Genetic variation at eight STR loci in the Korean population

The frequency distributions of eight STR loci were surveyed in 510 unrelated individuals from the Korean population     

A Molecular Method to Correlate Bloodstains with Wound Site for Crime Scene Reconstruction

Bloodstain pattern analysis to determine the wound‐of‐origin of bloodstains is problematic with nonspecific patterns. In this proof‐of‐concept study, the authors examined a molecular approach to correlate bloodstains with injuries using the rat as a model. Specifically, investigations were conducted on the rat brain marker, rno‐miR‐124‐3p, with the QIAGEN miScript System and real‐time PCR analysis. Rno‐miR‐124‐3p was detected in brain homogenates diluted 100,000 times; in 3‐week‐old, room temperature stored, simulated brain–blood stains; and in bloodstains from head gunshot wounds collected with swabs and subsequently frozen for 9–18 months; however, rno‐miR‐124‐3p was not detected in whole blood. Proof‐of‐principle was demonstrated by the ability to distinguish bloodstains from a gunshot wound to the head versus bloodstains from a gunshot wound to the chest, by the testing of otherwise identical bloodstains from the two patterns for the presence of the marker. The results suggest a viable approach to a longstanding problem in casework.     

Establishment of the measurement uncertainty of 11-nor-D9-tetrahydrocannabinol-9-carboxylic acid in hair

The quantitative analysis of 11-nor-D(9)-tetrahydrocannabinol-9-carboxylic acid (THCCOOH) in hair requires a sensitive method to detect a low-pg level. Before applying the method to real hair samples, the method was validated; in this study, we examined the uncertainty obtained from around the cut-off level of THCCOOH in hair. We calculated the measurement uncertainty (MU) of THCCOOH in hair as follows: specification of the measurand, identification of parameters using "cause and effect" diagrams, quantification of the uncertainty contributions using three factors, the uncertainty of weighing the hair sample, the uncertainty from calibrators and the calibration curve, and the uncertainty of the method precision. Finally, we calculated the degrees of freedom and the expanded uncertainty (EU). The concentration of THCCOOH in the hair sample with its EU was (0.60 ± 0.1) × 10(-4)ng/mg. The relative uncertainty percent for the measurand 0.60 × 10(-4)ng was 9.13%. In this study, we also selected different concentrations of THCCOOH in real hair samples and then calculated the EU, the relative standard uncertainty (RSU) of the concentration of THCCOOH in the test sample [u(r)(c0)], the relative uncertainty percent, and the effective degree of freedom (v(eff)). When the concentrations of THCCOOH approached the cut-off level, u(r)(c0) and the relative uncertainty percent increased but absolute EU and v(eff) decreased.     

A study on the concentrations of 11-nor-Δ(9)-tetrahydrocannabinol-9-carboxylic acid (THCCOOH) in hair root and whole hair

In this study, we investigated the patterns of cannabis users (n=412) according to their sex, age, and the results of urinalysis and hair analysis, and classified the concentrations of THCCOOH in hair into three categories to examine the levels of cannabis use. We also compared the concentrations of THCCOOH in hair root, hair without the hair root and whole hair and examined the relationship among them according to the results of urinalysis. The hair samples were washed, digested with 1ml of 1M NaOH at 85°C for 30min and extracted with 2ml of n-hexane:ethyl acetate (9:1) two times after adding 1ml of 0.1N sodium acetate buffer (pH 4.5) and 200μl of acetic acid. The final mixture was derivatized with 50μl of PFPA and 25μl of PFPOH for 30min at 70°C. The solution was evaporated, and the residue was reconstituted in 40μl of ethyl acetate and transferred to an autosampler vial. One microlitre was injected into the GC/MS/MS-NCI system. The concentrations of THCCOOH ranged from 0.06 to 33.44pg/mg (mean 2.96; median 1.32) in hair from cannabis users who had positive urine results and ranged from 0.05 to 7.24pg/mg (mean 1.35; median 0.37) in hair from cannabis users who had negative urine results. The average concentration of THCCOOH in hair from cannabis users who had positive urine results was higher than that from cannabis users who had negative urine results. Male cannabis users in their forties were predominant. We classified the concentrations of THCCOOH in hair into three groups (low, medium and high), and could use the grouping of THCCOOH in hair as a guide for determining the level of use. The low, medium and high concentration ranges for THCCOOH in hair were 0.05-0.24, 0.25-2.60 and 2.63-33.44pg/mg, respectively. We also investigated 28 hair samples with the root. The highest concentrations of THCCOOH were seen in the hair root from 18 out of the 28 hair samples. The average concentrations of THCCOOH in hair root, hair without hair root and whole hair from cannabis users who had positive urine results were higher than those who had negative urine results.     

Collaborative Partnerships and Crime in Disorganized Communities

Collaborative partnerships can be an effective strategy for crime prevention, especially in disorganized communities. Using ordinary least squares regression with 414 American cities, this article finds that police departments with many collaborative partnerships are able to promote informal social control within their communities and capitalize on the resources available to them with the help of other groups. This contention is supported by the effects of collaborative partnerships on crime rates in disorganized communities in comparison to well‐organized communities. Thus, collaborative partnerships of public organizations with other groups may insulate disorganized communities from the effects of community disorganization on levels of crime.     

Appointee Confirmation and Tenure: The Succession of U.S. Federal Agency Appointees, 1989–2009

This article analyzes the confirmation and tenure of 2,300 Senate‐confirmed, presidential appointees to U.S. government agencies between 1989 and 2009, linking patterns of appointee confirmation and tenure to institutional politics, appointee independence, and agency context. Consistent with prior research, the authors find that nominees of new, powerful, and popular presidents enjoy expedited Senate confirmation. Contentious congressional committee oversight, by contrast, tends to delay confirmation and reduce tenure. Agency heads and positions insulated from removal, such as for fixed‐term positions and inspectors general, increase tenure. Extending empirical research, the analysis highlights program‐ and agency‐level variations that speak to the many contingencies shaping appointee politics. Appointee positions associated with national security and broad statutory discretion receive expedited confirmation. Agencies with more professionals are associated with increased tenure, whereas agencies with more appointees among managers see shorter tenures. The results speak to scholarship on appointee politics and to public knowledge about the role of appointments in American government.     

Cross-examination of liquid-liquid extraction (LLE) and solid-phase microextraction (SPME) methods for impurity profiling of methamphetamine

Impurities in 48 methamphetamine (MA) samples were analyzed by liquid-liquid extraction (LLE) and headspace solid-phase microextraction (HS-SPME) methods. MPS-2 autosampler was used to improve reproducibility of SPME method, and nonadecane (C(19)) diluted with potassium bromide (KBr) powder was used as an internal standard for standardizing retention time. Impurities identified by SPME method showed different patterns compared with LLE method. Non-volatile impurities like methamphetamine dimer were not identified by SPME method, but some volatile impurities like diphenylketone, caprolactam and lots of unknowns were identified only by SPME method. 1-Phenyl-2-propanone (P2P), 1-phenyl-2-propanol and benzylcyanide peaks could be discriminated clearly by SPME method without interference of amphetamine, an artifact originates from MA degradation. Differences in the impurity patterns resulted in different clustering results. When 48 MA samples were classified into 5 LLE and 5 SPME clusters, cross-matching of the clusters resulted in 8 sub-clusters. It shows that combination of the different extraction methods can distinguish the differences which cannot be distinguished by LLE or SPME method alone, and can improve reliability of the profiling results.     

A Molecular Method to Detect Wound Cells in Bloodstains Resultant of Sharp Force Injuries for Crime Scene Reconstruction

Previous research by the authors on an animal model showed that bloodstains can contain additional information about their somatic origin in the form of wound cells. Bloodstains produced by a gunshot wound to the head were distinguished from bloodstains produced by a gunshot wound to the chest by testing the stains for a brain microRNA marker. In this study, the effectiveness of the technique was examined on blood drops shed externally from a stab wound to the liver of rat carcasses. Specifically, investigations were conducted on the liver microRNA marker, rno‐mir‐122‐3p, with the QIAGEN miScript System, and PCR analysis. Between the two stabbing methods used, 67% of the scalpel blades and 57% of the blood drops tested positive for rno‐mir‐122‐3p; however, other samples tested negative giving inconclusive results as to the wound‐of‐origin. The amount of the liver cells in the bloodstains appeared to be related to the extent of trauma.