Differential cross sections for single ionization of Li in collisions with fast protons and O8+^{8+} ions

We study the process of single ionization of Li in collisions with H$^+$ and O$^{8+}$ projectile ions at 6 MeV and 1.5-MeV/amu impact energies, respectively. Using the frameworks of the independent-electron model and the impact parameter picture, fully (FDCS) and doubly (DDCS) differential cross sections are evaluated in the continuum distorted-wave with eikonal initial-state approximation. Comparisons are made with the recent measurements of LaForge \textit{et al} [J. Phys. B \textbf{46} 031001 (2013)] for the DDCS and Hubele \textit{et al} [Phys. Rev. Lett. \textbf{110} 133201 (2013)] for the FDCS, respectively. For O$^{8+}$ impact inclusion of the heavy particle (NN) interaction in the calculations is crucial and effects of polarization due to the presence of the projectile ion have also to be taken into account for getting very good agreement with the measured data. Our calculation reproduces the satellite peak structure seen in the FDCS for the Li(2s) measurement, which we explain as being formed by a combination of the binary and NN interactions

Hierarchical coordinate systems for understanding complexity and its evolution with applications to genetic regulatory networks

Original article can be found at : http://www.mitpressjournals.org/ Copyright MIT PressBeyond complexity measures, sometimes it is worth in addition investigating how complexity changes structurally, especially in artificial systems where we have complete knowledge about the evolutionary process. Hierarchical decomposition is a useful way of assessing structural complexity changes of organisms modeled as automata, and we show how recently developed computational tools can be used for this purpose, by computing holonomy decompositions and holonomy complexity. To gain insight into the evolution of complexity, we investigate the smoothness of the landscape structure of complexity under minimal transitions. As a proof of concept, we illustrate how the hierarchical complexity analysis reveals symmetries and irreversible structure in biological networks by applying the methods to the lac operon mechanism in the genetic regulatory network of Escherichia coli.Peer reviewe

Exploring the concept of interaction computing through the discrete algebraic analysis of the Belousov–Zhabotinsky reaction

Interaction computing (IC) aims to map the properties of integrable low-dimensional non-linear dynamical systems to the discrete domain of finite-state automata in an attempt to reproduce in software the self-organizing and dynamically stable properties of sub-cellular biochemical systems. As the work reported in this paper is still at the early stages of theory development it focuses on the analysis of a particularly simple chemical oscillator, the Belousov-Zhabotinsky (BZ) reaction. After retracing the rationale for IC developed over the past several years from the physical, biological, mathematical, and computer science points of view, the paper presents an elementary discussion of the Krohn-Rhodes decomposition of finite-state automata, including the holonomy decomposition of a simple automaton, and of its interpretation as an abstract positional number system. The method is then applied to the analysis of the algebraic properties of discrete finite-state automata derived from a simplified Petri net model of the BZ reaction. In the simplest possible and symmetrical case the corresponding automaton is, not surprisingly, found to contain exclusively cyclic groups. In a second, asymmetrical case, the decomposition is much more complex and includes five different simple non-abelian groups whose potential relevance arises from their ability to encode functionally complete algebras. The possible computational relevance of these findings is discussed and possible conclusions are drawn

Haematopinus Infestations and Mycoplasma Infections of Water Buffalo (Bubalus bubalis) Herds in National Parks of Hungary

The biology, epidemiology and pathology of sucking louse infestation and Mycoplasma infection of water buffalo (Bubalus bubalis) herds in Hungarian national parks were studied between 19 December 2011 and 4 May 2012. A total of 333 water buffaloes were examined in buffalo stocks of the Balaton Uplands, Fertő-Hanság and Kiskunság National Parks. The objective was to determine the prevalence and rate of sucking louse infestation and mycoplasma infection among water buffaloes. Always an area of identical size (2 cm2) was examined on the right or left side of the middle part of the animals' neck. A total of 3106 eggs, 10 nymphs and 105 adults of the sucking louse Haematopinus tuberculatus were identified with the help of a Conrad USB microscopic camera and a Wild-Leitz-Leica M420 photomacroscope. The data were evaluated using the Quantitative Parasitology software QP 3.0. The prevalence of mycoplasmas was determined in 20 randomly selected buffaloes of two national parks with the help of sterile nasal and vaginal transport swabs (Sarstedt). All of the 10 nasal swabs collected from buffaloes in the Balaton Uplands National Park contained Mycoplasma bovirhinis and three swab samples yielded M. bovis as well. Mycoplasma bovirhinis was cultured from 8 out of 10 swabs taken from the vagina, and three vaginal samples also yielded M. bovis. Similar results were obtained by testing samples collected from buffaloes in the Kiskunság National Park (Mórahalom). All ten nasal swab samples yielded M. bovirhinis. From two samples a mixture of M. bovirhinis and M. bovis was cultured. Nine out of the 10 vaginal swabs yielded M. bovirhinis while two showed a combined infection by M. bovis and M. bovirhinis