Dartmouth Institute for Health Policy and Clinical Practice
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What\u27s the 411?
Get PDFThis class invites students to reflect on gossip and the role it plays in their lives. As they complete activities such as a game of telephone and round-table discussions, they will walk away with a further understanding of gossip’s history, benefits, consequences, and ethics. My hope as an educator is that students will take these lessons and apply them to their relationships and interactions, so that a more gossip-conscious community can be fostered
Misery\u27s Company: Modeling the Public and Private Faces of Suicidal Thought and Behavior in the Digital Era
No full textMore than 700,000 individuals across the globe die by suicide each year, making suicide a leading cause of death. To improve suicide risk assessment and prediction, addressing the limitations surrounding the conceptualization of suicidal thought and behavior (STB) is essential. Research within the past decade has laid the groundwork for the application of more complex models (e.g., machine learning and deep learning architectures) to probe STB phenomenology. Such work has tended to analyze content from ubiquitous social media and online communication platforms which, despite advantages related to data volume and density, nevertheless offer censored and incomplete representations of STB. As a result, the markers and models that stem from these efforts ultimately paint a constrained and artificial picture of STB expression. The current body of work sought to address this limitation by leveraging behavioral data that is derived from both social and personal contexts, emphasizing situations where STB can be expressed in manners that are ecologically valid, minimally censored, and temporally rich. To this end, this research first explored the public face of suicide by modeling the semantic and social dynamic properties of STB on the pro-choice suicide forum, Sanctioned Suicide. The written and temporal properties of private-facing suicidal expression were then interrogated through ecological momentary assessment-based diary entries of individuals with major depressive disorder as well as through online search engine queries of anonymous Internet users. Via the primary application of natural language processing, network analysis, and machine learning-based techniques, this research provides novel insights regarding the presentation of suicide and highlights potentially useful markers of STB expression that may serve to bolster progress toward more sophisticated prevention, intervention, and mitigation of STB within the modern digital arena
CYCLIC THERMAL STABILITY OF NATIVE OXIDE SOLAR THERMAL ABSORBERS ON FeMnNiAlCr HIGH ENTROPY ALLOYS FOR ENERGY APPLICATIONS
Get PDFHigh entropy alloys (HEAs) are promising candidates for cost-effective high-temperature materials in high-efficiency power cycles. A potential application is in concentrated solar power (CSP) systems, where native oxides of cost-effective FeMnNiAlCr HEAs can also synergistically serve as a high-efficiency solar thermal absorber. However, the huge and repetitive temperature change of the CSP system in day-night cycles greatly challenges its thermal stability. In this thesis, we investigated the cyclic oxidation behavior of FeMnNiAlCr HEAs to improve the optical performance and thermal stability of their native oxides as a solar absorber for next-generation CSP systems. We found that the duplex oxide scale on the two-phase FeMnNiAlCr HEAs consists of Mn2O3 on the surface contributing to solar absorption, and Al2O3 along the oxide/HEA interface serving as a protective layer to prevent excessive oxidation. To enhance the spallation resistance during thermal cycles, a steady flux of Al diffusion to the oxide/alloy interface is crucial not only to ensure the establishment of the protective layer at the early-stage oxidation but also to sustain its continuity during the thermal cycles. An initial attempt to increase the Al content by replacing Mn helped the establishment of the protective scale Al2O3 but prevented the diffusion of Mn to the surface to form a continuous solar absorbing layer. We developed a more effective approach to maintain the integrity of the interfacial Al2O3 layer by engineering the HEA’s microstructures through cold-working and annealing, which results in finer microstructures and new phase boundaries to enhance Al supply through short-cut diffusion. Using this approach, the native oxides sustained \u3e20 simulated day-night thermal cycles with ~87% optical-to-thermal energy conversion efficiency. Additionally, we examined the effect of reactive elements on the spallation resistance. Y doping shows promising improvement in the strength of the oxide/alloy interface
Pyrophosphate-free glycolysis in Clostridium thermocellum increases both thermodynamic driving force and ethanol titers
Get PDFBackground
Clostridium thermocellum is a promising candidate for production of cellulosic biofuels, however, its final product titer is too low for commercial application, and this may be due to thermodynamic limitations in glycolysis. Previous studies in this organism have revealed a metabolic bottleneck at the phosphofructokinase (PFK) reaction in glycolysis. In the wild-type organism, this reaction uses pyrophosphate (PPi) as an energy cofactor, which is thermodynamically less favorable compared to reactions that use ATP as a cofactor. Previously we showed that replacing the PPi-linked PFK reaction with an ATP-linked reaction increased the thermodynamic driving force of glycolysis, but only had a local effect on intracellular metabolite concentrations, and did not affect final ethanol titer. Results
In this study, we substituted PPi-pfk with ATP-pfk, deleted the other PPi-requiring glycolytic gene pyruvate:phosphate dikinase (ppdk), and expressed a soluble pyrophosphatase (PPase) and pyruvate kinase (pyk) genes to engineer PPi-free glycolysis in C. thermocellum. We demonstrated a decrease in the reversibility of the PFK reaction, higher levels of lower glycolysis metabolites, and an increase in ethanol titer by an average of 38% (from 15.1 to 21.0 g/L) by using PPi-free glycolysis. Conclusions
By engineering PPi-free glycolysis in C. thermocellum, we achieved an increase in ethanol production. These results demonstrate that optimizing the thermodynamic landscape through metabolic engineering can enhance product titers. While further increases in ethanol titers are necessary for commercial application, this work represents a significant step toward engineering glycolysis in C. thermocellum to increase ethanol titers
Smart Toys for Sensing and Soothing Distress in Pediatric Patients
Get PDFThis thesis develops and evaluates child-centered technologies to support remote monitoring of pediatric patients, with an emphasis on childhood cancer and pediatric chronic pain. For these and many other health conditions, current therapies tend to focus on treating physical symptoms yet neglect the psycho-emotional aspects of managing the illness. However, such mental states play a major role in recovery. Research has shown that cancer patients with better mental health have better prognoses, higher possibilities of remission, and faster healing processes, while chronic pain patients with better mental health report lower levels of pain. To enable more personalized, continuous, and scalable monitoring of emotional status and distress in pediatric patients, this thesis works to develop an affordable, acceptable sensor device with a toy-based form factor that can be deployed in both clinical and home settings to augment care.
Specifically, we report on the design, implementation, and evaluation of prototypes that integrate sensors for assessing markers of distress related to heart rate, oximetry, and movement. Results indicate that these sensor signals are useful emotional measures for therapists and families and that the toy-based design appeals to children, promotes playful engagement, and scores very high on measures of enjoyment and likeability. Preliminary findings related to the potential for the toy to deliver adaptive interventions and/or therapeutic support indicate an improvement in overall mood after half an hour of playing with the device. Future steps include optimizing the microcontroller functions, creating machine learning algorithms to predict behavioral patterns, and improving therapeutic components (e.g., soothing) and just-in-time support. Overall, this project lays the foundations for future technological enhancements at the intersection of healthcare technology and therapeutic play
Silent Era Motion Picture Camera Operators
Get PDFAlthough the most significant role in the early years of motion picture production was undoubtedly that of the camera operator, there is relatively little known about the people who performed this job during cinema’s silent era. The development of the fledgling motion picture business relied almost entirely on the technological and aesthetic advancements involved in capturing moving images, and much of the credit for these advancements can be attributed to the camera operators themselves who often functioned as roving inventors, photographers, technicians, and directors simultaneously. What follows draws on a decade of research into the men and women who operated cameras during this era compiled from trade journals, newspaper reports, census records, and other fragments of archival evidence about the lives and careers of some of these individuals. It is, no doubt, imperfect and incomplete—but we hope that is a useful starting point for further research in this area
Between Naïveté and Desire: Analyzing Collective Intimacy in Sun Yu’s Films with a Time-based Annotation Tool
No full textThe collective affords a prominent presence in Sun Yu’s extant silent era films. Along with his dedicated portrayal of athletic bodies and sanguine spirit, family-like communities contribute to his optimistic outlook against a backdrop of national crisis. Sun’s collective tends to envelop romantic plots, bringing individuals to a grander national narrative, while at the same time it is alive with tension between childlike innocence and sexual allure. This paper employs time-based annotation tool to analyze the performance and cinematography that contribute to the representation of a loving community. By annotating scenes of reoccurring gestures and collective intimacy in Wild Rose, Little Toys and Big Road how tension between desire and naïveté often lurks under playful touches and affectionate gazes. It is through such ambiguity and collective interactions that Sun finds room to address serious issues of national salvation and class struggle with cheerfulness and humanistic complexity
The Digital Commercial Revolution: U.S. Business Sales and the Entrepreneurial Exploitation of Information and Communications Technology
Get PDFBusinesses have taken the opportunities, made possible by information and communications technology (ICT), to develop and use digital platform services and other digital tools to support sales. This paper estimates a model of U.S. business sales and uses the estimated model to assess the economic impact of the digital commercial revolution of the first two decades of the twenty-first century. The estimations show that the entrepreneurial initiatives—that drove the digital revolution in commerce by capitalizing on the new technologies made available by the ICT revolution—came to fruition in the wake of the Great Recession. For 2019, the last year before the COVID-19 pandemic, the digital commercial revolution’s contribution to value added in the U.S. manufacturing, wholesale trade, and retail trade sectors alone has an estimated expected value that is 4.0% to 5.9% of GDP
Comedy Tonight? Maximizing Theatre Audiences Using a Game Theory Model
No full textExisting theatre industry literature is comprised of several arguments regarding the amount of literature on the theatre industry. Several scholars argue that the theatre industry is not extensively studied in economics due to misconceptions about the profitability of theatre, the misalignment between artists’ actions and economic “rationality,” and the contributions of the arts industries to the broader U.S. economy. Beyond this academic debate, economic research on the theatre industry explores the nuances of theatre demand and the influence of audience preferences and demographics on theatre ticket demand.
This paper presents a game-theoretic model to study the strategic season selection decisions of theaters. This model describes a two-theater city where theaters are competing to maximize their audience turnout under the assumption that increased ticket sales results in increased profits. Based on the relative locations of the two theaters and the preferences of local theatergoers, the two theaters select one of two show genres to produce. The model seeks to understand the conditions under which two theaters may produce the same show genre. The model is simulated by varying the locations of both theaters, the strengths of local audience preferences, and the proportions of audience types; the results of this model are presented in a series of graphs identifying the conditions under which pure and mixed strategy equilibria occur.
This analysis is unique to the theatre industry due to the industry’s uniquely high risk factor and the complete commitment of each player to a singular strategy. By framing theaters as profit-maximizing organizations that must generate enough revenue to support the theatre they are creating, game theory offers insights into the genres theaters should produce in order to maximize audience turnout, using audience turnout as an instrument for revenue