10,889 research outputs found
Energy inequalities for cutoff functions and some applications
We consider a metric measure space with a local regular Dirichlet form. We
establish necessary and sufficient conditions for upper heat kernel bounds with
sub-diffusive space-time exponent to hold. This characterization is stable
under rough isometries, that is it is preserved under bounded perturbations of
the Dirichlet form. Further, we give a criterion for stochastic completeness in
terms of a Sobolev inequality for cutoff functions. As an example we show that
this criterion applies to an anomalous diffusion on a geodesically incomplete
fractal space, where the well-established criterion in terms of volume growth
fails
Critical connectedness of thin arithmetical discrete planes
An arithmetical discrete plane is said to have critical connecting thickness
if its thickness is equal to the infimum of the set of values that preserve its
-connectedness. This infimum thickness can be computed thanks to the fully
subtractive algorithm. This multidimensional continued fraction algorithm
consists, in its linear form, in subtracting the smallest entry to the other
ones. We provide a characterization of the discrete planes with critical
thickness that have zero intercept and that are -connected. Our tools rely
on the notion of dual substitution which is a geometric version of the usual
notion of substitution acting on words. We associate with the fully subtractive
algorithm a set of substitutions whose incidence matrix is provided by the
matrices of the algorithm, and prove that their geometric counterparts generate
arithmetic discrete planes.Comment: 18 pages, v2 includes several corrections and is a long version of
the DGCI extended abstrac
Direct evidence for ferromagnetic spin polarization in gold nanoparticles
We report the first direct observation of ferromagnetic spin polarization of
Au nanoparticles with a mean diameter of 1.9 nm using X-ray magnetic circular
dichroism (XMCD). Owing to the element selectivity of XMCD, only the gold
magnetization is explored. Magnetization of gold atoms estimated by XMCD shows
a good agreement with the results obtained by conventional magnetometry. This
result is evidence of intrinsic spin polarization in nano-sized gold.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Let
Service-based survey of dystonia in Munich
We performed a service-based epidemiological study of dystonia in Munich, Germany. Due to favourable referral and treatment patterns in the Munich area, we could provide confident data from dystonia patients seeking botulinum toxin treatment. A total of 230 patients were ascertained, of whom 188 had primary dystonia. Point prevalence ratios were estimated to be 10.1 (95% confidence interval 8.4-11.9) per 100,000 for focal and 0.3 (0.0-0.6) for generalised primary dystonia. The most common focal primary dystonias were cervical dystonia with 5.4 (4.2-6.7) and essential blepharospasm with 3.1 (2.1-4.1) per 100,000 followed by laryngeal dystonia (spasmodic dysphonia) with 1.0 (0.4-1.5) per 100,000. Copyright (C) 2002 S. Karger AG, Base
Características microbianas e degradação do pirazosulfuron-etil em um solo cultivado com arroz no sistema pré-germinado.
bitstream/item/30589/1/boletim-120.pd
Histological, Immunohistological, and Clinical Features of Merkel Cell Carcinoma in Correlation to Merkel Cell Polyomavirus Status
Merkel cell carcinoma is a rare, but highly malignant tumor of the skin with high rates of metastasis and poor survival. Its incidence
rate rises and is currently about 0.6/100000/year. Clinical differential diagnoses include basal cell carcinoma, cyst, amelanotic melanoma, lymphoma and atypical
fibroxanthoma. In this review article clinical, histopathological and immunhistochemical features of Merkel cell carcinoma are reported. In addition, the role of Merkel cell polyomavirus is discussed
OpenGM: A C++ Library for Discrete Graphical Models
OpenGM is a C++ template library for defining discrete graphical models and performing inference on these models, using a wide range of state-of-the-art algorithms. No restrictions are imposed on the factor graph to allow for higher-order factors and arbitrary neighborhood structures. Large models with repetitive structure are handled efficiently because (i) functions that occur repeatedly need to be stored only once, and (ii) distinct functions can be implemented differently, using different encodings alongside each other in the same model. Several parametric functions (e.g. metrics), sparse and dense value tables are provided and so is an interface for custom C++ code. Algorithms are separated by design from the representation of graphical models and are easily exchangeable. OpenGM, its algorithms, HDF5 file format and command line tools are modular and extendible
Percolating through networks of random thresholds: Finite temperature electron tunneling in metal nanocrystal arrays
We investigate how temperature affects transport through large networks of
nonlinear conductances with distributed thresholds. In monolayers of
weakly-coupled gold nanocrystals, quenched charge disorder produces a range of
local thresholds for the onset of electron tunneling. Our measurements
delineate two regimes separated by a cross-over temperature . Up to
the nonlinear zero-temperature shape of the current-voltage curves survives,
but with a threshold voltage for conduction that decreases linearly with
temperature. Above the threshold vanishes and the low-bias conductance
increases rapidly with temperature. We develop a model that accounts for these
findings and predicts .Comment: 5 pages including 3 figures; replaced 3/30/04: minor changes; final
versio
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