Nuclear shadowing arises from multiple scattering of the hadronic uctuations (jq qi; jq qg:::i) of the virtual photon in a nucleus. We predict di erent longitudinal and transverse shadowing and an A{dependence of R L= T which can be up to a 50% e ect. The possibility of detecting nuclear e ects on R at HERA is discussed. To be published in the Proceedings of the Workshop on \Future Physics at H...

The segmental identity in animal development is determined by a set ofhomeotic selector genes clustered in the invertebrate HOM or vertebrate Hox homeo box complexes. These genes encode proteins with very smilar homeodomains and highly diverged Nand C-terminal sequences. The Antennapedia (Antp) homeodomain, for Instance, differs at only five amino acid positions from that of Sex combs reduced (...

At least 35 deletions involving the p globin cluster on chromosome 1 1 have been described.’ Analysis of the phenotypes associated with the different deletions has provided much insight into the normal regulation of expression of the human /3 globin gene cluster, leading to the identification of several important regulatory elements including the major upstream locus control region (LCR) 5‘ to ...

To learn a visual code in an unsupervised manner, one may attempt to capture those features of the stimulus set that would contribute significantly to a statistically efficient representation (as dictated, e.g., by the Minimum Description Length principle). Paradoxically, all the candidate features in this approach need to be known before statistics over them can be computed. This paradox may b...

This is the text of lectures delivered at the RIMS (Kyoto University) in July 1998. It presents the basic structures of the theory of noncommutative symmetric functions, with emphasis on the parallel with the commutative theory and on the representation theoretical interpretations. Some examples involving descent algebras and characters of symmetric groups are discussed in detail. Introduction ...