Linear Mixed-effects Model Analysis Research Articles

Toddlers' prior social experience with speakers influences their word learning.

Toddlers prefer to learn from familiar adults, particularly their caregivers, and perform better on word learning tasks when taught by caregivers than by strangers. However, it remains unclear why toddlers learn better from caregivers than from strangers. One possibility is that toddlers are more receptive to learning from individuals whom they have found to be engaging in previous interactions. The current study tested whether toddlers learn more from an unfamiliar adult who was previously engaging than from an unfamiliar adult who was previously unengaging. Toddlers (27-29months, N=40) were taught labels for novel objects by two different experimenters. Prior to word learning, toddlers watched pre-recorded videos of one experimenter utilizing engaging behaviors (i.e., using infant-directed speech, gestures, eye contact, and positive affect) and one experimenter utilizing unengaging behaviors (i.e., using adult-directed speech, no gestures, no eye contact, and neutral affect). Both experimenters were equally engaging during labeling. Word learning was then tested using a looking-while-listening paradigm. The results of linear mixed-effects model, cluster-based permutation, and growth curve analyses suggest heightened performance for words that were taught by the experimenter who was previously engaging. These results begin to reveal the kinds of social experiences that promote success in early word learning.

Comparative performance of contact plate metod and swab method for surface microbial contamination on medical fabrics

BackgroundThe contact plate method is widely accepted and used in various fields where hygiene and contamination levels are crucial. Evidence regarding the applicability of the contact plate method for sampling fabric microbial contamination levels in real medical environments was limited. This study aimed to assess the applicability of the contact plate method for detecting microbial contamination on medical fabrics in a real healthcare environment, thereby providing a benchmark for fabric microbial sampling methods.MethodsIn a level three obstetrics ward of a hospital, twenty-four privacy curtains adjacent to patient beds were selected for this study. The contact plate and swab method were used to collect microbial samples from the privacy curtains on the 1st, 7th, 14th, and 28th days after they were hung. The total colony count on each privacy curtain surface was calculated, and microbial identification was performed.ResultsAfter excluding the effects of time, room type, and curtain location on the detected microbial load, the linear mixed-effects model analysis showed that contact plate method yielded lower colony counts compared to swab method (P < 0.001). However, the contact plate method isolated more microbial species than swab method (P < 0.001). 291 pathogenic strains were isolated using the contact plate method and 133 pathogenic strains were isolated via the swab method. There was no difference between the two sampling methods in the detection of gram-negative bacteria (P = 0.089). Furthermore, the microbial load on curtains in double-occupancy rooms was lower than those in triple-occupancy rooms (P = 0.021), and the microbial load on curtains near windows was lower than that near doors (P = 0.004).ConclusionContact plate method is superior to swab method in strain isolation. Swab method is more suitable for evaluating the bacterial contamination of fabrics.

Effect of adding Schroth physiotherapeutic scoliosis specific exercises to standard care in adolescents with idiopathic scoliosis on posture assessed using surface topography: A secondary analysis of a Randomized Controlled Trial (RCT).

Adolescent idiopathic scoliosis (AIS) is a three-dimensional structural asymmetry of the spine and trunk affecting 2-4% of adolescents. Standard treatment is observation, bracing, and surgery for small, moderate, and large curves, respectively. Schroth exercises aim to correct posture and reduce curve progression. This study aimed to determine the effect of Schroth exercises added to the standard care compared to standard care alone on torso asymmetry in AIS. In a randomized controlled trial (NCT01610908), 124 participants with AIS (age: 10-18, Cobb: 10°-45°, Risser: ≤3) were randomly assigned to the control (Standard care only) or Schroth (Standard care + Schroth treatment) group. Schroth treatment consisted of 1-hour weekly supervised sessions and 30-45 minutes of daily home exercises for six months. The control group received Schroth exercises in the last six months of the 1-year monitoring period. Markerless 3D surface topography assessed torso asymmetry measured by maximum deviation (MaxDev) and root mean square (RMS). Intention to treat linear mixed effects model analysis was compared to the per protocol analysis. In the intention to treat analysis, the Schroth group (n = 63) had significantly larger decreased RMS (-1.2 mm, 95%CI [-1.5,-0.9]mm, p = 0.012) and MaxDev (-1.9mm, 95%CI [-2.4,-1.5]mm, p = 0.025) measurements compared to controls (n = 57) after six months of intervention. In the per protocol analysis (Schroth n = 39, control n = 36), the Schroth group also had a significantly larger decrease compared to the control in both the RMS (-1.0mm, 95%CI [-1.9, -0.2]mm, p = 0.013) and MaxDev measurements (-2.0mm, 95%CI [-3.3,-0.5]mm, p = 0.037). For the control group, both the intention to treat and per protocol analysis showed no difference in RMS and MaxDev in the last six months of Schroth intervention (p>0.5). Schroth Exercise treatment added to standard care (observation or bracing) reduced asymmetry measurements in AIS. As expected, a greater effect was observed for participants who followed the prescribed exercise treatment per protocol.

Suboptimal self-reported sleep efficiency and duration are associated with faster accumulation of brain amyloid beta in cognitively unimpaired older adults.

This study investigated whether self-reported sleep quality is associated with brain amyloid beta (Aβ) accumulation. Linear mixed effect model analyses were conducted for 189 cognitively unimpaired (CU) older adults (mean±standard deviation 74.0±6.2; 53.2% female), with baseline self-reported sleep data, and positron emission tomography-determined brain Aβ measured over a minimum of three time points (range 33.3-72.7 months). Analyses included random slopes and intercepts, interaction for apolipoprotein E (APOE) ε4 allele status, and time, adjusting for sex and baseline age. Sleep duration<6hours, in APOE ε4 carriers, and sleep efficiency<65%, in the whole sample and APOE ε4 non-carriers, is associated with faster accumulation of brain Aβ. These findings suggest a role for self-reported suboptimal sleep efficiency and duration in the accumulation of Alzheimer's disease (AD) neuropathology in CU individuals. Additionally, poor sleep efficiency represents a potential route via which individuals at lower genetic risk may progress to preclinical AD. In cognitively unimpaired older adults self-report sleep is associated with brain amyloid beta (Aβ) accumulation.Across sleep characteristics, this relationship differs by apolipoprotein E (APOE) genotype.Sleep duration<6hours is associated with faster brain Aβ accumulation in APOE ε4 carriers.Sleep efficiency< 65% is associated with faster brain Aβ accumulation in APOE ε4 non-carriers.Personalized sleep interventions should be studied for potential to slow Aβ accumulation.

The impact of the acidic polysaccharides pool on CO2 concentrations and fluxes: A case study on urban waters of China

Urban rivers and lakes are major components of inland waters. A deeper understanding of how carbon dioxide (CO2) emissions are impacted in urban waters is important for quantifying the contributions of urban waters to the global carbon budget. Acidic polysaccharides (APS) are a major component of the carbon pool, though there is still much uncertainty associated with CO2 concentrations and fluxes. Here, we measured the dissolved APS (DAPS), particulate APS (PAPS), and CO2 concentrations and fluxes in a typical urban river (the Ganjiang River) and two lakes (Xiang Lake and Qingshan Lake) in China, and assessed the impact of different APS fractions on CO2 concentrations and fluxes. Our results show abundant DAPS and PAPS in urban waters, with PAPS being the main form in winter while DAPS the main component in other seasons. The Ganjiang River and the urban lakes were supersaturated with CO2 at concentrations of 35.67 ± 19.99 μmol·L−1 & 27.79 ± 17.52 μmol·L−1 and emissions of 64.52 ± 53.38 mmol·(m2 d)−1& 36.56 ± 56.97 mmol·(m2 d)−1 from river and lake waters, respectively. Linear mixed-effects model analysis further revealed that increased DAPS concentration led to significantly higher CO2 concentrations and fluxes, whereas PAPS exhibited a negative influence on CO2 concentrations and fluxes in the urban lakes. Our work provides deeper insight into CO2 evasion in inland freshwater ecosystems as well as carbon neutrality in urban waters.

Load and recovery monitoring in Swiss top-level youth soccer players: Exploring the associations of a new web application-based score with recognised load measures

Load and recovery monitoring in Swiss top-level youth soccer players: Exploring the associations of a new web application-based score with recognised load measures

Association between visuo-spatial working memory and gait motor imagery

Although motor imagery and working memory (WM) appear to be closely linked, no previous studies have demonstrated direct evidence for the relationship between motor imagery and WM abilities. This study investigated the association between WM and gait motor imagery and focused on the individual differences in young adults. This study included 33 participants (mean age: 22.2 ± 0.9 years). We used two methods to measure the ability of different WM domains: verbal and visuo-spatial WM. Gait motor imagery accuracy was assessed via the mental chronometry paradigm. We measured the times participants took to complete an actual and imagined walk along a 5 m walkway, with three different path widths. The linear mixed effects model analysis revealed that visuo-spatial WM ability was a significant predictor of the accuracy of gait motor imagery, but not of verbal WM ability. Specifically, individuals with lower visuo-spatial WM ability demonstrated more inaccuracies in the difficult path-width conditions. However, gait motor imagery was not as accurate as actual walking even in the easiest path width or in participants with high visuo-spatial WM ability. Further, visuo-spatial WM ability was significantly correlated with mental walking but not with actual walking. These results suggest that visuo-spatial WM is related to motor imagery rather than actual movement.

Assessment of Peripapillary Retinal Nerve Fiber Layer Optical Density Ratios in Healthy Eyes Using Optical Coherence Tomography with Different Analytical Radii

Purpose To explore the characteristics and determinants of peripapillary retinal nerve fiber layer (RNFL) optical density (OD) by optical coherence tomography (OCT) in healthy eyes with varied analytical radii. Methods Peripapillary OCT scans centered at the optic disc of 150 eyes from 150 healthy subjects (64 males and 86 females) were included. Under 5 analytical circles with different radii (1.45 mm, 1.7 mm, 1.95 mm, 2.2 mm and 2.45 mm), the circumpapillary circular cross-sectional images were exported for further analysis using Image J. Peripapillary RNFL and retinal pigment epithelium (RPE) OD in different quadrants and clock-hours were obtained. RNFL optical density ratio (ODR) was then calculated as RNFL OD divided by RPE OD. A linear mixed-effects model analysis was performed to assess the relationship between RNFL ODR and analytical radius, accounting for axial length, age, spherical equivalent, thickness and image score. Results The RNFL ODRs had a double-hump pattern with peaks in the superior and inferior quadrants and troughs in the temporal and nasal areas. In the linear mixed-effects model analysis, a trend of decreasing mean RNFL ODR with increasing analytical radius was found (0.9227 ± 0.0689, 0.9063 ± 0.0620, 0.8916 ± 0.0552, 0.8729 ± 0.0553 and 0.8575 ± 0.0564 respectively, p = 0.034). RNFL ODR values was negatively correlated with age (p < 0.001), positively correlated with corresponding RNFL thickness (p < 0.001). No significant correlation was found between RFNL ODR and image score, axial length and spherical equivalent. Conclusions RNFL ODR profile showed a comparable double-hump configuration with RNFL thickness. RNFL ODR values tended to decrease with larger analytical circles and older age, and increase with corresponding RNFL thickness. These factors should be considered when interpreting RNFL ODR in glaucoma assessment.

Suboptimal sleep efficiency and duration predict faster cognitive decline in cognitively unimpaired older adults

AbstractBackgroundResearch indicates a role for suboptimal sleep, in cognitive ageing. An increasing, though inconsistent body of evidence has associated aspects of suboptimal self‐reported sleep quality with poorer cognitive performance. The current study investigated whether self‐reported sleep quality parameters predict the slope of domain specific cognitive performance.MethodParticipants were drawn from the Australian Imaging, Biomarkers and Lifestyle study of ageing. Linear mixed effect model (LMM) analyses were conducted on 525 cognitively unimpaired, older adults (M = 74.1, SD = 5.5, 56.4% female), characterised by apolipoprotein E (APOE) ε4 status, with baseline self‐reported sleep characteristics. Comprehensive cognitive assessments were conducted over a minimum 3 timepoints (range 29.64 ‐ 98.16 months). All models included random slopes, random intercepts, interaction effects for time, and APOE ε4 carriage, with each model adjusted based on the model of best fit for each cognitive outcome variable of interest.ResultFollowing Bonferroni correction, sleep duration &lt;6 hours and sleep efficiency &lt;65% in the whole cohort, and in APOE ε4 non‐carriers, forecasted accelerated decline in attention and speed of processing. In the same groups, greater sleep efficiency (%) forecasted greater preservation within the attention and speed of processing domain. No associations were observed for other sleep variables or cognitive domains of interest.ConclusionThese findings suggest a role for self‐reported suboptimal sleep efficiency and duration in the early stages of cognitive decline, represented by declining attention and speed of processing performance, in cognitively unimpaired individuals. Additionally, short sleep duration and poor sleep efficiency may increase future risk of cognitive decline independent of APOE ε4 carriage. Our findings also suggest the potential utility of self‐report screening for sleep efficiency and duration as a marker for increased risk of declining attention and speed of processing performance. Individuals with suboptimal sleep may benefit from an intervention to improve sleep efficiency and duration to lessen future risk of cognitive decline.

Acute influence of resistance exercise on basketball shooting mechanics and accuracy.

The purpose of the present study was to examine the acute impact of resistance exercise on basketball shooting mechanics and accuracy. Ten resistance-trained recreationally active men with previous basketball playing experience (x̄ ± SD; height = 182.6 ± 9.7 cm; body mass = 79.2 ± 13.9 kg; age = 25.6 ± 5.5 years) performed control, upper-body, and lower-body training sessions in randomized order followed by 5 sets of stationary free-throw (4.57 m), two-point (5.18 m) and three-point (6.75 m) basketball shooting drills in 30 min time increments. Each testing session was separated 3-7 days apart. Kinematic variables during both the preparatory and release phases of the shooting motion were derived from a high-definition camera recording at 120 fps positioned 10 m away perpendicular to the participant's shooting plane of motion. Restricted maximum likelihood linear mixed-effects model analysis revealed that a combination of all fixed effects could account for <1% of the total variance in each dependent variable pertaining to basketball shooting mechanics. A 9.9-11.8% decrease in two-point and three-point shooting accuracy was observed immediately following an upper-body training session. However, the observed performance suppression disappeared 30 min post-exercise completion. Overall, the findings suggest that performing upper-body or lower-body resistance training prior to on-court practice sessions has no impact on free-throw, two-point, and three-point biomechanical parameters examined in the present study and a minor acute impact on mid-range and long-range shooting accuracy in male basketball players.

Association between Fundus Tessellation and Contrast Sensitivity in Myopic Eyes

Purpose To assess the association of fundus tessellation with contrast sensitivity, Quality of Vision questionnaire, and other factors at five years postcorneal refractive surgery. Methods This is a cross-sectional study. Both eyes of 98 subjects (196 eyes) who received femtosecond laser in situ keratomileusis (FS-LASIK) or small incision lenticular extraction (SMILE) five years prior were enrolled in this study. Fundus tessellation was imaged using wide-angle fundus photographs and graded into four categories with the assistance of the ETDRS grid. Photopic and mesopic contrast sensitivity were measured under the best correction. The Quality of Vision (QoV) questionnaire was used to assess visual symptoms. Results Fundus tessellation was classified as follows: 19 eyes were grade 0 (9.7%), 28 eyes were grade 1 (14.3%), 59 eyes were grade 2 (30.1%), and 90 eyes were grade 3 (45.9%). Higher degrees of fundus tessellation were associated with lower photopic contrast sensitivity, a significant difference was observed at spatial frequencies of 6cpd (p = 0.030, grade 1 >grade 3 p = 0.011). Higher degrees of fundus tessellation were also associated with lower mesopic contrast sensitivity, a significant difference was observed at spatial frequencies of 18cpd (p = 0.011, grade 0 >grade 3 p = 0.012). The preoperative degree of myopia was positively associated with fundus tessellation grade (p < 0.001). However, in linear mixed-effect model analysis, no significant influence of parameters (contrast sensitivity, preoperative myopia, and QoV scores) upon different tessellation grades was found (p > 0.05). Conclusions Patients with moderate and high myopia were more likely to have higher grades of fundus tessellation. Higher degree of fundus tessellation associates with lower contrast sensitivity. Patients with moderate and high myopia should be concerned with retinal-choroidal changes. Contrast sensitivity could be a clinical sign for progression of tessellation and used to screen for early retinal-choroidal changes to prevent pathologic myopia.

Sensorimotor Adaptation to Formant-Shifted Auditory Feedback Is Predicted by Language-Specific Factors in L1 and L2 Speech Production.

Auditory feedback plays an important role in the long-term updating and maintenance of speech motor control; thus, the current study explored the unresolved question of how sensorimotor adaptation is predicted by language-specific and domain-general factors in first-language (L1) and second-language (L2) production. Eighteen English-L1 speakers and 22 English-L2 speakers performed the same sensorimotor adaptation experiments and tasks, which measured language-specific and domain-general abilities. The experiment manipulated the language groups (English-L1 and English-L2) and experimental conditions (baseline, early adaptation, late adaptation, and end). Linear mixed-effects model analyses indicated that auditory acuity was significantly associated with sensorimotor adaptation in L1 and L2 speakers. Analysis of vocal responses showed that L1 speakers exhibited significant sensorimotor adaptation under the early adaptation, late adaptation, and end conditions, whereas L2 speakers exhibited significant sensorimotor adaptation only under the late adaptation condition. Furthermore, the domain-general factors of working memory and executive control were not associated with adaptation/aftereffects in either L1 or L2 production, except for the role of working memory in aftereffects in L2 production. Overall, the study empirically supported the hypothesis that sensorimotor adaptation is predicted by language-specific factors such as auditory acuity and language experience, whereas general cognitive abilities do not play a major role in this process.

The Effects of Cognitive Control on the Subcomponents of Language Control in Spoken and Written Productions.

The present study aimed to investigate whether and how the subcomponents of language control during spoken and written productions were modulated by cognitive control. In the current study, unbalanced Chinese-English bilinguals were recruited from a convenience sample at a university to complete the cued language naming task in spoken production and written production, which measured the local language control (as indexed by language switch costs) and the global language control (as indexed by language mixing costs and reversed language dominance effect). In addition, all the participants performed the Simon task, which measured their general inhibitory control ability by calculating the Simon effect, and performed the AX-CPT task to measure their reactive/proactive control preference by calculating their BSI score. All the data were collected using E-prime 2.0 and analyzed in R. Linear mixed-effect model analyses were conducted to reveal the similarities and differences between spoken production and written production for the first-step analysis. Then, the Simon effect and BSI scores were inserted into the mixed-effect models of the switch costs and mixing costs in spoken production and written production, respectively, to explore whether cognitive control can predict the subcomponents of bilingual control. The results showed similar symmetrical switch costs in spoken and written modalities. In contrast, there was a reversed language dominance effect (in the mixed language context) and asymmetrical mixing costs in spoken production but neither in written production. Furthermore, we found that the Simon effect significantly negatively predicted the L2 mixing costs in spoken production, whereas the BSI score significantly negatively predicted both the L1 and L2 mixing costs in written production. The findings indicated that, for unbalanced bilinguals, local language control is shared between two modalities, while global language control is modality-independent between spoken production and written production. More importantly, the findings also suggested that global language control in spoken production relies more on the individuals' general inhibitory control, while in written production, it relies more on their cognitive control strategy. Global language control in spoken and written productions separately engages specific aspects of cognitive control, which may account for different forms of processing in global language control between speaking and writing.

Participation in the Chronic Phase after Traumatic Brain Injury: Variations and Key Predictors.

Participation is of major importance for individuals with traumatic brain injury (TBI). This study evaluates participation over a period of one year among persons with TBI in the chronic phase and explores sociodemographic, psychological, and environmental predictors of levels and trajectories of participation. One hundred and twenty home-living survivors of TBI with persistent injury-related consequences at least two years post-injury who participated in a goal-oriented randomized trial were assessed at baseline and after four and twelve months. Linear mixed-effects model analysis was applied to evaluate height, trajectory slope, and predictors of the Participation Assessment with the Recombined Tools-Objective (PART-O) total score and the subscales Productivity, Social Relations, and Being Out and About. Being married, having a higher education, and having good global functioning predicted more frequent participation. Education, executive- and global functions predicted Productivity, while age and being married predicted Social Relations. Participating in the study during the COVID-19 pandemic had a negative impact on Productivity. Participation was relatively stable over 12 months, with a slight decline, but may be influenced by demographic factors and functional consequences. Rehabilitation services should particularly focus on people with TBI living alone with lower levels of global and executive function.

Investigating the role of chlorogenic acids and coffee type in coffee-induced teeth discoloration

Objective Coffee is one of the most popular beverages in the world, with millions of people consuming it every day. The effect of coffee on teeth discoloration has long been a concern for both coffee drinkers and dental professionals. To address this concern, this study aimed to investigate the role of chlorogenic acids (CGAs) and the type of coffee in coffee-induced teeth discoloration. Materials and Methods High-performance liquid chromatography with a photodiode array detector was used to determine the CGA contents of instant coffee produced by five manufacturers (Starbucks, Dunkin’ Donuts, Kanu, Ediya, Coffee Bean). A total of 180 bovine tooth specimens were immersed in the coffee samples for varying durations (3, 9, 24, 48, and 72 h), and the discoloration levels were measured using a spectrophotometer. A linear mixed-effects model analysis was used to determine the significance of L*, a*, and b* values in relation to the duration of coffee immersion and coffee type. Results Both immersion time and coffee type had significant effects on tooth discoloration (p < 0.001), with some types of coffee being more strongly associated with tooth discoloration than others. The amount of CGAs present in coffee was found to be positively correlated with the degree of discoloration (p = 0.030). Conclusions Prolonged exposure to coffee can exacerbate teeth staining, and different types of coffee can cause varying degrees of discoloration. Furthermore, coffee with higher levels of CGAs may lead to greater tooth discoloration.

Factors Governing Organic Amendments and NPK Fertilizers Effects on Sweet Maize in Old and Intensively Cultivated Experimental Farm

Applying organic amendment (OA) containing humic compounds (HC) and phytohormones is a promising solution to intensify sustainable food production under increasing global food needs, declining environmental carrying capacity and changing climate. However, most positive claims on OA efficacy often came from controlled, greenhouse experiments. The field trial was conducted on an intensively cultivated experimental farm station, Department of Soil Science and Land Resources, Faculty of Agriculture, IPB University. The OA testing was done on sweet maize (Zea mays L. saccharata) using a fractional factorial randomized block design by comparing five rates of the organic amendment (0, ½, 1, 1½, and 2 standards OA) with three rates of NPK fertilizer (0, 1, and ¾ standards NPK). The results revealed that a single OA application did not significantly boost the growth and biomass of sweet maize, especially when applied to an old and intensively cultivate and organically manured farm. OA had significant interaction with NPK at most of the yields and biomass parameters. Amending soils more than 12 L OA ha-1 could improve the sweet maize’s growth and development while saving 25% NPK fertilizers. Linear mixed effect model and multivariate analysis uncovered higher heterogeneity in trial plots controlled maize growth, biomass, and agronomic effectivity, regardless of the given treatments. This study highlighted three important marks for future research: (1) soil plowing, harrowing and mixing must be intensively done across plots, (2) adequate HC contents must be increased from the OA current rate, and (3) the greater role of phytohormone in stimulating maize growth and production at the OA current rate.

Enhancing patient-centred care in Taiwan's dental education system: Exploring the feasibility of doctor-patient communication education and training

Background/purposeImproved communication can optimize treatment outcomes and patient satisfaction. Findings emphasize the need for tailored communication strategies based on patient characteristics. Implementing communication courses can enhance patient-centered care and reduce conflicts. Therefore, this study examined the feasibility of integrating doctor-patient communication education in Taiwan's dental education system. Materials and methodsUsing interviews and questionnaires, we conducted descriptive statistics and generalized linear mixed-effects model analysis on the importance of doctor-patient communication from the dentist and patient perspectives. ResultsMore than 600 patient surveys and four interviewed dentists with 20+ years of experience stressed doctor-patient communication in dentistry. Patients' age and income were positively related to the emphasis on physician-patient communication but negatively associated with dental assistants' communication. Dentists valued communication education but differed in its execution and importance. ConclusionIt is recommended to initiate dentist-patient communication education during university studies and continue its practice to adapt to the changing societal dynamics. Individuals with higher socioeconomic status and older age show a greater appreciation for dentist-patient communication, potentially driven by self-promotion, thereby highlighting the diverse nature of doctor-patient relationships. Based on our findings, we suggest to implement the doctor-patient communication courses in Taiwan.

Pulse rate variability: An alternative to heart rate variability in adults with spinal cord injury.

Pulse rate variability (PRV) is often used as an alternative to heart rate variability (HRV) to measure psychophysiological function. However, its validity to do so is unclear, especially in adults with spinal cord injury (SCI). This study compared PRV and HRV in adults with higher-level SCI (SCI-H, n = 23), lower-level SCI (SCI-L, n = 22), and able-bodied participants (AB n = 44), in a seated position as a function of performance in a reactivity task (Oxford Sleep Resistance Test: OSLER). PRV and HRV was measured using reflective finger-based photoplethysmography (PPG) and electrocardiography, respectively, at baseline, immediately post-OSLER, and after five-minute recovery. Agreement between PRV and HRV was determined by Bland-Altman analysis and differences between PRV and HRV over time by linear mixed effects model (LMM) analysis. Concurrent validity was assessed through correlation analyses between PRV and HRV. Additional correlation analyses were performed with psychosocial factors. Results indicated insufficient to moderate agreement between PRV and HRV. LMM analyses indicated no differences over time for standard deviation of normal-to-normal intervals and low-frequency power but significant differences for root mean square of successive differences and high frequency power. Nevertheless, PRV and HRV were highly correlated (Median r = .878 (.675-.990)) during all assessment periods suggesting sufficient concurrent validity. Similar correlation patterns were also found for PRV and HRV with psychosocial outcomes. While differences existed, results suggest PRV derived from reflective finger-based PPG is a valid proxy of HRV in tracking psychophysiological function in adults with SCI and could therefore be used as a more accessible monitoring tool.

Clinical outcomes of amyloid and tau markers according to vascular markers

AbstractBackgroundAlzheimer’s disease (AD) is characterized by amyloid beta (Aβ) aggregation [A] and tau aggregation reflecting neurofibrillary tangles [T]. These AD markers lead to neurodegeneration [N] and cognitive impairments. Recently, the ATN research framework of was presented by National Institute on Aging and Alzheimer’s Association. Cerebral small vessel disease (CSVD, [V]), which is one of most important cause of cognitive impairments, has an additive or synergistic effect on cognitive impairments with AD markers. In the present study, we investigated the frequency of ATV abnormalities in participants with varying degree of AD and CSVD markers. We also determined whether CSVD might synergistically affect cognitive decline with AD markers.MethodWe consecutively recruited 195 subjects (105 AD‐related cognitive impairment subjects, 86 subcortical vascular cognitive impairment subjects) from Samsung Medical Center. [A] and [T] positivities were determined by cut‐off values of Aβ and tau uptakes on PET using iterative outlier methods. [V] was assessed by the presence of severe white matter hyperintensity. All subjects underwent neuropsychological tests including Mini‐Mental State Exam (MMSE) and clinical dementia rating‐sum of boxes (CDR‐SOB). A linear mixed effect model was used to compare cognitive changes over time.ResultThe number of subjects of A‐T‐, A+T‐, and A+T+ groups were 16 (15.1%), 29 (27.4%), and 56 (52.8%) in the V‐ group; and 46 (51.7%), 33 (37.1%), and 8 (9.0%) in the V+ group. The linear mixed effects model analysis showed that A+/T+ were associated with worse cognitive decline, and its impact is higher in the V+ group than in the V‐ group (Figure).ConclusionOur findings suggested that there were interactive effects of AD markers and CSVD on cognitive decline. These findings demonstrate the importance of vascular factor management in patients with cognitive impairment and suggest that the ATV framework is useful in predicting cognitive decline in clinical practice.

Is the use of the coefficient of variation a valid way to assess the swimming intra-cycle velocity fluctuation?

Swimming intra-cycle velocity fluctuation has often been assessed using the coefficient of variation, which requires a mathematical assumption of a positive linear relationship between the velocity mean and standard deviation. As this assumption has never been tested, the current study aimed to investigate the within-participant relationship between the mean and standard deviation of the intra-cycle velocity. Cross-sectional study. The intra-trial mean and standard deviation of one stroke cycle centre of mass velocity (vCMmean and vCMSD, respectively) were obtained from 80 front crawl trials (10 participants × eight swimming speeds) using whole-body three-dimensional motion analysis. The linear mixed-effect model and intra-class correlation analysis were used to test the linear relationship between vCMmean and vCMSD (n = 80) and the absolute agreement between vCMmean and vCMSD relative to those during the fastest trial (n = 70). Neither the linear regression model (95 % confidence interval range of the fixed effect of vCMmean: -0.003-0.031) nor the intra-class correlation coefficient (ICC = 0.07; p = 0.26) verified linear relationships between vCMmean and vCMSD, which violated the background assumption of coefficient of variation calculation. When investigating the intra-cycle velocity fluctuation, the coefficient of variation should not be used alone. Researchers and practitioners should always interpret/report the obtained results together with the mean and standard deviation to avoid misleading conclusions and feedback because the coefficient of variation obtained from one cycle velocity data is likely biased by mean velocity.