Latent Fingermark Aging Patterns (Part III): Discontinuity Index as One Indicator of Degradation

This article is the third in a series of reports exploring quantifiable visual parameters of the aging process of latent fingermarks. On this occasion, research is focused on the occurrence of ridge discontinuities (i.e. breakages) as a function of time. Experiment variables included type of secretion (eccrine and sebaceous), substrate (glass and plastic), and exposure to natural light (dark, shade, and direct light) over a 6 months period. Fingermarks were sequentially visualized with titanium dioxide powder, photographed, and the number of naturally occurring ridge discontinuities subsequently evaluated. A semi‐quantitative value, named Discontinuity Index, was used to better characterize this aging parameter. Results indicated that ridges of sebaceous depositions on glass were generally less affected by the environmental conditions compared with those on plastic surface. In addition, aging in darkness was not always the best condition for preservation, and the direct exposure to light seemed not to affect the degradation under certain conditions.     

Identification of some factors influencing soil transfer on shoes

In criminal activities, soil can be transferred from a crime scene to items linked with a perpetrator; for example, shoes, cars or tools. Several parameters will influence the quantity of soil transferred in a given scenario. The knowledge of the most influential factors can help the expert to assess the evidence using a logical approach at the activity level or to predict the amount of soil that can be expected in a given scenario. The influence of five chosen parameters, namely the shoe profile, shoe size, walker's weight, soil type and soil humidity were assessed using Design of Experiment (DOE) in order to understand their influence on soil quantity transferred on shoes.The Faced Central Composite Design (FCCD) using a quadratic model was found to be highly significant, thus they could be adequately used to model and to interpret the amount of soil recovered from one shoe.These designs demonstrate that the characteristics of the donor (soil type and soil humidity), as well as a combination of these two factors have a very significant impact on the soil transfer. The characteristics of the receptor (shoe profile, shoe size and walker's weight) also have an impact on the transfer but to a lesser extent.Globally, this research provides valuable information for the forensic scientist both in investigative mode: evaluation of the soil quantity possibly transferred on shoes, and in the evaluative steps: is the quantity of soil found on the suspect shoes in accordance to the proposition/scenario given by the prosecution and the defence?     

Using an evolutionary perspective to understand the relationship between physical aggression and academic performance in late adolescents

In this study, we applied an evolutionary perspective to analyze the relationship between aggressiveness, academic performance, and sociality in a population of 528 adolescents of both sexes. In men, we expect physical aggression (PA) and sociality to be negative predictors of academic performance. However, in women, PA would be a negative predictor of academic performance, and sociality a positive one. Our results report a negative association between academic performance and PA in both sexes. As we expected, social effect derived from the use of PA seems to be different for each sex, where men could display a rebellious attitude to increase chances of finding a mate. In contrast, results for women are not conclusive, because no relationship between academic performance and any aggressive mechanism, were predicted by sociality. We conclude that an evolutionary framework, which includes sex-specific hypotheses, is appropriate to obtain a holistic perspective of this phenomenon.     

Impact of aging on fingerprint ridge density: Anthropometry and forensic implications in sex inference

The variation in the epidermal ridge's width between the sexes, during various growth stages, and among different populations has been previously assessed. However, the changes that occur with aging are barely known.The goal of this study was to analyse the degree of variation in epidermal ridge width due to aging. So that, fingerprint ridge density was estimated to establish their relationship with body and hand size changes that typically occur in adulthood.In this study, a sample of 213 adults of both sexes from a Spanish native population of different age ranges—18–30?years old (“junior” group) and 50–66?years old (“senior” group)—was used. Ridge density was assessed in three counting areas of the distal phalanx of each finger (radial, ulnar, and proximal). Height, weight, and a set of anthropometric measurements for both hands were also taken.Our results show that ridge density is higher in females than males throughout adulthood and decreases with aging in the radial and ulnar areas (as the hands widen) but not in the proximal region. Thus, a relationship between hand dimensions and ridge density was found.The data indicate that aging changes may conceal the recognized sex differences in ridge density, and so a better understanding of the topological variations in the epidermal ridge width throughout the life cycle and the factors involved would facilitate the interpretation of the differences between the sexes and different age groups.     

Determination of glyphosate in biological fluids by 1H and 31P NMR spectroscopy

Identification of glyphosate in four cases of poisoning, using nuclear magnetic resonance spectroscopy of biological fluids is reported. It has been performed by using a combination of 1H and 31P NMR analyses. Characterization of the N-(phosphonomethyl) glycine herbicide was achieved by chemical shift considerations and coupling constant patterns: CH2-(P) presents specific resonance at 3.12 ppm and appears as a doublet with a H-P characteristic coupling constant of 12.3 Hz. Moreover, resonances due to isopropylamine were present, confirming the ingestion of the considered trade formulation. After a calibration step, quantitation was performed by 1H and 31P NMR spectroscopy. The benefit and reliability of NMR investigations of biological fluids are discussed, particularly when the clinical picture is quite confusing.     

A fatal case of mercuric cyanide poisoning

A 57-year-old pharmacist was found dead 11 days after his disappearance. At the autopsy, samples of blood, urine, gastric content were obtained. Presence of ethanol, cyanide and mercury were detected in some samples. Cyanide and mercury were identified and quantified using high-performance liquid chromatography with diode array detector (HPLC) in fluorescence mode and ICP with mass selective detector (ICP-MS) respectively. Whole blood concentrations of ethanol was 1.72 g/L. Cyanide and mercury concentrations in whole blood were respectively 0.16 and 3.8 mg/L. Concentrations of cyanide (27 mg/L) and mercury (150 mg/L) in gastric contents prove a massive oral ingestion of mercuric cyanide or mercuric oxycyanide occurred. In this case report, the death was attributed to the combined toxicity of cyanide and mercury.