Epidemiology and fitness effects of wood mouse herpesvirus in a natural host population

Rodent gammaherpesviruses have become important models for understanding human herpesvirus diseases. In particular, interactions between murid herpesvirus 4 and Mus musculus (a non-natural host species) have been extensively studied under controlled laboratory conditions. However, several fundamental aspects of murine gammaherpesvirus biology are not well understood, including how these viruses are transmitted from host to host, and their impacts on host fitness under natural conditions. Here, we investigate the epidemiology of a gammaherpesvirus in free-living wood mice (Apodemus sylvaticus) and bank voles (Myodes glareolus) in a 2-year longitudinal study. Wood mouse herpesvirus (WMHV) was the only herpesvirus detected and occurred frequently in wood mice and also less commonly in bank voles. Strikingly, WMHV infection probability was highest in reproductively active, heavy male mice. Infection risk also showed a repeatable seasonal pattern, peaking in spring and declining through the summer. We show that this seasonal decline can be at least partly attributed to reduced recapture of WMHV-infected adults. These results suggest that male reproductive behaviours could provide an important natural route of transmission for these viruses. They also suggest that gammaherpesvirus infection may have significant detrimental effects in wild hosts, questioning the view that these viruses have limited impacts in natural, co-evolved host species

From Service to Experience: Understanding and Defining the Hospitality Business

Failure adequately to define or understand hospitality as a commercial phenomenon has created a fragmented academic environment and a schizophrenia in the industry that has the potential to limit its development as a global industry. This article suggests that, by redefining hospitality as behaviour and experience, a new perspective emerges that has exciting implications for the management of hospitality businesses. A framework to describe hospitality in the commercial domain is proposed. This framework suggests a focus on the host–guest relationship, generosity, theatre and performance, ‘lots of little surprises’, and the security of strangers – a focus that provides guests with experiences that are personal, memorable and add value to their lives

Extreme UV QSOs

We present a sample of spectroscopically confirmed QSOs with FUV-NUV color (as measured by GALEX photometry) bluer than canonical QSO templates and than the majority of known QSOs. We analyze their FUV to NIR colors, luminosities and optical spectra. The sample includes a group of 150 objects at low redshift (z $<$ 0.5), and a group of 21 objects with redshift 1.7$<$z$<$2.6. For the low redshift objects, the "blue" FUV-NUV color may be caused by enhanced Ly$\alpha$ emission, since Ly$\alpha$ transits the GALEX FUV band from z=0.1 to z=0.47. Synthetic QSO templates constructed with Ly$\alpha$ up to 3 times stronger than in standard templates match the observed UV colors of our low redshift sample. The H$\alpha$ emission increases, and the optical spectra become bluer, with increasing absolute UV luminosity. The UV-blue QSOs at redshift about 2, where the GALEX bands sample restframe about 450-590A (FUV) and about 590-940A(NUV), are fainter than the average of UV-normal QSOs at similar redshift in NUV, while they have comparable luminosities in other bands. Therefore we speculate that their observed FUV-NUV color may be explained by a combination of steep flux rise towards short wavelengths and dust absorption below the Lyman limit, such as from small grains or crystalline carbon. The ratio of Ly$\alpha$ to CIV could be measured in 10 objects; it is higher (30% on average) than for UV-normal QSOs, and close to the value expected for shock or collisional ionization. FULL VERSION AVAILABLE FROM AUTHOR'S WEB SITE: http://dolomiti.pha.jhu.edu/papers/2009_AJ_Extreme_UV_QSOs.pdfComment: Astronomical Journal, in pres

Highly Ionized Collimated Outflow from HE 0238 - 1904

We present a detailed analysis of a highly ionized, multiphased and collimated outflowing gas detected through O V, O VI, Ne VIII and Mg X absorption associated with the QSO HE 0238 - 1904 (z_em ~ 0.629). Based on the similarities in the absorption line profiles and estimated covering fractions, we find that the O VI and Ne VIII absorption trace the same phase of the absorbing gas. Simple photoionization models can reproduce the observed N(Ne VIII), N(O VI) and N(Mg X) from a single phase whereas the low ionization species (e.g. N III, N IV, O IV) originate from a different phase. The measured N(Ne VIII)/N(O VI) ratio is found to be remarkably similar (within a factor of ~ 2) in several individual absorption components kinematically spread over ~ 1800 km/s. Under photoionization this requires a fine tuning between hydrogen density (nH) and the distance of the absorbing gas from the QSO. Alternatively this can also be explained by collisional ionization in hot gas with T > 10^{5.7} K. Long-term stability favors the absorbing gas being located outside the broad line region (BLR). We speculate that the collimated flow of such a hot gas could possibly be triggered by the radio jet interaction.Comment: Minor revision (accepted for publication in MNRAS letter

Psychometric Analysis of the Adult Sickle Cell Quality of Life Measurement Information System (ACSQ-Me) in a UK Population

Background: The Adult Sickle Cell Quality of Life Measurement Information System (ASCQ-Me) has been shown to be a reliable and valid questionnaire measuring health-related quality of life (HRQoL) in the US sickle cell disease (SCD) population. The study objective was to test the validity and reliability of the ASCQ-Me for use in the UK. Methods: The US ASCQ-Me, Hospital Anxiety and Depression Scale (HADS), self-reported symptoms, and Medical Outcome Survey Short Form 36 (SF-36) were administered to 173 patients with SCD. Clinical severity was assessed by the number of painful episodes indicated by hospital admissions. Results: The results showed that the item banks of the UK ASCQ-Me had good internal consistency. Anxiety and depression were strongly correlated with the emotional, and social item banks of the UK ASCQ-Me, with moderate correlations between the UK ASCQ-Me item banks and SF-36 components suggesting convergent validity. A confirmatory factor analysis confirmed the conceptual framework of the scale as being the same as the US ASCQ-Me, indicating construct validity. Known groups validity was found, with the ASCQ-Me being able to differentiate by SCD severity groups. Conclusion: The analysis of the sample shows evidence of both validity and reliability of the ACCQ-Me for use in the UK SCD population

Near-zone sizes and the rest frame extreme ultra-violet spectral index of the highest redshift quasars

The discovery of quasars with redshifts higher than six has prompted a great deal of discussion in the literature regarding the role of quasars, both as sources of reionization, and as probes of the ionization state of the IGM. However the extreme ultra-violet (EUV) spectral index cannot be measured directly for high redshift quasars owing to absorption at frequencies above the Lyman limit, and as a result, studies of the impact of quasars on the intergalactic medium during reionization must assume a spectral energy distribution in the extreme ultra-violet based on observations at low redshift, z<1. In this paper we use regions of high Ly-alpha transmission (near-zones) around the highest redshift quasars to measure the quasar EUV spectral index at z~6. We jointly fit the available observations for variation of near-zone size with both redshift and luminosity, and propose that the observed relation provides evidence for an EUV spectral index that varies with absolute magnitude in the high redshift quasar sample, becoming softer at higher luminosity. Using a large suite of detailed numerical simulations we find that the typical value of spectral index for a luminous quasar at z~6 is constrained to be alpha=1.3+/-0.4 for a specific luminosity of the form L\propto\nu^{-alpha}. We find the scatter in spectral index among individual quasars to be in the range ~0.75-1.25. These values are in agreement with direct observations at low redshift, and indicate that there has been no significant evolution in the EUV spectral index of quasars over 90% of cosmic time.Comment: 12 pages, 8 figures. Submitted to MNRA

A Composite HST Spectrum of Quasars

We construct a composite quasar spectrum from 284 HST FOS spectra of 101 quasars with redshifts z > 0.33. The spectrum covers the wavelengths between 350 and 3000 A in the rest frame. There is a significant steepening of the continuum slope around 1050 A. The continuum between 1050 and 2200 A can be modeled as a power law with alpha = -0.99. For the full sample the power-law index in the extreme ultraviolet (EUV) between 350 and 1050 A is alpha = -1.96. The continuum flux in the wavelengths near the Lyman limit shows a depression of about 10 percent. The break in the power-law index and the slight depression of the continuum near the Lyman limit are features expected in Comptonized accretion-disk spectra.Comment: 10 figures To appear in the February 1, 1997, issue of the Ap.

Wavefront-Error Performance Characterization for the James Webb Space Telescope (JWST) Integrated Science Instrument Module (ISIM) Science Instruments

The science instruments (SIs) comprising the James Webb Space Telescope (JWST) Integrated Science Instrument Module (ISIM) were tested in three cryogenic-vacuum test campaigns in the NASA Goddard Space Flight Center (GSFC)'s Space Environment Simulator (SES) test chamber. In this paper, we describe the results of optical wavefront-error performance characterization of the SIs. The wavefront error is determined using image-based wavefront sensing, and the primary data used by this process are focus sweeps, a series of images recorded by the instrument under test in its as-used configuration, in which the focal plane is systematically changed from one image to the next. High-precision determination of the wavefront error also requires several sources of secondary data, including 1) spectrum, apodization, and wavefront-error characterization of the optical ground-support equipment (OGSE) illumination module, called the OTE Simulator (OSIM), 2) F-number and pupil-distortion measurements made using a pseudo-nonredundant mask (PNRM), and 3) pupil geometry predictions as a function of SI and field point, which are complicated because of a tricontagon-shaped outer perimeter and small holes that appear in the exit pupil due to the way that different light sources are injected into the optical path by the OGSE. One set of wavefront-error tests, for the coronagraphic channel of the Near-Infrared Camera (NIRCam) Longwave instruments, was performed using data from transverse translation diversity sweeps instead of focus sweeps, in which a sub-aperture is translated and/or rotated across the exit pupil of the system. Several optical-performance requirements that were verified during this ISIM-level testing are levied on the uncertainties of various wavefront-error-related quantities rather than on the wavefront errors themselves. This paper also describes the methodology, based on Monte Carlo simulations of the wavefront-sensing analysis of focus-sweep data, used to establish the uncertainties of the wavefront-error maps