Optical, X-ray, and γ-ray observations of the candidate transitional millisecond pulsar 4FGL J0427.8-6704

We present an optical, X-ray, and γ-ray study of 1SXPS J042749.2-670434, an eclipsing X-ray binary that has an associated γ-ray counterpart, 4FGL J0427.8-6704. This association has led to the source being classified as a transitional millisecond pulsar (tMSP) in an accreting state. We analyse 10.5 yr of Fermi LAT data and detect a γ-ray eclipse at the same phase as optical and X-ray eclipses at the >5 σ level, a significant improvement on the 2.8 σ level of the previous detection. The confirmation of this eclipse solidifies the association between the X-ray source and the γ-ray source, strengthening the tMSP classification. However, analysis of several optical data sets and an X-ray observation do not reveal a change in the source’s median brightness over long time-scales or a bi-modality on short time-scales. Instead, the light curve is dominated by flickering, which has a correlation time of 2.6 min alongside a potential quasi-periodic oscillation at ∼21 min. The mass of the primary and secondary stars is constrained to be M1=1.43+0.33−0.19 M⊙ and M2=0.3+0.17−0.12 M⊙ through modelling of the optical light curve. While this is still consistent with a white dwarf primary, we favour the tMSP in a low accretion state classification due to the significance of the γ-ray eclipse detection

Hepatic Spheroid Formation on Carbohydrate-Functionalized Supramolecular Hydrogels

Two synthetic supramolecular hydrogels, formed from bis-urea amphiphiles containing lactobionic acid (LBA) and maltobionic acid (MBA) bioactive ligands, are applied as cell culture matrices in vitro. Their fibrillary and dynamic nature mimics essential features of the extracellular matrix (ECM). The carbohydrate amphiphiles self-assemble into long supramolecular fibers in water, and hydrogels are formed by physical entanglement of fibers through bundling. Gels of both amphiphiles exhibit good self-healing behavior, but remarkably different stiffnesses. They display excellent bioactive properties in hepatic cell cultures. Both carbohydrate ligands used are proposed to bind to asialoglycoprotein receptors (ASGPRs) in hepatic cells, thus inducing spheroid formation when seeding hepatic HepG2 cells on both supramolecular hydrogels. Ligand nature, ligand density, and hydrogel stiffness influence cell migration and spheroid size and number. The results illustrate the potential of self-assembled, carbohydrate-functionalized hydrogels as matrices for liver tissue engineering.</p

Development of the impact of tinnitus in children questionnaire (iTICQ)

Introduction: Tinnitus is a common disorder of the auditory system. Questionnaires are essential tools for clinical assessment and research. Whilst many questionnaires are available to measure different aspects of tinnitus complaint in adults, there is currently no self-report questionnaire measure of tinnitus that has been developed for or is suitable for use with children. This study describes the development of the first self-report measure of tinnitus impact for children aged 8–16 years old. Methods: Two phases of questionnaire development were conducted. In Phase 1 children's tinnitus-related problems were elicited from interviews with children with tinnitus (n = 11; aged 9–16 years old), parents (n = 5), and clinicians (n = 8). Interview transcripts were analyzed using qualitative content analysis. Findings were combined with problems identified by the clinical co-authors, researchers, and clinicians in a conference workshop, and those previously reported in service evaluation of UK National Health Service pediatric tinnitus services and in a scoping review. From this, a conceptual framework of tinnitus impact on health-related quality of life in children was developed. Based on the conceptual framework, a 38-item pilot questionnaire was drafted. In Phase 2, content validity of the pilot questionnaire was assessed in cognitive interviews with six children who had tinnitus (aged 8–15 years old) and an online survey with clinicians working in pediatric tinnitus services (n = 8 services and 28 clinicians). Finally, readability assessments were conducted. Feedback led to iterative revisions to the questionnaire. The final questionnaire was named the Impact of Tinnitus in Children Questionnaire (iTICQ). Results: The iTICQ contains three scene setting (non-scoring) items, and 33 scoring items covering six domains of tinnitus impact: Sleep and Feeling Tired, Learning, Emotional Health, Hearing and Listening, Taking Part, and Relationships. Conclusions: The iTICQ is a new self-report measure of tinnitus impact that can be self-completed by children aged 8–16 years old. It shows good content validity and can be used to measure problem severity across the domains of core relevance to children with tinnitus. Further validation studies and translations of the iTICQ are indicated to determine its psychometric properties in different child populations and to make it widely accessible

Rotating Resonator-Oscillator Experiments to Test Lorentz Invariance in Electrodynamics

In this work we outline the two most commonly used test theories (RMS and SME) for testing Local Lorentz Invariance (LLI) of the photon. Then we develop the general framework of applying these test theories to resonator experiments with an emphasis on rotating experiments in the laboratory. We compare the inherent sensitivity factors of common experiments and propose some new configurations. Finally we apply the test theories to the rotating cryogenic experiment at the University of Western Australia, which recently set new limits in both the RMS and SME frameworks [hep-ph/0506074].Comment: Submitted to Lecture Notes in Physics, 36 pages, minor modifications, updated list of reference

Open tubular liquid-chromatography and the analysis of single neurons

Liquid chromatography in open tubular columns (OTLC) offers a means of achieving separations of high resolving power within analysis times of minutes to hours. A theory which predicts the optimal dimensions for an open tubular column for a given set of analytical conditions has been developed [1]. This theory predicts that for a wide range of possible inlet pressures and analysis times the most efficient columns will result when the column inner diameter is between 1.5 and 3 μm. A column of 2 μm diameter and 2 meter length should be capable of producing a million theoretical plates for an analyte with a capacity factor of 10 (strongly retained) and a retention time of 100 minutes

Quantum spin systems at positive temperature

We develop a novel approach to phase transitions in quantum spin models based on a relation to their classical counterparts. Explicitly, we show that whenever chessboard estimates can be used to prove a phase transition in the classical model, the corresponding quantum model will have a similar phase transition, provided the inverse temperature $\beta$ and the magnitude of the quantum spins \CalS satisfy \beta\ll\sqrt\CalS. From the quantum system we require that it is reflection positive and that it has a meaningful classical limit; the core technical estimate may be described as an extension of the Berezin-Lieb inequalities down to the level of matrix elements. The general theory is applied to prove phase transitions in various quantum spin systems with \CalS\gg1. The most notable examples are the quantum orbital-compass model on $\Z^2$ and the quantum 120-degree model on $\Z^3$ which are shown to exhibit symmetry breaking at low-temperatures despite the infinite degeneracy of their (classical) ground state.Comment: 47 pages, version to appear in CMP (style files included

Aerostructural design optimization of a 100-passenger regional jet with surrogate-based mission analysis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106481/1/AIAA2013-4372.pd

The Intentional Use of Service Recovery Strategies to Influence Consumer Emotion, Cognition and Behaviour

Service recovery strategies have been identified as a critical factor in the success of. service organizations. This study develops a conceptual frame work to investigate how specific service recovery strategies influence the emotional, cognitive and negative behavioural responses of . consumers., as well as how emotion and cognition influence negative behavior. Understanding the impact of specific service recovery strategies will allow service providers' to more deliberately and intentionally engage in strategies that result in positive organizational outcomes. This study was conducted using a 2 x 2 between-subjects quasi-experimental design. The results suggest that service recovery has a significant impact on emotion, cognition and negative behavior. Similarly, satisfaction, negative emotion and positive emotion all influence negative behavior but distributive justice has no effect

Optimal designs for rational function regression

We consider optimal non-sequential designs for a large class of (linear and nonlinear) regression models involving polynomials and rational functions with heteroscedastic noise also given by a polynomial or rational weight function. The proposed method treats D-, E-, A-, and $\Phi_p$-optimal designs in a unified manner, and generates a polynomial whose zeros are the support points of the optimal approximate design, generalizing a number of previously known results of the same flavor. The method is based on a mathematical optimization model that can incorporate various criteria of optimality and can be solved efficiently by well established numerical optimization methods. In contrast to previous optimization-based methods proposed for similar design problems, it also has theoretical guarantee of its algorithmic efficiency; in fact, the running times of all numerical examples considered in the paper are negligible. The stability of the method is demonstrated in an example involving high degree polynomials. After discussing linear models, applications for finding locally optimal designs for nonlinear regression models involving rational functions are presented, then extensions to robust regression designs, and trigonometric regression are shown. As a corollary, an upper bound on the size of the support set of the minimally-supported optimal designs is also found. The method is of considerable practical importance, with the potential for instance to impact design software development. Further study of the optimality conditions of the main optimization model might also yield new theoretical insights.Comment: 25 pages. Previous version updated with more details in the theory and additional example

Extreme Ultra-Violet Spectroscopy of the Lower Solar Atmosphere During Solar Flares

The extreme ultraviolet portion of the solar spectrum contains a wealth of diagnostic tools for probing the lower solar atmosphere in response to an injection of energy, particularly during the impulsive phase of solar flares. These include temperature and density sensitive line ratios, Doppler shifted emission lines and nonthermal broadening, abundance measurements, differential emission measure profiles, and continuum temperatures and energetics, among others. In this paper I shall review some of the advances made in recent years using these techniques, focusing primarily on studies that have utilized data from Hinode/EIS and SDO/EVE, while also providing some historical background and a summary of future spectroscopic instrumentation.Comment: 34 pages, 8 figures. Submitted to Solar Physics as part of the Topical Issue on Solar and Stellar Flare