Shieling activity in the Norse Eastern Settlement : palaeoenvironment of the 'Mountain Farm', Vatnahverfi, Greenland

Peer reviewedPostprin

World squid fisheries

Peer reviewedPublisher PD

Stomach contents of sperm whales Physeter macrocephalus stranded in the North Sea 1990-1996

Stomach contents of 17 sperm whales Physeter macrocephalus stranded in Scotland and Denmark during 1990-96 were analysed. All were sub-adult or adult males and stranded between November and March. They had presumably entered the North Sea during their southward migration from feeding grounds in Arctic waters. Other studies indicate that the majority of the whales were apparently healthy. The diet of these whales was found to consist almost entirely of cephalopods, principally squid of the genus Gonatus (hereafter 'Gonatus', but probably G. fabricii, an oceanic species characteristic of Arctic waters). The other prey species identified were also mostly oceanic cephalopods: the squids Histioteuthis bonnellii, Teuthowenia megalops and Todarodes sagittatus and the octopus Haliphron atlanticus. Although these results are consistent with other recent studies in the area based on single stranded whales, they differ from results of work on whales caught during commercial whaling operations in Icelandic waters (1960s to 1980s) in that little evidence of predation on fish was found in the present study. Remains of single individuals of the veined squid Loligo forbesi, the northern octopus Eledone cirrhosa and the saithe Pollachius virens provided the only possible evidence of feeding in the North Sea. We infer that sperm whales do not enter the North Sea to feed. The timing, and large and uniform sizes of the Gonatus species eaten (most had mantle lengths in the range 195 to 245 mm), as estimated from measurements of the lower beaks, and the seasonality of the strandings is consistent with the whales having fed on mature squid, possibly spawning concentrations--as has recently been reported for bottlenose whales. Assuming that the diet recorded in this study was representative of sperm whales during the feeding season, as much as 500000 t of Gonatus could be removed by sperm whales in Norwegian waters each year and up to 3 times that figure from the eastern North Atlantic as a whole. Evidence from other studies indicates that Gonatus is an important food resource for a wide range of marine predators in Arctic waters

Rate of exposure of a sentinel species, invasive American mink (Neovison vison) in Scotland, to anticoagulant rodenticides

Anticoagulant rodenticides (ARs) are highly toxic compounds that are exclusively used for the control of rodent pests. Despite their defined use, they are nonetheless found in a large number of non-target species indicating widespread penetration of wildlife. Attempts to quantify the scale of problem are complicated by non-random sampling of individuals tested for AR contamination. The American mink (Neovison vison) is a wide ranging, non-native, generalist predator that is subject to wide scale control efforts in the UK. Exposure to eight ARs was determined in 99 mink trapped in NE Scotland, most of which were of known age. A high percentage (79%) of the animals had detectable residues of at least one AR, and more than 50% of the positive animals had two or more ARs. The most frequently detected compound was bromadiolone (75% of all animals tested), followed by difenacoum (53% of all mink), coumatetralyl (22%) and brodifacoum (9%). The probability of mink exposure to ARs increased by 4.5% per month of life, and was 1.7 times higher for mink caught in areas with a high, as opposed to a low, density of farms. The number of AR compounds acquired also increased with age and with farm density. No evidence was found for sexual differences in the concentration and number of ARs. The wide niche and dietary overlap of mink with several native carnivore species, and the fact that American mink are culled for conservation throughout Europe, suggest that this species may act as a sentinel species, and the application of these data to other native carnivores is discussed

Consultant-2: pre- and post processing of machine learning applications.

The knowledge acquisition bottleneck in the development of large knowledge-based applications has not yet been resolved. One approach which has been advocated is the systematic use of Machine Learning (ML) techniques. However, ML technology poses difficulties to domain experts and knowledge engineers who are not familiar with it. This paper discusses Consultant-2, a system which makes a first step towards providing system support for a pre- and post-processing methodology where a cyclic process of experiments with an ML tool, its data, data description language and parameters attempts to optimize learning performance. Consultant-2 has been developed to support the use of Machine Learning Toolbox (MLT), an integrated architecture of 10 ML tools, and has evolved from a series of earlier systems. Consultant-0 and Consultant-1 had knowledge only about how to choose an ML algorithm based on the nature of the domain data. Consultant-2 is the most sophisticated. It, additionally, has knowledge about how ML experts and domain experts pre-process domain data before a run with the ML algorithm, and how they further manipulate the data and reset parameters after a run of the selected ML algorithm, to achieve a more acceptable result. How these several KBs were acquired and encoded is described. In fact, this knowledge has been acquired by interacting both with the ML algorithm developers and with domain experts who had been using the MLT toolbox on real-world tasks. A major aim of the MLT project was to enable a domain expert to use the toolbox directly; i.e. without necessarily having to involve either a ML specialist or a knowledge engineer. Consultant's principal goal was to provide specific advice to ease this process

Geoarchaeological Approaches to Pictish Settlement Sites: Assessing Heritage at Risk

Due to the poor preservation of Pictish period buildings and the occupation deposits within them, very little is known of daily life in early medieval Scotland. In lowland and coastal areas, Pictish buildings are generally truncated by deep ploughing, coastal erosion, or urban development, while those uncovered in upland areas seem to have no preserved floor deposits for reasons that remain poorly understood. Geoarchaeological techniques are particularly effective in clarifying site formation processes and understanding post-depositional transformations. They are also a powerful research tool for identifying floor deposits, distinguishing their composition, and linking this to daily activities. However, archaeologists are often reluctant to apply geoarchaeological methods if they suspect preservation is poor or stratigraphy is not visible in the field. This study therefore employs an innovative suite of geoarchaeological techniques to evaluate the preservation of Pictish period buildings and the potential that fragmentary buildings have to reconstruct daily life in early medieval Scotland. Alongside literature analysis and a desk-based comparison with national soil datasets, over 400 sediment samples from three key settlement sites were subjected to integrated soil micromorphology, x-ray fluorescence, magnetic susceptibility, loss-on-ignition, pH, electrical conductivity and microrefuse analysis. The combined data were successful in generating new information about the depositional and post-depositional history of the sites, preservation conditions of the occupation deposits, and activity areas within domestic dwellings. Most significantly, the integrated approach demonstrated that ephemeral and fragmented occupation surfaces retain surviving characteristics of the use of space, even if floors are not preserved well enough to be clearly defined in the field or in thin-section. A partnership with Historic Environment Scotland has channelled this work into research-led guidelines aimed at communicating geoarchaeological methods and principles to a wider audience

Learning about sex: Results from Natsal 2000.

11-13 September 2002

Development, implementation and evaluation of harm reduction techniques for drug users.

Recent strategies within health and social care state policies and interventions should be selected on the basis of evidence available to demonstrate their benefits. The provision of services for drug users is no exception to this. Harm reduction is a broad term used to describe drug policies and interventions that aim to reduce the risks to the individual and society, recognising that drug use is an inevitable part of society. Arguably, attention has largely focused on establishing the evidence of the benefits of harm reduction interventions that affect society, with little attention paid to those that are for the benefit of the individual alone. The work presented here explores two aspects of harm reduction interventions, using a combination of pharmaceutical science and social science. The first is a laboratory-based study that gathered evidence to establish the role of filters and acidifiers in the injection preparation processes. No previous work had been done in this field, yet anecdotal evidence shows that such materials are being provided by some UK drugs services. The illegal nature of drug use means that the results from this work cannot be taken as absolutes. Instead, they are indicators of the consequence that will result from using such paraphernalia. The results suggest that providing syringe filters to injecting drug users could reduce the incidence of health problems cause by the injection of insoluble materials, because the filters were found to greatly reduce the content of insoluble particles in injections prepared with street drugs and tablets, simulating techniques established from information collected from injecting drug users, drugs workers and published materials. Makeshift filters were also tested. These were cigarette filters, hand rolling cigarette filters and cotton bud tips. They caused some reduction in particle content, to a lesser extent than that seen with the syringe filters. There is concern regarding their use due to them not being designed for this purpose and the potential risk of fibre shedding from their fibrous materials. The work also illustrated the need for acidifiers to promote the solubility of street heroin obtained in the base form. However, this also raises questions around their use and safety, indicating the pathway of future work. The second aspect of this work was a case study to explore the provision of a pharmacist-led information and advice service at a voluntary sector drugs agency. This work was done because much emphasis is placed on the importance of multidisciplinary teamwork within drugs services. However, the benefit of including an expert on drugs, namely the pharmacist, has been previously overlooked. This work was undertaken as a field study, monitoring and evaluating the role of a pharmacist within a voluntary sector drugs service. The environment in which the work was conducted and the combination of factors and people involved will have Influenced the work of the pharmacist and the findings. Therefore the results can be Interpreted to show that it is possible to implement such a service and future study should expand on such service provision to investigate this matter further in a multi-centred study. Further work should also pay more attention to establishing the benefits or otherwise of such services to the team and clients. Overall, this work has provided foundation evidence to support the provision of certain harm reduction interventions that have previously been unexplored. It also illustrates how the knowledge and skills of pharmacists can be used to conduct unique research in this field

Factors that impact scale inhibitor mechanisms

The formation of mineral scales such as barium sulphate and calcium carbonate remains an issue for the oil industry, after many years of oil exploration. In the last 10 years, the difficulty in dealing with scale deposition has been accentuated by the appearance of more complex conditions, involving complicated well completions for deepwater or long sub-sea tiebacks. If scale control measures fail in these situations then long distances between the scale deposits and the production platform are present. Intervention into such systems is either impossible or extremely expensive. To combat such problems, the front end engineering design stage (FEED) now attempts to bring together multidisciplinary teams to provide a full risk assessment of all areas in which production chemistry problems might arise. Hence, benefits come from each discipline team having as much knowledge as possible available to them. This thesis aims to fuel this knowledge by developing a fundamental understanding of how various factors, conditions or environmental, impact scale inhibitor mechanisms, so that the results can be incorporated into the FEED process. Key areas affecting scale inhibitor operation were investigated. From these studies, a number of important findings can be highlighted. The presence of calcium was found to improve scale inhibitor (SI) performance, especially phosphonate types, whilst magnesium ions had little effect on polymeric performances and detrimentally affected the phosphonates’ inhibition efficiency (IE). These trends were related to the SI affinity for the divalent ions – polymer PPCA binds to calcium but shows incompatibility at [Ca2+] > 1000ppm - observed as low IE, whilst the phosphonate DETPMP binds with either ion but prefers calcium. Two inhibition mechanisms - nucleation and crystal growth blocking - were identified for different types of SI species and were illustrated using static IE tests relating IE to [SI] left in solution. High IE corresponds to high [SI] and similarly low IE with low [SI]. These initial results have since been investigated further in a additional study. An extensive range of phosphonate and polymeric scale inhibitor species can now be classified as i. either Type 1 or 2 (based on IE, Ca2+ and Mg2+ sensitivity ration and SI consumption tests) or ii. either Type A or B (based on compatibility/incompatibility with [Ca2+]= ~1000-2000ppm+). A requirement for both homogeneous and heterogeneous nucleation to be investigated for a scaling system was identified, as deposition kinetics can vary requiring different ii levels of SI. A [SI] falling below minimum inhibitor concentration (MIC), can promote surface scaling. Hence, scaling systems should be studied experimentally over a range of temperatures, to represent the conditions from sub-sea tiebacks to the production well. A model was developed from experimental data enabling the prediction of safe sulphate levels and mass of barite deposited. This model can be applied to un-seeded and seeded tests where, as expected, the foreign particles accelerated the reaction to equilibrium with the greatest deposition rate for barite over sand and for a higher surface area over a lower one. Both theoretical and experimental confirmation of each retention mechanism occurring in a porous medium was achieved. This adsorption/precipitation model has been incorporated into Squeeze VII, an in-house squeeze design software, to allow a better physical description of a squeeze treatment. The predictions of Squeeze VII have also been improved by using the more accurate data for the scale inhibitor return concentrations from core floods due to the better developed analysis techniques. The direct value of these improvements to industry is significant. These advances reduce OPEX costs and deferred oil production whilst giving the industry the opportunity of improved future lifetime predictions and operations