RECONSTRUCTING LATE HOLOCENE PALEOFLOODS ALONG THE MIDDLE TENNESSEE RIVER AND EXPLORING LINKS WITH CLIMATE AND LAND USE

Sediment stored in floodplains and low alluvial terraces along the middle Tennessee River reflects flood frequency and magnitude during the past ca. 2800 years. This study uses the stratigraphy, sedimentology, and geochronology of three alluvial terraces to infer past flooding and explore links with climate change and anthropogenic land-use practices. Four sites located on different geomorphic landforms adjacent to the Tennessee River preserve records of at least 11 major flood events from 2780 ± 185 BP to 100 ± 10 BP. Buried soils at three sites are older than ca. 1380 BP and suggest a relatively recent period of landscape stability compared to buried soils formed on a natural levee which suggest landscape stability prior to 2780 ±185 BP. Each site has clear evidence of distinct flood deposits following periods of stability, however, depositional units within the natural levee suggest a more complete record over a longer time interval. Differential preservation of flood events across landforms is likely due to differences in elevation, distance to the river channel, hydraulics, sedimentation rates, vegetation, and weathering. Despite these differences, each site retains flood deposits and highlights the importance of increasing the spatial resolution of sampled locations in order to build a more robust paleoflood histor

Identifying Rural Comparative Advantage: Ethanol Plant Location Determinants and Tennessee Value Chains

As rural areas struggle to adjust to the changing U.S. economy with increasing unemployment, falling wages, and constrained capital markets, economic developers look for strategies to promote economic expansion. Development strategies identifying and evaluating county comparative advantage may offer the promise of economic growth in rural areas. This thesis develops two models whereby county comparative advantage can be empirically identified and evaluated. The study first examines ethanol plant location determinants at the county level, in the contiguous forty-eight United States, the second identified industry clusters within Tennessee at the county level and estimated the extent to which these clusters contributed to growth in labor productivity. In the first study, the location of grain-based ethanol plants is determined by infrastructure, product and input markets, fiscal attributes of local communities, and state and federal incentives. Bivariate probit regression along with spatial clustering methods are used to analyze investment activity of ethanol plants at the county level for the contiguous 48 United States from 2000-2007. The ability of a county to supply feedstock, and the absence of previously established ethanol plants, dominated the site selection decision between 2000 and 2007. Other factors, such as access to railroads or navigable rivers, product markets, low worker wages, producer credit and excise tax incentives, and methyl tertiary-butyl ether bans gave some counties comparative advantage with respect to attracting grain-based ethanol plant investment. The second study identified industry clusters or economic linkages between purchasers and suppliers, at the county and regional level for 447 economic sectors in Tennessee. Information about value-added activities or innovative potential is possible by determining the sector composition of the value chains defining an industry cluster. The cluster analysis was extended to estimate the extent to which specific value chains contributed to economic growth between 2001 and 2006 across Tennessee’s 95 counties using an econometric model. County and regional comparative advantage was determined by testing whether the presence of a particular value chain in a given county increased labor productivity during this period

Ethanol Plant Location Determinants and County Comparative Advantage

The location of ethanol plants is determined by infrastructure, product and input markets, fiscal attributes of local communities, and state and federal incentives. This empirical analysis uses probit regression along with spatial clustering methods to analyze investment activity of ethanol plants at the county level for the lower U.S. 48 states from 2000 to 2007. The availability of feedstock dominates the site selection decision. Other factors, such as access to navigable rivers or railroads, product markets, producer credit and excise tax exemptions, and methyl tertiary-butyl ether bans provided some counties with a comparative advantage in attracting ethanol plants.cluster analysis, comparative advantage, ethanol production, location model, Community/Rural/Urban Development, Environmental Economics and Policy, Political Economy, R1, R3,

Selective Foraging For Anthropogenic Resources By Black Bears: Minivans In Yosemite National Park

Black bears (Ursus americanus) forage selectively in natural environments. To determine if bears also forage selectively for anthropogenic resources we analyzed data on vehicles broken into by bears from Yosemite National Park, California. We classified vehicles into 9 categories based on their make and model and collected data on use (2001–2007) and availability (2004–2005). From 2001 to 2007 bears broke into 908 vehicles at the following rates: minivan (26.0%), sport–utility vehicle (22.5%), small car (17.1%), sedan (13.7%), truck (11.9%), van (4.2%), sports car (1.7%), coupe (1.7%), and station wagon (1.4%). Only use of minivans (29%) during 2004–2005 was significantly higher than expected (7%). We discuss several competing hypotheses about why bears selected minivans

Effect of previous handling experiences on responses of dairy calves to routine husbandry procedures

The nature of human–animal interactions is an important factor contributing to animal welfare and productivity. Reducing stress during routine husbandry procedures is likely to improve animal welfare. We examined how the type of early handling of calves affected responses to two common husbandry procedures, ear-tagging and disbudding. Forty Holstein–Friesian calves (n = 20/treatment) were exposed to one of two handling treatments daily from 1 to 5 weeks of age: (1) positive (n = 20), involving gentle handling (soft voices, slow movements, patting), and (2) negative (n = 20), involving rough handling (rough voices, rapid movements, pushing). Heart rate (HR), respiration rate (RR) and behaviour (activity, tail flicking) were measured before and after ear-tagging and disbudding (2 days apart). Cortisol was measured at −20 (baseline), 20 and 40 min relative to disbudding time. There were no significant treatment differences in HR, RR or behaviour in response to either procedure. However, the following changes occurred across both treatment groups. HR increased after disbudding (by 14.7 ± 4.0 and 18.6 ± 3.8 bpm, positive and negative, respectively; mean ± s.e.m.) and ear-tagging (by 8.7 ± 3.1 and 10.3 ± 3.0 bpm, positive and negative, respectively). After disbudding, there was an increase in RR (by 8.2 ± 3.4 and 9.3 ± 3.4 breaths/min, positive and negative, respectively), overall activity (by 9.4 ± 1.2 and 9.9 ± 1.3 frequency/min, positive and negative, respectively) and tail flicking (by 13.2 ± 2.8 and 11.2 ± 3.0 frequency/min, positive and negative, respectively), and cortisol increased from baseline at 20 min post procedure (by 10.3 ± 1.1 and 12.3 ± 1.1 nmol/l positive and negative, respectively). Although we recorded significant changes in calf responses during ear-tagging and disbudding, the type of prior handling had no effect on responses. The effects of handling may have been overridden by the degree of pain and/or stress associated with the procedures. Further research is warranted to understand the welfare impact and interaction between previous handling and responses to husbandry procedures

PALEOFLOODS AND LANDFORM DEVELOPMENT INFLUENCE CARBON STORAGE IN A HUMID-SUBTROPICAL RIVER VALLEY

Floodplains can store large amounts of soil organic carbon (SOC) despite covering a small fraction of the global land area. Since these valley-bottom landforms build through the action of flooding, the century to millennial-scale record of overbank deposition could be important in understanding controls on deep (\u3e30 cm) SOC storage. Yet, the influence of flood history and landform development on carbon content is surprisingly not well known. I use a combined geological and pedological approach to characterize the sedimentation, soil development, and SOC of fluvial terraces along an impounded reach of the humid-subtropical Tennessee River valley, U.S.A. The standardized \u3e0.25 mm sand fraction from both relict levee and floodplain alluvial soil profiles record a Late Holocene paleoflood history where inferred paleo-magnitude increased after 2000 yr BP coincident with increased paleohurricane activity from the Caribbean to the Gulf Coast. This valley-wide increase in flood magnitude coincides with a decrease in deep SOC content. However, this deep SOC also varies by landform type. Fine-grained floodplains store more SOC than the coarse-grained levee. However, the buried SOC content of the latter is more reliant on clay and silt, which is an important supply limit in a conceptual model of fluvial landform development. That is, in silt- and clay-limited fluvial landforms (e.g., levees), changes in the amount of fine sediment added during flooding will have a more direct effect on the SOC content by means of aggregate formation and clay film development. In contrast, variations in flood magnitude will have little to no effect on the SOC content of fine-grained landforms (e.g., flood basin) as lower flood energy contributes to deposition of detrital organic matter and silt and clay act which act to protect SOC through elluviation-illuviation and aggregate formation. This study emphasizes that parent material layering from flooding and the subsequent translocation of fine particles down profile are interdependent processes that can influence the storage of SOC on longer timescales (\u3e102 yr). Conservation measures should consider how natural flooding affects landform development and the SOC storage in floodplains

Resonance-continuum interference in the di-photon Higgs signal at the LHC

A low mass Standard Model Higgs boson should be visible at the Large Hadron Collider through its production via gluon-gluon fusion and its decay to two photons. We compute the interference of this resonant process, gg -> H -> gamma gamma, with the continuum QCD background, gg -> gamma gamma induced by quark loops. Helicity selection rules suppress the effect, which is dominantly due to the imaginary part of the two-loop gg -> gamma gamma scattering amplitude. The interference is destructive, but only of order 5% in the Standard Model, which is still below the 10-20% present accuracy of the total cross section prediction. We comment on the potential size of such effects in other Higgs models.Comment: 10 pages, 2 figure