The role of mechanical forces in cardiomyocyte differentiation in 3D culture

Heart disease is the leading cause of death in many developing and industrialized countries. The loss of cardiomyocyte (CM) proliferation in the post-natal myocardium is the major barrier to myocardial regeneration, which leads to a loss of functional myocytes and thus contractile function after injury. While significant advances in cardiac tissue engineering as an alternative strategy for treatment have been made in the recent years, the application for repair of the injured myocardium remains to be realized. However, tissue engineering as an in vitro model system for characterizing functional properties of cardiac tissue can be used as a powerful tool now. The overall goal of this doctoral thesis was to determine the role of mechanical strain on CM differentiation within a 3D engineered tissue to use as a system for evaluation of strategies for enhancing directed CM differentiation and tissue contractile properties. Substantial progress towards this goal was made by a combination of testing new strategies for monitoring differential CM differentiation and contractile function, such as using MDSCs in a 3D collagen gel bioreactor to induce CM differentiation and applying mechanical strain to determine the responsive cell type, and by developing new tools and methods for characterizing CM differentiation and cell morphology changes. Our in vitro engineered cardiac tissue from fetal/developing native cardiac cells maintained CM proliferative activity and contractile properties similar to the native myocardium which increased in response to mechanical stretch. The implanted graft maintained CM proliferative activity in vivo, survived as a donor myocardial tissue, and contributed to the cardiac functional recovery of injured myocardium better than a graft with post-natal cardiac cells. Skeletal muscle derived stem cell (MDSC) aggregate formation and 3D collagen gel bioreactor (3DGB) culture (MDSC-3DGB) triggered differentiation of cells with an immature functioning CM phenotype in vitro. In addition, mechanical strain directed cell morphology changes were significant factors in directing CM differentiation from MDSCs within MDSC-3DGB. In conclusion, our 3D collagen gel bioreactor culture, with capabilities for spatial and temporal monitoring, represents a powerful model for elucidating the role of specific environmental factors and their underlying mechanisms on directed cell proliferation and differentiation

The Path To The Sea: Leatherback Hatchling Orientation at Sandy Point National Wildlife Refuge

Once sea turtle hatchlings emerge from their nest, they must find their way to the ocean by using cues such as a bright horizon and the slope of the beach. While moving toward the water, hatchlings often must navigate past predators and through vegetation, sticks, footprints in the sand, and other dangers such as ghost crab holes. Sometimes hatchlings become confused (or disoriented) and turn in circles to find the right route to the water. Sea turtle hatchlings also may become disoriented as a result of human impacts such as town lights or trash. The purpose of our experiment was to evaluate the path hatchlings took from the nest to the water and to record if they became disoriented because of human impacts. We took 10 leatherback hatchlings each from 11 nests that naturally emerged at Sandy Point National Wildlife Refuge (St. Croix, USVI) and released them from their nest location between 14 July and 27 July 2014. We recorded the time it took for each of them to reach the high tide line, compass direction of their travel, distance from the nest to the water, distance and compass direction of the most direct route to the water, time of the experiment, and weather conditions. Our results show that the majority of hatchlings were not drawn toward town lights or disoriented by trash. In conclusion, town lights and trash are not a major concern at Sandy Point except on nights when there is a lot of sky glow from town

Co-creative media: theorising digital storytelling as a platform for researching and developing participatory culture

This paper considers the question, 'what is co-creative media, and why is it a useful idea in social media research'? The term 'co-creative media' is now used by Creative Industries researchers at QUT to theoretically frame their use of digital storytelling as an action research platform for investigating participatory new media culture. Digital storytelling is a set of collaborative digital media production techniques that have been used to facilitate social participation in numerous Australian and international contexts. Digital storytelling has been adapted by Creative Industries researchers at QUT as a platform for researching the potential of vernacular creativity in a variety of contexts, including social inclusion of marginalized and disadvantaged groups; inclusion in public histories of narratives that might be overlooked; and articulation of voices that otherwise remain silent in the formulation of social and economic development strategies. The adaption of digital storytelling to different contexts has been shaped by the reflexive, recursive, and pragmatic requirements of action research. Amongst other things, this activity draws attention to the agency of researchers in facilitating these kinds of participatory media processes and outcomes. This discussion serves to problematise concepts of participatory media by introducing the term 'co-creative media' and differentiating these from other social media production practices

AN ANALYSIS OF THE FEASIBILITY AND ENVIRONMENTAL IMPACT OF INCORPORATING CLEAN ENERGY INTO AN ISLANDED MICROGRID IN SIERRA LEONE

Clarity Project is a fine jewelry company and social enterprise that recently began mining diamonds in Sierra Leone as part of its mission to improve the quality of life of artisanal miners in West African communities. This has presented a new challenge to the company: the site of Clarity Project’s new mining compound is distant from the country’s modest electric grid, leaving Clarity Project to procure its own electric power. The purpose of this project is to determine Clarity Project’s electricity needs, analyze its alternatives for meeting those needs, and evaluate the costs and environmental impacts of those alternatives. Using data obtained on site in Sierra Leone and meteorological data from NASA, we developed a model that predicts the load profile of the mining compound, forecasts the expected amount and temporal availability of electricity from photovoltaic arrays on site, and projects the use of diesel generators and battery storage to supplement the solar power. The model then calculates the present value of the capital and operating expenses for the microgrid as well as the carbon dioxide emissions associated with generating electricity for the compound. Our analysis has determined that (1) the least expensive option, based on capital expenses and operating expenses discounted to present value, would be to rely solely on diesel generators; (2) the cost of relying solely on renewable energy during Sierra Leone’s dry season would be approximately double the all-diesel option over a five-year time horizon and about 60 percent greater over a 25-year time horizon (and the availability of renewable energy falls significantly during the rainy season); and (3) incorporating solar power and battery storage, while more expensive, would allow Clarity Project to avoid emitting nearly 20 metric tonnes of carbon dioxide per year

Forging Relationships and Filling Repositories

Poster presentation for 2018 United States Agricultural Information Network (USAIN) 16th Biennial Conference at Washington State UniversityPoster presentation for 2018 United States Agricultural Information Network (USAIN) 16th Biennial Conference at Washington State Universit

Synthetic (p)ppGpp analogue is an inhibitor of stringent response in mycobacteria

Bacteria elicit an adaptive response against hostile conditions such as starvation and other kinds of stresses. Their ability to survive such conditions depends, in part, on stringent response pathways. (p)ppGpp, considered to be the master regulator of the stringent response, is a novel target for inhibiting the survival of bacteria. In mycobacteria, the (p)ppGpp synthetase activity of bifunctional Rel is critical for stress response and persistence inside a host. Our aim was to design an inhibitor of (p)ppGpp synthesis, monitor its efficiency using enzyme kinetics, and assess its phenotypic effects in mycobacteria. As such, new sets of inhibitors targeting (p)ppGpp synthesis were synthesized and characterized by mass spectrometry and nuclear magnetic resonance spectroscopy. We observed significant inhibition of (p)ppGpp synthesis by Rel(Msm) in the presence of designed inhibitors in a dose-dependent manner, which we further confirmed by monitoring the enzyme kinetics. The Rel enzyme inhibitor binding kinetics were investigated by isothermal titration calorimetry. Subsequently, the effects of the compounds on long-term persistence, biofilm formation, and biofilm disruption were assayed in Mycobacterium smegmatis, where inhibition in each case was observed. In vivo, (p)ppGpp levels were found to be downregulated in M. smegmatis treated with the synthetic inhibitors. The compounds reported here also inhibited biofilm formation by the pathogen Mycobacterium tuberculosis. The compounds were tested for toxicity by using an MTT assay with H460 cells and a hemolysis assay with human red blood cells, for which they were found to be nontoxic. The permeability of compounds across the cell membrane of human lung epithelial cells was also confirmed by mass spectrometry

Fostering PT-PTA Student Relationships, Pilot Study

Purpose: The purpose of this study was to assess physical therapist (PT) and physical therapist assistant (PTA) students\u27 attitudes toward working in a team, direction and supervision, preparation for effective communication, and respect for and the value of physical therapist/physical therapist assistant (PT/PTA) teams following an interactive classroom session via a brief online questionnaire. Methods: PT students in the second year of their doctor of physical therapy graduate studies in St Louis, MO and PTA students in the second year of their associate’s degree program in St Louis, MO were involved. A questionnaire was completed prior to and after attending an interactive classroom session. The interactive session included four stations; curriculum and education, communication and documentation, PT/PTA teamwork scenarios in different practice settings, and social interaction. The questionnaire consisted of six questions asking students to indicate their level of agreement or disagreement. Results: Attendance status at the interactive session was related to student responses on the questionnaire for both PT and PTA students. Among PTA students, responses on three of six questionnaire items were found not to be independent of attendance status. PTA students indicated they felt more prepared for PT/PTA communication, had more respect for the similarities in roles of PTs and PTAs, and felt more strongly that effective PT/PTA teams were essential to optimal patient care. Among the PT student population, the only questionnaire item found to be independent of interactive session attendance status was the belief in effective PT/PTA teams. Generally, students’ responses tended to be more positive after attending the interactive session, with “Strongly agree” responses increasing by as much as 24 percent on some questionnaire items. Increases in weighted means for PTA students were not found to be statistically significant; however, among PT students these increases were significant across three questionnaire items. Conclusions: The findings suggest that both PT and PTA students experienced increased comfort with the idea of working as part of a PT/PTA team after the interactive event where communication was the focus. The affective behavior of “comfort” in working as part of a PT/PTA team increased in our study among both PT and PTA students. The interactive session was easy to implement and had no cost associated with it. Follow-up study or methodologies could provide more robust results to further support these findings. This activity could also be replicated across healthcare professions that utilize professional and paraprofessional assistant relationships