Quadratic forms of dimension 8 with trivial discrimiand and Clifford algebra of index 4

Izhboldin and Karpenko proved in 2000 that any quadratic form of dimension 8 with trivial discriminant and Clifford algebra of index 4 is isometric to the transfer, with respect to some quadratic \'etale extension, of a quadratic form similar to a 2-fold Pfister form. We give a new proof of this result, based on a theorem of decomposability for degree 8 and index 4 algebras with orthogonal involution

The 13-C(p,d) Reaction at 120 MeV

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

Identification of new states in 26Si using the29Si(3He,6He)26Si reaction and consequences for the 25Al(p,y)26Si reaction rate in explosive hydrogen burning environments

We have studied the [Formula Presented] reaction and have identified new states in [Formula Presented] at [Formula Presented] and [Formula Presented] Based on these measurements and other recent evidence, we suggest spin-parity assignments of [Formula Presented] for the 5.678 MeV state and [Formula Presented] for the 5.945 MeV state, which would account for all the “missing” unnatural parity states in [Formula Presented] in the excitation energy region important to hydrogen burning in novae. New reaction rates are presented for the [Formula Presented] reaction based on this possible assignment of states

Reductions in radiographic progression in early RA over 25-years: changing contribution from RF in 2 multi-centre UK inception cohorts

Objectives: To assess 5-year progression of erosions and Joint Space Narrowing (JSN), and their associations with RF status in two large, multi-centre early-RA cohorts spanning 25-years. Methods: Radiographic joint damage was recorded using the Sharp/van der Heijde (SvdH) method in the Early RA Study (ERAS) 1986-2001, and the Early RA Network (ERAN) 2002-2013. Mixed-effects negative-binomial regression estimated changes in radiographic damage over 5-years, including erosions and JSN separately. Rheumatoid Factor (RF), along with age, sex and baseline markers of disease activity were controlled for. Results: 1,216 patients from ERAS and 446 from ERAN had radiographic data. Compared to ERAS, ERAN patients had a lower mean total SvdH score at baseline (ERAN=6.2 vs. ERAS=10.5, p<0.001), and mean annual rate of change (ERAN=2.5 vs. ERAS=6.9 per year, p<0.001). 74% of ERAS and 27% of ERAN patients progressed ≥5 units. Lower scores at baseline in ERAN were largely driven by reductions in JSN (ERAS=3.9 vs. ERAN=1.2, p<0.001), along with erosions (ERAS=1.9 vs. ERAN=0.8, p<0.001). RF was associated with greater progression in each cohort, but the absolute difference in mean annual rate of change for RF positive patients was substantially higher for ERAS (RF+= 8.6 vs. RF-= 5.1, p<0.001), relative to ERAN (RF+= 2.0 vs. RF-= 1.9, p=0.855). Conclusion: Radiographic progression has significantly reduced between the two cohorts, associated with lower baseline damage and other factors, including changes in early DMARD use. The impact of RF status as a prognostic marker of clinically meaningful change in radiographic progression has markedly diminished in the context of more modern treatment. This article is protected by copyright. All rights reserved

The UKIDSS Galactic Plane Survey

'The definitive version is available at www.blackwell-synergy.com .' Copyright Blackwell Publishing DOI: 10.1111/j.1365-2966.2008.13924.xThe UKIDSS Galactic Plane Survey (GPS) is one of the five near-infrared Public Legacy Surveys that are being undertaken by the UKIDSS consortium, using the Wide Field Camera on the United Kingdom Infrared TelescopePeer reviewe

Non-detection of a statistically anisotropic power spectrum in large-scale structure

We search a sample of photometric luminous red galaxies (LRGs) measured by the Sloan Digital Sky Survey (SDSS) for a quadrupolar anisotropy in the primordial power spectrum, in which P(\vec{k}) is an isotropic power spectrum P(k) multiplied by a quadrupolar modulation pattern. We first place limits on the 5 coefficients of a general quadrupole anisotropy. We also consider axisymmetric quadrupoles of the form P(\vec{k}) = P(k){1 + g_*[(\hat{k}\cdot\hat{n})^2-1/3]} where \hat{n} is the axis of the anisotropy. When we force the symmetry axis \hat{n} to be in the direction (l,b)=(94 degrees,26 degrees) identified in the recent Groeneboom et al. analysis of the cosmic microwave background, we find g_*=0.006+/-0.036 (1 sigma). With uniform priors on \hat{n} and g_* we find that -0.41<g_*<+0.38 with 95% probability, with the wide range due mainly to the large uncertainty of asymmetries aligned with the Galactic Plane. In none of these three analyses do we detect evidence for quadrupolar power anisotropy in large scale structure.Comment: 23 pages; 10 figures; 3 tables; replaced with version published in JCAP (added discussion of scale-varying quadrupolar anisotropy

Optimal surgical care for adolescent idiopathic scoliosis: an international consensus

Purpose The surgical management of adolescent idiopathic scoliosis (AIS) has seen many developments in the last two decades. Little high-level evidence is available to support these changes and guide treatment. This study aimed to identify optimal operative care for adolescents with AIS curves between 40° and 90° Cobb angle. Methods From July 2012 to April 2013, the AOSpine Knowledge Forum Deformity performed a modified Delphi survey where current expert opinion from 48 experienced deformity surgeons, representing 29 diverse countries, was gathered. Four rounds were performed: three web-based surveys and a final face-to-face meeting. Consensus was achieved with ≥70 % agreement. Data were analyzed qualitatively and quantitatively. Results Consensus of what constitutes optimal care was reached on greater than 60 aspects including: preoperative radiographs; posterior as opposed to anterior (endoscopic) surgical approaches; use of intraoperative spinal cord monitoring; use of local autologous bone (not iliac crest) for grafts; use of thoracic and lumbar pedicle screws; use of titanium anchor points; implant density of <80 % for 40°–70° curves; and aspects of postoperative care. Variability in practice patterns was found where there was no consensus. In addition, there was consensus on what does not constitute optimal care, including: routine pre- and intraoperative traction; routine anterior release; use of bone morphogenetic proteins; and routine postoperative CT scanning. Conclusions International consensus was found on many aspects of what does and does not constitute optimal operative care for adolescents with AIS. In the absence of current high-level evidence, at present, these expert opinion findings will aid health care providers worldwide define appropriate care in their regions. Areas with no consensus provide excellent insight and priorities for future researchpublished_or_final_versio

Destruction of 18F via 18F(p,α) 15O burning through the Ec.m.=665 keV resonance

Knowledge of the astrophysical rate of the 18F(p,α)15O reaction is important for understanding the γ-ray emission expected from novae and heavy-element production in x-ray bursts. The rate of this reaction is dominated at temperatures above ∼0.4 GK by a resonance near 7.08 MeV excitation energy in 19Ne. The 18F(p,α)15O rate has been uncertain in part because of disagreements among previous measurements concerning the resonance strength and excitation energy of this state. To resolve these uncertainties, we have made simultaneous measurements of the 1H(18F,p)18F and 1H(18F,α)15O excitation functions using a radioactive 18F beam at the ORNL Holifield Radioactive Ion Beam Facility. A simultaneous fit of the data sets has been performed, and the best fit was obtained with a center-of-mass resonance energy of 664.7±1.6 keV (Ex = 7076±2 keV), a total width of 39.0±1.6 keV, a proton branching ratio of Γp/Γ = 0.39±0.02, and a resonance strength of ωγ= 6.2±0.3 keV

Kinematically complete measurement of the 1H(18F,p)18F excitation function for the astrophysically important 7.08-MeV state in 19Ne

Knowledge of the astrophysical [Formula Presented] rate is important for understanding gamma-ray emission from novae and heavy-element production in x-ray bursts. A state with [Formula Presented] in [Formula Presented] provides an s-wave resonance and, depending on its properties, could dominate the [Formula Presented] rate. By measuring a kinematically complete [Formula Presented] excitation function with a radioactive [Formula Presented] beam at the ORNL Holifield Radioactive Ion Beam Facility, we find that the [Formula Presented] state lies at a center-of-mass energy of [Formula Presented] has a total width of [Formula Presented] and a proton partial-width of [Formula Presented]

Gravitational Lensing at Millimeter Wavelengths

With today's millimeter and submillimeter instruments observers use gravitational lensing mostly as a tool to boost the sensitivity when observing distant objects. This is evident through the dominance of gravitationally lensed objects among those detected in CO rotational lines at z>1. It is also evident in the use of lensing magnification by galaxy clusters in order to reach faint submm/mm continuum sources. There are, however, a few cases where millimeter lines have been directly involved in understanding lensing configurations. Future mm/submm instruments, such as the ALMA interferometer, will have both the sensitivity and the angular resolution to allow detailed observations of gravitational lenses. The almost constant sensitivity to dust emission over the redshift range z=1-10 means that the likelihood for strong lensing of dust continuum sources is much higher than for optically selected sources. A large number of new strong lenses are therefore likely to be discovered with ALMA, allowing a direct assessment of cosmological parameters through lens statistics. Combined with an angular resolution <0.1", ALMA will also be efficient for probing the gravitational potential of galaxy clusters, where we will be able to study both the sources and the lenses themselves, free of obscuration and extinction corrections, derive rotation curves for the lenses, their orientation and, thus, greatly constrain lens models.Comment: 69 pages, Review on quasar lensing. Part of a LNP Topical Volume on "Dark matter and gravitational lensing", eds. F. Courbin, D. Minniti. To be published by Springer-Verlag 2002. Paper with full resolution figures can be found at ftp://oden.oso.chalmers.se/pub/tommy/mmviews.ps.g