Observations of QSO J2233-606 in the Southern Hubble Deep Field

The Hubble Deep Field South (HDF-S) HST observations are expected to begin in October 1998. We present a composite spectrum of the QSO in the HDF-S field covering UV/optical/near IR wavelengths, obtained by combining data from the ANU 2.3m Telescope with STIS on the HST. This intermediate resolution spectrum covers the range 1600-10000A and allows us to derive some basic information on the intervening absorption systems which will be important in planning future higher resolution studies of this QSO.Comment: 9 pages and 2 figures, submitted to ApJ

Being an English academic:a social domains account

This paper considers the differential placements of social actors in the contemporary English university, as practices consistent with neoliberal ideologies become increasingly influential. It uses Layder's theory of ‘social domains’ and the first-hand experiences of the author to explore how the options available–to students, those on precarious conditions of employment, and those occupying more influential roles in the institution–change in relation to alterations in structured social relations. Examples are provided of interventions by people opposed to both the rhetoric and the reality of developments in the sector, and reasons for their limited effectiveness are also discussed

Molecular ecology and risk factors for third-generation cephalosporin-resistant Escherichia coli carriage by dogs living in urban and nearby rural settings

OBJECTIVES: To compare faecal third-generation cephalosporin-resistant (3GC-R) Escherichia coli isolates from dogs living in a city and in a rural area ∼30 km away; to compare isolates from dogs, cattle and humans in these regions; and to determine risk factors associated with 3GC-R E. coli carriage in these two cohorts of dogs. METHODS: Six hundred dogs were included, with faecal samples processed to recover 3GC-R E. coli using 2 mg/L cefotaxime. WGS was by Illumina and risk factor analyses were by multivariable linear regression using the results of an owner-completed survey. RESULTS: 3GC-R E. coli were excreted by 20/303 rural and 31/297 urban dogs. The dominant canine 3GC-R ST was ST963 (bla(CMY-2)), which also accounted for 25% of CMY-2-producing E. coli in humans. Phylogenetic overlap between cattle and rural dog CTX-M-14-producing E. coli ST117 was observed as well as acquisition of pMOO-32-positive E. coli ST10 by a rural dog, a plasmid common on cattle farms in the area. Feeding raw meat was associated with carrying 3GC-R E. coli in rural dogs, but not in urban dogs, where swimming in rivers was a weak risk factor. CONCLUSIONS: Given clear zoonotic potential for resistant canine E. coli, our work suggests interventions that may reduce this threat. In rural dogs, carriage of 3GC-R E. coli, particularly CTX-M producers, was phylogenetically associated with interaction with local cattle and epidemiologically associated with feeding raw meat. In urban dogs, sources of 3GC-R E. coli appear to be more varied and include environments such as rivers

Geology of Rum Cay, Bahamas: A Field Trip Guide

See other Smith authored Field Trip Guides of Gerace Research Centre

Delineation of individual human chromosomes in metaphase and interphase cells by in situ suppression hybridization using recombinant DNA libraries

A method of in situ hybridization for visualizing individual human chromosomes from pter to qter, both in metaphase spreads and interphase nuclei, is reported. DNA inserts from a single chromosomal library are labeled with biotin and partially preannealed with a titrated amount of total human genomic DNA prior to hybridization with cellular or chromosomal preparations. The cross-hybridization of repetitive sequences to nontargeted chromosomes can be markedly suppressed under appropriate preannealing conditions. The remaining single-stranded DNA is hybridized to specimens of interest and detected with fluorescent or enzymelabeled avidin conjugates following post-hybridization washes. DNA inserts from recombinant libraries for chromosomes 1, 4, 7, 8, 13, 14, 18, 20, 21, 22, and X were assessed for their ability to decorate specifically their cognate chromosome; most libraries proved to be highly specific. Quantitative densitometric analyses indicated that the ratio of specific to nonspecific hybridization signal under optimal preannealing conditions was at least 8:1. Interphase nuclei showed a cohesive territorial organization of chromosomal domains, and laserscanning confocal fluorescence microscopy was used to aid the 3-D visualization of these domains. This method should be useful for both karyotypic studies and for the analysis of chromosome topography in interphase cells

On the relevance of the mathematics curriculum to young people

In this paper we draw upon focus group data from a large study of learner trajectories through 14-19 mathematics education to think about the notion of relevance in the mathematics curriculum. Drawing on data from three socially distanced sites we explore how different emphases on what might be termed practical, process and/or professional forms of relevance affect the experiences and aspirations of learners of mathematics. We consider whether an emphasis on practical relevance in schools serving relatively disadvantaged communities might aid the reproduction of students’ social position. This leads us to suggest that a fourth category of curriculum relevance – political relevance – is largely missing from classrooms

Plasticity of fimbrial genotype and serotype within populations of <em>Bordetella pertussis</em>:analysis by paired flow cytometry and genome sequencing

The fimbriae of Bordetella pertussis are required for colonization of the human respiratory tract. Two serologically distinct fimbrial subunits, Fim2 and Fim3, considered important vaccine components for many years, are included in the Sanofi Pasteur 5-component acellular pertussis vaccine, and the World Health Organization recommends the inclusion of strains expressing both fimbrial serotypes in whole-cell pertussis vaccines. Each of the fimbrial major subunit genes, fim2, fim3, and fimX, has a promoter poly(C) tract upstream of its −10 box. Such monotonic DNA elements are susceptible to changes in length via slipped-strand mispairing in vitro and in vivo, which potentially causes on/off switching of genes at every cell division. Here, we have described intra-culture variability in poly(C) tract lengths and the resulting fimbrial phenotypes in 22 recent UK B. pertussis isolates. Owing to the highly plastic nature of fimbrial promoters, we used the same cultures for both genome sequencing and flow cytometry. Individual cultures of B. pertussis contained multiple fimbrial serotypes and multiple different fimbrial promoter poly(C) tract lengths, which supports earlier serological evidence that B. pertussis expresses both serotypes during infection.</jats:p