4,561 research outputs found
An Analysis of Ocular Counterrolling in Response to Body Positions in Three-Dimensional Space
CMB Lensing Reconstruction in Real Space
We explore the reconstruction of the gravitational lensing field of the
cosmic microwave background in real space showing that very little statistical
information is lost when estimators of short range on the celestial sphere are
used in place of the customary estimators in harmonic space, which are nonlocal
and in principle require a simultaneous analysis of the entire sky without any
cuts or excisions. Because virtually all the information relevant to lensing
reconstruction lies on angular scales close to the resolution scale of the sky
map, the gravitational lensing dilatation and shear fields (which unlike the
deflection field or lensing potential are directly related to the observations
in a local manner) may be reconstructed by means of quadratic combinations
involving only very closely separated pixels. Even though harmonic space
provides a more natural context for understanding lensing reconstruction
theoretically, the real space methods developed here have the virtue of being
faster to implement and are likely to prove useful for analyzing realistic maps
containing a galactic cut and possibly numerous small excisions to exclude
point sources that cannot be reliably subtracted.Comment: 21 pages, 8 figure
Single port laparoscopic repair of primary and incisional ventral hernia: Re: Single port laparoscopic repair of incarcerated ventral hernia, MacDonald et al. (2009) Hernia, March 24 (Epub ahead of print)
Anyons in discrete gauge theories with Chern-Simons terms
We study the effect of a Chern-Simons term in a theory with discrete gauge
group H, which in (2+1)-dimensional space time describes (non-abelian) anyons.
As in a previous paper, we emphasize the underlying algebraic structure, namely
the Hopf algebra D(H). We argue on physical grounds that the addition of a
Chern-Simons term in the action leads to a non-trivial 3-cocycle on D(H).
Accordingly, the physically inequivalent models are labelled by the elements of
the cohomology group H^3(H,U(1)). It depends periodically on the coefficient of
the Chern-Simons term which model is realized. This establishes a relation with
the discrete topological field theories of Dijkgraaf and Witten. Some
representative examples are worked out explicitly.Comment: 18 page
Single port totally extraperitoneal laparoscopic inguinal hernia repair: Re: Single incision total extraperitoneal (one SITE) laparoscopic inguinal hernia repair using a single access port device, B. P. Jacob et al. (2009) Hernia, June 27 (Epub ahead of print)
SO(10) Cosmic Strings and SU(3) Color Cheshire Charge
Certain cosmic strings that occur in GUT models such as can carry a
magnetic flux which acts nontrivially on objects carrying
quantum numbers. We show that such strings are non-Abelian Alice strings
carrying nonlocalizable colored ``Cheshire" charge. We examine claims made in
the literature that strings can have a long-range, topological
Aharonov-Bohm interaction that turns quarks into leptons, and observe that such
a process is impossible. We also discuss flux-flux scattering using a
multi-sheeted formalism.Comment: 37 Pages, 8 Figures (available upon request) phyzzx, iassns-hep-93-6,
itp-sb-93-6
The initial conditions of the universe: how much isocurvature is allowed?
We investigate the constraints imposed by the current data on correlated
mixtures of adiabatic and non-adiabatic primordial perturbations. We discover
subtle flat directions in parameter space that tolerate large (~60%)
contributions of non-adiabatic fluctuations. In particular, larger values of
the baryon density and a spectral tilt are allowed. The cancellations in the
degenerate directions are explored and the role of priors elucidated.Comment: 4 pages, 4 figures. Submitted to PR
VEGF188 promotes corneal reinnervation after injury
Vascular endothelial growth factor A (VEGF) induces angiogenesis and vascular hyperpermeability in ocular tissues and is therefore a key therapeutic target for eye conditions in which these processes are dysregulated. In contrast, the therapeutic potential of VEGF's neurotrophic roles in the eye has remained unexploited. In particular, it is not known whether modulating levels of any of the 3 major alternatively spliced VEGF isoforms might provide a therapeutic approach to promote neural health in the eye without inducing vascular pathology. Here, we have used a variety of mouse models to demonstrate differences in overall VEGF levels and VEGF isoform ratios across tissues in the healthy eye. We further show that VEGF isoform expression was differentially regulated in retinal versus corneal disease models. Among the 3 major isoforms - termed VEGF120, VEGF164, and VEGF188 - VEGF188 was upregulated to the greatest extent in injured cornea, where it was both necessary and sufficient for corneal nerve regeneration. Moreover, topical VEGF188 application further promoted corneal nerve regeneration without inducing pathological neovascularization. VEGF isoform modulation should therefore be explored further for its potential in promoting neural health in the eye
Field-dependent specific heat and multiple superconducting phases in UPt_3
We have measured the specific heat, C, of single-crystal UPt_3 in the superconducting regime as a function of temperature, T, and magnetic field, H, parallel to the c axis. We find that C(T) at fixed H<H_(c2) shows no evidence for different superconducting states. In contrast, our field-sweep data, C(H) at fixed T, have sharp changes in slope at H≊H_(c2)/2. The phase diagram deduced from these features agrees with neutron-scattering and torsional-oscillator results on the same samples. These thermodynamic measurements as a function of magnetic field constrain theories of exotic superconductivity in UPt_3
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