The modulatory effects of lipid A (diphosphoryl lipid A (DLA) and monophosphoryl lipid A (MLA)) on apoptosis induction and DNA structure damage (singleand double-strand breaks (SSBs and DSBs, respectively)) in peripheral human blood lymphocytes are studied for Co gamma irradiation. It is shown that in the presence of these agents the number of apoptotic cells increases compared with the irradia...

The perturbative QCD approach to multiparticle production assuming Local Parton Hadron Duality (LPHD) and some recent results are discussed. Finite asymptotic scaling limits are obtained for various observables, after an appropriate rescaling, in the Double Logarithmic Approximation (DLA). Nonasymptotic corrections are also known in some cases. The DLA applies also to very soft particle product...

We simulate 50 off-lattice DLA clusters, one million particles each. The probability distribution of the angle of attachment of arriving particles with respect to the local radial direction is obtained numerically. For increasing cluster size, N , the distribution crosses over extremely accurately to a cosine, whose amplitude decreases towards zero as a power-law in N . From this viewpoint, asy...

We use a recently developed a priori theory of diffusion-limited aggregation (DLA) to compute multifractal dimensions and their fluctuations, using methods analogous to field theoretical resummations. There are two regimes, depending upon n, the number of particles in the DLA cluster, as well as on the multifractal moment q. In the strongly fluctuating regime quenched and annealed dimensions di...

We study the relation between stochastic and continuous transport-limited growth models. We derive a nonlinear integro-differential equation for the average shape of stochastic aggregates, whose mean-field approximation is the corresponding continuous equation. Focusing on the advection-diffusion-limited aggregation (ADLA) model, we show that the average shape of the stochastic growth is simila...

We report the Giant Metrewave Radio Telescope detection of HI 21cm absorption from the z ∼ 3.39 damped Lyman-α absorber (DLA) towards PKS 0201+113, the highest redshift at which 21cm absorption has been detected in a DLA. The absorption is spread over ∼ 115 km s−1 and has two components, at z = 3.387144(17) and z = 3.386141(45). The stronger component has a redshift and velocity width in agreem...

We present a new study of the effects of quasar obscuration on the statistics of Damped Lyα (DLA) systems. We show that the extinction of any Galactic or extragalactic H i region, Aλ, increases linearly with the column density of zinc, with a turning point ∂Aλ/∂(logNZn) = 1, above which background sources are suddenly obscured. We derive a relation Aλ = Aλ(NH, Z, z) between the extinction of a ...

In recent work, we have shown that it is possible to link quantitatively many aspects of damped Lyman α (DLA) absorbers in the spectra of quasars to high-resolution simulations of galaxy formation. Using runs from the same series of hydrodynamic numerical studies, we consider the expected properties of intrinsic Lyman α absorbers seen in the spectra of high-redshift (z > 2) gamma-ray burst afte...