1,224 research outputs found
Evolutionary trees: an integer multicommodity max-flow-min-cut theorem
In biomathematics, the extensions of a leaf-colouration of a binary tree to the whole vertex set with minimum number of colour-changing edges are extensively studied. Our paper generalizes the problem for trees; algorithms and a Menger-type theorem are presented. The LP dual of the problem is a multicommodity flow problem, for which a max-flow-min-cut theorem holds. The problem that we solve is an instance of the NP-hard multiway cut problem
Immunofluorescence staining of paraffin sections: creating DAB staining like virtual digital images using CMYK color conversion
Crystal violet treatment of formalin fixed paraffin embedded tissue slides greatly reduces the endogenous autofluorescence, and allows immunofluorescence (IF) staining with FITC or Alexa488 conjugated antibodies. Using cold CCD camera to capture the fluorescence images makes this staining method very sensitive. Here we show that combination of IF with the simultaneous recording of crystal violet induced red and Hoechst 33258 induced blue fluorescence permits the localization of the IF signal over a cytoplasmic: nuclear red:blue stain that visualizes the microscopic anatomy of the underlying tissue. To make the visual interpretation of the IF staining easier for microscopists, who are used to DAB staining over weak hematoxilin-eosin background, we created a simple color conversion procedure that turns the captured three-color fluorescence RGB (red, green, blue) images over a black background into four color CMYK (cyan, magenta, yellow, key color (black)) images.Окраска кристаллическим фиолетовым парафиновых срезов, полученных из ткани, фиксированной в формалине, значительно
уменьшает явления аутофлуоресценции и обеспечивает иммунофлуоресцентную (ИФ) окраску антителами, конъюгированными
сFITC или Aleхa-488. Использование CCD-камер для регистрации флуоресцентных изображений делает этот метод очень
чувствительным. Наша цель — разработать метод трансформации RGB (red, green, blue) — флуоресцентных изображений в
CMYC (cyan, magenta, yellow, key color (black) ) изображения. Показано, что комбинация ИФ с одновременной регистрацией
красной и голубой флуоресценции, индуцированной соответственно кристаллическим фиолетовым и Hoechst33258, позволяет
определять ИФ-сигнал как цитоплазматично-ядерное красно-голубое окрашивание, которое визуализирует морфологические
особенности прилегающей ткани. Для упрощения интерпретации ИФ-окраски патологами, привыкшими к окрашиванию
ДАБ на фоне гематоксилин-эозина, нами была создана технология простого цветового перехода, который превращает зарегистрированные
трехцветные RGB-флуоресцентные изображения на черном фоне в четырехцветные CMYC-изображения
на белом фоне, используя программы работы с изображениями
A Test of Independence in Two-Way Contingency Tables Based on Maximal Correlation
Cataloged from PDF version of article.Maximal correlation has several desirable properties as a measure of dependence, including the fact that it vanishes if and only if the variables are independent. Except for a few special cases, it is hard to evaluate maximal correlation explicitly. We focus on two-dimensional contingency tables and discuss a procedure for estimating maximal correlation, which we use for constructing a test of independence. We compare the maximal correlation test with other tests of independence by Monte Carlo simulations. When the underlying continuous variables are dependent but uncorrelated, we point out some cases for which the new test is more powerful
Differential Functional Connectivity of Rostral Anterior Cingulate Cortex During Emotional Interference
The rostral-ventral subdivision of the anterior cingulate cortex (rACC) plays a key role in the regulation of emotional processing. Although rACC has strong anatomical connections with anterior insular cortex (AIC), amygdala, prefrontal cortex and striatal brain regions, it is unclear whether the functional connectivity of rACC with these regions changes when regulating emotional processing. Furthermore, it is not known whether this connectivity changes with deficits in emotion regulation seen in different kinds of anxiety and depression. To address these questions regarding rACC functional connectivity, non-patients high in self-reported anxious apprehension (AP), anxious arousal (AR), anhedonic depression (AD) or none (CON) indicated the ink color of pleasant, neutral and unpleasant words during functional magnetic resonance imaging. While ignoring task-irrelevant unpleasant words, AD and CON showed an increase in the functional connectivity of rACC with AIC, putamen, caudate and ventral pallidum. There was a decrease in this connectivity in AP and AR, with AP showing greater reduction than AR. These findings provide support for the role of rACC in integrating interoceptive, emotional and cognitive functions via interactions with insula and striatal regions during effective emotion regulation in healthy individuals and a failure of this integration that may be specific to anxiety, particularly AP
Activity of 50 Long-Period Comets Beyond 5.2 AU
Remote investigations of the ancient solar system matter has been
traditionally carried out through the observations of long-period (LP) comets
that are less affected by solar irradiation than the short-period counterparts
orbiting much closer to the Sun. Here we summarize the results of our
decade-long survey of the distant activity of LP comets. We found that the most
important separation in the dataset is based on the dynamical nature of the
objects. Dynamically new comets are characterized by a higher level of activity
on average: the most active new comets in our sample can be characterized by
afrho values >3--4 higher than that of our most active returning comets. New
comets develop more symmetric comae, suggesting a generally isotropic outflow.
Contrary to this, the coma of recurrent comets can be less symmetrical,
ocassionally exhibiting negative slope parameters, suggesting sudden variations
in matter production. The morphological appearance of the observed comets is
rather diverse. A surprisingly large fraction of the comets have long, teniouos
tails, but the presence of impressive tails does not show a clear correlation
with the brightness of the comets.Comment: 21 pages, 4 figures, accepted for publication in A
A More Flexible Realization of The SUNRED Algorithm
The high dissipation of integrated circuits means serious problems for packaging and for the design of complex electronic systems. Another important area of research and development nowadays is the integration of sensors and micromechanical systems (MEMS) with electronic circuits. The original Successive Node Reduction (SUNRED) algorithm handles well the first area but require revision for electro-thermal or mechanical fields. As a first stage the updated algorithm is able to solve thermal fields as the original, but with the application of flexible boundary connection handling, it can be much faster than the original. By using object-oriented program model the algorithm can handle non-rectangular 3D fields, and SUNRED mesh resolution is arbitrary, not have to be the power of two anymore
Differential Functional Connectivity of Rostral Anterior Cingulate Cortex During Emotional Interference
The rostral-ventral subdivision of the anterior cingulate cortex (rACC) plays a key role in the regulation of emotional processing. Although rACC has strong anatomical connections with anterior insular cortex (AIC), amygdala, prefrontal cortex and striatal brain regions, it is unclear whether the functional connectivity of rACC with these regions changes when regulating emotional processing. Furthermore, it is not known whether this connectivity changes with deficits in emotion regulation seen in different kinds of anxiety and depression. To address these questions regarding rACC functional connectivity, non-patients high in self-reported anxious apprehension (AP), anxious arousal (AR), anhedonic depression (AD) or none (CON) indicated the ink color of pleasant, neutral and unpleasant words during functional magnetic resonance imaging. While ignoring task-irrelevant unpleasant words, AD and CON showed an increase in the functional connectivity of rACC with AIC, putamen, caudate and ventral pallidum. There was a decrease in this connectivity in AP and AR, with AP showing greater reduction than AR. These findings provide support for the role of rACC in integrating interoceptive, emotional and cognitive functions via interactions with insula and striatal regions during effective emotion regulation in healthy individuals and a failure of this integration that may be specific to anxiety, particularly AP
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