Dendrochronological dating of Rebel’s Rest (40FR512), Franklin County,Tennessee, USA

The structure named Rebel’s Rest was a two-story, Reconstruction-era house located on the campus of the University of the South in Sewanee, Tennessee, before being severely damaged by fire in July 2014. The house was constructed of squared timbers and round logs, with later additions built using sawn lumber. Dendrochronological analyses of timbers and logs salvaged from the house reveals wood from four genera: oak (Quercus spp.), tulip poplar (Liriodendron tulipifera L.), American chestnut (Castanea dentata [Marshall] Borkh.), and pine (Pinus spp.). We statistically and graphically crossdated a total of 251 samples (24,410 rings) with regional chronologies from the ITRDB, resulting in three dated chronologies comprised of oak (1645–1874), tulip poplar (1725–1865), and American chestnut (1710–1864). The majority of samples with cutting dates (95.6%) ended in years 1865–1866, confirming the historically reported construction date of 1866 for the initial structure. The cutting date analysis also confirms two rooms as later additions, Room M (1867) and Room B (1875). Based on ring count and the number of chronologies produced, this research represents the largest known dataset from a single historic structure in the Southeastern US.     

Trichodorus elefjohnsoni n. sp. (Nemata: Trichodoridae) from Undisturbed Appalachian Forest

A new species of Trichodoridae, Trichodorus elefjohnsoni, is described from undisturbed regions of Great Smoky Mountains National Park, United States. It resembles T. orientalis De Waele &Hashim, 1984, T. persicus De Waele &Sturhan, 1987, and T. taylori De Waele, Mancini, Roca, '' Lamberti, 1982 in arrangement of ventromedian cervical papillae and posterior preanal supplements, but differs by combinations of the following characteristics: body length 516-731 μm; spicule length 33-50 μm, spicules densely striated, constricted medially; vaginal sclerotizations ovate; one pair of lateral body pores near vulva.     

Celebrate Darwin Day, An Event for Education and Outreach in Evolutionary Biology

Darwin Day is an international celebration of Charles Darwin’s birthday, February 12, and is used as an occasion for education and outreach in evolutionary biology. I describe the history and structure of Darwin Day at the University of Tennessee, one of the oldest Darwin Day organizations in the world. I detail past events including speakers, themes, and advertising ideas that have worked for us and suggestions for getting a Darwin Day started. I encourage interested groups especially those at schools, museums, libraries, nature centers, and other institutions to adapt ideas from our organization to fit their own circumstances and to start planning their own Darwin Days for the celebration of Darwin’s 200th birthday in 2009.     

Agricultural Seed Biomass for Migrating and Wintering Waterfowl in the Southeastern United States

ABSTRACT Waterfowl frequently acquire high-energy agricultural seeds in harvested and unharvested croplands during migration and winter. Estimates of agricultural seed biomass in harvested and unharvested corn, soybean, and grain sorghum fields do not exist or are outdated for the southeastern United States. Therefore, we estimated seed biomass in 105 harvested and 59 unharvested corn, soybean, and grain sorghum fields across 4 climate regions in Tennessee, USA, from September through January 2006 and 2007. We also used estimates of seed biomass to calculate duck-energy days (DEDs) in December and January when migratory waterfowl abundance peaks in the southeastern United States. Mean biomass of corn, soybean, and grain sorghum seed in harvested fields declined 239 kg/ha to 39 kg/ha, 118 kg/ha to 26 kg/ha, and 392 kg/ha to 19 kg/ha, respectively, from postharvest to January. Continuous monthly rates of decline were 64% for corn, 84% for soybean, and 74% for grain sorghum. Agricultural seed biomass in harvested corn and grain sorghum fields dropped below the waterfowl giving-up density (i.e., 50 kg/ha) in 3 months; soybean dropped below this threshold 1 month postharvest. Mean DEDs/ha in harvested corn, soybean, and grain sorghum fields were low (274, 90, and 27, respectively) in January, and DEDs were zero in >85% of fields. In unharvested corn, soybean, and grain sorghum fields, mean DEDs/ha in January were high (69,000, 18,000, and 26,000, respectively), and continuous rates of decline (3%, 7%, and 18%, respectively) were much lower than for harvested crops. Waterfowl biologists in the Southeast should use our estimates of agricultural seed biomass in DED calculations. We also recommend that biologists provide unharvested grain fields and natural wetlands for migrating and wintering waterfowl because seed resources are low in harvested agricultural fields.     

The historical dendroarchaeology of two log structures at the Wynnewood State Historic Site,Castalian Springs,Tennessee, USA

Tree rings of eastern red cedar (Juniperus virginiana L.) were examined from cores extracted from two log cabins located at the Wynnewood State Historic Site in Castalian Springs, Sumner County, Tennessee. One cabin was reportedly built by the first explorer in the area, Isaac Bledsoe, sometime between 1772 and his death in 1793. The second cabin was known as Spencer's Cabin after the first settler of the region, Thomas Sharp Spencer, who lived in the immediate vicinity from 1776 to 1779. The goal of this research was to determine the probable construction year(s) for both cabins and determine whether Bledsoe and Spencer did indeed build these structures. Forty-one cores were extracted from Bledsoe's Cabin, and 30 were used for crossdating and building a floating chronology using COFECHA. The Bledsoe's Cabin chronology was then statistically and graphically crossdated using the eastern red cedar reference tree-ring chronology (ITRDB #TN031) from Norris Dam, Tennessee. We found a statistically significant correlation (r = 0.42, t = 4.18, n = 85, p < 0.0001) between the Bledsoe's Cabin chronology and the reference chronology, anchoring the chronology between 1720 and 1804, with nearly all cores indicating tree harvesting between February and April 1805. Twenty-two cores were extracted from Spencer's Cabin, and 17 were used to build a floating chronology for the cabin. Again, we found a statistically significant correlation (r = 0.44, t = 4.85, n = 100, p < 0.00001) with the reference chronology, which anchored the Spencer's Cabin chronology between 1726 and 1825. All trees appear to have been harvested between February and August in 1826. Therefore, neither structure was built by its historical namesake. No known historical documents suggest who the potential builders were, although the property was owned between ca. 1797 and 1829 by General James Winchester. He and his family, however, never resided on the Wynnewood property because Winchester had built a large multi-room structure in nearby Gallatin, Tennessee, by 1802.     

Effects of plumbous ion on guanine metabolism.

The enzyme guanine aminohydrolase (guanase) is inhibited by low levels of Pb2+. The inhibition is noncompetitive and the Ki is 3.0 X 10(-6) M. The only other heavy metals that are inhibitory at low concentrations are Ag+, which is 36% more, and Hg2+, which is about 50% less inhibitory than Pb2+. The inhibition of guanase by Pb2+ and Hg2+ is synergistic and the inhibition of the enzyme was readily reversed by EDTA. The relationship of these studies with guanase and to the etiology and treatment of saturnine gout, which appears in humans suffering from lead poisoning, is discussed.