Composite Machine Learning Algorithm for Material Sourcing,

This study developed a composite machine learning algorithm for attribution of materials of forensic interest (like ammonium nitrate) to original sources. k-nearest neighbor and random forest models were used for source elimination and classification, respectively, in a two-step, composite algorithm based on particle color, size/shape, and trace element concentration features. Novel approaches for simulation to supplement within-source reference features based on empirically measured multi-lot analyses, an improved hold-one-lot-out method for cross-validation, an assessment of the likelihood of the presence of a reference sample, fusion of the source probabilities from the respective classification models, and the calculation of metrics for assessing ensemble sourcing performance are described. Excellent sourcing predictions were obtained; the sourcing algorithm identified the correct source as the top choice 89% of the time, and the correct source was identified to be an average of 2.7 times more likely than the most likely incorrect source.     

Distribution of the Minutiae in Hypothenar Palm Prints in Slovak Adults: Indications for Personal Identification

Minutiae are small distinguishing features found along every ridge flow, which make each friction ridge print unique. The most common friction ridge prints found at the crime scene are fingerprints; therefore, the most of the minutiae studies are focused exactly on this kind of prints. The authors believe that further examination and enlargement of the palm print database could result in better use of the palm prints for personal identification. We analyzed a total of 160 palm prints from 40 females and 40 males aged between 18 and 70 years from Slovakia. For the evaluation of the minutiae, the area of the hypothenar had to be marked out. The classification of the minutiae used for this study was based on a modified version of the classification system using the total of 13 types of minutiae. The frequency of every minutiae type was calculated and, using the chi-square test with Yates's correction, bilateral and sex differences were assessed. The relationship between the different types of minutiae was examined with Pearson's correlation test. During the initial phases of the identification process, the focus should be on the least common types of minutiae (Y or M and return), which were found not to correlate; thus, their mutual occurrence is random (e.g., overlap—Y or M, crossbar—return, or Y or M—dock). The results of the present study show which specific minutiae types are the most suitable for personal identification. These findings may be beneficial in more effective outcome of the identification process.     

Improved Area of Origin Estimation for Bloodstain Pattern Analysis Using 3D Scanning

An important component of crime scene reconstruction is bloodstain pattern analysis (BPA). Where BPA concerns impact patterns, estimating the area of origin is critical information for scene reconstruction. Traditionally, this is achieved by measuring individual bloodstains and performing trigonometric calculations; however, 3D scanning has been proposed as a viable alternative for overcoming logistical and practical concerns with the manual method. Therefore, this project aimed to establish whether the FARO Focus 3D scanner and FARO Zone 3D software can improve the accuracy of area of origin estimates relative to the manual method. We created a series of eight bloodstain impact patterns and performed paired analysis using the two methods to estimate areas of origin for each pattern. Our data suggested that FARO-derived estimates were generally more accurate than using the manual method. FARO-estimated heights of origin areas were generally closer to the true distance. Both methods underestimated the distance from the wall for most patterns originating 150mm or greater from the wall, but overestimated distances for patterns originating closer to the wall. The degree to which distances were underestimated increased significantly the further the blood source was from the wall and was greater for FARO-derived estimates. The results of this research contribute to the validation of these instruments for operational implementation for BPA and should be considered alongside the practical benefits of 3D scanning relative to manual methods. Further, 3D scanning can provide reliable BPA reconstruction documentation for technical review and court presentation.     

DNA Recovery From Tape-Lifting Kits: Methodology and Practice

In the case of suspicious deaths, the technique of 1:1 taping is often used in Belgium. It consists of affixing a large number of adhesive tapes to the body of the victim. It is conventionally aimed at obtaining microtraces (e.g., fibers, hair) and is usually not used for DNA analysis. However, in some cases, DNA analysis of certain areas of interest identified on the 1:1 taping material can offer a last resort solution. The four-step method that is described in this article involves the selection of areas of interest on the body (Step 1), the selection of the corresponding tapes (Step 2), the decontamination of the tapes (Step 3), the selection of areas of interest on the tapes, for DNA sampling (Step 4). The method is illustrated by its successful application in four murder cases. In each case, DNA profiles of good quality could be identified, including profiles of persons different from the victim.     

Prevalence of organic gunshot residues in police vehicles

The present study investigated the organic gunshot residue (OGSR) background level of police vehicles in Switzerland. Specimens from 64 vehicles belonging to two regional police services were collected and analysed by LC-MS in positive mode. The driver’s and back seats were sampled separately to monitor potential differences between locations and to assess the risks of a suspect being contaminated by OGSR during transportation to a police station.The results showed that most of the 64 vehicles were uncontaminated (44 driver’s seats and 38 back seats respectively). Up to six of the seven targeted compounds were detected in a single sample, once on a driver’s seat and twice on back seats. The contamination frequency generally decreased as the number of compounds detected together increased. The amounts detected were in the low ng range and less than amounts generally detected just after discharge on a shooter. Our data indicated that detecting a combination of four or more compounds on a police vehicle seat appears to be a relatively rare occurrence. The background contamination observed was most probably due to secondary transfer from police officers (e.g. through recent participation in a shooting session or firearm manipulation) or from firearms stored in the vehicles. The present results might be used as a recommendation to minimize contact of a suspect with contaminated surfaces if OGSR is implemented in routine work in parallel to IGSR analysis.     

Stealing into the wild: conservation science,plant breeding and the makings of new seed enclosures

Faced with pressing climatic changes, scientific and industrial interests are vying to develop crops that can survive drought, floods and shifting pest regimes. Increasingly, they look for solutions in an unlikely place: the gene pools of wild plants. Crop wild relatives (CWR) – species closely related to crops, including their ancestors – offer breeders the allure of retracing the domestication bottleneck, infusing genomes of modern crops with ‘lost’ genetic variety. Yet wild relatives also confront threats from climate change, urbanization and expansion of industrial agri-food. Thus, CWR, seen as both salvational and threatened, have become an international conservation and food-security priority. It is my contention that, in their common project to harness wild-relative potential, conservation and breeding science are co-evolving to extend seed commodity relations into new spheres. I examine enclosures along two fronts: first within ‘systematic CWR conservation’, where ‘in situ’ approaches, typically regarded as empowering and sustainable alternatives to ‘ex situ’, instead may support a complementary system of value extraction; second, in breeding and biotechnology research, which produces new value for CWR while profoundly shaping upstream conservation priorities. An important finding is that although today’s ‘ex situ-centric’ complementarity favors dispossession, an ‘in situ-centric’ approach could foster democratic renewal of biocultural diversity.     

Opening up to OERs: Electronic Original Sourcebook Versus Traditional Textbook in the Introduction to American Government Course

Traditional American Government textbooks are expensive and often unpopular with students. New technologies and Open Educational Resources (OERs) open up the potential for change, but questions of quality are ever present: can OERs really help students learn better, or are they just cheaper? I developed an OER based on original sources and compared student learning outcomes with the OER section to those in a free digital textbook section. While the OER I created did not work as well as I had hoped, I nonetheless developed a redesign of my course and my approach to teaching, which is the true benefit of adopting OERs.     

Universities and State Policy Formation: Rationalizing a Nanotechnology Strategy in Pennsylvania

Technology‐based economic development programs have become a salient feature of the state policy landscape since the 1980s. While much research exists on the topic, little attention has been given to the processes of policy formation. State programs have moved towards high technology areas emphasized at the federal level over the past decades, and nanotechnology became one of the latest targets. This paper examines the eight‐year process through which Pennsylvania adopted a “state‐wide strategy,” culminating in the Pennsylvania Initiative for Nanotechnology. In this process, programs that responded to the interests of multiple agents came first, and a state policy was formulated after the fact. This pattern of “rationalized policy formation,” as opposed to rational policy formation, may be more common than suspected. Its strengths and weaknesses in this Pennsylvania case are discussed.