Soil forensics: How far can soil clay analysis distinguish between soil vestiges?

Soil traces are useful as forensic evidences because they frequently adhere to individuals and objects associated with crimes and can place or discard a suspect at/from a crime scene. Soil is a mixture of organic and inorganic components and among them soil clay contains signatures that make it reliable as forensic evidence. In this study, we hypothesized that soils can be forensically distinguished through the analysis of their clay fraction alone, and that samples of the same soil type can be consistently distinguished according to the distance they were collected from each other. To test these hypotheses 16 Oxisol samples were collected at distances of between 2 m and 1.000 m, and 16 Inceptisol samples were collected at distances of between 2 m and 300 m from each other. Clay fractions were extracted from soil samples and analyzed for hyperspectral color reflectance (HSI), X-ray diffraction crystallographic (XRD), and for contents of iron oxides, kaolinite and gibbsite. The dataset was submitted to multivariate analysis and results were from 65% to 100% effective to distinguish between samples from the two soil types. Both soil types could be consistently distinguished for forensic purposes according to the distance that samples were collected from each other: 1000 m for Oxisol and 10 m for Inceptisol. Clay color and XRD analysis were the most effective techniques to distinguish clay samples, and Inceptisol samples were more easily distinguished than Oxisol samples. Soil forensics seems a promising field for soil scientists as soil clay can be useful as forensic evidence by using routine analytical techniques from soil science.     

Factors affecting turnover rates of public child welfare front line workers: comparing cohorts of title IV-E program graduates with regularly hired and trained staff

ABSTRACT

The purpose of the study is to examine the impact of a statewide intervention (BSW level Title IV-E Program) on both the workers’ intent to leave the job and their actual exit from a state administered public child welfare agency. Employees completed an extensive survey including scales assessing individual, team, and organizational variables that might impact turnover. Results show that more Title IV-E graduates stay with the agency than do regular hires and leave at a slower rate. Different variables impact intent to leave compared to actual exit and vary across type of employee. Implications for the workforce are discussed.     

A new method for the recovery and evidential comparison of footwear impressions using 3D structured light scanning

Footwear impressions are one of the most common forms of evidence to be found at a crime scene, and can potentially offer the investigator a wealth of intelligence. Our aim is to highlight a new and improved technique for the recovery of footwear impressions, using three-dimensional structured light scanning. Results from this preliminary study demonstrate that this new approach is non-destructive, safe to use and is fast, reliable and accurate. Further, since this is a digital method, there is also the option of digital comparison between items of footwear and footwear impressions, and an increased ability to share recovered footwear impressions between forensic staff thus speeding up the investigation.     

Further Validation of the Test of Memory Malingering (TOMM) Trial 1 Performance Validity Index: Examination of False Positives and Convergent Validity

Assessment of performance validity is an essential part of a neuropsychological evaluation, with the inclusion of two or more performance validity tests (PVTs) becoming routine practice. Considering the time to administer multiple tests, there has been some support for use of the Test of Memory Malingering (TOMM) Trial 1 (T1) as an independent, “one and done” PVT. Notably, cutoffs for TOMM T1 need further validation, with an emphasis on minimizing false-positive classifications among those with bona fide cognitive impairment. In a clinically referred sample of 127 veterans, this study examined the role of cognitive impairment in TOMM performance and the utility of a TOMM T1 as an independent PVT. Examinees were administered the TOMM and three additional PVTs as part of a comprehensive neuropsychological battery. Sixty-eight percent of examinees were classified valid (35% of valid examinees were cognitively impaired). TOMM T1?≤?40 had excellent observed sensitivity (83%) and specificity (93%) overall, with minimal false-positive classification. TOMM T1 was also significantly correlated and concordant with other memory-based PVTs. Given score ranges and failure rates for TOMM T1?≤?40 among those with neurological/neurocognitive conditions, scores in the 37–40 range may merit administration of additional TOMM trials to maximize accuracy in identifying valid-cognitively impaired versus noncredible performance. Otherwise, an abbreviated TOMM administration (i.e., only T1) using a cutoff of ≤?40—in conjunction with one or more additional PVTs—may be sufficient for detecting noncredible/invalid test performance in the absence of known or suspected neurological/neurocognitive disorders.     

The Gorbachev Reform: A Maximal Case

Assumptions that major reform in the Soviet economy cannot be realized are challenged. Beliefs that Gorbachev is unable or unwilling to take necessary political risks, that bureaucratic resistance will forestall efforts at incremental change, and that Communist ideology lacks themes that can be used to mobilize support for innovation are analyzed. Assessment of reform should be based on an awareness of the advantages (as well as risks) of a strategy tying Gorbachev's political fate to reform and of the effectiveness of a timetable that consolidates gains in services and agriculture before confronting an entrenched industrial bureaucracy. Journal of Economic Literature, Classification Numbers: 052, 113, 124.     

Economic Interdependence and Security on the Korean Peninsula: The Impact of North Korean Special Economic Zones

Abstract

Given North Korea’s desire to maintain nuclear weapons—and barring its unexpected collapse—how can the US and its allies establish and maintain a peaceful Northeast Asia? Current US policy alternatives do not offer an effective means for removing North Korean nuclear weapons without creating many more serious problems that jeopardize a stable future for Northeast Asia. However, by engaging in foreign direct investment (FDI) through North Korea’s special economic zones, the United States and other nations can engage North Koreans at all levels of society and build a future environment of cooperation and stability. Such a long-term engagement policy will prove more successful than isolation, sanctions, or military force, and will bolster regional actors’ efforts to develop additional stability-inducing policies.