Aggregation with Multiple Conservation Laws

Aggregation processes with an arbitrary number of conserved quantities are investigated. On the mean-field level, an exact solution for the size distribution is obtained. The asymptotic form of this solution exhibits nontrivial ``double'' scaling. While processes with one conserved quantity are governed by a single scale, processes with multiple conservation laws exhibit an additional diffusion-like scale. The theory is applied to ballistic aggregation with mass and momentum conserving collisions and to diffusive aggregation with multiple species.Comment: 18 pages, te

L'hyperoxalurie primitive de type 1, maladie des peroxysomes: conséquences thérapeutiques

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Questionable Thymic Nurse Cell

Since their discovery in 1980, thymic nurse cells (TNCs) have been controversial. Questions pertaining to the existence of the TNC as a “unit” cell with thymocytes completely enclosed within its cytoplasm were the focus of initial debates. Early skeptics proposed the multicellular complex to be an artifact of the procedures used to isolate TNCs from the thymus. Since that time, TNCs have been found in fish, frogs, tadpoles, chickens, sheep, pigs, rats, mice, and humans. Their evolutionary conservation throughout the animal kingdom relieved most speculations about the existence of TNCs and at the same time demonstrated their apparent importance to the thymus and T-cell development. In this review we will discuss and debate reports that describe (i) the organization or structure of TNCs, (ii) the thymocyte subset(s) found within the cytoplasm of TNCs and their uptake and release, and (iii) the function of this fascinating multicellular interaction that occurs during the process of T-cell development. Discussions about the future of the field and experimental approaches that will lead to answers to remaining questions are also presented