Radioactive isotope analyses of skeletal materials in forensic science: a review of uses and potential uses

A review of information that can be provided from measurements made on natural and anthropogenic radionuclide activities in human skeletal remains has been undertaken to establish what reliable information of forensic anthropological use can be obtained regarding years of birth and death (and hence post-mortem interval (PMI)). Of the anthropogenic radionuclides that have entered the environment, radiocarbon (14C) can currently be used to generate the most useful and reliable information. Measurements on single bones can indicate whether or not the person died during the nuclear era, while recent research suggests that measurements on trabecular bone may, depending on the chronological age of the remains, provide estimates of year of death and hence PMI. Additionally, 14C measurements made on different components of single teeth or on teeth formed at different times can provide estimates of year of birth to within 1–2 years of the true year. Of the other anthropogenic radionuclides, 90Sr shows some promise but there are problems of (1) variations in activities between individuals, (2) relatively large analytical uncertainties and (3) diagenetic contamination. With respect to natural series radionuclides, it is concluded that there is no convincing evidence that 210Pb dating can be used in a rigorous, quantitative fashion to establish a PMI. Similarly, for daughter/parent pairs such as 210Po/210Pb (from the 238U decay series) and 228Th/228Ra (from the 232Th decay series), the combination of analytical uncertainty and uncertainty in activity ratios at the point of death inevitably results in major uncertainty in any estimate of PMI. However, observation of the disequilibrium between these two daughter/parent pairs could potentially be used in a qualitative way to support other forensic evidence

The structure and dynamics of molecular crystals

Structural and dynamical properties of a number of molecular crystals have been investigated by coherent inelastic neutron scattering,Raman scattering and neutron powder diffraction. Measurements of the phonon dispersion relations in perdeuteronaphthalene have been assigned with the aid of a rigid molecule lattice dynamics calculation. The intermolecular forces were derived from semi - empirical potential functions which represented the interactions between non -bonded atoms. An attempt was made to improve the model by altering the potential function parameters to get a closer correspondence between observed and calculated frequencies. The method of total profile refinement has been used in the analysis of neutron powder diffraction data from perfluorodiphenyl, octafluoro- naphthalene and para- .diiodo and para -dibromo -tetrafluorobenzene. It has been shown that it is possible, by means of reasonable constraints, to refine a molecular structure involving a large number of atoms. The Rietveld program for structure refinement was used for perfluorodiphenyl but the constraint facilities of this program have been found to be inadequate for the lower symmetry systems of interest. The development and use of a new refinement program, embodying more versatile constraint facilities is described. The Raman spectrum of perfluorodiphenyl has been interpreted in terms of a simple polarisability model. The low frequency totally symmetric spectra are explained by the coupling of a lattice vibration with a torsional mode of the molecule. The phase transition in octafluoronaphthalene has been investigated by Raman scattering and neutron powder diffraction. The weight of experimental evidence points to a unit cell doubling with no change in space group symmetry. Lattice dynamics calculations support this, and indicate that an instability in a zone boundary acoustic mode, may be associated with the transition

Observations on cardiogenic shock

The circulatory, arterial blood gas tension and metabolic changes following acute myocardial infarction have been studied serially in patients with and without cardiogenic shock. The effects of oxygen administration on these changes has been investigated. Follow-up studies have been undertaken following recovery from shock and at various stages of convalescence in most patients. Cardiogenic shock has been shown to be associated with a severe impairment of left ventricular function with a reduced cardiac output and markedly reduced stroke volume* an elevated central venous pressure and an inadequate compensatory increase in systemic vascular resistance. These circulatory changes were accompanied by a very considerable degree of arterial blood hypoxaemia, as well as a metabolic acidosis, lactic acidaemia and hyperglycaemia. In uncomplicated acute myocardial infarction the circulatory changes were found to be highly variable. The cardiac output and stroke volume varied from normal to very low values. The systemic vascular resistance varied between high and low values, resulting in the maintenance of the blood pressure at moderate to normal levels. Uncomplicated acute myocardial infarction was accompanied by only a mild degree of arterial blood hypoxaemia and a complete lack of metabolic disturbance. The patients without shock showed a normal rise in arterial blood oxygen tension when breathing oxygen. In contrast, those with shock showed a relatively small increase of arterial blood oxygen tension following oxygen therapy. This impaired response has been shown to be due to the shunting of about 25% of the cardiac output through vessels inaccessible to pulmonary gas exchange. These patients are therefore in urgent need of oxygen and this must be given in as high a concentration as possible. The circulatory effects of oxygen therapy in patients with uncomplicated myocardial infarction are similar to those found in normal subjects - that is, a fall in heart rate and cardiac output with a slight increase in systemic vascular resistance and arterial blood pressure. It is possible that the poor and variable response of arterial blood oxygenation in cases of cardiogenic shock accounts for the less marked and equally variable circulatory response to such therapy. Recovery from cardiogenic shock was found to be associated with a reduction in tachycardia and central venous pressure with an increase in blood pressure* stroke volume and cardiac output and only small variable changes in systemic vascular resistance. The arterial hypoxacmia, metaoolic acidosis and lactic acicaemia progressively declined with recovery. Progressive recovery from uncomplicated acute myocardial infarction was associated with a reduction in central venous pressure and an increase in strrke volume. There was a progressive increase in the arterial blood oxygen tension levels towards normal with increasing recovery. The pathophysiological and therapeutic implications of these findings are discussed

Chucking buns across the fence? Governmental planning and regeneration projects in the Scottish Highland economy, 1945-82

This thesis investigates the creation, operation and impact of four industrial developments in the Highlands of Scotland in Corpach, Aviemore, Dounreay and Invergordon in the period 1945 to 1982. The thesis is structured as follows: the introduction details the development of economic policy towards the Highlands and Scotland more generally, encompassing a literature survey to provide the necessary background and context of the developments, followed by individual case study analysis of the four developments, followed by a conclusion that assesses the overall themes present in the preceding case studies and introduction. Within the conclusion is a discussion of the regional policy aspect of the four developments, the effect the developments had on the areas in which they were located in terms of population and unemployment change and the political economy and politics of Highland development. The argument developed in the thesis is that the motivations behind the four industrial projects detailed in the case studies were more complex than the publicly and privately stated justification for creating and establishing the developments that they would act as growth centres and attract further industries to the areas in which they were located. The thesis posits that developments in the Highlands only took place as a consequence of Scottish Office actions ‘winning’ large industrial projects for the area and only when Scottish Office policy aims converged with UK national economic and political interests. Consequently, short-term political goals usurped effective long-term economic development, resulting in a lack of infrastructural development that severely hindered the stated aims and justification of each development acting as a growth centre. Further, the argument is made that as a result of these short-term political goals, a policy of grand gestures of large-scale industrial developments that were inappropriate for the areas in which they were located was pursued, resulting in the eventual closure of all but the Aviemore complex. In short, the thesis is about the implementation failure of large-scale industry in the Highlands, post-1945

Group O - Lacrosse Ball Passer

The goal of our design group was to make a lacrosse ball passer that could be used in a team practice or individual setting. Wayne Jaekle, WashU’s head lacrosse coach defined major customer needs as producing a consistent pass speed and angle, an interactive interface allowing an automatic time interval between passes, and being easy to load. These needs lead to our main design goals: 1. A ball capacity of 30, 2. A minimum pass speed of 30 mph, and 3. A 5 second time interval between passes. Mock ups and brainstorming exercises led to our team’s selection of a concept to move forward with, a horizontal, two-wheeled design with a conveyor system used to feed balls between the wheels to launch the ball. Different engineering equations were used to determine the theoretical speed we could shoot a ball based on the diameter of our wheels, which helped guide us in the selection of motors and wheels. Once these parts were specified, they were mounted on a sheet of plywood at a ten degree angle, and the feeding mechanism was built off of this. We set a five gallon bucket above the motors with spiraled HVAC tube inside to hold the balls. The ball would drop from this bucket into a jai-Alai stick, which rolled the ball into a modified PVC pipe and into the wheels, launching the ball. This design met the goals of holding 30 balls and producing a 30 mph pass. Due to cost considerations and lack of time, a conveyor feeding system was not used, nor was a time interval for passes developed. After completing this project, our team learned the importance of sticking to a formulated design process and have become more inspired to attempt new designs

Temporal trend in the transfer of Sellafield-derived 14C into different size fractions of the carbonate component of NE Irish Sea sediment

From 1994 onwards, 14C discharges from the Sellafield nuclear fuel reprocessing plant have been made largely to the Northeast Irish Sea. They represent the largest contributor to UK and European populations of the collective dose commitment derived from the entire nuclear industry discharges. Consequently, it is important to understand the long-term fate of 14C in the marine environment. Research undertaken in 2000 suggested that the carbonate component of Northeast Irish Sea sediments would increase in 14C activity as mollusc shells, which have become enriched in Sellafield-derived 14C, are broken down by physical processes including wave action and incorporated into intertidal and sub-tidal sediments. The current study, undertaken in 2011, tested this hypothesis. The results demonstrate significant increases in 14C enrichments found in whole mussel shells compared to those measured in 2000. Additionally, in 2000, there was an enrichment above ambient background within only the largest size fraction (>500 μm) of the intertidal inorganic sediment at Nethertown and Flimby (north of Sellafield). In comparison, the present study has demonstrated 14C enrichments above ambient background in most size fractions at sites up to 40 km north of Sellafield, confirming the hypothesis set out more than a decade ago