EFFECTS OF SHOE COLLAR HEIGHT ON SAGITTAL ANKLE ROM, KINETICS AND POWER OUTPUT DURING SINGLE-LEG AND DOUBLE-LEG JUMPS

The aim of this research was to examine the effects of high-top shoes and low-top shoes on sagittal ankle ROM, kinetics and power output during single-leg and double-leg jumps. Twelve male subjects were requested to wear high-top and low-top shoes to perform single-leg and double-leg jumps. Ankle joint kinematics and kinetics data were collected using Vicon system and force plates. Shoe collar heights did not influence the jump height in both single-leg and double-leg jump tasks. However, high-top shoes adopted in this study resulted in a significant smaller sagittal ankle ROM during a quasi-static movement. In addition, wearing high-top shoe could also decrease the dorsiflexion ankle joint torque and power output during the push-off phase in single-leg jump. These findings provide preliminary evidence suggesting that a changed ankle kinematic and kinetic behaviour in the sagittal plane may be induced when wearing high-top shoes

Exclusive production of double light neutral mesons at the e+e−e^+e^- colliders

In this work we investigate the exclusive production of a pair of light neutral mesons in $e^+e^-$ annihilation, where the final state bears an even $C$-parity. The production processes can be initiated via the photon fragmentation or the non-fragmentation mechanism. While the fragmentation contribution can be rigorously accounted, the non-fragmentation contributions are calculated within the framework of collinear factorization, where only the leading-twist light-cone distribution amplitudes (LCDAs) of mesons are considered. Mediately solely by the non-fragmentation mechanism, the production rates of double light neutral pseudoscalar mesons are too small to be observed at the commissioning $e^+e^-$ facilities. In contrast, the production rates of a pair of light neutral vector mesons are greatly amplified owing to the significant kinematic enhancement brought by the fragmentation mechanism. It is found that, at $\sqrt{s}=3.77$ GeV, after including the destructive interference between the non-fragmentation and fragmentation contributions, the production rates for $e^+e^-\to \rho^{0}\rho^{0}$ and $\rho^0\omega$ can be lowered by about 10\% and 30\% relative to the fragmentation predictions. Future precise measurement of these exclusive double neutral vector meson production channels at {\tt BESIII} experiment may provide useful constraints on the LCDAs of light vector mesons.Comment: 20 pages, 4 tables, 6 figure

Hard-scattering approach to strongly hindered electric dipole transitions between heavy quarkonia

The conventional wisdom in dealing with electromagnetic transition between heavy quarkonia is the multipole expansion, when the emitted photon has a typical energy of order quarkonium binding energy. Nevertheless, in the case when the energy carried by the photon is of order typical heavy quark momentum, the multipole expansion doctrine is expected to break down. In this work, we apply the "hard-scattering" approach originally developed to tackle the strongly hindered magnetic dipole ($M1$) transition [Y.~Jia {\it et al.}, Phys. \ Rev. \ D. 82, 014008 (2010)] to the strongly hindered electric dipole ($E1$) transition between heavy quarkonia. We derive the factorization formula for the strongly hindered $E1$ transition rates at the lowest order in velocity and $\alpha_s$ in the context of the non-relativistic QCD (NRQCD), and conduct a detailed numerical comparison with the standard predictions for various bottomonia and charmonia $E1$ transition processes.Comment: 18 pages, 2 figures, 4 table

Research on optimization of approach procedures for airports in an alpine environment

Obstacles in alpine environments pose significant challenges to aircraft safety during terminal operations. Key challenges include constraints from obstacles within the terminal clearance area and the labor-intensive manual calculations of flight procedures. The focal point of concern lies in the design of approach procedures, particularly due to the heightened risk of collisions with obstacles during the descent segment in such terrain. To address these challenges, initially, this paper proposes processing the terrain data and visualizing and extracting the topographic data of the alpine airport by adopting a bi-cubic b-spline interpolation and cellular automatic machine model. Then, the paper proposes improving the A* path algorithm to make sure it can obey the standards of flight procedure design, utilizing the improved A* path algorithm to design approach procedures. As fuel consumption is directly connected with the economy of aviation companies, this research finally suggests employing the fuel consumption evaluation model to select the most efficient approach flight procedures. This research takes a case study of a Yunnan airport and simulates and designs the optimized approach procedures by A* path algorithm and evaluation based on fuel consumption. Results indicate that the parameters of optimized approach procedures align with the regulation of flight procedure design and meet the requirements of real flight operation. Therefore, the core tenant of this research can provide a feasible idea for flight procedures with alpine airports and has the potential to reduce workload and enhance operational efficiency

Application of Magnetic Nanoseparation Technology in Rapid Detection of Foodborne Pathogens

Foodborne pathogens are important factors that contribute to foodborne illnesses, posing significant threats to food safety and human health, and presenting a major challenge for global healthcare systems. Contaminated food matrices are complex and often have low concentrations of early-stage pathogens, which hinder the sensitivity of existing detection methods. Traditional microbial culture methods are typically used to increase the concentration of pathogens for detection purposes, but these methods are time-consuming and labor-intensive, making them inadequate for the rapid testing needs of regulatory authorities. Therefore, there is an urgent need for effective methods of isolating and enriching foodborne pathogens to accurately detect early-stage contamination in food and ensure food safety. In recent years, magnetic nanoparticles have been extensively studied. By modifying their surfaces with recognition elements that can specifically bind to pathogens, they can effectively isolate and enrich foodborne pathogens in complex food matrices. When combined with existing highly sensitive detection methods, these magnetic nanoparticles enable rapid early-stage detection of foodborne pathogens. This article provides an overview of Magnetic nanoseparation technology, the coupling methods of magnetic nanoparticles with recognition elements, the types of recognition elements, and the application of combined detection methods. The aim is to provide reference for the development of rapid detection methods for foodborne pathogens

Ultraquantum magnetoresistance in Kramers Weyl semimetal candidate β\beta-Ag2Se

The topological semimetal $\beta$-Ag2Se features a Kramers Weyl node at the origin in momentum space and a quadruplet of spinless Weyl nodes, which are annihilated by spin-orbit coupling. We show that single crystalline $\beta$-Ag2Se manifests giant Shubnikov-de Haas oscillations in the longitudinal magnetoresistance which stem from a small electron pocket that can be driven beyond the quantum limit by a field less than 9 T. This small electron pocket is a remainder of the spin-orbit annihilatedWeyl nodes and thus encloses a Berry-phase structure. Moreover, we observed a negative longitudinal magnetoresistance when the magnetic field is beyond the quantum limit. Our experimental findings are complemented by thorough theoretical band structure analyses of this Kramers Weyl semimetal candidate, including first-principle calculations and an effective k*p model.Comment: A new version based on arXiv:1502.0232

Tetraodon nigroviridis as a nonlethal model of infectious spleen and kidney necrosis virus (ISKNV) infection

AbstractInfectious spleen and kidney necrosis virus (ISKNV) is the type species of the genus Megalocytivirus, family Iridoviridae. We have previously established a high mortality ISKNV infection model of zebrafish (Danio rerio). In this study, a nonlethal Tetraodon nigroviridis model of ISKNV infection was established. ISKNV infection did not cause lethal disease in Tetraodon but could infect almost all the organs of this species. Electron microscopy showed ISKNV particles were present in infected tissues. Immunofluorescence and quantitative real-time PCR analysis showed that nearly all the virions and infected cells were cleared at 14d postinfection. The expression profiles of interferon-γ and tumor necrosis factor-α gene in response to ISKNV infection were significantly different in Tetraodon and zebrafish. The establishment of the nonlethal Tetraodon model of ISKNV infection can offer a valuable tool complementary to the zebrafish infection model for studying megalocytivirus disease, fish immune systems, and viral tropism