Texas A&M University-Kingsville: AKM Digital Repository
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A critical vocabulary comparison of Texas 1938-39 adopted readers, the preprimer to the second reader, inclusive
No full text1. SELECTION OF PROBLEM
This problem was suggested to the writer by his experiences while supervising the teaching program In two schools that enroll only Spanish-speaking children (p.2). One school was a primary unit and the other was an elementary unit of the Mission Independent School District, Mission, Texas. These two units enrolled 998 pupils during the school year 1938-39, of which 729 were in the primary unit. The research was made because of the need for definite, accurate information concerning the reading materials that are available in the schools of South Texas
Multidisciplinary research in agriculture science
No full textWith an increased need for distance education, the need to understand student's ability to cope and learn within the distance learning environment is of utmost importance. The purpose of this study was to measure students’ perceptions of the distance education learning environment within the College of Agriculture and Natural Resources and to determine if there were any differences based upon participant demographics including biological sex, ethnicity, or major. This study was guided by the Distance Education Learning Environments Survey (DELES). The researcher found the highest student scores related to Instructor Support, and lowest related to Enjoyment of Distance Education. In a separate study, grain sorghum production faces important annual yield losses due to stalk lodging across Texas. The purpose of this study was to develop an implement to test sorghum hybrids for induced stalk lodging in the field. The implement was tested in the field to evaluate eight sorghum hybrids for stalk lodging at different heights and speeds. Data on plant characteristics was collected before and after being exposed to the treatments. The researcher found the 9 MPH treatment caused the most impact to the sorghum hybrids. The researcher also found the most impact within the sorghum hybrid containing charcoal rot
Population trends of land birds on East Foundation Ranches: an analysis of ten years of data
No full textBird surveys have been conducted on East Foundation properties in South Texas annually from 2010 to 2020 to document species occurrence, richness, and abundance. Both breeding and non-breeding bird surveys have been conducted on San Antonio Viejo, El Sauz, and Santa Rosa properties. Non-breeding surveys were conducted from August–April through the use of transect surveys. During May and June, breeding bird point count surveys were conducted. The East Foundation properties have a unique mix of avian species and vast diversity of landscape types due to their varying locations. Large ranches in South Texas, such as the ranches owned by the East Foundation, help preserve large continuous tracts of land that are critical to the survival of birds during migration. Many private landowners understand the value of documenting trends and managing for non-game birds on their property; however, few long-term bird studies exist from the ranchlands of South Texas. Long-term data sets of 10 years or longer are relatively rare, yet such data can provide unique insights into population dynamics and processes.
Two-hundred and twenty-three species were documented on the East Foundation ranches throughout the study period. However, only 52 of these species were detected frequently enough to establish population trends
P150 re-expression via targeted demethylation in ovarian cancer cells
No full textOvarian cancers rank fifth among cancer-related deaths in women in the United States. In 2019, a report estimated that 60,880 deaths occurred due to ovarian cancer. The p150 protein, encoded by Spalt-like gene2 (SALL2), is the transcriptional factor that exhibits growth arrest and pro-apoptotic properties in human ovarian cells. A high level of the p150 protein is seen in normal ovarian epithelial cells. In comparison to normal cells, the p150 protein levels were low in many human ovarian cancers, suggesting its tumor suppressor function and pro-apoptotic property.
The present study was focused on reactivation of the p150 expression through Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR-mediated) demethylation of the SALL2 promoter. The p150 protein level is reduced with methylation of the SALL2 promoter region in many ovarian carcinomas. Small guide RNA clones were constructed to target specific sites on the promoter region. This system has been modified to contain a dCas9 fused with demethylase Tet1 (Ten-Eleven Translocation Dioxygenase1), to achieve the targeted demethylation. SK-OV-3 ovarian cancer cells were transfected with a plasmid carrying pdCas9-Tet1 and guide RNAs to test if the clone leads to demethylation of the SALL2 promoter and re-expression of the p150. Western blot assays showed only negative results with the clones
Novel acceptor materials design for bulk heterojunction organic solar cells applications
No full textThe primary goal of this dissertation is to develop a new acceptor material structure to enhance the bulk heterojunction (BHJ) organic solar cells (OSC) conversion efficiency. The OPV’s efficiency has historically increased over time due to the novelty of the acceptor materials’ developments. So far, novel adjustments on the Phenyl-C61-butyric acid methyl ester (PCBM) acceptor material have improved power conversion efficiency (PCE). The adjustments affect the PCBM molecular structure by including organic compounds: Pyrazine, Pyridazine, Pyridine, and Pyrimidine instead of the Phenyl group to produce four new PCBM derivatives. These new molecules are H1-PCBM, H2-PCBM, H3-PCBM, and H4-PCBM respectively. The results show that the addition of these organic compounds into the PCBM molecule structure will adjust the PCBM fermi level for higher open-circuit voltage with Poly 3-hexylthiophene-2,5-diyl (P3HT) donor material. In addition, the new PCBM derivatives show the capability to produce more current due to the lower effective mass of the electron and the higher mobility compared to original PCBM. The electronic properties of the new derivatives are calculated by using the Density Functional Theory (DFT) on Gaussian 16 software. The results show that the new derivatives can enhance BHJ efficiency by 68%, which is greater than the previous attempts to modify the PCBM performance. The reported PCE values are 2.62%, 3.13%, 4.81%, 3.7%, and 4.41% for PCBM, H1-PCBM, H2-PCBM, H3-PCBM, and H4-PCBM respectively.
Furthermore, this dissertation explores the possibility of enhancing the Tandem organic photovoltaic (TOPV) efficiency by finding new combinations of the front and back cells that have never been reported before and with higher efficiency. This dissertation proposed a way to find new TOPV devices from the best single-junction BHJs. The results show that the use of PBDTS-TDZ: ITIC in the front cells and PTB7-Th: O6T-4F:PC71BM in the back cell gives 18.6% efficiency, while, the highest reported efficiency for TOPV was 17.3%. There are also other new combinations found here such as the use of PBDB-T-2F:TfIF-4FIC (front cell) and PTB7-Th:O6T-4F:PC71BM ( back cell) to produce 18.06% efficiency
This dissertation also includes further studies to enhance the BHJ efficiency by finding the optimum light-trapping profile for more power conversion. The results show that the calculated light-trapping profile can enhance BHJ conversion efficiency by 8%-12 %.
Moreover, this dissertation investigates the use of silver nanoparticles (AgNPs) plasmonics with different shell coating materials for more light trapping and power conversion. The simulation results show that the use of SiO2 and TiO2 will make the PCE of PTB7: PC70BM to jump from 7.79% to 8.1% and 8.03% respectively. However, the use of LiF and MgF2 will send the PCE for the same material to 8.15% and 8.13% level respectively
The transformation of a higher education change agent: women in digital administration
No full textInstitutions of higher education are no strangers to change and innovation. For these institutions to implement change there must be strong leaders who are able to act as the main change agents of the institution. Women have proven that they are capable of achieving at high standards and have the potential to be administrative leaders in higher education. In a world that is dominated by male leadership, female leaders are excelling in academics and in their career choices, especially in the field of distance education. The purpose of this quantitative, survey-based research was to examine the transformation that has occurred to the role of female leaders in higher education distance learning and to identify which factors are prevalent in this transformation. Through this research, the goal was to also identify the differences that are prevalent between women and men leaders in higher education to help exemplify the transformation of the leadership role based on gender. In addition, the study allowed for the gathering of personal perspectives on leadership and how leadership roles have been attained in higher education administration and higher education digital administration. Data collected through an internet survey helped construct a relevant relationship between the firsthand experiences and the overall success of the participants. This study employed a cross sectional, survey-based design. The dependent variable, career progression, was simply defined as the progress to better jobs or professional opportunities, while the independent variables of personal experiences, age and motivation were continuously and categorically defined. The sample for this study included 100 women administrators, which included 54 respondents that were females in the role of a digital administrator. The researcher utilized the statistical findings from the Qualtrics software to help support conclusions that extend beyond the immediate data alone. With the study data to help support the research questions, the researcher found that there was a significant relationship between career progression and the personal and professional experiences and motivation of female leaders. In addition, there were many characteristics that women in digital administration share. The researcher found that there were important factors that women deem significant in relation to their achievement and acquisition of their current position and that there is a significant relationship between those factors. Lastly, the researcher found that there is a significant relationship between the competencies and attributes identified by women administrators for leaders today
Synthesis and characterization of rhodium(III) complexes containing a bisphosphine ligand
No full textRhodium complexes containing phosphorous based ligands have been extensively studied for their ability to catalyze a myriad of reactions including hydroamination of olefins. This reaction is important for the synthesis of alkylated amines for building blocks in pharmaceuticals and fine chemicals. As of current no efficient catalytic method for hydroamination has been developed. In previous studies the synthesis of cationic rhodium(I) complexes was explored using hemilabile bisphosphine monoxide ligands (PPO). In this project one-pot reactions of RhCl3・nH2O with bisphosphine ligands PP (1,2-bis(diphenylphosphino)ethane = dppe; 1,2-bis(diphenylphosphino)-benzene = dppbz) in acetonitrile and benzonitrile were studied in detail. These reactions resulted in new rhodium(III) complexes of the type [RhCl3(PP)(RCN)] (PP = dppe, dppbz; R = Me, Ph) which were isolated and characterized by 31P NMR and IR spectroscopy, and mass spectrometry. A single crystal X-ray diffraction analysis of [RhCl3(dppbz)(MeCN)] shows a fac configuration. When the reaction of RhCl3・nH2O and dppbz was performed in THF/H2O (10 : 1) and in the presence of triphenylphosphine, a crystalline product was obtained and analyzed by X-Ray diffraction revealing a structure containing a bisphosphine monoxide ligand mer-[Rh(dppbzO)(THF)Cl3]. The reaction mechanism for the formation of this complex was investigated in detailed by 31P NMR spectroscopy and mass spectrometry, suggesting that PPh3 is acting as an oxygen shuttle and the dinuclear complex [Rh2(μ-dppbz)2Cl6] exhibits one of the key intermediates. These studies open new synthetic approaches for the synthesis of bisphosphine and bisphosphine monoxide rhodium(III) complexes, which may be useful as pre-catalyst for the alkene hydroamination reaction
Real-time face recognition with bounding box using mobile-net classifier
No full textThis work develops a system utilizing machine learning for face recognition and face detection to get the bounding boxes of faces from an input image. The proposed system uses the Haar-cascade classifier for face detection to reduce the time complexity in detecting the face and to deduce the bounding boxes of the faces quickly so that it can detect the faces in a real-time application. The system uses the bounding boxes to extract the faces from the image. The method removes the noise from the extracted face by using the edge-aware filter. The system then uses the edge detection on the extracted face to detect the edges from the face. The edges are then overlapped on the face image to improve the features, and this combined image is given to a neural network. The neural network can decide whether or not the extracted face belongs to some person within the training dataset or not. If the face belongs to a person within the training dataset, the system can display the individual name and detection accuracy percentage on the image in a label above the bounding box around the face region. The proposed method of this work reduces the time complexity for detecting the face, with an average of 0.2 seconds of computation time per image, and also has a high accuracy rate of 99%. Thus, the proposed method performs with high accuracy combined with a lower computation time, as compared to other previous methods
Analysis of survey methods and development of habitat suitability models for Rio Grande wild turkeys
No full textEstimation of population parameters are critical for effective wildlife management. However, despite research efforts, surveying low-density populations continues to be a challenge for wildlife managers. The aim of this project was to help the Texas Military Department obtain information about the abundance and habitat relationships of, low-density Rio Grande wild turkey populations on two sites. The specific objectives of this research was to (1) determine the reliability of road, roost, and camera-trap methods for estimating Rio Grande wild turkey distribution, and (2) develop habitat suitability models (HSMs) to allow Texas Military Department staff to determine the areas with the highest probability of harboring Rio Grande wild turkeys. I used Camps Swift and Bowie as my study sites. To achieve the first objective, I conducted road, roost, and camera-traps surveys on both sites for two winter seasons. Road and roost surveys resulted in very low detection rates for Rio Grande wild turkeys. On Camp Swift, morning roost surveys detected the most turkeys at 1.7 turkeys detected per hour. On Camp Bowie turkey were only detected during evening road surveys at 0.8 turkeys detected per hour. I also ran an occupancy model using camera-trap data to determine the spatial distribution of turkeys. I performed an occupancy analysis on the Camp Swift breeding season data indicated an occupancy of 38%. To achieve the second objective, I developed HSMs using landscape metrics shown to be related to landscape characteristics preferred by Rio Grande wild turkeys. I developed models for both sites during the winter and breeding season. I applied the gradient model to my HSMs to estimate a gradient of suitability across the landscape. Model results were compared to locations where turkeys were detected in the field. The model for Camp Swift breeding habitat predicted Rio Grande wild turkeys use of breeding habitat. This research shows the value of camera-trap surveys and HSMs that follow the gradient model, especially when surveying low-density populations. Camera-trap surveys can reveal how low-density populations use the landscape; and HSMs can predict the habitat use by a low-density population
The history of the oil development of Nueces County
No full textThe oil producing district of South Texas is unusual in that its trends provide producing levels from the oldest geological zones to the most recent ones at depths ranging from a few feet of the surface to many thousands of feet below the surface. Portions of the district have no limit in depth possibilities, while other areas have basement rocks at the surface. South Texas is divided into three general districts, namely Corpus Christi, Laredo, and San Antonio. These districts, in turn, are divided geologically as follows: The Corpus Christi district consists of the Greta-Frio trend, the Pettus district, the Vicksburg trend, and the Marginulina area