Chromatin on the mammalian inactive X chromosome differs in a number of ways from that on the active X. One protein, macroH2A, whose amino terminus is closely related to histone H2A, is enriched on the heterochromatic inactive X chromosome in female cells. Here, we report the identification and localization of a novel and more distant histone variant, designated H2A-Bbd, that is only 48% identi...

A run in a word is a periodic factor whose length is at least twice its period and which cannot be extended to the left or right (by a letter) to a factor with greater period. In recent years a great deal of work has been done on estimating the maximum number of runs that can occur in a word of length n. A number of associated problems have also been investigated. In this paper we consider a ne...

We consider the model of random trees introduced by Devroye [SIAM J Comput 28, 409– 432, 1998]. The model encompasses many important randomized algorithms and data structures. The pieces of data (items) are stored in a randomized fashion in the nodes of a tree. The total path length (sum of depths of the items) is a natural measure of the efficiency of the algorithm/data structure. Using renewa...

The total radiation pulse consists of NS spikes, and the total pulse length is LP=NSLc. In a normal configuration all the spikes have the same line-width and the same central frequency. Chirping the pulse, i.e. changing the frequency of each spike by a quantity proportional to the spike longitudinal position inside the pulse, allow us to compress the pulse using a pair of diffraction gratings. ...

Drosophila NURF is an ISWI-containing chromatin remodeling complex that catalyzes ATP-dependent nucleosome sliding. By sliding nucleosomes, NURF can alter chromatin structure and regulate transcription. NURF301/BPTF is the only NURF-specific subunit of NURF and is instrumental in recruiting the complex to target genes. Here we demonstrate that three NURF301 isoforms are expressed and that these...

Leg-length discrepancy after total hip arthroplasty can pose a substantial problem for the orthopaedic surgeon. Such discrepancy has been associated with complications including nerve palsy, low back pain, and abnormal gait. Careful preoperative measurement and assessment, as well as preoperative and postoperative patient education, are important factors in achieving an acceptable result. Howev...

Mammals compensate X chromosome gene dosage between the sexes by silencing of one of the two female X chromosomes. X inactivation is initiated in the early embryo and requires the non-coding Xist RNA, which encompasses the inactive X chromosome (Xi) and triggers its silencing. In differentiated cells, several factors including the histone variant macroH2A and the scaffold attachment factor SAF-...

MacroH2A1 is an unusual variant of the core histone H2A which is enriched in chromatin on the inactive X chromosome of female mammals. The N-terminal third of the protein shares 65% amino acid identity with core histone H2A, while the remaining two-thirds of the protein are novel, with a small stretch of basic amino acids and a putative leucine zipper motif. We have now cloned a second macroH2A...