scholarly journals Does Day-to-Day Variability in Stool Consistency Link to the Fecal Microbiota Composition?

2021 ◽  
Vol 11 ◽  
Author(s):  
Lisa Vork ◽  
John Penders ◽  
Jonna Jalanka ◽  
Svetlana Bojic ◽  
Sander M. J. van Kuijk ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Fecal Microbiota ◽  
Mixed Effects ◽  
Time Effect ◽  
Mixed Effects Models ◽  
Stool Consistency ◽  
Microbial Composition ◽  
Linear Mixed Effects Models ◽  
Linear Mixed Effects ◽  
Over Time

IntroductionStool consistency has been associated with fecal microbial composition. Stool consistency often varies over time, in subjects with and without gastrointestinal disorders, raising the question whether variability in the microbial composition should be considered in microbiota studies. We evaluated within-subject day-to-day variability in stool consistency and the association with the fecal microbiota in irritable bowel syndrome (IBS) and healthy subjects, over seven days.MethodsTwelve IBS patients and 12 healthy subjects collected fecal samples during seven consecutive days. Stool consistency was determined by the patient-reported Bristol Stool Scale (BSS) and fecal dry weight percentage. 16S rRNA V4 gene sequencing was performed and microbial richness (alpha diversity; Chao1 index, observed number of species, effective Shannon index) and microbial community structure (beta diversity; Bray-Curtis distance, generalized UniFrac, and taxa abundance on family level) were determined.ResultsLinear mixed-effects models showed significant associations between stool consistency and microbial richness, but no time effect. This implies that between-subject but not within-subject variation in microbiota over time can partially be explained by variation in stool consistency. Redundancy analysis showed a significant association between stool consistency and microbial community structure, but additional linear mixed-effects models did not demonstrate a time effect on this.ConclusionThis study supports an association between stool consistency and fecal microbiota, but no effect of day-to-day fluctuations in stool consistency within seven days. This consolidates the importance of considering stool consistency in gut microbiota research, though confirms the validity of single fecal sampling to represent an individual’s microbiota at a given time point. NCT00775060.

scholarly journals Nusinersen Treatment in Adults with Spinal Muscular Atrophy

2021 ◽  
pp. 10.1212/CPJ.0000000000001033
Author(s):  
Tina Duong ◽  
Connie Wolford ◽  
Michael P. McDermott ◽  
Chelsea E. Macpherson ◽  
Amy Pasternak ◽  
...  
Keyword(s):  
Spinal Muscular Atrophy ◽  
Muscular Atrophy ◽  
Mixed Effects ◽  
Rate Of Change ◽  
Mixed Effects Models ◽  
Linear Mixed Effects Models ◽  
Progressive Decline ◽  
Linear Mixed Effects ◽  
Patient Reported ◽  
Over Time

Abstract:Purpose To determine change in motor function after treatment with nusinersen in adults with spinal muscular atrophy (SMA) during the first two years of commercial availability.Recent Findings All forty-two adult SMA patients (mean age: 34 years, range 17-66) receiving nusinersen at PNCR sites were assessed for a mean of 12.5 months (range 3-24 months). Data collected prospectively generated a mean annual rate of change over time determined using linear mixed effects models. Motor and ventilatory measures showed positive changes distinct from the progressive decline expected in untreated adults. All participants tolerated nusinersen with normal surveillance labs and no significant adverse events.Summary Trends of improvement in functional motor, patient-reported, and ventilatory measures, suggested nusinersen benefit in adults with SMA, including the chronic, weaker phenotype. Longer duration and larger studies are needed to more firmly establish nusinersen efficacy in adults with SMA.

scholarly journals Change in Dyslipidemia with Declining Glomerular Filtration Rate and Increasing Proteinuria in Children with CKD

2019 ◽  
Vol 14 (12) ◽  
pp. 1711-1718 ◽  
Author(s):  
Jeffrey M. Saland ◽  
Juan C. Kupferman ◽  
Christopher B. Pierce ◽  
Joseph T. Flynn ◽  
Mark M. Mitsnefes ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Filtration Rate ◽  
Hdl Cholesterol ◽  
Mixed Effects ◽  
Mixed Effects Models ◽  
Linear Mixed Effects Models ◽  
Linear Mixed Effects ◽  
Changes Over Time ◽  
Over Time

Background and objectivesDyslipidemia, a risk factor for cardiovascular disease, is common in CKD but its change over time and how that change is influenced by concurrent progression of CKD have not been previously described.Design, setting, participants, & measurementsIn the CKD in Children study we prospectively followed children with progressive CKD and utilized multivariable, linear mixed-effects models to quantify the longitudinal relationship between within-subject changes in lipid measures (HDL cholesterol, non-HDL cholesterol, triglycerides) and within-subject changes in GFR, proteinuria, and body mass index (BMI).ResultsA total of 508 children (76% nonglomerular CKD, 24% glomerular CKD) had 2–6 lipid measurements each, with a median follow-up time of 4 (interquartile range [IQR], 2.1–6.0) years. Among children with nonglomerular CKD, dyslipidemia was common at baseline (35%) and increased significantly as children aged; 43% of children with glomerular CKD had dyslipidemia at baseline and demonstrated persistent levels as they aged. Longitudinal increases in proteinuria were independently associated with significant concomitant increases in non-HDL cholesterol (nonglomerular: 4.9 [IQR, 3.4–6.4] mg/dl; glomerular: 8.5 [IQR, 6.0–11.1] mg/dl) and triglycerides (nonglomerular: 3% [IQR, 0.8%–6%]; glomerular: 5% [IQR, 0.6%–9%]). Decreases in GFR over follow-up were significantly associated with concomitant decreases of HDL cholesterol in children with nonglomerular CKD (−1.2 mg/dl; IQR, −2.1 to −0.4 mg/dl) and increases of non-HDL cholesterol in children with glomerular CKD (3.9 mg/dl; IQR, 1.4–6.5 mg/dl). The effects of increased BMI also affected multiple lipid changes over time. Collectively, glomerular CKD displayed stronger, deleterious associations between within-subject change in non-HDL cholesterol (9 mg/dl versus 1.2 mg/dl; P<0.001) and triglycerides (14% versus 3%; P=0.004), and within-subject change in BMI; similar but quantitatively smaller differences between the two types of CKD were noted for associations of within-subject change in lipids to within-subject change in GFR and proteinuria.ConclusionsDyslipidemia is a common and persistent complication in children with CKD and it worsens in proportion to declining GFR, worsening proteinuria, and increasing BMI.

Pitfalls of linear regression for estimating slopes over time and how to avoid them by using linear mixed-effects models

2018 ◽  
Vol 34 (4) ◽  
pp. 561-566 ◽  
Author(s):  
Cynthia J Janmaat ◽  
Merel van Diepen ◽  
Roula Tsonaka ◽  
Kitty J Jager ◽  
Carmine Zoccali ◽  
...  
Keyword(s):  
Linear Regression ◽  
Mixed Effects ◽  
Mixed Effects Models ◽  
Linear Mixed Effects Models ◽  
Linear Mixed Effects ◽  
Over Time

scholarly journals Musical Aesthetic Sensitivity_Postprint

2021 ◽  
Author(s):  
Ana Clemente ◽  
Marcus Thomas Pearce ◽  
Marcos Nadal
Keyword(s):  
Individual Differences ◽  
Mixed Effects ◽  
Mixed Effects Models ◽  
Aesthetic Appreciation ◽  
Linear Mixed Effects Models ◽  
Linear Mixed Effects ◽  
Personal Trait ◽  
Stimulus Features ◽  
Shed Light ◽  
Over Time

Empirical aesthetics has mainly focused on general and simple relations between stimulus features and aesthetic appreciation. Consequently, to explain why people differ so much in what they like and prefer continues to be a challenge for the field. One possible reason is that people differ in their aesthetic sensitivity, i.e., the extent to which they weigh certain stimulus features. Studies have shown that people vary substantially in their aesthetic sensitivities to visual balance, contour, symmetry, and complexity, and that this variation explains why people like different things. Our goal here was to extend this line of research to music and examine aesthetic sensitivity to musical balance, contour, symmetry, and complexity. Forty-eight non-musicians rated their liking for 96 4-second Western tonal musical motifs, arranged in four subsets varying in balance, contour, symmetry, or complexity. We used linear mixed-effects models to estimate individual differences in the extent to which each musical attribute determined their liking. The results showed that participants differed remarkably in the extent to which their liking was explained by musical balance, contour, symmetry, and complexity. Furthermore, a retest after two weeks showed that this measure of aesthetic sensitivity is reliable, and suggests that aesthetic sensitivity is a stable personal trait. Finally, cluster analyses revealed that participants divided into two groups with different aesthetic sensitivity profiles, which were also largely stable over time. These results shed light on aesthetic sensitivity to musical content and are discussed in relation to comparable existing research in empirical aesthetics.

The Use of Theory of Linear Mixed-Effects Models to Detect Fraudulent Erasures at an Aggregate Level

2021 ◽  
pp. 001316442199489
Author(s):  
Luyao Peng ◽  
Sandip Sinharay
Keyword(s):  
Type I Error ◽  
Real Data ◽  
Mixed Effects ◽  
Error Rates ◽  
Mixed Effects Models ◽  
Type I ◽  
Aggregate Level ◽  
Linear Mixed Effects Models ◽  
Linear Mixed Effects ◽  
Best Linear Unbiased

Wollack et al. (2015) suggested the erasure detection index (EDI) for detecting fraudulent erasures for individual examinees. Wollack and Eckerly (2017) and Sinharay (2018) extended the index of Wollack et al. (2015) to suggest three EDIs for detecting fraudulent erasures at the aggregate or group level. This article follows up on the research of Wollack and Eckerly (2017) and Sinharay (2018) and suggests a new aggregate-level EDI by incorporating the empirical best linear unbiased predictor from the literature of linear mixed-effects models (e.g., McCulloch et al., 2008). A simulation study shows that the new EDI has larger power than the indices of Wollack and Eckerly (2017) and Sinharay (2018). In addition, the new index has satisfactory Type I error rates. A real data example is also included.

scholarly journals Association of body condition with lameness in dairy cattle: a single-farm longitudinal study

2021 ◽  
pp. 1-4
Author(s):  
Michaela Kranepuhl ◽  
Detlef May ◽  
Edna Hillmann ◽  
Lorenz Gygax
Keyword(s):  
Body Condition ◽  
Body Condition Score ◽  
Mixed Effects ◽  
Mixed Effects Models ◽  
Linear Mixed Effects Models ◽  
Linear Mixed Effects ◽  
Confounding Variables ◽  
Condition Score ◽  
The Impact ◽  
The Relationship

Abstract This research communication describes the relationship between the occurrence of lameness and body condition score (BCS) in a sample of 288 cows from a single farm that were repeatedly scored in the course of 9 months while controlling for confounding variables. The relationship between BCS and lameness was evaluated using generalised linear mixed-effects models. It was found that the proportion of lame cows was higher with decreasing but also with increasing BCS, increased with lactation number and decreased with time since the last claw trimming. This is likely to reflect the importance of sufficient body condition in the prevention of lameness but also raises the question of the impact of overcondition on lameness and the influence of claw trimming events on the assessment of lameness. A stronger focus on BCS might allow improved management of lameness that is still one of the major problems in housed cows.

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