An improved method for post-PCR purification for mtDNA sequence analysis

Mitochondrial DNA (mtDNA) analysis of forensic samples typically is performed when the quantity and quality of DNA are insufficient for nuclear DNA analysis or when maternal relatives may be the only reference source. Many of the steps required in the analytical process are both lengthy and labor intensive. Therefore, improvements in the process that reduce labor without compromising the quality of the data are desirable. The current procedure requires purification of the amplicons by centrifugal filtration after PCR and prior to cycle sequencing. Because this method requires several manipulations to perform, alternate cleanup procedures were investigated. These include the use of 1) Qiagen QlAquick PCR Purification columns, 2) Concert Rapid PCR Purification columns, and 3) ExoSAP-IT reagent. When the yield of purified amplicons, quality of the sequence profile, and ease of assay were evaluated, the use of ExoSAP-IT reagent for post-amplification purification was chosen to replace the filtration method.     

Spatial and Temporal Patterns of Terrorist Attacks by ETA 1970 to 2007

Rational choice perspectives maintain that seemingly irrational behavior on the part of terrorist organizations may nevertheless reflect strategic planning. In this paper we examine spatial and temporal patterns of terrorist attacks by the Spanish group ETA between 1970 and 2007. Our analysis is guided by a public announcement by ETA in 1978 that the group would shift from emphasizing attacks in the Basque territory to instead launch attacks more widely in the hopes of exhausting the Spanish government and forcing it to abandon the Basque territory. This announcement suggests that prior to the end of 1978 ETA attacks were based mostly on controlling territory in the Basque region that they hoped to rule; and after 1978 the organization decided to instead undertake a prolonged war of attrition. Accordingly, we argue that before the end of 1978 ETA was mostly perpetrating control attacks (attacking only within the Basque territories) and that the diffusion of attacks between provinces was mostly contagious (spreading contiguously). After the 1978 proclamation, we argue that the attack strategy shifted toward attrition (attacking in areas outside of the Basque territories) and that the attacks were more likely to diffuse hierarchically (spreading to more distant locations). As predicted, we find that after ETA moved toward a more attrition based attack strategy, subsequent attacks were significantly more likely to occur outside the Basque region and to target non-adjacent regions (consistent with hierarchical diffusion). We also find that hierarchical diffusion was more common when a longer time elapsed between attacks (a likely consequence of the fact that more distant attacks require more resources and planning) and that attacks against Madrid were unlikely to be followed immediately by more attacks on Madrid or surrounding provinces. After ETA announced a shift in policy, they maintained a highly dispersed attack strategy even during their period of decline. Using information about where and when prior attacks occurred could provide useful information for policy makers countering groups like ETA.     

Visual detection of trace nitroaromatic explosive residue using photoluminescent metallole-containing polymers

The detection of trace explosives is important for forensic, military, and homeland security applications. Detection of widely used nitroaromatic explosives (trinitrotoluene [TNT], 2,4-dinitrotoluene [DNT], picric acid [PA]) was carried out using photoluminescent metallole-containing polymers. The method of detection is through the quenching of fluorescence of thin films of the polymer, prepared by spray coating organic solutions of the polymer, by the explosive analyte. Visual quenching of luminescence (lambda(em) approximately 400-510 nm) in the presence of the explosive is seen immediately upon illumination with near-UV light (lambda(ex)=360 nm). Detection limits were observed to be as low as 5 ng for TNT, 20 ng for DNT, and 5 ng for PA. In addition, experiments with normal production line explosives and their components show that this technology is also able to detect composition B, Pyrodex, and nitromethane. This method offers a convenient and sensitive method of detection of trace nitroaromatic explosive residue.     

Identifying Unit-Dependency and Time-Specificity in Longitudinal Analysis: A Graphical Methodology

Longitudinal analysis in criminology and other social sciences has become an important research tool because it allows us to draw conclusions from observing how multiple units change over time. Unfortunately, its results are more vulnerable to potential influences of unusual observational units or periods of time. Current leverage diagnostics are designed for cross-sectional analysis and are fallible when applied to longitudinal models. This article introduces a graphical diagnostic methodology to systematically examine the sensitivity of longitudinal results to extreme observational units and periods of time—unit-dependency and time-specificity. Further the article illustrates its use with an example testing policy effects on black and white female victimization of intimate partner homicide. Results are displayed in an easily understood graph that provides a snapshot of the results' time-specific patterns and robustness to unit-dependency. Currently, comparable tests for panel analysis are tedious and cumbersome. With this new illuminating methodology, researchers and policy-makers can easily decide whether a time-specific or unit-dependent pattern is consequential.     

Does US presidential rhetoric affect asymmetric political violence?

Although political violence has proven to be difficult for governments to manage, predict or control, previous research on the impact of relevant federal government actions and US presidential rhetoric on terrorist attacks and hate crimes demonstrates that what the US government does matters in ways that are both expected and unexpected. In the US, government counterterrorism strategies changed rapidly in response to the September 11th, 2001 attacks on the US. The Bush administration formed a new executive department, centralised intelligence agencies, invested in tangible counterterrorism measures, implemented two invasions and occupations, and spoke publicly about terrorism on a near-daily basis. Yet much has changed since that research, as the US has since elected a president whose presidential campaign relied upon espousing antagonism towards Muslims, immigrants and other minority groups. Further, President Trump’s administration has repeatedly demonstrated its commitment to isolate and suppress Muslims as a strategy to combat Islamist extremism in contrast to previous administrations’ more cooperative approaches. This article considers what existing research tells us about whether and how the different actions of the Trump administration may fuel both Jihadi and far-right extremism.     

Selective detection of trace nitroaromatic, nitramine, and nitrate ester explosive residues using a three-step fluorimetric sensing process: a tandem turn-off, turn-on sensor

Detection of trace quantities of explosive residues plays a key role in military, civilian, and counter-terrorism applications. To advance explosives sensor technology, current methods will need to become cheaper and portable while maintaining sensitivity and selectivity. The detection of common explosives including trinitrotoluene (TNT), cyclotrimethylenetrinitramine, cyclotetramethylene-tetranitramine, pentaerythritol tetranitrate, 2,4,6-trinitrophenyl-N-methylnitramine, and trinitroglycerin may be carried out using a three-step process combining "turn-off" and "turn-on" fluorimetric sensing. This process first detects nitroaromatic explosives by their quenching of green luminescence of polymetalloles (lambda em approximately 400-510 nm). The second step places down a thin film of 2,3-diaminonaphthalene (DAN) while "erasing" the polymetallole luminescence. The final step completes the reaction of the nitramines and/or nitrate esters with DAN resulting in the formation of a blue luminescent traizole complex (lambda(em) = 450 nm) providing a "turn-on" response for nitramine and nitrate ester-based explosives. Detection limits as low as 2 ng are observed. Solid-state detection of production line explosives demonstrates the applicability of this method to real world situations. This method offers a sensitive and selective detection process for a diverse group of the most common high explosives used in military and terrorist applications today.     

Exposure Reduction or Retaliation? The Effects of Domestic Violence Resources on Intimate‐Partner Homicide

Rates of homicide involving intimate partners have declined substantially over the past 25 years in the United States, while public awareness of and policy responses to domestic violence have grown. To what extent has the social response to domestic violence contributed to the decline in intimate‐partner homicide? We evaluate the relationship between intimate‐partner homicide and domestic violence prevention resources in 48 large cities between 1976 and 1996. Controlling for other influences, several types of prevention resources are linked to lower levels of intimate‐partner homicide, which we interpret in terms of their capacity to effectively reduce victims' exposure to abusive or violent partners. Other resources, however, are related to higher levels of homicide, suggesting a retaliation effect when interventions stimulate increased aggression without adequately reducing exposure. In light of other research on deficiencies in accessing and implementing prevention resources, our results suggest that too little exposure reduction in severely violent relationships may be worse than none at all.     

Threat,emboldenment, or both? The effects of political power on violent hate crimes*

How do expressions of support or opposition by the U.S. federal government, influence violent hate crimes against specific racial and ethnic minorities? In this article, we test two hypotheses derived from Blalock's (1967) conceptualization of intergroup power contests. The political threat hypothesis predicts that positive government attention toward specific groups would lead to more hateful violence directed against them. The emboldenment hypothesis predicts that negative government attention toward specific groups would also lead to more hateful violence directed against them. Using combined data on U.S. government actions and federal hate crime statistics from 1992 through 2012, vector autoregression models provide support for both hypotheses, depending on the protected group involved. We conclude that during this period, African Americans were more vulnerable to hate crimes motivated by political threat, and Latinx persons were more vulnerable to hate crimes motivated by emboldenment.     

The Series Hazard Model: An Alternative to Time Series for Event Data

An important pursuit by a body of criminological research is its endeavor to determine whether interventions or policy changes effectively achieve their intended goals. Because theories predict that interventions could either improve or worsen outcomes, estimators designed to improve the accuracy of identifying program or policy effects are in demand. This article introduces the series hazard model as an alternative to interrupted time series when testing for the effects of an intervention on event-based outcomes. It compares the two approaches through an example that examines the effects of two interventions on aerial hijacking. While series hazard modeling may not be appropriate for all event-based time series data or every context, it is a robust alternative that allows for greater flexibility in many contexts.