The utility of post-conviction polygraph testing among sexual offenders

It is often difficult to ascertain the true extent and nature of sexually deviant behavior, as much relies on self-report or historic information. The polygraph has been proposed as a useful tool in the treatment and supervision of sex offenders. The current review aims to provide a coherent, objective, and recent synthesis of evaluation studies exploring the utility of the post-conviction polygraph (PCSOT) in the treatment and management of sexual offenders. This was assessed based on offense recidivism rates and disclosure; self-reported utility was also considered. Nineteen studies were identified from the United States, the United Kingdom, and the Netherlands with no randomized controlled trials identified. Overall, there was a significant increase in relevant disclosures associated with the polygraph. The impact on reoffending rates was significant for violent but not sexual offenses. A number of methodological factors introduced the potential for bias in a significant number of studies reviewed in this review

Spatial variation of trace metals within intertidal beds of native mussels (Mytilus edulis) and non-native Pacific oysters (Crassostrea gigas): implications for the food web?

Abstract Pollution is of increasing concern within coastal regions and the prevalence of invasive species is also rising. Yet the impact of invasive species on the distribution and potential trophic transfer of metals has rarely been examined. Within European intertidal areas, the non-native Pacific oyster (Crassostrea gigas) is becoming established, forming reefs and displacing beds of the native blue mussel (Mytilus edulis). The main hypothesis tested is that the spatial pattern of metal accumulation within intertidal habitats will change should the abundance and distribution of C. gigas continue to increase. A comparative analysis of trace metal content (cadmium, lead, copper and zinc) in both species was carried out at four shores in south-east England. Metal concentrations in bivalve and sediment samples were determined after acid digestion by inductively coupled plasma-optical emission spectrometry. Although results showed variation in the quantities of zinc, copper and lead (mg m-2) in the two bivalve species, differences in shell thickness are also likely to influence the feeding behaviour of predators and intake of metals. The availability and potential for trophic transfer of metals within the coastal food web, should Pacific oysters transform intertidal habitats, is discussed