Laser-induced nonsequential double ionization at and above the recollision-excitation-tunneling threshold

We perform a detailed analysis of the recollision-excitation-tunneling (RESI) mechanism in laser-induced nonsequential double ionization (NSDI), in which the first electron, upon return, promotes a second electron to an excited state, from which it subsequently tunnels, based on the strong-field approximation. We show that the shapes of the electron momentum distributions carry information about the bound-state with which the first electron collides, the bound state to which the second electron is excited, and the type of electron-electron interaction. Furthermore, one may define a driving-field intensity threshold for the RESI physical mechanism. At the threshold, the kinetic energy of the first electron, upon return, is just sufficient to excite the second electron. We compute the distributions for helium and argon in the threshold and above-threshold intensity regime. In the latter case, we relate our findings to existing experiments. The electron-momentum distributions encountered are symmetric with respect to all quadrants of the plane spanned by the momentum components parallel to the laser-field polarization, instead of concentrating on only the second and fourth quadrants.Comment: 14 pages, 7 figure

Influence of peptidylarginine deiminase type 4 genotype and shared epitope on clinical characteristics and autoantibody profile of rheumatoid arthritis.

Background: Recent evidence suggests that distinction of subsets of rheumatoid arthritis (RA) depending on anticyclic citrullinated peptide antibody (anti-CCP) status may be helpful in distinguishing distinct aetiopathologies and in predicting the course of disease. HLA-DRB1 shared epitope (SE) and peptidylarginine deiminase type 4 (PADI4) genotype, both of which have been implicated in anti-CCP generation, are assumed to be associated with RA. Objectives: To elucidate whether PADI4 affects the clinical characteristics of RA, and whether it would modulate the effect of anti-CCPs on clinical course. The combined effect of SE and PADI4 on autoantibody profile was also analysed. Methods: 373 patients with RA were studied. SE, padi4_94C.T, rheumatoid factor, anti-CCPs and antinuclear antibodies (ANAs) were determined. Disease severity was characterised by cumulative therapy intensity classified into ordinal categories (CTI-1 to CTI-3) and by Steinbrocker score. Results: CTI was significantly associated with disease duration, erosive disease, disease activity score (DAS) 28 and anti-CCPs. The association of anti-CCPs with CTI was considerably influenced by padi4_94C.T genotype (C/C: ORadj=0.93, padj=0.92; C/T: ORadj=2.92, padj=0.093; T/T: ORadj=15.3, padj=0.002). Carriage of padi4_94T exhibited a significant trend towards higher Steinbrocker scores in univariate and multivariate analyses. An association of padi4_94C.T with ANAs was observed, with noteworthy differences depending on SE status (SE2: ORadj=6.20, padj,0.04; SE+: ORadj=0.36, padj=0.02) and significant heterogeneity between the two SE strata (p=0.006). Conclusions: PADI4 genotype in combination with anti- CCPs and SE modulates clinical and serological characteristics of RA

Laser-induced nonsequential double ionization: kinematic constraints for the recollision-excitation-tunneling mechanism

We investigate the physical processes in which an electron, upon return to its parent ion, promotes a second electron to an excited state, from which it subsequently tunnels. Employing the strong-field approximation and saddle-point methods, we perform a detailed analysis of the dynamics of the two electrons, in terms of quantum orbits, and delimit constraints for their momentum components parallel to the laser-field polarization. The kinetic energy of the first electron, upon return, exhibits a cutoff slightly lower than $10U_p$, where $U_p$ is the ponderomotive energy, as in rescattered above-threshold ionization (ATI). The second electron leaves the excited state in a direct ATI-like process, with the maximal energy of $2U_p$. We also compute electron-momentum distributions, whose maxima agree with our estimates and with other methods.Comment: 13 pages, 4 figure

Kitasato Symposium 2009: New Prospects for Cytokine Inhibition

The Kitasato Symposium 2009: New Prospects for Cytokine Inhibition was held in Berlin, Germany from 7 to 9 May 2009. The key aims of this meeting were to bring together a group of front-line researchers and rheumatologists to evaluate the use of cytokine blockade and to examine the role of certain cytokines in the pathogenesis of rheumatoid arthritis and other autoimmune diseases. A keynote lecture delivered by Professor Jean-Michel Dayer provided an up-to-date overview of the interactions occurring between the immune system and acute phase proteins. Other speakers discussed the role of cytokines in rheumatoid arthritis, including their role in joint destruction, as well as their regulatory role upon T cells and B cells. The involvement of cytokines in other autoimmune diseases was also addressed

Life (low voice or medium voice and piano)

In this paper we describe the design and implementation of a multi-purpose object-oriented authoring system for interactive virtual environments and presentations, semi-interactive 3D visualization, and non-interactive photo-realistic animations. Its main design criteria are reusability and flexibility, especially in the support of a wide range of input and output formats. Input data may be provided from any type of event-oriented simulation system as well as from an interactive scene modeling tool. The primary output system is a Java-based VRML browser, but a concept of output driver channels allows the use of other rendering systems, such as off-line renderers for the production of photo-realistic video streams. Objects used in the system consist of both geometry and behavior, where the latter is defined in C++ and/or Java. Objects are provided in different abstraction levels and are stored in an animation element library for reuse in different application scenarios

Gambling in young adults aged 17-24 years: a population-based study

A large contemporary UK cohort study, the Avon Longitudinal Study of Parents and Children, was used to investigate gambling behavior and to explore the antecedents of regular gambling in the 17–24-year age group. Participants completed computer-administered gambling surveys in research clinics, on paper, and online. The sample sizes were 3566 at age 17 years, 3940 at 20 years, and 3841 at 24 years; only 1672 completed all three surveys. Participation in gambling in the last year was reported by 54% of 17-year-olds, rising to 68% at 20 years, and 66% at 24 years, with little overall variance. Regular (weekly) gambling showed a strong gender effect, increasing among young men from 13% at 17 years to 18% at 20 years, and 17% at 24 years. Although gambling frequency increased between the ages of 17 and 20 years, gambling behaviors showed little variance between 20 and 24 years, except online gambling and betting on horseraces. The commonest forms of gambling were playing scratchcards, playing the lottery, and private betting with friends. Gambling on activities via the internet increased markedly between 17 and 24 years, especially among males. In the fully adjusted model, individual antecedents of regular gambling were being male, and having a low IQ, an external locus of control, and high sensation seeking scores. Parental gambling behavior and maternal educational background were associated with regular gambling in both sexes. Regular gambling was associated with smoking cigarettes and frequent and harmful use of alcohol, but no associations with depression were found