2,781 research outputs found
Area contraction for harmonic automorphisms of the disk
A harmonic self-homeomorphism of a disk does not increase the area of any
concentric disk.Comment: 7 page
Existence of energy-minimal diffeomorphisms between doubly connected domains
The paper establishes the existence of homeomorphisms between two planar
domains that minimize the Dirichlet energy. Specifically, among all
homeomorphisms f : R -> R* between bounded doubly connected domains such that
Mod (R) < Mod (R*) there exists, unique up to conformal authomorphisms of R, an
energy-minimal diffeomorphism. No boundary conditions are imposed on f.
Although any energy-minimal diffeomorphism is harmonic, our results underline
the major difference between the existence of harmonic diffeomorphisms and the
existence of the energy-minimal diffeomorphisms. The existence of globally
invertible energy-minimal mappings is of primary pursuit in the mathematical
models of nonlinear elasticity and is also of interest in computer graphics.Comment: 34 pages, no figure
Assessing statistical significance of periodogram peaks
The least-squares (or Lomb-Scargle) periodogram is a powerful tool which is
used routinely in many branches of astronomy to search for periodicities in
observational data. The problem of assessing statistical significance of
candidate periodicities for different periodograms is considered. Based on
results in extreme value theory, improved analytic estimations of false alarm
probabilities are given. They include an upper limit to the false alarm
probability (or a lower limit to the significance). These estimations are
tested numerically in order to establish regions of their practical
applicability.Comment: 7 pages, 6 figures, 1 table; To be published in MNRA
Modelling of atmospheric boundary layer: Generation of shear.
Roughness length, z0 and friction velocity, u* are the defining parameters of wind log profile that must be matched in wind tunnel simulation. To fully understand the role of these parameters, the basics and review from the primitive equations and its relation to the logarithmic profile obtained for wind tunnel conditions were discussed. The problem of roughness, although well known, still needs to be addressed more rigorously especially when determining values of z0 and u* from wind tunnel data and their relation to the roughness element geometry. A review of classic literature and new published material were carried out, focusing on the applicability to wind tunnel modelling
Dr. Martin Hillenbrand to Receive University of Dayton Distinguished Alumnus Award
News release announcing the University of Dayton will Award Assistant Secretary of State for European Affairs, Dr. Martin Hillenbrand, with the Distinguished Alumnus Award
Pneumococcal serotyping for surveillance of invasive pneumococcal diseases in Singapore, 2011
Evidence that autosomal recessive spastic cerebral palsy-1 (CPSQ1) is caused by a missense variant in HPDL.
A subset of individuals diagnosed with cerebral palsy will have an underlying genetic diagnosis. Previously, a missense variant in GAD1 was described as a candidate mutation in a single family diagnosed with autosomal recessive spastic cerebral palsy-1 (CPSQ1; OMIM 603513). Following the ascertainment of a further branch of the CPSQ1 kindred, we found that the previously reported GAD1 variant did not segregate with the neurological disease phenotype in the recently ascertained branch of the kindred. Following genetic linkage studies to map autozygous regions and whole-exome sequencing, a missense variant (c.527 T > C; p. Leu176Pro, rs773333490) in the HPDL gene was detected and found to segregate with disease status in both branches of the kindred. HPDL encodes a 371-amino acid protein (4-Hydroxyphenylpyruvate Dioxygenase Like) that localizes to mitochondria but whose function is uncertain. Recently, biallelic loss of function variants and missense substitution-causing variants in HPDL were reported to cause a childhood onset progressive spastic movement disorder with a variable presentation. These findings suggest that HPDL-related neurological disease may mimic spastic cerebral palsy and that GAD1 should not be included in diagnostic gene panels for inherited cerebral palsy.NIH
Compact Vertically-Coupled Microring Laser Array Dual-Wavelength Source for Terahertz Mode Beating
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