Domain State Research Articles

Anisotropy of magnetic susceptibility impressed during rock magnetic procedures (AF, IRM) and information on the domain state of the magnetic carriers

We present and interpret anisotropy of magnetic susceptibility (AMS) fabrics in various rocks, focusing on the effects of Alternating Field (AF) demagnetization and Isothermal Remanent Magnetization (IRM). Our findings reveal that AMS in samples from intrusive rocks with large multidomain magnetite grains is minimally affected by IRM or static AF demagnetization. In nearly isotropic volcanic rocks with titanomagnetite pseudo single domain (PSD) carriers, AMS fabrics caused by static AF demagnetization are easily identifiable, with the most prominent effect being a well-defined AMS lineation (up to 1.04) in the direction of the applied AF demagnetization. Conversely, in samples from rapidly cooled volcanic rocks with titanomagnetite of smaller magnetic grain size, an AMS foliation (∼1.02) is observed orthogonal to the direction of the applied AF field, instead of a lineation. In such samples, an IRM produces a much larger AMS foliation up to 1.3 orthogonal to the IRM. The IRM-impressed AMS is also particularly strong in metamorphic rocks in the greenschist facies with either titano-hematite or pyrrhotite magnetic carriers. Samples with the largest IRM-impressed fabric have very high Mrs/Ms ratio (>∼0.4). Mrs/Ms ratios above 0.5 may indicate the contribution of SD magnetic grains with multiaxial anisotropy. As the apparent multiaxial anisotropy is especially observed in volcanic rocks with micron size dendrites of titanomagnetites, the complex shape of the magnetic particles and their chemical composition likely play a key role in IRM-impressed AMS. AMS fabric in volcanic rocks should not be measured after static AF demagnetization. Tumbling AF demagnetization does not alter significantly the initial magnetic fabric and could be safely used in rocks with strong magnetization related to lightning possibly recording an IRM impressed AMS.

Mechanistic insights into the allosteric inactivation mechanism of ZAP-70 induced by the hot spot W165C mutation

Zeta chain-associated protein kinase 70 (ZAP-70) is a non-receptor tyrosine kinase that interacts with the activated T-cell receptor to transduce downstream signals, and thus plays an important role in the adaptive immune system. The biphosphorylated immunotyrosine-based activation motifs (ITAM-Y2P) binds to the N-SH2 and C-SH2 domains of ZAP-70 to promote the activation of ZAP-70. The present study explores molecular mechanisms of allosteric inactivation of ZAP-70 induced by the hot spot W165C mutation through atomically detailed molecular dynamics simulation approaches. We report microsecond-length simulations of two states of the tandem SH2 domains of ZAP-70 in complex with the ITAM-Y2P motif, including the wild-type and W165C mutant. Extensive analysis of local flexibility and dynamical correlated motions show that W165C mutation changes coupled motions of protein domains and community networks. The binding affinities of the ITAM-Y2P motif to the wild-type and W165C mutant of ZAP-70 are predicted using binding free energy calculations. The results suggest that the driving force to decrease the binding affinity in the W165C mutant derives from the difference in the protein-protein electrostatic interactions. Moreover, the per-residue free energy decomposition unravels that the contributions from residues in the phosphorylated Tyr315 (pY315) binding site, in particular pY315 of ITAM-Y2P, and Arg43, Tyr240 of ZAP-70, are the key determinants for the loss of binding affinity. This study may insights into our understanding of the pathological mechanism of ZAP-70. Communicated by Ramaswamy H. Sarma

Analysis of multi-center topological domain states in BiFeO3 nanodot arrays

High-density ferroelectric BiFeO3 (BFO) nanodot arrays were developed through template-assisted tailoring of epitaxial thin films. By combining piezoresponse force microscopy (PFM) and Kelvin probe force microscopy (KPFM) imaging techniques, we found that oxygen vacancies in nanodot arrays can be transported in the presence of an electric field. Besides triple-center domains, quadruple-center domains with different vertical polarizations were also identified. This was confirmed by combining the measurements of the domain switching and polarization vector distribution. The competition between the accumulation of mobile charges, such as oxygen vacancies, on the interface and the geometric constraints of nanodots led to the formation of these topological domain states. These abnormal multi-center topological defect states pave the way for improving the storage density of ferroelectric memory devices.

Comprehensive magnetic analysis of the tephras in Middle-Late Pleistocene loess records of Serbia, and implications for tephra identification, correlation and loess chronology

Tephras are highly valuable for achieving precise chronologies and secure correlations for sedimentary sequences. Rock magnetic investigations provide a simple, rapid tool for tephra identification especially for weathered tephra, cryptotephra (hidden tephra), thin and dispersed distal tephra. But so far, the most diagnostic magnetic properties for tephra identification and for differentiation of specific tephras are still uncertain. Three laterally continuous and representative tephras/cryptotephras embedded in Serbian loess deposits provide a rare opportunity to explore application of magnetic approaches in tephrostratigraphy. Systematic rock magnetic and petrographic comparison of tephra and its host loess reveal that the characteristic magnetic mineral of the studied tephras is moderate-Ti titanomagnetite of magmatic origin, with a dominant magnetic grain size of non-interacting single domain (SD) and pseudo-single domain (PSD) state. We identify the most diagnostic magnetic properties for tephra identification in loess and many other sediments. The Curie temperature of titanomagnetite is the most diagnostic property of tephras. A low-temperature alternating current (AC) magnetic susceptibility peak at ∼20–100 K is a sensitive indicator of coarse-grained titanomagnetite. SIRM-χfd and χARM-χfd plots can easily differentiate tephras from loess-paleosol sequences and possibly other pedogenesis-influenced sediments. Furthermore, our results suggest Curie temperatures can be a promising tool of regional tephra correlation. Our magnetic evidence and mineral composition analysis support the same origin of Tephra-L5 as Tephra-L4 from Alban Hills Volcanic District, possibly from the ∼457 ka eruption, which would promote a robust chronostratigraphic model of Danube loess.

Phase field study on the flexoelectric response of dielectric–ferroelectric multilayers

We report a theoretical modeling of the flexoelectric response of dielectric–ferroelectric (DE–FE) multilayers based on phase field simulations in the framework of the Landau–Ginzburg–Devonshire (LGD) theory. The correlation between negative capacitance and flexoelectric response is revealed, and the single-domain and multi-domain models are compared. It shows that the dielectric layers drive the ferroelectric layer into a negative capacitance regime, and the flexoelectric response of the multilayer is maximal when the negative capacitance of the ferroelectric layer has a minimal absolute value. Moreover, the flexoelectric response peak will be shifted to a lower temperature by increasing the thickness of dielectric layer, indicating a possibility of achieving a stronger flexoelectric response at room temperature compared with that of pure ferroelectric. However, while the single-domain model shows that the flexoelectric response peak is simply shifted to a lower temperature with near constant peak value and width, the multi-domain model reveals a significant suppressing of the flexoelectric peak by the dielectric layer. This is attributed to the formation of the vortex domain state, which eases the depolarization effect and leads to large absolute value of negative capacitance of the ferroelectric layer. Our work provides new insights into flexoelectricity in ferroelectric heterostructures.

Freestanding Oxide Membranes for Epitaxial Ferroelectric Heterojunctions.

Since facile routes to fabricate freestanding oxide membranes were previously established, tremendous efforts have been made to further improve their crystallinity, and fascinating physical properties have been also reported in heterointegrated freestanding membranes. Here, we demonstrate our synthetic recipe to manufacture highly crystalline perovskite SrRuO3 freestanding membranes using new infinite-layer perovskite SrCuO2 sacrificial layers. To accomplish this, SrRuO3/SrCuO2 bilayer thin films are epitaxially grown on SrTiO3 (001) substrates, and the topmost SrRuO3 layer is chemically exfoliated by etching the SrCuO2 template layer. The as-exfoliated SrRuO3 membranes are mechanically transferred to various nonoxide substrates for the subsequent BaTiO3 film growth. Finally, freestanding heteroepitaxial junctions of ferroelectric BaTiO3 and metallic SrRuO3 are realized, exhibiting robust ferroelectricity. Intriguingly, the enhancement of piezoelectric responses is identified in freestanding BaTiO3/SrRuO3 heterojunctions with mixed ferroelectric domain states. Our approaches will offer more opportunities to develop heteroepitaxial freestanding oxide membranes with high crystallinity and enhanced functionality.

The impact of migrants' knowledge about their social rights on their subjective wellbeing

IntroductionIn this contribution I examine the role of migrants' knowledge about their social rights (system knowledge) for their subjective well-being. Based on the Social Production Function Theory, I expect system knowledge to be positively associated with migrants' well-being. Migrants who are well informed about their social rights are likely to have better access to resources that are crucial for their well-being such as healthcare or financial security. Moreover, I expect that knowledge in certain domains which affect daily life, such as healthcare, matter more than knowledge in other domains, which are life-course specific, such as childcare.MethodsI make use of the Migrants' Welfare State Attitudes (MIFARE) data which includes the perspective on the welfare state of migrants from nine different origin countries across three receiving countries: Denmark, the Netherlands, and Germany. Linear regression analyses were applied.ResultsResults indicate that migrants differ extensively in their social rights knowledge. Moreover, migrants' knowledge about their social rights is indeed positively associated with subjective well-being, though the effect is not equally strong in all three receiving countries and differs by welfare domain (healthcare, childcare, unemployment benefits, social assistance, and state pensions).DiscussionKnowledge about social rights matters for migrants' well-being. Policy advisors should therefore pay special attention to migrants' access to information about social right policies in order to increase their well-being.

Ultrafast Infrared-to-Visible Photon Upconversion on Plasmon/TiO2 Solid Films.

Optical upconversion via a multiphoton absorption process converts incoherent low-energy photons to shorter wavelengths. In this contribution, we report a solid-state thin film for infrared-to-visible upconversion composed of plasmonic/TiO2 interfaces. When excited at λ = 800 nm, three photons are absorbed, leading to the excitation of TiO2 trap states into an emissive state in the visible domain. The plasmonic nanoparticle enhances the light absorption capabilities of the semiconductor, increasing emission efficiency by 20 times. We demonstrate that the plasmonic nanoparticle only changes the optical absorption of the semiconductor; i.e., the process is purely photonic. The process occurs in the ultrafast domain (<10 ps), contrasting with molecular triplet-triplet exciton annihilation, the commonly used method in photon upconversion, in the nano- to microsecond time scales. The process utilizes pre-existing trap states within the semiconductor bandgap and involves three-photon absorption.

Characterization of a transitionally occupied state and thermal unfolding of domain 1.1 of factor of RNA polymerase from Bacillus subtilis.

factors are essential parts of bacterial RNA polymerase (RNAP) as they allow to recognize promotor sequences and initiate transcription. Domain 1.1 of vegetative factors occupies the primary channel of RNAP and also prevents binding of the factor to promoter DNA alone. Here, we show that domain 1.1 of Bacillus subtilis exists in more structurally distinct variants in dynamic equilibrium. The major conformation at room temperature is represented by a previously reported well-folded structure solved by nuclear magnetic resonance (NMR), but 4% of the protein molecules are present in a less thermodynamically favorable state. We show that this population increases with temperature and we predict its significant elevation at higher but still biologically relevant temperatures. We characterized the minor state of the domain 1.1 using specialized methods of NMR. We found that, in contrast to the major state, the detected minor state is partially unfolded. Its propensity to form secondary structure elements is especially decreased for the first and third helices, while the second helix and strand close to the C-terminus are more stable. We also analyzed thermal unfolding of the domain 1.1 and performed functional experiments with full length and its shortened version lacking domain 1.1 ( ). The results revealed that while full length increases transcription activity of RNAP with increasing temperature, transcription with remains constant. In summary, this study reveals conformational dynamics of domain 1.1 and provides a basis for studies of its interaction with RNAP and effects on transcription regulation.

Pensions and retirement systems research: a retrospective assessment from 1910 to 2022 using bibliometric analysis

PurposeThis study aims to present a bibliometric analysis of research on pensions and retirement systems over the past 100 years. The study examines the intellectual structure and mapping in the field of pension and retirement; uncovers growth and publication patterns; identifies thematic areas in the pension domain; provides analysis of gaps; and recommends direction for future research.Design/methodology/approachThe study sourced data from the Scopus database between 1910 and 2022 covering a 112-year period. Employing bibliometric techniques, a total of 6,661 papers were selected and analyzed using SPSS and VOSviewer software.FindingsResults from the cluster analysis suggest research in this domain has focused on five thematic areas namely pension plans, retirement systems, pension schemes, demographic, and socio-economic determinants of pension and retirement decisions. The authors show from the overlay visualization output how these themes have evolved within the period under review. The study further presents major developments, conclusions and suggestions for future research directions based on insights obtained from the research themes to enrich the field of pension and retirement planning.Research limitations/implicationsThe study is useful for informing researchers and practitioners on the state of the pension domain, and findings are useful avenues in developing the research field.Originality/valueThe study adds to existing literature on pension and retirement by offering an analysis of the state of pension research over a century and highlighting areas for future research.

Policymaking in the EU under crisis conditions: Covid and refugee crises compared

We study how crises situations shape the political decision-making structure of the EU and the responses adopted by European policy makers by comparing EU decision-making in the first wave of the COVID-19 crisis (March 2020-July 2020) and in the refugee crisis (2015 to 2019), based on a new data-set on policymaking. Similarities between the two crises include: comparable polarization and conflict intensity, executive dominance, a greater role of EU institutions in policy domains where the EU has higher competence, more conflict and greater resistance by coalitions of member states in domains where it has lower competence, and minority coalitions of critical member states have been crucial for possible solutions in both crises. The key difference between the two crises lies in the fact that, in the refugee crisis, the opposing coalition was able to prevent any kind of reform, while in the first wave of the Covid crisis, the opposition was more amenable to a joint solution in the crucial fiscal policy domain, where the conflict became most intense. We suggest that this key difference is ultimately rooted in the character of the original problem pressure and the different distribution of spatial incidence in the two crises.

Drug interference with biochemical laboratory tests.

Clinical laboratory practice represents an essential part of clinical decision-making, as it influences 60-70% of medical decisions at all levels of health care. Results of biochemical laboratory tests (BLTs) have a key role in establishment of adequate diagnosis as well as in evaluation of treatment progress and outcome. The prevalence of drug-laboratory test interactions (DLTIs) is up to 43% of patients who had laboratory results influenced by drugs. Unrecognized DLTIs may lead to misinterpreted BLTs results, incorrect or delayed diagnosis, extra costs for unnecessary additional tests or inadequate therapy, as all may cause false clinical decisions. The significance of timely and adequate recognition of DLTIs is to prevent common clinical consequences such as incorrectly interpreted test results, delayed or non-treated condition due to erroneous diagnosis or unnecessary extra tests or therapy. Medical professionals should be educated that it is essential to obtain patient data about medications especially for the drugs used in the last 10 days before biological material collection. Our mini-review aims to provide a comprehensive overview of the current state in this important domain of medical biochemistry with detailed analysis of the effect of drugs on BLTs and to give detailed information to medical specialists.

Deep Reinforcement Learning-Based Joint Scheduling of 5G and TSN in Industrial Networks

5th-Generation (5G) and Time-Sensitive Networking (TSN) are regarded as competitive new technologies for future industrial networks; 5G-TSN collaboration transmission has drawn more attention because it can provide a guarantee of low-latency, ultra-reliable and deterministic transmission for time-critical automation applications. However, the methodologies of resource scheduling mechanisms in 5G and Time-Sensitive Networking (TSN) are quite different, which may lead to an inefficient Quality of Service (QoS) guarantee for deterministic transmission across 5G and TSN. Therefore, an efficient 5G-TSN joint scheduling algorithm based on Deep Deterministic Policy Gradient (DDPG) is proposed and analyzed in this article. The proposed algorithm takes both 5G radio channel information and the Gate Control List (GCL) state in the TSN domain into consideration, aiming to provide a latency guarantee for time-triggered applications across 5G and TSN as well as a throughput guarantee for video applications in 5G systems. The simulation results compare the latency and throughput performance of the proposed joint scheduling algorithm with several traditional 5G scheduling algorithms; meanwhile, several GCL setting methods are given to verify the impacts on latency and throughput performance within the proposed algorithm. The simulation results demonstrate that the proposed DDPG-based joint scheduling algorithm can significantly enhance the multi-application-carrying capability of 5G-TSN collaboration architecture.

Oligomeric state of the N-terminal domain of DnaT for replication restart in Escherichia coli

DNA replication stops when chemical or physical damage occurs to the DNA. Repairing genomic DNA and reloading the replication helicase are crucial steps for restarting DNA replication. The Escherichia coli primosome is a complex of proteins and DNA responsible for reloading the replication helicase DnaB. DnaT, a protein found in the primosome complex, contains two functional domains. The C-terminal domain (89–179) forms an oligomeric complex with single-stranded DNA. Although the N-terminal domain (1–88) forms an oligomer, the specific residues responsible for this oligomeric structure have not yet been identified.In this study, we proposed that the N-terminal domain of DnaT has a dimeric antitoxin structure based on its primary sequence. Based on the proposed model, we confirmed the site of oligomerization in the N-terminal domain of DnaT through site-directed mutagenesis. The molecular masses and thermodynamic stabilities of the site-directed mutants located at the dimer interface, namely Phe42, Tyr43, Leu50, Leu53, and Leu54, were found to be lower than those of the wild-type. Moreover, we observed a decrease in the molecular masses of the V10S and F35S mutants compared to the wild-type DnaT. NMR analysis of the V10S mutant revealed that the secondary structure of the N-terminal domain of DnaT was consistent with the proposed model. Additionally, we have demonstrated that the stability of the oligomer formed by the N-terminal domain of DnaT is crucial for its function. Based on these findings, we propose that the DnaT oligomer plays a role in replication restart in Escherichia coli.

Frequency-domain engineering of bright squeezed vacuum for continuous-variable quantum information.

Multimode bright squeezed vacuum is a non-classical state of light hosting a macroscopic photon number while offering promising capacity for encoding quantum information in its spectral degree of freedom. Here, we employ an accurate model for parametric down-conversion in the high-gain regime and use nonlinear holography to design quantum correlations of bright squeezed vacuum in the frequency domain. We propose the design of quantum correlations over two-dimensional lattice geometries that are all-optically controlled, paving the way toward continuous-variable cluster state generation on an ultrafast timescale. Specifically, we investigate the generation of a square cluster state in the frequency domain and calculate its covariance matrix and the quantum nullifier uncertainties, that exhibit squeezing below the vacuum noise level.

A Novel Ship Domain-oriented Parameter of Ship Collision Risk Considering the Ship Maneuverability and Encounter Situation

The identification of ship collision risks is an important element in maritime safety and management. The concept of the ship domain has also been studied and developed since it was proposed. Considering the existing trend that the ship domain is increasingly widely used in collision risk-related research, a new domain-oriented collision risk factor, i.e., the current state of domain (CSD), is introduced in this paper, which can effectively reflect the current state and show a certain predictability of collision risk from the perspective of the ship domain. To further prove the rationality of the CSD, a series of different simulations consisting of three typical encounter scenarios were conducted, verifying the superiority of the proposed parameter.

A comparison of modified extremal optimization algorithm vs quenching for electron glass system optimization

Coulomb glass or electron glass refers to a system of localized electrons interacting via unscreened Coulomb interactions. The electrons are localized on a square lattice site, and the site's energies are random. This model was mainly used to represent amorphous and compensated semiconductors at high disorders and low temperatures. Recently, the model has been used to model granular systems, an array of nanocrystals, and graphene. In this work, we have obtained the ground state of an electron glass model in two dimensions using a modified extremal optimization. The work is done for disorders less than the critical disorder and at half-filling. For this case, the ground state has anti-ferromagnetic ordering, unlike the high disorder case. This allows us to check the efficiency of our new algorithm.The results are compared with quenching using Monte Carlo simulation. In the electron glass model, the number of electrons is conserved, and the interaction is long-ranged. Extremal optimization was developed to obtain the ground state of short-ranged spin systems with a non-conserved magnetization. The algorithm was extended to find the ground state of a long ranged anti-ferromagnet with conserved magnetization. We show that the efficiency of extremal optimization is comparable to the quenching method. The efficiency for both ways decreases as the disorder is increased. The minimum energy states obtained consist of mainly two large domains when the ground state was not achieved. These meta-stable states are stable, and increasing the run time increases the efficiency only by a small amount. The stability of the domains is analyzed using an activity graph. A comparison of the activity graphs for the same disorder configuration for the two algorithms shows that the formation of a meta-stable state is a general feature independent of the algorithm used. The formation of domain states is more prevalent for specific disorder configurations. These results can be explained in terms of domain formation theory.

Thermal Resolution of Unblocking Temperatures (TROUT): A Method for “Unmixing” Multi‐Component Magnetizations

AbstractSome rocks contain multiple remanence “components,” each of which preserves a record of a different magnetic field. The temperature ranges over which these remanence components unblock can overlap, making it difficult to determine their directions. We present a data analysis tool called Thermal Resolution Of Unblocking Temperatures (TROUT) that treats the process of thermal demagnetization as a function of temperature (or alternating field demagnetization as a function of coercivity). TROUT models the unblocking temperature/coercivity distributions of components in a demagnetization experiment, allowing these distributions to overlap. TROUT can be used to find the temperatures/coercivities over which paleomagnetic directions change and when two directional components overlap resulting in curved demagnetization trajectories. When applied to specimens given multi‐component Thermoremanent Magnetizations (TRMs) in the laboratory, the TROUT method estimates the temperature at which the partial TRMs were acquired to within one temperature step, even for specimens with significant overlap. TROUT has numerous applications: knowing the temperature at which the direction changes is useful for experiments in which the thermal history of a specimen is of interest (e.g., emplacement temperature of pyroclastic deposits, re‐heating of archaeological artifacts, reconstruction of cooling rates of igneous bodies). The ability to determine whether a single component or multiple components are demagnetizing at a given temperature is useful for choosing appropriate ranges of temperatures to use in paleodirection/intensity experiments. Finally, the width of the range of temperature overlap may be useful for inferring the composition, grain size and domain state of magnetic mineral assemblages.

Exchange biased surface acoustic wave magnetic field sensors

Magnetoelastic composites which use surface acoustic waves show great potential as sensors of low frequency and very low amplitude magnetic fields. While these sensors already provide adequate frequency bandwidth for most applications, their detectability has found its limitation in the low frequency noise generated by the magnetoelastic film. Amongst other contributions, this noise is closely connected to domain wall activity evoked by the strain from the acoustic waves propagating through the film. A successful method to reduce the presence of domain walls is to couple the ferromagnetic material with an antiferromagnetic material across their interface and therefore induce an exchange bias. In this work we demonstrate the application of a top pinning exchange bias stack consisting of ferromagnetic layers of (Fe90Co10)78Si12B10 and Ni81Fe19 coupled to an antiferromagnetic Mn80Ir20 layer. Stray field closure and hence prevention of magnetic edge domain formation is achieved by an antiparallel biasing of two consecutive exchange bias stacks. The set antiparallel alignment of magnetization provides single domain states over the complete films. This results in a reduction of magnetic phase noise and therefore provides limits of detection as low as 28 pT/Hz1/2 at 10 Hz and 10 pT/Hz1/2 at 100 Hz.

Extrusion foaming of multiphasic polyethylene/ethylene-vinyl acetate copolymer/carbon nanotube mixtures: Tailoring foam properties by selective localization of nanoparticles

Semi-conductive foams based on low-density polyethylene/ethylene-vinyl acetate copolymer (LDPE/EVA) blends in the presence of carbon nanotubes (CNTs) were prepared using a twin-screw extrusion process. The effects of CNTs content and localization state in the binary mixture on the physical and structural properties of LDPE/EVA/CNT foams were investigated. The results confirmed that the void fraction, cell density, bubble size and cell size distribution of foams are optimal against CNT loading. The lightest LDPE/EVA/CNT foam was obtained by the CNT localization in the LDPE matrix. This foam containing 2.5 phr of CNT had smaller cells and more uniform cell size comparing to the pure blend foam. The cell density of this foam was 1.598 × 106 cells/cm3, which is much larger than that for the blend foam, 8.64 × 105 cells/cm3. However, the CNT localization state in the dispersed EVA domains resulted in lower void fractions and cell densities comparing with the LDPE/EVA blend foam. The findings clarify the profound impact of the nanofiller localization state on the foam properties of the binary polymeric systems. Light semiconductive LDPE/EVA foams with small cells, uniform cell size and high cell densities were achieved by localizing and dispersing the CNT nanoparticles in the LDPE matrix phase.