Category: Statistics

Med Oral Patol Oral Cir Bucal. 2023 Aug 25:26167. doi: 10.4317/medoral.26167. Online ahead of print.

ABSTRACT

BACKGROUND: Although Le Fort I surgeries are safe and successful procedures; nasolacrimal duct injuries may be observed due to these surgeries. The study aimed to investigate the prevalence of nasolacrimal duct injury in Le Fort I osteotomy patients.

MATERIAL AND METHODS: The authors conducted a retrospective cohort study consisting of patients who underwent Le Fort I osteotomies between 2017 and 2021 in the Erciyes University Faculty of Dentistry. The primary predictor variables were the distance of the nasolacrimal canal to the outer cortex of the maxilla and the nasal floor, as well as the superior-inferior level of the superiorly positioned screw inserted in the maxilla aperture region relative to the nasolacrimal canal. The outcome variable was the presence of a nasolacrimal duct injury. Mann Whitney U test was used for quantitative variables between the two groups. A Pearson chi-squared analysis was used to compare categorical data. A p-value <0.05 was considered statistically significant.

RESULTS: A total of 290 nasolacrimal canals were evaluated in 145 patients, 87 females, and 58 males. The mean age was 23.47± 6.67. There was a statistically significant relationship between screw level and nasolacrimal canal perforation (p<0,001). The distance between the most anterior border of the nasolacrimal canal and the outer cortical of the maxilla was significantly less in the perforation group (p<0,001). The fixation screw was significantly closer to the nasolacrimal canal in the perforation group (p<0,001).

CONCLUSIONS: In Le Fort I surgery, nasolacrimal duct injury may occur during screw fixation to the aperture region. Superiorly positioned fixation screws in the aperture region may damage the nasolacrimal canal. In patients where the nasolacrimal canal is close to the outer cortex, care should be taken when applying the fixation screws to the aperture region to avoid damaging the canal.

PMID:37622429 | DOI:10.4317/medoral.26167

Ophthalmic Physiol Opt. 2023 Aug 25. doi: 10.1111/opo.13221. Online ahead of print.

ABSTRACT

PURPOSE: To quantify the magnitude of central and peripheral scleral lens-induced corneal oedema for a range of fluid reservoir thicknesses, and to compare these experimental results with theoretical models of corneal oedema both with and without limbal metabolic support (i.e., the lateral transport of metabolites and the influence of the limbal vasculature).

METHODS: Ten young healthy participants wore scleral lenses (KATT™, Capricornia Contact Lenses) fitted with low (mean 141 μm), medium (482 μm) and high (718 μm) central fluid reservoir thickness values across three separate study visits. The scleral lens thickness, fluid reservoir thickness and stromal corneal oedema were measured using optical coherence tomography. Oedema was quantified across the central (0-2.5 mm from the corneal apex) and peripheral (1.25-3 mm from the scleral spur) cornea. Experimental data were compared with published theoretical models of central to peripheral corneal oedema.

RESULTS: Stromal oedema varied with fluid reservoir thickness (p < 0.001) for both central and peripheral regions. The mean (standard deviation) stromal oedema was greater for the medium (2.08 (1.21)%) and high (2.22 (1.31)%) fluid reservoir thickness conditions compared to the low condition (1.00 (1.01)%) (p ≤ 0.01). Stromal oedema gradually increased from the corneal centre to the periphery by ~0.3% on average (relative increase of 18%), but the change did not reach statistical significance. This trend of increasing, rather than decreasing, oedema towards the limbus is consistent with theoretical modelling of peripheral oedema without metabolic support from the limbus.

CONCLUSIONS: The central and peripheral cornea displayed a similar magnitude of oedema, with increasing levels observed for medium and high fluid reservoir thicknesses. The gradual increase in oedema towards the limbus is consistent with a ‘without limbal metabolic support’ theoretical model.

PMID:37622425 | DOI:10.1111/opo.13221

Schizophr Bull. 2023 Aug 25:sbad129. doi: 10.1093/schbul/sbad129. Online ahead of print.

ABSTRACT

BACKGROUND AND HYPOTHESIS: Hallucinations are characterized by disturbances in perceptual decision-making about environmental stimuli. When integrating across multiple stimuli to form a perceptual decision, typical observers engage in “robust averaging” by down-weighting extreme perceptual evidence, akin to a statistician excluding outlying data. Furthermore, observers adapt to contexts with more unreliable evidence by increasing this down-weighting strategy. Here, we test the hypothesis that hallucination-prone individuals (n = 38 high vs n = 91 low) would show a decrease in this robust averaging and diminished sensitivity to changes in evidence variance.

STUDY DESIGN: We used a multielement perceptual averaging task to elicit dichotomous judgments about the “average color” (red/blue) of an array of stimuli in trials with varied strength (mean) and reliability (variance) of decision-relevant perceptual evidence. We fitted computational models to task behavior, with a focus on a log-posterior-ratio (LPR) model which integrates evidence as a function of the log odds of each perceptual option and produces a robust averaging effect.

STUDY RESULTS: Hallucination-prone individuals demonstrated less robust averaging, seeming to weigh inlying and outlying extreme or untrustworthy evidence more equally. Furthermore, the model that integrated evidence as a function of the LPR of the two perceptual options and produced robust averaging showed poorer fit for the group prone to hallucinations. Finally, the weighting strategy in hallucination-prone individuals remained insensitive to evidence variance.

CONCLUSIONS: Our findings provide empirical support for theoretical proposals regarding evidence integration aberrations in psychosis and alterations in the perceptual systems that track statistical regularities in environmental stimuli.

PMID:37622401 | DOI:10.1093/schbul/sbad129

J Esthet Restor Dent. 2023 Aug 25. doi: 10.1111/jerd.13125. Online ahead of print.

ABSTRACT

OBJECTIVE: The purpose of this study was to evaluate the effect of aging and fiber-reinforcement on the color stability, translucency, and microhardness of single-shade resin composites versus multi-shade resin composite.

MATERIALS AND METHODS: Four resin composites (Filtek Z250, Omnichroma, Vittra APS Unique, Zenchroma) were tested. Three subgroups of specimens were prepared for each of the composites: control, polyethylene fiber-reinforcement, and glass fiber-reinforcement- groups (n = 10/per group). The samples were subjected to aging for 10,000 thermal cycles. Color differences (ΔE₀₀ ) were calculated after aging. Relative translucency parameter (RTP₀₀ ) and microhardness values were calculated before and after aging. A two-way analysis of variance and the generalized linear model was used (p < 0.05).

RESULTS: The lowest and highest ΔE₀₀ values were found for Filtek Z250 (0.6 ± 0.2) and Omnichroma resin composites (1.6 ± 0.4), respectively. The ΔE₀₀ value of the polyethylene fiber-reinforcement group (1.2 ± 0.6) was significantly higher than the ΔE₀₀ value of the glass fiber-reinforcement group (1.0 ± 0.4, p < 0.001). The RTP₀₀ value of the glass fiber-reinforcement group (1.92 ± 0.78) was significantly higher than the RTP₀₀ value of the polyethylene fiber-reinforcement group (1.72 ± 0.77, p < 0.001). The highest microhardness values were found in glass fiber-reinforcement group (76.48 ± 17.07, p < 0.001).

CONCLUSION: Single-shade resin composites were more translucent, had higher color change, and lower hardness than multi-shade resin composite. For relative translucency and microhardness, statistical significance was found in the material and fiber type interaction. The glass fiber-reinforcement provided higher translucency, lower color change and higher microhardness values than polyethylene fiber-reinforcement group after aging. Thermocycling had a significant impact on the color stability, translucency parameter, and microhardness of the tested resin composite materials.

CLINICAL SIGNIFICANCE: Single-shade resin composite materials have greater color-changing potential. The glass fiber-reinforcement optimize resin material mechanical properties and color stability more than polyethylene fiber-reinforcement.

PMID:37622399 | DOI:10.1111/jerd.13125

Stat Appl Genet Mol Biol. 2023 Aug 25;22(1). doi: 10.1515/sagmb-2021-0067. eCollection 2023 Jan 1.

ABSTRACT

Permutation tests are widely used for statistical hypothesis testing when the sampling distribution of the test statistic under the null hypothesis is analytically intractable or unreliable due to finite sample sizes. One critical challenge in the application of permutation tests in genomic studies is that an enormous number of permutations are often needed to obtain reliable estimates of very small p-values, leading to intensive computational effort. To address this issue, we develop algorithms for the accurate and efficient estimation of small p-values in permutation tests for paired and independent two-group genomic data, and our approaches leverage a novel framework for parameterizing the permutation sample spaces of those two types of data respectively using the Bernoulli and conditional Bernoulli distributions, combined with the cross-entropy method. The performance of our proposed algorithms is demonstrated through the application to two simulated datasets and two real-world gene expression datasets generated by microarray and RNA-Seq technologies and comparisons to existing methods such as crude permutations and SAMC, and the results show that our approaches can achieve orders of magnitude of computational efficiency gains in estimating small p-values. Our approaches offer promising solutions for the improvement of computational efficiencies of existing permutation test procedures and the development of new testing methods using permutations in genomic data analysis.

PMID:37622330 | DOI:10.1515/sagmb-2021-0067

J Eur Acad Dermatol Venereol. 2023 Sep;37(9):1811-1814. doi: 10.1111/jdv.4396.

ABSTRACT

BACKGROUND: Acrochordons are common and benign skin tumours. A few studies with contradictory results have been reported regarding the abnormalities of carbohydrate and/or lipid metabolisms in patients with acrochordons.

OBJECTIVES: We aimed to determine if the presence of acrochordons could be a marker of diabetes, hyperlipidemia, liver enzyme abnormalities and hypertension by comparing with a control group.

METHODS: A total of 110 patients having two or more acrochordons and age- and gender-matched 110 controls were included in the study. Localization, size and the total number of acrochordons were recorded in the patient group. Fasting plasma glucose (FPG), serum lipids and liver enzyme levels were tested in patient and controls. All participants underwent a standard 2-h oral glucose tolerance test with 75 g glucose. Diabetes mellitus and impaired glucose intolerance were diagnosed according to the American Diabetes Association criteria. Arterial blood pressures were measured in two groups.

RESULTS: A total of 56 patients and 10 controls were diagnosed with overt DM. Thirteen per cent of the patients and 9% of controls had an impaired glucose tolerance test. The difference was statistically significant for the diagnosis of DM and not significant for the impaired glucose tolerance. The mean levels of FPG, total cholesterol, LDL cholesterol, triglyceride, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase and alkaline phosphatase were significantly higher in patients than those in controls. Furthermore, serum levels of HDL were less in patients. Patients with acrochordons had higher systolic and diastolic blood pressures than controls.

CONCLUSIONS: The results of our study suggest that acrochordons may represent a cutaneous sign for impaired carbohydrate or lipid metabolism, liver enzyme abnormalities and hypertension.

PMID:37622223 | DOI:10.1111/jdv.4396

Anal Methods. 2023 Aug 24;15(33):4119-4133. doi: 10.1039/d3ay00711a.

ABSTRACT

The Standard Practices for Infrared Multivariate Quantitative Analysis (ASTM E1655) provide a guide for determining physicochemical properties of materials using multivariate calibration techniques applied to chemical sources that have high multicollinearity and correlated information. Partial least squares (PLS) is the most widely used multivariate regression method due to its excellent prediction capabilities and easy optimization. Initially applied to chromatographic data, PLS has also shown great results in near-infrared (NIR) and mid-infrared (MIR) spectroscopies. However, complex chemical matrices with low correlation may not be efficiently modeled using PLS or other multivariate analyses limited by grouping similar information (such as latent variables or principal components). Therefore, this study aims to evaluate the multicollinearity of different analytical techniques, such as high-temperature gas chromatography (HTGC), NIR, MIR, hydrogen nuclear magnetic resonance (¹H NMR), carbon-13 nuclear magnetic resonance (¹³C NMR), and Fourier transform ion cyclotron resonance mass spectrometry coupled to the electrospray source in positive and negative ionization modes (ESI(±)FT-ICR). Descriptive statistics (coefficient of determination, R²) and principal component analysis (PCA) were used to identify the distribution of correlated information. Results showed that NIR and MIR spectroscopies exhibited a higher percentage of correlated variables, while ¹³C NMR and ESI(±)FT-ICR MS had more discrete profiles. Therefore, PLS development may be more effectively applied to NIR, MIR, and ¹H NMR data, while ¹³C NMR and mass spectra may require other algorithms or variable selection methods in combination with PLS.

PMID:37622198 | DOI:10.1039/d3ay00711a

Dela J Public Health. 2023 Jun 12;9(2):134-140. doi: 10.32481/djph.2023.06.025. eCollection 2023 Jun.

ABSTRACT

OBJECTIVE: Assess differences in postpartum contraceptive use and pregnancy intentions in women with a recent live birth who delivered a neonatal abstinence syndrome (NAS) affected infant.

STUDY DESIGN: Using linked Delaware Birth Certificate Data, Hospital Discharge Data and PRAMS data for 2012-2018 (n = 6,358 singleton births), we assessed differences among women with and without a delivery of an NAS-affected infant by effective postpartum contraceptive use and pregnancy intentions. We calculated prevalence estimates, crude (cPOR), and prevalence odds ratios adjusted (aPOR) for NAS by maternal characteristics. We used alpha ≤ 0.05 to determine statistical significance.

RESULTS: Prevalence of NAS was 2.2% (95% CI: 1.8 – 2.6). Effective postpartum contraceptive use was 60.4% (95% CI: 51.9-69.0) among women with delivery of an NAS-affected infant compared with a non-NAS delivery 56.4% (95% CI: 55.1-57.8%) and cPOR was 1.2 (95% CI: 0.8-1.7). Prevalence of intended pregnancy was 26.5% (95% CI: 18.9-34.0) among women with delivery of an NAS-affected infant compared with a non-NAS delivery 53.0% (95% CI: 51.7-54.4) and cPOR was 0.3 (95% CI: 0.2-0.5). After adjustment, women who delivered an NAS-affected infant had lower odds (aPOR = 0.5; 95% CI: 0.3-0.8) of indicating that their pregnancy was intended as compared to those who did not deliver an NAS-affected infant.

CONCLUSIONS: Our study found no association between delivery of an NAS-affected infant and use of an effective postpartum contraceptive method. However, we found that pregnancy intendedness was lower among women delivering an NAS-affected infant compared with women without an NAS delivery even after accounting for maternal characteristics.

PMID:37622155 | PMC:PMC10445619 | DOI:10.32481/djph.2023.06.025

Front Big Data. 2023 Aug 8;6:1198097. doi: 10.3389/fdata.2023.1198097. eCollection 2023.

ABSTRACT

The proliferation of atmospheric datasets is a key outcome from the continued development and advancement of our collective scientific understanding. Yet often datasets describing ostensibly identical processes or atmospheric variables provide widely varying results. As an example, we analyze several datasets representing rainfall over Nepal. We show that estimates of extreme rainfall are highly variable depending on which dataset you choose to look at. This leads to confusion and inaction from policy-focused decision makers. Scientifically, we should use datasets that sample a range of creation methodologies and prioritize the use of data science techniques that have the flexibility to incorporate these multiple sources of data. We demonstrate the use of a statistically interpretable data blending technique to help discern and communicate a consensus result, rather than imposing a priori judgment on the choice of dataset, for the benefit of policy decision making.

PMID:37622101 | PMC:PMC10446837 | DOI:10.3389/fdata.2023.1198097

Proc Priv Enhanc Technol. 2023 Jul;2023(4):5-20. doi: 10.56553/popets-2023-0095.

ABSTRACT

Location-based services have brought significant convenience to people in their daily lives, and the collected location data are also in high demand. However, directly releasing those data raises privacy and liability (e.g., due to unauthorized distribution of such datasets) concerns since location data contain users’ sensitive information, e.g., regular moving patterns and favorite spots. To address this, we propose a novel fingerprinting scheme that simultaneously identifies unauthorized redistribution of location datasets and provides differential privacy guarantees for the shared data. Observing data utility degradation due to differentially-private mechanisms, we introduce a utility-focused post-processing scheme to regain spatiotemporal correlations between points in a location trajectory. We further integrate this post-processing scheme into our fingerprinting scheme as a sampling method. The proposed fingerprinting scheme alleviates the degradation in the utility of the shared dataset due to the noise introduced by differentially-private mechanisms (i.e., adds the fingerprint by preserving the publicly known statistics of the data). Meanwhile, it does not violate differential privacy throughout the entire process due to immunity to post-processing, a fundamental property of differential privacy. Our proposed fingerprinting scheme is robust against known and well-studied attacks against a fingerprinting scheme including random flipping attacks, correlation-based flipping attacks, and collusions among multiple parties, which makes it hard for the attackers to infer the fingerprint codes and avoid accusation. Via experiments on two real-life location datasets and two synthetic ones, we show that our scheme achieves high fingerprinting robustness and outperforms existing approaches. Besides, the proposed fingerprinting scheme increases data utility for differentially-private datasets, which is beneficial for data analyzers.

PMID:37622059 | PMC:PMC10449389 | DOI:10.56553/popets-2023-0095