3,258 research outputs found
Achieving Thoracic Oncology data collection in Europe: a precursor study in 35 Countries
Background: A minority of European countries have participated in international comparisons with high level data
on lung cancer. However, the nature and extent of data collection across the continent is simply unknown, and
without accurate data collection it is not possible to compare practice and set benchmarks to which lung cancer
services can aspire.
Methods: Using an established network of lung cancer specialists in 37 European countries, a survey was distributed
in December 2014. The results relate to current practice in each country at the time, early 2015. The results were
compiled and then verified with co-authors over the following months.
Results: Thirty-five completed surveys were received which describe a range of current practice for lung cancer
data collection. Thirty countries have data collection at the national level, but this is not so in Albania, BosniaHerzegovina, Italy, Spain and Switzerland. Data collection varied from paper records with no survival analysis, to
well-established electronic databases with links to census data and survival analyses.
Conclusion: Using a network of committed clinicians, we have gathered validated comparative data reporting an
observed difference in data collection mechanisms across Europe. We have identified the need to develop a welldesigned dataset, whilst acknowledging what is feasible within each country, and aspiring to collect high quality
data for clinical research
Timeline analysis and wavelet multiscale analysis of the AKARI All-Sky Survey at 90 micron
We present a careful analysis of the point source detection limit of the
AKARI All-Sky Survey in the WIDE-S 90 m band near the North Ecliptic Pole
(NEP). Timeline Analysis is used to detect IRAS sources and then a conversion
factor is derived to transform the peak timeline signal to the interpolated 90
m flux of a source. Combined with a robust noise measurement, the point
source flux detection limit at S/N for a single detector row is
Jy which corresponds to a point source detection limit of the
survey of 0.4 Jy.
Wavelet transform offers a multiscale representation of the Time Series Data
(TSD). We calculate the continuous wavelet transform of the TSD and then search
for significant wavelet coefficients considered as potential source detections.
To discriminate real sources from spurious or moving objects, only sources with
confirmation are selected. In our multiscale analysis, IRAS sources selected
above can be identified as the only real sources at the Point Source
Scales. We also investigate the correlation between the non-IRAS sources
detected in Timeline Analysis and cirrus emission using wavelet transform and
contour plots of wavelet power spectrum. It is shown that the non-IRAS sources
are most likely to be caused by excessive noise over a large range of spatial
scales rather than real extended structures such as cirrus clouds.Comment: 16 pages, 19 figures, 5 tables, accepted for publication in MNRA
Radial velocities of RR Lyrae stars in and around NGC 6441
Detailed elemental abundance patterns of metal-poor ([Fe/H] ~ -1~dex) stars
in the Galactic bulge indicate that a number of them are consistent with
globular cluster (GC) stars and may be former members of dissolved GCs. This
would indicate that a few per cent of the Galactic bulge was built up from
destruction and/or evaporation of globular clusters. Here an attempt is made to
identify such presumptive stripped stars originating from the massive, inner
Galaxy globular cluster NGC~6441 using its rich RR Lyrae variable star (RRL)
population. We present radial velocities of forty RRLs centered on the globular
cluster NGC~6441. All of the 13 RRLs observed within the cluster tidal radius
have velocities consistent with cluster membership, with an average radial
velocity of 24 +- 5~km/s and a star-to-star scatter of 11~km/s. This includes
two new RRLs that were previously not associated with the cluster. Eight RRLs
with radial velocities consistent with cluster membership but up to three time
the distance from the tidal radius are also reported. These potential
extra-tidal RRLs also have exceptionally long periods, which is a curious
characteristic of the NGC~6441 RRL population that hosts RRLs with periods
longer than seen anywhere else in the Milky Way. As expected of stripped
cluster stars, most are inline with the cluster's orbit. Therefore, either the
tidal radius of NGC~6441 is underestimated and/or we are seeing dissolving
cluster stars stemming from NGC~6441 that are building up the old spheroidal
bulge.Comment: accepted to A
Probing the Circumgalactic Medium at High-Redshift Using Composite BOSS Spectra of Strong Lyman-alpha Forest Absorbers
We present composite spectra constructed from a sample of 242,150 Lyman-alpha
(Lya) forest absorbers at redshifts 2.4<z<3.1 identified in quasar spectra from
the Baryon Oscillation Spectroscopic Survey (BOSS) as part of Data Release 9 of
the Sloan Digital Sky Survey III. We select forest absorbers by their flux in
bins 138 km/s wide (approximately the size of the BOSS resolution element). We
split these absorbers into five samples spanning the range of flux -0.05 <
F<0.45. Tests on a smaller sample of high-resolution spectra show that our
three strongest absorption bins would probe circumgalactic regions (projected
separation < 300 proper kpc and |Delta v| < 300km/s) in about 60% of cases for
very high signal-to-noise ratio. Within this subset, weakening Lya absorption
is associated with decreasing purity of circumgalactic selection once BOSS
noise is included. Our weaker two Lya absorption samples are dominated by the
intergalactic medium.
We present composite spectra of these samples and a catalogue of measured
absorption features from HI and 13 metal ionization species, all of which we
make available to the community. We compare measurements of seven Lyman series
transitions in our composite spectra to single line models and obtain further
constraints from their associated excess Lyman limit opacity. This analysis
provides results consistent with column densities over the range 14.4 <~ Log
(N_HI) <~ 16.45. We compare our measurements of metal absorption to a variety
of simple single-line, single-phase models for a preliminary interpretation.
Our results imply clumping on scales down to ~30 pc and near-solar
metallicities in the circumgalactic samples, while high-ionization metal
absorption consistent with typical IGM densities and metallicities is visible
in all samples.Comment: 23 pages, 15 figures, 5 tables, link to downloadable data included.
Accepted by MNRAS 2014 March 20. New sections 3.4 and 6.1 limiting the
occurrence and impact of Lyman limit system
Family-Based Association Analysis Confirms the Role of the Chromosome 9q21.32 Locus in the Susceptibility of Diabetic Nephropathy
A genome-wide association scan of type 1 diabetic patients from the GoKinD collections previously identified four novel diabetic nephropathy susceptibility loci that have subsequently been shown to be associated with diabetic nephropathy in unrelated patients with type 2 diabetes. To expand these findings, we examined whether single nucleotide polymorphisms (SNPs) at these susceptibility loci were associated with diabetic nephropathy in patients from the Joslin Study of Genetics of Nephropathy in Type 2 Diabetes Family Collection. Six SNPs across the four loci identified in the GoKinD collections and 7 haplotype tagging SNPs, were genotyped in 66 extended families of European ancestry. Pedigrees from this collection contained an average of 18.5 members, including 2 to 14 members with type 2 diabetes. Among diabetic family members, the 9q21.32 locus approached statistical significance with advanced diabetic nephropathy (P = 0.037 [adjusted P = 0.222]). When we expanded our definition of diabetic nephropathy to include individuals with high microalbuminuria, the strength of this association improved significantly (P = 1.42×10−3 [adjusted P = 0.009]). This same locus also trended toward statistical significance with variation in urinary albumin excretion in family members with type 2 diabetes (P = 0.032 [adjusted P = 0.192]) and in analyses expanded to include all relatives (P = 0.019 [adjusted P = 0.114]). These data increase support that SNPs identified in the GoKinD collections on chromosome 9q21.32 are true diabetic nephropathy susceptibility loci
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