Nonlocal effects in high energy charged particle beams

Within the framework of the thermal wave model, an investigation is made of the longitudinal dynamics of high energy charged particle beams. The model includes the self-consistent interaction between the beam and its surroundings in terms of a nonlinear coupling impedance, and when resistive as well as reactive parts are included, the evolution equation becomes a generalised nonlinear Schroedinger equation including a nonlocal nonlinear term. The consequences of the resistive part on the propagation of particle bunches are examined using analytical as well as numerical methods.Comment: 6 pages, 6 figures, uses RevTeX

Brane World Dynamics and Conformal Bulk Fields

In the Randall-Sundrum scenario we investigate the dynamics of a spherically symmetric 3-brane world when matter fields are present in the bulk. To analyze the 5-dimensional Einstein equations we employ a global conformal transformation whose factor characterizes the $Z_2$ symmetric warp. We find a new set of exact dynamical collapse solutions which localize gravity in the vicinity of the brane for a stress-energy tensor of conformal weight -4 and a warp factor that depends only on the coordinate of the fifth dimension. Geometries which describe the dynamics of inhomogeneous dust and generalized dark radiation on the brane are shown to belong to this set. The conditions for singular or globally regular behavior and the static marginally bound limits are discussed for these examples. Also explicitly demonstrated is complete consistency with the effective point of view of a 4-dimensional observer who is confined to the brane and makes the same assumptions about the bulk degrees of freedom.Comment: 26 pages, latex, no figures. Minor revisions. Some references added. Revised version to appear in Phys. Rev.

Drug Nanocarriers Labeled With Near-infrared-emitting Quantum Dots (Quantoplexes): Imaging Fast Dynamics of Distribution in Living Animals

The knowledge of the biodistribution of macromolecular drug formulations is a key to their successful development for specific tissue- and tumor-targeting after systemic application. Based on the polyplex formulations, we introduce novel drug nanocarriers, which we denote as “quantoplexes” incorporating near-infrared (IR)-emitting cadmium telluride (CdTe) quantum dots (QDs), polyethylenimine (PEI), and a macromolecular model drug [plasmid DNA (pDNA)], and demonstrate the ability of tracking these bioactive compounds in living animals. Intravenous application of bare QD into nude mice leads to rapid accumulation in the liver and peripheral regions resembling lymph nodes, followed by clearance via the liver within hours to days. Quantoplexes rapidly accumulate in the lung, liver, and spleen and the fluorescent signal is detectable for at least a week. Tracking quantoplexes immediately after intravenous injection shows rapid redistribution from the lung to the liver within 5 minutes, depending on the PEI topology and quantoplex formulation used. With polyethyleneglycol (PEG)-modified quantoplexes, blood circulation and passive tumor accumulation was measured in real time. The use of quantoplexes will strongly accelerate the development of tissue and tumor-targeted macromolecular drug carriers

Journée sans culture : Troubler la fête, rallumer notre joie = To Spoil the Party, To Set Our Joy Ablaze

"Composed as an extension of the conversations that took place during the 2015 Journée sans culture, To Spoil the Party, to Set Our Joy Ablaze gathers contributions from those who moderated the discussions of the day as well as those who set up its sites of rest, reflection, and play. These authors work to remain true to the spirit of what they lived, led by the desire to find a source of collective energy that exceeds the pervasive effects of tiredness and resignation. Their texts are joined by others, commissioned by the editorial team, which explore matters of concern not sufficiently addressed during the day." -- Publisher's website