Life Sciences Commons^™

Hiv-1 Transcription Elongation By Tat-Mediated Recruitment Of P-Tefb, Elizabeth Griggs

Honors Theses

Over 38.0 million people live with the human immunodeficiency virus (HIV) as of 462019. HIV hijacks the host's cellular machinery to replicate its viral DNA and transcribe the corresponding RNA. HIV-1 transcription relies on both cellular and viral transcription factors for proper regulation. The viral transcriptional activator Tat is a primary regulator. Transcription activation and elongation is controlled through the interaction of Tat with Positive Transcription Elongation Factor b (P-TEFb), a cellular transcriptional activator. The focus of this paper is 1) an in-depth understanding of the interaction between P-TEFb and Tat in HIV transcription, and 2) a review of recent …

Analysis Of Single-Site Cysteine Mutation, I412c, In Human A Glycine Receptor States To Further Refine Structure And Allostery, Leah Engquist

Honors Theses

The glycine receptor (GlyR) is the major inhibitory receptor in the brain and spinal cord. A member of the pentameric ligand gated ion channel superfamily, crystal structures are available but there are still unresolved areas, specifically the C-terminal tail and TM3-TM4 intracellular loop. Further refinement can provide deeper understanding of the molecular mechanism and allow the creation of novel therapeutics to modulate its function. We propose to insert a single cysteine mutation, I412C, into a Cys null background (C41S/C290A/C345S) to study non- conducting states (resting, desensitized) or with F207G/A288G mutations to study the open state. Purified, reconstituted GlyR is crosslinked …

Teaching Muscle Function And Physical Fitness: An Afterschool Program For Elementary Schools, Julianna Peters

Honors Theses

For this creative project, a nine-week club curriculum about muscle function and exercise was designed for upper elementary students (4^th-6^th grade), integrating science and physical education. This curriculum aims to introduce students to a basic understanding of muscle function and their body utilizing a scientific lens while also encouraging movement through the education of different muscle groups. It principally covers the three types of muscle with an emphasis on skeletal muscles. Students engage in experiments and activities focused on different aspects of muscle function and then do exercises focused on certain muscle groups. Additionally, it aims to …

How To Effectively Reach Farmers And Assist Them In Reaching Their Precision Management Goals, Courtney Nelson

Honors Theses

Precision and digital agriculture have been popular buzz words floating around the last several years. These broad terms cover a plethora of topics including GPS ear tags for livestock, soil moisture probes, and aerial imagery. With such a wide number of technological advances at their fingertips, it can be overwhelming for farmers to know where to start.

A study conducted by Purdue University in 2019 took a deeper look at data and software usage across 800 farms larger than 1000 acres (DeLay et al, 2020). Their research revealed that over half of farmers who don’t use farm data or software …

The Effect Of Agkistrodon Contortrix And Crotalus Horridus Venom Toxicity On Strike Locations With Live Prey., Chase Giese

Honors Theses

This paper aims to uncover if there is a significant difference in the strike location of snake species that have different values of LD50% venom. It is thought that most snakes strike their prey in the anterior (head) area in order for their venom to work quicker in killing them. Venom toxicity is measured by its LD50% value, which is the amount of venom, in mg/kg, to kill 50% of a test population. The Copperhead has an LD50% value of 10.9 mg/kg, and the Timber Rattlesnake has an LD50% value of 1.64 mg/kg. The hypothesis was that if venom toxicity …

The Importance Of Nutrition And Preventing Malnutrition In Older Adults: A Literature Review And Informational Booklet, Sophie Johnson

Honors Theses

Over years of studying nutrition science and gerontology, there was very little information in classes that combined these two important topics. Older adults are often classified as those above the age of 65 years old. There is a growing number of older adults in the United States, which increases the need for information on how nutrition and aging are interlaced. As humans age, multiple factors can impact nutrition. Nutrition involves consuming the proper amount of nutrients to maintain body function. There are physiological, physical, socioeconomic and medication factors that can all influence nutrition status. It is important to be aware …

A Mathematical Model Of Pancreatic Cancer Growth And Response To Treatment, Allison Cruikshank

Honors Theses

Pancreatic cancer is one of the leading causes of death due to cancer in the United States. Analyzing the effects of radiation is extremely valuable in determining when a patient is allowed surgical resection, which is, presently, the only potentially curative treatment for pancreatic cancer. This study examines pancreatic tumor growth and shrinkage to predict tumor response and change of resectability for pancreatic cancer patients undergoing radiation therapy. This is done using ordinary differential equations as a mathematical model. Mathematical models have increasingly been applied to various biological systems/processes to analyze the principles involved. In our project, a population dynamical …

Exploring Factors In Choosing Stem Majors And Careers: Improving Science Education Through The Lens Of Self-Determination Theory, Lauren Mott

Honors Theses

Several barriers currently exist for students who could be successful in science/STEM careers but have not had the support they needed throughout their science/STEM education. This study of the literature applies Self-Determination Theory (SDT) to existing research to identify steps educators can take to remove these unnecessary barriers for their students. SDT defines competence, relatedness, and autonomy as three innate psychological needs that must be met for well-being. An exploratory review of the literature was conducted, and findings were organized using SDT. The results showed that competence, relatedness, and autonomy were all key factors in students’ self-determination of science/STEM careers. …

Using Crispr-Cas9 To Construct Knockout Mutants In Dna-Repair Genes In Arabidopsis Thaliana, David Campbell

Honors Theses

The mitochondria are known as the powerhouse of the cell, and just like a real powerhouse, it can be a dangerous place to store sensitive information. Energy generation and redox reactions in the mitochondria can cause damage to the DNA stored there, resulting in a higher mutation rate. Compared to their animal counterparts, however, plant mitochondria exhibit a lower mutation rate and a higher recombination rate. It is hypothesized that the unique DNA repair methods present in plant mitochondria are responsible for the phenomena observed there. To study the mechanics of DNA-repair in this organelle, however, researchers must be able …

Engineering Src Homology 2 Domains With Improved Specificity For Sulfotyrosine, Anya Morozov

Honors Theses

Protein tyrosine O-sulfation (PTS) is a common post-translational modification that has been implicated in a variety of biological processes and human illnesses. Despite continued progress in the field of sulfoproteomics, the extent and function of sulfated tyrosine (sulfotyrosine) residues is a topic of ongoing research. Previous work in the Guo Lab has identified Src Homology-2 (SH2) mutants that have a high affinity for sulfotyrosine along with retained high affinity for their natural ligand, phosphorylated tyrosine (phosphotyrosine). In this thesis, I attempted to generate SH2 mutants that have high affinity and specificity for sulfotyrosine over phosphotyrosine. While I successfully generated …

Structure Of Clostridium Perfringens Type Iv Pili, Alexander R. Meyer

Honors Theses

Type IV pili (T4P) are thin, hair-like bacterial appendages composed of protein subunits polymerized into a helical fiber. T4P perform diverse functions such as host cell adhesion, biofilm formation, natural competence, and twitching motility. While T4P are well characterized in Gram-negative bacteria, they have more recently been found in Gram-positive bacteria as well. In this work we aimed to solve the crystal structure of the type IV major pilin protein PilA2 from Clostridium perfringens, the predominant pilus subunit which makes up about 99% of the pilus fiber. We report expression, purification, and crystallization conditions which are sufficient for X-ray …

A Kinesiological Analysis Of Dancers At The University Of Nebraska-Lincoln, Vanessa Reiser

Honors Theses

Supplemental conditioning can improve a dancer’s performance of important skills without taking away from class and rehearsal time. To investigate this further, an individualized conditioning plan based on a specific skill was created for eight student dancers, and the effects were analyzed using a survey and rating scale by a trained dance professor. The results showed improvement of skills for the majority of dancers, along with improved fitness in qualities such as strength and balance. In conclusion, individualized conditioning plans based on a specific skill may benefit student dancers who are juggling intense class and rehearsal schedules.

Effects Of Mindfulness Meditation On Selective, Sustained Attention, Brain Neural Oscillations, And Short-Term Memory, Anamaria Guzman

Honors Theses

The following extended literature review and research proposal study started initially as a complete research proposal but, due to the challenges COVID-19 has brought, it has become a stand-alone piece of work without data collection. The goal is to synthesize a broad range of literature and previous research on mindfulness meditation and its effects on attention, memory, and brain activity and thus, offering a new perspective and a proposed research path on this subject. This proposed research study, besides previous studies, indicates that mindfulness meditation is expected to improve and enhance selective and sustained attention, which results in better attentional …

Spatiotemporal Interactions Between Deer And Cattle, Sydney Brewer

Honors Theses

Mule deer, white-tailed deer, and cattle are sympatric on the landscape throughout many portions of Nebraska and encounter each other in time and space. By considering variation in daily activity patterns and non-random patterns in the timing of passage through specific locations, we can better understand whether animals may be avoiding each other temporally when sharing space. I investigated temporal activity patterns and avoidance/attraction ratios to investigate if deer altered their activity patterns in the presence of cattle and if they exhibited avoidance at a study site near McCook, Nebraska, USA. We collected data from 19 game cameras that were …