Mixed Polarity Research Articles

Limit of geometric quantizations on Kähler manifolds with T‐symmetry

AbstractA compact Kähler manifold with ‐symmetry admits a natural mixed polarization whose real directions come from the ‐action. In Leung and Wang [Adv. Math. 450 (2024), 109756], we constructed a one‐parameter family of Kähler structures ’s with the same underlying Kähler form and , such that (i) there is a ‐equivariant biholomorphism between and and (ii) Kähler polarizations ’s corresponding to ’s converge to as goes to infinity. In this paper, we study the quantum analog of above results. Assume that is a prequantum line bundle on . Let and be quantum spaces defined using polarizations and , respectively. In particular, . They are both representations of . We show that (i) there is a ‐equivariant isomorphism between and and (ii) for regular ‐weight , corresponding ‐weight spaces ’s converge to as goes to infinity.

A Power Optimization Approach for Large-scale RM-TB Dual Logic Circuits Based on an Adaptive Multi-Task Intelligent Algorithm

Logic synthesis is a crucial step in integrated circuit design, and power optimization is an indispensable part of this process. However, power optimization for large-scale Mixed Polarity Reed-Muller (MPRM) logic circuits is an NP-hard problem. In this article, we divide Boolean circuits into small-scale circuits based on the idea of divide and conquer using the proposed Dynamic Adaptive Grouping Strategy (DAGS) and the proposed circuit decomposition model (CDM). Each small-scale Boolean circuit is transformed into an MPRM logic circuit by a polarity transformation algorithm. Based on the gate-level integration, we integrate small-scale circuits into an MPRM and Boolean Dual Logic (RBDL) circuit. Furthermore, the power optimization problem of RBDL circuits is a multi-task, multi-extremal, high-dimensional combinatorial optimization problem, for which we propose an Adaptive Multi-task Intelligent Algorithm (AMIA), which includes global task optimization, population reproduction, valuable knowledge transfer (VKT), and local exploration to search for the lowest power for RBDL circuits. Moreover, based on the proposed Fast Power Decomposition Algorithm (FPDA), we proposed a Power Optimization Approach (POA) for an RBDL circuit with the lowest power using the AMIA. Experimental results based on Microelectronics Center of North Carolina (MCNC) Benchmark test circuits demonstrate the effectiveness and superiority of the POA compared to state-of-the-art POAes.

The radial-tangential anisotropy of numerosity perception.

Humans can estimate the number of visually presented items without counting. In most studies on numerosity perception, items are uniformly distributed across displays, with identical distributions in central and eccentric parts. However, the neural and perceptual representation of the human visual field differs between the fovea and the periphery. For example, in peripheral vision, there are strong asymmetries with regard to perceptual interferences between visual items. In particular, items arranged radially usually interfere more strongly with each other than items arranged tangentially (the radial-tangential anisotropy). This has been shown for crowding (the deleterious effect of clutter on target identification) and redundancy masking (the reduction of the number of perceived items in repeating patterns). In the present study, we tested how the radial-tangential anisotropy of peripheral vision impacts numerosity perception. In four experiments, we presented displays with varying numbers of discs that were predominantly arranged radially or tangentially, forming strong and weak interference conditions, respectively. Participants were asked to report the number of discs. We found that radial displays were reported as less numerous than tangential displays for all radial and tangential manipulations: weak (Experiment 1), strong (Experiment 2), and when using displays with mixed contrast polarity discs (Experiments 3 and 4). We propose that numerosity perception exhibits a significant radial-tangential anisotropy, resulting from local spatial interactions between items.

Observation of tropical positive cloud-to-ground flashes accompanied by chaotic and regular pulse trains

This study investigates the occurrence of chaotic pulse trains (CPTs) and regular pulse trains (RPTs) in tropical positive cloud-to-ground (CG) lightning flashes. These flashes are categorized into four types based on the initial polarity of the initial breakdown (IB) pulses and their relationship to the first return stroke (RS). A total of 71 positive CG flashes from five thunderstorm events were analyzed. The analysis reveals instances of CPTs and RPTs both before and after the first positive RS, along with the occurrence of mixed polarities in RPTs. Variations in IB pulse polarities and the presence of CPTs and RPTs before the first positive RS were observed, contrasting with previous findings in negative CG flashes. All positive CG flashes have been detected when cloud top height occurrences were between 12 and 18 km. In contrast, for negative CG flashes with CPTs and RPTs the cloud top height occurrences were between 5 and 12 km. It is interesting that CPTs and RPTs can be detected during IB process of positive CG flashes at relatively high altitude in the thundercloud. Perhaps due to low pressure at higher altitudes in the cloud, electrical process associated with CPTs and RPTs are easily discharged before the occurrence first positive return stroke. The altitudes of cloud top heights for the inverse polarity of IB pulses were located between 16 and 18 km. This research enhances the understanding of positive CG lightning initiation process and their relationship with CPTs and RPTs, as well as the occurrence of recoil leaders.

Legume: A free implementation of the guided-mode expansion method for photonic crystal slabs

We describe legume, a free electromagnetic solver that implements the guided-mode expansion method for patterned multilayer waveguides, or photonic crystal slabs. legume has a built-in tool for automatic differentiation, which makes it suitable for the inverse design of photonic crystal structures with desired physical properties. Compared to a previous version of the method (M. Minkov et al., 2020 [12]), here we introduce several new features of the code, we discuss additional technical aspects of the method and its numerical implementation. The novel features that are treated in this paper include: (i) the separation of modes according to their mirror symmetry with respect to a vertical symmetry plane of the photonic structure, (ii) the problem of polarization mixing in coupling to far-field radiation modes, and (iii) the description of active two-dimensional layers through a suitably formulated radiation-matter coupling Hamiltonian, allowing to describe the physics of both weakly and strongly coupled exciton-photon modes, the latter leading to photonic crystal polariton eigenmodes. Detailed and direct comparisons with rigorous coupled-wave analysis simulations are used to test the accuracy of the method and the numerical efficiency of the code. These newly added features of the legume code significantly increase the prospective applications of guided-mode expansion, making it a very practical and versatile tool enabling the design of advanced photonic structures and the description of radiation-matter interaction. Program summaryProgram Title:legumeCPC Library link to program files:https://doi.org/10.17632/kf3cwknx4d.1Developer's repository link:https://github.com/fancompute/legumeLicensing provisions: MITProgramming language: PythonNature of problem: Dispersion and radiative losses of photonic eigenmodes in patterned multilayer waveguides/photonic crystal slabs/periodic metasurfaces. Interaction of photonic modes with exciton resonances leading to exciton-polaritons. Inverse design by optimization of the parameters.Solution method: Finite-basis expansion using a basis of guided modes of an effective homogeneous waveguide, perturbation theory to describe coupling with far-field radiation. Quantum theory of excitons, photons and their interaction to describe the occurrence of exciton-polaritons. Automatic differentiation via Autograd to implement inverse design. In this upgraded version of the legume code we implement symmetrization with respect to a vertical mirror plane and light-matter interaction for exciton-polaritons. Inverse design has been described previously, here we focus on the new features and applications of the code.

Granuloma Annulare Exhibits Mixed Immune and Macrophage Polarization Profiles with Spatial Transcriptomics

Granuloma annulare (GA) is an idiopathic condition characterized by granulomatous inflammation in the skin. Prior studies have suggested that GA develops from various triggers, leading to a complex interplay involving innate and adaptive immunity, tissue remodeling, and fibrosis. Macrophages are the major immune cells comprising GA granulomas; however, the molecular drivers and inflammatory signaling cascade behind macrophage activation are poorly understood. Histologically, GA exhibits both palisaded and interstitial patterns on histology; however, the molecular composition of GA at the spatial level remains unexplored. GA is a condition without Food and Drug Administration-approved therapies despite the significant impact of GA on QOL. Spatial transcriptomics is a valuable tool for profiling localized, genome-wide gene expression changes across tissues, with emerging applications in clinical medicine. To improve our understanding of the spatially localized gene expression patterns underlying GA, we profiled the spatial gene expression landscape from 6 patients with GA. Our findings revealed mixed T helper 1 and T helper 2 signals comprising the GA microenvironment and spatially distinct M1 and M2 macrophage polarization characteristics. IFN-γ and TNF signals emerged as important regulators of GA granulomatous inflammation, and IL-32 emerged as a key driver of granulomatous inflammation. Overall, our spatial transcriptomics data indicate that GA exhibits mixed immune and macrophage polarization.

Understanding the thermal and magnetic properties of an X-class flare in the low solar atmosphere

We analyse the spatial distribution and vertical stratification of the physical parameters of the solar atmosphere when an X-class flare occurs. We made use of observations acquired by the Interferometric Bidimensional Spectropolarimeter instrument when observing the full Stokes parameters for the Fe I 6173 Å and Ca II 8542 Å transitions. We analysed the observed spectra using the newly developed DeSIRe code to infer the atmospheric parameters at photospheric and chromospheric layers over the entire observed field of view. Our findings reveal that the chromosphere is characterised by temperature enhancements and strong upflows in the flare ribbon area, which indicates that the flaring event is producing hot material that is moving outwards from the Sun. We did not detect any trace of temperature enhancements or strong velocities (of any sign) at photospheric layers, signalling that the impact of the flaring event mainly happens at the middle and upper layers. The information about the magnetic field vector revealed relatively smooth stratifications with height for both magnetic field strength and inclination. Still, when examining the spatial distribution of the magnetic field inclination, we observed the presence of large-scale mixed polarities in the regions where the flare ribbon is located. These results suggest that the interaction between those mixed polarities could be the flare’s triggering mechanism.

F-actin architecture determines the conversion of chemical energy into mechanical work

Mechanical work serves as the foundation for dynamic cellular processes, ranging from cell division to migration. A fundamental driver of cellular mechanical work is the actin cytoskeleton, composed of filamentous actin (F-actin) and myosin motors, where force generation relies on adenosine triphosphate (ATP) hydrolysis. F-actin architectures, whether bundled by crosslinkers or branched via nucleators, have emerged as pivotal regulators of myosin II force generation. However, it remains unclear how distinct F-actin architectures impact the conversion of chemical energy to mechanical work. Here, we employ in vitro reconstitution of distinct F-actin architectures with purified components to investigate their influence on myosin ATP hydrolysis (consumption). We find that F-actin bundles composed of mixed polarity F-actin hinder network contraction compared to non-crosslinked network and dramatically decelerate ATP consumption rates. Conversely, linear-nucleated networks allow network contraction despite reducing ATP consumption rates. Surprisingly, branched-nucleated networks facilitate high ATP consumption without significant network contraction, suggesting that the branched network dissipates energy without performing work. This study establishes a link between F-actin architecture and myosin energy consumption, elucidating the energetic principles underlying F-actin structure formation and the performance of mechanical work.

Admixture Analysis of Age of Onset in Bipolar Disorder and Impact of Anxiety Comorbidity.

The present study aimed to examine clinical differences between subjects with early-onset (<21 years) and adult-onset (>30 years) bipolar I disorder, in particular, in relation to anxiety comorbidity. Subjects were selected from a cohort of 161 consecutive patients with bipolar disorder type I as diagnosed by the Structured Clinical Interview for DSM Disorder(SCID-I). Clinical characteristics and axis I comorbidity were compared between those whose illness first emerged before the age of 21 years (n=58) and those whose first episode occurred after the age of 30 years (n=27). Psychopathology was assessed using the 18-item version of the Brief Psychiatric Rating Scale (BPRS). The frequency of delusions, hallucinations, and formal thought disorders was evaluated with the SCID-I. Overall, social and occupational functioning was assessed by the Global Assessment of Functioning (GAF). Most subjects with early-onset bipolar disorder were males, had panic disorder and substance abuse comorbidity, longer duration of illness, exhibited mood-incongruent delusions, and presented with a mixed episode at onset more frequently than the later adult-onset subjects. Mixed mania at the first episode of illness and lifetime panic disorder comorbidity predicted mixed polarity at the first hospitalization episode in the early-onset subjects. Overall, early age at onset seems to delineate a distinct bipolar I disorder subtype characterized by a greater likelihood of mixed episodes, lifetime panic disorder comorbidity, and schizophrenia-like delusions.

Polarization mixing, bound states in a continuum, and exciton-polaritons in photonic crystal slabs by a guided-mode expansion approach

Photonic crystal (PhC) slabs, or patterned multilayer waveguides, are known to support truly guided modes with no losses, as well as quasi-guided modes that lie in the continuum of far-field radiation. In this contribution, we present a guided-mode expansion approach – and the corresponding free software named legume – that allows calculating a number of features of PhC slabs: (a) symmetry properties and the issue of polarization mixing in coupling to far-field radiation; (b) the occurence of bound states in a continuum, which have infinite Q-factor and give rise to topological singularities of the far-field polarization; (c) the description of active two-dimensional layers through a suitably formulated light-matter coupling Hamiltonian, allowing to describe the regime of strong coupling leading to photonic crystal polaritons. Comparison with rigorous coupled-wave analysis, and the insurgence of non-hermitian features in the optical properties, are also addressed.

Polarization distribution of transverse ULF waves according to Van Allen Probe A data: whether toroidal and poloidal waves exist separately in the magnetosphere?

Ultralow-frequency (ULF) waves play an important role in energy transfer within Earth's magnetosphere due to intensive interaction with the surrounding plasma. Previous works have assumed that these waves are strictly divided by polarization into toroidal, when the magnetic field oscillates in the azimuthal direction, and poloidal, when it oscillates in the radial direction. The former are azimuthally large-scale and are excited by external sources, whereas the latter are small-scale and are generated by internal plasma instabilities. Observations show, however, that waves of mixed polarization often occur, and the nature of this mixing has not been explained. In this paper, we carry out a statistical study and show that the polarization of transverse waves has a normal distribution, and the maximum corresponds to oscillations of the toroidal and poloidal components with the same amplitude. At the same time, the spatial distributions of toroidal and poloidal waves are clearly different, but only lead to a small shift in the position of the distribution maximum. This result suggests that in order to compare the theory with ULF wave observations it is necessary to take into account the processes of polarization change, which can affect wave-particle interactions in the magnetosphere.

Распределение поляризации поперечных УНЧ-волн по данным Van Allen Probe A: существуют ли раздельно тороидальные и полоидальные волны в магнитосфере?

Ultralow-frequency (ULF) waves play an important role in energy transfer within Earth's magnetosphere due to intensive interaction with the surrounding plasma. Previous works have assumed that these waves are strictly divided by polarization into toroidal, when the magnetic field oscillates in the azimuthal direction, and poloidal, when it oscillates in the radial direction. The former are azimuthally large-scale and are excited by external sources, whereas the latter are small-scale and are generated by internal plasma instabilities. Observations show, however, that waves of mixed polarization often occur, and the nature of this mixing has not been explained. In this paper, we carry out a statistical study and show that the polarization of transverse waves has a normal distribution, and the maximum corresponds to oscillations of the toroidal and poloidal components with the same amplitude. At the same time, the spatial distributions of toroidal and poloidal waves are clearly different, but only lead to a small shift in the position of the distribution maximum. This result suggests that in order to compare the theory with ULF wave observations it is necessary to take into account the processes of polarization change, which can affect wave-particle interactions in the magnetosphere.

Conformations of Macrocyclic Peptides Sampled by Nuclear Magnetic Resonance: Models for Cell-Permeability.

The biological activities and pharmacological properties of peptides and peptide mimetics are determined by their conformational states. Therefore, a detailed understanding of the conformational landscape is crucial for rational drug design. Nuclear magnetic resonance (NMR) is the only method for structure determination in solution. However, it remains challenging to determine the structures of peptides using NMR because of very weak nuclear Overhauser effects (NOEs), the semiquantitative nature of the rotating frame Overhauser effect (ROE), and the low number of NOEs/ROEs in N-methylated peptides. In this study, we introduce a new approach to investigating the structures of modified macrocyclic peptides. We utilize exact NOEs (eNOEs) in viscous solvent mixtures to replicate various cellular environments. eNOEs provide detailed structural information for highly dynamic modified peptides. Structures of high precision were obtained for cyclosporin A, with a backbone atom rmsd of 0.10 Å. Distinct conformational states in different environments were identified for omphalotin A (OmphA), a fungal nematotoxic and multiple backbone N-methylated macrocyclic peptides. A model for cell-permeation is presented for OmphA, based on its structures in polar, apolar, and mixed polarity solvents. During the transition from a polar to an apolar environment, OmphA undergoes a rearrangement of its H-bonding network, accompanied by a cis to trans isomerization of the ω torsion angle within a type VIa β-turn. We hypothesize that the kinetics of these conformational transitions play a crucial role in determining the membrane-permeation capabilities of OmphA.

Locate transmission axis of a polarizer by one-shot spatial modulation of a q-plate: Principle, configuration and analysis

Transmission axis of a linear polarizer was generally measured by conventional rotation-Malus approach, which inevitably required mechanical motions, ultra-stable illumination and additional high-accuracy polarizer for calibration. Researchers have been studying how to locate the transmission axis of a polarizer conveniently, directly and accurately. Our group focuses on solving the problem by spatial solution via a nano-fabricated vortex retarder. This work introduces the fundamental measurement principle, the home-developed practical configuration and detailed analysis. Compared with conventional rotation-Malus approach, our approach shows superiorities in no mechanical motion, extremely compact configuration and one-shot measurement. We layout our work as follows: i) it is the circularly-polarized component that functions for the measurement; ii) how to achieve a more practical measurement: a mixed-mode polarized light, which contains a circular-polarization component, can work for the measurement; iii) an experimental system is developed for verification; iv) we specifically analyze how the mixed polarization effect influences the measurement.

Influence of growth temperature on the properties of aluminum nitride thin films prepared by magnetron sputter epitaxy

High quality, uni-polar, epitaxial AlN with minimum oxygen content promises excellent surface acoustic wave and bulk acoustic wave resonator characteristics such as high electromechanical coupling coefficient and power handling capabilities, which is particularly useful for RF filter applications. By systematically varying the growth temperature, the study investigates its impact on the oxygen levels, defect states, and crystallographic texture of the AlN thin films using a combination of atomic force microscopy, X-ray diffraction, time-of-flight secondary ion mass spectrometry, spectroscopic ellipsometry, scanning transmission electron microscopy, as well as room temperature and temperature dependent I–V measurements. The research demonstrates that the films grown at a temperature of 700°C exhibit the most favorable results. These films exhibit the lowest oxygen levels, possess epitaxial growth, and display the highest crystalline quality (XRD AlN 0002 ω−FWHM=1.3°). Additionally, these films demonstrate a significant reduction in sub-bandgap absorption. By comparing the cathode current measured during deposition, we suggest that the presence of an impurity layer formed during idle time between depositions as a possible source of oxygen in the sputter chamber. In addition, the study presents a possible model to explain the mixed polarity observed in AlN and proposes various ways to achieve uni-polar AlN on silicon substrates.

Single pulse polarization study of pulsars B0950 + 08 and B1642 − 03: micropulse properties and mixing of orthogonal modes

ABSTRACT We present the results of a high-time resolution polarization study of single pulses from pulsars B0950 + 08 and B1642 − 03. Single pulses from pulsar B0950 + 08 sometimes show isolated micropulses without any significant associated subpulse emission. Assuming that the properties of such micropulses represent the intrinsic nature of micropulse emission, we characterize the width and polarization properties of these ‘intrinsic’ microstructures. Most of the ‘intrinsic’ micropulses ($\sim 90~{{\ \rm per\ cent}}$) follow common characteristic polarization properties, while the average width of these micropulses is consistent with the general micropulse population from this pulsar. Single pulses from these pulsars show a diverse range of polarization properties, including depolarization and mixing of two orthogonal modes resulting in polarization position angle jumps. We present a superposition model of the two orthogonal modes which can explain depolarization, the observed position angle jumps, and associated changes in other polarization parameters.

Small-Scale Upflows in a Coronal Hole – Tracked from the Photosphere to the Corona

Coronal transients are known as sources of coronal upflows. With the commissioning of Solar Orbiter, it became apparent that coronal small-scale features are even more frequent than previously estimated. It was found that even small coronal features seen by Solar Orbiter can produce visible upflows. Therefore, it is important to study the plasma flows on small scales better and understand their atmospheric driving mechanisms.In this article, we present the results from a two-week coordinated multi-spacecraft observation campaign with Hinode, IRIS, and the GREGOR telescope. We identify a small region of coronal upflows with Doppler velocities of up to 16.5 km s−1. The upflows are located north of a coronal bright point in a coronal hole. We study the corona, the transition region, the chromosphere and the photospheric magnetic field to find evidence of underlying mechanisms for the coronal upflow. We find a complex photospheric magnetic field with several small mixed polarities that are the footpoints of different loops. Flux emergence and cancellation are observed at the constantly changing footpoints of the coronal loops. Reconnection of loops can be identified as the driver of the coronal upflow. Furthermore, the impact of the coronal activity triggers plasma flows in the underlying layers. This work highlights that frequent small coronal features can cause considerable atmospheric response and ubiquitously produce plasma upflows that potentially feed into the solar wind.

MPMCT gate decomposition method reducing T-depth quickly in proportion to the number of work qubits

We propose a method for efficient mixed polarity multiple controlled Toffoli (MPMCT) gate decomposition from the perspective of a cost metric related to Toffoli gates, namely Toffoli-depth. When using the technique presented in a previous study, there is a range in which Toffoli-depth (consequently T-depth) of the implemented circuit increases proportionally as the number of provided (clean) work qubits increases. In other words, using the previous technique may result in more inefficient MPMCT gates even though the number of helpful work qubits has increased. In this work, a technique is devised to provide sufficient help from clean work qubits at the central part of the implemented circuit as many as possible, thereby addressing the issues with the previous technique. Meanwhile, one of the representative algorithms that use MPMCT gates is Grover’s algorithm. We show the implementation results for MPMCT gates according to the number of work qubits, using Grover’s algorithm as an example. It is experimentally demonstrated that T-depth decreases much more quickly when using our method than the previous method.

Polarization and Spatial Distribution Features of Pc4 and Pc5 Waves in the Magnetosphere

AbstractUltra‐low frequency waves interact with different particle populations all over the magnetosphere. Some interaction mechanisms are associated with certain wave modes, but is it really so and what about waves interaction between each other? We present a statistical analysis of Pc4 and Pc5 waves in the magnetosphere of the Earth that were observed by Arase satellite from March 2017 to December 2020. These waves were classified by polarization into toroidal, poloidal, and compressional waves. Toroidal and poloidal waves are thought to be Alfvén waves that are eigenoscillations of Earth's magnetic field lines. The former are believed to be generated by external sources, while the latter one—by internal sources. We compared spatial distribution features with well‐known case studies to reveal their nature for all three polarizations. A high inclination of Arase orbit supported a wave field‐aligned structure research. We found that toroidal waves are mostly odd harmonics and poloidal waves are both even and odd harmonics of Alfvén waves, while compressional waves were observed in a narrow equatorial region only. Different wave generation mechanisms that cause a clear difference in spatial distributions of toroidal, poloidal, and compressional waves could excite a specific wave polarization. Surprisingly, the statistics of wave polarization has a normal distribution without separate clusters. We suggest that polarization change and mode coupling processes make mixed polarization the most common type of polarization in the magnetosphere. This result raises the question of how the polarization change process affects wave‐particle interactions responsible for energy transport throughout the magnetosphere.

Entropic Penalty Switches Li+ Solvation Site Formation and Transport Mechanisms in Mixed Polarity Copolymer Electrolytes.

Emerging solid polymer electrolyte (SPE) designs for efficient Li-ion (Li+) conduction have relied on polarity and mobility contrast to improve conductivity. To further develop this concept, we employ simulations to examine Li+ solvation and transport in poly(oligo ethylene methacrylate) (POEM) and its copolymers with poly(glycerol carbonate methacrylate) (PGCMA). We find that Li+ is solvated by ether oxygens instead of the highly polar PGCMA, due to lower entropic penalties. The presence of PGCMA promotes single-chain solvation, thereby suppressing interchain Li+ hopping. The conductivity difference between random copolymer PGCMA-r-POEM and block copolymer PGCMA-b-POEM is explained in terms of a hybrid solvation site mechanism. With diffuse microscopic interfaces between domains, PGCMA near the POEM contributes to Li+ transport by forming hybrid solvation sites. The formation of such sites is hindered when PGCMA is locally concentrated. These findings help explain how thermodynamic driving forces govern Li+ solvation and transport in mixed SPEs.