CSF oligoclonal bands in multiple sclerosis

Objective: To study the significance of oligoclonal bands in neurological disorders, specifically in Multiple Sclerosis (MS). Methods: The study was designed to assess the sensitivity and specificity of the test methodology of CSF electrophoresis by performing the retrospective analysis of CSF samples sent for oligoclonal bands (OCB). A total of 603 samples were received by the Clinical Laboratories, Department of Pathology of The Aga Khan University, during a period of 54 months (January 1993-June 1997). All of these samples were analyzed by performing CSF protein electrophoresis. One hundred thirty three out of 603 samples showed evidence of OCB. Out of these, 24 patients were registered with Section of Neurology, Department of Medicine, The Aga Khan University Hospital. These 24 patients were finally selected for analysis. Relevant clinical details such as age, sex and clinical presentations were recorded. Results: Fifteen (62%) out of 24 patients with positive OCB were diagnosed as cases of MS. Four (17%) patients were diagnosed to have subacute sclerosing panencephalitis (SSPE). Five (21%) patients were having other inflammatory neurological disorders. Conclusion: The overall relative sensitivity and specificity for multiple sclerosis were found to be 100% and 62.5% respectively. Lack of specificity was attributed to the fact that OCB were positive in other neurological disorders as well

The Phases and Triviality of Scalar Quantum Electrodynamics

The phase diagram and critical behavior of scalar quantum electrodynamics are investigated using lattice gauge theory techniques. The lattice action fixes the length of the scalar (``Higgs'') field and treats the gauge field as non-compact. The phase diagram is two dimensional. No fine tuning or extrapolations are needed to study the theory's critical behovior. Two lines of second order phase transitions are discovered and the scaling laws for each are studied by finite size scaling methods on lattices ranging from $6^4$ through $24^4$. One line corresponds to monopole percolation and the other to a transition between a ``Higgs'' and a ``Coulomb'' phase, labelled by divergent specific heats. The lines of transitions cross in the interior of the phase diagram and appear to be unrelated. The monopole percolation transition has critical indices which are compatible with ordinary four dimensional percolation uneffected by interactions. Finite size scaling and histogram methods reveal that the specific heats on the ``Higgs-Coulomb'' transition line are well-fit by the hypothesis that scalar quantum electrodynamics is logarithmically trivial. The logarithms are measured in both finite size scaling of the specific heat peaks as a function of volume as well as in the coupling constant dependence of the specific heats measured on fixed but large lattices. The theory is seen to be qualitatively similar to $\lambda\phi^{4}$. The standard CRAY random number generator RANF proved to be inadequateComment: 25pages,26figures;revtex;ILL-(TH)-94-#12; only hardcopy of figures availabl

Monopole Percolation in the Compact Abelian Higgs Model

We have studied the monopole-percolation phenomenon in the four dimensional Abelian theory that contains compact U(1) gauge fields coupled to unitary norm Higgs fields. We have determined the location of the percolation transition line in the plane $(\beta_g, \beta_H)$. This line overlaps the confined-Coulomb and the confined-Higgs phase transition lines, originated by a monopole-condensation mechanism, but continues away from the end-point where this phase transition line stops. In addition, we have determined the critical exponents of the monopole percolation transition away from the phase transition lines. We have performed the finite size scaling in terms of the monopole density instead of the coupling, because the density seems to be the natural parameter when dealing with percolation phenomena.Comment: 13 pages. REVTeX. 16 figs. included using eps

Moyamoya disease: an elusive diagnosis

Moyamoya disease is an idiopathic vasculopathy, affecting vessels of Circle of Willis.1 It usually manifests as stroke, but can also cause seizures and cognitive impairment.2 Ischemic strokes are common in children and hemorrhagic strokes in adults.1 We describe our experience with moyamoya disease in four patients who presented with ischemic strokes, at an academic tertiary care center and emphasize that this diagnosis should be considered in young patients, especially children, who present with stroke

DYNAMIC DETECTION OF DESIGN INCONSISTENCY DURING SOFTWARE DEVELOPMENT USING DAID APPROACH

Evolution of software has lead to the fast growth of technology whose impact can be witnessed in all the domains of scientific and engineering applications. Hence engineering high quality software is one of the core challenges of all IT industries. The software models which are being used for the development of the software products may lead to inconsistencies. Nevertheless, theexistence of several methodologies during the development process in order to overcome inconsistencies operates at static mode leading towards expensive nature of rework on those inconsistencies. Therefore, this paper presents a dynamic model which resolves the aforementioned issue by capturing inconsistencies dynamically in an automated mode using Dynamic automated inconsistency detection (DAID) model. The implementation results of DAID capture the design inconsistencies dynamically at the time of their injection points in lieu of inconsistency detection during validation testing. This approach of dynamic design inconsistency detection reduces cost, time and its associated overheads. Further implementation of DAID in an automated mode increases productivity, quality and sustainability in IT industries

Banti\u27s syndrome: case report and review of literature.

In 1898 Banti described a disorder characterized by splenomegaly and hypersplenism, resulting in portal hypertension and anemia in the absence of hematological disease. 1 Banti\u27s syndrome is also known as non-cirrhotic portal hypertension (NCPH) in India and Idiopathic Portal Hypertension (IPH) in Japan. Hepatoportal sclerosis seems to be its counterpart in the United States. 2,3 Banti\u27s syndrome is a disorder of unknown etiology, clinically characterized by portal hypertension (varices and portosystemic collateral vessels), splenomegaly, and anemia (hypersplenism). 3 It has been reported from Indian subcontinent. 4-6 In a Pakistani case series of portal hypertension, 18 out of 37 patients were found to have IPH as the etiology. 6 We report a case of Banti\u27s syndrome in an 20-year old girl presenting to us with anemia and splenomegaly

On the Logarithmic Triviality of Scalar Quantum Electrodynamics

Using finite size scaling and histogram methods we obtain numerical results from lattice simulations indicating the logarithmic triviality of scalar quantum electrodynamics, even when the bare gauge coupling is chosen large. Simulations of the non-compact formulation of the lattice abelian Higgs model with fixed length scalar fields on $L^{4}$ lattices with $L$ ranging from $6$ through $20$ indicate a line of second order critical points. Fluctuation-induced first order transitions are ruled out. Runs of over ten million sweeps for each $L$ produce specific heat peaks which grow logarithmically with $L$ and whose critical couplings shift with $L$ picking out a correlation length exponent of $0.50(5)$ consistent with mean field theory. This behavior is qualitatively similar to that found in pure $\lambda\phi^{4}$.Comment: 9 page

Communication of Spin Directions with Product States and Finite Measurements

Total spin eigenstates can be used to intrinsically encode a direction, which can later be decoded by means of a quantum measurement. We study the optimal strategy that can be adopted if, as is likely in practical applications, only product states of $N$-spins are available. We obtain the asymptotic behaviour of the average fidelity which provides a proof that the optimal states must be entangled. We also give a prescription for constructing finite measurements for general encoding eigenstates.Comment: 4 pages, minor changes, version to appear in PR

Optimal strategies for sending information through a quantum channel

Quantum states can be used to encode the information contained in a direction, i.e., in a unit vector. We present the best encoding procedure when the quantum state is made up of $N$ spins (qubits). We find that the quality of this optimal procedure, which we quantify in terms of the fidelity, depends solely on the dimension of the encoding space. We also investigate the use of spatial rotations on a quantum state, which provide a natural and less demanding encoding. In this case we prove that the fidelity is directly related to the largest zeros of the Legendre and Jacobi polynomials. We also discuss our results in terms of the information gain.Comment: 4 pages, RevTex, final version to appear in Phys.Rev.Let

On gonihedric loops and quantum gravity

We present an analysis of the gonihedric loop model, a reformulation of the two dimensional gonihedric spin model, using two different techniques. First, the usual regular lattice statistical physics problem is mapped onto a height model and studied analytically. Second, the gravitational version of this loop model is studied via matrix models techniques. Both methods lead to the conclusion that the model has $c_{matter}=0$ for all values of the parameters of the model. In this way it is possible to understand the absence of a continuous transition