Alliance One Tobacco (Malawi)
Academic Research Repository at the Institute of Developing EconomiesNot a member yet
52305 research outputs found
Sort by
ボツワナの 2024 年総選挙と初の政権交代
Get PDF2024 年10 月にボツワナ共和国（以下、ボツワナ）で行われた国民議会選挙で初めての政権交代が起きた。ボツワナでは1966 年の独立以来、ボツワナ民主党（Botswana Democratic Party: BDP）がすべての複数政党制選挙を制してきたが、2024 年選挙で野党連合の「民主改革のためのアンブレラ（Umbrella for Democratic Change: UDC）」が勝利した。政権交代の要因としては、(1)貧困格差、高い失業率、経済低迷といった経済社会状況の悪化、(2)国民の現政権への失望、大統領と前大統領の決裂による与党内の分裂、(3)野党連合による効果的な選挙キャンペーンが挙げられる。PJa/3/Af4articl
The search for a Potential Novel Receptor for Human Transferrin on APCs
No full textIt is canonically known that Dendritic Cells (DCs) can activate T cells through its peptide-MHC binding to the T cell receptor (signal 1), in addition to its CD80/86 binding to CD28 on the T cell (signal 2). To facilitate this process, antigens undergo processing and presentation in DCs which then present linear peptides from the original protein antigen on MHC molecules. On the other hand, the ability of DCs to activate B cells has been studied less extensively. B cells, unlike T cells, are activated through direct recognition of specific epitopes on the antigen by the BCR. Based on prior data obtained in the laboratory, murine DCs appear to have a specific receptor for the display of HSA (human serum albumin); this receptor does not bind efficiently to bovine serum albumin (BSA). For the purposes of my thesis, I will be investigating the possible existence of a novel receptor that can present human transferrin to B cells. I show through flow cytometry that there is variation in the display of human transferrin on the surface of different immune cell subsets in the mouse spleen. I also show a high level of capture and display of human transferrin on the human B cell line BJAB, RAMOS and on a macrophage cell line. Preliminary data suggests that the distribution of CD71 and the receptor for display of human transferrin broadly but not completely overlap. Additionally, blocking experiments of CD71 were conducted and they showed that the blocking antibody is working properly and the data implies that a novel receptor exists. However, further data is needed before confirming these statements about the presence of a novel receptor.Graduate Educatio
Elevated ALDH Expression Impairs Dendritic Cell Function and Contributes to Immunotherapy Resistance in Bladder Cancer
No full textImmunotherapy has significantly improved cancer treatment, but a significant proportion of patients do not respond to therapy. This study investigates the role of aldehyde dehydrogenase 1A1 (Aldh1A1) and its metabolite retinoic acid (RA) in shaping the tumor microenvironment and influencing immunotherapy response in bladder cancer. Analysis of two murine bladder cancer cell lines, BBNF2 and BBNF9, revealed that BBNF9 tumors, which are resistant to anti-PD-1 therapy, express higher levels of Aldh1A1 compared to immunotherapy responsive BBNF2 tumors. In vitro studies demonstrated that RA impairs dendritic cell maturation, IL-12 production, and capacity to stimulate T cells, a process mediated by the retinoic acid receptor RXRα. To further elucidate the role of Aldh1A1 in immunotherapy resistance, Aldh1A1 was knocked out in BBNF9 cells using CRISPR-Cas9. Aldh1A1-deficient BBNF9 tumors exhibited increased dendritic cell infiltration, enhanced trafficking of cross-presenting cDC1s to tumor-draining lymph nodes, and reduced recruitment of immunosuppressive neutrophil subsets. Importantly, Aldh1A1 knockout sensitized BBNF9 tumors to anti-PD-1 therapy, characterized by increased T cell infiltration and exhaustion phenotypes. These findings provide mechanistic insights into how the Aldh1a1-RA axis modulates dendritic cell function and contributes to immunotherapy resistance in bladder cancer.Graduate Educatio
Reconnection-Driven Flares in Magnetized Astrophysical Plasmas: From the Solar Atmosphere to Sagittarius A*
No full textEnergetic flares are observed across magnetized astrophysical systems, from stellar coronae to the inner regions of black hole accretion flows. Interpreting their emission remains a challenge, as the underlying physics spans a vast range of spatial and temporal scales—from kinetic-scale particle acceleration to large-scale magnetic structures that govern global energy release.
On the observational side, I present the development and first flight of a high-cadence soft X-ray imaging system flown in the 2024 NASA Solar Flare Sounding Rocket Campaign. The instrument leverages delta-doped, back-illuminated CMOS sensors to achieve sub-second imaging in the 0.5–10 keV band, enabling improved temporal resolution of flare dynamics in the solar corona.
On the theoretical side, I present fully three-dimensional general relativistic particle-in-cell (GRPIC) simulations of magnetic reconnection in relativistic, high–guide field plasmas, motivated by flares from the supermassive black hole at the center of our galaxy. Through analysis of particle acceleration and synchrotron emission, we offer a physical explanation for the observed diversity in infrared and X-ray flares from Sagittarius A*.
Taken together, these efforts demonstrate how new observational tools and high-fidelity simulations can jointly advance our understanding of reconnection-driven energy release across astrophysical environments.Astronom
Advancing Foundation Models for Medical Diagnosis and Biological Discovery
No full textThe open-ended and complex nature of medicine and biology poses fundamental challenges for building robust artificial intelligence (AI) and machine learning (ML) systems. This dissertation addresses key obstacles to the development of effective foundation models for medical diagnosis and biological discovery through three complementary contributions. First, I introduce frameworks designed to systematically decompose intricate and open-ended problems into tractable sub-components, facilitating the creation of meaningful benchmarks that accurately reflect scientific and clinical advancements. Chapter 1 introduces CRAFT-MD, an evaluation framework that simulates multi-turn doctor–patient conversations to assess diagnostic accuracy of Large Language Models (LLMs) in conversational settings. Chapter 4 presents a novel approach for evaluating the large-scale experimental viability of biological hypotheses generated by LLMs. Second, I develop scalable methods for identifying, curating, and harmonizing high-quality medical datasets crucial for training and evaluating foundation models. This is demonstrated in Chapter 3 through the construction of PanEndoAtlas, the largest endoscopic image dataset to date organized in a clinically meaningful hierarchy, and the accompanying PanEndoX benchmark. Third, I describe the development of specialized models tailored to medical and biological applications. Chapter 2 introduces BEANIE, a non-parametric statistical method for precise nomination of biological hypotheses from single-cell RNA-seq data in patient oncology cohorts. Chapter 3 presents PanEndoFM, a foundation model trained for endoscopic diagnosis on over 10 million images covering the entire GI tract. Together, these contributions advance the methodological, data-centric, and model-building foundations necessary for complex medical and biological domains.Biological and Biomedical Science
The Future as Warning: Narrative Voice and Literary Form in Modern Dystopian Novels
No full textSince modern dystopian fiction appeared in the wake of the First World War and the Russian Revolution, texts in the genre have warned against the dreadful consequences that could result from current sociopolitical trends and have sought to intervene in the present to prevent the manifestation of nightmarish futures. During this time, Anglophone dystopian novels have frequently eschewed the transparent first- and third-person narrators that dominate both realist literary fiction and genre fiction, instead favoring conspicuous and estranging voices. Putting narrative theory in dialogue with dystopian scholarship, “The Future as Warning” investigates this under-researched phenomenon, exploring the relationship between narratorial form, thematic content, and ideological messaging in dystopian fiction. Analyzing texts by American, British, and Canadian writers, as well as one influential Russian, this dissertation examines four narratorial forms that recur across twentieth- and twenty-first-century dystopian novels: the plural first-person we-voice, narration in an invented future version of English, the diary conceit, and the found-document conceit.Englis
Essays on Global Bond Market Integration: The Roles of Foreign Ownership, Auction Signals, and Currency Risk
No full textThis dissertation investigates how global investors shape bond market integration through three interconnected mechanisms: cross-border asset ownership, informational dynamics in bond auctions, and currency-related risk preferences. The first chapter demonstrates that increased foreign ownership of sovereign bonds significantly strengthens the co-movement of bond yields across countries, using China's 2017 bond market liberalization as a case study. The second chapter identifies U.S. Treasury auctions as uniquely informative events that reveal global investor demand for long-term bonds, resulting in systematic declines in global yields. The third chapter explores how currency risk influences investor behavior, documenting systematic differences in return sensitivity and capital flow volatility driven by currency denomination and hedging practices.Economic