Winners and Losers from Enacting the Financial Modernization Statute

Previous studies of the announcement effects of relaxing administrative and legislative restraints show that signal events leading up to the enactment of the Financial Services Modernization Act (FSMA) increased the prices of several classes of financial-institution stocks. An unsettled question is whether the gains observed for these stocks arise mainly from projected increases in efficiency or from reductions in customer or competitor bargaining power. This paper documents that the value increase came at the expense of customers and competitors. The stock prices of credit-constrained customers declined during FSMA event windows and experienced significant increases in beta in the wake of its enactment. These findings reinforce evidence in the literature on bank mergers that large-bank consolidation is adversely affecting access to credit for capital-constrained firms.

Non‐Rayleigh Statistics of Ultrasonic Backscattered Echo from Tissues

The envelope of the backscattered signal from tissues can exhibit non‐Rayleigh statistics if the number density of scatterers is small or if the variations in the scattering cross sections are random. The K distribution which has been used extensively in radar, is introduced to model this non‐Rayleigh behavior. The generalized K distribution is extremely useful since it encompasses a wide range of distributions such as Rayleigh, Lognormal, and Rician. Computer simulations were conducted using a simple one‐dimensional discrete scatteringmodel to investigate the properties of the echo envelope. In addition to cases of low number densities, significant departures from Rayleigh statistics were seen as the scattering cross sections of the scatterers become random. The validity of this model was also tested using data from tissue mimicking phantoms. Results indicate that the density function of the envelope can be modeled by the K distribution and the parameters of the K distribution can provide information on the nature of the scattering region in terms of the number density of the scatterers as well as the scattering cross sections of the scatterers in the range cell. [Work was supported by NSF Grant No. BCS‐9207385.

Confinement, Turbulence and Diffraction Catastrophes

Many features of large N_c transition that occurs in the spectral density of Wilson loops as a function of loop area (observed recently in numerical simulations of Yang-Mills theory by Narayanan and Neuberger) can be captured by a simple Burgers equation used to model turbulence. Spectral shock waves that precede this asymptotic limit exhibit universal scaling with N_c, with indices that can be related to Berry indices for diffraction catastrophes.Comment: Presented at PANIC 200

On the continuum limit of fermionic topological charge in lattice gauge theory

It is proved that the fermionic topological charge of SU(N) lattice gauge fields on the 4-torus, given in terms of a spectral flow of the Hermitian Wilson--Dirac operator, or equivalently, as the index of the Overlap Dirac operator, reduces to the continuum topological charge in the classical continuum limit when the parameter $m_0$ is in the physical region $0<m_0<2$.Comment: latex, 18 pages. v2: Several comments added. To appear in J.Math.Phy

Domain wall fermion zero modes on classical topological backgrounds

The domain wall approach to lattice fermions employs an additional dimension, in which gauge fields are merely replicated, to separate the chiral components of a Dirac fermion. It is known that in the limit of infinite separation in this new dimension, domain wall fermions have exact zero modes, even for gauge fields which are not smooth. We explore the effects of finite extent in the fifth dimension on the zero modes for both smooth and non-smooth topological configurations and find that a fifth dimension of around ten sites is sufficient to clearly show zero mode effects. This small value for the extent of the fifth dimension indicates the practical utility of this technique for numerical simulations of QCD.Comment: Updated fig. 3-7, small changes in sect. 3, added fig. 8, added more reference

Identification of the promoter of amidase gene for expression of useful mycobacterial genes

The genetics of mycobacteria has lagged behind because of several reasons. Mycobacteria grow very slowly. their generation time ranging anywhere between 12-24 hrs. Mycobacteria are rather hydrophobic and tend to grow in clusters and there is difficulty in purifying individual cells for genetic analysis. Very few genetic markers have been found in mycobacteria because there is no known naturally occurring genetic exchange in mycobacteria. With the creation of genomic libraries of M. tuberculosis more than 50 genes have been characterised. Many of them are not expressed efficiently in Escherichia coli (E.coli) under the control of their own promoters, since very few mycobacterial promoters are recognised by the E. coli transcription machinery. This clearly shows that mycobacteria use a different system of gene regulation. Understanding the gene regulation of mycobacteria might throw light on the slow growth rate, about their persistence in a resting phase and also about their intracellular survival. Besides this if inducible or strong promoters are identified they can be used in over expression of genes coding for proteins useful in diagnosis and protection

Vector like gauge theories with almost massless fermions on the lattice

A truncation of the overlap (domain wall fermions) is studied and a criterion for reliability of the approximation is obtained by comparison to the exact overlap formula describing massless quarks. We also present a truncated version of regularized, pure gauge, supersymmetric models. The mechanism for generating almost masslessness is shown to be a generalized see-saw which can also be viewed as a version of Froggatt-Nielsen's method for obtaining natural large mass hierarchies. Viewed in this way the mechanism preserving the mass hierarchy naturally avoids preserving even approximately axial U(1). The new insights into the source of the mass hierarchy suggest ways to increase the efficiency of numerical simulations of QCD employing the truncated overlap.Comment: 35 pages, TeX, 4 figures using eps