A Poset Connected to Artin Monoids of Simply Laced Type

Let W be a Weyl group whose type is a simply laced Dynkin diagram. On several W-orbits of sets of mutually commuting reflections, a poset is described which plays a role in linear representatons of the corresponding Artin group A. The poset generalizes many properties of the usual order on positive roots of W given by height. In this paper, a linear representation of the positive monoid of A is defined by use of the poset

BMW algebras of simply laced type

It is known that the recently discovered representations of the Artin groups of type A_n, the braid groups, can be constructed via BMW algebras. We introduce similar algebras of type D_n and E_n which also lead to the newly found faithful representations of the Artin groups of the corresponding types. We establish finite dimensionality of these algebras. Moreover, they have ideals I_1 and I_2 with I_2 contained in I_1 such that the quotient with respect to I_1 is the Hecke algebra and I_1/I_2 is a module for the corresponding Artin group generalizing the Lawrence-Krammer representation. Finally we give conjectures on the structure, the dimension and parabolic subalgebras of the BMW algebra, as well as on a generalization of deformations to Brauer algebras for simply laced spherical type other than A_n.Comment: 39 page

Progress in Electroweak Baryogenesis

Recent work on generating the excess of matter over antimatter in the early universe during the electroweak phase transition is reviewed.Comment: 50 pages (figures on request), uses harvmac (table of contents correct for "l" format), UCSD-93-2,BU-HEP-93-

Tangle and Brauer Diagram Algebras of Type Dn

A generalization of the Kauffman tangle algebra is given for Coxeter type Dn. The tangles involve a pole or order 2. The algebra is shown to be isomorphic to the Birman-Murakami-Wenzl algebra of the same type. This result extends the isomorphism between the two algebras in the classical case, which in our set-up, occurs when the Coxeter type is of type A with index n-1. The proof involves a diagrammatic version of the Brauer algebra of type Dn in which the Temperley-Lieb algebra of type Dn is a subalgebra.Comment: 33 page

Hospital implementation of health information technology and quality of care: are they related?

Recently, there has been considerable effort to promote the use of health information technology (HIT) in order to improve health care quality. However, relatively little is known about the extent to which HIT implementation is associated with hospital patient care quality. We undertook this study to determine the association of various HITs with: hospital quality improvement (QI) practices and strategies; adherence to process of care measures; risk-adjusted inpatient mortality; patient satisfaction; and assessment of patient care quality by hospital quality managers and front-line clinicians.This work was supported by a grant from the Commonwealth Fund. We are indebted to Anthony Shih and Anne-Marie Audet of the Fund for their advice, support, and constructive suggestions throughout the design and conduct of the study. We thank our colleagues - Raymond Kang, Peter Kralovec, Sally Holmes, Frances Margolin, and Deborah Bohr - for their valuable contributions to the development of the QAS, the CPS, and the database on which the analytic findings reported here were based. We also thank 3 M (TM) Health Information Systems' for use of its All Patient Refined Diagnosis Related Groups (APR-DRGs) software. We especially wish to thank Jennifer Drake for her contributions not only to survey development, but also to earlier analysis of survey findings relevant to this paper. (Commonwealth Fund)Published versio

Improving Care for Individuals With Limited English Proficiency: Facilitators and Barriers to Providing Language Services in California Public Hospitals

Evaluates twelve public hospitals' efforts to improve language services for patients with limited English proficiency: policies and procedures, organizational commitment, strategies for change, training, effectiveness, and facilitators and barriers

The Delta-Delta Intermediate State in 1S0 Nucleon-Nucleon Scattering From Effective Field Theory

We examine the role of the Delta-Delta intermediate state in low energy NN scattering using effective field theory. Theories both with and without pions are discussed. They are regulated with dimensional regularization and MSbar subtraction. We find that the leading effects of the Delta-Delta state can be absorbed by a redefinition of the contact terms in a theory with nucleons only. It does not remove the requirement of a higher dimension operator to reproduce data out to moderate momentum. The explicit decoupling of the Delta-Delta state is shown for the theory without pions.Comment: 16 pages, 3 figures, uses harvma

The Skyrmion strikes back: baryons and a new large NcN_c limit

In the large $N_c$ limit of QCD, baryons can be modeled as solitons, for instance, as Skyrmions. This modeling has been justified by Witten's demonstration that all properties of baryons and mesons scale with $N_c^{-1/2}$ in the same way as the analogous meson-based soliton model scales with a generic meson-meson coupling constant $g$. An alternative large $N_c$ limit (the orientifold large $N_c$ limit) has recently been proposed in which quarks transform in the two-index antisymmetric representation of $SU(N_c)$. By carrying out the analog of Witten's analysis for the new orientifold large $N_c$ limit, we show that baryons and solitons can also be identified in the orientifold large $N_c$ limit. However, in the orientifold large $N_c$ limit, the interaction amplitudes and matrix elements scale with $N_c^{-1}$ in the same way as soliton models scale with the generic meson coupling constant $g$ rather than as $N_c^{-1/2}$ as in the traditional large $N_c$ limit.Comment: 10 pages, 26 figure