Phosphine stabilized diiododiborenes: isolable diborenes with six labile bonds

The lability of B=B, B‐P and B‐halide bonds is combined in the syntheses of the first diiododiborenes. In a series of reactivity tests, these diiododiborenes demonstrate cleavage of all six of their central bonds in different ways, leading to products of B=B hydrogenation and dihalogenation as well as halide exchange

South African universities and human development : Towards a theorisation and operationalisation of professional capabilities for poverty reduction

This paper reports on a research project investigating the role of universities in South Africa in contributing to poverty reduction through the quality of their professional education programmes. The focus here is on theorising and the early operationalisation of multi-layered, multi-dimensional transformation based on ideas from Amartya Sen's capability approach. Key features of a professionalism oriented to public service, which in South Africa must mean the needs and lives of the poor, are outlined. These features include: the demand from justice; the expansion of the comprehensive capabilities both of the poor and professional capability formation to be able to act in ‘pro-poor’ ways; and, praxis pedagogies which shape this connected process. This theorisation is then tentatively operationalised in a process of selecting transformation dimensions

Prostasin is a glycosylphosphatidylinositol-anchored active serine protease

A recombinant human prostasin serine protease was expressed in several human cell lines. Subcellular fractionation showed that this serine protease is synthesized as a membrane-bound protein while a free-form prostasin is secreted into the culture medium, Prostasin was identified in nuclear and membrane fractions. Membrane-bound prostasin can be released by phosphatidylinositol-specific phospholipase C treatment, or labeled by [H-3]ethanolamine, indicating a glycosylphosphatidylinositol anchorage. A prostasin-binding protein was identified in mouse and human seminal vesicle fluid. Both the secreted and the membrane-bound prostasin were able to form a covalently linked 82-kDa complex when incubated with seminal vesicle fluid. The complex formation between prostasin and the prostasin-binding protein was inhibited by a prostasin antibody, heparin, and serine protease inhibitors. Prostasin\u27s serine protease activity was inhibited when bound to the prostasin-binding protein in mouse seminal vesicle fluid. This study indicates that prostasin is an active serine protease in its membrane-bound form

Ena/VASP proteins have an anti-capping independent function in filopodia formation

Author Posting. © American Society for Cell Biology, 2007. This article is posted here by permission of American Society for Cell Biology for personal use, not for redistribution. The definitive version was published in Molecular Biology of the Cell 18 (2007): 2579-2591, doi:10.1091/mbc.E06-11-0990.Filopodia have been implicated in a number of diverse cellular processes including growth-cone path finding, wound healing, and metastasis. The Ena/VASP family of proteins has emerged as key to filopodia formation but the exact mechanism for how they function has yet to be fully elucidated. Using cell spreading as a model system in combination with small interfering RNA depletion of Capping Protein, we determined that Ena/VASP proteins have a role beyond anticapping activity in filopodia formation. Analysis of mutant Ena/VASP proteins demonstrated that the entire EVH2 domain was the minimal domain required for filopodia formation. Fluorescent recovery after photobleaching data indicate that Ena/VASP proteins rapidly exchange at the leading edge of lamellipodia, whereas virtually no exchange occurred at filopodial tips. Mutation of the G-actin–binding motif (GAB) partially compromised stabilization of Ena/VASP at filopodia tips. These observations led us to propose a model where the EVH2 domain of Ena/VASP induces and maintains clustering of the barbed ends of actin filaments, which putatively corresponds to a transition from lamellipodial to filopodial localization. Furthermore, the EVH1 domain, together with the GAB motif in the EVH2 domain, helps to maintain Ena/VASP at the growing barbed ends.This work was supported in part by National Institutes of Health Grants GM7542201 to D.A.A., GM58801 to F.B.G., and GM62431 to G.G.B. and by Cell Migration Consortium Grants GM64346 to D.A.A and G.G.B

Tetraiododiborane(4) (B2_2I4_4) is a Polymer based on sp3^3 Boron in the Solid State

Herein we present the first solid‐state structures of tetraiododiborane(4) (B$_2$I$_4$), which was long believed to exist in all phases as discrete molecules with planar, tricoordinate boron atoms, like the lighter tetrahalodiboranes(4) B$_2$F$_4$, B$_2$Cl$_4$, and B$_2$Br$_4$. Single‐crystal X‐ray diffraction, solid‐state NMR, and IR measurements indicate that B$_2$I$_4$ in fact exists as two different polymeric forms in the solid state, both of which feature boron atoms in tetrahedral environments. DFT calculations are used to simulate the IR spectra of the solution and solid‐state structures, and these are compared with the experimental spectra

Hydromorphological conditions of small streams in North Italy and West Austria

Considering the entire fluvial network of Tyrol and South Tyrol, 81 sampling sites were selected according to the following requirements: (1) degree of hydrological disturbance (undisturbed, residual water, temporal residual water or hydropeaking); (2) type of water regime (e.g. groundwater, glacial, nivo-pluvial); (3) degree of morphological disturbance (either near natural conditions or anthropogenic changed conditions); (4) dominant land use type in the catchment with a total area of 4 ha (either grassland, forest, vineyard/orchard or urban settlement); (5) hormone pollution (based on the location of the sample point - before or after sewage treatment plant, or pesticide suspicion). Hydrological and morphological indicators as well as derived indices are based on a standardized methodical approach: (1) survey of morphological and hydrological stream characteristics using standardised field manual and entry form. The hydrological indicators were identified through flow-duration curves, which represent quantitative characterisation of the streamflow regime and harmonised data provided by local agencies and on-site probes; (2) standardized index calculations, starting with the hydrological index IH and morphological index IM, which were summed up to the hydromorphological index IHM. Further details regarding the methodical approach and its application are explained in the publication resulting from the analysis of this hydromorphological data (see Supplement to)

Dibortetraiodid (B2_2I4_4) ist im Festkörper ein Polymer aus sp3‐hybridisiertem Bor

Anhand der ersten Festkörperstrukturen von Dibortetraiodid (B$_2$I$_4$) wird gezeigt, dass dieses nicht, wie lange angenommen, analog zu den leichteren Dibortetrahalogeniden B$_2$F$_4$, B$_2$Cl$_4$ und B$_2$Br$_4$ in allen Aggregatzuständen in Form diskreter Moleküle mit planaren, dreifach koordinierten Boratomen vorliegt. Röntgenstrukturanalysen, Festkörper‐NMR‐ und IR‐Messungen zeigen, dass B$_2$I$_4$ im Festkörper in zwei polymeren Konformeren vorkommt, die tetraedrisch koordinierte Boratome enthalten. Anhand von DFT‐Rechnungen werden die IR‐Spektren in Lösung und im Festkörper simuliert und mit den experimentellen Daten verglichen

Stable Lewis Base Adducts of Tetrahalodiboranes: Synthetic Methods and Structural Diversity

A series of 22 new bis(phosphine), bis(carbene) and bis(isonitrile) tetrahalodiborane adducts has been synthesized, either by direct adduct formation with highly sensitive B2X4 precursors (X = Cl, Br, I) or by ligand exchange at stable B2X4(SMe2)2 precursors (X = Cl, Br) with labile dimethylsulfide ligands. The isolated compounds have been fully characterized using NMR spectroscopic, (C,H,N)- elemental and, for 20 of these compounds, X-ray crystallographic analysis, revealing an unexpected variation in the bonding motifs. Besides the classical B2X4L2 diborane(6) adducts, some of the more sterically demanding carbene ligands induce a halide displacement leading to the first halide-bridged monocationic diboron species, [B2X3L2]A (A = BCl4, Br, I). Furthermore, low-temperature 1:1 reactions of B2Cl4 with sterically demanding N-heterocyclic carbenes led to the formation of kinetically unstable mono-adducts, one of which was structurally characterized. A comparison of the NMR and structural data of new and literature-known bis-adducts shows several trends pertaining to the nature of the halides and the stereoelectronic properties of the Lewis bases employed