Digital Commons Network^™

A Case Study Of Hispanic Students In Cooperative Learning, Louis Lee

Theses and Dissertations

This research is an exploratory case study in regard to cooperative group learning. The research participants are Hispanic students taking the researcher’s physics course at a higher education institution in South Texas. Theoretical framework of this research is grounded on the theories of social interdependence, behaviorism, and cognition. The main research questions to be explored are: 1) How do students perceive cooperative learning in a community college? 2) How do students experience cooperative learning in a community college? 3) How can an instructor facilitate better cooperative learning in a community college? Pre-surveys, field journal records from observation of research participants, …

Pm2.5 Data Reliability And Air Quality Improvement Trends In Beijing, Huimin Li

Theses and Dissertations

PM2.5 has been a main environmental concern due to its adverse effects on human health and society. We used data from two sources: monitoring station of the U.S. Embassy in Beijing, and several nearby monitoring stations of the Chinese Ministry of Environmental Protection. This study includes investigating (1) PM2.5 historical data reliability, (2) PM2.5 real-time data reliability, and (3) air quality improvement trends in Beijing over the past decade. We used graphical methods, descriptive statistics, correlation analysis, and inferential analyses including paired samples t-test, ANOVA, and Kruskal-Wallis test. We reported effect sizes to aid study on practical significance. Inferential procedures' …

Polymeric Pvdf Fibers For Piezoelectric Applications In Energy Harvesting, Misael E. Martinez

Theses and Dissertations

This work focuses on developing and characterizing the piezoelectric response of Cerium doped Polyvinylidene Fluoride (PVDF) fine fibers and the effects of dopants and alignment on the formation of the β-phase and consequently on the piezoelectric performance. Six sets of fiber mats were prepared varying the concentration (2.5–7.5wt%) of Cerium (III) Nitrate-Hexahydrate and Ammonium-Cerium (IV) Sulfate-Dihydrate. Fiber mats were developed using the Forcespinning® technique and the angular velocity and dopant concentration were adjusted to obtain a synergy between fiber yield and fiber diameter. Fourier Transform Infrared Spectroscopy showed a significant enhancement in the PVDF β-phase and inhibition of the non-polar …

Effects Of Global Warming On Gonadal Functions, Cellular Apoptosis, And Oxidative Stress In The American Oyster, Sarah B. Nash

Theses and Dissertations

Global warming due to climate change is predicted to intensify the heat stress in marine and coastal organisms, affecting their development, growth and reproductive functions. In this study. I analyzed gonadal development, heat shock protein 70 (HSP70), nitrotyrosine protein (NTP), dinitrophenyl (DNP) expressions, cellular apoptosis, and coelomic fluid (CF) conditions in American oyster. Oysters were placed in six aquariums and exposed to control (24°C), medium (28°C), and high (32°C) temperatures for one week. Higher temperature significantly decreased the number of eggs and sperm. CF protein concentrations also declined compared to control. In contrast, CF pH and HSP70 expression in gonad …

Blockchain Technology Based Supply Chain Systems And Supply Chain Performance: A Resource-Based View, Madhavi Latha Nandi

Theses and Dissertations

Blockchain technology (BCT) is set to transform firms’ present ways of managing supply chains. This thesis explores how the efforts by firms to integrate BCT into their supply chain systems and activities, can enable certain supply chain capabilities and subsequently, improve supply chain performance. Using an abductive research approach, qualitative content analyses of 126 cases of firms’ efforts in BCT-based supply chain systems (BCT-SCS) across multiple industries are conducted to identify the BCT-enabled supply chain capabilities and their performance outcomes. Findings reveal that the present BCT-SCS efforts are mainly oriented towards improving the operational-level capabilities namely, information sharing and coordination …

Comment On Rojas-Bracho And Colleagues (2019): Unsubstantiated Claims Can Lead To Tragic Conservation Outcomes, Karl W. Flessa, Luis Calderon-Aguilera, Carlos E. Cintra-Buenrostro, David L. Dettman, Gregory P. Dietl, David H. Goodwin, David K. Jacobs, Michal Kowalewski, Steven M. Nelson, Kirsten Rowell, Bernard R. Schone, Jansen A. Smith, Francisco Zamora-Arroyo

School of Earth, Environmental, & Marine Sciences Faculty Publications

The vaquita’s decline is a tragic story indeed. However, the lack of action to prevent the extinction of this species is not due to unsubstantiated claims and scientific uncertainty.

Modelling Water Fluxes In Plants: From Tissues To Biosphere, Maurizio Mencuccini, Stefano Manzoni, Bradley O. Christoffersen

School of Earth, Environmental, & Marine Sciences Faculty Publications

Contents Summary 1207 I. Introduction 1207 II. A brief history of modelling plant water fluxes 1208 III. Main components of plant water transport models 1208 IV. Stand-scale water fluxes and coupling to climate and soil 1213 V. Water fluxes in terrestrial biosphere models and feedbacks to community dynamics 1215 VI. Outstanding challenges in modelling water fluxes in the soil-plant-atmosphere continuum 1217 Acknowledgements 1218 References 1218 SUMMARY: Models of plant water fluxes have evolved from studies focussed on understanding the detailed structure and functioning of specific components of the soil-plant-atmosphere (SPA) continuum to architectures often incorporated inside eco-hydrological and terrestrial biosphere …

The Role Of Technology In Bilingual Education: Developing A Culture Of Excellence, Belinda Gomez

Theses and Dissertations

According to the PEW Research Center (2014), Texas' Hispanic population comprises 39% of its overall population, twice the U. S. Hispanic population. Texas Education Agency (TEA) predicts a 14% increase in the next seven years, with a surge of about 40% in its English Language Learners (ELLs) population. Already, it reports Texas experienced a 20% student enrollment growth in the last ten years within the predominately Mexican-Americans in South Texas border. With a perpetual ELL student population increase, bilingual education programs need to consider emerging best practices. This qualitative case study explored the role of technology in bilingual education, focusing …

Object Enhancement, Noise Reduction, Conversion And Collection Of Spatiotemporal Image Data, Michael Izaguirre Jr.

Theses and Dissertations

In this report, a variety of cellular dynamics are enhanced and analyzed utilizing various algorithms and filter for contrast enhancement. This report will also illustrate the underlying complexities of processing compressed data received from certain type of sensors, their default applications, various methods in converting compressed data to compatible universal uncompressed formats allowed in scientific applications, various methods of image and video capture, guidelines in ethical image manipulation, various methods of frame extraction, and analyzing/processing video images. These methods and processes purposely utilize freeware and public domain software to lower the cost of reproducibility for all.

Comparative, Lithology-Based Biogeography Of Phreatophytic And Non-Phreatophytic Matrices Along A North-South Gradient Of The South Texas Sand Sheet, Christopher Joaquin Munoz

Theses and Dissertations

A 70km-long, N-S stratigraphic cross-section spanning the entirety of the South Texas Sand Sheet (STSS) has been rendered along Texas Interstate 69C. The cross-section indicates localized zones of substantial STSS thickness (>4m) as well as zones where the underlying Goliad Formation is either exposed or just below the surface (<0.5m). Spatial patterns of both phreatophytic and non-phreatophytic vegetation assemblages were analyzed by means of remote sensing and in situ herbaceous species evaluations. Biogeographic patterns were comprised of three vegetation matrices: P. glandulosa-dominated, Q. virginiana-dominated and a matrix of herbaceous plants. The geographic distribution of vegetation assemblages corresponded to specific lithological parameters and features. Namely, Q. virginiana concentration exhibited a positive linear relationship with the lithological parameter of STSS thickness (P =2.122x10-11) (α = 0.05). P. glandulosa/V. farnesiana …

High-Powered Led Assembly As Replacement For Conventional Hbo Lamps In High Resolution, High Magnification Microscopy System, Christian Y. Miranda Solis

Theses and Dissertations

Through decades, fluorescence microscopy has relied on mercury vapor lamps as its main light source due to their high power, broad spectrum, and bright bands generated. The use of mercury vapor lamps has remained fundamentally associated with the required lighting equipment of research laboratories. However, as time progresses, mercury vapor lamps have been slowly replaced with technologies that offered longer lifetimes, less hazardous waste, and output light at similar intensities. LED technology has been actively used in biological research, but was limited by price, lower intensities, and stability. The recent development of LED technology has allowed for further understanding and …

Teachers' Attitudes And Perceptions On Bring Your Own Device Programs In The Secondary Classroom, Michelle Marie Cavazos

Theses and Dissertations

Cavazos, Michelle M., Teachers' Attitudes and Perceptions on Bring Your Own Device Programs in the Secondary Classroom. Doctor of Education (Ed.D.), March 2019, 105 pp., 3 tables, 4 figures. The purpose of this research is to investigate teacher attitudes and perceptions of Bring Your Own Device (BYOD) on learning in the secondary classroom. The study was completed as a qualitative narrative inquiry. The study took place in a high school that has had BYOD policies in place since the beginning of the establishment of the campus. The manuscript brings forward the themes and reflections that represent teacher attitudes and perceptions …

Roles Of Oxygen Vacancies And Ph Induced Size Changes On Photo- And Radioluminescence Of Undoped And Eu3+-Doped La2zr2o7 Nanoparticles, Santosh K. Gupta, Maya Abdou, Jose P. Zuniga, Partha Sarathi Ghosh, Enrique Molina, Ben Xu, Mircea Chipara, Yuanbing Mao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Defect, doping and particle size play important roles on the optical performance of nanophosphors. In this study, undoped La2Zr2O7 NPs (LZO) displayed multicolor emission under UV irradiation due to the presence of ionized oxygen vacancies in the band gap. In addition, we explored the effect of particle size of La2Zr2O7:Eu3+ (LZOE) NPs on their structure, surface area, photoluminescence, radioluminescence, lifetime and quantum yield. There is progressive decrease in luminescence output and quantum yield as the coprecipitation pH is raised to prepare the single-source precursors for the molten salt synthesis of the NPs. Under X-ray irradiation, the LZOE …

First Measurement Of The Hubble Constant From A Dark Standard Siren Using The Dark Energy Survey Galaxies And The Ligo/Virgo Binary–Black-Hole Merger Gw170814, M. Soares-Santos, A. Palmese, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Karla E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, Wenhui Wang, Adam Zadrozny

Physics & Astronomy Faculty Publications

We present a multi-messenger measurement of the Hubble constant H0 using the binary–black-hole merger GW170814 as a standard siren, combined with a photometric redshift catalog from the Dark Energy Survey (DES). The luminosity distance is obtained from the gravitational wave signal detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO)/Virgo Collaboration (LVC) on 2017 August 14, and the redshift information is provided by the DES Year 3 data. Black hole mergers such as GW170814 are expected to lack bright electromagnetic emission to uniquely identify their host galaxies and build an object-by-object Hubble diagram. However, they are suitable for a statistical measurement, …

Bayesian Inference Of Hydraulic Properties In And Around A White Fir Using A Process-Based Ecohydrologic Model, Elias C. Massoud, A. J. Purdy, Bradley O. Christoffersen, L. S. Santiago, C. Xu

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

We present a parameter estimation study of the Soil-Tree-Atmosphere Continuum (STAC) model, a process-based model that simulates water flow through an individual tree and its surrounding root zone. Parameters are estimated to optimize the model fit to observations of sap flux, stem water potential, and soil water storage made for a white fir (Abies concolor) in the Sierra Nevada, California. Bayesian inference is applied with a likelihood function that considers temporal correlation of the model errors. Key vegetation properties are estimated, such as the tree's root distribution, tolerance to drought, and hydraulic conductivity and retention functions. We find …

Luminomagnetic Nd3+ Doped Fluorapatite Coated Fe3o4 Nanostructures For Biomedical Applications, Sekar Karthi, Raji Govindan, Ajithkumar Gangadharan, Gamage Chamath Dannangoda, Karen S. Martirosyan, Dhiraj K. Sardar, Santhosh Chidangil, Girija Easwaradas Kreedapathy

Physics & Astronomy Faculty Publications

Luminomagnetic nanostructured Nd3+ doped fluorapatite (FAP) coated Fe3O4 nanoparticles were produced by hydrothermal method. X-ray diffraction analysis indicates that the prepared nanoparticles contain both FAP and Fe3O4 phases. Electron microscope analysis shows the formation of nanoparticles of Fe3O4 encased in rod shaped FAP nanoparticles of average length 40 nm. Magnetic measurements confirm the room temperature superparamagnetic nature of the nanoparticles with saturation magnetization value up to 7.8 emu/g. The prepared nanoparticles display strong near infrared (NIR) emission at 1060 nm under 800 nm excitation. Cell viability studies for 72 hour demonstrate the survival rate of over 84% with 500 μg/mL …

Effects Of Elevated Temperature On Gonadal Functions, Cellular Apoptosis, And Oxidative Stress In Atlantic Sea Urchin (Arbacia Punctulata), Jackson B. Johnstone

Theses and Dissertations

Increasing surface sea water temperatures effect on growth, reproduction and development in marine organisms. Sea urchins are excellent indicator species and ideal model organisms to focus on. In this study, I tested the effect of higher temperatures on reproductive functions, heat shock protein (HSP, a chaperone protein produced by cells in response to heat stress) and nitrotyrosine protein (NTP, an indicator of reactive nitrogen species, RNS) expressions, cellular apoptosis, and ceolomic fluid (CF, a body fluid which regulates important physiological processes) conditions in Atlantic sea urchin at three different temperatures. Ten sea urchins were placed in each of six aquariums …

A Snapshot Of The Age, Growth, And Reproductive Status Of Gray Triggerfish (Balistes Capriscus, Gmelin 1789) On Three Artificial Reefs In The Northwest Gulf Of Mexico, Adam M. Lee

Theses and Dissertations

Age, growth, and reproductive status of gray triggerfish (Balistes capriscus) were identified from 2015-2016 on artificial reefs in the northwest Gulf of Mexico. Individuals ranged from 232-432 mm fork length with and a mean fork length of 319 mm. Individuals from age 0.2 to 5.2 yrs were observed with a weight to length relationship of Wg = 1.1 x -104 x FL2.7 (r2 = 0.94, n = 112), where FL = fork length (mm) and Wg = weight (g). A von Bertalanffy growth equation of Lt = 326(1 - e - 0.9 (t + 1.71)) was calculated irrespective …

Molten-Salt Synthesized Pyrochlore Nanoparticles For Multifunctional Applications, Jose P. Zuniga

Theses and Dissertations

There is a need in the scientific world to design and develop high quality nanomaterials with multifunctional applications. In this work, we explore the molten-salt method (MSS) as a new green method for the synthesis of complex metal oxides. We adjusted all synthesis parameters such as time, temperature and pH to generate an optimum La2Hf2O7 nanoparticle with a well define shape and surface. Activator ions such as Eu3+, Tb3+, Dy3+, Bi3+ and uranium ion (U4+, U6+) were used to monitor its structural and optical behavior effect when doped.

Our results showed effective quantum yield, thermal, pressure stability, near to white …

How Chess Relates To Theory Of Mind, Noemi Trevino

Theses and Dissertations

This study aims to investigate the how playing chess relates to Theory of Mind. By design, the study will call for 160 participants recruited through social media, email, and SONA system. 60 of the participants are USCF rated players. The other 100 participants are not be USCF rated. Pending the results, the hypothesis being tested are that chess players would have a higher ToM score and that higher rated players would have a higher ToM score.

Tree-Ring Reconstructions Of Streamflow For The Tennessee Valley, Sallyrose Anderson, Ross Ogle, Glenn Tootle, Abdoul Oubeidillah

Civil Engineering Faculty Publications

This study reports the preliminary results from a statistical screening of tree-ring width records from the International Tree-Ring Data Bank (ITRDB), to evaluate the strength of the hydrological signal, in dendrochronological records from the Tennessee Valley. We used United States Geological Survey (USGS) streamflow data from 11 gages, within the Tennessee Valley, and regional tree-ring chronologies, to analyze the dendroclimatic potential of the region, and create seasonal flow reconstructions. Prescreening methods included correlation, date, and temporal stability analysis of predictors to ensure practical and reliable reconstructions. Seasonal correlation analysis revealed that large numbers of regional tree-ring chronologies were significantly correlated …

Agricultural Intensification And Urbanization Negatively Impact Soil Nematode Richness And Abundance: A Meta-Analysis, Satyendra K. Pothula, Parwinder Grewal, Robert M. Auge, Arnold M. Saxton, Ernest C. Bernard

School of Earth, Environmental, & Marine Sciences Faculty Publications

Human activity has extensively transformed the land surface by agricultural intensification and urbanization. In soil, nematodes are the most abundant invertebrates. The effect of human interventions was assessed on overall richness, overall abundance, richness and abundance of nematodes of each trophic group and colonizer-persister (c-p) guild by comparing urban, agriculture and disturbed grassland (DGL) with natural grassland (NGL) and forest ecosystems. Meta-analyses were conducted to generate quantitative summaries from 111 published articles that met the inclusion criteria, 91 expressed data in grams and 20 expressed data in cm3. Results from data expressed per 100 g of soil indicated that overall …

Low-Latency Gravitational-Wave Alerts For Multimessenger Astronomy During The Second Advanced Ligo And Virgo Observing Run, B. P. Abbott, R. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Satzhan Sitmukhambetov, Robert Stone, Darkhan Tuyenbayev, Wenhui Wang, Adam Zadrozny

Physics & Astronomy Faculty Publications

Advanced LIGO's second observing run (O2), conducted from 2016 November 30 to 2017 August 25, combined with Advanced Virgo's first observations in 2017 August, witnessed the birth of gravitational-wave multimessenger astronomy. The first ever gravitational-wave detection from the coalescence of two neutron stars, GW170817, and its gamma-ray counterpart, GRB 170817A, led to an electromagnetic follow-up of the event at an unprecedented scale. Several teams from across the world searched for EM/neutrino counterparts to GW170817, paving the way for the discovery of optical, X-ray, and radio counterparts. In this article, we describe the online identification of gravitational-wave transients and the distribution …

Palladium-Catalyzed Direct Α‑C(Sp3) Heteroarylation Of Ketones Under Microwave Irradiation, Andrew Quillen, Quynh Nguyen, Matthew Neiser, Kara Lindsay, Alexander Rosen, Stephen Ramirez, Stefana Costan, Oscar Rodriguez, Diego Rivera, Abdurrahman Atesin, Tülay A. Ateşin

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Heteroaryl compounds are valuable building blocks in medicinal chemistry and chemical industry. A palladium-catalyzed direct α-C(sp3) heteroarylation of ketones under microwave irradiation is developed and reported in this study. Under optimized conditions, twenty-eight (28) heteroarylated ketones were prepared in this study to demonstrate the substrate scope of this reaction. The ground-state optimized structure of Pd(0) active catalyst with 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (XPhos) in toluene, and the products of its reaction with 3-bromopyridine and acetophenone were studied using all-atom density functional theory. This study provided insightful information for palladium catalytic system design to generate heteroaryl compounds.

Evaluating A New Algorithm For Satellite-Based Evapotranspiration For North American Ecosystems: Model Development And Validation, Bassil El Masri, Abdullah F. Rahman, Danilo Dragoni

School of Earth, Environmental, & Marine Sciences Faculty Publications

Highlights

• We developed an algorithm to estimate evapotranspiration based solely on satellite data.

• Our model is able to track the seasonal changes in the flux tower observations.

• The errors in the model ET output were lower than the MODIS ET product.

• The modeled and observed ET strong relationship implies that our model has the potential to be applied to different ecosystems.

Abstract

We introduce a different operational approach to estimate 8-day average daily evapotranspiration (ET) using both routinely available data and the Penman-Monteith (P-M) equation for canopy transpiration and evaporation of intercepted water and Priestley and Taylor for soil evaporation. …

Vaquita Face Extinction From Bycatch. Comment On Manjarrez-Bringas, N. Et Al., Lessons For Sustainable Development: Marine Mammal Conservation Policies And Its Social And Economic Effects., Karl W. Flessa, Luis Calderon-Aguilera, Carlos E. Cintra-Buenrostro, David L. Dettman, Gregory P. Dietl, David H. Goodwin, David K. Jacobs, Michal Kowalewski, Steven M. Nelson, Kirsten Rowell, Bernard R. Schone, Jansen A. Smith, Francisco Zamora-Arroyo

School of Earth, Environmental, & Marine Sciences Faculty Publications

We are among the scientists who have documented the environmental and ecological changes to the Upper Gulf of California following the reduction in the Colorado River’s flow. We object to any suggestion that our research supports Manjarrez-Bringas et al.’s conclusion that the decline in the Colorado River’s flow is the reason for the decline in the population of the endangered vaquita porpoise (Phocoena sinus). Manjarrez-Bringas et al.’s conclusions are incongruent with their own data, their logic is untenable, their analyses fail to consider current illegal fishing practices, and their recommendations are unjustified and misdirected. Vaquita face extinction because of bycatch, …

The Rider (2019-04-08), Victor G. Ramirez

The Rider Archives

Vol.4 No.26

The Rider (2019-04-01), Victor G. Ramirez

The Rider Archives

Vol.4 No.25

Phytochemical Investigation Of Magnolia Grandiflora Green Seed Cones: Analytical And Phytoceutical Studies, Bo Garza, Alondra Echeverria, Felipe Gonzalez, Orlando Castillo, Thomas Eubanks, Debasish Bandyopadhyay

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Phytochemicals are inevitable part of human civilization. It is impossible to say exactly when menfolk started to take plant portions to cure various diseases. Phytochemical investigation of diethyl ether and ethanol extracts of Magnolia grandiflora green seed cones has been carried out. Extraction, isolation, and identification of the phytochemicals were carried out. Structures were determined by various analytical methods including extensive nuclear magnetic resonance, gas chromatography‐ mass spectroscopy, and X‐ray crystallographic analyses. Structures of the three compounds viz. 5,5′‐diallyl‐[1,1′‐biphenyl]‐2,2′‐diol (I), 3′,5‐diallyl‐[1,1′‐biphenyl]‐2,4′‐ diol (II), and (3S,3aS,8S,9aS,10aR,10bS,E)‐8‐hydroxy‐3,6,9a‐trimethyl‐3a,4,5,8,9,9a, 10a,10b‐octahydrooxireno[2′,3′:9,10]cyclodeca[1,2‐b]furan‐2(3H)‐one (III) were confirmed by X‐ray crystallographic analysis. GS‐MS studies of the isolated oil, eluted …

The Day The Shaman Came To Town, Manuel F. Medrano

History Faculty Publications

A personal narrative is presented in which author share his experience of visiting Don Jacinto Tzab Chac, a traditional Mayan shaman, to Rio Grande Valley in South Texas.