Category: Statistics

Clin Nutr. 2022 Jan 29;41(3):680-686. doi: 10.1016/j.clnu.2022.01.020. Online ahead of print.

ABSTRACT

BACKGROUND & AIMS: Osteoporosis is the most common bone disease and is characterized by low bone mineral density (BMD) and a high risk of fracture. Despite advances in our understanding of the pathogenesis of osteoporosis, complex gene-environment interactions that influence osteoporosis development remain largely unexplored. In this study, we aimed to identify genetic loci associated with low BMD and to evaluate these genetic variants under individual and environmental factors.

METHODS: A genome-wide association analysis was conducted using 500,568 single-nucleotide polymorphisms (SNPs) in 8842 individuals aged 40-69 years using clinical, demographic, and dietary data (>260 traits) established by the Korean Genome and Epidemiology Study. The gPLINK program was used to detect SNPs associated with osteoporosis at a genome-wide significance level (P < 1.0 × 10^-05) and conduct a haplotype analysis. Statistical differences between the osteoporosis and control groups in categorical variables (sex and dietary profiles) were assessed based on frequency distributions using the chi-squared test.

RESULTS: Of the seven SNPs that were associated with osteoporosis, both rs10977574 and rs4390000 lay in the PTPRD locus encoding a protein tyrosine phosphatase-receptor type D, which has been implicated in bone metabolism. Haplotype analysis identified two minor alleles, C and G, at the rs10977574 and rs4390000 loci, respectively, forming a linkage disequilibrium block. The subsequent gender-stratified analysis using dietary calcium intake revealed an increased correlation between the CG haplotype and osteoporosis (OR = 2.069) in the low-calcium-intake-female group but not in the high-calcium-intake-female or any male group.

CONCLUSIONS: This study revealed novel evidence of the sex-specific association of the CG haplotype in the PTPRD locus with osteoporosis and indicated that the association can be influenced by dietary calcium intake.

PMID:35151124 | DOI:10.1016/j.clnu.2022.01.020

Clin Biomech (Bristol, Avon). 2022 Feb 4;93:105593. doi: 10.1016/j.clinbiomech.2022.105593. Online ahead of print.

ABSTRACT

BACKGROUND: Maintaining an upright stance involves a complex interaction of sensory processing and motor outputs to adequately perform this fundamental motor skill. Aging and cannabis use independently disrupt balance performance, but our recent data did not find differences in static balance performance between older cannabis Users and older Non-Users using traditional linear measures (i.e., characteristics of the center of pressure sway). The purpose of this analysis was to determine whether an unbiased entropy measure (sample entropy) can differentiate postural control (standing posture) strategies between older cannabis Users and Non-Users when typical linear measures could not.

METHODS: Eight medical cannabis Users and eight age- and sex-matched controls completed static posturography testing in an eyes-open condition for 60 s. Linear measures included pathlength of the anterior-posterior and medio-lateral directions and an ellipse that encapsulates 95% of the 2D area explored. The nonlinear measure was the sample entropy of the center of pressure time-series in anterior-posterior and medio-lateral directions. Group comparisons were accomplished via pairwise testing and effect size calculations.

FINDINGS: The statistical testing revealed that sample entropy in the anterior-posterior direction was significantly larger in the Users (mean ± SD = 0.29 ± 0.08) compared to the Non-Users (0.19 ± 0.05; P = 0.01, d = 1.55).

INTERPRETATION: This finding indicates that the Users had a decreased regularity of their center of pressure signal in the anterior-posterior direction, which might reflect reduced balance adaptability and accompanies the increased fall risk observed in our recent report on these same subjects.

PMID:35151108 | DOI:10.1016/j.clinbiomech.2022.105593

Accid Anal Prev. 2022 Feb 9;168:106576. doi: 10.1016/j.aap.2022.106576. Online ahead of print.

ABSTRACT

Predicting pedestrian crashes on urban roads is one of the most important issues related to urban traffic safety. Due to the lack of spatial correlation and instability in the crash data, the statistical reliability of Empirical Bayesian method in the combination of the observed and predicted crash frequency is questionable. In this study, an EB model has been developed to estimate the expected frequency of pedestrian crashes in urban areas using the over-dispersion parameter taking into account the spatial correlation of crash data. The objective of this study is to estimate the expected geographical frequency of pedestrian crashes using the Empirical Bayesian (EB) approach using weighted geographical regression models for pedestrian crashes in Tehran. For doing so, four models of geographic weighted Poisson regression (GWPR), geographic weighted zero-inflated Poisson regression (GWZIPR), geographic weighted Negative Binomial regression (GWNBR) and the geographic weighted zero-inflated Negative Binomial regression (GWZINBR) have been used. In this study, the areas analyzed for the development of the EB model based on pedestrian exposure variables include traffic analysis zones (TAZs). Finally, the EB model was extended to the Geographic Empirical Bayesian (Ge-EB) model. The results showed that GWZIPR and GWZINBR models make more accurate predictions. These models had the lowest values of Akaike Information Criterion (AIC), the lowest values of Cross Validation and the lowest values of Root Mean Square Error (RMSE). The Moran and Variance Inflated Factor (VIF) indices were also within acceptable limits. The weighted negative binomial distribution could moderate the amount of heterogeneity of crash data to some extent. This study has shown the dispersion and density of pedestrian crashes without having the volume of pedestrians and thus can be done by taking safety measures in places prone to pedestrian crashes.

PMID:35151094 | DOI:10.1016/j.aap.2022.106576

Accid Anal Prev. 2022 Feb 9;168:106590. doi: 10.1016/j.aap.2022.106590. Online ahead of print.

ABSTRACT

Understanding the associations between crash characteristics facilitates the development of traffic safety policies for improving traffic safety. This study investigates the temporal stability of associations between crash characteristics at different temporal levels using multiple correspondence analysis (MCA). For each date in 2020, crash data from the previous week, month, season, half year, one year, two years, three years, and four years are collected respectively as eight temporal levels. MCA plots and chi-square distance analysis are used to assess the temporal stability of associations between crash characteristics across dates in 2020 with data from various temporal levels. The key findings of this study demonstrate that associations between crash characteristics at lower temporal levels show notable and potential cyclical variations across dates, while more stable and long-term trend of associations between crash characteristics may be identified as the temporal level increases, especially at the two-year level and higher temporal levels at which temporal stability may be expected. The study contributes to the literature by presenting a challenge for traffic analysts in that both temporally stable and unstable associations between crash characteristics may be observed at any point in time when different temporal levels are considered as study periods. Therefore, it may serve as a foundation for future research and practical works to identify traffic safety issues and optimal policies as well as facilitate the interpretation of statistical modeling in the presence of temporally unstable data.

PMID:35151096 | DOI:10.1016/j.aap.2022.106590

J Electromyogr Kinesiol. 2022 Feb 7;63:102641. doi: 10.1016/j.jelekin.2022.102641. Online ahead of print.

ABSTRACT

In motor control studies, the F-wave (a recurrent discharge evoked by an axonal antidromic volley) widely used for obtaining information on motoneuron pool behavior. However, such F-wave using is a matter of discussion and still has been not validated experimentally. The aim of the present study was investigation of F-wave properties of single firing motor units (MUs) in healthy humans, the properties, which could give evidence for F-wave origin in motoneuron soma and, therefore, could be used for estimation of a relation between MU firing and motoneuron firing behavior. In total, 91 MUs in five muscles of six healthy subjects, during gentle voluntary contractions, were studied. Peri-stimulus time histograms of single MUs were plotted. None of them revealed statistically significant increasing in MU firing probability at the F-wave latency. Analysis of relationships between characteristics of motoneuron firing behavior (mean firing frequency and target interspike interval duration) and properties of F-waves showed their independence. At the same time, it was found that F-waves were recorded in MUs, whose axons possessed the marked supernormal period in excitability recovery cycle after a discharge. Thus, the present results are in contrast to that which should be expected if the F-wave originated in the motoneuronal soma and could provide evidence for motoneuron firing behavior.

PMID:35151066 | DOI:10.1016/j.jelekin.2022.102641

Mar Pollut Bull. 2022 Feb 9;175:113390. doi: 10.1016/j.marpolbul.2022.113390. Online ahead of print.

ABSTRACT

Sustainable management of groundwater needs comprehensive study on water quality in present scenario. Hence, an understanding on the hydro geochemistry, saltwater intrusion, spatiotemporal-seasonal variations and irrigational suitability of groundwater becomes a must, especially in coastal regions. Our study area is one such place where all the parameters play a major role against sustainable management. The study pointed out that majority of the samples is brackish with two notable geochemical facies for pre monsoon and post monsoon. Factor and cluster analyses revealed that EC, TDS, Na⁺, Cl^–, Mg²⁺ and Ca²⁺ are the major contributors. Gibb’s diagram supported the dominance of rock weathering and evaporation in controlling the groundwater chemistry. Sea water intrusion was mapped using HFE diagrams and the Irrigational suitability is studied using USSL, SAR, %Na, etc. The data and results from this study might provide crucial information to water management authorities in dealing groundwater scarcity and pollution problems.

PMID:35151074 | DOI:10.1016/j.marpolbul.2022.113390

J Clin Neurosci. 2022 Feb 9;98:96-103. doi: 10.1016/j.jocn.2022.01.032. Online ahead of print.

ABSTRACT

INTRODUCTION: Growth of some pituitary tumors is driven by hormones which vary in concentration along the lines of patient socioeconomic status. Thus, pituitary tumors may exhibit disparities in incidence upon stratification by socioeconomic variables. Exploring for these disparities could provide direction in tumor etiology elucidation and identification of healthcare inequalities.

METHODS: To investigate pituitary adenoma and carcinoma incidence (per 100,000) with respect to sex, age, income, residence, and race/ethnicity, we searched the largest American administrative dataset (1997-2016), the National (Nationwide) Inpatient Sample (NIS), which surveys 20% of United States (US) discharges.

RESULTS: Annual national incidence was 2.80 for adenomas and 0.046 for carcinomas. For adenomas, males had an incidence of 2.63, similar (p = 0.17) to females at 2.78; likewise, for carcinomas, males had a statistically equivalent (p = 0.24) incidence at 0.051 to females at 0.041. Amongst age groups, for adenomas incidence progressively rose, peaking 65-84 years old (6.12), before declining. For adenomas and carcinomas respectively, patients with low income had an incidence of 2.66 and 0.044, similar (p = 0.11; p = 0.72) to the 3.01 and 0.041 of middle/high income patients. Incidence was greatest for adenomas amongst urban centers (3.47), followed by rural (3.16) and suburban (3.01) communities. Examining race/ethnicity (p = 0.0000016), for adenomas, incidences amongst Blacks, Asian/Pacific Islanders, Hispanics, and Whites were as follows, respectively: 3.64, 2.57, 2.54, 2.44. Annually, incidence for adenomas was increasing (τ = 0.63, p = 0.00021), but decreasing (τ = -0.60, p = 0.00085) for carcinomas. Specifically, for carcinomas incidence was only decreasing for females and the middle/high income.

CONCLUSION: In the US, time-enduring healthcare disparities were identified for pituitary adenomas and carcinomas, against the background of sociodemographic strata. For carcinomas, annual incidence was declining only for middle/high income patients and females, which supporting prior investigations that low income patients and males are experiencing barriers to definitive treatment for pituitary adenomas. Incidence was also found to be greatest Blacks and urban residents.

PMID:35151063 | DOI:10.1016/j.jocn.2022.01.032

Arch Oral Biol. 2022 Feb 3;135:105368. doi: 10.1016/j.archoralbio.2022.105368. Online ahead of print.

ABSTRACT

OBJECTIVE: It is unclear whether tea infusions with or without sucrose supplementation alter oral biofilm development, so we evaluated the effect of unsweetened and sucrose-sweetened black and green tea infusions on in vitro saliva-derived biofilms.

DESIGN: Biofilms were developed from human saliva for 20 h in cell-free 25% human saliva within static glass-bottom microplates. During biofilm development, biofilms were treated with either (i) unsweetened black tea, (ii) unsweetened green tea, (iii) 10% sucrose-sweetened black tea, (iv) 10% sucrose-sweetened green tea (v) deionized water (negative control), or (vi) 10% sucrose (positive control). Biofilms were incubated at 37 °C in 5% CO₂. After 20 h of development, biofilms were imaged using a CLSM, and biofilm architecture and viability were evaluated.

RESULTS: All the tea infusions reduced biofilm biomass and altered some other biofilm architectural outcomes (e.g., biofilm surface area) compared to the control groups. Statistically significant differences in biofilm biomass, number of objects, surface area, and convex-hull porosity were observed between biofilms treated with green and black tea. The addition of sugar to tea did not significantly modify the ability of tea to alter biofilm architecture. Only the treatment of biofilms with unsweetened black tea significantly reduced bacterial viability.

CONCLUSIONS: While both teas reduced biofilm biomass and altered biofilm architecture, black tea had an enhanced effect that may relate to this tea’s observed antimicrobial activity. The addition of sucrose to tea infusions did not appear to reduce the impact of either tea in modifying oral biofilm architecture.

PMID:35151028 | DOI:10.1016/j.archoralbio.2022.105368

Neuroimage Clin. 2022 Feb 7;33:102956. doi: 10.1016/j.nicl.2022.102956. Online ahead of print.

ABSTRACT

Rolandic epilepsy is the most common form of epileptic encephalopathy, characterized by sleep-potentiated inferior Rolandic epileptiform spikes, seizures, and cognitive deficits in school-age children that spontaneously resolve by adolescence. We recently identified a paucity of sleep spindles, physiological thalamocortical rhythms associated with sleep-dependent learning, in the Rolandic cortex during the active phase of this disease. Because spindles are generated in the thalamus and amplified through regional thalamocortical circuits, we hypothesized that: 1) deficits in spindle rate would involve but extend beyond the inferior Rolandic cortex in active epilepsy and 2) regional spindle deficits would better predict cognitive function than inferior Rolandic spindle deficits alone. To test these hypotheses, we obtained high-resolution MRI, high-density EEG recordings, and focused neuropsychological assessments in children with Rolandic epilepsy during active (n = 8, age 9-14.7 years, 3F) and resolved (seizure free for > 1 year, n = 10, age 10.3-16.7 years, 1F) stages of disease and age-matched controls (n = 8, age 8.9-14.5 years, 5F). Using a validated spindle detector applied to estimates of electrical source activity in 31 cortical regions, including the inferior Rolandic cortex, during stages 2 and 3 of non-rapid eye movement sleep, we compared spindle rates in each cortical region across groups. Among detected spindles, we compared spindle features (power, duration, coherence, bilateral synchrony) between groups. We then used regression models to examine the relationship between spindle rate and cognitive function (fine motor dexterity, phonological processing, attention, and intelligence, and a global measure of all functions). We found that spindle rate was reduced in the inferior Rolandic cortices in active but not resolved disease (active P = 0.007; resolved P = 0.2) compared to controls. Spindles in this region were less synchronous between hemispheres in the active group (P = 0.005; resolved P = 0.1) compared to controls; but there were no differences in spindle power, duration, or coherence between groups. Compared to controls, spindle rate in the active group was also reduced in the prefrontal, insular, superior temporal, and posterior parietal regions (i.e., “regional spindle rate”, P < 0.039 for all). Independent of group, regional spindle rate positively correlated with fine motor dexterity (P < 1e-3), attention (P = 0.02), intelligence (P = 0.04), and global cognitive performance (P < 1e-4). Compared to the inferior Rolandic spindle rate alone, models including regional spindle rate trended to improve prediction of global cognitive performance (P = 0.052), and markedly improved prediction of fine motor dexterity (P = 0.006). These results identify a spindle disruption in Rolandic epilepsy that extends beyond the epileptic cortex and a potential mechanistic explanation for the broad cognitive deficits that can be observed in this epileptic encephalopathy.

PMID:35151039 | DOI:10.1016/j.nicl.2022.102956

Neural Netw. 2022 Feb 1;148:194-205. doi: 10.1016/j.neunet.2022.01.016. Online ahead of print.

ABSTRACT

High quality end-to-end speech translation model relies on a large scale of speech-to-text training data, which is usually scarce or even unavailable for some low-resource language pairs. To overcome this, we propose a target-side data augmentation method for low-resource language speech translation. In particular, we first generate large-scale target-side paraphrases based on a paraphrase generation model which incorporates several statistical machine translation (SMT) features and the commonly used recurrent neural network (RNN) feature. Then, a filtering model which consists of semantic similarity and speech-word pair co-occurrence was proposed to select the highest scoring source speech-target paraphrase pairs from candidates. Experimental results on English, Arabic, German, Latvian, Estonian, Slovenian and Swedish paraphrase generation show that the proposed method achieves significant and consistent improvements over several strong baseline models on PPDB datasets (http://paraphrase.org/). To introduce the results of paraphrase generation into the low-resource speech translation, we propose two strategies: audio-text pairs recombination and multiple references training. Experimental results show that the speech translation models trained on new audio-text datasets which combines the paraphrase generation results lead to substantial improvements over baselines, especially on low-resource languages.

PMID:35151006 | DOI:10.1016/j.neunet.2022.01.016