Encoding of low-quality DNA profiles as genotype probability matrices for improved profile comparisons, relatedness evaluation and database searches

Many DNA profiles recovered from crime scene samples are of a quality that does not allow them to be searched against, nor entered into, databases. We propose a method for the comparison of profiles arising from two DNA samples, one or both of which can have multiple donors and be affected by low DNA template or degraded DNA. We compute likelihood ratios to evaluate the hypothesis that the two samples have a common DNA donor, and hypotheses specifying the relatedness of two donors. Our method uses a probability distribution for the genotype of the donor of interest in each sample. This distribution can be obtained from a statistical model, or we can exploit the ability of trained human experts to assess genotype probabilities, thus extracting much information that would be discarded by standard interpretation rules. Our method is compatible with established methods in simple settings, but is more widely applicable and can make better use of information than many current methods for the analysis of mixed-source, low-template DNA profiles. It can accommodate uncertainty arising from relatedness instead of or in addition to uncertainty arising from noisy genotyping. We describe a computer program GPMDNA, available under an open source license, to calculate LRs using the method presented in this paper.Comment: 28 pages. Accepted for publication 2-Sep-2016 - Forensic Science International: Genetic

Photon Funnels for One-Way Energy Transfer: Multimetallic Assemblies Incorporating Cyclometallated Iridium or Rhodium Units Accessed by Sequential Cross-Coupling and Bromination

The generation of multimetallic assemblies is a widely explored theme, owing to the relevance of controlling energy and electron transfer between metal centres to many fields of contemporary importance. Boronic acid substituted coordination and organometallic complexes have been shown to be useful synthons in the formation of such structures through cross-coupling with halogenated complexes. In this work we used such a methodology to generate an octanuclear mixed-metal compound of composition Ir7Ru having a dendrimer wedge-like structure. The method combined cross-coupling with regiospecific bromination of phenylpyridine (ppy) ligands at the position para to the C–Ir bond. The propensity of Ir(ppy)2-based complexes to electrophilic bromination was found to be deactivated by the introduction of fluorine atoms. The coupling methodology was extended to rhodium-containing systems, exemplified by a tetranuclear system of composition Rh2Ir1Ru1. The synthesis required the use of boronic acid appended RhIII complexes, which could be accessed by the introduction of a neopentyl boronate ester appended bipyridine into the coordination sphere of RhIII. The excited-state energies of the constituent metal units in the resulting multinuclear complexes are such that unidirectional energy transfer occurs from the RhIII/IrIII branches to the RuII core. The luminescence thus resembles that of an isolated [Ru(bpy)3]2+ unit, but the ability of the structure to collect light is greatly enhanced

Time-resolved velocity map imaging of methyl elimination from photoexcited anisole

To date, H-atom elimination from heteroaromatic molecules following UV excitation has been extensively studied, with the focus on key biological molecules such as chromophores of DNA bases and amino acids. Extending these studies to look at elimination of other non-hydride photoproducts is essential in creating a more complete picture of the photochemistry of these biomolecules in the gas-phase. To this effect, CH3 elimination in anisole has been studied using time resolved velocity map imaging (TR-VMI) for the first time, providing both time and energy information on the dynamics following photoexcitation at 200 nm. The extra dimension of energy afforded by these measurements has enabled us to address the role of πσ* states in the excited state dynamics of anisole as compared to the hydride counterpart (phenol), providing strong evidence to suggest that only CH3 fragments eliminated with high kinetic energy are due to direct dissociation involving a 1πσ* state. These measurements also suggest that indirect mechanisms such as statistical unimolecular decay could be contributing to the dynamics at much longer times

Complement inhibitors for age-related macular degeneration

Given the relatively high prevalence of age-related macular degeneration (AMD) and the increased incidence of AMD as populations age, the results of trials of novel treatments are awaited with much anticipation. The complement cascade describes a series of proteolytic reactions occurring throughout the body that generate proteins with a variety of roles including the initiation and promotion of immune reactions against foreign materials or micro-organisms. The complement cascade is normally tightly regulated, but much evidence implicates complement overactivity in AMD and so it is a logical therapeutic target in the treatment of AMD

Divergence or convergence? Health inequalities and policy in a devolved Britain

Since the advent of political devolution in the UK, it has been widely reported that markedly different health policies have emerged. However, most of these analyses are based on a comparison of health care policies and, as such, only tell part of a complex and evolving story. This paper considers official responses to a shared public health policy aim, the reduction of health inequalities, through an examination of national policy statements produced in England, Scotland and Wales respectively since 1997. The analysis suggests that the relatively consistent manner in which the ‘policy problem’ of health inequalities has been framed combined with the dominance of a medical model of health have constrained policy responses. Our findings differ from existing analyses, raising some important questions about the actuality of, and scope for, policy divergence since devolution

Four activities to promote student engagement with referencing skills

Teaching academic writing skills in a way that engages students in deep learning is difficult and there is a risk of encouraging surface learning approaches. Moreover, linking the experience of the research process to understanding the provenance of research studies is difficult for students as they tend to experience research, referencing, citing, and related areas in disparate and unconnected ways. We report our initial experiences of designing a series of four mutually supportive tutorial activities that are based on the principles of scaffolding, social interaction, and experiential learning. The aim was to help students identify suitable research material that could be used as evidence in assignments and to promote their understanding of how evidence can be used effectively, through referencing, when writing reports and essays

Four activities to promote student engagement with referencing skills

Teaching academic writing skills in a way that engages students in deep learning is difficult and there is a risk of encouraging surface learning approaches. Moreover, linking the experience of the research process to understanding the provenance of research studies is difficult for students as they tend to experience research, referencing, citing, and related areas in disparate and unconnected ways. We report our initial experiences of designing a series of four mutually supportive tutorial activities that are based on the principles of scaffolding, social interaction, and experiential learning. The aim was to help students identify suitable research material that could be used as evidence in assignments and to promote their understanding of how evidence can be used effectively, through referencing, when writing reports and essays