Dimension on Discrete Spaces

In this paper we develop some combinatorial models for continuous spaces. In this spirit we study the approximations of continuous spaces by graphs, molecular spaces and coordinate matrices. We define the dimension on a discrete space by means of axioms, and the axioms are based on an obvious geometrical background. This work presents some discrete models of n-dimensional Euclidean spaces, n-dimensional spheres, a torus and a projective plane. It explains how to construct new discrete spaces and describes in this connection several three-dimensional closed surfaces with some topological singularities It also analyzes the topology of (3+1)-spacetime. We are also discussing the question by R. Sorkin [19] about how to derive the system of simplicial complexes from a system of open covering of a topological space S.Comment: 16 pages, 8 figures, Latex. Figures are not included, available from the author upon request. Preprint SU-GP-93/1-1. To appear in "International Journal of Theoretical Physics

Phase transformation B1 to B2 in TiC, TiN, ZrC and ZrN under pressure

Phase stability of various phases of MX (M = Ti, Zr; X = C, N) at equilibrium and under pressure is examined based on first-principles calculations of the electronic and phonon structures. The results reveal that all B1 (NaCl-type) MX structures undergo a phase transition to the B2-structures under high pressure in agreement with the previous total-energy calculations. The B1-MX structures are dynamically stable under very high pressure (210-570 GPa). The pressure-induced B2 (CsCl-type) MC phases are dynamically unstable even at high pressures, and TiN and ZrN are found to crystallize with the B2-structure only at pressures above 55 GPa. The first-order B1-to-B2 phase transition in these nitrides is not related to the softening of phonon modes, and the dynamical instability of B2-MX is associated with a high density of states at the Fermi level.Comment: 9 pages, 4 figure

High-Resolution Three-Dimensional NMR Structure Of The KRAS Proto-Oncogene Promoter Reveals Key Features Of A G-Quadruplex Involved In Transcriptional Regulation

Non-canonical base pairing within guanine-rich DNA and RNA sequences can produce G-quartets, whose stacking leads to the formation of a G-quadruplex (G4). G4s can coexist with canonical duplex DNA in the human genome and have been suggested to suppress gene transcription, and much attention has therefore focused on studying G4s in promotor regions of disease-related genes. For example, the human KRAS proto-oncogene contains a nuclease-hypersensitive element located upstream of the major transcription start site. The KRAS nuclease-hypersensitive element (NHE) region contains a G-rich element (22RT; 5′-AGGGCGGTGTGGGAATAGGGAA-3′) and encompasses a Myc-associated zinc finger-binding site that regulates KRAS transcription. The NEH region therefore has been proposed as a target for new drugs that control KRAS transcription, which requires detailed knowledge of the NHE structure. In this study, we report a high-resolution NMR structure of the G-rich element within the KRAS NHE. We found that the G-rich element forms a parallel structure with three G-quartets connected by a four-nucleotide loop and two short one-nucleotide double-chain reversal loops. In addition, a thymine bulge is found between G8 and G9. The loops of different lengths and the presence of a bulge between the G-quartets are structural elements that potentially can be targeted by small chemical ligands that would further stabilize the structure and interfere or block transcriptional regulators such as Myc-associated zinc finger from accessing their binding sites on the KRAS promoter. In conclusion, our work suggests a possible new route for the development of anticancer agents that could suppress KRAS expression

Загальна хімічна технологія. Лабораторний практикум : методичні вказівки до вивчення курсу. Ч.1

Методичний посібник містить робочу програму курсу, методичні розробки чотирьох лабораторних робіт, що виконуються в першому семестрі. Для самоконтролю при підготовці до лабораторних занять подаються окремі теоретичні питання та ряд вправ для самостійного розв’язування. Для студентів хімічного факультету (напрям підготовки: 6.051301 – “Хімічна технологія”) денної форми навчання, викладачів та лаборантів, які проводять лабораторні й семінарські заняття

Загальна хімічна технологія : методичні вказівки до вивчення курсу. Ч. 3

Методичний посібник містить приклад розрахунку матеріального балансу печі для випалювання колчедану. Для студентів хімічного факультету (напрям підготовки: 6.051301 – “Хімічна технологія”) денної форми навчання

Загальна хімічна технологія. Лабораторний практикум : методичні вказівки до вивчення курсу. Ч. 2

Методичний посібник містить план лабораторного практикуму, методичні розробки лабораторних робіт, що виконуються в другому семестрі. Для самоконтролю при підготовці до лабораторних занять подаються окремі теоретичні питання та ряд вправ для самостійного розв’язування. Для студентів хімічного факультету (напрям підготовки: 6.051301 – “Хімічна технологія”) денної форми навчання, викладачів та лаборантів, які проводять лабораторні й семінарські заняття

Development of personnel technologies in the customs system of the Russian Federation

In the paper, the authors study the main reasons for introducing economic sanctions against the Russian Federation and how to counteract them. At the same time, the current situation requires intensified development of the international business to modernize the Russian economy. For this, it has become imperative to understand the role and place of the customs of the Russian Federation in this process and to further improve the approaches to staffing a federal executive body – the Federal Customs Service (FCS of Russia) in terms of selecting highly skilled personnel. In the end, a unified methodology for evaluating candidates taking civil service postsin the customs bodies is propose

Cosmological scalar fields that mimic the ΛCDM\Lambda CDM cosmological model

We look for cosmologies with a scalar field (dark energy without cosmological constant), which mimic the standard $\Lambda CDM$ cosmological model yielding exactly the same large-scale geometry described by the evolution of the Hubble parameter (i.e. photometric distance and angular diameter distance as functions on $z$). Asymptotic behavior of the field solutions is studied in the case of spatially flat Universe with pressureless matter and separable scalar field Lagrangians (power-law kinetic term + power-law potential). Exact analytic solutions are found in some special cases. A number of models have the field solutions with infinite behavior in the past or even singular behavior at finite redshifts. We point out that introduction of the cosmological scalar field involves some degeneracy leading to lower precision in determination of $\Omega_m$. To remove this degeneracy additional information is needed beyond the data on large-scale geometry.Comment: VIII International Conference "Relativistic Astrophysics, Gravitation and Cosmology": May 21-23, 2008, Kyiv, Ukrain