The potential for geochemical discrimination of single- and mixed-source soil samples from close proximity urban parkland locations

This initial study assessed the feasibility of geochemical analysis to discriminate single- and mixed-source soil/sediment samples from close proximity sites, a key attribute for forensic comparison and crime reconstruction. Key techniques including ICP-MS, ICP-AES and XRF were able to discriminate between the sites used in this study. The findings of this experimental study provide empirical evidence that highlights the difficulties associated with interpreting data from the elemental analysis of soil samples from geographically similar locations, and demonstrates the issues associated with samples of mixed provenance. Statistical analysis of mixed-provenance samples in comparison with the single-source control sites revealed no significant difference between the mixed and single source samples illustrating that, in this particular case, the samples could not be excluded from having a similar source in direct contrast to previously published findings. This study underlines the necessity to understand further the degree of complexity that exists for the analysis and interpretation of both single- and mixed-source forensic soil/sediment samples and confirms the need for multiple independent methods to be used in order to begin to draw meaningful conclusions of forensically relevant provenance

The evaluation of geochemical analysis techniques for forensic provenance and interpretation

This thesis investigates the feasibility of geochemical analysis techniques in forensic investigation, the issues associated with interpreting mixed provenance geochemical evidence and factors that could potentially influence the conclusions drawn. Two forensically relevant locations in the UK were selected for the study. Within these locations three sites were selected with differing land-use characteristics to assess the feasibility of X-ray Fluorescence Spectroscopy, Inductively Coupled Plasma-Atomic Emission Spectroscopy, Inductively Coupled Plasma-Mass Spectroscopy, Isotope Ratio Mass Spectroscopy and Quantitative Evaluation of Materials by Scanning Electron Microscopy techniques in distinguishing between geographically similar samples. The ability of these techniques to provide intelligence from material recovered from exhibits that are pertinent to a forensic investigation, e.g. footwear, was also assessed through the analysis of artificially created mixtures containing material from these sites. Sampling was conducted at quarterly intervals over a 12 month period to monitor the degree of temporal variation between samples from each site. Additionally, differences in the plastic sample bag packaging and storage conditions were explored to identify the optimum packaging, sample state, storage temperature and storage duration for soil/sediment material that is to undergo chemical analysis. Statistical analysis of the geochemical data revealed inter-site variation to be significant while intra-site variation and temporal variance was non-significant at each location and no significant difference was identified between packaging material, storage conditions and storage duration. The interpretation of mixed provenance samples was far more complex and identified the potential for false negative and false positive conclusions to be drawn. This thesis presents the first systematic empirical data set that addresses the issue of mixed and single source sample comparison by geochemical analysis, outlines a procedure for the hand ling of geological evidence, and provides a basis upon which to build future research that addresses the interpretation issues that have been identified

HIV-related stigma in the UK then and now: to what extent are we on track to eliminate stigma? A qualitative investigation

Background The introduction of effective antiretroviral treatment in the late 1990s led to the perception that HIV was a chronic but manageable condition. Nevertheless, stigma remains one of the major hurdles for people living with HIV (PLWH) to accessing healthcare and biomedical preventions. Thus, Fast Track Cities has set a target of zero HIV discrimination by 2030 as part of its strategy to end HIV transmission. Methods Fifty-three participants from the United Kingdom, including PLWH (n = 21, 40%), health and social care workers (n = 24, 45%), and charity workers and activists (n = 13, 25%), were recruited. Semi-structured interviews investigated stigma and discrimination, focusing on both before and after the widespread use of effective antiretroviral treatment in the late 1990s. Data were analysed using a thematic approach. Results Before effective antiretroviral treatment narratives were shaped by two main themes: 1) the media’s role in influencing public opinion and contributing to misunderstandings of HIV transmission; and 2) personal experiences of HIV-related stigma, which for PLWH included incidents of physical violence and aggression, as well as fears of their HIV status being publicised. Contemporary narratives on stigma experiences were organised around four themes: 1) discrimination in healthcare settings; 2) stigma amongst men who have sex with men (MSM); 3) stigma towards African and Afro-Caribbean PLWH; and 4) the limits of change in public HIV-related knowledge and attitudes. Contemporary narratives indicated a reduction in enacted stigma, but continued anticipation of discrimination and self-reported shame, particularly in MSM and African and Afro-Caribbean PLWH. Conclusion The nature of stigma against those with HIV has evolved. The intersection of PLWH and minority groups (e.g. MSM and African and Afro-Caribbean persons) may enhance anticipatory and internalised stigma, with some suggestion that this may contribute to reduced engagement in HIV care and prevention services. Our findings indicate the need for further research in this area, as well as proactive interventions with community groups to enhance knowledge of HIV

A2_1 How to train your Kraken

We investigate wave propagation through water and its frequency dependance to determine the maximum distance Davy Jones’ Kraken can be from the Flying Dutchman and still hear his summoning call. We found the range to be 3.2 ± 0.7 km, which is much less than expected as the Flying Dutchman is unlikely to be able to produce sounds loud enough for a greater range

A2_4 Playing Hungry Hungry Hippos with Black Holes

In this paper we investigate the relationship between the mass and density of a black hole. It leads to the interesting conclusion that a black hole may be less dense than water. By taking this further we find that at certain points a star is no longer tidally disrupted and is instead swallowed whole as the black holecontinuous to grow in size

A2_7 Breeding Like Rabbits

We investigate an augmented logistics model for determining how long it will take for the human population to recover after a zombie epidemic. We find that the time for the human population to reach one billion people depends on the growth rate while the maximum population possible depends on the value of the Mill parameter. We find that if the growth rate increases by 0.01 (from 0.01 to 0.02) the human population will recover almost 1000 years faster

A2_2 What If It's Always Sunny In Philadelphia?

We calculate the solar flux that would reach Philadelphia if it were 'Always Sunny in Philadelphia'. We first model how the solar flux varies from the Sun to the Earth, then we investigate how the intensity of the flux varies depending on the Earth's orientation with respect to the Sun. We find that a sunny Philadelphia would recieve roughly 4 times as much solar flux