Developing descriptive standards: a renewed call to action

Just over a quarter of a century ago (1987) Canadian archivists published a call to action. More specifically they called for the development of descriptive standards. Moving forward to today, a number of standards are now in existence, information exchange about holdings is commonplace and archivists have not failed to take advantage (although arguably not full advantage) of the opportunities automation offers. This article provides a selective overview of the history of descriptive standards development to propose that despite a long history of such development, there is still no standard for archival description. To support this perspective, it draws a distinction between information exchange and archival description, and suggests that the use of such a distinction will offer a clearer vision of the area to inform future action

Grounded Theory: A Straightfoward and Complicated Exposition

Grounded Theory is a popular and yet much-contested approach to research. Attempting to steer a course through the many shades of meaning which employ the label Grounded Theory, this narrative outlines Grounded Theory’s origin, subsequent development, and techniques, highlights what the author finds it useful to see as its defining distinctions and tenets, and explores the philosophical and epistemological implications of those distinctions and tenets. In so doing it seeks to communicate a better sense of Grounded Theory, both within and without the context of Archival Science

Contrasting environmental drivers of adult and juvenile growth in a marine fish: implications for the effects of climate change

Many marine fishes have life history strategies that involve ontogenetic changes in the use of coastal habitats. Such ontogenetic shifts may place these species at particular risk from climate change, because the successive environments they inhabit can differ in the type, frequency and severity of changes related to global warming. We used a dendrochronology approach to examine the physical and biological drivers of growth of adult and juvenile mangrove jack (Lutjanus argentimaculatus) from tropical north-western Australia. Juveniles of this species inhabit estuarine environments and adults reside on coastal reefs. The Niño-4 index, a measure of the status of the El Niño-Southern Oscillation (ENSO) had the highest correlation with adult growth chronologies, with La Niña years (characterised by warmer temperatures and lower salinities) having positive impacts on growth. Atmospheric and oceanographic phenomena operating at ocean-basin scales seem to be important correlates of the processes driving growth in local coastal habitats. Conversely, terrestrial factors influencing precipitation and river runoff were positively correlated with the growth of juveniles in estuaries. Our results show that the impacts of climate change on these two life history stages are likely to be different, with implications for resilience and management of populations

On the Evolution of Hexose Transporters in Kinetoplastid Potozoans

Glucose, an almost universally used energy and carbon source, is processed through several well-known metabolic pathways, primarily glycolysis. Glucose uptake is considered to be the first step in glycolysis. In kinetoplastids, a protozoan group that includes relevant human pathogens, the importance of glucose uptake in different phases of the life cycles is well established, and hexose transporters have been proposed as targets for therapeutic drugs. However, little is known about the evolutionary history of these hexose transporters. Hexose transporters contain an intracellular N- and C- termini, and 12 transmembrane spans connected by alternate intracellular and extracellular loops. In the present work we tested the hypothesis that the evolutionary rate of the transmembrane span is different from that of the whole sequence and that it is possible to define evolutionary units inside the sequence. The phylogeny of whole molecules was compared to that of their transmembrane spans and the loops connecting the transmembrane spans. We show that the evolutionary units in these proteins primarily consist of clustered rather than individual transmembrane spans. These analyses demonstrate that there are evolutionary constraints on the organization of these proteins; more specifically, the order of the transmembrane spans along the protein is highly conserved. Finally, we defined a signature sequence for the identification of kinetoplastid hexose transporters

Prevalence of non Helicobacter pylori species in patients presenting with dyspepsia

<p>Abstract</p> <p>Background</p> <p>Helicobacter species associated with human infection include <it>Helicobacter pylori, Helicobacter heilmannii </it>and <it>Helicobacter felis </it>among others. In this study we determined the prevalence of <it>H. pylori </it>and non-<it>Helicobacter pylori </it>organisms <it>H. felis and H. heilmannii </it>and analyzed the association between coinfection with these organisms and gastric pathology in patients presenting with dyspepsia. Biopsy specimens were obtained from patients with dyspepsia on esophagogastroduodenoscopy (EGD) for rapid urease test, histology and PCR examination for Helicobacter genus specific 16S rDNA, <it>H. pylori </it>phosphoglucosamine mutase (<it>glmM</it>) and urease B (<it>ureB</it>) gene of <it>H. heilmannii </it>and <it>H. felis</it>. Sequencing of PCR products of <it>H. heilmannii </it>and <it>H. felis </it>was done.</p> <p>Results</p> <p>Two hundred-fifty patients with dyspepsia were enrolled in the study. The mean age was 39 ± 12 years with males 162(65%). Twenty-six percent (66 out of 250) were exposed to cats or dogs. PCR for Helicobacter genus specific 16S rDNA was positive in 167/250 (67%), <it>H. pylori glmM </it>in 142/250 (57%), <it>H. heilmannii </it>in 17/250 (6%) and <it>H. felis </it>in 10/250 (4%), respectively. All the <it>H. heilmannii </it>and <it>H. felis </it>PCR positive patients were also positive for <it>H. pylori </it>PCR amplification. The occurrence of coinfection of <it>H. pylori </it>and <it>H. heilmannii </it>was 17(6%) and with <it>H. felis </it>was 10(4%), respectively. Only one out of 66 exposed to pets were positive for <it>H. heilmannii </it>and two for <it>H. felis</it>. Histopathology was carried out in 160(64%) of 250 cases. Chronic active inflammation was observed in 53(56%) (p = 0.001) of the patients with <it>H. pylori </it>infection alone as compared to 3(37%) (p = 0.73) coinfected with <it>H. heilmannii </it>and <it>H. pylori </it>and 3(60%) coinfected with <it>H. felis </it>and <it>H. pylori </it>(p = 0.66). Intestinal metaplasia was observed in 3(3%)(p = 1.0) of the patients with <it>H. pylori </it>infection alone as compared to 2(25%) (p = 0.02) coinfected with <it>H. heilmannii </it>and <it>H. pylori </it>and 1(20%) coinfected with <it>H. felis </it>and <it>H. pylori </it>(p = 0.15).</p> <p>Conclusion</p> <p>The prevalence of <it>H. heilmannii </it>and <it>H. felis </it>was low in our patients with dyspepsia. Exposure to pets did not increase the risk of <it>H. heilmannii </it>or <it>H. felis </it>infection. The coinfection of <it>H. pylori </it>with <it>H. heilmannii </it>was seen associated with intestinal metaplasia, however this need further confirmation.</p

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

X-ray emission from the Sombrero galaxy: discrete sources

We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200 ks. With a detection limit of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30 kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-low indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC LF at fainter luminosities down to 1E35 erg/s. The derived index rules out a faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres