116 research outputs found

    Correlation Between the Deuteron Characteristics and the Low-energy Triplet np Scattering Parameters

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    The correlation relationship between the deuteron asymptotic normalization constant, ASA_{S}, and the triplet np scattering length, ata_{t}, is investigated. It is found that 99.7% of the asymptotic constant ASA_{S} is determined by the scattering length ata_{t}. It is shown that the linear correlation relationship between the quantities AS2A_{S}^{-2} and 1/at1/a_{t} provides a good test of correctness of various models of nucleon-nucleon interaction. It is revealed that, for the normalization constant ASA_{S} and for the root-mean-square deuteron radius rdr_{d}, the results obtained with the experimental value recommended at present for the triplet scattering length ata_{t} are exaggerated with respect to their experimental counterparts. By using the latest experimental phase shifts of Arndt et al., we obtain, for the low-energy scattering parameters (ata_{t}, rtr_{t}, PtP_{t}) and for the deuteron characteristics (ASA_{S}, rdr_{d}), results that comply well with experimental data.Comment: 19 pages, 1 figure, To be published in Physics of Atomic Nucle

    Changing a semantics: opportunism or courage?

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    The generalized models for higher-order logics introduced by Leon Henkin, and their multiple offspring over the years, have become a standard tool in many areas of logic. Even so, discussion has persisted about their technical status, and perhaps even their conceptual legitimacy. This paper gives a systematic view of generalized model techniques, discusses what they mean in mathematical and philosophical terms, and presents a few technical themes and results about their role in algebraic representation, calibrating provability, lowering complexity, understanding fixed-point logics, and achieving set-theoretic absoluteness. We also show how thinking about Henkin's approach to semantics of logical systems in this generality can yield new results, dispelling the impression of adhocness. This paper is dedicated to Leon Henkin, a deep logician who has changed the way we all work, while also being an always open, modest, and encouraging colleague and friend.Comment: 27 pages. To appear in: The life and work of Leon Henkin: Essays on his contributions (Studies in Universal Logic) eds: Manzano, M., Sain, I. and Alonso, E., 201

    "Oh! What a tangled web we weave": Englishness, communicative leisure, identity work and the cultural web of the English folk morris dance scene

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    In this paper, we consider the relationship between Englishness and the English folk morris dance scene, considering how the latter draws from and reinforces the former. Englishness is considered within the context of the cultural web; a tool more often applied to business management but linked to a sociological viewpoint here. By doing so, we draw the connections between this structured business model and the cultural identity of Englishness. Then, we use the framework of the cultural web and theories of leisure, culture and identity to understand how morris dancers see their role as dancers and ‘communicative leisure’ agents in consciously defending Englishness, English traditions and inventions, the practices and traditions of folk and morris, and the various symbolic communities they inhabit. We argue that most morris dancers in our research become and maintain their leisured identities as dancers because they are attracted to the idea of tradition – even if that tradition is invented and open to change

    General-elimination stability

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    General-elimination harmony articulates Gentzen's idea that the elimination-rules are justified if they infer from an assertion no more than can already be inferred from the grounds for making it. Dummett described the rules as not only harmonious but stable if the E-rules allow one to infer no more and no less than the I-rules justify. Pfenning and Davies call the rules locally complete if the E-rules are strong enough to allow one to infer the original judgement. A method is given of generating harmonious general-elimination rules from a collection of I-rules. We show that the general-elimination rules satisfy Pfenning and Davies' test for local completeness, but question whether that is enough to show that they are stable. Alternative conditions for stability are considered, including equivalence between the introduction- and elimination-meanings of a connective, and recovery of the grounds for assertion, finally generalizing the notion of local completeness to capture Dummett's notion of stability satisfactorily. We show that the general-elimination rules meet the last of these conditions, and so are indeed not only harmonious but also stable.Publisher PDFPeer reviewe

    A Social Identity Approach to Sport Psychology: Principles, Practice, and Prospects.

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    Drawing on social identity theory and self-categorization theory, we outline an approach to sport psychology that understands groups not simply as features of sporting contexts but rather as elements that can be, and often are, incorporated into a person's sense of self and, through this, become powerful determinants of their sport-related behavior. The underpinnings of this social identity approach are outlined, and four key lessons for sport that are indicative of the analytical and practical power of the approach are presented. These suggest that social identity is the basis for sports group (1) behavior, (2) formation and development, (3) support and stress appraisal, and (4) leadership. Building on recent developments within sport science, we outline an agenda for future research by identifying a range of topics to which the social identity approach could fruitfully contribute

    Antibodies to Malaria Peptide Mimics Inhibit Plasmodium falciparum Invasion of Erythrocytes

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    Apical membrane antigen 1 (AMA1) is expressed on the surfaces of Plasmodium falciparum merozoites and is thought to play an important role in the invasion of erythrocytes by malaria parasites. To select for peptides that mimic conformational B-cell epitopes on AMA1, we screened a phage display library of >10(8) individual peptides for peptides bound by a monoclonal anti-AMA1 antibody, 4G2dc1, known to inhibit P. falciparum invasion of erythrocytes. The most reactive peptides, J1, J3, and J7, elicited antibody responses in rabbits that recognized the peptide immunogen and both recombinant and parasite AMA1. Human antibodies in plasma samples from individuals exposed to chronic malaria reacted with J1 and J7 peptides and were isolated using immobilized peptide immunoadsorbents. Both rabbit and human antibodies specific for J1 and J7 peptides were able to inhibit the invasion of erythrocytes by P. falciparum merozoites. This is the first example of phage-derived peptides that mimic an important epitope of a blood-stage malaria vaccine candidate, inducing and isolating functional protective antibodies. Our data support the use of J1 and J7 peptide mimics as in vitro correlates of protective immunity in future AMA1 vaccine trials
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