Gauge-invariant tree-level photoproduction amplitudes with form factors

We show how the gauge-invariance formulation given by Haberzettl is implemented in practice for photoproduction amplitudes at the tree level with form factors describing composite nucleons. We demonstrate that, in contrast to Ohta's gauge-invariance prescription, this formalism allows electric current contributions to be multiplied by a form factor, i.e., it does not require that they be treated like bare currents. While different in detail, this nevertheless lends support to previous ad hoc approaches which multiply the Born amplitudes by an overall form factor. Numerical results for kaon photoproduction off the nucleon are given. They show that the gauge procedure by Haberzettl leads to much improved $\chi^2$ values as compared to Ohta's prescription.Comment: 5 pages, RevTeX, two eps figure

Quantum Chinos Game: winning strategies through quantum fluctuations

We apply several quantization schemes to simple versions of the Chinos game. Classically, for two players with one coin each, there is a symmetric stable strategy that allows each player to win half of the times on average. A partial quantization of the game (semiclassical) allows us to find a winning strategy for the second player, but it is unstable w.r.t. the classical strategy. However, in a fully quantum version of the game we find a winning strategy for the first player that is optimal: the symmetric classical situation is broken at the quantum level.Comment: REVTEX4.b4 file, 3 table

NSG mouse strain, health monitoring and microbiological findings

The NSG strain is one of the most immunodeficient mice available, and provides an effective model for studies where the engraftment of human cells is required

Form factors and photoproduction amplitudes

We examine the use of phenomenological form factors in tree level amplitudes for meson photoproduction. Two common recipes are shown to be fundamentally incorrect. An alternate form consistent with gauge invariance and crossing symmetry is proposed.Comment: To be published in PR

Evaluation of PV and QV based Voltage Stability Analyses in Converter Dominated Power Systems

PV and QV analyses have been widely used in industry. It has already been proven that these steady state methods can be used to assess power system's load ability from voltage stability perspective and that their use in terms of accuracy is justified when compared to time domain simulations. However, this prior validation was carried out for conventional synchronous generator dominated power systems. With increasing levels of power electronics interfaced generation (PEIG) being integrated in power systems, the accuracy of the PV and QV methods for these `green' power systems can be challenged. This paper investigates to what extend the use of these methods is justified when the power system faces a displacement of conventional generation with PEIG. To this end, assessments with the IEEE 9 bus system and full converter wind turbine generators have been performed in this study. It is shown that, when compared to time domain simulations, the traditional PV and QV analyses do not always accurately predict the saddle-node bifurcation point. Steady state PV analyses show inaccuracies between 1.8% and 16.8% (when compared to time domain simulations) in identification of the instability point. The mismatch between steady state and time domain QV analyses is between 6.1% and 22.9%. Based on the achieved results, QV analysis is shown to be typically less accurate than PV analysis for PEIG rich systems

Quantum dynamics of a model for two Josephson-coupled Bose--Einstein condensates

In this work we investigate the quantum dynamics of a model for two single-mode Bose--Einstein condensates which are coupled via Josephson tunneling. Using direct numerical diagonalisation of the Hamiltonian, we compute the time evolution of the expectation value for the relative particle number across a wide range of couplings. Our analysis shows that the system exhibits rich and complex behaviours varying between harmonic and non-harmonic oscillations, particularly around the threshold coupling between the delocalised and self-trapping phases. We show that these behaviours are dependent on both the initial state of the system as well as regime of the coupling. In addition, a study of the dynamics for the variance of the relative particle number expectation and the entanglement for different initial states is presented in detail.Comment: 15 pages, 8 eps figures, accepted in J. Phys.

Future expectations and worst-case future scenarios of patients with rheumatoid arthritis: a focus group study

Objective:\ud Over the past 15 years, developments in the treatment of rheumatoid arthritis (RA) have resulted in better clinical outcomes. The aim of the present study was to explore how patients think their RA will influence their lives in the future, and which of these future expectations would be the worst for them to experience.\ud \ud Methods:\ud A focus group study was performed in 16 RA patients. Three groups were heterogeneously composed, based on age group (18–40, 40–65, 65–80), gender and having a paid job or not. Patients were asked about the expected future impact of RA and worst-case future scenarios. Transcripts were coded by three researchers under the main components of the International Classification of Functioning, Disability and Health. The codes were discussed until agreement was reached about all codes.\ud \ud Results:\ud Dependency on others, increasing dependency on medication, inability to walk, activity limitations and worsening fatigue were mentioned as worst-case future scenarios. Further concerns were raised about the acceptance of RA and possible disappearance of physicians' expertise. Nevertheless, hope and positive feelings were expressed toward continuous medication improvements.\ud \ud Conclusion:\ud The present study provided insight into RA patients' future expectations and worst-case future scenarios. The results may be of help in the development of support interventions to put concerns and worst-case future scenarios into a realistic perspective. Furthermore, insight into patients' worst-case future scenarios could be used to improve the validity and responsiveness of the Time Trade-Off, an instrument to measure preference-based health-related quality of life

Experience of aging in patients with rheumatic disease: A comparison with the general population

Objectives: Self-perceptions of aging have been shown to predict mental and physical health and even longevity. This study examined the aging perceptions of patients with rheumatic disease and compared them with the general Dutch population.\ud \ud Methods: Consecutive patients visiting a rheumatology clinic completed the Personal Experience of Aging Scale (PEAS) subscales: physical decline, social loss, continuous growth, and two sentence stems from the SELE instrument (What I like/do not like about getting older …) as qualitative measures of the subjective experience of aging. A representative sample from the general Dutch population between 40 and 85 years was used as a comparison group. Participants included in this study were 208 patients with a rheumatic disease and 975 persons from the Dutch Aging Survey (DAS).\ud \ud Results: Both quantitative and qualitative data showed that patients perceived aging more strongly as physical decline. These negative experiences did not extend to social and psychological domains of aging. Age-group comparisons revealed that patients in middle adulthood experienced physical aging similar to older people without a rheumatic disease.\ud \ud Conclusion: The negative experience of aging in patients is limited to the physical domain and does not extend to other domains of life. The negative experience of physical aging even in middle-aged groups warrants further studies on its effects on mental and physical health outcomes and health behavior in patients with rheumatic disease

Ratification vote on taxonomic proposals to the International Committee on Taxonomy of Viruses (2016)

This article lists the changes to virus taxonomy approved and ratified by the International Committee on Taxonomy of Viruses (ICTV) in April 2016. Changes to virus taxonomy (the Universal Scheme of Virus Classification of the International Committee on Taxonomy of Viruses [ICTV]) now take place annually and are the result of a multi-stage process. In accordance with the ICTV Statutes (http://​www.​ictvonline.​org/​statutes.​asp), proposals submitted to the ICTV Executive Committee (EC) undergo a review process that involves input from the ICTV Study Groups (SGs) and Subcommittees (SCs), other interested virologists, and the EC. After final approval by the EC, proposals are then presented for ratification to the full ICTV membership by publication on an ICTV web site (http://​www.​ictvonline.​org/​) followed by an electronic vote. The latest set of proposals approved by the EC was made available on the ICTV website by January 2016 (https://​talk.​ictvonline.​org/​files/​proposals/​). A list of these proposals was then emailed on 28 March 2016 to the 148 members of ICTV, namely the EC Members, Life Members, ICTV Subcommittee Members (including the SG chairs) and ICTV National Representatives. Members were then requested to vote on whether to ratify the taxonomic proposals (voting closed on 29 April 2016)

Systemic Effects Induced by Hyperoxia in a Preclinical Model of Intra-abdominal Sepsis

Supplemental oxygen is a supportive treatment in patients with sepsis to balance tissue oxygen delivery and demand in the tissues. However, hyperoxia may induce some pathological effects. We sought to assess organ damage associated with hyperoxia and its correlation with the production of reactive oxygen species (ROS) in a preclinical model of intra-abdominal sepsis. For this purpose, sepsis was induced in male, Sprague-Dawley rats by cecal ligation and puncture (CLP). We randomly assigned experimental animals to three groups: control (healthy animals), septic (CLP), and sham-septic (surgical intervention without CLP). At 18 h after CLP, septic (n = 39), sham-septic (n = 16), and healthy (n = 24) animals were placed within a sealed Plexiglas cage and randomly distributed into four groups for continuous treatment with 21%, 40%, 60%, or 100% oxygen for 24 h. At the end of the experimental period, we evaluated serum levels of cytokines, organ damage biomarkers, histological examination of brain and lung tissue, and ROS production in each surviving animal. We found that high oxygen concentrations increased IL-6 and biomarkers of organ damage levels in septic animals, although no relevant histopathological lung or brain damage was observed. Healthy rats had an increase in IL-6 and aspartate aminotransferase at high oxygen concentration. IL-6 levels, but not ROS levels, are correlated with markers of organ damage. In our study, the use of high oxygen concentrations in a clinically relevant model of intra-abdominal sepsis was associated with enhanced inflammation and organ damage. These findings were unrelated to ROS release into circulation. Hyperoxia could exacerbate sepsis-induced inflammation, and it could be by itself detrimental. Our study highlights the need of developing safer thresholds for oxygen therapy