The complex architecture of the liv er biliary network represents a structural prerequisite for the formation and secretion of bile as well as excretion of toxic substances through bile ducts. Disorders of the biliary tract affect a significant portion of the worldwide population, often leading to cholestatic liver diseases. Cholestatic liver disease is a condition that results from an impairment of bile formation or bile flow to the gallbladder and duodenum. Cholestasis leads to dramatic changes in biliary tree architecture, worsening liver disease and systemic illness. Recent studies show that the preva lence of cholestatic liver diseases is increasing. The availability of well characterized animal models, as well as development of visualization approaches constitutes a critical asset to develop novel pathogenetic concepts and new treatment strategies., L. Sarnova, M. Gregor., and Obsahuje bibliografii
We give one sufficient and two necessary conditions for boundedness between Lebesgue or Lorentz spaces of several classes of bilinear multiplier operators closely connected with the bilinear Hilbert transform.
A mathematical model of the microalgal growth under various light regimes is required for the optimization of design parameters and operating conditions in a photobioreactor. As its modelling framework, bilinear system with single input is chosen in this paper. The earlier theoretical results on bilinear systems are adapted and applied to the special class of the so-called intermittent controls which are characterized by rapid switching of light and dark cycles. Based on such approach, the following important result is obtained in the present paper: as the light/dark cycle frequency is going to infinity, the value of resulting production rate in the microalgal culture goes to a certain limit value, which depends on average irradiance in the culture only. As a case study, the so-called three-state model of photosynthetic factory, being a simple four-parameter model, is analyzed. The present paper shows various numerical simulations for the model parameters previously published and analyzed experimentally in the biotechnological literature. These simulation results are in a very good qualitative compliance with the well-known flashing light experiments, thereby confirming viability of the approach presented here.
Většina léčiv se po absorpci váže na specifické bílkoviny krevní plazmy. Změny koncentrací plazmatických bílkovin ovlivní množství vázané a volné frakce jednotlivého léčiva a tím i jeho účinek. U starších pacientů se častěji setkáváme s hypalbuminemií danou především malnutricí a malabsorbcí, dále též nižší funkční synteticko u kapacitou jater a častějšími ztrátami proteinů. Tato hypalbuminemie zvyšuje volno u frakci léčiv a tím i účinnost léků, které se váží na albumin. Při chronických zánětech, infekcích, nádorových onemocněních se zvyšuje alfa-1- kyselý glykoprotein a tím se snižuje volná frakce léčiv, jež se váží na tuto bílkovinu akutní fáze. Proto je nutné v indikovaných případech vedle celkové hladiny léčiv v plazmě stanovovat plazmatické koncentrace volných frakcí: u léčiv, kde je známa významná vazba na proteiny a kde je úzké terapeutické rozmezí; u stavů, které vedou k změně hladiny proteinů v plazmě., Following their absorption, the majority of drugs bind to specific plasma proteins. Any change to plasma protein concentrations affects the proportion of bound and free fraction of the drug and thus also its effect. Older patients suffer more frequently from hypo albuminemia, mostly due to malnutrition and malabsorption but also due to lower functional capacity of the liver and recurring protein loses. This hypo albuminemi a increases the free fraction of drugs and thus the efficacy of the drugs that bind to albumin. Alfa-1-acid glycoprotein concentration increases in patients with chronic inflammatory diseases, infections and tumours and this leads to decrease in the free fraction of drugs that bind to this acute phase protein. Consequently, it is necessary in indicated cases to, apart from the total drug plasma concentrations, to also me asure plasma concentrations of free fractions: for drugs that are known to significantly bind to plasma proteins and that have narrow therapeutic index; in patients whose health status could result in plasma proteins levels deviations., Tomáš Adámek, Zoltán Paluch, Štefan Alušík, and Lit.: 16
Five hundred and eight phytosociological relevés from pine forests on sand, calcareous gravel and rock in NE and S Germany were analysed with respect to the frequency of Ellenberg indicator values of vascular plants for nutrients (N). Principal component analysis revealed that after the average nitrogen value (mN), the distribution shape and modality are the second most important sources of variation in the N-spectra of relevés. Of the five spectral types defined by combinations of mN and modality, the unimodal low nutrient type (66.5%) prevailed, followed by bimodal distributions with many indicators for low and high N-supply, with few in the intermediate classes 4 and 5 (27.4%), whereas spectra with a single mode at high (3.9%) or intermediate (2.2%) N- values were rare. Two explanations for the frequent coexistence of vascular plant indicators of N-deficiency with those indicating eutrophication are discussed: (a) Bimodality may be a consequence of the low capacity of pine forests to sequestre the excess input of anthropogenic nitrogen from the atmosphere, and/or (b) the natural dynamics of humus accumulation and mineralization following disturbance. To avoid misinterpretation of mN, inspection of modality of the N-spectra should be standard practice when analysing pine forest or other long-lived vegetation with low N-sequestration. Predominance of high N- over low N-indicators in relevés may be interpreted as a signal of advanced anthropogenic eutrophication, N-saturation and increased risk of N-leaching to groundwater. Bimodal spectra with prevailing deficiency indicators, on the other hand, may be either due to short-term N-release or indicate the beginning of eutrophication.
The unsupervised learning of feature extraction in high-dimesional patterns is a central problem for the neural network approach. Feature extraction is a procedure which maps original patterns into the feature (or factor) space of reduced dimension. In this paper we demonstrate that Hebbian learning in Hopfield-like neural network is a natural procedure for unsupervised learning of feature extraction. Due to this learning, factors become the attractors of network dynamics, hence they can be revealed by the random search. The neurodynamics is analysed by Single-Step approximation which is known [8] to be rather accurate for sparsely encoded Hopfield-network. Thus, the analysis is restricted by the case of sparsely encoded factors. The accuracy of Single-Step approximation is confirmed by Computer simulations.
We deal with a sequencing problem that arises when there are multiple repair actions available to fix a broken man-made system and the true cause of the system failure is uncertain. The system is formally described by a probabilistic model, and it is to be repaired by a sequence of troubleshooting actions designed to identify the cause of the malfunction and fix the system. The task is to find a course of repair with minimal expected cost. We propose a binary integer programming formulation for the problem. This can be used to solve the problem directly or to compute lower bounds of the minimal expected cost using linear programming relaxation. We also present three greedy algorithms for computing initial feasible solutions.
Purpose of this work is to show that the Particle Swarm Optimization Algorithm may improve the results of some well known Machine Learning methods in the resolution of discrete classification problems. A binary version of the PSO algorithm is used to obtain a set of logic rules that map binary masks (that represent the attribute values), to the available classes. This algorithm has been tested both in a single pass mode and in an iterated mode on a well-known set of problems, called the MONKS set, to compare the PSO results against the results reported for that domain by the application of some common Machine Learning algorithms.
We introduce the function Z(x;ξ,ν):=∫x−∞φ(t−ξ)⋅Φ(νt)dt, where φ and Φ are the pdf and cdf of N(0,1), respectively. We derive two recurrence formulas for the effective computation of its values. We show that with an algorithm for this function, we can efficiently compute the second-order terms of Bonferroni-type inequalities yielding the upper and lower bounds for the distribution of a max-type binary segmentation statistic in the case of small samples (where asymptotic results do not work), and in general for max-type random variables of a certain type. We show three applications of the method -- (a) calculation of critical values of the segmentation statistic, (b) evaluation of its efficiency and (c) evaluation of an estimator of a point of change in the mean of time series.
K běžnému bio-psycho-sociálnímu modelu zdraví a nem oci, přidává autor ve své úvaze filosofický aspekt. Klade si otázku, proč vlastně k ritizujeme Descarta za neřešitelnou karteziánskou podvojnost těla a duše, když jde skut ečně o dvě odlišné úrovně lidského žití? K plnému porozumění člověka, jenž je charakte rizován autopoezou a svobodnou volbou, patří i pochopení a smysl, čemuž odpovídají konotativní teorie. Zde se hodí k poznání vnitřního světa a chování druhého empatie, příběhy, obrazy, přirovnání a metafory, tak je třeba chápat i psychoanalytické te orie a interpretace., The author, in his essay, adds a philosophical asp ect to the current bio-psycho-social model of health and illness. The question “Why is D escartes criticized for intractable Cartesian duality of body and soul when it is reall y two different levels of human life?” is being raised. Both understanding and sense are i nvolved in full understanding of a human being, who is characterized by autopoiesis an d free choice, with which connotative theories correspond. Empathy, stories, images, similes and metaphors suit to the knowledge of the inner world and the behavio ur of the others. It is to be even understood psychoanalytic theories and interpretati ons., Poněšický J., and Literatura