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Eskers are ridges of stratified glaciofluvial material deposited in englacial, subglacial or supraglacial channels and ice-walled canyons. Eskers have been used to infer the dynamics and palaeo-hydrology of large ice sheets, despite observations of palaeo-esker sedimentary architecture lacking rigorous constraints on depositional timescale. This research aims to identify the hydrological, glaciological and sedimentary controls on the sedimentary architecture of single event outburst flood (jokulhlaup) eskers at SkeiOarârjOkull and Bering Glacier. These eskers formed during monitored outbursts, providing time constraints on the depositional events, thereby making the eskers ideal analogues for palaeo-eskers. GPR data was collected using a pulseEKKO Pro 1100 system at SkeiOarârjOkull and Bering Glacier during field seasons in 2006 and 2007. At SkeiOarãrjOkull grids of 100 MHz GPR lines were collected on the glacier surface and 200 MHz GPR grids were collected on all workable sections of an esker and ice-walled canyon fill generated by a jokulhlaup in November 1996. At Bering Glacier 200 MHz GPR grids were collected on workable sections of an ice-walled canyon fill and esker generated during outbursts in July-August and October 1994, respectively. Examination of the GPR data has allowed development of site-specific models for esker and ice-walled canyon fill deposition, providing the first detailed insight into the sedimentary architecture of single event jokulhlaup eskers. These models show that single high-magnitude jOkulhlaups can generate eskers with complexities previously unexpected for single events. The englacial position of an esker is controlled by the presence of structural weaknesses within the ice and the jokulhlaup release mechanism. Esker sedimentary architecture, on the other hand, is controlled by a complex interaction between hydrological, glaciological and sedimentary factors. The most fundamental control on jokulhlaup esker sedimentary architecture is conduit geometry, which determines the type of macroform from which the esker is composed. Thus, eskers deposited during jOkulhlaups should be made up of both wide ridges as composite macroforms in areas of conduit expansion and narrow ridges composed of upper-stage plane beds in constricted conduits. The smaller scale sedimentary features, which include antidunes and boulder clusters, as well as the frequency of erosional structures, are controlled by interactions between the flow conditions and sediment supply. The eskers generated during the 1996 SkeiOarãrhlaup and 1994 Bering Glacier outburst flood demonstrate sedimentary architectures that are similar to those identified in many palaeo-eskers described from previous studies. The research suggests that jOkulhlaups may have had a greater role in palaeo-esker sedimentary architecture than previously hypothesised.

Future climate and land use change are predicted to have a concomitant impact on ecological communities. Some sources have proposed that at global scales, and for particular regions, land use change will have a greater impact than changes in climate. This research aimed to test this assertion for the semi-natural landscape of Northumberland National Park (NNP) in the north east of England. The methodology applied a simple habitat suitability model to simulate changes in the distribution of relevant vegetation communities through changes in land use occurring under two future land use scenarios formulated for the study area. Appropriate landscape metrics were then applied to the results to gauge how the associated changes in patch characteristics impacted on the sensitivity and adaptive capacity of the communities. A relatively simple bioclimatic envelope model was also applied to the results of the land use modelling to estimate the sensitivity of vegetation communities to changes in climate predicted under the UKCP09 Medium emissions scenario. Together the applied measures offer a simple and accessible method for estimating the current and future vulnerability of Broad Vegetation Communities (BVCs) within the study area. Results were analysed at the landscape level for NNP, as well as the five National Character Areas (NCAs), which wholly or partially coincide with its area. Class level results were analysed for nine Priority Broad Vegetation Communities (PBVCs) for NNP and each of the NCAs. Overall the results strongly suggest that the climate changes predicted to affect the park in the future are likely to have a notably greater impact on the vulnerability of the PBVCs than the simulated changes in land use. Landscape level results suggest that vulnerability is likely to be notably reduced in the future under both land use scenarios. This is due the majority of PBVCs exhibiting significant reductions in overall vulnerability in the future, largely due to significant reductions in their levels of climate stress. However, two PBVCs (Blanket Bog and Raised Bog) exhibited considerable increases in vulnerability, due to the increases in the climate stress that they experience. These PBVCs may be regarded as a potential focus for future conservation efforts. The approach adopted within this research has allowed a number of relevant management recommendations to be made for NNP and for individual PBVCs and NCAs. PBVCs most at risk have been identified and relevant causes investigated. The characteristics of the methodology (simplicity, accessibility, robustness) mean that it provides a useful framework for providing meaningful vulnerability assessments for whole ecological communities across entire landscapes with comparative ease and speed.

Cadmium has been widely used in various industries for the past fifty years, with current world production standing at around 16,755 tonnes per year. Very little cadmium is ever recycled and the ultimate fate of all cadmium is the environment. In view of ~eports that cadmium in the environment is increasing, this thesis aims to identify population groups 'at risk' of receiving dietary intakes of cadmium up to or above the current Food and Agricultural Organisation/World Health Organisation maximum tolerable intake of 70 ug/day. The study involves the investigation of one hundred households (260 individuals) who grow a large proportion of their vegetable diet in garden soils in the Borough of Walsall, part of an urban/industrial area in the United Kingdom. Measurements were made of the cadmium levels in atmospheric deposition, soil, house dust, diet and urine from the partiCipants. Atmospheric deposition of cadmium was found to be comparable with other urban/industrial areas in the European ~ommunity, with deposition rates as high as 209 g ha- yr-1. The garden soils of the study hauseholds were found to contain up to 33 mg 'kg- total cadmium, eleven times the highest level usually found in agricultural soils. Dietary intakes of cadmium by the residents from food were calculated to be as high as 68 ug/day. It is suggested that with intakes f~om other sources, such as air, adventitious ingestion, smoking and occupational exposure, total intakes Df cadmium may reach or exceed the FAO/WHO limit. Urinary excretion of cadmium amongst a non-smoking, nonoccupationally exposed sub-group of the study population was found to be Significantly higher than that of a similar urban population who did not rely on homeproduced vegetables. The results from this research indicate that present levels of cadmium in urban/industrial areas can increase dietary intakes and body burdens of cadmium. As cadmium serves no useful biological function and has been found to be highly toxic, it is recommended that policy measures to reduce human exposure on the European scale be considered.

Accelerated climate change and increasing climate variability caused by increasing anthropogenic greenhouse gas emissions is the single largest threat to the international goals of sustainable development, the Millennium Development Goals (MDGs) and disaster risk reduction. Global discourses recognise the need for effective and sustainable responses to produced climate risks. The risk types likely to occur are known, but only in broad terms. That they are produced by human action is accepted; but their scale, severity, longevity and frequency are not known. The challenge for policymakers is developing an effective framework within which sustainable responses can be formulated. Addressing the problems of produced risks requires a comprehensive approach to risk management to be effective. The mechanisms within the climate change, sustainable development and disaster risk reduction discourses are not sufficiently effective or integrated to respond to this challenge. Fundamental reform to current modes of risk reduction is needed, but this can only be achieved by a shift in the dominant perspective on formulating sustainable responses. This requires a shift to an enabling policy framework that encourages bottom-up resilient responses. Resilience is argued as a tool for policy development that can enhance adaptive capacity to current climate risks and shape energy policy to respond to mitigate future climate risks.

This research explores disaster vulnerability in Nepal. Disaster vulnerability is increasing due to the following reasons: weak governance; demographic growth; rapid urban expansion; relatively weak land use planning; the growth of informal settlements; poor construction methods; steep land farming practices; the encroachment of river plains and forest areas; and environmental degradation. This research is divided into three parts; problem overview, mapping past disaster events and community vulnerability. Often disaster management practice at the national level has tended to focus on large-scale events. In Nepal, there is a history of government responses to large-scale disasters; however, evidence increasingly shows that small-scale disasters have a more significant impact on people’s livelihoods. This is the case in Nepal and it is unclear whether small-scale disasters have prompted policy change. The purpose of this research is to evaluate the impact of small-scale disasters and to ascertain if there is any evidence of a shift in government disaster management policy. Local disasters seem to dominate the lived risk experience, but there is little understanding of how small-scale disasters can contribute to disaster risk reduction knowledge. Urban and rural communities differ in their understanding of small-scale disaster knowledge base, not least because both populations have little experience of the risks they take as a result of migration to new environments. This study captures 10 years of field experience in Nepal. This research has found that:- Small-scale disasters have a greater impact than larger disasters. Without an integrated policy and legislative framework approach from government and a focus on small-scale disasters, it is unlikely that effective disaster risk reduction measures will be integrated into sector development planning. People’s knowledge of, relationship to, and interactions with small-scale hazards in a changing climate produce new risks and vulnerabilities at the local level. This thesis concludes with recommendations for improving disaster risk reduction at the local level in Nepal.

In nuclear reprocessing, PUREX, a solvent extraction process, has long been the separation method employed for the separation of the bulk components of irradiated nuclear fuel (namely uranium and plutonium) from the fission products and other minor actinides produced during the fuel use. The uranium and plutonium constitutes approximately 96 % by mass of the irradiated fuel and for this to be removed, requires large volumes of extractant and equipment with large surface area contactors and therefore floor space requirements. The PUREX process has for nearly 60 years been the largely unchallenged separation technology for the reprocessing of irradiated fuel, for both nuclear weapon production and commercial nuclear power generation. The merits and ability of this process are unquestionable since it achieves the objectives of highly purified plutonium and uranium which both can be eventually recycled. Although well proven and predictable, the PUREX process is not without its challenges: the generation of significant quantities of highly active aqueous liquid containing fission products (FPs) and minor actinides (MAs), and the degradation of the solvent phase reagents and non-specific nature of the extractant TriButylPhosphate (TBP) may have contributed to only a fraction of the total annual output of irradiated fuel being reprocessed. Fission products are elements which are produced in a nuclear reactor and are the atomic fragments left after a large atomic nucleus (typically uranium-235) undergoes nuclear fission, splitting into two smaller nuclei, along with a few neutrons, the release of heat energy (kinetic energy of the nuclei), and gamma rays. Minor actinides such as neptunium, americium, curium, berkelium, californium, einsteinium, and fermium are the actinide elements in irradiated nuclear fuel other than uranium and plutonium; they are minor as they represent a very small proportion of actinides in comparison to U and Pu. This thesis explores the possibility of using a continuous chromatographic method to extract the lesser components of the irradiated fuel. One of the major problems with the use of chromatography as an industrial process is the expansion from the batch separations on the bench top to a continuous efficient process, capable of processing large volumes. This thesis, through existing concepts, will describe a proof of concept chromatographic separation of surrogates and isotopes of the components of irradiated fuels which can be readily scaled up to a continuous chromatographic separation. The project is a radical departure from PUREX and will offer many advantages over PUREX. It is based on the separation of FPs and MAs from uranium and plutonium isotopes using continuous chromatographic separation. This thesis assesses a number of commercial resins for their suitability for the proposed continuous chromatography reprocessing method. The experiments were all undertaken at elevated nitric acid concentrations and as such are describing interactions which are rarely required commercially and therefore seldom reported, with batch studies to assess separation factors between ions, uptake kinetics and isotherms over a range of nitric acid concentrations to more dynamic column breakthrough and eventually separations. The research demonstrates that a separation can be achieved at an elevated HNO3 concentration on a commercially available ion exchange resin.

An analysis of the photoperiodic induction of flowering in Arabidopsis thaliana (L.) Heyne, Landsberg erecta ecotype, was carried out. This revealed that 4 day old seedlings, at which time the cotyledons where expanding and greening, could differentiate between a LD and a SD. At this stage the critical daylength was between 8 and 10 hours. Plants grown in daylengths of 8 hours, a short day, flowered after 50-70 days and when grown in 16 hour daylengths, a long day, flowered after 24-27 days. At 7 days seedlings required five long days to fully induce flowering and as the seedlings aged in short days they became more sensitive to interposed long days, so that by day 20 one long day was fully inductive. It was found that there were two different photomorphogenic responses shown by plants grown in short days, firstly flowering was delayed and secondly further leaves were induced. The short days delay of flowering occurred in newly germinated seedlings older than 4 days and further leaves were induced in plants older than 10 days. From light quality experiments it was concluded that both a blue light photoreceptor and phytochrome promoted flowering. The induction of flowering by phytochrome was through a HIR mode. Three of the photoreceptor mutants, hy, isolated by Koornneef et al. (1980) were used. In daylength transfer experiments all the hy mutants studied showed delay in flowering by short days and all responded to long days by flowering earlier. Both hy2 and hy3 produced far fewer leaves than Ler when grown in short days. The hy4 mutants flowered later in both long days and short days than Ler and had an increased leaf number. A scheme is proposed in which photoperiodic induction depends on the ability of the plant to sense photoperiod, the stage of development and the photobiological input. It also proposes that phyA or C and the blue light photoreceptor promote flowering whereas phyB promotes vegetative development. Two screens were set up to isolate novel photoperiodic mutants. Six mutants were isolated, from ethtylmethane sulphonate mutated seed, which all flowered earlier than Ler in SD. They were called FUN 1-6, flowering pjcoupled. Genetic analysis showed that all were non allelic and that they were recessive except .tun4 which was semi-dominant. Physiological studies showed that there were two types of mutants: firstly funl and 2 whose flowering was not significantly delayed by SD in comparison to long day treatments and flowered early in the dark; and secondly fun3-6 which all showed a delay in flowering when grown in SD. The .funl, and 2 mutants had poorly developed leaves as did fun5. The other mutants did not show any other clearly defined phenotypes. These results suggest that funl and 2 mutants are constitutive flowering mutants and the remaining mutants are transduction chain mutants.

Microbial attachment and proliferation on a surface leads to the formation of a structure known as a biofllm. In this thesis attention is directed towards the attachment of microorganisms to submerged surfaces in private swimming pools Samples were taken from two private swimming pools located in West Lancashire, England. The planktonic phase of the water was sampled using a standard fluid grab technique and the submerged surfaces (e.g. the pool lining, the steps and the water recirculation trap) were sampled using swabs and a scalpel blade to scrape the surface. Using these techniques, thirteen different bacteria (e.g. Pseudomonas spp. and Staphylococcus spp.) and one alga (Chlorella vulgaris) were isolated from the two private swimming poois. In both cases the use of a swimming pool sanitiser (Baquacil, ICI Chemicals) showed excellent control of the planktonic population. Only algae were recovered from the fluid grab sample when incubated in appropriate media. Bacteria were found to be present only on plates incubated aerobically and from areas where swabbing/scraping had taken place. No anaerobic bacteria were isolated even after a long incubation period of 120 h. On further investigation it was shown that two of the isolated species, Pseudomonas maltophilia and Ps.putida, were capable of producing extracellular polymeric substance (EPS). Production of this material has been implicated in the initial adhesion of bacteria, and further, it can act as a barrier against the diffusion of the sanitiser so that organisms exhibit higher levels of tolerance to the added swimming pooi sanitiser. Laboratory studies demonstrated that planktonic populations of one of the isolates, Pseudomonas fluorescens, attached rapidly to the surface of PVC coupons from a planktonic population thereby mimicking the in vivo situation. The shortest time investigated for attachment (3.5 h) demonstrated that up to 1x10 7 cells/cm2 were firmly adhered to the surface. Attacimient to the coupons wasalso shown to provide resistance to the swimming pool sanitiser below, at and above the recommended levels (Chapter 2), the greatest increase in resistance being two fold. Planktonic populations of bacteria were reduced to acceptable levels after incubation for only 3 hours in a dilute medium. It was also shown that the organism attached to the surface produced extracellular material. On screening of Ps.fluorescens mutants (approximately 2000, induced by transposon mutagenesis, Chapter 4) for altered sanitiser resistance, it was found that 14 of these mutants had an increased resistance to the sanitiser above that shown by the wild type cells. Polyacrylamide gel electrophoresis of total cell protein extracts of thirteen of these mutants revealed that in 11 cases, a band with a molecular weight between 52,000 and 54,000 was induced or enhanced when biocide was added to the system. If a swimming pool is not to become a potential source of infection to the bathers then attention must be paid to the submerged surface-attached population of microorganisms. Planktonic sampling will indicate that there is little microbial activity within the main body of the pool water but the techniques used only assess the quality of the bulk fluid phase of the system and not the submerged surfaces. The attachment of potentially pathogenic micro-organisms to submerged surfaces must be accepted as a nornrnl occurrence. In this state, the organisms often exhibit increased resistance to the swimming pool sanitiser. Therefore, regular cleaning (i.e. scrubbing/vacuuming) of the submerged surfaces is suggested as a part of the recommended maintenance programme for domestic swimming pools of this type.