Non-destructive cavity QED probe of Bloch oscillations in a gas of ultracold atoms

We describe a scheme for probing a gas of ultracold atoms trapped in an optical lattice and moving in the presence of an external potential. The probe is non-destructive and uses the existing lattice fields as the measurement device. Two counter-propagating cavity fields simultaneously set up a conservative lattice potential and a weak quantum probe of the atomic motion. Balanced heterodyne detection of the probe field at the cavity output along with integration in time and across the atomic cloud yield information about the atomic dynamics in a single run. The scheme is applied to a measurement of the Bloch oscillation frequency for atoms moving in the presence of the local gravitational potential. Signal-to-noise ratios are estimated to be as high as $10^4$.Comment: 8 pages, 6 figures, submitted to Phys. Rev.

Quantized Vortex States of Strongly Interacting Bosons in a Rotating Optical Lattice

Bose gases in rotating optical lattices combine two important topics in quantum physics: superfluid rotation and strong correlations. In this paper, we examine square two-dimensional systems at zero temperature comprised of strongly repulsive bosons with filling factors of less than one atom per lattice site. The entry of vortices into the system is characterized by jumps of 2 pi in the phase winding of the condensate wavefunction. A lattice of size L X L can have at most L-1 quantized vortices in the lowest Bloch band. In contrast to homogeneous systems, angular momentum is not a good quantum number since the continuous rotational symmetry is broken by the lattice. Instead, a quasi-angular momentum captures the discrete rotational symmetry of the system. Energy level crossings indicative of quantum phase transitions are observed when the quasi-angular momentum of the ground-state changes.Comment: 12 Pages, 13 Figures, Version

Status of drowning in Nepal: A study of central police data

Background: Drowning is a serious and mostly preventable injury-related cause of death. Low-and-middle income countries represent 90% of total drowning deaths worldwide. There is lack of epidemiological studies of drowning in Nepal. The aim of this paper is to describe the status of drowning in Nepal. Methods: Cases of drowning, occurring between January 2013 and December 2015 were extracted from the Daily Incident Recording System of Nepal Police. Variables on age, sex of the deceased, types of water bodies, places, season when drowning occurred and activities of deceased were extracted and descriptive analysis was done. Results: A total of 1,507 drowning cases were recorded over a 3 year period. The rate of drowning was 1.9 per 100,000 (2.95 for males and 0.92 for females). Majority of drowning occurred among males (76%) and more than half were (53%) under 20 years of age. Mostly drowning occurred in rivers (natural water bodies). The findings provide strong indication that drowning occurs throughout the year in Nepal. Children were highly vulnerable to drowning. The magnitude of drowning was found to be lower than estimated by global burden of disease (GBD) study. Conclusion: The burden of drowning in Nepal is considerable, but mostly unknown to the public. Despite only having access to a limited data source, this study provides useful evidence that comprehensive research in Nepal is needed urgently

Demographic profile and epidemiology of injury in Mthatha, South Africa

Objective: To determine the magnitude, socio-demographic and epidemiological characteristics of injury at a Provincial referral hospital.Methods: This review was conducted on all trauma patients admitted at the Mthatha Hospital Complex and Nelson Mandela Academic Hospital from the 1st January 1997 to the 31st December 2000.Results: The incident rate of injuries was 3.2% (n=2460/75,833 total admissions). Injured patients were mostly black (80%) and males (ratio: 5 men: 1 woman). Only 8.1% of injured patients were transported to hospital by ambulances. The leading causes of injuries were inter-personal violence accounting for 60% of cases, and motor vehicle accidents accounting for 19%; of them 38% were due to poor visibility, over speeding, and fatigue. The overall mortality was 33% (n=821) independently predicted by poverty (OR=8.2 95%CI 6-11.1; P40 years(OR=7.8 95%CI 7.7-12.1;P<0.0001).Conclusion: The burden of injury is a mass issue that warrants regional attention with quality of care and training.Keywords: Injuries, violence, poverty, mortality, South AfricaAfrican Health Sciences 2013; 13(4): 1144 - 114

All-optical 3D atomic loops generated with Bessel light fields

The propagation invariance of Bessel beams as well as their transversal structure are used to perform a comparative analysis of their effect on cold atoms for four different configurations and combinations thereof. We show that, even at temperatures for which the classical description of the atom center of mass motion is valid, the interchange of momentum, energy and orbital angular momentum between light and atoms yields efficient tools for all-optical trapping, transporting and, in general, manipulating the state of motion of cold atoms.Comment: 13 pages, 9 figure

Abnormal prion protein in the retina of the most commonly occurring subtype of sporadic Creutzfeldt-Jakob disease

Background: Involvement of the eye has been reported in patients with variant Creutzfeldt-Jakob disease (vCJD), but there is disagreement on whether retinal involvement occurs in sporadic Creutzfeldt-Jakob disease (sCJD). Methods: Western blotting, paraffin embedded tissue blotting, and immunohistochemistry were used to test whether the abnormal form of the prion protein (PrP(Sc)) accumulates to detectable levels in the eye in a case of the most common subtype of sCJD (MM1). Results: Low levels of PrP(Sc) were detectable in the retina, localised to the plexiform layers of the central retina. PrP(Sc) was not detectable in other ocular tissues. Conclusions: The abnormal form of the prion protein is present in the retina in the most common sCJD subtype (MM1), albeit at levels lower than those found previously in vCJD and in sCJD of the VV2 subtype

Surface Core Level Shifts of Clean and Oxygen Covered Ru(0001)

We have performed high resolution XPS experiments of the Ru(0001) surface, both clean and covered with well-defined amounts of oxygen up to 1 ML coverage. For the clean surface we detected two distinct components in the Ru 3d_{5/2} core level spectra, for which a definite assignment was made using the high resolution Angle-Scan Photoelectron Diffraction approach. For the p(2x2), p(2x1), (2x2)-3O and (1x1)-O oxygen structures we found Ru 3d_{5/2} core level peaks which are shifted up to 1 eV to higher binding energies. Very good agreement with density functional theory calculations of these Surface Core Level Shifts (SCLS) is reported. The overriding parameter for the resulting Ru SCLSs turns out to be the number of directly coordinated O atoms. Since the calculations permit the separation of initial and final state effects, our results give valuable information for the understanding of bonding and screening at the surface, otherwise not accessible in the measurement of the core level energies alone.Comment: 16 pages including 10 figures. Submitted to Phys. Rev. B. Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

Phosphorylation of p65 Is Required for Zinc Oxide Nanoparticle–Induced Interleukin 8 Expression in Human Bronchial Epithelial Cells

BackgroundExposure to zinc oxide (ZnO) in environmental and occupational settings causes acute pulmonary responses through the induction of proinflammatory mediators such as interleukin-8 (IL-8).ObjectiveWe investigated the effect of ZnO nanoparticles on IL-8 expression and the underlying mechanisms in human bronchial epithelial cells.MethodsWe determined IL-8 mRNA and protein expression in primary human bronchial epithelial cells and the BEAS-2B human bronchial epithelial cell line using reverse-transcriptase polymerase chain reaction and the enzyme-linked immunosorbent assay, respectively. Transcriptional activity of IL-8 promoter and nuclear factor kappa B (NFκB) in ZnO-treated BEAS-2B cells was measured using transient gene transfection of the luciferase reporter construct with or without p65 constructs. Phosphorylation and degradation of IκBα, an inhibitor of NF-κB, and phosphorylation of p65 were detected using immunoblotting. Binding of p65 to the IL-8 promoter was examined using the chromatin immunoprecipitation assay.ResultsZnO exposure (2–8 μg/mL) increased IL-8 mRNA and protein expression. Inhibition of transcription with actinomycin D blocked ZnO-induced IL-8 expression, which was consistent with the observation that ZnO exposure increased IL-8 promoter reporter activity. Further study demonstrated that the κB-binding site in the IL-8 promoter was required for ZnO-induced IL-8 transcriptional activation. ZnO stimulation modestly elevated IκBα phosphorylation and degradation. Moreover, ZnO exposure also increased the binding of p65 to the IL-8 promoter and p65 phosphorylation at serines 276 and 536. Overexpression of p65 constructs mutated at serines 276 or 536 significantly reduced ZnO-induced increase in IL-8 promoter reporter activity.Conclusionp65 phosphorylation and IκBα phosphorylation and degradation are the primary mechanisms involved in ZnO nanoparticle-induced IL-8 expression in human bronchial epithelial cells