Taylor D.,Forensic Science South Australia |
Taylor D.,Flinders University |
Forensic Science International: Genetics | Year: 2015
A set of low template mixed DNA profiles with known ground truths was examined using software that utilised peak heights (STRmix™ V2.3) and an adapted version that did not use peak heights and mimicked models based on a drop-out probability [1,2] (known as semi-continuous or 'drop' models) (STRmix™ lite). The use of peak heights increased the LR when Hp was true in the vast majority of cases. The effect was most notable at moderate template levels but was also present at quite low template levels. There is no level at which we can say that height information is totally uninformative. Even at the lowest levels the bulk of the data show some improvement from the inclusion of peak height information. © 2014 Elsevier Ireland Ltd. All rights reserved.
Croft Additive Manufacturing (CAM, and ESR Space have combined expertise to research the use of )additive manufacturing (AM) and use prototypes to develop bespoke spacecraft mechanisms. The research, which was funded by Centre for Earth Observation Instrumentation and Space Technology CEOI-ST, aims to develop components for use in mechanism applications. While the main emphasis of the study is on spacecraft applications, it also supports the development of supply chain capability in AM and the suitability of the processes in a range of markets, including telecommunications, science and robotics. In space applications, there are a number of disadvantages to using a liquid or grease-based lubricant, such as low temperature viscosity, evaporation, loss of lubricant and contamination of other parts of the spacecraft. To address these issues, two concept designs were developed using Croft’s Realiser SLM-250 machine. These were both focused on managing the lubricant within the bearing system more effectively, with a particular emphasis on the challenges of the space environment. 'It is always advised to have several options when seeking to identify a bespoke solution using innovative technologies,’ said Neil Burns, director at Croft Additive Manufacturing. ‘Following the creation and analysis of the two prototypes in this instance, it was deemed more valuable to develop the lubricant retaining cage further.’ ‘We learnt a number of valuable lessons during this study, the most important of which was in the design process – while AM technology can give greater design freedom relative to conventional machining, it is not without constraints,’ added Grant Munro, project manager at ESR Space.’ In terms of next steps, a roadmap has been created to show timescales for exploitation within the space industry and beyond.’ While it is likely that the component developed will be initially used for spacecraft applications alone, the use of the technology in other industries such as nuclear, aerospace and medical will be explored in parallel. This story uses material from Croft Additive Manufacturing, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.
Curran J.M.,University of Auckland |
Forensic Science International: Genetics | Year: 2011
There is a variety of methods for assessing sampling uncertainty in likelihood ratio calculations in DNA casework. Sampling uncertainty arises because all DNA statistical methods rely on a database of collected profiles. Such databases can be regarded as a sample from the population of interest. The act of taking a sample incurs sampling uncertainty. In some circumstances it may be desirable to provide some estimate of this uncertainty. We have addressed this topic in two previous publications [1,2]. In this paper we reconsider the performance of the methods using 15 locus Identifiler™ profiles, rather than the 6 locus data used in . We also examine the differences in performance observed when using a uniform prior versus a 1/k prior in the Bayesian highest posterior density (HPD) method of Curran et al. . © 2010 Elsevier Ireland Ltd.
Curran J.M.,University of Auckland |
Forensic Science International: Genetics | Year: 2014
The effect of masking on the assignment of the number of contributors is assessed for the European Standard Set of loci by simulation. The risk that a two person mixture presents as single source is assessed as 2.6 × 10 -13, a three person mixture presents as a two person 6.7 × 10-4 and a four person mixture presents as a three person 0.165. © 2014 Elsevier Ireland Ltd. All rights reserved.
Gill P.,Center for Forensic Science |
Gill P.,University of Oslo |
Forensic Science International: Genetics | Year: 2010
In this paper we critically examine the causes of the underlying confusion that relates to the issue of low-template (LT) DNA profile interpretation. Firstly, there is much difficulty in attempting to distinguish between LT-DNA vs. conventional DNA because there is no discrete 'cut-off' point that can be reasonably defined or evaluated. LT-DNA is loosely characterised by drop-out (where alleles may be missing) and drop-in (where additional alleles may be present). We have previously described probabilistic methods that can be used to incorporate these phenomena using likelihood ratio (LR) principles. This is preferred to the random man not excluded (RMNE) method, because we cannot identify a coherent way forward within the restrictions provided by this framework. Most LT-DNA profiles are interpreted using a 'consensus' profile method, we called this the 'biological model', where only those alleles that are duplicated in consecutive tests are reported. We recognise that there is an increased need for probabilistic models to take precedence over the biological model. These models are required for all kinds of DNA profiles, not just those that are believed to be low-template. We also recognise that there is a need for education and training if the methods we recommend are to be widely introduced. © 2009 Elsevier Ireland Ltd. All rights reserved.