Modelling the ArH+^+ emission from the Crab Nebula

We have performed combined photoionization and photodissociation region (PDR) modelling of a Crab Nebula filament subjected to the synchrotron radiation from the central pulsar wind nebula, and to a high flux of charged particles; a greatly enhanced cosmic ray ionization rate over the standard interstellar value, $\zeta_0$, is required to account for the lack of detected [C I] emission in published Herschel SPIRE FTS observations of the Crab Nebula. The observed line surface brightness ratios of the OH$^+$ and ArH$^+$ transitions seen in the SPIRE FTS frequency range can only be explained with both a high cosmic ray ionization rate and a reduced ArH$^+$ dissociative recombination rate compared to that used by previous authors, although consistent with experimental upper limits. We find that the ArH$^+$/OH$^+$ line strengths and the observed H$_2$ vibration-rotation emission can be reproduced by model filaments with $n_{\rm{H}} = 2 \times 10^4$ cm$^{-3}$, $\zeta = 10^7 \zeta_0$ and visual extinctions within the range found for dusty globules in the Crab Nebula, although far-infrared emission from [O I] and [C II] is higher than the observational constraints. Models with $n_{\rm{H}} = 1900$ cm$^{-3}$ underpredict the H$_2$ surface brightness, but agree with the ArH$^+$ and OH$^+$ surface brightnesses and predict [O I] and [C II] line ratios consistent with observations. These models predict HeH$^+$ rotational emission above detection thresholds, but consideration of the formation timescale suggests that the abundance of this molecule in the Crab Nebula should be lower than the equilibrium values obtained in our analysis.Comment: Accepted by MNRAS. Author accepted manuscript. Accepted on 05/09/2017. Deposited on 05/09/1

Atomic Gas in Debris Discs

We have conducted a search for optical circumstellar absorption lines in the spectra of 16 debris disc host stars. None of the stars in our sample showed signs of emission line activity in either H$_{\alpha}$, Ca II or Na I, confirming their more evolved nature. Four stars were found to exhibit narrow absorption features near the cores of the photospheric Ca II and Na I D lines (when Na I D data were available). We analyse the characteristics of these spectral features to determine whether they are of circumstellar or interstellar origins. The strongest evidence for circumstellar gas is seen in the spectrum of HD110058, which is known to host a debris disc observed close to edge-on. This is consistent with a recent ALMA detection of molecular gas in this debris disc, which shows many similarities to the $\beta$ Pictoris system.Comment: Accepted 13/12/2016. Received 2/12/2016; Deposited on 22/11/2016. - 13 Pages, 9 Figures - MNRAS Advance Access published December 15, 201

Communications Biophysics

Contains a report on a research project.National Science Foundation (Grant GP-2495)National Institutes of Health (Grant MH-04737-04)National Aeronautics and Space Administration (Grant NsG-496

A research protocol for developing a Point-Of-Care Key Evidence Tool 'POCKET': a checklist for multidimensional evidence reporting on point-of-care in vitro diagnostics.

INTRODUCTION: Point-of-care in vitro diagnostics (POC-IVD) are increasingly becoming widespread as an acceptable means of providing rapid diagnostic results to facilitate decision-making in many clinical pathways. Evidence in utility, usability and cost-effectiveness is currently provided in a fragmented and detached manner that is fraught with methodological challenges given the disruptive nature these tests have on the clinical pathway. The Point-of-care Key Evidence Tool (POCKET) checklist aims to provide an integrated evidence-based framework that incorporates all required evidence to guide the evaluation of POC-IVD to meet the needs of policy and decisionmakers in the National Health Service (NHS). METHODS AND ANALYSIS: A multimethod approach will be applied in order to develop the POCKET. A thorough literature review has formed the basis of a robust Delphi process and validation study. Semistructured interviews are being undertaken with POC-IVD stakeholders, including industry, regulators, commissioners, clinicians and patients to understand what evidence is required to facilitate decision-making. Emergent themes will be translated into a series of statements to form a survey questionnaire that aims to reach a consensus in each stakeholder group to what needs to be included in the tool. Results will be presented to a workshop to discuss the statements brought forward and the optimal format for the tool. Once assembled, the tool will be field-tested through case studies to ensure validity and usability and inform refinement, if required. The final version will be published online with a call for comments. Limitations include unpredictable sample representation, development of compromise position rather than consensus, and absence of blinding in validation exercise. ETHICS AND DISSEMINATION: The Imperial College Joint Research Compliance Office and the Imperial College Hospitals NHS Trust R&D department have approved the protocol. The checklist tool will be disseminated through a PhD thesis, a website, peer-reviewed publication, academic conferences and formal presentations

EFFECTS OF ANKLE BRACE AND TAPE SUPPORT ON FOOT AND ANKLE MOTION ON BASKETBALL-SPECIFIC PERFORMANCE

Six male basketball players participated in a study to establish the effectiveness of a brace and taping to restrict passive ankle motion and to assess their effects on basketball-specific performance. Results indicated a significant main effect for time of measurement and ankle dorsiflexion (both p = 0.0005). Both support systems significantly restricted inversion and dorsiflexion following application (p ≤ 0.05), while exercise only affected the support properties for inversion. No significant differences were found for performance of a 20 m sprint, vertical jump and a four-point run. On the basis of the support provided, neither the tape nor brace can be recommended, although the latter has advantages in terms of both cost and ease of use

Evidence for Rotation in the Galaxy at z=3.15 Responsible for a Damped Lyman-alpha Absorption System in the Spectrum of Q2233+1310

Proof of the existence of a significant population of normal disk galaxies at redshift z>2 would have profound implications for theories of structure formation and evolution. We present evidence based on Keck HIRES observations that the damped Lyman-alpha absorber at z=3.15 toward the quasar Q2233+1310 may well be such an example. Djorgovski et al have recently detected the Lyman-alpha emission from the absorber, which we assume is at the systemic redshift of the absorbing galaxy. By examining the profiles of the metal absorption lines arising from the absorbing galaxy in relation to its systemic redshift, we find strong kinematical evidence for rotation. Therefore the absorber is likely to be a disk galaxy. The inferred circular velocity for the galaxy is >200 km/s. With a separation of ~17 kpc between the galaxy and the quasar sightline, the implied dynamic mass for the galaxy is >1.6x10(11) solar mass. The metallicity of the galaxy is found to be [Fe/H]=-1.4, typical of damped Lyman-alpha galaxies at such redshifts. However, in another damped galactic rotation is evident. In the latter case, the damped Lyman-alpha absorber occurs near the background quasar in redshift so its properties may be influenced by the background quasar. These represent the only two cases at present for which the technique used here may be applied. Future applications of the same technique to a large sample of damped Lyman-alpha galaxies may allow us to determine if a significant population of disk galaxies already existed only a few billion years after the Big Bang.Comment: AASTEX, 2 PS figures, accepted by ApJ, 6 pages total, replaced on 1-22-97, the only change is the enlarged figure

Atomic and molecular interstellar absorption lines toward the high galactic latitude stars HD~141569 and HD~157841 at ultra-high resolution

We present ultra-high resolution (0.32 km/s) spectra obtained with the 3.9m Anglo-Australian Telescope (AAT) and Ultra-High-Resolution Facility (UHRF), of interstellar NaI D1, D2, Ca II K, K I and CH absorption toward two high galactic latitude stars HD141569 and HD157841. We have compared our data with 21-cm observations obtained from the Leiden/Dwingeloo HI survey. We derive the velocity structure, column densities of the clouds represented by the various components and identify the clouds with ISM structures seen in the region at other wavelengths. We further derive abundances, linear depletions and H2 fractional abundances for these clouds, wherever possible. Toward HD141569, we detect two components in our UHRF spectra : a weak, broad component at - 15 km/s, seen only in CaII K absorption and another component at 0 km/s, seen in NaI D1, D2, Ca II K, KI and CH absorption. In the case of the HD157841 sightline, a total of 6 components are seen on our UHRF spectra in NaI D1, D2 Ca II K, K I and CH absorption. 2 of these 6 components are seen only in a single species.Comment: 16 pages, Latex, 4 figures, ps files Astrophysical Journal (in press