Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 15 of 15 for “"mcmurdo dry valleys"”.
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Lacustrine biogeochemistry of the McMurdo Dry Valleys, Antarctica.
Lacustrine biogeochemistry of the McMurdo Dry Valleys, Antarctica.
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Microbial Mat Abundance and Activity in the McMurdo Dry Valleys, Antarctica
… suited to remote environments, such as in the McMurdo Dry Valleys (MDV) of Antarctica, where cyanobacterial communities are the main drivers of primary production. These microbial communities form multi-layered sheets (i.e., microbial mats) on top of desert pavement. The cryptic nature of these …
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The impacts of thermokarst activity on a stream in the McMurdo Dry Valleys
The McMurdo Dry Valleys (MDV) of Antarctica are a unique ice-free landscape that is host to vibrant ecosystems despite the harsh environment (<10 cm water equivalent/yr, -20°C mean air temperature). Aquatic ecosystems in the MDV are dependent on the ephemeral glacial runoff streams which feed the …
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Controls over the distribution of soil micro-invertebrates in the McMurdo Dry Valleys, Antarctica
The McMurdo Dry Valleys of Antarctica are a cold desert ecosystem where soil micro-invertebrate communities are shaped by extreme abiotic conditions, particularly low soil moisture, organic carbon availability, and high salinity. In this thesis I combine long-term ecological data with spatial …
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Resolving functional resilience of microbial communities to climate-induced change in the McMurdo Dry Valleys of Antarctica
The McMurdo Dry Valleys of Antarctica are an abiotically driven ecosystem characterized by having a very simple trophic structure dominated by microbial communities, whose diversity is shaped by extreme abiotic gradients, particularly extreme aridity and oligotrophy. Regional isolation and …
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Multi-scale Studies of Microbial Mats and Biocrusts: Integrating Remote Sensing with Field Investigations in Antarctica's McMurdo Dry Valleys
… cohesion and stability to soil surfaces. In the McMurdo Dry Valleys of Antarctica, microbial mats are the main source of fixed carbon in lentic and lotic environments, but their contribution to soil carbon and nitrogen cycling has not been systematically examined. In my dissertation, I …
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Influence of landscape-variation in geochemistry on taxonomic and functional composition of microbial mat communities in the McMurdo Dry Valleys, Antarctica
… mat and underlying soil communities in the McMurdo Dry Valleys of Antarctica across a gradient of phosphorus availability on glacial tills of distinct age and mineral composition in Taylor Valley, Antarctica. Microbial mat and soil DNA were extracted and sequenced on an Illumina NextSeq500 …
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Screening for novel cold-adapted nitrile hydratases in Antarctic metagenornic libraries
… libraries constructed from soil taken from the McMurdo Dry Valleys in Antarctica were used for both functional and sequence based screens of NHases. Functional screens that were trialled were based on pH change and oligotrophic selective growth.
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Human impact on the McMurdo Dry Valley soils of Antarctica: Extending the limits of DNA detection
… out an evidence-based risk assessment of the McMurdo Dry Valley ecosystem (DryVER project), this research quantified human impact, in the form of DNA released from humans and human-associated microbiota, across spatial and temporal scales. This project was part of the MBIE grant entitled …
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Environmental controls on the distribution of bacterial membrane lipids
… Chile and in two ice-covered lakes of the McMurdo Dry Valleys, Antarctica. The results will enhance our ability to interpret the molecular fossil record, particularly those biomarkers that might preserve evidence of ancient marine and glacial environments. I will provide evidence that …
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Constraining the pathways and fluxes of subglacial meltwater beneath the palaeo-Antarctic Ice Sheet
… system of channels known as the Labyrinth in the McMurdo Dry Valleys whose genesis has been attributed to catastrophic outburst floods, sourced from subglacial lakes during the Miocene. A similar process origin is proposed for the channels observed on the Antarctic continental shelf, formed …
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Repair eXtreme - DNA repair proteins from Antarctic extremophiles
The McMurdo Dry valleys (DV) in Antarctica are one of the harshest environments on Earth, with high levels of UV radiation, freeze-thaw cycles, low moisture, and nutrient content. Bacteria in this extreme environment have adapted to slow growth and low-nutrient conditions. It is proposed that …
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Environmental Controls Over the Distribution and Function of Antarctic Soil Microbial Communities
… performed in the polar desert of Antarctica's McMurdo Dry Valleys, a model ecosystem which hosts microbially-dominated soil foodwebs and displays heterogeneously distributed soil properties across the landscape. Results for Chapter 2 indicate differential effects of resource availability and …
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The resilience of Polar Collembola to climate change
… largest ice-free area in continental Antarctica, McMurdo Dry Valleys. I tested whether the genetic variation found between coastal and inland individuals of G. hodgsoni corresponded with differences in physiological tolerances of hot and cold temperatures was tested. Individuals from the …
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Landscape history and contemporary environmental drivers of microbial community structure and function
… Within each till unit, I sampled from dry areas and areas with visible evidence of recent surface water movement generated by seasonal melting of ephemeral snow packs and hillslope ground ice. Using T-RFLP 16S rRNA gene profiles of microbial communities, I analyzed the contribution of …