Channeling of Electrons in a Crossed Laser Field

In this article a new analytical description of the effective interaction potential for a charged particle in the field of two interfering laser beams is presented. The potential dependence on the lasers intensities, orientation and parameters of the particle entering the considered system is analyzed. It is shown for the case of arbitrary lasers crossing angle that for different values of projectile velocity the attracting potential becomes a scattering one so that the channel axes and borders interchange each other. In addition the projectile radiation spectral distribution is given and general estimations on the expected beam radiation yield are outlined

Experience of caregivers with the survivors of Hepatitis C

Objectives: To assess and describe the experiences of those caring for hepatitis C patients in Karachi, Pakistan. Methods: Using a qualitative approach, the study adopted a descriptive exploratory design for which 8 caregirers were selected through snowball sampling technique from different parts of Karachi. Data was collected between May and July 2010 through semi-structured interviews from the caregivers. The interviews were recorded on tape and were transcribed verbatim. The data was manually analysed for extracting themes and categories. Results: The analyses of data led to one theme - \\u27deadly, dangerous, and devastating. Two associated categories could also be noted: \\u27perceptions and misperceptions of the caregivers about hepatitis C\\u27 and \\u27challenges and adversities of the disease.\\u27 Conclusion: The diagnosis of hepatitis C had a profound impact on patients\\u27 and the caregivers\\u27 wellbeing. Although to some extent, caregivers were found to have fulfilled their role, but it was evident that better disease knowledge, funds and social support could have further helped them to address issues related to the disease

Superfluid 4He dynamics beyond quasiparticle excitations

The dynamics of superfluid 4He at and above the Landau quasiparticle regime is investigated by high precision inelastic neutron scattering measurements of the dynamic structure factor. A highly structured response is observed above the familiar phonon-maxon-roton spectrum, characterized by sharp thresholds for phonon-phonon, maxon-roton and roton-roton coupling processes. The experimental dynamic structure factor is compared to the calculation of the same physical quantity by a Dynamic Many-body theory including three-phonon processes self-consistently. The theory is found to provide a quantitative description of the dynamics of the correlated bosons for energies up to about three times that of the Landau quasiparticles.Comment: 5 pages, 3 figure