Stiff behavior occurs in a variety of ODE systems relevant in applications. The notion of stiffness is a phenomenological one, and a stability and error analysis of numerical methods has been based either on simple models or particular problem structures. In particular, stiff initial value problems in standard singular perturbation form are well understood. However, problems of this type exhibi...

– We analyze the deformations of the Fermi surface induced by electron-electron interactions in anisotropic two dimensional systems. We use perturbation theory to treat, on the same footing, the regular and singular regions of the Fermi surface. It is shown that, even for weak local coupling, the self-energy presents a nontrivial behavior showing momentum dependence and interplay with the Fermi...

For REX-ISOLDE (Radioactive beam EXperiments at ISOLDE / CERN) [1], a test beamline is built up at the Garching Accelerator Lab to perform He-experiments with the RFQ [2], the matching (rebunching) section between RFQ and IH-DT-linac, the IH-structure [3] and several electrostatic lenses of the REX-ISOLDE-mass separator [4]. In a first step, the beamline is conceived for tests with the RFQ. Thi...

BACKGROUND Treatment strategies for the highly invasive brain tumor, glioblastoma multiforme, require that cells which have invaded into the surrounding brain be specifically targeted. The inherent tumor-tropism of neural stem cells (NSCs) to primary and invasive tumor foci can be exploited to deliver therapeutics to invasive brain tumor cells in humans. Use of the strategy of converting prodru...

TIGER integral-field spectrography and Hubble Space Telescope WFPC2 imaging of the E3 galaxy NGC 2974 are used to derive the kinematics of the stellar and ionized gas components in its central 500 pc. We derive a numerical two-integral distribution function from a Multi-Gaussian Expansion (MGE) mass model using the Hunter & Qian formalism. The TIGER as well as published long-slit stellar kinema...

Comparative analysis answers questions about how and why a system will react to perturbations of its parameters. For example, comparative analysis can explain why the period of a spring/block system would increase if the mass of the block were larger. This paper formalizes the problem of comparative analysis and describes a solution technique, differential qualitative analysis; the technique on...

The weakly bound HOONO product of the OH+NO2+M reaction is studied using the vibrational predissociation that follows excitation of the first OH overtone (2nu1). We observe formation of both cis-cis and trans-perp conformers of HOONO. The trans-perp HOONO 2nu1 band is observed under thermal (223-238 K) conditions at 6971 cm(-1). We assign the previously published (warmer temperature) HOONO spec...

The Ward identities for amplitudes at the tree level are derived from symmetries of the corresponding classical dynamical systems. The result are aplied to some 2 → n amplitudes supported by the Lódź University grant No. 269. supported by KBN grant No. 5 P03B 060 21 1 I Introducion Threshold amplitudes provide one of the rare examples of problems in quantum field theory which are both interesti...

OSDR-techniques based on local phase pertubation induced by IRor UV-laser radiation are used for spatial characterization of fiber Bragg gratings. Experimental results are in good agreement with those obtained by the side-diffraction technique. Both techniques are compared with respect to simplicity of the setup and the yield of information. Fiber Bragg gratings (FBGs) are widely used for telec...

BACKGROUND Owing to the extreme virulence and case fatality rate of ebola virus disease (EVD), there had been so much furore, panic and public health emergency about the possible pandemic from the recent West African outbreak of the disease, with attendant handful research, both in the past and most recently. The magnitude of the epidemic of ebola virus disease has prompted global interest and ...