise when compared to traditional measures of HRR and both HRrest and VO2peak influence these results.

Download Full-text

The Effect of Kalman-Weighted Averaging and Artifact Rejection on Residual Noise During Auditory Brainstem Response Testing

American Journal of Audiology ◽

10.1044/2018_aja-18-0123 ◽

2019 ◽

Vol 28 (1) ◽

pp. 114-124

Author(s):

Linda W. Norrix ◽

Julie Thein ◽

David Velenovsky

Keyword(s):

Repeated Measures ◽

Auditory Brainstem ◽

Weighted Averaging ◽

Auditory Brainstem Responses ◽

Residual Noise ◽

Electrophysiological Recordings ◽

Artifact Rejection ◽

Brainstem Response ◽

Active Motor ◽

Averaging Time

Purpose Low residual noise (RN) levels are critically important when obtaining electrophysiological recordings of threshold auditory brainstem responses. In this study, we examine the effectiveness and efficiency of Kalman-weighted averaging (KWA) implemented on the Vivosonic Integrity System and artifact rejection (AR) implemented on the Intelligent Hearing Systems SmartEP system for obtaining low RN levels. Method Sixteen adults participated. Electrophysiological measures were obtained using simultaneous recordings by the Vivosonic and Intelligent Hearing Systems for subjects in 2 relaxed conditions and 4 active motor conditions. Three averaging times were used for the relaxed states (1, 1.5, and 3 min) and for the active states (1.5, 3, and 6 min). Repeated-measures analyses of variance were used to examine RN levels as a function of noise reduction strategy (i.e., KWA, AR) and averaging time. Results Lower RN levels were obtained using KWA than AR in both the relaxed and active motor states. Thus, KWA was more effective than was AR under the conditions examined in this study. Using KWA, approximately 3 min of averaging was needed in the relaxed condition to obtain an average RN level of 0.025 μV. In contrast, in the active motor conditions, approximately 6 min of averaging was required using KWA. Mean RN levels of 0.025 μV were not attained using AR. Conclusions When patients are not physiologically quiet, low RN levels are more likely to be obtained and more efficiently obtained using KWA than AR. However, even when using KWA, in active motor states, 6 min of averaging or more may be required to obtain threshold responses. Averaging time needed and whether a low RN level can be attained will depend on the level of motor activity exhibited by the patient.

Download Full-text

Vestibular Function and Motion Sickness Susceptibility: Videonystagmographic Evidence From Oculomotor and Caloric Tests

American Journal of Audiology ◽

10.1044/2020_aja-19-00050 ◽

2020 ◽

Vol 29 (2) ◽

pp. 188-198

Author(s):

Cynthia G. Fowler ◽

Margaret Dallapiazza ◽

Kathleen Talbot Hadsell

Keyword(s):

Phase Velocity ◽

Motion Sickness ◽

Repeated Measures ◽

Short Form ◽

Vestibular Function ◽

Slow Phase ◽

Test Results ◽

Normal Range ◽

Slow Phase Velocity ◽

Caloric Tests

Purpose Motion sickness (MS) is a common condition that affects millions of individuals. Although the condition is common and can be debilitating, little research has focused on the vestibular function associated with susceptibility to MS. One causal theory of MS is an asymmetry of vestibular function within or between ears. The purposes of this study, therefore, were (a) to determine if the vestibular system (oculomotor and caloric tests) in videonystagmography (VNG) is associated with susceptibility to MS and (b) to determine if these tests support the theory of an asymmetry between ears associated with MS susceptibility. Method VNG was used to measure oculomotor and caloric responses. Fifty young adults were recruited; 50 completed the oculomotor tests, and 31 completed the four caloric irrigations. MS susceptibility was evaluated with the Motion Sickness Susceptibility Questionnaire–Short Form; in this study, percent susceptibility ranged from 0% to 100% in the participants. Participants were divided into three susceptibility groups (Low, Mid, and High). Repeated-measures analyses of variance and pairwise comparisons determined significance among the groups on the VNG test results. Results Oculomotor test results revealed no significant differences among the MS susceptibility groups. Caloric stimuli elicited responses that were correlated positively with susceptibility to MS. Slow-phase velocity was slowest in the Low MS group compared to the Mid and High groups. There was no significant asymmetry between ears in any of the groups. Conclusions MS susceptibility was significantly and positively correlated with caloric slow-phase velocity. Although asymmetries between ears are purported to be associated with MS, asymmetries were not evident. Susceptibility to MS may contribute to interindividual variability of caloric responses within the normal range.

Download Full-text

Effects of Aging on the Subcortical Encoding of Stop Consonants

American Journal of Audiology ◽

10.1044/2020_aja-19-00044 ◽

2020 ◽

Vol 29 (3) ◽

pp. 391-403

Author(s):

Dania Rishiq ◽

Ashley Harkrider ◽

Cary Springer ◽

Mark Hedrick

Keyword(s):

Older Adults ◽

Repeated Measures ◽

Mixed Model ◽

Auditory Brainstem ◽

Auditory Brainstem Responses ◽

Aging Effects ◽

Formant Frequency ◽

Place Of Articulation ◽

Second Formant ◽

Effects Of Aging

Purpose The main purpose of this study was to evaluate aging effects on the predominantly subcortical (brainstem) encoding of the second-formant frequency transition, an essential acoustic cue for perceiving place of articulation. Method Synthetic consonant–vowel syllables varying in second-formant onset frequency (i.e., /ba/, /da/, and /ga/ stimuli) were used to elicit speech-evoked auditory brainstem responses (speech-ABRs) in 16 young adults ( M age = 21 years) and 11 older adults ( M age = 59 years). Repeated-measures mixed-model analyses of variance were performed on the latencies and amplitudes of the speech-ABR peaks. Fixed factors were phoneme (repeated measures on three levels: /b/ vs. /d/ vs. /g/) and age (two levels: young vs. older). Results Speech-ABR differences were observed between the two groups (young vs. older adults). Specifically, older listeners showed generalized amplitude reductions for onset and major peaks. Significant Phoneme × Group interactions were not observed. Conclusions Results showed aging effects in speech-ABR amplitudes that may reflect diminished subcortical encoding of consonants in older listeners. These aging effects were not phoneme dependent as observed using the statistical methods of this study.

Download Full-text

Evaluation of Acoustic Analyses of Voice in Nonoptimized Conditions

Journal of Speech Language and Hearing Research ◽

10.1044/2020_jslhr-20-00212 ◽

2020 ◽

Vol 63 (12) ◽

pp. 3991-3999

Author(s):

Benjamin van der Woerd ◽

Min Wu ◽

Vijay Parsa ◽

Philip C. Doyle ◽

Kevin Fung

Keyword(s):

Repeated Measures ◽

Voice Quality ◽

Data Sets ◽

Acoustic Measurements ◽

Sample Collection ◽

Experimental Conditions ◽

Environment Analysis ◽

Acoustic Measures ◽

Recording Conditions ◽

Cepstral Peak Prominence

Objectives This study aimed to evaluate the fidelity and accuracy of a smartphone microphone and recording environment on acoustic measurements of voice. Method A prospective cohort proof-of-concept study. Two sets of prerecorded samples (a) sustained vowels (/a/) and (b) Rainbow Passage sentence were played for recording via the internal iPhone microphone and the Blue Yeti USB microphone in two recording environments: a sound-treated booth and quiet office setting. Recordings were presented using a calibrated mannequin speaker with a fixed signal intensity (69 dBA), at a fixed distance (15 in.). Each set of recordings (iPhone—audio booth, Blue Yeti—audio booth, iPhone—office, and Blue Yeti—office), was time-windowed to ensure the same signal was evaluated for each condition. Acoustic measures of voice including fundamental frequency ( f o ), jitter, shimmer, harmonic-to-noise ratio (HNR), and cepstral peak prominence (CPP), were generated using a widely used analysis program (Praat Version 6.0.50). The data gathered were compared using a repeated measures analysis of variance. Two separate data sets were used. The set of vowel samples included both pathologic ( n = 10) and normal ( n = 10), male ( n = 5) and female ( n = 15) speakers. The set of sentence stimuli ranged in perceived voice quality from normal to severely disordered with an equal number of male ( n = 12) and female ( n = 12) speakers evaluated. Results The vowel analyses indicated that the jitter, shimmer, HNR, and CPP were significantly different based on microphone choice and shimmer, HNR, and CPP were significantly different based on the recording environment. Analysis of sentences revealed a statistically significant impact of recording environment and microphone type on HNR and CPP. While statistically significant, the differences across the experimental conditions for a subset of the acoustic measures (viz., jitter and CPP) have shown differences that fell within their respective normative ranges. Conclusions Both microphone and recording setting resulted in significant differences across several acoustic measurements. However, a subset of the acoustic measures that were statistically significant across the recording conditions showed small overall differences that are unlikely to have clinical significance in interpretation. For these acoustic measures, the present data suggest that, although a sound-treated setting is ideal for voice sample collection, a smartphone microphone can capture acceptable recordings for acoustic signal analysis.

Download Full-text