Geotransformación and Overcoming Underdevelopment in Socialist Cuba

The term geotransformación, coined and theorized by Cuban geographer and revolutionary Antonio Núñez Jiménez in his 1968 book Geotransformación de Cuba, is an analytic frame which emphasizes the interconnectedness of social and natural transformation. As such, geotransformación functions as a conceptual weapon against not only theories of geographic determinism attempting to depoliticize history, but also grand historical narratives which center the human by overstating its independence from the forces of nature. Taking geotransformación as a conceptual compass for a return to the Cuban Revolution’s decisive early years, I engage in close readings of primary texts including geographic treatises, legal documents, and poetry. Drawing on key passages from Geotransformación de Cuba, I argue that agrarian reform cannot be separated from the social transformations of the revolution. Then, I theorize the plantation as an engine of underdevelopment and show how overcoming the structure of the colonial plantation formed the central task of agrarian reform. An analysis of Hurricane Flora and Cuba’s response to its devastation highlights the importance of geotransformación’s conceptual frame for understanding the interconnections between social and natural transformations in Cuba, and how these transformations relate to overcoming the long history of Cuba’s underdevelopment. I conclude by arguing geotransformación forms an important contribution to the wave of ecological thought which emerged in Marxist theory beginning the 1960s

Bridging the Gap Between Molecular Components and Functional Electronic Chemical Sensing Devices with 2D Layered, Conductive Metal–Organic Frameworks

Layered, conductive framework materials are a class of materials with properties that make them ideal sensing materials in electronic chemical sensors. My thesis is focused on the development of these materials for electrochemical sensing of liquid phase analytes, and on understanding the material–analyte and material–electrode interfaces, and their self-assembly and deposition onto surfaces. Chapter 1 provides a summary of the use of layered conductive metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) in electronic chemical sensors, detailing the materials and sensor architectures employed, and the analytes detected. Relevant performance metrics are compared, and investigations into material–analyte interactions are highlighted. Chapter 2 investigates the use of hexahydroxytriphenylene-based MOFs as the working electrode material for voltammetric detection of nitric oxide, comparing the impact of the metal node on electrode sensitivity to NO. A nickel-based material showed sensitivity to NO, but displayed limited stability on a glassy carbon substrate, which was improved by employing a conductive polymer adhesive, highlighting the impact of the MOF-electrode interface on sensing performance. Optimized electrodes detected NO at nanomolar concentrations and exhibited moderate selectivity against potential interferents. Chapter 3 describes the investigation into the self-assembly of Ni3(HHTP)2, a layered conductive MOF. A novel method for monitoring MOF deposition with ATR-FTIR was developed to study the impact of oxidants on the rate of MOF formation. The presence of oxidants impacted the crystallinity and morphology of the resulting MOF particles, with oxidant-free conditions inhibiting MOF formation, and excesses of oxidant resulting in irregularly shaped particles. The initial phase of Ni3(HHTP)2 self-assembly was identified as the formation of Ni-HHTP coordination complexes in solution, which then assembled into crystalline MOF with the addition of oxidant. The appendices provide preliminary data that highlight promising future directions: that of exploring phthalocyanine-based frameworks for NO sensing (Appendix A), and that of depositing MOFs onto threads for flexible sensors (Appendix B). Taken together, the chapters of my thesis provide new understanding of the molecular interactions by which layered conductive MOFs self-assemble, adhere to substrates, and interact with analytes, which lays the groundwork for employing these materials in a variety of biosensing applications

Microglial Dynamics and Mechanisms Underlying the Phagocytosis of Dying Oligodendrocytes

Myelin is a complex multilamellar structure, generated by oligodendrocytes, that ensheaths axons and is a vital component for neural processing. Degeneration of both oligodendrocytes and their myelin sheaths is a common pathological feature associated with aging and neurodegenerative diseases. Efficient removal of the cellular and myelin debris is crucial for remyelination and prevention of further degeneration. Microglia, the primary phagocytes of the CNS, are thought to play a key role in this process. To investigate the cellular dynamics underlying microglia-mediated clearance of degenerating oligodendrocytes and myelin sheaths, at the single cell level, we developed a novel model for inducible cortical demyelination called oligodendrocyte 2Phatal. This model activates a non-inflammatory stereotyped degeneration cascade, leading to remyelination by local oligodendrocyte precursor cells. Using this model of single-cell demyelination, I observed microglia engaging with both the targeted oligodendrocyte and its myelin sheaths followed by a stereotyped and efficient removal of both. Following the removal of the myelin sheath, I observed rapid remyelination, suggesting that efficient clearance of the myelin debris plays a vital role in successful remyelination. Deletion of the fractalkine receptor, CX3CR1, delayed microglia engagement with the targeted oligodendrocyte but did not affect the clearance of myelin sheaths. Surprisingly, the deletion of the phosphatidylserine receptor, MERTK, had no impact on the clearance of either the targeted oligodendrocyte or the myelin sheaths. These new findings reveal the underlying cellular dynamics involved in myelin debris clearance and repair and highlight the role of CX3CR1 signaling in the efficient removal of dying oligodendrocytes

Reading in the Margins: Cosmopolitan Women Readers in Sijie Dai’s Balzac and the Little Chinese Seamstress and Yoko Tawada’s “Persona”

This paper examines two pieces of fiction that foregrounds an Asian woman’s reading of western literature, Balzac and the Little Chinese Seamstress (2000) by Chinese-French writer Sijie Dai and “Persona” (1993) by Japanese-German writer Yoko Tawada. These female readers are positioned on an overdetermined “margin”: their femininity defines them as either wanting of cultural enlightenment or inadequate to engage with the canon; their foreignness renders the reading process to be either superficial or torturing; however, it is also this marginal position that constitutes a unique approach to building their world through literature, that is, a perspective that neither align them with the imperialist ideology, nor confine them to a national consciousness. This paper provides a countering framework of reading-as-worlding against orientalism from the perspective of East Asian women–how they develop their own sense of cosmopolitanism via engagement with foreign literature and how they modify and uphold this sense of cosmopolitanism in the increasingly globalized space. By putting these two texts together, I want to pinpoint the act of reading as an encounter with the cultural other, which insufficiently illuminates the knowledge of the other, yet heuristically leads towards an exploration into one’s self

Analysis, Optimization, and Design of Small-Scale Hybrid-Core Inductor Designs that Achieve High Energy Densities and Low Loss

As the size of power converters and other electronics has shrunk over time, miniaturization of passive magnetic components, namely inductors and transformers, has fallen behind. Much of this is due to magnetic scaling laws, which degrade inductor performance at reduced sizes, in contrast to other common power converter components, such as transistors and capacitors, which are conducive to construction from smaller parallel cells. This does not mean high performance and small sizes are unachievable with magnetic components, but rather that intelligent and creative magnetics design is increasingly critical. Typical inductors utilize a conductive winding wrapped around a magnetic core, with loss occurring in both elements. This loss releases heat that sets minimum inductor size and, consequently, peak energy density. However, what often prevents reducing loss, particularly winding loss, are core material saturation limits that set minimum winding turns, since the best low-loss core materials, such as ferrites, have low saturation flux densities while high-saturation-flux-density materials, such as steels, have high core loss. This work explores two novel hybrid-core-inductor types, a hybrid-steel core and a hybrid-permanent-magnet (hybrid-PM) core, that achieve small size and increased energy density by strategically utilizing the strengths and mitigating the weaknesses of their core materials. Theory behind these two hybrid-core designs is established with reluctance models, and these models are used in an optimization routine to develop designs and characterize spaces where hybrid cores are most beneficial. Finite element simulation procedures unique to each hybrid core verify designs and refine the reluctance model. Simulation results show a hybrid-steel-core inductor at a frequency of 1.5 MHz in a 16 mm3 package increases energy density over 550% compared to a ferrite-core inductor at the same DC resistance while a hybrid-PM-core inductor increases energy density nearly 100% at 4 MHz. The successful completion of a proof-of-concept hybrid-steel-core inductor prototype and a small-scale hybrid-PM-core inductor prototype in a 1210 package is also discussed, including a new winding construction method using electroplating to form a 3D winding

Balanced Meals, Balanced Minds

The growing stress in the academic environment takes a huge toll on students\u27 routines, including their dietary practices. Hence, this lesson has the goal of equipping students with mindful practices and habits in order to support them in navigating their college careers. Through meditations, activities, discussions, and reflections, students will understand the role of bringing awareness to their diet, using mindful eating as a tool to alleviate stress regarding their current diet

Shader-based Real-time Image Tracking for Mobile Augmented Reality

Image target tracking is a technique widely used in a variety of augmented reality (AR) applications to trigger AR interaction and accurately locate virtual objects relative to physical space. This project is a Unity image tracking pipeline based on the ORB feature detection and description technique that seeks to be robust enough to track images despite partial occlusion, uneven lighting, and image target depth. This pipeline employs compute shader code to conduct image tracking computations on the GPU to track images in real-time for mobile AR apps

Regulation of Lipid Composition of the Golgi during Tissue Formation: Where Does PI 4-Kinase Stand?

Four Wheel Drive (Fwd), the Drosophila homologue of PI 4-kinase IIIβ, is a conserved phosphatidylinositol 4-kinase (PI4K) that localizes to the Golgi apparatus and functions in protein trafficking from the Golgi to the plasma membrane. The goal of this project was to determine how the localization of Fwd to the Golgi is regulated during early embryogenesis in Drosophila. Our initial observations suggested that Fwd was only localized to a subset of Golgi apparatus, raising the question of whether distinct types of Golgi apparatus exist in early Drosophila embryos. By optimizing imaging conditions, we found that many Golgi compartments initially identified as Fwd-negative showed weak Fwd-GFP signals, arguing against the existence of a sub-population of Golgi that completely lack Fwd. In addition, we found that phosphatidylinositol 4-phosphate (PI4P), the lipid product of PI4Ks, were both strongly enriched on the plasma membrane and weakly associated with intracellular puncta-like structures. These intracellular signals appear to overlap with Fwd-GFP, suggesting that Fwd colocalizes with its lipid product on the Golgi apparatuses. Together, our findings demonstrate that Golgi apparatuses differ in their capacity to recruit Fwd, which may impact their rate of PI4P production. These observations raise the question of how the activity of individual Golgi apparatuses are regulated in developing tissues.https://digitalcommons.dartmouth.edu/wetterhahn_2024/1003/thumbnail.jp