An integrated analysis of sediment geochemistry and flood history of floodplain lakes in the Athabasca Region

This research advances understanding of trace metal deposition in floodplain lakes within the context of the Athabasca oil sands. This thesis begins with an evaluation of geomorphometric changes and flood history in two floodplain lakes of the Athabasca region over the past century. Analyses of historical aerial photographs, weather data, and hydrometric data present a temporal perspective on changes occurring to the floodplain lake environment. These results show that, despite no corresponding climatic shifts or changes to flood frequency, there appears to have been an increase in the area of both Shipyard Lake and Isadore’s Lake, though their position with respect to the Athabasca River remains unchanged. Building on the exploration of floodplain lake geomorphometry, this thesis then presents an analysis of metals in three lakes in the Athabasca region as related to the early development and continuing expansion of the nearby oil sands mining operations. Physical and chemical characteristics of sediment cores, and the concentration of environmentally relevant metals, linked to the timing of development of oil sands mining operations by Pb-210 dating, present an evaluation of temporal changes in the sediment of lake NE20. Due to dynamic depositional environments in Isadore’s Lake and Shipyard Lake, no accurate age model could be constructed. Results show that, despite an initial increase in the normalized metal concentrations of As, Ni, and V in each of the lakes following the onset of oil sands mining operations, there appears to be no recent enrichment of trace metals corresponding to the continuing expansion of operations. Results also indicate that disturbances to sedimentation in floodplain lakes, most likely associated with flooding, are an important factor affecting changes in metal deposition. Overall, this research contributes to the following aspects of our understanding of trace metal content in lake sediments of the Athabasca Region by: i) elucidating trends in sediment quality within floodplain lakes adjacent to oil sands mining operations; ii) investigating methods of normalizing different fractions of metal concentration data to increase understanding of metal transportation and deposition; and iii) assessing the effect disturbances to sedimentation can have on the concentration of metals in lake environments

Growth and form of the mound in Gale Crater, Mars: Slope wind enhanced erosion and transport

Ancient sediments provide archives of climate and habitability on Mars. Gale Crater, the landing site for the Mars Science Laboratory (MSL), hosts a 5-km-high sedimentary mound (Mount Sharp/Aeolis Mons). Hypotheses for mound formation include evaporitic, lacustrine, fluviodeltaic, and aeolian processes, but the origin and original extent of Gale’s mound is unknown. Here we show new measurements of sedimentary strata within the mound that indicate ∼3° outward dips oriented radially away from the mound center, inconsistent with the first three hypotheses. Moreover, although mounds are widely considered to be erosional remnants of a once crater-filling unit, we find that the Gale mound’s current form is close to its maximal extent. Instead we propose that the mound’s structure, stratigraphy, and current shape can be explained by growth in place near the center of the crater mediated by wind-topography feedbacks. Our model shows how sediment can initially accrete near the crater center far from crater-wall katabatic winds, until the increasing relief of the resulting mound generates mound-flank slope winds strong enough to erode the mound. The slope wind enhanced erosion and transport (SWEET) hypothesis indicates mound formation dominantly by aeolian deposition with limited organic carbon preservation potential, and a relatively limited role for lacustrine and fluvial activity. Morphodynamic feedbacks between wind and topography are widely applicable to a range of sedimentary and ice mounds across the Martian surface, and possibly other planets

The Lonely Reason Impeding Compliance with COVID-19 Prevention Guidelines

To reduce transmission of the 2019 coronavirus (COVID-19), the US Center for Disease Control recommends that all individuals follow a series of prevention guidelines (e.g., wearing a mask, physical distancing, and vigilant handwashing). However, some individuals have been unwilling to comply with them. In this research, we use reciprocal altruism theory to investigate the role of loneliness in compliance with COVID-19 prevention guidelines. Specifically, we find that lonely (vs. non-lonely) consumers report less willingness to comply with these guidelines. Process evidence demonstrates that this occurs because lonely individuals experience a lower sense of obligation to reciprocate. Importantly, the negative impact of loneliness on compliance with COVID-19 prevention guidelines can be offset through advertising messaging strategies when information about COVID-19 is framed using an agentic (vs. communal) advertising messaging. Thus, marketers may want to consider the important role of loneliness when tailoring messaging appeals that encourage compliance with COVID-19 prevention guidelines

The Impact of Gender and Agentic-Communal Orientations on Consumer Skepticism about Corporate Social Responsibility

Companies are increasingly emphasizing corporate social responsibility (CSR). However, consumers are often skeptical of the sincerity of companies’ CSR claims, particularly when the claim comes directly from the company. This research examines how the gender and genderrelated characteristics of a company’s spokesperson can alleviate CSR skepticism. Study 1 finds that consumers are less skeptical of a company’s CSR claim when it is made by a female (vs. male) spokesperson. Study 2 expands on this by finding that female consumers are less skeptical of a company’s CSR efforts when they are promoted by a communal spokesperson. In contrast, male consumers are less skeptical of a company’s CSR efforts when they are promoted by an agentic spokesperson. These findings should guide companies and their brands in choosing ideal spokespeople for making CSR claims, depending on the target market

Anomalous ordering in inhomogeneously strained materials

We study a continuous quasi-two-dimensional order-disorder phase transition that occurs in a simple model of a material that is inhomogeneously strained due to the presence of dislocation lines. Performing Monte Carlo simulations of different system sizes and using finite size scaling, we measure critical exponents describing the transition of beta=0.18\pm0.02, gamma=1.0\pm0.1, and alpha=0.10\pm0.02. Comparable exponents have been reported in a variety of physical systems. These systems undergo a range of different types of phase transitions, including structural transitions, exciton percolation, and magnetic ordering. In particular, similar exponents have been found to describe the development of magnetic order at the onset of the pseudogap transition in high-temperature superconductors. Their common universal critical exponents suggest that the essential physics of the transition in all of these physical systems is the same as in our model. We argue that the nature of the transition in our model is related to surface transitions, although our model has no free surface.Comment: 5 pages, 3 figure

Percutaneous elastic intramedullary nailing of metacarpal fractures: Surgical technique and clinical results study

<p>Abstract</p> <p>Background</p> <p>We reviewed our results and complications of using a pre-bent 1.6 mm Kirschner wire (K-wire) for extra-articular metacarpal fractures. The surgical procedure was indicated for angulation at the fracture site in a true lateral radiograph of at least 30 degrees and/or in the presence of a rotatory deformity.</p> <p>Methods</p> <p>A single K-wire is pre-bent in a lazy-S fashion with a sharp bend at approximately 5 millimeters and a longer smooth curve bent in the opposite direction. An initial entry point is made at the base of the metacarpal using a 2.5 mm drill by hand. The K-wire is inserted blunt end first in an antegrade manner and the fracture reduced as the wire is passed across the fracture site. With the wire acting as three-point fixation, early mobilisation is commenced at the metacarpo-phalangeal joint in a Futuro hand splint.</p> <p>The wire is usually removed with pliers post-operatively at four weeks in the fracture clinic.</p> <p>Results</p> <p>We studied internal fixation of 18 little finger and 2 ring finger metacarpal fractures from November 2007 to August 2009. The average age of the cohort was 25 years with 3 women and 17 men. The predominant mechanism was a punch injury with 5 diaphyseal and 15 metacarpal neck fractures. The time to surgical intervention was a mean 13 days (range 4 to 28 days). All fractures proceeded to bony union. The wire was extracted at an average of 4.4 weeks (range three to six weeks). At an average follow up of 8 weeks, one fracture had to be revised for failed fixation and three superficial wound infections needed antibiotic treatment.</p> <p>Conclusions</p> <p>With this simple and minimally invasive technique performed as day-case surgery, all patients were able to start mobilisation immediately. The general outcome was good hand function with few complications.</p

The future of citizen science: emerging technologies and shifting paradigms

Citizen science creates a nexus between science and education that, when coupled with emerging technologies, expands the frontiers of ecological research and public engagement. Using representative technologies and other examples, we examine the future of citizen science in terms of its research processes, program and participant cultures, and scientific communities. Future citizen‐science projects will likely be influenced by sociocultural issues related to new technologies and will continue to face practical programmatic challenges. We foresee networked, open science and the use of online computer/video gaming as important tools to engage non‐traditional audiences, and offer recommendations to help prepare project managers for impending challenges. A more formalized citizen‐science enterprise, complete with networked organizations, associations, journals, and cyberinfrastructure, will advance scientific research, including ecology, and further public education

The future of citizen science: emerging technologies and shifting paradigms

Citizen science creates a nexus between science and education that, when coupled with emerging technologies, expands the frontiers of ecological research and public engagement. Using representative technologies and other examples, we examine the future of citizen science in terms of its research processes, program and participant cultures, and scientific communities. Future citizen‐science projects will likely be influenced by sociocultural issues related to new technologies and will continue to face practical programmatic challenges. We foresee networked, open science and the use of online computer/video gaming as important tools to engage non‐traditional audiences, and offer recommendations to help prepare project managers for impending challenges. A more formalized citizen‐science enterprise, complete with networked organizations, associations, journals, and cyberinfrastructure, will advance scientific research, including ecology, and further public education