Calculations of K−K^- nuclear quasi-bound states based on chiral meson-baryon amplitudes

In-medium ${\bar K}N$ scattering amplitudes developed within a new chirally motivated coupled-channel model due to Cieply and Smejkal that fits the recent SIDDHARTA kaonic hydrogen 1s level shift and width are used to construct $K^-$ nuclear potentials for calculations of $K^-$ nuclear quasi-bound states. The strong energy and density dependence of scattering amplitudes at and near threshold leads to $K^-$ potential depths $-Re V_K \approx 80 -120$ MeV. Self-consistent calculations of all $K^-$ nuclear quasi-bound states, including excited states, are reported. Model dependence, polarization effects, the role of p-wave interactions, and two-nucleon $K^-NN\rightarrow YN$ absorption modes are discussed. The $K^-$ absorption widths $\Gamma_K$ are comparable or even larger than the corresponding binding energies $B_K$ for all $K^-$ nuclear quasi-bound states, exceeding considerably the level spacing. This discourages search for $K^-$ nuclear quasi-bound states in any but lightest nuclear systems.Comment: 12 pages, 11 figure

In-medium antikaon and eta-meson interactions and bound states

The role played by subthreshold meson-baryon dynamics is demonstrated in kaonic-atom, Kbar-nuclear and eta-nuclear bound-state calculations within in-medium models of Kbar-N and eta-N interactions. New analyses of kaonic atom data reveal appreciable multi-nucleon contributions. Calculations of eta-nuclear bound states show, in particular, that the eta-N scattering length is not a useful indicator of whether or not eta mesons bind in nuclei nor of the widths anticipated for such states.Comment: invited talk at the Second International Symposium on Mesic Nuclei, Cracow, Sept.22-24 2013, matches published versio

Preparing to coming teachers of physics in The Czech Republic

katedra: KFY

PREDICTIVE FUNCTIONAL CONTROLLER – SIMPLE PREDICTIVE CONTROLLER APPLICATION

Článek pojednává o regulaci reálného zařízení jednoduchým a výpočetně nenáročným prediktivním regulátorem PFC (Predictive Functional Controller). Reálnou soustavu v našem případě představuje laboratorní model Hydraulickopneumatická soustava. Programově je regulace zajišťována z prostředí MATLAB Simulink.Paper deals with real system control by a simple predictive controller (Predictive Functional Controller). The real plant is a laboratory model of Hydraulicpneumatic system. Process control is realized in the program MATLAB Simulink

Determination of the Strength of Adhesion between Lipid Vesicles

A commonly used method to determine the strength of adhesion between adhering lipid vesicles is measuring their effective contact angle from experimental images. The aim of this paper is to estimate the interobserver variations in vesicles effective contact angle measurements and to propose a new method for estimating the strength of membrane vesicle adhesion. Theoretical model shows for the old and for the new measure a monotonic dependence on the strength of adhesion. Results obtained by both measuring techniques show statistically significant correlation and high interobserver reliability for both methods. Therefore the conventional method of measuring the effective contact angle gives qualitatively relevant results as the measure of the lipid vesicle adhesion. However, the new measuring technique provides a lower variation of the measured values than the conventional measures using the effective contact angle. Moreover, obtaining the adhesion angle can be automatized more easily than obtaining the effective contact angle

In-medium antikaon interactions and bound states

Correct treatment of subthreshold Kbar-N dynamics is mandatory in kaonic-atom and Kbar-nuclear bound-state calculations, as demonstrated by using in-medium chirally-based models of Kbar-N interactions. Recent studies of kaonic-atom data reveal appreciable multi-nucleon contributions. Kbar-nuclear widths larger than 50 MeV are anticipated.Comment: Invited talk by A. Gal in MESON 2014, Cracow, May-June 2014, written up for EPJ Web of Conferences, updating an earlier Conference Proceedings (arXiv:1402.3778

Dynamics of digestive proteolytic system during blood feeding of the hard tick Ixodes ricinus

<p>Abstract</p> <p>Background</p> <p>Ticks are vectors of a wide variety of pathogens causing severe diseases in humans and domestic animals. Intestinal digestion of the host blood is an essential process of tick physiology and also a limiting factor for pathogen transmission since the tick gut represents the primary site for pathogen infection and proliferation. Using the model tick <it>Ixodes ricinus</it>, the European Lyme disease vector, we have previously demonstrated by genetic and biochemical analyses that host blood is degraded in the tick gut by a network of acidic peptidases of the aspartic and cysteine classes.</p> <p>Results</p> <p>This study reveals the digestive machinery of the <it>I. ricinus </it>during the course of blood-feeding on the host. The dynamic profiling of concentrations, activities and mRNA expressions of the major digestive enzymes demonstrates that the <it>de novo </it>synthesis of peptidases triggers the dramatic increase of the hemoglobinolytic activity along the feeding period. Overall hemoglobinolysis, as well as the activity of digestive peptidases are negligible at the early stage of feeding, but increase dramatically towards the end of the slow feeding period, reaching maxima in fully fed ticks. This finding contradicts the established opinion that blood digestion is reduced at the end of engorgement. Furthermore, we show that the digestive proteolysis is localized intracellularly throughout the whole duration of feeding.</p> <p>Conclusions</p> <p>Results suggest that the egressing proteolytic system in the early stage of feeding and digestion is a potential target for efficient impairment, most likely by blocking its components via antibodies present in the host blood. Therefore, digestive enzymes are promising candidates for development of novel 'anti-tick' vaccines capable of tick control and even transmission of tick-borne pathogens.</p