Predator population depending on lemming cycles

In this paper, a Langevin equation for predator population with multiplicative correlated noise is analyzed. The noise source, which is a nonnegative random pulse noise with regulated periodicity, corresponds to the prey population cycling. The increase of periodicity of noise affects the average predator density at the stationary state

Protein-DNA interactions: statistical analysis of interatomic contacts in major and minor grooves

The interactions between protein and DNA in essence underlie all processes in a living cell. Understanding the principles of specific recognition of DNA sites will open the way to understand how these processes are controlled and to interfere in their operation. In the paper we studied contacts between the protein and DNA at the atomic level in the structures of all the 3 518 protein­DNA complexes available in PDB by the Voronoi–Delaunay tessellation method. The method unambiguously defines contacts between atoms without any parameters, and characterizes each contact by the distance between atoms and the contact area, which is determined by the corresponding face of the Voronoi polyhedron. It was shown that most contacts are formed between the protein atoms and the sugarphosphate backbone of the DNA (72.9 %). The contact with the atoms of the nucleic bases emerging into the grooves of DNA is 17.0 % for a major groove and 10.1 % for all atomic contacts for a minor groove. Totally, the interaction between protein atoms and nucleic base atoms accounts for 27.1 % of all contacts. Analysis of the accessible surface area of atoms in the major and the minor grooves showed a correlation with the number of contacts (coefficient of linear correlation 0.94 and 0.93, respectively), however, nucleic acid atoms forming hydrogen bonds make contacts more often than may be expected from statistical considerations. It was shown that conformationally stable peptides occur sometimes in the binding regions with DNA. Analysis of the residues in a predefined conformation in 3 518 protein­DNA complexes revealed 159 amino acid residues in a predefined β­bend type I conformation, 15 residues in the conformation of β­bend type I’, and 6 residues in the conformation of β­bend type II. No residues in the conformation of β­bend type II’ were found. Analysis of contacts showed that such residues virtually do not form contacts with DNA. Contacts with nucleic base atoms are found only in the two homologous structures 3qea and 3qe9, where threonine atoms form contacts with atoms of nucleotide bases of the AT­pair

Analysis of Information Security Threats for Developing DLP-systems

The motivation of investigation is explained by the problem of keeping organisations’ information and private ones secure. One reason for this is insufficiency of information protection systems, and another – vulnerability in such kind of systems. The article is devoted to defining and analyzing the types and sources of information security threats for an automated system. It can be useful for developing the model method, having the purpose of detecting and further preventing of hazards. The safeness of Data Leak Prevention (DLP) system itself is also under investigation. The analysis was carried out by an expert method with system analysis. A DLP system was considered, on the one hand, as a way of information protection to prevent information leakage, and on the other hand, as an object of protection which is vulnerable to threats of information security. The presented threat model includes the sources of threats, divided into three large groups: anthropogenic, technogenic and spontaneous; and types of threats: intentional and unintentional

Technologie zorientowane na Toyotę jako narzędzia zarządzania ekologicznego dla przedsiębiorstw transportowych

The authors studied the managing principles for running a modern transport enterprise. In research process the experience and results of foreign scientists were analyzed and different company management tools were compared. Special focus is given to ecological approach due to crucial relevance of environmental problem. In this connection, the importance of Toyota technologies and BOST method, created by a Polish scientist Borkowski S., is emphasized. The research has been carried out for transport enterprises, which are high-demand in any country of the world. The case study is the largest Russian railway company - JSC Russian Railways. As the result, the guidelines to the improvement of management principles for JSC Russian Railways have been developed.Autorzy badali zasady zarządzania związane z prowadzeniem nowoczesnego przedsiębiorstwa transportowego. W procesie badawczym przeanalizowano doświadczenie i wyniki zagranicznych naukowców i porównano różne narzędzia do zarządzania firmą. Szczególną uwagę poświęca się podejściu biologicznemu ze względu na kluczowe znaczenie dla problemu ochrony środowiska. W tym względzie podkreślone jest znaczenie technologii Toyota i metody BOST, stworzonej przez polskiego naukowca S. Borkowskiego. Badania przeprowadzone zostały dla przedsiębiorstw transportowych, które są dużym zapotrzebowaniem w każdym kraju na świecie. Studium przypadku to największa rosyjska firma kolejowa - JSC Rosyjskie Koleje. W efekcie, opracowane zostały wytyczne do poprawy zasad gospodarowania dla Rosyjskich Koleji JSC