1,544 research outputs found
China Returns to Africa: Anatomy of an Expansive Engagement
This paper presents a scoping analysis of the main contours of relations, offering an anatomy of key dimensions of an expansive Chinese engagement in the continent that remains dynamic
Impact of incomplete percutaneous revascularization in patients With multivessel coronary artery disease: a systematic review and meta-analysis
Background: Up to half of patients undergoing percutaneous coronary intervention have multivessel coronary artery disease (MVD) with conflicting data regarding optimal revascularization strategy in such patients. This paper assesses the evidence for complete revascularization (CR) versus incomplete revascularization in patients undergoing percutaneous coronary intervention, and its prognostic impact using metaâanalysis.
Methods and Results: A search of PubMed, EMBASE, MEDLINE, Current Contents Connect, Google Scholar, Cochrane library, Science Direct, and Web of Science was conducted to identify the association of CR in patients with multivessel coronary artery disease undergoing percutaneous coronary intervention with major adverse cardiac events and mortality. Randomâeffects metaâanalysis was used to estimate the odds of adverse outcomes. Metaâregression analysis was conducted to assess the relationship with continuous variables and outcomes. Thirtyâeight publications that included 156Â 240 patients were identified. Odds of death (OR 0.69, 95% CI 0.61â0.78), repeat revascularization (OR 0.60, 95% CI 0.45â0.80), myocardial infarction (OR 0.64, 95% CI 0.50â0.81), and major adverse cardiac events (OR 0.63, 95% CI 0.50â0.79) were significantly lower in the patients who underwent CR. These outcomes were unchanged on subgroup analysis regardless of the definition of CR. Similar findings were recorded when CR was studied in the chronic total occlusion (CTO) subgroup (OR 0.65, 95% CI 0.53â0.80). A metaâregression analysis revealed a negative relationship between the OR for mortality and the percentage of CR.
Conclusion: CR is associated with reduced risk of mortality and major adverse cardiac events, irrespective of whether an anatomical or a scoreâbased definition of incomplete revascularization is used, and this magnitude of risk relates to degree of CR. These results have important implications for the interventional management of patients with multivessel coronary artery disease
A Sample of Ultra Steep Spectrum Sources Selected from the Westerbork In the Southern Hemisphere (WISH) survey
The 352 MHz Westerbork In the Southern Hemisphere (WISH) survey is the
southern extension of the WENSS, covering 1.60 sr between -9 < DEC < -26 to a
limiting flux density of ~18 mJy (5sigma). Due to the very low elevation of the
observations, the survey has a much lower resolution in declination than in
right ascension (54" x 54"cosec(DEC)). A correlation with the 1.4 GHz NVSS
shows that the positional accuracy is less constrained in declination than in
right ascension, but there is no significant systematic error. We present a
source list containing 73570 sources.
We correlate this WISH catalogue with the NVSS to construct a sample of faint
Ultra Steep Spectrum (USS) sources, which is accessible for follow-up studies
with large optical telescopes in the southern hemisphere. This sample is aimed
at increasing the number of known high redshift radio galaxies to allow
detailed follow-up studies of these massive galaxies and their environments in
the early Universe.Comment: 12 Pages, including 5 PostScript figures. Accepted for publication in
Astronomy & Astrophysics. The full WISH catalog with 73570 sources is
available from http://www.strw.leidenuniv.nl/wenss
The final two redshifts for radio sources from the equatorial BRL sample
Best, Rottgering and Lehnert (1999, 2000a) defined a new sample of powerful
radio sources from the Molonglo Reference Catalogue, for which redshifts were
compiled or measured for 177 of the 178 objects. For the final object,
MRC1059-010 (3C249), the host galaxy is here identified using near-infrared
imaging, and the redshift is determined from VLT spectroscopy. For one other
object in the sample, MRC0320+053 (4C05.14), the literature redshift has been
questioned: new spectroscopic observations of this object are presented,
deriving a corrected redshift. With these two results, the spectroscopic
completeness of this sample is now 100%.
New redshifts are also presented for PKS0742+10 from the Wall & Peacock 2.7
GHz catalogue, and PKS1336+003 from the Parkes Selected Regions. PKS0742+10
shows a strong neutral hydrogen absorption feature in its Lyman-alpha emission
profile.Comment: 4 pages. LaTeX. Accepted for publication in MNRA
A Deep 150 MHz GMRT Survey in Eridanus
We present results of a 150 MHz survey of a field centered on Epsilon
Eridani, undertaken with the Giant Metrewave Radio Telescope (GMRT). The survey
covers an area with a diameter of 2 deg, has a spatial resolution of 30" and a
noise level of 3.1 mJy at the pointing centre. These observations provide a
deeper and higher resolution view of the 150 MHz radio sky than the 7C survey
(although the 7C survey covers a much larger area). A total of 113 sources were
detected, most are point-like, but 20 are extended. We present an analysis of
these sources, in conjunction with the NVSS (at 1.4 GHz) and VLSS (at 74 MHz).
This process allowed us to identify 5 Ultra Steep Spectrum (USS) radio sources
that are candidate high redshift radio galaxies (HzRGs). In addition, we have
derived the dN/dS distribution for these observations and compare our results
with other low frequency radio surveys.Comment: 12 pages, 11 figures, 3 tables, accepted for publication in MNRA
ATPMN: accurate positions and flux densities at 5 and 8 GHz for 8,385 sources from the PMN survey
We present a source catalogue of 9,040 radio sources resulting from
high-resolution observations of 8,385 PMN sources with the Australia Telescope
Compact Array. The catalogue lists flux density and structural measurements at
4.8 and 8.6 GHz, derived from observations of all PMN sources in the
declination range -87 deg < delta < -38.5 deg (exclusive of galactic latitudes
|b| 70 mJy (50 mJy south of delta = -73
deg). We assess the quality of the data, which was gathered in 1992-1994,
describe the population of catalogued sources, and compare it to samples from
complementary catalogues. In particular we find 127 radio sources with probable
association with gamma-ray sources observed by the orbiting Fermi Large Area
Telescope.Comment: 20 pages, 21 figure
Spatial and Temporal Scales of Sverdrup Balance
Sverdrup balance underlies much of the theory of ocean circulation and provides a potential tool for describing the interior ocean transport from only the wind stress. Using both a model state estimate and an eddy-permitting coupled climate model, this study assesses to what extent and over what spatial and temporal scales Sverdrup balance describes the meridional transport. The authors find that Sverdrup balance holds to first order in the interior subtropical ocean when considered at spatial scales greater than approximately 5°. Outside the subtropics, in western boundary currents and at short spatial scales, significant departures occur due to failures in both the assumptions that there is a level of no motion at some depth and that the vorticity equation is linear. Despite the ocean transport adjustment occurring on time scales consistent with the basin-crossing times for Rossby waves, as predicted by theory, Sverdrup balance gives a useful measure of the subtropical circulation after only a few years. This is because the interannual transport variability is small compared to the mean transports. The vorticity input to the deep ocean by the interaction between deep currents and topography is found to be very large in both models. These deep transports, however, are separated from upper-layer transports that are in Sverdrup balance when considered over large scales
What Remains: Pseudotranslation as Salvage
Pseudotranslations are literary works which purport to be translations of lost or suppressed originals, i.e. to be âsalvagedâ from oblivion or obscurity. Pseudotranslation has attracted a good deal of attention within translation studies in recent years, but as a practice it can be traced back a long way. This article discusses a number of examples of the type, from Cervantesâ Don Quixote and modern works treating Shakespeare as pseudotranslated (Star Trek VI, Tom Stoppardâs Arcadia) through notable eighteenth-century examples (Walpoleâs The Castle of Otranto, MacPhersonâs Ossian) to non-fictional fictions The Book of Mormon and âNietzscheâsâ fraudulent late autobiography My Sister and I. Readers of translations usually trust that an original exists, and pseudotranslations abuse that trust. But even when an original does exist, translation performs a kind of salvage operation, acting as a kind of lifeboat which rescues a text from the passing of time and keeps it afloat for posterity
GPS radio sources: new optical observations and an updated master list
* Aims. Identify optical counterparts, address uncertain identifications and
measure previously unknown redshifts of the host galaxies of candidate GPS
radio sources, and study their stellar populations. * Methods. Long slit
spectroscopy and deep optical imaging in the B, V and R bands, obtained with
the Very Large Telescope. * Results. We obtain new redshifts for B0316+161,
B0407-658, B0904+039, B1433-040, and identify the optical counterparts of
B0008-421 and B0742+103. We confirm the previous identification for B0316+161,
B0407-658, B0554-026, and B0904+039, and find that the previous identification
for B0914+114 is incorrect. Using updated published radio spectral information
we classify as non GPS the following sources: B0407-658, B0437-454, B1648+015.
The optical colors of typical GPS sources are consistent with single
instantaneous burst stellar population models but do not yield useful
information on age or metallicity. A new master list of GPS sources is
presented.Comment: 10 pages + GPS master list. Accepeted for publication by A&
Towards a free-free template for CMB foregrounds
A full-sky template map of the Galactic free-free foreground emission
component is increasingly important for high sensitivity CMB experiments. We
use the recently published \ha data of both the northern and southern skies as
the basis for such a template.
The first step is to correct the \ha maps for dust absorption using the 100
m dust maps of Schlegel, Finkbeiner & Davis (1998). We show that for a
range of longitudes, the Galactic latitude distribution of absorption suggests
that it is 33 per cent of the full extragalactic absorption. A reliable
absorption-corrected \ha map can be produced for per cent of the sky;
the area for which a template cannot be recovered is the Galactic plane area
, and some isolated
dense dust clouds at intermediate latitudes.
The second step is to convert the dust-corrected \ha data into a predicted
radio surface brightness. The free-free emission formula is revised to give an
accurate expression (1 per cent) for the radio emission covering the frequency
range 100 MHz to 100 GHz and the electron temperature range 3000 to 20000 K.
The main uncertainty when applying this expression is the variation of electron
temperature across the sky. The emission formula is verified in several
extended H{\sc ii} regions using data in the range 408 to 2326 MHz.
A full-sky free-free template map is presented at 30 GHz; the scaling to
other frequencies is given. The Haslam et al. all-sky 408 MHz map of the sky
can be corrected for this free-free component, which amounts to a
per cent correction at intermediate and high latitudes....Comment: 18 pages, 11 figures, accepted for publication in M.N.R.A.S.
High-resolution versions of figs 2,7 (in colour), 9 and 11 can be obtained
from ftp://ftp.jb.man.ac.uk/pub/cdickins/ff_paper/FINAL_FIGURES
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