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Do Themes Improve Visitor Outcomes in Interpretive Programs?
Get PDFThematic interpretation is widely promoted as being integral to an effective interpretive program. Some studies have suggested that thematic interpretation may enhance visitor outcomes; however, park visitor demographics have changed over the last decade, and others have suggested alternative approaches. In this study, we systematically observed live interpretive programs at 330 programs at 52 National Parks across the United States, monitored the extent and characteristics of theme usage, and collected visitor surveys immediately following each program. We used these data to determine the influence of the presence and characteristics of themes and theme questions on visitor outcomes. The results suggest that programs with a theme enhanced perceptions of quality, appreciation, personal and societal relevance, stewardship intentions, respect for others, and interpersonal relationships. The results also suggest that themes with higher levels of integration, connection to universal concepts, and meaning-making improved visitor outcomes. These results have significant implications for theory and practice
Association Between Gene Family Expansion and the Rapid Diversification of Pleurocarpous Mosses
Get PDFMosses are the second most species-rich group of land plants. They represent a critical group for understanding the evolution and diversity of land plants. Mosses comprise two major groups, acrocarps and pleurocarps. Despite having a more recent evolutionary origin than acrocarps, pleurocarps are exceptionally diverse. The difference in species richness reflects a rapid species diversification, roughly coincident with the origin and diversification of flowering plants. The speciation events giving rise to pleurocarp diversity happened so rapidly, making it historically difficult to produce strongly supported phylogenies with which to test evolutionary hypotheses. One such hypothesis is whether large-scale changes at the genome level contributed to the rapid diversification of pleurocarps. Genome duplication has been implicated in the origin and speciation of other plant groups. To identify whether whole genome duplication (WGD) events coincided with the species diversification of pleurocarps, we used transcriptomes to reconstruct the number of individual gene duplication events in the inferred ancestor of pleurocarps and determined whether these duplicated genes were biased towards specific functions. We built a species tree including 14 acrocarps and 64 pleurocarps upon which gene duplications and losses inferred from gene trees were placed. We found that the rapid speciation of pleurocarpous mosses may not have been the direct result of a WGD event but rather smaller gene duplication events over time. The results reveal some candidate genes and associated pathways coincident with the transition from acrocarps to pleurocarps, suggesting that WGD was not instrumental in the evolution of pleurocarps
Cultivation of Botryococcus Braunii for the Production of Hydrocarbons Suitable for Fuel Use
Get PDFEnergy security, rural poverty, and climate change are pressing issues of our time. Biofuels provide a solution to these issues, with a focus on sustainable aviation fuel, SAF, due to compatibility with aircraft infrastructure and energy density. This research aims to review and produce knowledge about a specific microalga, Botryococcus braunii, for its potential for SAF. First a literature review on the process was conducted followed by an experimental study on the impact of aqueous media and inorganic carbon its growth and hydrocarbon content. The literature review found the process consists of cultivation followed by lipid extraction or hydrothermal liquefaction followed by catalytic upgrading to SAF. Certain bifunctional transition metal catalysts with clay supports may be best for production of SAF from B. braunii. Gaps with this pathway may be specific to kinetic parameters and specific design of reactors optimized for production. Current research should be dedicated to mechanisms of conversion of B. braunii to SAF with respect to reactor design, harvesting, lipid extraction, feasibility, cost, and implementation of policy along with other pathways to ensure avoidance of emissions and depletion of resources.
The Showa strain of Botyrococcus braunii was cultivated in batch conditions with artificial lighting in modified versions of BG-11 and MChu13 media. BG-11 medium contains approximately 10 times the nitrogen concentration of MChu13 medium and has 2.3 mg/L added inorganic carbon while MChu13 has none. In the first experiment, the specific growth rates for cultivation in BG-11 LN, BG-11, MChu13, and MChu13-HN were 0.30, 0.23, 0.56, and 0.78 d-1 respectively during exponential growth. In the second experiment an agar isolate derived culture was used as a seed for cultivation in MChu13-HN media with varying inorganic carbon levels supplied as NaHCO3, at 0, 10, 20, and 40 times the inorganic carbon level specified in BG-11 media which are 0, 22.7, 45.4, and 90.7 mg C/L. This cultivation was carried out for 21 days and found 2 subsequent exponential phases, with the first fitting Monod model with inorganic carbon by nonlinear regression in JMP, with a maximum specific growth rate, µmax of 1.09 d-1 (with a standard error of 0.30 d-1), and a half-saturation constant, Ks, of 38.7 mg C/L (with a standard error of 27.3 mg C/L). Squalene content was found to range from 1.9% for the 20XC treatment to 10.6% for the 10XC treatment
Impact of Cysteine and Tyrosine Dipeptides on CHO Cell Performance in a Perfusion Mimic
Get PDFPerfusion cell cultures typically achieve higher cell densities and generate higher volumetric productivities than fed-batch cultures due to continuous nutrient supply and spent media removal. Despite these advantages, perfusion cell cultures remain underutilized for licensed product manufacturing, primarily due to the lack of small-scale perfusion models for high-throughput process development and the complexities involved in media formulation capable of supporting high cell densities during long-term continuous operation. To avoid nutrient limitation at high cell densities, current perfusion processes rely on using higher perfusion rates, which results in significant media wastage and downstream product dilution. Therefore, there has been an effort to formulate perfusion media by enriching amino acids that can meet the nutrient demands at lower perfusion rates to lower overall media consumption while generating higher volumetric productivity. However, critical amino acids, such as cysteine and tyrosine, that are important for cellular redox homeostasis, metabolism, and biomass synthesis in CHO cultures, cannot be concentrated in liquid media at neutral pH due to poor solubility. To address these challenges, this project focused on developing a small-scale perfusion mimic for high-throughput process development and enriching essential amino acids in perfusion media, with particular emphasis on evaluating cysteine- and tyrosine-containing dipeptides to overcome solubility limitations. This enrichment strategy aimed to enhance cellular glucose uptake and increase productivity by alleviating amino acid v bottlenecks in CHO cell cultures. A 50 mL spin tube perfusion mimic was developed by optimizing working volume and bleed strategy. The system maintained a steady-state culture at ~19 million cells/mL for 13 days, with an average bleed rate of ~0.33 d⁻¹ with a working volume of 7.5 mL. Amino acid analysis during steady-state operation revealed ten amino acids (Asn, Cys, Val, Ser, Leu, His, Tyr, Phe, Met, and Trp) depleted to limiting levels. An enriched perfusion medium was formulated by increasing the concentrations of these amino acids. Cysteine and tyrosine, which could not be supplemented directly due to poor solubility, were instead delivered using dipeptide variants. Alanyl-cystine (AC) and lysyl-cystine (KC) were used as cysteine sources, while alanyl-tyrosine (AY) and glycyl-tyrosine (GY) were evaluated for tyrosine. Dipeptides were supplemented in combinations (AC–AY, AC–GY, KC–AY, and KC– GY) to identify optimal pairing. The effects of limiting amino acid enrichment and dipeptide supplementation were assessed using the spin tube model. Overall, amino acid enrichment significantly improved glucose uptake, titer, and cell productivity; however, no major differences were observed between the dipeptide combinations and the control without dipeptides. In conclusion, this study advances the understanding of nutrient limitations in CHO perfusion cultures and presents a systematic approach for media optimization through targeted amino acid enrichment and dipeptide supplementation. Additionally, the establishment of a small-scale perfusion model offers a cost-effective platform for accelerating media development through high-throughput screening studies
Decision Field Theory for Human-Multi-robot Collaboration: Human-centric decision-making for multi-robot systems
Get PDFAt first glance, choosing between an apple and an orange appears to be a straightforward matter of personal taste; however, this seemingly simple preference opens a window into the multifaceted world of decision-making, revealing the complex interplay of cognitive processes, psychological, and behavioral-economic principles that guide our choices \cite{bandyopadhyayRoleAffectDecision2013}. By unpacking these nuanced perspectives, we uncover insights that can drive more effective human-robot interaction and collaboration.
Modeling human cognition requires understanding the evolution of choice utility and the influence of emotions. Decision Field Theory (DFT) stands out by capturing the fluctuating nature in human preferences over time, explaining why choices are inconsistent under stress and/or uncertainty. This study leverages sequential-sampling to analyze human response and interaction, while machine learning technique is used to derive and optimize DFT parameters. This enables robots to adapt their decision-making process based on human-cognitive dynamics. Conversely, the approach also allows robots to better gauge human-risk attitude, fostering a more effective collaboration.
This thesis explores evolving decision-making theories shifting from traditional Expected Utility and Non-Expected Utility models toward frameworks that incorporate the influence of human emotions on judgment with respect to time. We review insights into their respective strengths and limitations. Machine learning framework grounded in cognitive science are designed and implemented to model user preferences, and situational judgment under uncertainty. The experiments validate the integration of trust, risk attitudes, and adaptive decision-making in human-robot interaction (HRI), demonstrating human-centric decision-making processes. Applications such as human-robot pairing in manufacturing warehouses and bounding overwatch scenarios illustrate how incorporating human-centric decision principles may potentially enhance situational awareness and operational flexibility in robots, fostering more intuitive collaboration
Restoring a Longleaf Pine Savanna in the Wiregrass Gap: Community Responses to Post-harvest Slash Manipulation
Get PDFNow reduced to just a fraction of their historical range, Longleaf pine savannas in the southeastern United States are home to a wide array of species, some of which are threatened or endemic. These characteristics have inspired widespread restoration initiatives in recent decades, accompanied by an expanding literature on how management techniques affect restoration outcomes. However, research is lacking in a unique region of longleaf pine’s range, where the dominant fire-carrying grasses are different: the Wiregrass Gap. This study investigated the effects of three different slash manipulation treatments on restoration outcomes of a Wiregrass Gap longleaf pine savanna. Specifically, we observed how understory vegetation and winter soil-dwelling invertebrates responded to slash mastication, slash removal, and conventional harvest treatments with time and prescribed fire. While our initial surveys of the understory community suggested mastication could have a suppressing effect on woody growth, vegetative communities across all treatments were equalized following prescribed fire. Additionally, no significant differences were observed in winter invertebrates communities between replicates, although observing each treatment as a whole paints a different picture. More research is needed to ensure these treatment-associated communities remain similar over time under continued management, but our study suggests land managers may see an equally robust restoration outcome regardless of slash manipulation technique
An Exploration of Elderly Representation & Stereotypes in Animation
Get PDFIn the world of animated features, supporting cast members are often reduced down to simple character traits in order to give the audience a simple idea of their personality or role in the story, or to support the creation of a work that is easier to understand for people of all ages. However, this can often result in the application of negative tropes that do not reflect kindly on those being depicted. The elderly are a group that often get caught in these stereotypes, being depicted as wrinkly, clumsy, overweight villains. While you can still find many positive portrayals in children’s media, studies show that these negative portrayals are often what kids remember the most. Drawing inspiration from elderly characters like Merlin (The Sword in the Stone) and Kamaji (Spirited Away), this thesis aims to analyze aged portrayals through the history of theater and animation, applying our findings to the character of Wilbur, a supporting cast member of the upcoming Digital Production Arts short film Kate Shelley and the Bridge of Darkness. Wilbur will be fully rigged and placed in an animated sequence, utilizing his character design as well as gathered research in order to present a character worthy of sympathy and respect, without any loss to his core as a source of comic relief
An inference approach for assessing place-based vulnerability to heat mortality
Get PDFA global increase in the frequency, severity, and scale of extreme heat raises concerns about human vulnerability to climate change and associated mortality. Heat vulnerability and mortality have largely been studied separately, lacking an understanding of their causation. Here, we create a non-parametric generalized inference approach that links socioeconomic, environmental, and infrastructure factors articulated in vulnerability theory and heat mortality between 2010 and 2020 for counties across the United States. We find that the lack of vegetation coverages drives mortality in the Southern U.S. and among Hispanic people. Limited air conditioning is a key factor in heat-related mortality among White people and the Northern U.S. A combination of poverty and education influences the heat mortality in the Southeastern U.S., while poverty is critical to the heat mortality of Black people. We also find that the effects of vegetation and air conditioning in reducing heat mortality have been on the rise in the past decade. However, socioeconomic factors, in particular poverty and education, remain the most influential constraints. To further explain this transition, a series of regression models is created. The results show that improving 1% in vegetation coverage or air conditioning installation rate can effectively complement the 1.16% negative effect of socioeconomic constraints on heat mortality. A 1% increase in vegetation area is found to be comparable to a 1.5% increase in air conditioning installation in terms of reducing heat-related mortality. Our findings bridge the gap between heat vulnerability theory and mortality, emphasizing the importance of location-based strategies and nature-based infrastructure in mitigating the health burden of extreme heat
Advancing Smart and Adaptive Living Spaces Through Design and Development of Reconfigurable Multifunctional Robot Rooms
No full textThis work explores and introduces prototype hardware for a new category of robots: ‘Robot Rooms’, in an effort to refine the concept of traditional smart spaces and human-robot interaction. Unlike traditional robots that tend to be compact and exist within a space, this new category of robots is designed to be expansive: they do not exist within a space but rather shape space around them. We present several design concepts for potential robotic elements of a Robot Room. We then develop and demonstrate, at full scale, a new and novel concept: a ‘slice’ of a Robot Room. This slice changes between an open space and various configurations identified as important to human activities in the home. It does so by creating chairs, a table, a bed, and a shelf, as desired by a human user. Testing of the prototype establishes the feasibility of the proposed Robot Room slice concept, and validates the ability to engineer it within prespecified specification
Low Energy Ion Irradiation Effects in Electronic Devices and Materials
Get PDFThe physics and engineering of ion-solid interactions are governed by the ion beam characteristics (flux, charge, energy) and target(s) in question. Here I present work on two projects related to the extraction of a high flux of low charge state Argon ions from a commercial plasma source and the irradiation of an engineered target, a transistor, with high charge state Argon ions.
An end-Hall ion source that produces a a high current plasma of ions and electrons in a rough vacuum environment is characterized. Using a Langmuir probe and multiple pressure measurements, the ion and electron content of the source flux is examined as a function of source operating parameters. In addition the heat load and flux-induced damage on the target and support structure is evaluated in relation to the application of this source for future high flux studies.
The effects of multiply charged ion damage on a semiconductor polymer, P3HT, is also examined using organic thin film transistors (OTFTs) with P3HT as a channel material. The current-voltage characteristics pre- and post-irradiation with Ar8+ ions are compared to determine the role of ion energy and charge in the damage or modification of the polymer layer