Conditioned Microplitis croceipes Cresson (Hymenoptera: Braconidae) detect and respond to 2,4-DNT: development of a biological sensor

We examined the ability of M. croceipes to learn, detect, and respond to 2,4-DNT, which is a volatile discriminator of trinitrotoluene (TNT). The percentage of conditioned wasps to detect and respond to the various concentrations of 2,4-DNT for > or = 15 sec was measured. Significantly more of the conditioned wasps responded to the concentration of 2,4-DNT used for conditioning than other concentrations examined. Accordingly, percent conditioned wasps to respond > or = 15 sec could be used as a suitable measure to screen air samples and distinguish between samples with or without the target odorant. The data recorded in this study indicate the measured behavior could be used to estimate the concentration of target odorants. Data in this study indicate M. croceipes can detect and respond to this compound, which provide further support for its development as a biological sensor.     

Assessing Violence Risk in Stalking Cases: A Regression Tree Approach

Advances in the field of risk assessment have highlighted the importance of developing and validating models for problematic or unique subgroups of individuals. Stalking offenders represent one such subgroup, where fears of and potential for violence are well-known and have important implications for safety management. The present study applies a Classification and Regression Tree (CART) approach to a sample of stalking offenders in order to help further the process of identifying and understanding risk assessment strategies. Data from 204 stalking offenders referred for psychiatric evaluation to a publicly-funded clinic were used to develop and assess putative risk factors. A series of nested models were used to generate tree algorithms predicting violence in this sample of offenders. Both simplified and more extensive models generated high levels of predictive accuracy that were roughly comparable to logistic regression models but much more straightforward to apply in clinical practice. Jack-knifed cross-validation analyses demonstrated considerable shrinkage in the CART, although the models were still comparable to many other actuarial risk assessment instruments. Logistic regression models were much more resilient to cross-validation, with relatively modest loss in predictive power.     

A Test of Two Methods of Recall for Violent Events

This project took advantage of an opportunity to test the comparability of two different methods for collecting self-reports of violent incidents. Using a life events calendar (LEC) approach, we collected data from individuals about violent incidents that occurred within a 1–3-year prior time period. These individuals had been research participants in a previous study that collected information about violent incidents using prospective, weekly interviews. Results using the LEC method were compared with the weekly self-reports of violence for an overlapping recall period. This allowed us to see how well the recall of violent incidents at a later date mapped onto reports obtained within seven days of any incidents. Overall results show a significant amount of under-reporting using the life-event calendar methodology compared to the weekly interview approach, but some higher concordance of reporting was found for serious rather than minor violence.     

Estimating Regression Models in Which the Dependent Variable Is Based on Estimates

e-mail: jblewis{at}ucla.edu (corresponding author) e-mail: dlinzer{at}ucla.edu Researchers often use as dependent variables quantities estimatedfrom auxiliary data sets. Estimated dependent variable (EDV)models arise, for example, in studies where counties or statesare the units of analysis and the dependent variable is an estimatedmean, proportion, or regression coefficient. Scholars fittingEDV models have generally recognized that variation in the samplingvariance of the observations on the dependent variable willinduce heteroscedasticity. We show that the most common approachto this problem, weighted least squares, will usually lead toinefficient estimates and underestimated standard errors. Inmany cases, OLS with White's or Efron heteroscedastic consistentstandard errors yields better results. We also suggest two simplealternative FGLS approaches that are more efficient and yieldconsistent standard error estimates. Finally, we apply the variousalternative estimators to a replication of Cohen's (2004) cross-nationalstudy of presidential approval.     

An assessment of four solvents for the recovery of 2-chlorobenzylidenemalononitrile and capsaicins from "CS" and "Pepper" type lachrymator sprays, and an examination of their persistence on cotton fabric

The rising incidence of assaults involving lachrymator sprays has led to an increase in items being submitted to this laboratory for the analysis of the associated chemical residues. The following work was undertaken to identify an efficient solvent with which to extract the compounds of interest from cotton fabric. The persistence and subsequent recovery of such compounds was also examined following protracted exposure to wind and rain. Ethyl acetate was established as the most efficient solvent of those examined for the extraction of 2-chlorobenzylidenemalononitrile and a range of capsaicins from "CS Gas" and '"Pepper" sprays respectively. Controlled experiments undertaken showed that capsaicins were recoverable after 72 h of exposure to the "elements" and 2-chlorobenzylidenemalononitrile was still recoverable after one week.     

Property tax in Indonesia: measuring and explaining administrative (under‐) performance

One of the arguments made by some Indonesian government officials in defence of continued central control over the property tax is that it has performed well under their authority and that its decentralisation would inevitably result in weaker operations and outcomes. The property tax has indeed grown remarkably well over the past 15 years. This growth, however, has been from a very low base, has been dominated by increased revenues from the mining sector and has been driven by a small number of sub‐national governments. Recently, only around 40% of local sector property tax potential has been realised under central control, given the existing tax rate and base. Property valuations are the most problematic aspect of administration but tax coverage and collections are also sub‐standard. While there may, in fact, be insufficient local government capacity to manage the property tax, even to current levels of performance, this problem could be solved by transferring the relevant central staff to local governments, as has been carried out in other newly decentralised sectors. But even before tax administration is devolved, local governments could at least be given some authority over the property tax rate, presently one of the lowest in the world. Copyright © 2003 John Wiley & Sons, Ltd.     

Differences in the predictive validity of actuarial risk assessments in relation to sex offender type

This study seeks to expand on the previously reported validity of the Static-99, RRASOR, MnSOST-R, and SORAG in predicting sexual recidivism utilizing a regional sample of offenders. The predictive validity of each test was determined utilizing subgroups of the sample based on each offender's known offense history. The effectiveness of each instrument varied depending on offender type. The Static-99 and SORAG were both significantly predictive of sexual, violent, and any recidivism for extra-familial child molesters, and all four tests were predictive of violent or any recidivism in this subgroup. For incest offenders, all four tests were at least moderately predictive of sexual recidivism, whereas the Static-99 and the SORAG were highly predictive of violent or any recidivism. None of the four tests established consistent predictive validity across recidivism categories in regard to rapists or hands-off offenders, however, the Static-99 and the SORAG were significant in terms of sexual recidivism.