790 research outputs found
GALEX J201337.6+092801: The lowest gravity subdwarf B pulsator
We present the recent discovery of a new subdwarf B variable (sdBV), with an
exceptionally low surface gravity. Our spectroscopy of J20136+0928 places it at
Teff = 32100 +/- 500, log(g) = 5.15 +/- 0.10, and log(He/H) = -2.8 +/- 0.1.
With a magnitude of B = 12.0, it is the second brightest V361 Hya star ever
found. Photometry from three different observatories reveals a temporal
spectrum with eleven clearly detected periods in the range 376 to 566 s, and at
least five more close to our detection limit. These periods are unusually long
for the V361 Hya class of short-period sdBV pulsators, but not unreasonable for
p- and g-modes close to the radial fundamental, given its low surface gravity.
Of the ~50 short period sdB pulsators known to date, only a single one has been
found to have comparable spectroscopic parameters to J20136+0928. This is the
enigmatic high-amplitude pulsator V338 Ser, and we conclude that J20136+0928 is
the second example of this rare subclass of sdB pulsators located well above
the canonical extreme horizontal branch in the HR diagram.Comment: 5 pages, accepted for publication in ApJ Letter
Coloured peak algebras and Hopf algebras
For a finite abelian group, we study the properties of general
equivalence relations on G_n=G^n\rtimes \SG_n, the wreath product of with
the symmetric group \SG_n, also known as the -coloured symmetric group. We
show that under certain conditions, some equivalence relations give rise to
subalgebras of \k G_n as well as graded connected Hopf subalgebras of
\bigoplus_{n\ge o} \k G_n. In particular we construct a -coloured peak
subalgebra of the Mantaci-Reutenauer algebra (or -coloured descent algebra).
We show that the direct sum of the -coloured peak algebras is a Hopf
algebra. We also have similar results for a -colouring of the Loday-Ronco
Hopf algebras of planar binary trees. For many of the equivalence relations
under study, we obtain a functor from the category of finite abelian groups to
the category of graded connected Hopf algebras. We end our investigation by
describing a Hopf endomorphism of the -coloured descent Hopf algebra whose
image is the -coloured peak Hopf algebra. We outline a theory of
combinatorial -coloured Hopf algebra for which the -coloured
quasi-symmetric Hopf algebra and the graded dual to the -coloured peak Hopf
algebra are central objects.Comment: 26 pages latex2
A coproduct structure on the formal affine Demazure algebra
In the present paper we generalize the coproduct structure on nil Hecke rings
introduced and studied by Kostant-Kumar to the context of an arbitrary
algebraic oriented cohomology theory and its associated formal group law. We
then construct an algebraic model of the T-equivariant oriented cohomology of
the variety of complete flags.Comment: 28 pages; minor revision of the previous versio
Effects of infliximab on markers of inflammation and bone turnover and associations with bone mineral density in patients with ankylosing spondylitis
Using a micro-extruder a new class of polyurethanes, polyacylurethanes (PAUs), based on poly (epsilon-caprol actone) (PCL) oligomers and terephthaloyl diisocyanate was synthesized. These polymers are anticipated to have potential for biodegradable and/or biomedical applications. Therefore, PAUs were synthesized without the use of any, possibly toxic, catalysts. PCL diols of different molecular mass were used, namely 750, 1000, 1250, 1500, 2000, 3000 and 4000 g/mol. These diols were synthesized by thermal polymerization at 150 degrees C without the use of any catalyst. The PAUs of terephthaloyl diisocyanate were synthesized by reactive extrusion using a micro-extruder of 5 cm 3 at 130 degrees C. The PAUs obtained were characterized using DSC, GPC, DMTA, SAXS and tensile testing. Surprisingly, PAUs based on PCL chains of 750, 1000, 1250 and 1500 g/mol were found to show microphase separation/micro crystallization as proven by SAXS data combined with DSC. This microphase separation creates elastomeric properties as is known from polyurethanes. In the PAUs based on PCL chains of 2000, 3000 and 4000 g/mol part of the PCL was found to crystallize and no evidence of any phase separation of the acylurethane block was found. (c) 2005 Elsevier Ltd. All rights reserved
Conjectures about certain parabolic Kazhdan--Lusztig polynomials
Irreducibility results for parabolic induction of representations of the
general linear group over a local non-archimedean field can be formulated in
terms of Kazhdan--Lusztig polynomials of type . Spurred by these results and
some computer calculations, we conjecture that certain alternating sums of
Kazhdan--Lusztig polynomials known as parabolic Kazhdan--Lusztig polynomials
satisfy properties analogous to those of the ordinary ones.Comment: final versio
Achievement of Remission Endpoints with Secukinumab Over 3 Years in Active Ankylosing Spondylitis: Pooled Analysis of Two Phase 3 Studies
INTRODUCTION: Clinical remission in patients with ankylosing spondylitis (AS) has been determined using composite indices such as the AS Disease Activity Score inactive disease (ASDAS-ID), Assessment of SpondyloArthritis international Society criteria partial remission (ASAS-PR), and low Bath AS Disease Activity Index (BASDAI) scores. The objective of this exploratory analysis was to evaluate the proportion of secukinumab-treated patients with AS achieving remission defined based on the ASDAS-ID (score < 1.3), ASAS-PR or BASDAI score ≤  2. METHODS: The analysis pooled data from the MEASURE 1 and 2 studies over 3 years. The proportion of patients who achieved ASDAS-ID, ASAS-PR, or BASDAI ≤ 2 with secukinumab was compared with placebo at week 16; results for secukinumab-treated patients were summarized through week 156. Sustainability of each criterion was assessed from week 16 to 156 using shift analysis. The association between each of these criteria and specific patient-reported outcomes (PROs), such as health-related quality of life, function, fatigue, and work impairment, was also explored. RESULTS: At week 16, a higher proportion of secukinumab-treated patients versus placebo achieved ASDAS-ID (17.6 vs. 3.5%), ASAS-PR (15.4 vs. 4.1%), or BASDAI ≤ 2 (22.3 vs. 6.4%) criteria (all P < 0.0001), which were sustained through 156 weeks. Shift analysis showed that the majority of secukinumab-treated patients achieving remission at week 16 maintained their status at week 156 (ASDAS-ID, 57.1%; ASAS-PR, 68.0% and BASDAI ≤ 2, 74.3%). Remission was also associated with improved PROs over 156 weeks. CONCLUSIONS: Secukinumab-treated patients maintained ASDAS-ID, ASAS-PR, or BASDAI ≤ 2 from week 16 up to 3 years. Patients who achieved at least one of the three responses/states, reported improvement in PROs, which suggests an association of clinical remission/ID with PROs in patients with active AS. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01358175, NCT01863732, and NCT01649375
Short-term changes on MRI predict long-term changes on radiography in rheumatoid arthritis: an analysis by an OMERACT Task Force of pooled data from four randomised controlled trials
Objective: In rheumatoid arthritis (RA), MRI provides earlier detection of structural damage than radiography (X-ray) and more sensitive detection of intra-articular inflammation than clinical examination. This analysis was designed to evaluate the ability of early MRI findings to predict subsequent structural damage by X-ray. Methods: Pooled data from four randomised controlled trials (RCTs) involving 1022 RA hands and wrists in early and established RA were analysed. X-rays were scored using van der Heijde-modified or Genant-modified Sharp methods. MRIs were scored using Outcome Measures in Rheumatology (OMERACT) RA MRI Score (RAMRIS). Data were analysed at the patient level using multivariable logistic regression and receiver operating characteristic curve analyses. Results: Progression of MRI erosion scores at Weeks 12 and 24 predicted progression of X-ray erosions at Weeks 24 and 52, with areas under the curve (AUCs) of 0.64 and 0.74, respectively. 12-week and 24-week changes in MRI osteitis scores were similarly predictive of 24-week and 52-week X-ray erosion progressions; pooled AUCs were 0.78 and 0.77, respectively. MRI changes in synovitis at Weeks 12 and 24 also predicted progression of X-ray joint damage (erosion and joint-space narrowing) at Weeks 24 and 52 (AUCs=0.72 and 0.65, respectively). Conclusions: Early changes in joint damage and inflammation detected with MRI predict changes in joint damage evident on subsequent X-rays. These findings support the use of MRI as a valid method for monitoring structural damage in short-duration RCTs
PEComa of the lung
Perivascular epithelioid cell tumor (PEComa), also called clear cell
\u2032sugar\u2032 tumor of the lung, is a rare benign tumor arising
from perivascular epithelioid cells (PECs). We report a case of a
15-year-old boy who presented with right lower lobe lesion which turned
out to be a clear cell tumor of the lung. An
[18F]-fluoro-2-deoxy-D-glucose (FDG) - positron emission tomography
(PET) scan revealed mild FDG uptake in the lung lesion (SUV< 1) with
no active uptake elsewhere in the body. We discuss the clinical,
radiologic and immunohistochemical features of clear cell
\u2032sugar\u2032 tumor of lung and compare them with published
literature
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