2,363 research outputs found

    Western Australia intercultural arts research project : an investigation into culturally and linguistically diverse art and artists in Western Australia

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    Background: The introduction of the Australia Council\u27s \u27Arts in a Multicultural Australia Policy\u27 (AIMAP) (2000) represented a shift in how the arts in multicultural communities were viewed. It has long been recognised that the arts play a significant role in promoting social cohesion, social policy goals, economic growth, and shaping a nation’s sense of identity. However, prior to the introduction of this policy, multicultural arts was typically seen as involving cultural retentive activities which had their roots in expressions of migrant cultural traditions. The introduction of the policy heralded the beginning of an era in which culturally and linguistically diverse (CaLD) Australians were seen as integral to the fabric of the Australian arts sector. Evaluation of the policy in 2005 however, revealed that culturally and linguistically diverse Australians were under-represented in most artistic categories. Western Australia is the most culturally diverse state in Australia. It is therefore of great interest to the State Government to have a comprehensive picture of the situation in that state. Hence, the Office of Multicultural Interests (OMI) commissioned Deakin University to undertake an investigation into the participation rates of CaLD artists in the arts sector in Western Australia.Scope: The project examined the participation in the arts of CaLD artists in Western Australia. The arts sector comprises many more individuals and organisations than artists. For example, there are arts agency administrators, venue operators, policy officers, curators, and countless others who work together to make up the arts sector. This project focused on the artists, the individuals such as those who make music, visual art, dance and theatre performances. In the past it has been shown that CaLD populations are not well represented in the broader arts sector. This research aimed to discover the current position for CaLD artists in terms of participation in the broader arts sector and what factors influence their situation

    Bayesian Optimization for Probabilistic Programs

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    We present the first general purpose framework for marginal maximum a posteriori estimation of probabilistic program variables. By using a series of code transformations, the evidence of any probabilistic program, and therefore of any graphical model, can be optimized with respect to an arbitrary subset of its sampled variables. To carry out this optimization, we develop the first Bayesian optimization package to directly exploit the source code of its target, leading to innovations in problem-independent hyperpriors, unbounded optimization, and implicit constraint satisfaction; delivering significant performance improvements over prominent existing packages. We present applications of our method to a number of tasks including engineering design and parameter optimization

    Screening for sequence-specific RNA-BPs by comprehensive UV crosslinking

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    BACKGROUND: Specific cis-elements and the associated trans-acting factors have been implicated in the post-transcriptional regulation of gene expression. In the era of genome wide analyses identifying novel trans-acting factors and cis-regulatory elements is a step towards understanding coordinated gene expression. UV-crosslink analysis is a standard method used to identify RNA-binding proteins. Uridine is traditionally used to radiolabel substrate RNAs, however, proteins binding to cis-elments particularly uridine poor will be weakly or not detected. We evaluate here the possibility of using UV-crosslinking with RNA substrates radiolabeled with each of the four ribonucleotides as an approach for screening for novel sequence specific RNA-binding proteins. RESULTS: The radiolabeled RNA substrates were derived from the 3'UTRs of the cloned Eg and c-mos Xenopus laevis maternal mRNAs. Specific, but not identical, uv-crosslinking signals were obtained, some of which corresponded to already identified proteins. A signal for a novel 90 kDa protein was observed with the c-mos 3'UTR radiolabeled with both CTP and GTP but not with UTP. The binding site of the 90 kDa RNA-binding protein was localised to a 59-nucleotide portion of the c-mos 3'UTR. CONCLUSION: That the 90 kDa signal was detected with RNAs radiolabeled with CTP or GTP but not UTP illustrates the advantage of radiolabeling all four nucleotides in a UV-crosslink based screen. This method can be used for both long and short RNAs and does not require knowledge of the cis-acting sequence. It should be amenable to high throughput screening for RNA binding proteins

    Entanglement Entropy, decoherence, and quantum phase transition of a dissipative two-level system

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    The concept of entanglement entropy appears in multiple contexts, from black hole physics to quantum information theory, where it measures the entanglement of quantum states. We investigate the entanglement entropy in a simple model, the spin-boson model, which describes a qubit (two-level system) interacting with a collection of harmonic oscillators that models the environment responsible for decoherence and dissipation. The entanglement entropy allows to make a precise unification between entanglement of the spin with its environment, decoherence, and quantum phase transitions. We derive exact analytical results which are confirmed by Numerical Renormalization Group arguments both for an ohmic and a subohmic bosonic bath. Those demonstrate that the entanglement entropy obeys universal scalings. We make comparisons with entanglement properties in the quantum Ising model and in the Dicke model. We also emphasize the possibility of measuring this entanglement entropy using charge qubits subject to electromagnetic noise; such measurements would provide an empirical proof of the existence of entanglement entropy.Comment: 38 pages, 8 figures, related to cond-mat/0612095 and arXiv:0705.0957; final version to appear in Annals of Physic

    Replacing energy by von Neumann entropy in quantum phase transitions

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    In the thermodynamic limit two distinct states of matter cannot be analytic continuations of each other. Classical phase transitions are characterized by non-analyticities of the free energy. For quantum phase transitions (QPTs) the ground state energy often assumes the role of the free energy. But in a number of important cases this criterion fails to predict a QPT, such as the three-dimensional metal-insulator transition of non-interacting electrons in a random potential (Anderson localization). It is therefore essential that we find alternative criteria that can track fundamental changes in the internal correlations of the ground state wavefunction. Here we propose that QPTs are generally accompanied by non-analyticities of the von Neumann (entanglement) entropy. In particular, the entropy is non-analytic at the Anderson transition, where it exhibits unusual fractal scaling. We also examine two dissipative quantum systems of considerable interest to the study of decoherence and find that non-analyticities occur if and only if the system undergoes a QPT.Comment: 8 pages, 6 figures; Annals of Physics, in press (2006

    Issues in determining alpha_s from hadronic tau decay and electroproduction data

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    We discuss some key issues associated with duality-violating and non-perturbative OPE contributions to the theoretical representations of light quark current-current two-point functions and relevant to precision determinations of alpha_s from hadronic tau decay and electroproduction cross-section data. We demonstrate that analyses with an explicit representation of duality-violating effects are required to bring theoretical errors in such extractions under control, motivating the accompanying paper in these proceedings, which presents the results of such an analysis.Comment: 5 pages, 4 figures. Prepared for the Proceedings of the International Workshop on e+e- collisions from Phi to Psi (PHIPSI11), Sep. 19-22, 2011, BINP, Novosibirsk, Russi

    Entanglement of spin chains with general boundaries and of dissipative systems

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    We analyze the entanglement properties of spins (qubits) close to the boundary of spin chains in the vicinity of a quantum critical point and show that the concurrence at the boundary is significantly different from the one of bulk spins. We also discuss the von Neumann entropy of dissipative environments in the vicinity of a (boundary) critical point, such as two Ising-coupled Kondo-impurities or the dissipative two-level system. Our results indicate that the entanglement (concurrence and/or von Neumann entropy) changes abruptly at the point where coherent quantum oscillations cease to exist. The phase transition modifies significantly less the entanglement if no symmetry breaking field is applied and we argue that this might be a general property of the entanglement of dissipative systems. We finally analyze the entanglement of an harmonic chain between the two ends as function of the system size.Comment: 21 pages, 9 figure

    An analysis of 1.55 mu m InAs/InP quantum dash lasers

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    Calculations show that electron states are not confined in the dashes in 1.55 mu m InAs/InP quantum dash-in-a-well laser structures. The combination of strain and three-dimensional confinement reduces the calculated density of states (DOS) near the valence band maximum, with the conduction and valence DOS then almost equal close to the band edges. Calculations and photoabsorption measurements show strongly polarized spontaneous emission and gain spectra. Experimental analysis shows the room temperature threshold current is dominated by nonradiative current paths. (C) 2008 American Institute of Physics. (DOI: 10.1063/1.2952194
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