The recoverability of fingerprints on paper exposed to elevated temperatures - Part 2: natural fluorescence

Previous work by the authors [1] investigated the recoverability of fingerprints on paper which had been exposed to elevated temperatures by comparing various chemical enhancement techniques (ninhydrin, 1,8-diazafluoren-9-one (DFO), and physical developer (PD)). During that study, it became apparent, as a consequence of observations made in operational work [2], that fingerprints on paper subjected to 150˚C fluoresced under examination with green light of waveband 473-548nm with a 549nm viewing filter. This work examined the three types of prints (eccrine, sebaceous, and ungroomed) after 20 min exposure to the temperature range 110˚C to 190˚C (in 10˚C increments) and found that the eccrine fingerprints fluoresced more brightly. This indicated that it was a component of the eccrine deposit which was causing the fluorescence. Luminance measurements found that the maximum fluorescence was experienced at 170˚C on both types of paper. As a consequence, eccrine heat-treated fingerprints were viewed under violet-blue (350-469nm), blue (352-509nm), and green light (473-548nm) which indicated that the greatest luminance intensities were obtained under blue light and the smallest under green light. In order to determine what component of the eccrine fingerprint was causing this fluorescence, five of the most prevalent amino acids (alanine, aspartic acid, glycine, lysine, and serine) [3-4] were exposed to this temperature range. The luminance measurements were taken under exposure to the green light in order for the minimum fluorescence to be observed, with an assumption that blue-violet or blue illumination will provide brighter fluorescence in practice. The results indicated that four of the amino acids are behaving similarly across the temperature range, but with slightly different luminance measurements, but all are exhibiting some level of fluorescence. Thermal degradation products of alanine and aspartic acid have been suggested by Richmond-Aylor et al. [5]. The structure of these thermal degradation products is cyclic in nature, and as such, there is a possibility that two of these products would fluorescence. Sodium chloride and urea were also exposed to the temperature range and they also fluoresced to some extent. This work shows that eccrine fingerprints that have been exposed to temperatures of between 130˚C to 180˚C will fluoresce under violet-blue, blue, and green light. This level of fluorescence for ungroomed fingerprints is much less but this will be dependent on the individual, the more eccrine the deposit, the stronger the fluorescence. This work shows that the amino acids, sodium chloride, and urea present in fingerprint deposits are all contributing to the fluorescence of the print, but may not be the sole contributor as other eccrine components have not yet been tested

Fingermark visualisation with iron oxide powder suspension:the variable effectiveness of iron (II/III) oxide powders, and Tween® 20 as an alternative to TritonTM X-100

The effectiveness of the current UK iron oxide powder suspension formulation, ‘C-IOPS-09’ (Triton X-100 based), for fingermark or latent fingerprint visualization is shown to be affected by variations between batches of the recommended iron oxide powder from Fisher Scientific (I/1100/53). When incorporated into the C-IOPS-09 formulation, a 2015 powder batch resulted in the detection of ∼19% fewer fingermarks, of broadly reduced contrast, when compared to powder suspension prepared with a 2008 batch of the same product. Furthermore, the 2015 powder batch was found to be unsuitable in experimental reduced-surfactant concentration powder suspension, because it caused surface-wide or background staining. The studies in this paper also investigated the use of Tween 20 surfactant as an alternative to the currently utilised Triton X-100, in preparation for the potential unavailability of Triton X-100 in the future. Powder suspensions prepared with Tween 20 surfactant solutions of 4% and 40% were shown to offer similar effectiveness to the currently recommended C-IOPS-09 formulation, when compared using the same batch of Fisher Scientific iron oxide powder (2008 or 2015). The difference between the 2008 and 2015 iron oxide batches was hence also evident with these alternative surfactant solutions. Particle size distribution analysis of the iron oxide powders in Tween 20 and Triton X-100 based surfactant solutions show that the more effective powder exhibits a higher sub-micrometre particle population than the less effective powder. This work leads to an improved specification for powder suspension formulations. This is demonstrated with an example powder suspension formulation which uses a 10% Tween 20 surfactant solution and iron oxide nanopowder (50–100 nm) from Sigma Aldrich, which was shown to visualise 27% more fingermarks than the C-IOPS-09 formulation prepared with the 2015 Fisher Scientific powder batch, in a comparative study

Individual differences in reproductive strategy are related to views about recreational drug use in Belgium, the Netherlands and Japan

Individual differences in moral views are often explained as the downstream effect of ideological commitments, such as political orientation and religiosity. Recent studies in the U.S. suggest that moral views about recreational drug use are also influenced by attitudes towards sex and that this relationship cannot be explained by ideological commitments. In this study, we investigate student samples from Belgium, the Netherlands, and Japan. We find that, in all samples, sexual attitudes are strongly related to views about recreational drug use, even after controlling for various ideological variables. We discuss our results in the light of reproductive strategies as determinants of moral views

The Present and Future Role of Insect-Resistant Genetically Modified Maize in IPM

Commercial, genetically-modified (GM) maize was first planted in the United States (USA, 1996) and Canada (1997) but now is grown in 13 countries on a total of over 35 million hectares (\u3e24% of area worldwide). The first GM maize plants produced a Cry protein derived from the soil bacteriumBacillus thuringiensis (Bt), which made them resistant to European corn borer and other lepidopteran maize pests. New GM maize hybrids not only have resistance to lepidopteran pests but some have resistance to coleopteran pests and tolerance to specific herbicides. Growers are attracted to the Btmaize hybrids for their convenience and because of yield protection, reduced need for chemical insecticides, and improved grain quality. Yet, most growers worldwide still rely on traditional integrated pest management (IPM) methods to control maize pests. They must weigh the appeal of buying insect protection “in the bag” against questions regarding economics, environmental safety, and insect resistance management (IRM). Traditional management of maize insects and the opportunities and challenges presented by GM maize are considered as they relate to current and future insect-resistant products. Four countries, two that currently have commercialize Bt maize (USA and Spain) and two that do not (China and Kenya), are highlighted. As with other insect management tactics (e.g., insecticide use or tillage), GM maize should not be considered inherently compatible or incompatible with IPM. Rather, the effect of GM insect-resistance on maize IPM likely depends on how the technology is developed and used