Sequence Of Transitions Research Articles

Vortices on cylinders and warped exponential networks

We study 3d N=2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {N}=2$$\\end{document}U(1) Chern–Simons-Matter QFT on a cylinder C×R\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$C\ imes \\mathbb {R}$$\\end{document}. The topology of C gives rise to BPS sectors of low-energy solitons known as kinky vortices, which interpolate between (possibly) different vacua at the ends of the cylinder and at the same time carry magnetic flux. We compute the spectrum of BPS vortices on the cylinder in an isolated Higgs vacuum, through the framework of warped exponential networks, which we introduce. We then conjecture a relation between these and standard vortices on R2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb {R}^2$$\\end{document}, which are related to genus-zero open Gromov–Witten invariants of toric branes. More specifically, we show that in the limit of large Fayet–Iliopoulos coupling, the spectrum of kinky vortices on C undergoes an infinite sequence of wall-crossing transitions and eventually stabilizes. We then propose an exact relation between a generating series of stabilized CFIV indices and the Gromov–Witten disk potential and discuss its consequences for the structure of moduli spaces of vortices.

Generalized XY Models with Arbitrary Number of Phase Transitions

We propose spin models that can display an arbitrary number of phase transitions. The models are based on the standard XY model, which is generalized by including higher-order nematic terms with exponentially increasing order and linearly increasing interaction strength. By employing Monte Carlo simulation we demonstrate that under certain conditions the number of phase transitions in such models is equal to the number of terms in the generalized Hamiltonian and, thus, it can be predetermined by construction. The proposed models produce the desirable number of phase transitions by solely varying the temperature. With decreasing temperature the system passes through a sequence of different phases with gradually decreasing symmetries. The corresponding phase transitions start with a presumably BKT transition that breaks the U(1) symmetry of the paramagnetic phase, and they proceed through a sequence of discrete Z2 symmetry-breaking transitions between different nematic phases down to the lowest-temperature ferromagnetic phase.

Biochemical analysis of packing and assembling heptad repeat motifs in the coronavirus spike protein trimer.

During a coronavirus infection, the spike protein undergoes sequential structural transitions triggered by its receptor and the host protease at the interface between the virus and cell membranes, thereby mediating membrane fusion. After receptor binding, the heptad repeat motif (HR1/HR2) within the viral spike protein bridges the viral and cellular membranes; however, the intermediate conformation adopted by the spike protein when drawing the viral and cellular membranes into close proximity remains unclear due to its transient and unstable nature. Here, we experimentally induced conformational changes in the spike protein of a murine coronavirus by incubating the virus with its receptor, followed by exposure to trypsin. We then treated the virus/receptor complex with proteinase K to probe the tightly packed core structure of the spike protein. The conformations of the spike protein were predicted from the sizes of the protease digestion products detected by western blot analysis. Upon receptor binding, two bands (each showing different reactivity with a fusion-inhibiting HR2-peptide) were detected; we propose that these bands correspond to the packed and unpacked HR1/HR2 motifs. After trypsin-mediated triggering, measurement of temperature and time dependency revealed that packing of the remaining unpacked HR1/HR2 motifs and assembly of three HR1 motifs in a trimer occur almost simultaneously. Thus, the trimeric spike protein adopts an asymmetric-unassembled conformation after receptor binding, followed by direct assembly into the post-fusion form triggered by the host protease. This biochemical study provides mechanistic insight into the previously unknown intermediate structure of the viral fusion protein.IMPORTANCEDuring infection by an enveloped virus, receptor binding triggers fusion between the cellular membrane and the virus envelope, enabling delivery of the viral genome to the cytoplasm. The viral spike protein mediates membrane fusion; however the molecular mechanism underlying this process is unclear. This is because using structural biology methods to track the transient conformational changes induced in the unstable spike trimer is challenging. Here, we harnessed the ability of protease enzymes to recognize subtle differences on protein surfaces, allowing us to detect structural differences in the spike protein before and after conformational changes. Differences in the size of the degradation products were analyzed by western blot analysis. The proposed model explaining the conformational changes presented herein is a plausible candidate that provides valuable insight into unanswered questions in the field of virology.

Retirement Transition Sequences and Well-Being Among Older Workers Focusing on Gender Differences

ABSTRACT This study examines retirement transition patterns and well-being in later life, focusing on gender differences using data from the 2004–2016 Health and Retirement Study (HRS) with 1,653 older workers. Sequence analysis identifies key retirement patterns, showing that men predominantly transitioned from full-time to mid-time voluntary retirement, while women experienced more gradual involuntary retirement. Involuntary retirees, both men and women, had precarious work histories and poorer mental health. The findings highlight gender-specific implications for social policy and emphasize the need for support in promoting successful aging and reducing social inequities among involuntary retirees.

Manipulation of Supramolecular Chirality in Bicontinuous Networks of Bent-Shaped Polycatenar Dimers.

Bicontinuous cubic liquid crystalline (LC) phases are of particular interest due their possible applications in electronic devices and special supramolecular chirality. Herein, we report the design and synthesis of first examples of achiral bent-shaped polycatenar dimers, capable of displaying mirror symmetry breaking in their cubic and isotropic liquid phases. The molecules have a taper-shaped 3,4,5-trialkoxybenzoate segment connected to rod-like building unit terminated with one terminal flexible chain. The two segments were connected using an aliphatic spacer with seven methylene units to induce bending of the whole structure. Investigated by the small-angle X-ray scattering (SAXS), a double network achiral cubic phase Cub/Ia3 d, which is a meso-structure, and a chiral triple network cubic phase Cub/I23[*] are formed. The molecules self-assemble into molecular helices and progress along the networks. Interestingly, different linking groups such as ester or azo linkages and core fluorination lead to distinct local helicity, resulting in an alkyl chain volume dependent phase transition sequence Ia3d(L)-I23*-Ia3d(S). The re-entry of Iad phase and loss of supramolecular chirality is attributed to the delicate influence of steric effect at the mono-substitute end and interhelix interaction. Besides, aromatic core fluorination was proved to be a successful tool stabilizing the cubic phases in these dimers.

Molecular Dynamics, Dielectric Properties, and Textures of Protonated and Selectively Deuterated 4'-Pentyl-4-biphenylcarbonitrile Liquid Crystal.

Using liquid crystals in near-infrared applications suffers from effects related to processes like parasitic absorption and high sensitivity to UV-light exposure. One way of managing these disadvantages is to use deuterated systems. The combined 1H and 2H nuclear magnetic resonance relaxometry method (FFC NMR), dielectric spectroscopy (DS), optical microscopy (POM), and differential scanning calorimetry (DSC) approach was applied to investigate the influence of selective deuteration on the molecular dynamics, thermal properties, self-organization, and electric-field responsiveness to a 4'-pentyl-4-biphenylcarbonitrile (5CB) liquid crystal. The NMR relaxation dispersion (NMRD) profiles were analyzed using theoretical models for the description of dynamics processes in different mesophases. Obtained optical textures of selectively deuterated 5CB showed the occurrence of the domain structure close to the I/N phase transition. The dielectric measurements showed a substantial difference in switching fields between fully protonated/deuterated 5CB and selectively deuterated molecules. The DSC thermograms showed a more complex phase transition sequence for partially deuterated 5CB with respect to fully protonated/deuterated molecules.

Tolerance to asynchrony in algorithms for multiplication and modulo

In this article, we study some parallel processing algorithms for multiplication and modulo operations. We demonstrate that the state transitions that are formed under these algorithms satisfy lattice-linearity, where these algorithms induce a lattice among the global states. Lattice-linearity implies that these algorithms can be implemented in asynchronous environments, where the nodes are allowed to read old information from each other. It means that these algorithms are guaranteed to converge correctly without any synchronization overhead. These algorithms also exhibit snap-stabilizing properties, i.e., starting from an arbitrary state, the sequence of state transitions made by the system strictly follows its specification.

Flow Characteristics and Heat Transfer Enhancement of Electro-Thermo-Convection in Dielectric Liquids With Residual Conductivity

Abstract The flow features and heat transfer enhancement of electro-thermo-convection (ETC) in dielectric liquids with residual conductivity between concentric electrodes are numerically studied based on an injection–conduction model. The strongly coupled flow field, electric field, and positive/negative charge density of the ETC system are solved numerically based on the finite volume framework of OpenFOAM®. The total variation-diminishing algorithm is adopted to handle the complex nonlinearity of the positive/negative charge transport equations. The bifurcation of plentiful flow states that are characterized by variable plumes and vortex pairs in the ETC system is investigated. It is discovered that the residual conductivity postpones the beginning of ETC flow, inhibits the convection intensity, and also diminishes heat transfer of the ETC system. In addition, the transition sequences of ETC flow are also influenced by residual conductivity. A higher residual conductivity suppresses the occurrence of different intermediate steady-states. Three different transition sequences of steady ETC states at different Rayleigh numbers (Ra) are identified. The critical point where the ETC flow bifurcates to S8 is postponed at higher Ra. And the ETC system is more prone to chaos in a system of higher Ra. The periodicity of the ETC system is analyzed and found that Ra has little influence on the periodicity.

Structural Phase Transitions and Metallization in Zirconium Disulfide (ZrS2) under High Pressure.

The high-pressure study on zirconium disulfide (ZrS2) has been conducted up to ∼33.9 GPa by using in-situ synchrotron X-ray diffraction at room temperature and electrical transport measurements, aiming to investigate the pressure-induced structural phase transitions and the metallization of the material. The experiments indicated that a progressive structural evolution occurs as the sequence below: hexagonal (space group (SG): P3̅m1) → monoclinic (SG: P21/m) started at 2.8 GPa → orthorhombic (SG: Immm) started at 9.9 GPa → tetragonal (SG: I4/mmm) started at 30.4 GPa. The lattice parameters and bulk modulus of the phases at high pressure are calculated. The decompression results demonstrate the coexistence of ZrS2 stability in monoclinic (SG: P21/m) and orthorhombic (SG: Immm) structures. The electrical transport results demonstrate a significant enhancement in the conductivity of ZrS2 at 8 GPa, and metallization occurs at ∼29.8 GPa. Combined with XRD results, the metallization is coincident with the phase transition to the tetragonal (SG: I4/mmm) structure. Our study presents a more precise phase transition sequence, calculates the cell parameters and bulk modulus of ZrS2 under high-pressure conditions based on experimental results, and confirms that metallization is induced by the structural phase transition. These findings provide an experimental basis for the further utilization of transition metal sulfides (TMDs) under high pressure.

Altered Patterns of Maternal Behavior Transitions in Rats Exposed to Limited Bedding and Nesting Material Paradigm.

Maternal care plays a fundamental role in early life, and the alteration of its patterns can negatively affect the developmental course of the offspring in a myriad of domains in both rats and humans. The limited bedding and nesting (LBN) protocol is an extensively used paradigm in rodents to address the impact of altered maternal behavior patterns on infants' neurodevelopment. Here, we explore the altered patterns of maternal care in rats in LBN conditions by describing sequences of transition between maternal behavior components using network analysis. Using this technique, we capture how often maternal behavior transitions take place during the LBN period and which behaviors play central roles in those transitions over time. Female rats and their pups were placed in standard and LBN housing conditions from Postpartum Days 2 to 9, during which maternal behavior was observed during the light and dark phases. We used inferential statistical analysis to compare the maternal behavior profiles of control and LBN dams, and network analysis was used to capture the altered sequence of maternal behavior transitions during the period of LBN. Compared to control dams, LBN dams significantly increased their high crouch nursing posture during light/dark phases (p=0.018), and the number of behavioral transitions increased only during the dark phase (p=0.0004). Network analysis revealed specific altered patterns of behavioral transitions in LBN dams, characterized by the predominance of switches between active nursing postures during the first five days of the LBN protocol. Nursing behavior was the most disrupted component of maternal behavior under the LBN protocol, mainly during the dark phase. Network analysis can complement and extend traditional methods to gain a more thorough understanding of maternal care strategies and behavioral patterns in LBN conditions and potential consequences for the offspring.

Establishing universality in entropy change and critical behavior for magnetocaloric effect in Si-substituted Mn50Ni40Sn10 inverse Heusler alloy

Magnetic refrigeration working based on the magnetocaloric effect can be the perfect replacement of the conventional gas compression-based refrigeration technology and reduces its harmful effects on the environment. The boundary between a first-order and a second-order phase transition would be where the perfect magnetocaloric material would be found. Therefore, establishing the sequence of phase transitions clearly is essential for the characterization of other phase change materials and for applied magnetocaloric research. A quantitative fingerprint of second-order thermomagnetic phase transitions is reported here in Si-substituted high content Mn-based inverse Heusler alloy systems, which are found to be crystallized in cubic structures. The second-order nature of the phase transition has been confirmed from the Arrott plot analysis and a correlation between magnetocaloric effect and local exponent is established. Using the Arrott plot, the critical exponents are evaluated employing different techniques such as modified Arrott plot, Kouvel–Fisher method, and critical isotherm. Their values are found to be in great agreement with each other and follow the mean-field model signifying the presence of long-range ordering in the materials. The high value of isothermal magnetic entropy change and the reversibility justifies the suitability of the reported materials in the practical application as magnetic refrigerants.

HoLens: A visual analytics design for higher-order movement modeling and visualization

AbstractHigher-order patterns reveal sequential multistep state transitions, which are usually superior to origin-destination analyses that depict only firstorder geospatial movement patterns. Conventional methods for higher-order movement modeling first construct a directed acyclic graph (DAG) of movements and then extract higher-order patterns from the DAG. However, DAG-based methods rely heavily on identifying movement keypoints, which are challenging for sparse movements and fail to consider the temporal variants critical for movements in urban environments. To overcome these limitations, we propose HoLens, a novel approach for modeling and visualizing higher-order movement patterns in the context of an urban environment. HoLens mainly makes twofold contributions: First, we designed an auto-adaptive movement aggregation algorithm that self-organizes movements hierarchically by considering spatial proximity, contextual information, and temporal variability. Second, we developed an interactive visual analytics interface comprising well-established visualization techniques, including the H-Flow for visualizing the higher-order patterns on the map and the higher-order state sequence chart for representing the higher-order state transitions. Two real-world case studies demonstrate that the method can adaptively aggregate data and exhibit the process of exploring higher-order patterns using HoLens. We also demonstrate the feasibility, usability, and effectiveness of our approach through expert interviews with three domain experts.

Theoretical study of the working process of a multivariate cabbage harvester

BACKGROUND. A multi-variant cabbage harvester of a block-modular design is proposed for small-scale farming in vegetable growing. At the same time, it is planned to complete the cabbage harvester in three versions: with an elevator, with a lower longitudinal conveyor, with an elevator and an upper longitudinal conveyor. AIMS – modeling the working process of a multivariate cabbage harvester to identify its main technological parameters that ensure the efficiency of its operation. MATERIALS AND METHODS. The working process of a multivariate cabbage harvester is presented as the functioning of a certain physical system, the state of which changes during the technological process over time depending on stochastic factors. The process of sequential transition of a system from one state to another is considered on the basis of queuing theory depending on the intensity of movement of the flow of heads of cabbage λ in the technological line of the machine and the intensity of service μ of this flow. In this work, the limiting probabilities of the model states are determined and the stochastic indicators of its functioning are calculated. RESULTS AND DISCUSSION. Based on the results of calculations of stochastic indicators of the functioning of the model, the optimal number of service personnel people was established, when the maximum probability of servicing cabbage heads can be up to 0.934. CONCLUSIONS. The workflow of a multivariate cabbage harvester is modeled as a stationary stochastic queuing process. Based on the research results, it is recommended to take the number of service personnel at the combine refining table as .

Dynamic formation of the protein-lipid prefusion complex

Synaptic vesicles (SVs) fuse with the presynaptic membrane (PM) to release neuronal transmitters. The SV protein synaptotagmin 1 (Syt1) serves as a Ca2+ sensor for evoked fusion. Syt1 is thought to trigger fusion by penetrating the PM upon Ca2+ binding; however, the mechanistic detail of this process is still debated. Syt1 interacts with the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) complex, a coiled-coil four-helical bundle that enables the SV-PM attachment. The SNARE-associated protein complexin (Cpx) promotes Ca2+-dependent fusion, possibly interacting with Syt1. We employed all-atom molecular dynamics to investigate the formation of the Syt1-SNARE-Cpx complex interacting with the lipid bilayers of the PM and SVs. Our simulations demonstrated that the PM-Syt1-SNARE-Cpx complex can transition to a “dead-end” state, wherein Syt1 attaches tightly to the PM but does not immerse into it, as opposed to a prefusion state, which has the tips of the Ca2+-bound C2 domains of Syt1 inserted into the PM. Our simulations unraveled the sequence of Syt1 conformational transitions, including the simultaneous docking of Syt1 to the SNARE-Cpx bundle and the PM, followed by Ca2+ chelation and the penetration of the tips of Syt1 domains into the PM, leading to the prefusion state of the protein-lipid complex. Importantly, we found that direct Syt1-Cpx interactions are required to promote these transitions. Thus, we developed the all-atom dynamic model of the conformational transitions that lead to the formation of the prefusion PM-Syt1-SNARE-Cpx complex. Our simulations also revealed an alternative dead-end state of the protein-lipid complex that can be formed if this pathway is disrupted.

In situ synchrotron X-ray diffraction study: Phase evolution in transition zone of TiAl/Ti2AlNb dual alloy fabricated by laser-directed energy deposition

The phase evolution in the transition zone (TZ) of TiAl/Ti2AlNb dual alloy during laser-directed energy deposition (L-DED) process was investigated using in situ synchrotron radiation X-ray diffraction. The as-solidified microstructure of the TZ forms through the following phase transitions: Liquid→ Liquid + β/B2 →β/B2→ β/B2 + α2. Thermal cycles promote the β/B2 to α2 phase transition with the α2 phase precipitates from the (011) plane of the β/B2 matrix during this transition. The phase transition sequence of the TZ during the first thermal cycle is: β/B2 + α2 → β/B2 → β/B2 + α2. The second thermal cycle leads to a partial transformation of β/B2 phase to α2 phase. The TZ experiences no phase transition from the third thermal cycle. This study provides a comprehensive understanding of the phase formation mechanism in the TZ of L-DEDed TiAl/Ti2AlNb dual alloys.

Experimental behaviour and fatigue life prediction of bonded joints subjected to variable amplitude fatigue

The variable amplitude fatigue behaviour of adhesive joints has not been extensively considered in literature and considerable knowledge gaps regarding its underlying mechanisms still exist, hindering accurate life prediction. This study investigates the effect of loading sequence and number of load transitions on single lap joints (SLJs) bonded with a toughened epoxy adhesive. Life prediction is also conducted using established cumulative rules: Palmgren–Miner (PM), Broutman and Sahu (BS) and, Hashin and Rotem (HR). To overcome their limitations, a modified Cortan–Dolan approach is proposed. For this, SLJs were subjected to single transition (low-to-high and high-to-low load transitions at different stages of the fatigue life and with different magnitudes) and multi-block loading spectra with different numbers of transitions.Results showed an extension of the fatigue life for high-to-low transitions. This was attributed to a combination of load interaction effects, as evidenced by an elastoplastic numerical simulation, and non-linear damage accumulation. Conversely, low-to-high transitions exhibited a damaging effect. For single transition spectra, BS and HR models were seen to improve prediction over PM by indirectly considering these effects. The proposed approach further improved this prediction. Multi-block results showed no significant influence of the number of load transitions and were satisfactorily predicted using PM.

Visible/near-infrared luminescence and concentration effects of Pr3+-doped Sr2Al2GeO7 downconversion phosphors

The Pr3+ ion has been widely doped into various materials as a red and near-infrared (NIR) emitting center for applications in lighting and solar spectrum downconversion. Herein, the preparation of a new library of Pr3+-doped Sr2Al2GeO7 phosphors was proved by powder x-ray diffraction patterns and Rietveld refinements and characterized by a scanning electron microscope with energy-dispersive x-ray spectrometry. The Sr2Al2GeO7:Pr3+ sample strongly absorbs blue photons over 420–500 nm and yields intense visible emissions with dominant peaks around 490 nm from the Pr3+ 3P0 → 3H4 transition, as well as robust NIR emission bands over 800–1200 nm. In addition to the typical transitions of 1D2 → 3F2 at 880 nm, 1G4 → 3H4 at 1000 nm, and 1D2 → 3F3,4 at 1070 nm, the distinguishable NIR emission at 929 nm was demonstrated from the 3P0 → 1G4 transition via static and dynamic spectroscopic analysis. Most interestingly, for the 3P0 blue-excited state, a considerably elevated concentration of about 10%Pr3+ was optimal for the visible/NIR emissions, in stark contrast to the diluted optimal 1%Pr3+ for the 1D2 state. The relevant cross-relaxation from the 3P0 and 1D2 states between Pr3+ was comprehensively treated by theoretical speculations and experimental results. Such concentrated Pr3+ blue activators would significantly facilitate the blue-to-NIR downconversion through a desired two-step sequential transition from the 3P0 initial state to the 1G4 intermediate level for quantum efficiency exceeding unity. The current results would consolidate the basis of concentrated Pr3+ donors to promote the novel Pr3+/Yb3+ codoping downconversion for greatly increasing Si solar cell efficiency.

A sequential transit network design algorithm with optimal learning under correlated beliefs

Mobility service route design requires demand information to operate in a service region. Transit planners and operators can access various data sources including household travel survey data and mobile device location logs. However, when implementing a mobility system with emerging technologies, estimating demand becomes harder because of limited data resulting in uncertainty. This study proposes an artificial intelligence-driven algorithm that combines sequential transit network design with optimal learning to address the operation under limited data. An operator gradually expands its route system to avoid risks from inconsistency between designed routes and actual travel demand. At the same time, observed information is archived to update the knowledge that the operator currently uses. Three learning policies are compared within the algorithm: multi-armed bandit, knowledge gradient, and knowledge gradient with correlated beliefs. For validation, a new route system is designed on an artificial network based on public use microdata areas in New York City. Prior knowledge is reproduced from the regional household travel survey data. The results suggest that exploration considering correlations can achieve better performance compared to greedy choices and other independent belief-based techniques in general. In future work, the problem may incorporate more complexities such as demand elasticity to travel time, no limitations to the number of transfers, and costs for expansion.

TripChain2RecDeepSurv: A novel framework to predict transit users’ lifecycle behavior status transitions for user management

Transit users’ lifecycle behavior pattern transition reflects the continuous and multi-phase changes in how frequently and regularly users utilize public transit over their lifetime. Predicting transit users’ lifecycle behavior pattern transition is vital for enhancing the efficiency and responsiveness of transportation systems. Thus, this study incorporates lifecycle analysis in predicting long-term sequential behavioral pattern transition processes to go beyond just examining user churning at a single point in time. Specifically, this study proposes the TripChain2RecDeepSurv, a novel model that pioneers the individual-level analysis of lifecycle behavior status transitions (LBST) within public transit systems. The TripChain2RecDeepSurv is composed of (1) the TripChain2Vec module for encoding transit users’ trip chains; (2) the self-attention Transformer module for exploring the latent features related to spatiotemporal patterns; (3) the recurrent deep survival analysis module for predicting LBSTs. We demonstrate TripChain2RecDeepSurv’s predictive performance for empirical analysis by employing Shenzhen Bus data. Our model achieves a 74.39% accuracy rate in churn determination and over 80% accuracy in status sequence identification on the churn path. In addition, our findings highlight the segmented nature of Kaplan-Meier curves and identify the optimal intervention time against the user churning process. Meanwhile, the proposed model provides individual-level heterogeneity analysis, which emphasizes the significance of customizing user engagement strategies, advocating for interventions that extend users’ engagement in patterns with high-frequency transit usage to curb the transition to less frequent travel usage.

Research on transition sequence partitioning based on dependency relationships

Research on transition sequence partitioning based on dependency relationships