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College of Science


Recent Publications

Understanding the Movement of Particles in Flow

Flow transports both non-living particles and living microorganisms from one place to another.   Studying particle movement in natural systems is logistically difficult as one must simultaneously measure particle behavior and flow. Using an oscillating grid flow facility in the Coastal Carolina University Environmental Fluids Laboratory, Erin Hackett Ph.D. and Roi Gurka Ph.D. (Department of Coastal and Marine Systems Science) developed a novel approach for simultaneous measurement of turbulent flow and particle motion. The method along with a companion video were recently published in the Journal of Visualized Experiments. Their approach makes use of a pulsed laser and LED line light that illuminate the flow field and particles. “This article details a relatively simple and effective way to simultaneously measure particles and their interactions with flow,” says Gurka. “The method has wide applicability, and can aid our understanding in problems such as spread of contaminants in air, water, and engineered systems as well as the movement of sand in the ocean” says Hackett.

Hackett, E.E. and R. Gurka, 2019. Simultaneous measurement of turbulence and particle kinematics using flow imaging techniques. Journal of Visualized Experiments 145:1-10. https://doi.org/10.3791/58036

 

The Egg Environment Affects Reptile Embryo Development

Many reptiles lay eggs that are deposited in nests. And, the selection of a nest site is presumably made to avoid egg predation and to provide an optimal incubation environment for embryo development. However, extreme weather may expose eggs to temperatures and oxygen conditions that are stressful to developing embryos. A recent paper published in Comparative Biochemistry and Physiology by Scott Parker, Ph.D., (Department of Biology) and his student Valerie Dimkovikj showed how variations in oxygen availability and temperature influenced development of embryonic leopard geckos. They reduced oxygen availability to the embryos by painting eggs with paraffin and then measured embryo growth and development after 15 and 30 days. Although the size of embryos was reduced by oxygen limitation, there were corresponding increases in relative heart mass suggesting that developing embryos can adjust the allocation of energy relative to the incubation environment. “The results are noteworthy because they demonstrate the extreme capacity of reptile embryos to withstand severe oxygen limitation during incubation. The remarkable tolerance to reduction in respiratory membrane surface area is likely a necessary adaptive trait which allows embryos to survive under variable nest environmental conditions,” says Parker. “Current studies in my lab are investigating effects of hypoxia during development on juvenile behavior and cognition. These studies will help inform our understanding of long-term consequences of oxygen limitation on survival and fitness of adult reptiles and possibly other vertebrates.”

Parker, S.L. and V.H. Dimkovikj. 2018. Effects of regional hypoxia and incubation temperature on growth, differentiation, heart mass, and oxygen consumption in embryos of the leopard gecko (Eublepharis macularius). Comparative Biochemistry and Physiology 227:51-59. https://doi.org/10.1016/j.cbpa.2018.09.006

Selenium: how do plants perceive and respond to its toxicity?

Selenium is a naturally occurring element with a broad range of biological effects. In humans, selenium is an essential trace element with clear health benefits, but becomes toxic above trace levels. Plants provide humans with most of their dietary selenium requirements, but the physiological mechanism for selenium toxicity in plants is poorly understood. However, a recent paper published in the Journal of Plant Physiology by Doug Van Hoewyk, Ph.D., (Department of Biology) and colleagues at the University of Szeged in Hungary examined how selenium toxicity can be mitigated in plants. A major conclusion of the paper was that “the plant hormone nitric oxide signals a stress response in plants,” says Van Hoewyk. With this finding it may be possible to create crop varieties with enhanced nitric oxide signaling that might improve selenium tolerance.

Kolbert, Z, Á. Molnár, G. Feigl and D. Van Hoewyk. 2019. Plant selenium toxicity: proteome in the crosshairs. Journal of Plant Physiology 232:291-300. https://doi.org/10.1016/j.jplph.2018.11.003

Measuring Groundwater Movement into a Tidal River

It is often assumed that the majority of water flows into tidal rivers as a result of surface flow from the connected network of smaller creeks and channels. However, a recent paper published in Estuarine, Coastal and Shelf Science by Richard Peterson, Ph.D., Leigha Peterson, and Matthew Carter (Department of Coastal and Marine Systems Science) and colleagues at the University of Georgia, characterized the flow of groundwater into a tidal river. Their study, based at Sapelo Island in Georgia, used geochemical tracers to track the flow of groundwater from the saltmarshes into the main channel and headwaters of the Duplin River. They found that groundwater flow toward the river headwaters was higher with greater levels of marsh flooding and that groundwater flow peaked as the tide fell. However, groundwater flow to the main channel of the river peaked during flood tides following extended dry periods. “This work has substantially increased our measured resolution (through both time and space) of water exchange between marshes and surface waters,” says Peterson. “This study was conducted as part of an NSF-funded Long-Term Ecological Research project. The project was just re-funded for another 6-year term, so we will continue involving CCU students in research to examine how these exchange processes may be altered as a result of climate, sea-level, and land-use changes.”

Peterson, R.N., C. Meile, L.E. Peterson, M. Carter, and D. Miklesh. 2019. Groundwater discharge dynamics into a salt marsh tidal river. Estuarine, Coastal and Shelf Science 218:324-333. https://doi.org/10.1016/j.ecss.2019.01.007

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Islands of Life on the High-Arctic Seabed

Much of what we know about the oceans is focused on a relatively small depth range at the surface where sunlight powers the flow of energy from plants to animals. But what about the deep sea where energy from the sun is non-existent and animals rely on food falling from the ocean’s surface? Recent papers published by William Ambrose, Ph.D., (Department of Coastal and Marine Systems Science) and colleagues in Norway examined a unique type of biological community growing on the floor of the Arctic Ocean near Svalbard. Using a remote coring device and camera the research group was able to measure sediment chemistry and community composition. The community, comprised of microbes and invertebrates, was associated with seepage of methane from the sediments and the hard substrate. Methane is an energy-rich molecule and in this community it appears to be used as a source of energy by worms. The use of methane in turn releases byproducts that create hard substrate that is colonized by many other organisms. “Methane and other cold-seep communities are well known from lower latitudes, our studies are the first to study the communities of high Arctic seeps,” says  Ambrose. “We are currently exploring to what extent chemical energy from these seeps provides supplemental energy to communities on the bottom and in the water column beyond the seep environment.”

Åström, E.K.L., M.L. Carroll, W.G. Ambrose Jr., A. Sen, A. Silyakova, and J. Carroll.  2018. Methane cold seeps as biological oases in the high-Arctic deep sea. Limnology and Oceanography 63:S209-S31. doi: 10.1002/lno.10732.

Åström, E.K.L., Carroll, M.L., Ambrose, W.G. Jr., Carroll, J.  2016. Arctic cold seeps in marine methane hydrate environments: Impacts on shelf macrobenthic community structure offshore Svalbard. Marine Ecology Progress Series 552:1-18. doi: 10.3354/meps11773.

The Business of College Sports

The National Collegiate Athletic Association (NCAA) governs college athletics in the United States. It operates with a business model that stresses revenue generation for participating institutions. However, some have questioned whether the NCAA should place more emphasis on non-financial outcomes of college sports. A recent paper written by Nicholas Schlereth, Ph.D., (Department of Recreation and Sport Management) and published in the Journal of Business Law and Ethics examines an alternative model of non-financial reporting developed in Europe. “The current model does not provide accurate financial reporting guidelines. The United States Department of Education has provided financial reporting guidelines to comply with the Equity in Athletics Act, but it does not include guidelines for reporting non-financial activities like community service actions,” says Schelereth. His paper provides a framework for how the NCAA could adopt a new financial model with improved reporting of both financial and non-financial outcomes of college sports. And, social media could be a significant vehicle for communicating the non-financial achievements. “The proposed model presents a unique approach introducing a 'triple bottom line' to college athletic departments,” says Schlereth.

Schlereth, N. 2018. Social reporting & NCAA. Journal of Business Law and Ethics 6:1-14.

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How to Best Age a Chain Pickerel?

Precise aging of individual fish is important for understanding population dynamics and for guiding management actions. For many fishes, growth rings form in some bones, scales, and other calcified tissues annually, and these visible rings can be counted with a microscope. The Chain Pickerel is a native sport fish in South Carolina, yet little information is available for estimating the age of this species. In a recent paper published in the North American Journal of Fisheries Management by Derek Crane, Ph.D., (Department of Biology) and CCU students Cory Bauerlien, Marinda Cornett and Emily Zielonka examined the utility of multiple structures (e.g., fin rays, otoliths, bones and scales) for estimating the age of Chain Pickerel. The study showed that for Chain Pickerels sampled from the Savannah River, otoliths were the most precise indicators of fish age. “Our study is important because it was the first study to provide guidance for estimating age of this relatively common species” says Crane. “This study also provided three of our undergraduate students with the opportunity to lead a scientific investigation and navigate the scientific peer-review process,” added Crane. James S. Bulak of the South Carolina Department of Natural Resources was a co-author.

Bauerlien, C.J., M.R. Cornett, E.A. Zielonka, D.P. Crane and J.S. Bulak. 2018. Precision of calcified structures used for estimating age of chain pickerel. North American Journal of Fisheries Management 38:930-939. DOI: 10.1002/nafm.10197

Some Blacktip Sharks Prefer Fishing Piers

Fishing piers located along recreational beaches can be areas of intense angler activity during certain times of the year. This activity inevitably leads to the discarding of bait and by-catch that can in turn be eaten by other organisms such as sharks. Graduate student Kelsey Martin (Coastal Marine and Wetland Studies M.S. Program) was interested in whether or not blacktip sharks were frequently found associated with fishing piers along the northeast coast of South Carolina. “Our study was unique because, to our knowledge, no studies have been conducted on Blacktip shark behavior at fishing piers,” says Martin. She tagged 12 sharks and then tracked their presence with acoustic receivers deployed near Grand Strand fishing piers. The results, recently published in the Journal of Fish Biology, showed that only three of 12 tagged sharks frequented the fishing piers and this behavior was commonly observed when angler activity was most intense. “Blacktip sharks have varying degrees of association with fishing piers that is likely fueled by opportunistic feeding on scraps/discards and smaller fish that congregate around piers,” says Martin. She plans further research to determine if adults vs. juveniles show different behaviors. The study was co-authored with CCU professors Dan Abel and Erin Burge (Department of Marine Science) and Derek Crane (Department of Biology), and Neil Hammerschlag (University of Miami).

Martin, K.L., D.C. Abel, D.P. Crane, N. Hammerschlag, and E.J. Burge. 2019. Blacktip shark Carcharhinus limbatus presence at fishing piers in South Carolina: association and environmental drivers. Journal of Fish Biology 94:469-480.

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A History of Our National Parks

Each year about 330 million people visit national parks in the U.S. where they hike, bike, camp, view scenic vistas and learn about our unique and outstanding natural resources. However, few people consider national parks as the subject of a college class. Sarah Diaz, Ph.D. and Linda Lane, Ed.D., both professors in the Department of Recreation and Sport Management at CCU, recognized the value of our natural parks as a learning resource and developed a new class, RSM 200 – History of the National Parks. In concert with developing the class they also designed and wrote a content resource that is being published by Kendall-Hunt as an interactive website. Each of the class chapters includes extensive text, discussions and activities that can either be completed online or downloaded, assignments, additional resources such as readings, links, videos and maps, a master glossary, a follow-up quiz, flashcards and dozens of references. The advantages of a web site relative to a textbook include lower cost at about $80 per student, beautiful pictures and interactive activities that can be regularly updated. “We think we have created something new that can help inform and excite people about our amazing National Park Service and we are very proud of it,” says Diaz.

Diaz, S. and Lane, L. (2019 in press). History of the National Parks. Kendall-Hunt Publishing Company: Dubuque, IA. Accessible from: www.kendallhunt.com.https://he.kendallhunt.com/product/history-national-parks.

High School Students and Risky Behavior

High school students in the U.S. express a wide range of risky behaviors, but few studies have examined how these behaviors may interact. Understanding such an interaction may help in developing new and more effective health campaigns targeting adolescents. A 2018 study published in the Journal of Adolescent and Family Health and written by Michael Dunn, Ph.D. and John Yannessa, Ph.D., both in the Department of Health Sciences at CCU, set out to determine if there was an interaction among non-medical use of prescription drugs, sexual behavior and depression among U.S. high school students. This study was undertaken to explore whether there was a relationship between depression and self-medication and the effects the behavior had on sexual risk-taking among adolescents. Using survey data collected from 15,624 individuals the researchers found that individuals who were frequently depressed and reported use of non-medical prescription drugs were also more likely to engage in risky sexual behaviors. “Our results are important because issues related to mental health and non-medical prescription drug abuse may influence other risk behaviors such as sexual risk taking” said Dunn and Yannessa. The results reported here support the need to address mental health issues before the teen years. Dunn and Yannessa added, “These results add to our growing body of work demonstrating the need for those working with youth to probe beyond the more apparent risky behaviors in the effort to uncover perhaps more deeply rooted negative mental health states. In so doing, schools and community organizations should endeavor to coordinate community campaigns designed to identify depressed youth before the teen years.”

Dunn, M.S. and J.F. Yannessa. 2018. Non-medical use of prescription drugs and sexual risk behaviors among depressed adolescents. Journal of Adolescent and Family Health 9:1-15.

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Breakdown of Wood and Leaves in Freshwater Streams: How Do Environmental Factors Interact?

Freshwater streams in forested landscapes receive large inputs of dead wood and leaves from the surrounding forest. The breakdown of this material, mediated largely by physical processes and fungi, in turn determines carbon, nutrient and energy availability for other stream-dwelling organisms. Two of the most common human changes to streams are increased nutrient loading from runoff of fertilizers and increasing temperature due to logging and global warming. Vlad Gulis, Ph.D. (Department of Biology) has spent many years studying the ecology of streams in the mountains of North Carolina. He and his colleagues set out to determine how nutrients and temperature affected fungal activity during the breakdown of wood and leaves. They manipulated the amounts of nitrogen and phosphorus in five streams at the Coweeta Hydrologic Laboratory and then tracked fungal activity in different seasons over a 3-year period. The results showed that microbial activity and plant litter decomposition increased with temperature and were also strongly stimulated by nutrient addition. The responses to these two factors were additive. “These findings mean that increased nutrients and temperature will lead to greater fluxes of carbon dioxide from streams and rivers to the atmosphere through stimulated microbial respiration and will also result in faster disappearance and decreased stocks of organic matter (leaves and wood) in these aquatic ecosystems,” Gulis said. The results are significant as “plant litter is an important food source to larvae of aquatic insects, which in turn are eaten by invertebrate predators, salamanders, and fish.”

Manning DWP, Rosemond AD, Gulis V, Benstead JP, Kominoski JS. Nutrients and temperature additively increase stream microbial respiration. Glob Change Biol. 2017;00:1–15. https://doi.org/10.1111/ gcb.13906

Popular R&B/Hip Hop Songs Change with the Economy

It is generally accepted that economic ups and downs are reflected in the mood or sentiment of the population. But just exactly how does this mood influence how people act and make choices? Such a question has broad relevance for those attempting to understand the continuously changing landscape of popular culture and associated media. A recent study published by two CCU faculty, Jason Eastman, Ph.D. (Department of Sociology) and Terry Pettijohn, Ph.D. (Department of Psychology), focused on R&B/Hip Hop songs that topped the Billboard chart from 1946 to 2010. They measured various parameters of the chart-topping songs and then searched for trends across different social and economic conditions. During difficult times, female artists were more popular. Furthermore, challenging social conditions produced songs that were longer, slower and less upbeat. “We were interested in expanding our past research on how pop and country genres change with the economy to R&B music,” said Pettijohn. “Similar to the pop and country investigations, people prefer older, more mature and comforting R&B artists when social and economic conditions are challenging. We discuss further differences between the genres in the article.

Eastman, J.T. and T.F. Pettijohn II (2017, online first). Good times and endless love: Billboard R&B/Hip Hop songs of the year across social and economic conditions. Psychology of Popular Media Culture Advance online publication. http://dx.doi.org/10.1037/ppm0000176

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