A Complete Atlas of HI Absorption toward HII Regions in the Southern Galactic Plane Survey (SGPS1)

We present a complete catalog of H I emission and absorption spectrum pairs, toward H II regions, detectable within the boundaries of the Southern Galactic Plane Survey (SGPS I), a total of 252 regions. The catalog is presented in graphical, numerical and summary formats. We demonstrate an application of this new dataset through an investigation of the locus of the Near 3kpc Arm.Comment: Accepted for publication by ApJS Feb 6, 2014. Data files and Figure Set (252 images) to appear in the on-line version of the journa

Different forms of the bovine PrP gene have five or six copies of a short, G-C-rich element within the protein-coding exon

Current models of the virus-like agents of scrapie and bovine spongiform encephalopathy (BSE) have to take into account that structural changes in a host-encoded protein (PrP protein) exhibit an effect on the time course of these diseases and the survival time of any man or animal exposed to these pathogens. We report here the sequence of different forms of the bovine PrP gene which contain either five or six copies of a short, G-C-rich element which encodes the octapeptide Pro-His-Gly-Gly-Gly-Trp-Gly-Gln or its longer variants Pro-Gln/His-Gly-Gly-Gly-Gly-Trp-Gly-Gln. Out of 12 cattle, we found eight animals homozygous for genes with six copies of the Gly-rich peptide (6:6), while four were heterozygous (6:5). Two confirmed cases of BSE occurred in (6: 6) homozygous animals. Bovine spongiform encephalopathy (BSE) is a transmissible disease (Fraser et al., 1988; Dawson et al., 1990; Barlow & Middleton, 1990) which produces neuropathological lesions in cattle similar to those seen in ovine scrapie (Wells et al., 1987) and the rare human dementias Creutzfeldt-Jakob disease (CJD) and Gerstmann-Str/iussler syndrome (GSS) (Beck & Daniel, 1987). A cellular membrane protein (PrP) has a key role in the transmission and development of these diseases. This protein accumulates in the brain and other tissues during the protracted time course of these diseases and, in a disease-specific, protease-resistant isoform (SAF-PrP), has been purified by subcellular fractionation of scrapie

HI Absorption Toward HII Regions at Small Galactic Longitudes

We make a comprehensive study of HI absorption toward HII regions located within Galactic longitudes less than 10 degrees. Structures in the extreme inner Galaxy are traced using the longitude-velocity space distribution of this absorption. We find significant HI absorption associated with the Near and Far 3kpc Arms, the Connecting Arm, Banias Clump 1 and the H I Tilted Disk. We also constrain the line of sight distances to HII regions, by using HI absorption spectra together with the HII region velocities measured by radio recombination lines.Comment: Complete figure set available in online version of journal. Accepted by ApJ August 8, 201

From feedback-as-information to feedback-as-process: a linguistic analysis of the feedback literature

Feedback is a term used so frequently that it is commonly taken that there is a shared view about what it means. However, in recent years, the notion of feedback as simply the provision of information to students about their work has been substantially challenged and learning-centred views have been articulated. This paper employs a corpus linguistics approach to analyse the use of the term ‘feedback’ in research articles published in key higher education journals on the topic over two five-year periods: 2009–2013 and 2015–2019. Analysis focused on the most common noun modifiers of ‘feedback’ and nouns modified by ‘feedback’, verbs with ‘feedback’ as the object, possessors of ‘feedback’, and prepositions representing an action or concept on or with ‘feedback’. Whilst the analysis demonstrated that transmission-focused conceptions dominate publications on feedback, linguistic signifiers of a shift over time in representation of feedback away from a transmission-focus towards a learning-focus were evident within each grammatical relation category. The data indicate that the term ‘feedback’ is used by different authors to refer to very different representations of the concept, and the paper proposes that greater clarity in the representation of feedback is needed

Scalar K pi form factor and light quark masses

Recent experimental improvements on K-decay data allow for a precise extraction of the strangeness-changing scalar K pi form factor and the related strange scalar spectral function. On the basis of this scalar as well as the corresponding pseudoscalar spectral function, the strange quark mass is determined to be m_s(2 GeV) = 92 +- 9 MeV. Further taking into account chiral perturbation theory mass ratios, the light up and down quark masses turn out to be m_u(2 GeV) = 2.7 +- 0.4 MeV as well as m_d(2 GeV) = 4.8 +- 0.5 MeV. As a by-product, we also find a value for the Cabibbo angle |V_{us}| = 0.2236(29) and the ratio of meson decay constants F_K/F_\pi = 1.203(16). Performing a global average of the strange mass by including extractions from other channels as well as lattice QCD results yields m_s(2 GeV) = 94 +- 6 MeV.Comment: 5 pages, 2 figures; comparison with lattice and global average added; version to appear in Phys. Rev.

Supergiant Shells and Molecular Cloud Formation in the LMC

We investigate the influence of large-scale stellar feedback on the formation of molecular clouds in the Large Magellanic Cloud (LMC). Examining the relationship between HI and 12CO(J=1-0) in supergiant shells (SGSs), we find that the molecular fraction in the total volume occupied by SGSs is not enhanced with respect to the rest of the LMC disk. However, the majority of objects (~70% by mass) are more molecular than their local surroundings, implying that the presence of a supergiant shell does on average have a positive effect on the molecular gas fraction. Averaged over the full SGS sample, our results suggest that ~12-25% of the molecular mass in supergiant shell systems was formed as a direct result of the stellar feedback that created the shells. This corresponds to ~4-11% of the total molecular mass of the galaxy. These figures are an approximate lower limit to the total contribution of stellar feedback to molecular cloud formation in the LMC, and constitute one of the first quantitative measurements of feedback-triggered molecular cloud formation in a galactic system.Comment: 14 pages, 6 figures. Accepted for publication in Ap

The Supershell-Molecular Cloud Connection in the Milky Way and Beyond

The role of large-scale stellar feedback in the formation of molecular clouds has been investigated observationally by examining the relationship between HI and 12CO(J=1-0) in supershells. Detailed parsec-resolution case studies of two Milky Way supershells demonstrate an enhanced level of molecularisation over both objects, and hence provide the first quantitative observational evidence of increased molecular cloud production in volumes of space affected by supershell activity. Recent results on supergiant shells in the LMC suggest that while they do indeed help to organise the ISM into over-dense structures, their global contribution to molecular cloud formation is of the order of only ~10%.Comment: Proceedings of IAUS 292 - Molecular Gas, Dust, and Star Formation in Galaxies, eds. T. Wong & J. Ott. 4 pages, 3 figure