Moscow State University

About: Moscow State University is a education organization based out in Moscow, Russia. It is known for research contribution in the topics: Laser & Population. The organization has 66747 authors who have published 123358 publications receiving 1753995 citations. The organization is also known as: MSU & Lomonosov Moscow State University.

Topological transitivity of billiards in polygons

Abstract: Consider a billiard in a polygon Q⊂R2 having all angles commensurate with π. For the majority of initial directions, density of every infinite semitrajectory in configuration space is proved. Also proved is the typicality of polygons for which some billiard trajectory is dense in phase space.

Relationship between pluronic block copolymer structure, critical micellization concentration and partitioning coefficients of low molecular mass solutes

Abstract: Using pyrene and homologous alkyl derivatives of fluorescein as fluorescent probes, this work examines the partitioning coefficients of hydrophobic solutes in aqueous dispersions of Pluronic block copolymers (poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide)). An incremental approach is developed, allowing measurement of the free energy of transfer of a methylene group from aqueous media into the micelles. Effects of variation of length of the ethylene oxide (EO) and the propylene oxide (PO) blocks in Pluronic molecules on the partitioning characteristics of the solutes are established. A simple reciprocal relationship between partitioning coefficients of the solute and critical micellization concentration is demonstrated.

Search for supersymmetry at the LHC in events with jets and missing transverse energy

Abstract: A search for events with jets and missing transverse energy is performed in a data sample of pp collisions collected at sqrt(s) = 7 TeV by the CMS experiment at the LHC. The analyzed data sample corresponds to an integrated luminosity of 1.14 inverse femtobarns. In this search, a kinematic variable, alphaT, is used as the main discriminator between events with genuine and misreconstructed missing transverse energy. No excess of events over the standard model expectation is found. Exclusion limits in the parameter space of the constrained minimal supersymmetric extension of the standard model are set. In this model, squark masses below 1.1 TeV are excluded at 95% CL. Gluino masses below 1.1 TeV are also ruled out at 95% CL for values of the universal scalar mass parameter below 500 GeV.

The spinal frog takes into account the scheme of its body during the wiping reflex

Abstract: The hindlimb of the spinal frog produces a wiping reflex evoked by electrically or chemically stimulating distal skin of the forelimb. The reflex was released in frogs supported on a flat surface or suspended. It was found to have two stages. During the first, the frog fixed the hindlimb in an intermediate posture irrespective of forelimb position. In the second, the movement depended on forelimb position, which determined the final posture of the hindlimb. In this final posure, all joints except the hip joint were fully extended; the hip angle was correlated with forelimb position and varied on repeated wipings. When the stimulus was applied to the skin of the back, the pattern of final postures was the same, but the intermediate postures differed. The organization of the wiping reflex is discussed in light of the hypothesis that movement is evoked according to changes in the equilibrium (postural state) of the system.

Alpha-smooth muscle actin is crucial for focal adhesion maturation in myofibroblasts.

Abstract: Cultured myofibroblasts are characterized by stress fibers, containing alpha-smooth muscle actin (alpha-SMA) and by supermature focal adhesions (FAs), which are larger than FAs of alpha-SMA-negative fibroblasts. We have investigated the role of alpha-SMA for myofibroblast adhesion and FA maturation. Inverted centrifugation reveals two phases of initial myofibroblast attachment: during the first 2 h of plating microfilament bundles contain essentially cytoplasmic actin and myofibroblast adhesion is similar to that of alpha-SMA-negative fibroblasts. Then, myofibroblasts incorporate alpha-SMA in stress fibers, develop mature FAs and their adhesion capacity is significantly increased. When alpha-SMA expression is induced in 5 d culture by TGFbeta or low serum levels, fibroblast adhesion is further increased correlating with a "supermaturation" of FAs. Treatment of myofibroblasts with alpha-SMA fusion peptide (SMA-FP), which inhibits alpha-SMA-mediated contractile activity, reduces their adhesion to the level of alpha-SMA negative fibroblasts. With the use of flexible micropatterned substrates and EGFP-constructs we show that SMA-FP application leads to a decrease of myofibroblast contraction, shortly followed by disassembly of paxillin- and beta3 integrin-containing FAs; alpha5 integrin distribution is not affected. FRAP of beta3 integrin-EGFP demonstrates an increase of FA protein turnover following SMA-FP treatment. We conclude that the formation and stability of supermature FAs depends on a high alpha-SMA-mediated contractile activity of myofibroblast stress fibers.