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En-lightning Ideas: The Physics of a Thunderstorm
No full textThunderstorms are powerful natural phenomena that have awed and endangered human societies for ages. As lightning strikes can cause significant harm to human health and infrastructure, understanding why thunderstorms occur and how to protect against them is crucial. This paper follows the complete development of a thunderstorm from the first cloud to the lightning strike. First, we introduce the physics of the lower atmosphere, including the dynamics of cloud formation, the global electric circuit, and the electrification of thunderclouds. Then, we introduce the stages of the lightning flash. Focusing on the return stroke, we derive the electric field and the current from the transmission line model. Finally, we briefly examine lightning protection technology, thunder, and the future of lightning science
Turning Up the Heat: Targeting the Unfolded Protein Response in Dendritic Cells to Improve T-Cell Infiltration and Antitumor Function in Ovarian Cancer
No full textSmear slide analysis of lake sediments to evaluate impacts of humans on eight lakes on the Lac du Flambeau Reservation in Northern Wisconsin
No full textManoomin (Ojibwe)/Psiη (Dakota), or wild rice, grows in the Upper Great Lakes region and is a sacred food, medicine, gift, and relative to the many Indigenous peoples. Unfortunately, Manoomin/Psiη has been declining in the area since the mid-1800s and is impacted by a number of environmental factors. This study involves sediment cores collected in 2013 from eight lakes that bear or have borne Manoomin/Psiη on the Lac du Flambeau Band of Superior Chippewa Indians Reservation, which is located in the area now known as northern Wisconsin. The smear slide method is one way to determine lake sediment composition based on the relative proportion of detrital mineral grains, algal and vascular plant material, carbonate minerals, and siliceous microfossils (diatoms). In this study, I use smear slide analysis of six to ten one-centimeter intervals of diatomaceous organic-rich sediment from eight lakes, spanning approximately the last 200 years. For these specific lakes, only the top two most abundant components within the sediment can be reproducibly estimated using smear slides. Changes in the dominant sediment components over time in each lake relate to historic sedimentation rates and human impacts in the area. The studied lakes are unique in how they respond to human events and results demonstrate that federal land allotment, logging, recent climate change-related droughts, and shoreline development impact these lakes and watersheds. Detailed understanding of how, within each lake, sedimentation records information about the lake’s response to human influenced environmental perturbation is necessary in order to understand how Manoomin/Psiη may be impacted in the future from similar events, as well as impending changes in climate
Cancer Catalysts: Extracellular Vesicle-Mediated Horizontal Gene Transfer and Genome Integration in Metastasis
No full textThe role of extracellular vesicles (EVs) in cancer has been heavily explored in recent years, especially in containing and transferring RNA and proteins between cells to confer cancer in the body. In looking at them through the lens of horizontal gene transfer (HGT), it can be seen that also DNA and oncogenes play a primary role in cancer metastasis. EVs are able to facilitate malignant transformation, maintain drug resistance among cancer cells, and aid in building the proper tumor microenvironment to support growth. Additionally, it can be seen that once DNA is transferred into recipient cells by EVs, it integrates directly into nuclear and mitochondrial genomes, presenting evidence of HGT, and enact genotypic and phenotypic changes. Further research must be done in looking at EV function in all different cancer types, specifically looking at the transfer of EV-DNA and genes to spread cancerous growth
The Role of Climate Change in Shaping Range Shifts and Disease Transmission Dynamics Between Plants and Insects
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Bootstrap Gone Wild: Because Your Data Doesn\u27t Play By The Rules
No full textTraditional bootstrapping techniques, such as the parametric and residual bootstraps, are used to make inferences on a multiple linear regression model. However, these methods often rely on underlying assumptions about the data, such as a known distribution or homoskedastic residuals. The wild bootstrap was proposed as a way to make inferences using data from unknown distributions or with heteroskedastic residuals. We performed a simulation study to compare the performance of the wild bootstrap to other bootstrap methods on creating 95% confidence intervals for a regression coefficient β. The simulation study included datasets of varying sample sizes and degrees of heteroskedasticity. We found that the wild bootstrap using the Rademacher and normal distributions performed better than the residual, parametric bootstraps, and comparable to the nonparametric bootstrap at higher levels of heteroskedasticity and greater sample sizes
Intervals, C_3 Structure, and Realization in Tournaments
No full textWe investigate the structure of tournaments, that is the set of vertices in 3-cycles within a complete digraph. We show that two tournaments with the same structures are equivalent under a sequence of transformations known as interval inversions. The equivalence of two tournaments under interval inversion shows that the tournaments have an equal \emph{quotient graph}. We also address the following question: What are necessary and sufficient conditions for a given structure to occur in some tournament? We obtain conditions by the realization of a 3-regular hypergraph. As an expository paper, this paper condenses, improves on, and succinctly presents past work by A. Boussaïri, B. Chergui, Pierre Ille, and M. Zaïdi
