Secondary water pore formation for proton transport in a ClC exchanger revealed by an atomistic molecular dynamics simulation

Several prokaryotic ClC proteins have been demonstrated to function as exchangers that transport both chloride ions and protons simultaneously in opposite directions. However, the path of the proton through the ClC exchanger and how the protein brings about the coupled movement of both ions are still unknown. In the present work, we demonstrate that a previously unknown secondary water pore is formed inside a ClC exchanger by using an atomistic molecular dynamics (MD) simulation. From the systematic simulations, it was determined that the glutamate residue exposed to the intracellular solution, E203, plays an important role as a trigger for the formation of the secondary water pore. Based on our simulation results, we conclude that protons in the ClC exchanger are conducted via a water network through the secondary water pore and we propose a new mechanism for the coupled transport of chloride ions and protons

On sacred ground: social identity and churchyard burial in Lincolnshire and Yorkshire, C. 700-1100 AD

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Fundamental flaws in the current cost regulatory capital value method of utility pricing

Jim Cuthbert and Margaret Cuthbert’s most recent analysis of the UK’s utility businesses (see QEC Vol 31 No 3) seeks to challenge the fundamental price setting methodology adopted by utility regulators. The basis of the challenge arises from an estimate of the size of the apparent super normal profits being made by utility companies. From this they conclude that the resultant equity return is too high and so leaves customers paying prices that are too high for the services provided1

Automatic transversality in contact homology I: Regularity

This paper helps to clarify the status of cylindrical contact homology, a conjectured contact invariant introduced by Eliashberg, Givental, and Hofer in 2000. We explain how heuristic arguments fail to yield a well-defined homological invariant in the presence of multiply covered curves. We then introduce a large subclass of dynamically convex contact forms in dimension 3, termed dynamically separated, and demonstrate automatic transversality holds, therby allowing us to define the desired chain complex. The Reeb orbits of dynamically separated contact forms satisfy a uniform growth condition on their Conley-Zehnder index under iteration, typically up to large action; see Definition 1.15 These contact forms arise naturally as perturbations of Morse-Bott contact forms such as those associated to $S^1$-bundles. In subsequent work, we give a direct proof of invariance for this subclass and, when further proportionality holds between the index and action, powerful geometric computations in a wide variety of examples.Comment: 68 pages, added more information about bad Reeb orbits, added a proof of a beloved folk theorem concerning the factorization of multiply covered curves, contains expository revisions helpfully suggested by the refere

Book Review: Cycles of disadvantage?

Review of Scott Boggess, Mary Corcoran and Stephen P Jenkins. Cycles of disadvantages