Life Sciences Commons^™

Characterization Of Mechanism Of Action Of Hydrogen Sulfide (H2s) In The Regulation Of Smooth Muscle Function, Ancy D. Nalli

Theses and Dissertations

Hydrogen sulfide (H₂S) is receiving increasing interest, as much as nitric oxide (NO) and carbon monoxide have received previously, to understand its physiological functions as it meets all the criteria to define as a third gasotransmitter. Endogenous synthesis from L-cysteine via cystathionine-γ-lyase (CSE) and cystathionine-β-synthase (CBS) and the function of H₂S as an inhibitor of smooth muscle contraction in gastrointestinal tract are known. However, the loci of generation and action of H₂S, and the mechanism of inhibition of contraction are unknown. Hence, my aims in the present study are to: i) identify the expression …

Citizen-Science Data Provides New Insight Into Annual And Seasonal Variation In Migration Patterns, S R. Supp, Frank A. La Sorte, Tina A. Cormier, Marisa C. W. Lim, Donald R. Powers, Susan M. Wethington, Scott Goetz, Catherine H. Graham

Faculty Publications - Department of Biological & Molecular Science

Current rates of global environmental and climate change pose potential challenges for migratory species that must cope with or adapt to new conditions and different rates of change across broad spatial scales throughout their annual life cycle. North American migratory hummingbirds may be especially sensitive to changes in environment and climate due to their extremely small body size, high metabolic rates, and dependence on nectar as a main resource. We used occurrence information from the eBird citizen-science database to track migratory movements of five North American hummingbird species (Archilochus alexandri, A. colubris, Selasphorus calliope, S. platycercus, and S. rufus) across …

Size Dependence In Non-Sperm Ejaculate Production Is Reflected In Daily Energy Expenditure And Resting Metabolic Rate, Christopher R. Friesen, Donald R. Powers, Paige E. Copenhaver-Parry, Robert T. Mason

Faculty Publications - Department of Biological & Molecular Science

The non-sperm components of an ejaculate, such as copulatory plugs, can be essential to male reproductive success. But the costs of these ejaculate components are often considered trivial. In polyandrous species, males are predicted to increase energy allocation to the production of non-sperm components, but this allocation is often condition dependent and the energetic costs of their production have never been quantified. Red-sided garter snakes (Thamnophis sirtalis parietalis) are an excellent model with which to quantify the energetic costs of non-sperm components of the ejaculate as they exhibit a dissociated reproductive pattern in which sperm production is temporally disjunct from …

A Simple Bioluminescent Method For Measuring D-Amino Acid Oxidase Activity, T. Spencer Bailey, Micah T. Donor, Sean P. Naughton, Michael D. Pluth

Faculty Publications - Department of Biological & Molecular Science

D-Amino acid oxidase (DAO) plays important roles in regulating D-amino acid neurotransmitters and was recently identified as a key enzyme integral to hydrogen sulfide production from D-Cys. We report here the development of a simple biocompatible, bioluminescent method for measuring DAO activity based on the highly selective condensation of D-Cys with 6-hydroxy-2-cyanobenzothiazole (CBT-OH) to form D-luciferin.

Cimrf Suppression Of Endogenous Tissue Developments In Ciona Intestinalis Embryos, Emmanuel Kofi Asieidu

Honors Projects

Trans-differentiation of non-muscle tissue to muscle tissue is a well-established property of vertebrate myogenic regulatory factors (MRFs). For instance the vertebrate MRF, MyoD, has been shown to convert nonmuscle cells to muscle cells. During this trans-differentiation, however, endogenous gene activity of the nonmuscle cells is down regulated. To test if this property is also found in invertebrate MRFs our lab has developed a system to analyze the ability of the MRF of Ciona intestinalis, CiMRF, to suppress endogenous gene activity during trans-differentiation. We did this by misexpressing CiMRF in the notochord and endoderm of Ciona embryos, two nonmuscle …

A Pilot Study Investigating The Reasons For Playing Through Pain And Injury: Emerging Themes In Men’S And Women’S Collegiate Rugby, Leilani Madrigal, Jamie Robbins, Diane L. Gill, Katherine Wurst

Athletic Performance Research

Collegiate rugby is a competitive, collision sport, yet insufficient empirical evidence exists regarding participants’ perspectives on pain and injury. This study addressed male and female rugby players’ experiences with injury, and their views about playing through pain and injury. Eleven rugby players (five male; six female) competing in USA Rugby’s National College 7’s tournament participated in semi structured interviews, which were recorded, transcribed, and content-analyzed. Two major themes emerged: passion for sport and sport ethic. Passion for sport was composed of (a) love of the sport, (b) meaning of the sport, and (c) desire to be on the field. Sport …

Genetic Control Of Morphometric Diversity In The Maize Shoot Apical Meristem, Samuel Leiboff, Xianran Li, Heng-Cheng Hu, Natalie Todt, Jinliang Yang, Xiao Li, Xiaoqing Yu, Gary J. Muehlbauer, Marja C.P. Timmermans, Jianming Yu, Patrick S. Schnable, Michael J. Scanlon

Department of Agronomy and Horticulture: Faculty Publications

The maize shoot apical meristem (SAM) comprises a small pool of stem cells that generate all above-ground organs. Although mutational studies have identified genetic networks regulating SAM function, little is known about SAM morphological variation in natural populations. Here we report the use of high-throughput image processing to capture rich SAM size variation within a diverse maize inbred panel. We demonstrate correlations between seedling SAM size and agronomically important adult traits such as flowering time, stem size and leaf node number. Combining SAM phenotypes with 1.2 million single nucleotide polymorphisms (SNPs) via genome-wide association study reveals unexpected SAM morphology candidate …

A Neuromechanics-Based Powered Ankle Exoskeleton To Assist Walking Post-Stroke: A Feasibility Study, Kota Z. Takahashi, Michael D. Lewek, Gregory S. Sawicki

Journal Articles

Background: In persons post-stroke, diminished ankle joint function can contribute to inadequate gait propulsion. To target paretic ankle impairments, we developed a neuromechanics-based powered ankle exoskeleton. Specifically, this exoskeleton supplies plantarflexion assistance that is proportional to the user’s paretic soleus electromyography (EMG) amplitude only during a phase of gait when the stance limb is subjected to an anteriorly directed ground reaction force (GRF). The purpose of this feasibility study was to examine the short-term effects of the powered ankle exoskeleton on the mechanics and energetics of gait.

Methods: Five subjects with stroke walked with a powered ankle exoskeleton …

The Effects Of Muscle Cross-Sectional Area On The Physical Working Capacity At The Fatigue Threshold, Meghan B. Barry, Jorge M. Zuniga, Makenna M. Brown, William M. Garnett, Zachary V. Hadden, Paul K. Nguyen, Geoffrey A. Supplee, Claire J. Svobada

Journal Articles

Purpose: The purpose of this study was to examine the effects of quadriceps cross-sectional area (CSA) of the dominant quadriceps muscle in the assessment of the physical working capacity at the fatigue threshold (PWCFT) during incremental cycle ergometry. Methods: Eighteen adults (9 men and 9 women; mean age ± SD = 20.5 ± 1.04 yr; mean body weight ± SD = 73.9 ± 18.2 kg; mean height ± SD = 172.3 ± 11.5 cm; mean dominant quadriceps CSA ± SD = 68.7 ± 14.5 cm2) performed an incremental cycle ergometry test to exhaustion while the electromyographic (EMG) signals …

Cover Crops And Ecosystem Services: Insights From Studies In Temperate Soils, Humberto Blanco-Canqui, Tim M. Shaver, John L. Lindquist, Charles A. Shapiro, Roger Wesley Elmore, Charles A. Francis, Gary W. Hergert

Department of Agronomy and Horticulture: Faculty Publications

Cover crops (CCs) can provide multiple soil, agricultural production, and environmental benefits. However, a better understanding of such potential ecosystem services is needed. We summarized the current state of knowledge of CC effects on soil C stocks, soil erosion, physical properties, soil water, nutrients, microbial properties, weed control, crop yields, expanded uses, and economics and highlighted research needs. Our review indicates that CCs are multifunctional. Cover crops increase soil organic C stocks (0.1–1 Mg ha^–1 yr^–1) with the magnitude depending on biomass amount, years in CCs, and initial soil C level. Runoff loss can decrease by up …

Flow Through The Nasal Cavity Of The Spiny Dogfish, Squalus Acanthias, L. L. Timm-Davis, Frank E. Fish

Biology Faculty Publications

The nasal cavity of spiny dogfish is a blind capsule with no internal connection to the oral cavity. Water is envisioned to flow through the cavity in a smooth, continuous flow pattern; however, this assumption is based on previous descriptions of the morphology of the olfactory cavity. No experimentation on the flow through the internal nasal cavity has been reported. Morphology of the head of the spiny dogfish (Squalus acanthias) does not suggest a close external connection between the oral and nasal systems. However, dye visualization showed that there was flow through the nasal apparatus and from the excurrent nostril …

Community Chairs As A Catalyst For Campus Collaboration In Stem, Neal Grandgenett, David Boocker, Hesham Ali, Angela M. Hodge, Brian Dorn, Christine E. Cutucache

Biology Faculty Publications

Strong collaborative partnerships are critical to the ongoing success of any urban or metropolitan university in its efforts to build the science, technology, engineering, and mathematics (STEM) career pathways so critical to our nation. At the University of Nebraska at Omaha, we have established a faculty leadership structure of "community chairs" that work across colleges to support campus priorities. This paper describes UNO’s STEM community chair model, including selected initiatives, impacts, and challenges to date.

Understanding Ocean Acidification Impacts On Organismal To Ecological Scales, Andreas J. Andersson, David I. Kline, Peter J. Edmunds, Stephen D. Archer, Nina Bednarsek, Robert C. Carpenter, Meg Chadsey, Philip Goldstein, Andrea G. Grottoli, Thomas P. Hurst, Andrew L. King, Janet E. Kübler, Ilsa B. Kuffner, Katherine R.M. Mackey, Bruce A. Menge, Adina Paytan, Ulf Riebesell, Astrid Schnetzer, Mark E. Warner, Richard C. Zimmerman

OES Faculty Publications

Ocean acidification (OA) research seeks to understand how marine ecosystems and global elemental cycles will respond to changes in seawater carbonate chemistry in combination with other environmental perturbations such as warming, eutrophication, and deoxygenation. Here, we discuss the effectiveness and limitations of current research approaches used to address this goal. A diverse combination of approaches is essential to decipher the consequences of OA to marine organisms, communities, and ecosystems. Consequently, the benefits and limitations of each approach must be considered carefully. Major research challenges involve experimentally addressing the effects of OA in the context of large natural variability in seawater …

Subsistence Strategies In Traditional Societies Distinguish Gut Microbiomes, Alexandra J. Obregon-Tito, Raul T. Tito, Jessica Metcalf, Krithvivasa Sankaranarayanan, Jose C. Clemente, Luke K. Ursell, Zhenjiang Zech Xu, Will Van Treuren, Rob Knight, Morris Foster

Office of Research Faculty & Staff Publications

Recent studies suggest that gut microbiomes of urban-industrialized societies are different from those of traditional peoples. Here we examine the relationship between lifeways and gut microbiota through taxonomic and functional potential characterization of faecal samples from hunter-gatherer and traditional agriculturalist communities in Peru and an urban-industrialized community from the US. We find that in addition to taxonomic and metabolic differences between urban and traditional lifestyles, hunter-gatherers form a distinct sub-group among traditional peoples. As observed in previous studies, we find that Treponema are characteristic of traditional gut microbiomes. Moreover, through genome reconstruction (2.2-2.5 MB, coverage depth x26-513) and functional potential …

Adp-Ribosylation Factor 6 (Arf6) Regulates Integrin Αiibβ3 Trafficking, Platelet Spreading, And Clot Retraction, Yunjie Huang

Theses and Dissertations--Molecular and Cellular Biochemistry

Endocytic trafficking of platelet surface receptors plays a role in the accumulation of granule cargo (i.e. fibrinogen and VEGF) and thus could contribute to hemostasis, angiogenesis, or inflammation. However, the mechanisms of platelet endocytosis are poorly understood. The small GTP-binding protein, ADP-ribosylation factor 6 (Arf6), regulates integrin trafficking in nucleated cells; therefore, we posited that Arf6 functions similarly in platelets. To address this, we generated platelet-specific, Arf6 knockout mice. Arf6^-/- platelets had a storage defect for fibrinogen but not other cargo, implying Arf6’s role in integrin αIIbβ3 trafficking. Additionally, platelets from Arf6^-/- mice injected with biotinylated-fibrinogen, showed …

Physical Interactions Between Neuropilin And Vegfrs, Integrins In Regulating Endothelial Cell Functions, Xiaobo Li

Theses and Dissertations--Molecular and Cellular Biochemistry

The neuropilin (Nrp) family consists of multifunctional cell surface receptors with critical roles in a number of different cell and tissue types. A core aspect of Nrp function is ligand-dependent cellular adhesion and migration, where it controls the multistep process of cellular motility through integration of ligand binding, receptor coupling and signaling via the coordinated action of its extracellular and intracellular domains. While Nrp regulates cellular adhesion and motility in the cardiovascular and nervous systems under physiological conditions, the emerging pathological role of Nrp in tumor cell migration and metastasis has been identified and provides motivation for continued efforts toward …

Differences In The Fatty-Acid Composition Of Rodent Spermatozoa Are Associated To Levels Of Sperm Competition, Javier Delbarco-Trillo, Rafael Mateo, Eduardo R. S. Roldan

Faculty Publications – Biological Sciences

Sperm competition is a prevalent phenomenon that drives the evolution of sperm function. High levels of sperm competition lead to increased metabolism to fuel higher sperm velocities. This enhanced metabolism can result in oxidative damage (including lipid peroxidation) and damage to the membrane. We hypothesized that in those species experiencing high levels of sperm competition there are changes in the fatty-acid composition of the sperm membrane that makes the membrane more resistant to oxidative damage. Given that polyunsaturated fatty acids (PUFAs) are the most prone to lipid peroxidation, we predicted that higher sperm competition leads to a reduction in the …

Elucidating The Conservation Status Of Michigan's Red-Eared Slider (Trachemys Scripta Elegans): A Phylogeographic Approach, Patrick J. Terry

Master's Theses and Doctoral Dissertations

The geographic origin of Michigan’s Trachemys scripta elegans has been a contentious subject since its first description in 1934. At that time two explanations were proposed: 1) populations of T. s. elegans are native to Michigan and naturally expanded their range from Ohio and Indiana; or 2) populations are non-native and have been introduced by humans via the pet-trade from throughout the United States. To differentiate between these possibilities, I compare the genetic structure of six populations throughout Indiana, Michigan, and Ohio, using six microsatellite markers. No isolation-by-distance was detected and model-based statistics support two genetic clusters with five populations …

An Investigation Of The Quality And Quantity Of Student Motivation In Physical Education, Trey Douglas Willoughby

LSU Master's Theses

Physical inactivity is a prevalent problem in the United States associated with numerous health risk factors. Over half the population fails to meet prescribed physical activity recommendations, suggesting that individuals become less active as they age. It is important to observe individuals in the Physical Education setting because it is an ideal environment to provide meaningful physical activity, while promoting lifetime physical activity. This research sought to understand motivational behaviors in high school adolescents, attempting to draw links between physical education, student satisfaction, and leisure-time physical activity. Three research questions were present: (1) What relationships do high school student perceive …

The Effects Of Lampricide 3-Trifluoromethyl-4-Nitrophenol Toxicity On The Gills Of Larval Sea Lamprey And Non-Target Rainbow Trout And Lake Sturgeon, Lisa A. Sorensen

Theses and Dissertations (Comprehensive)

The pesticide, 3-trifluoromethyl-4-nitrophenol (TFM), is widely used in the Great Lakes to control invasive sea lampreys (Petromyzon marinus) populations, but much about its sub-lethal effects remains unknown. A better understanding of its toxicity is needed to improve TFM effectiveness and to protect non-target organisms from its potential adverse effects. The objectives of this thesis were to test the following two hypotheses: (1) impairment of mitochondrial ATP production by TFM interferes with ATP-dependent ion-uptake by fish, leading to altered electrolyte balance, and (2) perturbations of gill function by TFM are exacerbated in soft, ion poor water (SW; 40 mg …

Experimental-Computational Analysis Of Vigilance Dynamics For Applications In Sleep And Epilepsy, Farid Yaghouby

Theses and Dissertations--Biomedical Engineering

Epilepsy is a neurological disorder characterized by recurrent seizures. Sleep problems can cooccur with epilepsy, and adversely affect seizure diagnosis and treatment. In fact, the relationship between sleep and seizures in individuals with epilepsy is a complex one. Seizures disturb sleep and sleep deprivation aggravates seizures. Antiepileptic drugs may also impair sleep quality at the cost of controlling seizures. In general, particular vigilance states may inhibit or facilitate seizure generation, and changes in vigilance state can affect the predictability of seizures. A clear understanding of sleep-seizure interactions will therefore benefit epilepsy care providers and improve quality of life in patients. …

Ebola Cases And Health System Demand In Liberia, John M. Drake, Rajreni B. Kaul, Laura W. Alexander, Suzanne M. O’Regan, Andrew M. Kramer, J. Tomlin Pulliam, Matthew J. Ferrari, Andrew W. Park

Integrative Biology Faculty and Staff Publications

In 2014, a major epidemic of human Ebola virus disease emerged in West Africa, where human-to-human transmission has now been sustained for greater than 12 months. In the summer of 2014, there was great uncertainty about the answers to several key policy questions concerning the path to containment. What is the relative importance of nosocomial transmission compared with community-acquired infection? How much must hospital capacity increase to provide care for the anticipated patient burden? To which interventions will Ebola transmission be most responsive? What must be done to achieve containment? In recent years, epidemic models have been used to guide …

Ebola Cases And Health System Demand In Liberia, John M. Drake, Rajreni B. Kaul, Laura W. Alexander, Suzanne M. O’Regan, Andrew M. Kramer, J. Tomlin Pulliam, Matthew J. Ferrari, Andrew W. Park

Integrative Biology Faculty and Staff Publications

In 2014, a major epidemic of human Ebola virus disease emerged in West Africa, where human-to-human transmission has now been sustained for greater than 12 months. In the summer of 2014, there was great uncertainty about the answers to several key policy questions concerning the path to containment. What is the relative importance of nosocomial transmission compared with community-acquired infection? How much must hospital capacity increase to provide care for the anticipated patient burden? To which interventions will Ebola transmission be most responsive? What must be done to achieve containment? In recent years, epidemic models have been used to guide …

Immigration Can Destabilize Tri-Trophic Interactions: Implications For Conservation Of Top Predators, Kevin L. S. Drury, Jesse D. Suter, Jacob B. Rendall, Andrew M. Kramer, John M. Drake

Integrative Biology Faculty and Staff Publications

Top predators often have large home ranges and thus are especially vulnerable to habitat loss and fragmentation. Increasing connectance among habitat patches is therefore a common conservation strategy, based in part on models showing that increased migration between subpopulations can reduce vulnerability arising from population isolation. Although three-dimensional models are appropriate for exploring consequences to top predators, the effects of immigration on tri-trophic interactions have rarely been considered. To explore the effects of immigration on the equilibrium abundances of top predators, we studied the effects of immigration in the three-dimensional Rosenzweig-MacArthur model. To investigate the stability of the top predator …

Dissolved Oxygen Dynamics During A Phytoplankton Bloom In The Ross Sea Polynya, By Queste, Kj Heywood, Walker O. Smith Jr., De Kaufman, Td Jickells, Ms Dinniman

VIMS Articles

The Ross Sea polynya is one of the most productive regions in the Southern Ocean. However, limited access and high spatio-temporal variability of physical and biological processes limit the use of conventional oceanographic methods to measure early season primary productivity. High-resolution observations from two Seagliders provide insights into the timing of a bloom in the southern Ross Sea polynya in December 2010. Changes in chlorophyll and oxygen concentrations are used to assess bloom dynamics. Using a ratio of dissolved oxygen to carbon, net primary production is estimated over the duration of the bloom showing a sensitive balance between net autotrophy …

The Exposed Surface Area To Volume Ratio: Is Shell More Efficient Than Limestone In Promoting Oyster Recruitment?, Km Kuykendall, P Moreno, En Powell, Tm Soniat, S Colley, Roger L. Mann, Dm Munroe

VIMS Articles

Planting oyster cultch is a common management approach used to enhance recruitment. The two most popular cultch materials are shell and limestone. Both are sold by volume or weight; however, once deposited on oyster grounds, only a small portion of the total surface area of each particle is available for recruitment. Shell and limestone have different surface area to volume properties, and thus provide differential settlement opportunities. Exposed surface area to volume (expSA/V) ratios of oyster shell and limestone fragments were compared, as an indicator of their recruitment potential and cost-effectiveness for cultch planting. Samples were collected from the Primary …

A Novel Mechanism To Explain Success Of Invasive Herbaceous Species At The Expense Of Natives In Eastern Hardwood Forests, Frank S. Gilliam

Biological Sciences Faculty Research

Among the more intriguing topics in general ecology courses are the symbiotic relationships (the ‘-isms’ as I sometimes present them – mutualism, commensalism, and parasitism). Of these, mutualism is typically the most appealing to students. The scenario that different species can not only co-exist, but can also provide essential resources/services for one another, resonates well with all but the least interested in the course. Ultimately, however, there is also the palpable degree of dismay when they discover that these relationships arise from mutual exploitation, rather than from some benign force of nature. A flip-side of this, in many ways a …

Coral–Algal Phase Shifts Alter Fish Communities And Reduce Fisheries Production, Cameron H. Ainsworth, Peter J. Mumby

Marine Science Faculty Publications

Anthropogenic stress has been shown to reduce coral coverage in ecosystems all over the world. A phase shift towards an algae-dominated system may accompany coral loss. In this case, the composition of the reef-associated fish assemblage will change and human communities relying on reef fisheries for income and food security may be negatively impacted. We present a case study based on the Raja Ampat Archipelago in Eastern Indonesia. Using a dynamic food web model, we simulate the loss of coral reefs with accompanied transition towards an algae-dominated state and quantify the likely change in fish populations and fisheries productivity. One …

Discovery, Prevalence, And Persistence Of Novel Circular Single-Stranded Dna Viruses In The Ctenophores Mnemiopsis Leidyi And Beroe Ovata, Mya Breitbart, Bayleigh Benner, Parker Jernigan, Karyna Rosario, Laura Birsa, Rachel Harbeitner, Sidney Fulford, Carina Graham, Anna Walters, Dawn Goldsmith, Stella Berger, Jens Nejstgaard

Marine Science Faculty Publications

Gelatinous zooplankton, such as ctenophores and jellyfish, are important components of marine and brackish ecosystems and play critical roles in aquatic biogeochemistry. As voracious predators of plankton, ctenophores have key positions in aquatic food webs and are often successful invaders when introduced to new areas. Gelatinous zooplankton have strong impacts on ecosystem services, particularly in coastal environments. However, little is known about the factors responsible for regulating population dynamics of gelatinous organisms, including biological interactions that may contribute to bloom demise. Ctenophores are known to contain specific bacterial communities and a variety of invertebrate parasites and symbionts; however, no previous …

What Happens To Soil Organic Carbon As Coastal Marsh Ecosystems Change In Response To Increasing Salinity? An Exploration Using Ramped Pyrolysis, Elizabeth K. Williams, Brad E. Rosenheim

Marine Science Faculty Publications

Coastal wetlands store vast amounts of organic carbon, globally, and are becoming increasingly vulnerable to the effects of anthropogenic sea level rise. To understand the effect of sea level rise on organic carbon fate and preservation in this global sink, it is necessary to characterize differences in the biogeochemical stability of coastal wetland soil organic carbon (SOC). Here we use ramped pyrolysis/oxidation decomposition characteristics as proxies for SOC stability to understand the fate of carbon storage in coastal wetlands comprising the Mississippi River deltaic plain, undergoing rapid rates of local sea level rise. Soils from three wetland types (fresh, brackish, …