Asymmetric Dynamics Research Articles

Parents’ and child welfare workers’ understandings of consent to emergency placements

ABSTRACT Emergency placements of children are often made in haste and experienced as dramatic. This article is based on interviews with 9 parents who have consented to emergency placements and their caseworkers. We explore parents’ reasons for giving their consent to placement and the child welfare workers’ understanding of these consents. This leads to a discussion of what constitutes valid consent from parents in emergency cases. Relational autonomy is applied as a perspective to understand the context and influencing factors of parental consent. The results, derived by thematic analysis, show three main themes regarding parents’ reasons for their consent: (1) The child wanted to move out, (2) the parents couldn’t manage the situation, and (3) parents felt the child welfare service (CWS) gave them no choice. Parents experience a high degree of pressure in the context of giving their consent, either from their child or the CWS. Asymmetrical power dynamics between the CWS and parents were highly present and relevant in parents’ reasons for consent, especially when the CWS communicated that the alternative to consent is coercive placement. Furthermore, it is often unclear to the parents what consent entails. This is especially evident through CWS’s regulation of child-parent contact. In the discussion, we emphasize a high degree of awareness on the part of CW workers with regards to understanding how contextual and relational factors influence parent’s choice to consent; when consent is valid; how far consent extends, and the potential weakening of parents’ legal security when a voluntary placement is conducted.

Asymmetric volatility in the cryptocurrency market: New evidence from models with structural breaks

Previous literature shows that major cryptocurrencies exhibit inverse asymmetric volatility: positive shocks increase price volatility more than negative ones. In this study, we revisit the asymmetric volatility dynamics of major cryptocurrencies using asymmetric GARCH models that incorporate endogenously detected structural breaks. Our results show that after incorporating structural breaks, volatility persistence decreases and asymmetric volatility increases for all cryptocurrencies in this study. Thus, prior research that ignores structural breaks underestimates the impact of unexpected news on price volatility in cryptocurrency markets. We also present important economic implications of our results: ignoring structural breaks adversely affects the hedging strategies, derivatives valuations, and risk exposure measurement of investors in cryptocurrency markets.

GARCH-MIDAS-GAS-copula model for CoVaR and risk spillover in stock markets

This study proposes a generalized autoregressive conditional heteroskedasticity (GARCH)-mixed data sampling (MIDAS)-generalized autoregressive score (GAS)-copula model to calculate conditional value at risk (CoVaR). Our approach leverages the GARCH-MIDAS model to enhance stock market volatility modeling and incorporates the GAS mechanism to create a copula with dynamic parameters. This approach allows for the precise calculation of both CoVaR and its changes over time (delta CoVaR). The results of our study demonstrate a significant improvement in CoVaR calculation accuracy compared to other models, showcasing the effectiveness of the GARCH-MIDAS-GAS-copula model. In addition, the CoVaR indicator provides a more comprehensive view of risk spillover relationships compared to value at risk (VaR), offering deeper insights into the asymmetrical risk transmission dynamics between the Chinese and US stock markets, providing valuable information for risk management and investment decisions.

Direct observation of a superconducting vortex diode

The interplay between magnetism and superconductivity can lead to unconventional proximity and Josephson effects. A related phenomenon that has recently attracted considerable attention is the superconducting diode effect, in which a nonreciprocal critical current emerges. Although superconducting diodes based on superconductor/ferromagnet (S/F) bilayers were demonstrated more than a decade ago, the precise underlying mechanism remains unclear. While not formally linked to this effect, the Fulde–Ferrell–Larkin–Ovchinikov (FFLO) state is a plausible mechanism due to the twofold rotational symmetry breaking caused by the finite center-of-mass-momentum of the Cooper pairs. Here, we directly observe asymmetric vortex dynamics that uncover the mechanism behind the superconducting vortex diode effect in Nb/EuS (S/F) bilayers. Based on our nanoscale SQUID-on-tip (SOT) microscope and supported by in-situ transport measurements, we propose a theoretical model that captures our key results. The key conclusion of our model is that screening currents induced by the stray fields from the F layer are responsible for the measured nonreciprocal critical current. Thus, we determine the origin of the vortex diode effect, which builds a foundation for new device concepts.

Interpersonal dynamics of fame: celebrity discourses in commercial music artist’s romantic relationships

ABSTRACT Commercial music artists seek celebrity capital, which has central value in the music industry and broader society. Previous literature suggests that besides advantages, fame is connected to interpersonal issues in close relationships. The marginalised celebrity discourses emerging from well-known artists’ close interpersonal relationships are examined to better understand the interpersonal dynamics of fame. Relational dialectics theory is applied to study celebrity discourses in the romantic relationships of 11 Finnish music artists. Contrapuntal analysis of the data indicates that fame emerges as competing celebrity discourses privileging separateness, closedness, asymmetry, publicity and inauthenticity. The discursive interplays illuminate the dominating celebrity persona, increased mistrust, social and emotional distance, and asymmetrical power dynamics in artists’ romantic relationships. These meaning-systems are linked to decreased self-disclosure and increased social distance, which are negatively connected to relationship formation and maintenance. The dominant perception of fame as harmful for relationships challenges the popular perceptions of fame as worth pursuing. Increased awareness of the interpersonal dynamics of fame can help individuals in managing the fame-related tensions in close interpersonal relationships, which are known as vital for well-being. The research adds to the understanding of the relational production of fame and introduces the interpersonal communication perspective on celebrity studies.

First person – Atsushi Taniguchi and Yukinori Nishigami

ABSTRACT First Person is a series of interviews with the first authors of a selection of papers published in Biology Open, helping researchers promote themselves alongside their papers. Atsushi Taniguchi and Yukinori Nishigami are co-first authors on ‘ Light-sheet microscopy reveals dorsoventral asymmetric membrane dynamics of Amoeba proteus during pressure-driven locomotion’, published in BiO. Atsushi is a postdoc in the lab of Toshiyuki Nakagaki at Research Institute for Electronic Science, Hokkaido University, Kita-Ward Sapporo, Japan, investigating algorithms for collective space exploration and use in ciliates and amoebae. Yukinori is an assistant professor in the lab of Toshiyuki Nakagaki at the Research Institute for Electronic Science, Hokkaido University, Kita-Ward Sapporo, Japan, investigating the behavior of protists.

Light-sheet microscopy reveals dorsoventral asymmetric membrane dynamics of Amoeba proteus during pressure-driven locomotion.

Amoebae are found all around the world and play an essential role in the carbon cycle in the environment. Therefore, the behavior of amoebae is a crucial factor when considering the global environment. Amoebae change their distribution through amoeboid locomotion, which are classified into several modes. In the pressure-driven mode, intracellular hydrostatic pressure generated by the contraction of cellular cortex actomyosin causes the pseudopod to extend. During amoeboid locomotion, the cellular surface exhibits dynamic deformation. Therefore, to understand the mechanism of amoeboid locomotion, it is important to characterize cellular membrane dynamics. Here, to clarify membrane dynamics during pressure-driven amoeboid locomotion, we developed a polkadot membrane staining method and performed light-sheet microscopy in Amoeba proteus, which exhibits typical pressure-driven amoeboid locomotion. It was observed that the whole cell membrane moved in the direction of movement, and the dorsal cell membrane in the posterior part of the cell moved more slowly than the other membrane. In addition, membrane complexity varied depending on the focused characteristic size of the membrane structure, and in general, the dorsal side was more complex than the ventral side. In summary, the membrane dynamics of Amoeba proteus during pressure-driven locomotion are asymmetric between the dorsal and ventral sides.

On the interplay between lipids and asymmetric dynamics of an NBS degenerate ABC transporter

Multidrug resistance-associated proteins are ABC C-family exporters. They are crucial in pharmacology as they transport various substrates across membranes. However, the role of the degenerate nucleotide-binding site (NBS) remains unclear likewise the interplay with the surrounding lipid environment. Here, we propose a dynamic and structural overview of MRP1 from ca. 110 μs molecular dynamics simulations. ATP binding to NBS1 is likely maintained along several transport cycles. Asymmetric NBD behaviour is ensured by lower signal transduction from NBD1 to the rest of the protein owing to the absence of ball-and-socket conformation between NBD1 and coupling helices. Even though surrounding lipids play an active role in the allosteric communication between the substrate-binding pocket and NBDs, our results suggest that lipid composition has a limited impact, mostly by affecting transport kinetics. We believe that our work can be extended to other degenerate NBS ABC proteins and provide hints for deciphering mechanistic differences among ABC transporters.

Tracing the asymmetry of religiosity-based loyalty of Islamic bank depositors

Religiosity is one of many essential aspects that stands as the motivation of people’s behaviour. Its importance expands to the field of banking, especially Islamic banks that take Islamic teaching as their backbone. This study aimed to seek religiosity motivation among Islamic bank depositors by exploring the possible asymmetric effect of interest rates on the type of deposits. By using the NARDL approach, this study investigates the relationship between the conventional deposit interest rate on the type of depositors and deposit maturity by using monthly data from April 2015 until March 2020 of Indonesia’s Islamic banks. The results show that government deposit in Islamic bank is not affected by the raise of interest rate. In addition, all deposits that showed the possibility of asymmetry effect indicated that the increase of interest rate (LIR+) has a positive coefficient. In general, Indonesian Islamic bank depositors’ are religiously loyal and not attracted to the fluctuation of interest rates. The result also found that short-run asymmetric dynamics show convergent to long-run asymmetry after an average of 15 months. As for the policy implications, stakeholders must ease the regulation of Islamic banks such as the conversion of conventional banks to Islamic banks, since it is proven that customers are mainly religiously driven.

Asymmetric Dynamics of Inflation Inertia in Some Selected Non-Eurozone European Countries

Relevance. Inflation inertia refers to the persistence of inflation over time and can be caused by a variety of factors, including expectations about future inflation, the structure of the economy, and the behavior of economic agents. Over the past two decades, the European economy has grappled with a range of challenges and currently seeks to mitigate the negative impacts of the global pandemic. Research objective. Persistent inflation can lead to uncertainty, decreased investment, and a loss of confidence in an economy. Non-eurozone economies can also face challenges in controlling inflation due to such factors as the lack of monetary integration with the eurozone, limited access to the European Central Bank's resources, and the lack of a unified currency. Hence, for a more effective monetary policy in these countries, it is necessary to measure and understand the inflation inertia. This paper offers a novel empirical study of the dynamics of inflation inertia for seven EU economies that are not part of the eurozone. Data and methods. To achieve the research objective, three non-linear unit root tests are employed to consider both structural changes and regime switching. These tests allowed for the inclusion of almost all non-linear dynamics observed in the inflation series. In addition, the tests involve the use of the dynamic rolling windows sample approach in order to provide more sensitive measurements of the effect of time-varying shocks on inflation inertia. Results. According to the static sample analysis of 200 observations, Bulgaria, Croatia, and the Czech Republic have inflation inertia. Sweden, Romania, Hungary, and Poland do not have inflation inertia when non-linear regime switching dynamics and structural change are considered. However, Croatia and the Czech Republic show a mostly non-stationary inflation in dynamic rolling windows sampling. Hungary has persistent inflation even though it was not detected in the static sample analysis. The shocks of inflation fade out in Bulgaria, Poland, Romania, and Sweden with non-linear dynamics. If non-linear dynamics is ignored, it can lead to misleading results in economic time series. Conclusions. Inflation inertia can be influenced by a variety of factors, including the global pandemic, global or regional conflicts and monetary policy preferences. The successful management of inflation inertia in Romania and Sweden may serve as a model for other economies that have demonstrated an ability to effectively address and mitigate the challenges posed by inflation inertia.

Asymmetric dynamics of the orbital angular momentum of vector beam propagation in nonlocal nonlinear media with -symmetric azimuthal potentials

We study the dynamics of vector beams (VBs) propagating in nonlocal nonlinear media with -symmetric azimuthal potentials. It is found that there is an apparent clockwise/counterclockwise symmetry (similar to left/right symmetry) breaking for the sub-beam with the opposite value of orbital angular momentum (OAM) of the VB. This symmetry breaking leads to the obvious asymmetric evolution of OAM, which results in net OAM generation. We numerically confirm that this phenomenon is induced by the -symmetric azimuthal potential.

Asymmetric Contact Loss Dynamics during Plating and Stripping in Solid‐State Batteries

AbstractSolid‐state batteries (SSBs) hold the potential to improve energy density and offer enhanced safety when compared to lithium‐ion batteries. However, the development of practical SSBs faces major challenges, such as filament growth and void formation, which necessitate a comprehensive understanding of the intrinsic solid–solid interfaces and limiting mechanisms. In this work, the underpinning asymmetry in the mechanistic interplay and resulting interface dynamics during Li plating and stripping is demonstrated, illustrating the critical effect of reaction heterogeneity on the contact loss behavior. With increasing stripping rates, the manifestation of solid–solid point contacts is identified as a key descriptor that signifies a transition in electrochemical response from a regime of continuous contact decay to current constriction. It is revealed that contact loss can also occur during plating at the Li/Li6PS5Cl interface; this severity scales with the reaction heterogeneity and is identified as an important challenge toward achieving faster charging rates in SSBs. The distinct nature of competing electrochemical–mechanical interactions that govern void formation during plating/stripping are delineated in this work. Coupled with these intrinsic mechanisms, non‐uniformities in external pressure and temperature fields drastically alter the contact dynamics, resulting in disparate void localization patterns.

High-order harmonic generation from periodic asymmetric potentials

High-order harmonic generation (HHG) from periodic asymmetric potentials is investigated by solving the real-space time-dependent Schrödinger equations and semi-conductor Bloch equations. Our results show that the periodic asymmetric potential will cause asymmetric excitation and HHG dynamics in the time domain, leading to the signal of even order harmonics. From the k-space perspective, a k-dependent transition dipole moment phase reflects the real-space asymmetry and causes the symmetry breaking of excitation and HHG dynamics. We also illustrate that the dephasing effect competes with the asymmetry of interband HHG dynamics. Large amplitude of the driving field is beneficial for observing the symmetry breaking of interband HHG. However, it is found symmetry breaking of intraband HHG dynamics is less influenced by dephasing. Moreover, a carrier-envelope phase controlled driving laser field can be utilized as an isolated attosecond pulse gating mechanism for HHG from the periodic asymmetric potentials.

Symmetric and asymmetric dynamics of a tethered satellite in nontypical planes

The dynamics of tethered satellite systems operating in typical planes (e.g., the orbital plane and the planes perpendicular to the orbital plane) has been well analyzed. However, studying the orbital system in nontypical planes might be more practical. Hence, this paper concentrates on the dynamic behaviors of a tethered system with two satellites in any plane, along with active out-of-plane suppressions. First, noninertial and inertial reference frames are introduced to build a billiard and a bead model for the original system. The low-dimensional model is applicable to efficient evaluation, while the high-dimensional model is more suitable for depicting the configuration changes of a flexible tether. Then, the in-plane motion stability in a transformed reference frame is examined via the Poincaré map. A numerical dynamic zone that depends on the system parameters and initial states is utilized to sketch the system spins, pendulum-like motions, and irregular oscillations. The simulation results demonstrate that the parameter zone is periodic. The symmetry and asymmetry of the dynamic forms are also presented. Finally, a corresponding relationship between model selection and dynamic behaviors is proposed.

A study on the nonlinear dynamics of ASEAN financial integration

PurposeThis study examines the co-integration relationships between Association of Southeast Nations (ASEAN) stock indices as a way to assess the feasibility of policy initiatives to strengthen market integration in ASEAN and identify implications for portfolio investors.Design/methodology/approach The authors employ threshold co-integration tests and a non-linear autoregressive distributed lag (NARDL) model to study the asymmetric dynamics of ASEAN equity markets. The study’s data cover the 2009–2022 period for seven member states: Cambodia, Indonesia, Malaysia, the Philippines, Singapore, Thailand and Vietnam.FindingsThe authors find evidence supporting co-integration relationships; adjustment toward equilibrium is asymmetric in the short run and symmetric in the long run for these countries. While co-movement in ASEAN equity markets seems encouraging for initiatives seeking to foster financial integration in regional economies, the benefits for international portfolio diversification appear to be neutralized.Originality/valueThe issue of stock market integration is important among policymakers, investors and academics. This study examines the level of stock market integration in ASEAN during the 2009–2022 period. For this purpose, advanced co-integration techniques are applied to different frequencies of data (daily, weekly and monthly) for comparison and completeness. The empirical analysis of this study is conducted using the Enders and Siklos (2001) co-integration and threshold adjustment procedure. This advanced co-integration technique is superior compared to other co-integration techniques by permitting asymmetry in the adjustment toward equilibrium.

Landing of the asteroid probe with three-legged cushioning: Planar asymmetric dynamics and safety margin

The probes landing on the surfaces of the asteroids can increase the scientific return of the exploration missions and also promote the development of deep space resources. Because of its excellent applicability to the uneven terrain and a lighter configuration than the four-legged mechanisms, the three-legged cushioning mechanisms are suitable for dissipating the impact energy and then quickly stabilizing the probe attitude when the probe lands on the micro-gravitational surfaces of the asteroids. Research on the landing dynamics of the probe facilitates to the design of the landing-cushioning mechanism and the optimization of its configuration, as well as the assessment of the landing safety. Comparing with the previous extensive related literature focusing on landing dynamics of the probes assisted by the four-legged cushioning mechanisms, this paper studies creatively the planar dynamics considering the asymmetric characteristic and the leg-leg coupling to understand the landing process of the asteroid probe with the three-legged cushioning mechanism and thereby to optimize the configuration of cushioning mechanism and assess safety margin of the landing. According to the touchdown status, the asymmetric landing modes are classified and the coupling issue in the construction of the landing models is explained. Consequently, two types of dynamics models describing the two-stages touchdown cushioning process of the probe are established. Then, five significant configuration factors of the cushioning mechanism are extracted, and their values combinations are designed according to the Taguchi orthogonal method. On this basis, the maximum safe landing attitude angles of the probe are solved by using these values combinations as the input conditions under the dangerous situations in different landing modes. The range analysis and nonlinear fitting methods are employed to discuss the influence of the configuration factors on the landing safety margin, and the favorable parameter values of the configuration factors are determined. Next, the influence of the ground obstacle on the landing safety margin and several methods to improve the margin are researched. Finally, the complete attitude changes of the probe in two representative landing cases are analyzed. The results studied in this paper can contribute to configuration optimization of the three-legged cushioning mechanisms and safety assessment of the legged probes landing on the asteroids, as well as to provide a reference for discussing the leg-leg coupling issue received less attention in landing dynamics of the probes with the four-legged cushioning mechanisms.

Scaling and spontaneous symmetry restoring of topological defect dynamics in liquid crystal

Topological defects-locations of local mismatch of order-are a universal concept playing important roles in diverse systems studied in physics and beyond, including the universe, various condensed matter systems, and recently, even life phenomena. Among these, liquid crystal has been a platform for studying topological defects via visualization, yet it has been a challenge to resolve three-dimensional structures of dynamically evolving singular topological defects. Here, we report a direct confocal observation of nematic liquid crystalline defect lines, called disclinations, relaxing from an electrically driven turbulent state. We focus in particular on reconnections, characteristic of such line defects. We find a scaling law for in-plane reconnection events, by which the distance between reconnecting disclinations decreases by the square root of time to the reconnection. Moreover, we show that apparently asymmetric dynamics of reconnecting disclinations is actually symmetric in a comoving frame, in marked contrast to the two-dimensional counterpart whose asymmetry is established. We argue, with experimental supports, that this is because of energetically favorable symmetric twist configurations that disclinations take spontaneously, thanks to the topology that allows for rotation of the winding axis. Our work illustrates a general mechanism of such spontaneous symmetry restoring that may apply beyond liquid crystal, which can take place if topologically distinct asymmetric defects in lower dimensions become homeomorphic in higher dimensions and if the symmetric intermediate is energetically favorable.

Quantile unit root inference for panel data with common shocks

This paper proposes new quantile unit root tests for panel data with common shocks, whose critical values can be simulated based on our asymptotic theory. The Monte Carlo simulation results indicate that our tests perform well in finite sample. An application for real effective exchange rates (REERs) suggests that the Purchasing Power Parity (PPP) hypothesis holds for higher quantiles but does not hold for lower ones, and the asymmetric dynamics of REERs provide a plausible explanation for the PPP puzzle. • We extend quantile unit root test to panel data with common shocks. • A simple and practical procedure for the tests is proposed, and the critical values can be obtained based on our asymptotic theory. • Monte Carlo simulations suggest the tests perform well in finite sample. • An application for real effective exchange rates (REERs) indicate that there are asymmetric dynamics in REER series, which provides a plausible explanation for the PPP puzzle.

Asymmetric vortex dynamics in two-dimensional Bose–Einstein condensate with harmonic trap potential

Based on the two-dimensional Gross–Pitaevskii equation model, we investigated the asymmetric vortex evolution of two-dimensional Bose–Einstein condensates in a harmonic potential trap with polar direction perturbation. This corresponds to the generation of an asymmetric vortex evolution mode under initial vortex light manipulation together with polar direction perturbation. Unlike most of the prior work on this topic that uses a pure numerical method for the system under study, we use an exact analytical method rather than numerical simulation to investigate the key features of the system evolution dynamics in this study. Based on the variational method, and for different system parameter settings including the strength of the harmonic oscillator potential and the nonlinear interaction, we derived two evolution modes, namely, the periodic evolution oscillation mode and the monotonic decay mode, and pictorially demonstrated the evolution patterns of the system. In addition, we investigated the scenario when the system is in the rotating state, which corresponds to the action of the quadratic centrifugal potential. Notably, we also identified the damping effects for the two modes with increasing angular velocity, whose upper limit value corresponds to the constant vortex pattern of the system. Our theoretical results can be used to guide the experimental investigation of asymmetric vortex evolution in two-dimensional Bose–Einstein condensates.

Multifrequency-based non-linear approach to analyzing implied volatility transmission across global financial markets

Research background: The contagious impact of the COVID-19 pandemic has heightened financial market's volatility, nonlinearity, asymmetric and nonstationary dynamics. Hence, the existing relationship among financial assets may have been altered. Moreover, the level of investor risk aversion and market opportunities could also alter in the pandemic. Predictably, investors in the heat of the moment are concerned about minimizing losses. In order to determine the level of hedge risks between implied volatilities in the COVID-19 pandemic through information flow, it is required to take into account the increased vagueness of economic projections as well as the increased uncertainty in asset values as a result of the pandemic. Purpose of the article: The study aims to examine the transmission of information between the VIX-implied volatility index for S&P 500 and fifteen other implied volatility indices in the COVID-19 pandemic. Methods: We relied on daily changes in the VIX and fifteen other implied volatility indices from commodities, currencies, and stocks. The study employed the improved complete ensemble empirical mode decomposition with adaptive noise which is in line with the heterogeneous expectations of market participants to denoise the data and extract intrinsic mode functions (IMFs). Subsequently, we clustered the IMFs based on common features into high, low, and medium frequencies. The analysis was carried out using Rényi transfer entropy (RTE), which allowed for the evaluation of both linear and non-linear, as well as varied distributions of the market dynamics. Findings & value added: Findings from the RTE revealed a bi-directional flow of negative information amid the VIX and each of the volatility indices, particularly in the long term. We found this behavior of the markets to be consistent at varying levels of investors' risk aversion. The findings help investors with their portfolio strategies in the time of the pandemic, which has resulted in fluctuating levels of risk aversion. Our findings characterize global financial markets to be ?non-linear heterogeneous evolutionary systems?. The results also lend support to the emerging delayed volatility of market competitiveness and external shocks hypothesis.