221 research outputs found

    Abstract Representation of Music: A Type-Based Knowledge Representation Framework

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    The wholesale efficacy of computer-based music research is contingent on the sharing and reuse of information and analysis methods amongst researchers across the constituent disciplines. However, computer systems for the analysis and manipulation of musical data are generally not interoperable. Knowledge representation has been extensively used in the domain of music to harness the benefits of formal conceptual modelling combined with logic based automated inference. However, the available knowledge representation languages lack sufficient logical expressivity to support sophisticated musicological concepts. In this thesis we present a type-based framework for abstract representation of musical knowledge. The core of the framework is a multiple-hierarchical information model called a constituent structure, which accommodates diverse kinds of musical information. The framework includes a specification logic for expressing formal descriptions of the components of the representation. We give a formal specification for the framework in the Calculus of Inductive Constructions, an expressive logical language which lends itself to the abstract specification of data types and information structures. We give an implementation of our framework using Semantic Web ontologies and JavaScript. The ontologies capture the core structural aspects of the representation, while the JavaScript tools implement the functionality of the abstract specification. We describe how our framework supports three music analysis tasks: pattern search and discovery, paradigmatic analysis and hierarchical set-class analysis, detailing how constituent structures are used to represent both the input and output of these analyses including sophisticated structural annotations. We present a simple demonstrator application, built with the JavaScript tools, which performs simple analysis and visualisation of linked data documents structured by the ontologies. We conclude with a summary of the contributions of the thesis and a discussion of the type-based approach to knowledge representation, as well as a number of avenues for future work in this area

    Studies in theory and method in sociolinguistics

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    PhD ThesisProblems raised in a pilot linguistic survey of a street in Newcastle upon Tyne (Pellowe 1967) are here treated positively. An informal normative model of the hearer's treatment of the speaker's output is developed in terms both of psychological processing and of social interpretation. This model is then interpreted methodologically and used to generate an analytical framework and a set of mete-interpretive procedures. These are tested in various ways on samples of speech from members of the Tyneside speech community, on experimental groups of hearers and speakers, and on various miscellaneous data. The generality, replicability and accountability of the methods are examined, and the consequences of the model and its techniques are contrasted with those of other studies

    Gorceixia decurrens (Compositae: Vernonieae): nova espécie para o estado da Bahia, Brasil

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    Recent fieldwork and collections have added a new genus to the Compositae flora of Bahia State, Brazil. Gorceixia decurrens is newly recorded for the State from Caatinga woodland along the lower part of the Estrada Real, in the municipality of Rio de Contas. A full description is provided, its distribution and conservation status discussed; likely affinities in the Vernonieae are discussed with the conclusion that it belongs to the subtribe Piptocarphinae.Trabalhos de campo e coletas recentes na Bahia, Brasil, permitiram adicionar mais um gênero para a flora do Estado. Gorceixia decurrens foi coletada em 2001, em área de Caatinga Arbórea, na base da Estrada Real no município a Rio de Contas. É fornecida uma completa descrição da espécie e discussão sobre sua distribuição e estado de conservação. Também, é apresentada discussão do posicionamento do gênero monotípico nas Vernonieae concluindo-se que o mesmo pertence à subtribo Piptocarphinae

    The Physics of Indirect Estimators of Lyman Continuum Escape and their Application to High-Redshift JWST Galaxies

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    Reliable indirect diagnostics of LyC photon escape from galaxies are required to understand which sources were the dominant contributors to reionization. While multiple escape fraction (fescf_{\rm esc}) indicators have been proposed to trace favourable conditions for LyC leakage from the interstellar medium of low-redshift ``analog'' galaxies, it remains unclear whether these are applicable at high redshifts where LyC emission cannot be directly observed. Using a library of 14,120 mock spectra of star-forming galaxies with redshifts 4.64≤z≤104.64 \leq z \leq 10 from the SPHINX20^{20} cosmological radiation hydrodynamics simulation, we develop a framework for the physics that leads to high fescf_{\rm esc}. We investigate LyC leakage from our galaxies based on the criteria that successful LyC escape diagnostics must \textit{i)} track a high specific star formation rate, \textit{ii)} be sensitive to stellar population age in the range 3.5−103.5-10~Myr representing the times when supernova first explode to when LyC production significantly drops, and \textit{iii)} include a proxy for neutral gas content and gas density in the interstellar medium. O32{\rm O}_{32}, ΣSFR\Sigma_{\rm SFR}, MUV_{\rm UV}, and Hβ\beta equivalent width select for one or fewer of our criteria, rendering them either necessary but insufficient or generally poor diagnostics. In contrast, UV slope (β\beta), and E(B−V){\rm E(B-V)} match two or more of our criteria, rendering them good fescf_{\rm esc} diagnostics (albeit with significant scatter). Using our library, we build a quantitative model for predicting fescf_{\rm esc} based on β\beta, E(B−V){\rm E(B-V)}, Hβ\beta, MUV_{\rm UV}, R23{\rm R_{23}}, and O32{\rm O_{32}}. When applied to bright z>6z > 6 Lyα\alpha emitters observed with JWST, we find that the majority of them have fesc≲10%f_{\rm esc} \lesssim 10\%.Comment: 16 pages, 15 figures, 1 table, submitted to MNRA

    Reviews

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    C.S. Lewis, Poetry, and the Great War 1914-1918. John Bremer. Reviewed by Joe R. Christopher. Collected Poems. Hope Mirrlees. Ed. and intro. Sandeep Parmar. Reviewed by Nicholas Birns. Fantasy, Art and Life: Essays on George MacDonald, Robert Louis Stevenson and Other Fantasy Writers. William Gray. Reviewed by Scott McLaren. C. S. Lewis and the Middle Ages. Robert Boenig. Reviewed by Holly Ordway. Sherlock Holmes for the 21st Century: Essays on New Adaptations. Edited by Lynnette Porter. Reviewed by Janet Brennan Croft. Dancing the Tao: Le Guin and Moral Development. Sandra J. Lindow. Reviewed by Carl Badgley. Hobbit Place-names: A Linguistic Excursion Through the Shire. Rainer Nagel. Reviewed by Troels Forchhammer. The Broken Scythe: Death and Immortality in the Works of J.R.R. Tolkien. Edited by Roberto Arduini and Claudio A. Testi. Reviewed by Harley J. Sims. The Hobbit Tarot. Terry Donaldson (author of guide pamphlet) and Peter Pracownik (artist). Reviewed by Emily A Auger. The Lord of the Rings Tarot Deck and Card Game. Terry Donaldson (author of guidebook), Peter Pracownik (artist), and Mike Fitzgerald (game rules). Reviewed by Emily A Auger. J.K. Rowling: Harry Potter. Edited by Cynthia J. Hallett and Peggy J. Huey. Reviewed by Janet Brennan Croft

    Identification of Differentially Expressed Proteins in Murine Embryonic and Postnatal Cortical Neural Progenitors

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    BACKGROUND: The central nervous system (CNS) develops from a heterogeneous pool of neural stem and progenitor cells (NSPC), the underlying differences among which are poorly understood. The study of NSPC would be greatly facilitated by the identification of additional proteins that mediate their function and that would distinguish amongst different progenitor populations. METHODOLOGY/PRINCIPAL FINDINGS: To identify membrane and membrane-associated proteins expressed by NSPC, we used a proteomics approach to profile NSPC cultured as neurospheres (NS) isolated from the murine cortex during a period of neurogenesis (embryonic day 11.5, E11.5), as compared to NSPC isolated at a peak of gliogenesis (postnatal day 1, P0) and to differentiated E11.5 NS. 54 proteins were identified with high expression in E11.5 NS, including the TrkC receptor, several heterotrimeric G proteins, and the Neogenin receptor. 24 proteins were identified with similar expression in E11.5 and P0 NS over differentiated E11.5 NS, and 13 proteins were identified with high expression specifically in P0 NS compared to E11.5 NS. To illustrate the potential relevance of these identified proteins to neural stem cell biology, the function of Neogenin was further studied. Using Fluorescence Activated Cell Sorting (FACS) analysis, expression of Neogenin was associated with a self-renewing population present in both E11.5 and adult subventricular zone (SVZ) NS but not in P0 NS. E11.5 NS expressed a putative Neogenin ligand, RGMa, and underwent apoptosis when exposed to a ligand-blocking antibody. CONCLUSIONS/SIGNIFICANCE: There are fundamental differences between the continuously self-renewing and more limited progenitors of the developing cortex. We identified a subset of differentially expressed proteins that serve not only as a set of functionally important proteins, but as a useful set of markers for the subsequent analysis of NSPC. Neogenin is associated with the continuously self-renewing and neurogenic cells present in E11.5 cortical and adult SVZ NS, and the Neogenin/RGMa receptor/ligand pair may regulate cell survival during development

    In Space Assembled Telescope (ISAT) Study Preliminary Findings

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    When is it advantageous to assemble telescopes in space rather than deploying them from launch vehicle fairings? This question forms the crux of the objectives of a NASA study we have been conducting in collaboration with colleagues from different NASA centers, industry and academia. In this study, we have engaged a broad cross section of experts from the various fields of optics engineering, that is, telescope design and instrument design, structure and thermal engineering, robotics, launch system engineering, orbital mechanics, integration and testing, astrophysics, and NASA programmatics among others. Initial efforts began with a quick review of the current state of art of the component technologies that contribute towards an in-space assembled telescope. Then, leveraging the collective expertise of the diverse group of experts, we formulated a reference telescope design and attempted to develop a baseline approach to modularize the telescope into components amenable for robotic assembly. The group identified different trades associated with modularization and also developed a set of criteria to discern between the different options as revealed by the trades. Based on the modularization of the telescope, we will assess the impact of various launch vehicles, orbits for assembly and operation, robotic systems and operational approaches, and other related variables. From this, a concept to assemble the reference telescope in space from modular components will be developed. Based on this concept, and definition of the modules, we will develop a mission lifecycle plan for an assembled telescope over different phases of preliminary design, detailed design, assembly-test-and-integration, and in space operations. The mission lifecycle plan will be used to evaluate cost and risk implications of in-space assembly toward answering our fundamental question of the advantages, if any, of assembling a telescope in space as compared to self-deployment. In this paper, we summarize the objectives of the study, a review of the status of the underlying component technologies, a description of the methodology, including three different multi-day technical interchange meetings (TIMs), summary of findings from the TIMs and other related activities. In addition, a detailed description of the various factors that impact in-space assembly, their interplay and criteria for discerning among them, a preliminary description of the life cycle plan, including the test and integration plan, and initial observations on cost and risk implications will be included in the paper
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