2,208 research outputs found
Degenerate neckpinches in Ricci flow
In earlier work, we derived formal matched asymptotic profiles for families
of Ricci flow solutions developing Type-II degenerate neckpinches. In the
present work, we prove that there do exist Ricci flow solutions that develop
singularities modeled on each such profile. In particular, we show that for
each positive integer , there exist compact solutions in all dimensions
that become singular at the rate (T-t)^{-2+2/k}$
Oscillatory approach to the singularity in vacuum symmetric spacetimes
A combination of qualitative analysis and numerical study indicates that
vacuum symmetric spacetimes are, generically, oscillatory.Comment: 2 pages submitted to the Ninth Marcel Grossmann Proceedings; v2, "all
known cases" changed to "various known cases" in the first paragrap
Areal Foliation and AVTD Behavior in T^2 Symmetric Spacetimes with Positive Cosmological Constant
We prove a global foliation result, using areal time, for T^2 symmetric
spacetimes with a positive cosmological constant. We then find a class of
solutions that exhibit AVTD behavior near the singularity.Comment: 15 pages, 0 figures, 2 references adde
Yang-Mills Flow and Uniformization Theorems
We consider a parabolic-like systems of differential equations involving
geometrical quantities to examine uniformization theorems for two- and
three-dimensional closed orientable manifolds. We find that in the
two-dimensional case there is a simple gauge theoretic flow for a connection
built from a Riemannian structure, and that the convergence of the flow to the
fixed points is consistent with the Poincare Uniformization Theorem. We
construct a similar system for the three-dimensional case. Here the connection
is built from a Riemannian geometry, an SO(3) connection and two other 1-form
fields which take their values in the SO(3) algebra. The flat connections
include the eight homogeneous geometries relevant to the three-dimensional
uniformization theorem conjectured by W. Thurston. The fixed points of the flow
include, besides the flat connections (and their local deformations), non-flat
solutions of the Yang-Mills equations. These latter "instanton" configurations
may be relevant to the fact that generic 3-manifolds do not admit one of the
homogeneous geometries, but may be decomposed into "simple 3-manifolds" which
do.Comment: 21 pages, Latex, 5 Postscript figures, uses epsf.st
Anti-IFNαR Mabs for the treatment of systemic lupus erythematosus
INTRODUCTION: The type 1 interferon pathway is known to play a role in the immunopathology of systemic lupus erythematosus (SLE). As a result, biologic agents targeting this pathway have been developed and are currently being investigated in clinical trials. AREAS COVERED: We review the biologic agents which have been developed to antagonize type I interferons in SLE. We focus on anifrolumab, a type I interferon receptor antagonist, and consider the complexities of defining efficacy in SLE clinical trials. EXPERT OPINION: Anifrolumab shows promise as an addition to the SLE therapeutic armamentarium. Despite discordant results between its two phase III studies, there is a convincing suggestion of benefit in both trials to encourage the view that this approach might be effective. Data acquired thus far look particularly useful for cutaneous disease. We await data on its effect on renal, pulmonary, cardiac, and central nervous system involvement, on patient reported outcomes, and its safety and efficacy with long-term use
Kidney disease in primary anti-phospholipid antibody syndrome
APS is an autoimmune disease defined by the presence of arterial or venous thrombotic events and/or pregnancy morbidity in patients who test positive for aPL. APS can be isolated (primary APS) or associated with other autoimmune diseases. The kidney is a major target organ in APS, and renal thrombosis can occur at any level within the vasculature of the kidney (renal arteries, intrarenal vasculature and renal veins). Histological findings vary widely, including ischaemic glomeruli and thrombotic lesions without glomerular or arterial immune deposits on immunofluorescence. Renal involvement in patients with definite APS is treated with long-term anticoagulants as warfarin, but new treatments are being tried. The aim of this article is to review the links between primary APS and kidney disease
The Singularity in Generic Gravitational Collapse Is Spacelike, Local, and Oscillatory
A longstanding conjecture by Belinskii, Khalatnikov, and Lifshitz that the
singularity in generic gravitational collapse is spacelike, local, and
oscillatory is explored analytically and numerically in spatially inhomogeneous
cosmological spacetimes. With a convenient choice of variables, it can be seen
analytically how nonlinear terms in Einstein's equations control the approach
to the singularity and cause oscillatory behavior. The analytic picture
requires the drastic assumption that each spatial point evolves toward the
singularity as an independent spatially homogeneous universe. In every case,
detailed numerical simulations of the full Einstein evolution equations support
this assumption.Comment: 7 pages includes 4 figures. Uses Revtex and psfig. Received
"honorable mention" in 1998 Gravity Research Foundation essay contest.
Submitted to Mod. Phys. Lett.
Brief Cognitive Screening Tools for Primary Care Practice
Early detection and diagnosis of Alzheimer’s disease and other cognitive impairment presents as a critical issue facing primary and specialty care providers in Washington State. In order to address the gaps and challenges faced by providers, the Dementia Action Collaborative offers the current paper to provide information and guidance around early detection and diagnosis of memory loss and dementia, including Alzheimer’s disease. At the conclusion of this paper, providers should be able to identify indications and opportunities for detection, appropriate tools, and care pathways for individuals and families affected by cognitive impairment and dementia
SLICC/ACR DAMAGE INDEX IS VALID, AND RENAL AND PULMONARY ORGAN SCORES ARE PREDICTORS OF SEVERE OUTCOME IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS
We investigated the Systemic Lupus International Collaborative Clinics/American College of Rheumatology (SLICC/ACR) Damage Index as a predictor of severe outcome and an indicator of morbidity in different ethnic groups, and in regard to its validity. We retrospectively studied disease course within 10 yr of diagnosis in an inception cohort of 80 patients with systemic lupus erythematosus (SLE). The mean renal damage score (DS) at 1 yr after diagnosis was a significant predictor of endstage renal failure and the mean pulmonary DS at 1 yr significantly predicted death within 10 yr of diagnosis. Compared to Caucasians, Afro-Caribbeans and Asians had significantly higher mean total DS at 5 and 10 yr, and higher mean renal DS at 10 yr. At 5 yr, the mean renal DS in Afro-Caribbeans and the mean neuropsychiatric DS in Asians were significantly higher than in Caucasians. The rate of endstage renal failure in Caucasians was significantly lower than in the other ethnic groups. Our results confirm the validity of the SLICC/ACR Damage Inde
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