Double-strand DNA breaks are the most lethal type of DNA damage induced by ionizing radiations. Previously, we reported that double-strand DNA breaks can be enzymatically produced from two DNA damages located on opposite DNA strands 18 or 30 base pairs apart in a cell-free double-strand DNA break formation assay (Vispé, S., and Satoh, M. S. (2000) J. Biol. Chem. 275, 27386-27392). In the assay ...

Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is a DNA repair enzyme that acts upon protein-DNA covalent complexes. Tdp1 hydrolyzes 3'-phosphotyrosyl bonds to generate 3'-phosphate DNA and free tyrosine in vitro. Mutations in Tdp1 have been linked to patients with spinocerebellar ataxia, and over-expression of Tdp1 results in resistance to known anti-cancer compounds. Tdp1 has been shown to be involve...

Using the radiomimetic drug, bleomycin, we have determined the mutagenic potential of DNA strand breaks in the shuttle vector pZ189 in human fibroblasts. The bleomycin treatment conditions used produce strand breaks with 3'-phosphoglycolate termini as > 95% of the detectable dose-dependent lesions. Breaks with this end group represent 50% of the strand break damage produced by ionizing radiatio...

A fully experimental modeling technique and a design optimization procedure are presented in this paper for push-pull electret loudspeakers. Conventional electrical impedance-based parameter identification methods are not completely applicable to electret speakers due to the extremely weak electromechanical coupling. This prompts the development of an experimental technique for identifying the ...

This paper describes the University Course Timetabling Problem (UCTP) used in the International Timetabling Competition 2003 organized by the Metaheuristics Network and presents a state-of-the-art heuristic approach towards the solution of the competition instances. It is a greatly improved version of the winning competition entry. The heuristic is divided into three phases: at first, a feasibl...

Quantum annealing (QA) serves as a specialized optimizer that is able to solve many NP-hard problems and that is believed to have a theoretical advantage over simulated annealing (SA) via quantum tunneling. With the introduction of the D-Wave programmable quantum annealer, a considerable amount of effort has been devoted to detect and quantify quantum speedup. While the debate over speedup rema...

The methods presented in this work provide a potential tool for characterizing contaminant source zones in terms of mass flux. The problem was conceptualized by considering contaminant transport through a vertical "flux plane" located between a source zone and a downgradient region where contaminant concentrations were measured. The goal was to develop a robust method capable of providing a sta...

3-Aminobenzamide, an inhibitor of polyadenosine diphosphoribose polymerase, produced rapid reversible changes in single-strand break frequencies in DNA from primary human fibroblasts damaged by alkylating agents, but it did not cause such changes in the DNA of cells damaged by ultraviolet light. The increase in single-strand peak frequencies was not due to an accumulation of blocked repair site...