1,744 research outputs found

    Auxiliary Fields for Super Yang-Mills from Division Algebras

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    Division algebras are used to explain the existence and symmetries of various sets of auxiliary fields for super Yang-Mills in dimensions d=3,4,6,10d=3,4,6,10. (Contribution to G\"ursey Memorial Conference I: Strings and Symmetries)Comment: 7 pages, plain TeX, CERN-TH.7470/9

    Is group psychotherapy feasible for oncology outpatients attenders selected on the basis of psychological morbidity?

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    Of 120 consecutive attenders at an oncology outpatients department, 108 were screened for psychological symptoms using the Hospital Anxiety and Depression Scale (Zigmond & Snaith, 1983). Thirty-nine patients had significant scores indicating moderate anxiety and/or depression. We felt that this warranted an offer of group psychotherapy in the belief that sharing issues and exploring personal concerns may alleviate some of the experienced psychological distress. Only 10 patients consented to and were able to attend this group, with which five patients persisted. Thus in this group of patients with advanced cancer group psychotherapy was applicable only to a limited number of selected patients. The nature of this study and the size of the population markedly limited our ability to comment on the usefulness of group psychotherapy. Many patients, particularly the most severely psychologically distressed, continued to require other forms of support, particularly domiciliary individual therapy

    Pathogenic Potential to Humans of Bovine Escherichia coli O26, Scotland

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    Escherichia coli O26 and O157 have similar overall prevalences in cattle in Scotland, but in humans, Shiga toxin–producing E. coli O26 infections are fewer and clinically less severe than E. coli O157 infections. To investigate this discrepancy, we genotyped E. coli O26 isolates from cattle and humans in Scotland and continental Europe. The genetic background of some strains from Scotland was closely related to that of strains causing severe infections in Europe. Nonmetric multidimensional scaling found an association between hemolytic uremic syndrome (HUS) and multilocus sequence type 21 strains and confirmed the role of stx<sub>2</sub> in severe human disease. Although the prevalences of E. coli O26 and O157 on cattle farms in Scotland are equivalent, prevalence of more virulent strains is low, reducing human infection risk. However, new data on E. coli O26–associated HUS in humans highlight the need for surveillance of non-O157 enterohemorrhagic E. coli and for understanding stx<sub>2</sub> phage acquisition

    Developing an improved soil moisture dataset by blending passive and active microwave satellite-based retrievals

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    Combining information derived from satellitebased passive and active microwave sensors has the potential to offer improved estimates of surface soil moisture at global scale. We develop and evaluate a methodology that takes advantage of the retrieval characteristics of passive (AMSR-E) and active (ASCAT) microwave satellite estimates to produce an improved soil moisture product. First, volumetric soil water content (m3 m−3) from AMSR-E and degree of saturation (%) from ASCAT are rescaled against a reference land surface model data set using a cumulative distribution function matching approach. While this imposes any bias of the reference on the rescaled satellite products, it adjusts them to the same range and preserves the dynamics of original satellite-based products. Comparison with in situ measurements demonstrates that where the correlation coefficient between rescaled AMSR-E and ASCAT is greater than 0.65 (“transitional regions”), merging the different satellite products increases the number of observations while minimally changing the accuracy of soil moisture retrievals. These transitional regions also delineate the boundary between sparsely and moderately vegetated regions where rescaled AMSR-E and ASCAT, respectively, are used for the merged product. Therefore the merged product carries the advantages of better spatial coverage overall and increased number of observations, particularly for the transitional regions. The combination method developed has the potential to be applied Correspondence to: Y. Y. Liu ([email protected]) to existing microwave satellites as well as to new missions. Accordingly, a long-term global soil moisture dataset can be developed and extended, enhancing basic understanding of the role of soil moisture in the water, energy and carbon cycles

    A study of the etapipi channel produced in central pp interactions at 450 GeV/c

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    The reaction pp -> pf (eta pi pi) ps has been studied at 450 GeV/c. There is clear evidence for an a2(1320)pi decay mode of the eta2(1645) and eta2(1870). In addition, there is evidence for an a0(980)pi$ decay mode of both resonances and an f2(1270)eta decay mode of the eta2(1870). No evidence is found for a JPC = 2++ a2(1320)pi wave.Comment: 15 pages, Latex, 4 Figures Branching ratio a2pi /f2 eta correcte

    Renormalized quantum tomography

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    The core of quantum tomography is the possibility of writing a generally unbounded complex operator in form of an expansion over operators that are generally nonlinear functions of a generally continuous set of spectral densities--the so-called "quorum" of observables. The expansion is generally non unique, the non unicity allowing further optimization for given criteria. The mathematical problem of tomography is thus the classification of all such operator expansions for given (suitably closed) linear spaces of unbounded operators--e.g. Banach spaces of operators with an appropriate norm. Such problem is a difficult one, and remains still open, involving the theory of general basis in Banach spaces, a still unfinished chapter of analysis. In this paper we present new nontrivial operator expansions for the quorum of quadratures of the harmonic oscillator, and introduce a first very preliminary general framework to generate new expansions based on the Kolmogorov construction. The material presented in this paper is intended to be helpful for the solution of the general problem of quantum tomography in infinite dimensions, which corresponds to provide a coherent mathematical framework for operator expansions over functions of a continuous set of spectral densities.Comment: 23 pages, no figure

    A study of the f0(1370), f0(1500), f0(2000) and f2(1950) observed in the centrally produced 4pi final states

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    The production and decay properties of the f0(1370), f0(1500), f0(2000) and f2(1950) have been studied in central pp interactions at 450 GeV/c. The dPT, phi and |t| distributions of these resonances are presented. For the J = 0 states, the f0(1370) and f0(2000) have similar dPT and phi dependences. These are different to the dPT and phi dependences of the f0(980), f0(1500) and f0(1710). For the J = 2 states the f2(1950) has different dependences to the f2(1270) and f2'(1520). This shows that the dPT and phi dependences are not just J phenomena.Comment: 14 pages, Latex, 4 Figure

    Topological Quantum Field Theories and Operator Algebras

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    We review "quantum" invariants of closed oriented 3-dimensional manifolds arising from operator algebras.Comment: For proceedings of "International Workshop on Quantum Field Theory and Noncommutative Geometry", Sendai, November 200

    Localization of gauge theory on a four-sphere and supersymmetric Wilson loops

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    We prove conjecture due to Erickson-Semenoff-Zarembo and Drukker-Gross which relates supersymmetric circular Wilson loop operators in the N=4 supersymmetric Yang-Mills theory with a Gaussian matrix model. We also compute the partition function and give a new matrix model formula for the expectation value of a supersymmetric circular Wilson loop operator for the pure N=2 and the N=2* supersymmetric Yang-Mills theory on a four-sphere. A four-dimensional N=2 superconformal gauge theory is treated similarly.Comment: 63 pages, 1 figure; v2: correction of mass parameter; v3: typos correcte
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