Two strand-specific origins of replication appear to be required for mammalian mitochondrial DNA (mtDNA) replication. Structural equivalents of these origins are found in the rep sequences of Saccharomyces cerevisiae mtDNA. These striking similarities have contributed to a universal model for the initiation of mtDNA replication in which a primer is created by cleavage of an origin region transc...

in this paper, we study the problem of minimizing the ratio of two quadratic functions subject to a quadratic constraint. first we introduce a parametric equivalent of the problem. then a bisection and a generalized newton-based method algorithms are presented to solve it. in order to solve the quadratically constrained quadratic minimization problem within both algorithms, a semidefinite optim...

We have identified the gene for transcription termination factor Rho in Staphylococcus aureus. Deletion of rho in S. aureus reveals that it is not essential for viability or virulence. We also searched the available bacterial genomic sequences for homologs of Rho and found that it is broadly distributed and highly conserved. Exceptions include Streptococcus pneumoniae, Streptococcus pyogenes, M...

The transcription termination factor Rho associates with most nascent bacterial RNAs as they emerge from RNA polymerase. However, pharmacological inhibition of Rho derepresses only a small fraction of these transcripts. What, then, determines the specificity of Rho-dependent transcription termination? We now report the identification of a Rho-antagonizing RNA element (RARE) that hinders Rho-dep...

FPGA AND ASIC IMPLEMENTATION OF RHO AND P-1 METHODS OF FACTORING Ramakrishna Bachimanchi, MS George Mason University, 2007 Thesis Director: Dr. Kris Gaj One of the main challenges in the cryptography is breaking RSA-1024. The problem can be explained as factoring large integers. The suitable methods for this purpose are Multiple Polynomial Quadratic Sieve (MPQS) and Number Field Sieve (NFS). Ou...

In this study, a primitive progenitor cell, the blast-cell colony-forming cell (BC-CFC), which is thought by some to be equivalent to the hematopoietic stem cell (HSC), those cells capable of long-term marrow repopulation, has been isolated from normal murine marrow. The cell separation method we employed has, as its final step, the purification of marrow cells based on their ability to take up...

The effect of RNA secondary structure on rho-independent and rho-dependent termination of transcription of T3 DNA by Escherichia coli RNA polymerase has been studied by incorporating, into nascent transcripts, base analogs that lead to altered base-pairing properties. A guanine --> hypoxanthine substitution, with attendant weakening of secondary structure, abolished the rho-independent terminat...

Using biochemical assays to determine the activation state of Rho-like GTPases, we show that the guanine nucleotide exchange factor Tiam1 functions as a specific activator of Rac but not Cdc42 or Rho in NIH3T3 fibroblasts. Activation of Rac by Tiam1 induces an epithelial-like morphology with functional cadherin-based adhesions and inhibits migration of fibroblasts. This epithelial phenotype is ...