545 research outputs found

    One-Sided Projections on C*-algebras

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    In [BEZ] the notion of a complete one-sided M-ideal for an operator space X was introduced as a generalization of Alfsen and Effros' notion of an M-ideal for a Banach space [AE72]. In particular, various equivalent formulations of complete one-sided M-projections were given. In this paper, some sharper equivalent formulations are given in the special situation that X=AX = \mathcal{A}, a C∗C^*-algebra (in which case the complete left M-projections are simply left multiplication on A\mathcal{A} by a fixed orthogonal projection in A\mathcal{A} or its multiplier algebra). The proof of the first equivalence makes use of a technique which is of interest in its own right--a way of ``solving'' multi-linear equations in von Neumann algebras. This technique is also applied to show that preduals of von Neumann algebras have no nontrivial complete one-sided M-ideals. In addition, we show that in a C∗C^*-algebra, the intersection of finitely many complete one-sided M-summands need not be a complete one-sided M-summand, unlike the classical situation

    FORTRAN programming - A self-taught course

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    Comprehensive programming course begins with numerical systems and basic concepts, proceeds systematically through FORTRAN language elements, and concludes with discussion of programming techniques. Course is suitable either for individual study or for group study on informal basis

    Operator *-correspondences in analysis and geometry

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    An operator *-algebra is a non-selfadjoint operator algebra with completely isometric involution. We show that any operator *-algebra admits a faithful representation on a Hilbert space in such a way that the involution coincides with the operator adjoint up to conjugation by a symmetry. We introduce operator *-correspondences as a general class of inner product modules over operator *-algebras and prove a similar representation theorem for them. From this we derive the existence of linking operator *-algebras for operator *-correspondences. We illustrate the relevance of this class of inner product modules by providing numerous examples arising from noncommutative geometry.Comment: 31 pages. This work originated from the MFO workshop "Operator spaces and noncommutative geometry in interaction

    Neutrophil apoptosis, phagocytosis and oxidative metabolism in septic patients

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    Sepse denota a continuidade de um processo de injuria tecidual onde a disfuncao organica multipla representa sua expressao mais grave. Trata-se de uma condicao patologica associada a altas taxas de mortalidade. Diferentes linhagens celulares estao relacionadas a sua fisiopatogenia. Neutrofilos, por exemplo, sao as primeiras celulas da linha de defesa a migrarem para os sitios de inflamacao e/ou infeccao. Suas funcoes primarias incluem fagocitose de bacterias, elaboracao de enzimas oxidativas e nao oxidativas de degradacao, e formacao de fatores quimiotaticos para recrutar outras celulas inflamatorias. O objetivo desse estudo foi avaliar os efeitos da sepse grave e do choque septico na apoptose e na funcao de neutrofilos, sendo esta analisada pela capacidade fagocitica e pelo metabolismo oxidativo. Para tanto, foram incluidos 10 pacientes com quadro clinico e laboratorial de sepse grave ou choque septico com menos de 48 horas de evolucao, classificados de acordo com as definicoes do consenso de 1992 do American College of Chest Physicians / Society of Critical Care Medicine Consensus Conference, internados em Unidade de Terapia Intensiva do Hospital São Paulo, e 10 individuos sadios, maiores de 18 anos, que nao se encontravam em uso de nenhum medicamento, considerados controles. De cada paciente ou voluntario sadio foram coletadas amostras de 10 ml de sangue arterial ou venoso periferico em tubos estereis com 100 U de heparina para realizacao dos ensaios de apoptose, fagocitose e metabolismo oxidativo, utilizando citometria de fluxo...(au)BV UNIFESP: Teses e dissertaçõe

    Noncommutative Figa-Talamanca-Herz algebras for Schur multipliers

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    We introduce a noncommutative analogue of the Fig\'a-Talamanca-Herz algebra Ap(G)A_p(G) on the natural predual of the operator space Mp,cb\frak{M}_{p,cb} of completely bounded Schur multipliers on Schatten space SpS_p. We determine the isometric Schur multipliers and prove that the space Mp\frak{M}_{p} of bounded Schur multipliers on Schatten space SpS_p is the closure in the weak operator topology of the span of isometric multipliers.Comment: 24 pages; corrected typo

    Eradication of poliomyelitis in South Africa

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    An international campaign under the leadership of the World Health Organisation is underway to eradicate polio from the world by the year 2000. South Africa may already be free of polio. However, to ensure eradication we need to move from a polio control programme to a polio eradication programme. This necessitates the institution of a surveillance programme for acute flaccid paralysis (AFP) and improvement of the delivery of polio vaccine. All children with AFP (including those with suspected GuillainBarre syndrome) should be investigated with stool culture to exclude polio. Primary care services need strengthening so that oral polio vaccine coverage greater than 90% is achieved in all regions by all authorities. Outbreak response activities need to be developed. Consideration needs to be given to national immunisation days and mopping-up activities
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