Boom and chassis articulation joints

The primary goal of our design project was to develop articulation joints for the chassis and boom of the proof-of-concept lunar vehicle. This is an ongoing project and the work of previous student groups was extensively reviewed. Some of the ideas generated are variations of past proposals. Although the project is funded by NASA/USRA, it is totally a student design effort

Sea Level Rise and the Dynamics of the Marsh-Upland Boundary

During sea level rise, salt marshes transgress inland invading low-lying forests, agricultural fields, and suburban areas. This transgression is a complex process regulated by infrequent storms that flood upland ecosystems increasing soil salinity. As a result upland vegetation is replaced by halophyte marsh plants. Here we present a review of the main processes and feedbacks regulating the transition from upland ecosystems to salt marshes. The goal is to provide a process-based framework that enables the development of quantitative models for the dynamics of the marsh-upland boundary. Particular emphasis is given to the concept of ecological ratchet, combining the press disturbance of sea level rise with the pulse disturbance of storms

Actuarial Prediction of ADHD Using Neuropsychological Data

Attention-Deficit/Hyperactivity Disorder (ADHD) is the most common psychiatric diagnosis in children and a frequent psychiatric diagnosis in adults. ADHD is a clinical diagnosis based on self-reported symptoms which makes accurate diagnosis challenging. Actuarial prediction has been demonstrated to be more accurate than clinical judgment. The current study explored an actuarial approach to predicting ADHD based on a comprehensive battery of neuropsychological tests. This project utilized test data from Meyers Neuropsychological Battery (MNB) to develop a logistic regression model to accurately predict diagnosed ADHD cases (n=65) from normal functioning cases (n=79) with a history of Mild Traumatic Brain Injury (mTBI). Binary logistic regression analysis was used to refine a predictive ADHD model based on all available test data. The final model correctly identified 73.4% of total cases. The model had 53.8% accuracy in identifying cases diagnosed with ADHD (sensitivity) and 90.5% accuracy in identifying the normal functioning mTBI control cases (specificity). This model was then compared to a theory-driven model of tests commonly associated with impaired performance in ADHD. The theory-driven model did not perform better than the data driven model. Further, as the data driven model was composed of predictor tests that are not typically associated with cognitive deficits in ADHD, the presented algorithm may be more robust to malingering than other diagnostic methods.

“Flooded Timelines: The Communicative Roles & Functions of Twitter in the 2013 Calgary Flood”

This study employs directed content analysis to examine the value and communicative uses of Twitter during the 2013 Calgary Flood from multiple perspectives. Using the Uses and Gratifications Theory (UGT) and Houston et al.’s (2014) UGT-based, framework for social media as a theoretical lens, this study finds that Twitter was a very useful tool with several affordances. It was actively used by individual citizens and several types of organizational users, whose psychological dispositions influenced how they interacted with the platform. Given that most previous disaster social media studies are written from the perspective of disaster management organizations utilizing crisis communication, this research contributes a greater understanding of both organizations’ and individuals’ communicative use of disaster social media

An Actuarial Prediction of ADHD Using Neuropsychological Data

Attention-Deficit/Hyperactivity Disorder (ADHD) is the most common psychiatric diagnosis in children and a frequent psychiatric diagnosis in adults. ADHD is a clinical diagnosis based on self-reported symptoms which makes accurate diagnosis challenging. Actuarial prediction has been demonstrated to be more accurate than clinical judgment. The current study explored an actuarial approach to predicting ADHD based on a comprehensive battery of neuropsychological tests. This project utilized test data from Meyers Neuropsychological Battery (MNB) to develop a logistic regression model to accurately predict diagnosed ADHD cases (n=65) from normal functioning cases (n=79) with a history of Mild Traumatic Brain Injury (mTBI). Binary logistic regression analysis was used to refine a predictive ADHD model based on all available test data. The final model correctly identified 73.4% of total cases. The model had 53.8% accuracy in identifying cases diagnosed with ADHD (sensitivity) and 90.5% accuracy in identifying the normal functioning mTBI control cases (specificity). This model was then compared to a theory-driven model of tests commonly associated with impaired performance in ADHD. The theory-driven model did not perform better than the data driven model. Further, as the data driven model was composed of predictor tests that are not typically associated with cognitive deficits in ADHD, the presented algorithm may be more robust to malingering than other diagnostic methods.https://jagworks.southalabama.edu/honors_college_posters/1031/thumbnail.jp

Native congeners provide biotic resistance to invasive Potentilla through soil biota

Soil biota can facilitate exotic plant invasions and these effects can be influenced by specific phylogenetic relationships among plant taxa. We measured the effects of sterilizing soils from different native plant monocultures on the growth of Potentilla recta, an exotic invasive forb in North America, and conducted plant–soil feedback experiments with P. recta, two native congeners, a close confamilial, and Festuca idahoensis, a native grass species. We also reanalyzed data comparing the ability of P. recta to invade experimentally constructed congeneric monocultures vs. monocultures of a broad suite of non-congeners. We found that monocultures as a group, other than those of the native P. arguta, were highly invasible by P. recta. In contrast, this was not the case for monocultures of P. arguta. In our first experiment, the biomass of P. recta was 50% greater when grown in soil from F. idahoensis monocultures compared to when it was grown in soils from P. arguta or P. recta monocultures. Sterilizing soil from F. idahoensis rhizospheres had no effect on the biomass of P. recta, but sterilizing soil from P. arguta and P. recta rhizospheres increased the biomass of P. recta by 108% and 90%, respectively. In a second experiment, soil trained by F. idahoensis resulted in a positive feedback for P. recta. In contrast, soils trained independently by each of the two native Potentilla species, or the closely related Dasiphora (formerly Potentilla) resulted in decreases in the total biomass of the invasive P. recta indicating strong negative feedbacks. Soil trained by P. recta also resulted in intraspecific negative feedbacks. Our results demonstrate substantial negative feedbacks for an invader in its nonnative range under certain conditions, and that native congeners can mount strong biotic resistance to an invader through the accumulation of deleterious soil biota

Prior hydration of Brassica tournefortii seeds reduces the stimulatory effect of karrikinolide on germination and increases seed sensitivity to abscisic acid

Background and Aims: The smoke-derived compound karrikinolide (KAR ) shows significant potential as a trigger for the synchronous germination of seeds in a variety of plant-management contexts, from weed seeds in paddocks, to native seeds when restoring degraded lands. Understanding how KAR interacts with seed physiology is a necessary precursor to the development of the compound as an efficient and effective management tool. This study tested the ability of KAR to stimulate germination of seeds of the global agronomic weed Brassica tournefortii, at different hydration states, to gain insight into how the timing of KAR applications in the field should be managed relative to rain events. Methods: Seeds of B. tournefortii were brought to five different hydration states [equilibrated at 15 relative humidity (RH), 47 RH, 96 RH, fully imbibed, or re-dried to 15 RH following maximum imbibition] then exposed to 1 nm or 1 μM KAR for one of five durations (3 min, 1 h, 24 h, 14 d or no exposure). Key Results: Dry seeds with no history of imbibition were the most sensitive to KAR ; sensitivity was lower in seeds that were fully imbibed or fully imbibed then re-dried. In addition, reduced sensitivity to KAR1 was associated with an increased sensitivity to exogenously applied abscisic acid (ABA). Conclusions: Seed water content and history of imbibition were found to significantly influence whether seeds germinate in response to KAR. To optimize the germination response of seeds, KAR should be applied to dry seeds, when sensitivity to ABA is minimized