A Population-Based Study of the Risk of Diabetic Retinopathy in Patients With Type 1 Diabetes and Celiac Disease

Objective: Celiac disease (CD) is associated with type 1 diabetes (T1D). In the current study, we examined whether CD affects the risk of diabetic retinopathy (DRP) in patients with T1D. Research design and methods: This was a population-based cohort study. Through the Swedish National Patient Register, we identified 41,566 patients diagnosed with diabetes in 1964–2009 and who were ≤30 years of age at diagnosis. CD was defined as having villous atrophy (Marsh stage 3) according to small intestinal biopsies performed between 1969 and 2008, with biopsy reports obtained from Sweden’s 28 pathology departments. During follow-up, 947 T1D patients had a diagnosis of CD. We used Cox regression analysis with CD as a time-dependent covariate to estimate adjusted hazard ratios (aHRs) for DRP in patients with T1D and CD and compared them with patients with T1D but no CD. Results: Duration of CD correlated with the risk of DRP. When results were stratified by time since CD diagnosis, individuals with T1D and CD were at a lower risk of DRP in the first 5 years after CD diagnosis (aHR 0.57 [95% CI 0.36–0.91]), followed by a neutral risk in years 5 to <10 (1.03 [0.68–1.57]). With longer follow-up, coexisting CD was a risk factor for DRP (10 to <15 years of follow-up, aHR 2.83 [95% CI 1.95–4.11]; ≥15 years of follow-up, 3.01 [1.43–6.32]). Conclusions: Having a diagnosis of CD for >10 years is a risk factor for the development of DRP in T1D. Long-standing CD in patients with T1D merits intense monitoring of DRP

Towards a New Standard Model for Black Hole Accretion

We briefly review recent developments in black hole accretion disk theory, emphasizing the vital role played by magnetohydrodynamic (MHD) stresses in transporting angular momentum. The apparent universality of accretion-related outflow phenomena is a strong indicator that large-scale MHD torques facilitate vertical transport of angular momentum. This leads to an enhanced overall rate of angular momentum transport and allows accretion of matter to proceed at an interesting rate. Furthermore, we argue that when vertical transport is important, the radial structure of the accretion disk is modified at small radii and this affects the disk emission spectrum. We present a simple model demonstrating how energetic, magnetically-driven outflows modify the emergent disk emission spectrum with respect to that predicted by standard accretion disk theory. A comparison of the predicted spectra against observations of quasar spectral energy distributions suggests that mass accretion rates inferred using the standard disk model may severely underestimate their true values.Comment: To appear in the Fifth Stromlo Symposium Proceedings special issue of ApS

Generation of two-mode nonclassical states and a quantum phase gate operation in trapped ion cavity QED

We propose a scheme to generate nonclassical states of a quantum system, which is composed of the one-dimensional trapped ion motion and a single cavity field mode. We show that two-mode SU(2) Schr\"odinger-cat states, entangled coherent states, two-mode squeezed vacuum states and their superposition can be generated. If the vibration mode and the cavity mode are used to represent separately a qubit, a quantum phase gate can be implemented.Comment: to appear in PR

Pure mathematics in Australia

I.D. Macdonald argued in this journal in 1968 that there was an inadequate number of mathematicians teaching in Australian universities who were qualified by international standards to conduct honours courses and supervise research students..

Generation of arbitrary two dimensional motional state of a trapped ion

We present a scheme to generate an arbitrary two-dimensional quantum state of motion of a trapped ion. This proposal is based on a sequence of laser pulses, which are tuned appropriately to control transitions on the sidebands of two modes of vibration. Not more than $(M+1)(N+1)$ laser pulses are needed to generate a pure state with upper phonon number $M$ and $N$ in the $x$ and $y$ direction respectively.Comment: to appear in PR

Online Makespan Minimization with Parallel Schedules

In online makespan minimization a sequence of jobs $\sigma = J_1,..., J_n$ has to be scheduled on $m$ identical parallel machines so as to minimize the maximum completion time of any job. We investigate the problem with an essentially new model of resource augmentation. Here, an online algorithm is allowed to build several schedules in parallel while processing $\sigma$. At the end of the scheduling process the best schedule is selected. This model can be viewed as providing an online algorithm with extra space, which is invested to maintain multiple solutions. The setting is of particular interest in parallel processing environments where each processor can maintain a single or a small set of solutions. We develop a (4/3+\eps)-competitive algorithm, for any 0<\eps\leq 1, that uses a number of 1/\eps^{O(\log (1/\eps))} schedules. We also give a (1+\eps)-competitive algorithm, for any 0<\eps\leq 1, that builds a polynomial number of (m/\eps)^{O(\log (1/\eps) / \eps)} schedules. This value depends on $m$ but is independent of the input $\sigma$. The performance guarantees are nearly best possible. We show that any algorithm that achieves a competitiveness smaller than 4/3 must construct $\Omega(m)$ schedules. Our algorithms make use of novel guessing schemes that (1) predict the optimum makespan of a job sequence $\sigma$ to within a factor of 1+\eps and (2) guess the job processing times and their frequencies in $\sigma$. In (2) we have to sparsify the universe of all guesses so as to reduce the number of schedules to a constant. The competitive ratios achieved using parallel schedules are considerably smaller than those in the standard problem without resource augmentation

Homodyne Bell's inequalities for entangled mesoscopic superpositions

We present a scheme for demonstrating violation of Bell's inequalities using a spin-1/2 system entangled with a pair of classically distinguishable wave packets in a harmonic potential. In the optical domain, such wave packets can be represented by coherent states of a single light mode. The proposed scheme involves standard spin-1/2 projections and measurements of the position and the momentum of the harmonic oscillator system, which for a light mode can be realized by means of homodyne detection. We discuss effects of imperfections, including non-unit efficiency of the homodyne detector, and point out a close link between the visibility of interference and violation of Bell's inequalities in the described scheme.Comment: 6 pages, 3 figures. Extended version, journal reference adde

Multipartite entangled states in coupled quantum dots and cavity-QED

We investigate the generation of multipartite entangled state in a system of N quantum dots embedded in a microcavity and examine the emergence of genuine multipartite entanglement by three different characterizations of entanglement. At certain times of dynamical evolution one can generate multipartite entangled coherent exciton states or multiqubit $W$ states by initially preparing the cavity field in a superposition of coherent states or the Fock state with one photon, respectively. Finally we study environmental effects on multipartite entanglement generation and find that the decay rate for the entanglement is proportional to the number of excitons.Comment: 9 pages, 4 figures, to appear in Phys. Rev.

Persistent mucosal damage and risk of epilepsy in people with celiac disease

BACKGROUND: Celiac disease (CD) is associated with an increased risk of developing epilepsy, a risk that persists after CD diagnosis. A significant proportion of CD patients have persistent villous atrophy (VA) on follow-up biopsy. This study's objective was to determine whether persistent VA on follow-up biopsy affects long-term epilepsy risk and epilepsy-related hospital emergency admissions. METHODS: Nationwide Cohort Study. We identified all people in Sweden with histological evidence of CD who underwent a follow-up small intestinal biopsy (1969-2008). We compared those with persistent VA to those who showed histological improvement, assessing the development of epilepsy and related emergency hospital admissions (defined according to relevant ICD codes in the Swedish Patient Register). Cox regression analysis was used to assess outcome measures. RESULTS: Of 7590 people with CD who had a follow-up biopsy, VA was present in 43%. The presence of persistent VA was significantly associated with a reduced risk of developing newly-diagnosed epilepsy (hazard ratio [HR] 0.61; 95% confidence interval [CI] 0.38-0.98). On stratified analysis this effect was primarily amongst males (HR 0.35; 95 CI 0.15-0.80). Among the 58 CD patients with a prior diagnosis of epilepsy, those with persistent VA were less likely to visit an emergency department with epilepsy (HR 0.37; 95%CI 0.09-1.09). CONCLUSIONS: In a population-based study of CD individuals, persisting VA on follow up biopsy was associated with reduced future risk of developing epilepsy but did not influence emergency epilepsy-related hospital admissions. Mechanisms as to why persistent VA confers this benefit requires further exploration