Species loss revisited

Among his books are The Economics of Population Growth; Effort, Opportunity, and Wealth;and Population Matters: People, Resources, Environment, and Immigration (the latter was published by Transaction).     

Using the Delphi process to analyze social policy implementation: A post hoc case from vocational rehabilitation

This study uses a Policy Delphi to discern differences in perspective among and within groups responsible for formulating and implementing vocational rehabilitation policy. Four groups of players were chosen for our analysis: government officials, academics, directors of rehabilitation centers, and the staff who interface with program participants. Significant differences were found between the groups regarding the relative importance of possible legislative goals. This suggests that the failure of vocational rehabilitation policy to promote a work agenda may be attributed to a lack of consensus among policy implementors. The Delphi technique could help policy planners understand the different perspectives within the implementation community, and hence craft more realistic legislation.     

Estimation and Inference Are Missing Data Problems: Unifying Social Science Statistics via Bayesian Simulation

Bayesian simulation is increasingly exploited in the socialsciences for estimation and inference of model parameters. Butan especially useful (if often overlooked) feature of Bayesiansimulation is that it can be used to estimate any function ofmodel parameters, including "auxiliary" quantities such as goodness-of-fitstatistics, predicted values, and residuals. Bayesian simulationtreats these quantities as if they were missing data, samplingfrom their implied posterior densities. Exploiting this principlealso lets researchers estimate models via Bayesian simulationwhere maximum-likelihood estimation would be intractable. Bayesiansimulation thus provides a unified solution for quantitativesocial science. I elaborate these ideas in a variety of contexts:these include generalized linear models for binary responsesusing data on bill cosponsorship recently reanalyzed in PoliticalAnalysis, item—response models for the measurement ofrespondent's levels of political information in public opinionsurveys, the estimation and analysis of legislators' ideal pointsfrom roll-call data, and outlier-resistant regression estimatesof incumbency advantage in U.S. Congressional elections     

Evaluation of sieving polymers for fast, reproducible electrophoretic analysis of short tandem repeats (STR) in capillaries

Efficient capillary electrophoretic STR analysis requires rapid, reproducible and robust separation of DNA fragments with reasonable capillary longevity--this is currently accomplished using proprietary commercial polymeric sieving matrices specifically developed for this separation. These matrices, while effective, are costly and do not provide adequate resolution of STR DNA fragments in capillaries with shorter effective separation lengths, increasing the time required to accomplish the separation and minimizing the potential extrapolation to other miniaturized platforms. As the forensic community looks toward next generation microchip technology as a means of processing casework more rapidly, new sieving polymers need to be evaluated for utilization in this platform. The research presented here describes the assessment of commercially-available polymeric sieving matrices for STR analysis, with consideration given to feasibility of incorporation into a microdevice. Polymer composition, molecular weight, and concentration were evaluated, along with an assessment of the effects of buffer composition, separation temperature, and capillary length. These variables were evaluated individually or collectively on the ability to resolve STR DNA fragments and the reproducibility of the separations and the results compared to a proprietary commercial product. A 600,000 Da MW poly(ethylene oxide) (PEO) solution at a 3% (w/v) concentration was determined to be the most suitable matrix for these separations. This polymer, in coated capillaries, provided highly robust and reproducible separations, with near baseline resolution of fragments having single base differences. Reductions in the temperature of the separation, from 60 degrees C to 40 degrees C, and the urea concentration of the buffer, from 7 M to 3.5 M, provided increased longevity of the PEO polymer for repeated separations. Comparison of this polymer with currently specified commercial products used for STR analysis showed that the optimized PEO matrix provided superior separations under all conditions tested. In addition, PEO could be utilized in shorter capillary systems, with a concurrent decrease in analysis time, highlighting its potential for use in shortened capillary or microdevice systems.     

Proficiency testing (external quality assessment) of drug detection in oral fluid

Eighteen external quality assessment (proficiency testing) samples were prepared from client specimens collected with the Intercept oral fluid collection device and by spiking drug-free oral fluid. Samples were circulated in pairs at quarterly intervals to 13 UK and USA based laboratories for analysis by a panel of OraSure micro-plate Intercept enzyme immunoassay kits and hyphenated mass spectrophotometric techniques. During the survey, there was a single case of non-specificity in a false report for methadone. The major errors were of lack of sensitivity relative to the concentration thresholds specified for the immunoassays. The sensitivity for overall "present"/"not found" reports calculated as true positives/(true positives+false negatives) were for the amphetamine specific assay 50%, methyl-amphetamines 93%, barbiturates 64%, cannabinoids 73%, cocaine and metabolites 100%, benzodiazepines 69%, methadone 95%, opiates 79% (opiates excluding oxycodone 93%), phencyclidine 93% and human gamma-globulin 97%. A small number of the sensitivity errors were attributable to errors in chromatographic confirmation techniques.     

Mandarins and kibitzers:men in and around the trenches of political power in Ottawa*

Book reviewed in this article: My Life and Work, A Happy Partnership: Memoirs of J. A. Corry. A Man of Influence: Norman A. Robertson and Canadian Statecraft, 1929–1968. The Ottawa Men: The Civil Service Mandarins 1935–1957.