Mitochondrial DNA error prophylaxis: assessing the causes of errors in the GEP'02-03 proficiency testing trial

A qualitative and quantitative analytical method was developed and validated for the determination of 49 licit and illicit drugs in oral fluid. Small oral fluid samples, volume 1mL, were collected from volunteers using a modified Omni-Sal device and the analytes were extracted from an oral fluid/buffer mixture using a single Bond Elut Certify solid phase extraction cartridge. Liquid chromatography-tandem mass spectrometry (LC-MS-MS) and gas chromatography-repetitive full scan mass spectrometry (GC-MS) were used in parallel to analyze the extracts for the targeted drugs. Extracts were analyzed by GC-MS in their underivatized form and as their pentafluoropropionyl derivatives. Deuterated internal standards were used for quantification of drugs of abuse by LC-MS-MS to minimize matrix effects. Methadone-d(9) and tumoxetine were used as the internal standards for quantification of non-derivatized and derivatized analytes respectively by GC-MS. Linearity was demonstrated over the range 5-200 ng/mL and limits of detection were less than 4 ng/mL for each drug analyzed. The method demonstrated acceptable recoveries for most of the analytes and good intra- and inter-day precision. Acquisition of data by repetitive full scan GC-MS allows the addition of further analytes to the target menu.     

The effect of the method of burial on adipocere formation

A controlled laboratory experiment was conducted in order to investigate the effect of the method of burial (i.e. the presence of coffin and clothing) on the formation of adipocere. This study follows previous studies by the authors who have investigated the effect of physical conditions on the formation of adipocere present in a controlled burial environment. The study utilises infrared spectroscopy to provide a preliminary lipid profile of the remains following a 12 month decomposition period. Inductively coupled plasma-mass spectrometry was employed as a technique for determining the salts of fatty acids present in adipocere. Gas chromatography-mass spectrometry (GC-MS) was used as the confirmatory test for the identification and determination of the chemical composition of adipocere which formed in the controlled burial environments. The results suggest that coffins will retard the rate at which adipocere forms but that clothing enhances its formation. The results concur with previous observations on adipocere formation in burial environments.     

Mobile phase influence on electrospray ionization for the analysis of smokeless powders by gradient reversed phase high-performance liquid chromatography-ESIMS

The solution parameters associated with gradient elution reversed phase high-performance liquid chromatography (HPLC) were characterized by evaluating the electrospray ionization mass spectrometry (ESIMS) response of selected smokeless powder additives. Using direct liquid infusion, the positive ion ESIMS responses were determined for three general classes of powder constituents: dialkylphthalate acid esters, N,N'-dialkyl-N,N'-diphenyl urea based stabilizers and nitroso-, nitro-, and dinitro- derivatives of diphenylamine. The relative ESIMS intensities of the powder components were investigated as a function of three solution parameters: ammonium acetate concentration, pH, and percent methanol. The effect of the ammonium acetate concentration demonstrates that the electrolyte is required for efficient ionization and the ESIMS intensity was optimal at a concentration of 2mM for the selected compounds, except 2,4'-dinitrodiphenylamine. The aqueous solution pH, corresponding to the available protons in solution, did not have a significant effect on the ESIMS intensity of the analytes. The percent methanol was evaluated with both decreasing and constant electrolyte concentrations to demonstrate the effects of droplet stability and ion transfer into the gas phase. These findings were applied to the analysis of the selected smokeless powder additives using HPLC-ESIMS to illustrate increased sensitivity for the protonated molecules.     

Measurement Properties of the Communities That Care<Superscript>®</Superscript> Youth Survey Across Demographic Groups

Prevention science has produced information about risk and protective factors that predict adolescent drug use and related problem behaviors. This paper investigates the Communities That Care Youth Survey that measures multiple risk and protective factors. Using a sample of 172,628 students who participated in surveys administered in seven states in 1998, analyses were conducted to test the factor structure of these risk and protective factors and to test the equivalence of the factor models across five racial/ethnic groups (African Americans, Asians or Pacific Islanders, Caucasians, Hispanic Americans, and Native Americans), four grade levels (6th, 8th, 10th, and 12th) and both gender groups. Results support the construct validity of the surveys risk and protective factor scales and indicate that the measures are equally reliable across males and females and five racial/ethnic groups. Implications of these findings for science-based prevention planning are discussed.     

Reporting recidivism rates: The criterion and follow-up issues

Although the topic of recidivism invariably elicits much interest, there appears to be considerable conflict and uncertainty as to even crude estimates of the recidivism rate for persons released from prison. The purpose of this research was to examine the extent to which this apparent confusion may be explained by different methodological choices of criterion measure or length of follow-up. Through the cooperation of the Federal Bureau of Investigation, rap sheet follow-up information for a six-year period was obtained for a relatively large random sample of federal prisoners released in 1970. This data enabled calculation of recidivism rates using various criterion measures and follow-up periods applied to the same sample. The effect of varying these definitions on the recidivism rate obtained can then be directly observed.     

Assets of new retired-worker beneficiaries: findings from the New Beneficiary Survey

Most new retired workers in 1982 owned some type of asset, usually a savings, checking, or credit union account, according to data obtained by the Social Security Administration (SSA) in its New Beneficiary Survey. Many recently retired workers also owned their home, often mortgage-free. Homeownership was their most significant asset in terms of its median value. Comparatively few retirees owned property other than a home, though for owners of such property, the median value was substantial. Married couples, whose assets included those of both partners, more frequently owned assets and their assets had higher median values than did unmarried individuals. A comparison of retired workers with persons aged 65 or older who were enrolled in the Medicare program but who had not yet received retired-worker benefits showed that these Medicare-only enrollees were much better off, both in the likelihood of owning assets and in having higher median values for their assets. Individuals who retired before reaching age 65 and therefore received a reduced social security benefit were not as well off as those whose first benefit was paid at age 65 or older. Overall, the asset situation of new retired workers in 1982 was better than that of men and unmarried women aged 58-63 in 1969, even when the 1969 assets were adjusted to constant 1982 dollars.