Texas A&M University – Corpus Christi
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Understanding experiences of faculty from the home institution in China-U.S. transnational education programs: A phenomological case study
No full textA dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Education in Educational Leadership.Transnational education (TNE) provides an innovative approach to international education, allowing students to study in one country with a curriculum supplied by an educational institution in another. The TNE program can be delivered in multiple ways, from twinning or franchise programs to joint/double/multiple (JDM) degree programs, co-founded institutions, distance education programs, and even international branch campuses (IBCs). TNE experienced rapid growth worldwide in the early 1990s. As of today, the United States, the United Kingdom, and Australia are the primary providers and source countries for TNE programs worldwide. China, as one of the largest education markets globally, actively engages in TNE, establishing extensive collaborations with global higher education institutions to enhance international education opportunities for Chinese students. Given the growing prominence of TNE, it naturally draws the attention and focus of scholars, educational experts, and policymakers. To delve into this phenomenon, this qualitative study employed a phenomenological case study approach, drawing data from a university in the central United States. The study delves into the experiences and perspectives of a U.S. home institution faculty who are involved in TNE with China. Three participants participated in this study. Analyzing data from one-on-one interviews, participants’ curriculum vitae, and professional development resources, this study uncovered three main themes: (1) embracing passion and expertise in cross-cultural education, (2) valuing, understanding, and recognizing the needs of the cultural context in teaching, and (3) recognizing the cultural cues for necessary adjustments in instructional strategy. The findings indicate that all participants agreed on the valuable experiences of working with students from diverse cultural backgrounds. Moreover, the findings also highlight the synergistic roles of enthusiasm, cultural cognizance, and adaptability in forging efficient, inclusive, and culturally sensitive educational environments. However, administrative challenges within both home and host institutions were a shared concern, indicating potential areas for improvement. These insights are pivotal for TNE leaders in establishing effective mechanisms and specifying strategies to improve the experiences of home institution faculty and host institution students in TNE programs.Educational Leadership, Curriculum & InstructionCollege of Education and Human Developmen
Two-Species competition model with diffustion and harvesting: A numerical study
No full textA thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Mathematics.Predicting well observed states in ecology such as co-existence, competitive exclusion of one competitor, and bi-stability is vital during multi-species competitions. Models that examine these aspects of living systems have extensive applications in the overlapping areas of applied mathematics, population ecology, invasion science, evolutionary biology, and economics. The present study investigated a twin species Lotka-Volterra competition system accommodating diffusion and harvesting environments – a scenario widely anticipated in mathematical ecology. Our mathematical setup converts the diffusion and harvesting incorporated physical model into a system of second order nonlinear partial differential equations (PDES) describing the competition of the two species in closed domains. A finite difference numerical scheme is developed to solve the nonlinear boundary value problem (BVP) with Neumann boundary conditions. We applied our model results to the case of Brown and Pink shrimp in southeastern Gulf of Campeche that compete for resources in Marine Protected Areas (MPAs). For this specific example, we computed theoretical results for the sustainable biomass yield due to the competition and the mobility in the presence of multiple fishing zones. Our numerical solutions reveal that the speed or mobility of species is critical for the design of MPAs to attain a maximum sustainable biomass yield. Additionally, the results indicate that harvesting rate is adjustable for larger number of MPAs along the coastal line for efficient fishing. Further, it is observed that a sustainable biomass can be achieved for low mobile species such as the brown and pink shrimps by having smaller MPAs and both the species can co-exist in Gulf of Campeche.Mathematics and StatisticsCollege of Scienc
Insights into glacial processes from micromorphology of silt-sized sediment
No full textMeltwater plume deposits (MPDs) from marine sediment cores have elucidated clearly connected, yet difficult to constrain, relationships between ice-marginal landform construction, grounding-zone retreat patterns, and subglacial hydrology for several glacial systems in both hemispheres. Few attempts have been made, however, to infer coveted details of subglacial hydrology, such as flow regime, drainage style, and mode(s) of sediment transport through time from grain-scale characteristics of MPDs. Using MPD, till, and ice-proximal diamicton samples collected offshore of six modern and relict glacial systems in both hemispheres, we examine whether grain-shape distributions and microtexture assemblages (collectively, grain micromorphology) of the silt fraction are the result of subglacial meltwater action, or are indistinguishable from glacial proximal and subglacial sediments from the same region. We find that of all grains imaged (n=9,400), three-quarters can be described by one-quarter of the full range of measured shape morphometrics, indicating widespread and efficient abrasive processes in subglacial environments. Microtexture analysis reveals that while grains comprising MPDs show evidence of edge rounding more often than tills, fluvial microtextures occur in modest amounts on grain surfaces. Furthermore, MPDs retain many mechanical (i.e., glacial) textures in comparable abundances to tills. Significant alteration of MPDs from till sources is observed for systems (1) for which intensive, potentially catastrophic, meltwater drainage events in the Holocene are inferred from marine geologic records, and (2) with comparatively less mature till grains and a contribution of supraglacial melt to the bed, indicating that quantifiable grain-shape alteration of MPDs may reflect a combination of young till, high-energy flow of subglacial meltwater, persistent sediment entrainment, and/or long sediment transport distances. We encourage future works to integrate grain micromorphology into site-specific marine sediment analyses, which may distinguish periods of persistent, well-connected subglacial discharge from periods of sporadic or disorganized drainage and provide context needed to estimate sediment fluxes and characterize ice response to subglacial meltwater transmission. In addition, this work demonstrates that glacial and fluvial surface textures are retained on silts in adequate abundance for microtexture analysis.The authors acknowledge the captains, crews, and science parties who over the decades collected the dozens of cores sampled for this research. Funding for this research comes from a subcontract to the University of Virginia to LEM as part of the larger collaborative Thwaites Offshore Research grant (NSF OPP Grant 1738942 and Natural Environment Research Council grant nos. NE/S006664/1 and NE/S006672/1). We thank M. Esteves, V. Stanley, and the curatorial staff at the Oregon State University Marine and Geology Repository for their assistance with sample requests. D. Buskard and M. Prakash were instrumental in developing the MATLAB script. The Quanta 650 SEM is housed in the Nanoscale Materials Characterization Facility, and we thank the staff for providing the first author instrument training. Figures use the colorblind-friendly palette “Java” from the MetBrewer color package developed by B. R. Mills (https://github.com/BlakeRMills/MetBrewer). Data analysis and interpretation presented in this study was conducted at the University of Virginia in Charlottesville, Virginia. The University of Virginia was built by enslaved laborers on the unceded lands of the Monacan Nation, who have protected and 545 cultivated these lands for thousands of years. The authors acknowledge and respect their stewardship of the land, past, present, and future
Factors influencing intention to use online consumer reviews: The case of Vietnam
No full textOnline consumer reviews have been shown to play an important role that can influence consumers’ attitudes, behaviors, and purchasing decisions. This study seeks to understand factors that affect user intention to use online consumer reviews. To examine this area, this paper theorizes multiple constructs that may influence intention to use. The subjects in this study were 466 online Vietnamese consumers. The data were analyzed using structural equation modeling, and five of the seven hypotheses were found to be significant. This study found several results not found in prior studies. The construct perceived online review importance is found to be important in influencing intention to use online reviews. Both perceived usefulness and perceived credibility influenced consumers’ perceptions on the importance of online reviews. The study findings contribute to the research field of online consumer reviews and provide new insights into intention to use online consumer reviews for a developing country, different from prior studies that have focused on developed countries
Mapping optimal recharge and extraction locations for groundwater resources in Southern Sinai, Egypt: Modelling and geophysical constraints
No full textA thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Environmental ScienceGroundwater resources are the only long-term solution for the local Bedouin community who live in southern Sinai. However, the Bedouin community as a whole lacks a basic understanding of how these resources are developed, recharged, distributed, and how to use them sustainably. The present study addresses this issue by utilizing publicly available remote sensing data and techniques to model potential groundwater recharge and extraction locations. Furthermore, the study investigates the influence of structural elements, including faults and shear zones, on the spatial distribution of these locations. To calibrate and validate remote sensing-derived results, near-surface geophysical surveys such as Vertical Electrical Sounding (VES), Seismic Refraction (SR), and Ground Penetrating Radar (GPR) were employed. The findings of this study are as follows: (1) The study area comprises 15% high potential recharge regions, 37% moderate potential recharge regions, and 47% low potential recharge regions; (2) A total of 334 locations were identified at the intersections of two or more fault/shear zone systems, representing optimal sites for drilling sustainable groundwater wells; (3) Two trends of structural elements, namely NW-SE and NE-SW, were identified in southern Sinai. The spatial distribution of these structural elements, along with surface gradient, predominantly controls groundwater accumulation by providing preferred pathways for groundwater flow; and (4) Geophysical surveys indicated that areas where two or more faults and shear zones intersected exhibited thicker and shallower saturated zones (thickness 18-23.5 m; depth 5.5-12.5 m) compared to other areas (thickness 5.5-16 m; depth 7-13 m). The comprehensive findings of this study provide valuable insights into the potential recharge and extraction locations for sustainable groundwater use in southern Sinai. Moreover, the study highlights the significance of structural elements and their spatial distribution in controlling groundwater availability. The methodologies employed in this research can be utilized as a framework for similar studies in other regions with highly fractured basement terrains.Environmental ScienceCollege of Scienc
Age, growth, and mortality of King Mackerel in the western Gulf of Mexico
No full textObjective
Temporal and spatial variation in growth can have significant implications for the assessment and management of exploited populations. Therefore, the age and growth of King Mackerel Scomberomorus cavalla were estimated for the western Gulf of Mexico, where there are large gaps in the available data.
Methods
A total of 727 sagittal otoliths from 411 females, 248 males, and 68 individuals of unknown sex were collected from headboats, private recreational anglers, tournaments, and fishery-independent sampling and aged.
Result
Ages ranged from 0 to 17 years with lengths ranging from 13 to 147 cm fork length. The distribution of lengths and ages differed marginally for fishing sector (i.e., tournament vs. headboat vs. private). The fish that were collected from tournaments were larger than those collected from headboats and private anglers. The distribution of lengths and ages did vary by sex, with females obtaining larger sizes than males. However, there was no difference in mean age by sex. Using the multimodel approach, the Richards model improved the fit for both the youngest and oldest fish in the sample relative to the other growth models that were evaluated. Sex-specific differences in the Richards model were detected, with females growing larger than males but more slowly. Although peak catch was observed at age 5, King Mackerel were not fully recruited to the recreational fishery until age 6. The Chapman-Robson Peak Plus estimate of Z was 0.37.
Conclusion
These data provide a contemporary snapshot of size structure, age, growth, and mortality for King Mackerel from an undersampled region of the Gulf of Mexico and highlight several key considerations for upcoming stock assessments
Lower-Dimensional model of the flow and transport processes in thin domains by numerical averaging technique
No full textIn this work, we present a lower-dimensional model for flow and transport problems in thin domains with rough walls. The full-order model is given for a fully resolved geometry, wherein we consider Stokes flow and a time-dependent diffusion–convection equation with inlet and outlet boundary conditions and zero-flux boundary conditions for both the flow and transport problems on domain walls. Generally, discretizations of a full-order model by classical numerical schemes result in very large discrete problems, which are computationally expensive given that sufficiently fine grids are needed for the approximation. To construct a computationally efficient numerical method, we propose a model-order-reduction numerical technique to reduce the full-order model to a lower-dimensional model. The construction of the lower-dimensional model for the flow and the transport problem is based on the finite volume method and the concept of numerical averaging. Numerical results are presented for three test geometries with varying roughness of walls and thickness of the two-dimensional domain to show the accuracy and applicability of the proposed scheme. In our numerical simulations, we use solutions obtained from the finite element method on a fine grid that can resolve the complex geometry at the grid level as the reference solution to the problem.This research received no external funding
Aggregation strategies to improve XAI for geoscience models that use correlated, high-dimensional rasters
No full textComplex machine learning architectures and high-dimensional gridded input data are increasingly used to develop highperformance geoscience models, but model complexity obfuscates their decision-making strategies. Understanding the learned patterns is useful for model improvement or scientific investigation, motivating research in eXplainable artificial intelligence (XAI) methods. XAI methods often struggle to produce meaningful explanations of correlated features. Gridded geospatial data tends to have extensive autocorrelation so it is difficult to obtain meaningful explanations of geoscience models. A recommendation is to group correlated features and explain those groups. This is becoming common when using XAI to explain tabular data. Here, we demonstrate that XAI algorithms are highly sensitive to the choice of how we group raster elements. We demonstrate that reliance on a single partition scheme yields misleading explanations. We propose comparing explanations from multiple grouping schemes to extract more accurate insights from XAI. We argue that each grouping scheme probes the model in a different way so that each asks a different question of the model. By analyzing where the explanations agree and disagree, we can learn information about the scale of the learned features. FogNet, a complex three-dimensional convolutional neural network for coastal fog prediction, is used as a case study for investigating the influence of feature grouping schemes on XAI. Our results demonstrate that careful consideration of how each grouping scheme probes the model is key to extracting insights and avoiding misleading interpretations.This research was supported by grants from the National Science Foundation (2019758) and the National Science Foundation (1828380)
Distribution of polymer types in Matagorda Bay & biofilm presence on surface of plastic pollution: A study using attenuated total reflectance-Fourier Transform Infrared Spectroscopy and principal component analysis
No full textA thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Coastal and Marine System Science.Global plastic pollution presents significant environmental and economic challenges, exacerbated by mismanagement and low recycling rates. Studies have shown other pollutants like persistent organic pollutants (POPs) and heavy metals can sorb to plastic debris in aquatic ecosystems, making them more readily dispersed throughout ecosystems. This study (1) quantified the spatial and seasonal distribution of different plastic polymer types along the Matagorda Bay system, and (2) explored the nature of the biofilm form on these plastic debris and any correlation between biofilm type and polymer type throughout different seasons. This comprehensive study, the most extensive of its kind with over 3,000 samples, investigates the distribution of plastic polymers AND biofilm formation in the Matagorda and San Antonio Bays across three seasons in 2022. Attenuated total reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) along with Principal Component Analysis (PCA) was employed to identify polymer types and investigate biofilm formation on the collected samples. Polyethylene and polypropylene were the predominant polymer types observed across all sites and seasons. PCA suggested that biofilm was prevalent across all polymer types and seasons, and it is made mainly of extracellular polymer substances (EPS) that are rich in carbohydrates and proteins. Spectra integration showed a positive linear relationship between carbohydrate and protein biofilm components. This study not only provides a deeper understanding of biofilm roles in pollutant adsorption, but also introduces a novel, nondestructive approach for examining bacterial biofilms, paving the way for improved environmental management strategies.Physical and Environmental SciencesCollege of Scienc
Texas teacher retention based on principal use of influence tactics
No full textA dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Education in Educational Leadership.Due to the continuous decrease in teacher retention rates in the state of Texas, it is important to understand principals’ use of influence tactics and its effects on teacher retention. The purpose of this quantitative, nonexperimental, cross-sectional, descriptive design (Creswell & Creswell, 2018; O’Dwyer & Bernauer, 2013) study was to examine principals’ use of influence tactics on teacher retention, as well as identify differences found in gender and the total number of years within teacher retention rates. The theoretical framework used in this research was Yukle and Falbe’s influence tactic theory. The sample consisted of 50 teachers from five school districts in the greater Corpus Christi, TX area with a 784 zip code. Participants completed four demographic questions, along with the Influence Behavior Questionnaire (IBQ-G). An independent samples t test and one-way ANOVA were used to analyze the data. This study included three research questions. The first research question used an independent samples t test and the following two research questions used a one-way ANOVA. Results did not indicate a statistically significant relationship comparing the mean scores of the 11 influence tactics with teacher gender in the first research question, nor was there a statistically significant relationship in the third research question that focused on the difference in a teacher’s total number of years based on a principal’s use of influence. The second research question compared the principal use of each of the 11 influence tactics from the retention rate at a campus and results showed two influence tactics with significant results.Educational Leadership, Curriculum & InstructionCollege of Education and Human Developmen