Observation of Topologically Stable 2D Skyrmions in an Antiferromagnetic Spinor Bose-Einstein Condensate

We present the creation and time evolution of two-dimensional Skyrmion excitations in an antiferromagnetic spinor Bose-Einstein condensate. Using a spin rotation method, the Skyrmion spin textures were imprinted on a sodium condensate in a polar phase, where the two-dimensional Skyrmion is topologically protected. The Skyrmion was observed to be stable on a short time scale of a few tens of ms but to have dynamical instability to deform its shape and eventually decay to a uniform spin texture. The deformed spin textures reveal that the decay dynamics involves breaking the polar phase inside the condensate without having topological charge density flow through the boundary of the finite-sized sample. We discuss the possible formation of half-quantum vortices in the deformation process.Comment: 5 pages, 5 figure

Relaxation of superfluid turbulence in highly oblate Bose-Einstein condensates

We investigate thermal relaxation of superfluid turbulence in a highly oblate Bose-Einstein condensate. We generate turbulent flow in the condensate by sweeping the center region of the condensate with a repulsive optical potential. The turbulent condensate shows a spatially disordered distribution of quantized vortices and the vortex number of the condensate exhibits nonexponential decay behavior which we attribute to the vortex pair annihilation. The vortex-antivortex collisions in the condensate are identified with crescent-shaped, coalesced vortex cores. We observe that the nonexponential decay of the vortex number is quantitatively well described by a rate equation consisting of one-body and two-body decay terms. In our measurement, we find that the local two-body decay rate is closely proportional to $T^2/\mu$, where $T$ is the temperature and $\mu$ is the chemical potential.Comment: 7 pages, 9 figure

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

A Keck/LRIS Spatially-Resolved Spectroscopic Study of a LINER Galaxy SDSS J091628.05+420818.7

Using spatially-resolved spectra obtained with the Low Resolution Imaging Spectrometer at the Keck I telescope, we investigate the nature of ionizing sources and kinematic properties of emission-line gas in a LINER galaxy SDSS J091628.05+420818.7, which is a nearby (z = 0.0241) and bright (M_r = -20.2) early-type galaxy. After subtracting stellar absorption features using a combination of simple stellar population models, we measure the flux, line-of-sight velocity, and velocity dispersion of four emission lines, i.e., H{\alpha}, H{\beta}, [O III] {\lambda}5007, and [N II] {\lambda}6584, to study radial change of emission-line fluxes and velocities. Compared to the point-spread-function of the observation, the emission-line region is slightly extended but comparable to the seeing size. The central concentration of emission-line gas suggests that ionization is triggered by a nuclear source, excluding old stellar population as ionizing sources. We find that emission-line gas is counter-rotating with respect to stellar component and that the [O III] {\lambda}5007 line is blueshifted compared to other emission lines, possibly due to an outflow.Comment: 10 pages, 8 figures; Accepted for publication in Ap

Favored serum albumin level and ICF volume after use of 1.1% aminoacid based peritoneal dialysis(PD) solution

Aminoacid based PD solution (AAD) has been shown to induce positive nitrogen balance and improve nutritional markers of malnourished patients. But its effcets on body fluid composition and various nutritional markers are contradictory. Nutritional markers may influenced by patient's ECF volume status. So we evaluate effects of AAD on nutritional markers and body composition by analysis using multi-frequency bioimpedance analyzer. 35 PD patients(>6months duration of CAPD) were prospectively randomized to 17 AAD(Nutrineal, one time use/day) and 18 GD group(keep their glucose based PD solution). After 3 months follow up, AAD group showed marginally increased body weight and fat mass, decreased ECF volume(12.45±0.54Lvs 12.10±0.57L, p=0.06), no changed ICF volume(22.2±0.9Lvs 22.3±0.9L, p>0.05) and marginally increased drainage volume(8.77±0.76Lvs 9.12±0.83L, p=0.09). AAD group also showed favored several markers include nPCR(1.59±0.07vs 1.98±0.08, p=0.00), BUN and albumin level (3.54±0.11 vs 3.74±0.11, p=0.02). Although serum albumin level was increased, correction with ECF volume(albumin level X ECF volume) makes it no difference (43.45±2.13vs 44.80±2.28, p=0.14). Furthermore △albumin vs △ECF showed negative correlation pattern(r=-0.46, p=0.07) that means serum albumin change was influenced by ECF volume change. In conclusion, AAD treatment improved markers of better nutritional status. However the change in serum albumin level was influenced by patient's ECF volume status, which can partially explain contradictory effect of aminoacid based PD solution on serum albumin level

International Family Migration and Labormarket Outcomes of Immigrant Couples : Do Types of Migration Matter?

This study examines whether immigrant womens labor-market outcomes relative to those of immigrant men vary across different types of family migration. Using matched pairs of husbands and wives from the 2000 U.S Census, this study investigates the impact of international family migration on immigrant women's employment status and hourly earnings. The results show that, for women, wife-initiated migration is positively associated with employment, compared to husband-initiated and simultaneous migration. In relation to the moderating effect of education, for wife-initiated migration, women are also more likely to be employed as education rises. Thus, for wife-initiated migration, the gender gap diminishes substantially with increasing education. Consistent with the analyses of employment status, for women, wife-initiated migration is positively associated with higher hourly earnings. The moderating effect of education also shows that, for women, the positive association between wife-initiated migration and hourly earnings increases with education

Tool to visualize and evaluate operator proficiency in laser hair-removal treatments

BACKGROUND: The uniform delivery of laser energy is particularly important for safe and effective laser hair removal (LHR) treatment. Although it is necessary to quantitatively assess the spatial distribution of the delivered laser, laser spots are difficult to trace owing to a lack of visual cues. This study proposes a novel preclinic tool to evaluate operator proficiency in LHR treatment and applies this tool to train novice operators and compare two different treatment techniques (sliding versus spot-by-spot). METHODS: A simulation bed is constructed to visualize the irradiated laser spots. Six novice operators are recruited to perform four sessions of simulation while changing the treatment techniques and the presence of feedback (sliding without feedback, sliding with feedback, spot-by-spot without feedback, and spot-by-spot with feedback). Laser distribution maps (LDMs) are reconstructed through a series of images processed from the recorded video for each simulation session. Then, an experienced dermatologist classifies the collected LDMs into three different performance groups, which are quantitatively analyzed in terms of four performance indices. RESULTS: The performance groups are characterized by using a combination of four proposed indices. The best-performing group exhibited the lowest amount of randomness in laser delivery and accurate estimation of mean spot distances. The training was only effective in the sliding treatment technique. After the training, omission errors decreased by 6.32% and better estimation of the mean spot distance of the actual size of the laser-emitting window was achieved. Gels required operators to be trained when the spot-by-spot technique was used, and imposed difficulties in maintaining regular laser delivery when the sliding technique was used. CONCLUSIONS: Because the proposed system is simple and highly affordable, it is expected to benefit many operators in clinics to train and maintain skilled performance in LHR treatment, which will eventually lead to accomplishing a uniform laser delivery for safe and effective LHR treatment