Digital Commons Network^™

Nematode Populations As Affected By Residue And Water Management In A Long-Term Wheat-Soybean Double Crop In Eastern Arkansas, Lucia Emperatriz Escalante Ortiz

Graduate Theses and Dissertations

Soybeans (Glycine max) are one of the major row crops in the United States, particularly in Arkansas. Soybean cyst nematode (SCN, Heterodera glycines) and southern root-knot nematode (RKN, Meloidogyne incognita) are two of the most damaging pests that cause major economic losses in soybeans. Little is known concerning the effects of common and alternative agronomic practices on nematodes in fields with nematode population densities below threshold levels. Therefore, the objective of this study was to evaluate the effects of the combination of tillage (conventional tillage and no-tillage), irrigation (irrigated and non-irrigated), wheat (Triticum aestivum) residue burning (burned and no burned), …

Women In Stem: Strategies And Recommendations For Academic Women And Institutional Leaders, Sarah Jensen

Graduate Theses and Dissertations

Women still comprise a small number of full professors in STEM disciplines in research universities, which have historically been male dominated. The National Science Foundation (NSF) has recognized the challenge of getting more women to enter the professoriate, earn tenure, and advance to full professor. These women can then encourage more women to enter into STEM as educators and researchers. The purpose of this study was to recognize, explore, and depict strategies used by women full professors to overcome obstacles they faced while advancing in academic STEM fields. The study participants also offered recommendations for women faculty desiring to become …

An Investigation Of Metal Sulfides As The Source Of The Low Emissivity Anomaly On The Highlands Of Venus, Sara Taeko Port

Graduate Theses and Dissertations

Since its detection in the 1960s the source of the unusual radar emissivity signal seen on several highlands on Venus has long eluded researchers. Researchers have determined that a mineral with a high dielectric constant could explain the signal. Using a Venus simulation chamber, we experimentally investigated this enigma to build upon the candidate mineral list that has been compiled over the last several decades. We tested the stability of 8 different minerals and elements at two to three different temperature/pressure regimes in three different gas mixtures meant to simulate the conditions found on Venus for a period of no …

Quantitative Analysis Techniques For Assessing Organelle Organization And Dynamics In Individual Cells, Isaac Vargas

Graduate Theses and Dissertations

In biomedical optics and microscopy, the organization and morphology of organelles have been widely studied. In spite of novel imaging techniques, there is still a lack of quantitative tools to easily measure cellular characteristics from image data. Previous studies have explored multiple approaches to assess organelle organization and alignment, resulting in complicated and extensive algorithms that are both subject to multiple steps of image processing and influenced by non-cellular artifacts. In this thesis, a technique called the Modified Blanket Method (MBM) is introduced to quantify organelle organization through measurements of fractal dimension (FD) on a pixel-by-pixel basis. With the use …

Studies Of Initial Growth Of Gan On Inn, Alaa Alnami

Graduate Theses and Dissertations

III-nitride materials have recently attracted much attention for applications in both the microelectronics and optoelectronics. For optoelectronic devices, III-nitride materials with tunable energy band gaps can be used as the active region of devices to enhance the absorption or emission. A such material is indium nitride (InN), which along with gallium nitride (GaN) and aluminum nitride (AlN) embody the very real promise of forming the basis of a broad spectrum, a high efficiency solar cell. One of the remaining complications in incorporating InN into a solar cell design is the effects of the high temperature growth of the GaN crystal …

Reactivity Of Photogenerated Amine Radical Cations, Qile Wang

Graduate Theses and Dissertations

Recently photoredox catalysis has emerged as a powerful tool in organic synthesis led by Professor McMillan, Stephenson, Yoon. Upon absorption of visible light, photocatalyst can be excited to its singlet state followed by intersystem crossing to form a long lived excited triplet state. While amine serves as electron donor, single electron transfer (SET) can happen between excited triplet photocatalyst and nitrogen atom on amine to give a reduced photocatalyst and amine radical cation.

Cyclopropylamines or cyclobutylamines can be oxidized by excited photocatalyst to generate amine radical cations and due to the ring strain, subsequent C-C bond cleavages can lead to …

Observations Of A Multi-Component Intervention For Elementary Students With Emotional Behavioral Disorder After Self-Efficacy Coaching, Anna Kristen Bensinger

Graduate Theses and Dissertations

Students with Emotional and Behavioral Disorders (EBD) experience more negative student outcomes compared to other special education disability categories, specifically, higher dropout rates, less access to higher education and incarceration. Mathematically, 73% of students with EBD achieve below the 50th percentile on standardized tests (Wagner, Kutash, Duchnowski, Epstein, & Sumi, 2005). This study focused on the exploration of a multi-component mathematics and behavior intervention targeting student self-efficacy for productive learning behaviors in the general education mathematics classroom setting for elementary students with EBD. Participants for this study were students from two 4th grade classrooms, who have been identified with co-occurring …

Suitability Assessment For Integrated Urban Development In Makkah City Of Saudi Arabia, Mislat Alotaibi

Graduate Theses and Dissertations

Makkah – the third most populated city in Saudi Arabia with a population of 1,684,408 according to the 2010 demographic survey conducted by the Saudi General Authority for Statistics – is experiencing urban sprawl, which can be defined as an unplanned urban expansion that might degrade the environment and diminish the aesthetic view. This is a persisting problem in Makkah driven by multitude of processes involving the random expansion in its undeveloped land and the removal of its historic mountains surrounding Al-Masjid Al-Haram (the Holy Mosque) in an attempt to push the city limit of urban capacity within its administrative …

Development Of A Comsol Microdialysis Model, Towards Creation Of Microdialysis On A Chip With Improved Geometries And Recovery, Patrick Pysz

Graduate Theses and Dissertations

Microdialysis (µD) sampling is a diffusion-limited sampling method that has been widely used in different biomedical fields for greater than 35 years. Device calibration for in vivo studies is difficult for current non-steady state analytes of interest correlated with both inflammatory response and microbial signaling molecules (QS); which exist in low ng/mL to pg/mL with molecular weights over a wide range of 170 Da to 70 kDa. The primary performance metric, relative recovery (RR), relating the collected sample to the extracellular space concentration varies from 10% to 60% per analyte even under controlled bench-top conditions. Innovations in microdialysis device design …

Improving Earthquake Disaster Models With Post-Event Data: Insights From The 2015 Gorkha, Nepal Earthquake, Bradley Steven Wilson

Graduate Theses and Dissertations

Immense amounts of data are collected following earthquake disasters. Yet, it remains unclear how researchers’ might take full advantage of diverse post-disaster datasets. Using data from the 2015 Gorkha Nepal earthquake, this dissertation explores three ways in which post- disaster survey and assessment datasets can be used to inform models of seismic risk, vulnerability, and recovery processes. The first article presents an empirical analysis of scale issues in disaster vulnerability indices using a novel dataset of 750,000 households. This study finds that using aggregated household data to create social vulnerability indices can produce results that are meaningfully different from equivalent …

Quantitative Study Of The Antimicrobial Effects Of Silver On The Motility Of Escherichia Coli, Benjamin Russell

Graduate Theses and Dissertations

In recent decades, the number of antibiotic-resistant bacterial infections has grown to become a serious global threat. This rise can be attributed to the widespread misuse of antibiotics and the lack of newly developed drugs to fight resistant organisms. Novel bactericidal substances have, therefore, garnered significant research interest. Silver, due to its powerful antimicrobial effects, is one such substance. Silver is typically most effective in cationic form; however, advancements in nanotechnology have paved the way for the controlled fabrication of nano-silver. Silver nanoparticles have been shown to have increased antibacterial potency for a variety of reasons, including the release of …

The Shelf To Basin Transition And Tectonostratigraphy Of The Atoka Formation (Lower Pennsylvanian) In The Arkoma Basin, Northwest Arkansas, Travis Gibson White

Graduate Theses and Dissertations

The east-to-west oriented Arkoma Basin is a peripheral foreland basin or depositional trough that developed during the Carboniferous Period. This formation covers an aerial extent of approximately 33,800 square miles and spans from west-central Arkansas into southeastern Oklahoma (McGilvery, Manger, and Zachry, 2016; Perry, 1995). The Atoka Formation, deposited during the early Pennsylvanian, is the largest Paleozoic formation by aerial extent in the state of Arkansas and is located within and comprises the bulk of Arkoma Basin sediments (McFarland, 2004; Nance, 2018). This formation has been informally divided into three divisions, the lower, middle, and upper, based on their stratigraphic …

The Van Hiele Analysis Of Curricular Materials: A Comparative Study, Vinay Kumar Kalyankar

Graduate Theses and Dissertations

The goal of this study is to investigate K-8 geometry curriculum standards and textbooks for their effectiveness in preparing students for high school geometry. The basis for the study is van Hiele theory pioneered by the Dutch educators and researchers of geometric understanding in adolescents, Dina van Hiele Geldof and Pierre van Hiele. Another driving force for this dissertation is research into mathematics textbooks and curriculum standards of school mathematics as seen in CCSSM and state specific standards documents, both of which influence the mathematics students have the opportunity to learn.

The K-8 geometry curriculum standards and textbook instructional segments …

Strategies To Improve Forage Utilization By Sheep Offered Forage Mixtures, Valens Niyigena

Graduate Theses and Dissertations

In the first experiment, alfalfa and novel endophyte-infected tall fescue (NE+) forages were harvested after a killing frost, then mixed to formulate 4 different treatments; alfalfa alone, 67% alfalfa +33% fescue, 33% alfalfa + 67% fescue, or 100% fescue. After 3 months of storage as silage, Dorper ewe lambs (n = 20; mean BW = 34.7 ± 6.65 kg) were fed silage for ad libitum consumption, using 5 animals per treatment. Increasing the proportion of NE+ tall fescue improved (P < 0.05) silage total acids and lactic acid concentrations and decreased silage ammonia concentration. Digestible dry matter and organic matter intake and nitrogen utilization parameters decreased with increasing inclusion of NE+ in diet. In the second experiment, 16 Dorper ewe lambs (41.8 ± 4.61 kg BW) were assigned to 4 different treatments; alfalfa silage alone (0 g/kg; CONT) or alfalfa silage mixed with chopped sericea lespedeza (SL) hay to provide 90 (LOW), 180 (MED), or 270 g/kg SL (HIGH) on a dry matter basis in a randomized complete block design experiment with 2 period to provide 4 observations per treatment for each experimental period. Increasing the proportion of sericea lespedeza in the diet decreased dry matter and organic matter digestibility but did not affect feed intake. Fecal nitrogen (g/kg N intake) increased linearly (P < 0.01) while urinary N (g/ day and g/ kg of N intake) tended to decreased linearly and quadratically (P ≤ 0.1) with increasing the proportion of SL in diet. In the third experiments, 16 gestating Dorper ewe lambs (49.1 ± 4.61 kg BW) were allocated to 4 treatments; alfalfa silage alone (0% g/kg; CONT) or alfalfa silage mixed with lablab purpureus(LP) hay to provide 90 (LOW), 180 (MED), or 270 g/kg LP (HIGH) on a dry matter (DM) basis, in a randomized complete block design experiment with a total 8 replication per treatment. Supplementation of LP in diet increased quadratically (P ≤ 0.04) forage dry matter, organic matter intake, digestible dry matter and digestible organic matter intake (P < 0.05). Nitrogen apparently absorbed and urinary N both decreased linearly (P < 0.01) with adding more LP hay in diet. Harvesting and mixing alfalfa and fescue after a killing frost improved silage fermentation characteristics and supplementation of tannins from SL and polyphenol from LP altered N excretion.

Key words: lablab, sericea lespedeza, alfalfa silage, nitrogen, sheep.

Contrasting Geometric Variations Of Mathematical Models Of Self-Assembling Systems, Michael Sharp

Graduate Theses and Dissertations

Self-assembly is the process by which complex systems are formed and behave due to the interactions of relatively simple units. In this thesis, we explore multiple augmentations of well known models of self-assembly to gain a better understanding of the roles that geometry and space play in their dynamics. We begin in the abstract Tile Assembly Model (aTAM) with some examples and a brief survey of previous results to provide a foundation. We then introduce the Geometric Thermodynamic Binding Network model, a model that focuses on the thermodynamic stability of its systems while utilizing geometrically rigid components (dissimilar to other …

Interpreting Potential Groundwater Policies Through Modeling Of Market And Non-Market Benefits And Costs, Grant H. West

Graduate Theses and Dissertations

Current policies leveraging financial incentives and improved irrigation efficiency to mitigate groundwater scarcity have not proven to curtail trends of resource depletion. Groundwater benefits cannot be appropriately valued solely on market forces, and so deeper policy consideration is warranted under a framework that considers the importance of groundwater across all its values to society. Understanding time preferences for groundwater management and preferences for alternative policies is vital to inform efficient policies. Furthermore, climate change remains politically controversial yet has important consequences for critical groundwater resources and their sustainable long-term management. Proliferating policy narratives concerning climate change could influence the way …

The Cognition Of Controversy: Examining Policy Elites’ Narrative Cognition And Communication Around Hydraulic Fracturing Practices In The U.S., Rachael M. Moyer

Graduate Theses and Dissertations

The use of hydraulic fracturing (HF) technologies to extract oil and gas in the United States has sparked contentious policy debates, producing inconsistent and inefficient policies that have done little to address the impacts of HF in any comprehensive way. Debates are accompanied by competing policy narratives that position HF as either an environmental threat or an economic opportunity, but little is known about how policy narratives around HF are used by individuals. This dissertation systematically examines how individuals cognitively internalize elements of competing HF policy narratives. Organized into three empirical chapters, this dissertation analyzes narrative cognition (Jones, Shanahan, and …

Aglycon Modifications Of Ipomoeassin F: Synthetic Route Development And Analog Synthesis To Enable Further Sar Studies, Eric Barber

Graduate Theses and Dissertations

The ipomoeassin family of resin glycosides were discovered to have a high potency against numerous cancer cell line, with ipomoeassin F being the most potent among the family of natural products. Interestingly, one of the few differences between ipomoeassin F and the other compounds is the length of the fatty-acid derived aglycon. As the mechanism of action for this family of resin glycosides is unknown and didn’t have any significant COMPARE correlation with the recorded anticancer agents in the National Cancer Institute (NCI), further SAR studies are needed. Drawing on the differences between ipomoeassin F and the other ipomoeassins, it …

Development Of Forward Osmosis Based Separations: A Novel Approach In Membrane Technology, Yu-Hsuan Chiao

Graduate Theses and Dissertations

Tackling the worldwide severe water shortage, the membrane technology is considered to be the most efficient approach and hence, used widely as a cost-effective sustainable solution. “Forward osmosis (FO)” has been the major attention in recent time. FO uses osmotic pressure as the driving force to draw the water passing the membrane and achieve the desired separation performance. In general, it is considered to be a process with tremendous potential to resolve the present-day water shortage with extremely low energy consumption. However, the challenges of membrane and draw solution regeneration associated with FO processes must be conquered prior to their …

Eastern Collared Lizard (Crotaphytus Collaris) Population Declines In Ozark Landscapes: An Assessment Of Environmental Constraints., Casey L. Brewster

Graduate Theses and Dissertations

The Eastern Collared Lizard (Crotaphytus collaris) has experienced extensive population declines over the past half century in the Ozark Mountains. Previous research suggests that glade habitat degradation through woody vegetation encroachment is an important factor resulting in population declines. In this dissertation I used information on time-energy budgets to investigate the link between habitat degradation and shifts in life history traits likely resulting in population declines of Eastern Collared Lizards (Crotaphytus collaris) in the Ozarks. In chapter one, I addressed the influence of dense woody vegetation encroachment on age-specific growth, body size, body condition and reproduction of C. collaris in …

The State Of State History: Teacher Perceptions Regarding The Place And Purpose Of State History In K–12 Social Studies, Shay Hopper

Graduate Theses and Dissertations

Social studies, history, and state history courses, in general, have long been broadly considered the least significant of the four core content courses in K – 12 education. State history is required and/or taught inconsistently throughout the 50 states, and in some cases, not at all. Teacher preparation and on-going support to teach state history in K – 12 education are also inconsistent and often disregarded. The purpose of this exploratory qualitative survey and interview study was to investigate teacher perceptions regarding place and purpose of state history in K – 12 social studies, and to identify teacher dispositions toward …

Countering Cybersecurity Vulnerabilities In The Power System, Fengli Zhang

Graduate Theses and Dissertations

Security vulnerabilities in software pose an important threat to power grid security, which can be exploited by attackers if not properly addressed. Every month, many vulnerabilities are discovered and all the vulnerabilities must be remediated in a timely manner to reduce the chance of being exploited by attackers. In current practice, security operators have to manually analyze each vulnerability present in their assets and determine the remediation actions in a short time period, which involves a tremendous amount of human resources for electric utilities. To solve this problem, we propose a machine learning-based automation framework to automate vulnerability analysis and …

Pixel-Level Deep Multi-Dimensional Embeddings For Homogeneous Multiple Object Tracking, Mateusz Mittek

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

The goal of Multiple Object Tracking (MOT) is to locate multiple objects and keep track of their individual identities and trajectories given a sequence of (video) frames. A popular approach to MOT is tracking by detection consisting of two processing components: detection (identification of objects of interest in individual frames) and data association (connecting data from multiple frames). This work addresses the detection component by introducing a method based on semantic instance segmentation, i.e., assigning labels to all visible pixels such that they are unique among different instances. Modern tracking methods often built around Convolutional Neural Networks (CNNs) and additional, …

Controlled Vocabularies Versus Social Tags: A Brief Literature Review, Arindam Sarkar, Prof. Udayan Bhattacharya

Library Philosophy and Practice (e-journal)

The present study is a literature review, based on the comparative study between controlled vocabularies and social tags from various perspectives. Critical comments of experts on similarities, co-relationship, uses, trends between controlled vocabularies and social tags have found their manifestation in this literature review. Through this study an effort has been made to portray the overall picture of previous research regarding this topic.

Information Visualization Research Publications During 1990-2018: A Scientometric Analysis, Kunwar Singh, Abhishek Ranjan, Somesh Rai

Library Philosophy and Practice (e-journal)

To understand the history and research status of information visualization, information visualization research citation data has been collected from the Scopus expanded during the period from 1990 to 2018. Results indicated that the research of information visualization has increased during the studied 29-year period. The country with the highest research output was the United States with 1996 publications, while the institution with the highest research output was the CNRS Centre National de la Recherche Scientifique. The majority of research articles have been contributed from developed countries. It also revealed that developed countries have more research advantages in comparison to developing …

Some Results And Examples On Vertex Equitable Labeling, Mohamed Saied Aboshady, Reda Amin Elbarkoki, Eliwa Mohamed Roshdy, Mohamed Abdel Azim Seoud

Basic Science Engineering

In this paper we present a survey for all graphs with order at most 6 whether they are vertex equitable or not and we get an upper bound for the number of edges of any graph with 𝑝 vertices to be a vertex equitable graph. Also, we establish vertex equitable labeling for the 𝑚-chain of the complete bipartite graph 𝐾2,𝑛 and for the graph 𝑃𝑛 × 𝑃𝑚.

Tracking Political Events In Social Media: A Case Study Of Hong Kong Protests, Haodi Qi, Hanyu Jiang, Wende Bu, Chengzi Zhang, Kyong Jin Shim

Research Collection School Of Computing and Information Systems

In this study, we analyze social conversations about Hong Kong Protests, a series of events that were widely seen and debated in social media in 2019. Our system collects data from Twitter and Reddit using their APIs. It performs sentiment analysis, and the analysis results show changes in public sentiment around major events. Social network analysis reveals influencers - users that are in the center of social conversations. Our interactive Tableau dashboard allows the user to easily monitor live social conversations about Hong Kong protests.

Punctuation Prediction For Vietnamese Texts Using Conditional Random Fields, Hong Quang Pham, Binh T. Nguyen, Nguyen Viet Cuong

Research Collection School Of Computing and Information Systems

We investigate the punctuation prediction for the Vietnamese language. This problem is crucial as it can be used to add suitable punctuation marks to machine-transcribed speeches, which usually do not have such information. Similar to previous works for English and Chinese languages, we formulate this task as a sequence labeling problem. After that, we apply the conditional random field model for solving the problem and propose a set of appropriate features that are useful for prediction. Moreover, we build two corpora from Vietnamese online news and movie subtitles and perform extensive experiments on these data. Finally, we ask four volunteers …

Pieces Of Contextual Information Suitable For Predicting Co-Changes? An Empirical Study, Igor Scaliante Wiese, Rodrigo Takashi Kuroda, Igor Steinmacher, Gustavo A. Oliva, Reginaldo Ré, Christoph Treude, Marco Aurélio Gerosa

Research Collection School Of Computing and Information Systems

Models that predict software artifact co-changes have been proposed to assist developers in altering a software system and they often rely on coupling. However, developers have not yet widely adopted these approaches, presumably because of the high number of false recommendations. In this work, we conjecture that the contextual information related to software changes, which is collected from issues (e.g., issue type and reporter), developers’ communication (e.g., number of issue comments, issue discussants and words in the discussion), and commit metadata (e.g., number of lines added, removed, and modified), improves the accuracy of co-change prediction. We built customized prediction models …

Strongly Leakage Resilient Authenticated Key Exchange, Revisited, Guomin Yang, Rongmao Chen, Yi Mu, Willy Susilo, Guo Fuchun, Jie Li

Research Collection School Of Computing and Information Systems

Authenticated Key Exchange (AKE) protocols allow two (or multiple) parties to authenticate each other and agree on a common secret key, which is essential for establishing a secure communication channel over a public network. AKE protocols form a central component in many network security standards such as IPSec, TLS/SSL, and SSH. However, it has been demonstrated that many standardized AKE protocols are vulnerable to side-channel and key leakage attacks. In order to defend against such attacks, leakage resilient (LR-) AKE protocols have been proposed in the literature. Nevertheless, most of the existing LR-AKE protocols only focused on the resistance to …