19,858 research outputs found
Fermionic Field Theory and Gauge Interactions on Random Lattices
Random-lattice fermions have been shown to be free of the doubling problem if
there are no interactions or interactions of a non-gauge nature. However, gauge
interactions impose stringent constraints as expressed by the Ward-Takahashi
identities which could revive the free-field suppressed doubler modes in loop
diagrams. After introducing a formulation for fermions on a new kind of random
lattice, we compare random, naive and Wilson fermions in two dimensional
Abelian background gauge theory. We show that the doublers are revived for
random lattices in the continuum limit, while demonstrating that gauge
invariance plays the critical role in this revival. Some implications of the
persistent doubling phenomenon on random lattices are also discussed.Comment: 16 A4 pages, UM-P-93/0
Tissue transglutaminase in normal and abnormal wound healing: review article
A complex series of events involving inflammation, cell migration and proliferation, ECM stabilisation and remodelling, neovascularisation and apoptosis are crucial to the tissue response to injury. Wound healing involves the dynamic interactions of multiple cells types with components of the extracellular matrix (ECM) and growth factors. Impaired wound healing as a consequence of aging, injury or disease may lead to serious disabilities and poor quality of life. Abnormal wound healing may also lead to inflammatory and fibrotic conditions (such as renal and pulmonary fibrosis). Therefore identification of the molecular events underlying wound repair is essential to develop new effective treatments in support to patients and the wound care sector. Recent advances in the understating of the physiological functions of tissue transglutaminase a multi functional protein cross-linking enzyme which stabilises tissues have demonstrated that its biological activities interrelate with wound healing phases at multiple levels. This review describes our view of the function of tissue trasnglutaminase in wound repair under normal and pathological situations and highlights its potential as a strategic therapeutic target in the development of new treatments to improve wound healing and prevent scarring
Simulations with Complex Measures
Towards a solution to the sign problem in the simulations of systems having
indefinite or complex-valued measures, we propose a new approach which yields
statistical errors smaller than the crude Monte Carlo using absolute values of
the original measures. The 1D complex-coupling Ising model is employed as an
illustration.Comment: 3 pages, postcript (95K), contribution to LAT93, UM-P-93/10
Two-fluid hydrodynamics of a Bose gas including damping from normal fluid transport coefficients
We extend our recent work on the two-fluid hydrodynamics of the condensate
and non-condensate in a trapped Bose gas by including the dissipation
associated with viscosity and thermal conduction. For purposes of illustration,
we consider the hydrodynamic modes in the case of a uniform Bose gas. A finite
thermal conductivity and shear viscosity give rise to a damping of the first
and second sound modes in addition to that found previously due to the lack of
diffusive equilibrium between the condensate and non-condensate. The
relaxational mode associated with this equilibration process is strongly
coupled to thermal fluctuations and reduces to the usual thermal diffusion mode
above the Bose-Einstein transition. In contrast to the standard Landau
two-fluid hydrodynamics, we predict a damped mode centered at zero frequency,
in addition to the usual second sound doublet.Comment: 18 pages, revtex, 4 postscript figures, Submitted to the Canadian
Journal of Physics for the Boris Stoicheff Festschrift issu
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