Clark Hill Research Articles

Treatment of preterm labor in multiple gestations.

Department of Obstetrics and Gynecology, Sarasota Memorial Hospital, Sarasota, Florida; Department of Obstetrics and Gynecology, University of South Florida, College of Medicine, Tampa, Florida Correspondence: Washington Clark Hill, MD, FACOG Chairman, Department of Obstetrics and Gynecology Director, Maternal-Fetal Medicine Sarasota Memorial Hospital 1700 South Tamiami Trail Sarasota, FL 34232-3555 941-917-6260 FAX 941-917-6266[email protected] We acknowledge support of the nurses, midwifes, and physicians of Sarasota Memorial Hospital. Submitted 8/23/03 for publication in Clinical Obstetrics and Gynecology, June 2004

Nested Species Subsets and Geographic Isolation: A Case Study

Insular systems tend to exhibit nonrandom patterns of species composition in which smaller species assemblages contain successive subsets of those found on richer ones. The fact that such nested patterns of species composition have usually been observed in systems where species number is correlated with island size has led to the hypothesis that differences among species in the effect of island size on the probability of extinction represent the main mechanism producing nested patterns of species composition. This study tested the hypothesis that differences among species in dispersal ability may interact with geographic isolation to produce nested subsets of species composition. This hypothesis was tested in a systems of woody plants inhibiting artificial islands that were created by the filling of the Clarks Hill Reservoir, Georgia, USA. All of the studied islands had been logged prior to their separation from the mainland and their species number 34 yr later was found to be negatively correlated with distance to the closest mainland. The results of the present analysis indicated that (1) species occupancy of the whole island system was highly nested, (2) nestedness occurred with respect to geographic isolation but not with respect to island size, (3) only a small portion of the overall species included in the study contributed to the observed nestedness, and (4) the degree to which individual species contributed to the observed nestedness was correlated with their dispersal properties, with wind—dispersed species showing no evidence for nestedness and species lacking adaptations for long—range dispersal showing the strongest patterns of nestedness. These results indicate that isolation effects may interact with species—specific dispersal properties to produce nested subsets of species composition.

Effects of isolation, logging and dispersal on woody-species richness of islands

Isolation effects on species richness of woody plants were investigated in a system of islands that were created by the filling of the Clarks Hill Reservoir, Georgia. This reservoir was built between 1946–1954. Some islands were logged and cleared of woody plants prior to the filling of the reservoir and others were not logged. The presence of logged versus unlogged islands in the same system allowed us to test whether and how geographical isolation interacts with island history and species-specific dispersal properties in determining patterns of among-island variation in species number. Thirty-six years after the islands were created, logged islands had significantly fewer species of woody plants than unlogged ones. On logged islands, total number of woody species was negatively correlated with distance to the closest mainland (r=−0.95). On unlogged islands, variation in species number was very low (CV=4.9%) and was not correlated with distance to the mainland. These results indicate that the studied system as a whole has not yet reached equilibrium. However, the mean number of species on unlogged islands was very close to the intercept of the regression obtained for logged islands, suggesting that islands close to the mainland have already reached their equilibrium species richness. This conclusion is consistent with predictions of island biogeography theory. When species representing different dispersal properties were analyzed separately, statistically significant distance effects were obtained for bird-dispersed species (r=0.88) and for species with no adaptations to bird or wind dispersal (r=0.81). Wind-dispersed species did not show a decrease in species number with increasing isolation, but their relative frequency was positively and significantly correlated with distance to the mainland (r=0.94). Historical factors, as well as differences among species in dispersal properties, are important in explaining patterns of among-island variation in species number.

Island Biogeography: Effect of Geographical Isolation on Species Composition

Island biogeography theory attempts to explain and predict among—island variation in species richness. However, two islands with the same number of species may still differ from each other considerably in their species composition. In this study we test the hypothesis that among—island variation in species composition is predictable and can be related to the corresponding differences in distance to the mainland. We focus on woody plants inhabiting islands in the Clarks Hill Lake, a reservoir completed in 1954 on the Savannah River, between Georgia and South Carolina, USA. Two groups of islands were sampled: islands that wee logged prior to the filling of the reservoir and islands that were not logged. Each island was surveyed for the presence of all tree and shrub species, and its distance from the mainland was determined. In both groups of islands, the degree to which two islands are similar in their species composition was negatively and significantly correlated with their difference in distance to the mainland. Species richness, however, was correlated with distance to the mainland only on logged islands. We conclude that geographic isolation may affect species composition on islands, and that such an effect may occur even in the absence of a corresponding effect on species richness.

Inter-reservoir interactions: Effects of a new reservoir on organic matter production and processing in a multiple-impoundment series

Impoundment of the R.B. Russell Reservoir (RBR) between two existing reservoirs (Hartwell Reservoir (HT) upstream and Clark Hill Reservoir (CH) downstream) on the Savannah River (Georgia-South Carolina, USA) provided an opportunity to investigate the limnological influence of interreservoir transfers of nutrients and organic matter down a multiple-impoundment series. The objective was to document within- and among-reservoir patterns in organic matter production and processing in the HT-RBR-CH reservoir series as organic matter dynamics were influenced by the inundation and subsequent stabilization of the RBR basin.

Dissolved Organic Phosphorus Compounds: Do They Satisfy Planktonic Phosphate Demand in Summer?

The rate of release of phosphate from dissolved organic phosphorus (DOP) compounds generally accounted for <1% of the phosphate uptake rate by seston in the open water of five diverse freshwater systems in summer. Surface water samples were taken during July and August 1984 from a eutrophic lake (East Twin Lake, OH), an acid bog lake (Triangle Bog Lake, OH), a freshwater estuarine marsh that empties into the western basin of Lake Erie (Old Woman Creek, OH), and two large mainstem reservoirs on the Savannah River (R. B. Russel Reservoir and Clarks Hill Lake, GA). In each of these, phosphatase hydrolysable phosphomonoesters (PME) often were the major fraction of DOP; phosphate release from photosensitive DOP was not detected in any of these systems at this time. The rate of release of phosphate from PME was calculated from Michaelis–Menten kinetics, and phosphatase activity was estimated spectrophotometrically using p-nitrophenyl phosphate as a model substrate. Radiometric analysis of the rate of phosphate uptake by seston showed that phosphate was sorbed to seston by at least two different processes. The total uptake rate by all uptake processes exhibited an apparent first-order dependence on the concentration of available phosphate. Typically, the velocity of uptake was 1–10 nmol∙L−1∙min−1, and the velocity of release from PME was 0.01–0.06 nmol∙L−1∙min−1.

Character of the Alleghanian orogeny in the southern Appalachians: Part II. Geochronological constraints on the tectonothermal evolution of the eastern Piedmont in South Carolina

A nearly concordant U-Pb zircon age of 550 ± 4 Ma is interpreted to closely date crystallization of the epizonal Little Mountain metatonalite in the southeastern part of the Charlotte belt in South Carolina. This confirms field studies which indicate that the Charlotte belt contains a plutonic metaigneous complex that developed as a sub-volcanic-arc infrastructure, contemporaneous with vulcanism manifested in the Carolina slate belt. Both paleontological and geochronological controls indicate that the South Carolina slate belt is mostly younger than 570 Ma (Cambrian?), whereas the slate belt in North Carolina and Virginia is mostly of late Proterozoic age. A regionally significant mid-Paleozoic (ca. 340–360 Ma) thermal event is suggested by discordant 40Ar/39Ar whole-rock age spectra of slate/phyllite in the northwestern Carolina slate belt and from hornblende in the southeastern Charlotte belt. It is uncertain if this event was associated with deformation in the eastern Piedmont; however, mid-Paleozoic deformation has been previously documented elsewhere in the western Piedmont. A slightly disconcordant U-Pb zircon age of 317 ± 4 Ma is interpreted to closely date initial crystallization of the deformed Edge-field granite and confirms a record of late Paleozoic penetrative deformation in the Kiokee belt of South Carolina. U-Pb isotope data for the Lake Murray orthogneiss and Clouds Creek granite are discordant and suggest that the magmas of these plutons were derived by partial melting of a sialic Precam-brian source and then emplaced in the eastern Piedmont at ca. 315 Ma (prior to or during the early stages of the Alleghanian orogeny). The thermal maximum of Alleghanian regional metamorphism (amphibolite facies in the Kiokee belt; greenschist facies in the southeastern part of the Carolina slate belt) occurred during ca. 295–315 Ma. During the late Carboniferous and Early Permian, the eastern Piedmont experienced differential uplift, erosion, and relatively rapid postmeta-morphic cooling. Isothermal surfaces were folded into an antiform-synform-antiform configuration corresponding to the Kiokee, Carolina slate, and Charlotte belts, respectively. The geochronological data provide the following calibration for the late Paleozoic deformational chronology recorded in the Kiokee and Carolina slate belts: D2 (Lake Murray deformation), ca. 295–315 Ma; D3 (Clarks Hill deformation), ca. 285–295 Ma; and D4 (Irmo deformation), ca. 268–290 Ma.

Influence of Ca concentration on micronutrient imbalances inin vitropropagatedprunusrootstock

Abstract In vitro propagated plums of St. Julien GF 655–2 [Prunus insititia (L.)] (655–2), Damas GF 1869 [Prunus domestica (L.)] (D1869), and Clark Hill Redleaf [Prunus salicina (Until.) X Prunus cerasifera (Ehrh.)] (CHR), were grown in the greenhouse in nutrient solutions of 2, 6, 22, 66, 202, and 404 μM Ca for 96 days. 655–2 plants became severely chlorotic in Ca treatments of 66, 202, and 404 μM concentration after 86 days of growth. D1869 plants in 202 and 404 μM Ca exhibited slight interveinal chlorosis of new growth, while CHR exhibited no chlorosis at any Ca concentration. The best tissue nutrient indicator of chlorosis among rootstocks was foliar P/Fe and P/Zn ratios. 655–2 plants absorbed more P at higher Ca concentrations than did the other rootstock, resulting in the highest stem and leaf P/Fe, and P/Zn ratios. CHR plum may provide an easily propagated, chlorosis‐resistant rootstock for use on calcareous soils.

Influence of ca concentration on growth, tissue concentration, and nutrient uptake ofin vitropropagated plums and lovell seedlings

Abstract Seedlings of ‘Lovell’ peach [Prunus persica (L.) Batsch], and in vitro propagated plums, ‘St. Julien A GF 655–2’ [Prunus institia (L.) Bullace] (655–2), ‘Damas GF 1869’ [Prunus domestica (L.)] (D1869), and ‘Clark Hill Red Leaf’ [Prunus saliciana (Lindl) x Prunus cerasifera (EHRH)] (CH redleaf) were grown in the greenhouse 45 or 51 days in nutrient solutions containing 2, 6, 22, 200, and 400 μM Ca. Terminal length, number of laterals, trunk cross‐sectional area, and root volume were increased by the 22 μM Ca treatments at harvest 1. The CH redleaf and 655–2 plums had the largest increase in growth for harvest 1, but the ‘Lovell’ peach seedlings and D1869 plum had the largest increase in growth for harvest 2. There were no leaf symptoms of Ca deficiency when the leaf Ca concentration in the tissue exceeded 2500 μg/g (dry wt.) Calcium concentration was increased from 1406 to 4109 μg/g (dry wt.) in the stems, and from 540 to 2633 μg/g (dry wt) in the roots by Ca treatments of 400 μM after 45 days of ...

Changes in phosphoadenylate concentrations and adenylate energy charge as an integrated biochemical measure of stress in invertebrates: The effects of cadmium on the freshwater clamCorbicula fluminea

Concentrations of phosphadenylates ATP, ADP and AMP were measured in foot muscle tissue of the Asian clam, Corbicula fluminea Muller, by the luciferin‐luciferase bioluminescence technique. Total adenylate concentration μM · g‐ 1, dry weight and adenylate energy charge [AEC = (ATP+1/2ADP)/(ATP + ADP + AMP] were calculated. The effects of laboratory acclimation, starvation and exposure to 0.005, 0.05, 0.5 and 5.0mgCd · l‐1 were investigated. We observed no significant difference between the AEC of clams collected from the Savannah River Channel below Augusta, Georgia and those collected from Clark Hill reservoir on the Savannah River above Augusta. When C. fluminea, collected from the Savannah River were taken to the laboratory and fed and maintained in aerated water at 21°C, the AEC increased from 0.76±0.06 to 0.95±0.01 (x±95% CI, n = 8). This indicates that C. fluminea in the Savannah River were living under sub‐optimal conditions. Starvation for 10 and 20 days did not significantly decrease the AEC. Howe...

Forecasting recreation demand in the upper Savannah River Basin

Saunders, Paul R., Herman F. Senter, and James P. Jarvis, Forecasting Recreation Demand in the Upper Savannah River Basin. Annals of Tourism Research 1981, VIII(2):236–256. The Upper Savannah River Basin in Georgia and South Carolina, USA, offers opportunities for a variety of recreation activities. Four major reservoirs, and a fifth one under construction, are available for recreation use. Most users live within 80 to 160 kilometers of the two principal reservoirs, Hartwell Lake and Clark Hill Lake. A recreation demand model was developed for these two reservoirs and the soon to be completed Russell Lake, basing total demand on projected population and participation rates for fourteen selected activities. Total demand, consisting of met and unmet demand, was predicted for 1976, 1980, 1990, 2000 and 2010. The model is a relatively simple tool which can be used by state, local, and regional planners to predict both demand for facilities, and the supply of facilities needed to meet future demand.

Hypolimnial oxygen injection: a benefit to downstream fish populations?

Changes in electrofishing catch rates downstream from Clark Hill Reservoir were only mildly affected by addition of oxygen to the hypolimnion waters prior to discharge in spite of increases in oxygen concentration. Changes in abundance and distribution of six major species were detectable and beneficial effects undoubtedly occur, but the overall benefit of oxygenation, at least at Clark Hill Dam, is questionable. At other dams with a more pronounced and prolonged oxygen-poor period, oxygenation may be worthwhile.

Microearthquake spectra in the southeastern United States

abstractDisplacement spectra from microearthquakes in the Clark Hill Reservoir Area and the Jocassee Reservoir Area, both in the Piedmont Crystalline Province, showed similar spectral properties typified by a sharp spectral corner, ω-cubic, high-frequency decay and ratios of P- and S-wave corner frequencies predominantly greater than unity. Displacement spectra from microearthquakes in the Maryville Tennessee Area in the Folded Appalachian Province showed transitional spectral corners, ω-square or less high-frequency decay and a ratio of P- to S-wave corner frequencies less than or equal to unity. These spectral characteristics are interpreted as evidence for a possible regional variation in the earthquake mechanism. The Clark Hill and Jocassee spectral characteristics are best explained by an earthquake mechanism typical of an equidimensional fault which nucleates rupture at a point of high resistance to slip and ruptures at a velocity greater than the S-wave velocity along an existing fracture. The Maryville spectral characteristics are best explained by rupture at velocities less than the S-wave velocity along faults which may show premature arrest of movement.

Modeling Reservoir System With Pumped Storage

The Richard B. Russell Dam and Lake Project is presently under construction and is being placed in tandem between Hartwell and Clark Hill, two existing multipurpose hydropower plants on the Savannah River. System operational simulations were performed in support of a feasibility study for the installation of pump turbines at Russell, using a version of the Corps of Engineers HEC-5C computer program modified for system power and pumped storage. Information developed from the simulations include system hydropower production, pumping energy requirements, daily reservoir pool fluctuations, and reservoir elevation statistics. This information was useful in judging the effects of the addition of pumped storage on system hydropower production and reservoir recreation useability, as well as in ascertaining efficient system operational methods.

Earthquakes associated with the Clark hill reservoir, South Carolina-a case of induced seismicity : Talwani, P Engng Geol, V10, N2–4, Dec 1976, P239–253

Earthquakes associated with the Clark hill reservoir, South Carolina-a case of induced seismicity : Talwani, P Engng Geol, V10, N2–4, Dec 1976, P239–253

Earthquakes associated with the Clark Hill reservoir, South Carolina — A case of induced seismicity

Following the McCormick County, South Carolina, local magnitude 4.3 earthquake on August 2, 1974, continuous seismic activity has been observed in the area. The epicenters are located within 3 km from the Clark Hill reservoir. The shallow seismic activity appears to be related to water level fluctuations in the reservoir, and follows them by about two days. The frequency of earthquakes is related to the rate of change of water level, while the energy release is seen to depend on the water level itself. Pore pressure fluctuations at focal depths in a regime of high tectonic stresses is the suggested cause for the triggering of earthquakes.

Preliminary Results of Aftershock Studies Following the Aug. 2nd, 1974, South Carolina Earthquake

Aftershock studies following the 2 August 1974 earthquake in McCormick County, South Carolina indicate continuing seismic activity with a pattern of increasing and decreasing seismicity near the Clark Hill reservoir. The shallow earthquakes have a predominantly strike slip motion, with the strike direction along the Appalachian trend. The activity appears to be associated with temporal velocity changes and bears several similarities to seismic activity near the Blue Mountain Lake area, New York.

Comparative Productivity of Four Carolina Lakes

Field data for 14C uptake in two reservoirs, a Carolina bay and an oxbow in South Carolina indicate that lakes of this region are low in primary productivity compared to lakes elsewhere for which published values are available. Par Pond, a reactor-cooling reservoir, is the only lake studied which shows even moderate productivity. Factors which may be related to productivity in these lakes include nutrient level, water temperature, light penetration as influenced by turbidity and water color, and stratification as influenced by local topography and lake morphometry. Limnological characteristics of the four South Carolina lakes are summarized. INTRODUCTION Relatively few limnological studies have been conducted on the lakes of South Carolina. This report presents the results of preliminary carbon fixation measurements during 1967 in four lakes in the vicinity of the Savannah River Laboratory. The four lakes include two reservoirs, a Carolina bay and a Savannah River oxbow. The reservoirs are Clark Hill, a 28,000-acre impoundment of the Savannah River, and Par Pond, a 2500-acre lake which receives reactor-cooling effluent on the Savannah River Plant site. The Carolina bay is Clear Pond, a 27-acre lake between Bamberg and Ehrhardt, S. C., off Route 601. The Savannah River oxbow is Big Snooks Lake, an 11-acre oxbow located along the Savannah River near Tillman, S. C. The lakes are in the coastal plain except Clark Hill which is in the Piedmont plateau. All lie in the Savannah River drainage except for Clear Pond which is in the Salkehatchie River drainage. Some of the basic limnological features of these lakes or their sampling stations are given in Tables 1 and 2. Marshall and LeRoy (1971) have described limnological features of Par Pond in greater detail, and Marshall and Tilly (1971) have presented information on the annual cycle of primary productivity. METHODS Samples were taken from the deepest area in each lake. In the reservoirs, this was near the dams. In an attempt to make comparisons meaningful, productivity determinations were made for 3 hr at about the same times of day, usually from 1030 to 1330 hr and never later than 1400 hr. Highly variable weather obviated plans to conduct experiments on only clear days; however, the darkest days were avoided, and all measurements were made under conditions of high average light intensity. Water was secured at 1-m depth intervals 1 This paper was prepared in connection with work under Contract No. AT(07-2)-1 with the U. S. Atomic Energy Commission.

Effects of Reservoir Impoundment on Water Quality

The problem of correcting the adverse effects of thermal stratification and low dissolved oxygen content in large reservoirs and controlling physical, chemical, and biological parameters of released water from impoundments in the South-eastern United States is described. The results of water quality investigations at the Clark Hill and Hartwell Reservoirs are outlined along with predictions of quality expected at West Point Reservoir. Comparisons are made of various possible corrective solutions investigated such as: (1) multilevel penstock intakes; (2) submerged weirs; (3) tailrace and turbine aeration; and (4) destratification systems. Emphasis is placed on a diffused air pumping system prototype equipment test at Allatoona Reservoir in North Georgia. A description is given of the destratification equipment being tested, and details the types and methods of sampling and data processing are described.

Fly production in relation to refuse disposal in recreational areas.

Fly production in garbage pits constructed by the U. S. Army Corps of Engineers on the Clark Hill Reservoir, Clark Hills, S. C., was found to be extremely variable from June 1 to Sept. 22, 1967. During the 15 weeks the traps were operated 26,434 flies were trapped, of which 9856 were Psychodidae, 10,954 were Phaenicia spp., and 3468 were the secondary screw-worm, Cochliomyia macellaria (F.). Dichlorvos dispensers (1/2 or 1 unit per pit) gave 95% or more reduction of all flies for 8 weeks and 73% to 88% reduction during weeks 9 through 12. Dimethoate or diazinon failed to significantly reduce the number of flies trapped at dosages of 1 or 2% spray. Dichlorvos dispensers, I unit per privy, gave greater than 70% reduction of Fannia spp. And Ophyra leucostoma (Wiedemann) for 4 weeks but were ineffective against Psychodidae and Hermetia illucens (L.).