Vafa-Witten Estimates for Compact Symmetric Spaces

We give an optimal upper bound for the first eigenvalue of the untwisted Dirac operator on a compact symmetric space G/H with rk G-rk H\le 1 with respect to arbitrary Riemannian metrics. We also prove a rigidity statement.Comment: LaTeX, 11 pages. V2: Rigidity statement added, minor changes. To appea

Angular EPR paradox

The violation of local uncertainty relations is a valuable tool for detecting entanglement, especially in multi-dimensional systems. The orbital angular momentum of light provides such a multi-dimensional system. We study quantum correlations for the conjugate variables of orbital angular momentum and angular position. We determine an experimentally testable criterion for the demonstration of an angular version of the EPR paradox. For the interpretation of future experimental results from our proposed setup, we include a model for the indeterminacies inherent to the angular position measurement. For this measurement angular apertures are used to determine the probability density of the angle. We show that for a class of aperture functions a demonstration of an angular EPR paradox, according to our criterion, is to be expected.Comment: 21 pages, 9 figures, to be published in J. Mod. Opt. special issue on quantum imagin

Matter-wave grating distinguishing conservative and dissipative interactions

We propose an optical grating for matter waves that separates molecules depending on whether their interaction with the light is conservative or dissipative. Potential applications include fundamental tests of quantum mechanics, measurement of molecular properties and the ability to selectively prepare matter waves with different internal temperatures

Prospective Survey of AntibioticUtilization in Pediatric Hospitalized Patients to IdentifyTargets for Improvement of Prescription

Abstract. : Background: : The rise in the use of antibiotics has resulted in increasing health care costs and the emergence of resistant bacteria. Little is known about the general misuse of antibiotics in hospitalized children. We evaluated the utilization of antibiotics in a pediatric teaching hospital aiming to identify targets for improvement of prescription. Patients and Methods: : Clinical, radiological, laboratory and treatment data of patients hospitalized in a pediatric medical and a pediatric surgery ward were prospectively collected during a 6-week period. A subsequent review of the collected data by a pediatric infectious diseases specialist, taking into consideration existing in-house treatment guidelines, was carried out. Results: : A total of 125 (36%) of 349 patients was prescribed 246 antibiotics. The median length of hospital stay for children prescribed antibiotics was 5 days (range, 2-30 days) and for those not prescribed 3 days (1-32 days; p < 0.001). Of 154 patients in the medical ward, 64 (42%) received antibiotics, compared to 61 (31%) of 195 patients in the surgical ward (p < 0.05). Empirical prescriptions were more frequent than prophylactic ones, which were more frequent than therapeutic prescriptions (136 [55%] vs 94 [38%] vs 16 [7%]; p < 0.001). Overall, 85% of the prescriptions were considered justified. The rates of inappropriate prescriptions were similar in the medical and surgical ward, and higher for therapeutic (19%) or prophylactic treatment (18%) than for empirical treatment (12%). Higher inappropriate prescription rates were noted for macrolides than for co-trimoxazole and β-lactams (50% vs 18% and 15%, respectively; p < 0.05). Conclusion: : Efforts need to be undertaken towards continuous education of medical staff on judicious antibiotic use, as well as ensuring compliance with existing guidelines. Improvement in the availability of rapid diagnostic methods to discern viral from bacterial infections may help reduce the numbers of empiric therapies in favor of pathogen-targeted therapeutic treatment

On lines of constant polarisation in structured light beams

We show that Skyrmion field lines, constructed from the local Stokes parameters, trace out lines of constant optical polarisation

Optical helicity and chirality: conservation and sources

We consider the helicity and chirality of the free electromagnetic field, and advocate the former as a means of characterising the interaction of chiral light with matter. This is in view of the intuitive quantum form of the helicity density operator, and of the dual symmetry transformation generated by its conservation. We go on to review the form of the helicity density and its associated continuity equation in free space, in the presence of local currents and charges, and upon interaction with bulk media, leading to characterisation of both microscopic and macroscopic sources of helicity

The relationship of renal function to outcome: A post hoc analysis from the EdoxabaN versus warfarin in subjectS UndeRgoing cardiovErsion of Atrial Fibrillation (ENSURE-AF) study.

The ENSURE-AF study (NCT 02072434) of anticoagulation for electrical cardioversion in nonvalvular atrial fibrillation (NVAF) showed comparable low rates of bleeding and thromboembolism between the edoxaban and the enoxaparin-warfarin treatment arms. This post hoc analysis investigated the relationship between renal function and clinical outcomes. METHODS: ENSURE-AF was a multicenter, PROBE evaluation trial of edoxaban 60 mg, or dose reduced to 30 mg/d for weight≤60 kg, creatinine clearance (CrCl; Cockcroft-Gault) ≤50 mL/min, or concomitant P-glycoprotein inhibitors compared with therapeutically monitored enoxaparin-warfarin in 2,199 NVAF patients undergoing electrical cardioversion. Efficacy and safety outcomes and time in therapeutic range in the warfarin arm were analyzed in relation to CrCl in prespecified ranges ≥15 and ≤30, >30 and ≤50, >50 and 30 to ≤50 compared with 71.8% in those with CrCl ≥80. The odds ratios for the primary efficacy and safety end points were comparable for the different predefined renal function strata; given the small numbers, the 95% CI included 1.0. In the subset of those with CrCl ≥95, the odds ratios showed consistency with the other CrCl strata. When CrCl was assessed as a continuous variable, there was a nonsignificant trend toward higher major or clinically relevant nonmajor bleeding with reducing CrCl levels, with no significant differences between the 2 treatment arms. When we assessed CrCl at baseline compared with end of treatment, there were no significant differences in CrCl change between the edoxaban and enoxaparin-warfarin arms. The proportions with worsening of renal function (defined as a decrease of >20% from baseline) were similar in the 2 treatment arms. CONCLUSION: Given the small number of events in ENSURE-AF, no effect of renal (dys)function was demonstrated in comparing edoxaban to enoxaparin-warfarin for cardioversion; efficacy and safety of edoxaban remained consistent even in patients with normal or supranormal renal function