Digital Commons Network^™

Analytical Modeling Of A Communication Channel Based On Subthreshold Stimulation Of Neurobiological Networks, Alireza Khodaei

School of Computing: Dissertations, Theses, and Student Research

The emergence of wearable and implantable machines manufactured artificially or synthesized biologically opens up a new horizon for patient-centered health services such as medical treatment, health monitoring, and rehabilitation with minimized costs and maximized popularity when provided remotely via the Internet. In particular, a swarm of machines at the scale of a single cell down to the nanoscale can be deployed in the body by the non-invasive or minimally invasive operation (e.g., swallowing and injection respectively) to perform various tasks. However, an individual machine is only able to perform basic tasks so it needs to exchange data with the others …

Latinx Students In Stem Education Research: A Crt And Latcrit Analysis Of Nsf Funded Projects, Hortencia Lara

Department of Educational Administration: Dissertations, Theses, and Student Research

This thesis used Critical Race Theory (CRT) and Latino Critical Race Theory (LatCrit) to conduct an in-depth analysis of whether literature funded through the use of National Science Foundation (NSF) research awards perpetuates race, racism, or other interacting systems of oppression in the research or if the investigators resisted inequalities against Latinx students in STEM research. This thesis examined how the investigators of twenty NSF-funded articles examined the experiences of Latinx students in STEM. From a CRT and LatCrit lens I analyze articles to see if and in what ways researchers are complicit with oppression and which ways they resist. …

The Influence Of Previous Subject Experience On Interactions During Peer Instruction In An Introductory Physics Course: A Mixed Methods Analysis, Judy A. Vondruska

College of Education and Human Sciences: Dissertations, Theses, and Student Research

Over the past decade, peer instruction and the introduction of student response systems has provided a means of improving student engagement and achievement in large-lecture settings. While the nature of the student discourse occurring during peer instruction is less understood, existing studies have shown student ideas about the subject, extraneous cues, and confidence level appear to matter in the student-student discourse. Using a mixed methods research design, this study examined the influence of previous subject experience on peer instruction in an introductory, one-semester Survey of Physics course. Quantitative results indicated students in discussion pairs where both had previous subject experience …

Examining The Relationships Between Prenatal Tobacco Exposure, Temperament, And Cognitive Ability In Early Childhood, Sam Pérez-González

College of Education and Human Sciences: Dissertations, Theses, and Student Research

Prenatal tobacco exposure (PTE) has been extensively researched and consistently associated with outcomes indicative of self-regulation deficits (e.g., ADHD, behavioral problems, and impaired cognitive function). Self-regulation is a multifaceted construct critical to children’s successful behavioral, emotional, and academic adjustment and involves the integration of a cognitive component (executive function) and a temperamental component (effortful control). Previous research suggests temperament may be a pathway through which PTE affects children’s future behavior and cognitive outcomes, but such studies have been limited to infancy and have not included measures of executive function. Thus, the current study had three aims: a) to examine clusters …

Spatial Variation In Western Corn Rootworm (Coleoptera: Chrysomelidae) Susceptibility To Bacillus Thuringiensis Corn Events In Nebraska, Jordan D. Reinders

Department of Entomology: Dissertations, Theses, and Student Research

The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is an economically important pest species of field corn (Zea mays L.) in the U.S. Corn Belt. Yield losses and control costs exceed greater than $1 billion annually. Over the past 10+ years, growers have adopted transgenic corn hybrids expressing rootworm-active Bacillus thuringiensis (Bt) proteins as a primary WCR management tactic. Field-evolved resistance to Cry3Bb1 and mCry3A proteins expressed in single-trait Bt hybrids has been confirmed in some areas of Nebraska. Growers have used different tactics as needed to prevent or mitigate resistance, resulting in a mosaic of selection pressure placed …

An Examination Of Political Attitudes And Behavior Using Regulatory Focus Theory, Kristen D. Deppe

Department of Political Science: Dissertations, Theses, and Student Research

Using Regulatory Focus Theory (RFT, Higgins 1997), I take a broad look at the manner in which political behaviors and attitudes are impacted by the promotion and prevention motivational systems. I first look at how behavior in life generally and political life specifically are similar in terms of regulatory focus. Second, I look at how RFT is related to political attitudes. Specifically, I look at whether there is a connection between regulatory focus and ideological attitudes, whether there is a relationship between policy context and motivational systems, and whether the status quo of a policy leads to a relationship between …

High Throughput Phenotyping Of Sorghum For The Study Of Growth Rate, Water Use Efficiency, And Chemical Composition, Piyush Pandey

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Plant phenotyping using digital images has increased the throughput of the trait measurement process, and it is considered to be a potential solution to the problem of the phenotyping bottleneck. In this study, RGB images were used to study relative growth rate (RGR) and water use efficiency (WUE) of a diverse panel of 300 sorghum plants of 30 genotypes, and hyperspectral images were used for chemical analysis of macronutrients and cell wall composition. Half of the plants from each genotype were subjected to drought stress, while the other half were left unstressed. Quadratic models were used to estimate the shoot …

Thermodynamic Limitations To Agricultural Productivity And Food Security: Livestock In Sub-Saharan Africa, Calvin Harman

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

By 2050, to feed a nearly tripling and more urbanized population in sub-Saharan Africa (SSA) will require significant increases in crop productivity throughout the region’s agricultural systems, if a greater reliance on imports is to be avoided. Increases in crop yields to maximum potential productivity (closure of crop yield gaps) can produce more calories and protein, but may be insufficient to sustain the burgeoning human population according to recent analysis (van Ittersum et al., 2016). In this thesis, alternative management options (i.e. crop allocation and crop substitutions) are found to increase total energy productivity and the thermodynamic efficiency of food …

Cultivation Of Chlorella Sorokiniana Using Beef Feedlot Runoff Holding Pond Effluent, Mitchell Klaus Goedeken

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

A study was conducted to test the suitability of utilizing beef feedlot runoff holding pond effluent for cultivating algae. The algae strain used, Chlorella sorokiniana, was previously identified as a potential energy feedstock for cattle. The previous research was initiated in pursuit of a goal to develop a cycle of utilizing nutrients from beef manure to cultivate algae and then utilizing dewatered algae as a feed supplement for beef cattle.

Runoff holding pond effluent samples were collected from commercial beef production operations in Nebraska during spring 2016. Equal portions of samples from each cooperating farm were composited and then aliquoted …

Use Of Long Term Weather Data And Spatially Delineated Field Attributes To Predict Water And Energy Conservation From Variable Rate Irrigation, Sahil Sharma

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The declining levels of the Ogallala aquifer calls for more judicious use of water. Studies have shown that VRI has the potential for water savings. But adoption of VRI is still very low. The major reason is lack of information on the returns from the VRI systems and its feasibility in different fields. Also, a quantification of the required reduction in prices of VRI is necessary. So, an economic return analysis of VRI strategies was done to compare it to uniform irrigation management (UIM) using a water balance model based on long term weather data and field properties for a …

Assessing Relationships Between Angling Effort And Larval Trematodes In Small Bluegill, Alexis Park

School of Natural Resources: Dissertations, Theses, and Student Research

I wanted to determine if catch-and-release angling increased larval trematodes in small (50-160 mm) bluegill (Lepomis macrochirus). I used angling effort as a proxy for amount of catch-and-release angling. I assumed bluegill assessed, due to their size and age, experienced catch-and-release events. I assessed larval trematode intensity, black spot (Crassiphiala bulboglossa), and white grub (Posthodiplostomum minimum centrarchi), in 750 bluegill. The first objective was to quantify the association between angling effort and reservoir area. Angling effort and reservoir area were positively correlated. The second objective was to determine if angling effort, reservoir area, bluegill …

Applying The Diffusion Of Innovation Theory To Characterize Stem Faculty Attending Professional Development Programs, Dihua Xue

Department of Chemistry: Dissertations, Theses, and Student Research

Instructional practices in undergraduate STEM courses have been static for decades, with a primary focus on lecture. Over the last twenty years, extensive research on how people learn science has led to the development of innovative instructional strategies that have been shown to enhance students’ learning and interest. These in turn have led to calls to reform instructional practices in STEM fields at the undergraduate level. However, evidence shows that these research-based instructional strategies have largely not been incorporated into classes. The promotion of these new strategies has been mostly conducted through workshops. Although numerous studies have evaluated the impact …

Developing Functionalized Peroxide Precursors For The Synthesis Of Cyclic And Spirocyclic Ethers, Anna J. Diepenbrock

Department of Chemistry: Dissertations, Theses, and Student Research

There is increasing interest in the development of methods for the synthesis of oxetanes and spirocyclic oxetanes, a class of molecules of interest to chemists as they synthesize libraries of possible drug target scaffolds with tunable physiochemical and biological properties.^1,2 Although most ethers are prepared through reaction of nucleophilic oxygen with electrophilic carbon, this work explores new reagents and routes for the synthesis of spirocyclic oxetanes based upon an application of "umpolung" or polarity reversal involving attack of nucleophilic carbon on the electrophilic oxygen of a peroxide (Scheme 1). In this work, a 2-carbon peroxide synthon for reverse etherification …

Effectiveness Of Chain Link Turtle Fence And Culverts In Reducing Turtle Mortality And Providing Connectivity Along U.S. Hwy 83, Valentine National Wildlife Refuge, Nebraska, Usa, Marcel P. Huijser, Kari E. Gunson, Elizabeth R. Fairbank

Nebraska Department of Transportation: Research Reports

We evaluated the effectiveness of existing turtle fences through collecting and analyzing turtle mortality data along U.S. Hwy 83, in and around Valentine National Wildlife Refuge, Nebraska, USA. We also investigated the level of connectivity for turtles provided through the culverts that were originally designed to pass water through a capture-mark-recapture experiment. While fenced valley sections had 33.1% fewer turtle observations than unfenced valley sections, the difference was not significant. However, we think that the effectiveness of the fence can be improved through fence repairs, other modifications of the fences, vegetation maintenance, and extending the length of the fences. Four …

Performance Assessment Of Electromagnetic Soil Water Sensors In Different Soil Textural, Temperature, And Salinity Conditions, Jasreman Singh

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Determination of accurate and continuous measurements of volumetric water content (θ_v) is extremely valuable for irrigation management and other agronomic decisions. Lately, electromagnetic (EM) sensors are being widely used to monitor θ_v continuously which also offer the benefits of ease of installation, fewer regulatory and safety concerns, and cost effectiveness. However, the accuracy of parameters [soil temperature, electrical conductivity (EC_a), dielectric permittivity (ε_ra), and θ_v] reported by EM sensors need to be evaluated for them to be utilized for agricultural water management. In the current study, the accuracy of a wide …

Parent-Teacher Communication About Children With Autism Spectrum Disorder: An Examination Of Collaborative Problem Solving, Gazi F. Azad, Mina Kim, Steven C. Marcus, David S. Mandell, Susan M. Sheridan Dr.

Department of Educational Psychology: Faculty Publications

Effective parent-teacher communication involves problem-solving concerns about students. Few studies have examined problem solving interactions between parents and teachers of children with autism spectrum disorder (ASD), with a particular focus on identifying communication barriers and strategies for improving them. This study examined the problem-solving behaviors of parents and teachers of children with ASD. Participants included 18 teachers and 39 parents of children with ASD. Parent-teacher dyads were prompted to discuss and provide a solution for a problem that a student experienced at home and at school. Parents and teachers also reported on their problem-solving behaviors. Results showed that parents and …

Zika Virus Encoding Nonglycosylated Envelope Protein Is Attenuated And Defective In Neuroinvasion, Arun Saravanakumar Annamalai, Aryamav Pattnaik, Bikash R. Sahoo, Ezhumalai Muthukrishnan, Sathish Kumar Natarajan, David Steffen, Hiep Vu, Gustavo A. Delhon, Fernando Osorio, Thomas M. Petro, Shi-Hua Xiang, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

ABSTRACT Zika virus (ZIKV), a mosquito-transmitted flavivirus responsible for sporadic outbreaks of mild and febrile illness in Africa and Asia, reemerged in the last decade causing serious human diseases, including microcephaly, congenital malformations, and Guillain-Barré syndrome. Although genomic and phylogenetic analyses suggest that genetic evolution may have led to the enhanced virulence of ZIKV, experimental evidence supporting the role of specific genetic changes in virulence is currently lacking. One sequence motif, VNDT, containing an N-linked glycosylation site in the envelope (E) protein, is polymorphic; it is absent in many of the African isolates but present in all isolates from the …

Setback Distance Requirements For Removal Of Swine Slurry Constituents In Runoff, John E. Gilley, Shannon L. Bartelt-Hunt, Kent M. Eskridge, Xu Li, Amy M. Schmidt, Daniel D. Snow

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The use of setback distances for manure application on cropland areas adjacent to surface water bodies could serve a function similar to vegetative filter strips. However, little information currently exists to identify the setback distances necessary to effectively reduce the transport of contaminants in runoff. The objective of this study was to determine the effects of setback distance and runoff rate on concentrations of selected constituents in runoff following land application of swine slurry to a no-till cropland area in southeast Nebraska. The study site had a residue cover of 7.73 Mg ha-1 and a slope gradient of 4.9%. The …

Small Rna-Dependent Gene Silencing In The Green Alga Chlamydomonas Reinhardtii: Functions And Mechanisms, Eun Jeong Kim

School of Biological Sciences: Dissertations, Theses, and Student Research

Small RNAs (sRNAs), ~20-30 nucleotides in length, are non-coding RNAs that play essential roles in the regulation of gene expression in eukaryotes. They lead to inactivation of cognate sequences at the post-transcriptional level via a variety of mechanisms involved in translation inhibition and/or RNA degradation.

In the Chlorophyta Chlamydomonas reinhardtii, however, the molecular machinery responsible for sRNA-mediated translational repression remains unclear. To address the mechanisms of translation inhibition by sRNA, we have isolated an RNAi defective mutant (Mut26), which contains a deletion of the gene encoding the homolog of CCR4 in Chlamydomonas. We investigated the expression …

Resource Allocation For Acorn Production: A Comparison Across Species Pairs Of Oaks With Contrasting Acorn Production Patterns And Water Use Strategies, Kyle A. Funk

School of Biological Sciences: Dissertations, Theses, and Student Research

Mast seeding, or masting, is a phenomenon where inter-annual seed production by individuals is synchronized across a population of plants. Masting is hypothesized to confer a selective advantage to plants by increasing rates of pollination or by decreasing rates of seed predation. Masting can also play a crucial role in ecosystem functioning as fluctuations in annual seed crops correspond with fluctuations in seed predator populations, which in turn have consequences that ripple throughout food webs. The mechanism(s) that causes masting is unresolved, but the high variability in seed production of masting plants is hypothesized to be caused, in part, by …

The Prairie Naturalist: The Journal Of The Great Plains Natural Science Society

The Prairie Naturalist

TABLE OF CONTENTS

45 EDITOR’S NOTE

RESEARCH ARTICLES

48 Avian Diversity, Abundance, and Nest Success among Managed Prairies and Agricultural Plots in Oklahoma and Texas Phillip J. Leonard, Douglas R. Wood, and Wayne E. Meyer

57 Severe Drought Impacts Female Pheasant Physiology in Southwest Nebraska Jessica A. Laskowski, Gwen C. Bachman, and Joseph J. Fontaine

66 Field Discrimination of Prairie Deer Mice and White-footed Mice using Morphological Characteristics Jacob L. Berl, Kelton M. Verble, Elizabeth A. Flaherty, and Robert K. Swihart

NOTES

72 Range Extension of the Virgina Opossum (Didelphis virginiana) in North Dakota Lisa L. Walsh

76 Prairie Falcon …

Book Reviews: Raptors Of Mexico And Central America. William S. Clark And N. John Schmitt., Jack Jack Eitniear

The Prairie Naturalist

Whether a raptor is cryptically perched in the shadows or is viewed only as a silhouette soaring in the clouds below the glaring midday sun, raptor identification can be challenging. If you are observing raptors in the North Temperate Zone, several guides (e.g., Clark and Wheeler 2001 Dunne et al.2012) will aid you with such identifications, but few resources exist for visitors south of this zone. So, if you are interested in identifying the 69 species of diurnal raptors found in Mexico and Central America, the recently released Raptors of Mexico and Central America by William S. Clark and N. …

The Great Plains Natural Science Society

The Prairie Naturalist

The Great Plains Natural Science Society, formerly the North Dakota Natural Science Society, was founded in 1967 and seeks to promote interest in and understanding of natural history in the Great Plains, to encourage the conservation of natural resources, and to provide communication among individuals, institutions, and organizations of like interests. The GPNSS actively promotes the study of natural history of the Great Plains region, including geology, plants, birds, mammals, fish, insects, and other forms of life. Together with local, state, and national conservation organizations, the GPNSS fosters natural resource conservation and preservation of outstanding natural areas. The GPNSS publishes …

Prairie Falcon Depredation Attempts On A Greater Prairie-Chicken Lek In South-Central Nebraska, Andrew J. Caven, Joshua D. Wiese, William R. Wallauer

The Prairie Naturalist

Little information exists concerning Prairie falcons’ (Falco mexicanus; PRFA) seasonal movements, habitat use, and diet outside of the breeding season; this is especially true in the eastern portion of its wintering and migratory range (Steenhof 1998, Sharpe et al. 2001, Steenhof et al. 2005). Prairie falcons prey on ground squirrels (Spermophilus spp.), prairie dogs (Cynomys spp.), wood rats (Neotoma spp.), and other rodents during the breeding season (Bond 1936, 1942, MacLaren et al. 1988, Steenhof 1998, Steenhof et al. 1999, Johnsgard 2013). They utilize avian prey regionally as well, including western meadowlarks (Sturnella neglecta …

Reduction Of Escherichia Coli Surrogates For Shiga Toxin-Producing Escherichia Coli On Beef Cuts By Dipping In Lactic Or Peroxyacetic Acid For Short Or Extended Times And The Effect On Ground Beef Quality, Ashley Rae Mccoy

Department of Animal Science: Dissertations, Theses, and Student Research

Shiga Toxin-producing Escherichia coli (STEC) are adulterants in ground beef. Antimicrobial interventions reduce STEC, but effectiveness may depend on application time and the impact on ground beef quality.

Objectives were to evaluate reductions in rifampicin-resistant E. coli (E. coli^RIF) on beef clod surfaces, and the effect on ground beef quality. Beef clods were sectioned and dipped in 4.5% lactic acid (LA) or 380 ppm peroxyacetic acid (PA) for 15 or 180 s. E. coli^RIF were inoculated (~5.3 log CFU/cm2) onto fat or lean tissue surfaces. Non- inoculated treatments were ground into ~454 g …

Horticulture For Pollinator Conservation, Carter M. Westerhold

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Pollinators worldwide are declining. Consequently, the agricultural and ecological services these insects provide are in danger of being lost. Land use intensification, via urbanization, has greatly influenced this decline in pollinators. Luckily, through targeted horticultural practices, stable populations of pollinators can be sustained within urban areas. The horticultural practices of planting diverse floral resources and managing pollinator habitat in urban areas can sustain these populations. Two studies were conducted with the intent to identify horticultural knowledge gaps that could be reduced to aid in pollinator conservation efforts. First, a study to compare Nebraska native and non-native ornamental plants was conducted. …

Factors Associated To Teacher Longevity In A Title I Elementary School: A Qualitative Narrative Inquiry Study, Richard Devney

Department of Educational Administration: Dissertations, Theses, and Student Research

The potential of our nation is hinged upon the strength of our educational system across all 50 states. Public education is the backbone of our country and continues to be a spotlight of focus for many. In 1983, President Ronald Regan shared the “Nation at Risk” report, based on the findings from the National Commission on Excellence in Education. The report claimed a level of mediocrity permeated the public education system and children were lagging behind compared to children in other first world countries. This landmark report put a level of accountability on school officials to create higher performing students …

Whole Grain Processing And Effects On Carbohydrate Digestion And Fermentation, Sandrayee Brahma

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Whole grains are a major source of dietary fibers in the human diet that provide specific nutrients to the gut microbiota and thereby plays a major role in modulating microbiota composition and increasing diversity of the gut ecosystem. A common approach of consuming whole grains is in the form of ready-to-eat extruded breakfast cereals. Studies reported herein established that extrusion conditions not only affected the physicochemical properties but also in vitro starch digestibility, β-glucan extractability and in vitro fermentation characteristics of whole grain oats. Moderate screw speed (300 rpm) led to higher slowly digestible starch (SDS) with an accompanying decrease …

Radiofrequency Processing For Inactivation Of Salmonella Spp. And Enterococcus Faecium Nrrl B-2354 In Whole Black Peppercorn And Ground Black Pepper, Xinyao Wei

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Black pepper has been implicated in several foodborne illness outbreaks and food product recalls due to Salmonella contamination. Conventional decontamination methods for black pepper are challenged by harmful residues or quality deterioration. Radiofrequency (RF) heating reduces the come-up time which allows to design a high-temperature short-time processing to inactivate Salmonella with minimal deterioration in product quality. The objectives of this study were to investigate RF heating for inactivation of Salmonella in whole black peppercorn and ground black pepper samples, evaluate Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella, and assess quality deterioration during RF heating of whole black peppercorn …

Increasing Cis-Lycopene Content Of The Oleoresin From Tomato Processing Byproducts Using Supercritical Carbon Dioxide And Assessment Of Its Bioaccessibility, Lisbeth Vallecilla Yepez

Department of Food Science and Technology: Dissertations, Theses, and Student Research

In recent years, health- and wellness-promoting foods have been one of the major focus of consumers; therefore, the food industry is increasing its efforts in developing these food products. Tomatoes, tomato-food products and their byproducts have gained special attention in virtue of the carotenoids-rich source that they represent, especially lycopene (~90%). The role of lycopene in human diet has been highlighted as a result of its direct relationship with the decrease of chronic diseases. Nevertheless, lycopene is water-insoluble making its extraction simple with organic-toxic solvents; in addition, lycopene degrades easily with light, time, and storage. Lycopene exist in nature mostly …