There is increasing consumer resistance to feeding antibiotic performance enhancers to beef cattle which has created interest in the use of yeast cultures as an alternative. Yeast cultures such as Diamond V ‘XP’ (Rumenco) are produced by growing selected yeast strains (on a semi-solid medium under stressed conditions) which are then dried. Yeast cultures are now used in a considerable number of North American beef feed lots. The objective of this work was to evaluate the effect of feeding ‘XP’ Yeast to finishing beef cattle on a typical UK grass silage-based diet.

We have made a detailed study of a sample of 28 hot DA white dwarfs detected in the ROSAT EUV and soft X-ray all-sky-survey.

In 2011 the Incidence Assay Critical Path Working Group reviewed the current state of HIV incidence assays and helped to determine a critical path to the introduction of an HIV incidence assay. At that time the Consortium for Evaluation and Performance of HIV Incidence Assays (CEPHIA) was formed to spur progress and raise standards among assay developers, scientists and laboratories involved in HIV incidence measurement and to structure and conduct a direct independent comparative evaluation of the performance of 10 existing HIV incidence assays, to be considered singly and in combinations as recent infection test algorithms. In this paper we report on a new framework for HIV incidence assay evaluation that has emerged from this effort over the past 5 years, which includes a preliminary target product profile for an incidence assay, a consensus around key performance metrics along with analytical tools and deployment of a standardized approach for incidence assay evaluation. The specimen panels for this evaluation have been collected in large volumes, characterized using a novel approach for infection dating rules and assembled into panels designed to assess the impact of important sources of measurement error with incidence assays such as viral subtype, elite host control of viraemia and antiretroviral treatment. We present the specific rationale for several of these innovations, and discuss important resources for assay developers and researchers that have recently become available. Finally, we summarize the key remaining steps on the path to development and implementation of reliable assays for monitoring HIV incidence at a population level.

We present phase-resolved spectroscopy of two dwarf novae, IP Peg and SS Cyg, observed in outburst with the WHT/ISIS spectropolarimeter. Doppler tomograms of several emission lines show peculiar narrow, stationary emission components.

The ALFA mission is designed to map the entire sky at frequencies between approximately 0.3 and 30 MHz with angular resolution limited by interstellar and interplanetary scattering. Most of this region of the spectrum is inaccessible from the ground because of absorption and refraction by the Earth’s ionosphere. A wide range of astrophysical questions concerning solar system, galactic, and extragalactic objects could be answered with high resolution images at low frequencies, where absorption effects and coherent emission processes become important and the synchrotron lifetimes of electrons are comparable to the age of the universe.

We derive the temperature and density structure of the accretion disk of the dwarf nova U Gem in quiescence from 3D radiative line and continuum transport calculations of a differentially rotating disk.

We present 3-D LTE radiative transfer calculations [1] for H, He and Ca in accretion disks (AD) of dwarf novae in quiescence. The model disk is assumed to be in hydrostatic equilibrium vertically, and to rotate with Keplerian velocities. Calculated emission lines are fitted to phase-averaged, continuum-subtracted spectra of U Gem (Fig. 1) and T Leo (Fig. 2). Up to four parameters of the AD have been fitted: distance D, baryonic number density N, isotropic turbulence V tu and disk temperature T; the latter two are assumed to be constant throughout the disk. Geometrical parameters are from [2] and [3].

We describe a method for imaging the accretion disc of a Cataclysmic Variable star. We use the two-dimensional information contained in the line profiles as they vary with phase to invert the line formation process. Asymmetries in the disc, as are caused by the bright-spot, for example, are accounted for naturally.

We report the discovery of 15 s oscillations in HST/STIS far-UV spectroscopic observations of WZ Sge in decline, one month after the start of its 2001 outburst. We discuss the implications of this finding for both the magnetic and pulsating white dwarf models that have been proposed to account for the 28 s oscillations.

The radial intensity profile at the extreme solar limb was measured with high angular resolution during the October, 1977 partial solar eclipse using the Owens Valley solar interferometer at 2.8 cm and the VLA at 6 cm. Substantial limb brightening was observed at 6 cm, with a peak brightness temperature corresponding to an 80% increase over the disk value. Much less limb brightening was observed at 2.8 cm. In each case an extended “tail” to the brightness distribution was detected. The results at both wavelengths are consistent with a simple model in which a rough chromosphere is overlaid by a corona in hydrostatic equilibrium with a density of 5 × 108 cm−3 at its base.

Observations of five impulsive microwave bursts were made during July 15–18, 1978 using the VLA at 4.9 GHz with temporal and spatial resolutions of 10 s and up to 1″ respectively. A series of 2-dimensional snapshot synthesis maps was made as a function of time, and compared with Hα photographs and magnetograms. Each flare was characterized by a single source of constant size, located on the magnetic neutral line between the Hα kernels.

We used data from the Genitourinary Medicine Clinic Activity Dataset (GUMCAD) over a 3-year period (2009–2011) to investigate the distribution and risk factors of Trichomonas vaginalis infection in England. Socio-demographic and clinical risk factors associated with a diagnosis of T. vaginalis were explored using multivariable logistic regression. Rates of T. vaginalis infection were highest in London and the West Midlands. For men and women, T. vaginalis infection was significantly associated with: older age compared to those aged 20–24 years, non-white ethnicity (in particular black Caribbean and black ‘other’ ethnic groups), and birth in the Caribbean vs. birth in the UK. Current gonorrhoea or chlamydia infection was associated with a diagnosis of T. vaginalis in women. Further research is required to assess the public health impact and cost-effectiveness of introducing targeted screening for women at high risk of infection in areas of higher prevalence.