The UNSW Extrasolar Planet Search: Methods and First Results from a Field Centred on NGC 6633

We report on the current status of the University of New South Wales Extrasolar Planet Search project, giving details of the methods we use to obtain millimagnitude precision photometry using the 0.5m Automated Patrol Telescope. We use a novel observing technique to optimally broaden the PSF and thus largely eliminate photometric noise due to intra-pixel sensitivity variations on the CCD. We have observed 8 crowded Galactic fields using this technique during 2003 and 2004. Our analysis of the first of these fields (centred on the open cluster NGC 6633) has yielded 49 variable stars and 4 shallow transit candidates. Follow-up observations of these candidates have identified them as eclipsing binary systems. We use a detailed simulation of our observations to estimate our sensitivity to short-period planets, and to select a new observing strategy to maximise the number of planets detected.Comment: 16 pages, 9 figures, version published in MNRAS Updated figures, references, and additional discussion in section

Symmetric eikonal model for projectile-electron excitation and loss in relativistic ion-atom collisions

At impact energies $\stackrel{>}{\sim}1$ GeV/u the projectile-electron excitation and loss occurring in collisions between highly charged ions and neutral atoms is already strongly influenced by the presence of atomic electrons. In order to treat these processes in collisions with heavy atoms we generalize the symmetric eikonal model, used earlier for considerations of electron transitions in ion-atom collisions within the scope of a three-body Coulomb problem. We show that at asymptotically high collision energies this model leads to an exact transition amplitude and is very well suited to describe the projectile-electron excitation and loss at energies above a few GeV/u. In particular, by considering a number of examples we demonstrate advantages of this model over the first Born approximation at impact energies $\sim 1$--30 GeV/u, which are of special interest for atomic physics experiments at the future GSI facilities.Comment: 14 pages, 5 figure

Adiabatic following criterion, estimation of the nonadiabatic excitation fraction and quantum jumps

An accurate theory describing adiabatic following of the dark, nonabsorbing state in the three-level system is developed. An analytical solution for the wave function of the particle experiencing Raman excitation is found as an expansion in terms of the time varying nonadiabatic perturbation parameter. The solution can be presented as a sum of adiabatic and nonadiabatic parts. Both are estimated quantitatively. It is shown that the limiting value to which the amplitude of the nonadiabatic part tends is equal to the Fourier component of the nonadiabatic perturbation parameter taken at the Rabi frequency of the Raman excitation. The time scale of the variation of both parts is found. While the adiabatic part of the solution varies slowly and follows the change of the nonadiabatic perturbation parameter, the nonadiabatic part appears almost instantly, revealing a jumpwise transition between the dark and bright states. This jump happens when the nonadiabatic perturbation parameter takes its maximum value.Comment: 33 pages, 8 figures, submitted to PRA on 28 Oct. 200

Landau-Zener-Stueckelberg effect in a model of interacting tunneling systems

The Landau-Zener-Stueckelberg (LZS) effect in a model system of interacting tunneling particles is studied numerically and analytically. Each of N tunneling particles interacts with each of the others with the same coupling J. This problem maps onto that of the LZS effect for a large spin S=N/2. The mean-field limit N=>\infty corresponds to the classical limit S=>\infty for the effective spin. It is shown that the ferromagnetic coupling J>0 tends to suppress the LZS transitions. For N=>\infty there is a critical value of J above which the staying probability P does not go to zero in the slow sweep limit, unlike the standard LZS effect. In the same limit for J>0 LZS transitions are boosted and P=0 for a set of finite values of the sweep rate. Various limiting cases such as strong and weak interaction, slow and fast sweep are considered analytically. It is shown that the mean-field approach works well for arbitrary N if the interaction J is weak.Comment: 13 PR pages, 15 Fig

The Impact of HAART on the Respiratory Complications of HIV Infection: Longitudinal Trends in the MACS and WIHS Cohorts

Objective: To review the incidence of respiratory conditions and their effect on mortality in HIV-infected and uninfected individuals prior to and during the era of highly active antiretroviral therapy (HAART). Design: Two large observational cohorts of HIV-infected and HIV-uninfected men (Multicenter AIDS Cohort Study [MACS]) and women (Women's Interagency HIV Study [WIHS]), followed since 1984 and 1994, respectively. Methods: Adjusted odds or hazards ratios for incident respiratory infections or non-infectious respiratory diagnoses, respectively, in HIV-infected compared to HIV-uninfected individuals in both the pre-HAART (MACS only) and HAART eras; and adjusted Cox proportional hazard ratios for mortality in HIV-infected persons with lung disease during the HAART era. Results: Compared to HIV-uninfected participants, HIV-infected individuals had more incident respiratory infections both pre-HAART (MACS, odds ratio [adjusted-OR], 2.4; 95% confidence interval [CI], 2.2-2.7; p<0.001) and after HAART availability (MACS, adjusted-OR, 1.5; 95%CI 1.3-1.7; p<0.001; WIHS adjusted-OR, 2.2; 95%CI 1.8-2.7; p<0.001). Chronic obstructive pulmonary disease was more common in MACS HIV-infected vs. HIV-uninfected participants pre-HAART (hazard ratio [adjusted-HR] 2.9; 95%CI, 1.02-8.4; p = 0.046). After HAART availability, non-infectious lung diseases were not significantly more common in HIV-infected participants in either MACS or WIHS participants. HIV-infected participants in the HAART era with respiratory infections had an increased risk of death compared to those without infections (MACS adjusted-HR, 1.5; 95%CI, 1.3-1.7; p<0.001; WIHS adjusted-HR, 1.9; 95%CI, 1.5-2.4; p<0.001). Conclusion: HIV infection remained a significant risk for infectious respiratory diseases after the introduction of HAART, and infectious respiratory diseases were associated with an increased risk of mortality. © 2013 Gingo et al

Inelastic Processes in the Collision of Relativistic Highly Charged Ions with Atoms

A general expression for the cross sections of inelastic collisions of fast (including relativistic) multicharged ions with atoms which is based on the genelazition of the eikonal approximation is derived. This expression is applicable for wide range of collision energy and has the standard nonrelativistic limit and in the ultrarelativistic limit coincides with the Baltz's exact solution ~\cite{art13} of the Dirac equation. As an application of the obtained result the following processes are calculated: the excitation and ionization cross sections of hydrogenlike atom; the single and double excitation and ionization of heliumlike atom; the multiply ionization of neon and argon atoms; the probability and cross section of K-vacancy production in the relativistic $U^{92+} - U^{91+}$ collision. The simple analytic formulae for the cross sections of inelastic collisions and the recurrence relations between the ionization cross sections of different multiplicities are also obtained. Comparison of our results with the experimental data and the results of other calculations are given.Comment: 25 pages, latex, 7 figures avialable upon request,submitted to PR

Respiratory and Bronchitic Symptoms Predict Intention to Quit Smoking among Current Smokers with, and at Risk for, Chronic Obstructive Pulmonary Disease

Rationale: Smoking cessation is the most important intervention for patients with chronic obstructive pulmonary disease (COPD). What leads smokers with COPD to quit smoking remains unknown

Simultaneous loss and excitation of projectile electrons in relativistic collisions of U90+^{90+}(1s2^2) ions with atoms

We study relativistic collisions between helium-like uranium ions initially in the ground state and atoms in which, in a single collision event, one of the electrons of the ion is emitted and the other is transferred into an excited state of the residual hydrogen-like ion. We consider this two-electron process at not very high impact energies, where the action of the atom on the electrons of the ion can be well approximated as occurring solely due to the interaction with the nucleus of the atom and, hence, the process can be regarded as a four-body problem. Using the independent electron model we show that a very substantial improvement in the calculated cross sections is obtained if, instead of the first order approximation, the relativistic symmetric eikonal and continuum-distorted-wave-eikonal-initial-state models are employed to describe the single-electron probabilities for the excitation and loss, respectively.Comment: 12 pages, 2 figures, submitted to J.Phys.

UK-Wide Multicenter Evaluation of Second-line Therapies in Primary Biliary Cholangitis

Background & Aims: Thirty-to-forty percent of patients with primary biliary cholangitis inadequately respond to ursodeoxycholic acid. Our aim was to assemble national, real-world data on the effectiveness of obeticholic acid (OCA) as a second-line treatment, alongside non-licensed therapy with fibric acid derivatives (bezafibrate or fenofibrate). Methods: This was a nationwide observational cohort study conducted from August 2017 until June 2021. Results: We accrued data from 457 patients; 349 treated with OCA and 108 with fibric acid derivatives. At baseline/pre-treatment, individuals in the OCA group manifest higher risk features compared with those taking fibric acid derivatives, evidenced by more elevated alkaline phosphatase values, and a larger proportion of individuals with cirrhosis, abnormal bilirubin, prior non-response to ursodeoxycholic acid, and elastography readings >9.6kPa (P <.05 for all). Overall, 259 patients (OCA) and 80 patients (fibric acid derivatives) completed 12 months of second-line therapy, yielding a dropout rate of 25.7% and 25.9%, respectively. At 12 months, the magnitude of alkaline phosphatase reduction was 29.5% and 56.7% in OCA and fibric acid groups (P <.001). Conversely, 55.9% and 36.4% of patients normalized serum alanine transaminase and bilirubin in the OCA group (P <.001). The proportion with normal alanine transaminase or bilirubin values in the fibric acid group was no different at 12 months compared with baseline. Twelve-month biochemical response rates were 70.6% with OCA and 80% under fibric acid treatment (P =.121). Response rates between treatment groups were no different on propensity-score matching or on sub-analysis of high-risk groups defined at baseline. Conclusion: Across the population of patients with primary biliary cholangitis in the United Kingdom, rates of biochemical response and drug discontinuation appear similar under fibric acid and OCA treatment