16,450 research outputs found

    Decoherence in a Two Slit Diffraction Experiment with Massive Particles

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    Matter-wave interferometry has been largely studied in the last few years. Usually, the main problem in the analysis of the diffraction experiments is to establish the causes for the loss of coherence observed in the interference pattern. In this work, we use different type of environmental couplings to model a two slit diffraction experiment with massive particles. For each model, we study the effects of decoherence on the interference pattern and define a visibility function that measures the loss of contrast of the interference fringes on a distant screen. Finally, we apply our results to the experimental reported data on massive particles C70C_{70}.Comment: 6 pages, 3 figure

    PACemakers of proteasome core particle assembly

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    The 26S proteasome mediates ubiquitin-dependent proteolysis in eukaryotic cells. A number of studies including very recent ones have revealed that assembly of its 20S catalytic core particle is an ordered process that involves several conserved proteasome assembly chaperones (PACs). Two heterodimeric chaperones, PAC1-PAC2 and PAC3-PAC4, promote the assembly of rings composed of seven alpha subunits. Subsequently, P subunits join to form half-proteasome precursor complexes containing all but one of the 14 subunits. These complexes lack the beta 7 subunit but contain UMP1, another assembly chaperone, and in yeast, at least to some degree, the activator protein Blm10. Dimerization of two such complexes is triggered by incorporation of beta 7, whose C-terminal extension reaches out into the other half to stabilize the newly formed 20S particle. The process is completed by the maturation of active sites and subsequent degradation of UMP1 and PAC1-PAC2.Fundacao para a Ciencia e Tecnologia; Deutsche Forschungsgemeinschaf

    An Analysis of the Origins of Ontology Mismatches on the Semantic Web

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    Despite the potential of domain ontologies to provide consensual representations of domain-relevant knowledge, the open, distributed and decentralized nature of the Semantic Web means that individuals will rarely, if ever, countenance a common set of terminological and representational commitments during the ontology design process. More often than not, differences between ontologies are likely to occur, and this is the case even when the ontologies describe identical or overlapping domains of interest. Differences between ontologies are often referred to as ontology mismatches and there is an extensive research literature geared towards the technology-mediated reconciliation of such mismatches. Our approach in the current paper is not to comment on the relative merits or demerits of the various technological solutions that could be used to resolve ontological differences; rather, we aim to explore the reasons why such differences may arise in the first place. In addition to a review of the various factors that contribute to ontology mismatches on the Semantic Web, we also discuss a number of focus areas for future research in this area. An improved understanding of the origins of ontology mismatches will, we argue, complement existing research into semantic integration techniques. In particular, by understanding more about the complex cognitive, epistemic and socio-cultural factors associated with the ontology development process, we may be able to develop knowledge acquisition and modeling tools/techniques that attenuate the impact of ontology mismatches for large-scale information sharing and data integration on the Semantic Web

    Washington’s Limited License Legal Technician Rule and Pathway to Expanded Access for Consumers

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    Washington’s 2012 adoption of a Limited License Legal Technician (LLLT) rule has been a topic of great interest throughout the United States and elsewhere. This Article is co-written by Steve Crossland, who is the Chair of the Washington Supreme Court’s Limited License Legal Technician Board, which is responsible for implementing the rule, and Paula Littlewood, who is the Executive Director of the Washington State Bar Association, which is the unified bar association charged, inter alia, with lawyer and LLLT regulation. This Article builds on the authors’ previous articles about Washington’s LLLT program by providing previously unpublished information about the LLLT program’s implementation and by offering reflections about the program that are informed by the authors’ five-year involvement with the rule (and multi-year involvement with the concept). This Article should prove useful to those interested in learning more about Washington’s rule and to jurisdictions that are considering whether and how to expand access to legal services to address the vast unmet legal needs and the anticipated shortage of lawyers in the future. There are rare moments in history when the opportunity and need for systemic change presents itself for an industry. The legal profession and legal education are at such a crossroads, and the question presented for the profession is what path they will take forward
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