Inhibition of Escherichia coli chemotaxis by omega-conotoxin, a calcium ion channel blocker

Escherichia coli chemotaxis was inhibited by omega-conotoxin, a calcium ion channel blocker. With Tris-EDTA-permeabilized cells, nanomolar levels of omega-conotoxin inhibited chemotaxis without loss of motility. Cells treated with omega-conotoxin swam with a smooth bias, i.e., tumbling was inhibited

Development in Lexicography: From Polyfunctional to Monofunctional Accounting Dictionaries

This article describes the theoretical foundation of the accounting dictionaries as well as its practical results. Furthermore, the implementation of the project shows how the constant interaction of lexicographical theory with practical dictionary work over a period of 10 years has led to lexicographical development and adaptation resulting in ongoing adjustments to the dictionaries and their theoretical foundation. This is exemplified by studying the transition from polyfunctional to monofunctional dictionaries in an attempt to provide help in several types of usage situations, typically in communicative situations, e.g. when reading, writing or translating English, Danish or Spanish accounting texts, or cognitive situations, i.e. when users want to know more about accounting matters or accounting language. The article also indicates that the creation of this project connects e-lexicography with the knowledge-based economy. Lexicographers work in the cloud being physically thousands of kilometres away; they work with experts in accounting, databases and the Internet with the aim of constructing and updating a high-quality tool with relatively low information costs for users. Finally, this article shows that the future of lexicography rests on designing, constructing, and updating information tools that take into consideration not only the true nature of lexicography but also the possibilities of the Internet and its technologies, as advocates of the Function Theory of Lexicography do on a regular basis.Keywords: specialized lexicography, function theory, polyfunctional dictionary, monofunctional dictionary, accounting dictionaries, information tools, lexicographical information costs, online dictionary, electronic lexicography, internet, meaning, writing, translation, knowledge, danish, english, spanis

Couplings between Chern-Simons gravities and 2p-branes

The interaction between Chern-Simons (CS) theories and localized external sources (2p-branes) is analyzed. This interaction generalizes the minimal coupling between a point charge (0-brane) and a gauge connection. The external currents that define the 2p-branes are covariantly constant (D-2p-1)-forms coupled to (2p-1) CS forms. The general expression for the sources --charged with respect to the corresponding gauge algebra-- is presented, focusing on two special cases: 0-branes and (D-3)-branes. In any dimension, 0-branes are constructed as topological defects produced by a surface deficit of (D-2)-sphere in AdS space, and they are not constant curvature spaces for D>3. They correspond to dimensionally continued black holes with negative mass. On the other hand, in the case of CS (super) gravities, the (D-3)-branes are naked conical singularities (topological defects) obtained by identification of points with a Killing vector. In 2+1 dimensions, extremal spinning branes of this type are BPS states. Stable (D-3)-branes are shown to exist also in higher dimensions, as well. Classical field equations are also discussed and in the presence of sources there is a large number of inequivalent and disconnected sectors in solution space.Comment: 29 pages, no figures; version accepted in PRD; extended introduction and several references added; some sections have been reorganized and several minor corrections mad

NMR structures of conotoxins

Journal ArticleThis review discusses the methodology, structural details, and biological implications regarding NMR structures of conotoxins. NMR and molecular modeling techniques have improved to the point that three-dimensional structures of conotoxins can now be determined with a significant degree of confidence. At the same time, biochemical techniques have made important progress in disseminating critical areas of the toxin receptors. As the two areas of research converge, they can begin to explain the extraordinary selectivity of conotoxin binding on a molecular level. An understanding of how molecular interactions between the toxins and their receptors leads to binding specificity should have broad applications in many fields. NMR structures of conotoxins have now been published for each of the major toxin classes. This review includes a brief discussion on the NMR and modeling techniques used for each of the published conotoxin structures to date. The secondary structure of the resulting models is then discussed along with potential implications for biological activity. Finally, relevant biochemical experiments regarding the toxin binding sites are included and discussed in light of the three-dimensional toxin model

T-superfamily of conotoxins

Journal ArticleWe report the discovery and initial characterization of the T-superfamily of conotoxins. Eight different T-superfamily peptides from five Conus species were identified; they share a consensus signal sequence, and a conserved arrangement of cysteine residues (- -CC- -CC-). T-superfamily peptides were found expressed in venom ducts of all major feeding types of Conus; the results suggest that the T-superfamily will be a large and diverse group of peptides, widely distributed in the 500 different Conus species

Dilogarithm ladders from Wilson loops

We consider a light-like Wilson loop in N = 4 SYM evaluated on a regular n-polygon contour. Sending the number of edges to infinity the polygon approximates a circle and the expectation value of the light-like WL is expected to tend to the localization result for the circular one. We show this explicitly at one loop, providing a prescription to deal with the divergences of the light-like WL and the large n limit. Taking this limit entails evaluating certain sums of dilogarithms which, for a regular polygon, evaluate to the same constant independently of n. We show that this occurs thanks to underlying dilogarithm identities, related to the so-called “polylogarithm ladders”, which appear in rather different contexts of physics and mathematics and enable us to perform the large n limit analytically.Instituto de Física La Plat

On a potential global role for vitamin K-dependent γ-carboxylation in animal systems

Journal ArticleThe vitamin K-dependent γ-carboxylation of glutamate to γ-carboxyglutamate was originally well characterized in the mammalian blood clotting cascade. γ-Carboxyglutamate has also been found in a number of other mammalian proteins and in neuropeptides from the venoms of marine snails belonging to the genus Conus, suggesting wider prevalence of γ-carboxylation

Defining a clade by morphological, molecular, and toxinological criteria: distinctive forms related to Conus praecellens A. Adams, 1854 (Gastropoda: Conidae)

Journal ArticleWe carried out a definition of the Conus praecellens A. Adams, 1854, species group using a combination of comparative morphological data, molecular phylogeny based on standard genetic markers, and toxinological markers. Prior to this work, Conus praecellens was generally postulated to belong to a clade of similarly high-spired, smaller species such as Conus pagodus Kiener, 1845, Conus memiae (Habe and Kosuge, 1970) and Conus arcuatus Broderip and Sowerby, 1829. The molecular phylogeny and toxinological data demonstrate that these earlier hypotheses are incorrect, and that instead, Conus praecellens is in a branch of Conus that includes Conus stupa (Kuroda, 1956), Conus stupella (Kuroda, 1956), Conus acutanguhis Lamarck, 1810, and surprisingly, some species that are morphologically strikingly different, Conus mitratus Sowerby, 1870, and Conus cilindraceus Broderip and Sowerby, 1830. A more careful analysis of the morphologically diverse forms assigned to Conus praecellens suggests that from the Philippine material alone, there are at least three additional species new to science, Conus andremenezi, Conus miniexcclsus, and Conus rizali

Developing a Model of Perceptions of Technological Multitasking

Multitasking is held to be essential to corporate survival (Manhart, 2005), but little attention has been paid to the social meaning of technological multitasking. We focus on technological multitasking as rapid task switching involving information technologies and, in particular, where one or more activities involve interpersonal interaction. Understanding how technological multitasking behavior is perceived by others has significant implications for individuals, managers, organizations, and educational institutions alike. To this end, a conceptual model has been developed and tested using a scenario-based approach to gain insights into the attributions of those engaged in this behavior

Aerosol synthesis of phosphor based on Eu3+ activated gadolinium oxide matrices

Poster presented at the Seventh International Conference on Ceramic Processing Science, Inuyama, Japan, May 15-18, 200