A Comparison of Thresholding Methods for Forensic Reconstruction Studies Using Fluorescent Powder Proxies for Trace Materials

Image segmentation is a fundamental precursor to quantitative image analysis. At present, no standardised methodology exists for segmenting images of fluorescent proxies for trace evidence. Experiments evaluated (i) whether manual segmentation is reproducible within and between examiners (with three participants repeatedly tracing three images) (ii) whether manually defining a threshold level offers accurate and reproducible results (with 20 examiners segmenting 10 images), and (iii) whether a global thresholding algorithm might perform with similar accuracy, while offering improved reproducibility and efficiency (16 algorithms tested). Statistically significant differences were seen between examiners’ traced outputs. Manually thresholding produced good accuracy on average (within ±1% of the expected values), but poor reproducibility (with multiple outliers). Three algorithms (Yen, MaxEntropy, and RenyiEntropy) offered similar accuracy, with improved reproducibility and efficiency. Together, these findings suggest that appropriate algorithms could perform thresholding tasks as part of a robust workflow for reconstruction studies employing fluorescent proxies for trace evidence.     

The influence of trust and collaboration with external partners on appropriability in open service firms

The Journal of Technology Transfer - This study explores how service firms in an open exchange of knowledge protect themselves against opportunistic behavior while trying to acquire some knowledge...     

What’s in an MSW? Graduate education for public child welfare workers,intention, engagement,and work environment

ABSTRACT

This study employs a mixed methods analysis of exit survey data gathered from public child welfare employees at their completion of a Title IV-E funded MSW program, distinct because it was initiated during a period of major reform and permitted students to continue employment during their studies. Findings suggest that opportunities for growth and manageable levels of stress were associated with intentions to stay and engagement with the work, reflected in respondents’ positive perceptions of their roles in the work environment and their retrospective assessments of the impact of their social work education.     

The Relationship between Homelessness and Behavior Problems among Youth in North Texas: a Brief Report

This study sought to examine the relationship between homelessness and behavior problems among a community-based sample of youth in North Texas. Data were obtained from a cross-sectional, probability sample of households and a targeted sample of homeless families in Dallas, Texas, with children older than 5 years old (N?=?5232). Parents were asked to report five behavior problems on behalf of their children including arrest or trouble with police, academic problems, behavior problems at school, suspension, and suicide attempts. Logistic and negative binomial regression procedures were used to examine the relationship between homelessness and behavior problems. Youth exposed to homelessness were 36% (OR?=?1.63; 95% CI 1.00–1.85) more likely to exhibit any kind of behavior problems than youth who had never experienced homelessness. Homeless youth had 5.51 times the odds of arrest (95% CI 2.60–11.68), 1.74 times the odds of academic problems (95% CI 1.24–2.43), and more than 3 times the odds of suicide attempts (95% CI 1.46, 7.61) than youth who had never been homeless. Homelessness was associated with higher rates of problem behavior, including arrests, academic problems, and suicide attempts. Because homeless youth are commonly enrolled in school and present at health care clinics and emergency departments, clinics and schools may aid in the identification of homeless youth, as well as referral to care. In this way, clinicians may help reduce the burden of behavioral problems that disproportionately affect homeless youth.     

“I Had a Confidence Epiphany!”: Obstacles to Combating Post-Identification Confidence Inflation

Research shows that eyewitnesses often become more confident with their selections from a lineup over time, a problem labeled "confidence inflation." Wells et al. (1998) Law and Human Behavior, 22, 603-647 suggested that eyewitnesses provide a confidence statement immediately following their selection to capture an unadulterated measure of confidence. Three experiments tested the effectiveness of introducing such a statement to combat the effects of confidence inflation on mock-juror judgments. All experiments provided evidence that the attributions participants formed about the eyewitness' confidence inflation differentially impacted their judgments. Although mock-jurors generally discredited eyewitnesses who showed confidence inflation and sometimes lowered probability of guilt ratings for the defendant, a clear exception occurred when mock-jurors attributed the inflation to an epiphany. Use of post-identification confidence statements to decrease the impact of confidence inflation in the courtroom may be insufficient.     

Modeling Change in Perceptions about Sanction Threats: The Neglected Linkage in Deterrence Theory

Deterrence theory describes a process of offender decision making that consists of two linkages—one in which official sanctions and other information affect a would-be offenders perceptions about the risks of criminal conduct, and another in which such perceptions influence the decision whether or not to offend. Decades worth of empirical research has concentrated virtually exclusively on this latter linkage, and in so doing, has produced an incomplete account of the deterrence process. This article develops a model of how perceptions of sanction certainty are modified in response to an individuals involvement in criminal activity and the consequences (if any) therefrom. Implications of the model are tested with data from a multi-wave, panel survey of 1,530 high school students from the southeastern U.S. Key findings include: the manner in which new information affects perceived certainty depends on the level of perceived certainty before the new information is received, and the extent of peer offending was one of the most influential factors in determining change in perceived sanction certainty over time.     

Partner Abuse and HIV Infection: Implications for Psychosocial Adjustment in African American Women

A prospective study of the effects of partner abuse among HIV-infected and noninfected African American women (N = 137) revealed that there were both concurrent and longitudinal effects of abuse on several indices of psychosocial adjustment. Specifically, higher levels of both verbal and physical abuse were found among the HIV-infected group. In addition, the effects of abuse on suicidal ideation were significantly stronger among the HIV-infected group (n = 53) than among their demographically similar noninfected counterparts (n = 84), resulting in significant HIV status by partner abuse interactions. The findings of this study advance our understanding of intimate relationships with regard to partner abuse by examining a group of women at high-risk for abuse, yet understudied in both the HIV/AIDS and relationship literatures.     

Suicidal contact gunshot wounds to the head with .38 Special Glaser Safety Slug ammunition

Glaser Safety Slug TM ammunition is a uniquely designed, essentially prefragmented ammunition. Tests performed by the U.S. Justice Department demonstrated that the ammunition possesses high kinetic energy, high relative incapacitation index (RII) and poses a very low risk to bystanders because of its total loss of kinetic energy in the target. Despite having been manufactured since 1974, no deaths from this ammunition have been previously reported. The authors herein describe the first three reported human deaths.