Synthesis of extracellular matrix components by human ciliary muscle cells in culture

The production and spatial organization of connective tissue components in ciliary muscle cell cultures was studied with immunohistochemical and ultrastructural methods. Antibodies against collagen types IV and VI, fibronectin and laminin were used. Laminin stains as pericellular network surrounding individual muscle cells. Type IV collagen shows positive cytoplasmic staining and only small foci of extracellular immunofluorescence. Staining for type VI collagen and fibronectin is seen near the ends of the bipolar cells, while the lateral sides of the cells remain unstained. Electronmicroscopy shows that cultured ciliary muscle cells are surrounded by an incomplete basal lamina. In addition, bundles of 5-20 nm thick extracellular microfibrils are seen. The bundles are oriented parallel to the axis of the cells and are in close contact with the cell membrane in areas where membrane-bound dense bands are formed. Immunoelectronmicroscopy indicates that the bundles contain fibronectin and type VI collagen fibrils. While the fibronectin fibrils approach the cell membrane directly, type VI collagen fibrils are usually separated from the cell membrane by fine fibrillous material of different nature. Quality and spatial organization of the extracellular material in ciliary muscle cell cultures shows marked similarities with the extracellular matrix of ciliary muscle in situ

Noncommuting spherical coordinates

Restricting the states of a charged particle to the lowest Landau level introduces a noncommutativity between Cartesian coordinate operators. This idea is extended to the motion of a charged particle on a sphere in the presence of a magnetic monopole. Restricting the dynamics to the lowest energy level results in noncommutativity for angular variables and to a definition of a noncommuting spherical product. The values of the commutators of various angular variables are not arbitrary but are restricted by the discrete magnitude of the magnetic monopole charge. An algebra, isomorphic to angular momentum, appears. This algebra is used to define a spherical star product. Solutions are obtained for dynamics in the presence of additional angular dependent potentials.Comment: 5 pages, RevTex4 fil

Flux- and volume-limited groups/clusters for the SDSS galaxies: catalogues and mass estimation

We provide flux-limited and volume-limited galaxy group and cluster catalogues, based on the spectroscopic sample of the SDSS data release 10 galaxies. We used a modified friends-of-friends (FoF) method with a variable linking length in the transverse and radial directions to identify as many realistic groups as possible. The flux-limited catalogue incorporates galaxies down to m_r = 17.77 mag. It includes 588193 galaxies and 82458 groups. The volume-limited catalogues are complete for absolute magnitudes down to M_r = -18.0, -18.5, -19.0, -19.5, -20.0, -20.5, and -21.0; the completeness is achieved within different spatial volumes, respectively. Our analysis shows that flux-limited and volume-limited group samples are well compatible to each other, especially for the larger groups/clusters. Dynamical mass estimates, based on radial velocity dispersions and group extent in the sky, are added to the extracted groups. The catalogues can be accessed via http://cosmodb.to.ee and the Strasbourg Astronomical Data Center (CDS).Comment: 16 pages, 18 figures, 2 tables, accepted for publication in A&

Elektronenmikroskopische und inununhistochemische Untersuchungenzur augendrucksenkenden Wirkung von Prostaglandin F2alpha [Electron microscopy and immunohistochemical studies of the intraocular pressure lowering effect of prostaglandin F2 alpha]

Topically applied prostaglandin F2 alpha (PGF2 alpha) has been shown to lower intraocular pressure in cynomolgus monkeys. In this study the morphological changes following topical treatment of seven cynomolgus monkeys with 4 micrograms PGF2 alpha isopropylester for 5-8 days were investigated and compared with the eyes of five normal animals. Quantitative light microscopical, ultrastructural and immunhistochemical methods were used. No cellular signs of inflammation were seen in any of the eyes. Slight edema in the most anterior part of the ciliary processes occurred in most eyes, but only in parts of the circumference. The most pronounced change was dilation of the intramuscular spaces within the ciliary muscle. No changes were observed in the extracellular matrix within the muscle bundles, which consist partly of type IV and VI collagen, laminin and fibronectin. In the connective tissue between the muscle bundles, loss of collagen type I and III fibrils was observed. Additionally, macrophages were found with phagolysosomes containing phagocytized collagen fibrils. We suggest that loss of extracellular material leads to a widening of the uveoscleral outflow pathways of ciliary muscle and thereby to a reduction in intraocular pressure

Topological surface state under graphene for two-dimensional spintronics in air

Spin currents which allow for a dissipationless transport of information can be generated by electric fields in semiconductor heterostructures in the presence of a Rashba-type spin-orbit coupling. The largest Rashba effects occur for electronic surface states of metals but these cannot exist but under ultrahigh vacuum conditions. Here, we reveal a giant Rashba effect ({\alpha}_R ~ 1.5E-10 eVm) on a surface state of Ir(111). We demonstrate that its spin splitting and spin polarization remain unaffected when Ir is covered with graphene. The graphene protection is, in turn, sufficient for the spin-split surface state to survive in ambient atmosphere. We discuss this result along with evidences for a topological protection of the surface state.Comment: includes supplementary informatio

Cherenkov radiation by particles traversing the background radiatio n

High energy particles traversing the Universe through the cosmic microwave backgroung radiation can, in principle, emit Cherenkov radiation. It is shown that the energy threshold for this radiation is extremely high and its intensity would be too low due to the low density of the "relic photons gas" and very weak interaction of two photons.Comment: 6 pages, LATEX, no Figs.; to be published in JETP Lett. 75 (N4) (2002