Dartmouth Institute for Health Policy and Clinical Practice
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Youth Activism and the City: An Urban Political Ecology of Flooding in Porto Alegre, Brazil
Get PDFThis thesis examines the catastrophic 2024 flooding in Rio Grande do Sul, Brazil—locally known as The Flood —through the lens of young environmental activists\u27 experiences in Porto Alegre. Drawing on urban political ecology, disaster studies, and climate justice frameworks, this research examines how colonial-era urban planning and infrastructure influenced the socio-environmental conditions that led to The Flood, how the disaster affected young activists\u27 relationships with their city, and what climate justice might entail in this context. Through (auto)ethnographic fieldwork conducted from July to August 2024, including semi-structured interviews, participant observation, walk-throughs, and social media analysis, this study engages primarily with Eco Pelo Clima, the local Fridays for Future chapter, and other youth-led organizations. The research reveals how The Flood disrupted Porto Alegre\u27s urban metabolism —the circulation of energy, water, materials, and waste through political, social, and economic networks that produce urban socio-natural relations. The findings demonstrate that The Flood was a violent socio-natural phenomenon rooted in centuries of exploitative human-lake relationships and capitalist urban governance that has systematically neglected flood prevention infrastructure. Young activists found themselves navigating contradictory roles as both disaster victims requiring aid and volunteers assisting their communities, filling gaps left by the state\u27s absence in low-income neighborhoods. The disaster created geographies of fear and took a significant bodily and psychological toll on youth, transforming Porto Alegre into what one interlocutor described as uncertain terrain for affections. This thesis argues against romanticizing youth responsibility for solving environmental crises caused by previous generations, instead advocating for confronting structural inequalities, challenging urban metabolic patterns that dominate nature, and amplifying youth-led initiatives as pathways toward genuine climate justice
The Idea of Ethiopia: Heritage Tourism in the Land of Origins
Get PDFHosaena Tilahun\u27s The Idea of Ethiopia explores how heritage tourism in Addis Ababa cultivates Ethiopian patriotism and exceptionalism. Through an in-depth, close reading of the National Museum of Ethiopia, Unity Park, and the Oromo Cultural Center, supplemented by observations at the Red Terror Memorial Museum and Dergue Prison, Tilahun examines how heritage sites shape the political memory of national resistance, revolution, and Black internationalist thought. Tilahun discovers omissions of Menelik II\u27s role in the Red Sea Slave network, encountering museum and archival silences about the internal conquest of peoples peripheral to the northern Abyssinian empire. As these heritage site renovations coincide with ongoing, popular ethno-nationalist struggles under Abiy Ahmed\u27s Prosperity Party\u27s regime, such as the Qeerroo movement and Tigray genocide, Ethiopian heritage tourism emerges as a political tool to encourage explicit interpretations of past fascist invasions, like resisting the Scramble for Africa, while deliberately obscuring modern parallels to contemporary state violence
HISTORICAL FICTION: ADAPTING PAGE TO STAGE
No full textThis tale of forbidden love is a historical fiction narrative inspired by the true crime reporting of Günter Litfin (1937-1961). Litfin was the first person shot by the border patrol attempting to flee East Berlin eleven days after the erection of the Berlin Wall began. The day Litfin tried to escape was the first day the guards received instruction and incentive to use guns to detain unlawful civilians who were illegally migrating to West Berlin. Litfin was twenty four years old when he was shot and killed on the afternoon of August 24th, 1961, in broad daylight. Had Litfin tried escaping the previous day, it is likely he would have made it to West Berlin alive
Of Mice and Men: The Regulation of Herpes Simplex Virus 1 Latency in Mouse and Human Neurons
No full textHerpes simplex virus 1 (HSV-1) establishes latent infections in sensory neurons, from which HSV sporadically reactivates, often due to external stress and other stimuli. Latency and reactivation are commonly studied using in vivo and ex vivo models in a variety of hosts, as well as in vitro models including primary mouse neurons and neurons derived from human pluripotent stem cells (iPSCs). The criteria for authentically modeling HSV latency include the ability to easily manipulate host genetics and biological pathways, as well as mimicking the immune response and viral pathogenesis in human infections. Presently, there remains a pressing need for models that more closely recapitulate human HSV infection. To address this, we used human iPSCs that have been genetically modified to rapidly differentiate into sensory neurons (iNeurons) as a model to study the mechanisms that regulate acute and latent HSV-1 infection.
The interferon (IFN)-based neuronal innate immune response is critical in controlling HSV-1 replication and HSV-1 counters these responses, in part, through infected-cell protein 34.5 (ICP34.5). ICP34.5 also promotes neurovirulence by preventing host translational shutoff and interfering with host cell autophagy through its interaction with the autophagy regulator Beclin 1. Here we demonstrate in iNeurons that ICP34.5 unexpectedly suppresses spontaneous reactivation and thereby is critical for maintenance of HSV-1 latency. Furthermore, our results suggest that both sustaining host translation and the interaction of ICP34.5 with Beclin 1 are important for maintaining latency in iNeurons. Experiments using primary mouse neurons show that ICP34.5 may be essential for maintaining latency but in an IRF3/7-dependent manner. In wild type mouse neurons, ICP34.5-null and ΔPP1⍺ viruses exhibited little spontaneous reactivation and had defects in induced reactivation suggesting that countering PKR-mediated responses is the key activity of ICP34.5 for enhancement of reactivation. These results highlight the value of studying HSV-1 latency and reactivation in different models and we explore explanations for how ICP34.5 may differentially impact latency in the two systems studied herein
Modal Building Blocks Across Species and Development
No full textThis dissertation investigates the phylogenetic and developmental foundations of modal thought—the ability to contemplate possibilities, impossibilities, and alternative outcomes—and how this capacity supports adaptive decision-making. In Chapter 1, I provide a theoretical framework for studying modal cognition across non-human animals, focusing on counterfactual reasoning as a case study. I examine current methodologies and introduce the modal building blocks approach as a method for studying counterfactual thought in non-human animals. In Chapter 2, I present two empirical studies investigating rats’ capacity for counterfactual modal building blocks including hierarchical reward reasoning, non-habitual decision-making, and reasoning about available and unavailable options. In Chapter 3, I turn to developmental evidence in humans, examining how children generate and evaluate multiple possible options when solving open-ended decision problems. I show that children generate a similar number of options as adults and exhibit the “Take the First” decision heuristic from an early age. Finally, in Chapter 4, I summarize these findings, highlight outstanding questions, and propose directions for future research
Intraoperative dynamic contrast-enhanced fluorescence imaging for navigating open orthopedic surgeries
Get PDFInfection following trauma is one of the most prevalent and challenging complications faced by orthopedic surgeons. Inadequate tissue perfusion plays a critical role in this complication, as poorly perfused bone can be a nidus for bacterial biofilm formation and promote resistance to antibiotic treatments. Consequently, the management of open fractures and fracture-related infections relies on aggressive and thorough debridement to remove all poorly perfused bone. This thesis focuses on developing an indocyanine green (ICG)-based dynamic contrast-enhanced fluorescence imaging (DCE-FI) to objectively measure bone perfusion during open orthopedic surgeries and guide surgical debridement of devitalized bone.
Novel methodologies were developed to address key technical challenges, including an automated motion correction algorithm based on mutual information to eliminate motion artifacts, and patient-specific arterial input functions (AIF) to normalize variations in manual ICG injection. Quantitative perfusion assessment was achieved through kinetic curve analysis and perfusion modeling using the adiabatic approximation to the tissue homogeneity model, yielding critical parameters such as maximum intensity (Imax), blood flow (BF) and volume transfer constant (Ktrans).
To date, DCE-FI from 256 patients were collected, including 15 lower extremity amputations, 106 infections, 120 open fractures, and 15 compartment syndromes. In three infection patients who underwent both DCE-FI and Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI), a strong correlation was found between Imax from DCE-FI and Ktrans from DCE-MRI, validating the feasibility of perfusion assessment by DCE-FI. Data analysis from 256 patients with varying degrees of bone damage revealed the following findings: 1) DCE-FI revealed trauma-induced perfusion changes that correlated with the severity of bone injury; 2) muscle perfusion quantified by DCE-FI was strongly associated with muscle necrosis; and 3) in patients with infections or open fracture, areas of low perfusion (identified by reduced maximum fluorescence intensity and blood flow) were strong predictors of early infection within 90 days post-surgery. Additionally, we developed a portable compact fluorescence imaging system (cBPI) suitable for austere environments and forward operating units near battlefields. These findings demonstrate that DCE-FI has significant prognostic value in assessing bone damage and predicting surgical outcomes. It holds strong potential as an intraoperative tool for guiding real-time debridement decisions
Quantum Control and Simulation Using Hamiltonian Engineering in Solid-State NMR
Get PDFLattices of dipolar coupled nuclear spins in natural crystals are large, interacting quantum systems -- ideal platforms to simulate non-equilibrium many-body dynamics. Using the magnetic resonance toolkit, which includes Dynamic Nuclear Polarization (DNP), Hamiltonian engineering, and multiple-quantum Nuclear Magnetic Resonance (NMR) experiments, we study aspects of coherent control, manipulation, and readout of the complex dynamics of the spin system in NMR quantum simulation.
First, applying Hamiltonian engineering sequences, we control the system evolution. Specifically, we use a combination of numerical simulations and NMR experiments on adamantane to evaluate and compare the performance of several known sequences that aim to suppress the magnetic dipolar interaction between spins. The effect of sequence parameters and control errors on sequence performance is explored and the presence of local disorder is established, perhaps unsurprisingly, as a distinguishing factor in the decoupling efficiency of spectroscopic and time-suspension sequences. Additionally, we use time-reversal multiple-quantum experiments to probe the growth of multi-spin correlations involving large clusters of spins and explore the ability of time-suspension sequences to protect these correlated initial states.
Furthermore, we study a Hamiltonian with tuneable interactions and disorder that can be engineered from the natural Hamiltonian of a heteronuclear NMR quantum simulator. Disorder plays a central role in determining the thermalization properties and dynamics of quantum Hamiltonians. We use numerical simulations of small 1D systems to demonstrate the possibility of a transition of the Hamiltonian dynamics from thermalizing to non-thermalizing behavior at high values of disorder. This transition is reflected in the change in behavior of multiple metrics of quantum thermalization and information scrambling including eigenstate entanglement, statistics of the eigenspectrum, entanglement dynamics, and growth of an out-of-time-ordered commutator.
Finally, we also show DNP to be a potential initial state preparation method in NMR quantum simulation that cools the nuclear spins to access the lower energy levels of the system. This is achieved by polarization transfer from electronic spins under resonant microwave excitation. We demonstrate high nuclear polarization and NMR signal enhancement of C spins in diamond using microwave irradiation of the substitutional nitrogen (P1) centers