699 research outputs found

    On Higgs-exchange DIS, physical evolution kernels and fourth-order splitting functions at large x

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    We present the coefficient functions for deep-inelastic scattering (DIS) via the exchange of a scalar phi directly coupling only to gluons, such as the Higgs boson in the limit of a very heavy top quark and n_f effectively massless light flavours, to the third order in perturbative QCD. The two-loop results are employed to construct the next-to-next-to-leading order physical evolution kernels for the system (F_2 F_phi) of flavour-singlet structure functions. The practical relevance of these kernels as an alternative to MSbar factorization is bedevilled by artificial double logarithms at small values of the scaling variable x, where the large top-mass limit ceases to be appropriate. However, they show an only single-logarithmic enhancement at large x. Conjecturing that this feature persists to the next order also in the present singlet case, the three-loop coefficient functions facilitate exact predictions (backed up by their particular colour structure) of the double-logarithmic contributions to the fourth-order singlet splitting functions, i.e., of the terms (1-x)^a ln^k(1-x) with k = 4, 5, 6 and k = 3, 4, 5, respectively, for the off-diagonal and diagonal quantities to all powers a in 1-x.Comment: 75 pages, LaTeX, 13 figures (.eps). FORM and Fortran files of main results appended to sourc

    Part 1: a process view of nature. Multifunctional integration and the role of the construction agent

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    This is the first of two linked articles which draw s on emerging understanding in the field of biology and seeks to communicate it to those of construction, engineering and design. Its insight is that nature 'works' at the process level, where neither function nor form are distinctions, and materialisation is both the act of negotiating limited resource and encoding matter as 'memory', to sustain and integrate processes through time. It explores how biological agents derive work by creating 'interfaces' between adjacent locations as membranes, through feedback. Through the tension between simultaneous aggregation and disaggregation of matter by agents with opposing objectives, many functions are integrated into an interface as it unfolds. Significantly, biological agents induce flow and counterflow conditions within biological interfaces, by inducing phase transition responses in the matte r or energy passing through them, driving steep gradients from weak potentials (i.e. shorter distances and larger surfaces). As with biological agents, computing, programming and, increasingly digital sensor and effector technologies share the same 'agency' and are thus convergent

    Диагностика патриотической культуры студентов

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    В статье раскрываются основные структурные компоненты патриотической культуры личности: гностический, мотивационный, эмоционально-волевой, поведенческий и нормативно-оценочный. Описывается алгоритм измерения сформированности патриотической культуры личности на основе шкалы суждений. Для обработки результатов опроса использован шкалограммный анализ Л. Гутмана

    Novel Psychoactive Substances (NPS): no longer legal, not always highs

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    Toward an ontology of tobacco, nicotine and vaping products.

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    Ontologies are ways of representing information that improve clarity and the ability to connect different data sources. This paper proposes an initial version of an ontology of tobacco, nicotine and vaping products with the aim of reducing ambiguity and confusion in the field. Terms related to tobacco, nicotine and vaping products were identified in the research literature and their usage characterised. Basic Formal Ontology was used as a unifying upper-level ontology to describe the domain, and classes with definitions and labels were developed linking them to this ontology. Labels, definitions and properties were reviewed and revised in an iterative manner until a coherent set of classes was agreed by the authors. Overlapping, but distinct classes were developed: 'tobacco-containing product', 'nicotine-containing product' and 'vaping device'. Subclasses of tobacco-containing products are 'combustible tobacco-containing product', 'heated tobacco product' and 'smokeless tobacco-containing product'. Subclasses of combustible tobacco-containing product include 'cigar', 'cigarillo', 'bidi' and 'cigarette' with further subclasses including 'manufactured cigarette'. Manufactured cigarettes have properties that include 'machine-smoked nicotine yield' and 'machine-smoked tar yield'. Subclasses of smokeless tobacco product include 'nasal snuff', 'chewing tobacco product', and 'oral snuff' with its subclass 'snus'. Subclasses of nicotine-containing product include 'nicotine lozenge' and 'nicotine transdermal patch'. Subclasses of vaping device included 'electronic vaping device' with a further subclass, 'e-cigarette'. E-cigarettes have evolved with a complex range of properties including atomiser resistance, battery power, properties of consumables including e-liquid nicotine concentration and flavourings, and the ontology characterises classes of product accordingly. Use of an ontology of tobacco, nicotine and vaping products should help reduce ambiguity and confusion in tobacco control research and practice. [Abstract copyright: © 2022 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.

    Toward an ontology of identity-related constructs in addiction, with examples from nicotine and tobacco research.

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    We aimed to create a basic set of definitions and relationships for identity-related constructs, as part of the Addiction Ontology and E-Cigarette Ontology projects, that could be used by researchers with diverse theoretical positions and so facilitate evidence synthesis and interoperability. We reviewed the use of identity-related constructs in psychological and social sciences and how these have been applied to addiction with a focus on nicotine and tobacco research. We, then, used an iterative process of adaptation and review to arrive at a basic set of identity-related classes with labels, definitions and relationships that could provide a common framework for research. We propose that 'identity' be used to refer to 'a cognitive representation by a person or group of themselves', with 'self-identity' referring to an individual's identity and 'group identity' referring to an identity held by a social group. Identities can then be classified at any level of granularity based on the content of the representations (e.g. 'tobacco smoker identity', 'cigarette smoker identity' and 'vaper identity'). We propose distinguishing identity from 'self-appraisal' to capture the distinction between the representation of oneself (e.g. as an 'ex-smoker') and (i) the importance and (ii) the positive or negative evaluation that we attach to what is represented. We label an identity that is appraised as enduring as a 'core identity', related to 'strong identity' because of the appraisal as important. Identities that are appraised positively or negatively involve 'positive self-appraisal' and 'negative self-appraisal' respectively. This allows us to create 'logically defined classes' of identity by combining them (e.g. 'positive core cigarette smoker identity' to refer to a cigarette smoker self-identity that is both positive and important). We refer to the totality of self-identities of a person as a 'composite self-identity'. An ontology of identity constructs may assist in improving clarity when discussing theories and evidence relating to this construct in addiction research. [Abstract copyright: © 2022 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.

    Reconstructing boulder deposition histories: extreme wave signatures on a complex rocky shoreline of Malta

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    The Żonqor coastline, southeast Malta, displays an exceptional range of geomorphic signatures of extreme coastal events. This paper brings together evidence acquired from a field survey, analysis of time-sequential imagery, and hydrodynamic modelling to investigate the histories of boulder groups identified by their intrinsic and contextual characteristics. Clear differences are revealed between the distribution of boulders recently moved and those of considerable age. Tracking the movement of boulders since 1957 confirms that storms of surprisingly frequent interval are capable of complex boulder movements, including lifting of megaclasts. Scrutiny of the ancient boulders, including weathering features and fascinating landward-facing (reverse) imbrication, cautiously suggests tsunami as the agent for their emplacement. A novel method is developed for depicting the velocity decay profiles of hypothetical waves, which overcomes some of the limitations of the Nott approach. Applied here, the wave run-up context further sets the ancient movers apart from their recent mover companions. The combined evidence implies a palimpsestic landscape where storm waves are regular geomorphic agents that add to and rework the distribution of boulders close to the shoreline, but over long time periods the landscape becomes reset by tsunami—a concept that is of value to agencies in Malta responsible for coastal safety, planning and management
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