Stable Curves Research Articles

On the Chow and cohomology rings of moduli spaces of stable curves

In this paper, we ask: For which (g, n) is the rational Chow or cohomology ring of \bar{\mathcal{M}}_{g,n} generated by tautological classes? This question has been fully answered in genus 0 by Keel (the Chow and cohomology rings are tautological for all n (1992)) and genus 1 by Belorousski (the rings are tautological if and only if n \leq 10 (1998)). For g \geq 2 , work of van Zelm (2018) shows the Chow and cohomology rings are not tautological once 2g + n \geq 24 , leaving finitely many open cases. Here, we prove that the Chow and cohomology rings of \bar{\mathcal{M}}_{g,n} are isomorphic and generated by tautological classes for g = 2 and n \leq 9 and for 3 \leq g \leq 7 and 2g + n \leq 14 . For such (g, n) , this implies that the tautological ring is Gorenstein and \bar{\mathcal{M}}_{g,n} has polynomial point count.

Dorsal Preservation Rhinoplasty-the Perspective of "Preservers" Versus "Structural" Surgeons.

The objective of this study was to describe the surgeons who have incorporated dorsal preservation (DP) into their practice and their techniques. An anonymous form reviewed by the Evidence-Based Rhinoplasty Research Group board was shared on its Telegram group. The study population was divided into three groups based on their answers: "Preservers," "Mainly Structural," and "Structural exclusively." This study included the answers of 145 worldwide surgeons. DP was more common among plastic surgeons than otolaryngologists/facial plastic surgeons; DP techniques were mostly preferred by surgeons with 10-20 years of experience, while structural techniques were mostly preferred by surgeons with > 20 years of experience; 50.8% of the surgeons who prefer DP techniques use it in more than 90% of primaries; surface techniques (ST) have been more used, mainly by surgeons who prefer structural techniques (p < 0.001). ST were considered more stable (p < 0.001), more predictable (p < 0.001), and shorter learning curve (p < 0.001). Many surgeons using DP still perform structural rhinoplasty. The most cited concern was hump persistence/recurrence. DP rhinoplasty is gaining acceptance, and ST are favored for their perceived short learning curve, stability, and predictability. However, concerns about hump recurrence cause some to continue using structural methods alongside DP.

Wada Basins Colourings and Ergodicity

The stable Birkhoff curve ergodic properties in dissipative situation have been discussed. The points of every regions have been coloured with their own colour, such that their common boundary would turns out to be white at the colours adding together. Quantitative conditions for colouring regions for boundary discolouration have been obtained. The prime example of the dynamic system action with fixed B- saddle and Birkhoff curve being four regions common boundary has been constructed. There subsist the Birkhoff curves different topologic types. For every Birkhoff curves can constructed to be two or more vortex streets with periodic structure.The regions colouring turns out to be the topological classification instrument.

Did Monetary Policy Kill the Phillips Curve? Some Simple Arithmetics

Abstract An apparent disconnect has taken place between inflation and economic activity in the pre-COVID US economy, causing some to believe that the Phillips curve has flattened. We argue that this view may be premature. Using New Keynesian theory and estimated SVAR models, we decompose fluctuations in US macro data into the components driven by demand and supply disturbances, and confront the inflation disconnect with some simple arithmetics. This exercise confirms a relatively stable Phillips curve slope while the demand curve has flattened substantially. Our results are consistent with a shift towards firmer monetary policy commitment to inflation stability.

Seismic performance of high-rise shear wall with concealed truss under high axial force ratio

In this paper, the high-rise shear wall with a concealed truss was proposed for improving seismic performance. Reinforcing bar truss and steel truss were used in the proposed shear walls. The innovative composite shear wall incorporates two combinations, i.e., one involving two load-bearing systems, including a truss and shear wall, while the other combines steel and concrete as distinct materials. Five specimens with different structural forms were tested under cyclic loading tests. The resulting failure characteristics, hysteretic performance, strength, deformation, energy dissipation capacity, stiffness, and strain characteristics were studied. The influence of various structural forms on the seismic performance of shear walls under the high axial force ratio was also analyzed. The results showed stable hysteresis curves for the innovative shear walls. Also, it was found that the high-rise shear walls with concealed trusses effectively control crack propagation compared to conventional high-rise shear walls. The proposed walls exhibited a uniform and broader crack distribution. Concealed trusses in the high-rise shear walls enhanced the plastic energy dissipation zone at the base, improving the corresponding energy dissipation capacity. Using different types of trusses did not exhibit any significant difference in the resulting seismic performance. Finally, an evaluation method for the ultimate strength and stiffness of the shear walls with concealed trusses was proposed and validated.

Stable cuspidal curves and the integral Chow ring of ℳ2,1

Stable cuspidal curves and the integral Chow ring of ℳ2,1

An innovative two-level yielding knee-braced frame with deformation-controlled ring damper

Previous earthquake experiences have shown that conventional yielding dampers designed for an earthquake intensity cannot perform adequately at higher intensity levels. This paper addresses this issue by proposing a two-level yielding configuration for knee-braced steel frames having an innovative deformation-controlled ring damper (CRD). The proposed configuration includes a knee element damper (KED) and a CRD with a deformation-control device. In weak or moderate earthquakes, the CRD serves as the primary energy absorber. In contrast, in higher-intensity earthquakes, the deformation of the CRD is controlled and the KED acts as a secondary fuse for energy dissipation. In this study, four traditional ring dampers with different geometric properties and two CRD were experimentally tested and their numerical models in Abaqus were successfully verified. The results demonstrated stable and asymmetric hysteretic curves with satisfactory ductility and energy absorption of the ring dampers. Additionally, the CRD revealed a proper control of deformation. Subsequently, a previously tested knee-braced frame specimen with the common ring damper was numerically modeled. After verifying the validity of the model, the behavior of a typical knee-braced frame equipped with a deformation-controlled multi-ring damper (CRD-KBF) was investigated and compared with a common KBF and ring-braced frame (RBF). The obtained results confirmed the expected two-level yielding behavior of the proposed configuration. The numerical analyses demonstrated higher ductility and energy dissipation capacity of the CRD-KBF compared to the other frames.

Experimental and numerical investigation on cyclic behavior of beam‑to‑column connection with a lateral steel slit damper

The objective of this research is to propose an innovative slit damper that can be installed in beam-to-column connections of steel structures as a fuse and energy dissipation device. These devices can be used as an effective and inexpensive way to mitigate earthquake risks to structures, and they can also improve the seismic behavior of building structures. Specifically, structures equipped with these devices can withstand more drift while their main members remain in an elastic state, thereby reducing the cost of rebuilding structures after earthquakes. In this study, four specimens were experimentally tested. Three beam-to-column connections were equipped with the proposed damper, and the fourth one was used as a reference sample. This damper can be referred to as a lateral slit damper (LSD). The test results show that all samples have stable and complete hysteresis curves without pinching. So, the LSDs can improve the ductility of beam-to-column connections. The test results showed that the innovative system can enhance the strength and ductility of the T-stub connection around 73 % and 21 %, respectively. To validate the LSD experimental findings, finite element models were employed for calibration. A numerical study using ABAQUS examined the system's hysteretic behavior under cyclic loading, revealing excellent agreement between the numerical and experimental results. Finally, the proposed LSDs demonstrate exceptional ductility, strength, effective hysteretic curves, and post-earthquake reparability. These qualities position it as a promising and practical damper for mitigating seismic risks in engineering structures.

Stiffness Hardening Effect of Wire Rope Isolators under Small Cyclic Loads for Vibration Isolation

Wire rope isolator (WRI) devices are widely used in vibration reduction industrial equipment, and stiffness is the key parameter that determines isolation effectiveness. WRI devices show slight nonlinearity under small loads, and the manufacturers generally only provide the initial parameters. To investigate the mechanical behavior changes in the WRI devices under repeated loads, five types of WRI specimens were tested under various amplitudes, loading speeds, and preloads. The test results of large symmetrical compression and tension loads showed that the WRI devices demonstrated stable hysteresis curves under repeated loads, while the hysteresis curves were independent of the loading speed. The test results of small cyclic loads with large preloads show that the stiffness of the WRI specimen follows the logarithmic law, with the cycle number under various loading conditions. Particularly, the stiffness of the specimen increases by about 10–30% after 50 cycles. The initial stiffness Ka decreases linearly with the preloads, while the decrease is quadratic in relation to the cyclic load. The hardening coefficient Ca shows a positive correlation with the loading capacity of the WRI devices, while it shows a negative correlation with the preload and cyclic load amplitudes. It is recommended to consider the stiffness increase in the WRI devices during the evaluation of isolation effectiveness.

Vehicle noise characteristics in magnetotelluric data and vehicle noise removal using waveform fitting

Magnetic field fluctuations due to vehicle noise were observed in magnetotelluric (MT) time-series data measured near roads. The observed vehicle noise had magnitudes ranging from tens to thousands of μA/m, whereas the observed weak natural MT signal magnitudes were approximately tens of μA/m. A small signal-to-noise ratio made it difficult to apply robust processing for removing vehicle noise. In addition, vehicle noise severely distorts the MT response in the MT deadband from 0.01 Hz to 0.3 Hz, where the MT signal is very weak, and methods to remove it are required for deep structure imaging. In this study, magnetic field fluctuations due to moving vehicles were simulated with a magnetic dipole and attempted to be removed using a waveform fitting method. A total of 378 vehicle noises were extracted from the near-road MT data and synthesized with the remote MT data without vehicle noises to investigate the effect of vehicle noise on the MT response. Removal of vehicle noise from synthesized remote MT data resulted in substantial restoration of the apparent resistivity and phase curves around the MT deadband and below 0.001 Hz. In the MT field data, the vehicle noise was simulated and removed with two moving dipoles; the magnitude of the remaining vehicle noise was reduced by approximately half compared to a single dipole, and very stable apparent resistivity and phase curves were obtained. Although electromagnetic noise distortion remains after vehicle noise removal, the waveform fitting method significantly improves the apparent resistivity and phase curve response in the 0.01–0.3 Hz frequency band.

Electrical conductivity of mantle minerals beneath East Asia revealed by geomagnetic observatory data

The electrical conductivity of the earth’s mantle can provide important information about geodynamic phenomena. East Asia is associated with complex tectonics and geodynamic processes. Hence, it is necessary to better understand the deep structure beneath East Asia. In this study, geomagnetic data obtained from East Asian observatories are employed to image the conductivity structure of the mantle at depths ranging from 410 to 900 km. First, the data are processed using the modified bounded influence remote reference processing (BIRRP) method and the ratio method is used to correct for the ocean effect. Thereafter, the stable C-response curves at the 27 observatories are estimated, and 1D electrical conductivity models for these observatories are established using the L-BFGS method. The conductivity-depth profiles reveal a heterogeneous distribution of the electrical conductivity beneath East Asia. The mantle transition zone (MTZ) beneath East China and Japan is found to be more conductive, whereas the MTZ beneath central and southern regions of China is more resistive. In East China, the dehydration of the stagnant Pacific slab may lead to an increase in the conductivity of the mantle minerals. There is also the possibility of upwelling of the thermal material from the lower mantle beneath the Japanese Island arc. In Northwest China, there exists a large high-conductive body beneath the Tarim area, which could indicate an upwelling of the Tarim mantle plume. Our results provide insights into the deep structure of the earth at the mantle scale.

The (almost) integral Chow ring of M~37\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\widetilde{{\\mathcal {M}}}_3^7$$\\end{document}

This paper is the third in a series of four papers aiming to describe the (almost integral) Chow ring of M¯3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\overline{\\mathcal {M}}_3$$\\end{document}, the moduli stack of stable curves of genus 3. In this paper, we compute the Chow ring of M~37\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\widetilde{{\\mathcal {M}}}_3^7$$\\end{document} with Z[1/6]\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mathbb {Z}}[1/6]$$\\end{document}-coefficients.

A Brown Dwarf Orbiting around the Planetary-nebula Central Binary KV Vel

KV Vel is a noneclipsing short-period (P = 0.3571 days) close binary containing a very hot subdwarf primary (77,000 K) and a cool low-mass secondary star (3400 K) that is located at the center of the planetary nebula DS 1. The changes in the orbital period of the close binary were analyzed based on 262 new times of light maximum together with those compiled from the literature. It is discovered that the O − C curve shows a small-amplitude (0.ͩ0034) cyclic period variation with a period of 29.55 yr. The explanation by the solar-type magnetic activity cycles of the cool component is ruled out because the required energies are much larger than the total radiant energy of this component in a whole cycle. Therefore, the cyclic variation was plausibly explained as the light-travel time effect via the presence of a tertiary component, which is supported by the periodic changes of the O − C curve and the rather symmetric and stable light curves obtained by the Transiting Exoplanet Survey Satellite. The mass of the tertiary companion is determined to be M3sini′=0.060(±0.007) M ⊙. If the third body is coplanar with the central binary (i.e., i′=62.°5 ), the mass of the tertiary component is computed as M 3 ∼ 0.068 M ⊙, and thus it would be below the stable hydrogen-burning limit and is a brown dwarf. The orbital separation is shorter than 9.35 au. KV Vel together with its surrounding planetary nebula and the brown-dwarf companion may be formed through the common-envelope evolution after the primary filled its Roche lobe during the early asymptotic giant branch stage.

In-office Maximal Voluntary Ventilation Testing Demonstrates Pulmonary Improvement Following Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis.

Pulmonary function can be impaired in patients with adolescent idiopathic scoliosis (AIS). Maximal voluntary ventilation (MVV) has been shown to be more strongly correlated with major coronal curve, and a more easily obtained measurement of pulmonary function, than forced vital capacity (FVC). We evaluated changes in pulmonary function using these 2 measures in patients with AIS in relation to changes in major coronal curves over time. Forty-seven patients with AIS with thoracic curves ≥10 degrees performed pulmonary function tests using the Carefusion MicroLoop Spirometer at enrollment and 1 year later. Major coronal curve worsening >5 degrees was considered curve progression. At enrollment, 47 patients had a mean major coronal curve of 38 degrees (range: 10 to 76 degrees). One year later, 17 patients had undergone posterior spinal fusion, 9 had curve progression >5 degrees, and 21 had no progression. MVV and major coronal curve were negatively correlated (r = -0.36, P = 0.01) at enrollment. After fusion, the major coronal curve improved by a mean of 41 degrees, and MVV improved by 23% (P < 0.01), but FVC did not improve significantly (6%, P = 0.29). In stable curves, MVV improved 12% (P = 0.01) and FVC improved 9% (P = 0.007). In patients without surgery whose curves progressed an average of 11 degrees, there was no significant change in MVV or FVC (P > 0.44). This is the first study using office-based spirometry in an orthopaedic clinic showing improved pulmonary function with posterior spinal fusion and growth in patients with AIS. It is notable that MVV improved after spinal fusion, but FVC did not, as MVV appears to be a more sensitive measurement for the assessment of pulmonary function in these patients. Level II.

Divisors and curves on logarithmic mapping spaces

We determine the rational class and Picard groups of the moduli space of stable logarithmic maps in genus zero, with target projective space relative a hyperplane. For the class group we exhibit an explicit basis consisting of boundary divisors. For the Picard group we exhibit a spanning set indexed by piecewise-linear functions on the tropicalisation. In both cases a complete set of boundary relations is obtained by pulling back the WDVV relations from the space of stable curves. Our proofs hinge on a controlled technique for manufacturing test curves in logarithmic mapping spaces, opening up the topology of these spaces to further study.

Development and characterization of ZIF-8/WS2 composites for NH3 detection at room temperature

This study successfully synthesized zeolitic imidazolate frameworks-8 (ZIF-8) particles and tungsten disulfide (WS2) nanosheets, forming ZIF-8/WS2 composites via a layer-by-layer filtration adsorption method. The morphological and structural characterization results revealed that ZIF-8 particles and WS2 nanosheets effectively combine under filtration to form a hierarchical film structure. Room temperature ammonia (NH3) detection results indicated that the ZIF-8/WS2 composites-based gas sensor, due to the high specific surface area (1458 m2/g) and strong gas adsorption capability of ZIF-8, exhibits response intensity to NH3 that is 4.98 times higher than that of pure WS2 nanosheets. Additionally, it demonstrated stable response and recovery curves with short response/recovery times (113.5 ± 3.9 s/115.0 ± 1.9 s). This work provides valuable insights and inspiration for the construction of composite materials involving 2D TMDs and the enhancement of their room-temperature gas sensing performance.

Long-acting bulleyaconitine A microspheres via intra-articular delivery for multidimensional therapy of rheumatoid arthritis

Bulleyaconitine A (BLA) is a promising candidate for treating rheumatoid arthritis (RA) with diverse pharmacological activities, including anti-inflammatory, analgesic and bone repair. Herein, the long-acting bulleyaconitine A microspheres (BLA-MS) were developed to treat RA comprehensively by forming drug reservoirs in joint cavities. The BLA-MS were prepared by emulsion/solvent evaporation method. The particle size and distribution were assessed by SEM. The crystalline state was investigated by DSC and PXRD. The drug loading (DL), encapsulation efficiency (EE) and cumulative release in vitro were determined by HPLC. The DL and EE were 23.93 ± 0.38 % and 95.73 ± 1.56 % respectively, and the cumulative release was up to 69 days with a stable release curve. The pharmacodynamic results in collagen induced arthritis (CIA) rats showed a noticeable reduction in paw thickness (5.66 ± 0.32 mm), and the decreasing expression level of PGE2, TNF-α and IL-6 which diminished the infiltration of inflammatory cells, thereby alleviating the progression of erosion and repairing the damaged bones (BV/TV (Bone Volume / Total Volume): 81.97 %, BS/BV (Bone Surface / Bone Volume): 6.08 mm−1). In conclusion, intra-articular injection of BLA-MS should have a promising application in the treatment of RA and may achieve clinical transformation in the future.

Seismic performance of shuttle-shaped double-restrained buckling-restrained brace: Experimental investigation and numerical analysis

To solve the problems of excessive cross-section size and self-weight and buckling instability of super-long buckling-restrained brace, a new lightweight shuttle-shaped double-restrained BRB (SDR-BRB) is proposed in this study. Firstly, cyclic loading experiments are conducted on three SDR-BRB specimens to investigate their failure mode and seismic performance. Then, a finite element model considering geometric, material, and contact nonlinearity is established and verified by experimental results. Finally, the effect of the restraining ratio on the hysteretic performance of SDR-BRB is studied by parameter analysis, and the restraining ratio requirement of the energy-dissipation type of SDR-BRB that meets the ductility requirements is obtained. The results show that SDR-BRB has stable and plump hysteretic curves, excellent energy-dissipation capacity, and low cycle fatigue performance, exhibiting obvious strain-strengthening characteristics. The restraining ratio is an important factor affecting the overall stability and failure mode of SDR-BRB, and it is recommended that the restraining ratio requirements of the SDR-BRB should be 2.25. The above research can provide a design reference for the practical engineering application of SDR-BRB.

Kaleckian Models of Conflict Inflation, Distribution and Employment: A Comparative Analysis

ABSTRACT This paper conducts a systematic comparison of two main textbook variants within the Kaleckian tradition of post-Keynesian conflict inflation and distribution theory: the Blecker and Setterfield (2019) and Lavoie (1992; 2022) (BSL) model based on Dutt (1987), and the Hein (2023a) and Hein and Stockhammer (2011) (HS) model founded on Rowthorn (1977). Focusing on a basic closed economy framework sans government, we explore various iterations of each approach. Our analysis reveals that disparities chiefly centre around the treatment of price inflation expectations (‘indexation’) and the incorporation of bargaining power in wage- and price-inflation equations. BSL variants generally yield stable price Phillips curves, stable distribution and employment curves, and hence stable equilibria. Only the BSL-3 variant with complete indexation and complete pass-through generates shifting Phillips and employment curves, implying instability. It is thus similar to the HS-0 approach, which has bargaining power and complete indexation representing adaptive expectations in wage inflation and incomplete pass-through in price inflation. Introducing a workers’ wage share target directly into the wage-inflation equation, but keeping full indexation/adaptive expectations in wage inflation and incomplete pass-through in price inflation, allows for stable and even flat Phillips curves, stable distribution and employment curves, and hence stable equilibria in the HS approach.

The (almost) integral Chow ring of ℳ̅3

Abstract This paper is the fourth in a series of four papers aiming to describe the (almost integral) Chow ring of M ̄ 3 \overline{\mathcal{M}}_{3} , the moduli stack of stable curves of genus 3. In this paper, we finally compute the Chow ring of M ̄ 3 \overline{\mathcal{M}}_{3} with Z ⁢ [ 1 / 6 ] \mathbb{Z}[1/6] -coefficients.