Observation of a Geometric Hall Effect in a Spinor Bose-Einstein Condensate with a Skyrmion Spin Texture

For a spin-carrying particle moving in a spatially varying magnetic field, effective electromagnetic forces can arise due to the geometric phase associated with adiabatic spin rotation of the particle. We report the observation of a geometric Hall effect in a spinor Bose-Einstein condensate with a skyrmion spin texture. Under translational oscillations of the spin texture, the condensate resonantly develops a circular motion in a harmonic trap, demonstrating the existence of an effective Lorentz force. When the condensate circulates, quantized vortices are nucleated in the boundary region of the condensate and the vortex number increases over 100 without significant heating. We attribute the vortex nucleation to the shearing effect of the effective Lorentz force from the inhomogeneous effective magnetic field.Comment: 9 pages, 11 figure

Determinants Of Enforcement Action By The Financial Supervisory Service Of Korea From The Perspective Of Audit Firms

In this study, we examine the determinants of enforcement action by the Financial Supervisory Service of Korea from the perspective of audit firms. Enforcement action is an indication of audit failure. Both client- and audit firm-specific factors are involved in its occurrence. Most published studies of enforcement after audit failure focus on client characteristics because details about audit firms from financial statements and information about organizational structure are not publicly available. However, examining the issues surrounding enforcement from the perspective of audit firms may also be valuable in elucidating the potential determinants of audit failure resulting in enforcement action. Utilizing publicly available data from audit firms in South Korea, we identify several audit firm characteristics as determinants of enforcement action. The results of our empirical analysis reveal that the likelihood of audit failure is positively associated with the ratio of accounts receivable to total assets, the ratio of audit fees to total revenue, the ratio of partners to the total number of CPAs, CEO ownership, and age of audit firms. In addition, the likelihood of audit failure is negatively associated with ownership concentration and profitability. These associations are more pronounced in non-affiliated audit firms than affiliated audit firms. Several useful implications for regulators are described for improving audit quality by means of enforcement action

Observation and Numerical Prediction of 2011 East Japan Tsunami Inpacific Ocean

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Higher Alpha/Theta Ratio May Indicate Decreased Brain Function in Older Adults during CSPFP10 Compared to Young Adults

Declined physical ability and brain function observed in elder can affect daily living activities and negatively influence the quality of life (QOL). While the extensive research has explored the changes in cortical activity related to motor control in elder, less is known about how the brain functions during a physical function test. PURPOSE: To examine the electrocortical activation in the older adults’ brain during the Continuous Scale Physical Function Performance-10 (CSPFP-10) compared to young adults. METHODS: Twenty five older adults (OLD; 75.40±7.32 yrs, 70.33±18.23 kg, 162.87±7.55 cm) and twenty five young (YOUNG; 19.88±1.72 yrs, 66.52±14.22 kg, 167.50±10.22 cm) completed CSPFP10 while frontal (F3, Fz, F4), central (C3, Cz, C4), temporal (T7, T8, P7, P8), parietal (P3, Pz P4), and occipital (O1, Oz, O2) regions’ electrocortical activation was measured using a mobile electroencephalograph (EEG). Spectral power values (μV2/Hz) for theta (θ: 4-8 Hz) and alpha (α: 8-13 Hz) band were averaged across the target electrodes. Then α/θ ratio was calculated. Data were analyzed using independent t-test. RESULTS: OLD exhibited significantly higher α/θ ratio in frontal (M=0.98 vs.0.95, pp=.02), temporal (M=1.02 vs. 0.98, p=.006) compared to YOUNG. The separated t-test showed YOUNG had higher θ and α in frontal (θ: M= 40.93 vs. 37.56, pp=.03), central (θ: M=39.68 vs. 36.43, pp=.038), and parietal θ (M=40.55 vs. 37.98, p=.001) compared to OLD. Pearson’s correlation analysis did not find any significance between brain function and CSPFP10 scores in both groups. CONCLUSION α/θ ratio in OLD showed that their α power was relatively higher than YOUNG. Increased α power indicates suppression/selective cortical processing. It might indicate that OLD had inhibitory cortical activation process during the CSPFP10 task. Decreased frontal and parietal θ in OLD may indicate diminished decision making speed and attention with aging, while lower θ power in a central region (motor cortex) implies disrupt motor control. Overall, our result may indicate that brain activation patterns become less active during aging. It’s important to enhance both physical and brain function to improve activities of daily living and QOL in elderly population

Microspinning: Local Surface Mixing via Rotation of Magnetic Microparticles for Efficient Small-Volume Bioassays

The need for high-throughput screening has led to the miniaturization of the reaction volume of the chamber in bioassays. As the reactor gets smaller, surface tension dominates the gravitational or inertial force, and mixing efficiency decreases in small-scale reactions. Because passive mixing by simple diffusion in tens of microliter-scale volumes takes a long time, active mixing is needed. Here, we report an efficient micromixing method using magnetically rotating microparticles with patterned magnetization induced by magnetic nanoparticle chains. Because the microparticles have magnetization patterning due to fabrication with magnetic nanoparticle chains, the microparticles can rotate along the external rotating magnetic field, causing micromixing. We validated the reaction efficiency by comparing this micromixing method with other mixing methods such as simple diffusion and the use of a rocking shaker at various working volumes. This method has the potential to be widely utilized in suspension assay technology as an efficient mixing strategy

Properties of Central Caustics in Planetary Microlensing

To maximize the number of planet detections, current microlensing follow-up observations are focusing on high-magnification events which have a higher chance of being perturbed by central caustics. In this paper, we investigate the properties of central caustics and the perturbations induced by them. We derive analytic expressions of the location, size, and shape of the central caustic as a function of the star-planet separation, $s$, and the planet/star mass ratio, $q$, under the planetary perturbative approximation and compare the results with those based on numerical computations. While it has been known that the size of the planetary caustic is \propto \sqrt{q}, we find from this work that the dependence of the size of the central caustic on $q$ is linear, i.e., \propto q, implying that the central caustic shrinks much more rapidly with the decrease of $q$ compared to the planetary caustic. The central-caustic size depends also on the star-planet separation. If the size of the caustic is defined as the separation between the two cusps on the star-planet axis (horizontal width), we find that the dependence of the central-caustic size on the separation is \propto (s+1/s). While the size of the central caustic depends both on $s$ and q, its shape defined as the vertical/horizontal width ratio, R_c, is solely dependent on the planetary separation and we derive an analytic relation between R_c and s. Due to the smaller size of the central caustic combined with much more rapid decrease of its size with the decrease of q, the effect of finite source size on the perturbation induced by the central caustic is much more severe than the effect on the perturbation induced by the planetary caustic. Abridged.Comment: 5 pages, 4 figures, ApJ accepte

Time-resolved pathogenic gene expression analysis of the plant pathogen Xanthomonas oryzae pv. oryzae

Virulence of wild-type and mutant Xoo strains on rice. (DOCX 16 kb

Comb-rooted multi-channel synthesis of ultra-narrow optical frequencies of few Hz linewidth

We report a multi-channel optical frequency synthesizer developed to generate extremely stable continuous wave lasers directly out of the optical comb of an Er-doped fiber oscillator. Being stabilized to a high-finesse cavity with a fractional frequency stability of $3.8\times10^{-15}$ at 0.1 s, the comb-rooted synthesizer produces multiple optical frequencies of ultra-narrow linewidth of 1.0 Hz at 1 s concurrently with an output power of tens of mW per each channel. Diode-based stimulated emission by injection locking is a key mechanism that allows comb frequency modes to sprout up with sufficient power amplification but no loss of original comb frequency stability. Channel frequencies are individually selectable with a 0.1 GHz increment over the entire comb bandwidth spanning 4.25 THz around a 1550 nm center wavelength. A series of out-of-loop test results is discussed to demonstrate that the synthesizer is able to provide stable optical frequencies with the potential for advancing diverse ultra-precision applications such as optical clocks comparison, atomic line spectroscopy, photonic microwaves generation, and coherent optical telecommunications.Comment: 19 pages, 4 figure