Aquatic Effects of a Localized Oil Spill on Lake Conway, AR and Its Tributaries

Oil spills, no matter where they occur, elicit environmental concern and avoiding these disasters should be a priority. Old pipelines that are not regularly maintained and carry large amounts of crude oil long distances are of particular concern. One such pipeline is the 65 year-old Pegasus pipeline owned by ExxonMobil. On March 29, 2013, 795,000 L of Wabasca Heavy Canadian crude oil spilled into a neighborhood of Mayflower, Arkansas, when the Pegasus pipeline ruptured. This spill led to the evacuation of many homes in the surrounding neighborhood. Drainage ditches in the affected neighborhood drained oil into a nearby cove of Lake Conway. This lake is popular for recreational fishing, thus concerns were raised not only about the potential effects of the oil spill on area residents, but also the lake and its biological communities. Ultimately, this project assessed the effect of the oil spill in water and sediment samples on freshwater test organisms. Samples were collected at 6 sites in the affected neighborhood and in Lake Conway. Chronic Whole Effluent Toxicity (WET) tests were performed on water samples using Pimephales promelas and Ceriodaphnia dubia. Acute sediment toxicity tests were performed using Chironomus dilutus. These tests measured sub-lethal toxicity in at least one of the sampled sites, indicating that further investigation of environmental after-effects is warranted

Characterization of temporal and spatial variation in subwatersheds of the Strawberry River, AR, prior to implementation of agricultural best management practices

Benthic macroinvertebrate (BMI) assessments indicate alterations in physical and/or chemical factors making them valuable tools when attempting to assess agricultural best management practices (BMPs). The purpose of this study was to obtain pre-BMP land cover and macroinvertebrate community data in order to characterize temporal and spatial variation in three catchments: Little Strawberry (LS), Greasy Creek (GC), and Sandy Creek (SC) of the Strawberry River Watershed, located in north central Arkansas, in order to establish baseline conditions. BMIs were collected for the three subwatersheds in 1995, 1999, 2002, 2003 and 2009. Taxa richness, Hilsenhoff Biotic Index (HBI) and Ephemeroptera, Plecoptera and Trichoptera (EPT) score, % dominant taxa, and % Diptera were used as indicators of water quality and habitat changes. All subwatersheds experienced decreased forest land cover indicating land use transition. All resulting BMI measures indicate overall stable habitat and water conditions in the LS subwatershed. Results for GC subwatershed vary with taxa richness, EPT and HBI indicating a stable habitat while increasing % dominant taxa and Diptera indicate a decreasing trend in overall habitat quality. All BMI measures in the SC subwatershed indicate decreasing trend in habitat quality. The most sensitive measure to temporal changes was % Diptera. Trends were not consistent among subwatersheds indicating the importance of continued data collection to establish baseline data and truly monitor changes in aquatic systems over time

Natural Nutrient Sources in the Cache River Watershed, Arkansas

The growth of the hypoxic ‘dead zone’ in the Gulf of Mexico in recent years has placed increased focus on potential sources of nutrient pollution, with most of the focus being placed on watersheds where practices, including fertilizer application and land alterations combine to increase non-point source runoff. In this study, nutrient concentrations in surface waters of altered and unaltered areas of the Cache River Watershed, Arkansas, were compared to determine if agricultural land usage was responsible for the majority of nutrient inputs. Results suggest that for dissolved nitrites and orthophosphates, agricultural (altered) sites contribute significantly more than relatively unaltered sites but that for dissolved nitrates, unaltered sites have a large contribution to overall nitrate concentrations, particularly in late summer and fall months

Establishing Baseline Nutrient and Sediment Input in the Lower Cache River Watershed, AR

Contaminants in waterways continue to be a problem especially in watersheds dominated by land use changes such as agriculture. Clearing the land for agricultural use is needed to support the population; however, agricultural contaminants are cited as contributing the greatest input of suspended solids and nutrients to waterways. Quantifying various contaminants in surface water is useful in determining their origin, thus aiding in their mitigation. This study, focused on the Cache River Watershed, reports pH, dissolved oxygen (DO), conductivity, turbidity, total suspended solids (TSS), NO3 - , NO2 - , and PO4 3- in the lower sub watersheds. It was determined that in the Cache River, at these particular sites, TSS, NO3 - , NO2 - , and PO4 3- concentrations differ due to varying sources of input and land use

Ferromagnetism of 3^3He Films in the Low Field Limit

We provide evidence for a finite temperature ferromagnetic transition in 2-dimensions as $H \to 0$ in thin films of $^3$He on graphite, a model system for the study of two-dimensional magnetism. We perform pulsed and CW NMR experiments at fields of 0.03 - 0.48 mT on $^3$He at areal densities of 20.5 - 24.2 atoms/nm$^2$. At these densities, the second layer of $^3$He has a strongly ferromagnetic tendency. With decreasing temperature, we find a rapid onset of magnetization that becomes independent of the applied field at temperatures in the vicinity of 1 mK. Both the dipolar field and the NMR linewidth grow rapidly as well, which is consistent with a large (order unity) polarization of the $^3$He spins.Comment: 4 figure

Book Reviews

Book reviews of: William F. Winter and the New Mississippi: A Biography. By Charles C. Bolton Jackson: University Press of Mississippi, 2013. Pp. vii, 368. Illustrations, map, acknowledgements, notes, index. $35.00 cloth. ISBN: 9781617037870. Born of Conviction: White Methodists and Mississippi’s Closed Society. By Joseph T. Reiff. (New York: Oxford University Press, 2016. Acknowledgements, illustrations, map, notes, index. Pp. xxi, 384.$35 Hardcover. ISBN: 9780190246815). In Katrina’s Wake: The U.S. Coast Guard and the Gulf Coast Hurricanes of 2005. By Donald L. Canney. (Gainesville: University Press of Florida, 2010. Foreword, notes, index. Pp. xv, 228. $27.50 cloth.) Slavery, Race and Conquest in the Tropic: Lincoln, Douglas and the Future of America. By Robert E. May. (New York: Cambridge University Press, 2013. Acknowledgements, illustrations, maps, notes, index. Pp. xi, 296.$80 cloth, $26.99 paper,$22 e-book. ISBN: 9780521132527.) Rivers of Sand: Creek Indian Emigration, Relocation, and Ethnic Cleansing in the American South. By Christopher D. Haveman. (Nebraska: University of Nebraska Press, 2016. Illustrations, preface, acknowledgments, notes on terminology, index. Pp. ix, 414. Trouble in Goshen: Plain Folk, Roosevelt, Jesus, and Marx in the Great Depression. By Fred C. Smith (Jackson: University Press of Mississippi, 2014. Acknowledgements, illustrations, map notes, index. Pp. xi, 214. $60.00 cloth. ISBN: 9781617039560.) Builders of a New South: Merchants, Capital, and the Remaking of Natchez, 1865-1914. By Aaron D. Anderson (Jackson: University Press of Mississippi, 2013. Acknowledgments, illustrations, photographs, notes, graphics, index. Pp. 279.$40 cloth. ISBN: 978-1- 61703-667-5.) Adventurism and Empire: The Struggle for Mastery in the Louisiana- Florida Borderlands 1762-1803. By David Narrett. (Chapel Hill: The University of North Carolina Press, 2015. Acknowledgements, illustrations, notes, index. Pp. xi, 365. $45 cloth,$44.99 e-book. ISBN: 978-1-4696-1833-3.) Empty Sleeves: Amputation in the Civil War South. By Brian Craig Miller. (Athens: University of Georgia Press, 2015. Illustrations, acknowledgments, appendix, notes, index. Pp. xvi, 257. $79.95 cloth,$29.95 paper. ISBN: 0820343327.) Signposts: New Directions in Southern Legal History. By Sally E. Hadden and Patricia Hagler Minter, eds. (Athens and London: The University of Georgia Press, 2013. Acknowledgements, illustrations, index. Pp. xi, 480. $69.95 cloth,$26.95 paper, $26.95 ebook. ISBN: 978-0-8203-4499-7.) The Color of Christ: The Son of God and the Saga of Race in America. By Edward J. Blum and Paul Harvey. (Chapel Hill: University of North Carolina Press, 2012. Pp. 325.$32.50 Cloth. ISBN: 9780807835722.

Hemotin, a regulator of phagocytosis encoded by a small ORF and xonserved across metazoans

Translation of hundreds of small ORFs (smORFs) of less than 100 amino acids has recently been revealed in vertebrates and Drosophila. Some of these peptides have essential and conserved cellular functions. In Drosophila, we have predicted a particular smORF class encoding ~80 aa hydrophobic peptides, which may function in membranes and cell organelles. Here, we characterise hemotin, a gene encoding an 88aa transmembrane smORF peptide localised to early endosomes in Drosophila macrophages. hemotin regulates endosomal maturation during phagocytosis by repressing the cooperation of 14-3-3ζ with specific phosphatidylinositol (PI) enzymes. hemotin mutants accumulate undigested phagocytic material inside enlarged endo-lysosomes and as a result, hemotin mutants have reduced ability to fight bacteria, and hence, have severely reduced life span and resistance to infections. We identify Stannin, a peptide involved in organometallic toxicity, as the Hemotin functional homologue in vertebrates, showing that this novel regulator of phagocytic processing is widely conserved, emphasizing the significance of smORF peptides in cell biology and disease