An efficient statistical procedure for interpreting DNA single locus profiling data in crime cases.

This paper describes a simplified approach to calculating the Bayesian likelihood ratio for the case where two DNA single locus profiles are to be compared. It explains how the calculation allows for band shift and also for the variation in precision with molecular weight. A simple basic theory section explains the principles of the analysis but more detailed explanations are given in an advanced theory section. Experiments on substantial data collections are described which demonstrate the robustness of the method.     

An investigation of the feasibility of inferring ethnic origin from DNA profiles.

A small experiment is described which uses databases of Afro-Caribbeans and Caucasians to establish the quality of information that might be given to an investigator about the ethnic group of the donor of an unknown crime stain. The results show that the technique can provide qualified indications, but categoric conclusions are not, in general, feasible. An appraisal is given of the technique within the operational context.     

Eliminating ill-founded eliminations in handwriting comparison cases.

Document examiners sometimes eliminate writers on the basis of differences which are given too much weight. This article is an attempt to explain some conditions whereby differences in the writing of one individual are misinterpreted as significant differences, when they are actually caused by conditions which are unknown to the examiner.     

The routine profiling of forensic heroin samples

A method for the routine profiling of illicit heroin samples received in casework has been developed which depends on simple and straightforward sample pretreatment, followed by gas chromatography on a capillary column using flame-ionization detection. The factors affecting the choice of each aspect of the procedure are discussed, as are the statistical data for sampling and the chromatography. Components of illicit heroin derived from opium and other adulterants have been identified. The significance of data from samples examined in 1986 is discussed.     

The morphogenesis of electrically and heat-induced dermal changes in pig skin

In order to establish pathological evidence in dermis for distinguishing between sequelae of electrical torture and those of other superficial injuries, the skin of eleven fully anaesthetized Danish Landrace pigs have been exposed to heat and electrical energy from either 50 Hz alternating current (a.c.) or direct current (d.c.) via 12 mm large contact knobs or via a pointed 0.5 mm large electrode (only 50 Hz a.c.). The lesions have been examined from 1 to 126 days after the injury. While heat lesions exposed to energy lower than 60 joule only gave minor changes, heat lesions exposed to more than 60 joule showed changes in both collagen fibres (basophilic or eosinophilic fibres without any birefringence or coarse cross-striation in polarized light, respectively) and dermal cells (granular cytoplasm). Areas exposed to 50 Hz a.c. via 0.5 mm. electrode showed basophilic collagen fibres and in a few biopsies on day 7 calcium salts on collagen fibres. Using 12 mm large electrodes the changes were minor, but basophilic and eosinophilic collagen fibres with no birefringence or with fine/coarse cross-striation respectively were seen. Even cells with 'vesicular nuclei' were seen on day 1 and 2 after the injury. The changes in the anode area showed resemblance to that of heat lesions (basophilic collagen fibres). Eosinophilic collagen fibres with fine densely spaced cross-striation in polarized light and 'vesicular nuclei' as well as collagen fibres with calcium salts were seen in the cathode lesions. It is concluded that the dermal changes in the cathode area are specific for electrical injury from day 1 to 14. However, earlier studies have demonstrated dermal changes specific for electrical injury at day 0 and the presence of calcified collagen fibres up to 2 months after injury. The dermal changes in anode lesions were non specific and could not be differentiated from those found in heat lesions. Alternating current lesions (50 Hz) were specific from day 1 to day 7, when the pointed electrode was used, but only in a few days when the energy was transferred via the 12-mm electrodes.     

Vitamin D binding protein (Gc) subtypes by isoelectric focusing and immunoblotting

The polymorphism of the human vitamin D binding protein (Gc system) was investigated in a total of 149 sera from unrelated healthy Egyptians residing in Tanta City, Gharbiya Governorate, Nile Delta of Egypt, using isoelectric focusing (IEF) in thin-layer polyacrylamide gel followed by immunoblotting. The estimated gene frequencies were Gc1s = 0.540, Gc1f = 0.242 and Gc2 = 0.218.     

A rapid method for the extraction of cocaine and benzoylecgonine from body fluids

A method has been developed for the rapid extraction of cocaine and benzoylecgonine from post-mortem blood and urine samples. Solid phase columns containing C8 packing material gave clean, emulsion free extracts from body fluids. The total time for each extraction was approx. 10 min and the system has the capacity for the simultaneous extraction of up to 10 samples. Urine can be extracted directly, blood samples were sonicated before extraction to allow for their easy passage through the columns. The method gave excellent recoveries of cocaine (98-100%) from spiked samples at concentrations of between 50 ng/ml and 10 micrograms/ml. Analysis of the extracts was by high performance liquid chromatography (HPLC).     

The Effect of Language on Political Appeal: Results from a Survey Experiment in Thailand

Political Behavior - Politicians have long engaged in marketing themselves by employing distinct speaking styles to signal social standing, competence, or a shared background with their audience....     

Gender diversity in aircraft maintenance: a cross-sectional triangulation of male perspectives

Certified aircraft mechanics represent the largest gender-based demographic disparity in aviation with a 49-to-1 male-to-female ratio. Recent research into women’s perspective on the aircraft mechanic career field revealed that a large majority of women felt unsure or negatively about their potential promotion opportunities and social acceptance. The purpose of this follow-on mixed-methods concurrent triangulation study was to explore the perspectives of men regarding the aforementioned topics to see if they differ from previously published research on women perceptions. A total of 587 men and 431 women completed an eight-question survey containing 5-point Likert-type and open-ended questions. The quantitative comparison consisted of the total 1018 responses, while only the survey responses from the 587 men were analysed for correlations and qualitative codes. Results indicated that there was a significant difference between the perceptions of men from those of the women regarding work environment safety and social acceptance. Additional correlation analysis revealed social acceptance to be a key variable when predicting career appropriateness, advancement opportunity and work environment safety. The 587 qualitative responses yielded results that differed from those of women, citing an assumption that women have the same advancement opportunities or be as socially accepted as men entering the field.