The role of Causality in Tunable Fermi Gas Condensates

We develop a new formalism for the description of the condensates of cold Fermi atoms whose speed of sound can be tuned with the aid of a narrow Feshbach resonance. We use this to look for spontaneous phonon creation that mimics spontaneous particle creation in curved space-time in Friedmann-Robertson-Walker and other model universes.Comment: 9 pages, 2 figures. In v.3 the formalism is different from the existing arXiv versions, but the final results are unchanged. Title changed, one author added. The article will be published in the special edition of Journal of Physics: Condensed Matter on "Condensed matter analogues of cosmology

Anomalous diffusion in polymers: long-time behaviour

We study the Dirichlet boundary value problem for viscoelastic diffusion in polymers. We show that its weak solutions generate a dissipative semiflow. We construct the minimal trajectory attractor and the global attractor for this problem.Comment: 13 page

A Holographic Model of Strange Metals

We give a review on our recent work arXiv:1006.0779 [hep-th] and arXiv:1006.1719 [hep-th], in which properties of holographic strange metals were investigated. The background is chosen to be anisotropic scaling solution in Einstein-Maxwell-Dilaton theory with a Liouville potential. The effects of bulk Maxwell field, an extra U(1) gauge field and probe D-branes on the DC conductivity, the DC Hall conductivity and the AC conductivity are extensively analyzed. We classify behaviors of the conductivities according to the parameter ranges in the bulk theory and characterize conditions when the holographic results can reproduce experimental data.Comment: 34 pages, 15 figures, minor correction

Ab initio diffusional potential energy surface for CO chemisorption on Pd{110} at high coverage: Coupled translation and rotation

[[abstract]]The ground statepotential energy surface for CO chemisorption across Pd{110} has been calculated using density functional theory with gradient corrections at monolayer coverage. The most stable site corresponds well with the experimental adsorption heat, and it is found that the strength of binding to sites is in the following order: pseudo-short-bridge>atop>long-bridge>hollow. Pathways and transition states for CO surfacediffusion, involving a correlation between translation and orientation, are proposed and discussed.[[notice]]補正完畢[[journaltype]]國外[[booktype]]紙本[[countrycodes]]US

Dark Energy in an Axion Model with Explicit Z(N) Symmetry Breaking

We point out that a well known axion model with an explicit Z(N) symmetry breaking term predicts both dark energy and cold dark matter. We estimate the parameters of this model which fit the observed densities of the dark components of the universe. We find that the parameters do not conflict with any observations.Comment: 5 pages, minor change

Under-utilization of antenatal care services in Timor-Leste: Results from Demographic and Health Survey 2009-2010

Background: Timor-Leste is a young country in the Asia-Pacific region with a high maternal mortality rate of 557 per 100,000 live births. As most maternal deaths can be prevented by providing quality antenatal care (ANC) and skilled assistance during childbirth, understanding the barriers to the utilization of ANC services can enhance program implementation. This study aimed to investigate the prevalence and factors associated with the under-utilization of ANC services in Timor-Leste. Methods: Timor-Leste Demographic and Health Survey (TDHS) 2009-2010 was a nationally representative multi-stage cross-sectional study involving 11,463 households and 9,828 childbirths. Information on last born child was recorded for 5,895 mother-child pairs. Factors influencing under-utilization of ANC were assessed using hierarchical logistic regression analysis. Results: Only 3311 (55.2, 95 % confidence interval (CI) 53.1 to 57.3 %) made the recommended four ANC visits, while 2584 (44.8; 95 % CI 42.7 to 46.9 %) of them reported attending three or less ANC services. Significant factors positively associated with the under-utilization of ANC were low wealth status (odds ratio (OR) 2.09; 95 % CI 1.68 to 2.60), no maternal education (OR 1.54; 95 % CI 1.30 to 1.82) or primary maternal education (OR 1.21; 95 % CI 1.04 to 1.41), no paternal education (OR 1.34; 95 % CI 1.13 to 1.60), and having a big problem in permission to visit health facility (OR 1.65; 95 % CI 1.39 to 1.96). Conclusions: Despite the apparently good progress made in re-establishing the healthcare infrastructure, 45 % of mothers remained in need of a focused intervention to increase their use of ANC services. Further prenatal care program should pay attention to women with low wealth status and those and their partners who are uneducated. Moreover, women should be encouraged to make decision on their own health

Non-orthogonal multiple access schemes with partial relay selection

In this paper, non-orthogonal multiple access (NOMA) in amplify-and-forward relay systems with partial relay selection (PRS) is investigated. More specifically, new exact closed-form expressions for the outage probabilities at two users are derived, based on which an asymptotic analysis at high signal- to-noise ratio (SNR) is carried out. Additionally, in order to investigate the performance gap between the NOMA and orthogonal multiple access (OMA) schemes, a closed-form approximate expression at high SNR for the sum rate is derived. Furthermore, relying on our results, the impact of the PRS on the sum rate and outage probability of the proposed NOMA scheme is examined. In particular, the derived asymptotic expressions show that the proposed scheme can improve over the traditional OMA not only the sum rate but also the user fairness. Finally, simulation results are presented to corroborate the analytical results

M22: A [Fe/H] Abundance Range Revealed

Intermediate resolution spectra at the Ca II triplet have been obtained for 55 candidate red giants in the field of the globular cluster M22 with the VLT/FORS instrument. Spectra were also obtained for a number of red giants in standard globular clusters to provide a calibration of the observed line strengths with overall abundance [Fe/H]. For the 41 M22 member stars that lie within the V-V_HB bounds of the calibration, we find an abundance distribution that is substantially broader than that expected from the observed errors alone. We argue that this broad distribution cannot be the result of differential reddening. Instead we conclude that, as has long been suspected, M22 is similar to omega Cen in having an intrinsic dispersion in heavy element abundance. The observed M22 abundance distribution rises sharply to a peak at [Fe/H] = -1.9 with a broad tail to higher abundances: the highest abundance star in our sample has [Fe/H] = -1.45 dex. If the unusual properties of omega Cen have their origin in a scenario in which the cluster is the remnant nucleus of a disrupted dwarf galaxy, then such a scenario likely applies also to M22.Comment: 29 pages, 9 figures, accepted for publication in the Astrophysical Journa

Symmetry energy of dense matter in holographic QCD

We study the nuclear symmetry energy of dense matter using holographic QCD. To this end, we consider two flavor branes with equal quark masses in a D4/D6/D6 model. We find that at all densities the symmetry energy monotonically increases. At small densities, it exhibits a power law behavior with the density, $E_{\rm sym} \sim \rho^{1/2}$.Comment: 9 pages, 3 figure