Absorption and opacity threshold for a thin foil in a strong circularly polarized laser field.

We show that a commonly accepted transparency threshold for a thin foil in a strong circularly polarized normally incident laser pulse needs a refinement. We present an analytical model that correctly accounts for laser absorption. The refined threshold is determined not solely by the laser amplitude, but by other parameters that are equally or even more important.

Unexpected impact of radiation friction: enhancing production of longitudinal plasma waves.

We study the penetration of ultra-intense (intensity I [Formula: see text] 10 W/cm) circularly polarized laser pulses into a thick subcritical plasma layer with accounting for radiation friction. We show that radiation pressure is enhanced due to radiation friction in the direction transverse to the laser pulse propagation, and that for stronger and longer laser pulses this mechanism dominates over the ordinary ponderomotive pressure, thus resulting in a substantionaly stronger charge separation than anticipated previously. We give estimates of the effect and compare them with the results of one and two dimensional particle-in-cell simulations.

Electron dynamics and γ and e(-)e(+) production by colliding laser pulses.

The dynamics of an electron bunch irradiated by two focused colliding super-intense laser pulses and the resulting γ and e(-)e(+) production are studied. Due to attractors of electron dynamics in a standing wave created by colliding pulses the photon emission and pair production, in general, are more efficient with linearly polarized pulses than with circularly polarized ones. The dependence of the key parameters on the laser intensity and wavelength allows us to identify the conditions for the cascade development and γe(-)e(+) plasma creation.

Same but different: tuberculosis treatment and care among migrants from different countries of origin in Israel.

Introduction: Israel hosts documented labor migrants (DLM), and recently also undocumented migrants (UDM), mostly from Horn of Africa. This study aims to compare treatment outcomes and other clinical aspects between a sample of 154 DLM and 113 UDM who were treated in two tuberculosis clinics between 2005 and 2010.

Results And Discussion: Compared to DLM, UDM were younger males, stayed in Israel for shorter periods, had lower coverage of medical insurance, were less likely to be employed, and had greater difficulties in communication with the medical staff.