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Earth analogue analysis of volcanic/tectonic interactions with applications to venusian stresses
No full textVenus shares many geological similarities with Earth, yet its tectonic processes and magma injection mechanisms remain poorly understood. A key question in planetary geology is how effusive volcanism persists despite the intense horizontal compression terrestrial bodies experience over time. To explore these issues, we examine the Spanish Peaks dike swarm in Colorado which serves as an ideal site for investigating magma intrusion under compressive stress conditions. Through field mapping, orientation measurements, and structural analysis, we identify a strong relationship between pre-existing joints and dike orientations, suggesting that these fractures serve as critical magma pathways in compressive regimes. Additionally, evidence of shear near dike intrusions, along with fracture angles indicative of hybrid failure, is observed in both the Spanish Peaks and the Bécuma Mons dike swarm on Venus. These findings suggest dike intrusions may locally alter the surrounding stress field, shifting it into a strike-slip regime that facilitates vertical magma migration
Utilizing novel application methods to mitigate antagonism with combinations of auxin and grass control herbicides
No full textAuxin and grass control herbicides are often applied in tank mixtures to provide multiple modes of action and to achieve broad-spectrum weed control. Literature indicates that auxin herbicides, when mixed in solution, may antagonize grass control herbicides, resulting in decreased grass weed control compared to the grass herbicide applied alone. Field and laboratory experiments were conducted in 2022, 2023, and 2024 at multiple locations in Mississippi. These experiments had three objectives: 1) evaluate grass weed control with glyphosate and clethodim in response to the simultaneous application with either dicamba or 2,4-D, using a commercially available direct-injection system compared to tank-mix combinations of the herbicides, 2) evaluate grass weed control with glyphosate and clethodim in response to the simultaneous sequential application of either dicamba or 2,4-D, utilizing a separate tank and boom sprayer system, compared to tank mix combinations of the herbicides, and 3) use non-radioactive absorption and translocation techniques to quantify and compare clethodim concentration differences in barnyardgrass (Echinochloa crus-galli (L.) P. Beauv.) plants, growing points, and the leaf surface following the application of clethodim alone, tank-mixed with dicamba, or the two herbicides applied sequentially. In general, results from field experiments suggest that grass control can be improved, compared to tank mixing, by using a direct-injection system or by applying auxin and grass control herbicides with one-pass sequential applications using separate tanks and booms. However, this conclusion is not all-encompassing for all auxin and grass control herbicide combinations. Results from the laboratory experiment indicate that clethodim and dicamba applied sequentially does not affect clethodim translocation to barnyardgrass growing points, compared to the two herbicides applied in tank mixture or clethodim applied alone when applied at 136 g ai ha-1 to barnyardgrass at the 3-4 leaf stage. However, the presence of dicamba, regardless of whether it was tank-mixed and/or applied sequentially with clethodim, elicited a delay in absorption of clethodim. These results suggest that the reduced grass activity associated with tank mix applications of clethodim and dicamba may not be due to biochemical antagonism within the plant. Rather, a delay in clethodim absorption could partly explain dicamba\u27s antagonistic impact on clethodim
Establishing a baseline for detecting LOTL attacks in Windows operating systems
No full textThere has been an increasing realization of the rise in living off the land (LOTL) attacks where adversaries misuse legitimate system tools, particularly with state-sponsored actors targeting critical infrastructure in the United States. These attacks are difficult to detect because they allow attackers to remain present in a system without the user’s knowledge for an extended period. This thesis establishes an initial baseline specifically for Windows operating systems to measure normal system activity, focusing on CPU usage, memory utilization, and process activity. It particularly examines the use of PowerShell alongside other applications. The findings from this baseline are used to develop detection rules that security tools can integrate to identify anomalies deviating from normal system metrics. Finally, recommendations are made to expand this research by analyzing additional system tools and incorporating network activity into baselines to enhance the detection of these increasingly sophisticated and damaging attacks
Digital twin technology for mobile robot navigation using Proximal Policy Optimization-enhanced RRT*-Smart algorithm
No full textDigital twin technology can play a significant role in mobile robots’ navigation by providing a virtual representation of the physical environment, robots, and their interactions. This high detail simulation can allow efficient and accurate navigation in difficult scenarios while enabling cost effective robot solutions. In this research a digital twin-based framework is proposed to facilitate mobile robot navigation throughout partially known, static environments, while making use of the strengths of a centralized system. The virtual complement digital twin of a real-world environment is first generated using previously known details such as static obstacles, walls, and passageways. The framework utilizes an improved version of RRT*-Smart for path planning, where Proximal Policy Optimization based reinforcement learning is trained using numerous planning trials of the simulation, slowly updating the algorithm’s parameters to fit the specific environment. During runtime, the digital twin system constantly updates itself in real-time using robot sensor data, allowing a dynamic window approach-based local navigation algorithm to path each robot to their respective destinations as well as improving any future path generation. The overall system is validated through the use of both path planning comparison studies as well as real-world simulation studies of navigation through a warehouse
Integrating case studies with meteorologists’ insight: Assessing meteorologists’ perception and utilization of composite indices
No full textMeteorologists from sectors, including broadcast, academia, and operations, use derived composite indices such as 0-1km and 0-3km energy helicity index (EHI), effective-layer supercell composite parameter (SCP), fixed-layer and effective layer significant tornado parameter (STP), in addition to other resources, when developing severe local storm forecasts. This study utilizes the Weather Research and Forecasting (WRF) model to create simulations of composite indices for two tornado-producing events: 31 March 2023 and 3 May 1999. With modifications to geographical location, these simulated scenarios are then utilized in the survey to gauge how meteorologists assess where tornado potential is highest. Additionally, a combination of qualitative and quantitative questions is incorporated to investigate how meteorologists perceive, interpret, and utilize these aforementioned composite indices in forecasting tornado potential. Findings may offer further improvement of the utility and reliability of forecasting tools in predicting tornado potential
Ecology and management of alligatorweed (Alternanthera philoxeroides) and an associated thrips biological control agent (Amynothrips andersoni)
No full textAlligatorweed (Alternanthera philoxeroides), native to South America, is a highly invasive aquatic macrophyte that is globally distributed and particularly problematic in the southeastern United States. In the United States, alligatorweed management has a long history, particularly of chemical and biological control. Alligatorweed management saw early success with a South American flea beetle (Agasicles hygrophila), but this agent’s utility has waned. Despite the long history of alligatorweed invasion, several important research questions remain, and the research in this dissertation seeks to answer some of these questions. This research focuses on multiple and diverse aspects of alligatorweed biology, ecology, and management: (1) the unusual development of seeds in invasive alligatorweed populations, (2) the role and utility of a South American thrips (Amynothrips andersoni) in alligatorweed biological control and integrated vegetation management (IVM), and (3) biotic and abiotic factors that predict the probability of alligatorweed invasion. Multiple instances of seed production were observed in alligatorweed growing under terrestrial, vs. aquatic conditions, but seeds seemed non-viable. Terrestrial conditions were proposed as a stimulus for seed production and polyploidy or low genetic diversity as potential mechanisms for putative non-viability. Ecological niche models of alligatorweed, the thrips, and the flea beetle confirm a poor climate match between the flea beetle and alligatorweed. These model predictions also suggest that the thrips is expected to continue to have a much greater niche overlap with alligatorweed under short-term climate change in the United States. Thrips biological control was tested alongside several submersed herbicide treatments for reducing alligatorweed biomass. While the thrips exhibited significant control, several herbicide chemistries exhibited better control. With the chemistries and rates tested in this research, no chemical controls significantly benefitted from the integration of thrips. Invasion ecology models of alligatorweed show that greater aquatic plant diversity and smaller lake perimeter best predict the presence of alligatorweed invasion in Mississippi lakes. The significant predictors of alligatorweed are contrasted with three other common invasive aquatic plants in the Southeast. Findings from this research will help direct future alligatorweed research and inform resource managers of alternative tools for alligatorweed IVM
Comparing a wearable smart sleeve to observational methods to measure ergonomic risk of Industrial Athletes on an automotive paint line
No full textWork-related musculoskeletal disorders (WMSDs) are a significant concern in industrial settings, where repetitive and awkward movements contribute to ergonomic risk. Quantifying this risk allows for a better understanding of operator movement patterns and potential adjustments that can aid in injury risk mitigation. Traditional observational methods, specifically the Rapid Upper Limb Assessment (RULA), provide ergonomic risk assessments but are limited by observer subjectivity and an inability to calculate movement durations. By utilizing wearable technology, precise kinematic and time data can be collected, allowing for more accurate assessments and a better understanding of the ergonomic risk.
To compare the effectiveness of these two methods, data was collected on an operator simultaneously by a wearable compression sleeve and a video-based assessment system. This data was analyzed to calculate a risk score based on the RULA, which is used to provide an in-depth understanding of operator movements. Wearable technology also offers additional assessment methods that can be effectively utilized over multiple individual shifts and weeks, providing near-constant measurement if desired. This more comprehensive understanding of operator kinematics can aid in lowering ergonomic risk and therefore helping to mitigate potential WMSDs. Further research is needed to continue to refine the data processing efficiency and feasibility of long-term use
Agent-based model outputs regarding error associated with drone-based animal surveys
No full textCount results from different scenarios of an agent-based model simulating various drone flight patterns across a survey area with differing animal distributions (clumped, random, uniform). Each Excel worksheet contains count results from surveys with specific numbers of animals (n = 4, 9, 25, 49, 100) programmed within the agent-based model survey area
Treasure Hunt Clues
Full text linkSix pages of brief clues to find a gift from James Franklin Frank Buchanan to his wife, Margaret Ray Buchanan.https://scholarsjunction.msstate.edu/mss-james-franklin-buchanan/1026/thumbnail.jp
Letter, James Franklin Buchanan to Mr. and Mrs. Foley, November 21, 1978
Full text linkIn this letter, dated November 21, 1978, James Franklin Buchana writes to Mr. and Mrs. Foley to check in with them and updated them on himself and his wife, Margaret. He goes on to reminisce about college life, mutual friends, and how he got started working in the Extension Services. A church schedule for the week is included as well as a page of handwritten notes.https://scholarsjunction.msstate.edu/mss-james-franklin-buchanan/1030/thumbnail.jp