Bayesian framework for the evaluation of fiber evidence in a double murder--a case report

Fiber evidence found on a suspect vehicle was the only useful trace to reconstruct the dynamics of the transportation of two corpses. Optical microscopy, UV-Vis microspectrophotometry and infrared analysis were employed to compare fibers recovered in the trunk of a car to those of the blankets composing the wrapping in which the victims had been hidden. A "pseudo-1:1" taping permitted to reconstruct the spatial distribution of the traces and to further strengthen the support to one of the hypotheses. The Likelihood Ratio (LR) was calculated, in order to quantify the support given by forensic evidence to the explanations proposed. A generalization of the Likelihood Ratio equation to cases analogous to this has been derived. Fibers were the only traces that helped in the corroboration of the crime scenario, being absent any DNA, fingerprints and ballistic evidence.     

A quantitative differentiation method for acrylic fibers by infrared spectroscopy

Absorbance peak areas of nitrile (2240 cm(-1)), carbonyl (1730 cm(-1)) and CH (1370 cm(-1)) groups were obtained for 48 colorless acrylic fibers by infrared (IR) microspectroscopy. The carbonyl signal, related to the comonomers most commonly used in acrylic fibers, was ratioed against the nitrile and CH bands, pertaining to the backbone of the polymer chains. The ratios A1730/A2240 and A1730/A1370, a relative measure of the comonomer content in the fiber, were used to differentiate the samples. A decrease in the crystallinity of fibers has been noted with increasing comonomer content. Relative standard deviation (R.S.D.) of the ratios were 1 and 3% for repetitive analyses on the same location and along the length of the same single fiber, respectively. When different fibers of the same sample were examined, results were reproducible within 6%. This simple method can greatly enhance the evidential value of colorless acrylic fibers, being able to discriminate them and thus helping the Court to better assess their significance.     

Employee Empowerment,Employee Attitudes,and Performance: Testing a Causal Model

The last three decades have witnessed the spread of employee empowerment practices throughout the public and private sectors. A growing body of evidence suggests that employee empowerment can be used to improve job satisfaction, organizational commitment, innovativeness, and performance. Nearly all previous empirical studies have analyzed the direct effects of employee empowerment on these outcome variables without taking into account the mediating role of employee attitudes. This article contributes to the growing literature on employee empowerment by proposing and testing a causal model that estimates the direct effect of employee empowerment on performance as well as its indirect effects as mediated by job satisfaction and innovativeness. The empirical analysis relies on three years of data from the Federal Human Capital Survey/Federal Employee Viewpoint Survey and a structural equation modeling approach, including the use of lagged variables. The results support the hypothesized causal structure. Employee empowerment seems to have a direct effect on performance and indirect effects through its influence on job satisfaction and innovativeness, two key causal pathways by which empowerment practices influence behavioral outcomes.     

Race,Gender, and Government Contracting: Different Explanations or New Prospects for Theory?

The U.S. Congress created the Small Disadvantaged Business (SDB) and Women‐Owned Small Business (WOSB) programs to promote fairness in government contracting. In this article, the authors examine whether increases in racial and gender representation in federal agencies correlate with the proportion of contract dollars awarded to women‐ and minority‐owned firms. Using the theory of representative bureaucracy as a starting point, they find evidence that increases in passive minority representation result in a larger proportion of contract dollars awarded to minority‐owned firms, which comports with previous empirical research. There is no evidence, however, that female representation leads directly or indirectly to substantive benefits for women‐owned small businesses. Given that the findings for women do not support representative bureaucracy, the authors provide potential alternative explanations. Specifically, they consider gender bias, social identity, and the “queen bee” phenomenon as possible explanations for why women are less inclined to advocate for other women.     

Suicidal poisoning with barium chloride

A 49-year-old male pharmacist suffering from depression phoned the emergency services telling of how he had ingested barium chloride. He was found semicomatose in bed and resuscitation attempts were to no avail and he died at the scene. A white plastic container labelled "Barium chloride... Poison", and a book with a writing on a blank page... "give sulphate... SO(4)" were found.At autopsy, 1l of whitish-yellow fluid was found in the stomach.Autopsy barium levels were: blood 9.9mg/l; bile 8.8mg/l; urine 6.3mg/l; gastric 10.0g/l.Cause of death was given as cardiorespiratory arrest due to barium chloride poisoning.The issue of barium toxicity in a variety of itatrogenic and non itatrogenic situation is discussed together with the two only other cases of suicidal barium ingestion, and the feasibility of early intervention at the scene by an emergency team.     

Establishing Tobacco Origin from Pollen Identification: An Approach to Resolving the Debate

Previous research into pollen content of tobacco resulted in a debate. We address this debate and determine that pollen analysis may be able to assist with identifying geographical origin of tobacco. However, the value of any results should be assessed on a case‐by‐case regional basis until sufficient database information is available for an objective interpretation to be undertaken on a global basis. As a first step toward developing comparative data for South America, we analyzed a tobacco sample from Brazil in an effort to identify signature taxa from the state of Minas Gerais. We also assessed the role of honey additives to tobacco to assess this issue. Comparing the data to previously published data, we conclude that pollen signatures can distinguish broad geographic areas. We conclude that this forensic interpretation framework needs to be developed in context of the National Academy of Sciences recommendations for tightening methods in forensic science.