Detection and analysis of DNA mixtures with the MiSeq FGx®

Recognizing and interpreting mixtures are challenges that occur frequently in forensic casework. Therefore, any new analysis methods that are implemented must handle the challenges of mixed forensic samples. Next generation sequencing offers advantages over capillary electrophoresis in amplicon multiplexing and degraded sample analysis; however, advantages with mixed samples rely heavily on the advancement of user-friendly analysis software. This research analyzed samples with the ForenSeq™ DNA Signature Prep Kit on the MiSeq FGx® and compared them with the GlobalFiler™ STR Kit for capillary electrophoresis. Metrics tested for both chemistries included concordance, limits of detection, and mixture analysis. Data analysis for mixture samples was completed with the MixtureAce™ plug-in and ArmedXpert™ software. Next generation sequencing offered distinct advantages in limits of detection and isoallele heterozygosity but suffered from increased variability in stutter and allele count ratios compared to capillary electrophoresis.     

Preparation and characterization of micro-bore wall-coated open-tubular capillaries with low phase ratios for fast-gas chromatography–mass spectrometry: Application to ignitable liquids and fire debris

Fast Gas Chromatography (GC) allows for analysis times that are a fraction of those seen in traditional capillary GC. Key modifications in fast GC include using narrow, highly efficient columns that can resolve mixtures using a shorter column length. Hence, a typical fast GC column has an inner diameter of 100–180 μm. However, to maintain phase ratios that are consistent with typical GC columns, the film thickness of fast GC stationary phases are also low (e.g., 0.1–0.18 μm). Unfortunately, decreased film thickness leads to columns with very low sample capacity and asymmetric peaks for analytes that are not sufficiently dilute. This paper describes micro-bore (50 μm i.d.) capillary columns with thick films (1.25 μm), and low phase ratios (10). These columns have greater sample capacity yet also achieve minimum plate heights as low as 110 μm. Hence, separation efficiency is much higher than would be obtained using standard GC columns. The capillary columns were prepared in-house using a simple static-coating procedure and their plate counts were determined under isothermal conditions. The columns were then evaluated using temperature programming for fast GC–MS analysis of ignitable liquids and their residues on fire debris exemplars. Temperature ramps of up to 75 °C min^?1 could be used and separations of ignitable liquids such as gasoline, E85 fuel, and lighter fluid (a medium petroleum distillate) were complete within 3 min. Lastly, simulated fire debris consisting of ignitable liquids burned on carpeting were extracted using passive headspace absorption-elution and the residues successfully classified.     

A Monte Carlo simulation and sensitivity cost benefit analysis for use of nylon 4N6FLOQSwabs®

Forensic genetic laboratories are challenged with implementing innovation even if the benefits to operational performance are well demonstrated often because of internal budget constraints. A prospective cost–benefit analysis (CBA) could support justification for an increased budget by effectively demonstrating in a system-based approach the relatively small cost of increasing a laboratory budget can substantially reduce costs to society (both qualitatively and monetarily). A Monte Carlo simulation and sensitivity CBA was performed using a more expensive swab (i.e., nylon 4N6FLOQSwabs®) compared with a less costly cotton swab. Ranges of input values and tangible and intangible benefits were considered. The outcome is that the relatively small increased cost of using a nylon swab pales compared with the potential tangible and intangible benefits to the overall system. This approach provides a sounder basis for requesting additional funds to support implementation of technologies and better approximates realistic situations while accommodating uncertainty of input values.     

The use of the M-Vac® wet-vacuum system as a method for DNA recovery

Collecting sufficient template DNA from a crime scene sample is often challenging, especially with low quantity samples such as touch DNA (tDNA). Traditional DNA collection methods such as double swabbing have limitations, in particular when used on certain substrates which can be found at crime scenes, thus a better collection method is advantageous. Here, the effectiveness of the M-Vac® Wet-Vacuum System is evaluated as a method for DNA recovery on tiles and bricks. It was found that the M-Vac® recovered 75% more DNA than double swabbing on bricks. However, double swabbing collected significantly more DNA than the M-Vac® on tiles. Additionally, it was found that cell-free DNA is lost in the filtration step of M-Vac® collection. In terms of peak height and number of true alleles detected, no significant difference was found between the DNA profiles obtained through M-Vac® collection versus double swabbing of tDNA depositions from 12 volunteers on bricks. The results demonstrate that the M-Vac® has potential for DNA collection from porous surfaces such as bricks, but that alterations to the filter apparatus would be beneficial to increase the amount of genetic material collected for subsequent DNA profiling. These results are anticipated to be a starting point to validate the M-Vac® as a DNA collection device, providing an alternative method when DNA is present on a difficult substrate, or if traditional DNA collection methods have failed.     

GeneMarker® HID: A reliable software tool for the analysis of forensic STR data

Abstract: GeneMarker^® HID was assessed as a software tool for the analysis of forensic short tandem repeat (STR) data and as a resource for analysis of custom STR multiplexes. The software is easy to learn and use, and includes design features that have the potential to reduce user fatigue. To illustrate reliability and accuracy, STR data from both single‐source and mixture profiles were analyzed and compared to profiles interpreted with another software package. A total of 1898 STR profiles representing 28,470 loci and more than 42,000 alleles were analyzed with 100% concordance. GeneMarker HID was also used to successfully analyze data generated from a custom STR multiplex, with simplified and rapid implementation. Finally, the impact of the user‐friendly design features of the software was assessed through a time scale study. The results suggest that laboratories can reduce the time required for data analysis by at least 25% when using GeneMarker HID.     

Terraskin® the paper made from stone: a study of a new writing support for forensic purposes

Can a mineral paper be called paper? Until now all known writing supports have been ancient stones and tablets, parchment, and paper of vegetable origin, such as papyrus and fiber pulp paper. Some years ago polymeric banknotes appeared in Australia, and in 2004 mineral paper (stone plus polymer) emerged as an ecological alternative to pulp paper. In this article we study the physical and elemental features of a mineral paper such as the behavior of Terraskin? paper. We also study its behavior as a writing support, either for handwriting or printing, and compare these results with those usually obtained for paper made from pulp.     

Accuracy and reliability in sex determination from skulls: a comparison of Fordisc® 3.0 and the discriminant function analysis

Identification in forensic anthropology and the definition of a biological profile in bioarchaeology are essential to each of those fields and use the same methodologies. Sex, age, stature and ancestry can be conclusive or dispensable, depending on the field. The Fordisc(?) 3.0 computer program was developed to aid in the identification of the sex, stature and ancestry of skeletal remains by exploiting the Forensic Data Bank (FDB) and computing discriminant function analyses (DFAs). Although widely used, this tool has been recently criticised, principally when used to determine ancestry. Two sub-samples of individuals of known sex were drawn from French (n=50) and Thai (n=91) osteological collections and used to assess the reliability of sex determination using Fordisc(?) 3.0 with 12 cranial measurements. Comparisons were made using the whole FDB as well as using select groups, taking into account the posterior and typicality probabilities. The results of Fordisc(?) 3.0 vary between 52.2% and 77.8% depending on the options and groups selected. Tests of published discriminant functions and the computation of specific DFA were performed in order to discuss the applicability of this software and, overall, to question the pertinence of the use of DFA and linear distances in sex determination, in light of the huge cranial morphological variability.     

Comparison of the M-Vac® Wet-Vacuum-Based Collection Method to a Wet-Swabbing Method for DNA Recovery on Diluted Bloodstained Substrates*†‡

A wet-vacuum-based collection method with the M-Vac^® was compared to a wet-swabbing collection method by examining the recovery of diluted blood on 22 substrates of varying porosity. The wet-vacuum method yielded more total nuclear DNA than wet-swabbing on 18 porous substrates, recovering on average 12 times more DNA. However, both methods yielded comparable amounts of total DNA on two porous and two nonporous substrates. In no instance did wet-swabbing significantly recover more DNA. The wet-vacuum method also successfully collected additional DNA on previously swabbed substrates. Mitochondrial DNA yields were assessed, and outcomes were generally similar to the nuclear DNA outcomes described above. Results demonstrate that wet-vacuuming may serve as an alternative collection method to swabbing on difficult porous substrates and could potentially recover additional DNA on previously swabbed substrates. However, swabbing remains the preferred collection method on substrates with visible stains and/or nonporous surfaces for reasons of convenience, simplicity, and lower cost relative to the wet-vacuum method.     

Innovation and standardization as drivers of companies’ success in public procurement: an empirical analysis

The Journal of Technology Transfer - There is a significant potential to improve the benefits from public procurement through a better understanding of drivers in company success at the...     

Development and validation of the AmpFℓSTR® Identifiler® Direct PCR Amplification Kit: a multiplex assay for the direct amplification of single-source samples

Abstract: The AmpF?STR^® Identifiler^® Direct PCR Amplification Kit is a new short tandem repeat multiplex assay optimized to allow the direct amplification of single‐source blood and buccal samples on FTA^® card without the need for sample purification and quantification. This multiplex assay has been validated according to the FBI/National Standards and SWGDAM guidelines. Validation results revealed that slight variations in primer concentration, master mix component concentration, and thermal cycling parameters did not affect the performance of the chemistry. The assay’s sensitivity was demonstrated by amplifying known amounts of white blood cells spotted onto FTA^® cards, and the assay’s specificity was verified by establishing minimal cross‐reactivity with nonhuman DNA. No effect on the age of the sample stored on the FTA^® substrate was observed and full concordance was established in the population study. These findings of the validation study support the use of the Identifiler^® Direct Kit for forensic standards and database samples genotyping.     

Application of LC−QTOF/MS for the validation and determination of organic explosive residues on Ionscan® swabs

The identification and confirmation of trace explosive residues along with potential precursors and degradation products require a comprehensive laboratory analysis procedure. This study presents the determination of organic explosives consisting of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,4,6-trinitrotoluene (TNT), 2,4,6,N-tetranitro-N-methylaniline (Tetryl), 1,3,5-trinitrobenzene (1,3,5-TNB) and pentaerythritol tetranitrate (PETN) by a high-resolution liquid chromatography quadrupole time-of-flight mass spectrometry (LC−QTOF/MS). The qualitative information including retention time, collision energy, precursor ions, and characteristic fragmentation pattern of each explosive were collected using an atmospheric pressure chemical ionization (APCI) in negative ion mode. The separation efficiency among five compounds was greatly achieved in this study. Four real explosive samples consisting of TNT, RDX, PETN and Tetryl and 12 Ionscan® quality control swabs from the Royal Thai Army were also tested to validate and verify the viability of the GC–MS method used to validate results from an Ionscan® system. The results showed that LC−QTOF/MS is a powerful technique for the identification and confirmation of thermally unstable organic explosives on Ionscan® swabs compared to a conventional GC−MS technique.     

Comparison of bulk and compound-specific δ13C isotope ratio analyses for the discrimination between cannabis samples

Five marijuana samples were compared using bulk isotope analysis compound-specific isotope ratio analysis of the extracted cannabinoids. Owing to the age of our cannabis samples, four of the five samples were compared using the isotope ratios of cannabinol (CBN), a stable degradation product of Δ(9)-tetrahydrocannabinol (THC). Bulk δ(13)C isotope analysis discriminated between all five samples at the 95% confidence level. Compound-specific δ(13)C isotope analysis could not distinguish between one pair of the five samples at the 95% confidence level. All the measured cannabinoids showed significant depletion in (13)C relative to bulk isotope values; the isotope ratios for THC, CBN, and cannabidiol were on average 1.6‰, 1.7‰, and 2.2‰ more negative than the bulk values, respectively. A more detailed investigation needs to be conducted to assess the degree fractionation between the different cannabinoids, especially after aging.     

Do Motivations for Malingering Matter? Symptoms of Malingered PTSD as a Function of Motivation and Trauma Type

Psychological disorders associated with traumatic events, such as post-traumatic stress disorder (PTSD), may be prone to malingering due to the subjective nature of trauma symptomology. In general, symptoms tend to be inflated when an external reward (i.e., compensation) is associated with the claim. The present study was designed to test whether malingered claims of PTSD symptoms differed as a function of the type of trauma being malingered (accident, disaster, sexual assault) and the motivation for malingering (compensation, attention, revenge, no motivation). Participants were randomly assigned into conditions, given malingering instructions, and then asked to complete three measures of trauma symptoms (Impact of Event Scale??Revised; Post-Traumatic Stress Disorder Checklist; Trauma Symptom Inventory). Results indicated that participants in the sexual assault condition produced higher symptom reports on nearly all scales. Revenge and compensation motivations yielded elevated symptom scores. Further, individuals rated high in fantasy proneness and dissociation produced elevated scores on atypical responding and most clinical scales. More research is needed to examine the extent to which different motivations and trauma types influence symptom reporting.     

The New Water Legislation of Zimbabwe and South Africa – Comparison of Legal and Institutional Reform

Recently, several new pieces of water legislation have been promulgated in both Zimbabwe and the Republic of South Africa. The new acts are an attempt to correct injustices of a colonial past and to trigger development towards effective, equitable and efficient integrated water resources management influenced by the policy decisions in Agenda 21 and the need to respect economic and social human rights. This article aims at identifying and describing factors of prime importance in the process of legal and institutional reform. Major factors are earmarked and derived from the proceedings in Zimbabwe and are compared with the situation in South Africa. Thorough analysis by the author of proceedings, preambles, memoranda, legislation and addenda has induced roughly 5 major reform issues: The call for equitable water distribution based on a widely consented water resources management strategy; The need for effective and efficient integrated water resources management conducive to stakeholder participation through decentralisation processes; The redressing of legal shortcomings in former water legislation with the emphasis on the introduction of integrated approaches; The introduction of instruments of cost recovery for water resources management; The need to develop human resources capacity and institutional strength within the implementing agencies.For both Southern African states, these issues appear to be of comparable importance as major triggers for legal and institutional reform, although not always in the same sense.The resulting most important legal and institutional changes are presented, discussed and compared. Finally, prospects for and constraints on implementation of the new water legislation in these countries are compared.     

Semiconductor chips, genes, and stem cells: new wine for new bottles?

This Article analogizes early semiconductor technology and its surrounding economics with isolated genes, stem cells, and related bioproducts, and their surrounding economics, to make the case for sui generis (of its own class) intellectual property protection for isolated bioproducts. Just as early semiconductors failed to meet the patent social bargain requiring novelty and non-obviousness in the 1980s, isolated genes and stem cells currently fail to meet the patent bargain requirements of non-obviousness and eligible subject matter that entitle them to traditional intellectual property protection. Like early semiconductor chip designs, nevertheless, the high cost of upstream bioproduct research and development, coupled with the need to sustain continued economic growth of the biotechnology industry, mandates that Congress provide some level of exclusive rights to ensure continued funding for this research. Sui generis intellectual property protection for isolated bioproducts would preserve the incentive to continue innovation in the field. As illustrated by the semiconductor industry, however, such sui generis protection for this technology must include limitations that address the need to provide an appropriate level of public access to facilitate downstream product development and enrich the public domain.     

Correlates of adolescent fire setting: examining the role of fire interest,fire-related attentional bias,impulsivity, empathy and callous–unemotional traits

Little is known about potential correlates of problematic fire setting that could guide risk assessments and intervention. The current study measured aspects of fire-setting behaviour, fire interest, attentional bias towards fire-related words on a modified Stroop task, impulsivity, cognitive and affective empathy and callous–unemotional traits among adolescent fire setters, non-fire-setting antisocial adolescents and age-matched school controls. Results showed that current fire setting was associated with earlier onset of lighter/match play and unsanctioned fire setting. Fire-setting adolescents were also characterised by high impulsivity, callousness, uncaring traits and low cognitive empathy. Fire-setting frequency was best predicted by high impulsivity. Fire interest correlated negatively with accuracy on fire-related words on the fire Stroop task. These findings suggest that impulsivity may be important in the assessment and treatment of problematic fire setting, and encourage further research on modified Stroop tasks as a novel means to assess fire interest.     

The ignitability of petrol vapours and potential for vapour phase explosion by use of TASER® law enforcement electronic control device

An experimental study was made of the potential of the TASER-X26™ law enforcement electronic control device to ignite petrol vapours if used by an officer to incapacitate a person soaked in petrol, or within a flammable atmosphere containing petrol vapour. Bench scale tests have shown that a wooden mannequin with pig skin covering the chest was a suitable representation of a human target. Full scale tests using the mannequin have shown that the arc from a TASER-X26™ is capable of igniting petrol/air vapours on a petrol-soaked person. Further tests in a 1/5 scale and a full scale compartment have shown that if a TASER is used within a compartment, a petrol vapour explosion (deflagration) may be achieved. It is evident from this research that if used in a flammable vapour rich environment, the device could prove fatal not only to the target but the TASER® operator as well.     

What really matters for TTOs efficiency? An analysis of TTOs in developed and developing economies

The Journal of Technology Transfer - The university’s role in reaping the benefits from research by transforming knowledge and technology into commercially usable forms is becoming...     

A systematic analysis of Decker's “A systematic analysis of diversion: Net widening and beyond”

A recent article, entitled “A Systematic Analysis of Diversion: Net Widening and Beyond,” carries on the tradition of condemning diversion by a labeling process rather than by a thorough analysis of consequences. In addition to objecting to the logical foundations of that article, this critique raises questions about the research design and statistical analyses upon which its results are based.