High resolution temperature and density profiles during the energy quench of density limit disruptions in Rijnhuizen tokamak project

Measurements of the electron temperature, Te, and density, ne, during the energy quench of a major disruption showed that the onset of Te erosion in the neighborhood of the m/n = 2/1 O point at the low field side (LFS) accelerates the well-known m/n = 1/1 erosion of the core temperature. During this phase Te(r) is only partially flat in the region between the q = 2 and the q = 1 surfaces and ne(r) decreases in the core and increases inside the m/n = 2/1 island. Immediately after the flattening of Te(r) a large peak in Te and to a lesser extent in ne has been observed. This peak is radially localized at the q = 2 radius at the LFS, is very short lived and is poloidally asymmetric. Te profiles measured by the heterodyne radiometer and the Thomson scattering agree very well up to the time Te(r) flattens but afterwards can be a factor of two different

Receptor Activation and Inositol Lipid Hydrolysis in Neural Tissues

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66228/1/j.1471-4159.1987.tb05618.x.pd

Disulphide Bridges of Phospholipase C of Chlamydomonas reinhardtii Modulates Lipid Interaction and Dimer Stability

BACKGROUND: Phospholipase C (PLC) is an enzyme that plays pivotal role in a number of signaling cascades. These are active in the plasma membrane and triggers cellular responses by catalyzing the hydrolysis of membrane phospholipids and thereby generating the secondary messengers. Phosphatidylinositol-PLC (PI-PLC) specifically interacts with phosphoinositide and/or phosphoinositol and catalyzes specific cleavage of sn-3- phosphodiester bond. Several isoforms of PLC are known to form and function as dimer but very little is known about the molecular basis of the dimerization and its importance in the lipid interaction. PRINCIPAL FINDINGS: We herein report that, the disruption of disulphide bond of a novel PI-specific PLC of C. reinhardtii (CrPLC) can modulate its interaction affinity with a set of phospholipids and also the stability of its dimer. CrPLC was found to form a mixture of higher oligomeric states with monomer and dimer as major species. Dimer adduct of CrPLC disappeared in the presence of DTT, which suggested the involvement of disulphide bond(s) in CrPLC oligomerization. Dimer-monomer equilibrium studies with the isolated fractions of CrPLC monomer and dimer supported the involvement of covalent forces in the dimerization of CrPLC. A disulphide bridge was found to be responsible for the dimerization and Cys7 seems to be involved in the formation of the disulphide bond. This crucial disulphide bond also modulated the lipid affinity of CrPLC. Oligomers of CrPLC were also captured in in vivo condition. CrPLC was mainly found to be localized in the plasma membrane of the cell. The cell surface localization of CrPLC may have significant implication in the downstream regulatory function of CrPLC. SIGNIFICANCE: This study helps in establishing the role of CrPLC (or similar proteins) in the quaternary structure of the molecule its affinities during lipid interactions

Transport reduction by current profile control in the reversed‐field pinch

This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder

Analysis of the Late Steps of Exocytosis: Biochemical and Total Internal Reflection Fluorescence Microscopy (TIRFM) Studies

1. Time with Julie in his laboratory at the NIH in the early 1970s is remembered. The experience led to a life-long interest in the regulation of catecholamine secretion. Here are summarized aspects of this work.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42879/1/10571_2006_Article_9049.pd

Microscopical methods for the localization of Na + , K + -ATPase

Na + , K + -ATPase plays a central role in the ionic and osmotic homeostasis of cells and in the movements of electrolytes and water across epithelial boundaries. Microscopic localization of the enzyme is, therefore, of crucial importance in establishing the subcellular routes of electrolyte flow across structurally complex and functionally polarized epithelia. Recently developed approaches to the localization of Na + , K + -ATPase are reviewed. These methods rely on different properties of the enzyme and encompass cytochemical localization of the K + -dependent nitrophenylphosphatase component of the enzyme, autoradiographic localization of tritiated ouabain binding sites, and immunocytochemical localization of the holoenzyme and of its catalytic subunit. The rationales for each of these techniques are outlined as are the critieria that have been established to validate each method. The observed localization of Na + , K + -ATPase in various tissues is discussed, particularly as it relates to putative and hypothetical mechanisms that are currently thought to mediate reabsorptive and secretory electrolyte transport.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42850/1/10735_2005_Article_BF01005056.pd