<p>A metagenomic gene library prepared from soil found beneath a mummified seal carcass in the Miers Valley, Antarctica, suggests an environment rich in uncharacterised biodiversity including enzymes with possible application to industrial processes. A sequence based gene mining investigation was performed on a clone, which archives a metagenomic sequence from this environment. The sequence was annotated using de novo bioinformatics and molecular biology techniques. A predicted NAD+-dependent DNA ligase, ligDB1 was selected for further characterisation. LigDB1 encodes a gene product that contains all the sequence features of a functional ligase. The protein was overexpressed in a heterologous E. coli host and purified to homogeneity. LigDB1 did not exhibit nick sealing activity, but was able to perform AMP-dependent DNA relaxation in the presence of high concentrations of enzyme. DNA modifying enzymes from cold environments perform optimally at low temperatures and may be of use as molecular tools in biotechnology. Complete characterisation of this enzyme is subject to further investigations.</p>

This thesis seeks a portable and accessible model for centralising photographs in enquiry. I argue that photographs are potent sites of human value making but are typically relegated to illustrating word-based considerations, while the vast mass of ‘ordinary’ photographs are excluded from even this function. The context in which I develop and test the model is the heroic era of Antarctic exploration, a time and place that is dominated by an entrenched mythology, and where photographs have been assigned a merely pictorial role. In seeking to reactivate these objects and pictures I turn to Elizabeth Edwards’ notion of using photographs to think with, tracing the evolution of this idea through generations of thinking about photography, and emphasising recent writers such as Geoffrey Batchen, Margaret Olin and Joan Schwartz. My work confirms a resonance with Edwards’ thinking but also a need to emphasise photographic materiality and the photographic collective. Further, I demonstrate that this thinking also resonates with the work of Walter Benjamin and Roland Barthes, confirming a construction of photographs as generative anchoring points in networks of identification that are both culturalised and subjective. My model for thinking with photographs draws in Kenneth Burke’s pentad of dramatistic analysis, arguing a productive fit with his concern to filter the rhetorical detritus of human behaviour as an entrée to viewing core motivations. The pentad has not previously been used to think with photographs but it is able to be deployed successfully for this purpose by refreshing its operation in line with writers such as Robert Cathcart, James Chesebro and Gregory Clark. For Antarctica, thinking with photographs involves negotiating margins – depicted, physical, temporal and ideological, and in addressing the photographic mass this thesis argues a reactivation of margins as points of insight rather than barriers of exclusion. Recent writers such as Francis Spufford, Stephen Pyne, John Wylie and Kathryn Yusoff have found new ways to construct the performance of Antarctic exploration, and, in this spirit, the thesis enacts Burke’s pentad to think with the photograph collection of ‘second tier’ Antarctic explorer, Ernest Joyce. It shows Antarctic exploration to be also an intensely personal experience, with the power to overhaul mindsets but offering no guarantee that new expectations can be delivered on. In Joyce’s photographs it finds a nexus of contested narratives and contested photographies, and the seeds of a Benjaminian modernity that speak of the personal implications of the dissolution of meta-narratives.

The Skelton Glacier is one of the many smaller outlet glaciers located in the Transantarctic Mountains, where it drains ice into the Ross Ice Shelf. These outlet glaciers are important when determining the past, present, and future state of the mass balance of the East Antarctic Ice Sheet. This research uses satellite imagery acquired over a period of 15 years to obtain a high resolution velocity field for the Skelton Glacier which is then used to calculate the mass flux and mass balance at ten flux gates along the glacier using the input-output method. The high resolution velocity field is combined with ice thickness data and accumulation data from other sources to obtain the total mass balance. The high resolution velocity field of the Skelton Glacier was created using European Remote-Sensing Satellite 1 and 2 (ERS-1/2) Synthetic Aperture Radar (SAR) data acquired in 1996 with the processing technique of SAR interferometry (InSAR). Because of the lack of differential InSAR pairs, new auxiliary data from the ICESat and TanDEM-X mission were included into the analysis. A velocity field was created at a spatial resolution of 50m which was validated with in situ GPS measurements from 2011/12, and compared to lower resolution velocity fields of the Skelton Glacier. The ice velocity field is at improved accuracy for this area compared to previous studies and is thought to be representative for the mean ice velocity. The analysis of ice flux at several flux gates allowed an improved error estimation of the applied technique to estimate the overall mass balance. Mass flux estimates along the glacier were calculated using the new velocity field and additional thickness data, which was then compared to two accumulation datasets to give mass balance estimates along the glacier at selected flux gates. The mass flux through the grounding line was found to be 1.2165 Gt a⁻¹, which needs to be balanced in a state of mass balance equilibrium by a mean annual snow accumulation of about 185 mm a⁻¹ water equivalent over the total catchment area determined with 6569 km². The mass balance at the grounding line is slightly negative, but the second flux gate is thought to be more representative of the mass balance, which is estimated to be 0.0441 Gt a⁻¹. Error analysis of the mass balance estimates found uncertainties in this data to be approximately 0.110 Gt a⁻¹. It is concluded from the analysis that further improvements in the overall mass balance estimate can be primarily obtained by a better knowledge of ice thickness and snow accumulation.

The Antarctic grounding zone has a disproportionately large effect on glacier dynamics and ice sheet stability relative to its size but remains poorly characterised across much of the continent. Accurate ice velocity and thickness information is needed in the grounding zone to determine glacier outflow and establish to what extent changing ocean and atmospheric conditions are affecting the mass balance of individual glacier catchments. This thesis describes new satellite remote sensing techniques for measuring ice velocity and ice thickness, validated using ground measurements collected on the Beardmore, Skelton and Darwin Glaciers and applied to other Transantarctic Mountain outlet glaciers to determine ice discharge. Outlet glaciers in the Transantarctic Mountains provide an important link between the East and West Antarctic Ice Sheets but remain inadequately studied. While long-term velocities in this region are shown here to be stable, instantaneous velocities are sensitive to stresses induced by ocean tides, with fluctuations of up to 50% of the mean observed in GPS measurements. The potential error induced in averaged satellite velocity measurements due to these effects is shown to be resolvable above background noise in the grounding zone but to decrease rapidly upstream. Using a new inverse finite-element modelling approach based on regularization of the elastic-plate bending equations, tidal flexure information from differential InSAR is used to calculate ice stiffness and infer thickness in the grounding zone. This technique is shown to be successful at reproducing the thickness distribution for the Beardmore Glacier, eliminating current issues in the calculation of thickness from freeboard close to the grounding line where ice is not in hydrostatic equilibrium. Modelled thickness agrees to within 10% of ground penetrating radar measurements. Calibrated freeboard measurements and tide-free velocities in the grounding zones of glaciers in the western Ross Sea are used to calculate grounding zone basal melt rates, with values between 1.4 and 11.8 m/a⁻¹ in this region. While strongly dependent on grounding line ice thickness and velocity, melt rates show no latitudinal trend between glaciers, although detailed error analysis highlights the need for much improved estimates of firn density distribution in regions of variable accumulation such as the Transantarctic Mountains.

This is a study of social and legal change among the Kuria people of Tanzania. It examines the transformation of the Kuria ideas and practices concerning marriage, children and property rights. The study covers a period following the colonial rule in Tanzania beginning about the turn of this century to the present. The aim of the study is to show the relationship between the integration of the Kuria economy into a world economic system and the transformation of extant social relations. Although we recognise that social change is an unceasing process in any society, this study argues that forces associated with capitalist penetration accelerated this process. Thus, for example, the authority and power of the elders who had for many generations dominated the Kuria society was undermined. There was radical transformation of kinship and property relations and elders were no longer influential in matters relating to production. There was progressive individualisation of property rights as sUbsistence production was transformed to serve the needs of the capitalist sector. The role of the law and state is also discussed. We argue that both the colonial and the post-colonial states were instrumental in this process of change even if some of their policies appear to have been aimed at conserving certain forms of traditional relations. Within this context of change the responses of the Kuria people to economic change is examined. The study argues that rather than being passive objects of capitalist penetration the Kuria tried to influence events even though their options were highly circumscribed. For the elders change represented an opportunity to utilise their traditional positions to secure resources from the non-traditional economic sector while for the younger generation and the women, change· opened up the means for them to extricate themselves from relations of subordination.

Salmonella is one of the most important enteropathogenic bacteria. It is responsible for about 5000 reported cases of human gastroenteritis each year in Sweden. Salmonellosis is a zoonotic disease, and the bacterium has the ability to infect a variety of both domestic and wild animal species. In studies of Swedish wild bird populations, we found that Black-headed gull may be the main reservoir for Salmonella in birds, and that Salmonella infection is expressed as carriage with no obvious disease manifestations. Black-headed gull is a migratory bird and can transport strains of Salmonella with virulence traits like antibiotic resistance, from sources outside Sweden. Genetic molecular methods, PFGE and IS200, also demonstrate that Black-headed gull play a role in the transmission chain of Salmonella in Sweden. In a study of the Swedish Peregrine Falcon population, Salmonella amager and Campylobacter jejuni were found. There were indications, based on serotyping of Salmonella and genetical typing by PFGE of Campylobacter that these isolates were transmitsted to the falcons from a human or domestic animal source. This bird of prey has sparse contact with humans but may be infected by Salmonella of human origin by feeding on other birds, like gull. Salmonella was found in penguins, albatrosses and mainly in seals in a study in Antarctica. Several features of the Salmonella serotypes found indicate a human source for Salmonella infection in these animals, and also a spread of Salmonella within and between animal species in Antarctica. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 2002</p> / digitalisering@umu

This thesis is concerned with the lived experience of placemaking in Argentina’s Antarctic gateway port Ushuaia. Based on 12 months ethnographic fieldwork, it explores the relations between tourism, urban development, and socio-economic difference. As such, it investigates how agents from across the social spectrum conceive of, and construct their sense of place “at the end of the world”. As the world’s southernmost city, Ushuaia is attractive to tourists for its stunning landscapes, unique location, and strategic proximity to Antarctica. However, the image of a friendly tourist destination crucial to everyday life in this Patagonian city is contested by its stakeholders. This thesis looks beyond the image presented to tourists to explore frictions among residents, the city council, and touristic enterprises. Ushuaia is revealed as an urban location beset by growing unrest due to issues of population growth and social polarization. This is analyzed in relation to its geopolitical significance for the Argentine state, territorial struggles with Chile, and economic incentives for in-migration. Consequently, this thesis considers the dynamic and shifting character of the city’s population through an engagement with economic and lifestyle migrants, including those dwelling in non-legal settlements, and tourists who occupy Ushuaian space alongside more longstanding citizens. The thesis demonstrates how conflicting views collide regarding issues of urbanization, industrialization, tourism, and environmental conservation, analyzed in relation to the interests and concerns of different social constituencies. Through extensive interviewing with a diverse array of social actors, this thesis also explores the different levels of economic and socio-cultural attachment to Antarctica, suggesting a schism between Ushuaia’s touristic representation, Antarctic alignment, and the needs and interests of its inhabitants. This thesis, then, explains the diverging place-based ideas and aspirations of different social groups in relation to the governmental, socio-economic, and socio-cultural forces implicated in placemaking.

The thesis analyses the expedition (TAE) led by Dr.Vivian Fuchs and Sir Edmund Hillary from three vantage points: 1)the years from 1948 to 1955 leading up to the expedition 2) the interaction between the IGY and the TAE projects and 3) the role of the US Navy as the expedition unfolded. The thesis also investigates key events including the purchase of the ship Endeavour from Britain, the competition for leadership of the UK and NZ parties, the 'dash to the Pole' by Hillary, and the search for base sites and routes to the Polar Plateau. The thesis contains an overview historical introduction, a comprehensive literature review as well as a broad-based set of conclusions.

<p>High-resolution bio-logging tools were used to examine the fine-scale foraging behaviors of humpback whales (Megaptera novaeangliae) in the coastal waters of the Western Antarctic Peninsula during the austral autumn of 2009 and 2010. Discrete feeding events (i.e., lunges) were inferred from the biologging records of thirteen whales, including a mother and her calf. In general, humpback whales exhibited efficient foraging behaviors that allowed them to maximize energetic gains and minimize energetic costs as predicted by optimal foraging theory. They fed at a continuous and high rate in the upper portion of the water column (< 100 m) from approximately dusk to dawn when their prey (Antarctic krill, Euphausia superba) were most vulnerable and less costly to acquire (i.e., near the surface). When forced to dive to greater depths, they adjusted their behaviors (e.g., descent and ascent rates) so that they could maximize their foraging durations and increase their lunging rates. In addition, humpbacks appeared to accept short term (i.e., dive by dive) costs associated with depleted oxygen stores in favor of maximizing long term (i.e., daily) energetic gains. Such efficient behaviors are particularly beneficial for mother-calf pairs who have additional energetic costs associated with foraging, such as lactation (mother), growth (calf), and maintaining proximity. In addition, because the physiology of humpback whales is poorly understood yet critically important for predicting their behaviors in response to fluctuations in their environmental conditions, foraging behaviors inferred from the bio-logging records were used to estimate their metabolic rates, oxygen storage capacities, and oxygen replenishment rates under the framework of optimal foraging theory. This research suggests that the current techniques used to estimate humpback whale oxygen stores is appropriate but that the estimation of metabolic rates of humpbacks while foraging and while traveling need to be addressed further. This work aims to increase the current understanding of humpback whale foraging behaviors along the Western Antarctic Peninsula so that appropriate measures can be taken to aid in their recovery and in the sustainability of the Antarctic marine ecosystem.</p> / Dissertation

A metagenomic gene library prepared from soil found beneath a mummified seal carcass in the Miers Valley, Antarctica, suggests an environment rich in uncharacterised biodiversity including enzymes with possible application to industrial processes. A sequence based gene mining investigation was performed on a clone, which archives a metagenomic sequence from this environment. The sequence was annotated using de novo bioinformatics and molecular biology techniques. A predicted NAD+-dependent DNA ligase, ligDB1 was selected for further characterisation. LigDB1 encodes a gene product that contains all the sequence features of a functional ligase. The protein was overexpressed in a heterologous E. coli host and purified to homogeneity. LigDB1 did not exhibit nick sealing activity, but was able to perform AMP-dependent DNA relaxation in the presence of high concentrations of enzyme. DNA modifying enzymes from cold environments perform optimally at low temperatures and may be of use as molecular tools in biotechnology. Complete characterisation of this enzyme is subject to further investigations. / Magister Scientiae - MSc