Determining the impact of unknown individuals in criminality using network analysis of DNA matches.

Criminal offenders missing from police files limit the capacity to reconstruct criminal networks for criminological research and operational purposes. Recent studies show that forensic DNA databanks offer potential to address this problem, through large-scale analysis of DNA matches, many of which involve unidentified offenders. Applying social network analysis (SNA) to 18 years of DNA match data from Québec, Canada, we found that 1400 unknowns do not occupy more marginal positions in the network than 13,000 known offenders, and explain up to 18% of SNA values (e.

Gene targeting in the Gram-Positive bacterium Lactococcus lactis, using various delta ribozymes.

The trans-acting antigenomic delta ribozyme, isolated from the human hepatitis delta virus, was shown to be highly stable and active in vitro, as well as in mammalian cell lines. However, the stability and gene-targeting competence of this small ribozyme have not been studied previously in bacterial cells. In this paper we describe the use of two variants of the trans-acting antigenomic delta ribozyme targeting the abundant EF-Tu mRNA in the industrially important gram-positive bacterium Lactococcus lactis.

Kinetic and binding analysis of the catalytic involvement of ribose moieties of a trans-acting delta ribozyme.

We have identified ribose 2'-hydroxyl groups (2'-OHs) that are critical for the activity of a trans-cleaving delta ribozyme derived from the antigenomic strand of the hepatitis delta virus. Initially, an RNA-DNA mixed ribozyme composed of 26 deoxyribo- (specifically the nucleotides forming the P2 stem and the P4 stem-loop) and 31 ribonucleotides (those forming the catalytic center) was engineered. This mixed ribozyme catalyzed the cleavage of a small substrate with kinetic parameters virtually identical to those of the all-RNA ribozyme.