USGS42 and USGS43: human-hair stable hydrogen and oxygen isotopic reference materials and analytical methods for forensic science and implications for published measurement results

Because there are no internationally distributed stable hydrogen and oxygen isotopic reference materials of human hair, the U.S. Geological Survey (USGS) has prepared two such materials, USGS42 and USGS43. These reference materials span values commonly encountered in human hair stable isotope analysis and are isotopically homogeneous at sample sizes larger than 0.2 mg. USGS42 and USGS43 human-hair isotopic reference materials are intended for calibration of δ(2)H and δ(18)O measurements of unknown human hair by quantifying (1) drift with time, (2) mass-dependent isotopic fractionation, and (3) isotope-ratio-scale contraction. While they are intended for measurements of the stable isotopes of hydrogen and oxygen, they also are suitable for measurements of the stable isotopes of carbon, nitrogen, and sulfur in human and mammalian hair. Preliminary isotopic compositions of the non-exchangeable fractions of these materials are USGS42(Tibetan hair)δ(2)H(VSMOW-SLAP) = -78.5 ± 2.3‰ (n = 62) and δ(18)O(VSMOW-SLAP) = +8.56 ± 0.10‰ (n = 18) USGS42(Indian hair)δ(2)H(VSMOW-SLAP) = -50.3 ± 2.8‰ (n = 64) and δ(18)O(VSMOW-SLAP) = +14.11 ± 0.10‰ (n = 18). Using recommended analytical protocols presented herein for δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) measurements, the least squares fit regression of 11 human hair reference materials is δ(2)H(VSMOW-SLAP) = 6.085δ(2)O(VSMOW-SLAP) - 136.0‰ with an R-square value of 0.95. The δ(2)H difference between the calibrated results of human hair in this investigation and a commonly accepted human-hair relationship is a remarkable 34‰. It is critical that readers pay attention to the δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) of isotopic reference materials in publications, and they need to adjust the δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) measurement results of human hair in previous publications, as needed, to ensure all results on are on the same scales.     

Poor parenting and antisocial behavior among homeless young adults: links to dating violence perpetration and victimization

Though research has examined risk factors associated with street victimization among homeless young people, little is known about dating violence experiences among this group. Given homeless youths' elevated rates of child maltreatment, it is likely that they are at high risk for dating violence. As such, the current study examined the association between child maltreatment and parental warmth with dating violence perpetration and victimization through substance use and delinquency among a sample of 172 homeless males and females. Results from path analysis revealed that physical abuse, sexual abuse, and neglect were all significant correlates of both substance use and delinquency, whereas lack of parental warmth was only associated with substance use. Neglect and substance use had direct effects on dating violence and substance use and was found to mediate the relationship between physical abuse and dating violence. Finally, females, older youth, and non-Whites had significantly higher levels of dating violence compared with their counterparts.     

Do Retributive and Restorative Justice Processes Address Different Symbolic Concerns?

In support of a unitary conceptualization of retributive justice (justice through the imposition of punishment) and restorative justice (justice through dialogue aimed at consensus), three studies using hypothetical and recalled experiences of victimization found that people’s endorsement of, and satisfaction with, either justice notion depends on the symbolic meaning of the transgression. In Study 1, perceiving the transgression as a status/power violation was uniquely related to the endorsement of retributive justice, whereas perceiving it as a violation of shared values was uniquely related to restorative justice. In Study 2, motivation to restore status/power was related to retributive responses, whereas motivation to restore value consensus with the offender was uniquely related to restorative responses. In Study 3, a scenario experiment, respondents called for greater additional sanction when the applied justice process (retributive vs. restorative) did not fit the salient meaning of the transgressions compared to when it did (status/power vs. values).     

Self-deception as the root of political failure

I consider models of political failure based on self-deception. Individuals discard free information when that information damages their self-image and thus lowers their utility. More specifically, individuals prefer to feel good about their previously chosen affiliations and shape their worldviews accordingly. This model helps explain the relative robustness of political failure in light of extensive free information, and it helps explain the rarity of truth-seeking behavior in political debate. The comparative statics predictions differ from models of either Downsian or expressive voting. For instance, an increased probability of voter decisiveness does not necessarily yield a better result. I also consider political parties as institutions and whether political errors cancel in the aggregate. I find that political failure based on self-deception is very difficult to eliminate.     

Social Identity Theory and EU Expansion

In this article, I build a theory of European Union (EU) expansion using Social Identity Theory. The theory proposes that the development of a national identity in relation to Europe is the most significant contributing factor to a policy to support/oppose expanding the EU to include applicant countries. According to the theory, strength of identity—whether more national or European—is the key variable in explaining the policy toward applicant countries. As a preliminary exploration of the theory, I look at why some decision-makers within EU countries support Turkey's accession while others do not. The identities among top decision-makers within Britain, Germany, and France are used to examine the policy preferences regarding Turkey's bid for membership into the EU during these three recent progressions: the recognition of Turkey as a candidate country in 1999, the development of a timeline for full membership in 2002, and the beginning of accession negotiations in 2005.     

Testing an Integration of Control Theories: The Role of Bonds and Self-Control in Decision Making

Since the redefinition of self-control (Hirschi, 2004) social bonding measures have been utilized as predictors or indicators of revised or decisional self-control. This approach departs from the prior literature which has hypothesized a selection effect of self-control on social bonds. To reconcile this discrepancy and explain the relationship among two self-control measures (attitudinal and revised self-control), an alternate model is proposed that explains the process of self-control on refrainment from offending at the situation level. Surveys using the vignette method for a hypothetical drunk-driving decision-making task were collected from large samples of young adults and inmates. Path analysis is used to model bonds and self-control as determinates of decisional self-control, thus indirectly influencing self-reported estimates of drunk-driving likelihood. Decisional self-control, attitudinal self-control and social bonds also directly affect intentions to drive drunk. Overall, the proposed model is supported. A strong direct effect of attitudinal self-control on drunk-driving likelihood remains while controlling for decisional self-control. There are relatively smaller indirect effects of social bonds and attitudinal self-control on drunk-driving likelihood, through their effects on decisional self-control. These findings support the need for the conceptual separation of bonds, attitudinal and decisional self-control as well as increased attention to differential effects of self-control.     

A qualitative study of early family histories and transitions of homeless youth

Using intensive qualitative interviews with 40 homeless youth, this study examined their early family histories for abuse, neglect, and other family problems and the number and types of transitions that youth experienced. Multiple forms of child maltreatment, family alcoholism, drug use, and criminal activity characterized early family histories of many youth. Leaving home because of either running away or being removed by child protective services often resulted in multiple transitions, which regularly included moving from foster care homes to a group home, back to their parents, and then again returning to the streets. Although having experienced family disorganization set youth on trajectories for early independence, there were many unique paths that youth traveled prior to ending up on the streets.