A solution to the problems of cusps and rotation curves in dark matter halos in the cosmological standard model

We discuss various aspects of the inner structure formation in virialized dark matter (DM) halos that form as primordial density inhomogeneities evolve in the cosmological standard model. The main focus is on the study of central cusps/cores and of the profiles of DM halo rotation curves, problems that reveal disagreements among the theory, numerical simulations, and observations. A method that was developed by the authors to describe equilibrium DM systems is presented, which allows investigating these complex nonlinear structures analytically and relating density distribution profiles within a halo both to the parameters of the initial small-scale inhomogeneity field and to the nonlinear relaxation characteristics of gravitationally compressed matter. It is shown that cosmological random motions of matter `heat up' the DM particles in collapsing halos, suppressing cusp-like density profiles within developing halos, facilitating the formation of DM cores in galaxies, and providing an explanation for the difference between observed and simulated galactic rotation curves. The analytic conclusions obtained within this approach can be confirmed by the N-body model simulation once improved spatial resolution is achieved for central halo regions.Comment: 44 pages, 16 figures, 1 tabl

Current-induced highly dissipative domains in high Tc thin films

We have investigated the resistive response of high Tc thin films submitted to a high density of current. For this purpose, current pulses were applied into bridges made of Nd(1.15)Ba(1.85)Cu3O7 and Bi2Sr2CaCu2O8. By recording the time dependent voltage, we observe that at a certain critical current j*, a highly dissipative domain develops somewhere along the bridge. The successive formation of these domains produces stepped I-V characteristics. We present evidences that these domains are not regions with a temperature above Tc, as for hot spots. In fact this phenomenon appears to be analog to the nucleation of phase-slip centers observed in conventional superconductors near Tc, but here in contrast they appear in a wide temperature range. Under some conditions, these domains will propagate and destroy the superconductivity within the whole sample. We have measured the temperature dependence of j* and found a similar behavior in the two investigated compounds. This temperature dependence is just the one expected for the depairing current, but the amplitude is about 100 times smaller.Comment: 9 pages, 9 figures, Revtex, to appear in Phys. Rev.

Energetic particle influence on the Earth's atmosphere

This manuscript gives an up-to-date and comprehensive overview of the effects of energetic particle precipitation (EPP) onto the whole atmosphere, from the lower thermosphere/mesosphere through the stratosphere and troposphere, to the surface. The paper summarizes the different sources and energies of particles, principally galactic cosmic rays (GCRs), solar energetic particles (SEPs) and energetic electron precipitation (EEP). All the proposed mechanisms by which EPP can affect the atmosphere are discussed, including chemical changes in the upper atmosphere and lower thermosphere, chemistry-dynamics feedbacks, the global electric circuit and cloud formation. The role of energetic particles in Earth’s atmosphere is a multi-disciplinary problem that requires expertise from a range of scientific backgrounds. To assist with this synergy, summary tables are provided, which are intended to evaluate the level of current knowledge of the effects of energetic particles on processes in the entire atmosphere

Mitral insufficiency: systematization, conservative and surgical treatment

The article concerns mechanisms, clinical features, diagnostics, possible complications and treatment of mitral insufficiency. Much attention is given to modern diagnostic methods, principles for case management and indications for surgical treatment

Особенности экспрессии коллагена IV типа в базалиоме кожи

Rationale: Type IV collagen is the main component of the basal membrane ensuring its integrity. Basal membrane destruction is associated with absent type IV collagen expression being directly related to an increased tumor invasion risk. Specifics of the protein expression in various morphological types of basal cell carcinoma have not been well described. Aim: To study the association between type IV collagen expression and basal cell carcinoma morphological structure and invasion potential. Materials and methods: We performed an immunohistochemistry analysis with anti-type IV collagen antibodies on 30 biopsy specimens of the skin involved with basal cell carcinoma. Results: The superficial multicentric type of basal cell carcinoma differed from the solid, micronodular, and infiltrative types by linear continuous type IV collagen expression (р 0.0083). Most often, there was no type IV collagen expression in the micronodular and infiltrative basal cell carcinomas; however, no significant difference of the solid type and each of the abovementioned types was found. Aggressive basal cell carcinoma types (micronodular and infiltrative, taken together) were significantly different (р = 0.033) from the solid type by the absence of type IV collagen expression. Linear continuous expression was seen exclusively in basal cell carcinomas with the invasion of 0.825 mm. Conclusion: We have identified the difference in type IV collagen expression depending on the morphological type of basal cell skin carcinoma, prevailing linear continuous expression in the superficial multicentric type and its absence in the micronodular and infiltrative types.Актуальность. Коллаген IV типа - основной компонент базальной мембраны, обеспечивающий ее целостность. При разрушении базальной мембраны отмечается исчезновение экспрессии коллагена IV типа, что напрямую связано с возрастанием инвазивного потенциала опухоли. В полной мере не определены особенности экспрессии этого белка при различных морфологических типах базалиомы. Цель - изучение взаимосвязи между экспрессией коллагена IV типа, морфологическим строением и инвазивным потенциалом базалиомы. Материал и методы. Проведено иммуногистохимическое исследование с антителами к коллагену IV типа биопсийного материала 30 базалиом кожи. Результаты. Линейная непрерывная экспрессия коллагена IV типа отличала (р 0,0083) поверхностный мульти-центрический тип от солидного, микронодулярного и инфильтративного. В микронодулярном и инфильтративном типах базалиомы чаще всего экспрессия коллагена IV отсутствовала, однако статистически значимого отличия солидного от каждого из этих типов получено не было. Суммарно агрессивные типы базалиомы (микронодулярный и инфильтративный) значимо (р = 0,033) отличались от солидного тем, что в них преимущественно отсутствовала экспрессия коллагена IV типа. Исключительно линейная непрерывная экспрессия наблюдалась в базалиомах глубиной 0,825 мм. Заключение. Установлены различия в экспрессии коллагена IV типа в зависимости от морфологического типа базалиомы, преобладание линейной непрерывной экспрессии в поверхностном мультицентрическом типе и ее отсутствие в ми-кронодулярном и инфильтративном