Texas A&M University – Corpus Christi
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The influence of distance on throwing kinematics in young health baseball players
No full textBiomechanics Lab, KinesiologyDue to the high-intensity and repetitive nature of the throwing motion, baseball players are prone to arm injuries. There is a sudden rise in angular velocity through the kinematic chain as players increase their throwing distance. (Loftice, J., 2004) Long-toss routine is seen as a tool implemented in the hopes to reduce injury. (Fleisig G. et. al, 2011) This regimen consisted of players gradually increasing their throwing distance on both flat and a mound. Distinguishing whether a program can be advantageous or detrimental in its implementation is crucial
Effect of observation on exhaustion and social physique anxiety
No full textA thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Kinesiology.Introduction: Exercising in a crowd could make some people more anxious regarding their body which can affect exercise performance (McCann et al., 2007; Gammage et al., 2009). A construct within anxiety, social physique anxiety (SPA) combines body image with social anxiety, by measuring the apprehension reported when one worries about others’ perception of one’s body structure (Hart et al., 1989). General anxiety has been found to be associated with fatigue (McCann et al., 2007), but whether crowd-related anxiety is also associated with more risk of fatigue is uncertain. Purpose Statement: This study examined the differences in exhaustion and SPA following exercising while being observed versus without observation. Methods: Fifteen recreationally active volunteers were recruited as participants. Exercise testing was performed in two different sessions through the cycling maximal oxygen consumption test, at fixed speed for each participant. SPA scoring was done using a nine-item questionnaire before and after each session. While one session of testing for everyone involved no recording, another included a recording device being set up. After each session, participants were requested to give their rate of perceived exertion (RPE) ratings. Repeated measure nonparametric test was used to analyze the differences in all scores between and within the two sessions. Results: Differences in each question of SPA were trivial to moderate. Large difference was observed for male participants’ respiratory exchange ratio (RER). Trivial differences were observed between the two sessions for time to exhaustion. Small negative correlations were noted between RPE and SPA and between SPA and time to exhaustion (TTE).KinesiologyCollege of Education and Human Developmen
Digital divide in ICT literacy among teachers in South Texas school districts
No full textA dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Education in Educational Leadership.The use of Information and Communication Technology (ICT) has profoundly impacted and transformed how schools operate, teach, and learn. Those without access to new technologies are cut off from the huge dividends that ICT provides, commonly referred to as the digital divide. The digital divide is a complex and layered phenomenon, which extends beyond issues of physical access. Digital learning tools are inaccessible and underutilized by students from low-income families in South Texas and beyond. The digital literacy skills of teachers play a key role in preparing students, particularly those without sufficient access to ICT, for meaningful participation in complex digital spaces. The purpose of this quantitative, non-experimental, predictive study was to examine the digital disparity at the second level among public school K-12 teachers in South Texas by evaluating their instructional ICT literacy based on their foundational internet skills and usage types. Using van Dijk’s causal and sequential model of access to ICT (2005) as the basis, this study focused on analyzing the digital divide among teachers along the lines of school socioeconomic status. This analysis was based on teachers' ICT access (motivational, physical, skills, and usage) and digital skills (namely operational, informational, and strategic). The research adds to the existing literature on the digital divide as well as strengthening the positional category from van Dijk's model in the field of education. The study employed two survey questionnaires—the 14-item Teachers' Literacy and Skills acquired in ICT (used to measure digital literacy skills) and the 19-item Internet Usage Types (used to measure internet skills and usage types). A multiple linear regression was performed to identify if internet usage and school socioeconomic status predicted teachers' instructional digital literacy. The results of this study contribute to a better understanding of teachers' digital self-efficacy, perceived computer skills, and perceived instructional technology literacy skills in ICT, particularly for those teaching in economically disadvantaged schools. The findings from the study will help South Texas school districts and campus leaders in planning for ICT integration, staff training, and support for school technology infrastructure.Educational Leadership, Curriculum & InstructionCollege of Education and Human Developmen
Death comes for all
No full textA presentation on Folk saints and Catholic ways. “His memory is perfectly clear and serves no good, no purpose at all. He has seen things before (the fly in the bottle, the indeterminate will). Santa Muerte, Saint Death, we pray to you to swallow our breath.” ― Michael Palmer, Threa
Las voces nuevas: Emerging scholarship on Latinas in leadership
No full textThis work is licensed under the Creative Commons Attribution-Non-Commercial-NoDerivatives 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.It has been our pleasure as a team of CEDER editors and reviewers at Texas A&M University-Corpus Christi, a designated Hispanic-Serving Institution, to first make this call and now humbly present the body of work produced by Las voces nuevas. The scholarship that moved us initially was a body of dissertations produced by our own Latina doctoral students, all of whom live, work, and lead in public schools in the Rio Grande Valley, serving majority Latina/o students living in poverty. Being incredibly honored to call them our colleagues, as well as inspired by and in awe of the enormity of their work and impact on students in the border region, we not only felt their struggles and heard their pain as they lead in their current roles but were implored to illuminate their work. Their studies are based on numerous pláticas (Guajardo & Guajardo, 2013) with and testimonios (Beverly, 2005) of Latina leaders from South Texas, as well as several studies specifically from the geographic border region of Texas and Mexico. Yet, we were impassioned to further broaden the call, inviting voces nuevas from across the country. We are incredibly pleased to include this cacophony of new scholars’ voices. As noted by Martinez and Mendez-Morse (2021), the field is overdue in welcoming and embracing the insight, passions, and perspectives of Latina leaders, which must be unearthed from unpublished dissertations and laid bare on the landscape of this critical transformative period in education.Published 2023 by CEDER, Texas A&M University-Corpus Christ
UAV swarm-based synchronous array imaging for coastal environments
No full textCommittee: Dr. Baca, Dr. Starek; Program: Geospatial Computer Science (GSCS)Types of imagery: Satellite, Crewed Aircraft, Unmanned Aerial Vehicles (UAVs), What is a UAV swarm? What is flocking? What is Remote ID (RID)
Experimental and theoretical screening of core gold nanoparticles and their binding mechanism to an anticancer drug, 2-Thiouracil
No full textThis study demonstrated the capability of two readily available optical spectroscopy tools, namely UV-Vis absorption spectrophotometry and Raman/surface-enhanced Raman spectroscopy, to select in a rapid and noninvasive manner the most homogenous gold nanoparticle (AuNP) models and to identify their chemical binding mechanism to 2-thiouracil (2-TU). 2-TU is an anticancer drug of great promise in the antiproliferative and photothermal therapies of cancer. The citrate-capped AuNPs emerged as the most stable as well as time- and cost-effective AuNP model out of the three widely used colloidal nanocores (citrate-, borohydride-citrate-, and sodium dodecyl sulfate (SDS)- capped AuNPs) that were examined. 2-TU chemically attached to the relatively monodispersed AuNPs via a chemisorption mechanism. The 2-TU-AuNPs complex formed through the covalent bonding of the S atom of 2-TU to the nanosurface in a vertical orientation. The spectroscopic results were then confirmed with the help of density functional theory (DFT) calculations and other physicochemical characterization tools for nanomaterials such as transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential. Overall, the purified 2-TU-AuNPs were found to be spherical, had an average diameter of 25 ± 2 nm, a narrow size distribution (1–30 nm), a sharp localized surface plasmon resonance (LSPR) peak at 525 nm, and a negative surface charge (−14 mV).This research was funded by the SLOAN Foundation; grant number G-2018-11025. Texas A&M University at Corpus Christi (22501 and 225685) and the Welch Scholarship Program are highly acknowledged for their funding support
Fraud detection using optimized machine learning tools under imbalance classes
No full textA thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in MathematicsFraud detection is considered to be a challenging task due to the changing nature of fraud patterns over time and the limited availability of fraud examples to learn such sophisticated patterns. Thus, fraud detection with the aid of smart versions of machine learning (ML) tools is essential to assure safety. Fraud detection is a primary ML classification task; however, the optimum performance of the corresponding ML tool relies on the usage of the best hyperparameter values. Moreover, classification under imbalanced classes is quite challenging as it causes poor performance in minority classes, which most ML classification techniques ignore. Thus, we investigate four ML techniques, namely, logistic regression, decision trees, random forest, and extreme gradient boost, that are suitable for handling imbalance classes to maximize recall and simultaneously reduce false negatives. First, these classifiers are trained on two original benchmark unbalanced fraud detection datasets, namely, phishing website URLs and fraudulent credit card transactions. Then, three synthetically balanced datasets are produced for each original data set by implementing the sampling frameworks, namely, random under sampler, synthetic minority oversampling technique (SMOTE), and SMOTE edited nearest neighbor (SMOTEENN). The optimum hyperparameters for all 16 experiments are revealed using the method RandomzedSearchCV. The validity of the 16 approaches in the context of fraud detection is compared using two benchmark performance metrics, namely, area under the curve of receiver operating characteristics (AUC ROC) and area under the curve of precision and recall (AUC PR). For both Malware datasets, phishing website URLs, and credit card fraud transaction datasets, the results indicate that extreme gradient boost trained on the original data shows trustworthy performance in the imbalanced dataset and manages to outperform the other three methods in terms of both AUC ROC and AUC PR.Mathematics & StatisticsCollege of Scienc
Macroinvertebrate communities and decomposition rates of leaf and stem litter in a Texas saltmarsh-mangrove ecotone
No full textA thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Coastal and Marine System Science.After an extreme freeze event in 2021 caused extensive mangrove mortality and widespread top-kill to surviving mangroves and salt marsh vegetation along much of the Texas coast, it produced a massive flush of dead leaf and stem material in the ensuing litterfall. I questioned if there was a difference in macroinvertebrate community composition in leaf and stem litter and litter decomposition rates between Avicennia germinans (L) L, the black mangrove, and Batis maritima L, a halophytic succulent forb. In a field experiment, I used mesh litter bags to either allow or exclude macroinvertebrates and found no difference in macroinvertebrate community composition between the two litter types, suggesting they are generalists within a mesohaline and hypersaline environment. Wetness level of bags varied from dry, partially damp, mostly damp, and wet, and was significant in determining community composition parameters, with mostly damp bags having the highest abundance, richness, and diversity of macroinvertebrates. However, wetness level was not significant in determining litter decomposition (k). I found that leaf and stem litter is rapidly colonized and decomposed at 2-weeks post placement and then faunal abundance and diversity decline after 2 weeks, suggesting litter serves as a temporary “oasis” for macroinvertebrates. There was no difference in litter decomposition rate between mesh sizes, implicating that colonization by macroinvertebrates does not have a significant effect on litter decomposition, and rather it is likely being affecting by other abiotic and biotic factors or a combination of both. This study was the first to quantify B. maritima litter decomposition, with a rate of 0.098 g day-1, as compared to A. germinans litter decomposition of 0.024 g day-1. This research should inform management decisions by coastal land managers and conservationists when making management decisions concerning small invertebrate use of and effects on litter as communities shift from herbaceous saltmarsh to woody mangrove and influence the food webs of which small invertebrates are an important component.Physical and Environmental SciencesCollege of Scienc
Nitrogen and phosphorus budgets in estuaries of the Texas Coast
No full textA Thesis Submitted In Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE in Environmental Science from Texas A&M University-Corpus Christi.Estuaries are highly valuable ecosystems that depend on nutrients for their productivity. On-going urbanization and socio-economic activities are constantly affecting nutrient dynamics and estuarine organisms. The purpose of this study was to determine how hydrology affects nutrient budgets in Texas estuaries through biogeochemical budget modeling under the land-ocean interaction in the coastal zone (LOICZ) guidelines. LOICZ budgets were applied to the seven major estuaries in Texas to address the long-term water, salt, and nutrient budgets to calculate daily averages using various datasets from multiple agencies. The Laguna Madre Estuary was further separated into two budgets: the Lower Laguna Madre Estuary and the Upper Laguna Madre Estuary. The results revealed that the climate gradient plays a crucial role in the water budgets indicating that precipitation is a main driving factor to inflow balance. In addition, inflow balance is a main driving factor to salinity and nutrient concentrations among these estuaries. However, external factors such as urbanization, return flows, and agricultural runoff have elevated the nutrient levels in two estuaries. The Trinity-San Jacinto Estuary had higher daily average dissolved inorganic phosphorus (DIP) and total phosphorus (TP) levels compared to the other estuaries due to the large population density of Houston, TX, and the frequent use of detergents and possible fecal and urine waste in wastewater return flows. In contrast, the Upper Laguna Madre Estuary higher total Kjeldahl nitrogen (TKN) compared to the other estuaries due to its unique geographical features and inflow primarily dominated by sewage and agricultural runoff. The implications of these results are that altered hydrology can alter the nutrient dynamics of these estuaries and can affect biological productivity and water quality in an estuary.Environmental ScienceCollege of Scienc