Variation In Asymmetry Research Articles

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.

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 <i>NmF2</i> 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

Jumping Asymmetries and Risk of Injuries in Preprofessional Ballet

Background: Preprofessional ballet dancers are exposed to the risk of injuries, primarily in the lower extremities, with most injuries occurring during jumping and landing activities. Interlimb asymmetry during jumping and landing activities has been associated with the injury risk in adolescent athletes, but this has not been examined in dancers. Purpose: To investigate associations between interlimb asymmetry during a double-leg countermovement jump (DL-CMJ) and single-leg jump (SLJ) and the injury risk in adolescent preprofessional ballet dancers. Study Design: Cohort study; Level of evidence, 2. Methods: Adolescent preprofessional ballet dancers (N = 255) performed 3 DL-CMJs and 3 SLJs on force plates during annual screening. Absolute and directional (separate values for left and right limb dominance) asymmetries in a set of kinetic variables during a DL-CMJ and in jump height during an SLJ were calculated. Each variable was characterized as having “high” or “normal” asymmetry according to the percentage of asymmetry (greater than or less than or equal to, respectively, the mean ± 0.5 SD) based on the present sample. Risk ratios (RRs) and 95% CIs were calculated based on the injury incidence in the subsequent academic year. Results: Of the 242 dancers that satisfied the inclusion criteria, 128 injuries were observed in the subsequent academic year. In the whole sample, 3 absolute, 7 left limb–dominant, and 1 right limb–dominant kinetic asymmetry in the eccentric, concentric, and landing phases of the DL-CMJ as well as left limb–dominant jump height asymmetry in the SLJ were associated with a significant (P < .001) increase in the injury risk (RR, 1.28-1.69 [95% CI, 1.02-2.37]). Separating by sex, asymmetries in the eccentric and landing phase of the DL-CMJ were not significant in boys, while in girls, RRs for asymmetries in the eccentric and landing phase of the DL-CMJ increased, and SLJ jump height asymmetry was not significant. Conclusion: Higher asymmetries in certain kinetic variables during the DL-CMJ and in jump height during the SLJ were associated with an elevated risk of injuries in elite preprofessional ballet dancers with some sex-specific differences. Associations were mainly identified for high left limb–dominant asymmetry in the takeoff phase, suggesting that the injury risk may be specific to a relative right limb deficit.

Inner ear morphology in wild versus laboratory house mice.

The semicircular canals of the inner ear are involved in balance and velocity control. Being crucial to ensure efficient mobility, their morphology exhibits an evolutionary conservatism attributed to stabilizing selection. Release of selection in slow-moving animals has been argued to lead to morphological divergence and increased inter-individual variation. In its natural habitat, the house mouse Mus musculus moves in a tridimensional space where efficient balance is required. In contrast, laboratory mice in standard cages are severely restricted in their ability to move, which possibly reduces selection on the inner ear morphology. This effect was tested by comparing four groups of mice: several populations of wild mice trapped in commensal habitats in France; their second-generation laboratory offspring, to assess plastic effects related to breeding conditions; a standard laboratory strain (Swiss) that evolved for many generations in a regime of mobility reduction; and hybrids between wild offspring and Swiss mice. The morphology of the semicircular canals was quantified using a set of 3D landmarks and semi-landmarks analyzed using geometric morphometric protocols. Levels of inter-population, inter-individual (disparity) and intra-individual (asymmetry) variation were compared. All wild mice shared a similar inner ear morphology, in contrast to the important divergence of the Swiss strain. The release of selection in the laboratory strain obviously allowed for an important and rapid drift in the otherwise conserved structure. Shared traits between the inner ear of the lab strain and domestic pigs suggested a common response to mobility reduction in captivity. The lab-bred offspring of wild mice also differed from their wild relatives, suggesting plastic response related to maternal locomotory behavior, since inner ear morphology matures before birth in mammals. The signature observed in lab-bred wild mice and the lab strain was however not congruent, suggesting that plasticity did not participate to the divergence of the laboratory strain. However, contrary to the expectation, wild mice displayed slightly higher levels of inter-individual variation than laboratory mice, possibly due to the higher levels of genetic variance within and among wild populations compared to the lab strain. Differences in fluctuating asymmetry levels were detected, with the laboratory strain occasionally displaying higher asymmetry scores than its wild relatives. This suggests that there may indeed be a release of selection and/or a decrease in developmental stability in the laboratory strain.

Dampak Efek Pengamat, Sistem Whistleblowing, Asimetri Informasi, dan Tekanan Finansial pada Terjadinya Kecurangan dalam Laporan Keuangan

This research was conducted to investigate the impact of the bystander effect, whistleblowing system, information asymmetry, and financial pressure on the condition of financial reports among employees of the Special Region of Yogyakarta Province and Central Java Province. A total of 102 employees were taken as samples using a purposive sampling method, and data collection was carried out through distributing questionnaires. Data analysis uses Multiple Linear Regression Analysis techniques. Research findings show that (1) the bystander effect variable has a significant positive influence on the condition of financial statements; (2) the violation reporting system variable has a significant positive effect on the condition of the financial statements; (3) the information asymmetry variable has a significant influence on the condition of financial statements; (4) The financial pressure variable also has a significant effect on the condition of the financial statements. These results provide an in-depth understanding of the factors that influence the condition of financial reports in the work environment. The implication is that organizations need to strengthen internal reporting systems, reduce information inequality, and manage financial pressures to prevent conditions from occurring. This research contributes to the context of corporate financial security and integrity and can be a basis for the development of more effective anti-fraud policies in the future..

Factors Influencing Accounting Fraud in Village Fund Management in South Kalimantan

Purpose: This study investigated the factors contributing to accounting fraud when handling village funds. The purpose of this study was to investigate and analyze how factors such as internal control systems, compliance with accounting regulations, personal morality, and information asymmetry in managing village funds are considered to influence accounting fraud. Method: Village officials and the Village Consultative Body at Tapin Selatan District, Kalimantan Selatan, were made up to be the study’s population. Purposive sampling was used in the sample selection process. One hundred twenty-six respondents served as the sample used in the analysis. The hypothesis was tested with multiple linear regression. Findings: Empirical evidence showed that accounting fraud was not affected by internal control systems. Another finding showed that compliance with accounting regulations and individual morality detrimentally impacted accounting fraud. On the contrary, accounting fraud is positively affected by asymmetric information. Novelty: The difference between this research and previous studies is related to the object studied, indicators on individual morality variables, and the addition of information asymmetry variables. Keywords: Accounting Fraud; Compliance with Accounting Regulations; Internal Control Systems; Individual Morality; Information Asymmetry

Fluctuating Asymmetry in Morphological Characters of the Invasive Round Goby Neogobius melanostomus Populations from Different Habitats of the Sava River Basin, Croatia

Abstract Round goby Neogobius melanostomus is one of the three invasive Ponto-Caspian gobies found in the Sava River basin in Croatia. It has a negative effect on the native ecosystems and is more abundant in highly polluted areas. The objective of this study was to determine the fluctuating asymmetry of four morphometric characters, as well as otolith width and length. Thirty individuals of N. melanostomus were collected and analysed at two sampling sites in the main course of the Sava (Babina Greda, Slavonski Brod) and in a modified habitat (Sava-Odra canal). The squared coefficient of asymmetry variation was used to analyse potential differences between populations. We identified variations in the asymmetry values of the analysed characters, as well as otolith width and length between sampling sites. The highest fluctuating asymmetry was observed in individuals at the Babina Greda sampling site, which could be due to high environmental stress. The results of the study show that the study of fluctuating asymmetry can be used on invasive fish species as a simple approach to identifying habitat quality.

Detecting differences in limb load asymmetry during walking between older adult fallers and non-fallers using in-shoe sensors

BackgroundPrevious studies have reported that clinical walk tests could not detect differences between fallers and non-fallers in older adults. With advancements in wearable technology, it may be possible to assess differences in loading parameters in clinical settings using portable data collection methods. Research question: The purpose of this study was to determine if wearable sensors (loadsol®) are reliable for assessing asymmetry of contact time, peak force, loading rate (LR), and impulse in older adults and determine if the insole can detect differences in these parameters between fallers and non-fallers during walking. MethodsFifty-five older adults (74.1 ± 6.1 years) walked at their maximum speed on a flat floor. Force data were collected from insoles (100 Hz) during a 10-m walk test. To assess reliability, an intraclass correlation coefficient [ICC(2,k)] was generated for each asymmetry variable. To determine differences between fallers and non-fallers, analysis of covariance (ANCOVA; covariate: body mass index) was completed for each variable. ResultsThe ICC of peak force asymmetry (PFA) was 0.942, but other ICCs were less than 0.75. The ANCOVA results indicate that the loadsol® can detect differences in PFA between fallers and non-fallers. The PFA was significantly greater in fallers than in non-fallers. SignificanceThe ability to collect force data while walking using loadsol® has the potential to broaden the research questions investigated, explore clinical applications, and increase generalizability.

Mandibular Asymmetry in Orthodontic Patients with Different Malocclusion Patterns an Orthopantomographic Evaluation

Objectives: To investigate the variation in mandibular asymmetry on right and left sides for different malocclusions. Study design and setting: It was a cross sectional study carried out in Orthodontic Department at Bahria University Dental College. OPG’s of 171 orthodontic patients were collected. The sample was divided into class I, II and III malocclusions. Methodology: The OPG was traced for condylar and ramal heights for both right and left sides. From these readings, the asymmetry index (AI) was calculated for each side. The significance of height variations between the right and left sides, for each malocclusion was calculated using independent sample t-test. Pearson correlation was used to find the association of asymmetry between the two sides when comparing each malocclusion with the other. One-way ANOVA was used to find the significance of differences in asymmetry index of both sides between different malocclusions. Results: The ramal heights were significantly different for each malocclusion with p values of 0.00 and 0.02 for right and left side, the p value of the variations in condylar heights was however 0.66 and 0.12 for the two sides. There was a strong positive correlation of the condylar and ramal height on both sides between all three malocclusions. The p value for condylar AI was 0.97 and 0.15 for ramal AI. Conclusion: The ramus height showed a significant variation in asymmetry while the asymmetry index variations were insignificant between different malocclusion groups.