78 research outputs found
THE STATE OF IMMUNE SYSTEM IN OLD-AGED PATIENTS WITH CHRONIC GENERALIZED PERIODONTITIS AND CORONARY HEART DISEASE
Chronic generalized periodontitis in the old-aged patients with coronary heart disease is accompanied by an imbalance in the content of some components of complement, hyperproduction s.IgA, IgG, IgM, elevated concentration of IL-8, IL-1α and low content of IL-4, high levels of the antibodies to HSP-70 in saliva and blood. Local anti-inflammatory therapy of chronic periodontitis does not restore normal immunity status. These data are pathogenic substantiation of the including immunocorrective therapies in to conventional treatment at periodontitis
Comparative analysis of cytosolic and mitochondrial ATP synthesis in embryonic and postnatal hippocampal neuronal cultures
ATP in neurons is commonly believed to be synthesized mostly by mitochondria via oxidative phosphorylation. Neuronal mitochondria have been studied primarily in culture, i.e., in neurons isolated either from embryos or from neonatal pups. Although it is generally assumed that both embryonic and postnatal cultured neurons derive their ATP from mitochondrial oxidative phosphorylation, this has never been tested experimentally. We expressed the FRET-based ATP sensor AT1.03 in cultured hippocampal neurons isolated either from E17 to E18 rat embryos or from P1 to P2 rat pups and monitored [ATP]c simultaneously with mitochondrial membrane potential ΔΨm; TMRM) and NAD(P)H autofluorescence. In embryonic neurons, transient glucose deprivation induced a near-complete decrease in [ATP]c, which was partially reversible and was accelerated by inhibition of glycolysis with 2-deoxyglucose. In the absence of glucose, pyruvate did not cause any significant increase in [ATP]c in 84% of embryonic neurons, and inhibition of mitochondrial ATP synthase with oligomycin failed to decrease [ATP]c. Moreover, ΔΨm was significantly reduced by oligomycin, indicating that mitochondria acted as consumers rather than producers of ATP in embryonic neurons. In sharp contrast, in postnatal neurons pyruvate added during glucose deprivation significantly increased [ATP]c (by 54 ± 8%), whereas oligomycin induced a sharp decline in [ATP]c and increased ΔΨm. These signs of oxidative phosphorylation were observed in all tested P1-P2 neurons. Measurement of ΔΨm with the potential-sensitive probe JC-1 revealed that neuronal mitochondrial membrane potential was significantly reduced in embryonic cultures compared to the postnatal ones, possibly due to increased proton permeability of inner mitochondrial membrane. We conclude that, in embryonic, but not postnatal neuronal cultures, ATP synthesis is predominantly glycolytic and the oxidative phosphorylation-mediated synthesis of ATP by mitochondrial F1Fo-ATPase is insignificant. © 2013 Surin, Khiroug, Gorbacheva, Khodorov, Pinelis and Khiroug.Peer reviewe
Exponential and moment inequalities for U-statistics
A Bernstein-type exponential inequality for (generalized) canonical
U-statistics of order 2 is obtained and the Rosenthal and Hoffmann-J{\o}rgensen
inequalities for sums of independent random variables are extended to
(generalized) U-statistics of any order whose kernels are either nonnegative or
canonicalComment: 22 page
The Bivariate Normal Copula
We collect well known and less known facts about the bivariate normal
distribution and translate them into copula language. In addition, we prove a
very general formula for the bivariate normal copula, we compute Gini's gamma,
and we provide improved bounds and approximations on the diagonal.Comment: 24 page
Clades and clans: a comparison study of two evolutionary models
The Yule-Harding-Kingman (YHK) model and the proportional to distinguishable
arrangements (PDA) model are two binary tree generating models that are widely
used in evolutionary biology. Understanding the distributions of clade sizes
under these two models provides valuable insights into macro-evolutionary
processes, and is important in hypothesis testing and Bayesian analyses in
phylogenetics. Here we show that these distributions are log-convex, which
implies that very large clades or very small clades are more likely to occur
under these two models. Moreover, we prove that there exists a critical value
for each such that for a given clade with size ,
the probability that this clade is contained in a random tree with leaves
generated under the YHK model is higher than that under the PDA model if
, and lower if . Finally, we extend our results
to binary unrooted trees, and obtain similar results for the distributions of
clan sizes.Comment: 21page
Towards Machine Wald
The past century has seen a steady increase in the need of estimating and
predicting complex systems and making (possibly critical) decisions with
limited information. Although computers have made possible the numerical
evaluation of sophisticated statistical models, these models are still designed
\emph{by humans} because there is currently no known recipe or algorithm for
dividing the design of a statistical model into a sequence of arithmetic
operations. Indeed enabling computers to \emph{think} as \emph{humans} have the
ability to do when faced with uncertainty is challenging in several major ways:
(1) Finding optimal statistical models remains to be formulated as a well posed
problem when information on the system of interest is incomplete and comes in
the form of a complex combination of sample data, partial knowledge of
constitutive relations and a limited description of the distribution of input
random variables. (2) The space of admissible scenarios along with the space of
relevant information, assumptions, and/or beliefs, tend to be infinite
dimensional, whereas calculus on a computer is necessarily discrete and finite.
With this purpose, this paper explores the foundations of a rigorous framework
for the scientific computation of optimal statistical estimators/models and
reviews their connections with Decision Theory, Machine Learning, Bayesian
Inference, Stochastic Optimization, Robust Optimization, Optimal Uncertainty
Quantification and Information Based Complexity.Comment: 37 page
Scaling properties of protein family phylogenies
One of the classical questions in evolutionary biology is how evolutionary
processes are coupled at the gene and species level. With this motivation, we
compare the topological properties (mainly the depth scaling, as a
characterization of balance) of a large set of protein phylogenies with a set
of species phylogenies. The comparative analysis shows that both sets of
phylogenies share remarkably similar scaling behavior, suggesting the
universality of branching rules and of the evolutionary processes that drive
biological diversification from gene to species level. In order to explain such
generality, we propose a simple model which allows us to estimate the
proportion of evolvability/robustness needed to approximate the scaling
behavior observed in the phylogenies, highlighting the relevance of the
robustness of a biological system (species or protein) in the scaling
properties of the phylogenetic trees. Thus, the rules that govern the
incapability of a biological system to diversify are equally relevant both at
the gene and at the species level.Comment: Replaced with final published versio
Universal scaling in the branching of the Tree of Life
Understanding the patterns and processes of diversification of life in the
planet is a key challenge of science. The Tree of Life represents such
diversification processes through the evolutionary relationships among the
different taxa, and can be extended down to intra-specific relationships. Here
we examine the topological properties of a large set of interspecific and
intraspecific phylogenies and show that the branching patterns follow
allometric rules conserved across the different levels in the Tree of Life, all
significantly departing from those expected from the standard null models. The
finding of non-random universal patterns of phylogenetic differentiation
suggests that similar evolutionary forces drive diversification across the
broad range of scales, from macro-evolutionary to micro-evolutionary processes,
shaping the diversity of life on the planet.Comment: 6 pages + 19 of Supporting Informatio
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