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Nevin Manimala Statistics

The effect of neck muscle fatigue on shoulder humeral rotation joint position sense

J Electromyogr Kinesiol. 2021 Apr 30;59:102554. doi: 10.1016/j.jelekin.2021.102554. Online ahead of print.

ABSTRACT

INTRODUCTION: Cervical extensor muscle (CEM) fatigue causes decrements in upper limb proprioceptive accuracy during constrained single-joint tasks. This study used a novel humeral rotation joint position sense (JPS) measurement device to compare JPS accuracy in participants who received acute CEM fatigue vs. non-fatigued controls.

METHODS: Participants had vision occluded and were passively guided into postures of internal humeral rotation from a baseline posture before and after a CEM fatigue or control protocol. Mixed model repeated measures ANOVAs were used to verify fatigue and compared absolute, constant, and variable JPS error between groups.

RESULTS: CEM fatigue was verified via pre-post reduction in CEM strength, and myoelectric indicators of fatigue. However, between-group comparisons of absolute, constant, and variable JPS error were not statistically significant, despite having large effect sizes.

DISCUSSION: Contrary to prevailing literature, unconstrained humeral rotation JPS did not appear to be affected by CEM fatigue in this study. However, between-group differences in JPS error were dwarfed by inter-trial variability, which likely arose due to the unconstrained nature of this task, conflating chances for a Type II error. Future research should perform a kinematic analysis of task constraints to highlight potential compensatory mechanisms obscuring significant findings in this otherwise robust effect.

PMID:34029973 | DOI:10.1016/j.jelekin.2021.102554

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Nevin Manimala Statistics

Testing the adaptive value of sporulation in budding yeast using experimental evolution

Evolution. 2021 May 24. doi: 10.1111/evo.14265. Online ahead of print.

ABSTRACT

Saccharomyces yeast grow through mitotic cell division, converting resources into biomass. When cells experience starvation, sporulation is initiated and meiosis produces haploid cells inside a protective ascus. The protected spore state does not acquire resources and is partially protected from desiccation, heat, and caustic chemicals. Because cells cannot both be protected and acquire resources simultaneously, committing to sporulation represents a trade-off between current and future reproduction. Recent work has suggested that passaging through insect guts selects for spore formation, as surviving insect ingestion represents a major way that yeasts are vectored to new food sources. We subjected replicate populations from five yeast strains to passaging through insects, and evolved control populations by pipette passaging. We assayed populations for their propensity to sporulate after resource depletion. We found that ancestral domesticated strains produced fewer spores, and all strains evolved increased spore production in response to passaging through flies, but domesticated strains responded less. Exposure to flies led to a more rapid shift to sporulation that was more extreme in wild-derived strains. Our results indicate that insect passaging selects for spore production and suggest that domestication led to genetic canalization of the response to cues in the environment and initiation of sporulation. This article is protected by copyright. All rights reserved.

PMID:34029382 | DOI:10.1111/evo.14265

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Nevin Manimala Statistics

Laser enucleation for prostates larger than 100 mL: Comparison of HoLEP and ThuLEP

Andrologia. 2021 May 24:e14125. doi: 10.1111/and.14125. Online ahead of print.

ABSTRACT

Recently, with the advancements in laser technology, Holmium laser enucleation of the prostate (HoLEP) and Thulium laser enucleation of the prostate (ThuLEP) have come to the fore in the surgical treatment of benign prostatic hyperplasia (BPH). We aimed to evaluate and compare the outcomes of HoLEP and ThuLEP in patients with >100 ml prostate volume. Patients who underwent HoLEP and ThuLEP between July 2017 and March 2020 were reviewed retrospectively. The patients were divided into two groups as HoLEP (Group 1, n = 121) and ThuLEP (Group 2, n = 104). Perioperative parameters, functional outcomes, continence status, intra and post-operative complications were compared between groups in the post-operative 1st and 6th month. No significant difference was found in terms of total laser energy (TLE), morcellation efficiency (ME), enucleated tissue weight (ETW), complication rates (CR) and continence status of patients between both groups (p > .05). In favour of ThuLEP group, there were statistically significant differences regarding total operation time (TOT), laser efficiency (LE), enucleation time (ET) and enucleation efficiency (EE) between groups (p ≤ .05). HoLEP and ThuLEP can be used safely and effectively in prostates larger than 100 ml.

PMID:34029399 | DOI:10.1111/and.14125

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Nevin Manimala Statistics

Collective states and their transitions in football

PLoS One. 2021 May 24;16(5):e0251970. doi: 10.1371/journal.pone.0251970. eCollection 2021.

ABSTRACT

Movement, positioning and coordination of player formations is a key aspect for the performance of teams within field-based sports. The increased availability of player tracking data has given rise to numerous studies that focus on the relationship between simple descriptive statistics surrounding team formation and performance. While these existing approaches have provided a high-level a view of team-based spatial formations, there is limited research on the nature of collective movement across players within teams and the establishment of stable collective states within game play. This study draws inspiration from the analysis of collective movement in nature, such as that observed within schools of fish and flocking birds, to explore the existence of collective states within the phases of play in soccer. Order parameters and metrics describing group motion and shape are derived from player movement tracks to uncover the nature of the team’s collective states and transitions. This represents a unique addition to the current body of work around the analysis of player movement in team sports. The results from this study demonstrate that sequences of ordered collective behaviours exist with relatively rapid transitions between highly aligned polar and un-ordered swarm behaviours (and vice-versa). Defensive phases of play have a higher proportion of ordered team movement than attacking phases, indicating that movements linked with attacking tactics, such as player dispersion to generate passing and shooting opportunities leads to lower overall collective order. Exploration within this study suggests that defensive tactics, such as reducing the depth or width to close passing opportunities, allows for higher team movement speeds and increased levels of collective order. This study provides a novel view of player movement by visualising the collective states present across the phases of play in football.

PMID:34029340 | DOI:10.1371/journal.pone.0251970

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Nevin Manimala Statistics

Spinal movement variability associated with low back pain: A scoping review

PLoS One. 2021 May 24;16(5):e0252141. doi: 10.1371/journal.pone.0252141. eCollection 2021.

ABSTRACT

OBJECTIVE: To identify suggestions for future research on spinal movement variability (SMV) in individuals with low back pain (LBP) by investigating (1) the methodologies and statistical tools used to assess SMV; (2) characteristics that influence the direction of change in SMV; (3) the methodological quality and potential biases in the published studies; and (4) strategies for optimizing SMV in LBP patients.

METHODS: We searched literature databases (CENTRAL, Medline, PubMed, Embase, and CINAHL) and comprehensively reviewed the relevant papers up to 5 May 2020. Eligibility criteria included studies investigating SMV in LBP subjects by measuring trunk angle using motion capture devices during voluntary repeated trunk movements in any plane. The Newcastle-Ottawa risk of bias tool was used for data quality assessment. Results were reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews.

RESULTS: Eighteen studies were included: 14 cross-sectional and 4 prospective studies. Seven linear and non-linear statistical tools were used. Common movement tasks included trunk forward bending and backward return, and object lifting. Study results on SMV changes associated with LBP were inconsistent. Two of the three interventional studies reported changes in SMV, one of which was a randomized controlled trial (RCT) involving neuromuscular exercise interventions. Many studies did not account for the potential risk of selection bias in the LBP population.

CONCLUSION: Designers of future studies should recognize that each of the two types of statistical tools assesses functionally different aspects of SMV. Future studies should also consider dividing participants into subgroups according to LBP characteristics, as three potential subgroups with different SMV characteristics were proposed in our study. Different task demands also produced different effects. We found preliminary evidence in a RCT that neuromuscular exercises could modify SMV, suggesting a rationale for well-designed RCTs involving neuromuscular exercise interventions in future studies.

PMID:34029347 | DOI:10.1371/journal.pone.0252141

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Nevin Manimala Statistics

Composition of cutaneous bacterial microbiome in seborrheic dermatitis patients: A cross-sectional study

PLoS One. 2021 May 24;16(5):e0251136. doi: 10.1371/journal.pone.0251136. eCollection 2021.

ABSTRACT

BACKGROUND: Seborrheic dermatitis (SD) is a chronic inflammatory skin disease with a multifactorial aetiology. Malassezia yeasts have been associated with the disease but the role of bacterial composition in SD has not been thoroughly investigated.

OBJECTIVES: To profile the bacterial microbiome of SD patients and compare this with the microbiome of individuals with no inflammatory skin disease (controls).

METHODS: This was a cross sectional study embedded in a population-based study. Skin swabs were taken from naso-labial fold from patients with seborrheic dermatitis (lesional skin: n = 22; non-lesional skin SD: n = 75) and controls (n = 465). Sample collection began in 2016 at the research facility and is still ongoing. Shannon and Chao1 α- diversity metrics were calculated per group. Associations between the microbiome composition of cases and controls was calculated using multivariate statistics (permANOVA) and univariate statistics.

RESULTS: We found an increased α-diversity between SD lesional cases versus controls (Shannon diversity: Kruskal-Wallis rank sum: Chi-squared: 19.06; global p-value = 7.7×10-5). Multivariate statistical analysis showed significant associations in microbiome composition when comparing lesional SD skin to controls (p-value = 0.03;R2 = 0.1%). Seven out of 13 amplicon sequence variants (ASVs) that were significantly different between controls and lesional cases were members of the genus Staphylococcus, most of which showed increased composition in lesional cases, and were closely related to S. capitis S. caprae and S. epidermidis.

CONCLUSION: Microbiome composition differs in patients with seborrheic dermatitis and individuals without diseases. Differences were mainly found in the genus Staphylococcus.

PMID:34029350 | DOI:10.1371/journal.pone.0251136

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Nevin Manimala Statistics

Geographical distribution of Burkholderia pseudomallei in soil in Myanmar

PLoS Negl Trop Dis. 2021 May 24;15(5):e0009372. doi: 10.1371/journal.pntd.0009372. eCollection 2021 May.

ABSTRACT

BACKGROUND: Burkholderia pseudomallei is a Gram-negative bacterium found in soil and water in many tropical countries. It causes melioidosis, a potentially fatal infection first described in 1911 in Myanmar. Melioidosis is a common cause of sepsis and death in South and South-east Asia, but it is rarely diagnosed in Myanmar. We conducted a nationwide soil study to identify areas where B. pseudomallei is present.

METHODOLOGY/PRINCIPAL FINDINGS: We collected soil samples from 387 locations in all 15 states and regions of Myanmar between September 2017 and June 2019. At each site, three samples were taken at each of three different depths (30, 60 and 90 cm) and were cultured for B. pseudomallei separately, along with a pooled sample from each site (i.e. 10 cultures per site). We used a negative binomial regression model to assess associations between isolation of B. pseudomallei and environmental factors (season, soil depth, soil type, land use and climate zones). B. pseudomallei was isolated in 7 of 15 states and regions. Of the 387 sites, 31 (8%) had one or more positive samples and of the 3,870 samples cultured, 103 (2.7%) tested positive for B. pseudomallei. B. pseudomallei was isolated more frequently during the monsoon season [RR-2.28 (95% CI: 0.70-7.38)] and less in the hot dry season [RR-0.70 (95% CI: 0.19-2.56)] compared to the cool dry season, and in the tropical monsoon climate zone [RR-2.26; 95% CI (0.21-6.21)] compared to the tropical dry winter climate zone. However, these associations were not statistically significant. B. pseudomallei was detected at all three depths and from various soil types (clay, silt and sand). Isolation was higher in agricultural land (2.2%), pasture land (8.5%) and disused land (5.8%) than in residential land (0.4%), but these differences were also not significant.

CONCLUSION/SIGNIFICANCE: This study confirms a widespread distribution of B. pseudomallei in Myanmar. Clinical studies should follow to obtain a better picture of the burden of melioidosis in Myanmar.

PMID:34029325 | DOI:10.1371/journal.pntd.0009372

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Nevin Manimala Statistics

Cluster analysis of men undergoing surgery for BPH/LUTS reveals prominent roles of both bladder outlet obstruction and diminished bladder contractility

PLoS One. 2021 May 24;16(5):e0251721. doi: 10.1371/journal.pone.0251721. eCollection 2021.

ABSTRACT

Lower urinary tract symptoms (LUTS) in aging men are commonly attributed to bladder outlet obstruction from benign prostatic hyperplasia (BPH) but BPH/LUTS often reflects a confluence of many factors. We performed a hierarchical cluster analysis using four objective patient characteristics (age, HTN, DM, and BMI), and five pre-operative urodynamic variables (volume at first uninhibited detrusor contraction, number of uninhibited contractions, Bladder Outlet Obstruction Index (BOOI), Bladder Contractility Index (BCI) and Bladder Power at Qmax) to identify meaningful subgroups within a cohort of 94 men undergoing surgery for BPH/LUTS. Two meaningful subgroups (clusters) were identified. Significant differences between the two clusters included Prostate Volume (95 vs 53 cc; p-value = 0.001), BOOI (mean 70 vs 49; p-value = 0.001), BCI (mean 129 vs 83; p-value <0.001), Power (689 vs 236; p-value <0.001), Qmax (8.3 vs 4.9 cc/sec; p-value <0.001) and post-void residual (106 vs 250 cc; p-value = 0.001). One cluster is distinguished by larger prostate volume, greater outlet resistance and better bladder contractility. The other is distinguished by smaller prostate volume, lower outlet resistance and worse bladder contractility. Remarkably, the second cluster exhibited greater impairment of urine flow and bladder emptying. Surgery improved flow and emptying for patients in both clusters. These findings reveal important roles for both outlet obstruction and diminished detrusor function in development of diminished urine flow and impaired bladder emptying in patients with BPH/LUTS.

PMID:34029333 | DOI:10.1371/journal.pone.0251721

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Nevin Manimala Statistics

Sequence learning recodes cortical representations instead of strengthening initial ones

PLoS Comput Biol. 2021 May 24;17(5):e1008969. doi: 10.1371/journal.pcbi.1008969. Online ahead of print.

ABSTRACT

We contrast two computational models of sequence learning. The associative learner posits that learning proceeds by strengthening existing association weights. Alternatively, recoding posits that learning creates new and more efficient representations of the learned sequences. Importantly, both models propose that humans act as optimal learners but capture different statistics of the stimuli in their internal model. Furthermore, these models make dissociable predictions as to how learning changes the neural representation of sequences. We tested these predictions by using fMRI to extract neural activity patters from the dorsal visual processing stream during a sequence recall task. We observed that only the recoding account can explain the similarity of neural activity patterns, suggesting that participants recode the learned sequences using chunks. We show that associative learning can theoretically store only very limited number of overlapping sequences, such as common in ecological working memory tasks, and hence an efficient learner should recode initial sequence representations.

PMID:34029315 | DOI:10.1371/journal.pcbi.1008969

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Nevin Manimala Statistics

On the effect of phylogenetic correlations in coevolution-based contact prediction in proteins

PLoS Comput Biol. 2021 May 24;17(5):e1008957. doi: 10.1371/journal.pcbi.1008957. Online ahead of print.

ABSTRACT

Coevolution-based contact prediction, either directly by coevolutionary couplings resulting from global statistical sequence models or using structural supervision and deep learning, has found widespread application in protein-structure prediction from sequence. However, one of the basic assumptions in global statistical modeling is that sequences form an at least approximately independent sample of an unknown probability distribution, which is to be learned from data. In the case of protein families, this assumption is obviously violated by phylogenetic relations between protein sequences. It has turned out to be notoriously difficult to take phylogenetic correlations into account in coevolutionary model learning. Here, we propose a complementary approach: we develop strategies to randomize or resample sequence data, such that conservation patterns and phylogenetic relations are preserved, while intrinsic (i.e. structure- or function-based) coevolutionary couplings are removed. A comparison between the results of Direct Coupling Analysis applied to real and to resampled data shows that the largest coevolutionary couplings, i.e. those used for contact prediction, are only weakly influenced by phylogeny. However, the phylogeny-induced spurious couplings in the resampled data are compatible in size with the first false-positive contact predictions from real data. Dissecting functional from phylogeny-induced couplings might therefore extend accurate contact predictions to the range of intermediate-size couplings.

PMID:34029316 | DOI:10.1371/journal.pcbi.1008957