Evaluating Criminal Justice Programs Designed to Reduce Crime by Targeting Repeat Gang Offenders

This paper suggests that a theory-driven approach be taken in the evaluation of gang crime reduction programs. The rationale for selecting this approach and an example of this type of evaluation are presented. The gang program evaluated involved close collaboration among law enforcement, probation, and prosecution toward incarcerating repeat gang offenders. Data were collected concerning incarceration and subsequent crime over a seven-year period. Trend analysis indicated a strong relationship between incarceration and gang crime trends, and an overall reduction of 47% in gang crime. It is suggested that policy makers and researchers consider replicating this model to further test its effects. Practical and methodological aspects of evaluating gang crime reduction programs are discussed. Communities throughout the United States are searching for ways to reduce violence and destruction of property caused by members of street gangs. Criminal justice agencies have implemented a variety of policies and programs intended to reduce gang crime, but little more than anecdotal information exists as to the actual effectiveness of these efforts. The lack of data about effective approaches has prompted leading scholars to declare program evaluation as a top priority in gang research (Howell, 1994 and Klein, 1993). This paper describes various types of gang programs, suggests an approach that could be used in the evaluation of gang programs, reports an evaluation of a criminal justice program intended to reduce gang crime, and concludes with a discussion of evaluation issues and recommendations

DNA sequence- and conformation-directed positioning of nucleosomes by chromatin-remodeling complexes

Chromatin-remodeling complexes can translocate nucleosomes along the DNA in an ATP-coupled reaction. This process is an important regulator of all DNA-dependent processes because it determines whether certain DNA sequences are found in regions between nucleosomes with increased accessibility for other factors or wrapped around the histone octamer complex. In a comparison of seven different chromatin-remodeling machines (ACF, ISWI, Snf2H, Chd1, Mi-2, Brg1, and NURF), it is demonstrated that these complexes can read out DNA sequence features to establish specific nucleosome-positioning patterns. For one of the remodelers, ACF, we identified a 40-bp DNA sequence element that directs nucleosome positioning. Furthermore, we show that nucleosome positioning by the remodelers ACF and Chd1 is determined by a reduced affinity to the end product of the translocation reaction. The results suggest that the linkage of differential remodeling activities with the intrinsic binding preferences of nucleosomes can result in establishing distinct chromatin structures that depend on the DNA sequence and define the DNA accessibility for other protein factors

A genome-wide role for CHD remodelling factors and Nap1 in nucleosome disassembly

Chromatin remodelling factors and histone chaperones were previously shown to cooperatively affect nucleosome assembly and disassembly processes in vitro. Here, we show that Schizosaccharomyces pombe CHD remodellers, the Hrp1 and Hrp3 paralogs physically interact with the histone chaperone Nap1. Genome-wide analysis of Hrp1, Hrp3 and Nap1 occupancy, combined with nucleosome density measurements revealed that the CHD factors and Nap1 colocalized in particular to promoter regions where they remove nucleosomes near the transcriptional start site. Hrp1 and Hrp3 also regulate nucleosome density in coding regions, where they have redundant roles to stimulate transcription. Previously, DNA replication-dependent and -independent nucleosome disassembly processes have been described. We found that nucleosome density increased in the hrp1 mutant in the absence of DNA replication. Finally, regions where nucleosome density increased in hrp1, hrp3 and nap1 mutants also showed nucleosome density and histone modification changes in HDAC and HAT mutants. Thus, this study revealed an important in vivo role for CHD remodellers and Nap1 in nucleosome disassembly at promoters and coding regions, which are linked to changes in histone acetylation