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

Evaluating the use of alternative normalization approaches on SARS-CoV-2 concentrations in wastewater: experiences from two catchments in northern Sweden

The detection of SARS-CoV-2 RNA fragments in feces has paved the way for wastewater-based epidemiology to contribute to COVID-19 mitigation measures, with its use in a public health context still under development. As a way to facilitate data comparison, this paper explores the impact of using alternative normalization approaches (wastewater treatment plant (WWTP) flow, population size estimates (derived using total nitrogen (TN), total phosphorus (TP) and census data) and pepper mild mottle virus (PMMoV)) on the relationship between viral wastewater data and clinical case numbers. Influent wastewater samples were collected at two WWTPs in Luleå, northern Sweden, between January and March 2021. TN and TP were determined upon sample collection, with RNA analysis undertaken on samples after one freeze–thaw cycle. The strength of the correlation between normalization approaches and clinical cases differed between WWTPs (r ≤ 0.73 or r ≥ 0.78 at the larger WWTP and r ≤ 0.23 or r ≥ 0.43 at the smaller WWTP), indicating that the use of wastewater as an epidemiological tool is context-dependent. Depending on the normalization approach utilized, time-shifted analyses imply that wastewater data on SARS-CoV-2 RNA pre-dated a rise in clinical cases by 0–2 and 5–8 days, for the lager and smaller WWTPs, respectively. SARS-CoV-2 viral loads normalized to the population or PMMoV better reflect the number of clinical cases when comparing wastewater data between sewer catchments

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

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

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

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