Life Sciences Commons^™

Establishing The Microcrustacean Daphnia As A Model System For Research On Aging, Charles Andrew Shumpert

Theses and Dissertations

Aging is a ubiquitous process pertaining to all biological systems around the planet. Although much has been learned from studies so far on the molecular mechanisms that lead to aging, a complete understanding of a healthy life span and longevity still eludes us. In this dissertation, we will examine the use of a freshwater microcrustacean Daphnia as a model system for studies on the biology of aging. The Introduction chapter presents a review of the general molecular alterations associated with cellular and organismal aging, and discusses the core model organisms currently used to study the aging process. The introduction chapter …

The Effects Of Elevated Circulating Levels Of Lipocalin 2 On Liver Metastasis Of Colorectal Cancer, John Gerard Bonapart

Theses and Dissertations

In the United States, colorectal cancer (CRC) is the third most diagnosed cancer and the second leading cause of cancer deaths. In 2015, approximately 143,000 new cases will be diagnosed and 50,000 deaths are predicted. Liver metastasis is the major cause of death. To understand the molecular and cellular mechanisms of liver metastasis, we used an orthotopic mouse model of CRC liver metastasis that recapitulated all stages of tumor growth and metastasis to perform whole genome microarray analysis to identify genetic changes in the liver microenvironment in response to primary tumor growth in the cecum. We identified lipocalin 2 (Lcn2) …

Vulnerable Species In A Changing Climate: The Genomic Response Of Antarctic Notothenioid Fishes To Predicted Oceanic Conditions As A Model Of Physiological Plasticity And Adaptive Capability, Troy James Huth

Theses and Dissertations

In its fifth report in 2014 the IPCC reinforced the contribution of anthropogenic CO2 to global climate change predicting widespread and significant changes to the global climate over a relatively short time scale. The polar regions, including the Southern Ocean surrounding Antarctica, were identified as ecosystems that may experience the most rapid and severe changes. As the Southern Ocean is one of the coldest and most oceanographically stable regions on earth, the endemic fauna likely have no alternative habitats available for migration. Further compounding the challenge these species will face is the substantial degree of adaptation to the extreme cold …

Linkages Among Fluorescent Dissolved Organic Matter, Dissolved Amino Acids And Lignin-Derived Phenols In River-Influenced Ocean Margins, Youhei Yamashita, Cédric G. Fichot, Yuan Shen, Rudolf Jaffé, Ronald Benner

Faculty Publications

Excitation emission matrix (EEM) fluorescence spectroscopy coupled with parallel factor analysis (PARAFAC) is commonly used to investigate the dynamics of dissolved organic matter (DOM). However, a lack of direct comparisons with known biomolecules makes it difficult to substantiate the molecular composition of specific fluorescent components. Here, coincident surface-water measurements of EEMs, dissolved lignin, and total dissolved amino acids (TDAA) acquired in the northern Gulf of Mexico were used to investigate the relationships between specific fluorescent components and DOM biomolecules. Two terrestrial humic-like components identified by EEM-PARAFAC using samples obtained from river to offshore waters were strongly linearly correlated with dissolved …

Sedentary Behavior In Preschoolers: How Many Days Of Accelerometer Monitoring Is Needed?, Wonwoo Byun, Michael W. Beets, Russell R. Pate

Faculty Publications

The reliability of accelerometry for measuring sedentary behavior in preschoolers has not been determined, thus we determined how many days of accelerometry monitoring are necessary to reliably estimate daily time spent in sedentary behavior in preschoolers. In total, 191 and 150 preschoolers (three to five years) wore ActiGraph accelerometers (15-s epoch) during the in-school (≥4 days) and the total-day (≥6 days) period respectively. Accelerometry data were summarized as time spent in sedentary behavior (min/h) using three different cutpoints developed for preschool-age children (

Assessing The Synergistic Effect Of Caffeine And Sugar On Cognitive Performance In Undergraduate Students, Sandra P. Urquiza, Michelle Vieyra

Journal of the South Carolina Academy of Science

Working independently, both caffeine and sugar provide benefits to attention and memory. However, there is sparse literature on the synergistic effects on improved cognitive performance between caffeine and sugar when taken together. This study explored the dynamics between caffeine and sugar when consumed under ordinary conditions – as a cup of coffee. Twenty-four undergraduate students (15 women and 9 men) were asked to complete a baseline cognitive test, and one of the three variables was given at random in the form of a cup of coffee: decaffeinated with sugar, caffeinated with no sugar, and caffeinated with sugar. The remaining two …

Predicting Phase Resetting Due To Multiple Stimuli, Kelsey M. Vollmer, Davy C. Vanderweyen, Derek R. Tuck, Sorinel A. Oprisan

Journal of the South Carolina Academy of Science

We generalized the phase resetting curve (PRC) to a more realistic case of neural oscillators receiving two or more inputs per cycle. The PRC tabulates the transient change in the firing period of a neuron due to an external perturbation, such as a presynaptic stimulus. We used a conductance-based model neuron to estimate experimentally the two-stimulus PRC and compared the results against our mathematical prediction based on the assumption of instantaneous recurrent stimulation. Within the limits of the recurrent stimulation assumptions, we found that the newly introduced prediction for the two-stimulus PRC matched experimental measurements. Our new results open the …

Reactive Oxygen Species-Mediated Neurodegeneration Is Independent Of The Ryanodine Receptor In Caenorhabditis Elegans, Lyndsay E.A. Young, Daniel C. Williams

Journal of the South Carolina Academy of Science

Despite the significant impacts on human health caused by neurodegeneration, our understanding of the degeneration process is incomplete. The nematode Caenorhabditis elegans is emerging as a genetic model organism well suited for identification of conserved cellular mechanisms and molecular pathways of neurodegeneration. Studies in the worm have identified factors that contribute to neurodegeneration, including excitotoxicity and stress due to reactive oxygen species (ROS). Disruption of the gene unc-68, which encodes the ryanodine receptor, abolishes excitotoxic cell death, indicating a role for calcium (Ca²⁺) signaling in neurodegeneration. We tested the requirement for unc-68 in ROS-mediated neurodegeneration using the …

Altered Activation Of Protein Kinase Pkr And Enhanced Apoptosis In Dystonia Cells Carrying A Mutation In Pkr Activator Protein Pact, Lauren S. Vaughn, D. Cristopher Bragg, Nutan Sharma, Sarah Camargos, Francisco Cardoso, Rekha C. Patel

Faculty Publications

PACT is a stress-modulated activator of the interferon-induced double-stranded RNA-activated protein kinase (PKR). Stress-induced phosphorylation of PACT is essential for PACT's association with PKR leading to PKR activation. PKR activation leads to phosphorylation of translation initiation factor eIF2α inhibition of protein synthesis and apoptosis.Arecessively inherited form of early-onset dystonia DYT16 has been recently identified to arise due to a homozygous missense mutation P222L in PACT. To examine if the mutant P222L protein alters the stress-response pathway, we examined the ability of mutant P222L to interact with and activate PKR. Our results indicate that the substitution mutant P222L activates PKR more …

Precise Repair Of Mping Excision Sites Is Facilitated By Target Site Duplication Derived Microhomology, David M. Gilbert, M. Catherine Bridges, Ashley E. Strother, Courtney E. Burckhalter, James M. Burnette Iii, C. Nathan Hancock

Faculty Publications

A key difference between the Tourist and Stowaway families of miniature inverted repeat transposable elements (MITEs) is the manner in which their excision alters the genome. Upon excision, Stowaway-like MITEs and the associated Mariner elements usually leave behind a small duplication and short sequences from the end of the element. These small insertions or deletions known as “footprints” can potentially disrupt coding or regulatory sequences. In contrast, Tourist-like MITEs and the associated PIF/Pong/Harbinger elements generally excise precisely, returning the genome to its original state. The purpose of this study was to determine the mechanisms underlying these …

Nanotechnology In The Real World: Redeveloping The Nanomaterial Consumer Products Inventory, Marina E. Vance, Todd Kuiken, Eric P. Vejerano, Sean P. Mcginnis, Michael F. Hochella Jr., David Rejeski, Matthew S. Hull

Faculty Publications

To document the marketing and distribution of nano-enabled products into the commercial marketplace, the Woodrow Wilson International Center for Scholars and the Project on Emerging Nanotechnologies created the Nanotechnology Consumer Products Inventory (CPI) in 2005. The objective of this present work is to redevelop the CPI by leading a research effort to increase the usefulness and reliability of this inventory. We created eight new descriptors for consumer products, including information pertaining to the nanomaterials contained in each product. The project was motivated by the recognition that a diverse group of stakeholders from academia, industry, and state/federal government had become highly …

Co-Extinction In A Host-Parasite Network: Identifying Key Hosts For Network Stability, Tad Dallas, Emily Cornelius

Faculty Publications

Parasites comprise a substantial portion of total biodiversity. Ultimately, this means that host extinction could result in many secondary extinctions of obligate parasites and potentially alter hostparasite network structure. Here, we examined a highly resolved fish-parasite network to determine key hosts responsible for maintaining parasite diversity and network structure (quantified here as nestedness and modularity). We evaluated four possible host extinction orders and compared the resulting co-extinction dynamics to random extinction simulations; including host removal based on estimated extinction risk, parasite species richness and host level contributions to nestedness and modularity. We found that all extinction orders, except the one …

The Adaptive Change Of Hla-Drb1 Allele Frequencies Caused By Natural Selection In A Mongolian Population That Migrated To The South Of China, Hao Sun, Zhaoqing Yang, Keqin Lin, Shuyuan Liu, Kai Huang, Xiuyun Wang, Jiayou Chu, Xinyu Huang

Faculty Publications

Pathogen-driven balancing selection determines the richness of human leukocyte antigen (HLA) alleles. Changes in the pathogen spectrum may cause corresponding changes in HLA loci. Approximately 700 years ago, a Mongolian population moved from the north of China to the Yunnan region in the south of China. The pathogen spectrum in the south of China differs from that in the north. In this study, changes in the HLA genes in the Yunnan Mongolian population, as well as the underlying mechanism, were investigated. A sequence-based typing method (SBT) was used to genotype HLA-DRB1 in 470 individuals from two Mongolian populations and another …

Anion-Responsive Metallopolymer Hydrogels For Healthcare Applications, Jiuyang Zhang, Jing Yan, Parasmani Pageni, Yi Yan, Adam Wirth, Yun-Ping Chen, Yali Qiao, Qian Wang, Alan W. Decho, Chuanbing Tang

Faculty Publications

Metallopolymers combine a processable, versatile organic polymeric skeleton with functional metals, providing multiple functions and methodologies in materials science. Taking advantage of cationic cobaltocenium as the key building block, organogels could be simply switched to hydrogels via a highly efficient ion exchange. With the unique ionic complexion ability, cobaltocenium moieties provide a robust soft substrate for recycling antibiotics from water. The essential polyelectrolyte nature offers the metallopolymer hydrogels to kill multidrug resistant bacteria. The multifunctional characteristics of these hydrogels highlight the potential for metallopolymers in the field of healthcare and environmental treatment.

When Nanoparticles Meet Biofilms—Interactions Guiding The Environmental Fate And Accumulation Of Nanoparticles, Kaoru Ikuma, Alan W. Decho, Boris T. Lau

Faculty Publications

Bacteria are essential components of all natural and many engineered systems. The most active fractions of bacteria are now recognized to occur as biofilms, where cells are attached and surrounded by a secreted matrix of “sticky” extracellular polymeric substances. Recent investigations have established that significant accumulation of nanoparticles (NPs) occurs in aquatic biofilms. These studies point to the emerging roles of biofilms for influencing partitioning and possibly transformations of NPs in both natural and engineered systems. While attached biofilms are efficient “sponges” for NPs, efforts to elucidate the fundamental mechanisms guiding interactions between NPs and biofilms have just begun. In …

The Identification Of Novel Protein-Protein Interactions In Liver That Affect Glucagon Receptor Activity, Junfeng Han, Ming Zhang, Sean Froese, Feihan F. Dai, Mélanie Robitaille, Alpana Bhattacharjee, Xinyu Huang, Weiping Jia, Stéphane Angers, Michael B. Wheeler, Li Wei

Faculty Publications

Glucagon regulates glucose homeostasis by controlling glycogenolysis and gluconeogenesis in the liver. Exaggerated and dysregulated glucagon secretion can exacerbate hyperglycemia contributing to type 2 diabetes (T2D). Thus, it is important to understand how glucagon receptor (GCGR) activity and signaling is controlled in hepatocytes. To better understand this, we sought to identify proteins that interact with the GCGR to affect ligand-dependent receptor activation. A Flag-tagged human GCGR was recombinantly expressed in Chinese hamster ovary (CHO) cells, and GCGR complexes were isolated by affinity purification (AP). Complexes were then analyzed by mass spectrometry (MS), and protein-GCGR interactions were validated by co-immunoprecipitation (Co-IP) …

Photosynthetic Performance And Anti-Oxidative Response Of Cornus Controversa Seedlings Under Cadmium And Lead Stress, Xinyu Huang, Yonglei Jiang, Xiaomao Cheng, Lilan Deng, Xuncheng Liu

Faculty Publications

The photosynthetic efficiency of Cornus controversa leaves was decreased significantly under Cd treatment while it was not affected by Pb exposure. Cd decreased while Pb treatment increased the chlorophyll contents of Cornus controversa leaves. Furthermore, the peroxidase (GPX) activities were decreased after Cd treatment while elevated by Pb exposure in Cornus controvera seedlings. In addition, both Cd and Pb exposures increased the malondialdehyde (MDA) and proline contents and elevated the superoxide dismutase (SOD) activities of Cornus controvera seedlings. Collectively, these results indicated that Cornus controversa may be more tolerant to Pb than Cd toxicity. This finding will contribute to the …

The Dynamic Effects Of Sea Level Rise On Low-Gradient Coastal Landscapes: A Review, Davina L. Passeri, Scott C. Hagen, Stephen C. Medeiros, Matthew V. Bilskie, Karim Alizad

Faculty Publications

Coastal responses to sea level rise (SLR) include inundation of wetlands, increased shoreline erosion, and increased flooding during storm events. Hydrodynamic parameters such as tidal ranges, tidal prisms, tidal asymmetries, increased flooding depths and inundation extents during storm events respond nonadditively to SLR. Coastal morphology continually adapts toward equilibrium as sea levels rise, inducing changes in the landscape. Marshes may struggle to keep pace with SLR and rely on sediment accumulation and the availability of suitable uplands for migration. Whether hydrodynamic, morphologic, or ecologic, the impacts of SLR are interrelated. To plan for changes under future sea levels, coastal managers …

The Dynamic Effects Of Sea Level Rise On Low‐Gradient Coastal Landscapes: A Review, Davina L. Passeri, Scott C. Hagen, Stephen C. Medeiros, Matthew V. Bilskie, Karim Alizad

Faculty Publications

Coastal responses to sea level rise (SLR) include inundation of wetlands, increased shore-line erosion, and increased flooding during storm events. Hydrodynamic parameters such as tidal ranges, tidal prisms, tidal asymmetries, increased flooding depths and inundation extents during storm events respond non additively to SLR. Coastal morphology continually adapts toward equilibrium as sea levels rise, inducing changes in the landscape. Marshes may struggle to keep pace with SLR and rely on sediment accumulation and the availability of suitable uplands for migration. Whether hydrodynamic, morphologic, or ecologic, the impacts of SLR are interrelated. To plan for changes under future sea lev-els, coastal …

Size-Fractionated Relationships Between Phytoplankton Production And Biomass, Luke Auman Bassett

Senior Theses

Phytoplankton are the autotrophic foundation of almost all marine ecosystems.

The flow of energy through an ecosystem is largely dependent how productivity moves through organisms of various sizes. For this reason, numerous studies have set out to quantify the respective contributions of these size-fractions to biomass and rates of primary production. This is done through field measurements of production or through mathematic models that infer production contributions from the easier field measured contributions to biomass. However, the accuracy of this method has been called into question. Can contributions to biomass really be used to accurately interpret contributions to production?

The …

Essential Oils From Apple Mint (Mentha Suaveolens) And Passionflower Fruit (Passiflora Incarnata): Studies On Cognition, Coordination, And Chemical Components., Evelyn F. Patrick *, Jessie Bowers *, Shannon Read *, Brett R. Lackey, Christine Murphy, Sandra L. Gray

Journal of the South Carolina Academy of Science

Plant essential oils (EO) are used as perfumes, lotions and air fresheners because of their pleasant aromas, but EO also have the ability to elicit changes in mood and behavior. These activities are influenced by the mode of administration and by multiple signaling pathways. The EO aromas from organically grown apple mint (Mentha suaveolens) and passionflower fruit (Passiflora incarnata) were assessed for their effects on cognition and coordination. Participants completed two tasks designed to test working memory and bimanual task efficiency in rooms infused with apple mint, passionflower fruit or control EO. Bimanual coordination was assessed using the Intercept2 program …

The Effects Of Suspended Sediment On Japanese Medaka (Oryzias Latipes) And Mosquitofish (Gambusia Affinis) Metabolism, Brandy L. Bossle, Ruben R. Goforth, Shem D. Unger, Olin E. Rhodes Jr.

Journal of the South Carolina Academy of Science

Sedimentation is recognized as a significant environmental stressor in aquatic ecosystems and high amounts of suspended sediments (SS) in streams are known to negatively affect aquatic organisms. In particular, it has been hypothesized that many fish species mayexhibit increased respiration rates when exposed to elevated SS. To evaluate this hypothesis, we evaluated the acute response (3 hour exposure) of two small, freshwater fish species exposed to high suspended sediment loads using experimental respirometry chambers which measure oxygen consumption as a proxy of metabolism. Our results indicate that Japanese Medaka (Oryzias latipes) did not exhibit a significantly greater oxygen …

Understanding Phylogenies: Constructing And Interpreting Phylogenetic Trees, Joseph L. Staton

Journal of the South Carolina Academy of Science

Interpretation of phylogenetic trees is fundamental in understanding the relationships between organisms, their traits or characteristics, their ecology and even their genomic and developmental biology. As trees appear more often in basic texts, many students, and even their teachers, clearly understand little of how they are constructed and even less about what can be inferred from them about the history of the representatives analyzed. Not only are these trees a source of confusion on what they do tell us, often non-specialists infer things wrongly or, worse, others misuse them in an attempt to negate the validity of evolutionary theory. In …

The Rise Of Carbon Nanoscience In South Carolina, Apparao M. Rao

Journal of the South Carolina Academy of Science

No abstract provided.

Marine Sequestration Of Carbon In Bacterial Metabolites, Oliver J. Lechtenfeld, Norbert Hertkorn, Yuan Shen, Matthias Witt, Ronald Benner

Faculty Publications

Linking microbial metabolomics and carbon sequestration in the ocean via refractory organic molecules has been hampered by the chemical complexity of dissolved organic matter (DOM). Here, using bioassay experiments and ultra-high resolution metabolic profiling, we demonstrate that marine bacteria rapidly utilize simple organic molecules and produce exometabolites of remarkable molecular and structural diversity. Bacterial DOM is similar in chemical composition and structural complexity to naturally occurring DOM in sea water. An appreciable fraction of bacterial DOM has molecular and structural properties that are consistent with those of refractory molecules in the ocean, indicating a dominant role for bacteria in shaping …

Engineering Nanoparticles To Silence Bacterial Communication, Kristen P. Miller, Lei Wang, Yung-Pin Chen, Perry J. Pellechia, Brian C. Benicewicz, Alan W. Decho

Faculty Publications

The alarming spread of bacterial resistance to traditional antibiotics has warranted the study of alternative antimicrobial agents. Quorum sensing (QS) is a chemical cell-to-cell communication mechanism utilized by bacteria to coordinate group behaviors and establish infections. QS is integral to bacterial survival, and therefore provides a unique target for antimicrobial therapy. In this study, silicon dioxide nanoparticles (Si-NP) were engineered to target the signaling molecules [i.e., acylhomoserine lactones (HSLs)] used for QS in order to halt bacterial communication. Specifically, when Si-NP were surface functionalized with β-cyclodextrin (β-CD), then added to cultures of bacteria (Vibrio fischeri), whose luminous output depends upon …

Upregulation Of Mir21 And Repression Of Grhl3 By Leptin Mediates Sinusoidal Endothelial Injury In Experimental Nonalcoholic Steatohepatitis, Sahar Pourhoseini, Ratanesh K. Seth, Suvarthi Das, Diptadip Dattaroy, Maria B. Kadiiska, Guanhua Xie, Gregory A. Michelotti, Mitzi Nagarkatti, Anna Mae Diehl, Saurabh Chatterjee

Faculty Publications

Sinusoidal endothelial dysfunction (SED) has been found to be an early event in nonalcoholic steatohepatitis (NASH) progression but the molecular mechanisms underlying its causation remains elusive. We hypothesized that adipokine leptin worsens sinusoidal injury by decreasing functionally active nitric oxide synthase 3 (NOS)3 via miR21. Using rodent models of NASH, and transgenic mice lacking leptin and leptin receptor, results showed that hyperleptinemia caused a 4-5 fold upregulation of hepatic miR21 as assessed by qRTPCR. The upregulation of miR21 led to a time-dependent repression of its target protein Grhl3 levels as shown by western blot analyses. NOS3-p/NOS3 ratio which is controlled …

The Candidate Cancer Gene Database: A Database Of Cancer Driver Genes From Forward Genetic Screens In Mice, Kenneth L. Abbott, Erik T. Nyre, Juan Abrahante, Yen Yi Ho, Rachel Isaksson Vogel, Timothy K. Starr

Faculty Publications

Identification of cancer driver gene mutations is crucial for advancing cancer therapeutics. Due to the overwhelming number of passenger mutations in the human tumor genome, it is difficult to pinpoint causative driver genes. Using transposon mutagenesis in mice many laboratories have conducted forward genetic screens and identified thousands of candidate driver genes that are highly relevant to human cancer. Unfortunately, this information is difficult to access and utilize because it is scattered across multiple publications using different mouse genome builds and strength metrics. To improve access to these findings and facilitate metaanalyses, we developed the Candidate Cancer Gene Database (CCGD, …

Familiarity Differentially Affects Right Hemisphere Contributions To Processing Metaphors And Literals, V. T. Lai, Wessel Van Dam, L. L. Conant, J. R. Binder, Rutvik Desai

Faculty Publications

The role of the two hemispheres in processing metaphoric language is controversial. While some studies have reported a special role of the right hemisphere (RH) in processing metaphors, others indicate no difference in laterality relative to literal language. Some studies have found a role of the RH for novel/unfamiliar metaphors, but not conventional/familiar metaphors. It is not clear, however, whether the role of the RH is specific to metaphor novelty, or whether it reflects processing, reinterpretation or reanalysis of novel/unfamiliar language in general. Here we used functional magnetic resonance imaging (fMRI) to examine the effects of familiarity in both metaphoric …

Map Kinase Signaling In Plant Responses To Biotic Stress, Carlton James Bequette

Theses and Dissertations

Plants must be able to perceive and properly respond to a multitude of environmental conditions and produce appropriate cellular responses for optimal growth and reproduction. Mitogen-activated protein kinase (MAPK) phosphorylation cascades are critical components of signal transduction networks that mediate cellular responses to a wide range of both biotic and abiotic extracellular stimuli. This thesis presents an investigation of three novel aspects of MAPK signaling, the role of MAPKs in the regulation of cell death, the organization of MAPKs in a multi-protein complex, and the negative regulation of MAPKs by MAPK phosphatases. In tomato, three MAPKs play an essential role …