23 research outputs found

    A Quasi-Experimental Evaluation of High-Intensity Inpatient Sex Offender Treatment in the Netherlands

    Get PDF
    The current study quasi-experimentally assessed the outcome of high-intensity inpatient sex offender treatment in the Netherlands in terms of sexual and violent (including sexual) recidivism. It was hypothesized that treated sex offenders would show lower recidivism rates than untreated sex offenders of the same risk level. In line with the risk principle of the Risk, Need, Responsivity (RNR) model, we predicted that this would especially hold true for offenders of higher risk levels. The study sample consisted of 25% of all convicted Dutch sex offenders not referred to any form of treatment and discharged from prison between 1996 and 2002, and all convicted Dutch sex offenders referred to inpatient treatment who were discharged between 1996 and 2002. Static- 99R risk levels of these 266 offenders were retrospectively assessed and survival curves regarding sexual and violent (including sexual) recidivism were compared between treated and untreated offenders, controlling for level of risk. Mean follow-up was 148.0 months (SD = 29.6) and the base rate of sexual recidivism was 15.0% and 38.4% for violent (including sexual) recidivism. Cox regression survival analyses showed marginally significant lower failure rates regarding sexual recidivism for treated high-risk offenders only, and significantly lower failure rates regarding violent (including sexual recidivism) for treated sex offenders of moderate-high and high-risk levels. No treatment effects for low and low-moderate risk offenders were found. Results underscore the risk principle of the RNR model: Treatment is more effective when its dosage is attuned to risk level

    P450-Mediated Non-natural Cyclopropanation of Dehydroalanine-Containing Thiopeptides

    Get PDF
    Thiopeptides are a growing class of ribosomally synthesized and post-translationally modified peptide (RiPP) natural products. Many biosynthetic enzymes for RiPPs, especially thiopeptides, are promiscuous and can accept a wide range of peptide substrates with different amino acid sequences; thus, these enzymes have been used as tools to generate new natural product derivatives. Here, we explore an alternative route to molecular complexity by engineering thiopeptide tailoring enzymes to do new or non-native chemistry. We explore cytochrome P450 enzymes as biocatalysts for cyclopropanation of dehydroalanines, chemical motifs found widely in thiopeptides and other RiPP-based natural products. We find that P450TbtJ1 and P450TbtJ2 selectively cyclopropanate dehydroalanines in a number of complex thiopeptide-based substrates and convert them into 1-amino-2-cyclopropane carboxylic acids (ACCAs), which are important pharmacophores. This chemistry takes advantage of the innate affinity of these biosynthetic enzymes for their substrates and enables incorporation of new pharmacophores into thiopeptide architectures. This work also presents a strategy for diversification of natural products through rationally repurposing biosynthetic enzymes as non-natural biocatalysts

    Risk Levels, Treatment Duration, and Drop Out in a Clinically Composed Outpatient Sex Offender Treatment Group

    Get PDF
    Previous research in the Netherlands documented that clinical judgment may yield a substantial amount of treatment referrals for sexual offenders that are inconsistent with actuarial risk assessment and the Risk Need Responsivity (RNR) principles. The present study tested the risk level distribution of a high-intensity, open-format outpatient treatment group. Eighty patients were enrolled during a 620-week period, and their STATIC-99R risk levels were retrospectively determined. The distribution of risk levels in this treatment group did not differ from the distribution of a representative sample of sex offenders referred to outpatient treatment in the Netherlands between 1996 and 2002 (n = 145), nor from the combined Canadian samples (n = 2011) used to assess STATIC-99R normative percentile. These findings suggest that no selection in terms of actuarial risk level occurred between conviction and treatment, leading to over-inclusion of low risk offenders in this high-intensity outpatient treatment group. It is concluded that the standard use of structured risk assessment for the compilation of treatment groups may improve both the effectiveness and efficiency of sex offender treatment in the Netherlands

    Treatment referral for sex offenders based on clinical judgment versus actuarial risk assessment: match and analysis of mismatch

    No full text
    The Risk Need Responsivity (RNR) principles (Andrews & Bonta, 2010) dictate that higher risk sex offenders should receive more intensive treatment. The present study investigates how clinically based treatment assignment relates to risk level in a sex offender sample from The Netherlands. Correlational analyses served to identify sources of mismatches: that is, variables differing significantly in their relation between treatment selection and risk level. Our study sample consisted of 194 convicted rapists and 214 convicted child molesters. All participants’ criminal files were retrospectively coded in terms of the items of the STATIC-99R, PCL: SV, and SVR-20. A low to moderate correlation was observed between clinical treatment selection and actuarial risk levels. A substantial part of the sex offenders, especially child molesters, received overly intensive treatment and another substantial part, especially rapists, received treatment of lesser intensity than indicated by their risk levels. General violent and antisocial risk factors seemed to be underemphasized in the clinical evaluation of sex offenders, especially rapists. A negative attitude toward intervention was negatively associated with clinical treatment selection. It is concluded that clinical treatment selection leads to an insufficient match between risk level and treatment level and systematic use of validated structured risk assessment instruments is necessary to ensure optimal adherence to the risk principle

    A comparison of the predictive properties of nine sex offender risk assessment instruments

    No full text
    Sex offender treatment is most effective when tailored to risk-need-responsivity principles, which dictate that treatment levels should match risk levels as assessed by structured risk assessment instruments. The predictive properties, missing values, and interrater agreement of the scores of 9 structured risk assessment instruments were compared in a national sample of 397 Dutch convicted sex offenders. The instruments included the Rapid Risk Assessment for Sexual Offense Recidivism, Static-99, Static-99R, a slightly modified version of Static-2002 and Static-2002R, Structured Anchored Clinical Judgments Minimum, Risk Matrix 2000, Sexual Violence Risk 20, and a modified version of the Sex Offender Risk Appraisal Guide; sexual and violent (including sexual) recidivism was assessed over 5- and 10-year fixed and variable follow-up periods. In general, the instrument scores showed moderate to large predictive accuracy for the occurrence of reoffending and the number of reoffenses in this sample. Predictive accuracy regarding latency showed more variability across instrument scores. Static-2002R and Static-99R scores showed a slight but consistent advantage in predictive properties over the other instrument scores across outcome measures and follow-up periods in this sample. The results of Sexual Violence Risk 20 and Rapid Risk Assessment for Sexual Offense Recidivism scores were the least positive. A positive association between predictive accuracy and interrater agreement at the item level was found for both sexual recidivism (r = .28, p = .01) and violent (including sexual) recidivism (r = .45, p < .001); no significant association was found between predictive accuracy and missing values at the item level. Results underscore the feasibility and utility of these instruments for informing treatment selection according to the risk-need-responsivity principles. (PsycINFO Database Record (c) 2014 APA, all rights reserved

    Impact of coastal East Antarctic ice rises on surface mass balance: insights from observations and modeling

    Get PDF
    About 20 % of all snow accumulation in Antarctica occurs on the ice shelves. There, ice rises control the spatial surface mass balance (SMB) distribution by inducing snowfall variability and wind erosion due to their topography. Moreover these ice rises buttress the ice flow and represent ideal drilling locations for ice cores. In this study we assess the connection between snowfall variability and wind erosion to provide a better understanding of how ice rises impact SMB variability, how well this is captured in the regional atmospheric climate model RACMO2 and the implications of this SMB variability for ice rises as an ice core drilling site. By combining ground-penetrating radar (GPR) profiles from two ice rises in Dronning Maud Land with ice core dating, we reconstruct spatial and temporal SMB variations from 1983 to 2018 and compare the observed SMB with output from RACMO2 and SnowModel. Our results show snowfall-driven differences of up to 1.5 times higher SMB on the windward side of both ice rises than on the leeward side as well as a local erosion-driven minimum at the ice divide of the ice rises. RACMO2 captures the snowfall-driven differences but overestimates their magnitude, whereas the erosion on the peak can be reproduced by SnowModel with RACMO2 forcing. Observed temporal variability of the average SMBs, retrieved from the GPR data for four time intervals in the 1983–2018 range, are low at the peak of the easternmost ice rise (∼0.06 mw.e.yr−1), while they are higher (∼0.09 mw.e.yr−1) on the windward side of the ice rise. This implies that at the peak of the ice rise, higher snowfall, driven by orographic uplift, is balanced out by local erosion. As a consequence of this, the SMB recovered from the ice core matches the SMB from the GPR at the peak of the ice rise but not at the windward side of the ice rise, suggesting that the SMB signal is damped in the ice core
    corecore