Classification of premium and regular gasoline by gas chromatography/mass spectrometry,principal component analysis and artificial neural networks

Detection and correct classification of gasoline is important for both arson and fuel spill investigation. Principal component analysis (PCA) was used to classify premium and regular gasolines from gas chromatography-mass spectrometry (GC-MS) spectral data obtained from gasoline sold in Canada over one calendar year. Depending upon the dataset used for training and tests, around 80-93% of the samples were correctly classified as either premium or regular gasoline using the Mahalanobis distances calculated from the principal components scores. Only 48-62% of the samples were correctly classified when the premium and regular gasoline samples were divided further into their winter/summer sub-groups. Artificial neural networks (ANNs) were trained to recognise premium and regular gasolines from the same GC-MS data. The best-performing ANN correctly identified all samples as either a premium or regular grade. Approximately 97% of the premium and regular samples were correctly classified according to their winter or summer sub-group.     

ASTM standards for fire debris analysis: a review

The American Society for Testing and Materials (ASTM) recently updated its standards E 1387 and E 1618 for the analysis of fire debris. The changes in the classification of ignitable liquids are presented in this review. Furthermore, a new standard on extraction of fire debris with solid phase microextraction (SPME) was released. Advantages and drawbacks of this technique are presented and discussed. Also, the standard on cleanup by acid stripping has not been reapproved.Fire debris analysts that use the standards should be aware of these changes.     

Measures of aggression and mood changes in male weightlifters with and without androgenic anabolic steroid use

Supraphysiologic doses of testosterone are associated with increased aggression that is hypothesized to be a function of testosterone serum concentrations, mood, and personality. The study attempted to characterize this relationship among weightlifters who were users (n = 10) and nonusers (n = 18) of anabolic steroids. Participants were interviewed using the Modified Mania Rating Scale and Hamilton Rating Scale for Depression to assess mood, the Buss-Durkee Hostility Inventory (BDHI) and Point Subtraction Aggression Paradigm (PSAP) to assess aggression, and the Personality Disorder Questionnaire (PDQ-R) to assess personality. Blood samples were obtained for the determination of total, free, and weakly bound testosterone. Comparisons of continuous variables between testosterone users and non-users were performed with a parametric (unpaired t-test) or non-parametric (Mann-Whitney) test where appropriate. Correlations with testosterone were examined separately for testosterone users and non-users, using Spearman rank correlation. The subjective (BDHI) and objective (PSAP) assessments of aggression found that supranormal testosterone concentrations were associated with increased aggression. However, the PDQ-R results suggest that this finding was confounded by the personality disorder profile of the steroid users, because steroid users demonstrated Cluster B personality disorder traits for antisocial, borderline, and histrionic personality disorder.     

Lifetime distributional effects of Social Security retirement benefits

This article presents three measures of the distribution of actual and projected net benefits (benefits minus payroll taxes) from Social Security's Old-Age and Survivors Insurance (OASI) for people born between 1931 and 1960. The results are based on simulations with the Social Security Administration's Model of Income in the Near Term (MINT), which projects retirement income through 2020. The base sample for MINT is the U.S. Census Bureau's Survey of Income and Program Participation panels for 1990 to 1993, matched with Social Security administrative records. The study population is grouped into 5-year birth cohorts and then ranked by economic status in three ways. First, the population is divided into five groups on the basis of individual lifetime covered earnings, and their lifetime present values of OASI benefits received and payroll taxes paid are calculated. By this measure, OASI provides much higher benefits to the lowest quintile of earners than to other groups, but it becomes less redistributive toward lower earners in more recent birth cohorts. Second, people are ranked by shared lifetime covered earnings, and the values of shared benefits received and payroll taxes paid are computed. Individuals are assumed to split covered earnings, benefits, and payroll taxes with their spouses in the years they are married. By the shared covered earnings measure, OASI is still much more favorable to persons in the lower income quintiles, although to a lesser degree than when people are ranked by individual covered earnings. OASI becomes more progressive among recent cohorts, even as net lifetime benefits decline for the entire population. Finally, individuals are ranked on the basis of their shared permanent income from age 62, when they become eligible for early retirement benefits, until death. Their annual Social Security benefits are compared with the benefits they would have received if they had saved their payroll taxes in individual accounts and used the proceeds to buy either of two annuities that provide level payments from age 62 until death: a unisex annuity that is based on the average life expectancy of the birth cohort or an age-adjusted annuity that is based on the worker's own life expectancy. On the permanent income measure, OASI is generally more favorable to people in higher income quintiles. Moreover, it is particularly unfavorable to those in the lowest quintile. Because people in the lowest quintile have a shorter life expectancy, they receive OASI benefits for a shorter period. This group would receive greater benefits in retirement if they invested their payroll taxes in the age-adjusted annuity. OASI is more favorable to them than the unisex annuity, however, OASI is becoming more progressive in that the net benefits it provides drop more rapidly among higher income quintiles than lower ones. This article also examines how OASI affects individuals by educational attainment, race, and sex. On both the lifetime covered earnings and the permanent income measures, OASI is more favorable to workers with less education and more favorable to women. The results by race and ethnicity are mixed. When people are ranked by the present value of their shared lifetime covered earnings, OASI appears more favorable to non-Hispanic blacks and Hispanics than to non-Hispanic whites. When people are ranked by shared permanent income in retirement, however, OASI produces negative returns for both non-Hispanic blacks and non-Hispanic whites in the most recent birth cohorts, with non-Hispanic blacks faring relatively worse. The changes across cohorts occur partly because of changes in tax rates and benefits, but more importantly because of changing demographics and earnings patterns of the workforce. Of particular importance is the increasing share of beneficiaries who receive worker benefits instead of auxiliary benefits as wives or widows. OASI benefits are based on the lifetime covered earnings of current or former married couples, as well as on earned retirement benefits of individuals. The reduced importance of auxiliary benefits (due to the higher lifetime covered earnings of women) and the increased proportion of divorced retirees make OASI more progressive--even as net benefits decline--for current and future cohorts than for cohorts who retired in the 1990s. Analysis of these findings suggests that simulations of policy changes in Social Security must take into account the decreasing importance of auxiliary benefits across birth cohorts and the complex changes in individuals' marital histories.     

Entrepreneurship, Secrecy, and Productivity: A Comparison of Clinical and Non-Clinical Life Sciences Faculty

This paper addresses research in the life sciences, responsible for significant national expenditures for scientific investigations funded by both the federal government and industry. Our investigation examines faculty members' involvement with industry in entrepreneurial ways that is, involved in translating their research into potentially marketable knowledge or products. First, this study examines whether there are differences in entrepreneurial behaviour between clinical and non-clinical faculty in the life sciences with industry relationships, and, second, to discover any linkage between entrepreneurship and secrecy or productivity in different ways for clinical and non-clinical faculty. The study is based on survey responses of a national sample of 4,000 clinical and non-clinical life sciences faculty in 49 U.S. research universities. The results show non-clinical faculty as more involved at the back end. The more entrepreneurial end of commercialization while clinical faculty are involved at the back end. The more entrepreneurial faculty (non-clinical) are more likely to be secretive about their research. Clinical faculty are less likely to have been denied access to research results or products. Entrepreneurial faculty are not less productive in their faculty roles. This investigation is preliminary in that it addresses one large area of academic research but excludes fields with longer historical relationships with industry.