Digital Commons Network^™

Surprising Impact Of Remote Groups On The Folding–Unfolding And Dimer-Chain Equilibria Of Bifunctional H-Bonding Unimers, Rui Liu, Shuang Cheng, Erin S. Baker, Richard D. Smith, Xiao Cheng Zeng, Rui Liu

Xiao Cheng Zeng Publications

Oligoamide 1, consisting of two H-bonding units linked by a trimethylene linker, was previously found to form a very stable, folded dimer. In this work, replacing the side chains and end groups of 1 led to derivatives that show the surprising impact of end groups on the folding and dimer-chain equilibria of the resultant molecules.

Sandstones And Utah’S Canyon Country: Deposition, Diagenesis, Exhumation, And Landscape Evolution, David Loope, Richard Kettler, Kendra Murray, Joel Pederson, Peter Reiners

Department of Earth and Atmospheric Sciences: Faculty Publications

South-central Utah’s prominent sandstones and deeply dissected landscapes are the focus of this four-day trip, which begins and ends in Grand Junction, Colorado. Studies of the apatite grains in sandstones adjacent to igneous intrusions are revealing new information on the timing and rate of Cenozoic erosion. Iron-oxide-cemented concretions in other rocks record how reduced-iron carbonates and subsurface microbes interacted when near-surface, oxygenated waters started to flush the reducing, CO₂-rich waters from Colorado Plateau aquifers. New geochronologic techniques that are being applied to the plateau rocks have the potential to expand our knowledge of how diagenetic episodes relate to …

2016 Extension Highlights

Lancaster County, Nebraska Extension: Reports

Nebraska Extension is your local connection to university research-based information. We extend knowledge, provide solutions and change lives. Nebraska Extension in Lancaster County is a partnership between the University of Nebraska–Lincoln, Lancaster County and the United States Department of Agriculture.

We extend knowledge, provide solutions and change lives in these educational program areas:
• Cropping & Water Systems
• Beef Systems
• Food, Nutrition & Health
• Community Environment
• Learning Child
• 4-H Youth Development
• Community Vitality

Here’s a look at some of Nebraska Extension in Lancaster County’s 2016 impacts.

X-Ray Absorption Study Of Ceria Nanorods Promoting The Disproportionation Of Hydrogen Peroxide, Tai-Sing Wu, Yunyun Zhou, Renat F. Sabirianov, Wai-Ning Mei, Yun-Liang Soo, Barry Chin Li Cheung

Barry Chin Li Cheung Publications

A quasi in situ X-ray absorption study demonstrated that the disproportionation of hydrogen peroxide (H₂O₂) promoted by ceria nanorods was associated with a reversible Ce³⁺/Ce⁴⁺ reaction and structural transformations in ceria. The direction of this reversible reaction was postulated to depend on the H2O2 concentration and the fraction of Ce³⁺ species in ceria nanorods.

Food Insecurity And Housing Instability In Vulnerable Families, Christian King

Department of Nutrition and Health Sciences: Faculty Publications

Reducing the prevalence of household food insecurity has been a long-standing objective of the federal government. Previous research has found many negative consequences of food insecurity for families and households but has not examined its relationship with housing instability. Using longitudinal data from the Fragile Families and Child Wellbeing Study, difference-in-difference models show that food insecurity is associated with housing instability. The association remains statistically significant after accounting for potential selection and unobserved heterogeneity using propensity score matching and excluding households that experienced prior housing instability from the sample. Examining potential mediating factors, I find that material hardship explains about …

Nutrigenomic Functions Of Ppars In Obesogenic Environments, Soonkyu Chung, Young Jun Kim, Soo Jin Yang, Yunkyoung Lee, Myoungsook Lee

Department of Nutrition and Health Sciences: Faculty Publications

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that mediate the effects of several nutrients or drugs through transcriptional regulation of their target genes in obesogenic environments.This review consists of three parts. First, we summarize current knowledge regarding the role of PPARs in governing the development of white and brown/beige adipocytes from uncommitted progenitor cells. Next, we discuss the interactions of dietary bioactive molecules, such as fatty acids and phytochemicals, with PPARs for the modulation of PPAR-dependent transcriptional activities and metabolic consequences. Lastly, the effects of PPAR polymorphism on obesity and metabolic outcomes are discussed. In this review, we aim …

Glucagon Regulates Hepatic Lipid Metabolism Via Camp And Insig-2 Signaling: Implication For The Pathogenesis Of Hypertriglyceridemia And Hepatic Steatosis, Hai Wang, Miaoyun Zhao, Neetu Sud, Patricia Christian, Jing Shen, Yongyan Song, Anjeza Pashaj, Kezhong Zhang, Timothy P. Carr, Qiaozhu Su

Department of Nutrition and Health Sciences: Faculty Publications

Insulin induced gene-2 (Insig-2) is an ER-resident protein that inhibits the activation of sterol regulatory element-binding proteins (SREBPs). However, cellular factors that regulate Insig-2 expression have not yet been identified. Here we reported that cyclic AMP-responsive element-binding protein H (CREBH) positively regulates mRNA and protein expression of a liver specific isoform of Insig-2, Insig-2a, which in turn hinders SREBP-1c activation and inhibits hepatic de novo lipogenesis. CREBH binds to the evolutionally conserved CRE-BP binding elements located in the enhancer region of Insig-2a and upregulates its mRNA and protein expression. Metabolic hormone glucagon and nutritional fasting activated CREBH, which upregulated expression …

Regulation Of Obesity And Metabolic Complications By Gamma And Delta Tocotrienols, Lu Zhao, Xiefan Fang, Maurice R. Marshall, Soonkyu Chung

Department of Nutrition and Health Sciences: Faculty Publications

Tocotrienols (T3s) are a subclass of unsaturated vitamin E that have been extensively studied for their anti-proliferative, anti-oxidative and anti-inflammatory properties in numerous cancer studies. Recently, T3s have received increasing attention due to their previously unrecognized property to attenuate obesity and its associated metabolic complications. In this review, we comprehensively evaluated the recent published scientific literature about the influence of T3s on obesity, with a particular emphasis on the signaling pathways involved. T3s have been demonstrated in animal models or human subjects to reduce fat mass, body weight, plasma concentrations of free fatty acid, triglycerides and cholesterol, as well as …

Site And Extent Of Digestion Of Finishing Diets Containing Syngenta Enhanced Feed Corn, Melissa L. Jolly- Breithaupt, Jana L. Harding, Jim C. Macdonald Donald, Galen E. Erickson, Matt K. Luebbe

Nebraska Beef Cattle Reports

Four ruminally and duodenally fistulated steers were utilized to evaluate the effects of Syngenta Enhanced Feed Corn™ containing an alpha amylase enzyme trait (SYT- EFC) compared to the isoline parental control corn without the alpha amylase enzyme trait (Negative Isoline) on site and extent of digestion in finishing diets. Cattle fed SYT- EFC dry rolled corn had numerically greater postruminal starch digestibility, excreted lower fecal starch, and had greater total tract starch digestibility compared to cattle fed Negative Isoline corn. These data would suggest that cattle are able to utilize more starch from corn containing the SYT- EFC trait, which …

Distinct And Shared Determinants Of Cardiomyocyte Contractility In Multi-Lineage Competent Ethnically Diverse Human Ipscs, Martin L. Tomov, Zachary T. Olmsted, Haluk Dogan, Eda Gongorurler, Maria Tsompana, Hasan H. Otu, Michael Buck, Eun-Ah Chang, Jose Cibelli, Janet L. Paluh

Department of Electrical and Computer Engineering: Faculty Publications

The realization of personalized medicine through human induced pluripotent stem cell (iPSC) technology can be advanced by transcriptomics, epigenomics, and bioinformatics that inform on genetic pathways directing tissue development and function. When possible, population diversity should be included in new studies as resources become available. Previously we derived replicate iPSC lines of African American, Hispanic-Latino and Asian self-designated ethnically diverse (ED) origins with normal karyotype, verified teratoma formation, pluripotency biomarkers, and tri-lineage in vitro commitment. Here we perform bioinformatics of RNA-Seq and ChIP-seq pluripotency data sets for two replicate Asian and Hispanic-Latino ED-iPSC lines that reveal differences in generation of …

Molecular Basis Of Mechanosensitivity, Josefina Ines Del Marmol

Student Theses and Dissertations

Mechanosensation is arguably the least understood of all senses. For most physiological processes, the first response to membrane stress is thought to be the opening or closing of mechanosensitive channels, but the clonal nature of the first mechanotransducers is still largely unknown. The objective of my research was to identify molecules involved in mechanosensory transduction by both studying known channels as well as performing screens to identify previously uncharacterized channels. Shortly before my research began, Daniel Schmidt from the MacKinnon Lab showed that certain voltage gated potassium channels, not previously associated with mechanosensation, are in fact remarkably sensitive to membrane …

Metabolic Regulation Of Gene Expression Through Differential Histone Acylation: The Regulation And Function Of Histone Crotonylation, Benjamin R. Sabari

Student Theses and Dissertations

Histone lysine acetylation (Kac) plays a critical role in gene regulation by affecting the accessibility of the DNA wrapped around histones and by recruiting effector complexes. Three major classes of proteins are associated with Kac, namely "writers," enzymes that covalently modify specific lysine residues, "readers," protein domains that specifically bind modified residues, and "erasers," enzymes that catalyze the removal of the modification. While histone acetylation is well characterized within this paradigm, little is known about the regulation and function of an expanding list of histone lysine acylations. Lysine propionylation, butyrylation, and crotonylation were all discovered by proteomics-based approaches as I …

Qualitative And Quantitative Regulation Of The Leptin Gene In Vivo, Yi-Hsueh Lu

Student Theses and Dissertations

The high prevalence of obesity is a major public health concern worldwide. Conventional strategies have failed to provide solid solutions, greater than 90% of individuals who lost weight by diet and exercise eventually regained the weight (Arner and Spalding, 2010a). As such, biological factors including genetic contributions have become the research focus on pathogenesis of obesity and the target of effective disease control. Central to energy homeostasis is the mechanism by which animals regulate and/or response to fluctuation in energy intake and output. Adipose tissues participate in metabolic regulation by serving as an energy store and by secreting adipokines such …

Escherichia Coli As A New Platform For The Study Of Phosphoinositides, Sergio Botero

Student Theses and Dissertations

Phosphoinositides are membrane phospholipids involved in a wide variety of processes across the tree of life. In eukaryotic cells they function though their role as integral membrane components, anchors for proteins, membrane identity markers, and signaling molecules. Phosphoinositides are regulated through the phosphorylation and dephosphorylation of the inositol head-group at the 3rd, 4th, and 5th positions, creating a complex and very dynamic interconversion network. They can also be hydrolyzed into an inositide head-group and diacylglycerol which are in turn signaling molecules. The wide variety of functions, and redundancy in their synthesis pathways, makes the in-vivo study of phosphoinositides complex since …

The Genetics Of Mosquito Heat-Seeking Behavior, Román A. Corfas

Student Theses and Dissertations

Temperature is a highly dynamic feature of the world, and one that deeply affects living things. Organisms have evolved sophisticated sensory-­motor systems to detect and avoid excessive heat or cold—a behavior termed thermotaxis. In rare cases, however, animals use thermosensation not only to regulate their body temperature, but also to locate food sources in their environment. One example of such an adaptation is found in the female Aedes aegypti mosquito, which becomes attracted to the body heat of endothermic ("warm­blooded") hosts when in pursuit of a blood meal. Mosquitoes are remarkably adept at finding hosts in their environment and have …

Analysis Of Hepatocyte Secretion Pathways: A Case Study On Hepatic Apolipoproteins, Serum Albumin, And Hepatitis C Virus, Constantin N. Takacs

Student Theses and Dissertations

The hepatocyte is one of the major secretory cell types in the body. It fulfills many of the liver's essential functions in protein secretion, lipid storage and transport, and excretion. Some of these functions are carried out via polarized secretion of simple protein cargo, such as serum albumin, or large macromolecular lipid-protein complexes, the lipoproteins. The hepatocyte is also the site of infection of several hepatotropic viruses. Of these, hepatitis C virus (HCV) is peculiar due to its close structural and functional association with the hepatic lipoproteins. All these cargoes are transported from the endoplasmic reticulum (ER) to the cell …

Regulation Of The Anaphase-Promoting Complex Examined At The Single Cell Level, Andrej Ondracka

Student Theses and Dissertations

Cell cycle transitions are driven by oscillations of cyclin-cyclin dependent kinase (CDK) activity and associated cyclin degradation, mediated by ubiquitylation by the anaphase-promoting complex (APC). In this work, I analyzed the regulation of the APC by its activator Cdh1 in budding yeast in single cells. Inactivation of APC-Cdh1 is an important regulatory transition leading to mitotic entry. I developed and characterized a fluorescent biosensor to measure the dynamics of APC-Cdh1 activity in single cells by quantitative time-lapse microscopy. I found that APC-Cdh1 is inactivated with very reliable timing, in contrast with other cell cycle events that occur with considerable variability …

Nanobody-Based Interactomic Studies Of Single Transcripts During Mrna Maturation, Peter C. Fridy

Student Theses and Dissertations

During and after transcription in the nucleus, messenger RNAs (mRNAs) undergo a variety of processing events before being exported to the cytoplasm through the nuclear pore complex. mRNA processing and nuclear export require a wide range of protein factors, which interact with maturing transcripts and each other to form dynamic mRNP complexes. While there are many core, essential mRNP factors, the pathways governing mRNA maturation are not uniform, and different transcripts can be associated with mRNP complexes of dramatically different composition or kinetics. To date though, it has been difficult to study RNP complexes specific to any single mRNA species, …

Natural Products From Functional Screening Of Soil Metagenomic Libraries, Hala Iqbal

Student Theses and Dissertations

Bacteria are a prolific source of therapeutically and industrially relevant natural products. Traditional routes of natural product discovery focus on cultured bacteria, a strategy that eludes 99% of the microbiome. Metagenomics offers a route to study uncultured bacteria by extracting DNA present in environmental samples and cloning this eDNA into a vector to make metagenomic libraries. Libraries can then be screened in various ways to find natural products with desired characteristics and activities. Functional screening uses phenotypically identifiable traits such as changes in color or antibiotic activity to discover clones of interest in a metagenomic library. This mode of screening …

Retrograde Activation Of A Somatic Transcriptional Program Regulates Distal Axon Degeneration, Jason Pitts

Student Theses and Dissertations

During development of the peripheral nervous system, sensory axons extend to the periphery in excess where they compete for limiting target-derived neurotrophic support. Local neurotrophin insufficiency triggers axon degeneration, resulting in the pruning of over half of all sensory axons during development. Although axon degeneration facilitates the essential sculpting of the developing nervous system, its improper activation may underlie several neurodegenerative disorders. This process can be modeled in vitro by culturing sensory neurons from mouse dorsal root ganglia in the presence of nerve growth factor either as explant cultures or in compartmented chambers that allow independent manipulation of cell bodies …

Tracking The In Vivo Dynamics Of Antigenic Variation In The African Trypanosome, Monica R. Mugnier

Student Theses and Dissertations

Trypanosoma brucei, a causative agent of African sleeping sickness in humans and nagana in animals, constantly changes its dense variant surface glycoprotein (VSG) coat to avoid elimination by the immune system of its mammalian host, using an extensive repertoire of dedicated genes. Although this process, referred to as antigenic variation, is the major mechanism of pathogenesis for T. brucei, the dynamics of VSG expression in T. brucei during an infection are poorly understood. In this thesis, I describe the development of VSG-seq, a method for quantitatively examining the diversity of expressed VSGs in any population of trypanosomes. Using VSG-seq, I …

Chemical Tools For Exploring Ifitm3 S-Palmitoylation And Mechanism, Xiaoqiu Yuan

Student Theses and Dissertations

Protein S-palmitoylation is a reversible post-translational lipid modification that regulates the trafficking, stability, and activity of proteins in eukaryotes. The detection of fatty-acylated proteins has been challenging but recent advances in chemical labeling methods have enabled more sensitive detection and proteomic analyses, which I summarize in Chapter 1. The proteomic analysis of S-palmitoylated proteins in dendritic cells and macrophages by our laboratory revealed that the interferon-induced transmembrane proteins (IFITMs) are S-fatty-acylated at conserved cysteine (Cys) residues. IFITMs are unique interferon-induced proteins that restrict the infection of multiple pathogenic viruses. Initial studies by our laboratory showed that S-fatty-acylation on three conserved …

Characterization Of Mechanisms That Mediate Cancer Metastatic Colonization, Alexander Huan Nguyen

Student Theses and Dissertations

Metastatic disease is the major cause of death in all solid tumor cancers. Current therapeutic strategies fail to target metastasis as the genes and mechanisms that regulate this process remain poorly understood. Metastatic colonization is the final step of the metastatic cascade whereby cancer cells form a tumor at a distant site. This final step is the culmination of clonal evolution of cancer populations that results in a highly aggressive population with enhanced metastatic capacity and often presents clinically as numerous inoperable tumor nodules that lead to mortality. Characterization of the mechanisms that govern metastatic colonization at cellular and molecular …

Plasticity Of The Nuclear Pore Complex Revealed With Proteomics, Zhanna Hakhverdyan

Student Theses and Dissertations

Cellular functions are performed by the concerted action of macromolecular assemblies. These protein machines rarely have permanent, invariable structures. Instead, the subunits forming the macromolecular assemblies exchange between free and bound states, changing the composition, conformation and function of the assembly. Characterizing the function of macromolecular assemblies, therefore, requires the study of their dynamics. I have developed a strategy for in vivo assessment of macromolecular plasticity and have successfully applied it to the yeast nuclear pore complex (NPC), one of the largest and most elaborate protein machines in the cell. NPC is a massive protein assembly situated in the nuclear …

Protein Regulators Of Phosphoinositides As Promoters Of Cancer Metastasis, Caitlin Anne Sengelaub

Student Theses and Dissertations

Metastasis, the spread of cancer cells from a primary tumor to a distal organ, represents the predominant cause of mortality in patients with solid tumors. However, the molecular mechanisms underpinning this multistep progression are poorly defined. Successful metastasis requires a cancer cell to acquire multiple capabilities, including the ability to migrate, invade, and co-opt the microenvironment in the distal organ for colonization. Many of these phenotypes require the actions of a family of lipids called phosphoinositides (PIs). Although structurally small molecules and minor components of the cellular lipidome, PIs are critical mediators of many cellular processes through their localization, abundance, …

Regulatory Architecture Of Non-Apoptotic Cell Death Program In C. Elegans, Maxime Jeremie Kinet

Student Theses and Dissertations

Cell death is prevalent in animal development, homeostasis, and disease. While apoptotic cell death has been extensively studied, many dying cells in development do not exhibit apoptotic morphology, and mice lacking core apoptotic regulators have mostly normal rates of developmental programmed cell death. However, little is known about how alternative death programs are set in motion. In the nematode Caenorhabditis elegans, most cells fated to die by apoptosis are eliminated as young, undifferentiated cells, for no obvious functional reasons. The male nematode's linker cell, in contrast, dies as an older, differentiated cell, whose life and death subserve precise and important …

Structural And Functional Characterization Of Spoa Domains In Salmonella Typhimurium Type Iii Secretion Systems, Ryan Q. Notti

Student Theses and Dissertations

Once optimistically believed to be a relic of the pre-antibiotic era, bacterial pathogens remain a substantial threat to human health, and the growing epidemic of antibiotic resistance has raised concerns for the long term prospects of antimicrobial therapy. By understanding the mechanisms used by bacteria to manipulate their host and cause disease, it is hypothesized that we might more rationally approach anti-infective therapeutic design. Type III secretion systems (T3SS) are employed by some gram-negative human pathogens to manipulate the host environment. One T3SS subtype, known as the "injectisome," delivers virulence factors directly into host cells. The other T3SS subtype secretes …

Studies Towards The Discovery Of Novel Natural Products Through Functional Analysis Of Environmental Dna-Encoded Type Ii Polyketide Synthases, Debjani Chakraborty

Student Theses and Dissertations

Natural products have historically served as a major source for most of the therapeutically relevant compounds. A significant fraction of these natural product-based drugs and leads are derived from microorganisms. Although the traditional culture-based strategy has proven very successful over the course of more than a century of investigation, it excludes a significant portion of the molecules present in environmental samples because majority of the bacteria are not readily amenable to culture-based strategies. This uncultured majority is believed to represent 99% of bacterial species in the environment. Therefore, it has remained a significant challenge to access the chemical diversity present …

Paleovirological Analyses Of Endogenous Retroviruses And Host Innate Immune Effectors, Daniel Blanco Melo

Student Theses and Dissertations

About 8 and 10 percent of the human and mouse genomes, respectively, are comprised of sequences of retroviral origin. Occasional infection of germ line can lead to integrated retroviral genomes being vertically inherited as host alleles. During thousands to millions of years, some of these sequences acquired inactivating mutations and were fixed in ancestral populations by genetic drift, while others became fixed by providing an evolutionary advantage to the host. Those inherited proviruses are termed endogenous retroviruses (ERVs) and have been identified in a variety of animal species representing an extensive viral "fossil" record of past retroviral infections. With the …

Characterization Of Skin Immune Reactions Induced By The Contact Sensitizer Diphencyprone In Healthy Volunteers And Metastatic Melanoma Patients, Nicholas Gulati

Student Theses and Dissertations

Melanoma is a life-threatening malignant disease, of which the standard of care treatment is rapidly becoming immunologically driven, due to favorable recent clinical trials using immune checkpoint inhibitors. Diphencyprone (DPCP), a topically applied contact sensitizer, has been used with an 84% success rate to treat cutaneous melanoma metastases, but the immune mechanisms underlying its efficacy are largely unknown. This thesis characterizes skin immune reactions induced by DPCP, both in healthy volunteers and patients with metastatic melanoma. In healthy volunteers, DPCP led to upgregulation of many immune molecules that may be anti-neoplastic effectors, including IFNγ, IL-24, and IL-9. We also examined …