Rotating binary Bose-Einstein condensates and vortex clusters in quantum droplets

Quantum droplets may form out of a gaseous Bose-Einstein condensate, stabilized by quantum fluctuations beyond mean field. We show that multiple singly-quantized vortices may form in these droplets at moderate angular momenta in two dimensions. Droplets carrying these precursors of an Abrikosov lattice remain self-bound for certain timescales after switching off an initial harmonic confinement. Furthermore, we examine how these vortex-carrying droplets can be formed in a more pertubation-resistant setting, by starting from a rotating binary Bose-Einstein condensate and inducing a metastable persistent current via a non-monotonic trapping potential.Comment: 5 page, 4 figure

Phase diagram of a rapidly-rotating two-component Bose gas

We derive analytically the phase diagram of a two-component Bose gas confined in an anharmonic potential, which becomes exact and universal in the limit of weak interactions and small anharmonicity of the trapping potential. The transitions between the different phases, which consist of vortex states of single and multiple quantization, are all continuous because of the addition of the second component.Comment: 5 pages, 3 figure

Rotational properties of non-dipolar and dipolar Bose-Einstein condensates confined in annular potentials

We investigate the rotational response of both non-dipolar and dipolar Bose-Einstein condensates confined in an annular potential. For the non-dipolar case we identify certain critical rotational frequencies associated with the formation of vortices. For the dipolar case, assuming that the dipoles are aligned along some arbitrary and tunable direction, we study the same problem as a function of the orientation angle of the dipole moment of the atoms.Comment: 5 pages, 4 figure

Finite-size effects in the dynamics of few bosons in a ring potential

We study the temporal evolution of a small number $N$ of ultra-cold bosonic atoms confined in a ring potential. Assuming that initially the system is in a solitary-wave solution of the corresponding mean-field problem, we identify significant differences in the time evolution of the density distribution of the atoms when it instead is evaluated with the many-body Schr\"odinger equation. Three characteristic timescales are derived: the first is the period of rotation of the wave around the ring, the second is associated with a "decay" of the density variation, and the third is associated with periodic "collapses" and "revivals" of the density variations, with a factor of $\sqrt N$ separating each of them. The last two timescales tend to infinity in the appropriate limit of large $N$, in agreement with the mean-field approximation. These findings are based on the assumption of the initial state being a mean-field state. We confirm this behavior by comparison to the exact solutions for a few-body system stirred by an external potential. We find that the exact solutions of the driven system exhibit similar dynamical features.Comment: To appear in Journal of Physics

Spin-orbit-coupled Bose-Einstein-condensed atoms confined in annular potentials

A spin-orbit-coupled Bose-Einstein-condensed cloud of atoms confined in an annular trapping potential shows a variety of phases that we investigate in the present study. Starting with the non-interacting problem, the homogeneous phase that is present in an untrapped system is replaced by a sinusoidal density variation in the limit of a very narrow annulus. In the case of an untrapped system there is another phase with a striped-like density distribution, and its counterpart is also found in the limit of a very narrow annulus. As the width of the annulus increases, this picture persists qualitatively. Depending on the relative strength between the inter- and the intra-components, interactions either favor the striped phase, or suppress it, in which case either a homogeneous, or a sinusoidal-like phase appears. Interactions also give rise to novel solutions with a nonzero circulation.Comment: Final, slightly revised versio

Patients With Kidney Cancer

To develop a preoperative prognostic model in order to predict recurrence-free survival in patients with nonmetastatic kidney cancer.A multi-institutional data base of 1889 patients who underwent surgical resection between 1987 and 2007 for kidney cancer was retrospectively analyzed. Preoperative variables were defined as age, gender, presentation, size, presence of radiological lymph nodes and clinical stage. Univariate and multivariate analyses of the variables were performed using the Cox proportional hazards regression model. A model was developed with preoperative variables as predictors of recurrence after nephrectomy. Internal validation was performed by Harrells concordance index.The median follow-up was 23.6 months (1222 months). During the follow-up, 258 patients (13.7) developed cancer recurrence. The median follow-up for patients who did not develop recurrence was 25 months. The median time from surgery to recurrence was 13 months. The 5-year freedom from recurrence probability was 78.6. All variables except age were associated with freedom from recurrence in multivariate analyses (P 0.05). Age was marginally significant in the univariate analysis. All variables were included in the predictive model. The calculated c-index was 0.747.This preoperative model utilizes easy to obtain clinical variables and predicts the likelihood of development of recurrent disease in patients with kidney tumors

Damping properties of open pore aluminum foams produced by vacuum casting and NaCl dissolution process

In this study,damping ratios of 3 samples made of aluminum foam material, which have different-density pores, were calculated, the effects pore density on damping were examined. Experimental modal analysis method was used for examining of the effects of the pore density on damping. In experimental modal analysis method, frequency charts were obtained by driving to the sample with a hammer. Through these frequency charts, damping ratios of each 3 samples were calculated with ME’scope VES program. It was observed in calculated damping ratios that pore density has influences on damping; thus, damping accordingly increases as the number of pores increases. It is seen that critical damping constant decreases as the material structure changes in terms of volume and density

Damping properties of open pore aluminum foams produced by vacuum casting and NaCl dissolution process

In this study,damping ratios of 3 samples made of aluminum foam material, which have different-density pores, were calculated, the effects pore density on damping were examined. Experimental modal analysis method was used for examining of the effects of the pore density on damping. In experimental modal analysis method, frequency charts were obtained by driving to the sample with a hammer. Through these frequency charts, damping ratios of each 3 samples were calculated with ME’scope VES program. It was observed in calculated damping ratios that pore density has influences on damping; thus, damping accordingly increases as the number of pores increases. It is seen that critical damping constant decreases as the material structure changes in terms of volume and density

The intensity of physical activity improves cognitive performance among aging Americans

Background: Currently there is no pharmacological cure for Alzheimer’s disease and related dementias, physical activity (PA) has emerged as a promising approach. The optimal intensity of PA to improve cognitive health remains unknown. Therefore, this study aimed to evaluate associations between different durations and intensities of PA on performance across cognitive domains (executive function, processing speed, and memory) among aging Americans. Methods: 2377 adults aged ≥ 60 years from the cross-sectional National Health and Nutrition Examination Survey 2011-2014, were included. Linear regression in hierarchical blocks and the size of effect (η2) were analyzed with R software. Results: The mean age was 69.3±6.73, 50.86% females. Despite the attenuation of association following adjustments for covariates, participants who engaged in 3-6 hr/wk of vigorous- and \u3e 1 hr/wk of moderate-intensity PA performed significantly higher in executive function and processing speed tests compared to inactive peers (η2= 0.005 & 0.007 respectively, p \u3c 0.05). However, there was no clear dose-response relationship between the executive function and processing speed test scores and duration of weekly moderate-intensity PA. For the adjusted model, the effects of 1-3 hr/wk of vigorous-intensity PA became trivial for the delayed recall memory test scores (β=0.33; 95% CI: -0.01, 0.67; η2=0.002; p=0.56). Interestingly, higher handgrip strength and higher late-life body-mass-index were associated with a higher performance across all cognitive domains. Conclusion: Observed associations provide evidence linking habitual PA with superior cognition health among older adults. Furthermore, increased muscle strength and higher late-life adiposity may impact cognition and require further investigation

Density functional theory for strongly-correlated bosonic and fermionic ultracold dipolar and ionic gases

We introduce a density functional formalism to study the ground-state properties of strongly-correlated dipolar and ionic ultracold bosonic and fermionic gases, based on the self-consistent combination of the weak and the strong coupling limits. Contrary to conventional density functional approaches, our formalism does not require a previous calculation of the interacting homogeneous gas, and it is thus very suitable to treat systems with tunable long-range interactions. Due to its asymptotic exactness in the regime of strong correlation, the formalism works for systems in which standard mean-field theories fail.Comment: 5 pages, 2 figure