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Sample records for alligator rivers uranium

  1. International Alligator Rivers Analog Project

    SciTech Connect

    Bichard, G.F.

    1988-01-01

    The Australian Nuclear Science and Technology Organization (ANSTO), the Japan Atomic Energy Research Institute, the Swedish Nuclear Power Inspectorate, the U.K. Department of the Environment, the US Nuclear Regulatory Commission (NRC), and the Power Reactor and Nuclear Fuel Development Corporation of Japan are participating under the aegis of the Nuclear Energy Agency in the International Alligator Rivers Analog Project. The project has a duration of 3 yr, starting in 1988. The project has grown out of a research program on uranium ore bodies as analogs of high-level waste (HLW) repositories undertaken by ANSTO supported by the NRC. A primary objective of the project is to develop an approach to radionuclide transport model validation that may be used by the participants to support assessments of the safety of radioactive waste repositories. The approach involves integrating mathematical and physical modeling with hydrological and geochemical field and laboratory investigations of the analog site. The Koongarra uranium ore body has been chosen as the analog site because it has a secondary ore body that has formed over the past million years as a result of leaching by groundwater flowing through fractures in the primary ore body.

  2. Radionuclide migration at the Koongarra uranium deposit, Northern Australia Lessons from the Alligator Rivers analogue project

    NASA Astrophysics Data System (ADS)

    Payne, Timothy E.; Airey, Peter L.

    The Koongarra uranium deposit in Northern Australia provides a ‘natural analogue’ for processes that are of relevance for assessing the safety of radioactive waste disposal. In an international project extending over two decades, the Koongarra ore body was studied to increase the understanding of radionuclide migration and retention mechanisms that might occur in the vicinity of a geological repository. The research effort included extensive characterisation of the geological, hydrological and geochemical conditions at the site. Patterns of the distribution of radionuclides (predominantly members of the 238U decay chain, but also the rare isotopes 239Pu, 99Tc and 129I) were studied in both solid and groundwater phases. The project included detailed studies of uranium adsorption on mineral surfaces, and of subsequent processes that may lead to long-term uranium immobilisation. Numerous models for uranium migration were developed during the project. This paper provides a comprehensive review of the research at Koongarra, and assesses the value of the site for integrating the results of a complex series of laboratory, modelling and field studies. The insights gained from this review of the Koongarra project may assist in maximising the potential scientific benefit of future natural analogue studies.

  3. 75 FR 34365 - Safety Zone, Alligator River, NC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-17

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone, Alligator River, NC AGENCY: Coast Guard... the waters of the Alligator River at East Lake, North Carolina. The safety zone is intended to... on the Alligator River makes safety zone regulations necessary to provide for the safety...

  4. Gender differences in haemogregarine infections in American alligators (Alligator mississippiensis) at Savannah River, South Carolina, USA.

    PubMed

    Davis, Andrew K; Horan, Robert V; Grosse, Andrew M; Harris, Bess B; Metts, Brian S; Scott, David E; Tuberville, Tracey D

    2011-10-01

    We report a host gender bias in haemogregarine infection characteristics in the American alligator (Alligator mississippiensis) at the Savannah River Site, South Carolina, USA. Prevalence and severity in female alligators was higher than it was in males. The reason for this pattern is not clear.

  5. Alligator rivers analogue project an OECD/NEA international project

    SciTech Connect

    Duerden, P.; Airey, P.; Pescatore, C.

    1994-12-31

    The Koongarra uranium deposit in the Alligator Rivers Region of the Northern Territory of Australia was studied as a natural analogue of the far field behaviour of high level waste repositories following groundwater ingress. A number of mathematical modelling approaches were developed for processes as diverse as groundwater transport, host rock weathering, radionuclide sorption, evolution of the uranium dispersion fan and the distribution of uranium series nuclides between mineral assemblages in weathered host rock. Some of these models are relevant to performance assessment at the level of individual processes and subsystem performance. Through the project, new insights into the application of the natural analogue approach to the assessment of potential waste repository sites were obtained.

  6. Ecological studies on the American alligator (Alligator mississippiensis) on the Savannah River Plant

    SciTech Connect

    Seigel, R.A.; Brandt, L.A.; Knight, J.L.; Novak, S.S.

    1986-06-01

    The American alligator (Alligator mississippiensis) is the largest vertebrate of the Savannah River Plant (SRP), reaching a maximum length of 3.7 meters (12 feet) and weighing up to 175 kg (385 pounds). Currently, populations in coastal South Carolina are considered Threatened, whereas populations in inland areas (such as the SRP) are still Endangered. Because of their legal status and economic and ecological importance, it is important to determine the environmental impacts of SRP operations on the local alligator population. The major objectives under the Endangered Species Program of the Comprehensive Cooling Water Study (CCWS) were as follows: (1) document and compare the present status and distribution of alligators on the SRP to previous surveys, in order to determine long-term changes in population abundance; (2) establish baseline population and ecological parameters of the Steel Creek population so that the ecological effects of L-Reactor operations can be determined, and (3) conduct ecological research on the immediate impacts of thermal effluents on American alligators. Gladden et al., (1985) summarized data on previous population surveys, temporal changes in the Par Pond population, preliminary results of the Steel Creek surveys and Savannah River Ecology Laboratory (SREL) research on the effects of thermal effluents. This report summarizes the current status of the SRP population, presents data on the abundance, movement patterns and activity cycles of the Steel Creek population, and presents additional data on the effect of cooling water releases on alligator ecology and behavior.

  7. Population status of the American alligator on the Savannah River Plant, South Carolina

    SciTech Connect

    Murphy, T.M.

    1981-04-01

    Estimates are presented of alligator numbers, size distribution, sex ratios, reproductive effort, and population trends for all major components of the entire Savannah River Plant (SRP) alligator population. Savannah River Plant operations have impacted the alligator population in many different ways. The formation of man-made reservoirs has dramatically increased the amount of aquatic habitat available to alligators and has therefore increased the carrying capacity of the SRP site for this species. The thermal alteration of aquatic habitats on the SRP has also impacted the resident alligator population. Temperature elevations of aquatic habitat to greater than 38/sup 0/C result in the loss of this habitat to alligators. Moderate thermal increases on the other hand are responded to by alligator movement. The current information available on the alligators of the SRP suggests the following future trends: low density populations distant from thermally altered areas will continue at a low density with the exception of localized increases.

  8. Ecological studies on the American alligator (Alligator mississippiensis) on the Savannah River Plant. Comprehensive Cooling Water Study: Final report

    SciTech Connect

    Seigel, R.A.; Brandt, L.A.; Knight, J.L.; Novak, S.S.

    1986-06-01

    The American alligator (Alligator mississippiensis) is the largest vertebrate of the Savannah River Plant (SRP), reaching a maximum length of 3.7 meters (12 feet) and weighing up to 175 kg (385 pounds). Currently, populations in coastal South Carolina are considered Threatened, whereas populations in inland areas (such as the SRP) are still Endangered. Because of their legal status and economic and ecological importance, it is important to determine the environmental impacts of SRP operations on the local alligator population. The major objectives under the Endangered Species Program of the Comprehensive Cooling Water Study (CCWS) were as follows: (1) document and compare the present status and distribution of alligators on the SRP to previous surveys, in order to determine long-term changes in population abundance; (2) establish baseline population and ecological parameters of the Steel Creek population so that the ecological effects of L-Reactor operations can be determined, and (3) conduct ecological research on the immediate impacts of thermal effluents on American alligators. Gladden et al., (1985) summarized data on previous population surveys, temporal changes in the Par Pond population, preliminary results of the Steel Creek surveys and Savannah River Ecology Laboratory (SREL) research on the effects of thermal effluents. This report summarizes the current status of the SRP population, presents data on the abundance, movement patterns and activity cycles of the Steel Creek population, and presents additional data on the effect of cooling water releases on alligator ecology and behavior.

  9. 33 CFR 165.T05-0091 - Safety Zone; Alligator River, NC.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety Zone; Alligator River, NC... SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY REGULATED NAVIGATION AREAS AND LIMITED ACCESS AREAS... Safety Zone; Alligator River, NC. (a) Definitions. For the purposes of this section, Captain of the...

  10. Uranium in river water

    SciTech Connect

    Palmer, M.R. ); Edmond, J.M. )

    1993-10-01

    The concentration of dissolved uranium has been determined in over 250 river waters from the Orinoco, Amazon, and Ganges basins. Uranium concentrations are largely determined by dissolution of limestones, although weathering of black shales represents an important additional source in some basins. In shield terrains the level of dissolved U is transport limited. Data from the Amazon indicate that floodplains do not represent a significant source of U in river waters. In addition, the authors have determined dissolved U levels in forty rivers from around the world and coupled these data with previous measurements to obtain an estimate for the global flux of dissolved U to the oceans. The average concentration of U in river waters is 1.3 nmol/kg, but this value is biased by very high levels observed in the Ganges-Brahmaputra and Yellow rivers. When these river systems are excluded from the budget, the global average falls to 0.78 nmol/kg. The global riverine U flux lies in the range of 3-6 [times] 10[sup 7] mol/yr. The major uncertainty that restricts the accuracy of this estimate (and that of all other dissolved riverine fluxes) is the difficulty in obtaining representative samples from rivers which show large seasonal and annual variations in runoff and dissolved load.

  11. Herpetofaunal diversity of Alligator River National Wildlife Refuge, North Carolina

    USGS Publications Warehouse

    Meyers, J.M.; Pike, D.A.

    2006-01-01

    In the past century, habitat alteration and fragmentation have increased dramatically, which increases the need for improving our understanding of how species and biological communities react to these modifications. A national strategy on biological diversity has focused attention on how these habitat modifications affect species, especially herpetofauna (i.e., changes in species richness, community evenness and similarity, and dominant/rare species). As part of this strategy, we surveyed Alligator River National Wildlife Refuge, a coastal, mixed second-growth forested swamp (MFS) and pocosin wetland (PW), in North Carolina for amphibians and reptiles from September 2000 to August 2001. We randomly selected three sites (3 x 3 km) in two major habitat types (MFS, PW) and completed random surveys and trapping using transects, quadrats, nighttime aural road surveys, drift fences, canal transects, coverboards, incidental captures, and evening road surveys. We also collected herpetofauna opportunistically throughout the refuge to establish an updated species list. For analysis, we used Shannon-Weiner species diversity (H'), evenness (1'), species richness and species detectability (COMDYN4), and community percent similarity index to determine herpetofaunal community differences. We estimated 39 species in MFS and 32 species in PW (P < 0.10). Species detectability was similar between habitats (0.84 to 0.86). More reptilian species (+ 31 %) inhabited MFS than PW, but estimated amphibian species richness was identical (17 spp.). H' was higher (P < 0.000 I) for PW (2.6680) than for MFS (2.1535) because of lower J' in the latter (0.6214 vs. 0.8010). Dominance of three Rana species caused lower J' and H' in MFS. Similarity between the communities was 56.6%; we estimated 22-24 species in common for each habitat (95% CI = 18 to 31 spp.). We verified 49 of the 52 herpetofaunal species on the refuge that were known to exist in the area. Restoration of natural water flows may

  12. Mining in the Alligator Rivers Region, northern Australia: assessing potential and actual effects on ecosystem and human health.

    PubMed

    van Dam, R A; Humphrey, C L; Martin, P

    2002-12-27

    This paper presents an overview of issues related to surface water contamination arising from uranium mining activities in the Alligator Rivers Region (ARR) of northern Australia, and a program of research and monitoring that must assess the potential and actual effects on ecosystem and human health. The program of assessing effects on aquatic ecosystems involves a four-tiered approach including the derivation of local water quality guideline trigger values, direct toxicity assessment of mine waters prior to their release, creekside or in situ monitoring for early warning of adverse effects during mine water release, and longer-term monitoring of macroinvertebrate and fish communities. Bioaccumulation in aquatic biota is also assessed, and is an issue of importance not only to ecosystem health, but also to the health of local Aboriginal people. The aquatic animals they consume represent potential sources of radiological dose, and as a result, a major component of the program to assess potential effects on human health is the prediction of doses to Aboriginal people living downstream of mining activities. Acknowledging the assumptions and uncertainties, the calculation of concentration factors for local aquatic (and other) food sources allows the prediction of potential radiological exposure to people following hypothetical mine water releases. The approaches described form the basis of best-practice protocols that are relevant at both regional and national levels.

  13. Thermoluminescence and excess 226Ra decay dating of late Quaternary fluvial sands, East Alligator River, Australia

    NASA Astrophysics Data System (ADS)

    Murray, Andrew; Wohl, Ellen; East, Jon

    1992-01-01

    Thermoluminescence (TL) dating was applied to seven samples of siliceous fluvial sands from the East Alligator River of Northern Australia, giving ages ranging from modern to 6000 yr B.P. Two methods of estimating the equivalent dose (ED), total bleach and regenerative, were applied to the 90- to 125-μm quartz fraction of the samples in order to determine the reliability and internal consistency of the technique. High-resolution γ and α spectroscopy were used to measure radionuclide contents; these measurements revealed an excess 226Ra activity compared with 230Th. This excess decreased with depth, and was used directly to derive mean sedimentation rates, and thus sediment ages. Both this method and one 14C date confirmed the validity of the TL values, which increased systematically with depth and were consistent with site stratigraphy. TL was of limited use in the dating of these late Holocene deposits because of age uncertainties of 500 to 1600 yr, resulting from a significant residual ED. This residual probably resulted from incomplete bleaching during reworking upstream of the sampling site. For Pleistocene deposits, the residual ED will be less significant because of higher total EDs, and TL dates will be correspondingly more accurate.

  14. Uranium mine rehabilitation: the story of the South Alligator Valley intervention.

    PubMed

    Waggitt, Peter W

    2004-01-01

    The rehabilitation of radioactively contaminated sites is an activity generally regarded with suspicion by the community. This is certainly the case for Australian Aboriginal traditional landowners. This paper describes the historical background to, and the successful development and implementation of, a consultation and planning process to rehabilitate former uranium mining and milling facilities on Aboriginal lands of the World Heritage-listed Kakadu National Park in northern Australia. The process of developing an appropriate community communication and consultation process to allay concerns about radioactivity is a cornerstone of the rehabilitation program. The initial stages of the program's implementation are also described. This program is also the first example of a radiological intervention under modern environmental and radiation protection legislation in the region. It was necessary to develop radiological standards for use in the program as none had been promulgated under existing relevant legislation.

  15. Mercury in alligators (Alligator mississippiensis) in the southeastern United States

    USGS Publications Warehouse

    Jagoe, C.H.; Arnold-Hill, B.; Yanochko, G.M.; Winger, P.V.; Brisbin, I.L.

    1998-01-01

    Mercury methylation may be enhanced in wetlands and humic-rich, blackwater systems that crocodiles and alligators typically inhabit. Given their high trophic level and long life-spans, crocodilians could accumulate significant burdens of Hg. Our objectives were to survey Hg concentrations in alligators from several areas in the southeastern United States to test their utility as sentinels of Hg contamination, to examine relationships among Hg concentrations in various tissues and to look for any differences in tissue Hg concentrations among locations. We measured total Hg concentrations in alligators collected in the Florida Everglades (n = 18), the Okefenokee National Wildlife Refuge, Georgia (n = 9), the Savannah River Site (SRS), South Carolina (n = 49) and various locations in central Florida ( n = 21), sampling tissues including blood, brain, liver, kidney, muscle, bone, fat, spleen, claws and dermal scutes. Alligators from the Everglades were mostly juvenile, but Hg concentrations in tissues were high (means: liver 41.0, kidney 36.4, muscle 5.6 mg Hg/kg dry wt.). Concentrations in alligators from other locations in Florida were lower (means: liver 14.6, kidney 12.6, muscle 1.8 mg Hg/kg dry wt.), although they tended to be larger adults. Alligators from the Okefenokee were smallest and had the lowest Hg concentrations (means: liver 4.3, kidney 4.8, muscle 0.8 mg Hg/kg dry wt.). At some locations, alligator length was correlated with Hg concentrations in some internal organs. However, at three of the four locations, muscle Hg was not related to length. Tissue Hg concentrations were correlated at most locations; however, claw or dermal scute Hg explained less than 74% of the variation of Hg in muscle or organs, suggesting readily-obtained tissues, such as scutes or claws, have limited value for nondestructive screening of Hg in alligator populations.

  16. A thermal history of the Proterozoic East Alligator River Terrain, N.T., Australia: a fission track study

    NASA Astrophysics Data System (ADS)

    Koul, Sohan L.; Wilde, A. R.; Tickoo, Awtar K.

    1988-01-01

    Radiometric data indicate a major thermal event in Proterozoic rocks of the East Alligator River Terrain, at 1870 Ma. These data, together with metamorphic mineral assemblages, demonstrate peak temperatures in excess of 600 ° C, close to the melting temperature of more deeply buried rocks. A cooling rate following peak metamorphism of 3°C/Ma is suggested. Fission-track dates of peak metamorphic phases, however, reveal a thermal event (or events), after 1650 Ma, rather than the peak metamorphic event. This rise in temperature was the result of thermal blanketing of the metamorphic basement by Carpentarian sediments and anomalous radiogenic heat flow from underlying granitoid gneiss. The temperatures so generated (≥ 175 ° C) were insufficient to reset Rb-Sr and K-Ar systems, but are clearly in excess of F.T. annealing temperatures for all the phases investigated. A cooling history, extending over 1000 m.y. and reflecting gradual erosion of the sedimentary cover, is revealed. This history is consistent with the extraordinary tectonic stability of the region. The importance of F.T. studies in establishing a thermal history is underscored, particularly when maximum temperatures experienced were less than those required to reset Rb-Sr and K-Ar systems.

  17. Uranium waste disposal at the Savannah River Site

    SciTech Connect

    Cook, J.R.; McDonell, W.R.; Wilhite, E.L.

    1990-12-31

    The Savannah River Site generates waste containing depleted, natural, and enriched uranium residue. The past and current practice for disposal of this waste at the Savannah River Site have been assessed using radionuclide pathway analysis to estimate environmental impact of closure alternatives for existing disposal sites, and to assist in the development of improved disposal facilities in the near future. This paper outlines the status of uranium waste management technology as currently practiced to maintain the environmental impact within an acceptable limit at the Savannah River Site, and indicates those steps being taken to improve future operations.

  18. Uranium waste disposal at the Savannah River Site

    SciTech Connect

    Cook, J.R.; McDonell, W.R.; Wilhite, E.L.

    1990-01-01

    The Savannah River Site generates waste containing depleted, natural, and enriched uranium residue. The past and current practice for disposal of this waste at the Savannah River Site have been assessed using radionuclide pathway analysis to estimate environmental impact of closure alternatives for existing disposal sites, and to assist in the development of improved disposal facilities in the near future. This paper outlines the status of uranium waste management technology as currently practiced to maintain the environmental impact within an acceptable limit at the Savannah River Site, and indicates those steps being taken to improve future operations.

  19. Radium concentration factors in passionfruit (Passiflora foetida) from the Alligator Rivers Region, Northern Territory, Australia.

    PubMed

    Medley, Peter; Bollhöfer, Andreas; Parry, David; Martin, Paul

    2013-12-01

    In this study, uptake of Ra from soil into the edible fruit of the wild passionfruit species Passiflora foetida was investigated, using selective extraction from the soil samples. A wide range of environmental exposure conditions were represented by the locations that were sampled, including both natural soils, and soils influenced by past and present uranium mining activities. The bioavailable (226)Ra fraction in soils was found to be a better predictor of (226)Ra fruit activity concentrations than the total soil activity concentration, or any of the other fractions studied. Concentration Factors (CFs) derived using the bioavailable fraction varied by only a factor of 7 between different locations, whereas CFs derived using other fractions and total soil varied by up to two orders of magnitude. CFs were highest for those soils containing the lowest concentrations of Mg, Ca and Ba, and approached a saturation value at higher soil concentrations. This finding suggests that group II elements influence radium uptake, most likely the result of increased pressure on the plant to take up essential nutrient group II elements from soil with the lower concentrations, with Ra being taken up as an analogue element. It is also possible that at higher concentrations of bioavailable Ca and Mg in the soil, these ions will outcompete Ra for adsorption sites in the soil and/or on the root surfaces. The study also shows that (228)Ra can potentially be a significant contributor to ingestion doses and should also be considered when assessing committed effective doses from the ingestion of fruits.

  20. Radium concentration factors in passionfruit (Passiflora foetida) from the Alligator Rivers Region, Northern Territory, Australia.

    PubMed

    Medley, Peter; Bollhöfer, Andreas; Parry, David; Martin, Paul

    2013-12-01

    In this study, uptake of Ra from soil into the edible fruit of the wild passionfruit species Passiflora foetida was investigated, using selective extraction from the soil samples. A wide range of environmental exposure conditions were represented by the locations that were sampled, including both natural soils, and soils influenced by past and present uranium mining activities. The bioavailable (226)Ra fraction in soils was found to be a better predictor of (226)Ra fruit activity concentrations than the total soil activity concentration, or any of the other fractions studied. Concentration Factors (CFs) derived using the bioavailable fraction varied by only a factor of 7 between different locations, whereas CFs derived using other fractions and total soil varied by up to two orders of magnitude. CFs were highest for those soils containing the lowest concentrations of Mg, Ca and Ba, and approached a saturation value at higher soil concentrations. This finding suggests that group II elements influence radium uptake, most likely the result of increased pressure on the plant to take up essential nutrient group II elements from soil with the lower concentrations, with Ra being taken up as an analogue element. It is also possible that at higher concentrations of bioavailable Ca and Mg in the soil, these ions will outcompete Ra for adsorption sites in the soil and/or on the root surfaces. The study also shows that (228)Ra can potentially be a significant contributor to ingestion doses and should also be considered when assessing committed effective doses from the ingestion of fruits. PMID:23994954

  1. Uranium in the Savannah River Site environment

    SciTech Connect

    Evans, A.G.; Bauer, L.R.; Haselow, J.S.; Hayes, D.W.; Martin, H.L.; McDowell, W.L.; Pickett, J.B.

    1992-12-09

    The purpose of this report is to consolidate the history of environmental uranium studies conducted by SRS and to describe the status of uranium in the environment. The report is intended to be a ``living document`` that will be updated periodically. This draft issue, February 1992, documents studies that occurred from 1954 to 1989. Data in this report are taken primarily from annual and semiannual environmental reports for SRS. Semiannual reports were published from 1954 through 1962. Annual reports have been published since 1963. Occasionally unpublished data are included in this report for completeness.

  2. Uranium in the Savannah River Site environment

    SciTech Connect

    Evans, A.G.; Bauer, L.R.; Haselow, J.S.; Hayes, D.W.; Martin, H.L.; McDowell, W.L.; Pickett, J.B.

    1992-12-09

    The purpose of this report is to consolidate the history of environmental uranium studies conducted by SRS and to describe the status of uranium in the environment. The report is intended to be a living document'' that will be updated periodically. This draft issue, February 1992, documents studies that occurred from 1954 to 1989. Data in this report are taken primarily from annual and semiannual environmental reports for SRS. Semiannual reports were published from 1954 through 1962. Annual reports have been published since 1963. Occasionally unpublished data are included in this report for completeness.

  3. Nonpineal melatonin in the alligator (Alligator mississippiensis).

    PubMed

    Roth, J J; Gern, W A; Roth, E C; Ralph, C L; Jacobson, E

    1980-10-31

    All living and most fossil representatives of the reptilian subclass Archosauria lack pineal bodies. Arrhythmic, low-level, nonpineal melatonin is present, however, in the blood of Alligator mississippiensis. Although pineal bodies have been implicated in circadian phenomena, these results suggest that arrhytmic melatonin in alligators may not be involved incircadian events and indicate that the pineal is not the only source of the hormone melatonin. The evolutionary loss of the pineal in Archosauria occurred during the Mesozoic, and era noted for its seasonal stability. Arrhythmic melatonin titers inalligators and pineal loss in alligators and other archosaurs may be related to Mesozoic seasonal stability.

  4. Effects of uranium mining, Puerco River, New Mexico

    USGS Publications Warehouse

    Lopes, Thomas J.

    1991-01-01

    Effluent from uranium-mine dewatering and acidic water released by a tailings-pond dike failure increased radionuclide activities in streamflow in the Puerco River in New Mexico and Arizona. Median dissolved gross-alpha activity in the streamflow was 1,130 picocuries per liter from 1975 to 1986 when mine discharges ceased and 6.2 picocuries per liter from 1986 to 1989. From 1975 to July 1979, major ions in streamflow at the Puerco River at Gallup streamflow-gaging station were sodium, bicarbonate, and sulfate. On July 16, 1979, the day of the tailing spill, major ions in streamflow were magnesium, calcium, and sulfate. From 1979 to 1984, major ions in streamflow had a greater proportion of calcium and sulfate than prior to the spill, indicating flushing of residual tailings solution. Geochemical modeling of mine effluent indicates that uranium was unlikely to precipitate from effluent between the mines and Gallup or when mixed with wastewater downstream from Gallup. Geochemical modeling of acidic-tailings solution indicates that uranium was in solution as far downstream as Gallup. When the acidic-tailings solution mixed with 10- to 40-percent wastewater, uranium may have precipitated from solution as carnotite [K2(UO2)2(VO4)2] and tyuyamunite [Ca(UO2)2(VO4)2].

  5. Uranium deposits in Fall River County, South Dakota

    USGS Publications Warehouse

    Bell, Henry; Bales, W.E.

    1954-01-01

    In 1951 uranium deposits contained carnotite were discovered in the southern Black Hills near Edgemont, Fall River County, S. Dak. Numerous carnotite deposits have since been found in sandstones in the Inyan Kara group of early Cretaceous age, and uranium-bearing material has been discovered in the Pennsylvania Minnelusa sandstone of Pennsylvanian age and the Deadwood formation of Cambrian age in the southern Black Hills. Ore has been produced only from the Inyan Kara group, mostly within an area of about 30 square miles along the southwest flank of the Black Hills uplift between Dewey and Hot Springs in Custer and Fall River Counties. In addition, occurrences of uranium in other parts of the Black Hills and the surrounding area are known or reported from sedimentary, igneous, and metamorphic rocks of pre-Cambrian to Tertiary age. The upper and lowermost formations of the Inyan Kara group - the Fall River and Lakota sandstones - contain the productive uranium deposits. These terrestrial formations are composed predominantly of massive sandstone lenses within units of thinly bedded sandstone and mudstone, but locally these formations contain abundant mudstone and thinly bedded sandstone. Massive sandstone lenses in the Lakota sandstone commonly overlap and truncate underlying lenses. The lenses are separated by thin units of thinly bedded sandstone and mudstone. Iron stain, carbonaceous material, thin seams of gypsum, ripple marks, concretions, and fossil roots are common in the mudstone and thinly bedded portions of these formations. Some high angle normal faults of small displacement are found in the area containing the largest number of uranium occurrences in the Inyan Kara group. Although no ore deposits seen were cut by faults, high-angle fractures parallel and at right angles to the faults contain carnotite for short distances. The productive uranium deposits are most common where the Fall River and Lakota sandstones locally contain a large proportion of

  6. TEMPORAL AND SPATIAL VARIATION IN PLASMA THYROXINE (T4) CONCENTRATIONS IN JUVENILE ALLIGATORS COLLECTED FROM LAKE OKEECHOBEE AND THE NORTHERN EVERGLADES, FLORIDA, USA

    EPA Science Inventory

    We examined variation in plasma thyroxine (T4) in juvenile American alligators (Alligator mississippiensis) collected from three sites within the Kissimmee River drainage basin (FL, USA). Based on historical sediment data, Moonshine Bay served as the low contaminant exposure site...

  7. Uranium series radionuclides in surface waters from the Shu river (Kazakhstan).

    PubMed

    Burkitbayev, Mukhambetkali; Uralbekov, Bolat; Nazarkulova, Sholpan; Matveyeva, Ilona; León Vintró, Luis

    2012-04-01

    The concentrations of (238)U, (234)U, (226)Ra, (210)Po and (210)Pb have been determined in surface waters collected along the course of the Shu River, lying on the border between Kazakhstan and Kyrgyzstan. In the study area, the river runs through some of the largest uranium deposits worldwide, which were actively exploited during the nuclear weapons and nuclear energy programmes of the former Soviet Union. The data show an increasing trend in uranium concentrations downstream the river from the city of Tokmak to the city of Shu, with good correlation between total uranium concentrations and total dissolved solids. Data on uranium isotopes disequilibrium show the presence of technogenic uranium inputs into the Shu River downstream from the city of Karasu, evidenced by a decrease in the measured (234)U/(238)U isotopic ratio from 1.63 in uncontaminated sites to 1.29 in sites affected by past mining activities. PMID:22378504

  8. Tuffaceous sediments as source rocks for uranium: A case study of the White River Formation, Wyoming

    USGS Publications Warehouse

    Zielinski, R.A.

    1983-01-01

    Fine-grained tuffaceous sediments of the White River Formation (Oligocene) are evaluated as a possible source of uranium for the sedimentary uranium deposits of Wyoming. The evaluation is based upon a model in which volcanic glass is considered to be a major host of uranium and thorium and in which uranium and silica are released during alteration of glass to montmorillonite. The evaluation scheme is applicable to other tuffaceous sediments in similar geologic settings. The average uranium and thorium contents of glass separates and glassy air-fall ashes of the White River Formation are 8 ppm and 22.4 ppm respectively, and these values approximate the average composition of glass deposited in Wyoming basins in Oligocene time. Comparison of these values with the uranium and thorium concentrations in montmorillonite separates indicates little change in thorium concentrations but reductions in uranium concentrations which average 3.3 ppm. In spite of the apparent major removal of uranium during alteration of glass to montmorillonite, whole-rock samples of tuffaceous siltstones show an average uranium loss of only 0.4 ?? 0.4 ppm, because of generally small amounts of clay alteration. This conclusion is generated by comparisons between glassy ash and partially altered vitric siltstones, the latter corrected for dilution of glass and clay-altered glass with uranium- and thorium-poor primary and detrital materials. The original volume of the White River Formation is adequate to generate economically significant quantities of mobile uranium, even with such modest losses. Uranium and silica which are mobilized during glass alteration can coprecipitate as uraniferous secondary silica in areas where solutions become silica saturated. These precipitates indicate pathways of ancient, uranium-rich solutions in tuffaceous rocks. Exploration efforts in the White River Formation and underlying units should concentrate on areas where such pathways intercept reducing environments

  9. Uranium-series isotopes from rivers to ocean

    NASA Astrophysics Data System (ADS)

    Robinson, L. F.; Thompson, W. G.; Swartz, J.

    2011-12-01

    Uranium series isotopes provide unique insights into the rates and amplitude of geologic processes through their range of chemical behaviors in different environments, and their radioactive decay. In this case we use 234U and 238U isotopes to examine and quantify the inputs of uranium from the continents to the oceans over glacial interglacial timescales. First we will show data from the critical zone in New Zealand and Chile that demonstrate that the strength of the hydrologic cycle plays a major role in controlling the 234U/238U ratio in river waters as they move through a water shed. Hydrothermal systems, subsurface processes and lakes may also act to affect the ratio. The hydrologic cycle is thought to have changed markedly over millennial and glacial interglacial timescales leading to the possibility of a shift in the 234U/238U ratio in seawater. Thus seawater 234U/238U may act as a global recorder of some aspects of the total activity in the critical zone. Although there may be biases from diagenesis, the uranium isotope ratio can be reconstructed in aragonite corals, both surface and deep dwelling. We have compiled high precision data from the Pacific, Atlantic and Southern Oceans for the last 50,000 years that point to a shift of 7 +/- 3 per mil from lower values to higher values during the deglaciation. There is no systematic difference between locations and we see no evidence for large, millennial-scale basin-wide oscillations. In this study we interpret this shift with consideration of changing activity in the critical zone.

  10. Engineering assessment of inactive uranium mill tailings, Green River Site, Green River, Utah

    SciTech Connect

    1981-08-01

    Ford, Bacon and Davis Utah Inc. has reevaluated the Green River site in order to revise the December 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Green River, Utah. This evaluation has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative remedial actions. Radon gas released from the 123,000 tons of tailings at the Green River site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors.

  11. Spatial and temporal variability in estuary habitat use by American alligators

    USGS Publications Warehouse

    Fujisaki, Ikuko; Hart, Kristen M.; Cherkiss, Michael S.; Mazzotti, Frank J.; Beauchamp, Jeffrey S.; Jeffery, Brian M.; Brandt, Laura A.

    2016-01-01

    Estuarine habitat occupied by Alligator mississippiensis, a primarily freshwater species, is spatially and temporally heterogeneous largely due to a salinity gradient that fluctuates. Using long-term night light survey data, we examined seasonal patterns in alligators’ habitat use by size classes in midstream and downstream estuary zones of Shark River, Everglades National Park, in southern Florida. We observed predominantly large-sized alligators (total length ≥ 1.75 m); observations of alligators in the small size classes (0.5 m ≤ total length < 1.25 m) were rare especially in the higher-salinity downstream zone. The density of alligators in the downstream zone was lower than that of the midstream zone during the dry season when salinity increases due to reduced precipitation. Conversely, the density of the large size alligators was higher in the downstream zone than in the midstream zone during the wet season, likely because of reduced salinity. We also found a significant declining trend over time in the number of alligators in the dry season, which coincides with the reported decline in alligator relative density in southern Florida freshwater wetlands. Our results indicated high adaptability of alligators to the fluctuating habitat conditions. Use of estuaries by alligators is likely driven in part by physiology and possibly by reproductive cycle, and our results supported their opportunistic use of estuary habitat and ontogenetic niche shifts.

  12. Importance of Organic Matter-Uranium Biogeochemistry to Uranium Plume Persistence in the Upper Colorado River Basin

    NASA Astrophysics Data System (ADS)

    Bargar, J.; Janot, N.; Jones, M. E.; Bone, S. E.; Lezama-Pacheco, J.; Fendorf, S. E.; Long, P. E.; Williams, K. H.; Bush, R. P.

    2014-12-01

    Recent evidence suggests that biologically driven redox reactions, fueled by sedimentary lenses enriched in detrital organic matter, play major roles in maintaining the persistent uranium groundwater plume in the subsurface at the U.S. Department of Enery's Rifle, CO field research site. Biogeochemical cycling of C, N, Fe, and S is highly active in these organic-rich naturally reduced zones (NRZs), and uranium is present as U(IV). The speciation of these elements profoundly influences the susceptibility of uranium to be reoxidized and remobiliized and contribute to plume persistence. However, uranim speciation in particular is poorly constrained in these sytems. To better evaluate the importance of NRZs to uranium mobility and plume persistence at the Rifle site, the DOE-BER-funded SLAC SFA team has characterized vertical concentration profiles and speciation of uranium, iron, sulfur, and NOM in well bores at high spatial resolution (4 inch intervals). Up to 95% of the sedimentary uranium pool was found to be concentrated in NRZs, where it occurs dominantly as non-crystalline forms of U(IV). Uranium accumulation and the presence of the short-lived sulfide mackinawite (FeS) at NRZ-aquifer interfaces indicate that NRZs actively exchange solutes with the surrounding aquifer. Moreover, sediment textures indicate that NRZs are likely to be abundant in riparian zones throughout the upper Colorado River basin (U.S.A.), which contains most of the contaminated DOE legacy uranium ore processing sites in the U.S. These results suggest that NRZ-uranium interactions may be important to plume persistence regionally and emphasize the importance of understanding molecular-scale processes.

  13. Summary of the engineering assessment of inactive uranium mill tailings, Green River site, Green River, Utah

    SciTech Connect

    1981-08-01

    Radon gas released from the 123,000 tons of tailings at the Green River site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The five alternative actions range from millsite decontamination with the addition of 3 m of stabilization cover material, to removal of the tailings to remote disposal sites and decontamination of the tailings site. Cost estimates for the five options range from about $4,300,000 for stabilization in-place, to about $9,600,000 for disposal at a distance of about 30 miles. Three principal alternatives for the reprocessing of the Green River tailings were examined: heap leaching, treatment at an existing mill, and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $1,800/lb by heap leach and $1,600/lb by conventional plant processes.

  14. A big alligator snacks on a smaller alligator

    NASA Technical Reports Server (NTRS)

    1998-01-01

    A large alligator attacks and eats a smaller one in a natural display of cannibalism. Although this event has been observed infrequently by Kennedy Space Center's staff photographers, it is common feeding behavior among the wild alligator population on the space center. Alligators are carnivorous and will eat any living thing that crosses their paths and is small enough for them to kill. For this reason, it is dangerous to feed wild alligators, and in Florida, it is also illegal. Kennedy Space Center is located on the Merritt Island National Wildlife Refuge which is operated by the U.S. Fish and Wildlife Service.

  15. The importance of colloids and mires for the transport of uranium isotopes through the Kalix River watershed and Baltic Sea

    SciTech Connect

    Porcelli, D.; Wasserburg, G.J.; Andersson, P.S.

    1997-10-01

    The importance of colloids and organic deposits for the transport of uranium isotopes from continental source regions and through the estuarine environment was investigated in the mire-rich Kalix River drainage basin in northern Sweden and the Baltic Sea. Ultrafiltration techniques were used to separate uranium and other elements associated with colloids > 10 kD and >3 kD from {open_quotes}solute{close_quotes} uranium and provided consistent results and high recovery rates for uranium as well as for other elements from large volume samples. Uranium concentrations in 0.45 {mu}m-filtered Kalix River water samples increased by a factor of 3 from near the headwaters in the Caledonides to the river mouth while major cation concentrations were relatively constant. {sup 234}U {sup 238}U ratios were high ({delta}{sup 234}U = 770-1500) throughout the basin, without showing any simple pattern, and required a supply of {sup 234}U-rich water. Throughout the Kalix River, a large fraction (30-90%) of the uranium is carried by >10 kD colloids, which is compatible with uranium complexation with humic acids. No isotopic differences were found between colloid-associated and solute uranium. Within the Baltic Sea, about half of the uranium is removed at low salinities. The proportion that is lost is equivalent to that of river-derived colloid-bound uranium, suggesting that while solute uranium behaves conservatively during estuarine mixing, colloid-bound uranium is lost due to rapid flocculation of colloidal material. The association of uranium with colloids therefore may be an important parameter in determining uranium estuarine behavior. Mire peats in the Kalix River highly concentrate uranium and are potentially a significant source of recoil {sup 234}U to the mirewaters and river waters. However, mirewater data clearly demonstrate that only small {sup 234}U/{sup 238}U shifts are generated relative to inflowing groundwater. 63 refs., 8 figs., 3 tabs.

  16. Determination of uranium distribution in the evaporation of simulated Savannah River Site waste

    SciTech Connect

    Barnes, M.J.; Chandler, G.T.

    1995-01-01

    The results of an experimental program addressing the distribution of uranium in saltcake and supernate for two Savannah River Site waste compositions are presented. Successive batch evaporations were performed on simulated H-Area Modified Purex low-heat and post-aluminum dissolution wastes spiked with depleted uranium. Waste compositions and physical data were obtained for supernate and saltcake samples. For the H-Area Modified Purex low-heat waste, the product saltcake contained 42% of the total uranium from the original evaporator feed solution. However, precipitated solids only accounted for 10% of the original uranium mass; the interstitial liquid within the saltcake matrix contained the remainder of the uranium. In the case of the simulated post-aluminum dissolution waste; the product saltcake contained 68% of the total uranium from the original evaporator feed solution. Precipitated solids accounted for 52% of the original uranium mass; again, the interstitial liquid within the saltcake matrix contained the remainder of the uranium. An understanding of the distribution of uranium between supernatant liquid, saltcake, and sludge is required to develop a material balance for waste processing operations. This information is necessary to address nuclear criticality safety concerns.

  17. Fibrous trabeculae in the liver of alligator (alligator mississippiensis).

    PubMed

    Beresford, W A

    1993-08-01

    In the mature alligator, fibrous trabeculae run from the portal areas and capsule through the hepatic parenchyma. The extent of these trabeculae becomes clear only after staining for collagen with, for example, Fast green or Picrosirius red. The trabeculae are less well developed in young caiman. The alligator's liver might use the trabeculae to withstand thrashing of the body.

  18. Impact of former uranium mining activities on the floodplains of the Mulde River, Saxony, Germany.

    PubMed

    Bister, S; Birkhan, J; Lüllau, T; Bunka, M; Solle, A; Stieghorst, C; Riebe, B; Michel, R; Walther, C

    2015-06-01

    The Mulde River drains the former uranium mining areas in Saxony (Germany), which has led to a large-scale contamination of the river and the adjacent floodplain soils with radionuclides of the uranium decay series. The objective of the investigation is to quantify the long-term effect of former uranium mining activities on a river system. All of the investigated environmental compartments (water, sediment, soil) still reveal an impact from the former uranium mining and milling activities. The contamination of water has decreased considerably during the last 20 years due to the operation of water treatment facilities. The uranium content of the sediments decreased as well (on average by a factor of 5.6), most likely caused by displacement of contaminated material during flood events. Currently, the impact of the mining activities is most obvious in soils. For some of the plots activity concentrations of >200 Bq/kg of soil were detected for uranium-238. Alluvial soils used as grassland were found to be contaminated to a higher degree than those used as cropland.

  19. Impact of former uranium mining activities on the floodplains of the Mulde River, Saxony, Germany.

    PubMed

    Bister, S; Birkhan, J; Lüllau, T; Bunka, M; Solle, A; Stieghorst, C; Riebe, B; Michel, R; Walther, C

    2015-06-01

    The Mulde River drains the former uranium mining areas in Saxony (Germany), which has led to a large-scale contamination of the river and the adjacent floodplain soils with radionuclides of the uranium decay series. The objective of the investigation is to quantify the long-term effect of former uranium mining activities on a river system. All of the investigated environmental compartments (water, sediment, soil) still reveal an impact from the former uranium mining and milling activities. The contamination of water has decreased considerably during the last 20 years due to the operation of water treatment facilities. The uranium content of the sediments decreased as well (on average by a factor of 5.6), most likely caused by displacement of contaminated material during flood events. Currently, the impact of the mining activities is most obvious in soils. For some of the plots activity concentrations of >200 Bq/kg of soil were detected for uranium-238. Alluvial soils used as grassland were found to be contaminated to a higher degree than those used as cropland. PMID:25791900

  20. The 'Angry Alligator'

    NASA Technical Reports Server (NTRS)

    1966-01-01

    The Augmented Target Docking Adapter (ATDA) as seen from the Gemini 9 spacecraft during one of their three rendezvous in space. The ATDA and Gemini 9 spacecraft are 66.5 ft. apart. Failure of the docking adapter protective cover to fully separate on the ATDA prevented the docking of the two spacecraft. The ATDA was described by the Gemini 9 crew as an 'angry alligator.'

  1. Isotopic Tracking of Hanford 300 Area Derived Uranium in the Columbia River

    SciTech Connect

    Christensen, John N.; Dresel, P. Evan; Conrad, Mark E.; Patton, Gregory W.; DePaolo, Donald J.

    2010-10-31

    Our objectives in this study are to quantify the discharge rate of uranium (U) to the Columbia River from the Hanford Site's 300 Area, and to follow that U down river to constrain its fate. Uranium from the Hanford Site has variable isotopic composition due to nuclear industrial processes carried out at the site. This characteristic makes it possible to use high-precision isotopic measurements of U in environmental samples to identify even trace levels of contaminant U, determine its sources, and estimate discharge rates. Our data on river water samples indicate that as much as 3.2 kg/day can enter the Columbia River from the 300 Area, which is only a small fraction of the total load of dissolved natural background U carried by the Columbia River. This very low-level of Hanford derived U can be discerned, despite dilution to < 1 percent of natural background U, 350 km downstream from the Hanford Site. These results indicate that isotopic methods can allow the amounts of U from the 300 Area of the Hanford Site entering the Columbia River to be measured accurately to ascertain whether they are an environmental concern, or are insignificant relative to natural uranium background in the Columbia River.

  2. Uranium speciation in moorland river water samples: a comparison of experimental results and computer model predictions.

    PubMed

    Unsworth, Emily R; Jones, Phil; Cook, Jennifer M; Hill, Steve J

    2005-06-01

    An on-line method has been developed for separating inorganic and organic bound uranium species present in river water samples. The method utilised a small chelating resin (Hyphan) column incorporated into the sample introduction manifold of an ICP-MS instrument. The method was evaluated for samples from rivers on Dartmoor (Devon, UK), an area of granite overlain with peat bogs. The results indicate that organic-uranium species form a major proportion (80%) of the total dissolved uranium present. Further work with synthetic water samples indicated that the level of dissolved organic carbon played a greater role in determining the level of organic-uranium species than did sample pH. Computer models for the water samples were constructed using the WHAM program (incorporating uranium data from the Nuclear Energy Agency Thermochemical Database project) in order to predict the levels of organic-uranium species that would form. By varying the proportion of humic and fulvic acids used in the humic component, predictions within 10% of the experimental results were obtained. The program did exhibit a low bias at higher pH values (7.5) and low organic carbon concentrations (0.5 microg ml(-1)), but under the natural conditions prevalent in the Dartmoor water samples, the model predictions were successful.

  3. Effects of uranium mining discharges on water quality in the Puerco River basin, Arizona and New Mexico

    USGS Publications Warehouse

    Van Metre, P.C.; Gray, J.R.

    1992-01-01

    From 1967 until 1986, uranium mine dewatering increased dissolved gross alpha, gross beta, uranium and radium activities and dissolved selenium and molybdenum concentrations in the Puerco River as indicated by time trends, areal patterns involving distance from the mines and stream discharge. Additionally, increased dissolved uranium concentrations were identified in groundwater under the Puerco River from where mine discharges entered the river to approximately the Arizona-New Mexico State line about 65 km downstream. Total mass of uranium and gross alpha activity released to the Puerco River by mine dewatering were estimated as 560 Mg (560 × 106 g) and 260 Ci, respectively. In comparison, a uranium mill tailings pond spill on 16 July 1979, released an estimated 1.5 Mg of uranium and 46 Ci of gross alpha activity. Mass balance calculations for alluvial ground water indicate that most of the uranium released did not remain in solution. Sorption of uranium on sediments and uptake of uranium by plants probably removed the uranium from solution.

  4. Distribution and isotopic composition of uranium in lower Nueces River, Nueces Bay and Corpus Christi Bay, Texas

    USGS Publications Warehouse

    Holmes, Charles W.; Slade, Elizabeth Ann

    1972-01-01

    The uranium concentration and isotopic composition of water and suspended sediment from the Nueces River, Nueces Bay and Corpus Christi Bay were determined by alpha-spectroscopy. The average dissolved uranium concentration and radioactivity ratio (U234/U238) of Nueces River water were determined to be 2.44 µg/1 and 1.15 respectively. Water from a tributary of the Nueces River, Cayamon Creek, was found to contain an average dissolved uranium concentration of 42.8 µg/1 with an isotopic radioactivity ratio of 1.56. Close inspection of the lateral concentration and isotopic activity ratio of uranium revealed an increase below the confluence of Cayamon Creek with the Nueces River. A model was derived based on equations used in isotopic dilution analysis, which predicts these increases within analytical error. This model may be useful in future studies to locate anomalous uranium within the hydrologic environment.

  5. Uranium-bearing sandstone in the White River badlands, Pennington County, South Dakota

    USGS Publications Warehouse

    Moore, George William; Levish, Murray

    1955-01-01

    The uranium mineral uranocircite, a barium uranyl phosphate, occurs in a channel sandstone in the Chadron formation of Oligocene age in the White River badlands, Pennington County, S. Dak. A vertical section of the basal l-foot of the channel contains 0.25 percent uranium. Small amounts of metatyuyamunite (?) occur in the upper part of a freshwater limestone bed in the Chadron formation, and carnotite occurs in chalcedony veins in the overlying Brule formation, also of Oligocene age. The source of the uranium is thought to have been volcanic ash in the Brule formation and the overlying rocks of Miocene age. Downward moving ground water may have leached this uranium and deposited it in the rocks below.

  6. OOGENESIS AND OVARIAN HISTOLOGY OF THE AMERICAN ALLIGATOR ALLIGATOR MISSISSIPPIENSIS

    EPA Science Inventory

    Although folliculogenesis and oogenesis have been observed in numerous reptiles, these phenomena have not been described in detail in a crocodilian. Oogenesis and histological features of the adult ovary of Alligator mississippiensis are described. Using a complex process, the ov...

  7. Evaluating recent taxonomic changes for alligator snapping turtles (Testudines: Chelydridae).

    PubMed

    Folt, Brian; Guyer, Craig

    2015-01-01

    The Alligator Snapping Turtle (Macrochelys temminckii Troost in Harlan 1835, sensu lato) has been historically treated as a single, wide-ranging species, until a recently published paper by Thomas et al. (2014; hereafter Thomas et al.) analyzed variation in morphology and mitochondrial DNA sequence data to describe two new species of Macrochelys: the Apalachicola Alligator Snapping Turtle (Macrochelys apalachicolae Thomas, Granatosky, Bourque, Krysko, Moler, Gamble, Suarez, Leone & Roman 2014) and the Suwannee Alligator Snapping Turtle (Macrochelys suwanniensis Thomas, Granatosky, Bourque, Krysko, Moler, Gamble, Suarez, Leone & Roman 2014). The specific epithet temminckii was retained for populations in drainages from the Yellow River in Alabama and Florida west to the San Antonio River, Texas. Because populations of Macrochelys have been historically exploited by humans (Pritchard 1989) and the life-history strategies of large, long-lived turtles make them susceptible to declines from harvest (Congdon et al. 1994), a sound understanding of species delimitation and richness is critical for the conservation of alligator snapping turtles, especially if the acceptance of a widely distributed species disguises the presence of multiple, smaller-ranged species. PMID:25947748

  8. Essential fatty acid nutrition of the American alligator (Alligator mississippiensis).

    PubMed

    Staton, M A; Edwards, H M; Brisbin, I L; Joanen, T; McNease, L

    1990-07-01

    The essential fatty acid (EFA) nutrition of young American alligators (Alligator mississippiensis) was examined by feeding a variety of fats/oils with potential EFA activity. Over a 12-wk period, alligators fed diets containing 2.5 or 5.0% chicken liver oil grew longer and heavier and converted feed to body mass more efficiently than alligators fed other fat/oil combinations that lacked or contained only trace amounts of arachidonic acid [20:4(n-6)]. Alligators fed an EFA-deficient diet (containing only coconut fat as the dietary fat) were the slowest-growing animals and converted feed to body mass least efficiently. However, over a 41-wk feeding period, alligators fed this diet showed no obvious external signs of deficiency other than being reduced in size and unthrifty. Fatty acid composition of heart, liver, muscle, skin and adipose tissue lipids was influenced markedly by dietary fat composition. Tissues varied significantly in response to dietary fat composition. Heart lipids contained the lowest levels of short- and medium-chain fatty acids and the highest levels of arachidonic acid. Arachidonic acid levels were less influenced by diet than were levels of other 20- and 22-carbon polyunsaturated fatty acids. Radiotracer studies indicated that linoleic acid was converted to arachidonic acid in the liver. Nevertheless, tissue arachidonic acid levels also appeared to be maintained by concentration from dietary sources and selective conservation. It appears that a dietary source of arachidonic acid may be required for a maximum rate of growth.

  9. Recent results on the solubility of uranium and plutonium in Savannah River Site waste supernate

    SciTech Connect

    Karraker, D.G.; Hobbs, D.T.

    1994-03-01

    High-level waste (HLW) is stored at the Savannah River Site (SRS) in a highly alkaline condition to prevent corrosion of the carbon steel storage tanks. Major components in the liquid phase include nitrate, hydroxide, nitrite, aluminate, carbonate and sulfate. Minor components include chloride, fluoride, oxalate and phosphate. The low solubility of uranium and plutonium in the HLW becomes significant to nuclear safety analyses when the supernate is evaporated to solids to conserve waste storage space and then redissolved to process for permanent disposal. The study of uranium and plutonium solubility in synthetic waste tank solutions was initiated to define actinide behavior during waste removal operations.

  10. Effects of uranium-mining releases on ground-water quality in the Puerco River Basin, Arizona and New Mexico

    USGS Publications Warehouse

    Van Metre, Peter C.; Wirt, Laurie; Lopes, T.J.; Ferguson, S.A.

    1997-01-01

    Shallow ground water beneath the Puerco River of Arizona and New Mexico was studied to determine the effects of uranium-mining releases on water quality. Ground-water samples collected from 1989 to 1991 indicate that concentrations of dissolved uranium have decreased. Most samples from the alluvial aquifer downstream from Gallup, New Mexico, met with U.S. Environmental Protection Agency's maximum contaminant levels for gross alpha, gross beta, and radium and the proposed maximum contaminant level for uranium.

  11. Mortality of American alligators attributed to cannibalism

    USGS Publications Warehouse

    Delany, Michael F.; Woodward, Allan R.; Kiltie, Richard A.; Moore, Clinton T.

    2011-01-01

    Mortality of juvenile (Alligator mississippiensis) attributed to cannibalism on Orange Lake, Florida was examined. Alligator web tags used in mark–recapture studies were found in 12% of 267 stomachs sampled from alligators ≥168 cm TL. Captive alligators retained 76% of force-fed tags during a 588-d tag-retention trial. Models relating the probability of tag recovery to the annual probabilities of juvenile survival, cannibalism, tag retention, adult survival, and adult harvest suggested that cannibalism may on average remove 6–7% of the juvenile alligator population annually. Vulnerability continued to 140 cm TL (age 6–8 yr). Cannibalism of juveniles may serve to regulate the alligator population on Orange Lake. Alligator cannibalism may vary widely among populations, depending on demography and environmental conditions. The role and importance of cannibalism in alligator population dynamics should be more fully assessed and environmental and population factors that influence cannibalism identified to better evaluate management programs.

  12. SOLUBILITY OF URANIUM AND PLUTONIUM IN ALKALINE SAVANNAH RIVER SITE HIGH LEVEL WASTE SOLUTIONS

    SciTech Connect

    King, W.; Hobbs, D.; Wilmarth, B.; Edwards, T.

    2010-03-10

    Five actual Savannah River Site tank waste samples and three chemically-modified samples were tested to determine solubility limits for uranium and plutonium over a one year time period. Observed final uranium concentrations ranged from 7 mg U/L to 4.5 g U/L. Final plutonium concentrations ranged from 4 {micro}g Pu/L to 12 mg Pu/L. Actinide carbonate complexation is believed to result in the dramatic solubility increases observed for one sample over long time periods. Clarkeite, NaUO{sub 2}(O)OH {center_dot} H{sub 2}O, was found to be the dominant uranium solid phase in equilibrium with the waste supernate in most cases.

  13. Glutamine synthetase in liver of the American alligator, Alligator mississippiensis.

    PubMed

    Smith, D D; Campbell, J W

    1987-01-01

    Glutamine synthetase was shown to be localized in liver mitochondria of the American alligator, Alligator mississippiensis, by immunofluorescent staining of frozen liver sections and by the detection of enzymatic activity and immunoreactive protein in the mitochondrial fraction following subcellular fractionation of liver tissue by differential centrifugation. The primary translation product of alligator liver glutamine synthetase mRNA was shown to have an Mr = 45,000 which is similar if not identical in size to that of the mature subunit. This mRNA was found to be heterogeneous in size with a major form corresponding to 2.8-3.0 kb and a lesser form corresponding to around 2 kb. Both are in excess of the size required to code for the glutamine synthetase subunit. The synthesis and presumably the mitochondrial import of glutamine synthetase in alligator liver are thus very similar to the same processes in avian liver. Despite the excretion of a high percentage of nitrogen as ammonia, the demonstration of a mitochondrial glutamine synthetase indicates the alligator has the typical avian-type uricotelic ammonia-detoxification system in liver. This suggests that the transition to uricotelism occurred in the sauropsid line of evolution and has persisted through both the lepidosaurian (snakes, lizards) and archosaurian (dinosaurs, crocodilians, birds) lines.

  14. Summary of the Preliminary Analysis of Savannah River Depleted Uranium Trioxide

    SciTech Connect

    NSTec Environmental Management

    2010-10-13

    This report summarizes a preliminary special analysis of the Savannah River Depleted Uranium Trioxide waste stream (SVRSURANIUM03, Revision 2). The analysis is considered preliminary because a final waste profile has not been submitted for review. The special analysis is performed to determine the acceptability of the waste stream for shallow land burial at the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site (NNSS). The Savannah River Depleted Uranium Trioxide waste stream requires a special analysis because the waste stream’s sum of fractions exceeds one. The 99Tc activity concentration is 98 percent of the NNSS Waste Acceptance Criteria and the largest single contributor to the sum of fractions.

  15. Growth rates of Chinese and American alligators.

    PubMed

    Herbert, J D; Coulson, T D; Coulson, R A

    2002-04-01

    Growth rates in two closely related species, Alligator mississippiensis (American alligator) and Alligator sinensis (Chinese alligator), were compared under identical conditions for at least 1 year after hatching. When hatched, Chinese alligators were approximately 2/3 the length and approximately 1/2 the weight of American alligator hatchlings. At the end of 1 year of growth in captivity in heated chambers, the Chinese alligators were approximately 1/2 as long and weighed approximately 1/10 as much as American alligator yearlings. When the animals were maintained at 31 degrees C, Chinese alligator food consumption and length gain rates dropped to near zero during autumn and winter and body weights decreased slightly, apparently in response to the change in day length. At constant temperature (31 degrees C), food consumption by American alligators remained high throughout the year. Length gain rates in American alligators decreased slowly as size increased, but were not affected by photoperiod. Daily weight gains in American alligators increased steadily throughout the year. In autumn, provision of artificial light for 18 h a day initially stimulated both length and weight gain in Chinese alligators, but did not affect growth in American alligators. Continuation of the artificial light regimen seemed to cause deleterious effects in the Chinese alligators after several months, however, so that animals exposed to the normal light cycle caught up to and then surpassed the extra-light group in size. Even after removal of the artificial light, it was several months before these extra-light animals reverted to a normal growth pattern. These findings may be of interest to those institutions engaged in captive growth programs intended to provide animals for reintroduction to the wild or to protected habitat. PMID:11897202

  16. National Uranium Resource Evaluation: Iron River Quadrangle, Michigan and Wisconsin

    SciTech Connect

    Frishman, D

    1982-09-01

    No area within the Iron River 1/sup 0/ x 2/sup 0/ Quadrangle, Michigan and Wisconsin, appears to be favorable for the existence of a minimum of 100 tons of U/sub 3/O/sub 8/ at a grade of 0.01 percent or better.

  17. Alligator diet in relation to alligator mortality on Lake Griffin, FL

    USGS Publications Warehouse

    Rice, A.N.; Ross, J.P.; Woodward, A.R.; Carbonneau, D.A.; Percival, H.F.

    2007-01-01

    Alligator mississippiensis (American Alligators) demonstrated low hatch-rate success and increased adult mortality on Lake Griffin, FL, between 1998 and 2003. Dying Lake Griffin alligators with symptoms of poor motor coordination were reported to show specific neurological impairment and brain lesions. Similar lesions were documented in salmonines that consumed clupeids with high thiaminase levels. Therefore, we investigated the diet of Lake Griffin alligators and compared it with alligator diets from two lakes that exhibited relatively low levels of unexplained alligator mortality to see if consumption of Dorosoma cepedianum (gizzard shad) could be correlated with patterns of mortality. Shad in both lakes Griffin and Apopka had high levels of thiaminase and Lake Apopka alligators were consuming greater amounts of shad relative to Lake Griffin without showing mortality rates similar to Lake Griffin alligators. Therefore, a relationship between shad consumption alone and alligator mortality is not supported.

  18. Research on uranium deposits as analogies of radioactive waste repositories

    SciTech Connect

    Hardy, C.J.

    1988-01-01

    The disposal of highly radioactive waste deep underground in suitable geological formations is proposed by many countries to protect public health and safety. The study of natural analogies of nuclear waste repositories is one method of validating mathematical models and assuring that a proposed repository site and design will be safe. Since 1981, the AAEC has studied the major uranium deposits in the Alligator Rivers region of the Northern Territory of Australia as natural analogues of radioactive waste repositories. Results have been obtained on the following: (1) the migration of uranium, thorium and radium isotopes, (2) the behavior of naturally occurring levels of selected fission products and transuranium nuclides, e.g. technetium-99, iodine-129 and plutonium-239; (3) the role of specific minerals in retarding migration, and (4) the importance of colloidal material, in the migration of thorium. The AAEC has initiated a wider international project entitled The Alligator Rivers Analogue Project which will enable participating organizations to obtain additional results and to apply them in modeling, planning and regulating waste repositories.

  19. River stage influences on uranium transport in a hydrologically dynamic groundwater-surface water transition zone

    DOE PAGES

    Zachara, John M.; Chen, Xingyuan; Murray, Chris; Hammond, Glenn

    2016-03-04

    In this study, a well-field within a uranium (U) plume in the groundwater-surface water transition zone was monitored for a 3 year period for water table elevation and dissolved solutes. The plume discharges to the Columbia River, which displays a dramatic spring stage surge resulting from snowmelt. Groundwater exhibits a low hydrologic gradient and chemical differences with river water. River water intrudes the site in spring. Specific aims were to assess the impacts of river intrusion on dissolved uranium (Uaq), specific conductance (SpC), and other solutes, and to discriminate between transport, geochemical, and source term heterogeneity effects. Time series trendsmore » for Uaq and SpC were complex and displayed large temporal and well-to-well variability as a result of water table elevation fluctuations, river water intrusion, and changes in groundwater flow directions. The wells were clustered into subsets exhibiting common behaviors resulting from the intrusion dynamics of river water and the location of source terms. Hot-spots in Uaq varied in location with increasing water table elevation through the combined effects of advection and source term location. Heuristic reactive transport modeling with PFLOTRAN demonstrated that mobilized Uaq was transported between wells and source terms in complex trajectories, and was diluted as river water entered and exited the groundwater system. While Uaq time-series concentration trends varied significantly from year-to-year as a result of climate-caused differences in the spring hydrograph, common and partly predictable response patterns were observed that were driven by water table elevation, and the extent and duration of river water intrusion.« less

  20. River stage influences on uranium transport in a hydrologically dynamic groundwater-surface water transition zone

    NASA Astrophysics Data System (ADS)

    Zachara, John M.; Chen, Xingyuan; Murray, Chris; Hammond, Glenn

    2016-03-01

    A well-field within a uranium (U) plume in the groundwater-surface water transition zone was monitored for a 3 year period for water table elevation and dissolved solutes. The plume discharges to the Columbia River, which displays a dramatic spring stage surge resulting from snowmelt. Groundwater exhibits a low hydrologic gradient and chemical differences with river water. River water intrudes the site in spring. Specific aims were to assess the impacts of river intrusion on dissolved uranium (Uaq), specific conductance (SpC), and other solutes, and to discriminate between transport, geochemical, and source term heterogeneity effects. Time series trends for Uaq and SpC were complex and displayed large temporal and well-to-well variability as a result of water table elevation fluctuations, river water intrusion, and changes in groundwater flow directions. The wells were clustered into subsets exhibiting common behaviors resulting from the intrusion dynamics of river water and the location of source terms. Hot-spots in Uaq varied in location with increasing water table elevation through the combined effects of advection and source term location. Heuristic reactive transport modeling with PFLOTRAN demonstrated that mobilized Uaq was transported between wells and source terms in complex trajectories, and was diluted as river water entered and exited the groundwater system. While Uaq time-series concentration trends varied significantly from year-to-year as a result of climate-caused differences in the spring hydrograph, common and partly predictable response patterns were observed that were driven by water table elevation, and the extent and duration of river water intrusion.

  1. River stage influences on uranium transport in a hydrologically dynamic groundwater-surface water transition zone

    DOE PAGES

    Zachara, John M.; Chen, Xingyuan; Murray, Chris; Hammond, Glenn

    2016-03-04

    A well-field within a uranium (U) plume in the groundwater-surface water transition zone was monitored for a 3 year period for water table elevation and dissolved solutes. The plume discharges to the Columbia River, which displays a dramatic spring stage surge resulting from snowmelt. Groundwater exhibits a low hydrologic gradient and chemical differences with river water. River water intrudes the site in spring. Specific aims were to assess the impacts of river intrusion on dissolved uranium (Uaq), specific conductance (SpC), and other solutes, and to discriminate between transport, geochemical, and source term heterogeneity effects. As a result of water tablemore » elevation fluctuations, river water intrusion, and changes in groundwater flow directions, time series trends for Uaq and SpC were found to be complex and displayed large temporal and well-to-well variability. The wells were clustered into subsets exhibiting common behaviors resulting from the intrusion dynamics of river water and the location of source terms. Hot-spots in Uaq varied in location with increasing water table elevation through the combined effects of advection and source term location. Heuristic reactive transport modeling with PFLOTRAN demonstrated that mobilized Uaq was transported between wells and source terms in complex trajectories, and was diluted as river water entered and exited the groundwater system. Moreover, while Uaq time-series concentration trends varied significantly from year-to-year as a result of climate-caused differences in the spring hydrograph, common and partly predictable response patterns were observed that were driven by water table elevation, and the extent and duration of river water intrusion.« less

  2. Distributions of selenium, iodine, lead, thorium and uranium in Japanese river waters

    SciTech Connect

    Tagami, K.; Uchida, S.

    2007-07-01

    Long-lived radionuclides released from nuclear facilities, such as deep underground disposal facilities, could reach humans through several transfer paths in the environment. Uses of ground water and river water for agricultural field irrigation and for drinking water are important paths. In order to understand behavior of long-lived radionuclides in the terrestrial water environment, we carried out a natural analogue study, that is, measurement of selenium (Se), iodine (I), lead (Pb), thorium (Th) and uranium (U) concentrations in 45 Japanese rivers at 10 sampling points from the upper stream to the river mouth for each river. Geometric mean concentrations for Se, I, Pb, Th and U were 0.057, 1.4, 0.039, 0.0055, 0.0109 ng/mL, respectively. Distribution patterns from upper stream to river mouth were different by elements, for instance, the concentrations of I, Th and U increased when the sampling points were nearer the river mouth, while that of Se were almost constant. For Pb, the highest value was observed in the middle part of each river in many cases. (authors)

  3. Seasonal uranium distributions in the coastal waters off the Amazon and Mississippi Rivers

    USGS Publications Warehouse

    Swarzenski, P.W.; McKee, B.A.

    1998-01-01

    The chemical reactivity of uranium was investigated across estuarine gradients from two of the world's largest river systems: the Amazon and Mississippi. Concentrations of dissolved (<0.45 ??m) uranium (U) were measured in surface waters of the Amazon shelf during rising (March 1990), flood (June 1990) and low (November 1991) discharge regimes. The dissolved U content was also examined in surface waters collected across estuarine gradients of the Mississippi outflow region during April 1992, August 1993, and November (1993). All water samples were analyzed for U by isotope dilution inductively coupled plasma mass spectrometry (ICP-MS). In Amazon shelf surface waters uranium increased nonconservatively from about 0.01 ??g l-1 at the river's mouth to over 3 ??g l-1 at the distal site, irrespective of river discharge stage. Observed large-scale U removal at salinities generally less than 15 implies a) that riverine dissolved U was extensively adsorbed by freshly-precipitated hydrous metal oxides (e.g., FeOOH, MnO2) as a result of flocculation and aggregation, and b) that energetic resuspension and reworking of shelf sediments and fluid muds on the Amazon shelf released a chemically reactive particle/colloid to the water column which can further scavenge dissolved U across much of the estuarine gradient. In contrast, the estuarine chemistry of U is inconclusive within surface waters of the Mississippi shelf-break region. U behavior is most likely controlled less by traditional sorption and/or desorption reactions involving metal oxides or colloids than by the river's variable discharge regime (e.g., water parcel residence time during estuarine mixing, nature of particulates, sediment storage and resuspension in the confined lower river), and plume dispersal. Mixing of the thin freshwater lens into ambient seawater is largely defined by wind-driven rather than physical processes. As a consequence, in the Mississippi outflow region uranium predominantly displays Conser

  4. AFFINITY OF THE ALLIGATOR ESTROGEN RECEPTOR FOR SERUM PESTICIDE CONTAMINANTS

    EPA Science Inventory

    Top predators, like the American alligator (Alligator mississippiensis) bioaccumulate and biomagnify persistent pollutants, such as organochlorine pesticides. In a recently published study, several pesticides and pesticide metabolites not previously reported in alligator eggs wer...

  5. Scale-Dependent Habitat Selection and Size-Based Dominance in Adult Male American Alligators.

    PubMed

    Strickland, Bradley A; Vilella, Francisco J; Belant, Jerrold L

    2016-01-01

    Habitat selection is an active behavioral process that may vary across spatial and temporal scales. Animals choose an area of primary utilization (i.e., home range) then make decisions focused on resource needs within patches. Dominance may affect the spatial distribution of conspecifics and concomitant habitat selection. Size-dependent social dominance hierarchies have been documented in captive alligators, but evidence is lacking from wild populations. We studied habitat selection for adult male American alligators (Alligator mississippiensis; n = 17) on the Pearl River in central Mississippi, USA, to test whether habitat selection was scale-dependent and individual resource selectivity was a function of conspecific body size. We used K-select analysis to quantify selection at the home range scale and patches within the home range to determine selection congruency and important habitat variables. In addition, we used linear models to determine if body size was related to selection patterns and strengths. Our results indicated habitat selection of adult male alligators was a scale-dependent process. Alligators demonstrated greater overall selection for habitat variables at the patch level and less at the home range level, suggesting resources may not be limited when selecting a home range for animals in our study area. Further, diurnal habitat selection patterns may depend on thermoregulatory needs. There was no relationship between resource selection or home range size and body size, suggesting size-dependent dominance hierarchies may not have influenced alligator resource selection or space use in our sample. Though apparent habitat suitability and low alligator density did not manifest in an observed dominance hierarchy, we hypothesize that a change in either could increase intraspecific interactions, facilitating a dominance hierarchy. Due to the broad and diverse ecological roles of alligators, understanding the factors that influence their social dominance

  6. Scale-Dependent Habitat Selection and Size-Based Dominance in Adult Male American Alligators

    PubMed Central

    Strickland, Bradley A.; Vilella, Francisco J.; Belant, Jerrold L.

    2016-01-01

    Habitat selection is an active behavioral process that may vary across spatial and temporal scales. Animals choose an area of primary utilization (i.e., home range) then make decisions focused on resource needs within patches. Dominance may affect the spatial distribution of conspecifics and concomitant habitat selection. Size-dependent social dominance hierarchies have been documented in captive alligators, but evidence is lacking from wild populations. We studied habitat selection for adult male American alligators (Alligator mississippiensis; n = 17) on the Pearl River in central Mississippi, USA, to test whether habitat selection was scale-dependent and individual resource selectivity was a function of conspecific body size. We used K-select analysis to quantify selection at the home range scale and patches within the home range to determine selection congruency and important habitat variables. In addition, we used linear models to determine if body size was related to selection patterns and strengths. Our results indicated habitat selection of adult male alligators was a scale-dependent process. Alligators demonstrated greater overall selection for habitat variables at the patch level and less at the home range level, suggesting resources may not be limited when selecting a home range for animals in our study area. Further, diurnal habitat selection patterns may depend on thermoregulatory needs. There was no relationship between resource selection or home range size and body size, suggesting size-dependent dominance hierarchies may not have influenced alligator resource selection or space use in our sample. Though apparent habitat suitability and low alligator density did not manifest in an observed dominance hierarchy, we hypothesize that a change in either could increase intraspecific interactions, facilitating a dominance hierarchy. Due to the broad and diverse ecological roles of alligators, understanding the factors that influence their social dominance

  7. Uranium and radon in ground water in the lower Illinois River basin

    USGS Publications Warehouse

    Morrow, William S.

    2001-01-01

    Uranium and radon are present in ground water throughout the United States, along with other naturally occurring radionuclides. The occurrence and distribution of uranium and radon are of concern because these radionuclides are carcinogens that can be ingested through drinking water. As part of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) program, water samples were collected and analyzed for uranium and radon from 117 wells in four aquifers in the lower Illinois River Basin (LIRB) from 1996 to 1997. The aquifers were the shallow glacial drift deposits of the Bloomington Ridged Plain (BRP) not overlying a buried bedrock valley (BRP N/O BV), shallow glacial drift deposits of the BRP overlying the Mahomet Buried Bedrock Valley (BRP O/L MBBV), shallow glacial drift deposits of the Galesburg/Springfield Plain not overlying a buried bedrock valley (GSP N/O BV), and the deep glacial drift deposits of the Mahomet Buried Bedrock Valley (MBBV). Uranium was detected in water samples from all aquifers except the MBBV and ranged in concentration from less than 1 microgram per liter ( ? g/L) to 17 ? g/L. Uranium concentrations did not exceed 20 ? g/L, the proposed U.S. Environmental Protection Agency (USEPA) Maximum Contaminant Level (MCL) at the time of sampling (1996?97). The current (2001) promulgated MCL is 30 ? g/L (U.S. Environmental Protection Agency, 2000). The highest median uranium concentration (2.0 ? g/L) among the four aquifers was in the BRP N/O BV. Uranium most often occurred in oxidizing and sulfate-rich water. Radon was detected in water samples from all aquifers in the LIRB. Radon concentrations in all aquifers ranged from less than 80 picocuries per liter (pCi/L) to 1,300 pCi/L. Of 117 samples, radon concentrations exceeded 300 pCi/L (the proposed USEPA MCL) in 34 percent of the samples. Radon concentrations exceeded 300 pCi/L in more than one-half of the samples from the GSP N/O BV and the BRP O/L MBBV. No sample exceeded the

  8. Morphology and histochemistry of juvenile American alligator (Alligator mississippiensis) nephrons.

    PubMed

    Moore, Brandon C; Hyndman, Kelly A; Cox, Ashley; Lawler, Ashley; Mathavan, Ketan; Guillette, Louis J

    2009-10-01

    Here we present a detailed morphological description of the alligator (Alligator mississippiensis) kidney and nephron. We present a series of histological, histochemical, and immunohistochemical markers that clearly define the seven regions of the alligator nephron. The alligator kidney is composed of many paired (mirrored) lobules on each kidney (lobe). Single nephrons span the width of lobules three times. The fine structure of glomeruli, lying in rows spanning the height of the lobule, is resolved by periodic acid methionine silver (PAMS) and periodic acid Schiff's (PAS) histochemistry. Glomeruli are connected to the proximal tubule (PT) via a neck segment. The PT is alcian blue-negative, making it distinct from the distal tubule (DT), connecting segment (CS), and collecting duct (CD). The PT is clearly identifiable by a PAS-positive brush border membrane. The PT is connected to the DT via an intermediate segment (IS) that makes a 180 degrees turn to connect these tubules. PAMS-positive material is found in the lumens of the PT, IS, and DT. Also, PAMS-positive granules are found in the DT, CS, and CD. Immunolocalization of the Na(+), K(+)-ATPase to the basolateral membrane of the DT, CS, and CD suggests a role of this enzyme in driving primary and secondary transport processes in these segments, including bicarbonate transport into the lumen of the DT (leading to an alkaline urine). Through the techniques described here, we have identified a series of distinct markers to be used by pathologists, veterinarians, and researchers to easily identify alligator nephron segments. Anat Rec, 2009. (c) 2009 Wiley-Liss, Inc.

  9. Protactinium-231 measurement and application to a uranium series transport model

    NASA Astrophysics Data System (ADS)

    Golian, C.; Nightingale, T.; Airey, P. L.

    1984-06-01

    Precise measurements of small deviations of 230Th/ 234U and 231Pa/ 235U contribute to the modelling of the geochemical transport of uranium series nuclides. The use of alpha-spectrometry to measure the second-order daughter product 227Th was the analytical technique chosen. It was thereby assumed that the intermediate 227Ac is immobile. Complete methematical expressions for the count rate in various regions of the spectrum have been developed. They allow calculation of the initial yield from the cumulative counts of 227Th and the interfering 223Ra. 224Ra and 212Bi for extended time periods. The resulting increase in precision is particularly useful at low levels. The approach to modelling the transport of uranium series nuclides down-gradient of deposits within the Alligator Rivers Uranium Province of the Northern Territory of Australia is outlined. Some preliminary data are presented which call into question the assumption of the immobility of the 227Ac.

  10. Alligators in the Sewers? Really?

    ERIC Educational Resources Information Center

    Egbert, Joy

    2009-01-01

    A large number of alligators, flushed down toilets as babies, have grown up and proliferated in the bowels of New York City. Over the years, they have grown in number and size and frequently terrorize those foolish enough to visit the subways. This tale has been making its way around the Internet ever since there's been an Internet. It's wild…

  11. Uranium and Its Decay Products in Floodplain Sediments from the River Fal

    NASA Astrophysics Data System (ADS)

    Millward, G. E.; Blake, W. H.; Little, R.; Couldrick, L.

    2012-04-01

    European river basins are subject to longer-term storage of legacy contaminants in sedimentary sinks and their potential release presents a credible risk to achieving water quality targets required by the EU Water Framework Directive. The catchment of the River Fal, south west England, is extensively mineralised and has been greatly impacted by heavy metal mining. Uranium and radium were extracted and processed between 1870 and 1930 and spoil tips along the channel banks are assumed to have been a source of radionuclides into the river. Radionuclides were determined in five cores obtained from the river floodplain, including a reference core positioned upstream of the uranium mine enabling evaluation of its impact on past and contemporary sediment quality. The core was sectioned into 1 cm thick slices and they were analysed by gamma spectrometry for products of the U-238 decay series, i.e. Th-234 (a surrogate for U-238), Pb-214 (a surrogate for Ra-226), Pb-210 and fallout Am-241 and Cs-137. Peak Cs-137 concentrations at mid-depth were associated with fallout after atmospheric nuclear tests in 1963 and were used to estimate sedimentation rates. However, the activity concentrations of Pb-210 were elevated at all depths and the result indicated a significant input of unsupported Pb-210 (linked to processed spoil material) throughout the period of deposition. At some sites, peak activity concentrations of Th-234 suggested inputs from mining activity during major release and/or flood events. The cores downstream of the mine all had higher radionuclide inventories, of the order 105 Bq m-2, compared to the reference core due to the presences of products from the U-238 decay series. In addition, the inventories did not decrease systematically downstream indicating storage regions within the river channel. Storage of such legacy contaminants at levels in excess of contemporary environmental quality guidelines raises important questions and challenges for floodplain use and

  12. Concentrations and fluxes of dissolved uranium in the Yellow River estuary: seasonal variation and anthropogenic (Water-Sediment Regulation Scheme) impact.

    PubMed

    Juanjuan, Sui; Zhigang, Yu; Bochao, Xu; Wenhua, Dong; Dong, Xia; Xueyan, Jiang

    2014-02-01

    The Water-Sediment Regulation Scheme (WSRS) of the Yellow River is a procedure implemented annually from June to July to expel sediments deposited in Xiaolangdi and other large middle-reach reservoirs and to scour the lower reaches of the river, by controlling water and sediment discharges. Dissolved uranium isotopes were measured in river waters collected monthly as well as daily during the 2010 WSRS (June 19-July 16) from Station Lijin (a hydrologic station nearest to the Yellow River estuary). The monthly samples showed dissolved uranium concentrations of 3.85-7.57 μg l(-1) and (234)U/(238)U activity ratios of 1.24-1.53. The concentrations were much higher than those reported for other global major rivers, and showed seasonal variability. Laboratory simulation experiments showed significant uranium release from bottom and suspended sediment. The uranium concentrations and activity ratios differed during the two stages of the WSRS, which may reflect desorption/dissolution of uranium from suspended river sediments of different origins. An annual flux of dissolved uranium of 1.04 × 10(8) g y(-1) was estimated based on the monthly average water discharge and dissolved uranium concentration in the lower reaches of the Yellow River. The amount of dissolved uranium (2.65 × 10(7) g) transported from the Yellow River to the sea during the WSRS constituted about 1/4 of the annual flux.

  13. Occurrence of decabromodiphenyl ethane in captive Chinese alligators (Alligator sinensis) from China.

    PubMed

    Hong, Bing; Wu, Ting; Zhao, Guangchao; Sun, Yuxin; Wang, Xinming; Zhao, Juan; Yi, Zhigang; Wu, Xiaobing; Mai, Bixian

    2015-01-01

    Decabromodiphenyl ethane (DBDPE), a replacement for decabromodiphenyl ether (deca-BDE), was investigated in captive Chinese alligators from China. DBDPE was detected in adult tissues, neonates and eggs of Chinese alligators with concentrations ranging from 4.74-192, 0.24-1.94, and 0.01-0.51 ng g(-1) lipid weight, respectively. Compared to PBDEs and PCBs, DBDPE contamination was limited in Chinese alligators. Additionally, DBDPE concentrations in adult muscles were one to three orders of magnitude higher than those in neonates and eggs, suggesting the limited maternal transfer potential of DBDPE in Chinese alligators. This is the first study to report the occurrence of DBDPE in Chinese alligators.

  14. Retention and chemical speciation of uranium in an oxidized wetland sediment from the Savannah River Site.

    PubMed

    Li, Dien; Seaman, John C; Chang, Hyun-Shik; Jaffe, Peter R; Koster van Groos, Paul; Jiang, De-Tong; Chen, Ning; Lin, Jinru; Arthur, Zachary; Pan, Yuanming; Scheckel, Kirk G; Newville, Matthew; Lanzirotti, Antonio; Kaplan, Daniel I

    2014-05-01

    Uranium speciation and retention mechanisms onto Savannah River Site (SRS) wetland sediments was studied using batch (ad)sorption experiments, sequential extraction, U L3-edge X-ray absorption near-edge structure (XANES) spectroscopy, fluorescence mapping and μ-XANES. Under oxidized conditions, U was highly retained by the SRS wetland sediments. In contrast to other similar but much lower natural organic matter (NOM) sediments, significant sorption of U onto the SRS sediments was observed at pH < 4 and pH > 8. Sequential extraction indicated that the U species were primarily associated with the acid soluble fraction (weak acetic acid extractable) and organic fraction (Na-pyrophosphate extractable). Uranium L3-edge XANES spectra of the U-bound sediments were nearly identical to that of uranyl acetate. Based on fluorescence mapping, U and Fe distributions in the sediment were poorly correlated, U was distributed throughout the sample and did not appear as isolated U mineral phases. The primary oxidation state of U in these oxidized sediments was U(VI), and there was little evidence that the high sorptive capacity of the sediments could be ascribed to abiotic or biotic reduction to the less soluble U(IV) species or to secondary mineral formation. Collectively, this study suggests that U may be strongly bound to wetland sediments, not only under reducing conditions by reductive precipitation, but also under oxidizing conditions through NOM-uranium bonding.

  15. Distribution of ventilation in American alligator Alligator mississippiensis

    SciTech Connect

    Bickler, P.E.; Spragg, R.G.; Hartman, M.T.; White, F.N.

    1985-10-01

    The regional distribution of ventilation in the multicameral lung of spontaneously ventilating alligators (Alligator mississippiensis) was studied with TTXe scintigraphy. Frequent gamma camera images of TTXe washin and washout were obtained and processed to allow evaluation of regional ventilation. Washin of TTXe to equilibrium occurred in three to four breaths in anterior, central, and posterior compartments. Washin was most rapid in the posterior compartment and slowest in the anterior. The structure of the lungs and distribution of ventilation of inspired gas is consistent with the rapid radial spread of gas through a parallel arrangement of lung units surrounding the central intrapulmonary bronchus. Washout to equilibrium of TTXe from all compartments occurred within three to four breaths. This rapid washin and washout of gas to all parts of the lung stands in contrast to the lungs of turtles and snakes, in which the caudal air sacs are relatively poorly ventilated.

  16. Bioprospecting the American Alligator (Alligator mississippiensis) Host Defense Peptidome

    PubMed Central

    Bishop, Barney M.; Juba, Melanie L.; Devine, Megan C.; Barksdale, Stephanie M.; Rodriguez, Carlos Alberto; Chung, Myung C.; Russo, Paul S.; Vliet, Kent A.; Schnur, Joel M.; van Hoek, Monique L.

    2015-01-01

    Cationic antimicrobial peptides and their therapeutic potential have garnered growing interest because of the proliferation of bacterial resistance. However, the discovery of new antimicrobial peptides from animals has proven challenging due to the limitations associated with conventional biochemical purification and difficulties in predicting active peptides from genomic sequences, if known. As an example, no antimicrobial peptides have been identified from the American alligator, Alligator mississippiensis, although their serum is antimicrobial. We have developed a novel approach for the discovery of new antimicrobial peptides from these animals, one that capitalizes on their fundamental and conserved physico-chemical properties. This sample-agnostic process employs custom-made functionalized hydrogel microparticles to harvest cationic peptides from biological samples, followed by de novo sequencing of captured peptides, eliminating the need to isolate individual peptides. After evaluation of the peptide sequences using a combination of rational and web-based bioinformatic analyses, forty-five potential antimicrobial peptides were identified, and eight of these peptides were selected to be chemically synthesized and evaluated. The successful identification of multiple novel peptides, exhibiting antibacterial properties, from Alligator mississippiensis plasma demonstrates the potential of this innovative discovery process in identifying potential new host defense peptides. PMID:25671663

  17. Biophysics of directional hearing in the American alligator (Alligator mississippiensis)

    PubMed Central

    Bierman, Hilary S.; Thornton, Jennifer L.; Jones, Heath G.; Koka, Kanthaiah; Young, Bruce A.; Brandt, Christian; Christensen-Dalsgaard, Jakob; Carr, Catherine E.; Tollin, Daniel J.

    2014-01-01

    Physiological and anatomical studies have suggested that alligators have unique adaptations for spatial hearing. Sound localization cues are primarily generated by the filtering of sound waves by the head. Different vertebrate lineages have evolved external and/or internal anatomical adaptations to enhance these cues, such as pinnae and interaural canals. It has been hypothesized that in alligators, directionality may be enhanced via the acoustic coupling of middle ear cavities, resulting in a pressure difference receiver (PDR) mechanism. The experiments reported here support a role for a PDR mechanism in alligator sound localization by demonstrating that (1) acoustic space cues generated by the external morphology of the animal are not sufficient to generate location cues that match physiological sensitivity, (2) continuous pathways between the middle ears are present to provide an anatomical basis for coupling, (3) the auditory brainstem response shows some directionality, and (4) eardrum movement is directionally sensitive. Together, these data support the role of a PDR mechanism in crocodilians and further suggest this mechanism is a shared archosaur trait, most likely found also in the extinct dinosaurs. PMID:24671963

  18. Age of uranium mineralization at the Jabiluka and Ranger deposits, Northern Territory, Australia: New U- Pb isotope evidence.

    USGS Publications Warehouse

    Ludwig, K. R.; Grauch, R.I.; Nutt, C.J.; Nash, J.T.; Frishman, D.; Simmons, K.R.

    1987-01-01

    The Ranger and Jabiluka uranium deposits are the largest in the Alligator Rivers uranium field, which contains at least 20% of the world's low-cost uranium reserves. Ore occurs in early Proterozoic metasediments, below an unconformity with sandstones of the 1.65 b.y.-old Kombolgie Formation. This study has used U-Pb isotope data from a large number of whole-rock drill core samples with a variety of mineral assemblages and textures. Both Ranger and Jabiluka reflect a common, profound isotopic disturbance at about 400 to 600 m.y. This disturbance, which was especially pronounced at Jabiluka, may correspond to the development of basins and associated basalt flows to the W and SW.-from Authors

  19. Fates of pollutants from uranium mining in floodplain of a meandering river (the Ploucnice, Czech Republic)

    NASA Astrophysics Data System (ADS)

    Matys Grygar, Tomas; Elznicova, Jitka; Majerova, Lucie; Babek, Ondrej; Kiss, Timea; Havelcova, Martina; Hosek, Michal

    2014-05-01

    The Ploucnice River (Czech Republic) received two groups of element pollutants. The first was Pb-Cu-Sb-Zn association with the onset early in 20th century; we attribute it to diffuse pollution at levels of the river watershed and/or mid European region with both atmospheric and fluvial transports. The second group was U-Zn-Ni-Co-Ba association related to uranium mining and mine-water processing during the 1970s and 1980s. Pollution hence allowed for identifying two chemostratigraphic units in 20th century floodplain fill, whose lower boundaries we interpret as isochronous at a given river reach. Historical and current maps and aerial photographs and current aerial lidar scanning allowed reconstructing the floodplain development. Electrical resistivity tomography (ERT) produced insight into the floodplain architecture. Three geomorphic levels were identified in the studied river reach: active floodplain, abandoned floodplain (paleochannels there are now inundated at >Q50), and pre-Holocene or early Holocene terrace. Each level has its own pattern of pollution by Pb, U and polyaromatic hydrocarbons. The terrace and abandoned floodplain sediments together with deeper sediments from active floodplain allowed construction of background functions for pre-industrial concentrations of target elements and subsequent calculation of enrichment factors. That approach corrects for grain-size effects and thus coarser unsorted terrace sediments, finer silty sands of the abandoned floodplain, and the finest muds of the active floodplain were jointly processed. Such data processing was a pre-requisite for evaluation of weak diffuse pollution from early 20th century and recognition of post-depositional changes in pollutant concentrations. The main portion of pollutants related to uranium mining got into the river system in 1970s with peak in 1981 during a summer flood with >Q50 discharge. The pollution impacted the entire river system (enhanced Ra-226 activities were detected at

  20. Jumping the Alligators in the Ditch.

    ERIC Educational Resources Information Center

    Barber, Rims

    Poor black young people in rural Mississippi contemplate their schooling with the same feelings as their friends who dare to jump the local ditches filled with alligators: the odds are against escaping the alligators, and the advantages of getting to the far side are not very apparent. Living in conditions of extreme poverty, these young people…

  1. Uranium Bio-accumulation and Cycling as revealed by Uranium Isotopes in Naturally Reduced Sediments from the Upper Colorado River Basin

    NASA Astrophysics Data System (ADS)

    Lefebvre, Pierre; Noël, Vincent; Jemison, Noah; Weaver, Karrie; Bargar, John; Maher, Kate

    2016-04-01

    Uranium (U) groundwater contamination following oxidized U(VI) releases from weathering of mine tailings is a major concern at numerous sites across the Upper Colorado River Basin (CRB), USA. Uranium(IV)-bearing solids accumulated within naturally reduced zones (NRZs) characterized by elevated organic carbon and iron sulfide compounds. Subsequent re-oxidation of U(IV)solid to U(VI)aqueous then controls the release to groundwater and surface water, resulting in plume persistence and raising public health concerns. Thus, understanding the extent of uranium oxidation and reduction within NRZs is critical for assessing the persistence of the groundwater contamination. In this study, we measured solid-phase uranium isotope fractionation (δ238/235U) of sedimentary core samples from four study sites (Shiprock, NM, Grand Junction, Rifle and Naturita, CO) using a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS). We observe a strong correlation between U accumulation and the extent of isotopic fractionation, with Δ238U up to +1.8 ‰ between uranium-enriched and low concentration zones. The enrichment in the heavy isotopes within the NRZs appears to be especially important in the vadose zone, which is subject to variations in water table depth. According to previous studies, this isotopic signature is consistent with biotic reduction processes associated with metal-reducing bacteria. Positive correlations between the amount of iron sulfides and the accumulation of reduced uranium underline the importance of sulfate-reducing conditions for U(IV) retention. Furthermore, the positive fractionation associated with U reduction observed across all sites despite some variations in magnitude due to site characteristics, shows a regional trend across the Colorado River Basin. The maximum extent of 238U enrichment observed in the NRZ proximal to the water table further suggests that the redox cycling of uranium, with net release of U(VI) to the groundwater by

  2. Comment and response document for the ground water protection strategy for the Uranium Mill Tailings Site at Green River, Utah

    SciTech Connect

    1995-09-01

    The US Department of Energy (DOE) responses to comments from both the US Nuclear Regulatory Commission (NRC) and the state of Utah are provided in this document. The Proposed Ground Water Protection Strategy for the Uranium Mill Tailings Site at Green River, Utah, presents the proposed (modified) ground water protection strategy for the disposal cell at the Green River disposal site for compliance with Subpart A of 40 CFR Part 192. Before the disposal cell was constructed, site characterization was conducted at the Green River Uranium Mill Tailings Remedial Action (UMTRA) Project site to determine an acceptable compliance strategy. Results of the investigation are reported in detail in the final remedial action plan (RAP) (DOE, 1991a). The NRC and the state of Utah have accepted the final RAP. The changes in this document relate only to a modification of the compliance strategy for ground water protection.

  3. Radiological survey of the inactive uranium-mill tailings at Green River, Utah

    SciTech Connect

    Haywood, F.F.; Christian, D.J.; Ellis, B.S.; Hubbard, H.M. Jr.; Lorenzo, D.; Shinpaugh, W.H.

    1980-03-01

    The uranium-mill tailings at Green River, Utah, are relatively low in /sup 226/Ra content and concentration (20 Ci and 140 pCi/g, respectively) because the mill was used to upgrade the uranium ore by separating the sand and slime fractions; most of the radium was transported along with the slimes to another mill site. Spread of tailings was observed in all directions, but near-background gamma exposure rates were reached at distances of 40 to 90 m from the edge of the pile. Water erosion of the tailings is evident and, since a significant fraction of the tailings pile lies in Brown's Wash, the potential exists for repetition of the loss of a large quantity of tailings such as occurred during a flood in 1959. In general, the level of surface contamination was low at this site, but some areas in the mill site, which were being used for nonuranium work, have gamma-ray exposure rates up to 143 ..mu..R/hr.

  4. Retention and chemical speciation of uranium in an oxidized wetland sediment from the Savannah River Site

    SciTech Connect

    Li, Dien; Seaman, John C.; Chang, Hyun-Shik; Jaffe, Peter R.; Koster van Groos, Paul; Jiang, De-Tong; Chen, Ning; Lin, Jinru; Arthur, Zachary; Pan, Yuanming; Scheckel, Kirk G.; Newville, Matthew; Lanzirotti, Antonio; Kaplan, Daniel I.

    2014-05-01

    Uranium speciation and retention mechanism onto Savannah River Site (SRS) wetland sediments was studied using batch (ad)sorption experiments, sequential extraction desorption tests and U L{sub 3}-edge X-ray absorption near-edge structure (XANES) spectroscopy of contaminated wetland sediments. U was highly retained by the SRS wetland sediments. In contrast to other similar but much lower natural organic matter (NOM) sediments, significant sorption of U onto the SRS sediments was observed at pH <4 and pH >8. Sequential extraction tests indicated that the U(VI) species were primarily associated with the acid soluble fraction (weak acetic acid extractable) and NOM fraction (Na-pyrophosphate extractable). Uranium L3- edge XANES spectra of the U-retained sediments were nearly identical to that of uranyl acetate. The primary oxidation state of U in these sediments was as U(VI), and there was little evidence that the high sorptive capacity of the sediments could be ascribed to abiotic or biotic reduction to the less soluble U(IV) species. The molecular mechanism responsible for the high U retention in the SRS wetland sediments is likely related to the chemical bonding of U to organic carbon.

  5. Isotopic studies of sources of uranium in sediments of the Ashtabula River, Ohio, U.S.A.

    SciTech Connect

    Ketterer, M.E.; Wetzel, W.C.; Layman, R.R.; Matisoff, G.; Bonniwell, E.C.

    2000-03-15

    Uranium contamination of anthropogenic origin has been identified in unconsolidated sediment of a 1.5 km portion of the Ashtabula River near its confluence with Lake Erie. Uranium concentrations as high as 188 {mu}g/g dry sediment are present. A small tributary of the Ashtabula River, Fields Brook, is the apparent point of origin of the uranium in the Ashtabula River sediments. {sup 137}Cs dating of a sediment core indicates that the U contamination occurred during the post-1964 time frame. The horizons of elevated U concentration also exhibit > 10x elevations in Zr, Nb, Hf, Ta, and W. {sup 238}U/{sup 235}U isotopic ratios indicate that the uranium is largely but not exclusively of natural composition. Distinct horizons of slightly {sup 235}U-depleted ({sup 238}U/{sup 235}U > 137.88) and slightly {sup 235}U-enriched ({sup 238}U/{sup 235}U < 137.88) uranium are also present. {sup 210}Pb activities and {sup 232}Th/{sup 230}Th isotopic measurements indicate that a significant portion of the uranium contains {sup 238}U daughters in approximate secular equilibrium. It is inferred that at least two distinct sources of anthropogenic U contamination exist: (a) discharges from the processing of enriched and depleted U metal by a DOE contractor facility and (B) U-bearing wastes from the production of TiO{sub 2} from limonite and associated minerals. These isotopic methodologies are potentially useful in settings where releases of nonnatural {sup 238}U/{sup 235}U composition materials and/or naturally occurring radioactive material (NORM) have taken place.

  6. Methyltestosterone alters sex determination in the American alligator (Alligator mississippiensis).

    PubMed

    Murray, Christopher M; Easter, Michael; Merchant, Mark; Rheubert, Justin L; Wilson, Kelly A; Cooper, Amos; Mendonça, Mary; Wibbels, Thane; Marin, Mahmood Sasa; Guyer, Craig

    2016-09-15

    Effects of xenobiotics can be organizational, permanently affecting anatomy during embryonic development, and/or activational, influencing transitory actions during adulthood. The organizational influence of endocrine-disrupting contaminants (EDC's) produces a wide variety of reproductive abnormalities among vertebrates that exhibit temperature-dependent sex determination (TSD). Typically, such influences result in subsequent activational malfunction, some of which are beneficial in aquaculture. For example, 17-αmethyltestosterone (MT), a synthetic androgen, is utilized in tilapia farming to bias sex ratio towards males because they are more profitable. A heavily male-biased hatchling sex ratio is reported from a crocodile population near one such tilapia operation in Guanacaste, Costa Rica. In this study we test the effects of MT on sexual differentiation in American alligators, which we used as a surrogate for all crocodilians. Experimentally, alligators were exposed to MT in ovo at standard ecotoxicological concentrations. Sexual differentiation was determined by examination of primary and secondary sex organs post hatching. We find that MT is capable of producing male embryos at temperatures known to produce females and demonstrate a dose-dependent gradient of masculinization. Embryonic exposure to MT results in hermaphroditic primary sex organs, delayed renal development and masculinization of the clitero-penis (CTP). PMID:27401264

  7. Coronary blood flow in the anesthetized American alligator (Alligator mississippiensis).

    PubMed

    Jensen, Bjarke; Elfwing, Magnus; Elsey, Ruth M; Wang, Tobias; Crossley, Dane A

    2016-01-01

    Coronary circulation of the heart evolved early within ectothermic vertebrates and became of vital importance to cardiac performance in some teleost fish, mammals and birds. In contrast, the role and function of the coronary circulation in ectothermic reptiles remains largely unknown. Here, we investigated the systemic and coronary arterial responses of five anesthetized juvenile American alligators (Alligator mississippiensis) to hypoxia, acetylcholine, adenosine, sodium nitroprusside, isoproterenol, and phenylephrine. We recorded electrocardiograms, monitored systemic blood pressure, blood flows in both aortae, and blood flow in a major coronary artery supplying most of the right ventricle. Coronary arterial blood flow was generally forward, but there was a brief retrograde flow during a ventricular contraction. Blood pressure was significantly changed in all conditions. Acetylcholine decreased coronary forward flow, but this response was confounded by the concomitant lowered work of the ventricles due to decreased heart rate and blood pressure. Coronary forward flow was poorly correlated with heart rate and mean arterial pressure across treatments. Overall changes in coronary forward flow, significant and not significant, were generally in the same direction as mean arterial pressure and ventricular power, approximated as the product of systemic cardiac output and mean arterial pressure. PMID:26436857

  8. Coronary blood flow in the anesthetized American alligator (Alligator mississippiensis).

    PubMed

    Jensen, Bjarke; Elfwing, Magnus; Elsey, Ruth M; Wang, Tobias; Crossley, Dane A

    2016-01-01

    Coronary circulation of the heart evolved early within ectothermic vertebrates and became of vital importance to cardiac performance in some teleost fish, mammals and birds. In contrast, the role and function of the coronary circulation in ectothermic reptiles remains largely unknown. Here, we investigated the systemic and coronary arterial responses of five anesthetized juvenile American alligators (Alligator mississippiensis) to hypoxia, acetylcholine, adenosine, sodium nitroprusside, isoproterenol, and phenylephrine. We recorded electrocardiograms, monitored systemic blood pressure, blood flows in both aortae, and blood flow in a major coronary artery supplying most of the right ventricle. Coronary arterial blood flow was generally forward, but there was a brief retrograde flow during a ventricular contraction. Blood pressure was significantly changed in all conditions. Acetylcholine decreased coronary forward flow, but this response was confounded by the concomitant lowered work of the ventricles due to decreased heart rate and blood pressure. Coronary forward flow was poorly correlated with heart rate and mean arterial pressure across treatments. Overall changes in coronary forward flow, significant and not significant, were generally in the same direction as mean arterial pressure and ventricular power, approximated as the product of systemic cardiac output and mean arterial pressure.

  9. Methyltestosterone alters sex determination in the American alligator (Alligator mississippiensis).

    PubMed

    Murray, Christopher M; Easter, Michael; Merchant, Mark; Rheubert, Justin L; Wilson, Kelly A; Cooper, Amos; Mendonça, Mary; Wibbels, Thane; Marin, Mahmood Sasa; Guyer, Craig

    2016-09-15

    Effects of xenobiotics can be organizational, permanently affecting anatomy during embryonic development, and/or activational, influencing transitory actions during adulthood. The organizational influence of endocrine-disrupting contaminants (EDC's) produces a wide variety of reproductive abnormalities among vertebrates that exhibit temperature-dependent sex determination (TSD). Typically, such influences result in subsequent activational malfunction, some of which are beneficial in aquaculture. For example, 17-αmethyltestosterone (MT), a synthetic androgen, is utilized in tilapia farming to bias sex ratio towards males because they are more profitable. A heavily male-biased hatchling sex ratio is reported from a crocodile population near one such tilapia operation in Guanacaste, Costa Rica. In this study we test the effects of MT on sexual differentiation in American alligators, which we used as a surrogate for all crocodilians. Experimentally, alligators were exposed to MT in ovo at standard ecotoxicological concentrations. Sexual differentiation was determined by examination of primary and secondary sex organs post hatching. We find that MT is capable of producing male embryos at temperatures known to produce females and demonstrate a dose-dependent gradient of masculinization. Embryonic exposure to MT results in hermaphroditic primary sex organs, delayed renal development and masculinization of the clitero-penis (CTP).

  10. On the variability of alligator sex ratios

    USGS Publications Warehouse

    Nichols, J.D.; Chabreck, R.H.

    1980-01-01

    Samples of alligators from wild and 'farm' populations exhibited disproportionate sex ratios. Males predominated among young alligators from wild populations, whereas females were much more abundant than males in the farm population, where resources were superabundant. These results and other considerations lead us to hypothesize that environmental factors influence sex determination in alligators. During favorable environmental conditions natural selection is expected to favor a preponderance of the sex whose individuals exhibit the greater environmentally associated variation in relative fitness. We hypothesize that environmentally associated variation in age at sexual maturity of females produces sufficient variation in relative fitness of females to result in selection for low sex ratios during periods of resource abundance.

  11. Improved accountability method for measuring enriched uranium in H-Canyon dissolver solution at the Savannah River Site

    SciTech Connect

    Maxwell, S.L. III; Satkowski, J.; Mahannah, R.N.

    1992-01-01

    At the Savannah River Site (SRS), accountability measurement of enriched uranium dissolved in H-Canyon is performed using isotope dilution mass spectrometry (IDMS). In the IDMS analytical method, a known quantity of uranium{sup 233} is added to the sample solution containing enriched uranium and fission products. The resulting uranium mixture must first be purified using a separation technique in the shielded analytical( hot'') cells to lower radioactivity levels by removing fission products. Following this purification, the sample is analyzed by mass spectrometry to determine the total uranium content and isotopic abundance. The magnitude of the response of each uranium isotope in the sample solution and the response of the U{sup 233} spike is measured. By ratioing these responses, relative to the known quantity of the U{sup 233} spike, the uranium content can be determined. A hexane solvent extraction technique, used for years at SRS to remove fission products prior to the mass spectrometry analysis of uranium, has several problems. The hexone method is tedious, requires additional sample clean-up after the purified sample is removed from the shielded cells and requires the use of Resource Conservation and Recovery Act (RCRA)-listed hazardous materials (hexone and chromium compounds). A new high speed separation method that enables a rapid removal of fission products in a shielded cells environment has been developed by the SRS Central Laboratory to replace the hexone method. The new high speed column extraction chromatography technique employs applied vacuum and columns containing tri (2-ethyl-hexyl) phosphate (TEHP) solvent coated on a small particle inert support (SM-7 Bio Beads). The new separation is rapid, user friendly, eliminates the use of the RCA-listed hazardous chemicals and reduces the amount of solid waste generated by the separation method. 2 tabs. 4 figs.

  12. Improved accountability method for measuring enriched uranium in H-Canyon dissolver solution at the Savannah River Site

    SciTech Connect

    Maxwell, S.L. III; Satkowski, J.; Mahannah, R.N.

    1992-08-01

    At the Savannah River Site (SRS), accountability measurement of enriched uranium dissolved in H-Canyon is performed using isotope dilution mass spectrometry (IDMS). In the IDMS analytical method, a known quantity of uranium{sup 233} is added to the sample solution containing enriched uranium and fission products. The resulting uranium mixture must first be purified using a separation technique in the shielded analytical(``hot``) cells to lower radioactivity levels by removing fission products. Following this purification, the sample is analyzed by mass spectrometry to determine the total uranium content and isotopic abundance. The magnitude of the response of each uranium isotope in the sample solution and the response of the U{sup 233} spike is measured. By ratioing these responses, relative to the known quantity of the U{sup 233} spike, the uranium content can be determined. A hexane solvent extraction technique, used for years at SRS to remove fission products prior to the mass spectrometry analysis of uranium, has several problems. The hexone method is tedious, requires additional sample clean-up after the purified sample is removed from the shielded cells and requires the use of Resource Conservation and Recovery Act (RCRA)-listed hazardous materials (hexone and chromium compounds). A new high speed separation method that enables a rapid removal of fission products in a shielded cells environment has been developed by the SRS Central Laboratory to replace the hexone method. The new high speed column extraction chromatography technique employs applied vacuum and columns containing tri (2-ethyl-hexyl) phosphate (TEHP) solvent coated on a small particle inert support (SM-7 Bio Beads). The new separation is rapid, user friendly, eliminates the use of the RCA-listed hazardous chemicals and reduces the amount of solid waste generated by the separation method. 2 tabs. 4 figs.

  13. Dissolved radon and uranium in groundwater in a potential coal seam gas development region (Richmond River Catchment, Australia).

    PubMed

    Atkins, Marnie L; Santos, Isaac R; Perkins, Anita; Maher, Damien T

    2016-04-01

    The extraction of unconventional gas resources such as shale and coal seam gas (CSG) is rapidly expanding globally and often prevents the opportunity for comprehensive baseline groundwater investigations prior to drilling. Unconventional gas extraction often targets geological layers with high naturally occurring radioactive materials (NORM) and extraction practices may possibly mobilise radionuclides into regional and local drinking water resources. Here, we establish baseline groundwater radon and uranium levels in shallow aquifers overlying a potential CSG target formation in the Richmond River Catchment, Australia. A total of 91 groundwater samples from six different geological units showed highly variable radon activities (0.14-20.33 Bq/L) and uranium levels (0.001-2.77 μg/L) which were well below the Australian Drinking Water Guideline values (radon; 100 Bq/L and uranium; 17 μg/L). Therefore, from a radon and uranium perspective, the regional groundwater does not pose health risks to consumers. Uranium could not explain the distribution of radon in groundwater. Relatively high radon activities (7.88 ± 0.83 Bq/L) in the fractured Lismore Basalt aquifer coincided with very low uranium concentrations (0.04 ± 0.02 μg/L). In the Quaternary Sediments aquifers, a positive correlation between U and HCO3(-) (r(2) = 0.49, p < 0.01) implied the uranium was present as uranyl-carbonate complexes. Since NORM are often enriched in target geological formations containing unconventional gas, establishing radon and uranium concentrations in overlying aquifers comprises an important component of baseline groundwater investigations. PMID:26867097

  14. Dissolved radon and uranium in groundwater in a potential coal seam gas development region (Richmond River Catchment, Australia).

    PubMed

    Atkins, Marnie L; Santos, Isaac R; Perkins, Anita; Maher, Damien T

    2016-04-01

    The extraction of unconventional gas resources such as shale and coal seam gas (CSG) is rapidly expanding globally and often prevents the opportunity for comprehensive baseline groundwater investigations prior to drilling. Unconventional gas extraction often targets geological layers with high naturally occurring radioactive materials (NORM) and extraction practices may possibly mobilise radionuclides into regional and local drinking water resources. Here, we establish baseline groundwater radon and uranium levels in shallow aquifers overlying a potential CSG target formation in the Richmond River Catchment, Australia. A total of 91 groundwater samples from six different geological units showed highly variable radon activities (0.14-20.33 Bq/L) and uranium levels (0.001-2.77 μg/L) which were well below the Australian Drinking Water Guideline values (radon; 100 Bq/L and uranium; 17 μg/L). Therefore, from a radon and uranium perspective, the regional groundwater does not pose health risks to consumers. Uranium could not explain the distribution of radon in groundwater. Relatively high radon activities (7.88 ± 0.83 Bq/L) in the fractured Lismore Basalt aquifer coincided with very low uranium concentrations (0.04 ± 0.02 μg/L). In the Quaternary Sediments aquifers, a positive correlation between U and HCO3(-) (r(2) = 0.49, p < 0.01) implied the uranium was present as uranyl-carbonate complexes. Since NORM are often enriched in target geological formations containing unconventional gas, establishing radon and uranium concentrations in overlying aquifers comprises an important component of baseline groundwater investigations.

  15. Uranium and diagenesis in evaporitic lacustrine mudstone of the Oligocene White River Group, Dawes County, Nebraska. Bulletin

    SciTech Connect

    Dickinson, K.A.

    1991-01-01

    The Oligocene White River Group consists of the Chadron and the overlying Brule Formations in northwestern Nebraska. The Chadron Formation consists of alluvial and colluvial vitric mudstone beds, but in addition contains white persistent layers (purplish-white layers) that probably resulted from soil formation on vitric parent material. West of the current study area a basal sandstone facies of the Chadron is host rock for the Crow Butte uranium deposit. The Brule, which consists mostly of pedogenically altered alluvial and fluvial vitric mudstone deposits, contains a uraniferous lacustrine facies northwest of Chadron, Nebraska. Detrital minerals in rocks of the White River Group include quartz, feldspar, volcanic glass, smectite, and illite. Chemical precipitate minerals in the lacustrine facies are calcite, dolomite, and gypsum. Authigenic minerals include calcite, dolomite, gypsum, smectite, opal, chalcedony, together with oxidized uranium minerals.

  16. Subsurface Nitrogen-Cycling Microbial Communities at Uranium Contaminated Sites in the Colorado River Basin

    NASA Astrophysics Data System (ADS)

    Cardarelli, E.; Bargar, J.; Williams, K. H.; Dam, W. L.; Francis, C.

    2015-12-01

    Throughout the Colorado River Basin (CRB), uranium (U) persists as a relic contaminant of former ore processing activities. Elevated solid-phase U levels exist in fine-grained, naturally-reduced zone (NRZ) sediments intermittently found within the subsurface floodplain alluvium of the following Department of Energy-Legacy Management sites: Rifle, CO; Naturita, CO; and Grand Junction, CO. Coupled with groundwater fluctuations that alter the subsurface redox conditions, previous evidence from Rifle, CO suggests this resupply of U may be controlled by microbially-produced nitrite and nitrate. Nitrification, the two-step process of archaeal and bacterial ammonia-oxidation followed by bacterial nitrite oxidation, generates nitrate under oxic conditions. Our hypothesis is that when elevated groundwater levels recede and the subsurface system becomes anoxic, the nitrate diffuses into the reduced interiors of the NRZ and stimulates denitrification, the stepwise anaerobic reduction of nitrate/nitrite to dinitrogen gas. Denitrification may then be coupled to the oxidation of sediment-bound U(IV) forming mobile U(VI), allowing it to resupply U into local groundwater supplies. A key step in substantiating this hypothesis is to demonstrate the presence of nitrogen-cycling organisms in U-contaminated, NRZ sediments from the upper CRB. Here we investigate how the diversity and abundances of nitrifying and denitrifying microbial populations change throughout the NRZs of the subsurface by using functional gene markers for ammonia-oxidation (amoA, encoding the α-subunit of ammonia monooxygenase) and denitrification (nirK, nirS, encoding nitrite reductase). Microbial diversity has been assessed via clone libraries, while abundances have been determined through quantitative polymerase chain reaction (qPCR), elucidating how relative numbers of nitrifiers (amoA) and denitrifiers (nirK, nirS) vary with depth, vary with location, and relate to uranium release within NRZs in sediment

  17. Chronic incidental lead ingestion in a group of captive-reared alligators (Alligator mississippiensis): possible contribution to reproductive failure.

    PubMed

    Lance, Valentine A; Horn, Thomas R; Elsey, Ruth M; de Peyster, Ann

    2006-01-01

    An American alligator (Alligator mississippiensis) breeding facility using male and female alligators raised from artificially incubated eggs was established in 1975. These alligators first reproduced at 6 years of age as compared to 10-12 years in wild alligators, but the eggs produced showed a lower hatching rate than those collected from the wild. By age 21 reproduction had failed almost completely. The alligators were sacrificed and tissues collected at necropsy from 44 captive and 15 wild animals and assayed for metals. Results showed that captive alligators had significantly higher tissue levels of lead than wild alligators. Cadmium did not differ between wild and captive and selenium was 50% higher in wild than captive alligator kidneys. Bone lead in captive alligators was 252,443 +/- 20,462 ng/g. High yolk lead was suggested as a probable cause for early embryonic death in alligator eggs. The high tissue lead levels in captive alligators was attributed to long-term consumption of nutria (Myocastor coypus) meat contaminated with lead shot. Liver, ovary, and testis were assayed for lipid peroxidation using the thiobarbituric acid (TBA) test. Captive alligators had 3.6 fold increased TBA-reactive materials in the liver tissue compared to wild. Lipid peroxidation was strongly suspected as having been enhanced by consumption of rancid nutria meat containing lead.

  18. SEASONAL VARIATION IN PLASMA SEX STEROID CONCENTRATION IN JUVENILE ALLIGATORS

    EPA Science Inventory

    Seasonal variation in plasma sex steroid concentrations is common in mature vertebrates, and is occasionally seen in juvenile animals. In this study, we examine the seasonal pattern of sex hormone concentration in juvenile American alligators (Alligator mississippiensis) and make...

  19. POPS IN ALLIGATOR LIVERS FROM LAKE APOPKA, FLORIDA, USA

    EPA Science Inventory

    Reproductive disorders in American alligators (Alligator mississippiensis) inhabiting Lake Apopka, Florida, have been observed for several years. Such disorders are hypothesized to be caused by endocrine disrupting contaminants occurring in the Lake due to pesticide spills and ...

  20. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Green River, Utah. Revision 1

    SciTech Connect

    1995-09-01

    The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (phase 1) and the Ground Water Project (phase 2). For the UMTRA Project site located near Green River, Utah, the Surface Project cleanup occurred from 1988 to 1989. The tailings and radioactively contaminated soils and materials were removed from their original locations and placed into a disposal cell on the site. The disposal cell is designed to minimize radiation emissions and minimize further contamination of ground water beneath the site. The UMTRA Project`s second phase, the Ground Water Project, evaluates the nature and extent of ground water contamination resulting from uranium processing and determines a strategy for ground water compliance with the Environmental Protection Agency (EPA) ground water standards established for the UMTRA Project. For the Green River site, the risk assessment helps determine whether human health risks result from exposure to ground water contaminated by uranium processing. This risk assessment report is the first site-specific document prepared for the UMTRA Ground Water Project at the Green River site. What follows is an evaluation of current and possible future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will be used to determine what is necessary, if anything, to protect human health and the environment while complying with EPA standards.

  1. Uranium plume persistence impacted by hydrologic and geochemical heterogeneity in the groundwater and river water interaction zone of Hanford site

    NASA Astrophysics Data System (ADS)

    Chen, X.; Zachara, J. M.; Vermeul, V. R.; Freshley, M.; Hammond, G. E.

    2015-12-01

    The behavior of a persistent uranium plume in an extended groundwater- river water (GW-SW) interaction zone at the DOE Hanford site is dominantly controlled by river stage fluctuations in the adjacent Columbia River. The plume behavior is further complicated by substantial heterogeneity in physical and geochemical properties of the host aquifer sediments. Multi-scale field and laboratory experiments and reactive transport modeling were integrated to understand the complex plume behavior influenced by highly variable hydrologic and geochemical conditions in time and space. In this presentation we (1) describe multiple data sets from field-scale uranium adsorption and desorption experiments performed at our experimental well-field, (2) develop a reactive transport model that incorporates hydrologic and geochemical heterogeneities characterized from multi-scale and multi-type datasets and a surface complexation reaction network based on laboratory studies, and (3) compare the modeling and observation results to provide insights on how to refine the conceptual model and reduce prediction uncertainties. The experimental results revealed significant spatial variability in uranium adsorption/desorption behavior, while modeling demonstrated that ambient hydrologic and geochemical conditions and heterogeneities in sediment physical and chemical properties both contributed to complex plume behavior and its persistence. Our analysis provides important insights into the characterization, understanding, modeling, and remediation of groundwater contaminant plumes influenced by surface water and groundwater interactions.

  2. THYROID STATUS IN JUVENILE ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS) FROM CONTAMINATED AND REFERENCE SITES ON LAKE OKEECHOBEE, FLORIDA, USA

    EPA Science Inventory

    Exposure to environmental contaminants has been shown to alter normal thyroid function in various wildlife species, including the American alligator (Alligator mississippiensis). Abnormalities in circulating levels of the thyroid hormone thyroxine (T4) have been reported in juven...

  3. Distribution of Uranium Isotopes in the Kaoping River Estuary, Southwestern Taiwan

    NASA Astrophysics Data System (ADS)

    Wang, R.; You, C.

    2011-12-01

    To gain a better understanding of the geochemical behavior of uranium (U) isotopes in estuarine mixing processes, we collected river waters along the Kaoping river estuary both during dry and wet seasons, and analyzed these for major and trace elements and Sr and U isotopes. Dissolved major elements (i.e. Na, Mg, Ca, and Cl) and Sr behave conservatively along with salinity in the estuary. Their vertical profiles reveal mixing between an upper layer of fresh water and a lower layer of intruded seawater. The Sr isotopes support a similar mixing scenario between a more radiogenic, continentally-derived fresh water and less radiogenic seawater. Dissolved B, Ba and U, however, indicate more complicated distribution patterns possibly related to groundwater input, benthic or diffusion flux and water/solid interactions. Riverine U signal normally has higher 234U/238U activity ratio due to the α-recoil and weathering effects than the constant value of open ocean seawater and, thus, potentially can be used as a tracer of terrigenous water inputs. The U isotopic ratios show negative correlation with U content in vertical profiles, with unusually low U concentrations occurring at 1 to 2 m depth where U isotopes are more radiogenic. However, the U isotopic ratios in the upper stations deviate from the mixing line between the fresh water and seawater, possibly due to the effect of groundwater seepage or coastal groundwater discharge. Data also seem to indicate that the wet season samples show high trace element concentrations due to inputs from top soils or atmospheric dusts. This study reveals that U isotopes are potential tracers for studying land/sea interactions and sensitive monitors of environmental changes in estuaries.

  4. Groundwater uranium origin and fate control in a river valley aquifer.

    PubMed

    Banning, Andre; Demmel, Thomas; Rüde, Thomas R; Wrobel, Michael

    2013-12-17

    Groundwater in a Quaternary gravel aquifer partly exhibits uranium (U) concentrations exceeding the new German drinking water limitation (22% of the samples >10 μg L(-1)). This study assesses relevant U reservoirs and hydrogeochemical processes responsible for U transfer between them. A large data set of solid materials (sediments and soils, 164 samples total) and groundwater (114 samples total) characteristics was created in terms of geo- and hydrochemistry, mineralogy, U microdistribution, and mobilization potential. Results show that U primarily derived from lignitic inclusions in Tertiary sediments is transported to and accumulated (complexation to organic substance and UO2 precipitation) in lowland moor peats of the river valley grown on the aquifer gravels. The alkaline character of the system predefines a hydrogeochemical framework fostering U mobility. Elevated concentrations (up to 96 μg L(-1) U) occur downstream of the moor areas and under Mn/NO3-reducing groundwater conditions. Oxic and stronger reduced settings are rather little affected. Supporting previous laboratory studies, this suggests enhanced U mobility in the presence of nitrate also in the field scale. While no anthropogenic U input was detected in the study area, agricultural usage of the moor areas triggers geogenic U release via nitrate fertilization, surface peat degradation, and erosion.

  5. Description of drill-hole VIIIV core from the Jabiluka unconformity-type uranium deposit, Northern Territory, Australia

    SciTech Connect

    Nutt, C.J.

    1984-01-01

    The Jabiluka unconformity-type uranium deposit is one of four large unconformity-type deposits in the Alligator Rivers Uranium Field in the eastern part of the Pine Creek geosyncline, Northern Territory, Australia. These unconformity-type uranium deposits occur as veins, disseminations, and breccia matrix in metasedimentary rocks of the Lower Proterozoic Cahill Formation and are near a regional unconformity that separates the Cahill from the sedimentary rocks of the Middle Proterozoic Kombolgie Formation. The study of unconformity-type deposits - a new type of uranium deposit typified by deposits discovered in the past 15 years in Australia and Canada - is part of the US Geological Survey uranium program; funding was also provided by the US Department of Energy National Uranium Resource Evaluation (NURE) program. Pancontinental Mining Limited kindly gave us access to Jabiluka core and made their geological and geophysical data available for inclusion in our reports. Data and interpretations from the mineralogy and stratigraphy of Jabiluka should aid in defining characteristics and setting of these world class deposits and guide exploration for similar deposits in the United States. 3 refs., 6 figs., 1 tab.

  6. Tracing and Apportioning Sources of Uranium to the Hanford Reach of the Columbia River Using Uranium Isotopes

    NASA Astrophysics Data System (ADS)

    Christensen, J. N.; Dresel, P. E.; Conrad, M. E.; Patton, G. W.; Depaolo, D. J.

    2004-12-01

    The U.S. Department of Energy's Hanford Site is situated along an unimpounded portion of the Columbia River, the highest discharge volume river west of the continental divide. Decades of nuclear related activities have left significant local contamination (e.g. nitrate, U, tritium, Cr6+, 99Tc) in the vadose zone and groundwater within the site. Some of this contamination has reached the Columbia River, and there remains the potential for further contaminant migration to the river. We collected and analyzed samples of Columbia River water for U and Sr isotopes in coordination with the ongoing sampling and monitoring of the river. The U and Sr isotopic data allow us to evaluate sources of U (e.g. natural background, Hanford related, agricultural runoff) and their relative contributions to the river's U budget. The data also provide constraints on the flux of contaminant U from the Hanford Site to the river. We analyzed two sample traverses across the Columbia, one near the Vernita Bridge, upstream from Hanford Site contamination, and a second about 5 km downstream of the Hanford Site. An island divides the downstream traverse into western (main channel) and eastern portions. Filtered (0.45 micron) water samples were analyzed for U isotopic composition (including 236U, one marker of spent U fuel) and U concentration, as well as 87Sr/86Sr and Sr concentration. The samples from the upstream traverse had no detectible 236U (236U/238U < 2x10-8), one marker of spent U fuel, natural 238U/235U, uniform (234U/238U, 87Sr/86Sr, U and Sr concentrations. In contrast, the downstream traverse showed variation in all of these parameters. Concentrations of U are 0.5 ppb to 1.2 ppb and are all well below the EPA MCL of 30 ppb for drinking water. In the western channel, measured 236U/238U is 3.4x10-5 to < 2x10-8, with a co-variation in 238U/235U toward enriched ratios. This correlation is consistent with the U isotopic compositions of a groundwater sample from the environs of a former

  7. Alterations in steroidogenesis in alligators (Alligator mississippiensis) exposed naturally and experimentally to environmental contaminants.

    PubMed Central

    Crain, D A; Guillette, L J; Rooney, A A; Pickford, D B

    1997-01-01

    Many environmental contaminants alter the reproduction of animals by altering the development and function of the endocrine system. The ability of environmental contaminants to alter the endocrine system of alligators was studied both in a descriptive study in which juvenile alligators from a historically contaminated lake were compared to animals from a control lake and in an experimental study in which hatchling control alligators were exposed in ovo to several endocrine-disrupting standards and two modern-use herbicides. Endocrine status was assessed by examining plasma hormone concentrations, gonadal-adrenal mesonephros (GAM) aromatase activity, and gonadal histopathology. In the descriptive study, juvenile alligators from the contaminated lake had significantly lower plasma testosterone concentrations (29.2 pg/ml compared to 51.3 pg/ml), whereas plasma 17 beta-estradiol concentrations did not vary when compared to controls. GAM aromatase activity was significantly decreased n the alligators from the contaminated lake (7.6 pmol/g/hr compared to 11.4 pmol/g/hr). In the experimental study, the endocrine-disrupting standards had the expected effects. 17 beta-Estradiol and tamoxifen caused sex reversal from male to female, with a corresponding increase in aromatase activity. Vinclozolin had no apparent effect on male or female alligators. Among the herbicides tested, atrazine induced GAM aromatase activity in male hatchling alligators that was neither characteristic of males nor females, although testicular differentiation was not altered. Exposure to 2,4-dichlorophenoxyacetic acid had no effect on the endocrine parameters that were measured. Together, these studies show that exposure to some environmental chemicals (such as atrazine) can alter steroidogenesis in alligators, but the endocrine alterations previously noted for Lake Apopka, Florida, alligators can not be fully explained by this mechanism. Images Figure 1. PMID:9222139

  8. Endogenous and exogenous estrogens during embryonic development affect timing of hatch and growth in the American alligator (Alligator mississippiensis).

    PubMed

    Cruze, Lori; Roark, Alison M; Rolland, Gabrielle; Younas, Mona; Stacy, Nicole; Guillette, Louis J

    2015-06-01

    Prenatal exposure to estrogenic endocrine disrupting chemicals (EDCs) can affect length of gestation and body mass and size of offspring. However, the dose, timing, and duration of exposure as well as sex and strain of the experimental animals determine the direction and magnitude of these effects. In this study, we examined the effects of a one-time embryonic exposure to either 17 β-estradiol (E2) or bisphenol A (BPA) on rate of development and growth in American alligators (Alligator mississippiensis). Our results indicate that BPA and E2-treated alligators hatched approximately 1.4 days earlier than vehicle-treated (control) alligators, suggesting that estrogenic chemicals hasten hatching in these animals. We assessed growth rates, growth allometry, and body condition for 21 weeks after hatching and found that BPA-treated alligators grew more quickly shortly after hatching but more slowly thereafter compared to control alligators. Conversely, E2-treated alligators grew more slowly shortly after hatching but more quickly thereafter compared to control alligators. As a result of differences in growth rate, BPA-treated alligators were heavier, longer, and fatter than control alligators at age 5 weeks but were similar in size and leaner than control alligators at age 21 weeks. Biochemical analytes were examined at the end of the 21-week study to assess overall metabolic condition. We found that E2-treated alligators had significantly higher circulating plasma concentrations of cholesterol and triglycerides than control alligators while BPA-treated alligators had blood profiles comparable to control alligators. Our results provide important insights into the effects of exogenous estrogens on morphology and metabolism in an oviparous, semi-aquatic reptile.

  9. Estimating spawning times of Alligator Gar (Atractosteus spatula) in Lake Texoma, Oklahoma

    USGS Publications Warehouse

    Snow, Richard A.; Long, James M.

    2015-01-01

    In 2013, juvenile Alligator Gar were sampled in the reservoir-river interface of the Red River arm of Lake Texoma. The Red River, which flows 860 km along Oklahoma’s border with Texas, is the primary in-flow source of Lake Texoma, and is impounded by Denison Dam. Minifyke nets were deployed using an adaptive random cluster sampling design, which has been used to effectively sample rare species. Lapilli otoliths (one of the three pair of ear stones found within the inner ear of fish) were removed from juvenile Alligator Gar collected in July of 2013. Daily ages were estimated by counting the number of rings present, and spawn dates were back-calculated from date of capture and subtracting 8 days (3 days from spawn to hatch and 5 days from hatch to swimup when the first ring forms). Alligator Gar daily age estimation ranged from 50 to 63 days old since swim-up. Spawn dates corresponded to rising pool elevations of Lake Texoma and water pulses of tributaries.

  10. A mother alligator protects her young

    NASA Technical Reports Server (NTRS)

    2000-01-01

    In the water near Kennedy Space Center, a mother alligator gathers her six offspring. American alligators feed and rest in the water, and lay their eggs in dens they dig into the banks. The young alligators spend their first several weeks in these dens. The Center shares a boundary with the Merritt Island National Wildlife Refuge, which encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  11. An algae-covered alligator rests warily

    NASA Technical Reports Server (NTRS)

    2000-01-01

    An algae-covered alligator keeps a wary eye open as it rests in one of the ponds at Kennedy Space Center. American alligators feed and rest in the water, and lay their eggs in dens they dig into the banks. The young alligators spend their first several weeks in these dens. The Center shares a boundary with the Merritt Island National Wildlife Refuge, which encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  12. Detailed geochemical study of the Dan River-Danville Triassic Basin, North Carolina and Virginia. National Uranium Resource Evaluation Program

    SciTech Connect

    Thayer, P. A.; Cook, J. R.

    1982-08-01

    This abbreviated data report presents results of surface geochemical reconnaissance in the Dan River-Danville Triassic Basin of north-central North Carolina and south-central Virginia. Unweathered rock samples were collected at 380 sites within the basin at a nominal sampling density of one site per square mile. Field measurements and observations are reported for each site; analytical data and field measurements are presented in tables and maps. A detailed four-channel spectrometric survey was conducted, and the results are presented as a series of symbol plot maps for eU, eTh, and eU/eTh. Data from rock sample sites (on microfiche in pocket) include rock type and color and elemental analyses for U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Na, Sc, Sm, Ti, V, and Yb. Elemental uranium in 362 sedimentary rock samples from the Dan River-Danville Basin ranges from a low of 0.1 to a maximum of 13.3 parts per million (ppM). The log mean uranium concentration for these same samples is 0.37 ppM, and the log standard deviation is 0.24 ppM. Elemental uranium in 10 diabase dike samples from within the basin is in the range 0.1 to 0.7 ppM. The log mean uranium concentration for diabase samples is -.65 ppM, and the log standard deviation is 0.27. This report is issued in draft form, without detailed technical and copy editing. This was done to make the report available to the public before the end of the NURE program.

  13. First data on the uranium content in water of the Yenisei River basin in the area affected by the operation of Rosatom plants

    NASA Astrophysics Data System (ADS)

    Bolsunovskii, A. Ya.; Zhizhaev, A. M.; Saprykin, A. I.; Degermendzhi, A. G.; Rubailo, A. I.

    2011-07-01

    This study is devoted to investigating the content of uranium isotopes in water of the Yenisei River and its tributaries within the territories affected by the operation of Rosatom plants (mining chemical combine, and electrochemical plant). Long-term monitoring of the 238U content by mass spectrometry carried out in two institutes of the Siberian Branch of the Russian Academy of Sciences first revealed the multiple excess of 238U over the background content in different areas of the Yenisei River basin, such as the region of the Yenisei River near the effluents of the mining and chemical combine (MCC), and the territories of the Bol'shaya Tel' and Kan rivers. In these regions, the 238U content in water reaches 2.1-4.0 μg/l, which exceeds its content upstream from the MCC (0.3-0.6 μg/l) by almost an order of magnitude. The studies of the isotopic composition of uranium in water samples, which were carried out at the Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, showed the presence of a technogenic isotope of uranium 236U in the samples from the Bolshaya Tel' River and revealed the deviation of the isotope ratio 238U/235U (167 ± 3 and 177 ± 3) from the equilibrium natural ratio (238U/235U = 138). These facts attest to the technogenic origin of part of the uranium in water of the Bol'shaya Tel' River connected with the activity of MCC. The excess uranium content in the Kan River requires additional studies to ascertain the fraction of uranium of technogenic origin connected with the activity of the electrochemical plant (ECP) (Fig. 1, Table 4).

  14. Uranium potential of precambrian rocks in the Raft River area of northwestern Utah and south-central Idaho. Final report

    SciTech Connect

    Black, B.A.

    1980-09-01

    A total of 1214 geochemical samples were collected and analyzed. The sampling media included 334 waters, 616 stream sediments, and 264 rocks. In addition, some stratigraphic sections of Elba and Yost Quartzites and Archean metasedimentary rock were measured and sampled and numerous radiation determinations made of the various target units. Statistical evaluation of the geochemical data permitted recognition of 156 uranium anomalies, 52 in water, 79 in stream sediment, and 25 in rock. Geographically, 68 are located in the Grouse Creek Mountains, 43 in the Raft River Mountains, and 41 in the Albion Range. Interpretation of the various data leads to the conclusion that uranium anomalies relate to sparingly and moderately soluble uraniferous heavy minerals, which occur as sparse but widely distributed magmatic, detrital, and/or metamorphically segregated components in the target lithostratigraphic units. The uraniferous minerals known to occur and believed to account for the geochemical anomalies include allanite, monazite, zircon, and apatite. In some instances samarskite may be important. These heavy minerals contain uranium and geochemically related elements, such as Th, Ce, Y, and Zr, in sufficient quantities to account for both the conspicuous lithologic preference and the generally observed low amplitude of the anomalies. The various data generated in connection with this study, as well as those available in the published literature, collectively support the conclusion that the various Precambrian W and X lithostratigraphic units pre-selected for evaluation probably lack potential to host important Precambrian quartz-pebble conglomerate uranium deposits. Moreover it is also doubted that they possess any potential to host Proterozoic unconformity-type uranium deposits.

  15. ALTERATIONS IN SEXUALLY DIMORPHIC BIOTRANSFORMATION OF TESTOSTERONE IN JUVENILE AMERICAN ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS) FROM CONTAMINATED LAKES

    EPA Science Inventory

    The goal of this study was to determine whether hepatic biotransformation of testosterone is normally sexually dimorphic in juvenile alligators and whether living in a contaminated environment affects hepatic dimorphism. Lake Woodruff served as our reference site. Moonshine Bay, ...

  16. MORPHOLOGICAL VARIATION IN HATCHLING AMERICAN ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS) FROM THREE FLORIDA LAKES

    EPA Science Inventory

    Morphological variation of 508 hatchling alligators from three lakes in north central Florida (Lakes Woodruff, Apopka, and Orange) was analyzed using multivariate statistics. Morphological variation was found among clutches as well as among lakes. Principal components analysis wa...

  17. Uranium in the Surrounding of San Marcos-Sacramento River Environment (Chihuahua, Mexico)

    PubMed Central

    Rentería-Villalobos, Marusia; Cortés, Manuel Reyes; Mantero, Juan; Manjón, Guillermo; García-Tenorio, Rafael; Herrera, Eduardo; Montero-Cabrera, Maria Elena

    2012-01-01

    The main interest of this study is to assess whether uranium deposits located in the San Marcos outcrops (NW of Chihuahua City, Mexico) could be considered as a source of U-isotopes in its surrounding environment. Uranium activity concentrations were determined in biota, ground, and surface water by either alpha or liquid scintillation spectrometries. Major ions were analyzed by ICP-OES in surface water and its suspended matter. For determining uranium activity in biota, samples were divided in parts. The results have shown a possible lixiviation and infiltration of uranium from geological substrate into the ground and surface water, and consequently, a transfer to biota. Calculated annual effective doses by ingestion suggest that U-isotopes in biota could not negligibly contribute to the neighboring population dose. By all these considerations, it is concluded that in this zone there is natural enhancement of uranium in all environmental samples analyzed in the present work. PMID:22536148

  18. Alligators, contaminants and steroid hormones.

    PubMed

    Guillette, Louis J; Edwards, Thea M; Moore, Brandon C

    2007-01-01

    Steroids are essential for successful reproduction in all vertebrate species. Over the last several decades, extensive research has indicated that exposure to various environmental pollutants can disrupt steroidogenesis and steroid signaling. Although steroidogenesis is regulated by the hypothalamic-pituitary axis, it is also modified by various paracrine and autocrine factors. Furthermore, the classical two-cell model of steroidogenesis in the developing ovarian follicle, involving the granulosa and theca cells in mammals, may not be universal. Instead, birds and probably reptiles use the two thecal compartments (theca interna and theca externa) as sites of steroid production. We have documented that embryonic or juvenile exposure to a complex mixture of contaminants from agricultural and storm water runoff leads to altered steroid hormone profiles in American alligators. Our observations suggest that alterations in plasma steroid hormone concentrations are due in part to altered gene expression, modified hepatic biotransformation and altered gonadal steroidogenesis. Future studies must examine the interplay between endocrine and paracrine regulation in the development and expression of gonadal steroidogenesis in individuals exposed to endocrine disrupting contaminants at various life stages if we are to fully understand potential detrimental outcomes.

  19. METALS AND METALLOIDS IN TISSUES OF AMERICAN ALLIGATORS IN THREE FLORIDA LAKES

    EPA Science Inventory

    Concentrations of metals and selenium were examined in tissues of American alligators (Alligator mississippiensis) from three lakes in central Florida, in one of which alligators have exhibited reproductive or developmental defects. Our overall objective was to determine whether ...

  20. Persistence of uranium groundwater plumes: contrasting mechanisms at two DOE sites in the groundwater-river interaction zone.

    PubMed

    Zachara, John M; Long, Philip E; Bargar, John; Davis, James A; Fox, Patricia; Fredrickson, Jim K; Freshley, Mark D; Konopka, Allan E; Liu, Chongxuan; McKinley, James P; Rockhold, Mark L; Williams, Kenneth H; Yabusaki, Steve B

    2013-04-01

    We examine subsurface uranium (U) plumes at two U.S. Department of Energy sites that are located near large river systems and are influenced by groundwater-river hydrologic interaction. Following surface excavation of contaminated materials, both sites were projected to naturally flush remnant uranium contamination to levels below regulatory limits (e.g., 30 μg/L or 0.126 μmol/L; U.S. EPA drinking water standard), with 10 years projected for the Hanford 300 Area (Columbia River) and 12 years for the Rifle site (Colorado River). The rate of observed uranium decrease was much lower than expected at both sites. While uncertainty remains, a comparison of current understanding suggests that the two sites have common, but also different mechanisms controlling plume persistence. At the Hanford 300 A, the persistent source is adsorbed U(VI) in the vadose zone that is released to the aquifer during spring water table excursions. The release of U(VI) from the vadose zone and its transport within the oxic, coarse-textured aquifer sediments is dominated by kinetically-limited surface complexation. Modeling implies that annual plume discharge volumes to the Columbia River are small (

  1. Persistence of uranium groundwater plumes: contrasting mechanisms at two DOE sites in the groundwater-river interaction zone.

    PubMed

    Zachara, John M; Long, Philip E; Bargar, John; Davis, James A; Fox, Patricia; Fredrickson, Jim K; Freshley, Mark D; Konopka, Allan E; Liu, Chongxuan; McKinley, James P; Rockhold, Mark L; Williams, Kenneth H; Yabusaki, Steve B

    2013-04-01

    We examine subsurface uranium (U) plumes at two U.S. Department of Energy sites that are located near large river systems and are influenced by groundwater-river hydrologic interaction. Following surface excavation of contaminated materials, both sites were projected to naturally flush remnant uranium contamination to levels below regulatory limits (e.g., 30 μg/L or 0.126 μmol/L; U.S. EPA drinking water standard), with 10 years projected for the Hanford 300 Area (Columbia River) and 12 years for the Rifle site (Colorado River). The rate of observed uranium decrease was much lower than expected at both sites. While uncertainty remains, a comparison of current understanding suggests that the two sites have common, but also different mechanisms controlling plume persistence. At the Hanford 300 A, the persistent source is adsorbed U(VI) in the vadose zone that is released to the aquifer during spring water table excursions. The release of U(VI) from the vadose zone and its transport within the oxic, coarse-textured aquifer sediments is dominated by kinetically-limited surface complexation. Modeling implies that annual plume discharge volumes to the Columbia River are small (

  2. Persistence of uranium groundwater plumes: Contrasting mechanisms at two DOE sites in the groundwater-river interaction zone

    SciTech Connect

    Zachara, John M.; Long, Philip E.; Bargar, John; Davis, James A.; Fox, Patricia M.; Fredrickson, Jim K.; Freshley, Mark D.; Konopka, Allan; Liu, Chongxuan; McKinley, James P.; Rockhold, Mark L.; Williams, Kenneth H.; Yabusaki, Steven B.

    2013-04-01

    We examine subsurface uranium (U) plumes at two U.S. Department of Energy sites that are located near large river systems and that are influenced by groundwater-river hydrologic interaction. Following surface excavation of contaminated materials, both sites were projected to naturally flush remnant uranium contamination to levels below regulatory limits (e.g., 30 µg/L or 0.126 µmol/L; U.S. EPA drinking water standard), with 10 years projected for the Hanford 300 Area (Columbia River) and 12 years for the Rifle site (Colorado River). The rate of observed uranium decrease was much lower than expected at both sites. While uncertainty remains, a comparison of current understanding suggests that the two sites have common, but also different mechanisms controlling plume persistence. At the Hanford 300 A, the persistent source is adsorbed U(VI) in the vadose zone that is released to the aquifer during spring water table excursions. The release of U(VI) from the vadose zone and its transport within the oxic, coarse-textured aquifer sediments is dominated by kinetically-limited surface complexation. Modeling implies that annual plume discharge volumes to the Columbia River are small (< one pore volume). At the Rifle site, slow oxidation of naturally reduced, contaminant U(IV) in the saturated zone and a continuous influx of U(VI) from natural, up-gradient sources influences plume persistence. Rate-limited mass transfer and surface complexation also control U(VI) migration velocity in the sub-oxic Rifle groundwater. Flux of U(VI) from the vadose zone at the Rifle site may be locally important, but it is not the dominant process that sustains the plume. A wide range in microbiologic functional diversity exists at both sites. Strains of Geobacter and other metal reducing bacteria are present at low natural abundance that are capable of enzymatic U(VI) reduction in localized zones of accumulated detrital organic carbon or after organic carbon amendment. Major differences

  3. Persistence of uranium groundwater plumes: Contrasting mechanisms at two DOE sites in the groundwater-river interaction zone

    NASA Astrophysics Data System (ADS)

    Zachara, John M.; Long, Philip E.; Bargar, John; Davis, James A.; Fox, Patricia; Fredrickson, Jim K.; Freshley, Mark D.; Konopka, Allan E.; Liu, Chongxuan; McKinley, James P.; Rockhold, Mark L.; Williams, Kenneth H.; Yabusaki, Steve B.

    2013-04-01

    We examine subsurface uranium (U) plumes at two U.S. Department of Energy sites that are located near large river systems and are influenced by groundwater-river hydrologic interaction. Following surface excavation of contaminated materials, both sites were projected to naturally flush remnant uranium contamination to levels below regulatory limits (e.g., 30 μg/L or 0.126 μmol/L; U.S. EPA drinking water standard), with 10 years projected for the Hanford 300 Area (Columbia River) and 12 years for the Rifle site (Colorado River). The rate of observed uranium decrease was much lower than expected at both sites. While uncertainty remains, a comparison of current understanding suggests that the two sites have common, but also different mechanisms controlling plume persistence. At the Hanford 300 A, the persistent source is adsorbed U(VI) in the vadose zone that is released to the aquifer during spring water table excursions. The release of U(VI) from the vadose zone and its transport within the oxic, coarse-textured aquifer sediments is dominated by kinetically-limited surface complexation. Modeling implies that annual plume discharge volumes to the Columbia River are small (< one pore volume). At the Rifle site, slow oxidation of naturally reduced, contaminant U(IV) in the saturated zone and a continuous influx of U(VI) from natural, up-gradient sources influence plume persistence. Rate-limited mass transfer and surface complexation also control U(VI) migration velocity in the sub-oxic Rifle groundwater. Flux of U(VI) from the vadose zone at the Rifle site may be locally important, but it is not the dominant process that sustains the plume. A wide range in microbiologic functional diversity exists at both sites. Strains of Geobacter and other metal reducing bacteria are present at low natural abundance that are capable of enzymatic U(VI) reduction in localized zones of accumulated detrital organic carbon or after organic carbon amendment. Major differences between

  4. Home range and movements of American alligators (Alligator mississippiensis) in an estuary habitat

    USGS Publications Warehouse

    Fujisaki, Ikuko; Hart, Kristen M.; Mazzotti, Frank J.; Cherkiss, Michael S.; Sartain-Iverson, Autumn R.; Jeffery, Brian M.; Beauchamp, Jeffrey S.; Denton, Mathew J.

    2014-01-01

    This study reveals consistent use of estuary habitat by American alligators. The alligators showed variations in their movement pattern and seasonal habitat, with movement attributable to environmental factors. Although satellite-derived locations were more dispersed compared to locations collected using VHF radio-tags, data collected from VHF tracking omitted some habitat used for a short period of time, indicating the effectiveness of satellite telemetry to continuously track animals for ecosystem-scale studies.

  5. The isolation of parvalbumin isoforms from the tail muscle of the American alligator (Alligator mississipiensis).

    PubMed

    Laney, E L; Shabanowitz, J; King, G; Hunt, D F; Nelson, D J

    1997-04-01

    Multiple parvalbumin isoforms have been detected in the tail (skeletal) muscle of the American alligator (Alligator mississipiensis). One of these isoforms (APV-1) has been highly purified and partially characterized. Protein purification involved mainly gel filtration and anion exchange chromatography, and characterization included gel electrophoresis, amino acid composition analysis, metal ion analysis, MALDI-TOF and ESI mass spectrometry, ultraviolet and fluorescence spectroscopy, and one- and two-dimensional 500 MHz proton NMR spectroscopy. The alligator isoforms are rich in phenylalanine and deficient in the other aromatic residues as is typical for parvalbumins. In fact, the one highly purified isoform that forms the basis of this study has only phenyl-alanine as an aromatic residue. Ion exchange chromatography further indicates that this isoform has a relatively high isoelectric point (pl approximately 5.0), indicating that it is an alpha-lineage parvalbumin. This alligator parvalbumin isoform is unusual in that it has an atypically high Ca2+ content (almost 3.0 mole of Ca2+ per mole of protein) following purification, a fact supported by terbium fluorescence titration experiments. Preliminary comparative analysis of the highly purified alligator parvalbumin isoform (in the Ca2-loaded state) by two-dimensional 1H-NMR (2D 1H TOCSY and 2D 1H NOESY) indicates that there is considerable similarity in structure between the alligator protein and a homologous protein obtained from the silver hake (a saltwater fish species). PMID:9076974

  6. Urinary Phthalate Metabolites in American Alligators (Alligator mississippiensis) from Selected Florida Wetlands.

    PubMed

    Brock, John W; Bell, Jane Margaret; Guillette, Louis J

    2016-07-01

    Phthalates have been shown to cause endocrine disruption in laboratory animals and are associated with altered development of the reproductive system in humans. Further, human have significant exposure to phthalates. However, little is known concerning the exposure of wildlife to phthalates. We report urinary phthalate metabolite concentrations from fifty juvenile alligators from three Florida lakes and a site in the Everglades. Urinary phthalate monoester concentrations varied widely among alligators from the different sites but also among alligators from the same site. Mono-2-ethylhexy phthalate and monobutyl phthalate were found in most samples of alligator urine with maximums of 35,700 ng/mL and 193 ng/mL, respectively. Monobenzyl phthalate was found in 5 alligators with a maximum of 66.7 ng/mL. Other monoesters were found in only one or two alligator urine samples. The wide variation within and among sites, in addition to the high levels of mEHP, mBP and mBzP, is consistent with exposure arising from the intermittent spraying of herbicide formulations to control invasive aquatic plants in Florida freshwater sites. Phthalate diesters are used as adjuvants in many of these formulations. PMID:26743198

  7. Survival and growth of American alligator (Alligator mississippiensis) hatchlings after artificial incubation and repatriation

    USGS Publications Warehouse

    Temsiripong, Y.; Woodward, A.R.; Ross, J.P.; Kubilis, P.S.; Percival, H.F.

    2006-01-01

    Hatchling American Alligators (Alligator mississippiensis) produced from artificially incubated wild eggs were returned to their natal areas (repatriated). We compared artificially incubated and repatriated hatchlings released within and outside the maternal alligator's home range with naturally incubated hatchlings captured and released within the maternal alligator's home range on Lake Apopka, Lake Griffin, and Orange Lake in Florida. We used probability of recapture and total length at approximately nine months after hatching as indices of survival and growth rates. Artificially incubated hatchlings released outside of the maternal alligator's home range had lower recapture probabilities than either naturally incubated hatchlings or artificially incubated hatchlings released near the original nest site. Recapture probabilities of other treatments did not differ significantly. Artificially incubated hatchlings were approximately 6% shorter than naturally incubated hatchlings at approximately nine months after hatching. We concluded that repatriation of hatchlings probably would not have long-term effects on populations because of the resiliency of alligator populations to alterations of early age-class survival and growth rates of the magnitude that we observed. Repatriation of hatchlings may be an economical alternative to repatriation of older juveniles for population restoration. However, the location of release may affect subsequent survival and growth. Copyright 2006 Society for the Study of Amphibians and Reptiles.

  8. Water hyacinths and alligator weeds for removal of lead and mercury from polluted waters

    NASA Technical Reports Server (NTRS)

    Wolverton, B. C.; Mcdonald, R. C.

    1975-01-01

    Removal of lead and mercury by water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxeroides) (Mart.) Griesb. was investigated. Water hyacinths demonstrated the ability to remove 0.176 mg of lead and 0.150 mg of mercury per gram of dry plant material from distilled water and river water in a 24-hour period. One acre of water hyacinths is potentially capable of removing 105.6 grams of lead and 90.0 grams of mercury per day. Alligator weeds removed 0.101 mg of lead per gram of dry plant material in a 24-hour period. This same plant also demonstrated the ability to remove a minimum of 0.153 mg of mercury per gram of dry plant material in a six hour period.

  9. Bio-gas production from alligator weeds

    NASA Technical Reports Server (NTRS)

    Latif, A.

    1976-01-01

    Laboratory experiments were conducted to study the effect of temperature, sample preparation, reducing agents, light intensity and pH of the media, on bio-gas and methane production from the microbial anaerobic decomposition of alligator weeds (Alternanthera philoxeroides. Efforts were also made for the isolation and characterization of the methanogenic bacteria.

  10. Crocodiles and Alligators. Young Discovery Library Series.

    ERIC Educational Resources Information Center

    Farre, Marie

    This book is written for children ages 5 through 10. Part of a series designed to develop their curiosity, fascinate them and educate them, this volume describes the physical characteristics, behavior, and peculiar habits of crocodiles, including how to distinguish them from close relatives such as alligators, cayman, and gharials. (YP)

  11. Alternathera philoxeroides (Martius) Grisebach - alligator weed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biological control of Alternanthera philoxeroides, alligator weed, began when George Vogt, USDA, conducted several surveys by public transport in South America during the 1960s. Three agents were released in USA and two of them, the flea beetle Agasicles hygrophila and the moth Arcola malloi were re...

  12. Elemental Levels Analyzed by PIXE in Florida Alligators

    NASA Astrophysics Data System (ADS)

    Kuharik, J. C.; Kravchenko, I. I.; Dunnam, F. E.; Van Rinsvelt, H. A.; Ross, J. P.

    2003-08-01

    Unusual and alarming mortality of alligators (Alligator mississippiensis) has been reported from Lake Griffin, Florida, where almost 400 dead alligators have been observed since 1997. In addition, the hatch rate for alligator eggs around Lake Griffin fell below 10% and remains low (30-45%) while the normal hatch rate is typically 80%. Standard diagnostic methods have been ineffective in determining the cause of the phenomenon. Many possibilities have been considered including pollutants, nutrition, and toxic algae. Particle Induced X-ray Emission (PIXE) analysis is highly suitable for investigating concentrations of a wide range of elements in animal tissue. Liver, kidney and spinal cord tissues from healthy and sick alligators have been analyzed by PIXE for elemental content. Initial results showed positive correlation between certain elements and neural impairment and morbidity of alligators in Lake Griffin, but have failed to prove significant.

  13. Elemental Levels Analyzed by PIXE in Florida Alligators

    SciTech Connect

    Kuharik, J.C.; Kravchenko, I.I.; Dunnam, F.E.; Rinsvelt, H.A. van; Ross, J.P.

    2003-08-26

    Unusual and alarming mortality of alligators (Alligator mississippiensis) has been reported from Lake Griffin, Florida, where almost 400 dead alligators have been observed since 1997. In addition, the hatch rate for alligator eggs around Lake Griffin fell below 10% and remains low (30-45%) while the normal hatch rate is typically 80%. Standard diagnostic methods have been ineffective in determining the cause of the phenomenon. Many possibilities have been considered including pollutants, nutrition, and toxic algae. Particle Induced X-ray Emission (PIXE) analysis is highly suitable for investigating concentrations of a wide range of elements in animal tissue. Liver, kidney and spinal cord tissues from healthy and sick alligators have been analyzed by PIXE for elemental content. Initial results showed positive correlation between certain elements and neural impairment and morbidity of alligators in Lake Griffin, but have failed to prove significant.

  14. A study on biliary ductal system and bile fistula in the American alligator, Alligator mississippiensis.

    PubMed

    Xu, G; Elsey, R M; Lance, V A; Javors, B; Chen, T S; Salen, G; Tint, G S

    1997-12-15

    The anomalous arrangement of bile ducts in the Crocodylia has not been fully appreciated. A clear understanding of biliary anatomy is necessary in order to create complete bile drainage in these reptiles. The object of this study was to clarify the anatomy of the bile ductal system and to establish total bile fistulas in the American alligator, Alligator mississippiensis. Bile duct anatomy was studied in 104 juvenile alligators, and bile fistulas were constructed in seven alligators. In 93 out of 104 (89%) of the juveniles dissected there was an interconnection between the right and left hepatic duct before the right hepatic duct emptied into the gallbladder. The left hepatic duct then entered the duodenum independently of the cystic duct which drained the gallbladder directly into the duodenum. In 8% of the animals, the left hepatic duct did not enter the duodenum but joined with the right duct, forming a common hepatic duct that emptied into the gallbladder. In 3% of the cases, the right hepatic duct emptied into the gallbladder, while the left duct had no communication with the right hepatic duct and drained separately into the duodenum. This arrangement of bile ducts is similar to that seen in birds and reflects the common ancestry of crocodiles and birds. In other reptiles, the biliary system shows much more variability and is different from the alligator. In five of seven alligators in which total biliary diversion was attempted, the biliary catheter remained in place and stayed patent from 2-7 weeks. Bile flow was extremely low (1.5-2.5 ml/24 h) when compared to that of mammals (80-100 ml/24 h). This study demonstrates the variable nature of the biliary ductal system in Alligator mississippiensis and suggest a method for constructing an effective total bile fistula in these animals.

  15. Levels of mercury in alligators (Alligator mississippiensis) collected along a transect through the Florida Everglades

    USGS Publications Warehouse

    Rumbold, D.G.; Fink, L.E.; Laine, K.A.; Niemczyk, S.L.; Chandrasekhar, T.; Wankel, Scott D.; Kendall, C.

    2002-01-01

    As part of a multi-agency study of alligator health, 28 American alligators (Alligator mississippiensis) were captured along a transect through the Florida Everglades in 1999. Liver and tail muscle tissues were sampled and analyzed on a wet weight basis for total mercury (THg) using cold-vapor atomic absorption spectrophotometry. All tissues had detectable concentrations of THg that ranged from 0.6 to 17 mg/kg in liver and from 0.1 to 1.8 mg/kg in tail muscle. THg was more concentrated in liver tissue than tail muscle, but levels were highly correlated between tissues. THg concentrations in tissue differed significantly among locations, with animals from Everglades National Park (ENP) having mean concentrations of THg in liver (10.4 mg/kg) and tail muscle (1.2 mg/kg) that were two-fold higher than basin-wide averages (4.9 and 0.64 mg/kg, respectively). The reasons for higher contamination of ENP alligators were unclear and could not be explained by differences in sex, length, weight or animal age. While ??15N values were positively correlated with THg concentrations in tail muscle, spatial patterns in isotopic composition did not explain the elevated THg levels in ENP alligators. Therefore, it appears that ENP alligators were more highly exposed to mercury in their environment than individuals in other areas. Comparisons to a previous survey by Yanochko et al. [Arch Environ Contam Toxicol 32 (1997) 323] suggest that mercury levels have declined in some Everglades alligators since 1994. ?? 2002 Elsevier Science B.V. All rights reserved.

  16. Identification and Characterization of the Androgen Receptor From the American Alligator, Alligator mississippiensis

    PubMed Central

    Miyagawa, Shinichi; Yatsu, Ryohei; Kohno, Satomi; Doheny, Brenna M.; Ogino, Yukiko; Ishibashi, Hiroshi; Katsu, Yoshinao; Ohta, Yasuhiko; Guillette, Louis J.

    2015-01-01

    Androgens are essential for the development, reproduction, and health throughout the life span of vertebrates, particularly during the initiation and maintenance of male sexual characteristics. Androgen signaling is mediated by the androgen receptor (AR), a member of the steroid nuclear receptor superfamily. Mounting evidence suggests that environmental factors, such as exogenous hormones or contaminants that mimic hormones, can disrupt endocrine signaling and function. The American alligator (Alligator mississippiensis), a unique model for ecological research in that it exhibits environment-dependent sex determination, is oviparous and long lived. Alligators from a contaminated environment exhibit low reproductive success and morphological disorders of the testis and phallus in neonates and juveniles, both associated with androgen signaling; thus, the alterations are hypothesized to be related to disrupted androgen signaling. However, this line of research has been limited because of a lack of information on the alligator AR gene. Here, we isolated A mississippiensis AR homologs (AmAR) and evaluated receptor-hormone/chemical interactions using a transactivation assay. We showed that AmAR responded to all natural androgens and their effects were inhibited by cotreatment with antiandrogens, such as flutamide, p,p′-dichlorodiphenyldichloroethylene, and vinclozolin. Intriguingly, we found a spliced form of the AR from alligator cDNA, which lacks seven amino acids within the ligand-binding domain that shows no response to androgens. Finally, we have initial data on a possible dominant-negative function of the spliced form of the AR against androgen-induced AmAR. PMID:25974402

  17. Blood and Plasma Biochemistry Reference Intervals for Wild Juvenile American Alligators ( Alligator mississippiensis ).

    PubMed

    Hamilton, Matthew T; Kupar, Caitlin A; Kelley, Meghan D; Finger, John W; Tuberville, Tracey D

    2016-07-01

    : American alligators ( Alligator mississippiensis ) are one of the most studied crocodilian species in the world, yet blood and plasma biochemistry information is limited for juvenile alligators in their northern range, where individuals may be exposed to extreme abiotic and biotic stressors. We collected blood samples over a 2-yr period from 37 juvenile alligators in May, June, and July to establish reference intervals for 22 blood and plasma analytes. We observed no effect of either sex or blood collection time on any analyte investigated. However, our results indicate a significant correlation between a calculated body condition index and aspartate aminotransferase and creatine kinase. Glucose, total protein, and potassium varied significantly between sampling sessions. In addition, glucose and potassium were highly correlated between the two point-of-care devices used, although they were significantly lower with the i-STAT 1 CG8+ cartridge than with the Vetscan VS2 Avian/Reptile Rotor. The reference intervals presented herein should provide baseline data for evaluating wild juvenile alligators in the northern portion of their range. PMID:27224213

  18. Identification and Characterization of the Androgen Receptor From the American Alligator, Alligator mississippiensis.

    PubMed

    Miyagawa, Shinichi; Yatsu, Ryohei; Kohno, Satomi; Doheny, Brenna M; Ogino, Yukiko; Ishibashi, Hiroshi; Katsu, Yoshinao; Ohta, Yasuhiko; Guillette, Louis J; Iguchi, Taisen

    2015-08-01

    Androgens are essential for the development, reproduction, and health throughout the life span of vertebrates, particularly during the initiation and maintenance of male sexual characteristics. Androgen signaling is mediated by the androgen receptor (AR), a member of the steroid nuclear receptor superfamily. Mounting evidence suggests that environmental factors, such as exogenous hormones or contaminants that mimic hormones, can disrupt endocrine signaling and function. The American alligator (Alligator mississippiensis), a unique model for ecological research in that it exhibits environment-dependent sex determination, is oviparous and long lived. Alligators from a contaminated environment exhibit low reproductive success and morphological disorders of the testis and phallus in neonates and juveniles, both associated with androgen signaling; thus, the alterations are hypothesized to be related to disrupted androgen signaling. However, this line of research has been limited because of a lack of information on the alligator AR gene. Here, we isolated A mississippiensis AR homologs (AmAR) and evaluated receptor-hormone/chemical interactions using a transactivation assay. We showed that AmAR responded to all natural androgens and their effects were inhibited by cotreatment with antiandrogens, such as flutamide, p,p'-dichlorodiphenyldichloroethylene, and vinclozolin. Intriguingly, we found a spliced form of the AR from alligator cDNA, which lacks seven amino acids within the ligand-binding domain that shows no response to androgens. Finally, we have initial data on a possible dominant-negative function of the spliced form of the AR against androgen-induced AmAR. PMID:25974402

  19. Uranium-bearing lignite and its relation to the White River and Arikaree formations in northwestern South Dakota and adjacent states

    USGS Publications Warehouse

    Denson, N.M.; Bachman, G.O.; Zeller, H.D.

    1954-01-01

    the original White River and Arikaree sediments. Individual maps showing the extent, thickness, and variations in mineral content of the important deposits in the Table Mountain, Cave Hills, Slim Buttes, Lodgepole, and Medicine Pole areas are included. Conditions controlling the concentration of uranium are described and their application as guides to finding additional reserves by the presently held concepts are explained and illustrated.

  20. Uranium isotopes (U-234/U-238) in rivers of the Yukon Basin (Alaska and Canada) as an aid in identifying water sources, with implications for monitoring hydrologic change in arctic regions

    USGS Publications Warehouse

    Kraemer, Thomas F.; Brabets, Timothy P.

    2012-01-01

    The ability to detect hydrologic variation in large arctic river systems is of major importance in understanding and predicting effects of climate change in high-latitude environments. Monitoring uranium isotopes (234U and 238U) in river water of the Yukon River Basin of Alaska and northwestern Canada (2001–2005) has enhanced the ability to identify water sources to rivers, as well as detect flow changes that have occurred over the 5-year study. Uranium isotopic data for the Yukon River and major tributaries (the Porcupine and Tanana rivers) identify several sources that contribute to river flow, including: deep groundwater, seasonally frozen river-valley alluvium groundwater, and high-elevation glacial melt water. The main-stem Yukon River exhibits patterns of uranium isotopic variation at several locations that reflect input from ice melt and shallow groundwater in the spring, as well as a multi-year pattern of increased variability in timing and relative amount of water supplied from higher elevations within the basin. Results of this study demonstrate both the utility of uranium isotopes in revealing sources of water in large river systems and of incorporating uranium isotope analysis in long-term monitoring of arctic river systems that attempt to assess the effects of climate change.

  1. Environmental risk assessment of compost prepared from salvinia, egeria densa, and alligator weed.

    PubMed

    Dorahy, C G; Pirie, A D; McMaster, I; Muirhead, L; Pengelly, P; Chan, K Y; Jackson, M; Barchia, I M

    2009-01-01

    Approximately 70,000 m(3) of salvinia (Salvinia molesta) was removed from the Hawkesbury-Nepean River, New South Wales (NSW), Australia, during 2004. This study assessed the risks associated with applying compost prepared from aquatic weeds (AWC) to land, namely, survival and spread of aquatic and terrestrial weeds, eutrophication of waterways, accumulation of heavy metals and phytotoxicity. The results demonstrate composting is an effective method of reducing the viability of aquatic and terrestrial weeds. However, mortality of alligator weed (Alternanthera philoxeroides), which was used as an indicator plant, was significantly (P < 0.001) correlated with the temperature within the windrows and the length of time the material was subjected to composting. Conditions within the central core of the windrow were sufficient to kill the alligator weed, although not all of the aquatic weed material was exposed to the windrows' central core. This resulted in alligator weed continuing to grow at the base of the windrow. To reduce the risk of weeds surviving and spreading in aquatic and terrestrial environments it is suggested compost windrows should be located on an appropriate hard pad to enable complete mixing of the material and ensure all material is exposed to temperatures >55 degrees C for greater than three consecutive days. The likelihood of other risks associated with the AWC was low. If composting is selected as the preferred method for managing organic material harvested from waterways, then ongoing monitoring and evaluation is required to validate the composting process and ensure consumer confidence in the final product.

  2. Analysis of the landsat remote sensing images of the types of habitats of Yangtze alligators

    NASA Astrophysics Data System (ADS)

    Huang, Zhujian; Lin, Hengzhang; Zhang, Shengkai

    1986-12-01

    The Chinese “Yangtze” alligator is a rare reptile that has been listed as an “endangered species” by the United Nations, so its preservation has become an urgent task. A study of its habitats through analysis of their Landsat images will provide a scientific basis for the government departments concerned to select the best locations for its breeding. The Chinese alligator is a subtropical reptile of freshwater rivers, lakes and ponds. Found only in China, it is now distributed only in the border region between the three provinces of Anhui, Zhejiang and Jiangsu. On the basis of previous investigations by Chinese scientists, and from an analysis and interpretation of their Landsat images, we made a special study, review, and classification of the natural environment of the alligator’s present habitats (and the modern changes in the natural background of these hatitats) so that the government departments concerned with the preservation of the reptiles may have a scientific basis for determining the best locations for the breeding and propagation of the alligator.

  3. Health assessment of free-ranging alligator snapping turtles (Macrochelys temminckii) in Georgia and Florida.

    PubMed

    Chaffin, Kristen; Norton, Terry M; Gilardi, Kirsten; Poppenga, Robert; Jensen, John B; Moler, Paul; Cray, Carolyn; Dierenfeld, Ellen S; Chen, Tai; Oliva, Marcie; Origgi, Francesco C; Gibbs, Samantha; Mazzaro, Lisa; Mazet, Jonna

    2008-07-01

    The Alligator Snapping Turtle (Macrochelys temminckii) is a large freshwater turtle endemic to river systems that drain into the Gulf of Mexico. Turtle populations were sharply reduced by commercial harvest in the 1970s and 1980s; however, the species has yet to be protected under the Endangered Species Act. While anthropogenic stressors such as habitat fragmentation and degradation and illegal capture continue to threaten populations, the degree to which disease may be contributing to any decline of the Alligator Snapping Turtle is unknown. Data were collected from 97 free-ranging Alligator Snapping Turtles in nine waterways in Florida and Georgia from 2001 to 2006. Eleven turtles were captured more than once, resulting in a total sample pool of 123. Reference ranges were established for complete blood count, plasma biochemistry values, trace metals (mercury, zinc, copper, lead, and arsenic), and nutrient parameters (vitamins A, E, D, and selenium). Variations by capture location, sex, and season were detected and likely resulted from external factors such as habitat and diet. Turtles sampled in one location were positive for tortoise herpesviral antibodies. Blood mercury values also differed among populations. This study provides justification for the use of these long-lived aquatic turtles as biologic monitors of the health of local freshwater ecosystems. PMID:18689653

  4. Very long hillslope transport timescales determined from uranium-series isotopes in river sediments from a large, tectonically stable catchment

    NASA Astrophysics Data System (ADS)

    Suresh, P. O.; Dosseto, A.; Hesse, P. P.; Handley, H. K.

    2014-10-01

    The uranium-series isotopic compositions of soils and sediments evolve in response to time and weathering conditions. Therefore, these isotopes can be used to constrain the timescales of river sediment transport. Catchment evolution depends on the sediment dynamic timescales, on which erosion imparts a major control. Erosion rates in tectonically stable catchments are expected to be lower than those in tectonically active catchments, implying longer sediment residence times in tectonically stable catchments. Mineralogical, elemental and isotopic data are presented for modern channel sediments, alluvial and colluvial deposits from the Murrumbidgee River, a large catchment in the passive margin highlands of south-eastern Australia and three of its tributaries from the headwaters to the alluvial plain. Low variability in Si-based Weathering Index indicates that there is little chemical weathering occurring in the Murrumbidgee River during sediment transport. However, quartz content increases and plagioclase content decreases downstream, indicating progressive mineralogical sorting and/or physical comminution with increasing transport distance. U-series isotopic ratios in the Murrumbidgee River trunk stream sediments show no systematic downstream variation. The weathering ages of sediments within the catchment were determined using a loss-gain model of U-series isotopes. Modern sediments from a headwater tributary, the Bredbo River at Frogs Hollow, have a weathering age of 76 ± 30 kyr but all other modern channel sediments from the length of the Murrumbidgee River and its main tributaries have weathering ages ∼400 ± 180 kyr. The two headwater colluvial deposits have weathering ages of 57 ± 13 and 47 ± 11 kyr, respectively. All the alluvial deposits have weathering ages similar to those of modern sediments. No downstream trend in weathering age is observed. Together with the soil residence time of up to 30 kyr for ridge-top soils at Frogs Hollow in the upper

  5. Assessment of the quality of groundwater and the Little Wind River in the area of a former uranium processing facility on the Wind River Reservation, Wyoming, 1987 through 2010

    USGS Publications Warehouse

    Ranalli, Anthony J.; Naftz, David L.

    2014-01-01

    In 2010, the U.S Geological Survey (USGS), in cooperation with the Wind River Environmental Quality Commission (WREQC), began an assessment of the effectiveness of the existing monitoring network at the Riverton, Wyoming, Uranium Mill Tailings Remedial Action (UMTRA) site. The USGS used existing data supplied by the U.S. Department of Energy (DOE). The study was to determine (1) seasonal variations in the direction of groundwater flow in the area of the former uranium processing facility toward the Little Wind River, (2) the extent of contaminated groundwater among the aquifers and between the aquifers and the Little Wind River, (3) whether current monitoring is adequate to establish the effectiveness of natural attenuation for the contaminants of concern, and (4) the influence of groundwater discharged from the sulfuric-acid plant on water quality in the Little Wind River.

  6. Respiratory bronchoscopy of subadult American alligators (Alligator mississippiensis) and tracheal wash evaluation.

    PubMed

    Lafortune, Maud; Göbel, Thomas; Jacobson, Elliot; Heard, Darryl; Brown, Dan; Alleman, Rick; Vliet, Kent; Harr, Kendal E; Hernandez, Jorge

    2005-03-01

    Twelve healthy approximately 3-yr-old captive-born 4.5-9 kg American alligators (Alligator mississipiensis) each had bronchoscopy and tracheal washes performed four times during a 10-mo period to evaluate seasonal respiratory microbiology and cytology. Cytologic evaluation of most samples showed a small amount of mucus and low numbers of ciliated columnar epithelium, cubodial epithelium, and keratinized squamous cells. No bacteria or parasites were observed, and there was no seasonal variation in the cytology. No significant bacterial or fungal growth was identified in any season. Hematology performed in the spring and fall evaluations showed seasonal variation in the red blood cell count, hemoglobin concentration, mean corpuscular volume, mean corpuscular hemoglobin concentration, eosinophil count, and thrombocyte count. The lower respiratory tract (at the tracheal level) of healthy subadult alligators appears to be sterile, and cytology is similar to that described in domestic mammals. PMID:17315452

  7. Low cost of pulmonary ventilation in American alligators (Alligator mississippiensis) stimulated with doxapram.

    PubMed

    Skovgaard, Nini; Crossley, Dane A; Wang, Tobias

    2016-04-01

    To determine the costs of pulmonary ventilation without imposing severe oxygen limitations or acidosis that normally accompany exposures to hypoxia or hypercapnia, we opted to pharmacologically stimulate ventilation with doxapram (5 and 10 mg kg(-1)) in alligators. Doxapram is used clinically to alleviate ventilatory depression in response to anaesthesia and acts primarily on the peripheral oxygen-sensitive chemoreceptors. Using this approach, we investigated the hypothesis that pulmonary ventilation is relatively modest in comparison to resting metabolic rate in crocodilians and equipped seven juvenile alligators with masks for concurrent determination of ventilation and oxygen uptake. Doxapram elicited a dose-dependent and up to fourfold rise in ventilation, primarily by increasing ventilatory frequency. The accompanying rise in oxygen uptake was very small; ventilation in resting animals constitutes no more than 5% of resting metabolic rate. The conclusion that pulmonary ventilation is energetically cheap is consistent with earlier studies on alligators where ventilation was stimulated by hypoxia or hypercapnia. PMID:26896538

  8. Cloning of the growth hormone cDNA of alligator gar Atractosteus spatula and its expression through larval development.

    PubMed

    Revol, Agnès; Garza Rodríguez, Maria de Lourdes; Hernández Montenegro, Víctor; Aguilera, Carlos; Barrera Saldaña, Hugo; Mendoza, Roberto

    2005-04-01

    The alligator gar (Atractosteus spatula) is the largest freshwater fish inhabiting rivers draining into the Gulf of Mexico. This primitive fish shows a fast growth rate since its early larval stages. This is attributed to the action of growth hormone (GH), an anterior pituitary gland hormone responsible for linear growth in vertebrates that can also be expressed in extrapituitary adult tissues and in fish embryos. The present research was aimed at obtaining the GH coding sequence of the alligator gar and studying its expression through larval development. A cDNA was obtained by RT-PCR, cloned and sequenced. The alligator gar GH cDNA sequence shares 98% nucleotide similarity with that reported for Lepisosteus osseus, indicating a very slow evolution of the GH within the primitive fish, in contrast with the burst of changes observed in euteleosts. Using RT-PCR and RNA nuclease protection assays, GH transcripts were detected at very high levels in eggs, embryos and in several larval stages. These data suggest that the GH may play an important role during embryogenesis in fish. The better understanding of alligator gar larval physiology will facilitate the culture of larvae and juvenile gar and consequently may allow the restoration of their natural populations. PMID:15936701

  9. Cloning of the growth hormone cDNA of alligator gar Atractosteus spatula and its expression through larval development.

    PubMed

    Revol, Agnès; Garza Rodríguez, Maria de Lourdes; Hernández Montenegro, Víctor; Aguilera, Carlos; Barrera Saldaña, Hugo; Mendoza, Roberto

    2005-04-01

    The alligator gar (Atractosteus spatula) is the largest freshwater fish inhabiting rivers draining into the Gulf of Mexico. This primitive fish shows a fast growth rate since its early larval stages. This is attributed to the action of growth hormone (GH), an anterior pituitary gland hormone responsible for linear growth in vertebrates that can also be expressed in extrapituitary adult tissues and in fish embryos. The present research was aimed at obtaining the GH coding sequence of the alligator gar and studying its expression through larval development. A cDNA was obtained by RT-PCR, cloned and sequenced. The alligator gar GH cDNA sequence shares 98% nucleotide similarity with that reported for Lepisosteus osseus, indicating a very slow evolution of the GH within the primitive fish, in contrast with the burst of changes observed in euteleosts. Using RT-PCR and RNA nuclease protection assays, GH transcripts were detected at very high levels in eggs, embryos and in several larval stages. These data suggest that the GH may play an important role during embryogenesis in fish. The better understanding of alligator gar larval physiology will facilitate the culture of larvae and juvenile gar and consequently may allow the restoration of their natural populations.

  10. A mother alligator protects her young

    NASA Technical Reports Server (NTRS)

    2000-01-01

    American alligators feed and rest in the water, and lay their eggs in dens they dig into the banks. The young alligators spend their first several weeks in these dens. The Center shares a boundary with the Merritt Island National Wildlife Refuge, which encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  11. In ovo and in vitro susceptibility of American alligators (Alligator mississippiensis) to avian influenza virus infection.

    PubMed

    Temple, Bradley L; Finger, John W; Jones, Cheryl A; Gabbard, Jon D; Jelesijevic, Tomislav; Uhl, Elizabeth W; Hogan, Robert J; Glenn, Travis C; Tompkins, S Mark

    2015-01-01

    Avian influenza has emerged as one of the most ubiquitous viruses within our biosphere. Wild aquatic birds are believed to be the primary reservoir of all influenza viruses; however, the spillover of H5N1 highly pathogenic avian influenza (HPAI) and the recent swine-origin pandemic H1N1 viruses have sparked increased interest in identifying and understanding which and how many species can be infected. Moreover, novel influenza virus sequences were recently isolated from New World bats. Crocodilians have a slow rate of molecular evolution and are the sister group to birds; thus they are a logical reptilian group to explore susceptibility to influenza virus infection and they provide a link between birds and mammals. A primary American alligator (Alligator mississippiensis) cell line, and embryos, were infected with four, low pathogenic avian influenza (LPAI) strains to assess susceptibility to infection. Embryonated alligator eggs supported virus replication, as evidenced by the influenza virus M gene and infectious virus detected in allantoic fluid and by virus antigen staining in embryo tissues. Primary alligator cells were also inoculated with the LPAI viruses and showed susceptibility based upon antigen staining; however, the requirement for trypsin to support replication in cell culture limited replication. To assess influenza virus replication in culture, primary alligator cells were inoculated with H1N1 human influenza or H5N1 HPAI viruses that replicate independent of trypsin. Both viruses replicated efficiently in culture, even at the 30 C temperature preferred by the alligator cells. This research demonstrates the ability of wild-type influenza viruses to infect and replicate within two crocodilian substrates and suggests the need for further research to assess crocodilians as a species potentially susceptible to influenza virus infection.

  12. HISTOPATHOLOGY OF GASTRIC WALL IN CHINESE ALLIGATOR ALLIGATOR SINENSIS INFECTED WITH ORTLEPPASCARIS SINENSIS (NEMATODA: ASCARIDOIDEA).

    PubMed

    Zhao, Jinhong; Wang, Shaosheng; Tu, Genjun; Zhou, Yongkang; Wu, Xiaobing; Li, Chaopin

    2015-01-01

    Crocodiles are susceptible to infection with a wide array of external and internal gastrointestinal helminths, yet little is known on the histopathology following infection or the effects of these parasites. The present study was aimed at evaluating the impact of infection by Ortleppascaris sinensis (Nematoda: Ascaridoidea) on the stomach of captive Alligator sinensis. The histological examination of the stomach revealed presence of superficial ulcer in mucous layer and granulomatous inflammation in submucous layer at entire gastric walls of the Alligator sinensis. Our findings also confirm that development of Ortleppascaris sinensis is in close association with the wall of the stomach. PMID:26319836

  13. Measurement of trace uranium-235 and plutonium-239, 240 in waste tank material at the Savannah River Site

    SciTech Connect

    Mahannah, F.N.; Maxwell, S.L. III

    1992-08-01

    At the Savannah River Site (SRS), large quantities of radioactive liquid waste are evaporated to reduce volume before eventual processing through the In-Tank Precipitation process. Actinides in the liquid waste are only slightly soluble in the highly alkaline waste solution. Since some of the actinide isotopes are fissionable, the quantities being processed through the evaporator system are of interest. To better quantify the concentration and mass of fissionable material entering the evaporator system and eventually deposited as salt, analysis of the actinide elements were necessary. The predominant fissionable actinide isotopes of interest are U{sup 235} and Pu{sup 239}. To enable the reliable measurement of these radionuclides, the Central Laboratory has developed high speed separation techniques to measure U{sup 235} content by Isotope Dilution Mass Spectrometry and Pu{sup 239,240} by alpha spectrometry. Due to the high radioactivity levels in the samples all separations are performed in shielded analytical cells. Uranium is purified and concentrated using a high speed extraction chromatography technique that employs applied vacuum and columns containing tri (2-ethylene) phosphate solvent coated on a small particle inert support. The uranium method enables measurement of U{sup 235} concentrations to 1 {times} 10{sup {minus}4} g/L. Plutonium is purified and concentrated using a high speed anion exchange technique. The Pu method enables measurements of Pu{sup 239,240} to 2 {times} 10{sup {minus}6} g/L.

  14. Measurement of trace uranium-235 and plutonium-239, 240 in waste tank material at the Savannah River Site

    SciTech Connect

    Mahannah, F.N.; Maxwell, S.L. III.

    1992-01-01

    At the Savannah River Site (SRS), large quantities of radioactive liquid waste are evaporated to reduce volume before eventual processing through the In-Tank Precipitation process. Actinides in the liquid waste are only slightly soluble in the highly alkaline waste solution. Since some of the actinide isotopes are fissionable, the quantities being processed through the evaporator system are of interest. To better quantify the concentration and mass of fissionable material entering the evaporator system and eventually deposited as salt, analysis of the actinide elements were necessary. The predominant fissionable actinide isotopes of interest are U{sup 235} and Pu{sup 239}. To enable the reliable measurement of these radionuclides, the Central Laboratory has developed high speed separation techniques to measure U{sup 235} content by Isotope Dilution Mass Spectrometry and Pu{sup 239,240} by alpha spectrometry. Due to the high radioactivity levels in the samples all separations are performed in shielded analytical cells. Uranium is purified and concentrated using a high speed extraction chromatography technique that employs applied vacuum and columns containing tri (2-ethylene) phosphate solvent coated on a small particle inert support. The uranium method enables measurement of U{sup 235} concentrations to 1 {times} 10{sup {minus}4} g/L. Plutonium is purified and concentrated using a high speed anion exchange technique. The Pu method enables measurements of Pu{sup 239,240} to 2 {times} 10{sup {minus}6} g/L.

  15. Hexavalent chromium is cytotoxic and genotoxic to American alligator cells.

    PubMed

    Wise, Sandra S; Wise, Catherine; Xie, Hong; Guillette, Louis J; Zhu, Cairong; Wise, John Pierce; Wise, John Pierce

    2016-02-01

    Metals are a common pollutant in the aquatic ecosystem. With global climate change, these levels are anticipated to rise as lower pH levels allow sediment bound metals to be released. The American alligator (Alligator mississippiensis) is an apex predator in the aquatic ecosystem and is considered a keystone species; as such it serves as a suitable monitor for localized pollution. One metal of increasing concern is hexavalent chromium (Cr(VI)). It is present in the aquatic environment and is a known human carcinogen and reproductive toxicant. We measured the cytotoxicity and genotoxicity of Cr(VI) in American alligator cells derived from scute tissue. We found that particulate and soluble Cr(VI) are both cytotoxic and genotoxic to alligator cells in a concentration-dependent manner. These data suggest that alligators may be used as a model for assessing the effects of environmental Cr(VI) contamination as well as for other metals of concern. PMID:26730726

  16. Hexavalent chromium is cytotoxic and genotoxic to American alligator cells.

    PubMed

    Wise, Sandra S; Wise, Catherine; Xie, Hong; Guillette, Louis J; Zhu, Cairong; Wise, John Pierce; Wise, John Pierce

    2016-02-01

    Metals are a common pollutant in the aquatic ecosystem. With global climate change, these levels are anticipated to rise as lower pH levels allow sediment bound metals to be released. The American alligator (Alligator mississippiensis) is an apex predator in the aquatic ecosystem and is considered a keystone species; as such it serves as a suitable monitor for localized pollution. One metal of increasing concern is hexavalent chromium (Cr(VI)). It is present in the aquatic environment and is a known human carcinogen and reproductive toxicant. We measured the cytotoxicity and genotoxicity of Cr(VI) in American alligator cells derived from scute tissue. We found that particulate and soluble Cr(VI) are both cytotoxic and genotoxic to alligator cells in a concentration-dependent manner. These data suggest that alligators may be used as a model for assessing the effects of environmental Cr(VI) contamination as well as for other metals of concern.

  17. Pathology, physiologic parameters, tissue contaminants, and tissue thiamine in morbid and healthy central Florida adult American alligators (Alligator mississippiensis)

    USGS Publications Warehouse

    Honeyfield, D.C.; Ross, J.P.; Carbonneau, D.A.; Terrell, S.P.; Woodward, A.R.; Schoeb, T.R.; Perceval, H.F.; Hinterkopf, J.P.

    2008-01-01

    An investigation of adult alligator (Alligator mississippiensis) mortalities in Lake Griffin, central Florida, was conducted from 1998-2004. Alligator mortality was highest in the months of April and May and annual death count peaked in 2000. Bacterial pathogens, heavy metals, and pesticides were not linked with the mortalities. Blood chemistry did not point to any clinical diagnosis, although differences between impaired and normal animals were noted. Captured alligators with signs of neurologic impairment displayed unresponsive and uncoordinated behavior. Three of 21 impaired Lake Griffin alligators were found to have neural lesions characteristic of thiamine deficiency in the telencephalon, particularly the dorsal ventricular ridge. In some cases, lesions were found in the thalamus, and parts of the midbrain. Liver and muscle tissue concentrations of thiamine (vitamin B"1) were lowest in impaired Lake Griffin alligators when compared to unimpaired alligators or to alligators from Lake Woodruff. The consumption of thiaminase-positive gizzard shad (Dorosoma cepedianum) is thought to have been the cause of the low tissue thiamine and resulting mortalities. ?? Wildlife Disease Association 2008.

  18. Global DNA methylation loss associated with mercury contamination and aging in the American alligator (Alligator mississippiensis).

    PubMed

    Nilsen, Frances M; Parrott, Benjamin B; Bowden, John A; Kassim, Brittany L; Somerville, Stephen E; Bryan, Teresa A; Bryan, Colleen E; Lange, Ted R; Delaney, J Patrick; Brunell, Arnold M; Long, Stephen E; Guillette, Louis J

    2016-03-01

    Mercury is a widespread environmental contaminant with exposures eliciting a well-documented catalog of adverse effects. Yet, knowledge regarding the underlying mechanisms by which mercury exposures are translated into biological effects remains incomplete. DNA methylation is an epigenetic modification that is sensitive to environmental cues, and alterations in DNA methylation at the global level are associated with a variety of diseases. Using a liquid chromatography tandem mass spectrometry-based (LC-MS/MS) approach, global DNA methylation levels were measured in red blood cells of 144 wild American alligators (Alligator mississippiensis) from 6 sites with variable levels of mercury contamination across Florida's north-south axis. Variation in mercury concentrations measured in whole blood was highly associated with location, allowing the comparison of global DNA methylation levels across different "treatments" of mercury. Global DNA methylation in alligators across all locations was weakly associated with increased mercury exposure. However, a much more robust relationship was observed in those animals sampled from locations more highly contaminated with mercury. Also, similar to other vertebrates, global DNA methylation appears to decline with age in alligators. The relationship between age-associated loss of global DNA methylation and varying mercury exposures was examined to reveal a potential interaction. These findings demonstrate that global DNA methylation levels are associated with mercury exposure, and give insights into interactions between contaminants, aging, and epigenetics.

  19. Perfluorinated Alkyl Acids in Plasma of American Alligators (Alligator Mississippiensis) from Florida and South Carolina

    NASA Technical Reports Server (NTRS)

    Bangma, Jacqueline T.; Bowden, John A.; Brunell, Arnold M.; Christie, Ian; Finnell, Brendan; Guillette, Matthew P.; Jones, Martin; Lowers, Russell H.; Rainwater, Thomas R.; Reiner, Jessica L.; Wilkinson, Philip M.; Guillette, Louis J., Jr.

    2016-01-01

    This study aimed to quantitate fourteen perfluoroalkyl acids (PFAAs) in 125 adult American alligators at twelve sites across the southeastern US. Of those fourteen PFAAs, nine were detected in 65% - 100% of the samples: PFOA, PFNA, PFDA, PFUnA, PFDoA, PFTriA, PFTA, PFHxS, and PFOS. Males (across all sites) showed significantly higher concentrations of four PFAAs: PFOS (p = 0.01), PFDA (p = 0.0003), PFUnA (p = 0.021), and PFTriA (p = 0.021). Concentrations of PFOS, PFHxS, and PFDA in plasma were significantly different among the sites in each sex. Alligators at Merritt Island National Wildlife Refuge and Kiawah Nature Conservancy both exhibited some of the highest PFOS concentrations (medians 99.5 ng/g and 55.8 ng/g respectively) in plasma measured to date in a crocodilian species. A number of positive correlations between PFAAs and snout-vent length (SVL) were observed in both sexes suggesting PFAA body burdens increase with increasing size. In addition, several significant correlations among PFAAs in alligator plasma may suggest conserved sources of PFAAs at each site throughout the greater study area. This study is the first to report PFAAs in American alligators, reveals potential PFAA hot spots in Florida and South Carolina, and provides and additional contaminant of concern when assessing anthropogenic impacts on ecosystem health.

  20. Periods of cardiovascular susceptibility to hypoxia in embryonic american alligators (Alligator mississippiensis).

    PubMed

    Tate, Kevin B; Rhen, Turk; Eme, John; Kohl, Zachary F; Crossley, Janna; Elsey, Ruth M; Crossley, Dane A

    2016-06-01

    During embryonic development, environmental perturbations can affect organisms' developing phenotype, a process known as developmental plasticity. Resulting phenotypic changes can occur during discrete, critical windows of development. Critical windows are periods when developing embryos are most susceptible to these perturbations. We have previously documented that hypoxia reduces embryo size and increases relative heart mass in American alligator, and this study identified critical windows when hypoxia altered morphological, cardiovascular function and cardiac gene expression of alligator embryos. We hypothesized that incubation in hypoxia (10% O2) would increase relative cardiac size due to cardiac enlargement rather than suppression of somatic growth. We exposed alligator embryos to hypoxia during discrete incubation periods to target windows where the embryonic phenotype is altered. Hypoxia affected heart growth between 20 and 40% of embryonic incubation, whereas somatic growth was affected between 70 and 90% of incubation. Arterial pressure was depressed by hypoxic exposure during 50-70% of incubation, whereas heart rate was depressed in embryos exposed to hypoxia during a period spanning 70-90% of incubation. Expression of Vegf and PdgfB was increased in certain hypoxia-exposed embryo treatment groups, and hypoxia toward the end of incubation altered β-adrenergic tone for arterial pressure and heart rate. It is well known that hypoxia exposure can alter embryonic development, and in the present study, we have identified brief, discrete windows that alter the morphology, cardiovascular physiology, and gene expression in embryonic American alligator. PMID:27101296

  1. Persistent halogenated compounds in captive Chinese alligators (Alligator sinensis) from China.

    PubMed

    Wu, Ting; Hong, Bing; Wu, Xiaobing; Wu, Jiangping; Wang, Xinming; Yi, Zhigang; Zhao, Juan; Zhan, Miao; Mai, Bixian

    2014-09-01

    While a number of studies have reported residual levels of persistent halogenated compounds (PHCs) in crocodilia, there is still a dearth of information on the Chinese alligator, a critically endangered crocodilian species. In the present study, several PHCs, including polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and dichlorodiphenyltrichloroethane and its metabolites (DDTs), were detected in the adult tissues, neonates, and eggs of captive Chinese alligators from China. The concentrations of ΣPBDEs, ΣPCBs, and ΣDDTs in Chinese alligators ranged from 0.11 to 16.1, 1.12 to 22.2, and 6.03 to 1020ngg(-1) wet weight, respectively, with higher levels of ΣPCBs and ΣDDTs in the neonates and eggs than in muscle tissues. The ΣDDT residues in the studied Chinese alligators were at the high end of reported ranges from crocodilia around the world, and some results exceeded levels known to cause a female-biased sex ratio in crocodilians.

  2. Periods of cardiovascular susceptibility to hypoxia in embryonic american alligators (Alligator mississippiensis).

    PubMed

    Tate, Kevin B; Rhen, Turk; Eme, John; Kohl, Zachary F; Crossley, Janna; Elsey, Ruth M; Crossley, Dane A

    2016-06-01

    During embryonic development, environmental perturbations can affect organisms' developing phenotype, a process known as developmental plasticity. Resulting phenotypic changes can occur during discrete, critical windows of development. Critical windows are periods when developing embryos are most susceptible to these perturbations. We have previously documented that hypoxia reduces embryo size and increases relative heart mass in American alligator, and this study identified critical windows when hypoxia altered morphological, cardiovascular function and cardiac gene expression of alligator embryos. We hypothesized that incubation in hypoxia (10% O2) would increase relative cardiac size due to cardiac enlargement rather than suppression of somatic growth. We exposed alligator embryos to hypoxia during discrete incubation periods to target windows where the embryonic phenotype is altered. Hypoxia affected heart growth between 20 and 40% of embryonic incubation, whereas somatic growth was affected between 70 and 90% of incubation. Arterial pressure was depressed by hypoxic exposure during 50-70% of incubation, whereas heart rate was depressed in embryos exposed to hypoxia during a period spanning 70-90% of incubation. Expression of Vegf and PdgfB was increased in certain hypoxia-exposed embryo treatment groups, and hypoxia toward the end of incubation altered β-adrenergic tone for arterial pressure and heart rate. It is well known that hypoxia exposure can alter embryonic development, and in the present study, we have identified brief, discrete windows that alter the morphology, cardiovascular physiology, and gene expression in embryonic American alligator.

  3. Global DNA methylation loss associated with mercury contamination and aging in the American alligator (Alligator mississippiensis).

    PubMed

    Nilsen, Frances M; Parrott, Benjamin B; Bowden, John A; Kassim, Brittany L; Somerville, Stephen E; Bryan, Teresa A; Bryan, Colleen E; Lange, Ted R; Delaney, J Patrick; Brunell, Arnold M; Long, Stephen E; Guillette, Louis J

    2016-03-01

    Mercury is a widespread environmental contaminant with exposures eliciting a well-documented catalog of adverse effects. Yet, knowledge regarding the underlying mechanisms by which mercury exposures are translated into biological effects remains incomplete. DNA methylation is an epigenetic modification that is sensitive to environmental cues, and alterations in DNA methylation at the global level are associated with a variety of diseases. Using a liquid chromatography tandem mass spectrometry-based (LC-MS/MS) approach, global DNA methylation levels were measured in red blood cells of 144 wild American alligators (Alligator mississippiensis) from 6 sites with variable levels of mercury contamination across Florida's north-south axis. Variation in mercury concentrations measured in whole blood was highly associated with location, allowing the comparison of global DNA methylation levels across different "treatments" of mercury. Global DNA methylation in alligators across all locations was weakly associated with increased mercury exposure. However, a much more robust relationship was observed in those animals sampled from locations more highly contaminated with mercury. Also, similar to other vertebrates, global DNA methylation appears to decline with age in alligators. The relationship between age-associated loss of global DNA methylation and varying mercury exposures was examined to reveal a potential interaction. These findings demonstrate that global DNA methylation levels are associated with mercury exposure, and give insights into interactions between contaminants, aging, and epigenetics. PMID:26748003

  4. Molecular and functional characterization of BAFF from the Yangtze alligator (Alligator sinensis, Alligatoridae).

    PubMed

    Zhang, Jia-Xin; Song, Ren; Sang, Ming; Sun, Si-Qing; Ma, Lei; Zhang, Jie; Zhang, Shuang-Quan

    2015-10-01

    B-cell activating factor (BAFF) from the TNF family is critical for B-cell survival and maturation. In this study, we identified a Yangtze alligator (Alligator sinensis, Alligatoridae) BAFF cDNA, designated as asBAFF, using reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The open reading frame of this cDNA encodes a 287-amino acid protein containing a predicted transmembrane domain and a furin protease cleavage site, similar to mammalian and avian BAFF. The amino acid identity between biologically soluble asBAFF (assBAFF) and csBAFF, hsBAFF, and msBAFF is 94, 76, and 71%, respectively. Real-time quantitative PCR analysis showed that the asBAFF gene is strongly expressed in the spleen. Since BAFF is always expressed as inclusion bodies in bacteria, it is difficult to purify. To enhance the soluble expression of assBAFF in Escherichia coli, we fused the extracellular region of the asBAFF gene to a small ubiquitin-related modifier gene (SUMO). Purified assBAFF was able to promote the survival of splenic lymphocytes and co-stimulate the proliferation of mouse B cells with anti-mouse IgM. These findings suggest that asBAFF plays an important role in the survival and proliferation of Yangtze alligator B cells, and because it is evolutionarily highly conserved, functional cross-reactivity exists between mammalian and Yangtze alligator BAFF. PMID:26116474

  5. Polychlorinated biphenyls in eggs and chlorioallantoic membranes of American alligators (Alligator mississippiensis) from coastal South Carolina

    SciTech Connect

    Cobb, G.P.; Wood, P.D.; O`Quinn, M.

    1997-07-01

    Assessing chemical exposure in threatened or endangered wildlife species presents unique analytical problems. Chorioallantoic membranes (CAMs) have been proposed as surrogate tissues for evaluation of polychlorinated biphenyl (PCB) exposure in oviparous species. Research was undertaken to determine the extent of PCB accumulation in alligators (Alligator mississippiensis) at sites along the coast of South Carolina and to evaluate the utility of CAMs as surrogate tissues for determining PCB concentrations in whole alligator eggs. Polychlorinated biphenyls were found in eggs and CAMs of alligators from both sites examined. Concentrations of PCBs were higher in CAMs (p = 0.02) and eggs (p = 0.001) from sites known to contain chlorinated hydrocarbons than from more pristine sites. Total PCBs partitioned predictably (r{sup 2} > 0.59; p < 0.02) between egg and CAM tissues indicating the utility of CAMs to serve as surrogate tissues when comparing total PCB concentrations in whole eggs. Tetrachloro through octachloro biphenyl homologues and total PCBs in CAMs from reference areas were correlated with concentrations of these homologues in eggs. At contaminated sites, total PCB concentrations in CAMs were correlated with total PCB concentrations in eggs.

  6. Global DNA methylation loss associated with mercury contamination and aging in the American alligator (Alligator mississippiensis)

    PubMed Central

    Nilsen, Frances M.; Parrott, Benjamin B.; Bowden, John A.; Kassim, Brittany L.; Somerville, Stephen E.; Bryan, Teresa A.; Bryan, Colleen E.; Lange, Ted R.; Delaney, J. Patrick; Brunell, Arnold M.; Long, Stephen E.; Guillette, Louis J.

    2016-01-01

    Mercury is a widespread environmental contaminant with exposures eliciting a well-documented catalog of adverse effects. Yet, knowledge regarding the underlying mechanisms by which mercury exposures are translated into biological effects remains incomplete. DNA methylation is an epigenetic modification that is sensitive to environmental cues, and alterations in DNA methylation at the global level are associated with a variety of diseases. Using a liquid chromatography tandem mass spectrometry-based (LC-MS/MS) approach, global DNA methylation levels were measured in red blood cells of 144 wild American alligators (Alligator mississippiensis) from 6 sites with variable levels of mercury contamination across Florida’s north-south axis. Variation in mercury concentrations measured in whole blood was highly associated with location, allowing the comparison of global DNA methylation levels across different “treatments” of mercury. Global DNA methylation in alligators across all locations was weakly associated with increased mercury exposure. However, a much more robust relationship was observed in those animals sampled from locations more highly contaminated with mercury. Also, similar to other vertebrates, global DNA methylation appears to decline with age in alligators. The relationship between age-associated loss of global DNA methylation and varying mercury exposures was examined to reveal a potential interaction. These findings demonstrate that global DNA methylation levels are associated with mercury exposure, and give insights into interactions between contaminants, aging, and epigenetics. PMID:26748003

  7. Characterization of microsatellite DNA markers for the alligator snapping turtle, Macrochelys temminckii: Primer note

    USGS Publications Warehouse

    Hackler, J.C.; Van Den Bussche, Ronald A.; Leslie, David M.

    2007-01-01

    Two trinucleotide and seven tetranucleotide microsatellite loci were isolated from an alligator snapping turtle Macrochelys temminckii. To assess the degree of variability in these nine microsatellite loci, we genotyped 174 individuals collected from eight river drainage basins in the southeastern USA. These markers revealed a moderate degree of allelic diversity (six to 16 alleles per locus) and observed heterozygosity (0.166-0.686). These polymorphic microsatellite loci provide powerful tools for population genetic studies for a species that is afforded some level of conservation protection in every state in which it occurs. ?? 2006 The Authors.

  8. Fluctuating water depths affect American alligator (Alligator mississippiensis) body condition in the Everglades, Florida, USA

    USGS Publications Warehouse

    Brandt, Laura A.; Beauchamp, Jeffrey S.; Jeffery, Brian M.; Cherkiss, Michael S.; Mazzotti, Frank J.

    2016-01-01

    Successful restoration of wetland ecosystems requires knowledge of wetland hydrologic patterns and an understanding of how those patterns affect wetland plant and animal populations.Within the Everglades, Florida, USA restoration, an applied science strategy including conceptual ecological models linking drivers to indicators is being used to organize current scientific understanding to support restoration efforts. A key driver of the ecosystem affecting the distribution and abundance of organisms is the timing, distribution, and volume of water flows that result in water depth patterns across the landscape. American alligators (Alligator mississippiensis) are one of the ecological indicators being used to assess Everglades restoration because they are a keystone species and integrate biological impacts of hydrological operations through all life stages. Alligator body condition (the relative fatness of an animal) is one of the metrics being used and targets have been set to allow us to track progress. We examined trends in alligator body condition using Fulton’s K over a 15 year period (2000–2014) at seven different wetland areas within the Everglades ecosystem, assessed patterns and trends relative to restoration targets, and related those trends to hydrologic variables. We developed a series of 17 a priori hypotheses that we tested with an information theoretic approach to identify which hydrologic factors affect alligator body condition. Alligator body condition was highest throughout the Everglades during the early 2000s and is approximately 5–10% lower now (2014). Values have varied by year, area, and hydrology. Body condition was positively correlated with range in water depth and fall water depth. Our top model was the “Current” model and included variables that describe current year hydrology (spring depth, fall depth, hydroperiod, range, interaction of range and fall depth, interaction of range and hydroperiod). Across all models, interaction

  9. Variations in hepatic biomarkers in American alligators (Alligator mississippiensis) from three sites in Florida, USA.

    PubMed

    Gunderson, Mark P; Pickett, Melissa A; Martin, Justin T; Hulse, Elizabeth J; Smith, Spenser S; Smith, Levi A; Campbell, Rachel M; Lowers, Russell H; Boggs, Ashley S P; Guillette, Louis J

    2016-07-01

    Sub-individual biomarkers are sub-lethal biological responses commonly used in the assessment of wildlife exposure to environmental contaminants. In this study, we examined the activity of glutathione-s-transferase (GST) and lactate dehydrogenase (LDH), and metallothionein (MT) concentrations among captive-raised alligator hatchlings, wild-caught juveniles, and wild-caught adults. Juveniles and adults were collected from three locations in Florida (USA) with varying degrees of contamination (i.e. Lake Apopka (organochlorine polluted site), Merritt Island National Wildlife Refuge (NWR) (metal polluted site), and Lake Woodruff NWR (reference site)). We examined whether changes in the response of these three biomarkers were age and sex dependent or reflected site-specific variations of environmental contaminants. Juvenile alligators from Merritt Island NWR had higher MT concentrations and lower GST activity compared to those from the other two sites. This outcome was consistent with higher metal pollution at this location. Sexually dimorphic patterns of MT and GST (F > M) were observed in juvenile alligators from all sites, although this pattern was not observed in adults. GST activity was lower in captive-raised alligators from Lake Apopka and Merritt Island NWR as compared to animals from Lake Woodruff NWR, suggesting a possible developmental modulator at these sites. No clear patterns were observed in LDH activity. We concluded that GST and MT demonstrate age and sex specific patterns in the alligators inhabiting these study sites and that the observed variation among sites could be due to differences in contaminant exposure. PMID:27111470

  10. Influence of calcite on uranium(VI) reactive transport in the groundwater–river mixing zone

    SciTech Connect

    Ma, Rui; Liu, Chongxuan; Greskowiak, Janek; Prommer, Henning; Zachara, John M.; Zheng, Chunmiao

    2014-01-23

    Calcite is an important mineral that can affect uranyl reactive transport in subsurface sediments. This study investigated the distribution of calcite and its influence on uranyl adsorption and reactive transport in the groundwater-river mixing zone at US Hanford 300A, Washington State. Simulations using a 2D reactive transport model under field-relevant hydrogeochemical conditions revealed a complex distribution of calcite concentration as a result of dynamic groundwater-river interactions. The calcite concentration distribution in turn affected the spatial and temporal changes in aqueous carbonate, calcium, and pH, which subsequently influenced U(VI) mobility and discharge rates into the river. The results implied that calcite distribution and its concentration dynamics is an important consideration for field characterization, monitoring, and reactive transport prediction.

  11. Uranium(VI) adsorption and surface complexation modeling onto background sediments from the F-Area Savannah River Site.

    PubMed

    Dong, Wenming; Tokunaga, Tetsu K; Davis, James A; Wan, Jiamin

    2012-02-01

    The mobility of an acidic uranium waste plume in the F-Area of Savannah River Site is of great concern. In order to understand and predict uranium mobility, U(VI) adsorption experiments were performed as a function of pH using background F-Area aquifer sediments and reference goethite and kaolinite (major reactive phases of F-Area sediments), and a component-additivity (CA) based surface complexation model (SCM) was developed. Our experimental results indicate that the fine fractions (≤45 μm) in sediments control U(VI) adsorption due to their large surface area, although the quartz sands show a stronger adsorption ability per unit surface area than the fine fractions at pH < 5.0. Kaolinite is a more important sorbent for U(VI) at pH < 4.0, while goethite plays a major role at pH > 4.0. Our CA model combines an existing U(VI) SCM for goethite and a modified U(VI) SCM for kaolinite along with estimated relative surface area abundances of these component minerals. The modeling approach successfully predicts U(VI) adsorption behavior by the background F-Area sediments. The model suggests that exchange sites on kaolinite dominate U(VI) adsorption at pH < 4.0, goethite and kaolinite edge sites cocontribute to U(VI) adsorption at pH 4.0-6.0, and goethite dominates U(VI) adsorption at pH > 6.0.

  12. Umbilical scarring in hatchling American alligators

    USGS Publications Warehouse

    Wiebe, J.J.; Sepulveda, M.S.; Buckland, J.E.; Anderson, S.R.; Gross, T.S.

    2004-01-01

    Umbilical scarring is the presence of excess scar tissue deposited between abdominal dermal layers at the site of yolk sac absorption in hatchling American alligators (Alligator mississippiensis). The presence of this dermal condition plays a key evaluatory role in the overall quality and subsequent value for various commercial leather products. Despite the prevalent nature of this condition, currently the industry has no standardized protocols for its quantification. The objectives of this study were to examine the relationship between hatchling weight and age and incidence of umbilical scarring and to develop a quantifiable and reproducible technique to measure this dermal condition in hatchling American alligators. Thirty eggs from each of nine clutches were incubated in two separate incubators at different facilities and hatchling umbilical scarring was measured at 2 and 10 days of age using digital calipers. Umbilical area was calculated by multiplying umbilical length times umbilical width. There was a significant effect of both age and clutch on umbilical area (overall decline of 64%) by 10 days post-hatch. However, only five of the nine clutches utilized expressed a noticeable decline in the size of this dermal condition (range 67-74%). We had hypothesized that larger hatchlings would have larger umbilical areas and a slower rate of improvement in this condition during the first few days post-hatch. The differences in umbilical area and percent decline with age across clutches, however, were not associated with differences in initial hatchling weights. Within clutches and time periods, hatchling weight had no significant effect on the size and/or rate of decline of this condition. ?? 2004 Published by Elsevier B.V.

  13. WILDLIFE - ALLIGATOR BEGINS TO CROSS KENNEDY PARKWAY

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Harold O'Connor, manager of the Merritt Island Wildlife Refuge, watches a 10-foot-long alligator inch its way toward a busy highway at the Kennedy Space Center. O'Connor, aided by assistant Jerome Carroll, not shown, guided the large gator to safety in a nearby pond, several miles south of the Vehicle Assembly Building, in background. The Apollo 12 astronauts will be launched no earlier than November 14, 1969, from the Kennedy Space Center on the Nation's second manned lunar landing mission.

  14. American Alligator Research on the Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Lowers, Russell H.

    2010-01-01

    This slide presentation reviews the research conducted at the Kennedy Space Center on the American Alligator. The objectives of the research were to establish life history baseline at the Kennedy Space Center and at the Merit Island National Wildlife Reserve (MINWR). Some of the factors that were examined are: nesting success, movement patterns, and population structure. Another objective was to determine the overall health of the alligator population, by analyzing blood and tissue chemistry, and urine analysis. A third objective was to compare alligators at KSC/MINWR to the statewide population. Some of the results are shown in charts and graphs.

  15. ENDOCRINE DISRUPTING CONTAMINANTS AND ALLIGATOR EMBRYOS: A LESSON FROM WILDLIFE?

    EPA Science Inventory

    Many xenobiotic compounds introduced into the environment by human activity adversely affect wildlife. A number of these contaminants have been hypothesized to induce non lethal, multigenerational effects by acting as endocrine disrupting agents. One case is that of the alligator...

  16. An alligator basks in the sun at KSC.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    On the bank of a levee near Schwartz Rd. at Kennedy Space Center, an alligator suns itself with a wary eye out for trespassers. Nearly 5,000 alligators can be found in canals, ponds, and waterways throughout the Center and the Merritt Island National Wildlife Refuge, which shares a boundary with the Center. American alligators feed and rest in the water, and lay their eggs in dens they dig into the banks. The young alligators spend their first several weeks in these dens. The Wildlife Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  17. 109. Doughton Park Recreation Area. View of alligator back and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    109. Doughton Park Recreation Area. View of alligator back and the parkway seen from bluff mountain. Looking west. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  18. Persistent Organochlorine Pesticides and their Metabolites in Alligator Livers from Lakes Apopka and Woodruff, Florida, USA

    EPA Science Inventory

    Reproductive disorders in American alligators (Alligator mississippiensis) inhabiting Lake Apopka, Florida, have been observed for several years. Such disorders are hypothesized to be caused by endocrine disrupting contaminants occurring in the Lake due to pesticide spills and ...

  19. Uranium-bearing minerals in placer deposits of the Red River Valley, Elk City district, Idaho County, Idaho

    USGS Publications Warehouse

    Armstrong, F.C.; Weis, P.L.

    1955-01-01

    The nonmagnetic, non-radioactive fractions of the samples assayed 0.2 percent niobium, but no columbite was recognized in the samples. The uranium-bearing placer mineals are brannerite. euxenitte, davidite. betafite, and also contain niobium; ilmenite in the gravels may also contain some niobium. Pegmatites are believed to be the somce of the uranium- and niobium-bearing minerals, but the possibility of finding a pegmatite in the area ,that can be mined economically for uranium or niobium is remote.

  20. Occurrence and distribution of dissolved solids, selenium, and uranium in groundwater and surface water in the Arkansas River Basin from the headwaters to Coolidge, Kansas, 1970-2009

    USGS Publications Warehouse

    Miller, Lisa D.; Watts, Kenneth R.; Ortiz, Roderick F.; ,

    2010-01-01

    In 2007, the U.S. Geological Survey (USGS), in cooperation with City of Aurora, Colorado Springs Utilities, Colorado Water Conservation Board, Lower Arkansas Valley Water Conservancy District, Pueblo Board of Water Works, Southeastern Colorado Water Activity Enterprise, Southeastern Colorado Water Conservancy District, and Upper Arkansas Water Conservancy District began a retrospective evaluation to characterize the occurrence and distribution of dissolved-solids (DS), selenium, and uranium concentrations in groundwater and surface water in the Arkansas River Basin based on available water-quality data collected by several agencies. This report summarizes and characterizes available DS, dissolved-selenium, and dissolved-uranium concentrations in groundwater and surface water for 1970-2009 and describes DS, dissolved-selenium, and dissolved-uranium loads in surface water along the main-stem Arkansas River and selected tributary and diversion sites from the headwaters near Leadville, Colorado, to the USGS 07137500 Arkansas River near Coolidge, Kansas (Ark Coolidge), streamgage, a drainage area of 25,410 square miles. Dissolved-solids concentrations varied spatially in groundwater and surface water in the Arkansas River Basin. Dissolved-solids concentrations in groundwater from Quaternary alluvial, glacial drift, and wind-laid deposits (HSU 1) increased downgradient with median values of about 220 mg/L in the Upper Arkansas subbasin (Arkansas River Basin from the headwaters to Pueblo Reservoir) to about 3,400 mg/L in the Lower Arkansas subbasin (Arkansas River Basin from John Martin Reservoir to Ark Coolidge). Dissolved-solids concentrations in the Arkansas River also increased substantially in the downstream direction between the USGS 07086000 Arkansas River at Granite, Colorado (Ark Granite), and Ark Coolidge streamgages. Based on periodic data collected from 1976-2007, median DS concentrations in the Arkansas River ranged from about 64 mg/L at Ark Granite to about

  1. Unidirectional airflow in the lungs of alligators.

    PubMed

    Farmer, C G; Sanders, Kent

    2010-01-15

    The lungs of birds move air in only one direction during both inspiration and expiration through most of the tubular gas-exchanging bronchi (parabronchi), whereas in the lungs of mammals and presumably other vertebrates, air moves tidally into and out of terminal gas-exchange structures, which are cul-de-sacs. Unidirectional flow purportedly depends on bellowslike ventilation by air sacs and may have evolved to meet the high aerobic demands of sustained flight. Here, we show that air flows unidirectionally through parabronchi in the lungs of the American alligator, an amphibious ectotherm without air sacs, which suggests that this pattern dates back to the basal archosaurs of the Triassic and may have been present in their nondinosaur descendants (phytosaurs, aetosaurs, rauisuchians, crocodylomorphs, and pterosaurs) as well as in dinosaurs. PMID:20075253

  2. Ontogenetic development of otoliths in Alligator Gar

    USGS Publications Warehouse

    Long, James M.; Snow, Richard A.

    2016-01-01

    The Alligator Gar Atractosteus spatula is a species of conservation concern throughout its range, and better definition of otoliths during early development would aid understanding its life history and ecology. We conducted X-ray computed tomography scans, scanning electron microscopy, and light microscopy to examine the three pairs of otoliths and how they developed over time in relation to fish size and age. The sagittae are the largest, possessing distinct dorsal and ventral lobes covered with small otoconia concentrated in the sulcul region. The sagittae exhibited allometric growth, increasing more rapidly in the ventral lobe than in the dorsal. The asterisci were smaller and also exhibited small otoconia on their surface, but much less than the sagittae. The lapilli were oriented laterally, in contrast to the sagittae and asterisci, which were oriented vertically, with a hump on the dorsum and very large otoconia on the lateral surface that appeared to fuse into the main otolith as the fish grew. Based on size measurements and ring counts in all three pairs of otoliths from 101 known-age Alligator Gar sampled weekly through 91 d after hatch, we developed regression models to examine otolith growth and predict age. All relationships were significant and highly explanatory, but the strongest relationships were between otolith and fish size (for measurements from sagittae) and for age predictions from the lapillus. Age prediction models all resulted in a slope near unity, indicating that ring deposition occurred approximately daily. The first ring in sagittae and lapilli corresponded to swim-up, whereas the first ring formed in asterisci approximately 8 d after swim-up. These results fill a gap in knowledge and can aid understanding of evolutionary processes as well as provide useful information for management and conservation.

  3. SAVANNAH RIVER SITE'S H-CANYON FACILITY: RECOVERY AND DOWN BLEND URANIUM FOR BENEFICIAL USE

    SciTech Connect

    Magoulas, V.

    2013-05-27

    For over fifty years, the H Canyon facility at the Savannah River Site (SRS) has performed remotely operated radiochemical separations of irradiated targets to produce materials for national defense. Although the materials production mission has ended, the facility continues to play an important role in the stabilization and safe disposition of proliferable nuclear materials. As part of the US HEU Disposition Program, SRS has been down blending off-specification (off-spec) HEU to produce LEU since 2003. Off-spec HEU contains fission products not amenable to meeting the American Society for Testing and Material (ASTM) commercial fuel standards prior to purification. This down blended HEU material produced 301 MT of ~5% enriched LEU which has been fabricated into light water reactor fuel being utilized in Tennessee Valley Authority (TVA) reactors in Tennessee and Alabama producing economic power. There is still in excess of ~10 MT of off-spec HEU throughout the DOE complex or future foreign and domestic research reactor returns that could be recovered and down blended for beneficial use as either ~5% enriched LEU, or for use in subsequent LEU reactors requiring ~19.75% enriched LEU fuel.

  4. Remedial Action Plan and final design for stabilization of the inactive uranium mill tailings at Green River, Utah. Volume 1, Text, Appendices A, B, and C: Final report

    SciTech Connect

    Matthews, M.L.; Alkema, K.

    1991-03-01

    This Remedial Action Plan (RAP) has been developed to serve a threefold purpose. It presents the series of activities that are proposed by the US Department of Energy (DOE) to accomplish long-term stabilization and control of radioactive materials at the inactive uranium processing site located near Green River, Utah. It provides a characterization of the present conditions of the site. It also serves to document the concurrence of the state of Utah and the US Nuclear Regulatory Commission (NRC) in the remedial action. This agreement, upon execution by the DOE and the state of Utah, and concurrence by the NRC, becomes Appendix 8 of the Cooperative Agreement.

  5. Age and paragenesis of mineralisation at Coronation Hill uranium deposit, Northern Territory, Australia

    NASA Astrophysics Data System (ADS)

    Orth, Karin; Meffre, Sebastien; Davidson, Garry

    2014-06-01

    Coronation Hill is a U + Au + platinum group elements deposit in the South Alligator Valley (SAV) field in northern Australia, south of the better known unconformity-style U East Alligator Rivers (EAR) field. The SAV field differs from the EAR by having a more complex basin-basement architecture. A volcanically active fault trough (Jawoyn Sub-basin) developed on older basement and then was disrupted by renewed faulting, before being buried beneath regional McArthur Basin sandstones that are also the main hanging wall to the EAR deposits. Primary mineralisation at Coronation Hill formed at 1607 ± 26 Ma (rather than 600-900 Ma as previously thought), and so it is likely that the SAV was part of a single west McArthur Basin dilational event. Most ore is hosted in sub-vertical faults and breccias in the competent volcanic cover sequence. This favoured fluid mixing, acid buffering (forming illite) and oxidation of Fe2+ and reduced C-rich assemblages as important uranium depositional mechanisms. However, reduction of U in fractured older pyrite (Pb model age of 1833 ± 67 Ma) is an important trap in diorite. Some primary ore was remobilised at 675 ± 21 Ma to form coarse uraninite + Ni-Co pyrite networks containing radiogenic Pb. Coronation Hill is polymetallic, and in this respect resembles the `egress'-style U deposits in the Athabascan Basin (Canada). However, these are all cover-hosted. A hypothesis for further testing is that Coronation Hill is also egress-style, with ores formed by fluids rising through basement-hosted fault networks (U reduction by diorite pyrite and carbonaceous shale), and into veins and breccias in the overlying Jawoyn Sub-basin volcano-sedimentary succession.

  6. The calculated solubility of platinum and gold in oxygen-saturated fluids and the genesis of platinum-palladium and gold mineralization in the unconformity-related uranium deposits

    NASA Astrophysics Data System (ADS)

    Jaireth, S.

    1992-01-01

    Thermodynamic calculations on the solubility of platinum and gold indicate that saline (1 m NaCl), fluids saturated with atmospheric oxygen can transport geologically realistic concentrations of platinum-group-elements (PGE), gold, and uranium as chloro-complexes. A number of calculations involving fluid-rock interaction suggest that the oxygen-saturated fluids flowing through rocks containing quartz, muscovite, kaolinite, magnetite and hematite, initially oxidize any magnetite to hematite, allowing subsequent batches of ore fluids to retain their high oxidation state. During their migration through the aquifer, the oxidizing fluids would move the oxidation-reduction interface deeper into the aquifer, leaching and redepositing platinum and gold. The redissolution of earlier precipitated platinum and gold depends on the fluid/ rock ratio and the associated increase in the oxidation state. Therefore, lowering of fluid/rock ratios and/or mixing of the oxidized fluids with a large amount of reduced fluid will precipitate uranium, PGE, and gold. It is suggested that this model can explain the genesis of gold and PGE mineralization in the unconformity-related uranium deposits of the Alligator Rivers Uranium Field in the Northern Territory, Australia.

  7. Morphological characteristics regulating phallic glans engorgement in the American alligator.

    PubMed

    Moore, Brandon C; Spears, David; Mascari, Taylor; Kelly, Diane A

    2016-10-01

    The distal part of the crocodilian phallus consists of a bulbous glans containing well-developed vascular tissues that can inflate before or during sexual activity, enlarging and elaborating the glans into a complex, though still functionally undefined, copulatory structure. An enlarged glans putatively interacts with the female cloaca and may change the shape of her reproductive tract to facilitate insemination and increase the probability of fertilization. Here, we investigated the cellular-level properties of the glans and other inflatable phallic tissues associated with the sperm-conducting sulcus spermaticus in the American alligator (Alligator mississippiensis). Using histochemical staining, we visualized and defined collagen and elastin fiber densities and orientations in these tissues. Extracellular matrix architectures provided insights about phallic glans material properties and how they may affect tissue strength and flexibility during inflation and in response to copulatory forces. We also investigated the potential sources of fluids that induce inflation in alligator phalli. Combining serial sectioning and three-dimensional reconstruction, we identified a pair of supracrucal plexus vascular bodies at the proximal end of the alligator phallus that extend distally adjacent to ventro-medial sulcus tissues. Together, our gross and histological examination of the American alligator phallic glans suggests that its tissues are arranged in a manner that would allow vascular inflation to expand the glans to a specific and repeatable shape, and potentially release secretory products into the female reproductive tract. Both elements could play roles in postcopulatory sexual selection, by mechanically and/or chemically affecting female reproductive physiology.

  8. Geology and recognition criteria for veinlike uranium deposits of the lower to middle Proterozoic unconformity and strata-related types. Final report

    SciTech Connect

    Dahlkamp, F.J.; Adams, S.S.

    1981-01-01

    The discovery of the Rabbit Lake deposit, Saskatchewan, in 1968 and the East Alligator Rivers district, Northern Territory, Australia, in 1970 established the Lower-Middle Proterozoic veinlike-type deposits as one of the major types of uranium deposits. The term veinlike is used in order to distinguish it from the classical magmatic-hydrothermal vein or veintype deposits. The veinlike deposits account for between a quarter and a third of the Western World's proven uranium reserves. Lower-Middle Proterozoic veinlike deposits, as discussed in this report include several subtypes of deposits, which have some significantly different geologic characteristics. These various subtypes appear to have formed from various combinations of geologic processes ranging from synsedimentary uranium precipitation through some combination of diagenesis, metamorphism, metasomatism, weathering, and deep burial diagenesis. Some of the deposit subtypes are based on only one or two incompletely described examples; hence, even the classification presented in this report may be expected to change. Geologic characteristics of the deposits differ significantly between most districts and in some cases even between deposits within districts. Emphasis in this report is placed on deposit descriptions and the interpretations of the observers.

  9. Estimating sighting proportions of American alligator nests during helicopter survey

    USGS Publications Warehouse

    Rice, Kenneth G.; Percival, H. Franklin; Woodward, Allan R.

    2000-01-01

    Proportions of American alligator (Alligator mississippiensis) nests sighted during aerial survey in Florida were estimated based upon multiple surveys by different observers. We compared sighting proportions across habitats, nesting seasons, and observer experience levels. The mean sighting proportion across all habitats and years was 0.736 (SE=0.024). Survey counts corrected by the mean sighting proportion reliably predicted total nest counts (7?2=0.933). Sighting proportions did not differ by habitat type (P=0.668) or year P=0.328). Experienced observers detected a greater proportion of nests (P<0.0001) than did either less experienced or inexperienced observers. Reliable estimates of nest abundance can be derived from aerial counts of alligator nests when corrected by the appropriate sighting proportion.

  10. The alligator gut microbiome and implications for archosaur symbioses

    PubMed Central

    Keenan, Sarah W.; Engel, Annette Summers; Elsey, Ruth M.

    2013-01-01

    Among vertebrate gastrointestinal microbiome studies, complete representation of taxa is limited, particularly among reptiles. Here, we provide evidence for previously unrecognized host-microbiome associations along the gastrointestinal tract from the American alligator, a crown archosaur with shared ancestry to extinct taxa, including dinosaurs. Microbiome compositional variations reveal that the digestive system consists of multiple, longitudinally heterogeneous microbiomes that strongly correlate to specific gastrointestinal tract organs, regardless of rearing histories or feeding status. A core alligator gut microbiome comprised of Fusobacteria, but depleted in Bacteroidetes and Proteobacteria common to mammalians, is compositionally unique from other vertebrate gut microbiomes, including other reptiles, fish, and herbivorous and carnivorous mammals. As such, modern alligator gut microbiomes advance our understanding of archosaur gut microbiome evolution, particularly if conserved host ecology has retained archosaur-specific symbioses over geologic time. PMID:24096888

  11. The alligator gut microbiome and implications for archosaur symbioses.

    PubMed

    Keenan, Sarah W; Engel, Annette Summers; Elsey, Ruth M

    2013-10-07

    Among vertebrate gastrointestinal microbiome studies, complete representation of taxa is limited, particularly among reptiles. Here, we provide evidence for previously unrecognized host-microbiome associations along the gastrointestinal tract from the American alligator, a crown archosaur with shared ancestry to extinct taxa, including dinosaurs. Microbiome compositional variations reveal that the digestive system consists of multiple, longitudinally heterogeneous microbiomes that strongly correlate to specific gastrointestinal tract organs, regardless of rearing histories or feeding status. A core alligator gut microbiome comprised of Fusobacteria, but depleted in Bacteroidetes and Proteobacteria common to mammalians, is compositionally unique from other vertebrate gut microbiomes, including other reptiles, fish, and herbivorous and carnivorous mammals. As such, modern alligator gut microbiomes advance our understanding of archosaur gut microbiome evolution, particularly if conserved host ecology has retained archosaur-specific symbioses over geologic time.

  12. An examination of the sensory structures in the oral cavity of the American alligator (Alligator mississippiensis).

    PubMed

    Rehorek, Susan J; Duffy, Michael; Zacherl, Janelle R; Anand, Kusuma; Elsey, Ruth M; Smith, Timothy S

    2014-11-01

    The location and distribution of mucosal sensory structures of the crocodilian oral cavity are poorly understood. Although there are several descriptions of these structures in adults, nothing is known about their development. The purpose of this study was to document location, morphology, and relative abundance of these mucosal sensory structures in both hatchling and subadult alligators. Numerous mucosal sensory structures and pale staining dome-shaped papillae were observed only in the upper palate and tongue. In hatchlings, these papillae, which house either mechanoreceptive or chemosensory (taste buds) structures, were larger and more prevalent on the tongue than the upper palate. In the subadult, however, these papillae housed primarily mechanoreceptive structures and possibly degenerate taste buds. Although the presence of the mechanoreceptive structures in the palates of the suabadult alligator are to be expected, the loss of most taste buds is hitherto undocumented. Thus, there is morphological support for an ontogenetic shift in the role of the sensory palate, from a prey detection gustatory sensory system in hatchlings to a prey-manipulative mechanoreceptive system in subadults.

  13. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Green River, Utah

    SciTech Connect

    Not Available

    1994-09-01

    This document evaluates potential impacts to public health and the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in a disposal cell on the site in 1989 by the US DOE`s Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, UMTRA Project is evaluating ground water contamination in this risk assessment.

  14. System-Scale Model of Aquifer, Vadose Zone, and River Interactions for the Hanford 300 Area - Application to Uranium Reactive Transport

    SciTech Connect

    Rockhold, Mark L.; Bacon, Diana H.; Freedman, Vicky L.; Parker, Kyle R.; Waichler, Scott R.; Williams, Mark D.

    2013-10-01

    This report represents a synthesis and integration of basic and applied research into a system-scale model of the Hanford 300 Area groundwater uranium plume, supported by the U.S. Department of Energy’s Richland Operations (DOE-RL) office. The report integrates research findings and data from DOE Office of Science (DOE-SC), Office of Environmental Management (DOE-EM), and DOE-RL projects, and from the site remediation and closure contractor, Washington Closure Hanford, LLC (WCH). The three-dimensional, system-scale model addresses water flow and reactive transport of uranium for the coupled vadose zone, unconfined aquifer, and Columbia River shoreline of the Hanford 300 Area. The system-scale model of the 300 Area was developed to be a decision-support tool to evaluate processes of the total system affecting the groundwater uranium plume. The model can also be used to address “what if” questions regarding different remediation endpoints, and to assist in design and evaluation of field remediation efforts. For example, the proposed cleanup plan for the Hanford 300 Area includes removal, treatment, and disposal of contaminated sediments from known waste sites, enhanced attenuation of uranium hot spots in the vadose and periodically rewetted zone, and continued monitoring of groundwater with institutional controls. Illustrative simulations of polyphosphate infiltration were performed to demonstrate the ability of the system-scale model to address these types of questions. The use of this model in conjunction with continued field monitoring is expected to provide a rigorous basis for developing operational strategies for field remediation and for defining defensible remediation endpoints.

  15. Potential molecular wires and molecular alligator clips

    NASA Astrophysics Data System (ADS)

    Schumm, Jeffry S.; Pearson, Darren L.; Jones, LeRoy, II; Hara, Ryuichiro; Tour, James M.

    1996-12-01

    The synthesis of oligo(2-ethylphenylene-ethynylene)s, oligo(2-(0957-4484/7/4/023/img1-ethylheptyl)phenylene-ethynylene)s, and oligo(3-ethylthiophene-ethynylene)s is described via an iterative divergent convergent approach. Synthesized were the monomer, dimer, tetramer, octamer and 16-mer of the oligo(3-ethylthiophene-ethynylene)s and oligo(2-0957-4484/7/4/023/img1-ethylheptyl)phenylene-ethynylene)s. The 16-mers are 100 Å and 128 Å long, respectively. At each stage in the iteration, the length of the framework doubles. Only three sets of reaction conditions are needed for the entire iterative synthetic sequence; an iodination, a protodesilylation, and a Pd/Cu-catalyzed cross coupling. The oligomers were characterized spectroscopically and by mass spectrometry. The optical properties are presented which show the stage of optical absorbance saturation. The size exclusion chromatography values for the number average weights, relative to polystyrene, illustrate the tremendous differences in the hydrodynamic volume of these rigid rod oligomers versus the random coils of polystyrene. These differences become quite apparent at the octamer stage. The preparation of thiol-protected end groups is described. These may serve as molecular alligator clips for adhesion to gold surfaces. These oligomers may act as molecular wires in molecular electronic devices and they also serve as useful models for understanding related bulk polymers.

  16. An urban Northeastern United States alligator bite.

    PubMed

    Shepherd, Suzanne Moore; Shoff, William H

    2014-05-01

    Individuals who live and work in the Southeastern coastal range of the 3 US crocodilian carnivores, American alligators, American crocodiles, and caiman, understand the risks of reptile-human encounters. Individuals who live in other parts of the country maybe exposed through contact with exotic pets at private homes, small menageries, or petting zoos or from escaped or abandoned animals. During these encounters, individuals may be severely injured.Emergency medical services, law enforcement, and animal welfare workers in nonhabitat areas are usually not trained in the handling and safe removal of injured individuals from the scene when the reptile is present. The emergency management of large crocodilian injuries is similar to that of other major trauma; however, providers also must take into consideration the significant crush component potentially inflicted by the tremendous bite power and shaking inflicting during attacks by these large reptiles, appropriate antibiotic coverage for less common organisms that inhabit their mouths, and management of possible psychological distress, including posttraumatic stress disorder produced by such an unusual attack. Emergency physicians should support the development of a readily available national database of scientifically collect information on attacks to inform appropriate care and support efforts to explore responsible measures that the USDA Animal and Plant Health Inspection Service and other appropriate local, state, and federal agencies can take to ensure ethical and biologically sustainable management of our large reptiles, which also helps to ensure the safety of the public. PMID:24332253

  17. Seasonal Variation of Total Mercury Burden in the American Alligator (Alligator Mississippiensis) at Merritt Island National Wildlife Refuge (MINWR), Florida

    NASA Technical Reports Server (NTRS)

    Nilsen, Frances M.; Dorsey, Jonathan E.; Long, Stephen E.; Schock, Tracey B.; Bowden, John A.; Lowers, Russell H.; Guillette, Louis J., Jr.

    2016-01-01

    Seasonal variation of mercury (Hg) is not well studied in free-ranging wildlife. Atmospheric deposition patterns of Hg have been studied in detail and have been modeled for both global and specific locations with great accuracy and correlates to environment impact. However, monitoring these trends in wildlife is complicated due to local environmental parameters (e.g., rainfall, humidity, pH, bacterial composition) that can affect the transformation of atmospheric Hg to the biologically available forms. Here, we utilized an abundant and healthy population of American alligators (Alligator mississippiensis) at Merritt Island National Wildlife Refuge (MINWR), FL, and assessed Hg burden in whole blood samples over a span of 7 years (2007 2014; n 174) in an effort to assess seasonal variation of total [Hg]. While the majority of this population is assumed healthy, 18 individuals with low body mass indices (BMI, defined in this study) were captured throughout the 7 year sampling period. These individual alligators exhibited [Hg] that were not consistent with the observed overall seasonal [Hg] variation, and were statistically different from the healthy population of alligators. The alligators with low BMI had elevated concentrations of Hg compared to their age/sex/season matched counterparts with normal BMI. Statistically significant differences were found between the winter and spring seasons for animals with normal BMI. The data in this report supports the conclusion that organismal total [Hg] do fluctuate directly with seasonal deposition rates as well as other seasonal environmental parameters, such as average rainfall and prevailing wind direction. This study highlights the unique environment of MINWR to permit annual assessment of apex predators, such as the American alligator, to determine detailed environmental impact of contaminants of concern.

  18. Atmospheric oxygen level affects growth trajectory, cardiopulmonary allometry and metabolic rate in the American alligator (Alligator mississippiensis)

    PubMed Central

    Owerkowicz, Tomasz; Elsey, Ruth M.; Hicks, James W.

    2009-01-01

    Summary Recent palaeoatmospheric models suggest large-scale fluctuations in ambient oxygen level over the past 550 million years. To better understand how global hypoxia and hyperoxia might have affected the growth and physiology of contemporary vertebrates, we incubated eggs and raised hatchlings of the American alligator. Crocodilians are one of few vertebrate taxa that survived these global changes with distinctly conservative morphology. We maintained animals at 30°C under chronic hypoxia (12% O2), normoxia (21% O2) or hyperoxia (30% O2). At hatching, hypoxic animals were significantly smaller than their normoxic and hyperoxic siblings. Over the course of 3 months, post-hatching growth was fastest under hyperoxia and slowest under hypoxia. Hypoxia, but not hyperoxia, caused distinct scaling of major visceral organs–reduction of liver mass, enlargement of the heart and accelerated growth of lungs. When absorptive and post-absorptive metabolic rates were measured in juvenile alligators, the increase in oxygen consumption rate due to digestion/absorption of food was greatest in hyperoxic alligators and smallest in hypoxic ones. Hyperoxic alligators exhibited the lowest breathing rate and highest oxygen consumption per breath. We suggest that, despite compensatory cardiopulmonary remodelling, growth of hypoxic alligators is constrained by low atmospheric oxygen supply, which may limit their food utilisation capacity. Conversely, the combination of elevated metabolism and low cost of breathing in hyperoxic alligators allows for a greater proportion of metabolised energy to be available for growth. This suggests that growth and metabolic patterns of extinct vertebrates would have been significantly affected by changes in the atmospheric oxygen level. PMID:19376944

  19. Estimating trends in alligator populations from nightlight survey data

    USGS Publications Warehouse

    Fujisaki, Ikuko; Mazzotti, F.J.; Dorazio, R.M.; Rice, K.G.; Cherkiss, M.; Jeffery, B.

    2011-01-01

    Nightlight surveys are commonly used to evaluate status and trends of crocodilian populations, but imperfect detection caused by survey- and location-specific factors makes it difficult to draw population inferences accurately from uncorrected data. We used a two-stage hierarchical model comprising population abundance and detection probability to examine recent abundance trends of American alligators (Alligator mississippiensis) in subareas of Everglades wetlands in Florida using nightlight survey data. During 2001-2008, there were declining trends in abundance of small and/or medium sized animals in a majority of subareas, whereas abundance of large sized animals had either demonstrated an increased or unclear trend. For small and large sized class animals, estimated detection probability declined as water depth increased. Detection probability of small animals was much lower than for larger size classes. The declining trend of smaller alligators may reflect a natural population response to the fluctuating environment of Everglades wetlands under modified hydrology. It may have negative implications for the future of alligator populations in this region, particularly if habitat conditions do not favor recruitment of offspring in the near term. Our study provides a foundation to improve inferences made from nightlight surveys of other crocodilian populations. ?? 2011 US Government.

  20. Estimating trends in alligator populations from nightlight survey data

    USGS Publications Warehouse

    Fujisaki, Ikuko; Mazzotti, Frank J.; Dorazio, Robert M.; Rice, Kenneth G.; Cherkiss, Michael; Jeffery, Brian

    2011-01-01

    Nightlight surveys are commonly used to evaluate status and trends of crocodilian populations, but imperfect detection caused by survey- and location-specific factors makes it difficult to draw population inferences accurately from uncorrected data. We used a two-stage hierarchical model comprising population abundance and detection probability to examine recent abundance trends of American alligators (Alligator mississippiensis) in subareas of Everglades wetlands in Florida using nightlight survey data. During 2001–2008, there were declining trends in abundance of small and/or medium sized animals in a majority of subareas, whereas abundance of large sized animals had either demonstrated an increased or unclear trend. For small and large sized class animals, estimated detection probability declined as water depth increased. Detection probability of small animals was much lower than for larger size classes. The declining trend of smaller alligators may reflect a natural population response to the fluctuating environment of Everglades wetlands under modified hydrology. It may have negative implications for the future of alligator populations in this region, particularly if habitat conditions do not favor recruitment of offspring in the near term. Our study provides a foundation to improve inferences made from nightlight surveys of other crocodilian populations.

  1. Combining U speciation and U isotope fractionation to evaluate the importance of naturally reduced sediments in controlling the mobility of uranium in the upper Colorado River Basin

    NASA Astrophysics Data System (ADS)

    Noel, V.; Lefebvre, P.; Boye, K.; Bargar, J.; Maher, K.; Lezama-Pacheco, J.; Cardarelli, E.; Bone, S.; Dam, W. L.; Johnson, R. H.

    2015-12-01

    Long-term persistence of uranium (U) in groundwater at legacy ore-processing sites in the upper Colorado River Basin (CRB) is a major concern for DOE, stakeholders, and local property owners. In the past year, we have investigated U distributions in contaminated floodplains at Grand Junction, Naturita, and Rifle (CO), Riverton (WY), and Shiprock (NM). We find that U is retained at all locations in fine-grained, organic-rich sulfidic sediments, referred to as naturally reduced zones (NRZs). The retention mechanisms (e.g., complexation, precipitation or adsorption) and the processes responsible for U accumulation in NRZs will directly determine the capacity of the sediments to prevent U mobilization. However, these processes remain poorly understood at local and regional scales yet they are critical to management and remediation of these sites. We have used U LIII/II-edge XANES to systematically characterize U oxidation states, and EXAFS and bicarbonate extractions to characterize U local structure and reactivity in order to distinguish the forms of U. We are measuring U isotopic signatures (δ238/235U) to better understand uranium sources and processes of accumulation in NRZs. We have found that high U concentrations correspond to reduced and relatively insoluble U forms, mainly non-crystalline U(IV), and co-occur with ferrous iron and sulfides. This suggests that reduction processes, fueled by the high organic matter content and constrained to the diffusion-limited environment in the fine-grained NRZs, are important for the retention of U in these sediments. We also observe a strong correlation between the U concentrations in the NRZs and the extent of isotopic fractionation, with up to +1.8 ‰ difference between uranium-enriched and low concentration zones. In some locations the δ238/235U values are within the range of values typical of the mine tailings, whereas at other sites the more positive δ238/235U values suggest that redox cycling and/or partial

  2. Alligators and crocodiles as indicators for restoration of Everglades ecosystems

    USGS Publications Warehouse

    Mazzotti, Frank J.; Best, G. Ronnie; Brandt, Laura A.; Cherkiss, Michael S.; Jeffery, Brian M.; Rice, Kenneth G.

    2009-01-01

    Alligators and crocodiles integrate biological impacts of hydrological operations, affecting them at all life stages through three key aspects of Everglades ecology: (1) food webs, (2) diversity and productivity, and (3) freshwater flow. Responses of crocodilians are directly related to suitability of environmental conditions and hydrologic change. Correlations between biological responses and environmental conditions contribute to an understanding of species' status and trends over time. Positive or negative trends of crocodilian populations relative to hydrologic changes permit assessment of positive or negative trends in restoration. The crocodilian indicator uses monitoring parameters (performance measures) that have been shown to be both effective and efficient in tracking trends. The alligator component uses relative density (reported as an encounter rate), body condition, and occupancy rates of alligator holes; the crocodile component uses juvenile growth and hatchling survival. We hypothesize that these parameters are correlated with hydrologic conditions including depth, duration, timing, spatial extent and water quality. Salinity is a critical parameter in estuarine habitats. Assessments of parameters defined for crocodilian performance measures support these hypotheses. Alligators and crocodiles are the charismatic megafauna of the Everglades. They are both keystone and flagship species to which the public can relate. In addition, the parameters used to track trends are easy to understand. They provide answers to the following questions: How has the number of alligators or crocodiles changed? Are the animals fatter or thinner than they should be? Are the animals in the places (in terms of habitat and geography) where they should be? As surely as there is no other Everglades, no other single species defines the Everglades as does the American alligator. The Everglades is the only place in the world where both alligators and crocodiles exist. Crocodilians

  3. Age of uranium ores at Ranger and Jabiluka unconformity vein deposits, Northern Territory, Australia

    SciTech Connect

    Ludwig, K.R.; Grauch, R.I.; Nutt, C.J.; Frishman, D.; Nash, J.T.; Simmons, K.R.

    1985-01-01

    The Ranger and Jabiluka uranium deposits are the largest in the Alligator Rivers Uranium Field (ARUF), which contains at least 20% of the world's low-cost uranium reserves. Ore occurs in early Proterozoic metasediments, below an unconformity with sandstones of the 1.65 Ga Kombolgie Formation. This study uses U-Pb isotope data from over 60 whole-rock drill core samples that contained a variety of mineral assemblages and textures. Data for Ranger samples indicate a well-defined age of 1.74 +/-.02 Ga. This 1.74 Ga age is distinctly pre-Kombolgie, so the Ranger deposit cannot have been formed by processes requiring its presence. This Ranger age is consistent, however, with mineralization related to heating associated with either the emplacement of early post-metamorphic granites, or possibly with intrusion of the nearby Oenpelli Dolerite. In contrast, data for the least-altered Jabiluka ores yield a concordia-intercept age of 1.44 +/-.02 Ga--significantly younger than the Ranger age, and also younger than the Komobolgie. This age may correspond to a regional thermal event, as indicated both by mafic dikes of roughly this age and a zircon lower-intercept age from a nearby granite-gneiss. Thus, together with the well-defined approx.900 Ma age of ores at the Nabarlek deposit, there are at least 3 distinct periods of major U-mineralization in the ARUF. Data for both Ranger and Jabiluka indicate the same, profound isotopic disturbance at some time in the interval of 0.4-0.6 Ga. Possibly this time corresponds to the development of basins and associated basalt flows to the W and SW, a suggested by Crick et. al. (1980).

  4. Concentrations of trace elements in American alligators (Alligator mississippiensis) from Florida, USA.

    PubMed

    Horai, Sawako; Itai, Takaaki; Noguchi, Takako; Yasuda, Yusuke; Adachi, Haruki; Hyobu, Yuika; Riyadi, Adi S; Boggs, Ashley S P; Lowers, Russell; Guillette, Louis J; Tanabe, Shinsuke

    2014-08-01

    Concentrations of 28 trace elements (Li, Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Tl, Hg, Pb, and Bi) in the livers of juvenile and adult American alligators inhabiting two central Florida lakes, Lake Apopka (LA), and Lake Woodruff National Wildlife Refuge (LW) and one lagoon population located in Merritt Island National Wildlife Refuge (MINWR; NASA), were determined. In juveniles from MINWR, concentrations of nine elements (Li, Fe, Ni, Sr, In, Sb, Hg, Pb and Bi) were significantly higher, whereas six elements (V, Fe, As, Sr, Hg and Bi) were elevated in adults (p<0.05) obtained from MINWR. Significant enrichment of some trace elements in adults, relative to juveniles, was observed at all three sampling areas. Specifically, Fe, Pb and Hg were significantly elevated in adults when compared to juveniles, suggesting age-dependent accumulation of these elements. Further, As, Se and Sn showed the same trend but only in animals collected from MINWR. Mean Fe concentrations in the livers of adults from LA, LW and MINWR were 1770 μg g(-1) DW, 3690 μg g(-1) DW and 5250 μg g(-1) DW, respectively. More than half of the adult specimens from LW and MINWR exhibited elevated hepatic Fe concentrations that exceed the threshold value for toxic effects in donkey, red deer and human. These results prompted us to express our concern on possible exposure and health effects in American alligators by some trace elements derived from NASA activities. PMID:24698170

  5. Ultrastructure of spermiogenesis in the American alligator, Alligator mississippiensis (Reptilia, Crocodylia, Alligatoridae).

    PubMed

    Gribbins, Kevin M; Siegel, Dustin S; Anzalone, Marla L; Jackson, Daniel P; Venable, Katherine J; Rheubert, Justin L; Elsey, Ruth M

    2010-10-01

    Testicular samples were collected to describe the ultrastructure of spermiogenisis in Alligator mississipiensis (American Alligator). Spermiogenesis commences with an acrosome vesicle forming from Golgi transport vesicles. An acrosome granule forms during vesicle contact with the nucleus, and remains posterior until mid to late elongation when it diffuses uniformly throughout the acrosomal lumen. The nucleus has uniform diffuse chromatin with small indices of heterochromatin, and the condensation of DNA is granular. The subacrosome space develops early, enlarges during elongation, and accumulates a thick layer of dark staining granules. Once the acrosome has completed its development, the nucleus of the early elongating spermatid becomes associated with the cell membrane flattening the acrosome vesicle on the apical surface of the nucleus, which aids in the migration of the acrosomal shoulders laterally. One endonuclear canal is present where the perforatorium resides. A prominent longitudinal manchette is associated with the nuclei of late elongating spermatids, and less numerous circular microtubules are observed close to the acrosome complex. The microtubule doublets of the midpiece axoneme are surrounded by a layer of dense staining granular material. The mitochondria of the midpiece abut the proximal centriole resulting in a very short neck region, and possess tubular cristae internally and concentric layers of cristae superficially. A fibrous sheath surrounds only the axoneme of the principal piece. Characters not previously described during spermiogenesis in any other amniote are observed and include (1) an endoplasmic reticulum cap during early acrosome development, (2) a concentric ring of endoplasmic reticulum around the nucleus of early to middle elongating spermatids, (3) a band of endoplasmic reticulum around the acrosome complex of late developing elongate spermatids, and (4) midpiece mitochondria that have both tubular and concentric layers of

  6. Concentrations of trace elements in American alligators (Alligator mississippiensis) from Florida, USA.

    PubMed

    Horai, Sawako; Itai, Takaaki; Noguchi, Takako; Yasuda, Yusuke; Adachi, Haruki; Hyobu, Yuika; Riyadi, Adi S; Boggs, Ashley S P; Lowers, Russell; Guillette, Louis J; Tanabe, Shinsuke

    2014-08-01

    Concentrations of 28 trace elements (Li, Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Tl, Hg, Pb, and Bi) in the livers of juvenile and adult American alligators inhabiting two central Florida lakes, Lake Apopka (LA), and Lake Woodruff National Wildlife Refuge (LW) and one lagoon population located in Merritt Island National Wildlife Refuge (MINWR; NASA), were determined. In juveniles from MINWR, concentrations of nine elements (Li, Fe, Ni, Sr, In, Sb, Hg, Pb and Bi) were significantly higher, whereas six elements (V, Fe, As, Sr, Hg and Bi) were elevated in adults (p<0.05) obtained from MINWR. Significant enrichment of some trace elements in adults, relative to juveniles, was observed at all three sampling areas. Specifically, Fe, Pb and Hg were significantly elevated in adults when compared to juveniles, suggesting age-dependent accumulation of these elements. Further, As, Se and Sn showed the same trend but only in animals collected from MINWR. Mean Fe concentrations in the livers of adults from LA, LW and MINWR were 1770 μg g(-1) DW, 3690 μg g(-1) DW and 5250 μg g(-1) DW, respectively. More than half of the adult specimens from LW and MINWR exhibited elevated hepatic Fe concentrations that exceed the threshold value for toxic effects in donkey, red deer and human. These results prompted us to express our concern on possible exposure and health effects in American alligators by some trace elements derived from NASA activities.

  7. Sex-steroid and thyroid hormone concentrations in juvenile alligators (Alligator mississippiensis) from contaminated and reference lakes in Florida, USA

    USGS Publications Warehouse

    Grain, D.A.; Guillette, L.J.; Pickford, D.B.; Percival, H.F.; Woodward, A.R.

    1998-01-01

    Sex-steroid and thyroid hormones are critical regulators of growth and reproduction in all vertebrates, and several recent studies suggest that environmental chemicals can alter circulating concentrations of these hormones. This study examines plasma concentrations of estradiol-171?? (E2), testosterone (T), triiodothyronine (T3), and thyroxine (T4) in juvenile alligators (60-140 cm total length) from two contaminated lakes and one reference lake in Florida. First, the data were analyzed by comparing hormone concentrations among males and females from the different lakes. Whereas there were no differences in plasma E2 concentrations among animals of the three lakes, male alligators from the contaminated lakes (Lake Apopka and Lake Okeechobee) had significantly lower plasma T concentrations compared 10 males from the reference take (Lake Woodruff). Concentrations of thyroid hormones also differed in animals of the three lakes, with T4 concentrations being elevated in Lake Okeechobee males compared to Lake Woodruff males. Second, the relationship between body size and hormone concentration was examined using regression analysis. Most notably for steroid hormones, no clear relationship was detected between E2 and total length in Apopka females (r2 0.09, p = 0.54) or between T and total length in Apopka males (r2 = 0.007, p = 0.75). Females from Apopka (r2 = 0.318, p = 0.09) and Okeechobee (r2 = 0.222, p = 0.09) exhibited weak correlations between T3 and total length. Males from Apopka (r2 = 0.015, p = 0.66) and Okeechobee (r2 = 0.128, p = 0.19) showed no correlation between T4 and total length. These results indicate: some of the previously reported abnormalities in steroid hormones of hatchling alligators persist, at least, through the juvenile years; steroid and thyroid hormones are related to body size in juvenile alligators from the reference lake, whereas alligators living in lakes Apopka and Okeechobee experience alterations in circulating thyroid and steroid

  8. INFORMATION: Management Alert on Environmental Management's Select Strategy for Disposition of Savannah River Site Depleted Uranium Oxides

    SciTech Connect

    2010-04-01

    The Administration and the Congress, through policy statements and passage of the American Recovery and Reinvestment Act of 2009 (Recovery Act), have signaled that they hope that proactive actions by agency Inspectors General will help ensure that Federal Recovery Act activities are transparent, effective and efficient. In that context, the purpose of this management alert is to share with you concerns that have been raised to the Office of Inspector General regarding the planned disposition of the Savannah River Site's (SRS) inventory of Depleted Uranium (DU) oxides. This inventory, generated as a by-product of the nuclear weapons production process and amounting to approximately 15,600 drums of DU oxides, has been stored at SRS for decades. A Department source we deem reliable and credible recently came to the Office of Inspector General expressing concern that imminent actions are planned that may not provide for the most cost effective disposition of these materials. During April 2009, the Department chose to use funds provided under the Recovery Act to accelerate final disposition of the SRS inventory of DU oxides. After coordination with State of Utah regulators, elected officials and the U.S. Nuclear Regulatory Commission, the Department initiated a campaign to ship the material to a facility operated by EnergySolutions in Clive, Utah. Although one shipment of a portion of the material has already been sent to the EnergySolutions facility, the majority of the product remains at SRS. As had been planned, both for the shipment already made and those planned in the near term, the EnergySolutions facility was to have been the final disposal location for the material. Recently, a member of Congress and various Utah State officials raised questions regarding the radioactive and other constituents present in the DU oxides to be disposed of at the Clive, Utah, facility. These concerns revolved around the characterization of the material and its acceptability under

  9. Survival of young American alligators on a Florida lake

    USGS Publications Warehouse

    Woodward, A.R.; Hines, T.C.; Abercrombie, C.L.; Nichols, J.D.

    1987-01-01

    A capture-recapture study was conducted on Orange Lake, Florida, from 1979 through 1984 to estimate survival rates of young in an American alligator (Alligator mississippiensis) populations. Hatchlings remained together in sibling groups (pods) for at least their 1st year and then began to disperse during their 2nd spring and summer. Mortality through mid-November of their 1st year was negligible. Jolly-Seber (JS) survival estimates of hatchlings for 6 and 12 months were 76 and 41%, respectively. The 2-year JS estimate for the 1980 cohort was 8%. Minimum-Known-Alive (MKA) survival values were 72 and 46% of JS estimates for 6 months and 1 year of age. Survival during the 2nd 6 months of life (spring-summer) tended to be lower than survival during the 1st 6 months (fall-winter).

  10. A new alligator-clip compound for molecular electronics

    NASA Astrophysics Data System (ADS)

    Jacob, Timo; Blanco, Mario; Goddard, William A.

    2004-06-01

    We used the B3LYP flavor of density functional calculations to study new alligator-clip compounds for molecular electronics with platinum electrodes. First, with commonly used S-based linkage molecule 3-methyl-1,2-dithiolane (MDTL) we find that after chemisorption on Pt(1 1 1) the most stable structure is ring-opened with a binding energy of 32.44 kcal/mol. Among several alternative alligator-clip compounds we find that P-based molecules lead to much higher binding energies. For the ring-closed structure of 3-methyl-1,2-diphospholane (MDPL) a binding energy of 47.72 kcal/mol was calculated and even 54.88 kcal/mol for the ring-opened molecule. Thus, MDPL provides a more stable link to the metal surface and might increase the conductance.

  11. Fixation of radionuclides in the 238U decay series in the vicinity of mineralized zones: 1. The Austatom Uranium Prospect, Northern Territory, Australia

    NASA Astrophysics Data System (ADS)

    Shirvington, P. J.

    1983-03-01

    The minimum age of a zone of secondary uranium mineralization, located at the Austatom Prospect in the Alligator Rivers region of Australia, is estimated to be 3.6 × 10 5y. This is derived from a geochronological model based on retarded leaching of 234U with respect to 238U and on ratios within the ore of these members of the 238U decay series. Although kaolinite is a dominant mineral in the weathered schist-host-rocks, retarded dissolution of 234U occurs only in the presence of the clay minerals illite and montmorillonite. In their absence the reverse occurs. A model is proposed to explain the results. Ratios of 230Th to 238U indicate that the mineralization has probably remained stationary within the weathered schist for at least 1 to 2 × 10 5y. Future use of clay minerals as buffers in radioactive waste repositories is supported by the excellent long-term retention obtained for oxidized uranium, probably due in part to isomorphic substitution into the clay crystal lattice.

  12. Water Hyacinths and Alligator Weeds for Final Filtration of Sewage

    NASA Technical Reports Server (NTRS)

    Wolverton, B. C.; Mcdonald, R. C.; Gordon, J.

    1976-01-01

    The potential of water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxerides) (Mart.) Griesb. as secondary and tertiary filtration systems for domestic sewage was demonstrated. These two vascular aquatic plants reduced the suspended solids, total Kjeldahl nitrogen, total phosphorus, BOD sub 5, and total organic carbon levels in domestic sewage from 60 percent to 98 percent within a two week period. These plants grown in domestic sewage were also free of toxic levels of trace heavy metals.

  13. Barrier cells in gills of the alligator gar.

    PubMed

    Henderson, V

    1999-10-01

    Studies of barrier cells in fishes are few and have been restricted primarily to salmonids. Moreover, these studies revealed the presence of barrier cells only in hematopoietic and lymphoid organs. The alligator gar, Lepisosteus spatula, possesses similar tissues within the gills which are readily accessible; therefore, they were the organs of choice. An electron microscopical analysis of the gills was undertaken to determine if barrier cells exist and if they possess an ultrastructural design comparable to their counterparts in the brain and lungs of higher vertebrates and hematopoietic/lymphoid tissues in fishes. The present study revealed that barrier cells were found only within non-hematopoietic/lymphoid areas. Barrier cells surrounded endocrine components, nerves, and sinusoids rather than capillary endothelium or hematopoietic/lymphoid tissues. Barrier cells in the alligator gar displayed a complex envelopment more similar to those found in the blood-cerebrospinal fluid, blood-brain, and blood-gas barriers in higher vertebrates than in salmonids. The barrier in the alligator gar consisted of: (1) an endothelium whose cells displayed tight junctions; (2) a basement membrane; and (3) an outer adventitia composed of fibrocytic cells in syncytium. PMID:18627869

  14. Barrier cells in gills of the alligator gar.

    PubMed

    Henderson, V

    1999-10-01

    Studies of barrier cells in fishes are few and have been restricted primarily to salmonids. Moreover, these studies revealed the presence of barrier cells only in hematopoietic and lymphoid organs. The alligator gar, Lepisosteus spatula, possesses similar tissues within the gills which are readily accessible; therefore, they were the organs of choice. An electron microscopical analysis of the gills was undertaken to determine if barrier cells exist and if they possess an ultrastructural design comparable to their counterparts in the brain and lungs of higher vertebrates and hematopoietic/lymphoid tissues in fishes. The present study revealed that barrier cells were found only within non-hematopoietic/lymphoid areas. Barrier cells surrounded endocrine components, nerves, and sinusoids rather than capillary endothelium or hematopoietic/lymphoid tissues. Barrier cells in the alligator gar displayed a complex envelopment more similar to those found in the blood-cerebrospinal fluid, blood-brain, and blood-gas barriers in higher vertebrates than in salmonids. The barrier in the alligator gar consisted of: (1) an endothelium whose cells displayed tight junctions; (2) a basement membrane; and (3) an outer adventitia composed of fibrocytic cells in syncytium.

  15. Mathematical models for growth in alligator (Alligator mississippiensis) embryos developing at different incubation temperatures.

    PubMed Central

    Bardsley, W G; Ackerman, R A; Bukhari, N A; Deeming, D C; Ferguson, M W

    1995-01-01

    A variety of model-based (growth models) and model-free (cubic splines, exponentials) equations were fitted using weighted-nonlinear least squares regression to embryonic growth data from Alligator mississippiensis eggs incubated at 30 and 33 degrees C. Goodness of fit was estimated using a chi 2 on the sum of squared, weighted residuals, and run and sign tests on the residuals. One of the growth models used (Preece & Baines, 1978) was found to be superior to the classical growth models (exponential, monomolecular, logistic, Gompertz, von Bertalanffy) and gave an adequate fit to all longitudinal measures taken from the embryonic body and embryonic mass. However, measurements taken from the head could not be fitted by growth models but were adequately fitted by weighted least squares cubic splines. Data for the stage of development were best fitted by a sum of 2 exponentials with a transition point. Comparison of the maximum growth rates and parameter values, indicated that the growth data at 30 degrees C could be scaled to 33 degrees C to multiplying the time by a scaling factor of 1.2. This is equivalent to a Q10 of about 1.86 or, after solving the Arrhenius equation, an E++ of 46.9 kJmol-1. This may be interpreted as indicating a common rate-limiting step in development at the 2 temperatures. PMID:7591979

  16. WILDLIFE - ALLIGATOR STROLLS FROM TURN BASIN TO LC 39 PRESS SITE GRANDSTAND

    NASA Technical Reports Server (NTRS)

    1985-01-01

    A 12-foot alligator worked his way up from the turn basin at Press Site 39 to the grandstand seats. The toothy reptile was later wrangled by wildlife trappers who relocated him to a less populated area on KSC. The alligator is one of approximately 4,000 on KSC/Merritt Island National Wildlife Refuge.

  17. PLASMA STEROID CONCENTRATIONS IN RELATION TO SIZE AND AGE IN JUVENILE ALLIGATORS FROM TWO FLORIDA LAKES.

    EPA Science Inventory

    Previous studies have reported a number of physiological differences among juvenile alligators from two well-studied populations (Lake Apopka and Lake Woodruff) in north central Florida. These studies obtained alligators of similar size from each lake under the assumption that th...

  18. Biomonitoring Heavy Metal Pollution Using an Aquatic Apex Predator, the American Alligator, and Its Parasites

    PubMed Central

    Tellez, Marisa; Merchant, Mark

    2015-01-01

    Monitoring the bioaccumulation of chemical elements within various organismal tissues has become a useful tool to survey current or chronic levels of heavy metal exposure within an environment. In this study, we compared the bioaccumulations of As, Cd, Cu, Fe, Pb, Se, and Zn between the American alligator, Alligator mississippiensis, and its parasites in order to establish their use as bioindicators of heavy metal pollution. Concomitant with these results, we were interested to determine if parasites were more sensitive bioindicators of heavy metals relative to alligators. We found parasites collectively accumulated higher levels of As, Cu, Se, and Zn in comparison to their alligator hosts, whereas Fe, Cd, and Pb concentrations were higher in alligators. Interestingly, Fe levels were significantly greater in intestinal trematodes than their alligator hosts when analyzed independently from other parasitic taxa. Further analyses showed alligator intestinal trematodes concentrated As, Cu, Fe, Se, and Zn at significantly higher levels than intestinal nematodes and parasites from other organs. However, pentastomids also employed the role as a good biomagnifier of As. Interestingly, parasitic abundance decreased as levels of As increased. Stomach and intestinal nematodes were the poorest bioaccumulators of metals, yet stomach nematodes showed their ability to concentrate Pb at orders of magnitude higher in comparison to other parasites. Conclusively, we suggest that parasites, particularly intestinal trematodes, are superior biomagnifiers of As, Cu, Se, and Zn, whereas alligators are likely good biological indicators of Fe, Cd, and Pb levels within the environment. PMID:26555363

  19. Biomonitoring Heavy Metal Pollution Using an Aquatic Apex Predator, the American Alligator, and Its Parasites.

    PubMed

    Tellez, Marisa; Merchant, Mark

    2015-01-01

    Monitoring the bioaccumulation of chemical elements within various organismal tissues has become a useful tool to survey current or chronic levels of heavy metal exposure within an environment. In this study, we compared the bioaccumulations of As, Cd, Cu, Fe, Pb, Se, and Zn between the American alligator, Alligator mississippiensis, and its parasites in order to establish their use as bioindicators of heavy metal pollution. Concomitant with these results, we were interested to determine if parasites were more sensitive bioindicators of heavy metals relative to alligators. We found parasites collectively accumulated higher levels of As, Cu, Se, and Zn in comparison to their alligator hosts, whereas Fe, Cd, and Pb concentrations were higher in alligators. Interestingly, Fe levels were significantly greater in intestinal trematodes than their alligator hosts when analyzed independently from other parasitic taxa. Further analyses showed alligator intestinal trematodes concentrated As, Cu, Fe, Se, and Zn at significantly higher levels than intestinal nematodes and parasites from other organs. However, pentastomids also employed the role as a good biomagnifier of As. Interestingly, parasitic abundance decreased as levels of As increased. Stomach and intestinal nematodes were the poorest bioaccumulators of metals, yet stomach nematodes showed their ability to concentrate Pb at orders of magnitude higher in comparison to other parasites. Conclusively, we suggest that parasites, particularly intestinal trematodes, are superior biomagnifiers of As, Cu, Se, and Zn, whereas alligators are likely good biological indicators of Fe, Cd, and Pb levels within the environment. PMID:26555363

  20. Recovery of fish communities in the Finniss River, northern Australia, following remediation of the Rum Jungle uranium/copper mine site.

    PubMed

    Jeffree, R A; Twining, J R; Thomson, J

    2001-07-15

    The Finniss River in the wet-dry tropics of northern Australia has received acid rock drainage (ARD) contaminants from the Rum Jungle uranium/copper mine site over more than four decades. Annual-cycle loads of Cu, Zn, Mn, and sulfate, calculated from daily water and flow measurements, have been determined both prior to and following mine-site remediation, that began in the early 1980s. The effects of varying contaminant loads on the relative abundances of seven fish species, sampled by enmeshing nets during dry seasons, were determined by nonmetric multidimensional scaling (nMDS), in combination with cluster-analysis and other nonparametric statistical techniques. These analyses showed that (i) prior to remediation, the impacted region of the Finniss River in 1974 had significantly dissimilar (P < 0.001) and more heterogeneous fish communities, generally characterized by reduced diversity and abundance, compared to sites unexposed to elevated contaminant water concentrations and (ii) postremediation, recovery in fish communities from the impacted region was indicated because they were not significantly dissimilar from those sampled at contemporary (P = 0.16) unimpacted sites, that were also similar to preremedial unimpacted sites. Even though considerable contaminant loads are still being delivered to the impacted region of the Finniss River over the annual cycle, the recovery in fish diversity and abundances is consistent with (a) reductions of in situ contaminant water concentrations at the time of fish sampling, (b) reductions in annual-cycle contaminant loads of sulfate, Cu, Zn, and Mn by factors of 3-7, (c) greatly reduced frequencies of occurrence and magnitude of elevated contaminant water concentrations over the annual cycle, that was most pronounced for Cu, and (d) the absence of extensive fish-kills during the first-flushes of contaminants into the Finniss river proper at the beginning of the wet season, that were observed prior to remediation. As such

  1. Sex-biased expression of sex-differentiating genes FOXL2 and FGF9 in American alligators, Alligator mississippiensis

    PubMed Central

    Janes, Daniel E.; Elsey, Ruth M.; Langan, Esther M.; Valenzuela, Nicole; Edwards, Scott V.

    2013-01-01

    Across amniotes, sex-determining mechanisms exhibit great variation yet the genes that govern sexual differentiation are largely conserved. Studies of evolution of sex-determining and sex-differentiating genes require an exhaustive characterization of functions of those genes such as FOXL2 and FGF9. FOXL2 is associated with ovarian development and FGF9 is known to play a role in testicular organogenesis in mammals and other amniotes. As a step toward characterization of the evolutionary history of sexual development, we measured expression of FOXL2 and FGF9 across three developmental stages and eight juvenile tissue types in male and female American alligators, Alligator mississippiensis. We report surprisingly high expression of FOXL2 before the stage of embryonic development when sex is determined in response to temperature and sustained and variable expression of FGF9 in juvenile male but not female tissue types. Novel characterization of gene expression in reptiles with temperature-dependent sex determination such as American alligators may inform the evolution of sex-determining and sex-differentiating gene networks as they suggest alternative functions from which the genes may have been exapted. Future functional profiling of sex-differentiating genes should similarly follow other genes and other species to enable a broad comparison across sex-determining mechanisms. PMID:23689672

  2. Proposed ground water protection strategy for the Uranium Mill Tailings Site at Green River, Utah. Final report

    SciTech Connect

    Not Available

    1994-11-01

    This document presents the US DOE water resources protection strategy for the Green River, Utah mill tailings disposal site. The modifications in the original plan are based on new information, including ground water quality data collected after remedial action was completed, and on a revised assessment of disposal cell design features, surface conditions, and site hydrogeology. All aspects are discussed in this report.

  3. Thorium-uranium disequilibrium dating of Late Quaternary ferruginous concretions and rinds

    NASA Astrophysics Data System (ADS)

    Short, Stephen A.; Lowson, Richard T.; Ems, John; Price, David M.

    1989-06-01

    Radioactive ferruginous nodules from the Alligator Rivers Uranium Province, Northern Territory, Australia, were systematically examined by optical microscopy, XRD, alpha- and fission-track autoradiography, and analysed for U, Th, Ra and major stable elements. Correlation of autoradiographs with microscopic structure and analyses of selective extractions confirmed that U and Th were strongly associated with Fe oxides. Fission-track autoradiography showed no concentration gradient evidence for postdepositional leaching of uranium. Strong acid leaching studies showed that irreversibly adsorbed U, and authigenic 234U and 230Th, but not 226Ra, are quantitatively retained by accumulated oxide/oxyhydroxide. Correlation of the groundwater activity ratio with oxidic 234U/ 238U activity ratios indicated the latter was radiogenically consistent with oxidic 230Th/ 234U activity ratios < 1. Dense, accumulated Fe/Mn oxide matrices are apparently capable of forming radiogenic closed systems in respect of the 230U → 234U → 230Th decay set. 234U/ 238U and 230Th/ 234U activity ratios were used to derive similar mean ages of rinds for four nodules in the same horizon. Th/U ages were also determined, using a Th-index detrital correction method previously used for impure carbonates, of pedogenic Fe/Mn accumulations having background concentrations of U and Th from other locations in Australia. These ages were compared with TL and 14C ages of the-host sediments. The comparisions suggest that Th/U dating could be used to age indurated layers of Fe/Mn oxides in soil horizons < 350 ka old.

  4. Gastric nematode diversity between estuarine and inland freshwater populations of the American alligator (Alligator mississippiensis, daudin 1802), and the prediction of intermediate hosts.

    PubMed

    Tellez, Marisa; Nifong, James

    2014-12-01

    We examined the variation of stomach nematode intensity and species richness of Alligator mississippiensis from coastal estuarine and inland freshwater habitats in Florida and Georgia, and integrated prey content data to predict possible intermediate hosts. Nematode parasitism within inland freshwater inhabiting populations was found to have a higher intensity and species richness than those inhabiting coastal estuarine systems. This pattern potentially correlates with the difference and diversity of prey available between inland freshwater and coastal estuarine habitats. Increased consumption of a diverse array of prey was also correlated with increased nematode intensity in larger alligators. Parasitic nematodes Dujardinascaris waltoni, Brevimulticaecum tenuicolle, Ortleppascaris antipini, Goezia sp., and Contracaecum sp. were present in alligators from both habitat types. Dujardinascaris waltoni, B. tenuicolle, and O. antipini had a significantly higher abundance among inland inhabiting alligators than hosts from estuarine populations. Our findings also suggest that host specific nematode parasites of alligators may have evolved to infect multiple intermediate hosts, particularly fishes, crabs, and turtles, perhaps in response to the opportunistic predatory behaviors of alligators. PMID:25426417

  5. Gastric nematode diversity between estuarine and inland freshwater populations of the American alligator (Alligator mississippiensis, daudin 1802), and the prediction of intermediate hosts

    PubMed Central

    Tellez, Marisa; Nifong, James

    2014-01-01

    We examined the variation of stomach nematode intensity and species richness of Alligator mississippiensis from coastal estuarine and inland freshwater habitats in Florida and Georgia, and integrated prey content data to predict possible intermediate hosts. Nematode parasitism within inland freshwater inhabiting populations was found to have a higher intensity and species richness than those inhabiting coastal estuarine systems. This pattern potentially correlates with the difference and diversity of prey available between inland freshwater and coastal estuarine habitats. Increased consumption of a diverse array of prey was also correlated with increased nematode intensity in larger alligators. Parasitic nematodes Dujardinascaris waltoni, Brevimulticaecum tenuicolle, Ortleppascaris antipini, Goezia sp., and Contracaecum sp. were present in alligators from both habitat types. Dujardinascaris waltoni, B. tenuicolle, and O. antipini had a significantly higher abundance among inland inhabiting alligators than hosts from estuarine populations. Our findings also suggest that host specific nematode parasites of alligators may have evolved to infect multiple intermediate hosts, particularly fishes, crabs, and turtles, perhaps in response to the opportunistic predatory behaviors of alligators. PMID:25426417

  6. Uranium immobilization in an iron-rich rhizosphere of a native wetland plant from the Savannah River Site under reducing conditions.

    PubMed

    Chang, Hyun-shik; Buettner, Shea W; Seaman, John C; Jaffé, Peter R; van Groos, Paul G Koster; Li, Dien; Peacock, Aaron D; Scheckel, Kirk G; Kaplan, Daniel I

    2014-08-19

    The hypothesis of this study was that iron plaques formed on the roots of wetland plants and their rhizospheres create environmental conditions favorable for iron reducing bacteria that promote the in situ immobilization of uranium. Greenhouse microcosm studies were conducted using native plants (Sparganium americanum) from a wetland located on the Savannah River Site, Aiken, SC. After iron plaques were established during a 73-day period by using an anoxic Fe(II)-rich nutrient solution, a U(VI) amended nutrient solution was added to the system for an additional two months. Compared to plant-free control microcosms, microcosms containing iron plaques successfully stimulated the growth of targeted iron reducing bacteria, Geobacter spp. Their population continuously increased after the introduction of the U(VI) nutrient solution. The reduction of some of the U(VI) to U(IV) by iron reducing bacteria was deduced based on the observations that the aqueous Fe(II) concentrations increased while the U(VI) concentrations decreased. The Fe(II) produced by the iron reducing bacteria was assumed to be reoxidized by the oxygen released from the roots. Advanced spectroscopic analyses revealed that a significant fraction of the U(VI) had been reduced to U(IV) and they were commonly deposited in association with phosphorus on the iron plaque.

  7. Dry years decrease abundance of American alligators in the Florida Everglades

    USGS Publications Warehouse

    Waddle, J. Hardin; Brandt, Laura A.; Jeffery, Brian M.; Mazzotti, Frank J.

    2015-01-01

    The Everglades has been greatly reduced and is threatened by land use change and altered hydrology. The Comprehensive Everglades Restoration Plan calls for monitoring and assessment of key ecosystem attributes, one of which is abundance of American alligators. We examined 10 years of alligator night spotlight counts from Arthur R. Marshall Loxahatchee National Wildlife Refuge along two canals and in the interior marsh to determine trends and how dry years affect alligator abundance. Alligators showed population response to hydrologic conditions. In particular, there were declines in abundance after dry years followed by an apparent recovery in abundance in subsequent years. Increases in abundance were lower in the marsh than L-40 Canal. In addition, there was evidence that intensity of dry events affected population dynamics with greater declines observed in years with drier conditions. Results revealed that overall population of alligators increased from 2004 to 2013, but that increases varied by survey route. These results demonstrate that dry years cause a decline in alligator abundance proportional to the intensity of the dry event, and that it is important to make a distinction between canals and marsh when measuring alligator response to hydrology.

  8. Growth plate formation and development in alligator and mouse metapodials: evolutionary and functional implications.

    PubMed

    Reno, Philip L; Horton, Walter E; Elsey, Ruth M; Lovejoy, C Owen

    2007-05-15

    Mammalian metapodials (metacarpals and metatarsals), unlike most long bones, form a single growth plate, and undergo longitudinal growth at only one end. The growth dynamics of non-mammalian tetrapod metapodials have not been systematically examined in order to determine if unidirectional growth is unique to mammals. Here we compare murine metapodial ossification in growth stages that parallel those of embryonic, juvenile and subadult American alligators (Alligator mississippiensis). Safranin O staining was used for qualitative histology, and chondrocyte differentiation and proliferation were assessed via immunohistochemistry for type X collagen and proliferative cell nuclear antigen (PCNA). We establish that growth plates form at both ends of alligator metapodials and are maintained in the subadult. PCNA results show that alligators and mice share common patterns of chondrocyte proliferation during growth plate formation. In addition, while alligators and mice differ initially in the degree of organization and pace of chondrocyte differentiation, these parameters are largely similar in established growth plates. However, the replacement of cartilage by bone is highly irregular throughout growth in the alligator, in contrast to the more uniform process in the mouse. These results indicate that while alligators and mammals share common mechanisms of chondrocyte regulation, they differ substantially in their processes of ossification. Phylogenetic analysis indicates that the direct ossification of one epiphysis and reliance on a single growth plate is a derived character (synapomorphy) in therian mammals and likely indicates an adaptation for erect quadrupedal gait. PMID:17285637

  9. Comparison of metabolic substrates in alligators and several birds of prey.

    PubMed

    Sweazea, Karen L; McMurtry, John P; Elsey, Ruth M; Redig, Patrick; Braun, Eldon J

    2014-08-01

    On average, avian blood glucose concentrations are 1.5-2 times those of mammals of similar mass and high concentrations of insulin are required to lower blood glucose. Whereas considerable data exist for granivorous species, few data are available for plasma metabolic substrate and glucoregulatory hormone concentrations for carnivorous birds and alligators. Birds and mammals with carnivorous diets have higher metabolic rates than animals consuming diets with less protein whereas alligators have low metabolic rates. Therefore, the present study was designed to compare substrate and glucoregulatory hormone concentrations in several birds of prey and a phylogenetically close relative of birds, the alligator. The hypothesis was that the combination of carnivorous diets and high metabolic rates favored the evolution of greater protein and fatty acid utilization leading to insulin resistance and high plasma glucose concentrations in carnivorous birds. In contrast, it was hypothesized that alligators would have low substrate utilization attributable to a low metabolic rate. Fasting plasma substrate and glucoregulatory hormone concentrations were compared for bald eagles (Haliaeetus leucocephalus), great horned owls (Bubo virginianus), red-tailed hawks (Buteo jamaicensis), and American alligators (Alligator mississippiensis). Avian species had high circulating β-hydroxybutyrate (10-21 mg/dl) compared to alligators (2.81 ± 0.16 mg/dl). In mammals high concentrations of this byproduct of fatty acid utilization are correlated with insulin resistance. Fasting glucose and insulin concentrations were positively correlated in eagles whereas no relationship was found between these variables for owls, hawks or alligators. Additionally, β-hydroxybutyrate concentrations were low in alligators. Similar to carnivorous mammals, ingestion of a high protein diet may have favored the utilization of fatty acids and protein for energy thereby promoting the development of insulin

  10. Comparison of metabolic substrates in alligators and several birds of prey.

    PubMed

    Sweazea, Karen L; McMurtry, John P; Elsey, Ruth M; Redig, Patrick; Braun, Eldon J

    2014-08-01

    On average, avian blood glucose concentrations are 1.5-2 times those of mammals of similar mass and high concentrations of insulin are required to lower blood glucose. Whereas considerable data exist for granivorous species, few data are available for plasma metabolic substrate and glucoregulatory hormone concentrations for carnivorous birds and alligators. Birds and mammals with carnivorous diets have higher metabolic rates than animals consuming diets with less protein whereas alligators have low metabolic rates. Therefore, the present study was designed to compare substrate and glucoregulatory hormone concentrations in several birds of prey and a phylogenetically close relative of birds, the alligator. The hypothesis was that the combination of carnivorous diets and high metabolic rates favored the evolution of greater protein and fatty acid utilization leading to insulin resistance and high plasma glucose concentrations in carnivorous birds. In contrast, it was hypothesized that alligators would have low substrate utilization attributable to a low metabolic rate. Fasting plasma substrate and glucoregulatory hormone concentrations were compared for bald eagles (Haliaeetus leucocephalus), great horned owls (Bubo virginianus), red-tailed hawks (Buteo jamaicensis), and American alligators (Alligator mississippiensis). Avian species had high circulating β-hydroxybutyrate (10-21 mg/dl) compared to alligators (2.81 ± 0.16 mg/dl). In mammals high concentrations of this byproduct of fatty acid utilization are correlated with insulin resistance. Fasting glucose and insulin concentrations were positively correlated in eagles whereas no relationship was found between these variables for owls, hawks or alligators. Additionally, β-hydroxybutyrate concentrations were low in alligators. Similar to carnivorous mammals, ingestion of a high protein diet may have favored the utilization of fatty acids and protein for energy thereby promoting the development of insulin

  11. Possible generational effects of habitat degradation on alligator reproduction

    USGS Publications Warehouse

    Fujisaki, Ikuko; Rice, K.G.; Woodward, A.R.; Percival, H.F.

    2007-01-01

    Population decline of the American alligator (Alligator mississippiensis) was observed in Lake Apopka in central Florida, USA, in the early 1980s. This decline was thought to result from adult mortality and nest failure caused by anthropogenic increases in sediment loads, nutrients, and contaminants. Reproductive impairment also was reported. Extensive restoration of marshes associated with Lake Apopka has been conducted, as well as some limited restoration measures on the lake. Monitoring by the Florida Fish and Wildlife Conservation Commission (FFWCC) has indicated that the adult alligator population began increasing in the early 1990s. We expected that the previously reported high proportion of complete nest failure (??0) during the 1980s may have decreased. We collected clutches from alligator nests in Lake Apopka from 1983 to 2003 and from 5 reference areas from 1988 to 1991, and we artificially incubated them. We used a Bayesian framework with Gibbs sampler of Markov chain Monte Carlo simulation to analyze ??0. Estimated ??0was consistently higher in Lake Apopka compared with reference areas, and the difference in ??0 ranged from 0.19 to 0.56. We conducted change point analysis to identify and test the significance of the change point in ??0in Lake Apopka between 1983 and 2003, indicating the point of reproductive recovery. The estimated Bayes factor strongly supported the single change point hypothesis against the no change point hypothesis. The major downward shift in ??0 probably occurred in the mid-1990s, approximately a generation after the major population decline in the 1980s. Furthermore, estimated ??0 values after the change point (0.21) were comparable with those of reference areas (0.07-0.31). These results combined with the monitoring by FFWCC seem to suggest that anthropogenic habitat degradation caused reproductive impairment of adult females and decreases in ??0 occurred with the sexual maturity of a new generation of breeding females. Long

  12. Traumatic Amputation of Finger From an Alligator Snapping Turtle Bite.

    PubMed

    Johnson, Robert D; Nielsen, Cynthia L

    2016-06-01

    Legend states that the alligator snapping turtle (Macrochelys temminckii) should be handled with extreme caution as it has jaw strength powerful enough to bite a wooden broomstick in half. Tales of bite injuries from what is the largest freshwater turtle in North America exist anecdotally, yet there are few descriptions of medical encounters for such. The risk of infection from reptilian bites to the hand in an aquatic environment warrants thorough antibiotic treatment in conjunction with hand surgery consultation. We present the first case report of a near total amputation of an index finger in an adolescent boy who had been bitten by a wild "gator snapper." PMID:27116923

  13. [Formation of the genome of the alligator gar Lepisosteus osseus (Ganoidomorpha) genome].

    PubMed

    Vladychenskaia, N S; Kedrova, O S; Petrov, N B

    1983-01-01

    Genome structure of the alligator gar was studied by means of a comparison of reassociation kinetics of short and long DNA fragments, an estimation of hyperchromicity of reassociated repetitive DNA as a function of fragments length, and length estimation of S1-resistant duplexes by gel filtration. It was shown that most of the repeated sequences in the alligator gar DNA are no less than 2000 b.p. long and weakly divergent. Little or no interspersion of unique and short repeated sequences were observed in this genome. No highly divergent repeats were found in the alligator gar genome. PMID:6855762

  14. [Formation of the genome of the alligator gar Lepisosteus osseus (Ganoidomorpha) genome].

    PubMed

    Vladychenskaia, N S; Kedrova, O S; Petrov, N B

    1983-01-01

    Genome structure of the alligator gar was studied by means of a comparison of reassociation kinetics of short and long DNA fragments, an estimation of hyperchromicity of reassociated repetitive DNA as a function of fragments length, and length estimation of S1-resistant duplexes by gel filtration. It was shown that most of the repeated sequences in the alligator gar DNA are no less than 2000 b.p. long and weakly divergent. Little or no interspersion of unique and short repeated sequences were observed in this genome. No highly divergent repeats were found in the alligator gar genome.

  15. Specialized stem cell niche enables repetitive renewal of alligator teeth.

    PubMed

    Wu, Ping; Wu, Xiaoshan; Jiang, Ting-Xin; Elsey, Ruth M; Temple, Bradley L; Divers, Stephen J; Glenn, Travis C; Yuan, Kuo; Chen, Min-Huey; Widelitz, Randall B; Chuong, Cheng-Ming

    2013-05-28

    Reptiles and fish have robust regenerative powers for tooth renewal. However, extant mammals can either renew their teeth one time (diphyodont dentition) or not at all (monophyodont dentition). Humans replace their milk teeth with permanent teeth and then lose their ability for tooth renewal. Here, we study tooth renewal in a crocodilian model, the American alligator, which has well-organized teeth similar to mammals but can still undergo life-long renewal. Each alligator tooth is a complex family unit composed of the functional tooth, successional tooth, and dental lamina. Using multiple mitotic labeling, we map putative stem cells to the distal enlarged bulge of the dental lamina that contains quiescent odontogenic progenitors that can be activated during physiological exfoliation or artificial extraction. Tooth cycle initiation correlates with β-catenin activation and soluble frizzled-related protein 1 disappearance in the bulge. The dermal niche adjacent to the dermal lamina dynamically expresses neural cell adhesion molecule, tenascin-C, and other molecules. Furthermore, in development, asymmetric β-catenin localization leads to the formation of a heterochronous and complex tooth family unit configuration. Understanding how these signaling molecules interact in tooth development in this model may help us to learn how to stimulate growth of adult teeth in mammals.

  16. Engineered In-Situ Precipitation of Technetium and Uranium in Groundwater at the Savannah River Site: Treatment Targeting Long-Term Stability (Invited)

    NASA Astrophysics Data System (ADS)

    Gillow, J. B.; Lutes, C. C.; Frizzell, A.; Clark, B.; Horst, J.

    2009-12-01

    The U.S. Department of Energy (DOE) Savannah River Site (SRS) is a former nuclear weapons facility that is undergoing clean-up of groundwater and soil contamination. Alternatives to conventional pump-and-treat are being evaluated through DOE’s Advanced Remediation Technologies (ART) program as part of the EM-22 Groundwater and Soil Remediation program. A pilot project is underway to evaluate an emerging approach to remediation through the in-situ precipitation of insoluble forms of technetium and uranium. The demonstration involves the injection of organic carbon into the aquifer to stimulate biogeochemical processes leading to the transformation of soluble radionuclides to insoluble forms. However, once carbon addition is ceased and geochemical conditions return to oxidizing, the insoluble radionuclides may re-dissolve. The pilot project will target long term stability by enhancing the creation of reduced mineral forms in and around the precipitated radionuclides to act as both a redox buffer for oxidizing groundwater and as a sorptive medium for any dissolved uranium and technetium. Successful treatment with respect to in situ radionuclide precipitation extends beyond numeric cleanup goals and invokes a standard of care that considers not only short-term solubility achieved during active remediation, but the range of factors that might erode/compromise the stability of the precipitated solids over the long-term. Long-term stability may be achieved by incorporating the targeted radionuclide in a matrix of other precipitates formed through the treatment process. In the short term, this can include the precipitates of other more abundant metals (e.g., iron) that can preferentially scavenge oxygen. Longer term, this is expected to transition to passivation within a matrix of more stable mineral phases, such that rates of rebound dissolution are sufficiently suppressed to maintain dissolved concentrations below remedial targets. The in situ reactive zone (IRZ

  17. A 3D interactive model and atlas of the jaw musculature of Alligator mississippiensis.

    PubMed

    Holliday, Casey M; Tsai, Henry P; Skiljan, Rebecca J; George, Ian D; Pathan, Sami

    2013-01-01

    Modern imaging and dissemination methods enable morphologists to share complex, three-dimensional (3D) data in ways not previously possible. Here we present a 3D interactive model of the jaw musculature of the American Alligator (Alligator mississippiensis). Alligator and crocodylian jaw musculature is notoriously challenging to inspect and interpret because of the derived nature of the feeding apparatus. Using Iodine-contrast enhanced microCT imaging, a segmented model of jaw muscles, trigeminal nerve, brain and skull are presented as a cross-sectional atlas and 3D, interactive pdf of the rendered model. Modern 3D dissemination methods like this 3D Alligator hold great potential for morphologists to share anatomical information to scientists, educators, and the public in an easily downloadable format. PMID:23762228

  18. ALTERED HISTOLOGY OF THE THYMUS AND SPLEEN IN CONTAMINANT-EXPOSED JUVENILE AMERICAN ALLIGATORS

    EPA Science Inventory

    Morphological difference in spleen and thymus are closely related to functional immune differences. Hormonal regulation of the immune system has been demonstrated in reptilian splenic and thymic tissue. Spleens and thymus were obtained from juvenile alligators at two reference si...

  19. Concentrations of contaminants in muscle of the American alligator in Florida

    SciTech Connect

    Delany, M.F.; Bell, J.U.; Sundlof, S.F.

    1988-01-01

    Samples of tail muscle from 32 American alligators (Alligator mississippiensis) in Florida were analyzed for contaminant concentrations to provide preliminary information on the potential public health hazard of meat consumption. Detectable levels were found for eight metals; copper, zinc, iron, chromium, mercury, lead, cadmium and arsenic. Mean residue was highest for mercury (geometric mean = 0.61 ppm). DDE, DDD, DDT, dieldrin, heptachlor epoxide, lindane, and PCB's were found. Mean residue concentrations were compared by lake. Alligators appeared to be suitable monitors of environmental pollution. Concentrations of contaminants found in these animals probably pose little threat to public health. However, recommendations must await analysis of larger sample sizes and information on amount and frequency of meat consumption. Alligators killed for human consumption should continue to be monitored for contaminant residues.

  20. WILDLIFE - ALLIGATOR STRADDLES TWO PARKING SPACES IN FRONT OF OFFICE TRAILER

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Double-parked, an angry alligator straddles two parking spaces outside an office trailer at NASA's Launch Complex 17. Hank Curtin of Pan Am watches from a safe perch as John Tanner gets ready to wrap a rope around the snout of the 10-foot, 9-inch beast. It's all in a day's work for Tanner, who has a contract with the state of Florida to remove nuisance alligators.

  1. The reproductive hormone cycle of adult female American alligators from a barrier island population.

    PubMed

    Hamlin, Heather J; Lowers, Russell H; Kohno, Satomi; Mitsui-Watanabe, Naoko; Amano, Haruna; Hara, Akihiko; Ohta, Yasuhiko; Miyagawa, Shinichi; Iguchi, Taisen; Guillette, Louis J

    2014-06-01

    Comparatively, little data are available detailing the geographic variation that exists in the reproductive endocrinology of adult alligators, especially those living in barrier islands. The Merritt Island National Wildlife Refuge (MI) is a unique barrier island environment and home to the Kennedy Space Center (FL, USA). Seasonal patterns of sex steroids were assessed in adult female American alligators from MI monthly from 2008 to 2009, with additional samples collected at more random intervals in 2006, 2007, and 2010. Plasma 17β-estradiol and vitellogenin concentrations peaked in April, coincident with courtship and mating, and showed patterns similar to those observed in adult female alligators in other regions. Plasma concentrations of progesterone, however, showed patterns distinctly different than those reported for alligator populations in other regions and remained relatively constant throughout the year. Plasma DHEA peaked in July around the time of oviposition, decreased in August, and then remained constant for the remaining months, except for a moderate increase in October. Circulating concentrations of DHEA have not been previously assessed in a female crocodilian, and plasma concentrations coincident with reproductive activity suggest a reproductive and/or behavioral role. Interestingly, plasma testosterone concentrations peaked in May of 2008, as has been shown in female alligator populations in other regions, but showed no peak in 2009, demonstrating dramatic variability from year to year. Surveys showed 2009 to be particularly depauperate of alligator nests in MI, and it is possible that testosterone could serve as a strong indicator of breeding success.

  2. Relationship between body condition of American alligators and water depth in the Everglades, Florida

    USGS Publications Warehouse

    Fujisaki, Ikuko; Rice, Kenneth G.; Pearlstine, Leonard G.; Mazzotti, Frank J.

    2009-01-01

    Feeding opportunities of American alligators (Alligator mississippiensis) in freshwater wetlands in south Florida are closely linked to hydrologic conditions. In the Everglades, seasonally and annually fluctuating surface water levels affect populations of aquatic organisms that alligators consume. Since prey becomes more concentrated when water depth decreases, we hypothesized an inverse relationship between body condition and water depth in the Everglades. On average, condition of adult alligators in the dry season was significantly higher than in the wet season, but this was not the case for juveniles/subadults. The correlation between body condition and measured water depth at capture locations was weak; however, there was a significant negative correlation between the condition and predicted water depth prior to capture for all animals except for spring juveniles/subadults which had a weak positive condition-water depth relationship. Overall, a relatively strong inverse correlation occurred at 10-49 days prior to the capture day, suggesting that current body condition of alligators may depend on feeding opportunities during that period. Fitted regression of body condition on water depth (mean depth of 10 days when condition-water depth correlation was greatest) resulted in a significantly negative slope, except for spring adult females and spring juveniles/subadults for which slopes were not significantly different from zero. Our results imply that water management practices may be critical for alligators in the Everglades since water depth can affect animal condition in a relatively short period of time.

  3. Detection of West Nile virus RNA in mosquitoes and identification of mosquito blood meals collected at alligator farms in Louisiana.

    PubMed

    Unlu, Isik; Kramer, Wayne L; Roy, Alma F; Foil, Lane D

    2010-07-01

    Since 2001, alligator farms in the United States have sustained substantial economic losses because of West Nile virus (WNV) outbreaks in American alligators (Alligator mississippiensis). Once an initial infection is introduced into captive alligators, WNV can spread among animals by contaminative transmission. Some outbreaks have been linked to feeding on infected meat or the introduction of infected hatchlings, but the initial source of WNV infection has been uncertain in other outbreaks. We conducted a study to identify species composition and presence of WNV in mosquito populations associated with alligator farms in Louisiana. A second objective of this study was to identify the origin of mosquito blood meals collected at commercial alligator farms. Mosquitoes were collected from 2004 to 2006, using Centers for Disease Control light traps, gravid traps, backpack aspirators, and resting boxes. We collected a total of 58,975 mosquitoes representing 24 species. WNV was detected in 41 pools of females from 11 mosquito species: Anopheles crucians, Anopheles quadrimaculatus, Coquillettidia perturbans, Culex coronator, Culex erraticus, Culex nigripalpus, Culex quinquefasciatus, Mansonia titillans, Aedes sollicitans, Psorophora columbiae, and Uranotaenia lowii. The blood meal origins of 213 field-collected mosquitoes were identified based on cytochrome B sequence identity. Alligator blood was detected in 21 mosquitoes representing six species of mosquitoes, including Cx. quinquefasciatus and Cx. nigripalpus. Our results showed that mosquitoes of species that are known to be competent vectors of WNV fed regularly on captive alligators. Therefore, mosquitoes probably are important in the role of transmission of WNV at alligator farms.

  4. Use of alligator hole abundance and occupancy rate as indicators for restoration of a human-altered wetland

    USGS Publications Warehouse

    Fujisaki, Ikuko; Mazzotti, Frank J.; Hart, Kristen M.; Rice, Kenneth G.; Ogurcak, Danielle; Rochford, Michael; Jeffery, Brian M.; Brandt, Laura A.; Cherkiss, Michael S.

    2012-01-01

    Use of indicator species as a measure of ecosystem conditions is an established science application in environmental management. Because of its role in shaping wetland systems, the American alligator (Alligator mississippiensis) is one of the ecological indicators for wetland restoration in south Florida, USA. We conducted landscape-level aerial surveys of alligator holes in two different habitats in a wetland where anthropogenic modification of surface hydrology has altered the natural system. Alligator holes were scarcer in an area where modified hydrology caused draining and frequent dry-downs compared to another area that maintains a functional wetland system. Lower abundance of alligator holes indicates lack of alligator activities, lower overall species diversity, and lack of dry-season aquatic refugia for other organisms. The occupancy rate of alligator holes was lower than the current restoration target for the Everglades, and was variable by size class with large size-class alligators predominantly occupying alligator holes. This may indicate unequal size-class distribution, different habitat selection by size classes, or possibly a lack of recruitment. Our study provides pre-restoration baseline information about one indicator species for the Everglades. Success of the restoration can be assessed via effective synthesis of information derived by collective research efforts on the entire suite of selected ecological indicators.

  5. Isolation and characterization of sulfite oxidase from Alligator mississipiensis

    SciTech Connect

    Robbins, A.; Neame, P.J.; Barber, M.J. )

    1991-03-11

    Sulfite oxidase has been isolated from fresh alligator liver using ammonium sulfate and acetone fractionation, DEAE chromatography and FPLC on Mono Q. The enzyme is dimeric and exhibits a subunit M. Wt. of approximately 58 kDa, larger than that of chicken SO. EPR spectroscopy of the partially-reduced enzyme revealed a single Mo(V) species while visible spectroscopy revealed the presence of cytochrome b{sub 557}. Maximal activities were obtained at pH 8 and 9, respectively. K{sub m}'s for SO{sub 3}{sup 2 {minus}}, cyt. c and Fe(CN){sub 6}{sup 3 {minus}} were 23.5 uM, 2.9 uM and 8.0 uM, respectively. Sequencing of peptides obtained by endoprotease K digestion indicated regions of extensive sequence similarity to chicken and rat enzymes in both heme and Mo-pterin domains. Regions of sequence dissimilarity were also found.

  6. A Chinese alligator in heliox: formant frequencies in a crocodilian

    PubMed Central

    Reber, Stephan A.; Nishimura, Takeshi; Janisch, Judith; Robertson, Mark; Fitch, W. Tecumseh

    2015-01-01

    ABSTRACT Crocodilians are among the most vocal non-avian reptiles. Adults of both sexes produce loud vocalizations known as ‘bellows’ year round, with the highest rate during the mating season. Although the specific function of these vocalizations remains unclear, they may advertise the caller's body size, because relative size differences strongly affect courtship and territorial behaviour in crocodilians. In mammals and birds, a common mechanism for producing honest acoustic signals of body size is via formant frequencies (vocal tract resonances). To our knowledge, formants have to date never been documented in any non-avian reptile, and formants do not seem to play a role in the vocalizations of anurans. We tested for formants in crocodilian vocalizations by using playbacks to induce a female Chinese alligator (Alligator sinensis) to bellow in an airtight chamber. During vocalizations, the animal inhaled either normal air or a helium/oxygen mixture (heliox) in which the velocity of sound is increased. Although heliox allows normal respiration, it alters the formant distribution of the sound spectrum. An acoustic analysis of the calls showed that the source signal components remained constant under both conditions, but an upward shift of high-energy frequency bands was observed in heliox. We conclude that these frequency bands represent formants. We suggest that crocodilian vocalizations could thus provide an acoustic indication of body size via formants. Because birds and crocodilians share a common ancestor with all dinosaurs, a better understanding of their vocal production systems may also provide insight into the communication of extinct Archosaurians. PMID:26246611

  7. A Chinese alligator in heliox: formant frequencies in a crocodilian.

    PubMed

    Reber, Stephan A; Nishimura, Takeshi; Janisch, Judith; Robertson, Mark; Fitch, W Tecumseh

    2015-08-01

    Crocodilians are among the most vocal non-avian reptiles. Adults of both sexes produce loud vocalizations known as 'bellows' year round, with the highest rate during the mating season. Although the specific function of these vocalizations remains unclear, they may advertise the caller's body size, because relative size differences strongly affect courtship and territorial behaviour in crocodilians. In mammals and birds, a common mechanism for producing honest acoustic signals of body size is via formant frequencies (vocal tract resonances). To our knowledge, formants have to date never been documented in any non-avian reptile, and formants do not seem to play a role in the vocalizations of anurans. We tested for formants in crocodilian vocalizations by using playbacks to induce a female Chinese alligator (Alligator sinensis) to bellow in an airtight chamber. During vocalizations, the animal inhaled either normal air or a helium/oxygen mixture (heliox) in which the velocity of sound is increased. Although heliox allows normal respiration, it alters the formant distribution of the sound spectrum. An acoustic analysis of the calls showed that the source signal components remained constant under both conditions, but an upward shift of high-energy frequency bands was observed in heliox. We conclude that these frequency bands represent formants. We suggest that crocodilian vocalizations could thus provide an acoustic indication of body size via formants. Because birds and crocodilians share a common ancestor with all dinosaurs, a better understanding of their vocal production systems may also provide insight into the communication of extinct Archosaurians. PMID:26246611

  8. Post-hatching development of Alligator mississippiensis ovary and testis

    PubMed Central

    Moore, Brandon C.; Hamlin, Heather J.; Botteri, Nicole L.; Lawler, Ashley N.; Mathavan, Ketan K.; Guillette, Louis J.

    2009-01-01

    We investigated ovary and testis development of Alligator mississippiensis during the first five months post-hatch. To better describe follicle assembly and seminiferous cord development, we employed histochemical techniques to detect carbohydrate-rich extracellular matrix components in one-week, one-month, three-month, and five-month-old gonads. We found profound morphological changes in both ovary and testis. During this time, oogenesis progressed up to diplotene arrest and meiotic germ cells increasingly interacted with follicular cells. Concomitant with follicles becoming invested with full complements of granulosa cells, a periodic acid Schiff’s (PAS)-positive basement membrane formed. As follicles enlarged and thecal layers were observed, basement membranes and thecal compartments gained periodic acid-methionine silver (PAMS)-reactive fibers. The ovarian medulla increased first PAS- and then PAMS-reactivity as it fragmented into wide lacunae lined with low cuboidal to squamous epithelia. During this same period, testicular germ cells found along the tubule margins were observed progressing from spermatogonia to round spermatids located within the center of tubules. Accompanying this meiotic development, interstitial Leydig cell clusters become more visible and testicular capsules thickened. During the observed testis development, the thickening tunica albuginea and widening interstitial tissues showed increasing PAS- and PAMS-reactivity. We observed putative inter-sex structures in both ovary and testis. On the coelomic aspect of testes were cell clusters with germ cell morphology and at the posterior end of ovaries, we observed “medullary rests” resembling immature testis cords. We hypothesize laboratory conditions accelerated gonad maturation due to optimum conditions, including nutrients and temperature. Laboratory alligators grew more rapidly and with increased body conditions compared to previous measured, field-caught animals. Additionally, we

  9. URANIUM COMPOSITIONS

    DOEpatents

    Allen, N.P.; Grogan, J.D.

    1959-05-12

    This patent relates to high purity uranium alloys characterized by improved stability to thermal cycling and low thermal neutron absorption. The high purity uranium alloy contains less than 0.1 per cent by weight in total amount of any ore or more of the elements such as aluminum, silicon, phosphorous, tin, lead, bismuth, niobium, and zinc.

  10. Ground water protection strategy for the Uranium Mill Tailings Site at Green River, Utah. Final, Revision 2, Version 5: Appendix E to the remedial action plan and site design for stabilization of the inactive uranium mill tailings site at Green River, Utah

    SciTech Connect

    1995-09-01

    The purpose of this appendix is to provide a ground water protection strategy for the Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site at Green River, Utah. Compliance with the US Environmental Protection Agency (EPA) ground water protection standards will be achieved by applying supplemental standards (40 CFR {section} 192.22(a); 60 FR 2854) based on the limited use ground water present in the uppermost aquifer that is associated with widespread natural ambient contamination (40 CFR {section} 192.11(e); 60 FR 2854). The strategy is based on new information, including ground water quality data collected after remedial action was completed, and on a revised assessment of disposal cell design features, surface conditions, and site hydrogeology. The strategy will result in compliance with Subparts A and C of the EPA final ground water protection standards (60 FR 2854). The document contains sufficient information to support the proposed ground water protection strategy, with monitor well information and ground water quality data included as a supplement. Additional information is available in the final remedial action plan (RAP) (DOE, 1991a), the final completion report (DOE, 1991b), and the long-term surveillance plan (LTSP) (DOE, 1994a).

  11. Thermal acclimation, mitochondrial capacities and organ metabolic profiles in a reptile (Alligator mississippiensis).

    PubMed

    Guderley, Helga; Seebacher, Frank

    2011-01-01

    Reptiles thermoregulate behaviourally, but change their preferred temperature and the optimal temperature for performance seasonally. We evaluated whether the digestive and locomotor systems of the alligator show parallel metabolic adjustments during thermal acclimation. To this end, we allowed juvenile alligators to grow under thermal conditions typical of winter and summer, providing them with seasonally appropriate basking opportunities. Although mean body temperatures of alligators in these groups differed by approximately 10°C, their growth and final anatomic status was equivalent. While hepatic mitochondria isolated from cold-acclimated alligators had higher oxidative capacities at 30°C than those from warm-acclimated alligators, the capacities did not differ at 20°C. Cold acclimation decreased maximal oxidative capacities of muscle mitochondria. For mitochondria from both organs and acclimation groups, palmitate increased oligomycin-inhibited respiration. GDP addition reduced palmitate-uncoupled rates more in liver mitochondria from warm- than cold-acclimated alligators. In muscle mitochondria, carboxyatractyloside significantly reduced palmitate-uncoupled rates. This effect was not changed by thermal acclimation. The aerobic capacity of liver, skeletal muscle and duodenum, as estimated by activities of cytochrome c oxidase (COX), increased with cold acclimation. At acclimation temperatures, the activities of COX and citrate synthase (CS) in these organs were equivalent. By measuring COX and CS in isolated mitochondria and tissue extracts, we estimated that cold acclimation did not change the mitochondrial content in liver, but increased that of muscle. The thermal compensation of growth rates and of the aerobic capacity of the locomotor and digestive systems suggests that alligators optimised metabolic processes for the seasonally altered, preferred body temperature. The precision of this compensatory response exceeds that typically shown by aquatic

  12. 50 CFR 23.70 - How can I trade internationally in American alligator and other crocodilian skins, parts, and...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... laws regulating harvest seasons and methods. (iii) Total allowable harvest of the species. (iv..., including harvest of nuisance alligators, methods used to determine harvest levels, demographics of the harvest, and methods used to determine the total number and population trends of alligators in the...

  13. 33 CFR 334.760 - Naval Support Activity Panama City and Alligator Bayou, a tributary of St. Andrew Bay, Fla...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Naval Support Activity Panama City and Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. 334.760 Section... Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. (a) The area. The waters...

  14. 33 CFR 334.760 - Naval Support Activity Panama City and Alligator Bayou, a tributary of St. Andrew Bay, Fla...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Naval Support Activity Panama City and Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. 334.760 Section... Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. (a) The area. The waters...

  15. 33 CFR 334.760 - Naval Support Activity Panama City and Alligator Bayou, a tributary of St. Andrew Bay, Fla...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Naval Support Activity Panama City and Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. 334.760 Section... Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. (a) The area. The waters...

  16. 33 CFR 334.760 - Naval Support Activity Panama City and Alligator Bayou, a tributary of St. Andrew Bay, Fla...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Naval Support Activity Panama City and Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. 334.760 Section... Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. (a) The area. The waters...

  17. Chronic Ingestion of Coal Fly-Ash Contaminated Prey and Its Effects on Health and Immune Parameters in Juvenile American Alligators (Alligator mississippiensis).

    PubMed

    Finger, John W; Hamilton, Matthew T; Metts, Brian S; Glenn, Travis C; Tuberville, Tracey D

    2016-10-01

    Coal-burning power plants supply approximately 37 % of the electricity in the United States. However, incomplete combustion produces ash wastes enriched with toxic trace elements that have historically been disposed of in aquatic basins. Organisms inhabiting such habitats may accumulate these trace elements; however, studies investigating the effects on biota have been primarily restricted to shorter-lived, lower-trophic organisms. The American alligator (Alligator mississippiensis), a long-lived, top-trophic carnivore, has been observed inhabiting these basins, yet the health or immune effects of chronic exposure and possible accumulation remains unknown. In this study, we investigated how chronic dietary ingestion of prey contaminated with coal combustion wastes (CCWs) for 25 months, and subsequent accumulation of trace elements present in CCWs, affected juvenile alligator immune function and health. Alligators were assigned to one of four dietary-treatment groups including controls and those fed prey contaminated with CCWs for one, two, or three times a week. However, no effect of Dietary Treatment (p > 0.05) was observed on any immune parameter or hematological or plasma analyte we tested. Our results suggest that neither exposure to nor accumulation of low doses of CCWs had a negative effect on certain aspects of the immune and hematological system. However, future studies are required to elucidate this further. PMID:27475646

  18. Phase I and II liver enzyme activities in juvenile alligators (Alligator mississippiensis) collected from three sites in the Kissimmee-Everglades drainage, Florida (USA).

    PubMed

    Gunderson, M P; Oberdörster, E; Guillette, L J

    2004-10-01

    We examined CYP1A (measured using hepatic EROD and MROD activities) and glutathione-S-transferase (GST) activities in juvenile alligators (Alligator mississippiensis) collected from three sites with varying contamination in the Kissimmee-Everglades drainage in south Florida. We hypothesized that contaminants present in areas with intermediate or higher contaminant concentrations would alter hepatic enzyme activities in juvenile alligators from those sites when compared to hepatic enzyme activity in animals from the area with the least contamination. EROD activity was found to be higher in animals from the site with lower reported levels of contamination relative to those from the site with the highest reported contamination suggesting an inhibition of CYP1A expression or activity. No differences among animals from the three sites were observed for hepatic MROD and GST activities. A significant negative relationship between EROD, MROD, and GST activities and body size was exhibited in alligators from the site with the lowest contamination. No relationship between body size and hepatic enzyme activity was found in animals from the sites with intermediate and higher contamination, suggesting that contaminants present at these sites act to alter this relationship. No correlation was observed in this study between plasma steroid concentrations (estradiol-17 beta or testosterone) and hepatic EROD, MROD, or GST activities.

  19. Effects of egg and hatchling harvest on American alligators in Florida

    USGS Publications Warehouse

    Rice, K.G.; Percival, H.F.; Woodward, A.R.; Jennings, Michael L.

    1999-01-01

    Harvest of crocodilian eggs and young for captive rearing (ranching) has been used worldwide as an option for producing crocodilian skins and meat from wild stock. The long-term effects of harvesting a certain proportion of early age class, wild American alligators (Alligator mississippiensis) without repatriation is unknown. We removed an estimated 50% of annual production of alligators on Lakes Griffin and Jesup in central Florida over an 11-year period and monitored population levels via night-light counts. Densities of the total alligator population increased (P 0.117), and subadult (122-182 cm TL) alligators increased (P < 0.011) on harvest areas. The density of juveniles on the control area increased (P = 0.006), and the density of subadults showed some evidence of increasing (P = 0.088). No changes were detected in size distributions on the treatment areas. Nest production, as observed from aerial helicopter surveys, increased (P < 0.039) on Lake Woodruff NWR and Lake Jesup and showed some evidence of an increase on Lake Griffin (P = 0.098) during 1983-91. A 50% harvest rate of eggs or hatchlings did not adversely affect recruitment into the subadult or adult size classes.

  20. American alligator digestion rate of blue crabs and its implications for stomach contents analysis

    USGS Publications Warehouse

    Nifong, James C.; Rosenblatt, Adam E.; Johnson, Nathan A.; Barichivich, William; Silliman, Brian; Heithaus, Michael R.

    2012-01-01

    Stomach contents analysis (SCA) provides a snap-shot observation of a consumer's diet. Interpretation of SCA data can be complicated by many factors, including variation in gastric residence times and digestion rates among prey taxa. Although some SCA methods are reported to efficiently remove all stomach contents, the effectiveness of these techniques has rarely been tested for large irregular shaped prey with hard exoskeletons. We used a controlled feeding trial to estimate gastric residency time and decomposition rate of a large crustacean prey item, the Blue Crab (Callinectes sapidus), which is consumed by American Alligators (Alligator mississippiensis), an abundant apex predator in coastal habitats of the southeastern United States. The decomposition rate of C. sapidus in the stomachs of A. mississippiensis followed a predictable pattern, and some crab pieces remained in stomachs for at least 14 days. We also found that certain portions of C. sapidus were prone to becoming caught within the stomach or esophagus, meaning not all crab parts are consistently recovered using gastric lavage techniques. However, because the state of decomposition of crabs was predictable, it is possible to estimate time since consumption for crabs recovered from wild alligators. This information, coupled with a detailed understanding of crab distributions and alligator movement tactics could help elucidate patterns of cross-ecosystem foraging by the American Alligator in coastal habitats

  1. The influence of regional hydrology on nesting behavior and nest fate of the American alligator

    USGS Publications Warehouse

    Ugarte, Cristina A.; Bass, Oron L.; Nuttle, William; Mazzotti, Frank J.; Rice, Kenneth G.; Fujisaki, Ikuko; Whelan, Kevin R.T.

    2013-01-01

    Hydrologic conditions are critical to the nesting behavior and reproductive success of crocodilians. In South Florida, USA, growing human settlement has led to extensive surface water management and modification of historical water flows in the wetlands, which have affected regional nesting of the American alligator (Alligator mississippiensis). Although both natural and anthropogenic factors are considered to determine hydrologic conditions, the aspects of hydrological patterns that affect alligator nest effort, flooding (partial and complete), and failure (no hatchling) are unclear. We deconstructed annual hydrological patterns using harmonic models that estimated hydrological matrices including mean, amplitude, timing of peak, and periodicity of surface water depth and discharge and examined their effects on alligator nesting using survey data from Shark Slough, Everglades National Park, from 1985 to 2005. Nest effort increased in years with higher mean and lesser periodicity of water depth. A greater proportion of nests were flooded and failed when peak discharge occurred earlier in the year. Also, nest flooding rates were greater in years with greater periodicity of water depth, and nest failure rate was greater when mean discharge was higher. This study guides future water management decisions to mitigate negative impacts on reproduction of alligators and provides wildlife managers with a tool for assessing and modifying annual water management plans to conserve crocodilians and other wetland species.

  2. Body temperatures and behavior of American alligators during cold winter weather

    SciTech Connect

    Brisbin, I.L., Jr.; Standora, E.A.; Vargo, M.J.

    1982-04-01

    Data from two large (188 and 135 kg) male alligators (Alligator mississippiensis) indicated that 4-5 C seemed to be the lowest body temperatures that they could endure with subsequent recovery. Although one animal in shallow water managed to keep a breathing hole open for several days, in ice that was 1.5 cm thick, it later died following a decrease of its body temperature to 4.0 C. The second alligator which was located in a deeper portion of the reservoir used both terrestrial and aquatic basking behavior to raise its body temperature and level of activity. Except in the case of basking events, there was not clear evidence of significant evaluations of the body temperatures of either the live or dead alligators above those of their adjacent water. When located side-by-side, diurnal cycles of deep body temperatures exceeding adjacent water temperatures to a maximum extent near dawn and usually falling below water temperatures during the afternoon and early evening hours. The physical properties and thermal inertia of the bodies of such large alligators, when placed in appropriate microclimates, may be sufficient in themselves to explain the general patterns and levels of body temperature changes observed at these low temperatures.

  3. The effects of hurricane Rita and subsequent drought on alligators in southwest Louisiana.

    PubMed

    Lance, Valentine A; Elsey, Ruth M; Butterstein, George; Trosclair, Phillip L; Merchant, Mark

    2010-02-01

    Hurricane Rita struck the coast of southwest Louisiana in September 2005. The storm generated an enormous tidal surge of approximately four meters in height that inundated many thousands of acres of the coastal marsh with full strength seawater. The initial surge resulted in the deaths of a number of alligators and severely stressed those who survived. In addition, a prolonged drought (the lowest rainfall in 111 years of recorded weather data) following the hurricane resulted in highly saline conditions that persisted in the marsh for several months. We had the opportunity to collect 11 blood samples from alligators located on Holly Beach less than a month after the hurricane, but were unable to collect samples from alligators on Rockefeller Wildlife Refuge until February 2006. Conditions at Rockefeller Refuge did not permit systematic sampling, but a total of 201 samples were collected on the refuge up through August 2006. The blood samples were analyzed for sodium, potassium, chloride, osmolality, and corticosterone. Blood samples from alligators sampled on Holly Beach in October 2005, showed a marked elevation in plasma osmolality, sodium, chloride, potassium, corticosterone, and an elevated heterophil/lymphocyte ratio. Blood samples from alligators on Rockefeller Refuge showed increasing levels of corticosterone as the drought persisted and elevated osmolality and electrolytes. After substantial rainfall in July and August, these indices of osmotic stress returned to within normal limits.

  4. Conservation genetics of the alligator snapping turtle: cytonuclear evidence of range-wide bottleneck effects and unusually pronounced geographic structure

    USGS Publications Warehouse

    Echelle, A.A.; Hackler, J.C.; Lack, Justin B.; Ballard, S. R.; Roman, J.; Fox, S. F.; Leslie,, David M.; Van Den Bussche, Ronald A.

    2010-01-01

    A previous mtDNA study indicated that female-mediated gene flow was extremely rare among alligator snapping turtle populations in different drainages of the Gulf of Mexico. In this study, we used variation at seven microsatellite DNA loci to assess the possibility of male-mediated gene flow, we augmented the mtDNA survey with additional sampling of the large Mississippi River System, and we evaluated the hypothesis that the consistently low within-population mtDNA diversity reflects past population bottlenecks. The results show that dispersal between drainages of the Gulf of Mexico is rare (F STmsat  = 0.43, ΦSTmtDNA = 0.98). Past range-wide bottlenecks are indicated by several genetic signals, including low diversity for microsatellites (1.1–3.9 alleles/locus; H e = 0.06–0.53) and mtDNA (h = 0.00 for most drainages; π = 0.000–0.001). Microsatellite data reinforce the conclusion from mtDNA that the Suwannee River population might eventually be recognized as a distinct taxonomic unit. It was the only population showing fixation or near fixation for otherwise rare microsatellite alleles. Six evolutionarily significant units are recommended on the basis of reciprocal mtDNA monophyly and high levels of microsatellite DNA divergence.

  5. Animal-borne imaging reveals novel insights into the foraging behaviors and Diel activity of a large-bodied apex predator, the American alligator (Alligator mississippiensis).

    PubMed

    Nifong, James C; Nifong, Rachel L; Silliman, Brian R; Lowers, Russell H; Guillette, Louis J; Ferguson, Jake M; Welsh, Matthew; Abernathy, Kyler; Marshall, Greg

    2014-01-01

    Large-bodied, top- and apex predators (e.g., crocodilians, sharks, wolves, killer whales) can exert strong top-down effects within ecological communities through their interactions with prey. Due to inherent difficulties while studying the behavior of these often dangerous predatory species, relatively little is known regarding their feeding behaviors and activity patterns, information that is essential to understanding their role in regulating food web dynamics and ecological processes. Here we use animal-borne imaging systems (Crittercam) to study the foraging behavior and activity patterns of a cryptic, large-bodied predator, the American alligator (Alligator mississippiensis) in two estuaries of coastal Florida, USA. Using retrieved video data we examine the variation in foraging behaviors and activity patterns due to abiotic factors. We found the frequency of prey-attacks (mean = 0.49 prey attacks/hour) as well as the probability of prey-capture success (mean = 0.52 per attack) were significantly affected by time of day. Alligators attempted to capture prey most frequently during the night. Probability of prey-capture success per attack was highest during morning hours and sequentially lower during day, night, and sunset, respectively. Position in the water column also significantly affected prey-capture success, as individuals' experienced two-fold greater success when attacking prey while submerged. These estimates are the first for wild adult American alligators and one of the few examples for any crocodilian species worldwide. More broadly, these results reveal that our understandings of crocodilian foraging behaviors are biased due to previous studies containing limited observations of cryptic and nocturnal foraging interactions. Our results can be used to inform greater understanding regarding the top-down effects of American alligators in estuarine food webs. Additionally, our results highlight the importance and power of using animal-borne imaging when

  6. Molecular cloning, characterization, tissue distribution and mRNA expression changes during the hibernation and reproductive periods of estrogen receptor alpha (ESR1) in Chinese alligator, Alligator sinensis.

    PubMed

    Zhang, Ruidong; Hu, Yuehong; Wang, Huan; Yan, Peng; Zhou, Yongkang; Wu, Rong; Wu, Xiaobing

    2016-10-01

    Chinese alligator, Alligator sinensis, is a critically endangered reptile species unique to China. Little is known about the mechanism of growth- and reproduction-related hormones gene expression in Chinese alligator. Estrogens play important roles in regulating multiple reproduction- and non-reproduction-related functions by binding to their corresponding receptors. Here, the full-length cDNA of estrogen receptor alpha (ERα/ESR1) was cloned and sequenced from Chinese alligator for the first time, which comprises 1764bp nucleotides and encodes a predicted protein of 587 amino acids. Phylogenetic analysis of ESR1 showed that crocodilians and turtles were the sister-group of birds. The results of real-time quantitative PCR indicated that the ESR1 mRNA was widely expressed in the brain and peripheral tissues. In the brain and pituitary gland, ESR1 was most highly transcribed in the cerebellum. But in other peripheral tissues, ESR1 mRNA expression level was the highest in the ovary. Compared with hibernation period, ESR1 mRNA expression levels were increased significantly in the reproductive period (P<0.05) in cerebellum, pituitary gland, liver, spleen, lung, kidney and ovary, while no significant change in other examined tissues (P>0.05). The ESR1 mRNA expression levels changes during the two periods of different tissues suggested that ESR1 might play an important role in mediation of estrogenic multiple reproductive effects in Chinese alligator. Furthermore, it was the first time to quantify ESR1 mRNA level in the brain of crocodilians, and the distribution and expression of ESR1 mRNA in the midbrain, cerebellum and medulla oblongata was also reported for the first time in reptiles. PMID:27212643

  7. Animal-Borne Imaging Reveals Novel Insights into the Foraging Behaviors and Diel Activity of a Large-Bodied Apex Predator, the American Alligator (Alligator mississippiensis)

    PubMed Central

    Nifong, James C.; Nifong, Rachel L.; Silliman, Brian R.; Lowers, Russell H.; Guillette, Louis J.; Ferguson, Jake M.; Welsh, Matthew; Abernathy, Kyler; Marshall, Greg

    2014-01-01

    Large-bodied, top- and apex predators (e.g., crocodilians, sharks, wolves, killer whales) can exert strong top-down effects within ecological communities through their interactions with prey. Due to inherent difficulties while studying the behavior of these often dangerous predatory species, relatively little is known regarding their feeding behaviors and activity patterns, information that is essential to understanding their role in regulating food web dynamics and ecological processes. Here we use animal-borne imaging systems (Crittercam) to study the foraging behavior and activity patterns of a cryptic, large-bodied predator, the American alligator (Alligator mississippiensis) in two estuaries of coastal Florida, USA. Using retrieved video data we examine the variation in foraging behaviors and activity patterns due to abiotic factors. We found the frequency of prey-attacks (mean = 0.49 prey attacks/hour) as well as the probability of prey-capture success (mean = 0.52 per attack) were significantly affected by time of day. Alligators attempted to capture prey most frequently during the night. Probability of prey-capture success per attack was highest during morning hours and sequentially lower during day, night, and sunset, respectively. Position in the water column also significantly affected prey-capture success, as individuals’ experienced two-fold greater success when attacking prey while submerged. These estimates are the first for wild adult American alligators and one of the few examples for any crocodilian species worldwide. More broadly, these results reveal that our understandings of crocodilian foraging behaviors are biased due to previous studies containing limited observations of cryptic and nocturnal foraging interactions. Our results can be used to inform greater understanding regarding the top-down effects of American alligators in estuarine food webs. Additionally, our results highlight the importance and power of using animal

  8. JACKETING URANIUM

    DOEpatents

    Saller, H.A.; Keeler, J.R.

    1959-07-14

    The bonding to uranium of sheathing of iron or cobalt, or nickel, or alloys thereof is described. The bonding is accomplished by electro-depositing both surfaces to be joined with a coating of silver and amalgamating or alloying the silver layer with mercury or indium. Then the silver alloy is homogenized by exerting pressure on an assembly of the uranium core and the metal jacket, reducing the area of assembly and heating the assembly to homogenize by diffusion.

  9. Coplanar PCB distribution between chorioallantoic membranes and eggs of alligators and Loggerhead sea turtles

    SciTech Connect

    Bargar, T.A.; Cobb, G.P.

    1995-12-31

    The relative distribution of coplanar polychlorinated biphenyls (PCBs) between chorioallantoic membranes (CAMS) and eggs was investigated in inviable American alligator (Alligator mississippiensis) and Loggerhead sea turtle (Caretta caretra) eggs. Cam and egg extracts were fractionated by HPLC using a porous graphitic column (PGC) and an in line switching valve to separate coplanar from non-coplanar PCBs. The fractions were collected, concentrated by nitrogen evaporation, and injected on GC-ECD (60M DB-5 capillary column) for quantification. Alligator and Loggerhead sea turtle eggs contain toxicologically significant coplanar PCBs. Mono-ortho substituted PCBs were present with greater frequency relative to non-ortho substituted PCBs in both eggs and CAMS. The presence of coplanar PCBs in eggs appears to be correlated to coplanar PCB presence in CAMS. The chorioallantoic membrane could serve as a biomarker of embryo exposure to coplanar PCBs.

  10. American alligator proximal pedal phalanges resemble human finger bones: Diagnostic criteria for forensic investigators.

    PubMed

    Ferraro, Joseph V; Binetti, Katie M

    2014-07-01

    A scientific approach to bone and tooth identification requires analysts to pursue the goal of empirical falsification. That is, they may attribute a questioned specimen to element and taxon only after having ruled out all other possible attributions. This requires analysts to possess a thorough understanding of both human and non-human osteology, particularly so for remains that may be morphologically similar across taxa. To date, forensic anthropologists have identified several potential 'mimics' for human skeletal remains, including pig teeth and bear paws. Here we document another possible mimic for isolated human skeletal elements--the proximal pedal phalanges of American alligators (Alligator mississippiensis) closely resemble the proximal and intermediate hand phalanges of adult humans. We detail morphological similarities and differences between these elements, with the goal of providing sufficient information for investigators to confidently falsify the hypothesis that a questioned phalanx is derived from an American alligator.

  11. [Comparison of the genome of the alligator gar with the genomes of several other fish].

    PubMed

    Kedrova, O S; Vladychenskaia, N S; Antonov, A S

    1983-01-01

    Hybridization of alligator gar (Lepisosteus osseus, Lepisosteiformes, Ganoidomorpha) [125I]- or [3H]DNA fractions with DNAs of more or less phylogenetically related fishes was studied. Almost all of the repeated and unique sequences of alligator gar DNA and DNA of the spotted gar (from the same genus) are highly homologous (1-2% of nucleotide substitutions). The degrees of homology between repeated and unique sequences of alligator gar DNA and DNAs of the representatives of Acipenseriformes (the same super-order Ganoidomorpha), Latimeria chalumnae (another subclass, Sarcopterygii) and a shark (another class, Chondrichthyes) are of the same order, and the levels of divergency of their DNAs sequences are similar. These results demonstrate, that the joining of Lepisosteiformes and Acipenseriformes in one and the same group of Ganoidomorpha is artificial, and that the superclass of fishes, Pisces, includes more taxons of the class rank then it has been taken in theory. PMID:6855763

  12. [Comparison of the genome of the alligator gar with the genomes of several other fish].

    PubMed

    Kedrova, O S; Vladychenskaia, N S; Antonov, A S

    1983-01-01

    Hybridization of alligator gar (Lepisosteus osseus, Lepisosteiformes, Ganoidomorpha) [125I]- or [3H]DNA fractions with DNAs of more or less phylogenetically related fishes was studied. Almost all of the repeated and unique sequences of alligator gar DNA and DNA of the spotted gar (from the same genus) are highly homologous (1-2% of nucleotide substitutions). The degrees of homology between repeated and unique sequences of alligator gar DNA and DNAs of the representatives of Acipenseriformes (the same super-order Ganoidomorpha), Latimeria chalumnae (another subclass, Sarcopterygii) and a shark (another class, Chondrichthyes) are of the same order, and the levels of divergency of their DNAs sequences are similar. These results demonstrate, that the joining of Lepisosteiformes and Acipenseriformes in one and the same group of Ganoidomorpha is artificial, and that the superclass of fishes, Pisces, includes more taxons of the class rank then it has been taken in theory.

  13. Water hyacinths and alligator weeds for removal of silver, cobalt, and strontium from polluted waters

    NASA Technical Reports Server (NTRS)

    Wolverton, B. C.; Mcdonald, R. C.

    1975-01-01

    Water hyacinths and alligator weeds demonstrated the ability to rapidly remove heavy metals from an aqueous system by root absorption and concentration. Water hyacinths demonstrated the ability to remove 0.439 mg of silver, 0.568 mg of cobalt, and 0.544 mg of strontium in an ionized form per gram of dry plant material in a 24-hour period. Alligator weeds removed a maximum of 0.439 mg of silver, 0.130 mg of cobalt, and 0.161 mg of strontium per gram of dry plant material per day.

  14. Dujardinascaris gigantea sp. n. (Nematoda: Ascaridida) from the critically endangered crocodile Alligator sinensis Fauvel (Reptilia: Crocodylia).

    PubMed

    Zhao, Jin-Hong; Li, Liang; Guo, Yan-Ning; Zhang, Lu-Ping

    2015-03-01

    The Chinese alligator Alligator sinensis Fauvel (Reptilia: Crocodylia) is considered as one of the most critically endangered species of the 23 extant crocodiles. However, our knowledge of the helminth parasites of this rare animal is completely lacking. During a helminthological survey of reptiles in China, we found a new ascaridoid nematode, Dujardinascaris gigantea sp. n. from A. sinensis. The morphology of D. gigantea sp. n. was studied using light and scanning electron microscopy. The new species was also characterised using molecular methods by sequencing and analysing the small ribosomal DNA (18S) and the second internal transcribed spacer (ITS-2).

  15. Patterns of sexual dimorphism in Mexican alligator lizards, Barisia imbricata

    PubMed Central

    Dashevsky, Daniel; Meik, Jesse M; Mociño-Deloya, Estrella; Setser, Kirk; Schaack, Sarah

    2013-01-01

    We compare morphological characteristics of male and female Barisia imbricata, Mexican alligator lizards, and find that mass, head length, coloration, incidence of scars from conspecifics, tail loss, and frequency of bearing the color/pattern of the opposite sex are all sexually dimorphic traits. Overall size (measured as snout–vent length), on the other hand, is not different between the two sexes. We use data on bite scar frequency and fecundity to evaluate competing hypotheses regarding the selective forces driving these patterns. We contend that sexual selection, acting through male-male competition, may favor larger mass and head size in males, whereas large females are likely favored by natural selection for greater fecundity. In addition, the frequency of opposite-sex patterning in males versus females may indicate that the costs of agonistic interactions among males are severe enough to allow for an alternative mating strategy. Finally, we discuss how sexual and natural selective forces may interact to drive or mask the evolution of sexually dimorphic traits. PMID:23467394

  16. Uranium Distribution along the Salinity Gradient

    NASA Astrophysics Data System (ADS)

    Yoon, C.; Yoon, H.; Seo, J.; Lee, J.; Chung, K.

    2006-12-01

    Uranium distribution has been examined in the estuarine waters of the Keum River, Korea. Water samples were collected along a salinity gradient, range from 0.2 to 31.5 psu. Dissolved uranium in the samples has been extracted by C-18 SPE cartridge after pre-treatment. Extraction of uranium by C-18 cartridge after complexation with APDC/DDDC shows about 90 % recovery. After concentration of sample onto C-18 cartridge, uranium complex has been sequentially extracted by 50 % and 100 % acetonitrile, respectively. Result shows good recovery efficiency at low pH (2.5 _ 3.0) during the pre-treatment of sample which was presumably related with destabilization of uranium-carbonate complex. In the estuary, uranium shows typical conservative behavior along the salinity gradient. The current result substantiates earlier reports that uranium is conservatively transported from the river to the ocean. Most of dissolved trace metals, except cadmium, decreased with increasing salinity in the estuary. Dissolved organic carbon also decreased along the salinity gradient. Copper was rapidly removed during the mixing with seawaters as a result of organic matter flocculation. Dissolved molybdenum, vanadium and uranium distribution in the estuary showed similarities that those concentration increase along the salinity gradient.

  17. Uranium Immobilization in an Iron-Rich Rhizosphere of a Native Wetland Plant from the Savannah River Site under Reducing Conditions

    EPA Science Inventory

    The hypothesis of this study was that iron plaque formed on the roots of wetland plants and their rhizospheres create environmental conditions favorable for iron reducing bacteria that promote the in situ immobilization of uranium. Greenhouse microcosm studies were conducted usin...

  18. Uranium bombs

    NASA Astrophysics Data System (ADS)

    DeGroot, Gerard

    2009-11-01

    Enrico Fermi was a brilliant physicist, but he did occasionally get things wrong. In 1934 he famously bombarded a sample of uranium with neutrons. The result was astounding: the experiment had, Fermi concluded, produced element 93, later called neptunium. The German physicist Ida Noddack, however, came to an even more spectacular conclusion, namely that Fermi had split the uranium nucleus to produce lighter elements. Noddack's friend Otto Hahn judged that idea preposterous and advised her to keep quiet, since ridicule could ruin a female physicist. She ignored that advice, and was, indeed, scorned.

  19. Evaluating the effect of sample type on American alligator (Alligator mississippiensis) analyte values in a point-of-care blood analyser.

    PubMed

    Hamilton, Matthew T; Finger, John W; Winzeler, Megan E; Tuberville, Tracey D

    2016-01-01

    The assessment of wildlife health has been enhanced by the ability of point-of-care (POC) blood analysers to provide biochemical analyses of non-domesticated animals in the field. However, environmental limitations (e.g. temperature, atmospheric humidity and rain) and lack of reference values may inhibit researchers from using such a device with certain wildlife species. Evaluating the use of alternative sample types, such as plasma, in a POC device may afford researchers the opportunity to delay sample analysis and the ability to use banked samples. In this study, we examined fresh whole blood, fresh plasma and frozen plasma (sample type) pH, partial pressure of carbon dioxide (PCO2), bicarbonate (HCO3 (-)), total carbon dioxide (TCO2), base excess (BE), partial pressure of oxygen (PO2), oxygen saturation (sO2) and lactate concentrations in 23 juvenile American alligators (Alligator mississippiensis) using an i-STAT CG4+ cartridge. Our results indicate that sample type had no effect on lactate concentration values (F 2,65 = 0.37, P = 0.963), suggesting that the i-STAT analyser can be used reliably to quantify lactate concentrations in fresh and frozen plasma samples. In contrast, the other seven blood parameters measured by the CG4+ cartridge were significantly affected by sample type. Lastly, we were able to collect blood samples from all alligators within 2 min of capture to establish preliminary reference ranges for juvenile alligators based on values obtained using fresh whole blood. PMID:27382469

  20. Evaluating the effect of sample type on American alligator (Alligator mississippiensis) analyte values in a point-of-care blood analyser

    SciTech Connect

    Hamilton, Matthew T.; Finger, John W.; Winzeler, Megan E.; Tuberville, Tracey D.

    2016-01-01

    The assessment of wildlife health has been enhanced by the ability of point-of-care (POC) blood analysers to provide biochemical analyses of non-domesticated animals in the field. However, environmental limitations (e.g. temperature, atmospheric humidity and rain) and lack of reference values may inhibit researchers from using such a device with certain wildlife species. Evaluating the use of alternative sample types, such as plasma, in a POC device may afford researchers the opportunity to delay sample analysis and the ability to use banked samples. In this study, we examined fresh whole blood, fresh plasma and frozen plasma (sample type) pH, partial pressure of carbon dioxide (PCO2), bicarbonate (HCO3₋), total carbon dioxide (TCO2), base excess (BE), partial pressure of oxygen (PO2), oxygen saturation (sO2) and lactate concentrations in 23 juvenile American alligators (Alligator mississippiensis) using an i-STAT CG4+ cartridge. Our results indicate that sample type had no effect on lactate concentration values (F2,65 = 0.37, P = 0.963), suggesting that the i-STAT analyser can be used reliably to quantify lactate concentrations in fresh and frozen plasma samples. In contrast, the other seven blood parameters measured by the CG4+ cartridge were significantly affected by sample type. In conclusion, we were able to collect blood samples from all alligators within 2 min of capture to establish preliminary reference ranges for juvenile alligators based on values obtained using fresh whole blood.

  1. Evaluating the effect of sample type on American alligator (Alligator mississippiensis) analyte values in a point-of-care blood analyser

    DOE PAGES

    Hamilton, Matthew T.; Finger, John W.; Winzeler, Megan E.; Tuberville, Tracey D.

    2016-01-01

    The assessment of wildlife health has been enhanced by the ability of point-of-care (POC) blood analysers to provide biochemical analyses of non-domesticated animals in the field. However, environmental limitations (e.g. temperature, atmospheric humidity and rain) and lack of reference values may inhibit researchers from using such a device with certain wildlife species. Evaluating the use of alternative sample types, such as plasma, in a POC device may afford researchers the opportunity to delay sample analysis and the ability to use banked samples. In this study, we examined fresh whole blood, fresh plasma and frozen plasma (sample type) pH, partial pressuremore » of carbon dioxide (PCO2), bicarbonate (HCO3₋), total carbon dioxide (TCO2), base excess (BE), partial pressure of oxygen (PO2), oxygen saturation (sO2) and lactate concentrations in 23 juvenile American alligators (Alligator mississippiensis) using an i-STAT CG4+ cartridge. Our results indicate that sample type had no effect on lactate concentration values (F2,65 = 0.37, P = 0.963), suggesting that the i-STAT analyser can be used reliably to quantify lactate concentrations in fresh and frozen plasma samples. In contrast, the other seven blood parameters measured by the CG4+ cartridge were significantly affected by sample type. In conclusion, we were able to collect blood samples from all alligators within 2 min of capture to establish preliminary reference ranges for juvenile alligators based on values obtained using fresh whole blood.« less

  2. Evaluating the effect of sample type on American alligator (Alligator mississippiensis) analyte values in a point-of-care blood analyser

    PubMed Central

    Hamilton, Matthew T.; Finger, John W.; Winzeler, Megan E.; Tuberville, Tracey D.

    2016-01-01

    The assessment of wildlife health has been enhanced by the ability of point-of-care (POC) blood analysers to provide biochemical analyses of non-domesticated animals in the field. However, environmental limitations (e.g. temperature, atmospheric humidity and rain) and lack of reference values may inhibit researchers from using such a device with certain wildlife species. Evaluating the use of alternative sample types, such as plasma, in a POC device may afford researchers the opportunity to delay sample analysis and the ability to use banked samples. In this study, we examined fresh whole blood, fresh plasma and frozen plasma (sample type) pH, partial pressure of carbon dioxide (PCO2), bicarbonate (HCO3−), total carbon dioxide (TCO2), base excess (BE), partial pressure of oxygen (PO2), oxygen saturation (sO2) and lactate concentrations in 23 juvenile American alligators (Alligator mississippiensis) using an i-STAT CG4+ cartridge. Our results indicate that sample type had no effect on lactate concentration values (F2,65 = 0.37, P = 0.963), suggesting that the i-STAT analyser can be used reliably to quantify lactate concentrations in fresh and frozen plasma samples. In contrast, the other seven blood parameters measured by the CG4+ cartridge were significantly affected by sample type. Lastly, we were able to collect blood samples from all alligators within 2 min of capture to establish preliminary reference ranges for juvenile alligators based on values obtained using fresh whole blood. PMID:27382469

  3. Follicle-stimulating hormone receptor (FSHR) in Chinese alligator, Alligator sinensis: molecular characterization, tissue distribution and mRNA expression changes during the female reproductive cycle.

    PubMed

    Zhang, Rui; Zhang, Shengzhou; Zhu, Xue; Zhou, Yongkang; Wu, Xiaobing

    2015-05-01

    The follicle-stimulating hormone (FSH) plays a central role in vertebrate reproduction, with the actions of FSH mediated by FSH receptors (FSHRs) on the granulosa cells of the ovary. The present study reports the cloning and characterization of FSHR in Chinese alligator, Alligator sinensis (caFSHR), and its tissue distribution and mRNA expression changes during the reproductive cycle. The mature protein of caFSHR displays typical features of the glycoprotein hormone receptor family, but also contains some remarkable differences when compared with other vertebrate FSHRs. The deduced amino acid sequence of the caFSHR shares identity of 85% with Chinese softshell turtle, 84-87% with birds, 77-78% with mammals, 67-73% with amphibians and 51-58% with fishes. Phylogenetic tree analysis of the FSHR amino acid sequence indicated that alligators cluster into the bird branch. Tissue expression analysis showed that caFSHR was not only expressed in the ovary, but also in the stomach, intestine, pancreas liver and oviduct at similar levels, while it was not detectable in heart, thymus or thyroid. Expression of caFSHR in the ovary is high in May (breeding prophase) and peaks in July during the breeding period, where it is maintained at high levels through September (breeding anaphase). Expression decreases significantly in November (hibernating period) and then remains relatively low from January to March (hibernating period). These temporal changes in FSHR expression suggest that it plays an important role in promoting ovarian development during the female reproductive cycle of Chinese alligator. PMID:25765682

  4. A group of alligators basks in the sun and rest in the water at KSC.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This pond near Schwartz Rd. at Kennedy Space Center is host to a least the nine alligators shown on the banks and in the water. Nearly 5,000 alligators can be found in canals, ponds, and waterways throughout the Center and the Merritt Island National Wildlife Refuge, which shares a boundary with the Center. American alligators feed and rest in the water, and lay their eggs in dens they dig into the banks. The young alligators spend their first several weeks in these dens. The Wildlife Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  5. TRPV4 associates environmental temperature and sex determination in the American alligator

    PubMed Central

    Yatsu, Ryohei; Miyagawa, Shinichi; Kohno, Satomi; Saito, Shigeru; Lowers, Russell H.; Ogino, Yukiko; Fukuta, Naomi; Katsu, Yoshinao; Ohta, Yasuhiko; Tominaga, Makoto; Guillette Jr, Louis J.; Iguchi, Taisen

    2015-01-01

    Temperature-dependent sex determination (TSD), commonly found among reptiles, is a sex determination mode in which the incubation temperature during a critical temperature sensitive period (TSP) determines sexual fate of the individual rather than the individual’s genotypic background. In the American alligator (Alligator mississippiensis), eggs incubated during the TSP at 33 °C (male producing temperature: MPT) yields male offspring, whereas incubation temperatures below 30 °C (female producing temperature: FPT) lead to female offspring. However, many of the details of the underlying molecular mechanism remains elusive, and the molecular link between environmental temperature and sex determination pathway is yet to be elucidated. Here we show the alligator TRPV4 ortholog (AmTRPV4) to be activated at temperatures proximate to the TSD-related temperature in alligators, and using pharmacological exposure, we show that AmTRPV4 channel activity affects gene expression patterns associated with male differentiation. This is the first experimental demonstration of a link between a well-described thermo-sensory mechanism, TRPV4 channel, and its potential role in regulation of TSD in vertebrates, shedding unique new light on the elusive TSD molecular mechanism. PMID:26677944

  6. Effects of salinity on growth and ion regulation of juvenile alligator gar Atractosteus spatula.

    PubMed

    Schwarz, Daniel E; Allen, Peter J

    2014-03-01

    The alligator gar (Atractosteus spatula) is a primitive euryhaline fish, found primarily in estuaries and freshwater drainages associated with the northern Gulf of Mexico. The extent of its hypo-osmotic regulatory abilities is not well understood. In order to determine how salinity affects growth rates and ionic and osmoregulation, juvenile alligator gar (330 days after hatch; 185 g) were exposed to 4 different salinities (0, 8, 16, and 24 ppt) for a 30-day period. Specific growth rate, plasma osmolality and ion concentrations, gill and gastrointestinal tract Na(+), K(+)-ATPase activities, and drinking rate were compared. Juvenile alligator gar were able to tolerate hyperosmotic salinities up to 24 ppt for a 30 day period, albeit with decreased growth resulting largely from decreased food consumption. Plasma osmolality and ionic concentrations were elevated in hyperosmotic salinities, and drinking rates and gastrointestinal tract Na(+), K(+)-ATPase activities increased, particularly in the pyloric caeca, presumably the primary location of water absorption. Therefore, juvenile alligator gar<1 year of age are capable of prolonged exposure to hyperosmotic salinities, but, based on the inference of these data, require access to lower salinities for long-term survival. PMID:24368134

  7. Achieving environmentally relevant organochlorine pesticide concentrations in eggs through maternal exposure in Alligator mississippiensis

    USGS Publications Warehouse

    Rauschenberger, R.H.; Wiebe, J.J.; Buckland, J.E.; Smith, Joe T.; Sepulveda, M.S.; Gross, T.S.

    2004-01-01

    Alligator mississippiensis eggs from organochlorine pesticide (OCP) contaminated sites in Florida exhibit high rates of embryonic mortality compared to reference sites (p<0.05). The objective of the present study was to use captive adult alligators to test the hypotheses that maternal exposure to OCPs results in increased OCP concentrations in eggs, and that increased exposure is associated with increased embryonic mortality. A total of 24 adult alligators (8 males and 16 females) were housed in eight pens. Eight females in four pens were dosed with a mixture of p,p'-DDE, toxaphene, dieldrin, and chlordane at a rate of 0.2 ? 0.01 mg/kg/day for 274 ? 8 days. Treated females produced eggs containing higher OCP concentrations (12,814 ? 813 ng/g yolk) than controls (38 ? 4 ng/g yolk). Eggs of treated females exhibited decreased viability (13 ? 22%) as compared to controls (45 ? 20%). Results indicated that 0.6% of administered OCPs were maternally transferred to the eggs of American alligators, and that maternal exposure is associated with decreased egg/embryo viability in this species.

  8. Effects of salinity on growth and ion regulation of juvenile alligator gar Atractosteus spatula

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The alligator gar (Atractosteus spatula) is a primitive euryhaline fish, found primarily in estuaries and freshwater drainages associated with the northern Gulf of Mexico. The extent of its hypo-osmotic regulatory abilities is not well understood. In order to determine how salinity affects growth ra...

  9. The evolutionary history of an invasive species: alligator weed, Alternanthera philoxeroides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The eco-evolutionary mechanisms of biological invasions are still not thoroughly understood. Alligator weed, Alternanthera philoxeroides (Martius) Gisebach (Amaranthaceae), is a plant native to South America and a weed in Australia and other countries. To better understand its success as an invader,...

  10. TRPV4 associates environmental temperature and sex determination in the American alligator.

    PubMed

    Yatsu, Ryohei; Miyagawa, Shinichi; Kohno, Satomi; Saito, Shigeru; Lowers, Russell H; Ogino, Yukiko; Fukuta, Naomi; Katsu, Yoshinao; Ohta, Yasuhiko; Tominaga, Makoto; Guillette, Louis J; Iguchi, Taisen

    2015-01-01

    Temperature-dependent sex determination (TSD), commonly found among reptiles, is a sex determination mode in which the incubation temperature during a critical temperature sensitive period (TSP) determines sexual fate of the individual rather than the individual's genotypic background. In the American alligator (Alligator mississippiensis), eggs incubated during the TSP at 33 °C (male producing temperature: MPT) yields male offspring, whereas incubation temperatures below 30 °C (female producing temperature: FPT) lead to female offspring. However, many of the details of the underlying molecular mechanism remains elusive, and the molecular link between environmental temperature and sex determination pathway is yet to be elucidated. Here we show the alligator TRPV4 ortholog (AmTRPV4) to be activated at temperatures proximate to the TSD-related temperature in alligators, and using pharmacological exposure, we show that AmTRPV4 channel activity affects gene expression patterns associated with male differentiation. This is the first experimental demonstration of a link between a well-described thermo-sensory mechanism, TRPV4 channel, and its potential role in regulation of TSD in vertebrates, shedding unique new light on the elusive TSD molecular mechanism. PMID:26677944

  11. Effects of salinity on growth and ion regulation of juvenile alligator gar Atractosteus spatula.

    PubMed

    Schwarz, Daniel E; Allen, Peter J

    2014-03-01

    The alligator gar (Atractosteus spatula) is a primitive euryhaline fish, found primarily in estuaries and freshwater drainages associated with the northern Gulf of Mexico. The extent of its hypo-osmotic regulatory abilities is not well understood. In order to determine how salinity affects growth rates and ionic and osmoregulation, juvenile alligator gar (330 days after hatch; 185 g) were exposed to 4 different salinities (0, 8, 16, and 24 ppt) for a 30-day period. Specific growth rate, plasma osmolality and ion concentrations, gill and gastrointestinal tract Na(+), K(+)-ATPase activities, and drinking rate were compared. Juvenile alligator gar were able to tolerate hyperosmotic salinities up to 24 ppt for a 30 day period, albeit with decreased growth resulting largely from decreased food consumption. Plasma osmolality and ionic concentrations were elevated in hyperosmotic salinities, and drinking rates and gastrointestinal tract Na(+), K(+)-ATPase activities increased, particularly in the pyloric caeca, presumably the primary location of water absorption. Therefore, juvenile alligator gar<1 year of age are capable of prolonged exposure to hyperosmotic salinities, but, based on the inference of these data, require access to lower salinities for long-term survival.

  12. Machining of uranium and uranium alloys

    SciTech Connect

    Morris, T.O.

    1981-12-14

    Uranium and uranium alloys can be readily machined by conventional methods in the standard machine shop when proper safety and operating techniques are used. Material properties that affect machining processes and recommended machining parameters are discussed. Safety procedures and precautions necessary in machining uranium and uranium alloys are also covered. 30 figures.

  13. Simple solar technology saves money for alligator farms

    SciTech Connect

    Goldman, A.

    1993-01-01

    In 1990, a high-volume solar thermal water-heating system in Florida was installed in Okeechobee County by Solar Development, Inc. (SDI). The system is designed to provide large quantities of hot water for commercial use and heat water to as high as 140[degrees]F. The design in Florida is known as a Shallow Solar Pond (SSP). It was completed with the help of the Florida Alligator Farmers Association, the Florida Energy Office, Foster Farms, and SDI. The SSP is a modular system built on site and modified to meet the specific needs of each application. The tank and the collector are the same unit, which keeps the system cost very low. The typical SSP module is 16 feet wide and up to 200 feet long. The module contains one or two reinforced-rubber flat water bags similar to a water bed. The bags rest on a layer of insulation or sand inside concrete or fiberglass curbs. In the Foster Farms SSP, the insulation was omitted and the water bags are placed on sand. The bag is protected against damage and heat loss by greenhouse-type glazing. At Foster Farms there are 3 SSPs, set in approximately 8,000 square feet, with two 5,000-gallon bags per unit. In addition, there is a pressurizing pump/tank system. Every morning, the heated water from the bags drains into a sump tank. While the bags are emptied into the backup system, well water is pumped in and the solar heating process starts all over again.

  14. URANIUM ALLOYS

    DOEpatents

    Seybolt, A.U.

    1958-04-15

    Uranium alloys containing from 0.1 to 10% by weight, but preferably at least 5%, of either zirconium, niobium, or molybdenum exhibit highly desirable nuclear and structural properties which may be improved by heating the alloy to about 900 d C for an extended period of time and then rapidly quenching it.

  15. Uranium, natural

    Integrated Risk Information System (IRIS)

    Uranium , natural ; CASRN 7440 - 61 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  16. Genome analysis and signature discovery for diving and sensory properties of the endangered Chinese alligator

    PubMed Central

    Wan, Qiu-Hong; Pan, Sheng-Kai; Hu, Li; Zhu, Ying; Xu, Peng-Wei; Xia, Jin-Quan; Chen, Hui; He, Gen-Yun; He, Jing; Ni, Xiao-Wei; Hou, Hao-Long; Liao, Sheng-Guang; Yang, Hai-Qiong; Chen, Ying; Gao, Shu-Kun; Ge, Yun-Fa; Cao, Chang-Chang; Li, Peng-Fei; Fang, Li-Ming; Liao, Li; Zhang, Shu; Wang, Meng-Zhen; Dong, Wei; Fang, Sheng-Guo

    2013-01-01

    Crocodilians are diving reptiles that can hold their breath under water for long periods of time and are crepuscular animals with excellent sensory abilities. They comprise a sister lineage of birds and have no sex chromosome. Here we report the genome sequence of the endangered Chinese alligator (Alligator sinensis) and describe its unique features. The next-generation sequencing generated 314 Gb of raw sequence, yielding a genome size of 2.3 Gb. A total of 22 200 genes were predicted in Alligator sinensis using a de novo, homology- and RNA-based combined model. The genetic basis of long-diving behavior includes duplication of the bicarbonate-binding hemoglobin gene, co-functioning of routine phosphate-binding and special bicarbonate-binding oxygen transport, and positively selected energy metabolism, ammonium bicarbonate excretion and cardiac muscle contraction. Further, we elucidated the robust Alligator sinensis sensory system, including a significantly expanded olfactory receptor repertoire, rapidly evolving nerve-related cellular components and visual perception, and positive selection of the night vision-related opsin and sound detection-associated otopetrin. We also discovered a well-developed immune system with a considerable number of lineage-specific antigen-presentation genes for adaptive immunity as well as expansion of the tripartite motif-containing C-type lectin and butyrophilin genes for innate immunity and expression of antibacterial peptides. Multifluorescence in situ hybridization showed that alligator chromosome 3, which encodes DMRT1, exhibits significant synteny with chicken chromosome Z. Finally, population history analysis indicated population admixture 0.60-1.05 million years ago, when the Qinghai-Tibetan Plateau was uplifted. PMID:23917531

  17. The Good, the Bad, and the Unknown: Microbial Symbioses of the American Alligator.

    PubMed

    Keenan, Sarah W; Elsey, Ruth M

    2015-12-01

    Vertebrates coexist with microorganisms in diverse symbiotic associations that range from beneficial to detrimental to the host. Most research has aimed at deciphering the nature of the composite microbial assemblage's genome, or microbiome, from the gastrointestinal (GI) tract and skin of mammals (i.e., humans). In mammals, the GI tract's microbiome aids digestion, enhances uptake of nutrients, and prevents the establishment of pathogenic microorganisms. However, because the GI tract microbiome of the American alligator (Alligator mississippiensis) is distinct from that of all other vertebrates studied to date, being comprised of Fusobacteria in the lower GI tract with lesser abundances of Firmicutes, Proteobacteria, and Bacteroidetes, the function of these assemblages is largely unknown. This review provides a synthesis of our current understanding of the composition of alligators' microbiomes, highlights the potential role of microbiome members in alligators' health (the good), and presents a brief summary of microorganisms detrimental to alligators' health (the bad) including Salmonella spp. and others. Microbial assemblages of the GI tract have co-evolved with their vertebrate host over geologic time, which means that evolutionary hypotheses can be tested using information about the microbiome. For reptiles and amphibians, the number of taxa studied at present is limited, thereby restricting evolutionary insights. Nevertheless, we present a compilation of our current understanding of reptiles' and amphibians' microbiomes, and highlight future avenues of research (the unknown). As in humans, composition of microbiome assemblages provides a promising tool for assessing hosts' health or disease. By further exploring present-day associations between symbiotic microorganisms in the microbiomes of reptiles and amphibians, we can better identify good (beneficial) and bad (detrimental) microorganisms, and unravel the evolutionary history of the acquisition of

  18. The oldest record of Alligator sinensis from the Late Pliocene of Western Japan, and its biogeographic implication

    NASA Astrophysics Data System (ADS)

    Iijima, Masaya; Takahashi, Keiichi; Kobayashi, Yoshitsugu

    2016-07-01

    The late Cenozoic fossil record of alligators in East Asia is crucial in understanding the origin and past distribution of Asian alligators that are now represented by a single species, Alligator sinensis. This study reports a partial skeleton of A. sinensis from the Late Pliocene (approximately 3.0 Ma) of western Japan. This Japanese A. sinensis is large in size (>200 cm total length), comparable to the maximum size of extant individuals. It demonstrates the oldest record of A. sinensis and wider distribution of this species in the past. Tectonic and geographic history of East Asia suggests that alligators presumably dispersed into Japan before 25 Ma or after 10 Ma, yet finally were wiped out from Japan due to the semi-isolated condition of the Japanese island arc and the deteriorated climate during the Plio-Pleistocene.

  19. Uranium geochemistry on the Amazon shelf: Evidence for uranium release from bottom sediments

    SciTech Connect

    McKee, B.A.; DeMaster, D.J.; Nittrouer, C.A. )

    1987-10-01

    In Amazon-shelf waters, as salinity increases to 36.5 x 10{sup {minus}3}, dissolved uranium activities increase to a maximum of 4.60 dpm 1{sup {minus}1}. This value is much higher than the open-ocean value (2.50 dpm 1{sup {minus}1}), indicating a source of dissolved uranium to shelf waters in addition to that supplied from open-ocean and riverine waters. Uranium activities are much lower for surface sediments in the Amazon-shelf sea bed (mean: 0.69 {plus minus} .09 dpm g{sup {minus}1}) than for suspended sediments in the Amazon river (1.82 dpm g{sup {minus}1}). Data suggest that the loss of particulate uranium from riverine sediments is probably the result of uranium desorption from the ferric-oxyhydroxide coatings on sediment particles, and/or uranium release by mobilization of the ferric oxyhydroxides. The total flux of dissolved {sup 238}U from the Amazon shelf (about 1.2 x 10{sup 15} dpm yr{sup {minus}1}) constitutes about 15% of uranium input to the world ocean, commensurate to the Amazon River's contribution to world river-water discharge. Measurement of only the riverine flux of dissolved {sup 238}U underestimates, by a factor of about 5, the flux of dissolved {sup 238}U from the Amazon shelf to the open ocean.

  20. Evaluation of the Incorporation of Uranium into Sodium Aluminosilicate Phases

    SciTech Connect

    Oji, L.N.

    2003-03-26

    This report describes batch laboratory experiments performed to determine the relative amounts of uranium incorporated in aluminosilicate structures during synthesis. The findings summarized here are based on laboratory experiments, which involved the synthesis of sodium aluminosilicates (NAS) structures, amorphous, zeolites A and sodalite phases in the presence of depleted uranium and the analytical search for incorporated uranium in NAS internal structures after synthesis. These studies will support the basis for continued operation of evaporators at the Savannah River Site (SRS).

  1. Taxonomic assessment of Alligator Snapping Turtles (Chelydridae: Macrochelys), with the description of two new species from the southeastern United States.

    PubMed

    Thomas, Travis M; Granatosky, Michael C; Bourque, Jason R; Krysko, Kenneth L; Moler, Paul E; Gamble, Tony; Suarez, Eric; Leone, Erin; Roman, Joe

    2014-01-01

    The Alligator Snapping Turtle, Macrochelys temminckii, is a large, aquatic turtle limited to river systems that drain into the Gulf of Mexico. Previous molecular analyses using both mitochondrial and nuclear DNA suggested that Macrochelys exhibits significant genetic variation across its range that includes three distinct genetic assemblages (western, central, and eastern = Suwannee). However, no taxonomic revision or morphological analyses have been conducted previously. In this study, we test previous hypotheses of distinct geographic assemblages by examining morphology, reanalyzing phylogeographic genetic structure, and estimating divergence dating among lineages in a coalescent framework using Bayesian inference. We reviewed the fossil record and discuss phylogeographic and taxonomic implications of the existence of three distinct evolutionary lineages. We measured cranial (n=145) and post-cranial (n=104) material on field-captured individuals and museum specimens. We analyzed 420 base pairs (bp) of mitochondrial DNA sequence data for 158 Macrochelys. We examined fossil Macrochelys from ca. 15-16 million years ago (Ma) to the present to better assess historical distributions and evaluate named fossil taxa. The morphological and molecular data both indicate significant geographical variation and suggest three species-level breaks among genetic lineages that correspond to previously hypothesized genetic assemblages. The holotype of Macrochelys temminckii is from the western lineage. Therefore, we describe two new species as Macrochelys apalachicolae sp. nov. from the central lineage and Macrochelys suwanniensis sp. nov. from the eastern lineage (Suwannee River drainage). Our estimates of divergence times suggest that the most recent common ancestor (MRCA) of M. temminckii (western) and M. apalachicolae (central) existed 3.2-8.9 Ma during the late Miocene to late Pliocene, whereas M. temminckii-M. apalachicolae and M. suwanniensis last shared a MRCA 5.5-13.4 Ma

  2. Uranium removal during low discharge in the Ganges-Brahmaputra mixing zone

    SciTech Connect

    Carroll, J.; Moore, W.S. )

    1993-11-01

    The Ganges-Brahmaputra river system supplies more dissolved uranium to the ocean than any other system in the world (Sarin et al., 1990; Sackett et al., 1973). However, there have been no investigations to determine whether riverine supplies of uranium are altered by geochemical reactions in the river-ocean mixing zone. In this study, uranium and salinity data were collected in the Ganges-Brahmaputra mixing zone during a period of low river discharge. The uranium distribution with salinity shows that in waters <12 ppt salinity, uranium activities are significantly lower than predicted from conservative mixing of river and seawater. This suggests that uranium is being removed within the mixing zone. The behavior of uranium in the Ganges-Brahmaputra is in sharp contrast to its behavior in the Amazon mixing zone where McKee et al. (1978) found uranium activities significantly higher than predicted from conservative mixing. The contrasting behaviors for uranium in these systems are due to the different locations where mixing between river and seawater occurs. For the Amazon, mixing takes place on the continental shelf whereas for the Ganges-Brahmaputra, mixing occurs within shoreline sedimentary environments. The physiochemical processes controlling uranium removal to sediment deposits in the Amazon are partly known. The authors discuss mechanisms which may be removing uranium to suspended and mangrove sediments in the Ganges-Brahmaputra.

  3. EAARL coastal topography--Alligator Point, Louisiana, 2010

    USGS Publications Warehouse

    Nayegandhi, Amar; Bonisteel-Cormier, J.M.; Wright, C.W.; Brock, J.C.; Nagle, D.B.; Vivekanandan, Saisudha; Fredericks, Xan; Barras, J.A.

    2012-01-01

    This project provides highly detailed and accurate datasets of a portion of Alligator Point, Louisiana, acquired on March 5 and 6, 2010. The datasets are made available for use as a management tool to research scientists and natural-resource managers. An innovative airborne lidar instrument originally developed at the National Aeronautics and Space Administration (NASA) Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multispectral color-infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for sub-meter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine aircraft, but the instrument was deployed on a Pilatus PC-6. A single pilot, a lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system, and the resulting data were then processed using the Airborne Lidar Processing System (ALPS), a custom-built processing system developed in a NASA-USGS collaboration. ALPS supports the exploration and processing of lidar data in an interactive or batch mode. Modules for presurvey flight-line definition, flight-path plotting, lidar raster and waveform investigation, and digital camera image playback have been developed. Processing algorithms have

  4. Uranium in runoff from the Gulf of Mexico distributive province: anomalous concentrations.

    PubMed

    Spalding, R F; Sackett, W M

    1972-02-11

    Uranium concentrations in North American rivers are higher than those reported 20 years ago. The increase is attributed to applications to agricultural land of larger amounts of phosphate fertilizer containing appreciable concentrations of uranium. Experiments showing a constant phosphorous-uranium ratio for various types of fertilizers and for the easily solubilized fraction of 0-46-0 fertilizers support this view.

  5. Characterization of streamflow, water quality, and instantaneous dissolved solids, selenium, and uranium loads in selected reaches of the Arkansas River, southeastern Colorado, 2009-2010

    USGS Publications Warehouse

    Ivahnenko, Tamara; Ortiz, Roderick F.; Stogner, Robert W.

    2013-01-01

    As a result of continued water-quality concerns in the Arkansas River, including metal contamination from historical mining practices, potential effects associated with storage and movement of water, point- and nonpoint-source contamination, population growth, storm-water flows, and future changes in land and water use, the Arkansas River Basin Regional Resource Planning Group (RRPG) developed a strategy to address these issues. As such, a cooperative strategic approach to address the multiple water-quality concerns within selected reaches of the Arkansas River was developed to (1) identify stream reaches where stream-aquifer interactions have a pronounced effect on water quality and (or) where reactive transport, and physical and (or) chemical alteration of flow during conveyance, is occurring, (2) quantify loading from point sources, and (3) determine source areas and mass loading for selected constituents. (To see the complete abstract, open Report PDF.)

  6. Derived enriched uranium market

    SciTech Connect

    Rutkowski, E.

    1996-12-01

    The potential impact on the uranium market of highly enriched uranium from nuclear weapons dismantling in the Russian Federation and the USA is analyzed. Uranium supply, conversion, and enrichment factors are outlined for each country; inventories are also listed. The enrichment component and conversion components are expected to cause little disruption to uranium markets. The uranium component of Russian derived enriched uranium hexafluoride is unresolved; US legislation places constraints on its introduction into the US market.

  7. Seasonal acclimatisation of muscle metabolic enzymes in a reptile (Alligator mississippiensis).

    PubMed

    Seebacher, Frank; Guderley, Helga; Elsey, Ruth M; Trosclair, Phillip L

    2003-04-01

    Reptiles living in heterogeneous thermal environments are often thought to show behavioural thermoregulation or to become inactive when environmental conditions prevent the achievement of preferred body temperatures. By contrast, thermally homogeneous environments preclude behavioural thermoregulation, and ectotherms inhabiting these environments (particularly fish in which branchial respiration requires body temperature to follow water temperature) modify their biochemical capacities in response to long-term seasonal temperature fluctuations. Reptiles may also be active at seasonally varying body temperatures and could, therefore, gain selective advantages from regulating biochemical capacities. Hence, we tested the hypothesis that a reptile (the American alligator Alligator mississippiensis) that experiences pronounced seasonal fluctuations in body temperature will show seasonal acclimatisation in the activity of its metabolic enzymes. We measured body temperatures of alligators in the wild in winter and summer (N=7 alligators in each season), and we collected muscle samples from wild alligators (N=31 in each season) for analysis of metabolic enzyme activity (lactate dehydrogenase, citrate synthase and cytochrome c oxidase). There were significant differences in mean daily body temperatures between winter (15.66+/-0.43 degrees C; mean +/- S.E.M.) and summer (29.34+/-0.21 degrees C), and daily body temperatures fluctuated significantly more in winter compared with summer. Alligators compensated for lower winter temperatures by increasing enzyme activities, and the activities of cytochrome c oxidase and lactate dehydrogenase were significantly greater in winter compared with summer at all assay temperatures. The activity of citrate synthase was significantly greater in the winter samples at the winter body temperature (15 degrees C) but not at the summer body temperature (30 degrees C). The thermal sensitivity (Q(10)) of mitochondrial enzymes decreased

  8. Uranium and Aluminosilicate Surface Precipitation Tests

    SciTech Connect

    Hu, M.Z.

    2002-11-27

    The 2H evaporator at the Savannah River Site has been used to treat an aluminum-rich waste stream from canyon operations and a silicon-rich waste stream from the Defense Waste Processing Facility. The formation of aluminosilicate scale in the evaporator has caused significant operational problems. Because uranium has been found to accumulate in the aluminosilicate solids, the scale deposition has introduced criticality concerns as well. The objective of the tests described in this report is to determine possible causes of the uranium incorporation in the evaporator scale materials. The scope of this task is to perform laboratory experiments with simulant solutions to determine if (1) uranium can be deposited on the surfaces of various sodium aluminosilicate (NAS) forms and (2) aluminosilicates can form on the surfaces of uranium-containing solids. Batch experiments with simulant solutions of three types were conducted: (1) contact of uranium solutions/sols with NAS coatings on stainless steel surfaces, (2) contact of uranium solutions with NAS particles, and (3) contact of precipitated uranium-containing particles with solutions containing aluminum and silicon. The results show that uranium can be incorporated in NAS solids through encapsulation in bulk agglomerated NAS particles of different phases (amorphous, zeolite A, sodalite, and cancrinite) as well as through heterogeneous deposition on the surfaces of NAS coatings (amorphous and cancrinite) grown on stainless steel. The results also indicate that NAS particles can grow on the surfaces of precipitated uranium solids. Particularly notable for evaporator operations is the finding that uranium solids can form on existing NAS scale, including cancrinite solids. If NAS scale is present, and uranium is in sufficient concentration in solution to precipitate, a portion of the uranium can be expected to become associated with the scale. The data obtained to date on uranium-NAS affinity are qualitative. A necessary

  9. Uranium Industry Annual, 1992

    SciTech Connect

    Not Available

    1993-10-28

    The Uranium Industry Annual provides current statistical data on the US uranium industry for the Congress, Federal and State agencies, the uranium and electric utility industries, and the public. The feature article, ``Decommissioning of US Conventional Uranium Production Centers,`` is included. Data on uranium raw materials activities including exploration activities and expenditures, resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities including domestic uranium purchases, commitments by utilities, procurement arrangements, uranium imports under purchase contracts and exports, deliveries to enrichment suppliers, inventories, secondary market activities, utility market requirements, and uranium for sale by domestic suppliers are presented in Chapter 2.

  10. Contaminants in American alligator eggs from Lake Apopka, Lake Griffin, and Lake Okeechobee, Florida

    USGS Publications Warehouse

    Heinz, G.H.; Percival, H.F.; Jennings, Michael L.

    1991-01-01

    Residues of organochlorine pesticides, polychlorinated biphenyls (PCBs), and 16 elements were measured in American alligator (Alligator mississippiensis) eggs collected in 1984 from Lakes Apopka, Griffin, and Okeechobee in central and south Florida. Organochlorine pesticides were highest in eggs from Lake Apopka. None of the elements appeared to be present at harmful concentrations in eggs from any of the lakes. A larger sample of eggs was collected in 1985, but only from Lakes Griffin, a lake where eggs were relatively clean, and Apopka, where eggs were most contaminated. In 1985, hatching success of artificially incubated eggs was lower for Lake Apopka, and several organochlorine pesticides were higher than in eggs from Lake Griffin. However, within Lake Apopka, higher levels of pesticides in chemically analyzed eggs were not associated with reduced hatching success of the remaining eggs in the clutch. Therefore, it did not appear that any of the pesticides we measured were responsible for the reduced hatching of Lake Apopka eggs.

  11. Regulatory peptides in the gastrointestinal tract of Alligator mississipiensis. An immunocytochemical study.

    PubMed

    Buchan, A M; Lance, V; Polak, J M

    1983-01-01

    The gastrointestinal tract of the alligator Alligator mississipiensis has been investigated for the presence of immunoreactivity to fourteen regulatory peptides all known to occur in the mammalian gut system. Mucosal endocrine cells reacting specifically with the antisera to neurotensin, C-terminal gastrin, somatostatin, bombesin, secretin, pancreatic glucagon and enteroglucagon were detectable, the distribution of these cells being, in general, similar to the mammalian pattern. Peripheral nerve cell bodies and nerve fibres were detected with the antisera to vasoactive intestinal polypeptide, substance P, bombesin and somatostatin again with a distribution similar to that seen in mammals. No immunoreactivity was observed with the available antisera to glicentin, motilin, gastric inhibitory polypeptide, gastrin 34, cholecystokinin 9-20 and met-enkephalin.

  12. Hydrodynamic analysis, performance assessment, and actuator design of a flexible tail propulsor in an artificial alligator

    NASA Astrophysics Data System (ADS)

    Philen, Michael; Neu, Wayne

    2011-09-01

    The overall objective of this research is to develop analysis tools for determining actuator requirements and assessing viable actuator technology for design of a flexible tail propulsor in an artificial alligator. A simple hydrodynamic model that includes both reactive and resistive forces along the tail is proposed and the calculated mean thrust agrees well with conventional estimates of drag. Using the hydrodynamic model forces as an input, studies are performed for an alligator ranging in size from 1 cm to 2 m at swimming speeds of 0.3-1.8 body lengths per second containing five antagonistic pairs of actuators distributed along the length of the tail. Several smart materials are considered for the actuation system, and preliminary analysis results indicate that the acrylic electroactive polymer and the flexible matrix composite actuators are potential artificial muscle technologies for the system.

  13. Determining the size of American alligators using hind-foot track length

    USGS Publications Warehouse

    Wilkinson, Philip M.; Rice, Kenneth G.

    2000-01-01

    Size distribution information is useful for crocodilian management, but can be hard to obtain. Indirect and less costly demographic inferences made from track measurements may be valuable for management decisions. We related hind-foot lengths (HF) with total length (TL) to determine if we could indirectly assess alligator size using track length. Regression showed that HF was an excellent predictor (F1,246= 15722.9, R2=0.98, P<0.01) of TL and track length was an exceptional predictor of HF (F1,14=7520.3, R2= 1.00, P<0.01). The correlation between track length and HF length also was significant (N= 15, r=0.99, P <0.01). Thus, alligator size can be accurately estimated from measures of track length at sites where capture and direct measurement is impractical.

  14. Measurement of enriched uranium and uranium-aluminum fuel materials with the AWCC

    SciTech Connect

    Krick, M.S.; Menlove, H.O.; Zick, J.; Ikonomou, P.

    1985-05-01

    The active well coincidence counter (AWCC) was calibrated at the Chalk River Nuclear Laboratories (CRNL) for the assay of 93%-enriched fuel materials in three categories: (1) uranium-aluminum billets, (2) uranium-aluminum fuel elements, and (3) uranium metal pieces. The AWCC was a standard instrument supplied to the International Atomic Energy Agency under the International Safeguards Project Office Task A.51. Excellent agreement was obtained between the CRNL measurements and previous Los Alamos National Laboratory measurements on similar mockup fuel material. Calibration curves were obtained for each sample category. 2 refs., 8 figs., 15 tabs.

  15. Removal of uranium from uranium-contaminated soils -- Phase 1: Bench-scale testing. Uranium in Soils Integrated Demonstration

    SciTech Connect

    Francis, C. W.

    1993-09-01

    To address the management of uranium-contaminated soils at Fernald and other DOE sites, the DOE Office of Technology Development formed the Uranium in Soils Integrated Demonstration (USID) program. The USID has five major tasks. These include the development and demonstration of technologies that are able to (1) characterize the uranium in soil, (2) decontaminate or remove uranium from the soil, (3) treat the soil and dispose of any waste, (4) establish performance assessments, and (5) meet necessary state and federal regulations. This report deals with soil decontamination or removal of uranium from contaminated soils. The report was compiled by the USID task group that addresses soil decontamination; includes data from projects under the management of four DOE facilities [Argonne National Laboratory (ANL), Los Alamos National Laboratory (LANL), Oak Ridge National Laboratory (ORNL), and the Savannah River Plant (SRP)]; and consists of four separate reports written by staff at these facilities. The fundamental goal of the soil decontamination task group has been the selective extraction/leaching or removal of uranium from soil faster, cheaper, and safer than current conventional technologies. The objective is to selectively remove uranium from soil without seriously degrading the soil`s physicochemical characteristics or generating waste forms that are difficult to manage and/or dispose of. Emphasis in research was placed more strongly on chemical extraction techniques than physical extraction techniques.

  16. Functional morphology of the Alligator mississippiensis larynx with implications for vocal production.

    PubMed

    Riede, Tobias; Li, Zhiheng; Tokuda, Isao T; Farmer, Colleen G

    2015-04-01

    Sauropsid vocalization is mediated by the syrinx in birds and the larynx in extant reptiles; but whereas avian vocal production has received much attention, the vocal mechanism of basal reptilians is poorly understood. The American alligator (Alligator mississippiensis) displays a large vocal repertoire during mating and in parent-offspring interactions. Although vocal outputs of these behaviors have received some attention, the underlying mechanism of sound production remains speculative. Here, we investigate the laryngeal anatomy of juvenile and adult animals by macroscopic and histological methods. Observations of the cartilaginous framework and associated muscles largely corroborate earlier findings, but one muscle, the cricoarytenoideus, exhibits a heretofore unknown extrinsic insertion that has important implications for effective regulation of vocal fold length and tension. Histological investigation of the larynx revealed a layered vocal fold morphology. The thick lamina propria consists of non-homogenous extracellular matrix containing collagen fibers that are tightly packed below the epithelium but loosely organized deep inside the vocal fold. We found few elastic fibers but comparatively high proportions of hyaluronan. Similar organizational complexity is also seen in mammalian vocal folds and the labia of the avian syrinx: convergent morphologies that suggest analogous mechanisms for sound production. In tensile tests, alligator vocal folds demonstrated a linear stress-strain behavior in the low strain region and nonlinear stress responses at strains larger than 15%, which is similar to mammalian vocal fold tissue. We have integrated morphological and physiological data in a two-mass vocal fold model, providing a systematic description of the possible acoustic space that could be available to an alligator larynx. Mapping actual call production onto possible acoustic space validates the model's predictions.

  17. Nutrient and organochlorine pesticide concentrations in American alligator eggs and their associations with clutch viability.

    PubMed

    Rauschenberger, R Heath; Sepúlveda, Maria S; Wiebe, Jon J; Wiebe, Janet E; Honeyfield, Dale C; Gross, Timothy S

    2009-12-01

    Since the early 1900s, the lakes of the Ocklawaha basin in central Florida have experienced ecological degradation due to anthropogenic development. One species affected by this degradation is the American alligator Alligator mississippiensis, which has suffered from poor clutch viability and embryo mortality. Although some studies indicate that organochlorine pesticides (OCPs) may be involved, OCPs do not account for all of the variation seen in hatch rates. Indeed, nutrition and non-OCP contaminants have been associated with developmental problems in fish and birds. Our study evaluated embryo mortality in alligators at reference and OCP-contaminated sites as a function of exposure to OCPs, polychlorinated biphenyls (PCBs), and polyaromatic hydrocarbons (PAHs), along with egg nutrients (Zn, Se, and vitamins A, E, and B1). The four-pronged study consisted of a case-control cohort study, an expanded field study, a topical egg treatment thiamine amelioration experiment, and a topical egg treatment thiamine antagonist experiment. The results from the two field studies suggested that the total thiamine levels in the eggs were positively associated with clutch viability and negatively associated with the lipid content and certain OCPs measured in egg yolks. In addition, PCBs, PAHs, Zn, Se, and vitamins A and E were not found to be associated with the observed clutch viability defects. The thiamine levels in the eggs explained 38% of the variation in clutch survival in the case-control cohort study and 27% in the expanded field study. The topical egg treatment experiments were successful in elevating the thiamine concentrations in the albumin but not the yolk. No significant differences were noted among treatment groups in either egg treatment experiment with respect to clutch survival. In summary, thiamine egg concentrations explain some of the variation in the clutch viability of free-ranging alligators, but the cause-effect relationships are still unclear. PMID

  18. WILDLIFE - ALLIGATOR NAMED KASEY LIVES IN POND IN FRONT OF HEADQUARTERS

    NASA Technical Reports Server (NTRS)

    1969-01-01

    A big, toothy saurian grin is flashed by this alligator in the pond in front of the KSC Headquarters Building. And wy not? After years of namelessness, he [or she] has a name. The 'gator was dubbed Kasey following a ''Name the Gator'' contest in which scores of Spaceport employees submitted name suggestions. Kasey is one of two 'gators placed in the pond in an attempt to restore its natural ecology.

  19. Modifications to the remedial action plan and site design for stabilization of the inactive Uranium Mill Tailings Site at Green River, Utah

    SciTech Connect

    Not Available

    1994-09-01

    Modifications to the water resources protection strategy detailed in the remedial action plan for the Green River, Utah, disposal site are presented. The modifications are based on new information, including ground water quality data collected after remedial action was completed and on a revised assessment of disposal cell design features, surface conditions, and site hydrogeology. The modifications will result in compliance with the U.S. EPA proposed ground water standards (52 FR 36000 (1987)).

  20. URANIUM EXTRACTION

    DOEpatents

    Harrington, C.D.; Opie, J.V.

    1958-07-01

    The recovery of uranium values from uranium ore such as pitchblende is described. The ore is first dissolved in nitric acid, and a water soluble nitrate is added as a salting out agent. The resulting feed solution is then contacted with diethyl ether, whereby the bulk of the uranyl nitrate and a portion of the impurities are taken up by the ether. This acid ether extract is then separated from the aqueous raffinate, and contacted with water causing back extractioa of the uranyl nitrate and impurities into the water to form a crude liquor. After separation from the ether extract, this crude liquor is heated to about 118 deg C to obtain molten uranyl nitrate hexahydratc. After being slightly cooled the uranyl nitrate hexahydrate is contacted with acid free diethyl ether whereby the bulk of the uranyl nitrate is dissolved into the ethcr to form a neutral ether solution while most of the impurities remain in the aqueous waste. After separation from the aqueous waste, the resultant ether solution is washed with about l0% of its volume of water to free it of any dissolved impurities and is then contacted with at least one half its volume of water whereby the uranyl nitrate is extracted into the water to form an aqueous product solution.

  1. Biosorption of As(V) onto dried alligator weed root: role of metal (hydro) oxides.

    PubMed

    Chen, Jian; Tao, Weihua; Sun, Cheng

    2016-01-01

    The present work investigates the adsorption of As(V) onto the dried powder of alligator weed root as bio-sorbent, using acid pre-treated alligator weed root powder as the reference. The isotherm study suggested there is a favorable As(V) adsorption happened on the AWR surface. The batch adsorption experimental results indicated that the ionic strength has little impact on the adsorption, while the solution pH has a significant effect on the adsorption with apparent inhibition appearing in both extreme acidic and alkaline pH region. In addition, the properties of the biosorbent were characterized by various techniques including SEM-EDS, FT-IR, and ICP detection. The analysis results suggested that the metals including Mn, Fe, and Al enrich over the alligator weed root surface in the morphology of metal (hydro) oxide. Based on the nature of the biosorbent and As(V) besides the adsorption performance, the metal (hydro) oxides over biosorbent surface is suggested as the essential role to drive the adsorption. With the metal (hydro) oxides denuded in the pre-treatment, the biosorbent loses its adsorption capability for As(V) totally.

  2. Incubation history prior to the canonical thermosensitive period determines sex in the American alligator.

    PubMed

    McCoy, Jessica A; Parrott, Benjamin B; Rainwater, Thomas R; Wilkinson, Phillip M; Guillette, Louis J

    2015-10-01

    Despite the widespread occurrence of environmental sex determination (ESD) among vertebrates, our knowledge of the temporal dynamics by which environmental factors act on this process remains limited. In many reptiles, incubation temperature determines sex during a discrete developmental window just prior to and coincident with the differentiation of the gonads. Yet, there is substantial variation in sex ratios among different clutches of eggs incubated at identical temperatures during this period. Here, we test the hypothesis that temperatures experienced prior to the reported thermosensitive period for alligators (Alligator mississippiensis) can impact how the sex determination system responds to thermal cues later in development. Temperature shift experiments on eggs collected from the field within 24  h of oviposition were employed to decouple various maternal influences from thermal effects, and results demonstrate a previously undefined window of thermosensitivity occurring by stage 15 of embryonic development, six stages earlier than previously reported. We also examine the intrasexual expression of several male- and female-biased genes and show that while male-biased genes display no intrasexual differences, ovarian CYP19A1 (aromatase) transcript abundance differs by approximately twofold depending on thermal exposures experienced at early stages of embryonic development. These findings expand our understanding of the ESD in the alligator and provide the rationale for reevaluation of the temporal dynamics of sex determination in other crocodilians. PMID:26183894

  3. Do egg-laying crocodilian (Alligator mississippiensis) archosaurs form medullary bone?

    PubMed

    Schweitzer, M H; Elsey, R M; Dacke, C G; Horner, J R; Lamm, E-T

    2007-04-01

    It is beyond question that Mesozoic dinosaurs, like Aves and Crocodylia, are archosaurs. However, within the archosaurian clade, the origin and distribution of some major features are less clear, particularly with respect to reproductive physiology. Medullary bone, a highly mineralized, bony reproductive tissue present in the endosteal cavities of all extant egg-laying birds thus far examined, has recently been reported in Tyrannosaurus rex. Its presence or absence in extant crocodilians, therefore, may shed light on the timing of its evolutionary appearance. If medullary bone is present in all three taxa, it arose before the three lineages diverged. However, if medullary bone arose after this divergence, it may be present in both extinct dinosaurs and birds, or in birds only. If present in extinct dinosaurs and birds, but not crocodilians, it would indicate that it arose in the common ancestor of this clade, thus adding support to the closer phylogenetic relationship of dinosaurs and birds relative to crocodilians. Thus, the question of whether the crocodilian Alligator mississippiensis forms medullary bone during the production of eggs has important evolutionary significance. Our examination of long bones from several alligators (two alligators with eggs in the oviducts, one that had produced eggs in the past but was not currently in reproductive phase, an immature female and an adult male) shows no differences on the endosteal surfaces of the long bones, and no evidence of medullary bone, supporting the hypothesis that medullary bone first evolved in the dinosaur-bird line, after the divergence of crocodilians from this lineage.

  4. Biosorption of As(V) onto dried alligator weed root: role of metal (hydro) oxides.

    PubMed

    Chen, Jian; Tao, Weihua; Sun, Cheng

    2016-01-01

    The present work investigates the adsorption of As(V) onto the dried powder of alligator weed root as bio-sorbent, using acid pre-treated alligator weed root powder as the reference. The isotherm study suggested there is a favorable As(V) adsorption happened on the AWR surface. The batch adsorption experimental results indicated that the ionic strength has little impact on the adsorption, while the solution pH has a significant effect on the adsorption with apparent inhibition appearing in both extreme acidic and alkaline pH region. In addition, the properties of the biosorbent were characterized by various techniques including SEM-EDS, FT-IR, and ICP detection. The analysis results suggested that the metals including Mn, Fe, and Al enrich over the alligator weed root surface in the morphology of metal (hydro) oxide. Based on the nature of the biosorbent and As(V) besides the adsorption performance, the metal (hydro) oxides over biosorbent surface is suggested as the essential role to drive the adsorption. With the metal (hydro) oxides denuded in the pre-treatment, the biosorbent loses its adsorption capability for As(V) totally. PMID:26458188

  5. PRODUCTION OF URANIUM TETRACHLORIDE

    DOEpatents

    Calkins, V.P.

    1958-12-16

    A process is descrlbed for the production of uranium tetrachloride by contacting uranlum values such as uranium hexafluoride, uranlum tetrafluoride, or uranium oxides with either aluminum chloride, boron chloride, or sodium alumlnum chloride under substantially anhydrous condltlons at such a temperature and pressure that the chlorldes are maintained in the molten form and until the uranium values are completely converted to uranlum tetrachloride.

  6. PRODUCTION OF URANIUM MONOCARBIDE

    DOEpatents

    Powers, R.M.

    1962-07-24

    A method of making essentially stoichiometric uranium monocarbide by pelletizing a mixture of uranium tetrafluoride, silicon, and carbon and reacting the mixture at a temperature of approximately 1500 to 1700 deg C until the reaction goes to completion, forming uranium monocarbide powder and volatile silicon tetrafluoride, is described. The powder is then melted to produce uranium monocarbide in massive form. (AEC)

  7. Summary of the Special Analysis of Savannah River Depleted Uranium Trioxide Demonstrating the Before and After Impacts on the DOE Order 435.1 Performance Objective and the Peak Dose

    SciTech Connect

    Shott, G.J.

    2011-01-15

    This report summarizes the special analysis (SA) of the Savannah River Depleted Uranium Trioxide waste stream (SVRSURANIUM03, Revision 1) demonstrating the before and after impacts of the waste stream to the DOE Order 435.1 performance objective at the disposal facility, and the peak dose. The Nevada Division of Environmental Protection (NDEP) requested this SA and asked the Nevada Site Office (NSO) to run the SA deterministically and assume that all the model conditions remain the same regardless of the length of time to the peak dose. Although the NDEP accepts that DOE Order 435.1 requires a compliance period of 1,000 years, it also requested to know what year, if any, the specific DOE performance objectives will be exceeded. Given the NDEP’s requested model conditions, the SA demonstrates the Rn-222 peak dose will occur in about 2 million years and will exceed the performance objective in about 6,000 years. The 0.25 mSv y-1 all-pathway performance objective was not exceeded for the resident scenario after reaching the 4 million year peak dose.

  8. DECONTAMINATION OF URANIUM

    DOEpatents

    Feder, H.M.; Chellew, N.R.

    1958-02-01

    This patent deals with the separation of rare earth and other fission products from neutron bombarded uranium. This is accomplished by melting the uranium in contact with either thorium oxide, maguesium oxide, alumnum oxide, beryllium oxide, or uranium dioxide. The melting is preferably carried out at from 1150 deg to 1400 deg C in an inert atmosphere, such as argon or helium. During this treatment a scale of uranium dioxide forms on the uranium whtch contains most of the fission products.

  9. Hepatic and renal trace element concentrations in American alligators (Alligator mississippiensis) following chronic dietary exposure to coal fly ash contaminated prey.

    PubMed

    Tuberville, Tracey D; Scott, David E; Metts, Brian S; Finger, John W; Hamilton, Matthew T

    2016-07-01

    Little is known about the propensity of crocodilians to bioaccumulate trace elements as a result of chronic dietary exposure. We exposed 36 juvenile alligators (Alligator mississippiensis) to one of four dietary treatments that varied in the relative frequency of meals containing prey from coal combustion waste (CCW)-contaminated habitats vs. prey from uncontaminated sites, and evaluated tissue residues and growth rates after 12 mo and 25 mo of exposure. Hepatic and renal concentrations of arsenic (As), cadmium (Cd) and selenium (Se) varied significantly among dietary treatment groups in a dose-dependent manner and were higher in kidneys than in livers. Exposure period did not affect Se or As levels but Cd levels were significantly higher after 25 mo than 12 mo of exposure. Kidney As and Se levels were negatively correlated with body size but neither growth rates nor body condition varied significantly among dietary treatment groups. Our study is among the first to experimentally examine bioaccumulation of trace element contaminants in crocodilians as a result of chronic dietary exposure. A combination of field surveys and laboratory experiments will be required to understand the effects of different exposure scenarios on tissue residues, and ultimately link these concentrations with effects on individual health. PMID:27149145

  10. URANIUM DECONTAMINATION

    DOEpatents

    Buckingham, J.S.; Carroll, J.L.

    1959-12-22

    A process is described for reducing the extractability of ruthenium, zirconium, and niobium values into hexone contained in an aqueous nitric acid uranium-containing solution. The solution is made acid-deficient, heated to between 55 and 70 deg C, and at that temperature a water-soluble inorganic thiosulfate is added. By this, a precipitate is formed which carries the bulk of the ruthenium, and the remainder of the ruthenium as well as the zirconium and niobium are converted to a hexone-nonextractable form. The rutheniumcontaining precipitate can either be removed from the solu tion or it can be dissolved as a hexone-non-extractable compound by the addition of sodium dichromate prior to hexone extraction.

  11. Uranium industry annual 1998

    SciTech Connect

    1999-04-22

    The Uranium Industry Annual 1998 (UIA 1998) provides current statistical data on the US uranium industry`s activities relating to uranium raw materials and uranium marketing. It contains data for the period 1989 through 2008 as collected on the Form EIA-858, ``Uranium Industry Annual Survey.`` Data provides a comprehensive statistical characterization of the industry`s activities for the survey year and also include some information about industry`s plans and commitments for the near-term future. Data on uranium raw materials activities for 1989 through 1998, including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment, are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2008, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, and uranium inventories, are shown in Chapter 2. The methodology used in the 1998 survey, including data edit and analysis, is described in Appendix A. The methodologies for estimation of resources and reserves are described in Appendix B. A list of respondents to the ``Uranium Industry Annual Survey`` is provided in Appendix C. The Form EIA-858 ``Uranium Industry Annual Survey`` is shown in Appendix D. For the readers convenience, metric versions of selected tables from Chapters 1 and 2 are presented in Appendix E along with the standard conversion factors used. A glossary of technical terms is at the end of the report. 24 figs., 56 tabs.

  12. Laser ablation ICP-MS analysis of the radial distribution of lead in the femur of Alligator mississippiensis.

    PubMed

    Seltzer, Michael D; Lance, Valentine A; Elsey, Ruth M

    2006-06-15

    A laser ablation ICP-MS technique has been used to examine the radial distribution of lead in transverse sections of alligator femur. Annual bone growth in the femur results in the deposition of incremental layers of calcified tissue at the periphery of existing bone. Patterns of lead concentration within these layers provide a record of time-dependent accumulation from which exposure history can potentially be deduced. Femur specimens obtained from captive-reared alligators exhibited levels of lead accumulation that were entirely consistent with previously documented clinical signs of lead intoxication. In contrast, femurs obtained from wild alligators contained only minor amounts of lead that were likely accumulated as a result of incidental exposure.

  13. Laser ablation ICP-MS analysis of the radial distribution of lead in the femur of Alligator mississippiensis.

    PubMed

    Seltzer, Michael D; Lance, Valentine A; Elsey, Ruth M

    2006-06-15

    A laser ablation ICP-MS technique has been used to examine the radial distribution of lead in transverse sections of alligator femur. Annual bone growth in the femur results in the deposition of incremental layers of calcified tissue at the periphery of existing bone. Patterns of lead concentration within these layers provide a record of time-dependent accumulation from which exposure history can potentially be deduced. Femur specimens obtained from captive-reared alligators exhibited levels of lead accumulation that were entirely consistent with previously documented clinical signs of lead intoxication. In contrast, femurs obtained from wild alligators contained only minor amounts of lead that were likely accumulated as a result of incidental exposure. PMID:15982720

  14. Surveys of tidal river systems in the northern territory of Australia and their crocodile populations

    SciTech Connect

    Vorlicek, G.C.; Messel, H.; Green, W.J.

    1986-01-01

    This book provides an update on the population dynamics of Crocodylus porous in the tidal waterways of Van Diemen Gulf and the Southern Gulf of Carpentaria, Australia, during 1984 and 1985. Contents: Prologue; Dedication; Introduction; Status of Crocodylus porous. July 1984, in the tidal waterways of the Alligator Region and in the Adelaide River System of Northern Australia: recovery underway; Resurvey of Crocodylus porous populations in the tidal waterways of the southern Gulf of Carpentaria, September - October 1985; Local knowledge - Northern Australia style.

  15. Comprehensive cooling water study annual report. Volume X: endangered species, Savannah River Plant

    SciTech Connect

    Gladden, J.B.; Lower, M.W.; Mackey, H.E.; Specht, W.L.; Wilde, E.W.

    1985-07-01

    Federally endangered species which occur on the Savannah River Plant (SRP) include the American alligator, red-cockaded woodpecker, the shortnose sturgeon, and the wood stork. Of these species, only the alligator, sturgeon, and wood stork are likely to be affected by the intake or release of cooling water at the SRP. The nearest colony of wood storks to the SRP is the Birdsville Colony, about 40-45 km southwest of potential foraging areas in the SRP Savannah River swamp. In 1983, it contained about six percent of the nesting pairs in the United States and produced about 250 fledglings. Its reproductive success was about the same in 1984. Based on the results of surveys made of foraging areas, both on SRP and offsite in 1983 and 1984, forage fish availability could be reduced by increased water depths in the Steel Creek delta area following L-Reactor restart with once-through cooling. Effluent discharge from SRP facilities probably limits the potential use of the SRP Savannah River swamp by foraging wood storks. The SRP supports a low-to-moderate alligator population. The current information available on the alligators of the SRP suggests that populations in suitable habitats (e.g., Beaver Dam Creek, Steel Creek, and Par Pond) should continue to benefit from the protection provided by the SRP and should remain stable or continue to increase. Based upon information from the literature and fisheries data for the Savannah River, the operations of the SRP do not appear to have adverse effects on the shortnose sturgeon. Based on known life history characteristics, there is no indication that spawning, rearing, or foraging habitats are affected by SRP operations. 64 refs., 20 figs., 12 tabs.

  16. Process for electroslag refining of uranium and uranium alloys

    DOEpatents

    Lewis, P.S. Jr.; Agee, W.A.; Bullock, J.S. IV; Condon, J.B.

    1975-07-22

    A process is described for electroslag refining of uranium and uranium alloys wherein molten uranium and uranium alloys are melted in a molten layer of a fluoride slag containing up to about 8 weight percent calcium metal. The calcium metal reduces oxides in the uranium and uranium alloys to provide them with an oxygen content of less than 100 parts per million. (auth)

  17. URANIUM RECOVERY PROCESS

    DOEpatents

    Bailes, R.H.; Long, R.S.; Olson, R.S.; Kerlinger, H.O.

    1959-02-10

    A method is described for recovering uranium values from uranium bearing phosphate solutions such as are encountered in the manufacture of phosphate fertilizers. The solution is first treated with a reducing agent to obtain all the uranium in the tetravalent state. Following this reduction, the solution is treated to co-precipitate the rcduced uranium as a fluoride, together with other insoluble fluorides, thereby accomplishing a substantially complete recovery of even trace amounts of uranium from the phosphate solution. This precipitate usually takes the form of a complex fluoride precipitate, and after appropriate pre-treatment, the uranium fluorides are leached from this precipitate and rccovered from the leach solution.

  18. PRODUCTION OF PURIFIED URANIUM

    DOEpatents

    Burris, L. Jr.; Knighton, J.B.; Feder, H.M.

    1960-01-26

    A pyrometallurgical method for processing nuclear reactor fuel elements containing uranium and fission products and for reducing uranium compound; to metallic uranium is reported. If the material proccssed is essentially metallic uranium, it is dissolved in zinc, the sulution is cooled to crystallize UZn/sub 9/ , and the UZn/sub 9/ is distilled to obtain uranium free of fission products. If the material processed is a uranium compound, the sollvent is an alloy of zinc and magnesium and the remaining steps are the same.

  19. Modification No. 2 to the remedial action plan and site design for stabilization of the inactive uranium mill tailings site at Green River, Utah: Final

    SciTech Connect

    1996-11-01

    Portions of the final Remedial Action Plan (RAP) for the Green River site, Volumes 1 and 2, Appendix B of the Cooperative Agreement No. DE-FC04-81AL16257, March 1991 (DOE, 1991) have been modified. The changes to the RAP are designated as RAP Modification No. 2. These changes have been placed in a three-ring binder that will supplement the original RAP (DOE, 1991), and include the following: addendum to the Executive Summary; Section 3.5 (Ground Water part of the Site Characterization Summary); Section 4.0 (Site Design); Section5.0 (Water Resources Protection Strategy Summary); Appendix D.5 (Ground Water Hydrology); and Appendix E (Ground Water Protection Strategy). In addition to these revisions, there have been editorial changes that clarify the text, but do not change the meaning. Also, certain sections of the document, which are included in the submittal for ease of review and continuity, have been updated to reflect the final ground water protection standards and the current UMTRA Project format and content of RAPs.

  20. NICKEL COATED URANIUM ARTICLE

    DOEpatents

    Gray, A.G.

    1958-10-01

    Nickel coatings on uranium and various methods of obtaining such coatings are described. Specifically disclosed are such nickel or nickel alloy layers as barriers between uranium and aluminum- silicon, chromium, or copper coatings.

  1. METHOD FOR PURIFYING URANIUM

    DOEpatents

    Knighton, J.B.; Feder, H.M.

    1960-04-26

    A process is given for purifying a uranium-base nuclear material. The nuclear material is dissolved in zinc or a zinc-magnesium alloy and the concentration of magnesium is increased until uranium precipitates.

  2. Uranium from phosphate ores

    SciTech Connect

    Hurst, F.J.

    1983-01-01

    The following topics are described briefly: the way phosphate fertilizers are made; how uranium is recovered in the phosphate industry; and how to detect covert uranium recovery operations in a phsophate plant.

  3. DIFFERENCES IN SENSITIVITY BUT NOT SELECTIVITY OF XENOESTROGEN BINDING TO ALLIGATOR VERSUS HUMAN ESTROGEN RECEPTOR ALPHA

    PubMed Central

    Rider, Cynthia V.; Hartig, Phillip C.; Cardon, Mary C.; Lambright, Christy R.; Bobseine, Kathy L.; Guillette, Louis J.; Gray, L. Earl; Wilson, Vickie S.

    2010-01-01

    Reproductive abnormalities in alligators exposed to contaminants in Lake Apopka, Florida, USA represent a clear example of endocrine disruption in wildlife. Several of these contaminants that are not able to bind to mammalian estrogen receptors (such as atrazine and cyanazine) have previously been reported to bind to the alligator estrogen receptor from oviductal tissue. Binding of known Lake Apopka contaminants to full length estrogen receptors alpha from human (hERα) and alligator (aERα) was assessed in a side-by-side comparison within the same assay system. Baculovirus-expressed recombinant hERα and aERα were used in a competitive binding assay. Atrazine and cyanazine were not able to bind to either receptor. p,p′-Dicofol was able to bind to aERα with a concentration inhibiting 50% of binding (IC50) of 4 μM, while only partially displacing 17β-estradiol (E2) from hERα and yielding a projected IC50 of 45 μM. Chemicals that only partially displaced E2 from either receptor, including some dichlorodiphenyltrichloroethane (DDT) metabolites and trans-nonachlor, appeared to have higher affinity for aERα than hERα. p,p′-Dicofol-mediated transcriptional activation through aERα and hERα was assessed to further explore the preferential binding of p,p′-dicofol to aERα over hERα. p,p′-Dicofol was able to stimulate transcriptional activation in a similar manner with both receptors. However, the in vitro results obtained with p,p′-dicofol were not reflected in an in vivo mammalian model, where Kelthane™ (mixed o,p′-and p,p′-dicofol isomers) did not elicit estrogenic effects. In conclusion, although there was no evidence of exclusively species-specific estrogen receptor binders, some xenoestrogens, especially p,p′-dicofol, had a higher affinity for aERα than for hERα. PMID:20821664

  4. Physiological response of alligator gar juveniles (Atractosteus spatula) exposed to sub-lethal doses of pollutants.

    PubMed

    González, Carlos Aguilera; Cruz, Julio; Alfaro, Roberto Mendoza

    2015-08-01

    Alligator gar populations have declined because of overfishing, habitat loss and pollution. Over time, the exposure to different pollutants have affected these fishes as a consequence of their high trophic level, bottom-dwelling habits and long life span. In order to evaluate the physiological effects of pollutants on alligator gar, juveniles (6, 12 and 24 months) were exposed to sub-lethal doses of diazinon, β-naphthoflavone (BNF) and 17 β-estradiol (E2) by intraperitoneal injection. After 2 days of exposure, liver samples were taken to determine the activities of acetylcholinesterase, butyrylcholinesterase and carboxylesterase; alkaline and acid phosphatases (ALP and ACP); ethoxyresorufin o-deethylase (EROD); glutathione s-transferase (GST); superoxide dismutase (SOD), and vitellogenin (VTG) concentration. Two additional bioassays consisting on the exposure of compounds through water or food were performed and after 4 and 28 days, respectively, biomarkers were determined. All esterases were inhibited in organisms exposed to diazinon as well as in 6-months gar exposed to E2 and BNF. In contrast, ALP activity increased in gar exposed to diazinon and E2, while ACP activity did not show any variations. No EROD activity was registered after exposure to the different pollutants, despite being one of the most sensitive and common detoxification biomarkers used for fishes. GST activity reduction was detected when gar were exposed to E2 and BNF, while SOD activity increased after exposure to diazinon and E2. Finally, VTG levels were higher in animals exposed to E2 compared to other treatments. Overall, these results suggest that alligator gar juveniles have a low biotransformation metabolism and show that they are especially sensitive to those pollutants affecting the nervous system. PMID:25948055

  5. Full-length cDNA cloning and structural characterization of preproinsulin in Alligator sinensis.

    PubMed

    Zhang, R; Zhang, S Z; Li, E; Wang, C; Wang, C L; Wu, X B

    2014-01-01

    Insulin is an important endocrine hormone that plays a critical physiological role in regulating metabolism and glucostasis in vertebrates. In this study, the complete cDNA of Alligator sinensis preproinsulin gene was cloned for the first time by reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends methods; the amino acid sequence encoded and protein structure were analyzed. The full-length of preproinsulin cDNA sequence consists of 528 base pairs (bp), comprising a 34-bp 5'-untranslated region, a 170-bp 3'-untranslated region and an open reading frame that is 324 bp in length. The open reading frame encodes a 107-amino acid preproinsulin with a molecular weight of approximately 12,153.8 Da, theoretical isoelectric point of 5.68, aliphatic index of 92.06, and grand average of hydropathicity of -0.157, from which a signal peptide, a B-chain, a C-peptide, and an A-chain are derived. Online analysis suggested that the deduced preproinsulin amino acid sequence contains a transmembrane region, and that it has a signal peptide whose cleavage site occurs between alanine 24 and alanine 25. Comparative analysis of preproinsulin amino acid sequences indicated that the A-chain and B-chain sequences of preproinsulins are highly conserved between reptiles and birds, and that the preproinsulin amino acid sequence of Alligator sinensis shares 89% similarity to that of Chelonia mydas, but low similarity of 48-63% to those of mammals and fishes. The phylogenetic tree constructed using the neighbor-joining method revealed that preproinsulin of Alligator sinensis had high homology with reptiles and birds, such as Chelonia mydas, Gallus gallus, and Columba livia. PMID:25366775

  6. Plasma steroid concentrations and male phallus size in juvenile alligators from seven Florida lakes

    USGS Publications Warehouse

    Guillette, L.J.; Woodward, A.R.; Crain, D.A.; Pickford, D.B.; Rooney, A.A.; Percival, H.F.

    1999-01-01

    Neonatal and juvenile alligators from contaminated Lake Apopka in central Florida exhibit abnormal plasma sex steroid concentrations as well as morphological abnormalities of the gonad and phallus. This study addresses whether similar abnormalities occur in juvenile alligators inhabiting six other lakes in Florida. For analysis, animals were partitioned into two subsets, animals 40-79 cm total length (1-3 years old) and juveniles 80-130 cm total length (3-7 years old). Plasma testosterone (T) concentrations were lower in small males from lakes Apopka, Griffin, and Jessup than from Lake Woodruff National Wildlife Refuge (NWR). Similar differences were observed in the larger juveniles, with males from lakes Jessup, Apopka, and Okeechobee having lower plasma T concentrations than Lake Woodruff males. Plasma estradiol-17?? (E2) concentrations were significantly elevated in larger juvenile males from Lake Apopka compared to Lake Woodruff NWR. When compared to small juvenile females from Lake Woodruff NWR, females from lakes Griffin, Apopka, Orange, and Okeechobee had elevated plasma E2 concentrations. Phallus size was significantly smaller in males from lakes Griffin and Apopka when compared to males from Lake Woodruff NWR. An association existed between body size and phallus size on all lakes except Lake Apopka and between phallus size and plasma T concentration on all lakes except lakes Apopka and Orange. Multiple regression analysis, with body size and plasma T concentration as independent covariables, explained the majority of the variation in phallus size on all lakes. These data suggest that the differences in sex steroids and phallus size observed in alligators from Lake Apopka are not limited to that lake, nor to one with a history of a major pesticide spill. Further work examining the relationship of sex steroids and phallus size with specific biotic and abiotic factors, such as antiandrogenic or estrogenic contaminants, is needed.

  7. Physiological response of alligator gar juveniles (Atractosteus spatula) exposed to sub-lethal doses of pollutants.

    PubMed

    González, Carlos Aguilera; Cruz, Julio; Alfaro, Roberto Mendoza

    2015-08-01

    Alligator gar populations have declined because of overfishing, habitat loss and pollution. Over time, the exposure to different pollutants have affected these fishes as a consequence of their high trophic level, bottom-dwelling habits and long life span. In order to evaluate the physiological effects of pollutants on alligator gar, juveniles (6, 12 and 24 months) were exposed to sub-lethal doses of diazinon, β-naphthoflavone (BNF) and 17 β-estradiol (E2) by intraperitoneal injection. After 2 days of exposure, liver samples were taken to determine the activities of acetylcholinesterase, butyrylcholinesterase and carboxylesterase; alkaline and acid phosphatases (ALP and ACP); ethoxyresorufin o-deethylase (EROD); glutathione s-transferase (GST); superoxide dismutase (SOD), and vitellogenin (VTG) concentration. Two additional bioassays consisting on the exposure of compounds through water or food were performed and after 4 and 28 days, respectively, biomarkers were determined. All esterases were inhibited in organisms exposed to diazinon as well as in 6-months gar exposed to E2 and BNF. In contrast, ALP activity increased in gar exposed to diazinon and E2, while ACP activity did not show any variations. No EROD activity was registered after exposure to the different pollutants, despite being one of the most sensitive and common detoxification biomarkers used for fishes. GST activity reduction was detected when gar were exposed to E2 and BNF, while SOD activity increased after exposure to diazinon and E2. Finally, VTG levels were higher in animals exposed to E2 compared to other treatments. Overall, these results suggest that alligator gar juveniles have a low biotransformation metabolism and show that they are especially sensitive to those pollutants affecting the nervous system.

  8. PREPARATION OF URANIUM HEXAFLUORIDE

    DOEpatents

    Lawroski, S.; Jonke, A.A.; Steunenberg, R.K.

    1959-10-01

    A process is described for preparing uranium hexafluoride from carbonate- leach uranium ore concentrate. The briquetted, crushed, and screened concentrate is reacted with hydrogen fluoride in a fluidized bed, and the uranium tetrafluoride formed is mixed with a solid diluent, such as calcium fluoride. This mixture is fluorinated with fluorine and an inert diluent gas, also in a fluidized bed, and the uranium hexafluoride obtained is finally purified by fractional distillation.

  9. PROCESS OF PURIFYING URANIUM

    DOEpatents

    Seaborg, G.T.; Orlemann, E.F.; Jensen, L.H.

    1958-12-23

    A method of obtaining substantially pure uranium from a uranium composition contaminated with light element impurities such as sodium, magnesium, beryllium, and the like is described. An acidic aqueous solution containing tetravalent uranium is treated with a soluble molybdate to form insoluble uranous molybdate which is removed. This material after washing is dissolved in concentrated nitric acid to obtaln a uranyl nitrate solution from which highly purified uranium is obtained by extraction with ether.

  10. Post-hatching development of mitochondrial function, organ mass and metabolic rate in two ectotherms, the American alligator (Alligator mississippiensis) and the common snapping turtle (Chelydra serpentina)

    PubMed Central

    Sirsat, Sarah K. G.; Sirsat, Tushar S.; Price, Edwin R.; Dzialowski, Edward M.

    2016-01-01

    ABSTRACT The ontogeny of endothermy in birds is associated with disproportionate growth of thermogenic organs and increased mitochondrial oxidative capacity. However, no similar study has been made of the development of these traits in ectotherms. For comparison, we therefore investigated the metabolism, growth and muscle mitochondrial function in hatchlings of a turtle and a crocodilian, two ectotherms that never develop endothermy. Metabolic rate did not increase substantially in either species by 30 days post-hatching. Yolk-free body mass and heart mass did not change through 30 days in alligators and heart mass was a constant proportion of body mass, even after 1 year. Yolk-free body mass and liver mass grew 36% and 27%, respectively, in turtles during the first 30 days post-hatch. The mass-specific oxidative phosphorylation capacity of mitochondria, assessed using permeabilized muscle fibers, increased by a non-significant 47% in alligator thigh and a non-significant 50% in turtle thigh over 30 days, but did not increase in the heart. This developmental trajectory of mitochondrial function is slower and shallower than that previously observed in ducks, which demonstrate a 90% increase in mass-specific oxidative phosphorylation capacity in thigh muscles over just a few days, a 60% increase in mass-specific oxidative phosphorylation capacity of the heart over a few days, and disproportionate growth of the heart and other organs. Our data thus support the hypothesis that these developmental changes in ducks represent mechanistic drivers for attaining endothermy. PMID:26962048

  11. Post-hatching development of mitochondrial function, organ mass and metabolic rate in two ectotherms, the American alligator (Alligator mississippiensis) and the common snapping turtle (Chelydra serpentina).

    PubMed

    Sirsat, Sarah K G; Sirsat, Tushar S; Price, Edwin R; Dzialowski, Edward M

    2016-01-01

    The ontogeny of endothermy in birds is associated with disproportionate growth of thermogenic organs and increased mitochondrial oxidative capacity. However, no similar study has been made of the development of these traits in ectotherms. For comparison, we therefore investigated the metabolism, growth and muscle mitochondrial function in hatchlings of a turtle and a crocodilian, two ectotherms that never develop endothermy. Metabolic rate did not increase substantially in either species by 30 days post-hatching. Yolk-free body mass and heart mass did not change through 30 days in alligators and heart mass was a constant proportion of body mass, even after 1 year. Yolk-free body mass and liver mass grew 36% and 27%, respectively, in turtles during the first 30 days post-hatch. The mass-specific oxidative phosphorylation capacity of mitochondria, assessed using permeabilized muscle fibers, increased by a non-significant 47% in alligator thigh and a non-significant 50% in turtle thigh over 30 days, but did not increase in the heart. This developmental trajectory of mitochondrial function is slower and shallower than that previously observed in ducks, which demonstrate a 90% increase in mass-specific oxidative phosphorylation capacity in thigh muscles over just a few days, a 60% increase in mass-specific oxidative phosphorylation capacity of the heart over a few days, and disproportionate growth of the heart and other organs. Our data thus support the hypothesis that these developmental changes in ducks represent mechanistic drivers for attaining endothermy. PMID:26962048

  12. PRODUCTION OF URANIUM TETRAFLUORIDE

    DOEpatents

    Shaw, W.E.; Spenceley, R.M.; Teetzel, F.M.

    1959-08-01

    A method is presented for producing uranium tetrafluoride from the gaseous hexafluoride by feeding the hexafluoride into a high temperature zone obtained by the recombination of molecularly dissociated hydrogen. The molal ratio of hydrogen to uranium hexnfluoride is preferably about 3 to 1. Uranium tetrafluoride is obtained in a finely divided, anhydrous state.

  13. Uranium Immobilization in Wetland Soils

    NASA Astrophysics Data System (ADS)

    Jaffe, Peter R.; Koster van Groos, Paul G.; Li, Dien; Chang, Hyun-Shik; Seaman, John C.; Kaplan, Daniel I.; Peacock, Aaron D.; Scheckel, Kirk

    2014-05-01

    stronger for the mesocosms with the higher Fe(II) load. Analysis via XANES showed that a fraction (up to ~1/3) of uranium was reduced to U(IV), for mesocosms operated under low iron loading, indicating that iron cycling in the rhizosphere also results in uranium reduction and immobilization. For mesocosms operating under the higher iron loading, the fraction of uranium immobilized as U(IV) was much lower, indicating that uranium co-precipitation with iron might have been the dominant immobilization process. In parallel to these mesocosm experiments, dialysis samplers have been deployed at the Savannah River National Laboratory near a creek with uranium contamination, to determine dissolved species, including Fe(II) and U(VI) in these wetland soils and their seasonal variability. The results show that there is a strong seasonal variability in dissolved iron and uranium, indicating a strong immobilization during the growing season, which is consistent with the mesocosm experimental results that the rhizosphere iron and uranium cycling are closely linked.

  14. Plutonium, cesium and uranium series radionuclides in the Hudson River estuary and other environments. Annual technical progress report, December 1, 1979-November 30, 1980

    SciTech Connect

    Simpson, H. J.; Trier, R. M.; Olsen, C. R.

    1980-01-01

    Radionuclide activities were measured in a large number of sediment cores and suspended particle samples throughout the salinity range of the Hudson River estuary. Activities of /sup 137/Cs, /sup 134/Cs and /sup 60/Co determined by gamma spectrometry and /sup 239/ /sup 240/Pu and /sup 238/Pu determined by alpha spectrometry indicate reasonably rapid accumulation rates in the sediments of marginal cove areas, and very rapid deposition in the harbor region adjacent to New York City, resulting in /sup 239/ /sup 240/Pu accumulations there more than an order of magnitude greater than the fallout delivery rate. Measurable amounts of reactor-derived /sup 134/Cs and /sup 60/Co are found in nearly al sediment samples containing appreciable /sup 137/Cs between 15 km upstream of Indian Point and the downstream extent of our sampling about 70 km south of the reactor. Fallout /sup 239/ /sup 240/Pu reaching the Hudson appears to be almost completely retained within the systems by particle deposition, while 70 to 90% of the /sup 137/Cs derived from both reactor releases and fallout has been exported to the coastal waters in solution. Activity levels of /sup 239/ /sup 240/Pu in New York harbor sediments indicate a significant source in addition to suspended particles carried down the Hudson. The most likely cause appears to be transport into the estuary of particles from offshore waters having higher specific activities of /sup 239/ /sup 240/Pu. Measurements of fallout /sup 239/ /sup 240/Pu in a saline lake with a high carbonate ion concentration yielded water column activities about two orders of magnitude greater than has been found for fallout plutonium in other continental waters, indicating extensive mobility in some natural water environments. Experiments using lake water suggest that carbonate ion may indeed be a critical factor in regulating plutonium solubility and that low molecular weight complexes are primarily responsible for enhanced plutonium solubility.

  15. URANIUM SEPARATION PROCESS

    DOEpatents

    Hyde, E.K.; Katzin, L.I.; Wolf, M.J.

    1959-07-14

    The separation of uranium from a mixture of uranium and thorium by organic solvent extraction from an aqueous solution is described. The uranium is separrted from an aqueous mixture of uranium and thorium nitrates 3 N in nitric acid and containing salting out agents such as ammonium nitrate, so as to bring ihe total nitrate ion concentration to a maximum of about 8 N by contacting the mixture with an immiscible aliphatic oxygen containing organic solvent such as diethyl carbinol, hexone, n-amyl acetate and the like. The uranium values may be recovered from the organic phase by back extraction with water.

  16. PRODUCTION OF URANIUM

    DOEpatents

    Spedding, F.H.; Wilhelm, H.A.; Keller, W.H.

    1958-04-15

    The production of uranium metal by the reduction of uranium tetrafluoride is described. Massive uranium metal of high purily is produced by reacting uranium tetrafluoride with 2 to 20% stoichiometric excess of magnesium at a temperature sufficient to promote the reaction and then mantaining the reaction mass in a sealed vessel at temperature in the range of 1150 to 2000 d C, under a superatomospheric pressure of magnesium for a period of time sufficient 10 allow separation of liquid uranium and liquid magnesium fluoride into separate layers.

  17. URANIUM RECOVERY PROCESS

    DOEpatents

    Yeager, J.H.

    1958-08-12

    In the prior art processing of uranium ores, the ore is flrst digested with nitric acid and filtered, and the uranium values are then extracted tom the filtrate by contacting with an organic solvent. The insoluble residue has been processed separately in order to recover any uranium which it might contain. The improvement consists in contacting a slurry, composed of both solution and residue, with the organic solvent prior to filtration. Tbe result is that uranium values contained in the residue are extracted along with the uranium values contained th the solution in one step.

  18. PROCESS OF RECOVERING URANIUM

    DOEpatents

    Carter, J.M.; Larson, C.E.

    1958-10-01

    A process is presented for recovering uranium values from calutron deposits. The process consists in treating such deposits to produce an oxidlzed acidic solution containing uranium together with the following imparities: Cu, Fe, Cr, Ni, Mn, Zn. The uranium is recovered from such an impurity-bearing solution by adjusting the pH of the solution to the range 1.5 to 3.0 and then treating the solution with hydrogen peroxide. This results in the precipitation of uranium peroxide which is substantially free of the metal impurities in the solution. The peroxide precipitate is then separated from the solution, washed, and calcined to produce uranium trioxide.

  19. Slow isotope turnover rates and low discrimination values in the American alligator: implications for interpretation of ectotherm stable isotope data.

    PubMed

    Rosenblatt, Adam E; Heithaus, Michael R

    2013-01-01

    Stable isotope analysis has become a standard ecological tool for elucidating feeding relationships of organisms and determining food web structure and connectivity. There remain important questions concerning rates at which stable isotope values are incorporated into tissues (turnover rates) and the change in isotope value between a tissue and a food source (discrimination values). These gaps in our understanding necessitate experimental studies to adequately interpret field data. Tissue turnover rates and discrimination values vary among species and have been investigated in a broad array of taxa. However, little attention has been paid to ectothermic top predators in this regard. We quantified the turnover rates and discrimination values for three tissues (scutes, red blood cells, and plasma) in American alligators (Alligator mississippiensis). Plasma turned over faster than scutes or red blood cells, but turnover rates of all three tissues were very slow in comparison to those in endothermic species. Alligator δ(15)N discrimination values were surprisingly low in comparison to those of other top predators and varied between experimental and control alligators. The variability of δ(15)N discrimination values highlights the difficulties in using δ(15)N to assign absolute and possibly even relative trophic levels in field studies. Our results suggest that interpreting stable isotope data based on parameter estimates from other species can be problematic and that large ectothermic tetrapod tissues may be characterized by unique stable isotope dynamics relative to species occupying lower trophic levels and endothermic tetrapods.

  20. Urinary iodine and stable isotope analysis to examine habitat influences on thyroid hormones among coastal dwelling American alligators.

    PubMed

    Boggs, Ashley S P; Hamlin, Heather J; Nifong, James C; Kassim, Brittany L; Lowers, Russell H; Galligan, Thomas M; Long, Stephen E; Guillette, Louis J

    2016-01-15

    The American alligator, generally a freshwater species, is known to forage in marine environments despite the lack of a salt secreting gland found in other crocodylids. Estuarine and marine foraging could lead to increased dietary uptake of iodine, a nutrient necessary for the production of thyroid hormones. To explore the influence of dietary iodine on thyroid hormone health of coastal dwelling alligators, we described the seasonal plasma thyroxine and triiodothyronine concentrations measured by radioimmunoassay and urinary iodine (UI) concentrations measured by inductively coupled plasma mass spectrometry. We also analyzed long-term dietary patterns through stable isotope analysis of scute tissue. Snout-to-vent length (SVL) was a significant factor among UI and stable isotope analyses. Large adult males greater than 135cm SVL had the highest UI concentrations but did not display seasonality of thyroid hormones. Alligators under 135 SVL exhibited seasonality in thyroid hormones and a positive relationship between UI and triiodothyronine concentrations. Isotopic signatures provided supporting evidence that large males predominantly feed on marine/estuarine prey whereas females showed reliance on freshwater/terrestrial prey supplemented by marine/estuarine prey. UI measurement provided immediate information that correlated to thyroid hormone concentrations whereas stable isotope analysis described long-term dietary patterns. Both techniques demonstrate that adult alligators in coastal environments are utilizing estuarine/marine habitats, which could alter thyroid hormone physiology.

  1. Nuclear β-catenin localization supports homology of feathers, avian scutate scales, and alligator scales in early development.

    PubMed

    Musser, Jacob M; Wagner, Günter P; Prum, Richard O

    2015-01-01

    Feathers are an evolutionary novelty found in all extant birds. Despite recent progress investigating feather development and a revolution in dinosaur paleontology, the relationship of feathers to other amniote skin appendages, particularly reptile scales, remains unclear. Disagreement arises primarily from the observation that feathers and avian scutate scales exhibit an anatomical placode-defined as an epidermal thickening-in early development, whereas alligator and other avian scales do not. To investigate the homology of feathers and archosaur scales we examined patterns of nuclear β-catenin localization during early development of feathers and different bird and alligator scales. In birds, nuclear β-catenin is first localized to the feather placode, and then exhibits a dynamic pattern of localization in both epidermis and dermis of the feather bud. We found that asymmetric avian scutate scales and alligator scales share similar patterns of nuclear β-catenin localization with feathers. This supports the hypothesis that feathers, scutate scales, and alligator scales are homologous during early developmental stages, and are derived from early developmental stages of an asymmetric scale present in the archosaur ancestor. Furthermore, given that the earliest stage of β-catenin localization in feathers and archosaur scales is also found in placodes of several mammalian skin appendages, including hair and mammary glands, we hypothesize that a common skin appendage placode originated in the common ancestor of all amniotes. We suggest a skin placode should not be defined by anatomical features, but as a local, organized molecular signaling center from which an epidermal appendage develops.

  2. Urinary iodine and stable isotope analysis to examine habitat influences on thyroid hormones among coastal dwelling American alligators.

    PubMed

    Boggs, Ashley S P; Hamlin, Heather J; Nifong, James C; Kassim, Brittany L; Lowers, Russell H; Galligan, Thomas M; Long, Stephen E; Guillette, Louis J

    2016-01-15

    The American alligator, generally a freshwater species, is known to forage in marine environments despite the lack of a salt secreting gland found in other crocodylids. Estuarine and marine foraging could lead to increased dietary uptake of iodine, a nutrient necessary for the production of thyroid hormones. To explore the influence of dietary iodine on thyroid hormone health of coastal dwelling alligators, we described the seasonal plasma thyroxine and triiodothyronine concentrations measured by radioimmunoassay and urinary iodine (UI) concentrations measured by inductively coupled plasma mass spectrometry. We also analyzed long-term dietary patterns through stable isotope analysis of scute tissue. Snout-to-vent length (SVL) was a significant factor among UI and stable isotope analyses. Large adult males greater than 135cm SVL had the highest UI concentrations but did not display seasonality of thyroid hormones. Alligators under 135 SVL exhibited seasonality in thyroid hormones and a positive relationship between UI and triiodothyronine concentrations. Isotopic signatures provided supporting evidence that large males predominantly feed on marine/estuarine prey whereas females showed reliance on freshwater/terrestrial prey supplemented by marine/estuarine prey. UI measurement provided immediate information that correlated to thyroid hormone concentrations whereas stable isotope analysis described long-term dietary patterns. Both techniques demonstrate that adult alligators in coastal environments are utilizing estuarine/marine habitats, which could alter thyroid hormone physiology. PMID:26684734

  3. The first fossil skull of Alligator sinensis from the Pleistocene, Taiwan, with a paleogeographic implication of the species

    NASA Astrophysics Data System (ADS)

    Hsi-yin, Shan; Yen-nien, Cheng; Xiao-chun, Wu

    2013-06-01

    A nearly complete fossil skull of Alligatoridae from the Pleistocene, Penghu Channel, east of Taiwan, is reported. It can be referred to the most latest clade of Alligatorinae, which includes Alligator sinensis, Alligator mississippiensis and Alligator mefferdi, on the basis of the following features: the splenial is excluded from the mandibular symphysis; the anterior tip of the splenial passes dorsal to the Meckelian groove; and the mandible is gently curved between the fourth alveoli and the mid dentary. It differs from A. mississippiensis and A. mefferdi mainly in the following characters: the breadth between the supratemporal fenestrae is approximately equal to the interorbital width, the snout is about half the length of the skull; and the anterior part of the snout is subtriangular in dorsal view. These features suggest that the Penghu alligator is most probably referable to A. sinensis. This is the only fossil skull of A. sinensis known. The discovery of the skull in Penghu Channel not only provides the first solid fossil evidence to indicate that the geological distribution of A. sinensis extended farther southeast than the historical/archeological range of the species but also adds new information on the biodiversity of the Penghu fauna.

  4. Uranium hydrogeochemical and stream sediment reconnaissance of the Newcastle NTMS Quadrangle, Wyoming, including concentrations of forty-two additional elements

    SciTech Connect

    Goff, S.J.; Sandoval, W.F.; Gallimore, D.L.; Talcott, C.L.; Martinez, R.G.; Minor, M.E.; Mills, C.F.

    1980-06-01

    Water and sediment samples were collected and each water sample was analyzed for U, and each sediment sample was analyzed for 43 elements, including U and Th. Uranium concentrations in water samples range from below the detection limit of 0.02 ppB to 702.26 ppB and have a median of 1.73 ppB and a mean of 11.76 ppB. Water samples containing high uranium concentrations generally are associated with known uranium mining activity or units known to be uranium bearing. About one-third of the water samples containing high uranium concentrations were collected from locations within the Pumpkin Buttes and Turnercrest-Ross Districts. Nearly half of the water samples containing high uranium concentrations were collected from locations just west of the Monument Hill and Highland Flats-Box Creek Districts. Similar anomalous uranium concentrations in this region have been reported updip from Exxon's Highland uranium deposits. High uranium concentrations were also found associated with the Lance Creek-Old Woman Anticline District. Uranium concentrations in sediment samples range from 1.14 to 220.70 ppM and have a median of 3.37 ppM and a mean of 4.03 ppM. Throughout the major uranium mining districts of the Powder River Basin, sediment samples with high uranium concentrations were collected from dry streams located near wells producing water samples with high uranium concentrations. High uranium concentrations were also found associated with the Lance Creek oil field where uranium mineralization is known in the White River formation. High uranium concentrations were also found in sediment samples in areas where uranium mineralization is not known. These samples are from dry streams in areas underlain by the White River formation, the Niobrara formation, and the Pierre, Carlisle, Belle Fourche, and Mowry shales.

  5. Method for converting uranium oxides to uranium metal

    DOEpatents

    Duerksen, Walter K.

    1988-01-01

    A process is described for converting scrap and waste uranium oxide to uranium metal. The uranium oxide is sequentially reduced with a suitable reducing agent to a mixture of uranium metal and oxide products. The uranium metal is then converted to uranium hydride and the uranium hydride-containing mixture is then cooled to a temperature less than -100.degree. C. in an inert liquid which renders the uranium hydride ferromagnetic. The uranium hydride is then magnetically separated from the cooled mixture. The separated uranium hydride is readily converted to uranium metal by heating in an inert atmosphere. This process is environmentally acceptable and eliminates the use of hydrogen fluoride as well as the explosive conditions encountered in the previously employed bomb-reduction processes utilized for converting uranium oxides to uranium metal.

  6. An Investigation into the Transportation of Irradiated Uranium/Aluminum Targets from a Foreign Nuclear Reactor to the Chalk River Laboratories Site in Ontario, Canada - 12249

    SciTech Connect

    Clough, Malcolm; Jackson, Austin

    2012-07-01

    This investigation required the selection of a suitable cask and development of a device to hold and transport irradiated targets from a foreign nuclear reactor to the Chalk River Laboratories in Ontario, Canada. The main challenge was to design and validate a target holder to protect the irradiated HEU-Al target pencils during transit. Each of the targets was estimated to have an initial decay heat of 118 W prior to transit. As the targets have little thermal mass the potential for high temperature damage and possibly melting was high. Thus, the primary design objective was to conceive a target holder to dissipate heat from the targets. Other design requirements included securing the targets during transportation and providing a simple means to load and unload the targets while submerged five metres under water. A unique target holder (patent pending) was designed and manufactured together with special purpose experimental apparatus including a representative cask. Aluminum dummy targets were fabricated to accept cartridge heaters, to simulate decay heat. Thermocouples were used to measure the temperature of the test targets and selected areas within the target holder and test cask. After obtaining test results, calculations were performed to compensate for differences between experimental and real life conditions. Taking compensation into consideration the maximum target temperature reached was 231 deg. C which was below the designated maximum of 250 deg. C. The design of the aluminum target holder also allowed generous clearance to insert and unload the targets. This clearance was designed to close up as the target holder is placed into the cavity of the transport cask. Springs served to retain and restrain the targets from movement during transportation as well as to facilitate conductive heat transfer. The target holder met the design requirements and as such provided data supporting the feasibility of transporting targets over a relatively long period of time

  7. Reengineering water treatment units for removal of Sr-90, I-129, Tc-99, and uranium from contaminated groundwater at the DOE's Savannah River Site

    SciTech Connect

    Serkiz, S.M.

    2000-02-09

    The 33 years of active operation of the F- and H-Area Seepage Basins to dispose of liquid low-level radioactive waste at the Department of Energy's Savannah River Site has resulted in the contamination of the groundwater underlying these basins with a wide variety of radionuclides and stable metals. The current Resource Conservation and Recovery Act (RCRA) Part B permit requires the operation of a pump-and-treat system capable of (1) maintaining hydraulic control of a specified contaminated groundwater plume, (2) treatment of the extracted groundwater, and (3) reinjection of the treated water hydraulically upgradient of the basins. Two multimillion-dollar water treatment units (WTUs) were designed and built in 1997 and the basic design consists of (1) reverse osmosis concentration, (2) chemical addition, neutralization, precipitation, polymer addition, flocculation, and clarification of the reverse osmosis concentrate, and (3) final polishing of the clarified water by ion exchange (IX) and sorption. During startup of these units numerous process optimizations were identified and, therefore, the WTUs have been recently reengineered. A systematic approach of: (1) developing a technical baseline through laboratory studies, (2) scale-up and plant testing, (3) plant modification, and (4) system performance monitoring was the basis for reengineering the WTUs. Laboratory experiments were conducted in order to establish a technical baseline for further scale-up/plant testing and system modifications. These studies focused on the following three areas of the process: (1) contaminant removal during chemical addition, neutralization and precipitation, (2) solids separation by flocculation, coagulation, clarification, and filtration, and (3) contaminant polishing of the clarified liquid by IX/sorption. Using standard laboratory-scale jar tests, the influences of pH and Fe concentration on contaminant removal during precipitation/neutralization were evaluated. The results of

  8. Gonadal steroidogenesis in vitro from juvenile alligators obtained from contaminated or control lakes.

    PubMed Central

    Guillette, L J; Gross, T S; Gross, D A; Rooney, A A; Percival, H F

    1995-01-01

    The ubiquitous distribution of many contaminants and the nonlethal, multigenerational effects of such contaminants on reproductive, endocrine, and immune systems have led to concerns that wildlife worldwide are affected. Although the causal agents and effects are known for some species, the underlying physiological mechanisms associated with contaminant-induced reproductive modifications are still poorly understood and require extensive research. We describe a study examining the steroidogenic activity of gonads removed from juvenile alligators (Alligator mississippiensis) obtained from contaminated or control lakes in central Florida. Synthesis of estradiol-17 beta (E2) was significantly different when ovaries from the contaminated and control lakes were compared in vitro. Additionally, testes from males obtained from the contaminated lake. Lake Apopka, synthesized significantly higher concentrations of E2 when compared to testes obtained from control males. In contrast, testosterone (T) synthesis from all testes examined in this study displayed a normal pattern and produced concentrations greater than that observed from ovaries obtained from either lake. Interestingly, the pattern of gonadal steroidogenesis differs from previously reported plasma concentrations of these hormones obtained from the same individuals. We suggest that the differences between the in vivo and in vitro patterns are due to modifications in the hepatic degradation of plasma sex steroid hormones. PMID:7556021

  9. In vivo bone strain and finite element modeling of the mandible of Alligator mississippiensis

    PubMed Central

    Porro, Laura B; Metzger, Keith A; Iriarte-Diaz, Jose; Ross, Callum F

    2013-01-01

    Forces experienced during feeding are thought to strongly influence the morphology of the vertebrate mandible; in vivo strain data are the most direct evidence for deformation of the mandible induced by these loading regimes. Although many studies have documented bone strains in the mammalian mandible, no information is available on strain magnitudes, orientations or patterns in the sauropsid lower jaw during feeding. Furthermore, strain gage experiments record the mechanical response of bone at a few locations, not across the entire mandible. In this paper, we present bone strain data recorded at various sites on the lower jaw of Alligator mississippiensis during in vivo feeding experiments. These data are used to understand how changes in loading regime associated with changes in bite location are related to changes in strain regime on the working and balancing sides of the mandible. Our results suggest that the working side mandible is bent dorsoventrally and twisted about its long-axis during biting, and the balancing side experiences primarily dorsoventral bending. Strain orientations are more variable on the working side than on the balancing side with changes in bite point and between experiments; the balancing side exhibits higher strain magnitudes. In the second part of this paper, we use principal strain orientations and magnitudes recorded in vivo to evaluate a finite element model of the alligator mandible. Our comparison demonstrates that strain orientations and mandibular deformation predicted by the model closely match in vivo results; however, absolute strain magnitudes are lower in the finite element model. PMID:23855772

  10. Spermiogenesis in the imbricate alligator lizard, Barisia imbricata (Reptilia, Squamata, Anguidae).

    PubMed

    Gribbins, Kevin M; Rheubert, Justin L; Touzinsky, Katherine; Hanover, Jessica; Matchett, Caroline L; Granados-González, Gisela; Hernández-Gallegos, Oswaldo

    2013-06-01

    Although the events of spermiogenesis are commonly studied in amniotes, the amount of research available for Squamata is lacking. Many studies have described the morphological characteristics of mature spermatozoa in squamates, but few detail the ultrastructural changes that occur during spermiogenesis. This study's purpose is to gain a better understanding of the subcellular events of spermatid development within the Imbricate Alligator Lizard, Barisia imbricata. The morphological data presented here represent the first complete ultrastructural study of spermiogenesis within the family Anguidae. Samples of testes from four specimens collected on the northwest side of the Nevado de Toluca, México, were prepared using standard techniques for transmission electron microscopy. Many of the ultrastructural changes occurring during spermiogenesis within B. imbricata are similar to that of other squamates (i.e., early acrosome formation, chromatin condensation, flagella formation, annulus present, and a prominent manchette). However, there are a few unique characteristics within B. imbricata spermatids that to date have not been described during spermiogenesis in other squamates. For example, penetration of the acrosomal granule into the subacrosomal space to form the basal plate of the perforatorium during round spermatid development, the clover-shaped morphology of the developing nuclear fossa of the flagellum, and the bulbous shape to the perforatorium are all unique to the Imbricate Alligator Lizard. These anatomical character differences may be valuable nontraditional data that along with more traditional matrices (such as DNA sequences and gross morphological data) may help elucidate phylogenetic relationships, which are historically considered controversial within Squamata.

  11. Quantification of intraskeletal histovariability in Alligator mississippiensis and implications for vertebrate osteohistology.

    PubMed

    Woodward, Holly N; Horner, John R; Farlow, James O

    2014-01-01

    Bone microanalyses of extant vertebrates provide a necessary framework from which to form hypotheses regarding the growth and skeletochronology of extinct taxa. Here, we describe the bone microstructure and quantify the histovariability of appendicular elements and osteoderms from three juvenile American alligators (Alligator mississippiensis) to assess growth mark and tissue organization within and amongst individuals, with the intention of validating paleohistological interpretations. Results confirm previous observations that lamellar and parallel fibered tissue organization are typical of crocodylians, and also that crocodylians are capable of forming woven tissue for brief periods. Tissue organization and growth mark count varies across individual skeletal elements and reveal that the femur, tibia, and humerus had the highest annual apposition rates in each individual. Cyclical growth mark count also varies intraskeletally, but data suggest these inconsistencies are due to differing medullary cavity expansion rates. There was no appreciable difference in either diaphyseal circumference or cyclical growth mark circumferences between left and right element pairs from an individual if diaphyses were sampled from roughly the same location. The considerable intraskeletal data obtained here provide validation for long-held paleohistology assumptions, but because medullary expansion, cyclical growth mark formation, and variable intraskeletal growth rates are skeletal features found in tetrapod taxa living or extinct, the validations presented herein should be considered during any tetrapod bone microanalysis. PMID:24949239

  12. Acanthostomum macroclemidis n. sp. (Digenea: Cryptogonimidae: Acanthostominae) from the alligator snapping turtle, Macroclemys temmincki.

    PubMed

    Tkach, Vasyl V; Snyder, Scott D

    2003-02-01

    Acanthostomum macroclemidis n. sp. is described from specimens found in the intestine of an alligator snapping turtle Macroclemys temmincki from southern Mississippi. The most important diagnostic features of the new species are the general shape and proportions of the body, the position of the pharynx (relative length of the prepharynx and esophagus), the egg size, the relative length and position of the vitelline fields, and the number, shape, and size of the circumoral spines. The new species has a very elongated body (length-width ratio, 8.9-13.0:1), 26 circumoral spines, which are almost oval in shape, a long prepharynx and a very short (shorter than the pharynx) esophagus, a seminal receptacle situated between the ovary and the anterior testis, a uterus not extending posterior to the anterior margin of the ovary, a long-stemmed and short-armed excretory vesicle, and 2 anal openings. Some features of the external morphology, such as the suckers, circumoral spines, sensory papillae, tegumental spines, and morphology of the posterior end, are examined using scanning electron microscopy. A diagnosis differentiating A. macroclemidis n. sp. from some other acanthostomine digeneans is provided. Acanthostomum macroclemidis n. sp. is the first digenean reported from an alligator snapping turtle and represents the northernmost record of an acanthostomine from turtles. PMID:12659321

  13. Three-dimensional skeletal kinematics of the shoulder girdle and forelimb in walking Alligator

    PubMed Central

    Baier, David B; Gatesy, Stephen M

    2013-01-01

    Crocodylians occupy a key phylogenetic position for investigations of archosaur locomotor evolution. Compared to the well-studied hindlimb, relatively little is known about the skeletal movements and mechanics of the forelimb. In this study, we employed manual markerless XROMM (X-ray Reconstruction Of Moving Morphology) to measure detailed 3-D kinematics of the shoulder girdle and forelimb bones of American alligators (Alligator mississippiensis) walking on a treadmill. Digital models of the interclavicle, scapulocoracoid, humerus, radius and ulna were created using a 3-D laser scanner. Models were articulated and aligned to simultaneously recorded frames of fluoroscopic and standard light video to reconstruct and measure joint motion. Joint coordinate systems were established for the coracosternal, glenohumeral and elbow joints. Our analysis revealed that the limb joints only account for about half of fore/aft limb excursion; the remaining excursion results from shoulder girdle movements and lateral bending of the vertebral column. Considerable motion of each scapulocoracoid relative to the vertebral column is consistent with coracosternal mobility. The hemisellar design of the glenohumeral joint permits some additional translation, or sliding in the fore-aft plane, but this movement does not have much of an effect on the distal excursion of the bone. PMID:24102540

  14. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed....

  15. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed....

  16. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed....

  17. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed....

  18. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed....

  19. Abnormal bone composition in female juvenile American alligators from a pesticide-polluted lake (Lake Apopka, Florida).

    PubMed Central

    Lind, P Monica; Milnes, Matthew R; Lundberg, Rebecca; Bermudez, Dieldrich; Orberg, Jan A; Guillette, Louis J

    2004-01-01

    Reproductive disorders have been found in pesticide-exposed alligators living in Lake Apopka, Florida (USA). These disorders have been hypothesized to be caused by exposure to endocrine- disruptive estrogen-like contaminants. The aim of this study was to expand our analysis beyond previous studies by investigating whether bone tissue, known to be affected by sex steroid hormones, is a potential target of endocrine disruptors. Long bones from 16 juvenile female alligators from Lake Apopka (pesticide-contaminated lake) and Lake Woodruff (control lake) were evaluated by peripheral quantitative computed tomography. We observed significant differences in bone composition, with female alligators from the contaminated lake having greater trabecular bone mineral density (BMD), total BMD, and trabecular mineral content compared with females from the control lake (p < 0.05). Increased trabecular and total BMD measurements suggest that juvenile female alligators from Lake Apopka were exposed to contaminants that created an internal environment more estrogenic than that normally observed. This estrogenic environment could be caused by both natural and anthropogenic compounds. Effects on BMD indicate interference with bone homeostasis. We hypothesize that contaminants present in the lake inhibit the natural and continuous resorption of bone tissue, resulting in increased bone mass. Although this is the only study performed to date examining effects of environmental estrogenic compounds on alligator bones, it supports previous laboratory-based studies in rodents. Further, this study is important in demonstrating that the alterations in morphology and physiology induced in free-ranging individuals living in environments contaminated with endocrine-active compounds are not limited to a few systems or tissues; rather, effects can be observed in many tissues affected by these hormones. PMID:14998753

  20. Developmental abnormalities of the gonad and abnormal sex hormone concentrations in juvenile alligators from contaminated and control lakes in Florida.

    PubMed Central

    Guillette, L J; Gross, T S; Masson, G R; Matter, J M; Percival, H F; Woodward, A R

    1994-01-01

    The reproductive development of alligators from a contaminated and a control lake in central Florida was examined. Lake Apopka is adjacent to an EPA Superfund site, listed due to an extensive spill of dicofol and DDT or its metabolites. These compounds can act as estrogens. Contaminants in the lake also have been derived from extensive agricultural activities around the lake that continue today and a sewage treatment facility associated with the city of Winter Garden, Florida. We examined the hypothesis that an estrogenic contaminant has caused the current failure in recruitment of alligators on Lake Apopka. Supporting data include the following: At 6 months of age, female alligators from Lake Apopka had plasma estradiol-17 beta concentrations almost two times greater than normal females from the control lake, Lake Woodruff. The Apopka females exhibited abnormal ovarian morphology with large numbers of polyovular follicles and polynuclear oocytes. Male juvenile alligators had significantly depressed plasma testosterone concentrations comparable to levels observed in normal Lake Woodruff females but more than three times lower than normal Lake Woodruff males. Additionally, males from Lake Apopka had poorly organized testes and abnormally small phalli. The differences between lakes and sexes in plasma hormone concentrations of juvenile alligators remain even after stimulation with luteinizing hormone. Our data suggest that the gonads of juveniles from Lake Apopka have been permanently modified in ovo, so that normal steroidogenesis is not possible, and thus normal sexual maturation is unlikely. Images p680-a Figure 1. Figure 2. Figure 3. A Figure 3. B Figure 3. C Figure 4. A Figure 4. B Figure 4. C Figure 4. D Figure 5. A Figure 5. B Figure 5. C PMID:7895709

  1. Study of red-sore disease in alligators. Final report, September 1, 1976-September 3, 1980. [Predisposing factors

    SciTech Connect

    Gorden, R.E.; Esch, G.W.

    1980-01-01

    Necropsies of eight alligators which died following capture within a thermally-altered reservoir demonstrated the presence of the gram negative, pathogenic bacterium Aeromonas hydrophila, in internal tissues. A study designed to demonstrate whether A. hydrophila were capable of causing infection and death of the ecologically threatened alligator and, if so, the mechanism of exposure and infection in natural habitats was undertaken. The pathology and response to infection were also studied. When juvenile alligators were exposed under experimental conditions to increasing concentrations of A. hydrophila in water, by oral inoculation, or by intramuscular injections at 20/sup 0/, 25/sup 0/, 30/sup 0/, and 35/sup 0/C, they developed external lesions. These lesions were likely to become severe and lead to death of the animal at 30 and 35/sup 0/C. Infected animals produced: (a) increased numbers of white blood cells; (b) increased specific antibody titer; and (c) alpha 2 peaks higher than albumen peaks (except at 35/sup 0/C). Biweekly intraperitoneal injections of live, washed A. hydrophila were apparently more effective in the prevention of infection and of external lesions than were the antibiotics Kanamycin and OTH-Puramycin. Topical applications of Neosporin ointment resulted in the healing of severe lesions on confined animals. Alligators which were shown to be exposed to A. hydrophila in their natural habitats showed no external evidence of infection by the bacteria. It is recommended that exposure to conditions of stress, including water temperatures greater than 30/sup 0/C, be kept to a minimum during the capture, transport, and captivity of alligators. (ERB)

  2. EFFECT OF ACUTE STRESS ON PLASMA CONCENTRATIONS OF SEX AND STRESS HORMONES IN JUVENILE ALLIGATORS LIVING IN CONTROL AND CONTAMINATED LAKES

    EPA Science Inventory

    Environmental contaminants can act as stressors, inducing elevated circulating concentrations of stress hormones such as corticosterone and cortisol. Development in contaminated eggs has been reported to modify circulating sex steroid hormone concentrations in alligators (Alligat...

  3. THE FUNCTIONAL AND STRUCTURAL OBSERVATIONS OF THE NEONATAL REPRODUCTIVE SYSTEM OF ALLIGATORS EXPOSED IN OVO TO ATRAZINE, 2,4-D, OR ESTRADIOL.

    EPA Science Inventory

    Wild alligators exposed to persistent organochlorine contaminants, municipal waste compounds, and contemporary-use herbicides exhibit reproductive alterations that are thought to be caused by endocrine disruption. This study tests the hypothesis that these alterations, at least i...

  4. Isotopic fractionation of uranium in sandstone

    USGS Publications Warehouse

    Rosholt, J.N.; Shields, W.R.; Garner, E.L.

    1963-01-01

    Relatively unoxidized black uranium ores from sandstone deposits in the western United States show deviations in the uranium-235 to uranium-234 ratio throughout a range from 40 percent excess uranium-234 to 40 percent deficient uranium-234 with respect to a reference uranium-235 to uranium-234 ratio. The deficient uranium-234 is leached preferentially to uranium-238 and the excess uranium-234 is believed to result from deposition of uranium-234 enriched in solutions from leached deposits.

  5. Uranium hexafluoride public risk

    SciTech Connect

    Fisher, D.R.; Hui, T.E.; Yurconic, M.; Johnson, J.R.

    1994-08-01

    The limiting value for uranium toxicity in a human being should be based on the concentration of uranium (U) in the kidneys. The threshold for nephrotoxicity appears to lie very near 3 {mu}g U per gram kidney tissue. There does not appear to be strong scientific support for any other improved estimate, either higher or lower than this, of the threshold for uranium nephrotoxicity in a human being. The value 3 {mu}g U per gram kidney is the concentration that results from a single intake of about 30 mg soluble uranium by inhalation (assuming the metabolism of a standard person). The concentration of uranium continues to increase in the kidneys after long-term, continuous (or chronic) exposure. After chronic intakes of soluble uranium by workers at the rate of 10 mg U per week, the concentration of uranium in the kidneys approaches and may even exceed the nephrotoxic limit of 3 {mu}g U per gram kidney tissue. Precise values of the kidney concentration depend on the biokinetic model and model parameters assumed for such a calculation. Since it is possible for the concentration of uranium in the kidneys to exceed 3 {mu}g per gram tissue at an intake rate of 10 mg U per week over long periods of time, we believe that the kidneys are protected from injury when intakes of soluble uranium at the rate of 10 mg U per week do not continue for more than two consecutive weeks. For long-term, continuous occupational exposure to low-level, soluble uranium, we recommend a reduced weekly intake limit of 5 mg uranium to prevent nephrotoxicity in workers. Our analysis shows that the nephrotoxic limit of 3 {mu}g U per gram kidney tissues is not exceeded after long-term, continuous uranium intake at the intake rate of 5 mg soluble uranium per week.

  6. Uranium provinces of North America; their definition, distribution, and models

    USGS Publications Warehouse

    Finch, Warren Irvin

    1996-01-01

    Uranium resources in North America are principally in unconformity-related, quartz-pebble conglomerate, sandstone, volcanic, and phosphorite types of uranium deposits. Most are concentrated in separate, well-defined metallogenic provinces. Proterozoic quartz-pebble conglomerate and unconformity-related deposits are, respectively, in the Blind River?Elliot Lake (BRELUP) and the Athabasca Basin (ABUP) Uranium Provinces in Canada. Sandstone uranium deposits are of two principal subtypes, tabular and roll-front. Tabular sandstone uranium deposits are mainly in upper Paleozoic and Mesozoic rocks in the Colorado Plateau Uranium Province (CPUP). Roll-front sandstone uranium deposits are in Tertiary rocks of the Rocky Mountain and Intermontane Basins Uranium Province (RMIBUP), and in a narrow belt of Tertiary rocks that form the Gulf Coastal Uranium Province (GCUP) in south Texas and adjacent Mexico. Volcanic uranium deposits are concentrated in the Basin and Range Uranium Province (BRUP) stretching from the McDermitt caldera at the Oregon-Nevada border through the Marysvale district of Utah and Date Creek Basin in Arizona and south into the Sierra de Pe?a Blanca District, Chihuahua, Mexico. Uraniferous phosphorite occurs in Tertiary sediments in Florida, Georgia, and North and South Carolina and in the Lower Permian Phosphoria Formation in Idaho and adjacent States, but only in Florida has economic recovery been successful. The Florida Phosphorite Uranium Province (FPUP) has yielded large quantities of uranium as a byproduct of the production of phosphoric acid fertilizer. Economically recoverable quantities of copper, gold, molybdenum, nickel, silver, thorium, and vanadium occur with the uranium deposits in some provinces. Many major epochs of uranium mineralization occurred in North America. In the BRELUP, uranium minerals were concentrated in placers during the Early Proterozoic (2,500?2,250 Ma). In the ABUP, the unconformity-related deposits were most likely formed

  7. Bioremediation of uranium contamination with enzymatic uranium reduction

    USGS Publications Warehouse

    Lovley, D.R.; Phillips, E.J.P.

    1992-01-01

    Enzymatic uranium reduction by Desulfovibrio desulfuricans readily removed uranium from solution in a batch system or when D. desulfuricans was separated from the bulk of the uranium-containing water by a semipermeable membrane. Uranium reduction continued at concentrations as high as 24 mM. Of a variety of potentially inhibiting anions and metals evaluated, only high concentrations of copper inhibited uranium reduction. Freeze-dried cells, stored aerobically, reduced uranium as fast as fresh cells. D. desulfuricans reduced uranium in pH 4 and pH 7.4 mine drainage waters and in uraniumcontaining groundwaters from a contaminated Department of Energy site. Enzymatic uranium reduction has several potential advantages over other bioprocessing techniques for uranium removal, the most important of which are as follows: the ability to precipitate uranium that is in the form of a uranyl carbonate complex; high capacity for uranium removal per cell; the formation of a compact, relatively pure, uranium precipitate.

  8. Chemical Equilibrium of the Dissolved Uranium in Groundwaters From a Spanish Uranium-Ore Deposit

    SciTech Connect

    Garralon, Antonio; Gomez, Paloma; Turrero, Maria Jesus; Buil, Belen; Sanchez, Lorenzo

    2007-07-01

    The main objectives of this work are to determine the hydrogeochemical evolution of an uranium ore and identify the main water/rock interaction processes that control the dissolved uranium content. The Mina Fe uranium-ore deposit is the most important and biggest mine worked in Spain. Sageras area is located at the north part of the Mina Fe, over the same ore deposit. The uranium deposit was not mined in Sageras and was only perturbed by the exploration activities performed 20 years ago. The studied area is located 10 Km northeast of Ciudad Rodrigo (Salamanca) at an altitude over 650 m.a.s.l. The uranium mineralization is related to faults affecting the metasediments of the Upper Proterozoic to Lower Cambrian schist-graywacke complex (CEG), located in the Centro-Iberian Zone of the Hesperian Massif . The primary uranium minerals are uraninite and coffinite but numerous secondary uranium minerals have been formed as a result of the weathering processes: yellow gummite, autunite, meta-autunite, torbernite, saleeite, uranotile, ianthinite and uranopilite. The water flow at regional scale is controlled by the topography. Recharge takes place mainly in the surrounding mountains (Sierra Pena de Francia) and discharge at fluvial courses, mainly Agueda and Yeltes rivers, boundaries S-NW and NE of the area, respectively. Deep flows (lower than 100 m depth) should be upwards due to the river vicinity, with flow directions towards the W, NW or N. In Sageras-Mina Fe there are more than 100 boreholes drilled to investigate the mineral resources of the deposit. 35 boreholes were selected in order to analyze the chemical composition of groundwaters based on their depth and situation around the uranium ore. Groundwater samples come from 50 to 150 m depth. The waters are classified as calcium-bicarbonate type waters, with a redox potential that indicates they are slightly reduced (values vary between 50 to -350 mV). The TOC varies between <0.1 and 4.0 mgC/L and the dissolved

  9. Investigating Freshwater Periphyton Community Response to Uranium with Phospholipid Fatty Acid and Denaturing Gradient Gel Electrophoresis Analyses

    SciTech Connect

    Small, Jack A.; Bunn, Amoret L.; McKinstry, Craig A.; Peacock, A. D.; Miracle, Ann L.

    2008-04-01

    Periphyton communities can be used as monitors of ecosystem health and as indicators of contamination in lotic systems. Measures of biomass, community structure and genetic diversity were used to investigate impacts of uranium exposure on periphyton. Laboratory exposures of periphyton in river water amended with uranium were performed for 5 days, followed by 2 days of uranium depuration in unamended river water. Productivity as measured by biomass was not affected by concentrations up to 100 µg L-1 uranium. Phospholipid fatty acid (PLFA) profiles and denaturing gradient gel electrophoresis (DGGE) banding patterns found no changes in community or genetic structure related to uranium exposure. We suggest that the periphyton community as a whole is not impacted by exposures of uranium up to a dose of 100 µg L-1. These findings have significance for the assessment and prediction of uranium impacts on aquatic ecosystems.

  10. National uranium resource evaluation program: hydrogeochemical and stream sediment reconnaissance basic data for Fresno quadrangle, California

    SciTech Connect

    Not Available

    1981-10-15

    Field and laboratory data are presented for 1038 sediment samples from the Fresno Quadrangle, California. The samples were collected by Savannah River Laboratory; laboratory analysis and data reporting were perfomed by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee.

  11. National uranium resource evaluation program: hydrogeochemical and stream sediment reconnaissance basic data for Sacramento quadrangle, California

    SciTech Connect

    Not Available

    1981-10-15

    Field and laboratory data are presented for 1890 sediment samples from the Sacramento Quadrangle, California. The samples were collected by Savannah River Laboratory; laboratory analysis and data reporting were performed by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee.

  12. Preparation of uranium compounds

    DOEpatents

    Kiplinger, Jaqueline L; Montreal, Marisa J; Thomson, Robert K; Cantat, Thibault; Travia, Nicholas E

    2013-02-19

    UI.sub.3(1,4-dioxane).sub.1.5 and UI.sub.4(1,4-dioxane).sub.2, were synthesized in high yield by reacting turnings of elemental uranium with iodine dissolved in 1,4-dioxane under mild conditions. These molecular compounds of uranium are thermally stable and excellent precursor materials for synthesizing other molecular compounds of uranium including alkoxide, amide, organometallic, and halide compounds.

  13. Metals fact sheet - uranium

    SciTech Connect

    1996-04-01

    About 147 million pounds of this radioactive element are consumed annually by the worldwide nuclear power and weapons industries, as well as in the manufacture of ceramics and metal products. The heaviest naturally occurring element, uranium is typically found in intrusive granites, igneous and metamorphic veins, tabular sedimentary deposits, and unconformity-related structures. This article discusses the geology, exploitation, market, and applications of uranium and uranium ores.

  14. Process for continuous production of metallic uranium and uranium alloys

    DOEpatents

    Hayden, Jr., Howard W.; Horton, James A.; Elliott, Guy R. B.

    1995-01-01

    A method is described for forming metallic uranium, or a uranium alloy, from uranium oxide in a manner which substantially eliminates the formation of uranium-containing wastes. A source of uranium dioxide is first provided, for example, by reducing uranium trioxide (UO.sub.3), or any other substantially stable uranium oxide, to form the uranium dioxide (UO.sub.2). This uranium dioxide is then chlorinated to form uranium tetrachloride (UCl.sub.4), and the uranium tetrachloride is then reduced to metallic uranium by reacting the uranium chloride with a metal which will form the chloride of the metal. This last step may be carried out in the presence of another metal capable of forming one or more alloys with metallic uranium to thereby lower the melting point of the reduced uranium product. The metal chloride formed during the uranium tetrachloride reduction step may then be reduced in an electrolysis cell to recover and recycle the metal back to the uranium tetrachloride reduction operation and the chlorine gas back to the uranium dioxide chlorination operation.

  15. Process for continuous production of metallic uranium and uranium alloys

    DOEpatents

    Hayden, H.W. Jr.; Horton, J.A.; Elliott, G.R.B.

    1995-06-06

    A method is described for forming metallic uranium, or a uranium alloy, from uranium oxide in a manner which substantially eliminates the formation of uranium-containing wastes. A source of uranium dioxide is first provided, for example, by reducing uranium trioxide (UO{sub 3}), or any other substantially stable uranium oxide, to form the uranium dioxide (UO{sub 2}). This uranium dioxide is then chlorinated to form uranium tetrachloride (UCl{sub 4}), and the uranium tetrachloride is then reduced to metallic uranium by reacting the uranium chloride with a metal which will form the chloride of the metal. This last step may be carried out in the presence of another metal capable of forming one or more alloys with metallic uranium to thereby lower the melting point of the reduced uranium product. The metal chloride formed during the uranium tetrachloride reduction step may then be reduced in an electrolysis cell to recover and recycle the metal back to the uranium tetrachloride reduction operation and the chlorine gas back to the uranium dioxide chlorination operation. 4 figs.

  16. Reconnaissance for uranium-bearing lignite in the Ekalaka Lignite Field, Carter County, Montana

    USGS Publications Warehouse

    Gill, James R.

    1954-01-01

    Uranium-bearing lignite beds 1.5 to 8 feet thick occur in the Fort Union formation of the southern part of the Ekalaka Hills, Carter County, Mont. Data from surface outcrops indicate that an area of about 1,400 acres is underlain by 16,500,000 tons of uranium-bearing lignite containing 700 tons of uranium. The uranium content of the lignite beds ranges from 0.001 to 0.034 percent. Ironstone concretions in the massive coarse-grained sandstones in the upper part of the Fort Union formation contain 0.005 percent uranium in the northern and eastern parts of the area. These sandstones are good potential host rocks for uranium mineralization and are lithologically similar to the massive coarse-grained uranium-bearing sandstones of the Wasatch formation in the Pumpkin Buttes area of the Powder River Basin.

  17. Forensic analysis of uranium

    SciTech Connect

    Stoyer, N.J.; Moody, K.J.

    1996-10-01

    As more and more offers for illicit {open_quotes}Black Market{close_quotes} radioactive materials are found, the forensic information contained within the radioactive material itself becomes more important. Many {open_quotes}Black Market{close_quotes} offers are for uranium in various forms and enrichments. Although most are scams, some countries have actually interdicted enriched uranium. We will discuss the forensic information that can be obtained from materials containing uranium along with examples of data that has been determined from analysis of uranium samples obtained from legitimate sources.

  18. METHOD OF ROLLING URANIUM

    DOEpatents

    Smith, C.S.

    1959-08-01

    A method is described for rolling uranium metal at relatively low temperatures and under non-oxidizing conditions. The method involves the steps of heating the uranium to 200 deg C in an oil bath, withdrawing the uranium and permitting the oil to drain so that only a thin protective coating remains and rolling the oil coated uranium at a temperature of 200 deg C to give about a 15% reduction in thickness at each pass. The operation may be repeated to accomplish about a 90% reduction without edge cracking, checking or any appreciable increase in brittleness.

  19. Uranium Dispersion & Dosimetry Model.

    SciTech Connect

    MICHAEL,; MOMENI, H.

    2002-03-22

    The Uranium Dispersion and Dosimetry (UDAD) program provides estimates of potential radiation exposure to individuals and to the general population in the vicinity of a uranium processing facility such as a uranium mine or mill. Only transport through the air is considered. Exposure results from inhalation, external irradiation from airborne and ground-deposited activity, and ingestion of foodstuffs. Individual dose commitments, population dose commitments, and environmental dose commitments are computed. The program was developed for application to uranium mining and milling; however, it may be applied to dispersion of any other pollutant.

  20. Uranium Dispersion & Dosimetry Model.

    2002-03-22

    The Uranium Dispersion and Dosimetry (UDAD) program provides estimates of potential radiation exposure to individuals and to the general population in the vicinity of a uranium processing facility such as a uranium mine or mill. Only transport through the air is considered. Exposure results from inhalation, external irradiation from airborne and ground-deposited activity, and ingestion of foodstuffs. Individual dose commitments, population dose commitments, and environmental dose commitments are computed. The program was developed for applicationmore » to uranium mining and milling; however, it may be applied to dispersion of any other pollutant.« less

  1. URANIUM RECOVERY PROCESS

    DOEpatents

    Kaufman, D.

    1958-04-15

    A process of recovering uranium from very low-grade ore residues is described. These low-grade uraniumcontaining hydroxide precipitates, which also contain hydrated silica and iron and aluminum hydroxides, are subjected to multiple leachings with aqueous solutions of sodium carbonate at a pH of at least 9. This leaching serves to selectively extract the uranium from the precipitate, but to leave the greater part of the silica, iron, and aluminum with the residue. The uranium is then separated from the leach liquor by the addition of an acid in sufficient amount to destroy the carbonate followed by the addition of ammonia to precipitate uranium as ammonium diuranate.

  2. PRODUCTION OF URANIUM

    DOEpatents

    Ruehle, A.E.; Stevenson, J.W.

    1957-11-12

    An improved process is described for the magnesium reduction of UF/sub 4/ to produce uranium metal. In the past, there have been undesirable premature reactions between the Mg and the bomb liner or the UF/sub 4/ before the actual ignition of the bomb reaction. Since these premature reactions impair the yield of uranium metal, they have been inhibited by forming a protective film upon the particles of Mg by reacting it with hydrated uranium tetrafluoride, sodium bifluoride, uranyl fluoride, or uranium trioxide. This may be accomplished by adding about 0.5 to 2% of the additive to the bomb charge.

  3. COATING URANIUM FROM CARBONYLS

    DOEpatents

    Gurinsky, D.H.; Storrs, S.S.

    1959-07-14

    Methods are described for making adherent corrosion resistant coatings on uranium metal. According to the invention, the uranium metal is heated in the presence of an organometallic compound such as the carbonyls of nickel, molybdenum, chromium, niobium, and tungsten at a temperature sufficient to decompose the metal carbonyl and dry plate the resultant free metal on the surface of the uranium metal body. The metal coated body is then further heated at a higher temperature to thermally diffuse the coating metal within the uranium bcdy.

  4. Re-evaluation of the petrogenesis of the Proterozoic Jabiluka unconformity-related uranium deposit, Northern Territory, Australia

    NASA Astrophysics Data System (ADS)

    Polito, Paul A.; Kurt Kyser, T.; Thomas, David; Marlatt, Jim; Drever, Garth

    2005-11-01

    The world class Jabiluka unconformity-related uranium deposit in the Alligator Rivers Uranium Field, Australia, contains >163,000 tons of contained U3O8. Mineralization is hosted by shallow-to-steeply dipping basement rocks comprising graphitic units of chlorite-biotite-muscovite schist. These rocks are overlain by flat-lying coarse-grained sandstones belonging to the Kombolgie Subgroup. The deposit was discovered in 1971, but has never been mined. The construction of an 1,150 m decline into the upper eastern sector of the Jabiluka II deposit combined with closely spaced underground drilling in 1998 and 1999 allowed mapping and sampling from underground for the first time. Structural mapping, drill core logging and petrographic studies on polished thin sections established a detailed paragenesis that provided the framework for subsequent electron microprobe and X-ray diffraction, fluid inclusion, and O-H, U-Pb and 40Ar/39Ar isotope analysis. Uranium mineralization is structurally controlled within semi-brittle shears that are sub-conformable to the basement stratigraphy, and breccias that are developed within the hinge zone of fault-related folds adjacent to the shears. Uraninite is intimately associated with chlorite, sericite, hematite ± quartz. Electron microprobe and X-ray diffraction analysis of syn-ore illite and chlorite indicates a mineralization temperature of 200°C. Pre- and syn-ore minerals extracted from the Kombolgie Subgroup overlying the deposit and syn-ore alteration minerals in the Cahill Formation have δ18Ofluid and δ D fluid values of 4.0±3.7 and -27±17‰, respectively. These values are indistinguishable from illite separates extracted from diagenetic aquifers in the Kombolgie Subgroup up to 70 km to the south and east of the deposit and believed to be the source of the uraniferous fluid. New fluid inclusion microthermometry data reveal that the mineralising brine was saline, but not saturated. U-Pb and 207Pb/206Pb ratios of uraninite by

  5. URANIUM LEACHING AND RECOVERY PROCESS

    DOEpatents

    McClaine, L.A.

    1959-08-18

    A process is described for recovering uranium from carbonate leach solutions by precipitating uranium as a mixed oxidation state compound. Uranium is recovered by adding a quadrivalent uranium carbon;te solution to the carbonate solution, adjusting the pH to 13 or greater, and precipitating the uranium as a filterable mixed oxidation state compound. In the event vanadium occurs with the uranium, the vanadium is unaffected by the uranium precipitation step and remains in the carbonate solution. The uranium-free solution is electrolyzed in the cathode compartment of a mercury cathode diaphragm cell to reduce and precipitate the vanadium.

  6. Uranium industry annual 1993

    SciTech Connect

    Not Available

    1994-09-01

    Uranium production in the United States has declined dramatically from a peak of 43.7 million pounds U{sub 3}O{sub 8} (16.8 thousand metric tons uranium (U)) in 1980 to 3.1 million pounds U{sub 3}O{sub 8} (1.2 thousand metric tons U) in 1993. This decline is attributed to the world uranium market experiencing oversupply and intense competition. Large inventories of uranium accumulated when optimistic forecasts for growth in nuclear power generation were not realized. The other factor which is affecting U.S. uranium production is that some other countries, notably Australia and Canada, possess higher quality uranium reserves that can be mined at lower costs than those of the United States. Realizing its competitive advantage, Canada was the world`s largest producer in 1993 with an output of 23.9 million pounds U{sub 3}O{sub 8} (9.2 thousand metric tons U). The U.S. uranium industry, responding to over a decade of declining market prices, has downsized and adopted less costly and more efficient production methods. The main result has been a suspension of production from conventional mines and mills. Since mid-1992, only nonconventional production facilities, chiefly in situ leach (ISL) mining and byproduct recovery, have operated in the United States. In contrast, nonconventional sources provided only 13 percent of the uranium produced in 1980. ISL mining has developed into the most cost efficient and environmentally acceptable method for producing uranium in the United States. The process, also known as solution mining, differs from conventional mining in that solutions are used to recover uranium from the ground without excavating the ore and generating associated solid waste. This article describes the current ISL Yang technology and its regulatory approval process, and provides an analysis of the factors favoring ISL mining over conventional methods in a declining uranium market.

  7. Isolation and structures of alligator gar (Lepisosteus spatula) insulin and pancreatic polypeptide.

    PubMed

    Pollock, H G; Kimmel, J R; Hamilton, J W; Rouse, J B; Ebner, K E; Lance, V; Rawitch, A B

    1987-09-01

    Insulin and a 36-residue peptide with homology to pancreatic polypeptide (PP) were isolated from the endocrine pancreas of the alligator gar (Lepisosteus spatula), a ganoid fish, by gel filtration and HPLC. Heterologous radioimmunoassays were used to detect insulin-like and PP-like immunoreactivities during purification of the two peptides. The sequence of the 36-amino acid peptide containing a C-terminal tyrosinamide was identical at 31 of 36 positions to porcine neuropeptide Y (NPY). The amino acid sequence of this peptide is YPPKPENPGEDAPPEELAKYYSALRHYINLITRQRY-NH2. The second peptide, gar insulin, contains 52 amino acid residues and is composed of a 21-residue A chain and a 31-residue B chain. The sequence of the A chain is GIVEQCCHKPCTIYELENYCN. The sequence of the B chain is AANQHLCGSHLVEALYLVCGEKGFFYNPNKV. PMID:3311873

  8. Isolation and structures of alligator gar (Lepisosteus spatula) insulin and pancreatic polypeptide.

    PubMed

    Pollock, H G; Kimmel, J R; Hamilton, J W; Rouse, J B; Ebner, K E; Lance, V; Rawitch, A B

    1987-09-01

    Insulin and a 36-residue peptide with homology to pancreatic polypeptide (PP) were isolated from the endocrine pancreas of the alligator gar (Lepisosteus spatula), a ganoid fish, by gel filtration and HPLC. Heterologous radioimmunoassays were used to detect insulin-like and PP-like immunoreactivities during purification of the two peptides. The sequence of the 36-amino acid peptide containing a C-terminal tyrosinamide was identical at 31 of 36 positions to porcine neuropeptide Y (NPY). The amino acid sequence of this peptide is YPPKPENPGEDAPPEELAKYYSALRHYINLITRQRY-NH2. The second peptide, gar insulin, contains 52 amino acid residues and is composed of a 21-residue A chain and a 31-residue B chain. The sequence of the A chain is GIVEQCCHKPCTIYELENYCN. The sequence of the B chain is AANQHLCGSHLVEALYLVCGEKGFFYNPNKV.

  9. Guidelines for choosing molecular "alligator clip" binding motifs in electron transport devices

    NASA Astrophysics Data System (ADS)

    Reuter, Matthew G.; Seideman, Tamar; Ratner, Mark A.

    2011-04-01

    We employ a one-electron, tight-binding model of an electrode-molecule-electrode junction to explore the fundamental relationship between adsorption geometry and electron transport, producing exact results (within this model). By varying the chemisorption location (e.g., atop a surface atom or in a hollow site between surface atoms) and the molecule-electrode coupling, we find that the largest currents are realized when the molecule (i) is highly coordinated by the surface and (ii) has favorable overlap with electrode states near the Fermi level. We also show the importance of electrode-induced molecular level shifting for certain adsorption geometries, which can cause molecular levels far from the Fermi level to conduct better than those near the Fermi level. Since all of these factors are greatly influenced by the chemical moiety used to link the molecule to an electrode, these results present a set of guidelines to help choose "alligator clips" for molecular electronic devices.

  10. Evolution of corticosteroid specificity for human, chicken, alligator and frog glucocorticoid receptors.

    PubMed

    Katsu, Yoshinao; Kohno, Satomi; Oka, Kaori; Baker, Michael E

    2016-09-01

    We investigated the evolution of the response of human, chicken, alligator and frog glucocorticoid receptors (GRs) to dexamethasone, cortisol, cortisone, corticosterone, 11-deoxycorticosterone, 11-deoxycortisol and aldosterone. We find significant differences among these vertebrates in the transcriptional activation of their full length GRs by these steroids, indicating that there were changes in the specificity of the GR for steroids during the evolution of terrestrial vertebrates. To begin to study the role of interactions between different domains on the GR in steroid sensitivity and specificity for terrestrial GRs, we investigated transcriptional activation of truncated GRs containing their hinge domain and ligand binding domain (LBD) fused to a GAL4 DNA binding domain (GAL4-DBD). Compared to corresponding full length GRs, transcriptional activation of GAL4-DBD_GR-hinge/LBD constructs required higher steroid concentrations and displayed altered steroid specificity, indicating that interactions between the hinge/LBD and other domains are important in glucocorticoid activation of these terrestrial GRs. PMID:27317937

  11. ALLIGATOR - An apparatus for ion beam assisted deposition with a broad-beam ion source

    NASA Astrophysics Data System (ADS)

    Wituschek, H.; Barth, M.; Ensinger, W.; Frech, G.; Rück, D. M.; Leible, K. D.; Wolf, G. K.

    1992-04-01

    Ion beam assisted deposition is a versatile technique for preparing thin films and coatings for various applications. Up to now a prototype setup for research purposes has been used in our laboratory. Processing of industrial standard workpieces requires a high current ion source with broad beam and high uniformity for homogeneous bombardment. In this contribution a new apparatus for large area samples will be described. It is named ALLIGATOR (German acronym of facility for ion assisted evaporation on transverse movable or rotary targets). In order to have a wide energy range available two ion sources are used. One delivers a beam energy up to 1.3 keV. The other is suitable for energies from 5 keV up to 40 keV. The ``high-energy'' ion source is a multicusp multiaperture source with 180-mA total current and a beam diameter of 280 mm at the target position.

  12. Development of Novel Sorbents for Uranium Extraction from Seawater

    SciTech Connect

    Lin, Wenbin; Taylor-Pashow, Kathryn

    2014-01-08

    evaluated for their uranium extraction efficiency. The initial testing of these materials for uranium binding will be carried out in the Lin group, but more detailed sorption studies will be carried out by Dr. Taylor-Pashow of Savannah River National Laboratory in order to obtain quantitative uranyl sorption selectivity and kinetics data for the proposed materials. The proposed nanostructured sorbent materials are expected to have higher binding capacities, enhanced extraction kinetics, optimal stripping efficiency for uranyl ions, and enhanced mechanical and chemical stabilities. This transformative research will significantly impact uranium extraction from seawater as well as benefit DOE’s efforts on environmental remediation by developing new materials and providing knowledge for enriching and sequestering ultralow concentrations of other metals.

  13. Ontogeny of the Middle-Ear Air-Sinus System in Alligator mississippiensis (Archosauria: Crocodylia).

    PubMed

    Dufeau, David L; Witmer, Lawrence M

    2015-01-01

    Modern crocodylians, including Alligator mississippiensis, have a greatly elaborated system of pneumatic sinuses invading the cranium. These sinuses invade nearly all the bones of the chondrocranium and several bony elements of the splanchnocranium, but patterns of postnatal paratympanic sinus development are poorly understood and documented. Much of crocodylomorph--indeed archosaurian--evolution is characterized by the evolution of various paratympanic air sinuses, the homologies of which are poorly understood due in large part to the fact that individual sinuses tend to become confluent in adults, obscuring underlying patterns. This study seeks to explore the ontogeny of these sinuses primarily to clarify the anatomical relations of the individual sinuses before they become confluent and thus to provide the foundation for later studies testing hypotheses of homology across extant and extinct Archosauria. Ontogeny was assessed using computed tomography in a sample of 13 specimens covering an almost 19-fold increase in head size. The paratympanic sinus system comprises two major inflations of evaginated pharyngeal epithelium: the pharyngotympanic sinus, which communicates with the pharynx via the lateral (true) Eustachian tubes and forms the cavum tympanicum proprium, and the median pharyngeal sinus, which communicates with the pharynx via the median pharyngeal tube. Each of these primary inflations gives rise to a number of secondary inflations that further invade the bones of the skull. The primary sinuses and secondary diverticula are well developed in perinatal individuals of Alligator, but during ontogeny the number and relative volumes of the secondary diverticula are reduced. In addition to describing the morphological ontogeny of this sinus system, we provide some preliminary exploratory analyses of sinus function and allometry, rejecting the hypothesis that changes in the volume of the paratympanic sinuses are simply an allometric function of braincase

  14. Plasma catecholamines and plasma corticosterone following restraint stress in juvenile alligators.

    PubMed

    Lance, V A; Elsey, R M

    1999-05-01

    Ten juvenile alligators, mean body mass 793 g, hatched from artificially incubated eggs and raised under controlled conditions, were held out of water with their jaws held closed for 48 hr. An initial blood sample was taken and further samples collected at 1, 2, 4, 8, 24, and 48 hr. Epinephrine, norepinephrine, and dopamine were measured in plasma aliquots of 1.5 ml using high pressure liquid chromatography with electrochemical detection. Corticosterone was measured by radioimmunoassay. Plasma glucose was measured using the Trinder method and plasma calcium, cholesterol, and triglycerides were measured in an autoanalyzer. Epinephrine was about 4 ng/ml at the initial bleed, but declined steadily to < 0.4 ng/ml by 24 hr. Norepinephrine was also about 4 ng/ml at the initial bleed, but rose to over 8 ng/ml at 1 hr, and then declined to < 0.2 ng/ml at 24 hr. A second, but smaller increase in plasma norepinephrine was seen at 48 hr. Plasma dopamine was low at the initial bleed (< 0.7 ng/ml), rose to over 8 ng/ml at 1 hr, then declined to < 0.2 ng/ml. Plasma corticosterone rose progressively for the first 4 hr, declined at 8 hr and 24 hr, then rose again at 48 hr. Plasma glucose rose significantly by 24 hr and remained elevated for 48 hr. Plasma calcium increased at 1, 2, and 4 hr then returned to levels not significantly different from the initial sample at 24 and 48 hr. The white blood cells showed changes indicating immune system suppression. By the end of the treatment the hetorophil/lymphocyte ratio increased to 4.7. These results suggest that handling alligators, taking multiple blood samples, and keeping them restrained for more than 8 hr is a severe stress to the animals.

  15. Ontogeny of the Middle-Ear Air-Sinus System in Alligator mississippiensis (Archosauria: Crocodylia)

    PubMed Central

    Dufeau, David L.; Witmer, Lawrence M.

    2015-01-01

    Modern crocodylians, including Alligator mississippiensis, have a greatly elaborated system of pneumatic sinuses invading the cranium. These sinuses invade nearly all the bones of the chondrocranium and several bony elements of the splanchnocranium, but patterns of postnatal paratympanic sinus development are poorly understood and documented. Much of crocodylomorph—indeed archosaurian—evolution is characterized by the evolution of various paratympanic air sinuses, the homologies of which are poorly understood due in large part to the fact that individual sinuses tend to become confluent in adults, obscuring underlying patterns. This study seeks to explore the ontogeny of these sinuses primarily to clarify the anatomical relations of the individual sinuses before they become confluent and thus to provide the foundation for later studies testing hypotheses of homology across extant and extinct Archosauria. Ontogeny was assessed using computed tomography in a sample of 13 specimens covering an almost 19-fold increase in head size. The paratympanic sinus system comprises two major inflations of evaginated pharyngeal epithelium: the pharyngotympanic sinus, which communicates with the pharynx via the lateral (true) Eustachian tubes and forms the cavum tympanicum proprium, and the median pharyngeal sinus, which communicates with the pharynx via the median pharyngeal tube. Each of these primary inflations gives rise to a number of secondary inflations that further invade the bones of the skull. The primary sinuses and secondary diverticula are well developed in perinatal individuals of Alligator, but during ontogeny the number and relative volumes of the secondary diverticula are reduced. In addition to describing the morphological ontogeny of this sinus system, we provide some preliminary exploratory analyses of sinus function and allometry, rejecting the hypothesis that changes in the volume of the paratympanic sinuses are simply an allometric function of braincase

  16. Uranium: A Dentist's perspective.

    PubMed

    Toor, R S S; Brar, G S

    2012-01-01

    Uranium is a naturally occurring radionuclide found in granite and other mineral deposits. In its natural state, it consists of three isotopes (U-234, U-235 and U-238). On an average, 1% - 2% of ingested uranium is absorbed in the gastrointestinal tract in adults. The absorbed uranium rapidly enters the bloodstream and forms a diffusible ionic uranyl hydrogen carbonate complex (UO2HCO3+) which is in equilibrium with a nondiffusible uranyl albumin complex. In the skeleton, the uranyl ion replaces calcium in the hydroxyapatite complex of the bone crystal. Although in North India, there is a risk of radiological toxicity from orally ingested natural uranium, the principal health effects are chemical toxicity. The skeleton and kidney are the primary sites of uranium accumulation. Acute high dose of uranyl nitrate delays tooth eruption, and mandibular growth and development, probably due to its effect on target cells. Based on all previous research and recommendations, the role of a dentist is to educate the masses about the adverse effects of uranium on the overall as well as the dental health. The authors recommended that apart from the discontinuation of the addition of uranium to porcelain, the Public community water supplies must also comply with the Environmental Protection Agency (EPA) standards of uranium levels being not more than 30 ppb (parts per billion).

  17. DECONTAMINATION OF URANIUM

    DOEpatents

    Spedding, F.H.; Butler, T.A.

    1962-05-15

    A process is given for separating fission products from uranium by extracting the former into molten aluminum. Phase isolation can be accomplished by selectively hydriding the uranium at between 200 and 300 deg C and separating the hydride powder from coarse particles of fissionproduct-containing aluminum. (AEC)

  18. Uranium and Thorium

    ERIC Educational Resources Information Center

    Finch, Warren I.

    1978-01-01

    The results of President Carter's policy on non-proliferation of nuclear weapons are expected to slow the growth rate in energy consumption, put the development of the breeder reactor in question, halt plans to reprocess and recycle uranium and plutonium, and expand facilities to supply enriched uranium. (Author/MA)

  19. Uranium: A Dentist's perspective

    PubMed Central

    Toor, R. S. S.; Brar, G. S.

    2012-01-01

    Uranium is a naturally occurring radionuclide found in granite and other mineral deposits. In its natural state, it consists of three isotopes (U-234, U-235 and U-238). On an average, 1% – 2% of ingested uranium is absorbed in the gastrointestinal tract in adults. The absorbed uranium rapidly enters the bloodstream and forms a diffusible ionic uranyl hydrogen carbonate complex (UO2HCO3+) which is in equilibrium with a nondiffusible uranyl albumin complex. In the skeleton, the uranyl ion replaces calcium in the hydroxyapatite complex of the bone crystal. Although in North India, there is a risk of radiological toxicity from orally ingested natural uranium, the principal health effects are chemical toxicity. The skeleton and kidney are the primary sites of uranium accumulation. Acute high dose of uranyl nitrate delays tooth eruption, and mandibular growth and development, probably due to its effect on target cells. Based on all previous research and recommendations, the role of a dentist is to educate the masses about the adverse effects of uranium on the overall as well as the dental health. The authors recommended that apart from the discontinuation of the addition of uranium to porcelain, the Public community water supplies must also comply with the Environmental Protection Agency (EPA) standards of uranium levels being not more than 30 ppb (parts per billion). PMID:24478959

  20. Uranium triamidoamine chemistry.

    PubMed

    Gardner, Benedict M; Liddle, Stephen T

    2015-07-01

    Triamidoamine (Tren) complexes of the p- and d-block elements have been well-studied, and they display a diverse array of chemistry of academic, industrial and biological significance. Such in-depth investigations are not as widespread for Tren complexes of uranium, despite the general drive to better understand the chemical behaviour of uranium by virtue of its fundamental position within the nuclear sector. However, the chemistry of Tren-uranium complexes is characterised by the ability to stabilise otherwise reactive, multiply bonded main group donor atom ligands, construct uranium-metal bonds, promote small molecule activation, and support single molecule magnetism, all of which exploit the steric, electronic, thermodynamic and kinetic features of the Tren ligand system. This Feature Article presents a current account of the chemistry of Tren-uranium complexes.

  1. Uranium dioxide electrolysis

    DOEpatents

    Willit, James L.; Ackerman, John P.; Williamson, Mark A.

    2009-12-29

    This is a single stage process for treating spent nuclear fuel from light water reactors. The spent nuclear fuel, uranium oxide, UO.sub.2, is added to a solution of UCl.sub.4 dissolved in molten LiCl. A carbon anode and a metallic cathode is positioned in the molten salt bath. A power source is connected to the electrodes and a voltage greater than or equal to 1.3 volts is applied to the bath. At the anode, the carbon is oxidized to form carbon dioxide and uranium chloride. At the cathode, uranium is electroplated. The uranium chloride at the cathode reacts with more uranium oxide to continue the reaction. The process may also be used with other transuranic oxides and rare earth metal oxides.

  2. METHOD FOR PURIFYING URANIUM

    DOEpatents

    Kennedy, J.W.; Segre, E.G.

    1958-08-26

    A method is presented for obtaining a compound of uranium in an extremely pure state and in such a condition that it can be used in determinations of the isotopic composition of uranium. Uranium deposited in calutron receivers is removed therefrom by washing with cold nitric acid and the resulting solution, coataining uranium and trace amounts of various impurities, such as Fe, Ag, Zn, Pb, and Ni, is then subjected to various analytical manipulations to obtain an impurity-free uranium containing solution. This solution is then evaporated on a platinum disk and the residue is ignited converting it to U2/sub 3//sub 8/. The platinum disk having such a thin film of pure U/sub 2/O/sub 8/ is suitable for use with isotopic determination techaiques.

  3. URANIUM PRECIPITATION PROCESS

    DOEpatents

    Thunaes, A.; Brown, E.A.; Smith, H.W.; Simard, R.

    1957-12-01

    A method for the recovery of uranium from sulfuric acid solutions is described. In the present process, sulfuric acid is added to the uranium bearing solution to bring the pH to between 1 and 1.8, preferably to about 1.4, and aluminum metal is then used as a reducing agent to convert hexavalent uranium to the tetravalent state. As the reaction proceeds, the pH rises amd a selective precipitation of uranium occurs resulting in a high grade precipitate. This process is an improvement over the process using metallic iron, in that metallic aluminum reacts less readily than metallic iron with sulfuric acid, thus avoiding consumption of the reducing agent and a raising of the pH without accomplishing the desired reduction of the hexavalent uranium in the solution. Another disadvantage to the use of iron is that positive ferric ions will precipitate with negative phosphate and arsenate ions at the pH range employed.

  4. 16. VIEW OF THE ENRICHED URANIUM RECOVERY SYSTEM. ENRICHED URANIUM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. VIEW OF THE ENRICHED URANIUM RECOVERY SYSTEM. ENRICHED URANIUM RECOVERY PROCESSED RELATIVELY PURE MATERIALS AND SOLUTIONS AND SOLID RESIDUES WITH RELATIVELY LOW URANIUM CONTENT. URANIUM RECOVERY INVOLVED BOTH SLOW AND FAST PROCESSES. (4/4/66) - Rocky Flats Plant, General Manufacturing, Support, Records-Central Computing, Southern portion of Plant, Golden, Jefferson County, CO

  5. Necropsy findings in American alligator late-stage embryos and hatchlings from northcentral Florida lakes contaminated with organochlorine pesticides

    USGS Publications Warehouse

    Sepulveda, M.S.; Del, Piero F.; Wiebe, J.J.; Rauschenberger, H.R.; Gross, T.S.

    2006-01-01

    Increased American alligator (Alligator mississippiensis) embryo and neonatal mortality has been reported from several northcentral Florida lakes contaminated with old-use organochlorine pesticides (OCPs). However, a clear relationship among these contaminants and egg viability has not been established, suggesting the involvement of additional factors in these mortalities. Thus, the main objective of this study was to determine the ultimate cause of mortality of American alligator late-stage embryos and hatchlings through the conduction of detailed pathological examinations, and to evaluate better the role of OCPs in these mortalities. Between 2000 and 2001, 236 dead alligators were necropsied at or near hatching (after ???65 days of artificial incubation and up to 1 mo of age posthatch). Dead animals were collected from 18 clutches ranging in viability from 0% to 95%. Total OCP concentrations in yolk ranged from ???100 to 52,000 ??g/kg, wet weight. The most common gross findings were generalized edema (34%) and organ hyperemia (29%), followed by severe emaciation (14%) and gross deformities (3%). Histopathologic examination revealed lesions in 35% of the animals, with over half of the cases being pneumonia, pulmonary edema, and atelectasis. Within and across clutches, dead embryos and hatchlings compared with their live cohorts were significantly smaller and lighter. Although alterations in growth and development were not related to yolk OCPs, there was an increase in prevalence of histologic lesions in clutches with high OCPs. Overall, these results indicate that general growth retardation and respiratory abnormalities were a major contributing factor in observed mortalities and that contaminants may increase the susceptibility of animals to developing certain pathologic conditions. ?? Wildlife Disease Association 2006.

  6. Nuclear β-catenin localization supports homology of feathers, avian scutate scales, and alligator scales in early development.

    PubMed

    Musser, Jacob M; Wagner, Günter P; Prum, Richard O

    2015-01-01

    Feathers are an evolutionary novelty found in all extant birds. Despite recent progress investigating feather development and a revolution in dinosaur paleontology, the relationship of feathers to other amniote skin appendages, particularly reptile scales, remains unclear. Disagreement arises primarily from the observation that feathers and avian scutate scales exhibit an anatomical placode-defined as an epidermal thickening-in early development, whereas alligator and other avian scales do not. To investigate the homology of feathers and archosaur scales we examined patterns of nuclear β-catenin localization during early development of feathers and different bird and alligator scales. In birds, nuclear β-catenin is first localized to the feather placode, and then exhibits a dynamic pattern of localization in both epidermis and dermis of the feather bud. We found that asymmetric avian scutate scales and alligator scales share similar patterns of nuclear β-catenin localization with feathers. This supports the hypothesis that feathers, scutate scales, and alligator scales are homologous during early developmental stages, and are derived from early developmental stages of an asymmetric scale present in the archosaur ancestor. Furthermore, given that the earliest stage of β-catenin localization in feathers and archosaur scales is also found in placodes of several mammalian skin appendages, including hair and mammary glands, we hypothesize that a common skin appendage placode originated in the common ancestor of all amniotes. We suggest a skin placode should not be defined by anatomical features, but as a local, organized molecular signaling center from which an epidermal appendage develops. PMID:25963196

  7. Uranium-bearing coal and carbonaceous rocks in the Fall Creek area, Bonneville County, Idaho

    USGS Publications Warehouse

    Vine, James D.; Moore, George Winfred

    1952-01-01

    Uraniferous coal, carbonaceous shale, and carbonaceous limestone occur in the Bear River formation of Early Cretaceous age at the Fall Creek prospect, in the Fall Creek area, Bonneville County, Idaho. The uranium compounds are believed to have been derived from mildly radioactive silicic volcanic rocks of Tertiary age that rest unconformably on all older rocks and once overlay the Bear River formation and its coal. Meteoric water, percolating downward through the silicic volcanic rocks and into the older rocks along joints and faults, is believed to have brought the uranium compounds into contact with the coal and carbonaceous rocks in which the uranium was absorbed.

  8. RECENT STUDIES OF URANIUM AND PLUTONIUM CHEMISTRY IN ALKALINE RADIOACTIVE WASTE SOLUTIONS

    SciTech Connect

    King, W; Bill Wilmarth, B; David Hobbs, D; Tommy Edwards, T

    2006-06-13

    Solubility studies of uranium and plutonium in a caustic, radioactive Savannah River Site tank waste solution revealed the existence of uranium supersaturation in the as-received sample. Comparison of the results to predictions generated from previously published models for solubility in these waste types revealed that the U model poorly predicts solubility while Pu model predictions are quite consistent with experimental observations. Separate studies using simulated Savannah River Site evaporator feed solution revealed that the known formation of sodium aluminosilicate solids in waste evaporators can promote rapid precipitation of uranium from supersaturated solutions.

  9. Uranium in the Near-shore Aquatic Food Chain: Studies on Periphyton and Asian Clams

    SciTech Connect

    Bunn, Amoret L.; Miley, Terri B.; Eslinger, Paul W.; Brandt, Charles A.; Napier, Bruce A.

    2007-12-31

    The benthic aquatic organisms in the near-shore environment of the Columbia River are the first biological receptors that can be exposed to groundwater contaminants coming from the U.S. Department of Energy's Hanford Site. The primary contaminant of concern in the former nuclear fuels processing area at the Site, known as the 300 Area, is uranium. Currently, there are no national clean up criteria for uranium and ecological receptors. This report summarizes efforts to characterize biological uptake of uranium in the food chain of the benthic aquatic organisms and provide information to be used in future assessments of uranium and the ecosystem.

  10. Cadmium and lead residues in field-collected red swamp crayfish (Procambarus clarkii) and uptake by alligator weed, Alternanthera philoxiroides

    SciTech Connect

    Naqvi, S.M.; Howell, R.D.; Sholas, M. . Dept. of Biological Sciences and Health Research Center)

    1993-01-01

    The whole-body residues of Cd and Pb in the tissues of Louisiana swamp crayfish (Procambarus clarkii) were determined by flame AAS technique. Test animals were collected from roadside ditches alongside major highways. The water and soil samples were also collected from the same sites. The mean Cd and Pb concentrations in crayfish tissues were 0.46 and 0.07, respectively. The levels of Cd and Pb in the water were 0.09 and 0.04; and in soil were 2.85 and 0.87 mg/1, respectively. The concentration of cadmium was 32 and Pb 12 times more than in the water. The bioaccumulation factors (BF) for Cd and Pb in crayfish tissues were 5.1 and 1.7, respectively. Alligator weed (Alternanthera philoxiroides) plants were exposed to 0.5 mg/1 Cd-chloride or Pb-nitrate solutions for 3 wk period, thrice. The mean Pb accumulation in roots was 1.31 mg/1, followed by stem (0.078 mg/1), but Cd only accumulated in root (0.83 mg/1). The BF for Pb and Cd in plant tissues were 14.8 and 16.6, respectively. The uptake of metals was time-dependent. These data suggest that although there is no biomagnification of Cd and Pb from alligator weed to crayfish, both metals readily accumulate in field-collected crayfish and laboratory-exposed alligator weed.

  11. Predicting maternal body burdens of organochlorine pesticides from eggs and evidence of maternal transfer in Alligator mississippiensis

    USGS Publications Warehouse

    Rauschenberger, R.H.; Sepulveda, M.S.; Wiebe, J.J.; Szabo, N.J.; Gross, T.S.

    2004-01-01

    Few data exist regarding maternal-embryonal transfer of organochlorine pesticides (OCPs) in reptiles. The objective of the present study was to evaluate maternal transfer of OCPs in American alligators (Alligator mississippiensis) from low-, intermediate-, and high-OCP-exposure sites. Overall, total OCP burdens ranged from less than 0.8 ppb in blood to more than 44,000 ppb in abdominal adipose tissue (wet wt concentrations). Lipid-adjusted ratios of maternal adipose burdens (total OCPs) to yolk burdens were close to one (0.94 ?? 0.31:1), suggesting that animals were in steady state and that OCPs in eggs originated from adipose lipids. In contrast, lipid-adjusted muscle and liver OCP burdens were greater than yolk OCP burdens, suggesting that lipids in muscle were not utilized during oogenesis and that nonlipid liver tissue sequesters OCPs. Predictive equations were derived for several tissues and several OCP analytes with r2 values ranging from 0.40 to 0.99 (p < 0.05). We suggest that yolk burdens are predictive of maternal tissue burdens for certain tissues and OCPs and that certain OCPs are maternally transferred in the American alligator. Furthermore, we suggest that future studies should investigate the applicability of these predictive equations for assessing maternal exposure in other crocodilian species.

  12. National Uranium Resource Evaluation: Wells Quadrangle, Nevada, Idaho, and Utah

    SciTech Connect

    Proffitt, J.L.; Mayerson, D.L.; Parker, D.P.; Wolverson, N.; Antrim, D.; Berg, J.; Witzel, F.

    1982-08-01

    The Wells 2/sup 0/ Quadrangle, Nevada, Idaho, and Utah, was evaluated using National Uranium Resource Evaluation criteria to delineate areas favorable for uranium deposits. Our investigation has resulted in the delineation of areas that contain Tertiary sedimentary rocks favorable for hydroallogenic deposits in the Mountain City area (Favorable Area A) and in the Oxley Peak area north of Wells (Favorable Area B). Environments considered to be unfavorable for uranium deposits include Tertiary felsic volcanic, felsic plutonic, intermediate to mafic volcanic, Paleozoic and Mesozoic sedimentary rocks, Precambrian rocks, and most Tertiary sedimentary rocks located outside the favorable areas. Present-day basins are unevaluated environments because of a paucity of adequate outcrop and subsurface data. However, the scarce data indicate that some characteristics favorable for uranium deposits are present in the Susie Creek-Tule Valley-Wild Horse basin, the Contact-Granite Range-Tijuana John stocks area, the Charleston Reservoir area, and the Wells-Marys River basin.

  13. Paleodrainage-unconformity model as guide to uranium deposits

    SciTech Connect

    Seeland, D.

    1984-04-01

    This paper considers a uranium occurrence model that shows how early Eocene and Oligocene depositional patterns and paleography can be used to identify favorable host rocks and to suggest where uraniferous ground water passed through these rocks. The uranium in the ground water was derived mostly from volcanic ash of the Oligocene White River Group. This model accounts for most known uranium deposits and occurrences in eastern Wyoming, western South Dakota, and western Nebraska. All major deposits in Eocene sandstones are in rocks of the fan-channel facies that were identified by sand grain size and shape studies, and most deposits are basinward of present-day major mountain valleys. Deposits occur only where rocks of this facies are less than 300 m (980 ft) below the reconstructed basal Oligocene surface, a distance calculated from roll-front migration and erosion rates. Uranium deposits in other than Eocene rocks also are related to the configuration of the pre-Oligocene surface. White River channel sandstones have deposits and occurrences along a 200-km (125-mi) section of a major Oligocene river in eastern Wyoming and Nebraska. Oligocene trans-mountain drainages localized uranium occurrences in Precambrian granitic rocks in the Laramie Mountains. Deposits in Cretaceous rocks in northern Colorado and along the flanks of the Black Hills lie beneath the axes of Oligocene channels. The channels were the major conduits that localized the movement of the uranium-bearing solutions. Rocks underlying the divides between the channels are unfavorable for uranium deposits where the channels are parallel to the regional dip, because the divides have a thick impervious lateritic soil cover.

  14. National Uranium Resource Evaluation: Jordan Valley Quadrangle, Oregon and Idaho

    SciTech Connect

    Berry, M R; Castor, S B; Robins, J W

    1982-04-01

    The Jordan Valley Quadrangle, Oregon and Idaho, was evaluated to identify and delineate areas favorable for uranium deposits in accordance with criteria developed for the National Uranium Resource Evaluation. Surface radiometric reconnaissance and geochemical sampling were used for overall evaluation of the quadrangle. Detailed rock sampling, geologic mapping, and examination of uranium deposits and occurrences were performed in areas suspected to be favorable. The northeast part of the McDermitt caldera within the quadrangle is favorable for volcanogenic deposits associated with the ring-fracture zone. The favorable area contains the Aurora uranium deposit, the Bretz mercury mine, and the Cottonwood Creek occurrence. The Triangle Ranch area and the Snake River Plain, both in the northeast part of the quadrangle, have environments that may be favorable for uranium deposits in sandstone but are considered unevaluated due to lack of subsurface data and lack of detailed investigations. Rocks in the remainder of the quadrangle are considered unfavorable for uranium deposits because of low uranium contents, basic to intermediate compositions, or lack of favorable structures.

  15. The provenance of alveolar and parabronchial lungs: insights from paleoecology and the discovery of cardiogenic, unidirectional airflow in the American alligator (Alligator mississippiensis).

    PubMed

    Farmer, C G

    2010-01-01

    Birds and mammals evolved greater aerobic abilities than their common ancestor had. This required expansion of the cardiopulmonary system's capacity for gas exchange, but while directional selection for this expanded capacity resulted in extremely similar avian and mammalian hearts, strikingly different lungs arose, and the reasons for this divergence in lung morphology are not understood. In birds, gas exchange occurs in the lungs as air moves through small tubes (parabronchi) in one direction; in mammals, air flows tidally into and out of the alveoli. Here, I present a scenario for the origin of both the alveolar and parabronchial lungs that explains when and how they could have arisen by a gradual sequence of steps. I argue that (1) the alveolar lung evolved in the late Paleozoic, when high levels of atmospheric oxygen relaxed selection for a thin blood-gas barrier within the lung; (2) unidirectional flow originated in the ectothermic ancestral archosaur, the forerunner of birds and crocodilians, to enable the heart to circulate pulmonary gases during apnea. This hypothesis would be supported by a demonstration of unidirectional flow in the lungs of crocodilians, the extant sister taxon of birds. Airflow in the lungs of juvenile alligators was measured during apnea using dual thermistor flowmeters, and cardiac activity was measured with electrocardiography. Coincident with each heartbeat, a pulse of air flowed in the pulmonary conduit under study with a bias in the direction of movement, yielding a net unidirectional flow. These data suggest the internal structures requisite for unidirectional flow were present in the common ancestors of birds and crocodilians and may have preadapted the lungs of archosaurs to function advantageously during the oxygen-poor period of the early Mesozoic.

  16. The provenance of alveolar and parabronchial lungs: insights from paleoecology and the discovery of cardiogenic, unidirectional airflow in the American alligator (Alligator mississippiensis).

    PubMed

    Farmer, C G

    2010-01-01

    Birds and mammals evolved greater aerobic abilities than their common ancestor had. This required expansion of the cardiopulmonary system's capacity for gas exchange, but while directional selection for this expanded capacity resulted in extremely similar avian and mammalian hearts, strikingly different lungs arose, and the reasons for this divergence in lung morphology are not understood. In birds, gas exchange occurs in the lungs as air moves through small tubes (parabronchi) in one direction; in mammals, air flows tidally into and out of the alveoli. Here, I present a scenario for the origin of both the alveolar and parabronchial lungs that explains when and how they could have arisen by a gradual sequence of steps. I argue that (1) the alveolar lung evolved in the late Paleozoic, when high levels of atmospheric oxygen relaxed selection for a thin blood-gas barrier within the lung; (2) unidirectional flow originated in the ectothermic ancestral archosaur, the forerunner of birds and crocodilians, to enable the heart to circulate pulmonary gases during apnea. This hypothesis would be supported by a demonstration of unidirectional flow in the lungs of crocodilians, the extant sister taxon of birds. Airflow in the lungs of juvenile alligators was measured during apnea using dual thermistor flowmeters, and cardiac activity was measured with electrocardiography. Coincident with each heartbeat, a pulse of air flowed in the pulmonary conduit under study with a bias in the direction of movement, yielding a net unidirectional flow. These data suggest the internal structures requisite for unidirectional flow were present in the common ancestors of birds and crocodilians and may have preadapted the lungs of archosaurs to function advantageously during the oxygen-poor period of the early Mesozoic. PMID:20377411

  17. PROCESS OF RECOVERING URANIUM

    DOEpatents

    Kilner, S.B.

    1959-12-29

    A method is presented for separating and recovering uranium from a complex mixure of impurities. The uranium is dissolved to produce an aqueous acidic solution including various impurities. In accordance with one method, with the uranium in the uranyl state, hydrogen cyanide is introduced into the solution to complex the impurities. Subsequently, ammonia is added to the solution to precipitate the uraniunn as ammonium diuranate away from the impurities in the solution. Alternatively, the uranium is precipitated by adding an alkaline metal hydroxide. In accordance with the second method, the uranium is reduced to the uranous state in the solution. The reduced solution is then treated with solid alkali metal cyanide sufficient to render the solution about 0.1 to 1.0 N in cyanide ions whereat cyanide complex ions of the metal impurities are produced and the uranium is simultaneously precipituted as uranous hydroxide. Alternatively, hydrogen cyanide may be added to the reduced solution and the uranium precipitated subsequently by adding ammonium hydroxide or an alkali metal hydroxide. Other refinements of the method are also disclosed.

  18. India's Worsening Uranium Shortage

    SciTech Connect

    Curtis, Michael M.

    2007-01-15

    As a result of NSG restrictions, India cannot import the natural uranium required to fuel its Pressurized Heavy Water Reactors (PHWRs); consequently, it is forced to rely on the expediency of domestic uranium production. However, domestic production from mines and byproduct sources has not kept pace with demand from commercial reactors. This shortage has been officially confirmed by the Indian Planning Commission’s Mid-Term Appraisal of the country’s current Five Year Plan. The report stresses that as a result of the uranium shortage, Indian PHWR load factors have been continually decreasing. The Uranium Corporation of India Ltd (UCIL) operates a number of underground mines in the Singhbhum Shear Zone of Jharkhand, and it is all processed at a single mill in Jaduguda. UCIL is attempting to aggrandize operations by establishing new mines and mills in other states, but the requisite permit-gathering and development time will defer production until at least 2009. A significant portion of India’s uranium comes from byproduct sources, but a number of these are derived from accumulated stores that are nearing exhaustion. A current maximum estimate of indigenous uranium production is 430t/yr (230t from mines and 200t from byproduct sources); whereas, the current uranium requirement for Indian PHWRs is 455t/yr (depending on plant capacity factor). This deficit is exacerbated by the additional requirements of the Indian weapons program. Present power generation capacity of Indian nuclear plants is 4350 MWe. The power generation target set by the Indian Department of Atomic Energy (DAE) is 20,000 MWe by the year 2020. It is expected that around half of this total will be provided by PHWRs using indigenously supplied uranium with the bulk of the remainder provided by breeder reactors or pressurized water reactors using imported low-enriched uranium.

  19. Recovery of uranium values

    DOEpatents

    Brown, K. B.; Crouse, Jr., D. J.; Moore, J. G.

    1959-03-10

    A liquid-liquid extraction method is presented for recovering uranium values from an aqueous acidic solution by means of certain high molecular weight amine fn the amine classes of primary, secondary, heterocyclic secondary, tertiary, or heterocyclic tertiary. The uranium bearing aqueous acidic solution is contacted with the selected anine dissolved in a nonpolar waterimmiscible organfc solvent such as kerosene. The uranium which is substantially completely extracted by the organic phase may be stripped therefrom by water, and recovered from the aqueous phase by treatment into ammonia to precipitate ammonium diuranate.

  20. RECOVERY OF URANIUM VALUES

    DOEpatents

    Brown, K.B.; Crouse, D.J. Jr.; Moore, J.G.

    1959-03-10

    A liquid-liquid extraction method is presented for recovering uranium values from an aqueous acidic solution by means of certain high molecular weight amine in the amine classes of primary, secondary, heterocyclic secondary, tertiary, or heterocyclic tertiary. The uranium bearing aqueous acidic solution is contacted with the selected amine dissolved in a nonpolar water-immiscible organic solvent such as kerosene. The uranium which is substantially completely exiracted by the organic phase may be stripped therefrom by waters and recovered from the aqueous phase by treatment into ammonia to precipitate ammonium diuranate.

  1. Uranium purchases report 1993

    SciTech Connect

    Not Available

    1994-08-10

    Data reported by domestic nuclear utility companies in their responses to the 1991 through 1993 ``Uranium Industry Annual Survey,`` Form EIA-858, Schedule B,`` Uranium Marketing Activities,`` are provided in response to the requirements in the Energy Policy Act 1992. Appendix A contains an explanation of Form EIA-858 survey methodologies with emphasis on the processing of Schedule B data. Additional information published in this report not included in Uranium Purchases Report 1992, includes a new data table. Presented in Table 1 are US utility purchases of uranium and enrichment services by origin country. Also, this report contains additional purchase information covering average price and contract duration. Table 2 is an update of Table 1 and Table 3 is an update of Table 2 from the previous year`s report. The report contains a glossary of terms.

  2. URANIUM RECOVERY PROCESS

    DOEpatents

    Stevenson, J.W.; Werkema, R.G.

    1959-07-28

    The recovery of uranium from magnesium fluoride slag obtained as a by- product in the production of uranium metal by the bomb reduction prccess is presented. Generally the recovery is accomplished by finely grinding the slag, roasting ihe ground slag air, and leaching the roasted slag with a hot, aqueous solution containing an excess of the sodium bicarbonate stoichiometrically required to form soluble uranium carbonate complex. The roasting is preferably carried out at between 425 and 485 deg C for about three hours. The leaching is preferably done at 70 to 90 deg C and under pressure. After leaching and filtration the uranium may be recovered from the clear leach liquor by any desired method.

  3. Uranium concentrations in asparagus

    SciTech Connect

    Tiller, B.L.; Poston, T.M.

    1992-05-01

    Concentrations of uranium were determined in asparagus collected from eight locations near and ten locations on the Hanford Site southcentral Washington State. Only one location (Sagemoor) had samples with elevated concentrations. The presence of elevated uranium in asparagus at Sagemoor may be explained by the elevated levels in irrigation water. These levels of uranium are comparable to levels previously reported upstream and downstream of the 300-FF-1 Operable Unit on the Hanford Site (0.0008 {mu}g/g), but were below the 0.020-{mu}g/g level reported for brush collected at Sagemoor in a 1982 study. Concentrations at all other onsite and offsite sample locations were considerably lower than concentrations reported immediately upstream and downstream of the 300-FF-1 Operable Unit. Using an earlier analysis of the uranium concentrations in asparagus collected from the Hanford Site constitutes a very small fraction of the US Department of Energy effective dose equivalent limit of 100 mrem.

  4. 300 AREA URANIUM CONTAMINATION

    SciTech Connect

    BORGHESE JV

    2009-07-02

    {sm_bullet} Uranium fuel production {sm_bullet} Test reactor and separations experiments {sm_bullet} Animal and radiobiology experiments conducted at the. 331 Laboratory Complex {sm_bullet} .Deactivation, decontamination, decommissioning,. and demolition of 300 Area facilities

  5. PURIFICATION OF URANIUM FUELS

    DOEpatents

    Niedrach, L.W.; Glamm, A.C.

    1959-09-01

    An electrolytic process of refining or decontaminating uranium is presented. The impure uranium is made the anode of an electrolytic cell. The molten salt electrolyte of this cell comprises a uranium halide such as UF/sub 4/ or UCl/sub 3/ and an alkaline earth metal halide such as CaCl/sub 2/, BaF/sub 2/, or BaCl/sub 2/. The cathode of the cell is a metal such as Mn, Cr, Co, Fe, or Ni which forms a low melting eutectic with U. The cell is operated at a temperature below the melting point of U. In operation the electrodeposited uranium becomes alloyed with the metal of the cathode, and the low melting alloy thus formed drips from the cathode.

  6. 300 Area Uranium Stabilization Through Polyphosphate Injection: Final Report

    SciTech Connect

    Vermeul, Vincent R.; Bjornstad, Bruce N.; Fritz, Brad G.; Fruchter, Jonathan S.; Mackley, Rob D.; Newcomer, Darrell R.; Mendoza, Donaldo P.; Rockhold, Mark L.; Wellman, Dawn M.; Williams, Mark D.

    2009-06-30

    amendment arrival response data indicate some degree of overlap between the reactive species and thus potential for the formation of calcium-phosphate mineral phases (i.e., apatite formation), the efficiency of this treatment approach was relatively poor. In general, uranium performance monitoring results support the hypothesis that limited long-term treatment capacity (i.e., apatite formation) was established during the injection test. Two separate overarching issues affect the efficacy of apatite remediation for uranium sequestration within the 300 Area: 1) the efficacy of apatite for sequestering uranium under the present geochemical and hydrodynamic conditions, and 2) the formation and emplacement of apatite via polyphosphate technology. In addition, the long-term stability of uranium sequestered via apatite is dependent on the chemical speciation of uranium, surface speciation of apatite, and the mechanism of retention, which is highly susceptible to dynamic geochemical conditions. It was expected that uranium sequestration in the presence of hydroxyapatite would occur by sorption and/or surface complexation until all surface sites have been depleted, but that the high carbonate concentrations in the 300 Area would act to inhibit the transformation of sorbed uranium to chernikovite and/or autunite. Adsorption of uranium by apatite was never considered a viable approach for in situ uranium sequestration in and of itself, because by definition, this is a reversible reaction. The efficacy of uranium sequestration by apatite assumes that the adsorbed uranium would subsequently convert to autunite, or other stable uranium phases. Because this appears to not be the case in the 300 Area aquifer, even in locations near the river, apatite may have limited efficacy for the retention and long-term immobilization of uranium at the 300 Area site..

  7. URANIUM EXTRACTION PROCESS

    DOEpatents

    Baldwin, W.H.; Higgins, C.E.

    1958-12-16

    A process is described for recovering uranium values from acidic aqueous solutions containing hexavalent uranium by contacting the solution with an organic solution comprised of a substantially water-immiscible organlc diluent and an organic phosphate to extract the uranlum values into the organic phase. Carbon tetrachloride and a petroleum hydrocarbon fraction, such as kerosene, are sultable diluents to be used in combination with organlc phosphates such as dibutyl butylphosphonate, trlbutyl phosphine oxide, and tributyl phosphate.

  8. ANODIC TREATMENT OF URANIUM

    DOEpatents

    Kolodney, M.

    1959-02-01

    A method is presented for effecting eloctrolytic dissolution of a metallic uranium article at a uniform rate. The uranium is made the anode in an aqueous phosphoric acid solution containing nitrate ions furnished by either ammonium nitrate, lithium nitrate, sodium nitrate, or potassium nitrate. A stainless steel cathode is employed and electrolysls carried out at a current density of about 0.1 to 1 ampere per square inch.

  9. URANIUM SEPARATION PROCESS

    DOEpatents

    Lyon, W.L.

    1962-04-17

    A method of separating uranium oxides from PuO/sub 2/, ThO/sub 2/, and other actinide oxides is described. The oxide mixture is suspended in a fused salt melt and a chlorinating agent such as chlorine gas or phosgene is sparged through the suspension. Uranium oxides are selectively chlorinated and dissolve in the melt, which may then be filtered to remove the unchlorinated oxides of the other actinides. (AEC)

  10. Method for the recovery of uranium values from uranium tetrafluoride

    DOEpatents

    Kreuzmann, A.B.

    1982-10-27

    The invention is a novel method for the recovery of uranium from dry, particulate uranium tetrafluoride. In one aspect, the invention comprises reacting particulate uranium tetrafluoride and calcium oxide in the presence of gaseous oxygen to effect formation of the corresponding alkaline earth metal uranate and alkaline earth metal fluoride. The product uranate is highly soluble in various acidic solutions whereas the product fluoride is virtually insoluble therein. The product mixture of uranate and alkaline earth metal fluoride is contacted with a suitable acid to provide a uranium-containing solution, from which the uranium is recovered. The invention can achieve quantitative recovery of uranium in highly pure form.

  11. Method for the recovery of uranium values from uranium tetrafluoride

    DOEpatents

    Kreuzmann, Alvin B.

    1983-01-01

    The invention is a novel method for the recovery of uranium from dry, particulate uranium tetrafluoride. In one aspect, the invention comprises reacting particulate uranium tetrafluoride and calcium oxide in the presence of gaseous oxygen to effect formation of the corresponding alkaline earth metal uranate and alkaline earth metal fluoride. The product uranate is highly soluble in various acidic solutions wherein the product fluoride is virtually insoluble therein. The product mixture of uranate and alkaline earth metal fluoride is contacted with a suitable acid to provide a uranium-containing solution, from which the uranium is recovered. The invention can achieve quantitative recovery of uranium in highly pure form.

  12. The orientation and navigation of juvenile alligators: evidence of magnetic sensitivity

    USGS Publications Warehouse

    Rodda, Gordon H.

    1984-01-01

    Displaced juvenile alligators, Alligator mississipiensis, were released on land in a 9 m diameter dodecagonal arena to test their ability to orient in the absence of terrestrial landmarks. Navigational ability seemed to improve with age. When displaced along a fairly direct route yearlings (age 7–14 months) compensated for their displacement, moving in the direction from the arena to their home sites. When displaced by a circuitous route, yearlings failed to compensate for their displacement, exhibiting instead simple compass orientation in a direction that would have returned them to water had they been released on land near the site where they were captured. The older juveniles were oriented in a homeward direction under all displacement and test conditions. The latter animals may have been using geomagnetic map information to select their homeward directions as the errors in their homeward bearings correlated with small deviations in the geomagnetic field's dip angle at the time of the test (1980r s=−0.6047,P=0.0131, all testsr s= −0.4652,P=0.0084). This effect appeared to depend on a very short-term assessment of geomagnetic conditions, as values measured 20 min before or 30 min after the tests began did not correlate with the directions the animals moved. The older juveniles appeared to use magnetically quiet hours on the night of their capture as the baseline from which to measure the geomagnetic deviations that occurred at the time of the arena test. The magnitude of the magnetic effect in the older animals suggests that the geomagnetic information may have been used to perform a ‘map’ step, as small fluctuations in dip angle correlated with much larger deviations in homeward bearings. In addition, the compass-oriented yearlings and the seemingly route-based behavior of the homeward-oriented yearlings did not appear to be influenced by geomagnetic conditions. These findings have many parallels in results obtained from bird orientation studies

  13. Primary alkaline magmas associated with the Quaternary Alligator Lake volcanic complex, Yukon Territory, Canada

    NASA Astrophysics Data System (ADS)

    Eiché, G. E.; Francis, D. M.; Ludden, J. N.

    1987-02-01

    The Alligator Lake complex is a Quaternary alkaline volcanic center located in the southern Yukon Territory of Canada. It comprises two cinder cones which cap a shield consisting of five distinct lava units of basaltic composition. Units 2 and 3 of this shield are primitive olivine-phyric lavas (13.5 19.5 cation % Mg) which host abundant spinel lherzolite xenoliths, megacrysts, and granitoid fragments. Although the two lava types have erupted coevally from adjacent vents and are petrographically similar, they are chemically distinct. Unit 2 lavas have considerably higher abundances of LREE, LILE, and Fe, but lower HREE, Y, Ca, Si, and Al relative to unit 3 lavas. The 87Sr/86Sr and 143Nd/144Nd isotopic ratios of these two units are, however, indistinguishable. The differences between these two lava types cannot be explained in terms of low pressure olivine fractionation, and the low concentrations of Sr, Nb, P, and Ti in the granitoid xenoliths relative to the primitive lavas discounts differential crustal contamination. The abundance of spinel lherzolite xenoliths and the high Mg contents in the lavas of both units indicates that their compositional differences originated in the upper mantle. The Al and Si systematics of these lavas suggests that, compared to unit 3 magmas, the unit 2 magmas may have segregated at greater depths from a garnet lherzolite mantle. The identical isotopic composition and similar ratios of highly incompatible elements in these two lava units argues against their differences being a consequence of random metasomatism or mantle heterogeneity. The lower Y and HREE contents but higher concentrations of incompatible elements in the unit 2 lavas relative to unit 3 can be most simply explained by differential partial melting of similar garnet-bearing sources. The unit 2 magmas thus appear to have been generated by smaller degrees of melting at a greater depth than the unit 3 magmas. The contemporaneous eruption of two distinct but

  14. Pribram uranium district

    SciTech Connect

    1990-11-01

    Pribram is one of the largest and richest vein uranium districts in the world. The Pribram district has accounted for about 60 percent of Czechoslovakia`s total uranium production. The Pribram uranium district is located about 60 kilometers southwest of Prague, in Cezechslovakia`s central Bohemia region. This district contains perigranitic, monometallic, vein-type uranium deposits. The deposits are within a northeast-southwest elongated area, about 20 kilometers long and 1-2 kilometers wide, located between Oboriste in the northeast and Tresko in the southwest. Several thousand veins have been discovered; about 1,600 have been mined. Most of the veins are grouped in clusters, which are intense accumulations of veins paralleling or intersecting each other within a narrow segment. Until this year, all uranium production was exported to the USSR, with only the amount required for Czechoslovakia`s nuclear power stations being returned (as fabricated fuel). Most of Czechoslovakia`s present and future uranium production will come from sandstone deposits in the North Bohemian Cretaceous Basin, such as Hamr and Straz.

  15. Oxygen isotope, fluid inclusion, microprobe and petrographic studies of the preCambrian granites from the southern Wind River range and the Granite Mountains, central Wyoming, U.S.A.: Constraints on origin, hydrothermal alteration and uranium genesis

    NASA Astrophysics Data System (ADS)

    Cheang, K. K.

    The Granite Mountain is comprised of the granite of Long Creek Mountain and the volumetrically dominant granite of Lankin Dome. Average delta 018 O values in per mil deg/00 of the granite of Long Creek Mountain is 8.2 + or - 0.3 deg/00 (N = 4) and average delta 018 8.5 + or - -0.5 deg/00 (N = 37), values of the two phases from the granite of Lankin Dome are: biotite granites = delta 018 8.5 + or 0.5 deg/00 (N = 37), leucocratic graphite = 8.4 + or - 0.3 deg/00 (N = 12). The average delta 018 values for Louis Lake Batholith are: hornblende-biotite granodiorite = 7.3 + or - 0.3 deg/00 (N = 13) and leucocratic biotite granite = 7.7 + or - 0.1 deg/00 (N = 6). It is concluded from the whole rock oxygen isotopic, mineralogical, chemical and strontium isotopic data that the unaltered granites in the Granite Mountains were probably derived from a uranium enriched source with some peraluminous metasedimentary component which favoured the preconcentration of uranium and thorium, whereas the Louis Lake Batholith was formed by partial melting of igneous source materials that are not strongly enriched in uranium.

  16. 77 FR 70486 - Supplemental Environmental Impact Statement for Proposed Dewey-Burdock In-Situ Uranium Recovery...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-26

    ...The U.S. Nuclear Regulatory Commission (NRC) is issuing for public comment a draft Supplemental Environmental Impact Statement (Draft SEIS) for the Dewey-Burdock In-Situ Uranium Recovery (ISR) Project in Custer and Fall River Counties, South Dakota. The Draft SEIS is Supplement 4 to NUREG-1910, ``Generic Environmental Impact Statement for In-Situ Leach Uranium Milling Facilities,'' May 2009.......

  17. Turning crocodilian hearts into bird hearts: growth rates are similar for alligators with and without right-to-left cardiac shunt

    PubMed Central

    Eme, John; Gwalthney, June; Owerkowicz, Tomasz; Blank, Jason M.; Hicks, James W.

    2010-01-01

    The functional and possible adaptive significance of non-avian reptiles' dual aortic arch system and the ability of all non-avian reptiles to perform central vascular cardiac shunts have been of great interest to comparative physiologists. The unique cardiac anatomy of crocodilians – a four-chambered heart with the dual aortic arch system – allows for only right-to-left (R–L; pulmonary bypass) cardiac shunt and for surgical elimination of this shunt. Surgical removal of the R–L shunt, by occluding the left aorta (LAo) upstream and downstream of the foramen of Panizza, results in a crocodilian with an obligatory, avian/mammalian central circulation. In this study, R–L cardiac shunt was eliminated in age-matched, female American alligators (Alligator mississippiensis; 5–7 months of age). We tested the hypothesis that surgical elimination of R–L cardiac shunt would impair growth (a readily measured proxy for fitness) compared with sham-operated, age-matched controls, especially in animals subjected to exhaustive exercise. While regular exercise caused a decrease in size (snout-to-vent length, head length and body mass), elimination of the capacity for R–L cardiac shunt did not greatly reduce animal growth, despite a chronic ventricular enlargement in surgically altered juvenile alligators. We speculate that, despite being slightly smaller, alligators with an occluded LAo would have reached sexual maturity in the same breeding season as control alligators. This study suggests that crocodilian R–L cardiac shunt does not provide an adaptive advantage for juvenile alligator growth and supports the logic that cardiac shunts persist in crocodilians because they have not been selected against. PMID:20639429

  18. Geologic controls of uranium mineralization in the Tallahassee Creek uranium district, Fremont County, Colorado

    SciTech Connect

    Dickinson, K.A.

    1981-10-01

    Two important orebodies have been defined by drilling in the Tallahassee Creek uranium district, Fremont County, Colorado. They are the Hansen orebody, which contains about 12 million kg of U/sub 3/O/sub 8/, and the Picnic Tree orebody, which contains about 1 million kg of U/sub 3/O/sub 8/. Host rock for the Hansen is the upper Eocene Echo Park Alluvium, and host rock for the Picnic Tree is the lower Oligocene Tallahassee Creek onglomerate. Average ore grade for both deposits is about 0.08 percent U/sub 3/O/sub 8/. The principal source rock for the uranium depsoits is the lower Oligocene Wall Mountain Tuff, although a younger volcanic rock, the Oligocene Thirtynine Mile Andesite, and Precambrian granitic rocks probably also contributed some uranium. Leaching and transportation of the uranium occurred in alkaline oxidizing ground water that developed during alteration of the ash in a semi-arid environment. The uranium was transported in the ground water to favorable sites where it was deposited in a reducing environment controlled by carbonaceous material and associated pyrite. Localization of the ore was controlled by ground-water flow conditions and by the distribution of organic matter in the host rock. Ground-water flow, which was apparently to the southeast in Echo Park Alluvium that is confined in the Echo Park graben, was impeded by a fault that offsets the southern end of the graben. This offset prevented efficient discharge into the ancestral Arkansas River drainage, and protected chemically reducing areas from destruction by the influx of large amounts of oxidizing ground water. The location of orebodies in the Echo Park Alluvium also may be related to areas where overlying rocks of low permeability were breached by erosion during deposition of the fluvial Tallahassee Creek Conglomerate allowing localized entry of uranium-bearing water.

  19. Updated Conceptual Model for the 300 Area Uranium Groundwater Plume

    SciTech Connect

    Zachara, John M.; Freshley, Mark D.; Last, George V.; Peterson, Robert E.; Bjornstad, Bruce N.

    2012-11-01

    The 300 Area uranium groundwater plume in the 300-FF-5 Operable Unit is residual from past discharge of nuclear fuel fabrication wastes to a number of liquid (and solid) disposal sites. The source zones in the disposal sites were remediated by excavation and backfilled to grade, but sorbed uranium remains in deeper, unexcavated vadose zone sediments. In spite of source term removal, the groundwater plume has shown remarkable persistence, with concentrations exceeding the drinking water standard over an area of approximately 1 km2. The plume resides within a coupled vadose zone, groundwater, river zone system of immense complexity and scale. Interactions between geologic structure, the hydrologic system driven by the Columbia River, groundwater-river exchange points, and the geochemistry of uranium contribute to persistence of the plume. The U.S. Department of Energy (DOE) recently completed a Remedial Investigation/Feasibility Study (RI/FS) to document characterization of the 300 Area uranium plume and plan for beginning to implement proposed remedial actions. As part of the RI/FS document, a conceptual model was developed that integrates knowledge of the hydrogeologic and geochemical properties of the 300 Area and controlling processes to yield an understanding of how the system behaves and the variables that control it. Recent results from the Hanford Integrated Field Research Challenge site and the Subsurface Biogeochemistry Scientific Focus Area Project funded by the DOE Office of Science were used to update the conceptual model and provide an assessment of key factors controlling plume persistence.

  20. Analysis of chorioallantoic membranes to assess PCB accumulation in American alligators and Loggerhead sea turtles from the coast of South Carolina

    SciTech Connect

    Cobb, G.P.; Wood, P.D.; O`Quinn, M.

    1995-12-31

    Investigation of contaminant burdens in threatened and endangered species is difficult due to the small number of samples that can be collected. Many samples can be collected if the sampling methods are non-lethal and more specifically non-invasive. Analysis of chorioallantoic membranes is demonstrated for American alligators and Loggerhead sea turtles. Significant differences were found in PCB, uptake by alligators from the Ashepoo-Combahee-Edisto Basin reference site and a contaminated site in Winyah Bay. Intrasite and intersite differences in uptake and distribution of PCB homologues were noted. These data will be discussed as they relate to egg viability and embryo development.

  1. Formation and regression of the corpus luteum of the American alligator

    USGS Publications Warehouse

    Guillette, L.J.; Woodward, A.R.; You-Xiang, Q.; Cox, M.C.; Matter, J.H.; Gross, T.S.

    1995-01-01

    Luteal morphology of the American alligator is unique when compared to other reptiles but is similar to that of its phylogenetic relatives, the birds. The theca is extensively hypertrophied, but the granulosa never fills the cavity formed following the ovulation of the ovum. The formation of the corpus luteum (CL) is correlated with elevated plasma progesterone concentrations, which decline dramatically after oviposition with the onset of luteolysis. Unlike those of most other reptiles, the central luteal cell mass is composed of two cell types; one presumably is derived from the granulosa, whereas the other is from the theca interna. Both cell types are present throughout gravidity but only one cell type is seen during mid to late luteolysis. A significant decline in luteal volume occurs following oviposition and continues throughout the post-oviposition period. The fastest decline in luteal volume occurs in the month immediately after oviposition; this rate then slows. Luteolysis appears to continue for a year or more following oviposition, as distinct structures of luteal origin can still be identified in animals 9 months after oviposition. The size of persistent CL can be used to determine whether a given female oviposited during the previous nesting season. Females with CL having volumes greater than 0.2 cm2 or CL diameters greater than 0.4 cm were active the previous season. 

  2. Microhabitat use, home range, and movements of the alligator snapping turtle, Macrochelys temminckii, in Oklahoma

    USGS Publications Warehouse

    Riedle, J.D.; Shipman, P.A.; Fox, S. F.; Leslie, David M.

    2006-01-01

    Little is known about the ecology of the alligator snapping turtle, Macrochelys temminckii, particularly dentography and behavior. To learn more about the species in Oklahoma, we conducted a telemetry project on 2 small streams at Sequoyah National Wildlife Refuge, an 8,417.5-ha refuge located in east-central Oklahoma. Between June 1999 and August 2000, we fitted 19 M. temminckii with ultrasonic telemetry tags and studied turtle movements and microhahitat use. Turtles were checked 2 to 3 times weekly in summer and sporadically in winter. Several microhabitat variables were measured at each turtle location and a random location to help quantify microhabitat use vs. availability. We recorded 147 turtle locations. Turtles were always associated with submerged cover with a high percentage of overhead canopy cover. Turtles used deeper depths in late summer (but not deeper depths than random locations) and deeper depths in mid-winter (and deeper depths than random locations) than in early summer. They used shallower depths than random locations in early summer. This seasonal shift in depth use might be thermoregulatory, although evidence for this is indirect. The mean linear home range for all turtles was 777.8 m. Females had larger home ranges than males, and juveniles had larger home ranges than adults, although the latter was not statistically significant. Macrochelys temminckii used submerged structures as a core site, and stayed at each core site for an average of 12.3 d.

  3. Sorption of sulphamethoxazole by the biochars derived from rice straw and alligator flag.

    PubMed

    Li, Tingqiang; Han, Xuan; Liang, Chengfeng; Shohag, M J I; Yang, Xiaoe

    2015-01-01

    The sorption ability of sulphamethoxazole (SMX) by biochar derived from rice straw (RS) and alligator flag (AF) at 600°C was studied to assess the ability of biochar as adsorbent to remove SMX from aqueous solution. The results indicated that sorption of SMX by biochars was well described using the Langmuir equation (R2>0.94), and the maximum sorption parameter (Q) of RS (3650 mg kg(-1)) was much higher than that of AF (1963 mg kg(-1)). Temperature had no effect on SMX sorption by biochars, while thermodynamics analysis indicated that the sorption of SMX on both biochars was a spontaneous physical process. The d 250 RS (diameter of RS sieved through 250 µm) and d 150 AF (diameter of AF sieved through 150 µm) showed excellent sorption ability for SMX. The sorption amount of RS was larger than that of AF when pH<7, whereas, the sorption amount of AF surpassed RS when pH≥7. The presence of Cu2+ and/or Cd2+ ion at low concentrations (20 mg L(-1)) significantly (P<0.05) increased the sorption of SMX on both RS and AF. Our study confirms that biochar derived from the wetland plants could be used as effective adsorbents to remove SMX from aqueous solution. PMID:25413119

  4. Macroderoides texanus n. sp. (Digenea: Macroderoididae) from alligator gar, Atractosteus spatula in Texas.

    PubMed

    Tkach, Vasyl V; Strand, Eric J; Froese, Leanne

    2008-12-01

    Macroderoides texanus n. sp. is described based on 16 specimens collected from the intestine of the North American alligator gar, Atractosteus spatula. Of the five established species of Macroderoides, the new species is morphologically most similar to Macroderoides spiniferus and Macroderoides trilobatus. M. texanus n. sp. differs from M. spiniferus by having the ovary situated immediately posterior to the cirrus sac rather than at mid-way between the cirrus sac and anterior testis, the ventral sucker situated further posteriorly, and the vitelline fields extending somewhat posterior to posterior testis rather than to the middle of posterior testis. M. texanus n. sp. differs from M. trilobatus by having the ovary positioned immediately adjacent to, or overlapping the cirrus sac rather than at some distance posterior to it, and by having significantly larger eggs. Additionally, the new species has two distinctive rows of spines on the postero-ventral surface of the oral sucker that are lacking in M. spiniferus and M. trilobatus. Comparison of approximately 2,700-base-pair sequences of nuclear rDNA (partial 18S, complete ITS region and partial 28S) from M. texanus n. sp., M. spiniferus and M. trilobatus, strongly supports the status of M. texanus n. sp. as a new species. PMID:18762983

  5. Structure and fracture resistance of alligator gar (Atractosteus spatula) armored fish scales.

    PubMed

    Yang, Wen; Gludovatz, Bernd; Zimmermann, Elizabeth A; Bale, Hrishikesh A; Ritchie, Robert O; Meyers, Marc A

    2013-04-01

    The alligator gar is a large fish with flexible armor consisting of ganoid scales. These scales contain a thin layer of ganoine (microhardness ~2.5 GPa) and a bony body (microhardness ~400 MPa), with jagged edges that provide effective protection against predators. We describe here the structure of both ganoine and bony foundation and characterize the mechanical properties and fracture mechanisms. The bony foundation is characterized by two components: a mineralized matrix and parallel arrays of tubules, most of which contain collagen fibers. The spacing of the empty tubules is ~60 μm; the spacing of those filled with collagen fibers is ~7 μm. Using micromechanical testing of such scales in a variable-pressure scanning electron microscope, we identify interactions between propagating cracks and the microstructure, and show that the toughness of the scales increases with crack extension in a classical resistance-curve response from the activation of extrinsic toughening mechanisms. We demonstrate how mechanical damage evolves in these structures, and further identify that the reinforcement of the mineral by the network of collagen fibers is the principal toughening mechanism resisting such damage. Additionally, we define the anisotropy of the toughness of the scales and relate this to the collagen fiber orientation. PMID:23274521

  6. Structure and fracture resistance of alligator gar (Atractosteus spatula) armored fish scales.

    PubMed

    Yang, Wen; Gludovatz, Bernd; Zimmermann, Elizabeth A; Bale, Hrishikesh A; Ritchie, Robert O; Meyers, Marc A

    2013-04-01

    The alligator gar is a large fish with flexible armor consisting of ganoid scales. These scales contain a thin layer of ganoine (microhardness ~2.5 GPa) and a bony body (microhardness ~400 MPa), with jagged edges that provide effective protection against predators. We describe here the structure of both ganoine and bony foundation and characterize the mechanical properties and fracture mechanisms. The bony foundation is characterized by two components: a mineralized matrix and parallel arrays of tubules, most of which contain collagen fibers. The spacing of the empty tubules is ~60 μm; the spacing of those filled with collagen fibers is ~7 μm. Using micromechanical testing of such scales in a variable-pressure scanning electron microscope, we identify interactions between propagating cracks and the microstructure, and show that the toughness of the scales increases with crack extension in a classical resistance-curve response from the activation of extrinsic toughening mechanisms. We demonstrate how mechanical damage evolves in these structures, and further identify that the reinforcement of the mineral by the network of collagen fibers is the principal toughening mechanism resisting such damage. Additionally, we define the anisotropy of the toughness of the scales and relate this to the collagen fiber orientation.

  7. Macroderoides texanus n. sp. (Digenea: Macroderoididae) from alligator gar, Atractosteus spatula in Texas.

    PubMed

    Tkach, Vasyl V; Strand, Eric J; Froese, Leanne

    2008-12-01

    Macroderoides texanus n. sp. is described based on 16 specimens collected from the intestine of the North American alligator gar, Atractosteus spatula. Of the five established species of Macroderoides, the new species is morphologically most similar to Macroderoides spiniferus and Macroderoides trilobatus. M. texanus n. sp. differs from M. spiniferus by having the ovary situated immediately posterior to the cirrus sac rather than at mid-way between the cirrus sac and anterior testis, the ventral sucker situated further posteriorly, and the vitelline fields extending somewhat posterior to posterior testis rather than to the middle of posterior testis. M. texanus n. sp. differs from M. trilobatus by having the ovary positioned immediately adjacent to, or overlapping the cirrus sac rather than at some distance posterior to it, and by having significantly larger eggs. Additionally, the new species has two distinctive rows of spines on the postero-ventral surface of the oral sucker that are lacking in M. spiniferus and M. trilobatus. Comparison of approximately 2,700-base-pair sequences of nuclear rDNA (partial 18S, complete ITS region and partial 28S) from M. texanus n. sp., M. spiniferus and M. trilobatus, strongly supports the status of M. texanus n. sp. as a new species.

  8. Sorption of sulphamethoxazole by the biochars derived from rice straw and alligator flag.

    PubMed

    Li, Tingqiang; Han, Xuan; Liang, Chengfeng; Shohag, M J I; Yang, Xiaoe

    2015-01-01

    The sorption ability of sulphamethoxazole (SMX) by biochar derived from rice straw (RS) and alligator flag (AF) at 600°C was studied to assess the ability of biochar as adsorbent to remove SMX from aqueous solution. The results indicated that sorption of SMX by biochars was well described using the Langmuir equation (R2>0.94), and the maximum sorption parameter (Q) of RS (3650 mg kg(-1)) was much higher than that of AF (1963 mg kg(-1)). Temperature had no effect on SMX sorption by biochars, while thermodynamics analysis indicated that the sorption of SMX on both biochars was a spontaneous physical process. The d 250 RS (diameter of RS sieved through 250 µm) and d 150 AF (diameter of AF sieved through 150 µm) showed excellent sorption ability for SMX. The sorption amount of RS was larger than that of AF when pH<7, whereas, the sorption amount of AF surpassed RS when pH≥7. The presence of Cu2+ and/or Cd2+ ion at low concentrations (20 mg L(-1)) significantly (P<0.05) increased the sorption of SMX on both RS and AF. Our study confirms that biochar derived from the wetland plants could be used as effective adsorbents to remove SMX from aqueous solution.

  9. Two modes of motion of the alligator lizard cochlea: Measurements and model predictions

    NASA Astrophysics Data System (ADS)

    Aranyosi, A. J.; Freeman, Dennis M.

    2005-09-01

    Measurements of motion of an in vitro preparation of the alligator lizard basilar papilla in response to sound demonstrate elliptical trajectories. These trajectories are consistent with the presence of both a translational and rotational mode of motion. The translational mode is independent of frequency, and the rotational mode has a displacement peak near 5 kHz. These measurements can be explained by a simple mechanical system in which the basilar papilla is supported asymmetrically on the basilar membrane. In a quantitative model, the translational admittance is compliant while the rotational admittance is second order. Best-fit model parameters are consistent with estimates based on anatomy and predict that fluid flow across hair bundles is a primary source of viscous damping. The model predicts that the rotational mode contributes to the high-frequency slopes of auditory nerve fiber tuning curves, providing a physical explanation for a low-pass filter required in models of this cochlea. The combination of modes makes the sensitivity of hair bundles more uniform with radial position than that which would result from pure rotation. A mechanical analogy with the organ of Corti suggests that these two modes of motion may also be present in the mammalian cochlea.

  10. Invertebrate community composition differs between invasive herb alligator weed and native sedges

    NASA Astrophysics Data System (ADS)

    Bassett, Imogen E.; Paynter, Quentin; Beggs, Jacqueline R.

    2012-05-01

    Chemical and/or architectural differences between native and exotic plants may influence invertebrate community composition. According to the enemy release hypothesis, invasive weeds should host fewer and less specialised invertebrates than native vegetation. Invertebrate communities were compared on invasive Alternanthera philoxeroides (alligator weed) and native sedges (Isolepis prolifer and Schoenoplectus tabernaemontani) in a New Zealand lake. A. philoxeroides is more architecturally and chemically similar to I. prolifer than to S. tabernaemontani. Lower invertebrate abundance, richness and proportionally fewer specialists were predicted on A. philoxeroides compared to native sedges, but with greatest differences between A. philoxeroides and S. tabernaemontani. A. philoxeroides is more architecturally and chemically similar to I. prolifer than to S. tabernaemontani. Invertebrate abundance showed taxa-specific responses, rather than consistently lower abundance on A. philoxeroides. Nevertheless, as predicted, invertebrate fauna of A. philoxeroides was more similar to that of I. prolifer than to S. tabernaemontani. The prediction of a depauperate native fauna on A. philoxeroides received support from some but not all taxa. All vegetation types hosted generalist-dominated invertebrate communities with simple guild structures. The enemy release hypothesis thus had minimal ability to predict patterns in this system. Results suggest the extent of architectural and chemical differences between native and invasive vegetation may be useful in predicting the extent to which they will host different invertebrate communities. However, invertebrate ecology also affects whether invertebrate taxa respond positively or negatively to weed invasion. Thus, exotic vegetation may support distinct invertebrate communities despite similar overall invertebrate abundance to native vegetation.

  11. Process for electrolytically preparing uranium metal

    DOEpatents

    Haas, Paul A.

    1989-01-01

    A process for making uranium metal from uranium oxide by first fluorinating uranium oxide to form uranium tetrafluoride and next electrolytically reducing the uranium tetrafluoride with a carbon anode to form uranium metal and CF.sub.4. The CF.sub.4 is reused in the fluorination reaction rather than being disposed of as a hazardous waste.

  12. Process for electrolytically preparing uranium metal

    DOEpatents

    Haas, Paul A.

    1989-08-01

    A process for making uranium metal from uranium oxide by first fluorinating uranium oxide to form uranium tetrafluoride and next electrolytically reducing the uranium tetrafluoride with a carbon anode to form uranium metal and CF.sub.4. The CF.sub.4 is reused in the fluorination reaction rather than being disposed of as a hazardous waste.

  13. Influence of uranium hydride oxidation on uranium metal behaviour

    SciTech Connect

    Patel, N.; Hambley, D.; Clarke, S.A.; Simpson, K.

    2013-07-01

    This work addresses concerns that the rapid, exothermic oxidation of active uranium hydride in air could stimulate an exothermic reaction (burning) involving any adjacent uranium metal, so as to increase the potential hazard arising from a hydride reaction. The effect of the thermal reaction of active uranium hydride, especially in contact with uranium metal, does not increase in proportion with hydride mass, particularly when considering large quantities of hydride. Whether uranium metal continues to burn in the long term is a function of the uranium metal and its surroundings. The source of the initial heat input to the uranium, if sufficient to cause ignition, is not important. Sustained burning of uranium requires the rate of heat generation to be sufficient to offset the total rate of heat loss so as to maintain an elevated temperature. For dense uranium, this is very difficult to achieve in naturally occurring circumstances. Areas of the uranium surface can lose heat but not generate heat. Heat can be lost by conduction, through contact with other materials, and by convection and radiation, e.g. from areas where the uranium surface is covered with a layer of oxidised material, such as burned-out hydride or from fuel cladding. These rates of heat loss are highly significant in relation to the rate of heat generation by sustained oxidation of uranium in air. Finite volume modelling has been used to examine the behaviour of a magnesium-clad uranium metal fuel element within a bottle surrounded by other un-bottled fuel elements. In the event that the bottle is breached, suddenly, in air, it can be concluded that the bulk uranium metal oxidation reaction will not reach a self-sustaining level and the mass of uranium oxidised will likely to be small in relation to mass of uranium hydride oxidised. (authors)

  14. Uranium deposits of Brazil

    SciTech Connect

    1991-09-01

    Brazil is a country of vast natural resources, including numerous uranium deposits. In support of the country`s nuclear power program, Brazil has developed the most active uranium industry in South America. Brazil has one operating reactor (Angra 1, a 626-MWe PWR), and two under construction. The country`s economic challenges have slowed the progress of its nuclear program. At present, the Pocos de Caldas district is the only active uranium production. In 1990, the Cercado open-pit mine produced approximately 45 metric tons (MT) U{sub 3}O{sub 8} (100 thousand pounds). Brazil`s state-owned uranium production and processing company, Uranio do Brasil, announced it has decided to begin shifting its production from the high-cost and nearly depleted deposits at Pocos de Caldas, to lower-cost reserves at Lagoa Real. Production at Lagoa Real is schedules to begin by 1993. In addition to these two districts, Brazil has many other known uranium deposits, and as a whole, it is estimated that Brazil has over 275,000 MT U{sub 3}O{sub 8} (600 million pounds U{sub 3}O{sub 8}) in reserves.

  15. Microbial reduction of uranium

    USGS Publications Warehouse

    Lovley, D.R.; Phillips, E.J.P.; Gorby, Y.A.; Landa, E.R.

    1991-01-01

    REDUCTION of the soluble, oxidized form of uranium, U(VI), to insoluble U(IV) is an important mechanism for the immobilization of uranium in aquatic sediments and for the formation of some uranium ores1-10. U(VI) reduction has generally been regarded as an abiological reaction in which sulphide, molecular hydrogen or organic compounds function as the reductant1,2,5,11. Microbial involvement in U(VI) reduction has been considered to be limited to indirect effects, such as microbial metabolism providing the reduced compounds for abiological U(VI) reduction and microbial cell walls providing a surface to stimulate abiological U(VI) reduction1,12,13. We report here, however, that dissimilatory Fe(III)-reducing microorganisms can obtain energy for growth by electron transport to U(VI). This novel form of microbial metabolism can be much faster than commonly cited abiological mechanisms for U(VI) reduction. Not only do these findings expand the known potential terminal electron acceptors for microbial energy transduction, they offer a likely explanation for the deposition of uranium in aquatic sediments and aquifers, and suggest a method for biological remediation of environments contaminated with uranium.

  16. PRODUCTION OF URANIUM HEXAFLUORIDE

    DOEpatents

    Fowler, R.D.

    1957-08-27

    A process for the production of uranium hexafluoride from the oxides of uranium is reported. In accordance with the method, the higher oxides of uranium may be reduced to uranium dioxide (UO/sub 2/), the latter converted into uranium tetrafluoride by reaction with hydrogen fluoride, and the UF/sub 4/ converted to UF/sub 6/ by reaction with a fluorinating agent, such as CoF/sub 3/. The UO/sub 3/ or U/sub 3/O/sub 8/ is placed in a reac tion chamber in a copper boat or tray enclosed in a copper oven, and heated to 500 to 650 deg C while hydrogen gas is passed through the oven. After nitrogen gas is used to sweep out the hydrogen and the water vapor formed, and while continuing to inaintain the temperature between 400 deg C and 600 deg C, anhydrous hydrogen fluoride is passed through. After completion of the conversion of UO/sub 2/ to UF/sub 4/ the temperature of the reaction chamber is lowered to about 400 deg C or less, the UF/sub 4/ is mixed with the requisite quantity of CoF/sub 3/, and after evacuating the chamber, the mixture is heated to 300 to 400 deg C, and the resulting UF/sub 6/ is led off and delivered to a condenser.

  17. Uranium hexafluoride handling. Proceedings

    SciTech Connect

    Not Available

    1991-12-31

    The United States Department of Energy, Oak Ridge Field Office, and Martin Marietta Energy Systems, Inc., are co-sponsoring this Second International Conference on Uranium Hexafluoride Handling. The conference is offered as a forum for the exchange of information and concepts regarding the technical and regulatory issues and the safety aspects which relate to the handling of uranium hexafluoride. Through the papers presented here, we attempt not only to share technological advances and lessons learned, but also to demonstrate that we are concerned about the health and safety of our workers and the public, and are good stewards of the environment in which we all work and live. These proceedings are a compilation of the work of many experts in that phase of world-wide industry which comprises the nuclear fuel cycle. Their experience spans the entire range over which uranium hexafluoride is involved in the fuel cycle, from the production of UF{sub 6} from the naturally-occurring oxide to its re-conversion to oxide for reactor fuels. The papers furnish insights into the chemical, physical, and nuclear properties of uranium hexafluoride as they influence its transport, storage, and the design and operation of plant-scale facilities for production, processing, and conversion to oxide. The papers demonstrate, in an industry often cited for its excellent safety record, continuing efforts to further improve safety in all areas of handling uranium hexafluoride. Selected papers were processed separately for inclusion in the Energy Science and Technology Database.

  18. Uranium resources: Issues and facts

    SciTech Connect

    Delene, J.G.

    1993-12-31

    Although there are several secondary issues, the most important uranium resource issue is, ``will there be enough uranium available at a cost which will allow nuclear power to be competitive in the future?`` This paper will attempt to answer this question by discussing uranium supply, demand, and economics from the perspective of the United States. The paper will discuss: how much uranium is available; the sensitivity of nuclear power costs to uranium price; the potential future demand for uranium in the Unites States, some of the options available to reduce this demand, the potential role of the Advanced Liquid Metal Cooled Reactor (ALMR) in reducing uranium demand; and potential alternative uranium sources and technologies.

  19. METHOD OF RECOVERING URANIUM COMPOUNDS

    DOEpatents

    Poirier, R.H.

    1957-10-29

    S>The recovery of uranium compounds which have been adsorbed on anion exchange resins is discussed. The uranium and thorium-containing residues from monazite processed by alkali hydroxide are separated from solution, and leached with an alkali metal carbonate solution, whereby the uranium and thorium hydrorides are dissolved. The carbonate solution is then passed over an anion exchange resin causing the uranium to be adsorbed while the thorium remains in solution. The uranium may be recovered by contacting the uranium-holding resin with an aqueous ammonium carbonate solution whereby the uranium values are eluted from the resin and then heating the eluate whereby carbon dioxide and ammonia are given off, the pH value of the solution is lowered, and the uranium is precipitated.

  20. Direct comparison of the electronic coupling efficiency of sulfur and selenium alligator clips for molecules adsorbed onto gold electrodes

    NASA Astrophysics Data System (ADS)

    Patrone, L.; Palacin, S.; Bourgoin, J. P.

    2003-05-01

    Scanning tunneling microscopy experiments have been performed to compare the electronic coupling provided by S and by Se used as alligator clips for bisthiol- and biselenol-terthiophene molecules adsorbed onto gold. The molecules were inserted in a dodecanethiol (DT) self-assembled monolayer. Their apparent height above the dodecanethiol matrix was used as a measure of the electronic coupling strength corresponding to S and Se, respectively. We show that the insertion behaviors of the two molecules are qualitatively the same, and that Se provides systematically a better coupling link than S, whatever the tunneling conditions.

  1. EXTRACTION OF URANIUM

    DOEpatents

    Kesler, R.D.; Rabb, D.D.

    1959-07-28

    An improved process is presented for recovering uranium from a carnotite ore. In the improved process U/sub 2/O/sub 5/ is added to the comminuted ore along with the usual amount of NaCl prior to roasting. The amount of U/sub 2/O/ sub 5/ is dependent on the amount of free calcium oxide and the uranium in the ore. Specifically, the desirable amount of U/sub 2/O/sub 5/ is 3.2% for each 1% of CaO, and 5 to 6% for each 1% of uranium. The mixture is roasted at about 1560 deg C for about 30 min and then leached with a 3 to 9% aqueous solution of sodium carbonate.

  2. Process for recovering uranium

    DOEpatents

    MacWood, G. E.; Wilder, C. D.; Altman, D.

    1959-03-24

    A process useful in recovering uranium from deposits on stainless steel liner surfaces of calutrons is presented. The deposit is removed from the stainless steel surface by washing with aqueous nitric acid. The solution obtained containing uranium, chromium, nickel, copper, and iron is treated with an excess of ammonium hydroxide to precipitnte the uranium, iron, and chromium and convert the nickel and copper to soluble ammonio complexions. The precipitated material is removed, dried and treated with carbon tetrachloride at an elevated temperature of about 500 to 600 deg C to form a vapor mixture of UCl/ sub 4/, UCl/sub 5/, FeCl/sub 3/, and CrCl/sub 4/. The UCl/sub 4/ is separated from this vapor mixture by selective fractional condensation at a temperature of about 500 to 400 deg C.

  3. PROCESS FOR RECOVERING URANIUM

    DOEpatents

    MacWood, G.E.; Wilder, C.D.; Altman, D.

    1959-03-24

    A process is described for recovering uranium from deposits on stainless steel liner surfaces of calutrons. The deposit is removed from the stainless steel surface by washing with aqueous nitric acid. The solution obtained containing uranium, chromium, nickels copper, and iron is treated with excess of ammonium hydroxide to precipitatc the uranium, irons and chromium and convert thc nickel and copper to soluble ammonia complexions. The precipitated material is removed, dried, and treated with carbon tetrachloride at an elevated temperature of about 500 to 600 deg C to form a vapor mixture of UCl/sub 4/, UCl/sub 5/, FeCl/ sub 3/, and CrCl/sub 4/. The UCl/sub 4/ is separated from this vapor mixture by selective fractional condensation at a temprrature of about 300 to400 deg C.

  4. National uranium resource evaluation: Mesa quaddrangle, Arizona

    SciTech Connect

    Luning, R.H.; Thiede, D.S.; O'Neill, A.J.; Nystrom, R.J.; White, D.L.

    1982-06-01

    The Mesa Quadrangle (2/sup 0/), Arizona, was evaluated to a depth of 1500 meters to identify geologic environments and delineate surface and subsurface areas favorable for the occurrence of uranium deposits. The criteria used to define uranium favorability were developed during the National Uranium Resource Evaluation program. Surface and subsurface studies were augmented by aerial radiometric surveys and hydrogeochemical and stream-sediment reconnaisance studies. The results of the investigations identified three favorable areas: older Precambrian quartz monzonite near Horseshoe Dam; the gray unit of the Dripping Spring quartzite of Precambrian age in the Sierra Ancha, Salt River Canyon, and Mescal Mountain regions; and Tertiary lake beds near Cave Creek, Horseshoe Dam, and northeastern Tonto Basin. Unfavorable environments include nearly all older Precambrian crystalline and metamorphic rocks, most younger Precambrian igneous and sedimentary rocks, parts of the Paleozoic section, igneous intrusives of Laramide age. Tertiary volcanic rocks, and late Tertiary sedimentary rocks. The eastern third of the quadrangle remains unevaluated because access was prohibited or could not be obtained in time. Environments were unevaluated in older Precambrian volcanic, sedimentary, and metamorphic rocks; the Naco and Supai Formations; Cretaceous sedimentary rocks; and many Tertiary sedimentary rocks in intermontane basins and within the southwestern portion of the quadrangle because of time constraints, land access restrictions, and sparsity of subsurface data.

  5. Uranium immobilization and nuclear waste

    SciTech Connect

    Duffy, C.J.; Ogard, A.E.

    1982-02-01

    Considerable information useful in nuclear waste storage can be gained by studying the conditions of uranium ore deposit formation. Further information can be gained by comparing the chemistry of uranium to nuclear fission products and other radionuclides of concern to nuclear waste disposal. Redox state appears to be the most important variable in controlling uranium solubility, especially at near neutral pH, which is characteristic of most ground water. This is probably also true of neptunium, plutonium, and technetium. Further, redox conditions that immobilize uranium should immobilize these elements. The mechanisms that have produced uranium ore bodies in the Earth's crust are somewhat less clear. At the temperatures of hydrothermal uranium deposits, equilibrium models are probably adequate, aqueous uranium (VI) being reduced and precipitated by interaction with ferrous-iron-bearing oxides and silicates. In lower temperature roll-type uranium deposits, overall equilibrium may not have been achieved. The involvement of sulfate-reducing bacteria in ore-body formation has been postulated, but is uncertain. Reduced sulfur species do, however, appear to be involved in much of the low temperature uranium precipitation. Assessment of the possibility of uranium transport in natural ground water is complicated because the system is generally not in overall equilibrium. For this reason, Eh measurements are of limited value. If a ground water is to be capable of reducing uranium, it must contain ions capable of reducing uranium both thermodynamically and kinetically. At present, the best candidates are reduced sulfur species.

  6. PROCESS OF PREPARING URANIUM CARBIDE

    DOEpatents

    Miller, W.E.; Stethers, H.L.; Johnson, T.R.

    1964-03-24

    A process of preparing uranium monocarbide is de scribed. Uranium metal is dissolved in cadmium, zinc, cadmium-- zinc, or magnesium-- zinc alloy and a small quantity of alkali metal is added. Addition of stoichiometric amounts of carbon at 500 to 820 deg C then precipitates uranium monocarbide. (AEC)

  7. PROCESS OF RECOVERING URANIUM

    DOEpatents

    Price, T.D.; Jeung, N.M.

    1958-06-17

    An improved precipitation method is described for the recovery of uranium from aqueous solutions. After removal of all but small amounts of Ni or Cu, and after complexing any iron present, the uranium is separated as the peroxide by adding H/sub 2/O/sub 2/. The improvement lies in the fact that the addition of H/sub 2/O/sub 2/ and consequent precipitation are carried out at a temperature below the freezing; point of the solution, so that minute crystals of solvent are present as seed crystals for the precipitation.

  8. PREPARATION OF URANIUM TRIOXIDE

    DOEpatents

    Buckingham, J.S.

    1959-09-01

    The production of uranium trioxide from aqueous solutions of uranyl nitrate is discussed. The uranium trioxide is produced by adding sulfur or a sulfur-containing compound, such as thiourea, sulfamic acid, sulfuric acid, and ammonium sulfate, to the uranyl solution in an amount of about 0.5% by weight of the uranyl nitrate hexahydrate, evaporating the solution to dryness, and calcining the dry residue. The trioxide obtained by this method furnished a dioxide with a considerably higher reactivity with hydrogen fluoride than a trioxide prepared without the sulfur additive.

  9. Corrosion-resistant uranium

    DOEpatents

    Hovis, V.M. Jr.; Pullen, W.C.; Kollie, T.G.; Bell, R.T.

    1981-10-21

    The present invention is directed to the protecting of uranium and uranium alloy articles from corrosion by providing the surfaces of the articles with a layer of an ion-plated metal selected from aluminum and zinc to a thickness of at least 60 microinches and then converting at least the outer surface of the ion-plated layer of aluminum or zinc to aluminum chromate or zinc chromate. This conversion of the aluminum or zinc to the chromate form considerably enhances the corrosion resistance of the ion plating so as to effectively protect the coated article from corrosion.

  10. Corrosion-resistant uranium

    DOEpatents

    Hovis, Jr., Victor M.; Pullen, William C.; Kollie, Thomas G.; Bell, Richard T.

    1983-01-01

    The present invention is directed to the protecting of uranium and uranium alloy articles from corrosion by providing the surfaces of the articles with a layer of an ion-plated metal selected from aluminum and zinc to a thickness of at least 60 microinches and then converting at least the outer surface of the ion-plated layer of aluminum or zinc to aluminum chromate or zinc chromate. This conversion of the aluminum or zinc to the chromate form considerably enhances the corrosion resistance of the ion plating so as to effectively protect the coated article from corrosion.

  11. PRODUCTION OF URANIUM TUBING

    DOEpatents

    Creutz, E.C.

    1958-04-15

    The manufacture of thin-walled uranium tubing by the hot-piercing techique is described. Uranium billets are preheated to a temperature above 780 d C. The heated billet is fed to a station where it is engaged on its external surface by three convex-surfaced rotating rollers which are set at an angle to the axis of the billet to produce a surface friction force in one direction to force the billet over a piercing mandrel. While being formed around the mandrel and before losing the desired shape, the tube thus formed is cooled by a water spray.

  12. TREATMENT OF URANIUM SURFACES

    DOEpatents

    Slunder, C.J.

    1959-02-01

    An improved process is presented for prcparation of uranium surfaces prior to electroplating. The surfacc of the uranium to be electroplated is anodized in a bath comprising a solution of approximately 20 to 602 by weight of phosphoric acid which contains about 20 cc per liter of concentrated hydrochloric acid. Anodization is carried out for approximately 20 minutes at a current density of about 0.5 amperes per square inch at a temperature of about 35 to 45 C. The oxidic film produced by anodization is removed by dipping in strong nitric acid, followed by rinsing with water just prior to electroplating.

  13. Solubility characterization of airborne uranium from a uranium recycling plant.

    PubMed

    Metzger, Robert; Cole, Leslie

    2004-07-01

    Solubility profiles of uranium dusts in a uranium recycling plant were determined by performing in vitro solubility tests on breathing zone air samples conducted in all process areas of the processing plant. The recycling plant produces high density shields, closed end tubes that are punched and formed from uranium sheet metal, and high-fired uranium oxide, which is used as a catalyst. The recycled uranium is cut and melted in a vacuum furnace, and part of the molten uranium is poured into molds for further processing. Air samples were taken in process areas under normal working conditions. The dissolution rate of the uranium in a simulant solution of extracellular airway lining fluid (Gamble's solution) was then determined over the next 28 d. Airborne uranium in the oxide section of the plant was found to be highly insoluble with 99% of the uranium having a dissolution half time in excess of 100 d. The solubility of the airborne uranium in other areas of the facility was only slightly more soluble with over 90% of the airborne uranium having dissolution half times in excess of 90 d.

  14. Occurrence of uranium-bearing coal, carbonaceous shale, and carbonaceous limestone in the Fall Creek area, Bonneville County, Idaho

    USGS Publications Warehouse

    Vine, James D.; Moore, George W.

    1952-01-01

    Uraniferous coal, carbonaceous shale, and carbonaceous limestone occur in the Bear River formation of Upper Crestaceous age at the Fall Creek prospect, in the Fall Creek area, Bonneville County, IDaho. The uranium compounds are believed to have been derived from mildly radioactive silicic volcanic rocks of the Tertiary age that rest unconformably on all older rocks and once overlay the Bear River formation and its coal. Meteoric water, percolating downward through the silicic volcanic rocks and into the older rocks along joints and faults, is believed to have brought the uranium compounds into contact with the coal and carbonaceous rocks in which the uranium was absorbed.

  15. Summary of investigations of uranium deposits in the Pumpkin Buttes area, Johnson and Campbell Counties, Wyoming

    USGS Publications Warehouse

    Troyer, Max L.; McKay, Edward J.; Soister, Paul E.; Wallace, Stewart R.

    1954-01-01

    Uranium minerals were discovered in the Pumpkin Buttes area, Campbell and Johnson Counties, Wyo., by the U. S. Geological Survey in October 1951. From June to November 1952, an area of about 750 square miles was examined for uranium deposits, and 211 localities having abnormally high radioactivity were found; uranium minerals are visible at 121 of these localities. All known uranium mineralization in the area is restricted to sandstones of the Wasatch formation, except sparsely disseminated uranium in the sandstone of the White River formation, which caps the Pumpkin Buttes, mid several localities on the Great Pine Ridge southwest of the Pumpkin Buttes where iron-saturated sandstone and clinker in the Fort Union formation have above-normal radioactivity. The uranium occurrences in the Wasatch formation are in a red sandstone zone 450 to 900 feet above the base of the formation and are of two types: small concretionary masses of uranium, iron, manganese and vanadium minerals in sandstone, and irregular zones in which uranium minerals are disseminated in sandstone. The second type is usually larger but of lower grade than the first. Most of the localities at which uranium occurs are in a north-trending belt about 60 miles long and 18 miles in maximum width.

  16. Summary of investigations of uranium deposits in the Pumpkin Buttes area, Johnson and Campbell Counties, Wyoming

    USGS Publications Warehouse

    Troyer, Max L.; McKay, Edward J.; Soister, Paul E.; Wallace, Stewart R.

    1953-01-01

    Uranium minerals were discovered in the Pumpkin Buttes area Campbell and Johnson Counties by the U.S. Geological Survey in October 1951 From June to November 1952 an area of about 750 square miles was examined for uranium deposits, and 211 localities with abnormally high radioactivity were found uranium minerals are visible at 121 of these localities. All known uranium mineralization is restricted to sandstones of the Wasatch formation exclusive of sparsely disseminated uranium in the White River sandstone which caps the Pumpkin Buttes and several localities on the Great Pine Ridge southwest of the Pumpkin Buttes where ironstone and clinker in the Fort Union formation have above normal radioactivity. The uranium occurrences in the Wasatch formation are in a red sandstone zone 450 to 900 feet above the base of formation and are of two types. (1) small concretionary masses of uranium, iron, and manganese minerals in sandstone and (2) irregular zones in which uranium minerals are disseminated in sandstone The second type is usually larger but lower grade than the first type. Most of the localities at which uranium occurs are in a north -trending belt approximately 60 miles long with a maximum width of 18 miles,

  17. RECOVERY OF URANIUM FROM PITCHBLENDE

    DOEpatents

    Ruehle, A.E.

    1958-06-24

    The decontamination of uranium from molybdenum is described. When acid solutions containing uranyl nitrate are contacted with ether for the purpose of extracting the uranium values, complex molybdenum compounds are coextracted with the uranium and also again back-extracted from the ether with the uranium. This invention provides a process for extracting uranium in which coextraction of molybdenum is avoided. It has been found that polyhydric alcohols form complexes with molybdenum which are preferentially water-soluble are taken up by the ether extractant to only a very minor degree. The preferred embodiment of the process uses mannitol, sorbitol or a mixture of the two as the complexing agent.

  18. High loading uranium fuel plate

    DOEpatents

    Wiencek, Thomas C.; Domagala, Robert F.; Thresh, Henry R.

    1990-01-01

    Two embodiments of a high uranium fuel plate are disclosed which contain a meat comprising structured uranium compound confined between a pair of diffusion bonded ductile metal cladding plates uniformly covering the meat, the meat having a uniform high fuel loading comprising a content of uranium compound greater than about 45 Vol. % at a porosity not greater than about 10 Vol. %. In a first embodiment, the meat is a plurality of parallel wires of uranium compound. In a second embodiment, the meat is a dispersion compact containing uranium compound. The fuel plates are fabricated by a hot isostatic pressing process.

  19. A moss-covered alligator rests in the sun at KSC. copy form; photos beginning with 99PD are only ava

    NASA Technical Reports Server (NTRS)

    2000-01-01

    On top of what may be a nest on the edge of an algae-coated canal near Schwartz Rd. at Kennedy Space Center, a moss-covered alligator rests while keeping a wary eye open for trespassers. Nearly 5,000 alligators can be found in canals, ponds, and waterways throughout the Center and the Merritt Island National Wildlife Refuge, which shares a boundary with the Center. American alligators feed and rest in the water, and usually lay their eggs in dens they dig into the banks. The young alligators spend their first several weeks in these dens. The Wildlife Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  20. National Uranium Resource Evaluation: Baker Quadrangle, Oregon and Idaho

    SciTech Connect

    Bernardi, M L; Robins, J W

    1982-05-01

    The Baker Quadrangle, Oregon, and Idaho, was evaluated to identify areas containing geologic environments favorable for uranium deposits. The criteria used was developed for the National Uranium Resource Evaluation program. Stream-sediment reconnaissance and detailed surface studies were augmented by subsurface-data interpretion and an aerial radiometric survey. Results indicate that lower Pliocene sedimentary rocks in the Lower Powder River Valley-Virtue Flat basin are favorable characteristics, they remain unevaluated because of lack of subsurface data. Tertiary sandstones, possibly present at depth in the Long and Cascade Valleys, also remain unevaluated due to lack of subsurface data. All remaining environments in the Baker Quadrangle are unfavorable for all classes of uranium deposits.