Decision support for using mobile rapid DNA analysis at the crime scene

Mobile Rapid DNA technology is close to being incorporated into crime scene investigations, with the potential to identify a perpetrator within hours. However, the use of these techniques entails the risk of losing the sample and potential evidence, because the device not only consumes the inserted sample, it is also is less sensitive than traditional technologies used in forensic laboratories. Scene of Crime Officers (SoCOs) therefore will face a ‘time/success rate trade-off’ issue when making a decision to apply this technology. In this study we designed and experimentally tested a Decision Support System (DSS) for the use of Rapid DNA technologies based on Rational Decision Theory (RDT). In a vignette study, where SoCOs had to decide on the use of a Rapid DNA analysis device, participating SoCOs were assigned to either the control group (making decisions under standard conditions), the Success Rate (SR) group (making decisions with additional information on DNA success rates of traces), or the DSS group (making decisions supported by introduction to RDT, including information on DNA success rates of traces). This study provides positive evidence that a systematic approach for decision-making on using Rapid DNA analysis assists SoCOs in the decision to use the rapid device. The results demonstrated that participants using a DSS made different and more transparent decisions on the use of Rapid DNA analysis when different case characteristics were explicitly considered. In the DSS group the decision to apply Rapid DNA analysis was influenced by the factors “time pressure” and “trace characteristics” like DNA success rates. In the SR group, the decisions depended solely on the trace characteristics and in the control group the decisions did not show any systematic differences on crime type or trace characteristic. Guiding complex decisions on the use of Rapid DNA analyses with a DSS could be an important step towards the use of these devices at the crime scene

Objective data on DNA success rates can aid the selection process of crime samples for analysis by rapid mobile DNA technologies

Mobile Rapid-DNA devices have recently become available on the market. These devices can perform DNA analyses within 90 min with an easy ‘sample in–answer out’ system, with the option of performing comparisons with a DNA database or reference profile. However, these fast mobile systems cannot yet compete with the sensitivity of the standard laboratory analysis. For the future this implies that Scene of Crime Officers (SoCOs) need to decide on whether to analyse a crime sample with a Rapid-DNA device and to get results within 2 h or to secure and analyse the sample at the laboratory with a much longer throughput time but with higher sensitivity. This study provides SoCOs with evidence-based information on DNA success rates, which can improve their decisions at the crime scene on whether or not to use a Rapid-DNA device. Crime samples with a high success rate in the laboratory will also have the highest potential for Rapid-DNA analysis. These include samples from e.g. headwear, cigarette ends, articles of clothing, bloodstains, and drinking items

The interface between forensic science and technology: how technology could cause a paradigm shift in the role of forensic institutes in the criminal justice system

In this paper, the importance of modern technol. in forensic investigations is discussed. Recent technol. developments are creating new possibilities to perform robust scientific measurements and studies outside the controlled lab. environment. The benefits of real-​time, on-​site forensic investigations are manifold and such technol. has the potential to strongly increase the speed and efficacy of the criminal justice system. However, such benefits are only realized when quality can be guaranteed at all times and findings can be used as forensic evidence in court. At the Netherlands Forensic Institute, innovation efforts are currently undertaken to develop integrated forensic platform solns. that allow for the forensic investigation of human biol. traces, the chem. identification of illicit drugs and the study of large amts. of digital evidence. These platforms enable field investigations, yield robust and validated evidence and allow for forensic intelligence and targeted use of expert capacity at the forensic institutes. This technol. revolution in forensic science could ultimately lead to a paradigm shift in which a new role of the forensic expert emerges as developer and custodian of integrated forensic platforms

Screening the Budding Yeast Genome Reveals Unique Factors Affecting K2 Toxin Susceptibility

Background: Understanding how biotoxins kill cells is of prime importance in biomedicine and the food industry. The budding yeast (S. cerevisiae) killers serve as a convenient model to study the activity of biotoxins consistently supplying with significant insights into the basic mechanisms of virus-host cell interactions and toxin entry into eukaryotic target cells. K1 and K2 toxins are active at the cell wall, leading to the disruption of the plasma membrane and subsequent cell death by ion leakage. K28 toxin is active in the cell nucleus, blocking DNA synthesis and cell cycle progression, thereby triggering apoptosis. Genome-wide screens in the budding yeast S. cerevisiae identified several hundred effectors of K1 and K28 toxins. Surprisingly, no such screen had been performed for K2 toxin, the most frequent killer toxin among industrial budding yeasts. Principal Findings: We conducted several concurrent genome-wide screens in S. cerevisiae and identified 332 novel K2 toxin effectors. The effectors involved in K2 resistance and hypersensitivity largely map in distinct cellular pathways, including cell wall and plasma membrane structure/biogenesis and mitochondrial function for K2 resistance, and cell wall stress signaling and ion/pH homeostasis for K2 hypersensitivity. 70% of K2 effectors are different from those involved in K1 or K28 susceptibility. Significance: Our work demonstrates that despite the fact that K1 and K2 toxins share some aspects of their killing strategies, they largely rely on different sets of effectors. Since the vast majority of the host factors identified here is exclusively active towards K2, we conclude that cells have acquired a specific K2 toxin effectors set. Our work thus indicates that K1 and K2 have elaborated different biological pathways and provides a first step towards the detailed characterization of K2 mode of action. © 2012 Servienė et al.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Characterization of Organics Consistent with b-Chitin Preserved in the Late Eocene Cuttlefish Mississaepia mississippiensis.

Background: Preservation of original organic components in fossils across geological time is controversial, but the potential such molecules have for elucidating evolutionary processes and phylogenetic relationships is invaluable. Chitin is one such molecule. Ancient chitin has been recovered from both terrestrial and marine arthropods, but prior to this study had not been recovered from fossil marine mollusks. Methodology/Principal Findings: Organics consistent with b-chitin are recovered in cuttlebones of Mississaepia mississippiensis from the Late Eocene (34.36 million years ago) marine clays of Hinds County, Mississippi, USA. These organics were determined and characterized through comparisons with extant taxa using Scanning Electron Microscopy/Energy Dispersive Spectrometry (SEM/EDS), Field Emission Scanning Electron Microscopy (Hyperprobe), Fourier Transmission Infrared Spectroscopy (FTIR) and Immunohistochemistry (IHC). Conclusions/Significance: Our study presents the first evidence for organics consistent with chitin from an ancient marine mollusk and discusses how these organics have been degraded over time. As mechanisms for their preservation, we propose that the inorganic/organic lamination of the cuttlebone, combined with a suboxic depositional environment with available free Fe2+ ions, inhibited microbial or enzymatic degradation.shell morphology and ultrastructure as a key to coleoid cephalopod phylogen