329 research outputs found
An inertial range length scale in structure functions
It is shown using experimental and numerical data that within the traditional
inertial subrange defined by where the third order structure function is linear
that the higher order structure function scaling exponents for longitudinal and
transverse structure functions converge only over larger scales, , where
has scaling intermediate between and as a function of
. Below these scales, scaling exponents cannot be determined for any
of the structure functions without resorting to procedures such as extended
self-similarity (ESS). With ESS, different longitudinal and transverse higher
order exponents are obtained that are consistent with earlier results. The
relationship of these statistics to derivative and pressure statistics, to
turbulent structures and to length scales is discussed.Comment: 25 pages, 9 figure
Local properties of extended self-similarity in 3D turbulence
Using a generalization of extended self-similarity we have studied local
scaling properties of 3D turbulence in a direct numerical simulation. We have
found that these properties are consistent with lognormal-like behavior of
energy dissipation fluctuations with moderate amplitudes for space scales
beginning from Kolmogorov length up to the largest scales, and in the
whole range of the Reynolds numbers: . The
locally determined intermittency exponent varies with ; it has a
maximum at scale , independent of .Comment: 4 pages, 5 figure
Molecular epidemiological tracing of a cattle rabies outbreak lasting less than a month in Rio Grande do Sul in southern Brazil
Abstract\ud
\ud
Background\ud
Vampire bat-transmitted cattle rabies cases are typically encountered in areas where the disease is endemic. However, over the period of a month in 2009, an outbreak of cattle rabies occurred and then ended spontaneously in a small area of the Rio Grande do Sul State in southern Brazil. To investigate the epidemiological characteristics of this rabies outbreak in Rio Grande do Sul, 26 nucleotide sequences of rabies virus (RABV) genomes that were collected in this area were analyzed phylogenetically.\ud
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Results\ud
Nucleotide sequence identities of the nucleoprotein gene and GâL intergenic region of the 26 RABVs were greater than 99.6Â %. Phylogenetic analysis showed that all RABVs clustered with the vampire bat-related cattle RABV strains and that the RABVs were mainly distributed in southern Brazil.\ud
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Conclusions\ud
The findings of the present study suggested that a small population of rabid vampire bats carrying a single RABV strain produced a spatiotemporally restricted outbreak of cattle rabies in southern Brazil.This study was supported in part by a Grant-in-Aid for Scientific Research\ud
(24580453) from the Japan Society for the Promotion of Science and the\ud
Strategic Research Base Development Program, âInternational joint research\ud
and training of young researchers for zoonosis control in a globalized worldâ,\ud
and a matching fund subsidy from the Ministry of Education, Culture, Sports,\ud
Science and Technology of Japan (S0991023 and S1491007)
Strong Universality in Forced and Decaying Turbulence
The weak version of universality in turbulence refers to the independence of
the scaling exponents of the th order strcuture functions from the
statistics of the forcing. The strong version includes universality of the
coefficients of the structure functions in the isotropic sector, once
normalized by the mean energy flux. We demonstrate that shell models of
turbulence exhibit strong universality for both forced and decaying turbulence.
The exponents {\em and} the normalized coefficients are time independent in
decaying turbulence, forcing independent in forced turbulence, and equal for
decaying and forced turbulence. We conjecture that this is also the case for
Navier-Stokes turbulence.Comment: RevTex 4, 10 pages, 5 Figures (included), 1 Table; PRE, submitte
Anomalous scaling, nonlocality and anisotropy in a model of the passively advected vector field
A model of the passive vector quantity advected by a Gaussian
time-decorrelated self-similar velocity field is studied; the effects of
pressure and large-scale anisotropy are discussed. The inertial-range behavior
of the pair correlation function is described by an infinite family of scaling
exponents, which satisfy exact transcendental equations derived explicitly in d
dimensions. The exponents are organized in a hierarchical order according to
their degree of anisotropy, with the spectrum unbounded from above and the
leading exponent coming from the isotropic sector. For the higher-order
structure functions, the anomalous scaling behavior is a consequence of the
existence in the corresponding operator product expansions of ``dangerous''
composite operators, whose negative critical dimensions determine the
exponents. A close formal resemblance of the model with the stirred NS equation
reveals itself in the mixing of operators. Using the RG, the anomalous
exponents are calculated in the one-loop approximation for the even structure
functions up to the twelfth order.Comment: 37 pages, 4 figures, REVTe
Versatile whole-organ/body staining and imaging based on electrolyte-gel properties of biological tissues
Whole-organ/body three-dimensional (3D) staining and imaging have been enduring challenges in histology. By dissecting the complex physicochemical environment of the staining system, we developed a highly optimized 3D staining imaging pipeline based on CUBIC. Based on our precise characterization of biological tissues as an electrolyte gel, we experimentally evaluated broad 3D staining conditions by using an artificial tissue-mimicking material. The combination of optimized conditions allows a bottom-up design of a superior 3D staining protocol that can uniformly label whole adult mouse brains, an adult marmoset brain hemisphere, an ~1 cm3 tissue block of a postmortem adult human cerebellum, and an entire infant marmoset body with dozens of antibodies and cell-impermeant nuclear stains. The whole-organ 3D images collected by light-sheet microscopy are used for computational analyses and whole-organ comparison analysis between species. This pipeline, named CUBIC-HistoVIsion, thus offers advanced opportunities for organ- and organism-scale histological analysis of multicellular systems
Gallbladder adenocarcinoma with human chorionic gonadotropin: a case report and review of literature
<p>Abstract</p> <p>Background</p> <p>The case of adenocarcinoma with human chorionic gonadtropin (HCG), primary in the male gallbladder, is extremely rare. A Medline search has shown only a few similar cases reported.</p> <p>Methods</p> <p>We herein describe a case of primary gallbladder adenocarcinoma associated by ectopic HCG positive tumor cells in a 79-year-old male.</p> <p>Results</p> <p>Pathological examination showed a mixture of moderately and poorly differentiated adenocarcinoma with ectopic HCG and placental alkaline phosphatase (PlAP) in tumor cells, though the increase of serum or urinary HCG secretion was not confirmed. The literatures were also reviewed.</p> <p>Conclusions</p> <p>A case of gallbladder cancer with ectopic HCG production is quite rare in the literature, though many similar cases in other site, especially in GI tract, are reported. Embryological consideration suggests the increased frequency of similar cases more than being thought now.</p
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