5,279 research outputs found

    Regulation of cAMP responses by the G12/13 pathway converges on adenylyl cyclase VII

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    Regulation of intracellular cyclic adenosine 3’, 5’-monophosphate (cAMP) by multiple pathways enables differential function of this ubiquitous second messenger in a context dependent manner. Modulation of Gs-stimulated intracellular cAMP has long been known to be modulated by the Gi and Gq/Ca2+ pathways. Recently, the G13 pathway was also shown to facilitate cAMP responses in murine macrophage cells. We report here that this synergistic regulation of cAMP synthesis by the Gs and G13 pathways is mediated by a specific isoform of adenylyl cyclase, AC7. Furthermore, this signaling paradigm exists in several hematopoietic lineages and can be recapitulated by exogenous expression of AC7 in HEK 293 cells. Mechanistic characterization of this synergistic interaction indicates that it occurs downstream of receptor activation and it can be mediated by the alpha subunit of either G12 or G13. Our results demonstrate that AC7 is a specific downstream effector of the G12/13 pathway

    3.3 Gigahertz Clocked Quantum Key Distribution System

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    A fibre-based quantum key distribution system operating up to a clock frequency of 3.3GHz is presented. The system demonstrates significantly increased key exchange rate potential and operates at a wavelength of 850nm.Comment: Presented at ECOC 05, Glasgow, UK, (September 2005

    Multifunctional Tanks for Spacecraft

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    A document discusses multifunctional tanks as means to integrate additional structural and functional efficiencies into designs of spacecraft. Whereas spacecraft tanks are traditionally designed primarily to store fluids and only secondarily to provide other benefits, multifunctional tanks are designed to simultaneously provide multiple primary benefits. In addition to one or more chamber(s) for storage of fluids, a multifunctional tank could provide any or all of the following: a) Passageways for transferring the fluids; b) Part or all of the primary structure of a spacecraft; c) All or part of an enclosure; d) Mechanical interfaces to components, subsystems, and/or systems; e) Paths and surfaces for transferring heat; f)Shielding against space radiation; j) Shielding against electromagnetic interference; h) Electrically conductive paths and surfaces; and i) Shades and baffles to protect against sunlight and/or other undesired light. Many different multifunctional-tank designs are conceivable. The design of a particular tank can be tailored to the requirements for the spacecraft in which the tank is to be installed. For example, the walls of the tank can be flat or curved or have more complicated shapes, and the tank can include an internal structure for strengthening the tank and/or other uses

    ‘They Called Them Communists Then … What D'You Call ‘Em Now? … Insurgents?’. Narratives of British Military Expatriates in the Context of the New Imperialism

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    This paper addresses the question of the extent to which the colonial past provides material for contemporary actors' understanding of difference. The research from which the paper is drawn involved interview and ethnographic work in three largely white working-class estates in an English provincial city. For this paper we focus on ten life-history interviews with older participants who had spent some time abroad in the British military. Our analysis adopts a postcolonial framework because research participants' current constructions of an amorphous 'Other' (labelled variously as black people, immigrants, foreigners, asylum-seekers or Muslims) reveal strong continuities with discourses deployed by the same individuals to narrate their past experiences of living and working as either military expatriates or spouses during British colonial rule. Theoretically, the paper engages with the work of Frantz Fanon and Edward Said. In keeping with a postcolonial approach, we work against essentialised notions of identity based on 'race' or class. Although we establish continuity between white working-class military emigration in the past and contemporary racialised discourses, we argue that the latter are not class-specific, being as much the creations of the middle-class media and political elite

    Aureobacterium resistens sp. nov., exhibiting vancomycin resistance and teicoplanin susceptibility

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    Two similar strains of a coryneform bacterium were isolated from human clinical material. Both strains were resistant to vancomycin but susceptible to teicoplanin. Detailed biochemical, chemotaxonomical, and molecular genetic investigations revealed that both isolates were members of a hitherto undescribed species of the genus Aureobacterium. The name Aureobacterium resistens sp. nov. is proposed for the new bacterium and the type strain is CCUG 3831

    High Magnetic Field Behaviour of the Triangular Lattice Antiferromagnet, CuFeO_2

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    The high magnetic field behaviour of the triangular lattice antiferromagnet CuFeO_2 is studied using single crystal neutron diffraction measurements in a field of up to 14.5 T and also by magnetisation measurements in a field of up to 12 T. At low temperature, two well-defined first order magnetic phase transitions are found in this range of applied magnetic field (H // c): at H_c1=7.6(3)/7.1(3) T and H_c2=13.2(1)/12.7(1) T when ramping the field up/down. In a field above H_c2 the magnetic Bragg peaks show unusual history dependence. In zero field T_N1=14.2(1) K separates a high temperature paramagnetic and an intermediate incommensurate structure, while T_N2=11.1(3) K divides an incommensurate phase from the low-temperature 4-sublattice ground state. The ordering temperature T_N1 is found to be almost field independent, while T_N2 decreases noticeably in applied field. The magnetic phase diagram is discussed in terms of the interactions between an applied magnetic field and the highly frustrated magnetic structure of CuFeO_2Comment: 7 pages, 8 figures in ReVTeX. To appear in PR
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