Visualization of latent fingerprints using fluorescence lifetime imaging on paper emitting strong fluorescence

Latent fingerprints were successfully visualized using fluorescence lifetime imaging (FLIM) on paper which emits strong fluorescence with a lifetime close to that of fingerprints and thus from which it is difficult for time-resolved spectroscopy to visualize fingerprints. Latent fingerprint samples on paper were excited using a 450 nm or 532 nm nanosecond pulsed-laser, and time-resolved fluorescence images were obtained at a delay time of 6–16 ns in intervals of 1 ns, to the excitation pulse. The excitation beam was expanded using a lens, and the fluorescence from the fingerprints was captured using an intensified CCD camera. Because of the large fluorescence intensity of the background paper of approximately two to four orders of magnitude larger than that of the fingerprint, the fingerprint was not visualized on each fluorescence image by time-resolved spectroscopy. However, the fingerprint was visualized in a FLIM image constructed using a series of the fluorescence images for the case with the fluorescence intensity of the background paper being four orders of magnitude larger than that of the fingerprint. The difference in fluorescence lifetime in the FLIM image of the visualized fingerprint and background paper was in the order of 0.1 ns, which was an order of magnitude smaller than the inherent fluorescence lifetime of a few nanoseconds for the fingerprints and paper. It was demonstrated that, at a background fluorescence intensity with a certain order of magnitude larger than that of fingerprints, FLIM has the potential to visualize latent fingerprints which cannot be visualized by time-resolved spectroscopy.     

State rules: Oil companies and armed conflict in Sudan

The strategic behaviour of international oil companies in war-torn Sudan was overwhelmingly driven by political pressure from governments. After almost 20 years of operating in Sudan, the US giant Chevron was pushed to withdraw as a result of deteriorating relations between Washington and Khartoum. The Canadian flagship oil company, Talisman, which helped kick-start oil development after Chevron's exit also fell victim to Washington's ire. On the other hand, the European junior oil companies, Lundin and omv, protected by the European Union's political standpoint of ‘constructive engagement’ in Sudan, were free to profit. Finally, the eastern parastatals, led by a surging China, eager to capture international energy resources to fuel their budding economies and supported by the plural relationships fostered between their respective governments and the ruling, riverine elite in Khartoum, tactfully established a dominating presence. While fervent international human rights advocacy alone seemingly drove susceptible Western firms out of Sudan, the real power behind corporate movements came from the rules dictated by states.     

Party Size and Portfolio Payoffs: The Proportional Allocation of Ministerial Posts in Coalition Governments

Over 30 years ago, Eric Browne and Mark Franklin demonstrated that parties in a coalition tend to receive portfolio payoffs in almost perfect proportionality to their seat share. Even though this result has been confirmed in several studies, few researchers have asked what the underlying mechanism is that explains why parties receive a proportional payoff. The aim of this paper is to investigate the causal mechanism linking party size and portfolio payoffs. To fulfil this aim, a small-n analysis is performed. By analysing the predictions from a statistical analysis of all post-war coalition governments in 14 Western European countries, two predicted cases are selected, the coalitions that formed after the 1976 Swedish election and the 1994 German election. In these case studies two hypotheses are evaluated: that the proportional distribution of ministerial posts is the result of a social norm, and that parties obtain payoffs according to their bargaining strength. The results give no support to the social norm hypothesis. Instead, it is suggested that proportionality serves as a bargaining convention for the actors involved, thus rendering proportional payoffs more likely.     

The Electoral Connection and Legislative Committees

This article examines whether the career needs of legislators – to be re-elected or to move on to another political post – allow us to explain the rules governing committee structures and the committee assignments individual legislators obtain. It uses the institutional variations provided by Argentina, Costa Rica, and Venezuela to test hypotheses about committee assignments and committee assignment mechanisms. It finds that incentives created by candidate selection procedures and electoral rules show some relationship to committee assignments, but with a good deal of variation across national cases and individual careers.     

Regime Shift in Japan?Two Decades of Neoliberal Reforms

This paper uses insights drawn from a paired comparison of Switzerland and Japan to give an account of the changes brought about by neoliberal policy adaptation in Japan over the last two decades. In Switzerland, notwithstanding further liberalization of the traditionally liberal regime prompted by the economic hardships of the 1990s, the referendum system helped the Social Democrats and unions to defend their rights and maintain the welfare schemes belatedly established in the 1980s. By contrast, the Japanese ruling party not only delayed liberalization of the protectionist state, but also aggravated fiscal problems by implementing a series of expansionary macroeconomic policies in the 1990s. Thus, without pursuing coherently such neoliberal policies as fiscal consolidation, privatization, or market deregulation, the Japanese state now faces a serious dilemma between the immediate need for structural reforms and the social unease that would result. Focusing on the reform packages of the Nakasone (1982‐87), Hashimoto (1996‐98), and Koizumi (2001‐) administrations, the paper reviews the sequences of reform policies as an interplay among economic challenges, actors’ aspirations, and institutional constraints, and further develops arguments about the segmented structure, peculiar to the Japanese state, that retards political changes.     

Contribution of thermal desorption and liquid-liquid extraction for identification and profiling of impurities in methamphetamine by gas chromatography-mass spectrometry

Impurity profiling of methamphetamine (MA) using thermal desorption (TD) and gas chromatography-mass spectrometry (GC-MS) was examined. Using TD/GC-MS, impurities were extracted and separated under various conditions. Optimal chromatograms were obtained when a 20 mg MA sample was extracted at 120 degrees C for 3 min using a TD instrument, followed by separation of the extracts using a non-polar capillary column coated with (5%phenyl)-methylpolysiloxane. MA samples from nine different batches were analyzed under optimized conditions. Compounds related to the structure of MA, such as benzaldehyde, benzyl alcohol, amphetamine, cis- and trans-1,2-dimethyl-3-phenylaziridine, dimethylamphetamine, and N-acetylephedrine, were detected in the chromatograms without any laborious extraction procedure. Compounds such as ethanol, diethyl ether, and acetic acid, which are considered reagents and solvents for MA synthesis, were also detected in some of the chromatograms. The numbers and intensities of the peaks detected were different among the samples. Impurity profiling of MA using TD was compared with that using liquid-liquid extraction (LLE). Better reproducibility of peak areas was obtained using LLE, whereas higher intensities and numbers of peaks were detected using TD. Solvents were extracted more effectively using TD. The nine batches of MA were classified using both extraction procedures. The nine batches were divided roughly into two groups using data from LLE. Subsequently, the groups were classified in detail using data from TD. TD can be used to provide supplemental information for LLE, and the combination of these extraction methods can be helpful for impurity profiling of MA.     

Research on the local regional similarity of automatic fingerprint identification system fingerprints based on close non-matches in a ten million people database—Taking the central region of whorl as an example

The local regional similarity of fingerprints has always been a hot issue in the field of fingerprint research. With the increasing size of ten-print databases, the appearance of close non-matches (CNMs) in automatic fingerprint identification system (AFIS) candidate lists has attracted increasing attention from forensic science departments worldwide. In this study, three categories (high-, medium-, and low-level) of standards for CNMs were established and 60 whorl samples were marked with different numbers of minutiae to explore the occurrence and influencing factors of CNMs in AFIS candidate lists based on a ten million people database. The results showed that all prints could be found with their corresponding CNMs. The average occurrence rate of CNMs for every query was 52.7% in the top 100 lists, and the most similar CNM was exactly the same in the local area of 12 coincidence points. CNMs appeared more in the middle and lower parts of the central region of the whorl. Moreover, shorter C2C distances and the same finger number and hand led to more CNMs being inspected. CNMs with higher similarity required a more extensive regional area and smaller minutiae density. We concluded that CNMs have a high occurrence rate in large-scale databases and many factors are closely related to them. Fingerprint examiners and researchers need to strengthen their understanding of CNMs to avoid the occurrence of misidentification like the Madrid bombings.     

Heat and let dye: Part II – Rapid heat-fixing of blood traces

Blood-contaminated shoeprints and footmarks contain valuable operational information as they may bind an individual who stepped in the crime scene with the incident and not merely with the location. As determining the age of a bloodstain remains a challenge, while processing the scene, it is difficult to determine whether the blood is completely, or partially, dry. Thus, executing a dye staining protocol may wash these marks away as they might still be soluble. However, to meet this challenge, it is possible to fix blood marks using heat. This study aims to find a solution for floor surfaces covered by heavier blood traces (shoeprints and footmarks). For this purpose, a new pseudo-operating device was constructed for examining the blood-fixing process of both mentioned trace types. Two trials were performed with depletion marks. The results revealed that fully developed fresh and heavily blood deposits were obtained by heating to 200°C for 7.5 min using the fixing device, followed by a staining protocol using amido black solution. The achieved sharp resolution of the examined bloody prints demonstrates that in certain cases the dehydration mechanism of heating is preferred over precipitating the proteins attributed to 5-sulfosalycilic acid; thus, reducing the risk of washing blood evidence while processing the crime scene.     

Uncertainty in probabilistic genotyping of low template DNA: A case study comparing STRMix™ and TrueAllele™

Two probabilistic genotyping (PG) programs, STRMix™ and TrueAllele™, were used to assess the strength of the same item of DNA evidence in a federal criminal case, with strikingly different results. For STRMix, the reported likelihood ratio in favor of the non-contributor hypothesis was 24; for TrueAllele it ranged from 1.2 million to 16.7 million, depending on the reference population. This case report seeks to explain why the two programs produced different results and to consider what the difference tells us about the reliability and trustworthiness of these programs. It uses a locus-by-locus breakdown to trace the differing results to subtle differences in modeling parameters and methods, analytic thresholds, and mixture ratios, as well as TrueAllele's use of an ad hoc procedure for assigning LRs at some loci. These findings illustrate the extent to which PG analysis rests on a lattice of contestable assumptions, highlighting the importance of rigorous validation of PG programs using known-source test samples that closely replicate the characteristics of evidentiary samples. The article also points out misleading aspects of the way STRMix and TrueAllele results are routinely presented in reports and testimony and calls for clarification of forensic reporting standards to address those problems.     

An innovative transfer DNA experimental design and qPCR assay: Protocol and pilot study

Forensic “touch” DNA samples are low-quantity samples that are recovered from surfaces that have been touched by single or multiple individuals. These samples can include DNA from primary contributors who directly touched the surface, as well as secondary contributors whose DNA was transferred to the surface through an intermediary. It is difficult to determine the type of transfer, or how often and under what conditions DNA transfer occurs. In this paper, we present an innovative protocol that combines (1) a paired male and female transfer DNA experimental design in which the presence of male DNA indicates secondary transfer and (2) a cost-effective quantitative PCR (qPCR) assay of a sex-specific region in the Amelogenin gene to detect male and female DNA. We evaluate the ability of the Amelogenin qPCR assay to detect low concentrations of male and female DNA in mixed samples. We also test experimental DNA samples using our transfer DNA protocol to differentiate primary and secondary DNA transfer. Male DNA was detected in the majority of known mixed samples, even in samples with 4× more female DNA—this result demonstrates the ability to detect low concentrations of male DNA and the presence of secondary transfer DNA in our experimental design. Primary DNA transfer was detected in 100% of our experimental trials and secondary DNA transfer was detected in 37.5% of trials. Our innovative protocol mimics realistic case scenarios to establish rates of primary and secondary DNA transfer in an inexpensive and simplified manner.