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HARD, UNSTABLE, SELF-SERVING STALEMATES (HUSSS) AND NEGOTIATION COLLAPSE: THE VENEZUELAN EXPERIENCE (2014-2021)
No full textConflicts and crises in a situation of deadlock that are highly resistant to peacemaking beg the question of why negotiation collapse persists, especially if the objective is to prevent these crises from becoming intractable and normalized. This research focuses on the aspect of deadlock in conflicts and its role in the likelihood of negotiation breakdown. Using the six cases of collapsed negotiations to solve the Venezuelan crisis from 2014 to 2021, a variant of stalemate where ripeness is absent is proposed. It is argued that not all deadlocks necessarily lead to the breakdown of peacemaking efforts, but under certain conditions —the presence of a Hard (polarization), Unstable (fragmentation), Self-Serving Stalemate (HUSSS)— is likely to lead to negotiation collapse. The cases of negotiations analyzed show that the combination of the three conditions of HUSSS produces a pattern of collapse, which can be overcome if there are intentional efforts at addressing the polarization between negotiating parties, fragmentation within domestic and international actors, and the self-serving nature of the status quo that has made the prospects of a negotiated agreement consistently unappealing
Characterization of the ferric reductase gene family in Candida albicans
Get PDFMetals are essential for life, serving as structural cofactors and catalysts in metabolic processes. Nutritional immunity is a host defense mechanism that capitalizes on the essentiality of metals to combat pathogens. Through co-evolution, fungal pathogens have developed strategies to endure metal-depleted conditions. The heme-containing transmembrane ferric reductase domain (FRD) plays a crucial role in maintaining metal homeostasis in pathogenic fungi by converting extracellular Fe+3 or Cu+2 to bioavailable Fe+2 or Cu+1 for cellular uptake. FRDs can also function as NADPH oxidases (NOX), producing reactive oxygen species (ROS) by reducing oxygen to superoxide. The opportunistic fungal pathogen Candida albicans possesses a family of 17 FRDs, of which only 4 have confirmed functions. The goal of this study was to characterize the role of the remaining FRDs and investigate their regulation. We predicted that reductases for Fe+3 and Cu+2 would be induced during metal starvation, and NOXs would be induced when abundant ROS is produced in the hyphal form of C. albicans. We grew wild-type C. albicans in the presence of iron or copper specific metal chelators and induced other cultures to make hyphae, and then analyzed expression of all 17 FRDs by qRT-PCR. We found that 8 FRD genes (FRE1, FRE2, FRE4, FRE5, FRE7, FRE9, FRE10, FRP1) were induced under Fe-starvation conditions, and 2 FRD genes (FRE7, FRE30) were induced under Cu-starvation conditions. 5 FRD genes (FRE2, FRE7, FRE8, FRE17, FRE30) were induced in hyphal cells. To further study our predictions on FRD genes, we conducted ferric reductase and cupric reductase assays on mutants in specific FRD genes and found that several of the genes we predicted to be cupric or ferric reductases showed either an increase or decrease in metalloreductase activity. Additionally, we found that Fe-responsive transcription factor SEF1 regulates the iron starvation induced expression of FRE1, FRE2, FRE4, FRE5, and FRP1. However, Fe-regulation
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of FRE7 and FRE9 occurs independent of SEF1. In addition to intracellular proteins like SEF1, certain unknown small molecule(s) secreted by C. albicans into the media were observed to influence FRD gene expression in response to Fe-starvation. Overall, our studies provide insight into the possible functions of several FRD genes and their regulatory factors
Deciphering Planet Formation From the Smallest Planetary Building Blocks
No full textDebris disks provide exciting opportunities to study planet formation through the composition and architecture of the smallest planetary building blocks. The Spitzer Space Telescope Infrared Spectrograph (IRS)'s comprehensive survey of debris disks enables us to study the composition of dust grains in both the terrestrial temperature zone and the exo-Kuiper belts. These mid-infrared spectra provide direct evidence for planetesimal formation processes, opening doors to new questions on small planet formation: Do planetesimal compositions in exoplanetary systems display a spatial pattern similar to our solar system? Are extrasolar planets assembled from differentiated planetesimals, similar to the solar system asteroids, or from undifferentiated materials? In my thesis work, I characterize the archetypal debris disk, beta Pictoris, to showcase the capability to constrain planetesimal properties as a function of their blackbody temperature, a proxy for stellocentric distance, for the first time. I discover trends in beta Pic also strikingly present in our solar system: the surfaces of large planetesimals are more Fe-rich and processed closer to the star and become more Fe-poor and primordial farther from the star.
Expanding on Chapter 2, I investigate the correlation between dust mineralogy and their host stars' properties with the most comprehensive debris disk catalog. I find a continuous range of mineralogy, ranging from the archetypal “silicate-dominated” and “silica-dominated” systems to those displaying a mixed ratio of compositions. I find that disk mineralogy has no correlation with stellar age or luminosity, implying that large collisional events can happen stochastically in a planetary system's lifetime and generate dust grains that dominate mineralogy in these disks.
In addition, I investigate the demographics of small exoplanets around late-type dwarf stars to infer the small planet formation mechanisms. I find that the occurrence of 2-5 Earth radii planets rises linearly with increases in their host star metallicity. I also find that the expected solid mass in planets around late-type dwarfs in the Kepler field is comparable to the total amount of planet-making solids in their protoplanetary disks.
My thesis bridges the gap between small planet formation processes and rocky planet bulk compositions, contributing valuable targets for future JWST detailed characterization
First-Year First-Generation College Students' Mental Health and the Creation of a Social Capital Instrument
No full textMental health concerns for college students have risen precipitously in the past decade and show no signs of abating in the near future. First-generation students are at higher risk of developing new or exacerbating existing mental health problems than continuing-generation students. Also of concern are first-year college students as this population reports increased rates of mental health problems in comparison to upperclassmen. As such, first-year first-generation college students are uniquely at risk for mental health problems. Both social capital and sense of belonging have been shown to impact mental health, and first-generation students report lower levels of both constructs in comparison to their continuing-generation student peers. While this study initially planned to implement an intervention aimed at increasing these constructs for first-year first-generation students, circumstances dictated a pivot to the development and testing of a new social capital instrument.
Although there are a variety of social capital instruments available, the originally planned intervention necessitated a specific tool which did not exist: a cross-sectional pre-post instrument that measured bonding and bridging social capital for individuals entering an unfamiliar environment. This study used social capital as a theoretical framework and frame analysis theory as a conceptual framework, and comparison to other social capital instruments, three focus groups, and two trials for the design and testing of the instrument. The results indicated that the survey was measuring perceived social capital rather than actual social capital; that the identities and frameworks of first-generation, low-income, and/or eldest-born have large impacts on students’ measured levels of social capital; and ensuring participant anonymity may be the best way to avoid non-response bias. Implications of these results as well as suggestions for future research and practice are discussed, including further refinement of the created survey and its use in the assessment and improvement of college student mental health
Toward Data and Annotation Efficient Algorithms for Medical Image Analysis
No full textIn recent years, the field of medical image analysis has witnessed tremendous progress with deep learning techniques. These methods achieve state-of-the-art performance in various tasks such as disease classification, report generation, organ, tumor or cell segmentation. However, large-scale datasets are usually required to train deep neural networks. Different from natural imaging, it is usually difficult to collect a large dataset like the ImageNet for medical images, due to the huge professional efforts required by the annotation process. In addition to the limited data size, other data-related issues that are not common in natural images put challenges on medical image analysis systems. For example, publicly released medical image datasets usually annotate different subsets of organs, bringing obstacles for learning a omnipotent model for all interested targets. More challenges come from the industry situation. For instance, some institutions and companies publicly release their pre-trained model, but are unwilling to release their internal used datasets for privacy considerations. It is desired that we are able to transfer the pre-trained model to other domains or targets with the minimal sacrifice on its original performance.
This dissertation investigates the aforementioned challenges in medical image analysis, and proposes data and annotation efficient methods that exploit traits of medial image data and improve the robustness of the system. The first part of the dissertation focuses on developing unsupervised methods to exploit unlabelled data, semi-supervised methods to utilizing partially labelled data, and weakly-supervised segmentation methods. The second part of the dissertation focuses on addressing practical challenges encountered in industry, improving the transferability and robustness of algorithms
UNDERSTANDING SOCIAL AND STRUCTURAL FACTORS ASSOCIATED WITH HIV AND TUBERCULOSIS OUTCOMES AMONG WOMEN LIVING WITH HIV IN SUB-SAHARAN AFRICA
No full textBackground. Two-thirds of the global population of people living with HIV are living in sub-Saharan Africa, and most new infections of HIV are among women. The leading cause of death among people living with HIV in Tuberculosis (TB). Sustained access and adherence to antiretroviral therapy (ART) is needed to reduce HIV morbidity and mortality among women living with HIV. The goal of this dissertation is to assess social and structural factors associated with ART use and recent TB diagnosis among women living with HIV; and evaluate the potential impact of violence reduction on HIV-related deaths.
Methods. This dissertation used data from 10719 women living with HIV who participated in the People Living with Stigma Index 2.0 Study from 11 countries in sub-Saharan Africa. First, we assessed the associations between violence, employment discrimination, and reproductive coercion with consistent ART use. Secondly, we assessed the associations between economic stability and employment discrimination with recent TB diagnosis. Lastly, we used a compartment model to assess the potential impact of reductions in violence on HIV-related deaths among women living with HIV in Kenya.
Results. Overall, 82.9% of women reported consistent ART use and 7.6% of participants reported recent TB diagnosis. Sexual violence, partner control, and verbal abuse were associated with a decreased odds of consistent ART use regardless of the presence of gender-based violence protection policies. Consistent ART use was negatively associated with recent experiences of reproductive coercion related to family planning and pregnancy regardless of the presence of non-discrimination protection policies. Among women in countries without non-discrimination protections, recent TB diagnosis was positively associated with being refused employment, income, or promotion due to HIV status, but these associations were not observed in setting with non-discrimination protections. Reducing new and recurrent violence by 25% may result in 1488 HIV-related deaths averted among women living with HIV in Kenya between 2023 and 2030.
Conclusions. Equitable access to safety, healthcare, economic opportunities, and protections for women living with HIV remains unmet. Establishment and enforcement of protective policies alongside interventions across social-ecological levels and sectors may improve ART adherence, TB control, and wellbeing among women living with HIV
THE THREAT OF FOREIGN INFLUENCE ON THE U.S. ACADEMIC RESEARCH AND NATIONAL SECURITY: CURRENT TRENDS, BEST PRACTICES, AND FUTURE DIRECTIONS
Get PDFSince 2018, the U.S. government has raised concerns about foreign influence in U.S. research threatening national security and undermining the country’s economy, science openness, academic reputation, and research integrity. Maintaining an open research environment and combating undue
foreign influence is an emerging challenge that demands serious action. The purpose of this paper is to investigate the reasons behind foreign influence and discuss the most recent federal changes. Several factors have contributed to foreign influence in U.S. academic research, such as the COI, morals/ ethics, new forms of employment, new organizational structures of modern research institutions, trends of global collaborations, and the FGTPs. Federal agencies such as the NIH, NSF, and DOD have made significant changes to strengthen their policies and increase their disclosure requirements in areas such as pre-award, post-award areas, and export control; these efforts are essential to pave the way for other necessary steps from research institutions to mitigate the risk. The DOD's new screening policy and decision matrix are beneficial in reducing research security risks and inspiring research institutions to create similar matrices using the DOD's indicators to develop risk management plans. Strict disclosure requirements and matrices to determine the risks for foreign influence are vital achievements from these federal agencies; however, more actions are required.
Honesty and transparency of disclosures are critical factors. These new policies are insufficient without transparency in the disclosure process because the disclosure of these activities falls under researchers' discretion and their perception of transparency; thus, due to the complexity of this issue and
the importance of global research collaborations, there is a need for a global academic unified digital system to serve as a real-time database for current employment and appointments of key researchers listed in research protocols. Universities can participate in this database and disclose their researchers’ appointments and employment
Alone with Cicero: authorship and community in an ancient letter collection
No full textCicero's letters occupy a vexed position in the classical canon. They were personal documents not circulated by the author himself, but rather collected and disseminated after his death. This gives the corpus a distinctly intimate feeling for scholars, inspiring both identification and rejection. This project uses close readings of letters ranging from Cicero's exile to the beginning of the Roman civil war to interrogate this intimacy, arguing that the letters not only provide access to Cicero himself, but also those he brought with him into his philosophical and literary endeavors, from scholarly influences in the past to desired collaborators in the present, as well as his enslaved literary assistants.
“Alone with Cicero” reads Cicero’s letters against the grain, highlighting the marginalized people who enabled the work of this central figure. It starts by carefully examining Cicero’s theory and practice of epistolary communication, focusing on his portrayal of himself as an author at work and as a member of an intellectual tradition. Cicero used his writing to create a community that stretched into the past, giving him refuge from the political pressures of his present. The evidence of these aspirations from the correspondence also contains traces made by individuals excluded from that community, whose work nevertheless made Cicero’s project possible: the enslaved scribes of his libraries. Their presence on the margins of Cicero’s texts has serious implications for how scholars read them, expanding our view of whose work we encounter in the works of classical literature
Marginal Cosmopolitans: US Colonial Law and Chinese Life in the Philippines, 1904-1947
No full textThis dissertation investigates how Chinese residents and their descendants troubled US governance in the Philippines between 1904 to 1947. In the early twentieth century Philippines, the US colonial government legally and socially marginalized Chinese migrants through various agencies like the Bureau of Customs and Immigration and the Bureau of Internal Revenue. Amidst exclusion and anti-Chinese commercial laws, Chinese migrants entered the islands in greater numbers, and their businesses boomed. Using legal records, oral histories, and community archives, this project analyzes a variety of tactics, ranging from formal legal instruments at local and appeals courts, as well as informal legal instruments, like smuggling. It highlights the inadequacies of colonial agencies due to corruption and underfunding. I argue that these strategies were shaped by a multi-lingual, highly networked, and legally savvy culture that characterized the Philippine Chinese. While the twentieth-century Philippines is often understood through the lens of empire, particularly as a US colony, these Chinese migrants in the islands demonstrate how these islands were also part of a vibrant and longstanding Southeast Asian world
MAGNETISM IN TOPOLOGICAL MATERIALS WITH STRONG CORRELATIONS
No full textA contemporary focus of condensed matter physics is to understand the connections between electronic band topology, magnetic excitations, and magnetic orders and the associated impacts on electronic transport properties. This thesis describes three projects exploring the magnetism of topological materials with strong electronic correlations using neutron scattering techniques.
We conducted a comprehensive neutron scattering study of low energy magnetic excitations in the breathing pyrochlore helimagnetic Cu2OSeO3. Fully documenting the four lowest energy magnetic modes that leave the ferrimagnetic confguration of the “strong tetrahedra” intact (|hω |<= 13 meV), we find gapless quadratic dispersion at the Γ point for energies above 0.2 meV, two doublets separated by 1.6(2) meV at the R point, and a bounded continuum at the X point. Our constrained rigid spin cluster model relates these features to Dzyaloshinskii-Moriya (DM) interactions and the incommensurate helical ground state. Combining conventional spin wave theory with a spin cluster form-factor accurately reproduces the measured equal time
structure factor through multiple Brillouin zones. An effective spin Hamiltonian describing the complex anisotropic inter-cluster interactions is obtained.
We used single-crystal neutron diffraction, small angle neutron scattering (SANS), and magnetization measurements to study the magnetic Weyl semimetal Co3Sn2S2.From our magnetization measurements, we fnd a separate ferromagnetic phase transition at Tc=175(5) K and a domain nucleation temperature T_nuc = 135(5) K where a single aligned domain breaks into multiple domains and the total magnetization drops to zero. However, neither the atomistic intra-domain magnetic structure probed by magnetic neutron diffraction nor the mesoscopic magnetic structure with length scale = 1.5 µm at T=145 K. This provides the first 3D characterization of the magnetic domain structure of Co3Sn2S2, which supports the abrupt domain nucleation phenomenon at T_nuc = 135(5) K.
We used time-of-flight inelastic neutron scattering to explore the exclusively dynamic magnetism of the topological Kondo insulator (TKI) candidate YbB12. Covering the entire Brillouin zone, the data juxtapose weak dispersion with a strongly Q-dependent oscillator strength for two resonant modes and a continuum. The absence of intensity at the Γ point shows the excitations are spatially extended as opposed to local transitions between crystal electric feld levels. They appear to be collective in-gap excitations of the d-f hybridized bands. The particular Q-dependence of the hω ≈ 40 meV and hω ≈ 15 meV oscillator strength correspond to AFM correlations between nearest and next-nearest Yb neighbors, respectively. Starting from a phenomenological tight-binding band structure, we use the Anderson lattice model to simulate the magnetic exciton modes and infer the topological class of the YbB12