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Towards Accessible Futures: Re-imagining Space and Inclusion in Higher Education
Full text linkSince the Americans with Disabilities Act (ADA), an increased number of people with disabilities have participated in higher education, yet their experiences continue to differ from their able-bodied peers. This thesis considers these differences utilizing Dolmage’s academic ableism, Foucault’s theory of Biopower, and Lefebvre’s theory on the Production of Space. This research shows how physical infrastructure and levels of power reproduce instances of academic ableism. Utilizing a case study of a private college in Minnesota, this research draws on interviews with stakeholders, offering guidance to correct the broader social and physical exclusions created that people with disabilities encounter in higher education
Settler Colonialism and Ecosystem Change: How Ideology Has Shaped Minnesota’s Environments
Full text linkThe formation of a uniquely American land ethic—defined by European political history and Christian biblical doctrine and forged through systems of dispossession—is central to the creation of environments within the United States today. Using Minnesota as a microcosm to understand how settler colonial interactions played out all across the United States, this paper analyzes connections between violent dispossession of Indigenous people and the degradation of environments. By understanding how Ojibwe and Dakota people think about and have shaped Minnesotan lands throughout their history and comparing Indigenous land-ethics to the Euro-American-settler land ethic, this paper evaluates the role that ideology and identity have played in environmental realities within the United States. Through the process of settler colonialism, European settlers reshaped environments within Minnesota—and North America broadly—and tied themselves to landscapes through their transformation. Under a Euro-American land ethic, though, and without Indigenous land-management, much of Minnesota has lost key relationships that its ecosystems depend on, fundamentally changing landscapes as a direct result of how settlers thought about and interacted with the world around them
A War on Resistance: Police Repression and Criminalization of Land Defense Movements
Full text linkStatement of Purpose:
In this paper, I examine the roles and functions of policing in the United States in relation to environmental justice movements and protest. Building upon analyses of the history of policing and their role in enforcing and maintaining racial capitalism, I explore how the police enable and protect the destruction of land and environments. To demonstrate the intersections of policing, racial capitalism, and environmental crises I use three case studies: the protests at Standing Rock to stop the Dakota Access Pipeline, the movement to Stop Line 3, and the movement to Stop Cop City. I found my way to this paper primarily from my own involvement in the movement to Stop Line 3 here in Minnesota, which I became increasingly involved with as the uprisings following the murder of George Floyd were unfolding across the country. Seeing firsthand the police violence that land and water protectors were met with as we took action to stop the construction of a tar sands oil pipeline on treaty land, opened my eyes to the mechanisms that the police state uses to support the interests of private corporations and the resulting destruction of land, and to criminalize those who resist these projects. In this paper, I seek to be in conversation with abolitionist scholars who are using their scholarship and activism to liberate communities everywhere
Bury the Empire: Cultivating Resistance
No full textCover artwork for Tapestries 2024 - Bury the Empire: Cultivating Resistance by Ikran J. Noor, Oli Palmera Tierney, Sophia Ahmed Cook, Vivian S. Tranhttps://digitalcommons.macalester.edu/tapestriesimages/1018/thumbnail.jp
Investigation of tantalum sodium lead borate glass using laser ionization time of flight mass spectrometry (LITOF-MS)
Full text linkLaser ionization time of flight mass spectrometry (LITOF-MS) is a spectrometry method which can measure, with exceptional accuracy, the composition of ions within a glass system. Additionally, unlike other spectroscopy and spectrometry methods, this technique allows insight into the abundance of each kind of ion within a given glass system. This specific project tackled the topic of tantalum-doped sodium and lead borate glasses, as sodium and lead borate glasses doped with a transition metal is a topic which has not been thoroughly explored. Our group synthesized such a glass and was able to use LITOF-MS to gain insights into how the glass structure of said glass differs from conventional lead borate glass
Probing Charge Recombination in Organic Solar Cells
Full text linkPrintable and flexible organic solar panels are promising sources of inexpensive, large-scale renewable energy, where panels can be manufactured by printing from polymer inks. There are some limitations to these types of solar cells, however. First, toxic halogenated solvents have historically been necessary to dissolve polymers to make the ink. In addition, organic solar cells typically have high rates of recombination, which limits their efficiency. Here, we use a transient photovoltage (TPV) technique to measure charge lifetimes in cells made from two different organic solvents. The first solvent is toxic, halogenated dichlorobenzene (DCB) which is typically used to make organic solar cells. The other is a less toxic, non-halogenated solvent, carbon disulfide (CS2). By varying the processing methods in this way, we find that cells made from CS2 have longer charge lifetimes and higher efficiencies than those made with DCB, as well as a different recombination rate order. Possible reasons for these differences are explored using simple analytic modeling. Our model indicates that while bimolecular recombination is dominant in both types of cells, those processed with DCB may have more trap-assisted recombination present than those processed with CS2. Overall, this work demonstrates that we may be able to decrease the toxicity of organic solar cell manufacturing and simultaneously improve the efficiency of the devices, bringing this powerful method of capturing solar energy to the forefront of sustainable energy solutions
Carrier Mobility in Methylammonium Lead Iodide Perovskite Solar Cells: Mobility Versus Composition in Spin Coated and Vapor Deposited Samples
Full text linkWe performed research on a set methylammonium lead iodide (MaPI) perovskite solar cell samples, including samples produced both by vapor deposition and spin coating. We used time resolved THz spectroscopy to measure carrier mobility in the samples and excitation of vibrational modes in the THz and IR spectra to gauge relative sample compositions (ratio of PbI to Ma). Plotting carrier mobilities against composition ratios, we found a peaked distribution of carrier mobilities suggesting an ideal ratio of lead iodide to methylammonium to maximize mobility. We also observed that the spin coated samples had considerably less variance in their composition ratios compared to the vapor deposited samples, and were clustered close to the peak of the graph. However, while the vapor deposited samples displayed a much higher compositional variation, vapor deposited samples with compositions similar to the spin coated ones also had similarly high mobilities. This indicates that the vapor deposited samples aren\u27t inherently bad, just have more variance in their compositions
Ultraconserved Elements Based Phylogeny of the New Zealand Mite Harvester Genus Rakaia
Full text linkNew Zealand is home to a remarkable number of endemic taxa, some of which existed on the archipelago before the breakup of Gondwana. The mite harvesters (suborder Cyphophthalmi), tiny arachnids which dwell in forest leaf litter and caves, are one such group. The mite harvester family Pettalidae exhibits a classic Gondwanan distribution, informative for describing ancient patterns of diversification. Within New Zealand, there are three genera of pettalids; our research focuses on the phylogeny of the most widespread and diverse of these: Rakaia. Through phylogenetic analysis, we provide a window into patterns of ancient diversification and infer historical biogeographic trends.
The culminating phylogeny, based on ultraconserved elements retrieved using an Arachnid designed probe-set, resulted in a total of 68 taxa. The taxa were of the following breakdown: 54 Rakaia specimens, six of the sister genus Aoraki, and eight part of Opiliones outgroups. The final 50% and 75% taxon-occupancy matrix retrieved 729 and 355 loci, a large improvement from historic attempts. The phylogeny retrieved was fully resolved, and time-calibration using Bayesian Analysis yielded divergence dates across the genus. The study validated that the origin of Rakaia predates that of Gondwana, and that divergence within the genus may have been spurred by geologic events such as the Oligocene Drowning and the Last Glacial Maximum. The results need further validation through repeated attempts at time-calibration using different models, as well as estimation of evolutionary rates using Bayesian Analysis of Macroevolutionary Mixtures (BAMM). But, this study provides a novel high resolution depiction of the genus Rakaia with accompanying deep-time divergences
Prescription for Prosperity: The Dual Miracle of Antiretroviral Therapy and African Growth
Full text linkThis paper investigates the effect of antiretroviral therapy (ART) coverage on economic growth in Sub-Saharan Africa. I model the relationship following the expanded Solow Growth Model, proposing a dual health capital and educational human capital mechanism through which ART impacts growth. While previous studies propose conflicting results, I use the most comprehensive dataset, and employ theory-backed specifications to provide the most accurate and reliable estimates of the effect. Using a panel of all 48 countries in Sub-Saharan Africa, I employ a two-stage least squares shift-share/Bartik instrumental variable approach, including two-way fixed effects to estimate the effect of a rapid expansion of ART coverage on economic growth between 2001 - 2019. I show that, contrary to previous estimates, ART coverage does not have a significant effect on economic growth. While naive estimates suggest a significant relationship, these results are not robust to various specifications. I posit possible reasons for the difference to previous estimates
The Future Of Brain Tumor Diagnosis: CNN And Transfer Learning Innovations
Full text linkFor the purpose of improving patient survival rates and facilitating efficient treatment planning, brain tumors need to be identified early and accurately classified. This research investigates the application of transfer learning and Convolutional Neural Networks (CNN) to create an automated, high-precision brain tumor segmentation and classification framework. Utilizing large-scale datasets, which comprise MRI images from open-accessible archives, the model exhibits the effectiveness of the method in various kinds of tumors and imaging scenarios. Our approach utilizes transfer learning techniques along with CNN architectures strengths to tackle the intrinsic difficulties of brain tumor diagnosis, namely significant tumor appearance variability and difficult segmentation tasks. The segmentation model, based on the U-Net architecture, excels in delineating tumor boundaries with remarkable precision, while the classification model, employing EfficientNet B3, achieves high accuracy in identifying tumor types. Our findings indicate a significant improvement in the speed and accuracy of brain tumor diagnosis, offering potential benefits for clinical practice and patient care