3,728 research outputs found
Loop Equations and the Topological Phase of Multi-Cut Matrix Models
We study the double scaling limit of mKdV type, realized in the two-cut
Hermitian matrix model. Building on the work of Periwal and Shevitz and of
Nappi, we find an exact solution including all odd scaling operators, in terms
of a hierarchy of flows of matrices. We derive from it loop
equations which can be expressed as Virasoro constraints on the partition
function. We discover a ``pure topological" phase of the theory in which all
correlation functions are determined by recursion relations. We also examine
macroscopic loop amplitudes, which suggest a relation to 2D gravity coupled to
dense polymers.Comment: 24p
Nanoparticle-coated microcrystals
Coprecipitation provides a rapid high-yield method for self-assembly of nanoparticles on the surface of flat water-soluble crystalline surfaces and a simple immobilisation technique prior to storage or thermal and chemical modification
Exact S-Matrix for 2D String Theory
We formulate simple graphical rules which allow explicit calculation of
nonperturbative -matrices. This allows us to investigate the
constraint of nonperturbative unitarity, which indeed rules out some theories.
Nevertheless, we show that there is an infinite parameter family of
nonperturbatively unitary -matrices. We investigate the dependence of
the -matrix on one of these nonperturbative parameters. In particular, we
study the analytic structure, background dependence, and high-energy behavior
of some nonperturbative -matrices. The scattering amplitudes display
interesting resonant behavior both at high energies and in the complex energy
plane.Comment: 42p
Macroscopic -Loop Amplitude for Minimal Models Coupled to Two-Dimensional Gravity: Fusion Rules and Interactions
We investigate the structure of the macroscopic -loop amplitude obtained
from the two-matrix model at the unitary minimal critical point . We
derive a general formula for the -resolvent correlator at the continuum
planar limit whose inverse Laplace transform provides the amplitude in terms of
the boundary lengths and the renormalized cosmological constant .
The amplitude is found to contain a term consisting of multiplied by the product of modified Bessel
functions summed over their degrees which conform to the fusion rules and the
crossing symmetry. This is found to be supplemented by an increasing number of
other terms with which represent residual interactions of loops. We reveal
the nature of these interactions by explicitly determining them as the
convolution of modified Bessel functions and their derivatives for the case
and the case . We derive a set of recursion relations which relate
the terms in the -resolvents to those in the -resolvents.Comment: 30 pages, Latex, figures: figures have been introduced to represent
our results on the resolvents. A better formula for the resolvents has been
put and the section on residual interactions has been expanded to a large
exten
Bayesian Spatiotemporal Pattern and Eco-climatological Drivers of Striped Skunk Rabies in the North Central Plains
Citation: Raghavan, R. K., Hanlon, C. A., Goodin, D. G., Davis, R., Moore, M., Moore, S., & Anderson, G. A. (2016). Bayesian Spatiotemporal Pattern and Eco-climatological Drivers of Striped Skunk Rabies in the North Central Plains. Plos Neglected Tropical Diseases, 10(4), 16. doi:10.1371/journal.pntd.0004632Striped skunks are one of the most important terrestrial reservoirs of rabies virus in North America, and yet the prevalence of rabies among this host is only passively monitored and the disease among this host remains largely unmanaged. Oral vaccination campaigns have not efficiently targeted striped skunks, while periodic spillovers of striped skunk variant viruses to other animals, including some domestic animals, are routinely recorded. In this study we evaluated the spatial and spatio-temporal patterns of infection status among striped skunk cases submitted for rabies testing in the North Central Plains of US in a Bayesian hierarchical framework, and also evaluated potential eco-climatological drivers of such patterns. Two Bayesian hierarchical models were fitted to point-referenced striped skunk rabies cases [n = 656 (negative), and n = 310 (positive)] received at a leading rabies diagnostic facility between the years 2007-2013. The first model included only spatial and temporal terms and a second covariate model included additional covariates representing eco-climatic conditions within a 4km(2) home-range area for striped skunks. The better performing covariate model indicated the presence of significant spatial and temporal trends in the dataset and identified higher amounts of land covered by low-intensity developed areas [Odds ratio (OR) = 3.41; 95% Bayesian Credible Intervals (CrI) = 2.08, 3.85], higher level of patch fragmentation (OR = 1.70; 95% CrI = 1.25, 2.89), and diurnal temperature range (OR = 0.54; 95% CrI = 0.27, 0.91) to be important drivers of striped skunk rabies incidence in the study area. Model validation statistics indicated satisfactory performance for both models; however, the covariate model fared better. The findings of this study are important in the context of rabies management among striped skunks in North America, and the relevance of physical and climatological factors as risk factors for skunk to human rabies transmission and the space-time patterns of striped skunk rabies are discussed
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Novel mutation in CCBE 1 as a cause of recurrent hydrops fetalis from Hennekam lymphangiectasia-lymphedema syndrome-1.
Whole exome sequencing (WES) was used to determine the etiology of recurrent hydrops fetalis in this case of Hennekam lymphangiectasia-lymphedema syndrome-1. WES is a useful approach for diagnosing rare single-gene conditions with nonspecific phenotypes and should be considered early in the diagnostic process of investigating fetal abnormalities
Open String Star as a Continuous Moyal Product
We establish that the open string star product in the zero momentum sector
can be described as a continuous tensor product of mutually commuting two
dimensional Moyal star products. Let the continuous variable parametrize the eigenvalues of the Neumann matrices; then the
noncommutativity parameter is given by .
For each , the Moyal coordinates are a linear combination of even
position modes, and the Fourier transform of a linear combination of odd
position modes. The commuting coordinate at is identified as the
momentum carried by half the string. We discuss the relation to Bars' work, and
attempt to write the string field action as a noncommutative field theory.Comment: 30 pages, LaTeX. One reference adde
Stringy Instantons in SU(N) N=2 Non-Conformal Gauge Theories
In this paper we explicitly obtain the leading corrections to the SU(N) N=2
prepotential due to stringy instantons both in flat space-time and in the
presence of a non-trivial graviphoton background field. We show that the
stringy corrections to the prepotential are expressible in terms of the
elementary symmetric polynomials. For N>2 the theory is not conformal; we
discuss the introduction of an explicit dependence on the string scale \alpha'
in the low-energy effective action through the stringy non-perturbative sector.Comment: 22 pages, 1 figur
Enantioselective Construction of Acyclic Quaternary Carbon Stereocenters: Palladium-Catalyzed Decarboxylative Allylic Alkylation of Fully-Substituted Amide Enolates
We report a divergent and modular protocol for the preparation of acyclic molecular frameworks containing newly created quaternary carbon stereocenters. Central to this approach is a sequence composed of a (1) regioselective and -retentive preparation of allyloxycarbonyl-trapped fully substituted stereodefined amide enolates and of a (2) enantioselective palladium-catalyzed decarboxylative allylic alkylation reaction using a novel bisphosphine ligand
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