Asymmetry Parameter Research Articles

127I Solid-State NMR Spectroscopy of Organic Periodates Featuring Halogen Bonded IO4̶ … IO4̶ Adducts.

Hydroxyanions and oxyanions can overcome electrostatic repulsion between like charges to form supramolecular architectures whose formation is driven by non-covalent interactions such as hydrogen bonds and halogen bonds (HaB). We report here a 127I solid-state nuclear magnetic resonance (SSNMR) study of a series of six organic periodates including compounds which feature I…O HaB between pairs of IO4- anions and control samples which do not feature HaB. 127I SSNMR spectra of powdered samples acquired under stationary conditions at 9.4, 11.75, and 21.1 T are simulated using an exact diagonalization of the Zeeman-quadrupolar Hamiltonian to provide the isotropic chemical shift, 127I nuclear quadrupolar coupling constant (CQ), and quadrupolar asymmetry parameter for each compound. One of the HaB compounds, 4-(pyrrolidin-1-yl)pyridinium periodate, is characterized by the largest CQ(127I) value measured to date for a periodate anion, 52.70 MHz. Control organic periodates which do not have HaBs have CQ(127I) values that are much lower than those seen in the halogen-bonded systems, thereby easily differentiating between these two sets of compounds. The CQ(127I) values for those compounds featuring only halogen-bonded periodate anions correlate with the shear strain of the anion, which may be attributed to the influence of the HaB on the local geometry.

Observation of Λ_{c}^{+}→Λa_{0}(980)^{+} and Evidence for Σ(1380)^{+} in Λ_{c}^{+}→Λπ^{+}η.

Based on 6.1 fb^{-1} of e^{+}e^{-} annihilation data collected at center-of-mass energies from 4.600 to 4.843GeV with the BESIII detector at the BEPCII collider, a partial wave analysis of Λ_{c}^{+}→Λπ^{+}η is performed, and branching fractions and decay asymmetry parameters of intermediate processes are determined. The process Λ_{c}^{+}→Λa_{0}(980)^{+} is observed for the first time, and evidence for the pentaquark candidate Σ(1380)^{+} decaying into Λπ^{+} is found with statistical significance larger than 3σ with mass and width fixed to theoretical predictions. The branching fraction product B[Λ_{c}^{+}→Λa_{0}(980)^{+}]B[a_{0}(980)^{+}→π^{+}η] is determined to be (1.05±0.16_{stat}±0.05_{syst}±0.07_{ext})%, which is larger than theoretical calculations by 1-2 orders of magnitude. Here the third (external) systematic is from B(Λ_{c}^{+}→Λπ^{+}η). Finally, we precisely obtain the absolute branching fraction B(Λ_{c}^{+}→Λπ^{+}η)=(1.94±0.07_{stat}±0.11_{syst})%.

Association between intra and inter-limb strength asymmetry with sprint kinematics and force-velocity profile in youth team athletes

Maximal force plays a pivotal role in enhancing performance across various dynamic sports, particularly in sprinting biomechanics. However, muscle strength asymmetry among major muscle groups like the hamstrings and quadriceps may hinder sprint performance and raise injury risks. This study examines how intra- and inter-limb strength asymmetry relates to sprint kinematics and the power-force-velocity profile in youth athletes. Seventy-four youth athletes from football, volleyball, and handball completed two testing sessions, 48h apart. Assessments included anthropometric measurements, sprint tests, and isokinetic dynamometer strength evaluations at 60°.s-1 and 180°.s-1. Sprint kinematics were analyzed using the Optojump Next system, and force-velocity profile variables were determined via Samozino's method. Asymmetry analysis used a standard percentage difference equation. Weak to moderate correlations (r=-0.46 to 0.45) were found between strength asymmetry and sprint parameters, suggesting limited impact of asymmetry on sprint kinematics and kinetics. Although most participants showed asymmetry levels below the 15% threshold deemed functionally significant, outliers had asymmetry values up to 42%, indicating considerable variability. Lower extremity strength asymmetry moderately affects sprint kinematics and force-velocity profiles in young team athletes, challenging traditional views. Further research is needed to explore the mechanisms between strength asymmetry and sprint performance, aiming to inform targeted training interventions that optimize performance and reduce injury risks in youth athletes.

GENDER DIFFERENCES IN MUSCLE STRENGTH AND TISSUE ASYMMETRY CHANGES OVER FIVE YEARS AMONG OLDER ADULTS

Abstract Background The declines in muscle strength during aging process is linked to reductions in tissue integrity and underlying cellular processes. It suggests potential gender differences in these fundamental mechanisms. The current study investigates whether the decline in muscle strength over a 5-year period correlates with changes in tissue asymmetry and explores potential gender differences between men and women. Methods The longitudinal study comprised 3156 participants residing in Reykjavik, Iceland, with a baseline mean age of 74.9. The analysis included 1,150 men and 1,587 women (n=2,737). Tissue asymmetry, assessed through CT scans, was defined by differences between the right and left sides across 11 soft tissue composition parameters for fat, muscle, and connective tissue. Changes in leg strength and asymmetry parameters over 5 years were calculated by subtracting follow-up values from baseline. Linear regression analysis was performed to assess the association between changes of maximum knee extension strengths and changes in soft-tissue asymmetry over 5 years, adjusting for confounders by gender. Results In men, a decline in leg strength over 5 years was significantly associated with an increased asymmetry across five parameters (2 related to fat and 3 related to muscle (p< 0.05)). In women, associations were observed with an increased asymmetry parameters involving fat, muscle, and connective tissue (p< 0.03). Conclusion Gender-specific variations in asymmetry parameters highlight how fat and muscle composition in men uniquely contribute to leg strength changes over time. This emphasizes the need to consider gender-specific factors in understanding age-related muscle strength changes, informing targeted interventions for older adults.

Angular Distributions and Polarization of Fluorescence in an XUV Pump–XUV Probe Scheme

This work provides theoretical calculations of fluorescence angular distribution and polarization within an XUV pump–XUV probe scheme designed for determining ultra-short lifetimes of highly charged heavy ions. The initial pumping leads to a non-zero alignment in the excited levels. After the probing stage, the anisotropies in angular distribution and polarization of subsequent fluorescence are significantly enhanced due to the existence of a previous alignment. Furthermore, two-photon sequential excitation from a ground state with zero angular momentum to a level with angular momentum one by two aligned linearly polarized photon beams is strictly prohibited by the selection rules and may be used as a diagnostic tool to determine beam misalignment. The present approach is based on the density matrix and statistical tensor framework. We provide the analytical form for the alignment parameters caused by successive photoexcitation either with linearly polarized photon beams, or with unpolarized photons. The analytical results can generally be used to compute angular distribution asymmetry parameters and linear polarization of subsequent fluorescence for a large array of atomic systems used in pump–probe experiments.

Sleep Stage Classification Through HRV, Complexity Measures, and Heart Rate Asymmetry Using Generalized Estimating Equations Models.

This study investigates whether heart rate asymmetry (HRA) parameters offer insights into sleep stages beyond those provided by conventional heart rate variability (HRV) and complexity measures. Utilizing 31 polysomnographic recordings, we focused exclusively on electrocardiogram (ECG) data, specifically the RR interval time series, to explore heart rate dynamics associated with different sleep stages. Employing both statistical techniques and machine learning models, with the Generalized Estimating Equation model as the foundational approach, we assessed the effectiveness of HRA in identifying and differentiating sleep stages and transitions. The models including asymmetric variables for detecting deep sleep stages, N2 and N3, achieved AUCs of 0.85 and 0.89, respectively, those for transitions N2-R, R-N2, i.e., falling in and out of REM sleep, achieved AUCs of 0.85 and 0.80, and those for W-N1, i.e., falling asleep, an AUC of 0.83. All these models were highly statistically significant. The findings demonstrate that HRA parameters provide significant, independent information about sleep stages that is not captured by HRV and complexity measures alone. This additional insight into sleep physiology potentially leads to a better understanding of hearth rhythm during sleep and devising more precise diagnostic tools, including cheap portable devices, for identifying sleep-related disorders.

Empty nose syndrome: new insights from a CFD approach.

Empty Nose Syndrome (ENS) is a debilitating condition which usually arises after aggressive turbinate reduction. However, objective tests to help in the diagnosis of this condition are lacking. Accurate diagnosis of ENS patients is critical for effective diagnosis and treatment. The article's objectives are to utilize computational fluid dynamics (CFD) to analyze nasal airflow resistance and symmetry in suspected ENS patients, classify them into distinct groups based on CFD data, and demonstrate the potential of CFD analysis in refining ENS diagnosis and guiding individualized treatment strategies. This study involved 48 patients diagnosed of ENS. However, we only considered those patients with documented prior turbinate surgery (eventually plus septal surgery), CT scan with signs of prior surgery, and a history of ENS with symptoms included in the ENS Q6. We employed computational fluid dynamics (CFD) to analyze nasal airflow resistance and symmetry. Patients were classified into three groups based on their CFD data: low resistance and normal symmetry, evident asymmetry, and normal CFD parameters. Half of patients (24 out of 48) were found in the low resistance and normal symmetry group, indicating 'typical' ENS. A smaller group (8) exhibited evident asymmetry, suggesting unilateral ENS or failure of previous surgery. Finally, 16 patients whose CFD parameters are inside the normal range of flow and resistance were classified in the normal breathing group. Our findings highlight the value of CFD analysis in classifying ENS patients based on airflow characteristics, as CFD analysis seems helpful in refining the diagnosis of ENS. This classification system can potentially aid in tailoring individual treatment strategies and improving patient outcomes. Further research is necessary to validate these results and explore the clinical implications of different ENS subgroups. Level 4 [1].

DESI Emission-line Galaxies: Unveiling the Diversity of [O ii] Profiles and Its Links to Star Formation and Morphology

We study the [O ii] profiles of emission-line galaxies (ELGs) from the Early Data Release of the Dark Energy Spectroscopic Instrument (DESI). To this end, we decompose and classify the shape of [O ii] profiles with the first two eigenspectra derived from principal component analysis. Our results show that DESI ELGs have diverse line profiles, which can be categorized into three main types: (1) narrow lines with a median width of ∼50 km s−1, (2) broad lines with a median width of ∼80 km s−1, and (3) two redshift systems with a median velocity separation of ∼150 km s−1, i.e., double-peak galaxies. To investigate the connections between the line profiles and galaxy properties, we utilize the information from the COSMOS data set and compare the properties of ELGs, including star formation rate (SFR) and galaxy morphology, with the average properties of reference star-forming galaxies with similar stellar mass, sizes, and redshifts. Our findings show that, on average, DESI ELGs have a higher SFR and more asymmetrical/disturbed morphology than the reference galaxies. Moreover, we uncover a relationship between the line profiles, the excess SFR, and the excess asymmetry parameter, showing that DESI ELGs with broader [O ii] line profiles have more disturbed morphology and higher SFR than the reference star-forming galaxies. Finally, we discuss possible physical mechanisms giving rise to the observed relationship and the implications of our findings on the galaxy clustering measurements, including the halo occupation distribution modeling of DESI ELGs and the observed excess velocity dispersion of the satellite ELGs.

Improved calculation of single-scattering properties of frozen droplets and frozen-droplet aggregates observed in deep convective clouds

Abstract. During multiple field campaigns, small quasi-spherical ice crystals, commonly referred to as frozen droplets (FDs), and their aggregates (frozen-droplet aggregates, FDAs) have been identified as the predominant habits in the upper regions of deep convective clouds (DCCs) and their associated anvils. These findings highlight the significance of FDs and FDAs for understanding the microphysics and radiative properties of DCCs. Despite the prevalence of FDs and FDAs at the tops of DCCs where they directly contribute to cloud radiative effect, the detailed single-scattering properties (e.g., scattering-phase function P11 and asymmetry parameter g) of FDs and FDAs remain highly uncertain. This uncertainty is mainly due to insufficient in situ measurements and the resolution of cloud probes, which hinder the development of idealized shape models for FDs and FDAs. In this study, two shape models, the Gaussian random sphere (GS) and droxtal (DX), are proposed as possible representations for the shapes of FDs and FDAs measured in situ. A total of 120 individual models of GSs and 129 models of DXs were generated by varying their shapes. Furthermore, by attaching these individual models in both a homogeneous and heterogeneous manner, three different types and a total of 404 models of FDAs were created: (1) aggregates of GSs; (2) aggregates of DXs; and (3) combinations of GSs and DXs, which are called habit mixtures (HMs). The P11 and g values of the developed models were calculated using a geometric optics method at a wavelength of 0.80 µm and then compared with those obtained using a polar nephelometer (PN) during the CIRCLE-2 field campaign to assess the models. Both individual-component ice crystals (i.e., either GS or DX) and homogeneous-component aggregates (i.e., either aggregates of GSs or aggregates of DXs) showed substantial differences compared with the PN measurements, whereas the P11 of the HMs was found to most accurately match the P11 measured in situ, reducing the differences to +0.87 %, +0.88 %, and −5.37 % in the forward-, lateral-, and backward-scattering regions, respectively. The g value of the HMs was found to be 0.80, which falls within the range of the PN measurement (0.78 ± 0.04). The root-mean-square error for the HM was minimized to a value of 0.0427. It was shown that the novel HMs developed in this study demonstrated better performance than in previous research where HMs were developed indirectly by weighting the calculated P11 of shape models to interpret in situ measurement. The results of this study suggest potential implications for enhancing the calculation of single-scattering properties of ice crystals in DCCs.

Exploring wobbling motion in triaxial even-even nuclei

Exploring wobbling motion in triaxial even-even nuclei

On the Influence of Beach Slope on Wave Non-Linearities on a Macrotidal Low-Tide Terrace Beach

This study examines the evolution of wave shapes as they propagate over a beach of varying morphology, information essential for understanding coastal dynamics and supporting coastal management. Our objective was to analyze the relationship between wave shape parameters and the local slope of the beach. To achieve this, we used data from pressure sensors and topographic measurements to evaluate the shape of waves on a cross-shore profile of a low-tide terrace beach. The analysis of wave conditions revealed a pronounced modulation of the tidal signal, which is augmented during storm events. Our findings demonstrate that the asymmetry and skewness parameters are more pronounced in the reflective zone of the beach. Considering these results, it can be concluded that the non-linearity of waves is significantly affected by the beach slope. The parameterization method employed in this study effectively incorporates this factor, offering improved accuracy in comparison to the existing approaches.

Comparison of the asymmetries in foot posture, gait and plantar pressure between patients with unilateral and bilateral knee osteoarthritis based on a cross-sectional study

This study aimed to observe the characteristics of foot posture asymmetry and abnormal gait in patients with unilateral and bilateral knee osteoarthritis (KOA) and to explore the association between foot posture asymmetry, abnormal gait and the clinical symptoms and severity of KOA. Sixty patients with KOA were allocated as follows: unilateral group (UG; n = 30) and bilateral group (BG; n = 30). We accessed foot posture, foot posture asymmetry, gait and plantar pressure parameters and symmetry index, clinical symptom-related scores and disease severity, and investigated the relationship between these variables. The results showed that the overall percentage of asymmetry and severe asymmetry in foot posture were lower in BG than in UG. There was substantial asymmetry in many gait indicators within the two groups, but no significant differences were observed between the two groups. Moreover, foot posture asymmetry, multiple gait and plantar pressure parameters and symmetry indices were closely related to clinical symptoms and disease severity. In conclusion, both unilateral and bilateral KOA patients have foot posture asymmetry and gait asymmetry, but the foot posture asymmetry of the former is more severe than that of the latter. Intervention for this population should treat simultaneously both knee joints. The evaluation and monitoring of foot posture asymmetry, gait and plantar pressure parameters and symmetry indices can provide a more comprehensive and scientific basis for the prevention and treatment of KOA.

Skew scattering and ratchet effect in photonic graphene

This paper is devoted to a comprehensive theoretical study of asymmetric (skew) scattering in photonic graphene, with the main focus on its realization with semiconductor microcavity exciton-polaritons. As an important consequence of the skew scattering, we prove the appearance of the ratchet effect in this system. Triangular defects in the form of missing micropillars in a regular honeycomb lattice are considered to be ones that break the spatial inversion symmetry, thus providing the possibility of the ratchet effect. By means of the numerical solution of the effective Schrödinger equation, we provide microscopical insight into the process of skew scattering and determine indicatrices, cross sections, and asymmetry parameters. In a system with multiple coherently oriented triangular defects, a macroscopic ratchet effect occurs as a unidirectional flux upon noiselike initial conditions. Our study broadens the concept of ratchet phenomena in the field of photonics and optics of exciton-polaritons. Published by the American Physical Society 2024

Bound states in the continuum in a dielectric metamaterial with symmetry breaking in two dimensions

Abstract Bound states in the continuum (BICs), since their ultra-high quality (Q)-factor to extremely enhance light matter interactions, have attracted extensive interest very recently. As a typical category, symmetry-protected BICs are predictive and easily manipulated by using structure’s symmetry. However, most of the studies focus only on the structures with symmetry breaking in one dimension, in which one BIC will emerge and exhibit an inverse square relationship to asymmetry parameter. The structures with symmetry breaking in two dimensions remain rather unexplored. We here propose a dielectric metamaterial made of a square lattice of disks with a small hole. As moving the hole away from the center, the in-plane inversion symmetry can be broken either in one dimension or in two dimensions. As usual, a symmetry-protected BIC dominated by magnetic dipole (MD) occurs in the first case. In the second case, symmetry-protected dual BICs arise, consisting of the usual MD-dominated BIC and a new electric dipole (ED)-dominated BIC that is in cross-polarization to incident wave. The new BIC possesses an even higher Q-factor, which can also be continuously tuned via the position of the hole. Besides the structural modulation, we show the polarization angle of incident wave will act as another degree of freedom for designing symmetry breaking in two dimensions, where the similar symmetry-protected dual BICs are observed as well. Our work provides an alternative scheme for engineering multiple BICs and improving Q-factor, which may pave the way for practical device applications.

Maximum Penalized Likelihood Estimation of the Skew–t Link Model for Binomial Response Data

A critical aspect of modeling binomial response data is selecting an appropriate link function, as an improper choice can significantly affect model precision. This paper introduces the skew–t link model, an extension of the skew–probit model, offering increased flexibility by incorporating both asymmetry and heavy tails, making it suitable for asymmetric and complex data structures. A penalized likelihood-based estimation method is proposed to stabilize parameter estimation, particularly for the asymmetry parameter. Extensive simulation studies demonstrate the model’s superior performance in terms of lower bias, root mean squared error (RMSE), and robustness compared to traditional symmetric models like probit and logit. Furthermore, the model is applied to two real-world datasets: one concerning women’s labor participation and another related to cardiovascular disease outcomes, both showing superior fitting capabilities compared to more traditional models (with probit and the skew–probit links). These findings highlight the model’s applicability to socioeconomic and medical research, characterized by skew and asymmetric data. Moreover, the proposed model could be applied in various domains where data exhibit asymmetry and complex structures.

Giant quadrupole resonances within neutron-induced α-particle emission?

Giant quadrupole resonances within neutron-induced α-particle emission?

Fatigue crack initiation and failure analysis of IN718 alloy after push–pull loading at room temperature and at 700 °C

Fatigue crack initiation and failure analysis of IN718 alloy after push–pull loading at room temperature and at 700 °C

Measurements of the branching fractions of Ξc0→Ξ0π0, Ξc0→Ξ0η, and Ξc0→Ξ0η′ and asymmetry parameter of Ξc0→Ξ0π0

We present a study of Ξc0→Ξ0π0, Ξc0→Ξ0η, and Ξc0→Ξ0η′ decays using the Belle and Belle II data samples, which have integrated luminosities of 980 fb−1 and 426 fb−1, respectively. We measure the following relative branching fractionsBΞc0→Ξ0π0/BΞc0→Ξ−π+=0.48±0.02stat±0.03syst,BΞc0→Ξ0η/BΞc0→Ξ−π+=0.11±0.01stat±0.01syst,BΞc0→Ξ0η′/BΞc0→Ξ−π+=0.08±0.02stat±0.01systfor the first time, where the uncertainties are statistical (stat) and systematic (syst). By multiplying by the branching fraction of the normalization mode, BΞc0→Ξ−π+, we obtain the following absolute branching fraction resultsBΞc0→Ξ0π0=6.9±0.3stat±0.5syst±1.3norm×10−3,BΞc0→Ξ0η=1.6±0.2stat±0.2syst±0.3norm×10−3,BΞc0→Ξ0η′=1.2±0.3stat±0.1syst±0.2norm×10−3,where the third uncertainties are from BΞc0→Ξ−π+. The asymmetry parameter for Ξc0→Ξ0π0 is measured to be αΞc0→Ξ0π0=−0.90±0.15stat±0.23syst.

Unveiling complex magnetic field configurations in red giant stars

The recent measurement of magnetic field strength inside the radiative interior of red giant stars has opened the way toward full 3D characterization of the geometry of stable large-scale magnetic fields. However, current measurements, which are limited to dipolar (ℓ = 1) mixed modes, do not properly constrain the topology of magnetic fields due to degeneracies on the observed magnetic field signature on such ℓ = 1 mode frequencies. Efforts focused toward unambiguous detections of magnetic field configurations are now key to better understand angular momentum transport in stars. We investigated the detectability of complex magnetic field topologies (such as the ones observed at the surface of stars with a radiative envelope with spectropolarimetry) inside the radiative interior of red giants. We focused on a field composed of a combination of a dipole and a quadrupole (quadrudipole) and on an offset field. We explored the potential of probing such magnetic field topologies from a combined measurement of magnetic signatures on ℓ = 1 and quadrupolar (ℓ = 2) mixed mode oscillation frequencies. We first derived the asymptotic theoretical formalism for computing the asymmetric signature in the frequency pattern for ℓ = 2 modes due to a quadrudipole magnetic field. To access asymmetry parameters for more complex magnetic field topologies, we numerically performed a grid search over the parameter space to map the degeneracy of the signatures of given topologies. We demonstrate the crucial role played by ℓ = 2 mixed modes in accessing internal magnetic fields with a quadrupolar component. The degeneracy of the quadrudipole compared to pure dipolar fields is lifted when considering magnetic asymmetries in both ℓ = 1 and ℓ = 2 mode frequencies. In addition to the analytical derivation for the quadrudipole, we present the prospect for complex magnetic field inversions using magnetic sensitivity kernels from standard perturbation analysis for forward modeling. Using this method, we explored the detectability of offset magnetic fields from ℓ = 1 and ℓ = 2 frequencies and demonstrate that offset fields may be mistaken for weak and centered magnetic fields, resulting in underestimating the magnetic field strength in stellar cores. We emphasize the need to characterize ℓ = 2 mixed-mode frequencies, (along with the currently characterized ℓ = 1 mixed modes), to unveil the higher-order components of the geometry of buried magnetic fields and to better constrain angular momentum transport inside stars.

Graphene-based hybrid metasurfaces with quasi-bound states in the continuum for manipulating terahertz absorption

We present a graphene-based hybrid metasurface with quasi-bound states in the continuum (BICs) for manipulating terahertz (THz) wave absorption. By the strategic application of structural perturbations for the THz metasurface, the symmetry-protected BICs transforms into quasi-BICs. The incorporation of graphene adeptly satisfies the critical coupling condition, thereby facilitating the attainment of the theoretical maximum absorption of 0.5 for the quasi-BICs in the THz region. And the Q-factor of the quasi-BIC can be up to 2755. Moreover, the metasurface exhibits a distinctive ability for unique tuning and efficient absorption of terahertz waves by varying the asymmetry parameter and Fermi levels. This work provides promising strategies for manipulating terahertz wave absorption.