Life Sciences Commons^™

Using Rare Earth Elements To Constrain Particulate Organic Carbon Flux In The East China Sea, Chin-Chang Hung, Ya-Feng Chen, Shih-Chieh Hsu, Kui Wang, Jianfang Chen, David J. Burdige

OES Faculty Publications

Fluxes of particulate organic carbon (POC) in the East China Sea (ECS) have been reported to decrease from the inner continental shelf towards the outer continental shelf. Recent research has shown that POC fluxes in the ECS may be overestimated due to active sediment resuspension. To better characterize the effect of sediment resuspension on particle fluxes in the ECS, rare earth elements (REEs) and organic carbon (OC) were used in separate two-member mixing models to evaluate trap-collected POC fluxes. The ratio of resuspended particles from sediments to total trap-collected particles in the ECS ranged from 82-94% using the OC mixing …

Sagittal Plane Gait Kinematics In Individuals With Chronic Ankle Instability, Matthew C. Hoch, David R. Mullineaux, Kyoungkyu Jeon, Patrick O. Mckeon

Rehabilitation Sciences Faculty Publications

Single joint kinematic alterations have been identified during gait in those with chronic ankle instability (CAI). The purpose of this study was to compare sagittal plane hip, knee, and ankle kinematics during walking in participants with and without CAI. Twelve individuals with CAI and 12 healthy individuals walked on a treadmill at 1.5 m/s. Three-dimensional kinematics were analyzed using mean ensemble curves and independent t tests. Participants with CAI demonstrated less lower extremity flexion during the absorption phase of stance and the limb placement phase of swing, which may have implications for limb placement at initial contact.

Multiple Sensory Modalities Used By Squid In Successful Predator Evasion Throughout Ontogeny, Carly A. York, Ian K. Bartol, Paul S. Kruger

Biological Sciences Faculty Publications

Squid rely on multiple sensory systems for predator detection. In this study we examine the role of two sensory systems, the lateral line analogue and vision, in successful predator evasion throughout ontogeny. Squid Doryteuthis pealeii and Lolliguncula brevis were recorded using high-speed videography in the presence of natural predators under light and dark conditions with their lateral line analogue intact or ablated via a pharmacological technique. Paralarval squid showed reduced escape responses when ablated; however, no differences were found between light and dark conditions in non-ablated paralarvae, as was previously shown in juveniles and adults, indicating that the lateral line …

Vascular Endothelial Growth Factor-A Gene Electrotransfer Promotes Angiogenesis In A Porcine Model Of Cardiac Ischemia, Anna A. Bulysheva, Barbara Hargrave, Nina Burcus, Cathryn G. Lundberg, Len Murray, Richard Heller

Bioelectrics Publications

This study aimed to assess safety and therapeutic potential of gene electrotransfer (GET) as a method for delivery of plasmid encoding vascular endothelial growth factor A (VEGF-A) to ischemic myocardium in a porcine model. Myocardial ischemia was induced by surgically occluding the left anterior descending coronary artery in swine. GET following plasmid encoding VEGF-A injection was performed at four sites in the ischemic region. Control groups either received injections of the plasmid without electrotransfer or injections of the saline vehicle. Animals were monitored for 7 weeks and the hearts were evaluated for angiogenesis, myocardial infarct size and left ventricular contractility. …

Cloning, Characteristics, And Functional Analysis Of Rabbit Nadph Oxidase 5, Feng Chen, Caiyong Yin, Christiana Dimitropoulou, David J.R. Fulton

Bioelectrics Publications

Background: Nox5 was the last member of the Nox enzyme family to be identified. Functionally distinct from the other Nox isoforms, our understanding of its physiological significance has been hampered by the absence of Nox5 in mouse and rat genomes. Nox5 is present in the genomes of other species such as the rabbit that have broad utility as models of cardiovascular disease. However, the mRNA sequence, characteristics, and functional analysis of rabbit Nox5 has not been fully defined and were the goals of the current study.

Methods: Rabbit Nox5 was amplified from rabbit tissue, cloned, and sequenced. COS-7 cells were …

Turning Performance In Squid And Cuttlefish: Unique Dual-Mode, Muscular Hydrostatic Systems, Rachel A. Jastrebsky, Ian K. Bartol, Paul S. Krueger

Biological Sciences Faculty Publications

Although steady swimming has received considerable attention in prior studies, unsteady swimming movements represent a larger portion of many aquatic animals' locomotive repertoire and have not been examined extensively. Squids and cuttlefishes are cephalopods with unique muscular hydrostat-driven, dual-mode propulsive systems involving paired fins and a pulsed jet. These animals exhibit a wide range of swimming behavior, but turning performance has not been examined quantitatively. Brief squid, Lolliguncula brevis, and dwarf cuttlefish, Sepia bandensis, were filmed during turns using high-speed cameras. Kinematic features were tracked, including the length-specific radius of the turn (R/L), a measure of maneuverability, and …

A 'Tissue Model' To Study The Barrier Effects Of Living Tissues On The Reactive Species Generated By Surface Air Discharge, Tongtong He, Dingxin Liu, Han Xu, Zhichao Liu, Dehui Xu, Dong Li, Qiosong Li, Mingzhe Rong, Michael G. Kong

Bioelectrics Publications

Gelatin gels are used as surrogates of human tissues to study their barrier effects on incoming reactive oxygen and nitrogen species (RONS) generated by surface air discharge. The penetration depth of nitrite into gelatin gel is measured in real time during plasma treatment, and the permeabilities of nitrite, nitrate, O₃ and H₂O₂ through gelatin gel films are quantified by measuring their concentrations in the water underneath such films after plasma treatment. It is found that the penetration speed of nitrite increases linearly with the mass fraction of water in the gelatin gels, and the permeabilities of …

Experimental Assessment Of Mouse Sociability Using An Automated Image Processing Approach, Frency Varghese, Jessica A. Burket, Andrew D. Benson, Stephen I. Deutsch, Christian W. Zemlin

Electrical & Computer Engineering Faculty Publications

Mouse is the preferred model organism for testing drugs designed to increase sociability. We present a method to quantify mouse sociability in which the test mouse is placed in a standardized apparatus and relevant behaviors are assessed in three different sessions (called session I, II, and III). The apparatus has three compartments (see Figure 1), the left and right compartments contain an inverted cup which can house a mouse (called “stimulus mouse”). In session I, the test mouse is placed in the cage and its mobility is characterized by the number of transitions made between compartments. In session II, a …

Membrane Channel Gene Expression In Human Costal And Articular Chondrocytes, A. Asmar, R. Barrett-Jolley, A. Werner, R. Kelly Jr., M. Stacey

Bioelectrics Publications

Chondrocytes are the uniquely resident cells found in all types of cartilage and key to their function is the ability to respond to mechanical loads with changes of metabolic activity. This mechanotransduction property is, in part, mediated through the activity of a range of expressed transmembrane channels; ion channels, gap junction proteins, and porins. Appropriate expression of ion channels has been shown essential for production of extracellular matrix and differential expression of transmembrane channels is correlated to musculoskeletal diseases such as osteoarthritis and Albers-Sch€onberg. In this study we analyzed the consistency of gene expression between channelomes of chondrocytes from human …

Experimental Demonstration Of An Allee Effect In Microbial Populations, Rajreni B. Kaul, Andrew M. Kramer, Fred C. Dobbs, John M. Drake

OES Faculty Publications

Microbial populations can be dispersal limited. However, microorganisms that successfully disperse into physiologically ideal environments are not guaranteed to establish. This observation contradicts the Baas-Becking tenet: ‘Everything is everywhere, but the environment selects’. Allee effects, which manifest in the relationship between initial population density and probability of establishment, could explain this observation. Here, we experimentally demonstrate that small populations of Vibrio fischeri are subject to an intrinsic demographic Allee effect. Populations subjected to predationby the bacterivore Cafeteria roenbergensis display both intrinsic and extrinsic demographic Allee effects. The estimated critical threshold required to escape positive densitydependence is around 5, 20 or …

Marine Disease Impacts, Diagnosis, Forecasting, Management And Policy, Kevin D. Lafferty, Eileen E. Hofmann

CCPO Publications

(First paragraph) As Australians were spending millions of dollars in 2014 to remove the coraleating crown of thorns sea star from the Great Barrier Reef, sea stars started washing up dead for free along North America’s Pacific Coast. Because North American sea stars are important and iconic predators in marine communities, locals and marine scientists alike were alarmed by what proved to be the world’s most widespread marine mass mortality in geographical extent and species affected, especially given its mysterious cause. Investigative research using modern diagnostic techniques implicated a never-before-seen virus [1]. The virus inspired international attention to marine diseases, …

Preferential Depletion Of Zinc Within Costa Rica Upwelling Dome Creates Conditions For Zinc Co-Limitation Of Primary Production, P. Dreux Chappell, Jagruti Vedmati, Karen E. Selph, Heather A. Cyr, Bethany D. Jenkins, Michael R. Landry, James W. Moffett

OES Faculty Publications

The Costa Rica Dome (CRD) is a wind-driven feature characterized by high primary production and an unusual cyanobacterial bloom in surface waters. It is not clear whether this bloom arises from top-down or bottom-up processes. Several studies have argued that trace metal geochemistry within the CRD contributes to the composition of the phytoplankton assemblages, since cyanobacteria and eukaryotic phytoplankton have different transition metal requirements. Here, we report that total dissolved zinc (Zn) is significantly depleted relative to phosphate (P) and silicate (Si) within the upper water column of the CRD compared with other oceanic systems, and this may create conditions …

Volumetric Flow Imaging Reveals The Importance Of Vortex Ring Formation In Squid Swimming Tail-First And Arms-First, Ian K. Bartol, Paul S. Krueger, Rachel A. Jastrebsky, Sheila Williams, Joseph T. Thompson

Biological Sciences Faculty Publications

Squids use a pulsed jet and fin movements to swim both arms-first (forward) and tail-first (backward). Given the complexity of the squid multi-propulsor system, 3D velocimetry techniques are required for the comprehensive study of wake dynamics. Defocusing digital particle tracking velocimetry, a volumetric velocimetry technique, and high-speed videography were used to study arms-first and tail-first swimming of brief squid Lolliguncula brevis over a broad range of speeds [0-10 dorsal mantle lengths (DML) s^-1) in a swim tunnel. Although there was considerable complexity in the wakes of these multi-propulsor swimmers, 3D vortex rings and their derivatives were prominent reoccurring features …

Marine Infectious Disease Dynamics And Outbreak Thresholds: Contact Transmission, Pandemic Infection, And The Potential Role Of Filter Feeders, Gorka Bidegain, Eric N. Powell, John M. Klinck, Tal Ben-Horin, Eileen E. Hofmann

CCPO Publications

Disease-causing organisms can have significant impacts on marine species and communities. However, the dynamics that underlie the emergence of disease outbreaks in marine ecosystems still lack the equivalent level of description, conceptual understanding, and modeling context routinely present in the terrestrial systems. Here, we propose a theoretical basis for modeling the transmission of marine infectious diseases (MIDs) developed from simple models of the spread of infectious disease. The models represent the dynamics of a variety of host-pathogen systems including those unique to marine systems where transmission of disease is by contact with waterborne pathogens both directly and through filter-feeding processes. …

Understanding The Structure And Functioning Of Polar Pelagic Ecosystems To Predict The Impacts Of Change, E. E. Murphy, R. D. Cavanagh, K. F. Drinkwater, S. M. Grant, J. J. Heymans, E. E. Hofmann, G. L. Hunt Jr., N. M. Johnston

CCPO Publications

The determinants of the structure, functioning and resilience of pelagic ecosystems across most of the polar regions are not well known. Improved understanding is essential for assessing the value of biodiversity and predicting the effects of change (including in biodiversity) on these ecosystems and the services they maintain. Here we focus on the trophic interactions that underpin ecosystem structure, developing comparative analyses of how polar pelagic food webs vary in relation to the environment. We highlight that there is not a singular, generic Arctic or Antarctic pelagic food web, and, although there are characteristic pathways of energy flow dominated by …

Neural Responses To Maternal Praise And Criticism: Relationship To Depression And Anxiety Symptoms In High-Risk Adolescent Girls, Robin L. Aupperle, Amanda S. Morris, Jennifer S. Silk, Michael M. Criss, Matt R. Judah, Sally G. Eagleton, Namik Kirlic, Jennifer Byrd-Craven, Raquel Phillips, Ruben P. Alvarez

Psychology Faculty Publications

Background: The parent-child relationship may be an important factor in the development of adolescent depressive and anxious symptoms. In adults, depressive symptoms relate to increased amygdala and attenuated prefrontal activation to maternal criticism. The current pilot study examined how depressive and anxiety symptoms in a high-risk adolescent population relate to neural responses to maternal feedback. Given previous research relating oxytocin to maternal behavior, we conducted exploratory analyses using oxytocin receptor (OXTR) genotype.

Methods: Eighteen females (ages 12-16) listened to maternal praise, neutral, and critical statements during functional magnetic resonance imaging. Participants completed the Mood and Feelings Questionnaire and the Screen …

Cell Electrosensitization Exists Only In Certain Electroporation Buffers, Janja Dermol, Olga N. Pakhomova, Andrei G. Pakhomov, Damijan Miklavčič

Bioelectrics Publications

Electroporation-induced cell sensitization was described as the occurrence of a delayed hypersensitivity to electric pulses caused by pretreating cells with electric pulses. It was achieved by increasing the duration of the electroporation treatment at the same cumulative energy input. It could be exploited in electroporation-based treatments such as electrochemotherapy and tissue ablation with irreversible electroporation. The mechanisms responsible for cell sensitization, however, have not yet been identified. We investigated cell sensitization dynamics in five different electroporation buffers. We split a pulse train into two trains varying the delay between them and measured the propidium uptake by fluorescence microscopy. By fitting …

Cytosolic Dna Sensor Upregulation Accompanies Dna Electrotransfer In B16.F10 Melanoma Cells, Katarina Znidar, Masa Bosnjak, Maja Cemazar, Loree C. Heller

Bioelectrics Publications

In several preclinical tumor models, antitumor effects occur after intratumoral electroporation, also known as electrotransfer, of plasmid DNA devoid of a therapeutic gene. In mouse melanomas, these effects are preceded by significant elevation of several proinflammatory cytokines. These observations implicate the binding and activation of intracellular DNA-specific pattern recognition receptors or DNA sensors in response to DNA electrotransfer. In tumors, IFN β mRNA and protein levels significantly increased. The mRNAs of several DNA sensors were detected, and DAI, DDX60, and p204 tended to be upregulated. These effects were accompanied with reduced tumor growth and increased tumor necrosis. In B16. F10 …

The Cytotoxic Synergy Of Nanosecond Electric Pulses And Low Temperature Leads To Apoptosis, Claudia Muratori, Andrei G. Pakhomov, Elena C. Gianulis, Sarah D. Jensen, Olga N. Pakhomova

Bioelectrics Publications

Electroporation by nanosecond electric pulses (nsEP) is an emerging modality for tumor ablation. Here we show the efficient induction of apoptosis even by a non-toxic nsEP exposure when it is followed by a 30-min chilling on ice. This chilling itself had no impact on the survival of U-937 or HPAF-II cells, but caused more than 75% lethality in nsEP-treated cells (300 ns, 1.8-7 kV/cm, 50-700 pulses). The cell death was largely delayed by 5-23 hr and was accompanied by a 5-fold activation of caspase 3/7 (compared to nsEP without chilling) and more than 60% cleavage of poly-ADP ribose polymerase (compared …

A Dielectric Rod Antenna For Picosecond Pulse Stimulation Of Neurological Tissue, Ross A. Petrella, Karl H. Schoenbach, Shu Xiao

Bioelectrics Publications

A dielectrically loaded wideband rod antenna has been studied as a pulse delivery system to subcutaneous tissues. Simulation results applying 100-ps electrical pulse show that it allows us to generate a critical electric field for biological effects, such as brain stimulation, in the range of several centimeters. In order to reach the critical electric field for biological effects, which is similar to 20 kV/cm, at a depth of 2 cm, the input voltage needs to be 175 kV. The electric field spot size in the brain at this position is similar to 1 cm(2). Experimental studies in free space with …

Conserved Intramolecular Interactions Maintain Myosin Interacting-Heads Motifs Explaining Tarantula Muscle Super-Relaxed State Structural Basis, Lorenzo Alamo, Dan Qi, Willy Wriggers, Antonio Pinto, Jingui Zhu, Aivett Bilbao, Richard E. Gillilan, Songnian Hu, Raúl Padrón

Mechanical & Aerospace Engineering Faculty Publications

Tarantula striated muscle is an outstanding system for understanding the molecular organization of myosin filaments. Three-dimensional reconstruction based on cryo-electron microscopy images and single-particle image processing revealed that, in a relaxed state, myosin molecules undergo intramolecular head head interactions, explaining why head activity switches off. The filament model obtained by rigidly docking a chicken smooth muscle myosin structure to the reconstruction was improved by flexibly fitting an atomic model built by mixing structures from different species to a tilt-corrected 2-nm three-dimensional map of frozen-hydrated tarantula thick filament. We used heavy and light chain sequences from tarantula myosin to build a …

Flexc: Protein Flexibility Prediction Using Context-Based Statistics, Predicted Structural Features, And Sequence Information, Ashraf Yaseen, Mais Nijim, Brandon Williams, Lei Qian, Min Li, Jianxin Wang, Yaohang Li

Computer Science Faculty Publications

The fluctuation of atoms around their average positions in protein structures provides important information regarding protein dynamics. This flexibility of protein structures is associated with various biological processes. Predicting flexibility of residues from protein sequences is significant for analyzing the dynamic properties of proteins which will be helpful in predicting their functions.

Aqueous Reactive Species Induced By A Surface Air Discharge: Heterogenous Mass Transfer And Liquid Chemistry Pathways, D. X. Liu, Z. C. Liu, C. Chen, A. J. Yang, D. Li, M. Z. Rong, H. L. Chen, M. G. Kong

Bioelectrics Publications

Plasma-liquid interaction is a critical area of plasma science and a knowledge bottleneck for many promising applications. In this paper, the interaction between a surface air discharge and its downstream sample of deionized water is studied with a system-level computational model, which has previously reached good agreement with experimental results. Our computational results reveal that the plasma-induced aqueous species are mainly H+, nitrate, nitrite, H2O2 and O-3. In addition, various short-lived aqueous species are also induced, regardless whether they are generated in the gas phase first. The production/loss pathways for aqueous species are quantified for an air gap width ranging …

Effects Of High Voltage Nanosecond Electric Pulses On Eukaryotic Cells (In Vitro): A Systematic Review, Tina Batista Napotink, Matej Reberšek, P. Thomas Vernier, Babara Mali, Damijan Miklavčič

Bioelectrics Publications

For this systematic review, 203 published reports on effects of electroporation using nanosecond high-voltage electric pulses (nsEP) on eukaryotic cells (human, animal, plant) in vitro were analyzed. A field synopsis summarizes current published data in the field with respect to publication year, cell types, exposure configuration, and pulse duration. Published data were analyzed for effects observed in eight main target areas (plasma membrane, intracellular, apoptosis, calcium level and distribution, survival, nucleus, mitochondria, stress) and an additional 107 detailed outcomes. We statistically analyzed effects of nsEP with respect to three pulse duration groups: A: 1–10 ns, B: 11–100 ns and C: …

Vanadium Toxicological Potential Versus Its Pharmacological Activity: New Developments And Research, Agnieszka Ścibior, Juan Llopis, Alvin A. Holder, Mario Altamirano-Lozano

Chemistry & Biochemistry Faculty Publications

Scibior, A., Llopis, J., Holder, A. A., & Altamirano-Lozano, M. (2016). Vanadium toxicological potential versus its pharmacological activity: New developments and research. Oxidative Medicine and Cellular Longevity, 2016, 1-2. doi: 10.1155/2016/7612347

Inactivation Of Acanthamoeba Spp. And Other Ocular Pathogens By Application Of Cold Atmospheric Gas Plasma, Wayne Heaselgrave, Gilbert Shama, Peter W. Andrew, Michael G. Kong

Bioelectrics Publications

Currently there are estimated to be approximately 3.7 million contact lens wearers in the United Kingdom and 39.2 million in North America. Contact lens wear is a major risk factor for developing an infection of the cornea known as keratitis due to poor lens hygiene practices. While there is an international standard for testing disinfection methods against bacteria and fungi (ISO 14729), no such guidelines exist for the protozoan Acanthamoeba, which causes a potentially blinding keratitis most commonly seen in contact lens wearers, and as a result, many commercially available disinfecting solutions show incomplete disinfection after 6 and 24 …

The Contribution Of Marine Aggregate-Associated Bacteria To The Accumulation Of Pathogenic Bacteria In Oysters: An Agent-Based Model, Andrew M. Kramer, J. Evan Ward, Fred C. Dobbs, Melissa L. Pierce

OES Faculty Publications

Bivalves process large volumes of water, leading to their accumulation of bacteria, including potential human pathogens (e.g., vibrios). These bacteria are captured at low efficiencies when freely suspended in the water column, but they also attach to marine aggregates, which are captured with near 100% efficiency. For this reason, and because they are often enriched with heterotrophic bacteria, marine aggregates have been hypothesized to function as important transporters of bacteria into bivalves. The relative contribution of aggregates and unattached bacteria to the accumulation of these cells, however, is unknown. We developed an agent-based model to simulate accumulation of vibrio-type bacteria …

Sex-Obsessed Or Just Sociable? Non-Copulatory Displays In The Hamerkop, Natasha Hagemeyer

Biological Sciences Faculty Publications

[First Paragraph] Non‐copulatory sexual behavior is surprisingly common among animals ranging from insects to vertebrates. Although sometimes considered unusual or aberrant within a species, in some taxa non‐copulatory sexual behavior is widespread, and may even represent the majority of sexual behavior. Such behavior can also happen in many other contexts, including accidental contact, courtship, social bonding, and social structuring (Bagemihl 1999).

The Small Mammals Of Southeastern Virginia As Revealed By Pitfall Trapping, Robert K. Rose

Biological Sciences Faculty Publications

Pitfall trapping is a poor method to catch small mammals but the only way to catch and study the Southeastern Shrew (Sorex longirostris), the primary mammal of interest in the field studies reported here. While learning much about its distribution and abundance, still more was learned about the other small mammals present in forests and fields of eastern Virginia. A total of 15 species was captured at 19 locations during the 1990-2013 period, including five shrews, two moles, and eight rodents, representing all but one of the common small mammals in eastern Virginia.

Local Avian Density Influences Risk Of Mortality From Window Strikes, Ann M. Sabo, Natasha D.G. Hagemeyer, Ally S. Lahey, Eric L. Walters

Biological Sciences Faculty Publications

Up to a billion birds die per year in North America as a result of striking windows. Both transparent and reflective glass panes are a cause for concern, misleading birds by either acting as invisible, impenetrable barriers to desired resources, or reflecting those resources over a large surface area. A high number of window strikes occur during migration, but little is known about the factors of susceptibility, or whether particular avian taxa are more vulnerable than others. We report on a study of window strikes and mist-netting data at the Virginia Zoological Park (Norfolk, Virginia, USA), conducted in the autumn …