Test Of Symmetry Research Articles

A Proposed Distribution-Free Test For Symmetry of Grouped Data

A Proposed Distribution-Free Test For Symmetry of Grouped Data

Oil Price Uncertainty and Consumer Sentiment in Advanced Economies

How does oil price uncertainty affect consumer sentiment in advanced economies? Is the response of consumer sentiment to exogenous positive and negative oil price shocks symmetric or asymmetric? Motivated to answer these questions, this paper provides a comprehensive examination of the effects of real oil price shocks on consumer sentiment in the G7 economies in the context of two classes of empirical models. With the application of a bivariate structural GARCH-in-Mean VAR model we find that (in general) oil price uncertainty has a negative and statistically significant effect on consumer sentiment in the G7 countries. Moreover, using a test of symmetry, we find that the relationship between oil prices and consumer sentiment is in general asymmetric. JEL Classification: C32, D12, Q43, O57

Isospin sum rules in charmed baryon weak decays

Isospin symmetry is the most precise flavor symmetry. The effective Hamiltonian of charm quark weak decay is zero under the isospin lowering operators I-n\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$I_-^n$$\\end{document}, which permits us to generate isospin sum rules through several master formulas. In this work, we derive the master formulas of isospin sum rules for the two- and three-body non-leptonic decays of singly and doubly charmed baryons. Hundreds of isospin sum rules are derived to test of isospin symmetry and provide hints for the new decay modes. The isospin sum rules for multi-body decays are not broken by the intermediate resonances and hence can be used to study the isospin partners of exotic hadrons.

Explicit bivariate simplicial depth

The simplicial depth (SD) is a celebrated tool defining elements of nonparametric and robust statistics for multivariate data. While many properties of SD are well-established, and its applications are abundant, explicit expressions for SD are known only for a handful of the simplest multivariate probability distributions. This paper deals with SD in the plane. It (i) develops a one-dimensional integral formula for SD of any properly continuous probability distribution, (ii) gives exact explicit expressions for SD of uniform distributions on (both convex and non-convex) polygons in the plane or on the boundaries of such polygons, and (iii) discusses several implications of these findings to probability and statistics: (a) An upper bound on the maximum SD in the plane, (b) an implication for a test of symmetry of a bivariate distribution, and (c) a connection of SD with the classical Sylvester problem from geometric probability.

CPT and Lorentz symmetry tests with hydrogen using a novel in-beam hyperfine spectroscopy method applicable to antihydrogen experiments

We present a Rabi-type measurement of two ground-state hydrogen hyperfine transitions performed in two opposite external magnetic field directions. This puts first constraints at the level of ▪ on a set of coefficients of the Standard Model Extension, which were not measured by previous experiments. Moreover, we introduce a novel method, applicable to antihydrogen hyperfine spectroscopy in a beam, that determines the zero-field hyperfine transition frequency from the two transitions measured at the same magnetic field. Our value, ▪, is in agreement with literature at a relative precision of 0.44 ppb. This is the highest precision achieved on hydrogen in a beam, improving over previous results by a factor of 6.

Conditional symmetry test based on empirical characteristic function

In this paper, we propose a method for testing the conditional symmetry of multivariate random variables, specifically testing whether or not the conditional distribution of one random variable is symmetric around zero given another. Both the conditional symmetry test for observable data and unobserved error terms in parametric models are considered. The proposed test statistics are built on the weighted L 2 -distance between empirical characteristic functions and require no distributional assumption about the data distribution. The asymptotic properties of the test statistics under the null and alternative hypotheses are investigated. Since the limiting null distributions are intractable, a nonparametric Monte Carlo resampling method is used to determine critical values. Simulation results show the good performance of the proposed method in various scenarios. Two real datasets are analysed to illustrate the practical usefulness of the proposed tests.

A Statistical Methodology for Evaluating Asymmetry after Normalization with Application to Genomic Data

This study evaluates the symmetry of data distributions after normalization, focusing on various statistical tests, including a few explored test named Rp. We apply normalization techniques, such as variance stabilizing transformations, to ribonucleic acid sequencing data with varying sample sizes to assess their effectiveness in achieving symmetric data distributions. Our findings reveal that while normalization generally induces symmetry, some samples retain asymmetric distributions, challenging the conventional assumption of post-normalization symmetry. The Rp test, in particular, shows superior performance when there are variations in sample size and data distribution, making it a preferred tool for assessing symmetry when applied to genomic data. This finding underscores the importance of validating symmetry assumptions during data normalization, especially in genomic data, as overlooked asymmetries can lead to potential inaccuracies in downstream analyses. We analyze postmortem lateral temporal lobe samples to explore normal aging and Alzheimer’s disease, highlighting the critical role of symmetry testing in the accurate interpretation of genomic data.

Forecasting and unveiling the impeded factors of total export of Bangladesh using nonlinear autoregressive distributed lag and machine learning algorithms

Rising global oil prices are a major challenge for an emerging oil-importing nation such as Bangladesh. The majority of prior research on the economic effects of an oil price shock has concentrated on developed countries, with emerging economies receiving comparatively less attention. Bangladesh is vulnerable to price shocks due to its rising oil consumption over the past decade. This study aims to investigate how changes in oil prices would affect Bangladesh's total export earnings and to forecast the overall export volume. This study utilized a nonlinear autoregressive distributed lag (NARDL) approach to account for the asymmetric behavior of oil prices from 1991 to 2021. To assess the accuracy of predictions, the study employed the Prophet forecasting model and the Long Short-Term Memory (LSTM) method. Additionally, the symmetry test revealed a nonlinear relationship between export volume and oil price but a linear relationship between inflation and export volume. According to the NARDL assessment, both positive and negative oil shocks increase export earnings over the long run. The short run summary clarifies that both positive and negative changes in oil prices exert a significant negative effect on exports. Also, Inflation influences export earnings negatively in the short run but positively over the long term. Moreover, using machine learning methods, it was found that the LSTM method outperforms the prophet model in prediction performance with a low root mean square error (RMSE) of 1.88. Also, the analysis revealed policymakers that the export sector requires diversification to reduce its exposure to oil price shocks.

CPT Symmetry Searches in the Neutral Meson System

A review of the landscape of CPT symmetry tests is presented, centered around the Standard-Model Extension and focusing on tests in the neutral meson system. A discussion of the relevant theories summarizes original ideas. It is followed by a short transition into phenomenology. A more detailed parameterization is presented. Various experiments are used to deliver an overview of testing CPT from every angle that the theory suggested and that the neutral meson (NM) system could accommodate.

Orders of Magnitude Improved Cyclotron-Mode Cooling for Nondestructive Spin Quantum Transition Spectroscopy with Single Trapped Antiprotons.

We demonstrate efficient subthermal cooling of the modified cyclotron mode of a single trapped antiproton and reach particle temperatures T_{+}=E_{+}/k_{B} below 200mK in preparation times shorter than 500s. This corresponds to the fastest resistive single-particle cyclotron cooling to subthermal temperatures ever demonstrated. By cooling trapped particles to such low energies, we demonstrate the detection of antiproton spin transitions with an error rate <0.000 023, more than 3 orders of magnitude better than in previous best experiments. This method has enormous impact on multi-Penning-trap experiments that measure magnetic moments with single nuclear spins for tests of matter and antimatter symmetry, high-precision mass spectrometry, and measurements of electron g factors bound to highly charged ions that test quantum electrodynamics and establish standards for magnetometry.

The Relationship Between Cryptocurrencies and the Trade Balance of Nigeria

Bitcoin has increased rapidly in value since the first day of its integration into today's markets. The increases experienced have directed the interest of global investors to this field over time. In addition to these developments, the increasing popularity of blockchain technology and the increase in the volume of cryptocurrencies have turned these currencies into an important tool for commercial activities. Although there are many studies to measure the international trade balance with exchange rates, no study has been found to examine the relationship between the change in cryptocurrency prices and the trade balance of countries. In this study, the relationship between the trade balance of Nigeria, one of the leading countries in the world in terms of cryptocurrency usage, and cryptocurrencies is analysed using NARDL analysis with coefficient symmetry test (2016/M4-2020/ M12). According to the research results, Bitcoin and Litecoin can have significant long-term impact on Nigeria's trade balance.

Reliability and validity of "My Jump 2" application for countermovement jump free arm and interlimb jump symmetry in different sports of professional athletes.

Vertical jumping is an important evaluation tool to measure muscle strength and power as well as lower limb symmetry. It is of practical importance and value to develop and utilize a portable and low-cost mobile application (APP) to evaluate jumping. The "My Jump 2" app is an iPhone camera-based application for measuring jumping movements, which is applied to the countermovement jump (CMJ) vertical jumps of the lower limbs of athletes in different sports. The validity of this application and previous versions applied to different forms of vertical jump tests has been preliminarily demonstrated in different population, which has an obvious progress in research. Therefore, the reliability and validity of the jump height, time of flight parameters and symmetry of the CMJ vertical jump of athletes in different sports are needed to be verified by more experiments. The purpose of this study is to verify whether "My Jump 2" can effectively and reliably assess jump height, flight practice and lower limb symmetry in CMJAM (countermovement jump free arm) tests in fencing, swimming and diving athletes. Seventy-nine fencers, swimmers and divers with training experience participated in this study. They completed a total of three CMJAM vertical jump and lower limb symmetry tests in 1 day, while being assessed by using the "My Jump 2" application and a force platform. The intra-group correlation coefficient (ICC) was used to verify reliability, while the Cronbach's alpha and coefficient of variation (CV%) was used to analyze the stability of the CMJAM vertical jump test over three jumps. The Pearson correlation coefficient was used to verify the strength of the relationship between methods (i.e., concurrent validity), and the Bland-Altman plot was used to represent consistency, meanwhile, the t-test was used to determine the systematic bias between methods. Compared with the force platform, the cumulative height values of the total number of jumps (r = 0.999; p = 0.000), the cumulative time to vacate (r = 0.999; p = 0.000) for the CMJAM test obtained by the "My Jump 2" application, the height (ICC = 0.999-1, p = 0.000), the time to vacate flight (ICC = 0.999-1, p = 0.000), contact time symmetry (ICC = 0.976-0.994, p = 0.000), and flight time symmetry (ICC = 0.921-0.982, p = 0.000), respectively. Showed high correlation between the results of "my jump 2" app and the force platform. The "My Jump 2" application is a valid tool to assess CMJAM vertical jump and lower limb symmetry in fencing, swimming and diving athletes with training experience.

Anterior Cruciate Ligament Reconstruction Augmentation With Bone Marrow Aspirate Concentrate, Demineralized Bone Matrix, and Suture Tape Shows No Difference in Outcomes—But Faster Functional Recovery—Versus Non-augmented Anterior Cruciate Ligament Reconstruction

PurposeTo compare outcomes after anterior cruciate ligament reconstruction (ACLR) with bone marrow aspirate concentrate (BMAC), demineralized bone matrix (DBM), and suture tape augmentation (STA) vs. ACLR without biologic augmentation or STA. MethodsA prospective randomized controlled trial at a single institution was performed to compare ACLR with BMAC, DBM, and STA (Group A) vs. ACLR without biologic or STA (Group NA). One hundred patients were required. Skeletally mature patients <25 years old received quadriceps tendon autografts, while patients ≥25 years old received allograft ACLR with an all-inside technique. Concomitant meniscal pathologies were included. Primary outcomes compared were range-of-motion (ROM), limb symmetry, and patient-reported outcomes (PROs). Secondary outcomes included radiographic outcomes and surgical complications. Univariate and mixed-model regression analysis were used to compare outcomes. ResultsFifty-nine patients were included (Group A: 29 patients, 11 females, 38%; Group NA: 30 patients, 15 females, 50%). Early range-of-motion at 6 weeks (125° vs 109° flexion, p<0.0001) and limb symmetry testing at 12 weeks (80.6 % vs. 36.7% [Delta 43.9%], p<0.001) were significantly improved in Group A. At two years, International Knee Documentation (IKDC) scores were similar (91.1 ± 12.7 vs. 85.3 ± 10.8, p=0.109). Knee Injury and Osteoarthritis and Outcome Score (KOOS) Quality of Life (QOL) scores were significantly enhanced in Group A (85.2 ± 20.9 vs. 72.1 ± 20.4, p=0.042). Twenty-two patients (12 Group A, 10 Group NA) underwent CT scans at 6-months to compare bone tunnel healing. Overall, the mean increase in bone tunnel diameter was significantly smaller in Group A vs. NA. No difference in graft re-ruptures or re-operations was observed. Seven of 59 patients (11.9%) underwent re-operation for stiffness (A: 3 (10%) vs. NA: 4 (13%), p=1.0). ConclusionThere were no differences in IKDC scores between groups at 2-year follow-up. Functional outcomes including early range-of-motion and limb symmetry were significantly improved in patients who received ACLR with BMAC, DBM, and STA. ACLRACLR.ACLR

The Garden of Forking Paths: Reinterpreting Haseman-Elston Regression for a Genotype-by-Environment Model.

Haseman-Elston regression (HE-reg) has been known as a classic tool for detecting an additive genetic variance component. However, in this study we find that HE-reg can capture GxE under certain conditions, so we derive and reinterpret the analytical solution of HE-reg. In the presence of GxE, it leads to a natural discrepancy between linkage and association results, the latter of which is not able to capture GxE if the environment is unknown. Considering linkage and association as symmetric designs, we investigate how the symmetry can and cannot hold in the absence and presence of GxE, and consequently we propose a pair of statistical tests, Symmetry Test I and Symmetry Test II, both of which can be tested using summary statistics. Test statistics, and their statistical power issues are also investigated for Symmetry Tests I and II. Increasing the number of sib pairs is important to improve statistical power for detecting GxE.

#2746 Long-term benefits in dRTA patients treated with Sibnayal®, a prolonged-release combination of potassium bicarbonate and citrate: 6-year results

Abstract Background and Aims Distal renal tubular acidosis (dRTA) is a rare disease, either inherited or acquired, characterized by an hyperchloremic metabolic acidosis leading to negative effects on growth, bone metabolism and kidney function, and hearing impairment. Sibnayal®, an oral twice-daily fixed and prolonged-release combination of potassium bicarbonate and potassium citrate3, is registered in the indication of dRTA, whatever the genetic or acquired form, in patients aged 1 year and older. Both efficacy and good tolerability profile of Sibnayal® versus alkali Standard of Care (SoC) were demonstrated in the short-term in children and adults dRTA patients (B21CS study1). B22CS study2 is the long-term follow-up study with safety profile as main objective and evaluation of the impact on the long-term complications as secondary or exploratory objectives. Method Thirty patients with genetic dRTA, previously enrolled in B21CS study, were followed-up for six years on average in a multicenter open-label extension trial (B22CS) to evaluate long-term impact of Sibnayal® on safety and efficacy on metabolic acidosis control, renal function, bone remodeling and growth. Tubular damages and kidney function were assessed by bicarbonatemia, kalemia, eGFR (CKiDU25 formula), nephrocalcinosis (paired-t-test) and urinary pH (UpH) (symmetry test). Bone remodeling was assessed with spine bone mineral density (BMD) Z-score (paired t-test, McNemar-test) from baseline to end of follow-up (EoF) and bone alkaline phosphatase (bALP) until M48. Growth was assessed by Z-score of height, weight, and body mass index (BMI) (paired t-test). Results Thirty patients (24 children, 6 adults), median age 10.6 (2-21) years, with inherited dRTA were included in B22CS study (mean study duration of 5.8 ± 1.3 years). Only 20% of patients reported at least one treatment related adverse event, mainly of gastro-intestinal type, which resolved without study treatment discontinuation. Bicarbonatemia was maintained stable in the normal range over the study duration (22.0 ± 3.2 mmol/L at baseline and 22.6 ± 2.5 mmol/L at EoF, p = NS). Kalemia was also maintained in the normal range (3.8 ± 0.5 mmol/L at baseline and 3.7 ± 0.4 mmol/L at EoF, p = NS). UpH was maintained between 7 and 8 in 70% of patients and when UpH was superior to 8 there was no impact on ACCP crystals presence (47% of patients at baseline versus 35.3% at EoF, p = NS). Nephrocalcinosis was reported in 89% of patients at baseline and in 93% at EoF (p = NS). Glomerular filtration rate remained stable all over the follow-up, eGFR was 105.2 ± 16.9 mL/min/1.73 m2 at baseline versus 103.9 ± 19.9 mL/min/1.73 m2 at EoF (p = NS). Bone metabolism was improved as spine BMD Z-score significantly increased from baseline (−1.1 ± 1.0) to EoF (−0.8 ± 0.9), p = 0.0053. In addition, 88% of patients had a spine BMD Z-score in the normal range (&amp;gt; -2SD) at EoF versus 71% of patients at baseline (p = NS). bALP Z-score was in normal range at baseline versus M48 (0.9 ± 2.22 at baseline vs 0.7 ± 1.3 at M48, p = NS). Growth was improved as Z-score for height significantly increased from baseline to EoF (p = 0.0323) while both Z-scores for weight and BMI were stable (p = NS). Conclusion These data confirm the long-term good tolerability profile and efficacy of Sibnayal® in the management of metabolic acidosis, in patients with dRTA. Sibnayal® showed a preventive effect on metabolic acidosis long-term complications in this population.

Do some levator avulsions improve over time?

To determine whether the sonographic appearance of levator avulsion after vaginal childbirth can improve significantly over the first few years postpartum. Retrospective study of women seen in the context of two prospective perinatal imaging studies. All subjects had undergone an interview, clinical examination and 4D translabial ultrasound (TLUS) on average 4.3 months and 3.1 years post-partum. Volume data sets were analysed at a later date blinded against all other data. The number of abnormal slices at both time points was compared using Mann- Whitney U Test. Patients in whom findings had changed over time were reviewed separately in parallel in order to reduce the impact of differences in slice location and imaging settings. The symmetry test was used to analyse changes between the two postnatal visits. Of 1148 women originally recruited, 315 had had at least two postnatal visits. 42 were excluded, leaving 273 women for analysis.They were first seen on average 4.3 (2.6-9.8) months after childbirth and the last time 3.1 (1.4-8) years postpartum. Cohen's kappa for the two assessments was 0.89, with agreement in 97% (264/273) of cases. At the first visit, complete avulsion was diagnosed in 20, partial avulsion in 32, and no avulsion in 221. While seven partial avulsions appeared sonographically normal at the second visit, there were no statistically significant changes in avulsion category between visits (P=0.4). Tomographic pelvic floor imaging obtained 2.5-10 months after childbirth may be used as a proxy for long- term outcomes. Findings at a mean of 3.1 years showed 97% agreement with imaging obtained at an average of 4.3 months. There was a non-significant reduction in abnormal slices affecting at most 3/12 slices. This may be explained by compensatory hypertrophy of remaining intact muscle. Sonographic normalisation of complete avulsion was not observed. This article is protected by copyright. All rights reserved.

Effects of Cervical Bracing on Elderly Patients With Dysphagia.

This study aimed to determine if cervical bracing with a PMT collar increases risk of airway invasion and pharyngeal residue in elderly patients with dysphagia. Additionally, it aimed to identify patient preference for cervical bracing during deglutition. Twenty-one patients underwent a videofluoroscopic swallow study. Thin liquid, nectar thick liquid, pudding, and cracker were administered with cervical collar on and off with order of condition randomized. The Penetration-Aspiration Scale (PAS) was used to grade swallows, with McNemar's test of symmetry used to determine whether the categorical PAS score was similar between conditions. Pharyngeal residue was measured following swallows. Patients were asked which condition they preferred, and which was more comfortable with "no difference" being a selection. No significant difference in PAS categorization score was measured for any consistency (p = .317-.919). Significantly more pyriform sinus residue was measured in the collar off condition (p = .003), albeit amounts were within normative range, with no difference measured in vallecula residue between conditions (p = .939). Forty-five percent of participants preferred to swallow with the collar off, while 55% indicated no preference. Forty-one percent of participants indicated increased comfort with collar off, while 59% indicated no difference in comfort. No participant preferred swallowing or indicated increased comfort with the collar on. Presence of a cervical collar in elderly patients with dysphagia did not result in a significant difference in airway invasion or total pharyngeal residue. There was significantly more residue in the pyriform sinuses when cervical bracing was removed. The majority of patients did not indicate a difference in preference or comfort between collar on/off conditions.

Breastfeeding Barriers for Preterm Infants in Neonatal Intensive Care Unit Environments: A Systematic Assessment and Meta-Analysis.

Background: Breast milk is vital for the growth and development of preterm infants. However, in Neonatal Intensive Care Units (NICUs), mothers often encounter significant challenges in breastfeeding. Objective: This study aims to systematically evaluate the barriers to breastfeeding in NICUs, thereby providing evidence-based support for clinical practices. Methods: A comprehensive search was conducted in the Cochrane Library, PubMed, Web of Science, Embase, and Scopus databases, up to September 2023. Meta-analysis was performed using Stata 15.0, applying fixed or random effects models to calculate odds ratios (OR) and their 95% confidence intervals (CI). Study quality was assessed using the Newcastle-Ottawa Scale for cases and cohorts and the Agency for Healthcare Research and Quality standards for cross-sectional studies. Heterogeneity was evaluated using Cochran's chi-squared test (Cochran's Q) and I2 statistics, and publication bias was assessed through funnel plots and symmetry tests. Results: A total of 32 studies were included, encompassing 96,053 preterm infants. The main barriers to breastfeeding in preterm infants included: low gestational age (OR = 1.36, 95% CI: 1.06-1.75), lower maternal education (OR = 1.64, 95% CI: 1.39-1.93), insufficient breast milk (OR = 2.09, 95% CI: 1.39-1.93), multiple births (OR = 1.615, 95% CI: 1.18-2.210), smoking (OR = 2.906, 95% CI: 2.239-3.771), and single motherhood (OR = 1.439, 95% CI: 1.251-1.654). Conclusion: This study underscores the need for individualized breastfeeding support strategies in NICUs, taking into account the diverse backgrounds of mothers. Future research should focus on unraveling the underlying mechanisms affecting breastfeeding in preterm infants, with the goal of enhancing breastfeeding rates and improving developmental outcomes.

Observation of magnetic amplification using dark spins

Quantum amplification enables the enhancement of weak signals and is of great importance for precision measurements, such as biomedical science and tests of fundamental symmetries. Here, we observe a previously unexplored magnetic amplification using dark noble-gas nuclear spins in the absence of pump light. Such dark spins exhibit remarkable coherence lasting up to 6 min and the resilience against the perturbations caused by overlapping alkali-metal gas. We demonstrate that the observed phenomenon, referred to as "dark spin amplification," significantly magnifies magnetic field signals by at least three orders of magnitude. As an immediate application, we showcase an ultrasensitive magnetometer capable of measuring subfemtotesla fields in a single 500-s measurement. Our approach is generic and can be applied to a wide range of noble-gas isotopes, and we discuss promising optimizations that could further improve the current signal amplification up to [Formula: see text] with [Formula: see text]Ne, [Formula: see text] with [Formula: see text]Xe, and [Formula: see text] with [Formula: see text]He. This work unlocks opportunities in precision measurements, including searches for ultralight dark matter with sensitivity well beyond the supernova-observation constraints.

Investigation of the ΔI=1/2 Rule and Test of CP Symmetry through the Measurement of Decay Asymmetry Parameters in Ξ^{-} Decays.

Using (10087±44)×10^{6} J/ψ events collected with the BESIII detector, numerous Ξ^{-} and Λ decay asymmetry parameters are simultaneously determined from the process J/ψ→Ξ^{-}Ξ[over ¯]^{+}→Λ(pπ^{-})π^{-}Λ[over ¯](n[over ¯]π^{0})π^{+} and its charge-conjugate channel. The precisions of α_{Λ0} for Λ→nπ^{0} and α[over ¯]_{Λ0} for Λ[over ¯]→n[over ¯]π^{0} compared to world averages are improved by factors of 4 and 1.7, respectively. The ratio of decay asymmetry parameters of Λ→nπ^{0} to that of Λ→pπ^{-}, ⟨α_{Λ0}⟩/⟨α_{Λ-}⟩, is determined to be 0.873±0.012_{-0.010}^{+0.011}, where the first and the second uncertainties are statistical and systematic, respectively. The ratio is smaller than unity more than 5σ, which signifies the existence of the ΔI=3/2 transition in Λ for the first time. Besides, we test for CP symmetry in Ξ^{-}→Λπ^{-} and in Λ→nπ^{0} with the best precision to date.