We previously reported gut dysbiosis in patients with Parkinson's disease (PD).
The aim of this study is to examine whether gut dysbiosis correlates with the progression of PD.
We examined changes in ...gut microbiota and demographic features in 2 years in 36 PD patients.
A change of total UPDRS scores in 2 years was predicted by the counts of Bifidobacterium and Atopobium cluster at year 0 with a correlation coefficient of 0.52. Correlation analysis additionally revealed that low counts of Bifidobacterium and Bacteroides fragilis at year 0 were associated with worsening of UPDRS I scores in 2 years. In addition, low counts of Bifidobacterium at year 0 were associated with worsening of hallucinations/delusions in 2 years. Similarly, low counts of B. fragilis at year 0 were associated with worsening of motivation/initiative in 2 years. The patients were evenly divided into the deteriorated and stable groups based on the degree of worsening of total UPDRS scores. The deteriorated group had lower counts of Bifidobacterium, B. fragilis, and Clostridium leptium than the stable group at year 0 but not at year 2, suggesting that the deteriorated group may demonstrate accelerated lowering of these bacteria at year 0.
The total counts of intestinal bacterial decrease in the course of PD progression. Temporal profiles of lowering of bacterial counts are likely to be different from bacteria to bacteria, and also between the deteriorating and stable groups, which may be able to be exploited to differentiate patients with rapidly and slowly progressive PD pathology.
Multi‐time correlation functions are especially well suited to study non‐equilibrium processes. In particular, two‐time correlation functions are widely used in X‐ray photon correlation experiments ...on systems out of equilibrium. One‐time correlations are often extracted from two‐time correlation functions at different sample ages. However, this way of analysing two‐time correlation functions is not unique. Here, two methods to analyse two‐time correlation functions are scrutinized, and three illustrative examples are used to discuss the implications for the evaluation of the correlation times and functional shape of the correlations.
Two ways to analyse two‐time correlation functions and the implications for the evaluation of the correlation times and functional shape of the correlations for equilibrium and non‐equilibrium systems are discussed.
The aim of this article is to develop a novel multiple criteria decision analysis (MCDA) method using a Pearson‐like correlation‐based Pythagorean fuzzy (PF) compromise approach under complex ...uncertainty based on PF sets and interval‐valued Pythagorean fuzzy (IVPF) sets. Because of the complexity and ambiguity involved in real‐life decision‐making situations, this article utilizes the theory of Pythagorean fuzziness, which is characterized by flexible degrees of membership, nonmembership, and indeterminacy to describe uncertain information more comprehensively. PF and IVPF sets possess exceptional abilities to accurately reflect the uncertainty, fuzziness, and vagueness inherent in the decision information. However, manipulating PF and IVPF information is a complicated and difficult task for most decision makers. In this regard, this article extends the well‐known and widely used concept of correlation coefficients to develop simple and effective compromise models for solving MCDA problems in PF and IVPF contexts. This article conducts an extended analysis of Pearson‐like correlation coefficients for PF and IVPF sets separately and introduces new concepts of PF and IVPF correlation coefficients to furnish a solid basis for the proposed methodology. Furthermore, this article develops useful concepts of PF and IVPF correlation‐based closeness coefficients to simultaneously measure the relative closeness to the positive‐ideal PF/IVPF solutions and the relative remoteness from the negative‐ideal PF/IVPF solutions. On the basis of the developed concepts, this article proposes a novel Pearson‐like correlation‐based PF/IVPF compromise approach to address uncertain MCDA problems involving PF/IVPF information and determine the ultimate priority orders among competing alternatives. Finally, this article provides an illustrative application about a financing decision of working capital management to verify the developed approach and demonstrate its feasibility and practicality.
The purpose of this study is to assess the prevalence of overweight/obesity, abdominal obesity and obesity-related risk factors in southern China.
A cross-sectional survey of 15,364 participants aged ...15 years and older was conducted from November 2013 to August 2014 in Jiangxi Province, China, using questionnaire forms and physical measurements. The physical measurements included body height, weight, waist circumference (WC), body fat percentage (BFP) and visceral adipose index (VAI). Multivariate logistic regression analysis was performed to evaluate the risk factors for overweight/obesity and abdominal obesity.
The prevalence of overweight was 25.8% (25.9% in males and 25.7% in females), while that of obesity was 7.9% (8.4% in males and 7.6% in females). The prevalence of abdominal obesity was 10.2% (8.6% in males and 11.3% in females). The prevalence of overweight/obesity was 37.1% in urban residents and 30.2% in rural residents, and this difference was significant (P < 0.001). Urban residents had a significantly higher prevalence of abdominal obesity than rural residents (11.6% vs 8.7%, P < 0.001). Among the participants with an underweight/normal body mass index (BMI), 1.3% still had abdominal obesity, 16.1% had a high BFP and 1.0% had a high VAI. Moreover, among obese participants, 9.7% had a low /normal WC, 0.8% had a normal BFP and 15.9% had a normal VAI. Meanwhile, the partial correlation analysis indicated that the correlation coefficients between VAI and BMI, VAI and WC, and BMI and WC were 0.700, 0.666, and 0.721, respectively. A multivariate logistic regression analysis indicated that being female and having a high BFP and a high VAI were significantly associated with an increased risk of overweight/obesity and abdominal obesity. In addition, living in an urban area and older age correlated with overweight/obesity.
This study revealed that obesity and abdominal obesity, which differed by gender and age, are epidemic in southern China. Moreover, there was a very high, significant, positive correlation between WC, BMI and VAI. However, further studies are needed to explore which indicator of body fat could be used as the best marker to indirectly reflect cardiometabolic risk.
Orcas (Orcinus orca) are known for complex vocalization. Their social structure consists of pods with unique call repertoires and clans sharing vocal traditions. Call repertoires are typically ...established visually and aurally and are used for pod identification. Automatic tools are, however, more suited for large data sets. An Icelandic orca pod occurring in 2019 in the Ligurian Sea provided a unique occasion for collecting recordings of an isolated pod in natural conditions. Recordings were analyzed visually and aurally to create a pod catalog. The R package “warbleR” was used for the first time on a small subsample of orca data to automatically detect sound samples and classify sound types. We found cross‐correlation methods with the Pearson correlation coefficient (PCC) to successfully classify sound types, though false positives occur. We compared our catalog to Icelandic and Antarctic ones checking for similarities and dissimilarities. We found five matches in the Icelandic catalog, two of which had high PCCs ranges (0.62–0.67; 0.60–0.65). Our automatic approach was limited by background noise and variability of orca vocalizations, and it was computationally demanding. We show cross‐correlation methods with the PCC can be a powerful tool to verify audio‐visual repertoire matches between orca from different regions.
Summary
Regional seismic risk assessments and quantification of portfolio losses often require simulation of spatially distributed ground motions at multiple intensity measures. For a given ...earthquake, distributed ground motions are characterized by spatial correlation and correlation between different intensity measures, known as cross‐correlation. This study proposes a new spatial cross‐correlation model for within‐event spectral acceleration residuals that uses a combination of principal component analysis (PCA) and geostatistics. Records from 45 earthquakes are used to investigate earthquake‐to‐earthquake trends in application of PCA to spectral acceleration residuals. Based on the findings, PCA is used to determine coefficients that linearly transform cross‐correlated residuals to independent principal components. Nested semivariogram models are then fit to empirical semivariograms to quantify the spatial correlation of principal components. The resultant PCA spatial cross‐correlation model is shown to be accurate and computationally efficient. A step‐by‐step procedure and an example are presented to illustrate the use of the predictive model for rapid simulation of spatially cross‐correlated spectral accelerations at multiple periods.
The electromagnetic (EM) inverse scattering problems (ISPs) exhibit strong nonlinearity, making it a challenge to reconstruct the relative permittivity of strong scatterers with high quality. Joint ...inversion can leverage the satisfactory solution obtained from acoustic inversion to mitigate the impact of strong nonlinearity on EM inversion. However, how to improve the precision of reconstructing the internal electrical parameter distribution through this kind of joint inversion approach is still a challenge. Aiming to improve the quality of reconstruction, a new joint inversion method based on the framework of the subspace-based optimization method (SOM) is proposed in this article. This new method utilizes the Pearson correlation coefficient (PCC) to construct structural similarity constraints, thereby enhancing the linear correlation between EM and acoustic parameters. In the inversion process, all data obtained from acoustic inversion can offer effective constraints. In order to improve the convergence speed and stability of the proposed method, a constraint that consists of cross-gradient function (CGF) is induced in the object function. By utilizing the results of the results of acoustic inversion, the inversion domain can be further refined, giving rise to better computational efficiency. With these treatments, the proposed method has a better performance in both accuracy and efficiency. The effectiveness and advantages of the proposed method are validated through several numerical examples.
Correlation implies association, but not causation. Conversely, causation implies association, but not correlation. Most studies include multiple response variables, and the dependencies among them ...are often of great interest. For example, we may wish to know whether the levels of mRNA and the matching protein vary together in a tissue, or whether increasing levels of one metabolite are associated with changed levels of another. This month we begin a series of columns about relationships between variables (or features of a system), beginning with how pairwise dependencies can be characterized using correlation.
A large space still exists for improving the measurements used in orthopaedics and sports medicine, especially as we face rapid technological progress in devices used for diagnostic or patient ...monitoring purposes. For a specific measure to be valuable and applicable in clinical practice, its reliability must be established. Reliability refers to the extent to which measurements can be replicated, and three types of reliability can be distinguished: inter-rater, intra-rater, and test–retest. The present article aims to provide insights into reliability as one of the most important and relevant properties of measurement tools. It covers essential knowledge about the methods used in orthopaedics and sports medicine for reliability studies. From design to interpretation, this article guides readers through the reliability study process. It addresses crucial issues such as the number of raters needed, sample size calculation, and breaks between particular trials. Different statistical methods and tests are presented for determining reliability depending on the type of gathered data, with particular attention to the commonly used intraclass correlation coefficient.
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