Using an ontology for interoperability and browsing of museum, library and archive information

Ontologies play an important part in the development of the future ‘semantic web’; the CIDOC conceptual reference model (CRM) is an ontology aimed at the cultural heritage domain. This paper describes a Concept Browser, developed for the EU/IST-funded SCULPTEUR project (semantic and content-based multimedia exploitation for European benefit environment (programme IST-2001-no. 35372); May 2002 to May 2005), which is able to access different museum information systems through a common ontology, the CRM. The development of this Concept Browser has required mappings from the legacy museum database systems to the CRM. The crucial process of creating the mappings is described, using the C2RMF catalogue (EROS) and library databases as a case study

Diversity of Arctic pelagic <i>Bacteria</i> with an emphasis on photoheterotrophs: a review

The Arctic Ocean is a unique marine environment with respect to seasonality of light, temperature, perennial ice cover, and strong stratification. Other important distinctive features are the influence of extensive continental shelves and its interactions with Atlantic and Pacific water masses and freshwater from sea ice melt and rivers. These characteristics have major influence on the biological and biogeochemical processes occurring in this complex natural system. Heterotrophic bacteria are crucial components of marine food webs and have key roles in controlling carbon fluxes in the oceans. Although it was previously thought that these organisms relied on the organic carbon in seawater for all of their energy needs, several recent discoveries now suggest that pelagic bacteria can depart from a strictly heterotrophic lifestyle by obtaining energy through unconventional mechanisms that are linked to the penetration of sunlight into surface waters. These photoheterotrophic mechanisms may play a significant role in the energy budget in the euphotic zone of marine environments. Modifications of light and carbon availability triggered by climate change may favor the photoheterotrophic lifestyle. Here we review advances in our knowledge of the diversity of marine photoheterotrophic bacteria and discuss their significance in the Arctic Ocean gained in the framework of the Malina cruise

Predicted Properties of Microhollow Cathode Discharges in Xenon

A fluid model has been developed and used to help clarify the physical mechanisms occurring in microhollow cathode discharges (MHCD). Calculated current-voltage (I-V) characteristics and gas temperatures in xenon at 100 Torr are presented. Consistent with previous experimental results in similar conditions, we find a voltage maximum in the I-V characteristic. We show that this structure reflects a transition between a low-current, abnormal discharge localized inside the cylindrical hollow cathode to a higher-current, normal glow discharge sustained by electron emission from the outer surface of the cathode. This transition, due to the geometry of the device, is a factor contributing to the well-known stability of MHCDs

The ‘PINIT’ motif, of a newly identified conserved domain of the PIAS protein family, is essential for nuclear retention of PIAS3L

AbstractPIAS proteins, cytokine-dependent STAT-associated repressors, exhibit intrinsic E3-type SUMO ligase activities and form a family of transcriptional modulators. Three conserved domains have been identified so far in this protein family, the SAP box, the MIZ-Zn finger/RING module and the acidic C-terminal domain, which are essential for protein interactions, DNA binding or SUMO ligase activity. We have identified a novel conserved domain of 180 residues in PIAS proteins and shown that its ‘PINIT’ motif as well as other conserved motifs (in the SAP box and in the RING domain) are independently involved in nuclear retention of PIAS3L, the long form of PIAS3, that we have characterized in mouse embryonic stem cells

Semimetalic antiferromagnetism in the half-Heusler compound CuMnSb

The half-Heusler compound CuMnSb, the first antiferromagnet (AFM) in the Mn-based class of Heuslers and half-Heuslers that contains several conventional and half metallic ferromagnets, shows a peculiar stability of its magnetic order in high magnetic fields. Density functional based studies reveal an unusual nature of its unstable (and therefore unseen) paramagnetic state, which for one electron less (CuMnSn, for example) would be a zero gap semiconductor (accidentally so) between two sets of very narrow, topologically separate bands of Mn 3d character. The extremely flat Mn 3d bands result from the environment: Mn has four tetrahedrally coordinated Cu atoms whose 3d states lie well below the Fermi level, and the other four tetrahedrally coordinated sites are empty, leaving chemically isolated Mn 3d states. The AFM phase can be pictured heuristically as a self-doped Cu$^{1+}$Mn$^{2+}$Sb$^{3-}$ compensated semimetal with heavy mass electrons and light mass holes, with magnetic coupling proceeding through Kondo and/or antiKondo coupling separately through the two carrier types. The ratio of the linear specific heat coefficient and the calculated Fermi level density of states indicates a large mass enhancement $m^*/m \sim 5$, or larger if a correlated band structure is taken as the reference

Enhancement of vaccinia virus based oncolysis with histone deacetylase inhibitors

Histone deacetylase inhibitors (HDI) dampen cellular innate immune response by decreasing interferon production and have been shown to increase the growth of vesicular stomatitis virus and HSV. As attenuated tumour-selective oncolytic vaccinia viruses (VV) are already undergoing clinical evaluation, the goal of this study is to determine whether HDI can also enhance the potency of these poxviruses in infection-resistant cancer cell lines. Multiple HDIs were tested and Trichostatin A (TSA) was found to potently enhance the spread and replication of a tumour selective vaccinia virus in several infection-resistant cancer cell lines. TSA significantly decreased the number of lung metastases in a syngeneic B16F10LacZ lung metastasis model yet did not increase the replication of vaccinia in normal tissues. The combination of TSA and VV increased survival of mice harbouring human HCT116 colon tumour xenografts as compared to mice treated with either agent alone. We conclude that TSA can selectively and effectively enhance the replication and spread of oncolytic vaccinia virus in cancer cells. © 2010 MacTavish et al

Waveguide-coupled detector in zero-change complementary metal–oxide–semiconductor

We report a waveguide-coupled photodetector realized in a standard CMOS foundry without requiring changes to the process flow (zero-change CMOS). The photodetector exploits carrier generation in the silicon-germanium normally utilized as stressor in pFETs. The measured responsivity and 3 dB bandwidth are of 0.023 A/W at a wavelength of 1180 nm and 32 GHz at −1 V bias (18 GHz at 0 V bias). The dark current is less than 10 pA and the dynamic range is larger than 60 dB.United States. Defense Advanced Research Projects Agency. Photonically Optimized Embedded Microprocessors Program (Award HR0011-11-C-0100)United States. Defense Advanced Research Projects Agency. Photonically Optimized Embedded Microprocessors Program (Contract HR0011-11-9-0009

ID-HALL, a new double stage Hall thruster design. I. Principle and hybrid model of ID-HALL

International audienceIn Hall thrusters, ions are extracted from a quasineutral plasma by the electric field induced by the local drop of electron conductivity associated with the presence of a magnetic barrier. Since the electric field is used both to extract and accelerate ions and to generate the plasma, thrust and specific impulse are not independent in a Hall thruster. There is a need for versatile thrusters that can be used for a variety of maneuvers, i.e., that can operate either at high thrust or at high specific impulse for a given power. The double stage Hall thruster (DSHT) design could allow a separate control of ionization and acceleration, and hence separate control of thrust and specific impulse. In the DSHT configuration, a supplementary plasma source (ionization stage), independent of the applied voltage, is added and placed upstream of the magnetic barrier (acceleration stage). The DSHT concept is also well adapted to the use of alternative propellants, lighter and with a less efficient ionization than xenon. Several designs of double stage Hall thrusters have been proposed in the past, but these attempts were not really successful. In this paper, we present a brief review of the main DSHT designs described in the literature, we discuss the relevance of the DSHT concept, and, on the basis of simple physics arguments and simulation results, we propose a new design, called ID-HALL (Inductive Double stage HALL thruster). In this design, the ionization stage is a magnetized inductively coupled RF plasma. The inductive coil is inside the central cylinder of the thruster and located nearby the acceleration stage. Preliminary modeling results of this DSHT are described. Published by AIP Publishing. https://doi

New combined PIC-MCC approach for fast simulation of a radio frequency discharge at low gas pressure

A new combined PIC-MCC approach is developed for accurate and fast simulation of a radio frequency discharge at low gas pressure and high density of plasma. Test calculations of transition between different modes of electron heating in a ccrf discharge in helium and argon show a good agreement with experimental data. We demonstrate high efficiency of the combined PIC-MCC algorithm, especially for the collisionless regime of electron heating.Comment: 6 paged, 8 figure