Variation In Asymmetry Research Articles

Hemispheric asymmetry of coronal bright point’s number and area over solar cycles 23–24

Abstract Temporal variations in the number and area of coronal bright points (CBPs) were studied separately in the northern and southern hemispheres over more than two solar cycles (years 1996–2022). Hemispheric asymmetry was identified in both the total number and area of CBPs, with differences reaching up to 15percnt. Statistical analysis using Student’s t-test confirms that these differences are statistically significant. The observed asymmetry arises from the asynchronous formation of CBPs in the hemispheres, rather than from the asymmetry of active regions. These variations in asymmetry are explained by the existence of two different types of CBP: ‘bright’ and ‘dim’. Differences in the asymmetry and overall number variations between these two types during solar cycles suggest distinct physical mechanisms underlying their formation. Bright CBPs closely follow the patterns of active regions, supporting the hypothesis that they are miniature active regions formed through similar mechanisms. In contrast, dim CBPs, predominantly located in quiet Sun regions, often display behavior opposite to sunspots, partially attributable to the visibility effect and influence of active regions. However, the temporal variations in the normalized asymmetry index indicate that visibility effect alone cannot fully explain the observed patterns. The relatively uniform asymmetry of dim CBPs across 11-year solar cycles supports the hypothesis of a cycle-independent (or dependent on a longer period) component of the solar dynamo, potentially linked to a small-scale turbulent dynamo.

Strength and dynamic balance performance in soccer players in the United States: age, sex, and bilateral differences.

Quantification of asymmetries between the two limbs is informative in assessing the risk of injury and performance deficits, but there is a paucity of studies investigating the effects of age and sex on bilateral asymmetry in young soccer players. This cross-sectional study aimed to investigate the effects of age and sex on strength and dynamic balance in 7- to 24-year-old soccer players in the United States. A total of 174 young soccer players participated in the study (Age 7-9 years: 26 females and 16 males; Age 10-12 years: 32 females and 31 males; Age 13-17 years: 17 females and 25 males; Age >18 years: 13 females and 14 males). Jump displacement, peak force, and asymmetry during countermovement jump with arm swing and landing, peak force and asymmetry during push-up, and normalized reaching distances for upper and lower extremity reaching tests were quantified. Preferred legs and arms were defined as the preferred kicking leg or throwing arm. As age increased, both preferred and non-preferred sides demonstrated decreased landing forces, increased jump displacement, and increased normalized peak forces during push-ups in both males and females (p < 0.05). Males showed greater jump displacement, normalized landing forces, and normalized peak forces in push-ups compared to females in several age groups (p < 0.05). No significant differences were observed for asymmetry variables between ages or sexes, and on average, most bilateral asymmetry variables were less than 5%. Age was associated with strength but not dynamic balance performance in healthy soccer players in the United States. Male and female players demonstrated similar changes, and bilateral asymmetries were on average small. Soccer players may need more dynamic balance training over time as they progress to higher levels of competition. Landing technique training may be implemented for young soccer players to decrease the high impact landing forces and landing related injury risk. Asymmetries and their relationships with injury risk should be evaluated on an individual basis, as their relationships with age and sex were weak. Future longitudinal and cohort studies are warranted to further elucidate the relationship among strength, dynamic balance, and injury risk in soccer players.

Modeling global surface dust deposition using physics-informed neural networks

Paleoclimatic measurements serve to understand Earth System processes and evaluate climate model performances. However, their spatial coverage is generally sparse and unevenly distributed across the globe. Statistical interpolation methods are the prevalent techniques to grid such data, but these purely data-driven approaches sometimes produce results that are incoherent with our knowledge of the physical world. Physics-Informed Neural Networks follow an innovative approach to data analysis and physical modeling through machine learning, as they incorporate physical principles into the data-driven learning process. Here, we develop a machine-learning algorithm to reconstruct global maps of atmospheric dust surface deposition fluxes from paleoclimatic archives for the Holocene and Last Glacial Maximum periods. We design an advection-diffusion equation that prevents dust particles from flowing upwind. Our physics-informed neural network improves on kriging interpolation by allowing variable asymmetry around data points. The reconstructions display realistic dust plumes from continental sources towards ocean basins following prevailing winds.

Bilateral asymmetrical variation of median artery in coexistence with bifid median nerve and variation in the origin and course of its palmar cutaneous branch: a case study with clinical implications.

The median artery typically regresses after two months of intrauterine life, although it may persist into adulthood in some individuals. The presence of a persistent median artery (PMA) may be associated with other anatomical variations including a bifid median nerve. In the present cadaveric study, we report a rare variation of bilateral asymmetry of PMA associated with the bifid median nerve, and unilateral variation of the origin and course of the palmar cutaneous branch of the median nerve (PCBMN) which to our knowledge, is the first study to report all these variations in an individual. Classical dissection of the upper limb was performed on a 45-year-old male cadaver. The cadaver was donated to the Department of Anatomy at Kerman University of Medical Sciences. Bilateral PMA was observed in both upper limbs. The PMA originated from the ulnar artery and contributed to the formation of an incomplete superficial palmar arch (SPA) on both sides; however, the branching pattern of these arteries was different between the right and left hands. Also, a bilateral high division of the median nerve was observed proximal to the carpal tunnel. We also encountered a very rare variation of PCBMN, in which it originated from the ulnar side of the median nerve, and passed beneath the flexor retinaculum of the left hand. Awareness of anatomical variations of the median nerve and also the presence of PMA is of utmost importance due to their implication in carpal tunnel syndrome and surgical complications.

A three-classification model for identifying migraine with right-to-left shunt using lateralization of functional connectivity and brain network topology: a resting-state fMRI study.

Right-to-left shunting has been significantly associated with migraine, although the neural mechanisms remain complex and not fully elucidated. The aim of this study was to investigate the variability of brain asymmetry in individuals with migraine with right-to-left shunting, migraine without right-to-left shunting and normal controls using resting-state fMRI technology and to construct a three-classification model. Firstly, asymmetries in functional connectivity and brain network topology were quantified to laterality indices. Secondly, the laterality indices were employed to construct a three-classification model using decision tree and random forest algorithms. Ultimately, through a feature score analysis, the key brain regions that contributed significantly to the classification were extracted, and the associations between these brain regions and clinical features were investigated. Our experimental results showed that the initial classification accuracy reached 0.8961. Subsequently, validation using an independent sample set resulted in a classification accuracy of 0.8874. Further, after expanding the samples by the segmentation strategy, the classification accuracies were improved to 0.9103 and 0.9099. Additionally, the third sample set yielded a classification accuracy of 0.8745. Finally, 9 pivotal brain regions were identified and distributed in the default network, the control network, the visual network, the limbic network, the somatomotor network and the salience/ventral attention network. The results revealed distinct lateralization features in the brains of the three groups, which were closely linked to migraine and right-to-left shunting symptoms and could serve as potential imaging biomarkers for clinical diagnosis. Our findings enhanced our understanding of migraine and right-to-left shunting mechanisms and offered insights into assisting clinical diagnosis.

All-dielectric structural coloration empowered by bound states in the continuum.

The technological requirements of low-power and high-fidelity color displays have been instrumental in driving research into advanced coloration technologies. At the forefront of these developments is the implementation of dye-free approaches, which overcome previous constraints related to color resolution and fading. Resonant dielectric nanostructures have emerged as a promising paradigm, showing great potential for high efficiency, high color saturation, wide gamut palette, and image reproduction. However, they still face limitations related to color accuracy, purity, and simultaneous brightness tunability. Here, we demonstrate an all-dielectric metasurface empowered by photonic bound states in the continuum (BICs), which supports sharp resonances throughout the visible spectral range, ideally suited for producing a wide range of structural colors. The metasurface design consists of TiO2 ellipses with carefully controlled sizes and geometrical asymmetry, allowing versatile and on-demand variation of the brightness and hue of the output colors, respectively.

Enlarged brain perivascular spaces correlate with blood plasma osmolality in the healthy population: A longitudinal study

Enlarged perivascular spaces (EPVS) are increasingly recognized as an MRI detectable feature of neuroinflammatory processes and age-related neurodegenerative changes. Understanding perivascular characteristics in healthy individuals is crucial for their applicability as a reference for pathological changes. Limited data exists on the EPVS load and interhemispheric asymmetry in distribution among young healthy subjects. Despite the known impact of hydration on brain morphometric studies, blood plasma osmolality's effect on EPVS remains unexplored.This study investigated the influence of age, total intracranial volume (TIV), and blood plasma osmolality on EPVS characteristics in 59 healthy adults, each undergoing MRI and osmolality assessment twice within 14.8 months (mean ± 4 months). EPVS analysis was conducted in the centrum semiovale using high-resolution automated segmentation, followed by an optimization algorithm to enhance EPVS segmentation accuracy. Linear Mixed Effects model was used for the statistical analysis, which unveiled significant inter-individual variability in EPVS load and inter-hemispheric asymmetry. EPVS volume increased with age, higher TIV and lower blood plasma osmolality levels. Our findings offer valuable insights into EPVS characteristics among the healthy population, establishing a foundation to further explore age-related and pathological changes.

The Orbit and Companion of PSR J1622-0315: Variable Asymmetry and a Massive Neutron Star

The companion to PSR J1622-0315, one of the most compact known redback millisecond pulsars, shows extremely low irradiation despite its short orbital period. We model this system to determine the binary parameters, combining optical observations from the New Technology Telescope in 2017 and the Nordic Optical Telescope in 2022 with the binary modeling code ICARUS. We find a best-fit neutron star mass of 2.3 ± 0.4 M ⊙, and a companion mass of 0.15 ± 0.02 M ⊙. We detect for the first time low-level irradiation from asymmetry in the minima as well as a change in the asymmetry of the maxima of its light curves over five years. Using starspot models, we find better fits than those from symmetric direct heating models, with consistent orbital parameters. We discuss an alternative scenario where the changing asymmetry is produced by a variable intrabinary shock. In summary, we find that PSR J1622-0315 combines low irradiation with variable light-curve asymmetry and a relatively high neutron star mass.

Determinan Budgetary Slack pada Satuan Perangkat Daerah Kabupaten Banyuwangi

This research aims to determine the influence of budget participation, information asymmetry, budget emphasis, and clarity of budget targets on budgetary slack in SKPD Banyuwangi Regency. This research used a Cluster Sampling sampling technique with a total of 81 respondents, consisting of heads of departments/agencies, treasurers, heads of planning sub-divisions. Data collection used a questionnaire research instrument using Likert scale measurements. Data analysis in this study used SPSS V.25.The research results show that simultaneously the variables Budget Participation, Information Asymmetry, Budget Emphasis, and Clarity of Budget Targets have a significant effect on Budgetary Slack. Meanwhile, partially the variables Budget Participation, Budget Emphasis, and Clarity of Budget Targets have no effect on Budgetary Slack, and the Information Asymmetry variable has a positive effect on Budgetary Slack

Rotation and Hα Emission in a Young SMC Cluster: A Spectroscopic View of NGC 330

We present an analysis of high-resolution optical spectra recorded for 30 stars of the split extended main-sequence turnoff of the young (∼40 Myr) Small Magellanic Cloud globular cluster NGC 330. Spectra were obtained with the Michigan/Magellan Fiber System and Magellan Inamori Kyocera Echelle spectrographs located on the Magellan-Clay 6.5 m telescope. These spectra revealed the presence of Be stars, occupying primarily the cool side of the split main sequence. Rotational velocity ( vsini ) measurements for most of the targets are consistent with the presence of two populations of stars in the cluster: one made up of rapidly rotating Be stars ( 〈vsini〉≈200 km s−1) and the other consisting of warmer stars with slower rotation ( 〈vsini〉≈50 km s−1). Core emission in the Hδ photospheric lines was observed for most of the Hα emitters. The shell parameter computed for the targets in our sample indicates that most of the observed stars should have inclinations below 75°. These results confirm the detection of Be stars obtained through photometry but also reveal the presence of narrow Hα and Hδ features for some targets that cannot be detected with low-resolution spectroscopy or photometry. Asymmetry variability of Hα line profiles on the timescales of a few years is also observed and could provide information on the geometry of the decretion disks. Observations revealed the presence of nebular Hα emission, strong enough in faint targets to compromise the extraction of spectra and to impact narrow-band photometry used to assess the presence of Hα emission.

Spatial Variation of Asymmetry in Velocity and Sediment Flux along the Artificial Aam Tidal Channel

Tidal flats, crucial for biodiversity and ecosystem services, are facing significant alterations due to human activities such as reclamation. In South Korea, over 65% of tidal flats have been reclaimed since the 1970s, resulting in morphological changes and altered sediment transport dynamics. This study investigates sediment transport processes in the artificial Aam tidal channel, created as part of the megacity development project in Incheon, Korea. Using data from Acoustic Doppler Current Profiler and Vector instruments deployed in 2019 and 2021, we analyzed tidal asymmetry, current velocities, shear stress, and suspended sediment concentration. Our results reveal a pronounced tidal asymmetry influencing sediment transport, with ebb-dominant currents near the channel entrance and flood-dominant currents in the interior. We observed significant sediment deposition in the landward section of the channel, driven by tidal mixing asymmetry and rainfall events. These findings highlight the complex interactions between artificial structures and natural sediment dynamics, informing future coastal development and management strategies.

Small‐sample properties of robust willingness‐to‐pay estimators

AbstractThe small‐sample properties of robust, binary choice willingness‐to‐pay (WTP) estimators are analyzed. A Monte Carlo simulation compares the bias and mean‐squared error of marginal and expected WTP estimates from probit, zero‐centered (“robit”), logit, and a generalized Tukey lambda distribution called a “pregibit” regression under normal and nonnormal distributional assumptions. Robust binary choice estimators allow for variation in tail thickness (the robit and pregibit) or tail asymmetry (the pregibit). No previous studies have compared the performance of these WTP estimators. The findings will interest researchers who use contingent validation methods to estimate WTP for nonmarket or hypothetical goods.

Gene expression asymmetry in Parkinson's Disease; variation of CCT and BEX gene expression levels are correlated with hemisphere specific severity.

Parkinson's Disease (PD) develops unilaterally, which may be related to brain hemispheric differences in gene expression. Here we measured bulk RNA-seq levels in neuronal nuclei obtained from prefrontal cortex postmortem brain samples from males and females with PD and from healthy controls. Left and right hemispheres from each brain were related the side of symptom onset and compared. We employed two a priori approaches; first we identified genes differentially expressed between PD and controls and between left vs right PD brain hemispheres. Second, we examined the presence of, and correlates to, variable asymmetry seen in candidate PD differentially expressed genes. We found large variation among individuals with PD, and PD stratification by gene expression similarity was required for patterns of genetic asymmetry to emerge. For a subset of PD brains, hemispherical variation of CCT and BEX gene levels correlated with the side of PD symptom onset.

The sensitivity of tidal asymmetry descriptors in the Ems estuary

Tidal asymmetry in estuaries and other tidally dominated coastal systems is commonly evaluated to assess system states or their development. Based on different methods, local states are classified as either flood or ebb dominant. An increasing number of descriptors for deriving tidal asymmetry in recent years calls for a comparison and discussion of their sensitivity on input data and its quality. We compared tidal asymmetry from water level and current velocity using various descriptors that deduce from harmonic, ratio, and skewness methods. Computed from one-year measurements at different stations along the Ems estuary, their comparability was enabled by a new approach of scaling. Our results on the variation of sampling intervals demonstrated a highly site-specific sensitivity of the descriptors that led up to changes in the asymmetry direction in tidal duration asymmetry and phase lag. The slack water asymmetry appeared most sensitive to the studied parameter settings. As expected, variability of tidal asymmetry reduced with an increasing number of analyzed tides. At the same time, uncertainty from the asymmetry during spring or neap phases compared to spring-neap periods remained in all analyzed descriptors. Hence, the characterization of the estuary in terms of flood- or ebb-dominance depends critically on the quality and extent of the input data. For all parameter settings, the impact of river discharge on tidal asymmetry was pronounced but varied depending on the location in the estuary. The actual characterization of the effect of asymmetry, e.g., on sediment transport, is not conducted in this study. We propose that this requires a more comprehensive dataset, such as depth and cross-sectional variability of currents and sediment concentrations.

UV‐Triggered Optical Asymmetry Modification of Gold Nanorods Helical Assemblies in a Cholesteric Liquid Crystal Host

AbstractThe creation and modulation of chirality innanomaterials is a well‐established and widely applied concept. Nevertheless, the direct approach of dynamically tuning their morphological asymmetry at thenanoscale to reveal their optical asymmetry variations is yet less well‐implemented. The helical templating of nanomaterials within a cholesteric liquidcrystal (CLC) host and the exploitation of their optical asymmetry change inconjunction with the host represent a means of circumventing technological limitations. In this study, a blending approach is employed to investigate the helical assemblies of gold nanorods (Au NRs) within a photo‐tunable CLC host, followed by their morphological asymmetry modulation through the use of UV irradiation. The results demonstrated that the optical asymmetry of the Au NR shelical assemblies increased in response to a reduction in pitch and the distance between the Au NRs, regardless of the azimuthal variations.Furthermore, the Au NRs blended with CLCs exhibited excellent and stable reflective properties comparable to those of conventional CLCs. Additionally,they can modulate the light flux of incident light at NIR wavelengths. The integrated modulation of reflection and transmission by Au NRs helical assemblies and CLC hosts represents a promising avenue for future research inthe field of multi‐level information encryption.

Parent-child coregulation as a dynamic system: a commentary on Wass etal. (2024).

In this commentary, I argue that including and operationalizing allostatic processes will become increasingly important in future research on parent-child biobehavioral coregulation. In particular, the conceptualization and modeling of dyadic oscillatory rhythms that align in expected ways with the child's developmental stage and that distinguish typical and atypical development will be useful in future work. Despite the inherent asymmetry characteristic of parent-child relationships, we should not forget to consider the child's effects on the parent within and across time, the additional environmental demands upon parents that shape parent-child coregulation, and variations in parent-child asymmetry by parental risk factors. Studying risk factors that are dyadic in nature, such as child maltreatment, may be particularly informative in gaining a deeper understanding of how parent-child coregulation interfaces with developmental psychopathology. To best model parent-child coregulation as a dynamic system, it will be critical to employ more nonlinear analytic models and better represent the multiple hierarchical domains of coregulation and their interactions, including affect, cognition, behavior, and biology. Finally, in future research, a deeper application of existing dyadic and dynamic theories, as well as the generation of new dyadic developmental theories, will aid us in obtaining a stronger understanding of the developmental function and intervention implications of parent-child biobehavioral coregulation.

Sentiment and energy price volatility: A nonlinear high frequency analysis

This study investigates the volatility dynamics of oil and gas prices in an environment characterized by post-coronavirus disease 2019 recovery, uncertainty, high inflation, and geopolitical tensions. Unlike previous studies, we examine a long-run series of high-frequency data on gas and oil prices from July 2007 to May 2022, which provides more than one million observations with which to analyze volatility. We compute realized volatility (RV) and decompose it into continuous volatility and jumps. We then investigate the relationship between uncertainty, investor sentiment, and RV, as well as its main components. Econometrically, we extend the heterogeneous autoregressive model of Corsi (2009) while considering not only disaggregate proxies for volatility (jumps and continuous volatility) and introducing uncertainty and heterogeneous investor sentiment, but also by allowing the model to include asymmetry, nonlinearity, and time variation according to the regime under consideration. Our results present three main findings. First, we find significant evidence of volatility decomposition, suggesting that both markets are characterized by significant jumps. Second, we show that trading volume, extra-financial news (uncertainty, investor sentiment), and jumps appear to drive commodity price volatility. Third, we find evidence of nonlinearity and threshold effects on energy price volatility. These findings are relevant for policymakers, regulators, investors, and portfolio managers, as they enable them to better characterize and forecast changes in commodity prices.

Fluctuating asymmetry of human morphometric features as a marker of developmental instability caused by adverse environmental conditions.

This article is an attempt to apply fluctuating asymmetry as amorphometric method of studying changes in specific structures of the right and the left side of the body to determine variables which may affect morphogenesis and, consequently, human morphology in adulthood. The main aim of this study was to use the fluctuating asymmetry level as an indicator of adverse living conditions in childhood by determining the impact of environmental components (socio-economic factors and air pollution) on the level of body asymmetry in young women and men. Data were collected from 877 students from various Polish universities, including 483 women and 394 men. Anthropometric data and questionnaire responses were recorded. As part of the surveys, respondents provided information about their place of residence, socio-economic status and lateralisation. The composite body FA (cFA) was assessed based on six bilateral features: the length of fingers II and IV of both hands, the length and width of the ear, and the length and width of the foot. The present study supports the hypothesis that asymmetry increases as socioeconomic status decreases and air pollution levels increase. Differences in asymmetry, depending on environmental factors, socioeconomic status (SES) and air quality, were in most cases greater in men than in women. The results confirm that variable asymmetry is a sensitive indicator of an individual's exposure to unfavorable environmental factors during ontogenesis. Moreover, the results of the conducted research suggest that environmental factors may influence the structure of the human body, and irreversible morphological alterations are the result of unfavorable conditions occurring in the early stages of biological development.

A spectropolarimetric study of the radio galaxy Pictor A using MeerKAT

ABSTRACT We present the results of a polarimetric study from our new high-sensitivity L-band (0.8–1.7 GHz) observation of Pictor A using the MeerKAT radio telescope. We confirm the presence of the radio jet extending from the nucleus to the western hotspot of this source. Additionally, we show the radio emission expected to coincide with previously observed X-ray emission in the radio lobes, confirming that the emission mechanism is of inverse Compton origin, as suggested by a previous study. Our spectropolarimetric analysis using the rotation measure synthesis technique reveals a relatively uniform mean rotation measure distribution across the lobes of Pictor A, with most lines of sight exhibiting single-peaked Faraday spectra. However, a number of the lines of sight exhibit single peaked spectra with a wide base or multiple peaks, suggesting the presence of multiple Faraday components or a Faraday thick structure along Pictor A’s lines of sight. We also confirm the asymmetry in rotation measure variability and depolarization between the two lobes of this source, as reported in a previous study.

Dependence of annual asymmetry in &lt;i&gt;NmF2&lt;/i&gt; on local time

Based on the global empirical model of the F2 layer critical frequency median (Satellite and Digisonde Data Model of the F2 layer, SDMF2), an analysis was made of the properties of diurnal variations in the annual asymmetry in the concentration of the F2 layer maximum NmF2 at different values of the solar activity index F. The AI index, which characterizes the relative difference in NmF2 averaged over all longitudes and latitudes between January and July at a given local time, was used as a parameter of this asymmetry. It was found that the diurnal variations of the AI index are dominated by a semidiurnal mode with maxima in the daytime and at night. The daytime maximum of the AI index is almost independent of the level of solar activity. The nighttime AI maximum decreases with increasing solar activity. For low solar activity, the daytime and nighttime AI maxima almost coincide in amplitude when AI = 16—17%. The difference in the solar radio flux between January and July due to the ellipticity of the Earth’s orbit relative to the Sun makes a significant contribution to the AI index at all hours of the day. On average, it is 3—4% and can reach 5% with low solar activity at night. The difference in the AI index for low and high activity according to the IRI model (with URSI and, especially, CCIR coefficients) is overestimated relative to the SDMF2 model at almost all hours of the day, apparently due to the limited number of experimental data when obtaining the CCIR and URSI coefficients especially over the oceans