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Sample records for freshwater production sites

  1. DIBUTYLPHTHALATE DEGRADATION IN ESTUARINE AND FRESHWATER SITES

    EPA Science Inventory

    Biotic and abiotic degradation of di-n-butylphthalate (DBP) in water and sediment/water systems from six different sites was investigated under laboratory conditions. Water and underlying sediment were collected from freshwater and estuarine sites in Florida, Mississippi, and Lou...

  2. Freshwater aquatic plant biomass production in Florida

    SciTech Connect

    Reddy, K.R.; Sutton, D.L.; Bowes, G.

    1983-01-01

    About 8% (1.2 million ha) of the total surface area of Florida is occupied by freshwater. Many of these water bodies are eutrophic. Nutrients present in these water bodies can be potentially used to culture aquatic plants as a possible feedstock for methane production. This paper summarizes the results of known research findings on biomass production potential of freshwater aquatic plants in Florida and identifies key research needs to improve the quality and quantity of biomass yields. Among floating aquatic plants, biomass yield potential was in the order of water-hyacinth > water lettuce > pennywort > salvinia > duckweed > azolla. Pennywort, duckweed, and azolla appear to perform well during the cooler months compared to other aquatic plants. Among emergent plants, biomass yield potential was in the order of southern wild rice > cattails > soft rush > bulrush. Cultural techniques, nutrient management, and environmental factors influencing the biomass yields were discussed. 68 references.

  3. Dispersion Of Crude Oil And Petroleum Products In Freshwater

    EPA Science Inventory

    The objective of this research was to investigate the relationship between dispersion effectiveness in freshwater and the surfactant composition for fresh and weathered crude oil. Although limited research on the chemical dispersion of crude oil and petroleum products in freshwat...

  4. PHYTOPLANKTON PRODUCTION AND NUTRIENT DISTRIBUTIONS IN A SUBTROPICAL ESTUARY: IMPORTANCE OF FRESHWATER FLOW

    EPA Science Inventory

    The relationships between phytoplankton productivity, nutrient distributions, and freshwater flow were examined in a seasonal study conducted in Escambia Bay, Florida, USA, located in the northeastern Gulf of Mexico. Five sites oriented along the salinity gradient were sampled 24...

  5. AN INTEGRATED WATERSHED APPROACH LINKING SALMONID PRODUCTIVITY TO FRESHWATER HABITAT

    EPA Science Inventory

    EPA's Western Ecology Division is undertaking research addressing catchment-scale dynamics of freshwater habitat productivity for native fishes. Through partnerships with state and federal agencies and private landowners, current field efforts focus on linkages among stream chemi...

  6. Potential Impacts of Food Production on Freshwater Availability

    NASA Astrophysics Data System (ADS)

    Yano, Shinjiro; Hanasaki, Naota; Itsubo, Norihiro; Kim, Hyungjun; Oki, Taikan

    2014-05-01

    The sustainability of freshwater use is often evaluated based on the total volume of water consumption or withdrawal. However, the renewable freshwater resource and potential impacts of water depletion differ with location and water source. In addition, most estimates of the environmental impacts of water use have focused on depletion from a single-source perspective without separating geographically different water sources. Therefore, comprehensive potential impacts from multiple water sources remain unclear. In this study, we quantified the potential impacts of the global food production on freshwater availability (water availability footprint), applying the Water Availability Factor (fwa). Each water source including rainfall, surface water, and groundwater had individual fwa, which is calculated based on the geophysical hydrological cycle, to reflect the differences among renewable freshwater resources by place and source. The fwa for each water source was estimated based on land area or time period required to obtain the reference volume of freshwater. The reference volume was regarded as 1 m3 of rainfall over an area of 1.0 m2 (1,000 mm/year), based on the global mean annual precipitation. This concept is consistent with the Ecological Footprint (EF), which measures how much biologically productive land area is required to provide the resources consumed. The EF concept is measured in global hectares, a standardized unit equal to one hectare with global average bioproductivity. We found that the current agriculture consumes freshwater resources at 1.3 times the rapid rate than sustainable water use. This rate can also indicate environmental water scarcity. Among environmentally water-scarce countries, well-financed countries tend to import cereal products as virtual water to compensate for their domestic water resources. Among water-abundant countries, well-financed countries tend to export cereal products by exploiting their freshwater availability. The fwa

  7. Comments on the Manuscript, "Biodiesel Production from Freshwater Algae"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recent publication (Vijayaragahavan, K.; Hemanathan, K., Biodiesel from freshwater algae, Energy Fuels, 2009, 23(11):5448-5453) on fuel production from algae is evaluated. It is discussed herein that the fuel discussed in that paper is not biodiesel, rather it probably consists of hydrocarbons. ...

  8. Factors controlling bacterial production in marine and freshwater sediments.

    PubMed

    Sander, B C; Kalff, J

    1993-09-01

    We collected benthic bacterial production data measured by (3)H thymidine incorporation (TTI) (25 studies), frequency of dividing cells (FDC) (3 studies), dark-C02 assimilation (1 study) and (3)H-adenine uptake (2 studies) from the literature, which included 18 marine, 6 river, and 2 lake studies. In all of the studies that used the TTI method, (3)H-DNA was isolated and incubations were carried out at in situ temperatures. Most of the researchers also determined (3)H-DNA extraction efficiencies and isotope dilution, thus interpretable estimates of bacterial production were used in the analysis. In marine sediments, bacterial production rates were linked to bacterial biomass, bacterial abundance, sediment organic matter, temperature, and sediment chlorophyll a, with these variables explaining between 40% and 68% of the variation in production rates. Simple relationships between production and bacterial biomass or bacterial abundance, or between production and sediment organic matter, were improved by also including temperature in the analysis of marine sediments. Sediment organic matter explained an appreciable fraction (58%) of the observed production in freshwater sediments. Temperature was the most powerful predictor of the observed variability in specific growth rates (r (2) = 0.48 and r (2) = 0.58) in marine and freshwater sediments, respectively. Thus, bacterial production and specific growth rates are most closely linked to substrate supply and temperature in marine and freshwater sediments. PMID:24190006

  9. The potential of freshwater macroalgae as a biofuels feedstock and the influence of nutrient availability on freshwater macroalgal biomass production

    NASA Astrophysics Data System (ADS)

    Yun, Jin-Ho

    Extensive efforts have been made to evaluate the potential of microalgae as a biofuel feedstock during the past 4-5 decades. However, filamentous freshwater macroalgae have numerous characteristics that favor their potential use as an alternative algal feedstock for biofuels production. Freshwater macroalgae exhibit high rates of areal productivity, and their tendency to form dense floating mats on the water surface imply significant reductions in harvesting and dewater costs compared to microalgae. In Chapter 1, I reviewed the published literature on the elemental composition and energy content of five genera of freshwater macroalgae. This review suggested that freshwater macroalgae compare favorably with traditional bio-based energy sources, including terrestrial residues, wood, and coal. In addition, I performed a semi-continuous culture experiment using the common Chlorophyte genus Oedogonium to investigate whether nutrient availability can influence its higher heating value (HHV), productivity, and proximate analysis. The experimental study suggested that the most nutrient-limited growth conditions resulted in a significant increase in the HHV of the Oedogonium biomass (14.4 MJ/kg to 16.1 MJ/kg). Although there was no significant difference in productivity between the treatments, the average dry weight productivity of Oedogonium (3.37 g/m2/day) was found to be much higher than is achievable with common terrestrial plant crops. Although filamentous freshwater macroalgae, therefore, have significant potential as a renewable source of bioenergy, the ultimate success of freshwater macroalgae as a biofuel feedstock will depend upon the ability to produce biomass at the commercial-scale in a cost-effective and sustainable manner. Aquatic ecology can play an important role to achieve the scale-up of algal crop production by informing the supply rates of nutrients to the cultivation systems, and by helping to create adaptive production systems that are resilient to

  10. Surface Water Quality Monitoring Site Optimization for Poyang Lake, the Largest Freshwater Lake in China

    PubMed Central

    Wang, Hua; Wu, Mengan; Deng, Yanqing; Tang, Chunyan; Yang, Rui

    2014-01-01

    In this paper, we propose a coupled method to optimize the surface water quality monitoring sites for a huge freshwater lake based on field investigations, mathematical analysis, and numerical simulation tests. Poyang Lake, the largest freshwater lake in China, was selected as the research area. Based on the field investigated water quality data in the 5 years from 2008 to 2012, the water quality inter-annual variation coefficients at all the present sites and the water quality correlation coefficients between adjacent sites were calculated and analyzed to present an optimization scheme. A 2-D unsteady water quality model was established to get the corresponding water quality data at the optimized monitoring sites, which were needed for the rationality test on the optimized monitoring network. We found that: (1) the water quality of Piaoshan (No. 10) fluctuated most distinguishably and the inter-annual variation coefficient of NH3-N and TP could reach 99.77% and 73.92%, respectively. The four studied indexes were all closely related at Piaoshan (No. 10) and Tangyin (No. 11), and the correlation coefficients of COD and NH3-N could reach 0.91 and 0.94 separately. (2) It was suggested that the present site No. 10 be removed to avoid repeatability, and it was suggested that the three sites of Changling, Huzhong, and Nanjiang be added to improve the representativeness of the monitoring sites. (3) According to the rationality analysis, the 21 optimized water quality monitoring sites could scientifically replace the primary network, and the new monitoring network could better reflect the water quality of the whole lake. PMID:25407419

  11. Can Species Distribution Models Aid Bioassessment when Reference Sites are Lacking? Tests Based on Freshwater Fishes

    NASA Astrophysics Data System (ADS)

    Labay, Ben J.; Hendrickson, Dean A.; Cohen, Adam E.; Bonner, Timothy H.; King, Ryan S.; Kleinsasser, Leroy J.; Linam, Gordon W.; Winemiller, Kirk O.

    2015-10-01

    Recent literature reviews of bioassessment methods raise questions about use of least-impacted reference sites to characterize natural conditions that no longer exist within contemporary landscapes. We explore an alternate approach for bioassessment that uses species site occupancy data from museum archives as input for species distribution models (SDMs) stacked to predict species assemblages of freshwater fishes in Texas. When data for estimating reference conditions are lacking, deviation between richness of contemporary versus modeled species assemblages could provide a means to infer relative biological integrity at appropriate spatial scales. We constructed SDMs for 100 freshwater fish species to compare predicted species assemblages to data on contemporary assemblages acquired by four independent surveys that sampled 269 sites. We then compared site-specific observed/predicted ratios of the number of species at sites to scores from a multimetric index of biotic integrity (IBI). Predicted numbers of species were moderately to strongly correlated with the numbers observed by the four surveys. We found significant, though weak, relationships between observed/predicted ratios and IBI scores. SDM-based assessments identified patterns of local assemblage change that were congruent with IBI inferences; however, modeling artifacts that likely contributed to over-prediction of species presence may restrict the stand-alone use of SDM-derived patterns for bioassessment and therefore warrant examination. Our results suggest that when extensive standardized survey data that include reference sites are lacking, as is commonly the case, SDMs derived from generally much more readily available species site occupancy data could be used to provide a complementary tool for bioassessment.

  12. Estimating the global oceanic net freshwater flux from Argo and comparing it with satellite-based freshwater flux products

    NASA Astrophysics Data System (ADS)

    Ren, Li; Hackert, Eric; Arkin, Phillip; Busalacchi, Antonio J.

    2014-11-01

    Following the idea that analysis of in situ information in the salt budget could be used as a surrogate for global "ocean rain gauge," the annual mean oceanic net freshwater flux (E-P) was estimated from the Argo profiles and the wind stress data on a global scale. The comparison between the independent E-P estimation from Argo and the E-P product sets, including the combination of precipitation from TRMM, GPCP, CMAP and evaporation from OAFlux, GSSTF3 and IFREMER and E-P set from NEWS formed from satellite, generally show similar spatial patterns, particularly on the large scale. However, there are differences among the different satellite-based E-P estimates and between satellite estimates and independent in situ estimates. Based on the pattern correlation and the RMSD, the evaporation and precipitation from OAFlux and TRMM agrees best with the E-P estimated from the independent Argo-based estimates.

  13. Production of enzymatic protein hydrolysates from freshwater catfish (Clarias batrachus)

    NASA Astrophysics Data System (ADS)

    Seniman, Maizatul Sarah Md; Yusop, Salma Mohamad; Babji, Abdul Salam

    2014-09-01

    Fish protein hydrolysate (FPH) was prepared from freshwater catfish (Clarias batrachus) by using Alcalase® 2.4L and Papain. The effect of hydrolysis time (30, 60, 120, 180 min) with enzyme concentration of 1% (v/w substrate); pH = 8.0, 7.0 was studied to determine the degree of hydrolysis (DH), peptide content, proximate composition and amino acid profile. Results showed that the highest DH of Alcalase and Papain FPH were 58.79% and 53.48% after 180 min at 55°C incubation respectively. The peptide content of both FPH increased as hydrolysis time increases. FPH showed higher crude protein content and lower fat, moisture and ash content compared to raw catfish. The major amino acids of both hydrolysates were Glu, Lys and Asp. Content of essential amino acids of Alcalase and Papain hydrolysates were 44.05% and 43.31% respectively.

  14. SUNLIGHT AND IRON(III)-INDUCED PHOTOCHEMICAL PRODUCTION OF DISSOLVED GASEOUS MERCURY IN FRESHWATER. (R827632)

    EPA Science Inventory

    Mechanistic understanding of sunlight-induced natural processes for
    production of dissolved gaseous mercury (DGM) in freshwaters has remained
    limited, and few direct field tests of the mechanistic hypotheses are available.
    We exposed ferric iron salt-spiked fresh s...

  15. Freshwater Biological Traits Database (Final Report)

    EPA Science Inventory

    sites/production/files/2015-07/traits_cover.jpg" vspace = "5" hspace="5" align="right" border="2" alt="Cover of the Freshwater Biological Traits Database Final Report"> This final report discusses the development of a database of freshwater biolo...

  16. Comparison of Freshwater Diatom Assemblages from a High Arctic Oasis to Nearby Polar Desert Sites and Their Application to Environmental Inference Models.

    PubMed

    Michelutti, Neal; McCleary, Kathryn; Douglas, Marianne S V; Smol, John P

    2013-02-01

    Arctic oases are regions of atypical warmth and relatively high biological production and diversity. They are small in area (<5 km(2) ) and uncommon in occurrence, yet they are relatively well studied due to the abundance of plant and animal life contained within them. A notable exception is the lack of research on freshwater ecosystems within polar oases. Here, we aim to increase our understanding of freshwater diatom ecology in polar oases. Diatoms were identified and enumerated from modern sediments collected in 23 lakes and ponds contained within the Lake Hazen oasis on Ellesmere Island, and compared with diatom assemblages from 29 sites located outside of the oasis across the northern portion of the island. There were significant differences in water chemistry variables between oasis and northern sites, with oasis sites having higher conductivity and greater concentrations of nutrients and related variables such as dissolved organic carbon (DOC). Taxa across all sites were typical of those recorded in Arctic freshwaters, with species from the genera Achnanthes sensu lato, Fragilaria sensu lato, and Nitzschia dominating the assemblages. A correspondence analysis (CA) ordination showed that oasis sites generally plotted separately from the northern sites, although the sites also appear to plot separately based on whether they were lakes or ponds. Canonical correspondence analysis (CCA) identified specific conductivity, DOC, and SiO2 as explaining significant (P < 0.05) and additional amounts of variation in the diatom data set. The most robust diatom-based inference model was generated for DOC, which will provide useful reconstructions on long-term changes in paleo-optics of high Arctic lakes. PMID:27008387

  17. A GIS cost model to assess the availability of freshwater, seawater, and saline groundwater for algal biofuel production in the United States.

    PubMed

    Venteris, Erik R; Skaggs, Richard L; Coleman, Andre M; Wigmosta, Mark S

    2013-05-01

    A key advantage of using microalgae for biofuel production is the ability of some algal strains to thrive in waters unsuitable for conventional crop irrigation such as saline groundwater or seawater. Nonetheless, the availability of sustainable water supplies will provide significant challenges for scale-up and development of algal biofuels. We conduct a partial techno-economic assessment based on the availability of freshwater, saline groundwater, and seawater for use in open pond algae cultivation systems. We explore water issues through GIS-based models of algae biofuel production, freshwater supply (constrained to less than 5% of mean annual flow per watershed) and costs, and cost-distance models for supplying seawater and saline groundwater. We estimate that, combined, these resources can support 9.46 × 10(7) m(3) yr(-1) (25 billion gallons yr(-1)) of renewable biodiesel production in the coterminous United States. Achievement of larger targets requires the utilization of less water efficient sites and relatively expensive saline waters. Despite the addition of freshwater supply constraints and saline water resources, the geographic conclusions are similar to our previous results. Freshwater availability and saline water delivery costs are most favorable for the coast of the Gulf of Mexico and Florida peninsula, where evaporation relative to precipitation is moderate. As a whole, the barren and scrub lands of the southwestern U.S. have limited freshwater supplies, and large net evaporation rates greatly increase the cost of saline alternatives due to the added makeup water required to maintain pond salinity. However, this and similar analyses are particularly sensitive to knowledge gaps in algae growth/lipid production performance and the proportion of freshwater resources available, key topics for future investigation. PMID:23495893

  18. Mist eliminators for freshwater production from open-cycle OTEC systems

    SciTech Connect

    Bharathan, D.; Penney, T.

    1983-12-01

    For freshwater production from open-cycle OTEC systems, the suitability of commercially available mist eliminators is examined. The mist eliminators are characterized in terms of their liquid collection efficiencies, allowable vapor velocities at the onset of reentrainment, and pressure losses. Suitable design modifications can be projected to allow steam velocities of up to 35 m/s, with a corresponding parasitic power loss of less than 5% of the gross potential of an open-cycle OTEC power system.

  19. Bacterial production of free fatty acids from freshwater macroalgal cellulose

    PubMed Central

    Hoovers, Spencer W.; Marner, Wesley D.; Brownson, Amy K.; Lennen, Rebecca M.; Wittkopp, Tyler M.; Yoshitani, Jun; Zulkifly, Shahrizim; Graham, Linda E.; Chaston, Sheena D.; McMahon, Katherine D.

    2013-01-01

    The predominant strategy for using algae to produce biofuels relies on the overproduction of lipids in microalgae with subsequent conversion to biodiesel (methyl-esters) or green diesel (alkanes). Conditions that both optimize algal growth and lipid accumulation rarely overlap, and differences in growth rates can lead to wild species outcompeting the desired lipid-rich strains. Here, we demonstrate an alternative strategy in which cellulose contained in the cell walls of multicellular algae is used as a feedstock for cultivating biofuel-producing micro-organisms. Cellulose was extracted from an environmental sample of Cladophora glomerata-dominated periphyton that was collected from Lake Mendota, WI, USA. The resulting cellulose cake was hydrolyzed by commercial enzymes to release fermentable glucose. The hydrolysis mixture was used to formulate an undefined medium that was able to support the growth, without supplementation, of a free fatty acid (FFA)-overproducing strain of Escherichia coli (Lennen et. al 2010). To maximize free fatty acid production from glucose, an isopropyl β-D-1-thiogalactopyranoside (IPTG)-inducible vector was constructed to express the Umbellularia californica acyl–acyl carrier protein (ACP) thioesterase. Thioesterase expression was optimized by inducing cultures with 50 μM IPTG. Cell density and FFA titers from cultures grown on algae-based media reached 50% of those (~90 μg/mL FFA) cultures grown on rich Luria–Bertani broth supplemented with 0.2% glucose. In comparison, cultures grown in two media based on AFEX-pretreated corn stover generated tenfold less FFA than cultures grown in algae-based media. This study demonstrates that macroalgal cellulose is a potential carbon source for the production of biofuels or other microbially synthesized compounds. PMID:21643704

  20. Microchip-based terminal restriction fragment length polymorphism for on-site analysis of bacterial communities in freshwater.

    PubMed

    Yamaguchi, Nobuyasu; Matsukawa, Syuhei; Shintome, Yoko; Ichijo, Tomoaki; Nasu, Masao

    2013-01-01

    Assessing microbiological quality assurance by monitoring bacteria in various sources of freshwater used for human consumption, recreation, and food preparation is important for a healthy life. Bacterial number and their community structure in freshwater should be determined as quickly as possible, and "real-time" and "on-site" microbiological methods are required. In this study, we examined the protocol for microchip-based terminal restriction fragment length polymorphism (T-RFLP) analysis, which uses microchip electrophoresis for rapid microbial community analysis. The availability of microchip-based T-RFLP was compared with conventional T-RFLP analysis, which uses a capillary electrophoresis system, with freshwater samples (spring water, river water, groundwater, and hydroponics solution). The detection limit of targeted bacteria by on-chip T-RFLP analysis was 1% (10(3) cells/mL). The fragment sizes determined by the two analysis methods were highly correlated (r(2)=0.98). On-chip T-RFLP analysis was completed within 15 min. T-RFLP profiles of nine hydroponics solution samples were analyzed by multidimensional scaling. Considerable changes and stability in bacterial community structure during hydroponic culture were detected by both analyses. These results show that on-chip T-RFLP analysis can monitor changes in bacterial community structure, as well as conventional T-RFLP analysis. The present results indicate that on-chip T-RFLP analysis is an effective tool for rapid and "on-site" bacterial community profiling in freshwater environments, as well as freshwater used for medical and industrial purposes. PMID:23902975

  1. Extensive Dark Biological Production of Reactive Oxygen Species in Brackish and Freshwater Ponds.

    PubMed

    Zhang, Tong; Hansel, Colleen M; Voelker, Bettina M; Lamborg, Carl H

    2016-03-15

    Within natural waters, photodependent processes are generally considered the predominant source of reactive oxygen species (ROS), a suite of biogeochemically important molecules. However, recent discoveries of dark particle-associated ROS production in aquatic environments and extracellular ROS production by various microorganisms point to biological activity as a significant source of ROS in the absence of light. Thus, the objective of this study was to explore the occurrence of dark biological production of the ROS superoxide (O2(-)) and hydrogen peroxide (H2O2) in brackish and freshwater ponds. Here we show that the ROS superoxide and hydrogen peroxide were present in dark waters at comparable concentrations as in sunlit waters. This suggests that, at least for the short-lived superoxide species, light-independent processes were an important control on ROS levels in these natural waters. Indeed, we demonstrated that dark biological production of ROS extensively occurred in brackish and freshwater environments, with greater dark ROS production rates generally observed in the aphotic relative to the photic zone. Filtering and formaldehyde inhibition confirmed the biological nature of a majority of this dark ROS production, which likely involved phytoplankton, particle-associated heterotrophic bacteria, and NADH-oxidizing enzymes. We conclude that biological ROS production is widespread, including regions devoid of light, thereby expanding the relevance of these reactive molecules to all regions of our oxygenated global habit. PMID:26854358

  2. Increasing pressure on freshwater resources due to terrestrial feed ingredients for aquaculture production.

    PubMed

    Pahlow, M; van Oel, P R; Mekonnen, M M; Hoekstra, A Y

    2015-12-01

    As aquaculture becomes more important for feeding the growing world population, so too do the required natural resources needed to produce aquaculture feed. While there is potential to replace fish meal and fish oil with terrestrial feed ingredients, it is important to understand both the positive and negative implications of such a development. The use of feed with a large proportion of terrestrial feed may reduce the pressure on fisheries to provide feed for fish, but at the same time it may significantly increase the pressure on freshwater resources, due to water consumption and pollution in crop production for aquafeed. Here the green, blue and gray water footprint of cultured fish and crustaceans related to the production of commercial feed for the year 2008 has been determined for the major farmed species, representing 88% of total fed production. The green, blue and gray production-weighted average feed water footprints of fish and crustaceans fed commercial aquafeed are estimated at 1629 m3/t, 179 m3/t and 166 m3/t, respectively. The estimated global total water footprint of commercial aquafeed was 31-35 km3 in 2008. The top five contributors to the total water footprint of commercial feed are Nile tilapia, Grass carp, Whiteleg shrimp, Common carp and Atlantic salmon, which together have a water footprint of 18.2 km3. An analysis of alternative diets revealed that the replacement of fish meal and fish oil with terrestrial feed ingredients may further increase pressure on freshwater resources. At the same time economic consumptive water productivity may be reduced, especially for carnivorous species. The results of the present study show that, for the aquaculture sector to grow sustainably, freshwater consumption and pollution due to aquafeed need to be taken into account. PMID:26258557

  3. Screening of freshwater and seawater microalgae strains in fully controlled photobioreactors for biodiesel production.

    PubMed

    Taleb, A; Kandilian, R; Touchard, R; Montalescot, V; Rinaldi, T; Taha, S; Takache, H; Marchal, L; Legrand, J; Pruvost, J

    2016-10-01

    Strain selection is one of the primary hurdles facing cost-effective microalgal biodiesel production. Indeed, the strain used affects both upstream and downstream biodiesel production processes. This study presents a screening procedure that considers the most significant criteria in microalgal biodiesel production including TAG production and wet extraction and recovery of TAGs. Fourteen freshwater and seawater strains were investigated. Large variation was observed between the strains in all the screening criteria. The overall screening procedure ultimately led to the identification of Parachlorella kessleri UTEX2229 and Nannochloropsis gaditana CCMP527 as the best freshwater and seawater strains, respectively. They featured the largest areal TAG productivity equal to 2.7×10(-3) and 2.3×10(-3)kgm(-2)d(-1), respectively. These two strains also displayed encouraging cell fragility in a high pressure bead milling process with 69% and 98% cell disruption at 1750bar making them remarkable strains for TAG extraction in wet environment. PMID:27394994

  4. Planning for Production of Freshwater Fish Fry in a Variable Climate in Northern Thailand

    NASA Astrophysics Data System (ADS)

    Uppanunchai, Anuwat; Apirumanekul, Chusit; Lebel, Louis

    2015-10-01

    Provision of adequate numbers of quality fish fry is often a key constraint on aquaculture development. The management of climate-related risks in hatchery and nursery management operations has not received much attention, but is likely to be a key element of successful adaptation to climate change in the aquaculture sector. This study explored the sensitivities and vulnerability of freshwater fish fry production in 15 government hatcheries across Northern Thailand to climate variability and evaluated the robustness of the proposed adaptation measures. This study found that hatcheries have to consider several factors when planning production, including: taking into account farmer demand; production capacity of the hatchery; availability of water resources; local climate and other area factors; and, individual species requirements. Nile tilapia is the most commonly cultured species of freshwater fish. Most fry production is done in the wet season, as cold spells and drought conditions disrupt hatchery production and reduce fish farm demand in the dry season. In the wet season, some hatcheries are impacted by floods. Using a set of scenarios to capture major uncertainties and variability in climate, this study suggests a couple of strategies that should help make hatchery operations more climate change resilient, in particular: improving hatchery operations and management to deal better with risks under current climate variability; improving monitoring and information systems so that emerging climate-related risks are known sooner and understood better; and, research and development on alternative species, breeding programs, improving water management and other features of hatchery operations.

  5. Planning for Production of Freshwater Fish Fry in a Variable Climate in Northern Thailand.

    PubMed

    Uppanunchai, Anuwat; Apirumanekul, Chusit; Lebel, Louis

    2015-10-01

    Provision of adequate numbers of quality fish fry is often a key constraint on aquaculture development. The management of climate-related risks in hatchery and nursery management operations has not received much attention, but is likely to be a key element of successful adaptation to climate change in the aquaculture sector. This study explored the sensitivities and vulnerability of freshwater fish fry production in 15 government hatcheries across Northern Thailand to climate variability and evaluated the robustness of the proposed adaptation measures. This study found that hatcheries have to consider several factors when planning production, including: taking into account farmer demand; production capacity of the hatchery; availability of water resources; local climate and other area factors; and, individual species requirements. Nile tilapia is the most commonly cultured species of freshwater fish. Most fry production is done in the wet season, as cold spells and drought conditions disrupt hatchery production and reduce fish farm demand in the dry season. In the wet season, some hatcheries are impacted by floods. Using a set of scenarios to capture major uncertainties and variability in climate, this study suggests a couple of strategies that should help make hatchery operations more climate change resilient, in particular: improving hatchery operations and management to deal better with risks under current climate variability; improving monitoring and information systems so that emerging climate-related risks are known sooner and understood better; and, research and development on alternative species, breeding programs, improving water management and other features of hatchery operations. PMID:26105968

  6. Associations between freshwater inflows and oyster productivity in Apalachicola Bay, Florida

    NASA Astrophysics Data System (ADS)

    Wilber, Dara H.

    1992-08-01

    Increased and varied demands for consumptive water uses on the Apalachicola-Chattahoochee-Flint River system threaten to reduce freshwater inflows to the Apalachicola estuary and thus may affect estuarine productivity. To investigate how freshwater inflows are associated with productive estuarine conditions, Apalachicola Bay oyster data from 1960-84 and river flows were analysed with linear regression models. Lag periods were incorporated into the analyses to examine the potential effects of various flow magnitudes and durations on different oyster life history stage. Oysters reach a harvestable size in 2 years in this region. Low flows were positively correlated with oyster catch per unit effort (C.P.U.E.) 2 years later, i.e. years with lower minimum flows were followed 2 years later by poor oyster productivity. A possible mechanism behind this association is that lower minimum flows result in higher estuarine salinities, permitting predation by marine species on newly settled spat, and thus reducing harvestable oyster population sizes 2 years later. High flows of short duration (⩽ 30 days) were not significantly correlated with oyster C.P.U.E. for the same year or any time lag period. Oyster landings were low, however, in those years in which flows exceeded 30 000 cfs for 100 days or more, suggesting sustained high flows were detrimental to the same year's harvestable oyster population. Experiments that investigate possible mechanistic causes of these associations are needed to more fully understand the potential impacts of future water allocation decisions.

  7. A GIS COST MODEL TO ASSESS THE AVAILABILITY OF FRESHWATER, SEAWATER, AND SALINE GROUNDWATER FOR ALGAL BIOFUEL PRODUCTION IN THE UNITED STATES

    SciTech Connect

    Venteris, Erik R.; Skaggs, Richard; Coleman, Andre M.; Wigmosta, Mark S.

    2013-03-15

    A key advantage of using microalgae for biofuel production is the ability of some algal strains to thrive in waters unsuitable for conventional crop irrigation such as saline groundwater or seawater. Nonetheless, the availability of sustainable water supplies will provide significant challenges for scale-up and development of algal biofuels. We conduct a limited techno-economic assessment based on the availability of freshwater, saline groundwater, and seawater for use in open pond algae cultivation systems. We explore water issues through GIS-based models of algae biofuel production, freshwater supply, and cost models for supplying seawater and saline groundwater. We estimate that combined, within the coterminous US these resources can support production on the order of 9.46E+7 m3 yr-1 (25 billion gallons yr-1) of renewable biodiesel. Achievement of larger targets requires the utilization of less water efficient sites and relatively expensive saline waters. Geographically, water availability is most favorable for the coast of the Gulf of Mexico and Florida peninsula, where evaporation relative to precipitation is moderate and various saline waters are economically available. As a whole, barren and scrub lands of the southwestern US have limited freshwater supplies so accurate assessment of alternative waters is critical.

  8. Calculation of cell production from ( sup 3 H)Thymidine incorporation with freshwater bacteria

    SciTech Connect

    Smits, J.D. ); Riemann, B. )

    1988-09-01

    The conversion factor for the calculation of bacterial production from rates of ({sup 3}H)thymidine incorporation was examined with diluted batch cultures of freshwater bacteria. Natural bacterial assemblages were grown in aged, normal, and enriched media at 10 to 20{degree}C. The generation time during 101 growth cycles covered a range from 4 to >200 h. The average conversion factor was 2.15 {times} 10{sup 18} cells mol{sup {minus}1} of thymidine incorporated into the trichloroacetic acid (TCA) precipitate, when the generation time exceeded 20 h. At generation times of <20 h, the average conversion factor was 11.8 {times} 10{sup 18} cells mol{sup {minus}1} of thymidine incorporated into TCA precipitate. The amount of radioactivity in purified DNA increased with decreasing generation time and increasing conversion factor (calculated from the TCA precipitate), corresponding to a decrease in the percentage in protein. The conversion factors calculated from purified DNA or from the TCA precipitate gave the same variability. Conversion factors did not change significantly with the medium, but were significantly higher at 20{degree}C that at 15 and 10{degree}C. Results suggests that incorporation of ({sup 3}H)thymidine into DNA is probably limited by uptake during period with generation times of <20 h and that freshwater bacterioplankton cell production sometimes is underestimated when a conversion factor of 2.15 {times} 10{sup 18} cells mol{sup {minus}1} of thymidine incorporated is used.

  9. Freshwater macroinvertebrates

    SciTech Connect

    Quigley, M.A.

    1982-06-01

    Major aspects of the biology of freshwater macroinvertebrates with emphasis on man-induced environmental changes were reviewed in this report with 183 references. The effects of both chemical and physical environmental alteration are examined. The population dynamics of the macroinvertebrates are controlled by factors such as food and feeding habits, periodicity and drift, productivity and animal-sediment interactions.(KRM)

  10. Primary production in the Chukchi Sea with potential effects of freshwater content

    NASA Astrophysics Data System (ADS)

    Yun, M. S.; Whitledge, T. E.; Stockwell, D.; Son, S. H.; Lee, J. H.; Park, J. W.; Lee, D. B.; Park, J.; Lee, S. H.

    2016-02-01

    The in situ primary production rates and various environmental variables were investigated in the Chukchi Sea during the RUSALCA expedition, which was conducted in 2012, to identify the current status of primary production. A 13C-15N dual-tracer technique was used to measure the daily primary production rates, which ranged from 0.02 to 1.61 g C m-2 d-1 (mean ±SD = 0.42 ± 0.52 g C m-2 d-1). The primary production rates showed large regional differences, with the southern region (0.66 ± 0.62 g C m-2 d-1) producing approximately 5 times as much as the northern region (0.14 ± 0.10 g C m-2 d-1), which was primarily due to the differences in phytoplankton biomasses induced by regional nutrient conditions. The primary production rates in the Chukchi Sea were averaged using data acquired during the three different RUSALCA expeditions (2004, 2009, and 2012) as 0.33 g C m-2 d-1 (SD = 0.40 g C m-2 d-1), which was significantly lower than previously reported rates. In addition to strong seasonal and interannual variations in primary production, recent decreases in the concentrations of major inorganic nutrients and chlorophyll a could be among the reasons for the recent low primary production in the Chukchi Sea because the primary production is mainly affected by nutrient concentration and phytoplankton biomass. The nutrient inventory and primary production appear to be largely influenced by the freshwater content (FWC) variability in the region due to the significant relationships between FWC, nitrate inventory (r = 0.54, p < 0.05), and primary production rates (r = 0.56, p < 0.05). Moreover, we found highly significant relationships between the nutrient inventory and the primary production rates (r = 0.75, p < 0.001). In conclusion, the primary production in the Chukchi Sea is primarily controlled by nutrient availability, which is strongly related to the FWC variability. Our results imply that the predicted increase in freshwater accumulation might cause a

  11. Subsurface storage of freshwater in south Florida; evaluation of surface-water discharge data at selected sites

    USGS Publications Warehouse

    Sonntag, W.H.

    1984-01-01

    Canal discharge in south Florida may consist of a potential source of freshwater for deep-well injection. Discharge data for the 1970-81 water years at 27 canal and river sites were analyzed. Flow was analyzed for 30-, 60-, 90-, 120-, and 183-consecutive-day low-mean discharges during the periods of highest flow to define minimum high-flow-period fresh surface-water discharges at the 27 sites. Curves show the magnitude and frequency of average minimum flows for consecutive-day periods during high-flow periods, and duration curves and tables show the percentage of time that selected discharges were equaled or exceeded. Canal discharge as high as 660 cubic feet per second occurred 70 percent of the time during the high-flow period at one site (Tamiami Canal Outlets, Levee 67A to 40-Mile Bend). At 11 sites, discharges of 110 to 370 cubic feet per second occurred 70 percent of the high-flow periods, while at 9 sites, discharges of 21 to 100 cubic feet per second occurred 70 percent of the time during the high-flow periods. At other sites (those in the Biscayne, Plantation Road, Middle River, C-111, and Cypress Creek Canals), discharges as low as 0.1 cubic foot per second occurred 70 percent of the time during the high-flow periods. Criteria for amounts of surplus freshwater considered adequate to support injection systems cannot be established, as they would vary greatly with water needs to be satisfied and with the efficiency of a particular injection system. However, based upon this analysis of discharge at 27 canal and river sites throughout south Florida, it appears that substantial amounts of water are available for surface injection and storage. (USGS)

  12. Screening factors influencing the production of astaxanthin from freshwater and marine microalgae.

    PubMed

    Binti Ibnu Rasid, Elda Nurafnie; Mohamad, Shaza Eva; Jamaluddin, Haryati; Salleh, Madihah Md

    2014-02-01

    Astaxanthin, a carotenoid pigment found in several aquatic organisms, is responsible for the red colour of salmon, trout and crustaceans. In this study, astaxanthin production from freshwater microalga Chlorella sorokiniana and marine microalga Tetraselmis sp. was investigated. Cell growth and astaxanthin production were determined spectrophotometrically at 620 and 480 nm, respectively. Astaxanthin was extracted using acetone and measured subsequent to biomass removal. Aerated conditions favoured astaxanthin production in C. sorokiniana, whereas Tetraselmis sp. was best cultured under unaerated conditions. C. sorokiniana produced more astaxanthin with the highest yield reached at 7.83 mg/l in 6.0 mM in nitrate containing medium compared to Tetraselmis sp. which recorded the highest yield of only 1.96 mg/l in 1.5 mM nitrate containing medium. Production in C. sorokiniana started at the early exponential phase, indicating that astaxanthin may be a growth-associated product in this microalga. Further optimization of astaxanthin production was performed using C. sorokiniana through a 2(3) full factorial experimental design, and a yield of 8.39 mg/l was achieved. Overall, the study has shown that both microalgae are capable of producing astaxanthin. Additionally, this research has highlighted C. sorokiniana as a potential astaxanthin producer that could serve as a natural astaxanthin source in the current market. PMID:24338298

  13. Climate warming reduces fish production and benthic habitat in Lake Tanganyika, one of the most biodiverse freshwater ecosystems.

    PubMed

    Cohen, Andrew S; Gergurich, Elizabeth L; Kraemer, Benjamin M; McGlue, Michael M; McIntyre, Peter B; Russell, James M; Simmons, Jack D; Swarzenski, Peter W

    2016-08-23

    Warming climates are rapidly transforming lake ecosystems worldwide, but the breadth of changes in tropical lakes is poorly documented. Sustainable management of freshwater fisheries and biodiversity requires accounting for historical and ongoing stressors such as climate change and harvest intensity. This is problematic in tropical Africa, where records of ecosystem change are limited and local populations rely heavily on lakes for nutrition. Here, using a ∼1,500-y paleoecological record, we show that declines in fishery species and endemic molluscs began well before commercial fishing in Lake Tanganyika, Africa's deepest and oldest lake. Paleoclimate and instrumental records demonstrate sustained warming in this lake during the last ∼150 y, which affects biota by strengthening and shallowing stratification of the water column. Reductions in lake mixing have depressed algal production and shrunk the oxygenated benthic habitat by 38% in our study areas, yielding fish and mollusc declines. Late-20th century fish fossil abundances at two of three sites were lower than at any other time in the last millennium and fell in concert with reduced diatom abundance and warming water. A negative correlation between lake temperature and fish and mollusc fossils over the last ∼500 y indicates that climate warming and intensifying stratification have almost certainly reduced potential fishery production, helping to explain ongoing declines in fish catches. Long-term declines of both benthic and pelagic species underscore the urgency of strategic efforts to sustain Lake Tanganyika's extraordinary biodiversity and ecosystem services. PMID:27503877

  14. The Skogaryd Research Site - Integration of terrestrial and freshwater greenhouse gas sources and sinks

    NASA Astrophysics Data System (ADS)

    Klemedtsson, L.

    2012-04-01

    Forests play an important role in the global carbon (C) cycle, and management as well as climate can cause major effects on the balance of C between the atmosphere and the plant/soil system. With regard to our commitments to the Kyoto and post-Kyoto actions on climate change, we need reliable predictions on how this balance is affected by management and climate. In 2006 the Skogaryd Research Forest was established in the southwest of Sweden (58°23'N, 12°09'E). The overall goal is to quantify net greenhouse gas (GHG) fluxes from drained spruce forest soils, by determining the individual fluxes and pools of C and nitrogen and elucidating their connection to site fertility, drainage status and abiotic parameters. The generated data will be used in GHG models, for model validations and ultimately emissions predictions. During 2006-2009 the research has focused on two sites, mineral and organic soils, both dominated by Norway spruce (Picea abies). Both sites are drained fertile soils but with different land-use history that have affected their physical properties. Measurements include: net ecosystem exchange of CO2, shoot photosynthesis and respiration at different locations within the canopy, stem respiration, emissions of N2O and CH4 using manual chambers, soil respiration with automatic chambers including a trenching experiment where root, ectomycorrhizal, and heterotrophic respiration are separated, fine root production using minirhizotrons, and ectomycorrhizal mycelia production. The organic site also includes a wood ash fertilization experiment. From 2010 the research has been expanded by the project Landscape Greenhouse Gas Exchange (LAGGE) to the whole watershed, from the pristine mire system via streams, riparian zones, forests, to lakes and the subsequent exchange between the atmosphere and surface waters. The current accounting of forests as carbon sinks has relied on measurements of vertical carbon dioxide (CO2) exchange between vegetation and the

  15. Growth and photosynthetic response of a freshwater alga, Selenastrum capricornutum, to an oil shale by-product water

    SciTech Connect

    Delistraty, D.

    1986-01-01

    Several recent studies have focused on toxic effects of various oil shale waters to freshwater algae (e.g., Cleave et al. 1980; McKnight et al. 1983). Algal bioassays are ecologically significant, since algae are the dominant primary producers in most freshwater environments. Furthermore, algae have been shown to be more sensitive to complex wastes than fish or invertebrates. Using a standard algal species provides a systematic approach to toxicant evaluation. One such species is Selenastrum capricornutum Printz, a freshwater unicellular green alga. A strategy to assess the hazards of complex effluents should include a battery of rapid, easily conducted, predictive tests within the larger framework of tier testing. This approach is used in this study to compare the growth and photosynthetic response of S. capricornutum to an oil shale by-product water and its organophilic and hydrophilic subfractions.

  16. History of Hanford Site Defense Production (Brief)

    SciTech Connect

    GERBER, M S

    2001-02-01

    This paper acquaints the audience with the history of the Hanford Site, America's first full-scale defense plutonium production site. The paper includes the founding and basic operating history of the Hanford Site, including World War II construction and operations, three major postwar expansions (1947-55), the peak years of production (1956-63), production phase downs (1964-the present), a brief production spurt from 1984-86, the end of the Cold War, and the beginning of the waste cleanup mission. The paper also delineates historical waste practices and policies as they changed over the years at the Hanford Site, past efforts to chemically treat, ''fractionate,'' and/or immobilize Hanford's wastes, and resulting major waste legacies that remain today. This paper presents original, primary-source research into the waste history of the Hanford Site. Finally, the paper places the current Hanford Site waste remediation endeavors in the broad context of American and world history.

  17. Site Products. Performance Criteria, Interim.

    ERIC Educational Resources Information Center

    State Univ. Construction Fund, Albany, NY.

    Performance criteria for the physical facilities of universities are reviewed to establish an understanding of the principles, policies and requirements that form the basis for an organized approach to building and site planning, development, design and construction. Guidelines are given emphasizing the designer's responsibility to analyze the…

  18. THE INFLUENCE OF FRESHWATER RUNOFF ON BIOMASS, MORPHOMETRICS, AND PRODUCTION OF THALASSIA TESTUDINUM. (R827453)

    EPA Science Inventory

    Efforts to restore more natural freshwater flows in South Florida will impact Biscayne Bay. In order to evaluate possible effects of decreased freshwater discharge on the seagrass Thalassia testudinum, we determined the biomass, density, morphometrics (width, length, nu...

  19. On the relative roles of hydrology, salinity, temperature, and root productivity in controlling soil respiration from coastal swamps (freshwater)

    USGS Publications Warehouse

    Krauss, Ken W.; Whitbeck, Julie L.; Howard, Rebecca J.

    2012-01-01

    Background and aims Soil CO2 emissions can dominate gaseous carbon losses from forested wetlands (swamps), especially those positioned in coastal environments. Understanding the varied roles of hydroperiod, salinity, temperature, and root productivity on soil respiration is important in discerning how carbon balances may shift as freshwater swamps retreat inland with sea-level rise and salinity incursion, and convert to mixed communities with marsh plants. Methods We exposed soil mesocosms to combinations of permanent flooding, tide, and salinity, and tracked soil respiration over 2 1/2 growing seasons. We also related these measurements to rates from field sites along the lower Savannah River, Georgia, USA. Soil temperature and root productivity were assessed simultaneously for both experiments. Results Soil respiration from mesocosms (22.7-1678.2 mg CO2 m-2 h-1) differed significantly among treatments during four of the seven sampling intervals, where permanently flooded treatments contributed to low rates of soil respiration and tidally flooded treatments sometimes contributed to higher rates. Permanent flooding reduced the overall capacity for soil respiration as soils warmed. Salinity did reduce soil respiration at times in tidal treatments, indicating that salinity may affect the amount of CO2 respired with tide more strongly than under permanent flooding. However, soil respiration related greatest to root biomass (mesocosm) and standing root length (field); any stress reducing root productivity (incl. salinity and permanent flooding) therefore reduces soil respiration. Conclusions Overall, we hypothesized a stronger, direct role for salinity on soil respiration, and found that salinity effects were being masked by varied capacities for increases in respiration with soil warming as dictated by hydrology, and the indirect influence that salinity can have on plant productivity.

  20. Stress hormone levels in a freshwater turtle from sites differing in human activity.

    PubMed

    Polich, Rebecca L

    2016-01-01

    Glucocorticoids, such as corticosterone (CORT), commonly serve as a measure of stress levels in vertebrate populations. These hormones have been implicated in regulation of feeding behaviour, locomotor activity, body mass, lipid metabolism and other crucial behaviours and physiological processes. Thus, understanding how glucocorticoids fluctuate seasonally and in response to specific stressors can yield insight into organismal health and the overall health of populations. I compared circulating CORT concentrations between two similar populations of painted turtle, Chrysemys picta, which differed primarily in the level of exposure to human recreational activities. I measured basal CORT concentrations as well as the CORT stress response and did not find any substantive difference between the two populations. This similarity may indicate that painted turtles are not stressed by the presence of humans during the nesting season. The results of this study contribute to our understanding of CORT concentrations in freshwater reptiles, a group that is historically under-represented in studies of circulating hormone concentrations; specifically, studies that seek to use circulating concentrations of stress hormones, such as CORT, as a measure of the effect of human activities on wild populations. They also give insight into how these species as a whole may respond to human recreational activities during crucial life-history stages, such as the nesting season. Although there was no discernable difference between circulating CORT concentrations between the urban and rural populations studied, I did find a significant difference in circulating CORT concentrations between male and female C. picta. This important finding provides better understanding of the sex differences between male and female painted turtles and adds to our understanding of this species and other species of freshwater turtle. PMID:27293763

  1. Stress hormone levels in a freshwater turtle from sites differing in human activity

    PubMed Central

    Polich, Rebecca L.

    2016-01-01

    Glucocorticoids, such as corticosterone (CORT), commonly serve as a measure of stress levels in vertebrate populations. These hormones have been implicated in regulation of feeding behaviour, locomotor activity, body mass, lipid metabolism and other crucial behaviours and physiological processes. Thus, understanding how glucocorticoids fluctuate seasonally and in response to specific stressors can yield insight into organismal health and the overall health of populations. I compared circulating CORT concentrations between two similar populations of painted turtle, Chrysemys picta, which differed primarily in the level of exposure to human recreational activities. I measured basal CORT concentrations as well as the CORT stress response and did not find any substantive difference between the two populations. This similarity may indicate that painted turtles are not stressed by the presence of humans during the nesting season. The results of this study contribute to our understanding of CORT concentrations in freshwater reptiles, a group that is historically under-represented in studies of circulating hormone concentrations; specifically, studies that seek to use circulating concentrations of stress hormones, such as CORT, as a measure of the effect of human activities on wild populations. They also give insight into how these species as a whole may respond to human recreational activities during crucial life-history stages, such as the nesting season. Although there was no discernable difference between circulating CORT concentrations between the urban and rural populations studied, I did find a significant difference in circulating CORT concentrations between male and female C. picta. This important finding provides better understanding of the sex differences between male and female painted turtles and adds to our understanding of this species and other species of freshwater turtle. PMID:27293763

  2. Utilization of secondary-treated wastewater for the production of freshwater microalgae.

    PubMed

    Gómez-Serrano, C; Morales-Amaral, M M; Acién, F G; Escudero, R; Fernández-Sevilla, J M; Molina-Grima, E

    2015-08-01

    In this work, we studied the potential use of secondary-treated wastewater as nutrient source in the production of freshwater microalgae strains. Experiments were performed indoors in a semicontinuous mode, at 0.3 day(-1), simulating outdoor conditions. We demonstrated that all the tested strains can be produced by using only secondary-treated wastewater as the nutrient source. The utilization of secondary-treated wastewater imposes nutrient-limiting conditions, with maximal biomass productivity dropping to 0.5 g l(-1) day(-1) and modifies the biochemical composition of the biomass by increasing the amount of lipids and carbohydrates while reducing the biomass protein content. We measured fatty acid content and productivity of up to 25 %d.wt. and 110 mg l(-1) day(-1), respectively. We demonstrated that all the tested strains were capable of completely removing the nitrogen and phosphorus contained in the secondary-treated wastewater, and while the use of this effluent reduced the cells' photosynthetic efficiency, the nitrogen and phosphorus coefficient yield increased. Muriellopsis sp. and S. subpicatus were selected as the most promising strains for outdoor production using secondary-treated wastewater as the culture medium; this was not only because of their high productivity but also their photosynthetic efficiency, of up to 2.5 %, along with nutrient coefficient yields of up to 96 gbiomass gN (-1) and 166 gbiomass gP (-1). Coupling microalgae production processes to tertiary treatment in wastewater treatment plants make it possible to recover nutrients contained in the water and to produce valuable biomass, especially where nutrient removal is required prior to wastewater discharge. PMID:26036706

  3. Hydrogen production under salt stress conditions by a freshwater Rhodopseudomonas palustris strain.

    PubMed

    Adessi, Alessandra; Concato, Margherita; Sanchini, Andrea; Rossi, Federico; De Philippis, Roberto

    2016-03-01

    Hydrogen represents a possible alternative energy carrier to face the growing request for energy and the shortage of fossil fuels. Photofermentation for the production of H2 constitutes a promising way for integrating the production of energy with waste treatments. Many wastes are characterized by high salinity, and polluted seawater can as well be considered as a substrate. Moreover, the application of seawater for bacterial culturing is considered cost-effective. The aims of this study were to assess the capability of the metabolically versatile freshwater Rhodopseudomonas palustris 42OL of producing hydrogen on salt-containing substrates and to investigate its salt stress response strategy, never described before. R. palustris 42OL was able to produce hydrogen in media containing up to 3 % added salt concentration and to grow in media containing up to 4.5 % salinity without the addition of exogenous osmoprotectants. While the hydrogen production performances in absence of sea salts were higher than in their presence, there was no significant difference in performances between 1 and 2 % of added sea salts. Nitrogenase expression levels indicated that the enzyme was not directly inhibited during salt stress, but a regulation of its expression may have occurred in response to salt concentration increase. During cell growth and hydrogen production in the presence of salts, trehalose was accumulated as a compatible solute; it protected the enzymatic functionality against salt stress, thus allowing hydrogen production. The possibility of producing hydrogen on salt-containing substrates widens the range of wastes that can be efficiently used in production processes. PMID:26762392

  4. Effects of lead on growth, photosynthetic characteristics and production of reactive oxygen species of two freshwater green algae.

    PubMed

    Dao, Ly H T; Beardall, John

    2016-03-01

    In the natural environment, heavy metal contamination can occur as long-term pollution of sites or as pulses of pollutants from wastewater disposal. In this study two freshwater green algae, Chlorella sp. FleB1 and Scenedesmus YaA6, were isolated from lead-polluted water samples and the effects of 24 h vs 4 and 8 d exposure of cultures to lead on growth, photosynthetic physiology and production of reactive oxygen species (ROS) of these algae were investigated. In Chlorella sp. FleB1, there was agreement between lead impacts on chlorophyll content, photosynthesis and growth in most case. However, in Scenedesmus acutus YaA6 growth was inhibited at lower lead concentrations (0.03-0.87 × 10(-9) M), under which ROS, measured by 2',7' dichlorodihydrofluorescein diacetate fluorescence, were 4.5 fold higher than in controls but photosynthesis was not affected, implying that ROS had played a role in the growth inhibition that did not involve direct effects on photosynthesis. Effects of short-term (5 h, 24 h) vs long-term (4 d and 8 d) exposure to lead were also compared between the two algae. The results contribute to our understanding of the mechanisms of lead toxicity to algae. PMID:26774308

  5. Influence of water allocation and freshwater inflow on oyster production: a hydrodynamic-oyster population model for Galveston Bay, Texas, USA.

    PubMed

    Powell, Eric N; Klinck, John M; Hofmann, Eileen E; McManus, Margaret A

    2003-01-01

    A hydrodynamic-oyster population model was developed to assess the effect of changes in freshwater inflow on oyster populations in Galveston Bay, Texas, USA. The population model includes the effects of environmental conditions, predators, and the oyster parasite, Perkinsus marinus, on oyster populations. The hydrodynamic model includes the effects of wind stress, river runoff, tides, and oceanic exchange on the circulation of the bay. Simulations were run for low, mean, and high freshwater inflow conditions under the present (1993) hydrology and predicted hydrologies for 2024 and 2049 that include both changes in total freshwater inflow and diversions of freshwater from one primary drainage basin to another. Freshwater diversion to supply the Houston metropolitan area is predicted to negatively impact oyster production in Galveston Bay. Fecundity and larval survivorship both decline. Mortality from Perkinsus marinus increases, but to a lesser extent. A larger negative impact in 2049 relative to 2024 originates from the larger drop in fecundity under that hydrology. Changes in recruitment and mortality, resulting in lowered oyster abundance, occur because the bay volume available for mixing freshwater input from the San Jacinto and Buffalo Bayou drainage basins that drain metropolitan Houston is small in comparison to the volume of Trinity Bay that presently receives the bulk of the bay's freshwater inflow. A smaller volume for mixing results in salinities that decline more rapidly and to a greater extent under conditions of high freshwater discharge.Thus, the decline in oyster abundance results from a disequilibrium between geography and salinity brought about by freshwater diversion. Although the bay hydrology shifts, available hard substrate does not. The simulations stress the fact that it is not just the well-appreciated reduction in freshwater inflow that can result in decreased oyster production. Changing the location of freshwater inflow can also

  6. Site History and Edaphic Features Override the Influence of Plant Species on Microbial Communities in Restored Tidal Freshwater Wetlands

    PubMed Central

    Prasse, Christine E.; Baldwin, Andrew H.

    2015-01-01

    Restored wetland soils differ significantly in physical and chemical properties from their natural counterparts even when plant community compositions are similar, but effects of restoration on microbial community composition and function are not well understood. Here, we investigate plant-microbe relationships in restored and natural tidal freshwater wetlands from two subestuaries of the Chesapeake Bay. Soil samples were collected from the root zone of Typha latifolia, Phragmites australis, Peltandra virginica, and Lythrum salicaria. Soil microbial composition was assessed using 454 pyrosequencing, and genes representing bacteria, archaea, denitrification, methanogenesis, and methane oxidation were quantified. Our analysis revealed variation in some functional gene copy numbers between plant species within sites, but intersite comparisons did not reveal consistent plant-microbe trends. We observed more microbial variations between plant species in natural wetlands, where plants have been established for a long period of time. In the largest natural wetland site, sequences putatively matching methanogens accounted for ∼17% of all sequences, and the same wetland had the highest numbers of genes coding for methane coenzyme A reductase (mcrA). Sequences putatively matching aerobic methanotrophic bacteria and anaerobic methane-oxidizing archaea (ANME) were detected in all sites, suggesting that both aerobic and anaerobic methane oxidation are possible in these systems. Our data suggest that site history and edaphic features override the influence of plant species on microbial communities in restored wetlands. PMID:25769832

  7. Single-cell activity of freshwater aerobic anoxygenic phototrophic bacteria and their contribution to biomass production.

    PubMed

    Garcia-Chaves, Maria C; Cottrell, Matthew T; Kirchman, David L; Ruiz-González, Clara; Del Giorgio, Paul A

    2016-07-01

    Aerobic anoxygenic phototrophic (AAP) bacteria are photoheterotrophs that despite their low abundances have been hypothesized to play an ecologically and biogeochemically important role in aquatic systems. Characterizing this role requires a better understanding of the in situ dynamics and activity of AAP bacteria. Here we provide the first assessment of the single-cell activity of freshwater AAP bacteria and their contribution to total bacterial production across lakes spanning a wide trophic gradient, and explore the role of light in regulating AAP activity. The proportion of cells that were active in leucine incorporation and the level of activity per cell were consistently higher for AAP than for bulk bacteria across lakes. As a result, AAP bacteria contributed disproportionately more to total bacterial production than to total bacterial abundance. Interestingly, although environmentally driven patterns in activity did not seem to differ largely between AAP and bulk bacteria, their response to light did, and exposure to light resulted in increases in the proportion of active AAP bacteria with no clear effect on their cell-specific activity. This suggests that light may play a role in the activation of AAP bacteria, enabling these photoheterotrophs to contribute more to the carbon cycle than suggested by their abundance. PMID:26771928

  8. Effect of stocking density on extensive production of freshwater shrimp in coal mine reclamation ponds

    SciTech Connect

    Tidwell, J.H.; Wynne, F.; Coyle, S.D.; Grey, B.; McGuire, J.

    1998-12-31

    The use of post-mining reclamation ponds for the production of freshwater shrimp was evaluated by examining different stocking densities. Juvenile shrimp (Macrobrachium rosenbergii) averaging 0.5g each were stocked into four existing ponds at Peabody`s Ken Surface Mine at 6,175; 12,350; 18,500; and 24,700/ha (2,500, 5,000, 7,500, and 10,000/acre) on June 1, 1995. Shrimp were fed twice a week for 103 days, with harvest conducted September 13, 1995. Survival averaged 40%, overall. Average individual weight size was inversely related to stocking density ranging from 52 g (8.7 shrimp/lb) at 6,175/ha to 20.3 g (22.7 shrimp/lb) at 18,500/acre. Total production was directly related to stocking density ranging from 97 kg/ha (86 lbs/acre) at low density to 211 kg/ha (188 lbs/acre) at 18,500/ha shrimp acre. The major difficulty was at harvest due to difficulty in draining ponds. Construction of designed culture ponds with gravity drains during reclamation could greatly enhance survival, harvestability, and commercial feasibility.

  9. Biodegradation of trichloroethylene and its anaerobic daughter products in freshwater wetland sediments

    USGS Publications Warehouse

    Lorah, M.M.; Olsen, L.D.

    2001-01-01

    Laboratory microcosms were prepared under methanogenic, sulfate-reducing, and aerobic conditions using sediment and groundwater from a freshwater wetland that is a discharge area for a trichloroethylene (TCE) to evaluate potential biodegradation rates of TCE and its anaerobic daughter products (cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, and vinyl chloride (VC)). Anaerobic degradation of TCE was about an order of magnitude faster under methanogenic conditions than under sulfate-reducing conditions. Both 12DCE and VC were found under sulfate-reducing conditions in the microcosms containing the wetland sediment, but their production, especially for VC, was substantially slower than under methanogenic conditions. Methane concentrations remained approximately constant (when losses in the formalin-amended controls are considered) in the microcosms amended with TCE and increased in the microcosms amended with the 12DCE isomers and VC during the first 18-25 days of incubation. The most rapid decrease in concentrations of TCE, cis-12DCE, trans-12DCE, and VC was found after aerobic methane-oxidizing conditions were definitely established.

  10. Freshwater wetlands and wildlife

    SciTech Connect

    Sharitz, R.R.; Gibbons, J.W.

    1989-01-01

    This volume is a product of the Freshwater Wetlands and Wildlife symposium held in Charleston, South Carolina, on March 24--27, 1986 and contains 94 papers. The stimulus for the symposium came from our interest in augmenting the findings of the long-term research programs on freshwater wetlands and wildlife that have been carried out on the US Department of Energy's Savannah River Site in South Carolina. The symposium provided a forum on an international scale for the exchange of data about freshwater ecosystems: their functions, uses, and their future. The papers in this volume address issues related to natural, man-managed, and degraded ecosystems. The volume is divided into two sections. The first section deals with the functions and values of wetlands, including their use as habitat for plants and animals, their role in trophic dynamics, and their basic processes. The second section treats the subject of their status and management, including techniques for assessing their value, laws for protecting them, and plans for properly managing them. Individual papers will be indexed and entered separately on the energy data base.

  11. Climatic variability, hydrologic anomaly, and methane emission can turn productive freshwater marshes into net carbon sources.

    PubMed

    Chu, Housen; Gottgens, Johan F; Chen, Jiquan; Sun, Ge; Desai, Ankur R; Ouyang, Zutao; Shao, Changliang; Czajkowski, Kevin

    2015-03-01

    Freshwater marshes are well-known for their ecological functions in carbon sequestration, but complete carbon budgets that include both methane (CH4 ) and lateral carbon fluxes for these ecosystems are rarely available. To the best of our knowledge, this is the first full carbon balance for a freshwater marsh where vertical gaseous [carbon dioxide (CO2 ) and CH4 ] and lateral hydrologic fluxes (dissolved and particulate organic carbon) have been simultaneously measured for multiple years (2011-2013). Carbon accumulation in the sediments suggested that the marsh was a long-term carbon sink and accumulated ~96.9 ± 10.3 (±95% CI) g C m(-2)  yr(-1) during the last ~50 years. However, abnormal climate conditions in the last 3 years turned the marsh to a source of carbon (42.7 ± 23.4 g C m(-2)  yr(-1) ). Gross ecosystem production and ecosystem respiration were the two largest fluxes in the annual carbon budget. Yet, these two fluxes compensated each other to a large extent and led to the marsh being a CO2 sink in 2011 (-78.8 ± 33.6 g C m(-2)  yr(-1) ), near CO2 -neutral in 2012 (29.7 ± 37.2 g C m(-2)  yr(-1) ), and a CO2 source in 2013 (92.9 ± 28.0 g C m(-2)  yr(-1) ). The CH4 emission was consistently high with a three-year average of 50.8 ± 1.0 g C m(-2)  yr(-1) . Considerable hydrologic carbon flowed laterally both into and out of the marsh (108.3 ± 5.4 and 86.2 ± 10.5 g C m(-2)  yr(-1) , respectively). In total, hydrologic carbon fluxes contributed ~23 ± 13 g C m(-2)  yr(-1) to the three-year carbon budget. Our findings highlight the importance of lateral hydrologic inflows/outflows in wetland carbon budgets, especially in those characterized by a flow-through hydrologic regime. In addition, different carbon fluxes responded unequally to climate variability/anomalies and, thus, the total carbon budgets may vary drastically among years. PMID:25287051

  12. Effects of dietborne cadmium on life history and secondary production of a tropical freshwater cladoceran.

    PubMed

    Souza, J P; Melo, D C; Lombardi, A T; Melão, M G G

    2014-11-01

    The presence of metals in aquatic environments has increased worldwide. Environmental assessments of metals in freshwater ecosystems presume that toxicity is mainly caused by aqueous exposure, but dietborne exposure (contaminated food) in zooplankton may occur because microalgae carry metal ions through adsorption/absorption of dissolved metal species, resulting in toxic effects once ingested by the animals. However, official regulations for ecotoxicological assays in most countries do not consider the toxic effects caused by dietborne exposure. Here, we provide life history parameters and secondary production of Simocephalus serrulatus (Koch 1841) (Cladocera: Daphniidae) fed with cadmium (Cd) contaminated algae during a 21-day bioassay. The microalgae Chlorophyceae Scenedesmus quadricauda was exposed for 96 h to dissolved Cd concentrations of 0.03; 5.87; 12.27 and 22.27 µg Cd l(-1) (equivalent to 1.6 × 10(-10); 3.2 × 10(-8); 6.7 × 10(-8); 1.2 × 10(-7) mol l(-1)) that resulted in algae internal Cd burdens of 0.004; 0.032; 0.270 and 0.280 pg Cd cell(-1), respectively. Significant toxic effects on life history parameters of S. serrulatus were observed. Time of embryonic development, generation time and age at first reproduction (primipara) showed significant delay. Length at first reproduction, number of eggs and clutches produced per female, hatching percentage, body length, survival and feeding rates were significantly reduced. Secondary production, that is, accumulated biomass for growth and reproduction, decreased significantly with dietborne Cd concentrations. Our results emphasize that food can be an important source of metals to zooplankton in aquatic ecosystems. Environmental regulations should consider the diet in ecotoxicological assessments. Furthermore, secondary production may be considered as a suitable endpoint in ecotoxicity tests. PMID:25248828

  13. Productivity and salinity structuring of the microplankton revealed by comparative freshwater metagenomics.

    PubMed

    Eiler, Alexander; Zaremba-Niedzwiedzka, Katarzyna; Martínez-García, Manuel; McMahon, Katherine D; Stepanauskas, Ramunas; Andersson, Siv G E; Bertilsson, Stefan

    2014-09-01

    Little is known about the diversity and structuring of freshwater microbial communities beyond the patterns revealed by tracing their distribution in the landscape with common taxonomic markers such as the ribosomal RNA. To address this gap in knowledge, metagenomes from temperate lakes were compared to selected marine metagenomes. Taxonomic analyses of rRNA genes in these freshwater metagenomes confirm the previously reported dominance of a limited subset of uncultured lineages of freshwater bacteria, whereas Archaea were rare. Diversification into marine and freshwater microbial lineages was also reflected in phylogenies of functional genes, and there were also significant differences in functional beta-diversity. The pathways and functions that accounted for these differences are involved in osmoregulation, active transport, carbohydrate and amino acid metabolism. Moreover, predicted genes orthologous to active transporters and recalcitrant organic matter degradation were more common in microbial genomes from oligotrophic versus eutrophic lakes. This comparative metagenomic analysis allowed us to formulate a general hypothesis that oceanic- compared with freshwater-dwelling microorganisms, invest more in metabolism of amino acids and that strategies of carbohydrate metabolism differ significantly between marine and freshwater microbial communities. PMID:24118837

  14. Productivity and salinity structuring of the microplankton revealed by comparative freshwater metagenomics

    PubMed Central

    Eiler, Alexander; Zaremba-Niedzwiedzka, Katarzyna; Martínez-García, Manuel; McMahon, Katherine D; Stepanauskas, Ramunas; Andersson, Siv G E; Bertilsson, Stefan

    2014-01-01

    Little is known about the diversity and structuring of freshwater microbial communities beyond the patterns revealed by tracing their distribution in the landscape with common taxonomic markers such as the ribosomal RNA. To address this gap in knowledge, metagenomes from temperate lakes were compared to selected marine metagenomes. Taxonomic analyses of rRNA genes in these freshwater metagenomes confirm the previously reported dominance of a limited subset of uncultured lineages of freshwater bacteria, whereas Archaea were rare. Diversification into marine and freshwater microbial lineages was also reflected in phylogenies of functional genes, and there were also significant differences in functional beta-diversity. The pathways and functions that accounted for these differences are involved in osmoregulation, active transport, carbohydrate and amino acid metabolism. Moreover, predicted genes orthologous to active transporters and recalcitrant organic matter degradation were more common in microbial genomes from oligotrophic versus eutrophic lakes. This comparative metagenomic analysis allowed us to formulate a general hypothesis that oceanic- compared with freshwater-dwelling microorganisms, invest more in metabolism of amino acids and that strategies of carbohydrate metabolism differ significantly between marine and freshwater microbial communities. PMID:24118837

  15. Seawater as Alternative to Freshwater in Pretreatment of Date Palm Residues for Bioethanol Production in Coastal and/or Arid Areas.

    PubMed

    Fang, Chuanji; Thomsen, Mette Hedegaard; Brudecki, Grzegorz P; Cybulska, Iwona; Frankaer, Christian Grundahl; Bastidas-Oyanedel, Juan-Rodrigo; Schmidt, Jens Ejbye

    2015-11-01

    The large water consumption (1.9-5.9 m(3) water per m(3) of biofuel) required by biomass processing plants has become an emerging concern, which is particularly critical in arid/semiarid regions. Seawater, as a widely available water source, could be an interesting option. This work was to study the technical feasibility of using seawater to replace freshwater in the pretreatment of date palm leaflets, a lignocellulosic biomass from arid regions, for bioethanol production. It was shown that leaflets pretreated with seawater exhibited lower cellulose crystallinity than those pretreated with freshwater. Pretreatment with seawater produced comparably digestible and fermentable solids to those obtained with freshwater. Moreover, no significant difference of inhibition to Saccharomyces cerevisiae was observed between liquids from pretreatment with seawater and freshwater. The results showed that seawater could be a promising alternative to freshwater for lignocellulose biorefineries in coastal and/or arid/semiarid areas. PMID:26487350

  16. Retrospective monitoring of mercury in fish from selected European freshwater and estuary sites.

    PubMed

    Nguetseng, Regine; Fliedner, Annette; Knopf, Burkhard; Lebreton, Benoit; Quack, Markus; Rüdel, Heinz

    2015-09-01

    Levels and trends of total mercury (THg) and methylmercury (MeHg) compounds in bream (Abramis brama) from different European sites were compared. Bream were collected between 2007 and 2013 in the estuaries of the rivers Scheldt (Netherlands), Rhône (France), Göta älv (Sweden), Tees (United Kingdom), and Mersey (UK), and in Lake Belau (Germany). A direct mercury analyzer was used to determine THg concentrations while MeHg was measured by gas chromatography/inductively coupled plasma-mass spectrometry applying stable isotope dilution. THg and MeHg in annual pool samples of bream ranged between 15.9 and 251 μg kg(-1) wet weight (ww) with lowest concentrations found at the reference site Lake Belau and highest in samples from the river Rhône. The EU environmental quality standard (EQS) of 20 μg kg(-1) ww was exceeded at all sites and in all years except at Lake Belau in 2012. Significantly decreasing trends over time were observed only in bream from the Rhône, while THg increased in bream from the Western Scheldt. The MeHg fractions of THg were always >80% and a significant difference between sites was detected only in one case (Rhône vs. Lake Belau). PMID:25989521

  17. Modeling Commercial Freshwater Turtle Production on US Farms for Pet and Meat Markets

    PubMed Central

    Mali, Ivana; Wang, Hsiao-Hsuan; Grant, William E.; Feldman, Mark; Forstner, Michael R. J.

    2015-01-01

    Freshwater turtles are being exploited for meat, eggs, traditional medicine, and pet trade. As a response, turtle farming became a booming aquaculture industry in the past two decades, specifically in the southeastern states of the United States of America (US) and across Southeast Asia. However, US turtle farms are currently producing turtles only for the pet trade while commercial trappers remain focused on catching the largest individuals from the wild. In our analyses we have created a biological and economic model that describes farming operations on a representative turtle farm in Louisiana. We first modeled current production of hatchling and yearling red-eared slider turtles (Trachemys scripta elegans) (i.e., traditional farming) for foreign and domestic pet markets, respectively. We tested the possibility of harvesting adult turtles from the breeding stock for sale to meat markets to enable alternative markets for the farmers, while decreasing the continued pressures on wild populations (i.e., non-traditional farming). Our economic model required current profit requirements of ~$13/turtle or ~$20.31/kg of meat from non-traditional farming in order to acquire the same profit as traditional farming, a value which currently exceeds market values of red-eared sliders. However, increasing competition with Asian turtle farms and decreasing hatchling prices may force the shift in the US toward producing turtles for meat markets. In addition, our model can be modified and applied to more desirable species on the meat market once more knowledge is acquired about species life histories and space requirements under farmed conditions. PMID:26407157

  18. Modeling Commercial Freshwater Turtle Production on US Farms for Pet and Meat Markets.

    PubMed

    Mali, Ivana; Wang, Hsiao-Hsuan; Grant, William E; Feldman, Mark; Forstner, Michael R J

    2015-01-01

    Freshwater turtles are being exploited for meat, eggs, traditional medicine, and pet trade. As a response, turtle farming became a booming aquaculture industry in the past two decades, specifically in the southeastern states of the United States of America (US) and across Southeast Asia. However, US turtle farms are currently producing turtles only for the pet trade while commercial trappers remain focused on catching the largest individuals from the wild. In our analyses we have created a biological and economic model that describes farming operations on a representative turtle farm in Louisiana. We first modeled current production of hatchling and yearling red-eared slider turtles (Trachemys scripta elegans) (i.e., traditional farming) for foreign and domestic pet markets, respectively. We tested the possibility of harvesting adult turtles from the breeding stock for sale to meat markets to enable alternative markets for the farmers, while decreasing the continued pressures on wild populations (i.e., non-traditional farming). Our economic model required current profit requirements of ~$13/turtle or ~$20.31/kg of meat from non-traditional farming in order to acquire the same profit as traditional farming, a value which currently exceeds market values of red-eared sliders. However, increasing competition with Asian turtle farms and decreasing hatchling prices may force the shift in the US toward producing turtles for meat markets. In addition, our model can be modified and applied to more desirable species on the meat market once more knowledge is acquired about species life histories and space requirements under farmed conditions. PMID:26407157

  19. Economical production and transshipment policy for coordinating multiple production sites

    NASA Astrophysics Data System (ADS)

    Kim, Taebok; Goyal, Suresh Kumar

    2012-05-01

    In this article, we study the coordination mechanism dealing with a production-transshipment policy across the multiple regions supplying multiple products. It is assumed that each production site has its own dedicated demand region consuming multiple products. The main concern is how to determine both the production quantity and the lot-apportioning policy while minimising the relevant supply chain cost. This decision issue is formulated as a non-linear mathematical model to determine several relevant decision variables. We propose the solution procedure for deriving the production-transshipment policy minimising the overall supply chain cost.

  20. Freshwater Macroinvertebrates.

    ERIC Educational Resources Information Center

    Nalepa, T. F.

    1978-01-01

    Presents a literature review of freshwater biology particularly freshwater macroinvertebrates and their effect on water pollution, covering publications of 1976-77. A list of 158 references is also presented. (HM)

  1. Identification of disinfection by-products in freshwater and seawater swimming pools and evaluation of genotoxicity.

    PubMed

    Manasfi, Tarek; De Méo, Michel; Coulomb, Bruno; Di Giorgio, Carole; Boudenne, Jean-Luc

    2016-03-01

    Exposure to disinfection byproducts (DBPs) in swimming pools has been linked to adverse health effects. Numerous DBPs that occur in swimming pools are genotoxic and carcinogenic. This toxicity is of a greater concern in the case of brominated DBPs that have been shown to have substantially greater toxicities than their chlorinated analogs. In chlorinated seawater swimming pools, brominated DBPs are formed due to the high content of bromide. Nevertheless, very little data is reported about DBP occurrence and mutagenicity of water in these pools. In the present study, three seawater and one freshwater swimming pools located in Southeastern France were investigated to determine qualitatively and quantitatively their DBP contents. An evaluation of the genotoxic properties of water samples of the freshwater pool and a seawater pool was conducted through the Salmonella assay (Ames test). The predominant DBPs identified in the freshwater pool were chlorinated species and included trichloroacetic acid, chloral hydrate, dichloroacetonitrile, 1,1,1-trichloropropanone and chloroform. In the seawater pools, brominated DBPs were the predominant species and included dibromoacetic acid, bromoform and dibromoacetonitile. Bromal hydrate levels were also reported. In both types of pools, haloacetic acids were the most prevalent chemical class among the analyzed DBP classes. The distribution of other DBP classes varied depending on the type of pool. As to genotoxicity, the results of Ames test showed higher mutagenicity in the freshwater pool as a consequence of its considerably higher DBP contents in comparison to the tested seawater pool. PMID:26735347

  2. Site-specific water quality criteria for lethal/sublethal protection of freshwater fish exposed to zinc in southern Taiwan.

    PubMed

    Chen, Wei-Yu; Chen, Tzu-Yin; Hsieh, Nan-Hung; Ju, Yi-Ting

    2016-09-01

    There were considerable concerns about the zinc (Zn) pollution caused by electroplating, chemical, and computer-related high-tech industrial discharges in Kaohsiung Rivers situated at south Taiwan. There is, however, a lack of site-specific water chemistry based toxicity assessment and little is known about the sublethal toxicity on freshwater fish. This study proposes an integrated framework to link experimental and mechanistic model-based data analysis of lethal and sublethal Zn toxicities for grass carp (Ctenopharyn odon idellus) populations for providing the site-specific Zn water quality threshold in Kaohsiung Rivers. A biotic ligand model (BLM) that relates toxicity impairment of physiological active sites impacted by Zn species was used to elucidate the site-specific water chemistry affecting the bioavailability and biological response of grass carp exposed to Zn. Results indicated that 96-h LC50 for mortality and 28-d EC50 for growth inhibition were 474.7 ± 1.3 (mean ± SE) and 149 ± 23.5 μg L(-1), respectively. Here the BLM-based predicted steady-state LC50s for mortality were 2110.7, 818.2, 1303.6, 563.3, and 497.1 μg L(-1), whereas measured steady-state EC50s for growth inhibition were 726.8, 326.2, 373.4, 193.9, and 170.5 μg L(-1) for the Agongdian, Houling, Love, Fengshan, and Gaoping Rivers, respectively. A positive correlation between Mg(2+) and EC50 values were found in both acute (r = 0.94, p < 0.01) and chronic (r = 0.97, p < 0.01) Zn exposures. This study suggests that the use of site-specific water chemistry data and ecophysiological traits would enhance the predictive capacities to assess the potential effect of metal toxicity posed to aquatic organisms. PMID:27337432

  3. Potential impacts of electric power production utilizing natural gas, renewables and carbon capture and sequestration on US Freshwater resources.

    PubMed

    Tidwell, Vincent C; Malczynski, Leonard A; Kobos, Peter H; Klise, Geoffrey T; Shuster, Erik

    2013-08-01

    Carbon capture and sequestration (CCS) has important implications relative to future thermoelectric water use. A bounding analysis is performed using past greenhouse gas emission policy proposals and assumes either all effected capacity retires (lower water use bound) or is retrofitted (upper bound). The analysis is performed in the context of recent trends in electric power generation expansion, namely high penetration of natural gas and renewables along with constrained cooling system options. Results indicate thermoelectric freshwater withdrawals nationwide could increase by roughly 1% or decrease by up to 60% relative to 2009 levels, while consumption could increase as much as 21% or decrease as much as 28%. To identify where changes in freshwater use might be problematic at a regional level, electric power production has been mapped onto watersheds with limited water availability (where consumption exceeds 70% of gauged streamflow). Results suggest that between 0.44 and 0.96 Mm(3)/d of new thermoelectric freshwater consumption could occur in watersheds with limited water availability, while power plant retirements in these watersheds could yield 0.90 to 1.0 Mm(3)/d of water savings. PMID:23789965

  4. Removing Constraints on the Biomass Production of Freshwater Macroalgae by Manipulating Water Exchange to Manage Nutrient Flux

    PubMed Central

    Cole, Andrew J.; de Nys, Rocky; Paul, Nicholas A.

    2014-01-01

    Freshwater macroalgae represent a largely overlooked group of phototrophic organisms that could play an important role within an industrial ecology context in both utilising waste nutrients and water and supplying biomass for animal feeds and renewable chemicals and fuels. This study used water from the intensive aquaculture of freshwater fish (Barramundi) to examine how the biomass production rate and protein content of the freshwater macroalga Oedogonium responds to increasing the flux of nutrients and carbon, by either increasing water exchange rates or through the addition of supplementary nitrogen and CO2. Biomass production rates were highest at low flow rates (0.1–1 vol.day−1) using raw pond water. The addition of CO2 to cultures increased biomass production rates by between 2 and 25% with this effect strongest at low water exchange rates. Paradoxically, the addition of nitrogen to cultures decreased productivity, especially at low water exchange rates. The optimal culture of Oedogonium occurred at flow rates of between 0.5–1 vol.day−1, where uptake rates peaked at 1.09 g.m−2.day−1 for nitrogen and 0.13 g.m−2.day−1 for phosphorous. At these flow rates Oedogonium biomass had uptake efficiencies of 75.2% for nitrogen and 22.1% for phosphorous. In this study a nitrogen flux of 1.45 g.m−2.day−1 and a phosphorous flux of 0.6 g.m−2.day−1 was the minimum required to maintain the growth of Oedogonium at 16–17 g DW.m−2.day−1 and a crude protein content of 25%. A simple model of minimum inputs shows that for every gram of dry weight biomass production (g DW.m−2.day−1), Oedogonium requires 0.09 g.m−2.day−1 of nitrogen and 0.04 g.m−2.day−1 of phosphorous to maintain growth without nutrient limitation whilst simultaneously maintaining a high-nutrient uptake rate and efficiency. As such the integrated culture of freshwater macroalgae with aquaculture for the purposes of nutrient recovery is a feasible solution for the

  5. Removing constraints on the biomass production of freshwater macroalgae by manipulating water exchange to manage nutrient flux.

    PubMed

    Cole, Andrew J; de Nys, Rocky; Paul, Nicholas A

    2014-01-01

    Freshwater macroalgae represent a largely overlooked group of phototrophic organisms that could play an important role within an industrial ecology context in both utilising waste nutrients and water and supplying biomass for animal feeds and renewable chemicals and fuels. This study used water from the intensive aquaculture of freshwater fish (Barramundi) to examine how the biomass production rate and protein content of the freshwater macroalga Oedogonium responds to increasing the flux of nutrients and carbon, by either increasing water exchange rates or through the addition of supplementary nitrogen and CO2. Biomass production rates were highest at low flow rates (0.1-1 vol.day-1) using raw pond water. The addition of CO2 to cultures increased biomass production rates by between 2 and 25% with this effect strongest at low water exchange rates. Paradoxically, the addition of nitrogen to cultures decreased productivity, especially at low water exchange rates. The optimal culture of Oedogonium occurred at flow rates of between 0.5-1 vol.day-1, where uptake rates peaked at 1.09 g.m-2.day-1 for nitrogen and 0.13 g.m-2.day-1 for phosphorous. At these flow rates Oedogonium biomass had uptake efficiencies of 75.2% for nitrogen and 22.1% for phosphorous. In this study a nitrogen flux of 1.45 g.m-2.day-1 and a phosphorous flux of 0.6 g.m-2.day-1 was the minimum required to maintain the growth of Oedogonium at 16-17 g DW.m-2.day-1 and a crude protein content of 25%. A simple model of minimum inputs shows that for every gram of dry weight biomass production (g DW.m-2.day-1), Oedogonium requires 0.09 g.m-2.day-1 of nitrogen and 0.04 g.m-2.day-1 of phosphorous to maintain growth without nutrient limitation whilst simultaneously maintaining a high-nutrient uptake rate and efficiency. As such the integrated culture of freshwater macroalgae with aquaculture for the purposes of nutrient recovery is a feasible solution for the bioremediation of wastewater and the supply of a

  6. Modeling potential freshwater ecotoxicity impacts due to pesticide use in biofuel feedstock production: the cases of maize, rapeseed, salix, soybean, sugar cane, and wheat.

    PubMed

    Nordborg, Maria; Cederberg, Christel; Berndes, Göran

    2014-10-01

    The inclusion of ecotoxicity impacts of pesticides in environmental assessments of biobased products has long been hampered by methodological challenges. We expanded the pesticide database and the regional coverage of the pesticide emission model PestLCI v.2.0, combined it with the impact assessment model USEtox, and assessed potential freshwater ecotoxicity impacts (PFEIs) of pesticide use in selected biofuel feedstock production cases, namely: maize (Iowa, US, two cases), rapeseed (Schleswig-Holstein, Germany), Salix (South Central Sweden), soybean (Mato Grosso, Brazil, two cases), sugar cane (São Paulo, Brazil), and wheat (Schleswig-Holstein, Germany). We found that PFEIs caused by pesticide use in feedstock production varied greatly, up to 3 orders of magnitude. Salix has the lowest PFEI per unit of energy output and per unit of cultivated area. Impacts per biofuel unit were 30, 750, and 1000 times greater, respectively, for the sugar cane, wheat and rapeseed cases than for Salix. For maize genetically engineered (GE) to resist glyphosate herbicides and to produce its own insecticidal toxin, maize GE to resist glyphosate, soybeans GE to resist glyphosate and conventional soybeans, the impacts were 110, 270, 305, and 310 times greater than for Salix, respectively. The significance of field and site-specific conditions are discussed, as well as options for reducing negative impacts in biofuel feedstock production. PMID:25207789

  7. Production and utilization of dissolved adenosine 5'-triphosphate in marine and freshwater ecosystems

    SciTech Connect

    Peele, E.R.

    1985-01-01

    Concentrations of dissolved adenosine triphosphate (DATP) were influenced primarily by in situ biological processes such as uptake by heterotrophic microorganisms and release by either phytoplankton or zooplankton or through zooplankton-phytoplankton interactions. Rapid turnover of dissolved ATP via uptake by bacterioplankton was observed in an estuary (Sapelo Island, Georgia) and two freshwater lakes (Lake Oglethorpe, Georgia and Lago Lake, Georgia). Turnover times for DATP, based on microbial assimilation of (/sup 3/H)ATP, were on the order of hours to days in all three environments. DATP was not taken up intact by the natural microbial populations; rather, it was degraded to adenine, ribose and inorganic phosphate prior to or during transport. The primary mechanism for DATP uptake was via dephosphorylation of the nucleotide and cleavage of resultant nucleoside to adenine and ribose which then entered the cells by separate transport systems. The rate of DATP assimilation by freshwater microorganisms varied markedly-over a diel cycle. Results from microcosm experiments in which the authors compared the rates of DATP release by phytoplankton (Chlamydomonas sp.) alone, zooplankton (Daphnia sp.) alone or phytoplankton and zooplankton together under feeding conditions supported those hypotheses. Net extracellular release of DATP by Chlamydomonas was negligible in short-term experiments, and in systems containing both Daphnia and Chlamydomonas, changes in DATP over time were approximately 3-fold greater than the sum of changes observed in systems containing either organism alone.

  8. Using Mesocosms to Test the Effect of Land Management Practices on Monomethylmercury Production in Freshwater Seasonal Wetlands

    NASA Astrophysics Data System (ADS)

    Heim, W. A.; Negrey, J.; Martenuk, S.; Bonnema, A.; Byington, A.; Masek, J.; Newman, A.; Stephenson, M.; Coale, K. H.

    2013-12-01

    Managed seasonal freshwater wetlands are an ideal habitat for the production of monomethylmercury (MMHg). Wetting and drying cycles created by water management promote growth of wetland vegetation for waterfowl food during the summer growing season. After fall floodup of the fields this vegetation decomposes creating anoxic conditions and an abundant carbon source utilized by MMHg producing microbes. This results in hot moments of MMHg production after floodup and increased MMHg loads from seasonal wetlands. In this work, we determine the effect land management practices have on MMHg production. A manipulative study was conducted during the fall (October-November) of 2012 in a 20 hectacre seasonally flooded wetland located in Yolo Wildlife Area, CA. Polycarbonate cylindrical mesocosms (0.75 m diameter, 0.6 m tall), were placed over 6 differing land management treatment types: disc, simulated cattle grazed, mowed with vegetation removed, mowed with vegetation left in place, scraped with all vegetation removed, and natural undisturbed. Each treatment had n = 5 replicates. Samples were collected for determination of mercury speciation and ancillary measurements. Sampling occurred bi-weekly or weekly over a period of thirty days. Dissolved MMHg concentrations peaked in all treatments by day 16 of the experiment. Comparison of treatments was done on a mass dissolved MMHg basis. Natural and mowed treatments were similar (2.2 and 2.1 μg MMHg respectively). Simulated grazing treatments (1.4 μg MMHg ) resulted in 36% reduction in MMHg relative to the natural treatment. Cleared (0.36 μg MMHg), disced (0.51 μg MMHg), and mowed with vegetation removed (0.88 μg MMHg) produced significantly less MMHg than the natural undisturbed treatment. Our results indicate specific management practices of seasonally flooded wetlands can reduce the net production of MMHg and potentially reduce loads to surrounding water. Net mass MMHg (ug) produced by treatment type within mesocosms in a

  9. Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2) in Colbert County, Alabama, USA

    PubMed Central

    Ebersole, Jun A.; Dickinson, William C.; Ciampaglio, Charles N.

    2016-01-01

    The Tennessee River Basin is considered one of the most important regions for freshwater biodiversity anywhere on the globe. The Tennessee River Basin currently includes populations of at least half of the described contemporary diversity of extant North American freshwater fishes, crayfish, mussel, and gastropod species. However, comparatively little is known about the biodiversity of this basin from the Pleistocene Epoch, particularly the late Pleistocene (∼10,000 to 30,000 years B.P.) leading to modern Holocene fish diversity patterns. The objective of this study was to describe the fish assemblages of the Tennessee River Basin from the late Pleistocene using a series of faunas from locales throughout the basin documented from published literature, unpublished reports, and an undocumented fauna from Bell Cave (site ACb-2, Colbert County, AL). Herein we discuss 41 unequivocal taxa from 10 late Pleistocene localities within the basin and include a systematic discussion of 11 families, 19 genera, and 24 identifiable species (28 unequivocal taxa) specific to the Bell Cave locality. Among the described fauna are several extirpated (e.g., Northern Pike Esox lucius, Northern Madtom Noturus stigmosus) and a single extinct (Harelip Sucker Moxostoma lacerum) taxa that suggest a combination of late Pleistocene displacement events coupled with more recent changes in habitat that have resulted in modern basin diversity patterns. The Bell Cave locality represents one of the most intact Pleistocene freshwater fish deposits anywhere in North America. Significant preservational, taphonomic, sampling, and identification biases preclude the identification of additional taxa. Overall, this study provides a detailed look into paleo-river ecology, as well as freshwater fish diversity and distribution leading up to the contemporary biodiversity patterns of the Tennessee River Basin and Mississippi River Basin as a whole. PMID:26855876

  10. Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2) in Colbert County, Alabama, USA.

    PubMed

    Jacquemin, Stephen J; Ebersole, Jun A; Dickinson, William C; Ciampaglio, Charles N

    2016-01-01

    The Tennessee River Basin is considered one of the most important regions for freshwater biodiversity anywhere on the globe. The Tennessee River Basin currently includes populations of at least half of the described contemporary diversity of extant North American freshwater fishes, crayfish, mussel, and gastropod species. However, comparatively little is known about the biodiversity of this basin from the Pleistocene Epoch, particularly the late Pleistocene (∼10,000 to 30,000 years B.P.) leading to modern Holocene fish diversity patterns. The objective of this study was to describe the fish assemblages of the Tennessee River Basin from the late Pleistocene using a series of faunas from locales throughout the basin documented from published literature, unpublished reports, and an undocumented fauna from Bell Cave (site ACb-2, Colbert County, AL). Herein we discuss 41 unequivocal taxa from 10 late Pleistocene localities within the basin and include a systematic discussion of 11 families, 19 genera, and 24 identifiable species (28 unequivocal taxa) specific to the Bell Cave locality. Among the described fauna are several extirpated (e.g., Northern Pike Esox lucius, Northern Madtom Noturus stigmosus) and a single extinct (Harelip Sucker Moxostoma lacerum) taxa that suggest a combination of late Pleistocene displacement events coupled with more recent changes in habitat that have resulted in modern basin diversity patterns. The Bell Cave locality represents one of the most intact Pleistocene freshwater fish deposits anywhere in North America. Significant preservational, taphonomic, sampling, and identification biases preclude the identification of additional taxa. Overall, this study provides a detailed look into paleo-river ecology, as well as freshwater fish diversity and distribution leading up to the contemporary biodiversity patterns of the Tennessee River Basin and Mississippi River Basin as a whole. PMID:26855876

  11. Surface sorption and nanoparticle production as a silver detoxification mechanism of the freshwater alga Parachlorella kessleri.

    PubMed

    Kadukova, Jana

    2016-09-01

    SEM, EDS, TEM, FTIR and UV-vis analysis were used to investigate the biosorption, bioaccumulation and bioreduction of silver by the freshwater green alga Parachlorella kessleri. The dead algal biomass showed high potential for silver removal; 75% of silver was removed within 2min. Surface sorption was the main mechanism; bioreduction contributed to the biosorption only to a small extent. In the presence of living P. kessleri cells a 68% decrease of silver concentration was observed within 24h, but subsequently the majority of silver was released back into the solution within the next 14days. According to UV-vis spectrometry, silver nanoparticles were formed in that time. The nanoparticles produced by the alga exhibited a lower toxicity against algal cells than silver ions at the same silver concentrations. The study demonstrated that living algal cells used a combination of two main mechanisms (sorption and reduction) for silver detoxification in their environment. PMID:27262095

  12. THE ANTIMICROBIAL TRICLOCARBAN STIMULATES EMBRYO PRODUCTION IN THE FRESHWATER MUDSNAIL POTAMOPYRGUS ANTIPODARUM

    PubMed Central

    Giudice, Ben D.; Young, Thomas M.

    2011-01-01

    Recent research has indicated that the antimicrobial chemical triclocarban (TCC) represents a new type of endocrine disruptor, amplifying the transcriptional activity of steroid hormones and their receptors while itself exhibiting little affinity for these receptors. The effects of TCC were studied in the freshwater mudsnail Potamopyrgus antipodarum. Specimens were exposed to concentrations ranging from 0.05 to 10.5 μg/L dissolved TCC and were removed and dissected, and embryos contained within the brood pouch were counted and classified as shelled or unshelled after2 and 4weeksof exposure. After 4 weeks, environmentally relevant TCC concentrations of 1.6 to 10.5 μg/L resulted in statistically significant increases in the number of unshelled embryos, while 0.2, 1.6, and 10.5 μg/L exposures significantly increased numbers of shelled embryos. The lowest observed effect concentration (LOEC) was 0.2 μg/L, the no observed effect concentration (NOEC) was 0.05 μg/L, and the EC10 and EC50 for unshelled effects were 0.5 μg/L and 2.5 μg/L, respectively. Given the widespread occurrence of TCC in the environment and effects shown at environmentally relevant concentrations, these results indicate that TCC may be causing reproductive effects in the environment. Furthermore, the present study indicates that environmental risk from a new class of EDCs is both qualitatively and quantitatively similar to risk from existing classes of EDCs. PMID:20821527

  13. Siting algae cultivation facilities for biofuel production in the United States: trade-offs between growth rate, site constructability, water availability, and infrastructure

    SciTech Connect

    Venteris, Erik R.; McBride, Robert; Coleman, Andre M.; Skaggs, Richard; Wigmosta, Mark S.

    2014-02-21

    Locating sites for new algae cultivation facilities is a complex task. The climate must support high growth rates, and cultivation ponds require appropriate land and water resources as well as key utility and transportation infrastructure. We employ our spatiotemporal Biomass Assessment Tool (BAT) to select promising locations based on the open-pond cultivation of Arthrospira sp. and a strain of the order Desmidiales. 64,000 potential sites across the southern United States were evaluated. We progressively apply a range of screening criteria and track their impact on the number of selected sites, geographic location, and biomass productivity. Both strains demonstrate maximum productivity along the Gulf of Mexico coast, with the highest values on the Florida peninsula. In contrast, sites meeting all selection criteria for Arthrospira were located along the southern coast of Texas and for Desmidiales were located in Louisiana and southern Arkansas. Site selection was driven mainly by the lack of oil pipeline access in Florida and elevated groundwater salinity in southern Texas. The requirement for low salinity freshwater (<400 mg L-1) constrained Desmidiales locations; siting flexibility is greater for salt-tolerant species such as Arthrospira. Combined siting factors can result in significant departures from regions of maximum productivity but are within the expected range of site-specific process improvements.

  14. Savannah River Site production reactor technical specifications. K Production Reactor

    SciTech Connect

    1996-02-01

    These technical specifications are explicit restrictions on the operation of the Savannah River Site K Production Reactor. They are designed to preserve the validity of the plant safety analysis by ensuring that the plant is operated within the required conditions bounded by the analysis, and with the operable equipment that is assumed to mitigate the consequences of an accident. Technical specifications preserve the primary success path relied upon to detect and respond to accidents. This report describes requirements on thermal-hydraulic limits; limiting conditions for operation and surveillance for the reactor, power distribution control, instrumentation, process water system, emergency cooling and emergency shutdown systems, confinement systems, plant systems, electrical systems, components handling, and special test exceptions; design features; and administrative controls.

  15. Environmental factors related to the production of a complex set of spicules in a tropical freshwater sponge.

    PubMed

    Matteuzzo, Marcela C; Volkmer-Ribeiro, Cecília; Varajão, Angélica F D C; Varajão, César A C; Alexandre, Anne; Guadagnin, Demetrio L; Almeida, Ariana C S

    2015-01-01

    Adverse natural conditions will, generally, induce gemmulation in freshwater sponges. Because of this environmental dependence, gemmoscleres are given exceptional value in taxonomic, ecological and paleoenvironmental studies. Other spicules categories such as microscleres and beta megascleres have received little attention with regard to their occurrence and function during the sponge biological cycle. Metania spinata, a South American species common to bog waters in the Cerrado biome, produces alpha and beta megascleres, microscleres and gemmoscleres. To detect the environmental factors triggering the production of all these kinds of spicules, the species annual seasonal cycle was studied. Artificial substrates were devised, supplied with gemmules and placed in Lagoa Verde pond which contained a natural population of M. spinata. Field monitoring was conducted for eight months in order to observe the growth of sponges and spicules formation. Samples of water were taken monthly for physical and chemical parameters determination. The appearance of the alpha megascleres was sequentially followed by that of microscleres, gemmoscleres and beta megascleres. The first ones built the new sponge skeleton, the last three were involved in keeping inner moisture in the sponge body or its gemmules. The water level, temperature and the silicon (Si) concentration in the pond were the most important factors related to this sequential production of spicules, confirming environmental reconstructions based on the presence or absence of alpha megascleres and gemmoscleres in past sediments. PMID:26628027

  16. LABORATORY EVALUATION OF OIL SPILL BIOREMEDIATION PRODUCTS IN SALT AND FRESHWATER SYSTEMS

    EPA Science Inventory

    Ten oil spill bioremediation products were tested in the laboratory for their ability to enhance biodegradation of weathered Alaskan North Slope crude oil in both fresh and salt-water media. The products included: nutrients to stimulate inoculated microorganisms, nutrients plus a...

  17. Siting algae cultivation facilities for biofuel production in the United States: trade-offs between growth rate, site constructability, water availability, and infrastructure.

    PubMed

    Venteris, Erik R; McBride, Robert C; Coleman, Andre M; Skaggs, Richard L; Wigmosta, Mark S

    2014-03-18

    Locating sites for new algae cultivation facilities is a complex task. The climate must support high growth rates, and cultivation ponds require appropriate land and water resources, as well as transportation and utility infrastructure. We employ our spatiotemporal Biomass Assessment Tool (BAT) to select promising locations based on the open-pond cultivation of Arthrospira sp. and strains of the order Sphaeropleales. A total of 64,000 sites across the southern United States were evaluated. We progressively applied screening criteria and tracked their impact on the number of potential sites, geographic location, and biomass productivity. Both strains demonstrated maximum productivity along the Gulf of Mexico coast, with the highest values on the Florida peninsula. In contrast, sites meeting all selection criteria for Arthrospira were located along the southern coast of Texas and for Sphaeropleales were located in Louisiana and southern Arkansas. Results were driven mainly by the lack of oil pipeline access in Florida and elevated groundwater salinity in southern Texas. The requirement for low-salinity freshwater (<400 mg L(-1)) constrained Sphaeropleales locations; siting flexibility is greater for salt-tolerant species like Arthrospira. Combined siting factors can result in significant departures from regions of maximum productivity but are within the expected range of site-specific process improvements. PMID:24559117

  18. Effects of Marine and Freshwater Macroalgae on In Vitro Total Gas and Methane Production

    PubMed Central

    Machado, Lorenna; Magnusson, Marie; Paul, Nicholas A.; de Nys, Rocky; Tomkins, Nigel

    2014-01-01

    This study aimed to evaluate the effects of twenty species of tropical macroalgae on in vitro fermentation parameters, total gas production (TGP) and methane (CH4) production when incubated in rumen fluid from cattle fed a low quality roughage diet. Primary biochemical parameters of macroalgae were characterized and included proximate, elemental, and fatty acid (FAME) analysis. Macroalgae and the control, decorticated cottonseed meal (DCS), were incubated in vitro for 72 h, where gas production was continuously monitored. Post-fermentation parameters, including CH4 production, pH, ammonia, apparent organic matter degradability (OMd), and volatile fatty acid (VFA) concentrations were measured. All species of macroalgae had lower TGP and CH4 production than DCS. Dictyota and Asparagopsis had the strongest effects, inhibiting TGP by 53.2% and 61.8%, and CH4 production by 92.2% and 98.9% after 72 h, respectively. Both species also resulted in the lowest total VFA concentration, and the highest molar concentration of propionate among all species analysed, indicating that anaerobic fermentation was affected. Overall, there were no strong relationships between TGP or CH4 production and the >70 biochemical parameters analysed. However, zinc concentrations >0.10 g.kg−1 may potentially interact with other biochemical components to influence TGP and CH4 production. The lack of relationship between the primary biochemistry of species and gas parameters suggests that significant decreases in TGP and CH4 production are associated with secondary metabolites produced by effective macroalgae. The most effective species, Asparagopsis, offers the most promising alternative for mitigation of enteric CH4 emissions. PMID:24465524

  19. PROTOCOL FOR LABORATORY TESTING OF CRUDE-OIL BIOREMEDIATION PRODUCTS IN FRESHWATER CONDITIONS

    EPA Science Inventory

    In 1993, the Environmental Protection Agency, National Risk Management Research Laboratory (EPA, NRMRL), with the National Environmental Technology Application Center (NETAC), developed a protocol for evaluation of bioremediation products in marine environments. The marine proto...

  20. Freshwater Wetlands.

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    Provides descriptions about freshwater wetlands, such as marshes, swamps, and bogs. Contains three learning activities which deal with unusual wetland plants, the animals and plants in a typical marsh, and the effects of a draught on a swamp. Included are reproducible handouts and worksheets for two of the activities. (TW)

  1. Variation in the production rate of biosonar signals in freshwater porpoises.

    PubMed

    Kimura, Satoko; Akamatsu, Tomonari; Wang, Ding; Li, Songhai; Wang, Kexiong; Yoda, Ken

    2013-05-01

    The biosonar (click train) production rate of ten Yangtze finless porpoises and their behavior were examined using animal-borne data loggers. The sound production rate varied from 0 to 290 click trains per 10-min time interval. Large individual differences were observed, regardless of body size. Taken together, however, sound production did not differ significantly between daytime and nighttime. Over the 172.5 h of analyzed recordings, an average of 99.0% of the click trains were produced within intervals of less than 60 s, indicating that during a 1-min interval, the number of click trains produced by each porpoise was typically greater than one. Most of the porpoises exhibited differences in average swimming speed and depth between day and night. Swimming speed reductions and usage of short-range sonar, which relates to prey-capture attempts, were observed more often during nighttime. However, biosonar appears to be affected not only by porpoise foraging, but also by their sensory environment, i.e., the turbid Yangtze River system. These features will be useful for passive acoustic detection of the porpoises. Calculations of porpoise density or abundance should be conducted carefully because large individual differences in the sound production rate will lead to large estimation error. PMID:23654415

  2. Assessment of Global Oceanic Net Freshwater Flux Products Using Argo Salinity Observations

    NASA Astrophysics Data System (ADS)

    Ren, L.; Arkin, P. A.; Hackert, E. C.; Busalacchi, A. J.

    2012-12-01

    The annual mean global upper ocean salt budget is investigated using the Argo profiling float data from 2006 to 2011, which provides a way to estimate the annual mean oceanic evaporation and precipitation (E-P) from the ocean salinity. Employing this "ocean rain gauge" concept, E-P estimated from the salt budget is compared with the various satellite based oceanic precipitation and evaporation observational products. In this study, twelve sets of E-P from the evaporation and precipitation products including the precipitation datasets GPCP, CMAP and TRMM and the evaporation datasets OAFlux, GSSTF2b, IFREMER and RSS are compared to the E-P estimated from the salinity. We will describe the spatial patterns of the various E-P products derived from the satellite based data sets and compare these patterns to those derived from the oceanic salinity on the annual mean time scale. We will also examine time series of near-global integrated E-P derived from satellite products and compare them to time series based on oceanic salinity observations as well as continental discharge. This intercomparison of independently derived estimates of fresh water flux at the ocean surface will improve our understanding of errors in remotely sensed estimates of evaporation and precipitation.

  3. Influence of zinc on bacterial populations and their proteolytic enzyme activities in freshwater environments: a cross-site comparison.

    PubMed

    Rasmussen, Lauren; Olapade, Ola A

    2016-04-01

    Temporal responses of indigenous bacterial populations and proteolytic enzyme (i.e., aminopeptidase) activities in the bacterioplankton assemblages from 3 separate freshwater environments were examined after exposure to various zinc (Zn) concentrations under controlled microcosm conditions. Zn concentrations (ranging from 0 to 10 μmol/L) were added to water samples collected from the Kalamazoo River, Rice Creek, and Huron River and examined for bacterial abundance and aminopeptidase activities at various time intervals over a 48 h incubation period in the dark. The results showed that the Zn concentrations did not significantly influence total bacterial counts directly; however, aminopeptidase activities varied significantly to increasing zinc treatments over time. Also, analysis of variance and linear regression analyses revealed significant positive relationships between bacterial numbers and their hydrolytic enzyme activities, suggesting that both probably co-vary with increasing Zn concentrations in aquatic systems. The results from this study serve as additional evidence of the ecological role of Zn as an extracellular peptidase cofactor on the dynamics of bacterial assemblages in aquatic environments. PMID:26877164

  4. Secondary production of freshwater zooplankton communities exposed to a fungicide and to a petroleum distillate in outdoor pond mesocosms.

    PubMed

    Bayona, Yannick; Roucaute, Ana; Roucaute, Marc; Gorzerino, Caroline; Cailleaud, Kevin; Lagadic, Laurent; Bassères, Anne; Caquet, Thierry

    2014-04-01

    Ecological risk assessment of chemicals in mesocosms requires measurement of a large number of parameters at the community level. Studies on invertebrate communities usually focus on taxonomic approaches, which only provide insights into taxonomic structure changes induced by chemicals. In the present study, abundance, biomass (B), theoretical production (P), and instantaneous P/B ratio were used as endpoints to assess the effects of the commercial form of the dithiocarbamate fungicide thiram (35 µg/L and 170 µg/L nominal concentrations) and of the hydrocarbon water accommodated fraction (HWAF) of a petroleum distillate (0.01 mg/L, 0.4 mg/L, 2 mg/L, and 20 mg/L loadings) on the zooplankton community in freshwater pond mesocosms. Endpoints were measured during a 4-wk treatment period (1 pulse/wk) followed by a 5-mo posttreatment period to evaluate zooplankton population recovery. The chlorophyll a concentration in water was significantly increased after treatment with HWAF, whereas it was not affected by thiram treatment. Zooplankton abundance-based analysis showed effects on a limited number of taxa, whereas other endpoints (mainly the P/B ratio) revealed that more taxa were impacted, with recovery depending on the chemical and concentration. Exposure to HWAF mainly had a negative impact on cladocerans, which resulted in top-down effects (between cladocerans and phytoplankton). Thiram negatively affected rotifers and copepods, suggesting more direct toxic effects. The results show that the use of secondary production as an endpoint provides a more comprehensive assessment of potential direct and indirect effects of chemicals on a community, and they also support evidence of alteration in functional processes. PMID:24375909

  5. Patterns of net primary production across sites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Net primary production (NPP) is a fundamentally important and commonly measured ecosystem process that provides an integrative estimate of energy capture and flow into systems, and consequently the energy available for use by other trophic levels. A wide range of productivity levels occurs globally ...

  6. Site Specific Management of Cotton Production in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Site-specific management or precision agriculture, as it is evolving in large-scale crop production, offers promising new methods for managing cotton production for optimized yields, maximized profitability, and minimized environmental pollution. However, adaptation of site-specific theory and meth...

  7. Identification and characterization of a freshwater microalga Scenedesmus SDEC-8 for nutrient removal and biodiesel production.

    PubMed

    Song, Mingming; Pei, Haiyan; Hu, Wenrong; Zhang, Shuo; Ma, Guixia; Han, Lin; Ji, Yan

    2014-06-01

    The selection of the right strains is of fundamental important to the success of the algae-based oil industry. From the six newly isolated microalgae strains tested for growth, fatty acid methyl ester (FAME) profiles and biodiesel properties, Scenedesmus SDEC-8, with favorable C16:0 fatty acids (73.43%), showed the best combined results. Then, morphological and molecular identification were examined. From the three wastewaters samples, Scenedesmus SDEC-8 showed good ability to yield oil and remove nutrients, which were comparable with other reports. In b artificial wastewater (TN 40 mg L(-1), TP 8 mg L(-1)), Scenedesmus SDEC-8 achieved the highest value of lipid productivity (53.84 mg L(-1) d(-1)), MUFA content (35.35%) and total FAME content (59.57±0.02 mg g(-1) DW), besides higher removal efficiencies of TN (99.18%) and TP (98.86%) helped effluent directly discharge and smaller dilution factor of N, P (3.3 and 9) which was good for lessening water utilization. PMID:24747391

  8. Defining optimal freshwater flow for oyster production: effects of freshet rate and magnitude of change and duration on eastern oysters and Perkinsus marinus infection

    USGS Publications Warehouse

    LaPeyre, Megan K.; Gossman, B.; La Peyre, Jerome F.

    2009-01-01

    In coastal Louisiana, the development of large-scale freshwater diversion projects has led to controversy over their effects on oyster resources. Using controlled laboratory experiments in combination with a field study, we examined the effects of pulsed freshwater events (freshet) of different magnitude, duration, and rate of change on oyster resources. Laboratory and field evidence indicate that low salinity events (<5 psu) decreased Perkinsus marinus infection intensities. Furthermore, when salinity was low (<5 psu), parasite infection intensities continued to decrease even as temperatures exceeded 20°C. At the same time, oyster growth was positively correlated with salinity. To maximize oyster production, data indicate that both low and high salinity events will be necessary.

  9. Impact of elevated copper on the rate and gaseous products of denitrification in freshwater sediments.

    PubMed

    Jacinthe, Pierre-Andre; Tedesco, Lenore P

    2009-01-01

    Application of Cu-containing algicides to water reservoirs for algal control leads to sediment Cu enrichment, but the impact of Cu accumulation on the NO(3)(-)-attenuation capacity of these ecosystems is uncertain. With the knowledge that the reduction of N(2)O to N(2) is mediated by a Cu-dependent enzyme, it is hypothesized that an inverse variation exists between Cu availability and the mole fraction of N(2)O (F(N2O)) in denitrification products. A study was conducted to test this hypothesis and also to assess the impact of elevated Cu on nitrification and denitrification. Sediments were collected from areas untreated (NCT) and treated (CT) with the algicide cutrine (Cu ethanolamine) in three central Indiana reservoirs, and were assayed at both in situ Cu content and after amendment with CuSO(4). Results showed that Cu addition had a depressive, but short-lived effect on the processes investigated, with nitrification being most sensitive. Past cutrine treatments did not significantly affect either denitrification or F(N2O). However, a significant difference (P < 0.04) among reservoirs was found with respect to denitrification (Eagle Creek: 3.2; Geist: 1.6 and Morse: 4.2 mg N kg(-1) h(-1)) and F(N2O) (0.51, 0.24, and 0.31, respectively). Negative relationships (r(2): 0.30-0.64) between F(N2O) and water extractable Cu were found only when the analysis was conducted separately for each reservoir, suggesting that Cu solubility is controlled by sediment properties specific to each reservoir. Overall, results of this study indicate that neither the NO(3)(-)-removal capacity of sediments nor the composition of denitrification N gases is affected by past treatments with cutrine. PMID:19398516

  10. Human freshwater demand for economic activity and ecosystems in Taiwan.

    PubMed

    Ferng, Jiun-Jiun

    2007-12-01

    Freshwater is necessary to economic activity, and humans depend on goods and services generated by water-dependent ecosystems. However, national freshwater management usually focuses on direct use of domestic freshwater. With an increasing scarcity of freshwater, attention has turned to two indirect uses of freshwater by humans. The first indirect use is freshwater used by foreign countries when producing products for export. The second use is freshwater required by local ecosystems: human survival and development depend on goods and services generated in these ecosystems. This work adopted Taiwan as a case study. In addition to two widely recognized ecosystem freshwater demands, evapotranspiration and reversed river flow, this study suggests that freshwater is a constituent of some abiotic components, such as groundwater in aquifers, because excessive withdrawal has already caused significant land subsidence in Taiwan. Moreover, the estimated results show that Taiwan's net imports of freshwater through trade amounts to approximately 25% of its total freshwater use for economic production. Integrating industrial policy, trade policy, and national freshwater management is a useful approach for developing strategies to limit the growing use of freshwater in Taiwan. Policy implications are then developed by further analyzing withdrawal sources of freshwater (domestic and foreign) for supporting economic production in Taiwan and identifying the factors (domestic final demand and export) driving freshwater-intensive products. PMID:17899249

  11. Human Freshwater Demand for Economic Activity and Ecosystems in Taiwan

    NASA Astrophysics Data System (ADS)

    Ferng, Jiun-Jiun

    2007-12-01

    Freshwater is necessary to economic activity, and humans depend on goods and services generated by water-dependent ecosystems. However, national freshwater management usually focuses on direct use of domestic freshwater. With an increasing scarcity of freshwater, attention has turned to two indirect uses of freshwater by humans. The first indirect use is freshwater used by foreign countries when producing products for export. The second use is freshwater required by local ecosystems: human survival and development depend on goods and services generated in these ecosystems. This work adopted Taiwan as a case study. In addition to two widely recognized ecosystem freshwater demands, evapotranspiration and reversed river flow, this study suggests that freshwater is a constituent of some abiotic components, such as groundwater in aquifers, because excessive withdrawal has already caused significant land subsidence in Taiwan. Moreover, the estimated results show that Taiwan’s net imports of freshwater through trade amounts to approximately 25% of its total freshwater use for economic production. Integrating industrial policy, trade policy, and national freshwater management is a useful approach for developing strategies to limit the growing use of freshwater in Taiwan. Policy implications are then developed by further analyzing withdrawal sources of freshwater (domestic and foreign) for supporting economic production in Taiwan and identifying the factors (domestic final demand and export) driving freshwater-intensive products.

  12. History of the production complex: The methods of site selection

    SciTech Connect

    Not Available

    1987-09-01

    Experience taught the Atomic Energy Commission how to select the best possible sites for its production facilities. AEC officials learned from the precedents set by the wartime Manhattan Project and from their own mistakes in the immediate postwar years. This volume discusses several site selections. The sites covered are: (1) the Hanford Reservation, (2) the Idaho reactor site, (3) the Savannah River Plant, (4) the Paducah Gaseous Diffusion Plant, (5) the Portsmouth Gaseous Diffusion Plant, (6) the Fernald Production Center, (7) the PANTEX and Spoon River Plants, (8) the Rocky Flats Fabrication Facility, and (9) the Miamisburg and Pinellas plants. (JDH)

  13. Converting Maturing Nuclear Sites to Integrated Power Production Islands

    DOE PAGESBeta

    Solbrig, Charles W.

    2011-01-01

    Nuclear islands, which are integrated power production sites, could effectively sequester and safeguard the US stockpile of plutonium. A nuclear island, an evolution of the integral fast reactor, utilizes all the Transuranics (Pu plus minor actinides) produced in power production, and it eliminates all spent fuel shipments to and from the site. This latter attribute requires that fuel reprocessing occur on each site and that fast reactors be built on-site to utilize the TRU. All commercial spent fuel shipments could be eliminated by converting all LWR nuclear power sites to nuclear islands. Existing LWR sites have the added advantage ofmore » already possessing a license to produce nuclear power. Each could contribute to an increase in the nuclear power production by adding one or more fast reactors. Both the TRU and the depleted uranium obtained in reprocessing would be used on-site for fast fuel manufacture. Only fission products would be shipped to a repository for storage. The nuclear island concept could be used to alleviate the strain of LWR plant sites currently approaching or exceeding their spent fuel pool storage capacity. Fast reactor breeding ratio could be designed to convert existing sites to all fast reactors, or keep the majority thermal.« less

  14. A comparison of diel nest temperature and nest site selection for two sympatric species of freshwater turtles

    SciTech Connect

    Bodie, J.R.; Burke, V.J.; Smith, K.R.

    1996-07-01

    Diel nest temperature profiles were recorded form natural nests of eastern mud turtles (Kinosternon subrubrum) and Florida cooters (Pseudemys floridana) to determine whether nest microhabitat selection compensates for the effect of interspecific differences in nest depth on nest temperature. Kinosternon subrubrum nest depths were significantly shallower than those of P. floridana (t = 2.93, P < 0.01). We predicted that differences in nest depth would result in K. subrubrum nests being cooler at night and warmer during daylight than the deeper P. floridana nests. Diel temperature patterns agreed with out predictions at night, but P. floridana nest temperatures were not lower than K. subrubrum nest temperatures during the day. Soil composition, slope and soil moisture were similar for the nest of both species. However, the amount of sunlight reaching the soil above K. subrubrum nest sites was substantially less than the amount above P. floridana nest sites. We suggest that these species select habitats for oviposition that differ in the amount and types of vegetative cover, which in turn affect exposure to sunlight and ultimately nest temperature. 27 refs., 2 figs.

  15. Distribution and health risk assessment of trace metals in freshwater tilapia from three different aquaculture sites in Jelebu Region (Malaysia).

    PubMed

    Low, Kah Hin; Zain, Sharifuddin Md; Abas, Mhd Radzi; Md Salleh, Kaharudin; Teo, Yin Yin

    2015-06-15

    The trace metal concentrations in edible muscle of red tilapia (Oreochromis spp.) sampled from a former tin mining pool, concrete tank and earthen pond in Jelebu were analysed with microwave assisted digestion-inductively coupled plasma-mass spectrometry. Results were compared with established legal limits and the daily ingestion exposures simulated using the Monte Carlo algorithm for potential health risks. Among the metals investigated, arsenic was found to be the key contaminant, which may have arisen from the use of formulated feeding pellets. Although the risks of toxicity associated with consumption of red tilapia from the sites investigated were found to be within the tolerable range, the preliminary probabilistic estimation of As cancer risk shows that the 95th percentile risk level surpassed the benchmark level of 10(-5). In general, the probabilistic health risks associated with ingestion of red tilapia can be ranked as follows: former tin mining pool > concrete tank > earthen pond. PMID:25660902

  16. Distribution and seasonality of microbial indicators and thermophilic campylobacters in two freshwater bathing sites on the River Lune in northwest England.

    PubMed

    Obiri-Danso, K; Jones, K

    1999-12-01

    Two freshwater bathing sites, the Crook O'Lune and the University Boathouse, on the River Lune in the north-west of England, were monitored over a 2 year period for the faecal indicators, faecal coliforms and faecal streptococci, the pathogens, Salmonella and Campylobacter, and compliance with the EU Directive on Bathing Water Quality. Faecal indicator numbers showed no seasonal variation, with numbers in the bathing season similar to those in the non-bathing season. They were consistently above the EU Guideline and Imperative standards so that if the EU Bathing Water Quality Directive (76/160/EEC) were applied, neither site would comply. Faecal indicator numbers in the sediments were an order of magnitude higher than in the overlying water. Campylobacter numbers showed seasonal variation in the water with higher counts in winter than in the summer, although numbers were low. Higher numbers were found in the sediments but there was no seasonal variation. Analysis of various inputs showed that indicators and campylobacters came from a mixture of sources, namely a sewage treatment works, agricultural run-off, streams and mallards. Microbial numbers in the water at the Crook O'Lune, which is closer to the sources of pollution, were twice those at the Boathouse. In the sediments they were six to eight times higher. Faecal coliforms were all identified as Escherichia coli of which 80% were a single biotype. Faecal streptococci were all enterococci of which 55% were E. avium, 38% E. faecalis and 7% E. durans. Salmonella was not isolated from either the water column or the sediments. Campylobacters were mainly Camp. jejuni, followed by Camp. coli, UPTC and Camp. lari. PMID:10664907

  17. Freshwater Flow Charts - 1995

    SciTech Connect

    Kaiper, G V

    2003-11-21

    This report covers the following: (1) Explanation of Charts Showing Freshwater Flow in 1995; (2) Estimated U.S. Freshwater Flow in 1995 (chart); (3) Estimated California Freshwater Flow in 1995 (chart); (4) Estimated New Mexico Freshwater Flow in 1995 (chart); and (5) Web locations and credits.

  18. Plutonium and tritium produced in the Hanford Site production reactors

    SciTech Connect

    Roblyer, S.P.

    1994-09-28

    In a news release on December 7, 1993, the Secretary of Energy announced declassification action that included totals for plutonium and tritium production in the Hanford Site production reactors. This information was reported as being preliminary because it was not fully supported by documentation. Subsequently, production data were made available from the US Department of Energy-Headquarters (DOE-HQ) records that indicated an increase of about one and one-half metric tons in total plutonium production. The Westinghouse Hanford Company was tasked by the US Department of Energy-Richland Operations Office to substantiate production figures and DOE-HQ data and to provide a defensible report of weapons- (6 wt% {sup 240}Pu) and nonweapons- (fuels-)grade (nominally 9 wt% or higher {sup 240}Pu) plutonium and tritium production in the Hanford Site production reactors. The task was divided into three parts. The first part was to determine plutonium and tritium production based on available reported accountability records. The second part was to determine plutonium production independently by calculational checks based on reactor thermal power generation and plutonium conversion factors representing the various reactor fuels. The third part was to resolve differences, if they occurred, in the reported and calculational results. In summary, the DOE-HQ-reported accountability records of plutonium and tritium production were determined to be the most defensible record of Hanford Site reactor production. The DOE-HQ records were consistently supported by the independent calculational checks and the records of operational data. Total production quantities are 67.4 MT total plutonium, which includes 12.9 MT of nonweapons-grade plutonium. The total tritium production was 10.6 kg.

  19. Factors Affecting the Contribution by Epiphytic Algae to the Primary Productivity of an Oligotrophic Freshwater Lake1

    PubMed Central

    Sheldon, Richard B.; Boylen, Charles W.

    1975-01-01

    A diatom-dominated population of epiphytic algae was studied in an oligotrophic lake to determine the factors which limit epiphyte growth and to measure their contribution to primary productivity. Algae were collected from plants growing at four sites in Lake George, N.Y., during the spring, summer, and fall of 1974. Samples were taken from 3 m, corresponding to the depth at which macrophytes were most productive. Algae exhibited an optimum temperature for H14CO3- uptake at 30 C, although the summer littoral lake temperature ranged from 18 to 25 C. Light saturation occurred at an intensity of 8,608 lux, approximating the environmental intensity at the depth from which algae were taken. Epiphytes exhibited their maximum photosynthetic capacity of 0.6 mg of carbon fixed/m2 of macrophyte surface area per h in the early afternoon in mid-August. They assimilated approximately 5% as much inorganic carbon as the macrophytes from which they were taken. Epiphyte population densities followed the seasonal growth patterns of the macrophytes, with maximal leaf colonization remaining essentially constant relative to the leaf position on the plant. There was little change in density between sampling sites at any given time. Productivities of epiphytes from bottom leaves were 10-fold greater than those of epiphytes from top leaves. Addition of PO4-3, NO3-, NH3, Si, and SO4-2 had no stimulatory effect on photosynthesis. Addition of HCO3- stimulated photosynthesis greater than 30%, suggesting that carbon may be a limiting nutrient for epiphytic algae in Lake George. PMID:16350036

  20. Utilization of Site-Specific Recombination in Biopharmaceutical Production

    PubMed Central

    Ahmadi, Maryam; Damavandi, Narges; Akbari, Mohammad Reza; Davami, Fatemeh

    2016-01-01

    Mammalian expression systems, due to their capacity in post-translational modification, are preferred systems for biopharmaceutical protein production. Several recombinant protein systems have been introduced to the market, most of which are under clinical development. In spite of significant improvements such as cell line engineering, introducing novel expression methods, gene silencing and process development, expression level is unpredictable and unstable because of the random location of integration in the genome. Site-specific recombination techniques are capable of producing stable and high producer clonal cells; therefore, they are gaining more importance in the biopharmaceutical production. Site-specific recombination methods increase the recombinant protein production by specifically inserting a vector at a locus with specific expression trait. The present review focused on the latest developments in site-specific recombination techniques, their specific features and comparisons. PMID:26602035

  1. Marine Incursion: The Freshwater Herring of Lake Tanganyika Are the Product of a Marine Invasion into West Africa

    PubMed Central

    Wilson, Anthony B.; Teugels, Guy G.; Meyer, Axel

    2008-01-01

    The spectacular marine-like diversity of the endemic fauna of Lake Tanganyika, the oldest of the African Great Lakes, led early researchers to suggest that the lake must have once been connected to the ocean. Recent geophysical reconstructions clearly indicate that Lake Tanganyika formed by rifting in the African subcontinent and was never directly linked to the sea. Although the Lake has a high proportion of specialized endemics, the absence of close relatives outside Tanganyika has complicated phylogeographic reconstructions of the timing of lake colonization and intralacustrine diversification. The freshwater herring of Lake Tanganyika are members of a large group of pellonuline herring found in western and southern Africa, offering one of the best opportunities to trace the evolutionary history of members of Tanganyika's biota. Molecular phylogenetic reconstructions indicate that herring colonized West Africa 25–50MYA, at the end of a major marine incursion in the region. Pellonuline herring subsequently experienced an evolutionary radiation in West Africa, spreading across the continent and reaching East Africa's Lake Tanganyika during its early formation. While Lake Tanganyika has never been directly connected with the sea, the endemic freshwater herring of the lake are the descendents of an ancient marine incursion, a scenario which may also explain the origin of other Tanganyikan endemics. PMID:18431469

  2. Food production and consumption near the Savannah River Site

    SciTech Connect

    Hamby, D.M.

    1991-01-01

    Routine operations at the Savannah River Site (SRS) result in the release of radionuclides to the atmosphere and to the Savannah River. The resulting radiological doses to the off-site maximum individual and the 80-km population are estimated on a yearly basis. These estimates are generated using dose models prescribed in the NRC Reg. Guide 1.109 for the commercial nuclear power industry. A study of land and water usage characteristics in the region of the Savannah River Site has been conducted to determine site-specific values of the NRC dose model parameters. The study's scope included local characteristics of meat, milk, vegetable production; Savannah River recreational activities and fish harvests; meat, milk, vegetable, and seafood consumption rates; and Savannah River drinking-water populations. Average and maximum consumption rates of beef, milk, vegetables, and fish have been determined for individuals residing in the southern United States. The study suggest that many of the consumption rates provided by the NRC may not be appropriate for residents of the South. Average consumption rates are slightly higher than the defaults provided by the NRC. Maximum consumption rates, however, are typically lower than NRC values. Agricultural productivity in the SRS region was found to be quite different than NRC recommendations. Off-site doses have been predicted using both NRC and SRS parameter values to demonstrate the significance of site-specific data.

  3. Food production and consumption near the Savannah River Site

    SciTech Connect

    Hamby, D.M.

    1991-12-31

    Routine operations at the Savannah River Site (SRS) result in the release of radionuclides to the atmosphere and to the Savannah River. The resulting radiological doses to the off-site maximum individual and the 80-km population are estimated on a yearly basis. These estimates are generated using dose models prescribed in the NRC Reg. Guide 1.109 for the commercial nuclear power industry. A study of land and water usage characteristics in the region of the Savannah River Site has been conducted to determine site-specific values of the NRC dose model parameters. The study`s scope included local characteristics of meat, milk, vegetable production; Savannah River recreational activities and fish harvests; meat, milk, vegetable, and seafood consumption rates; and Savannah River drinking-water populations. Average and maximum consumption rates of beef, milk, vegetables, and fish have been determined for individuals residing in the southern United States. The study suggest that many of the consumption rates provided by the NRC may not be appropriate for residents of the South. Average consumption rates are slightly higher than the defaults provided by the NRC. Maximum consumption rates, however, are typically lower than NRC values. Agricultural productivity in the SRS region was found to be quite different than NRC recommendations. Off-site doses have been predicted using both NRC and SRS parameter values to demonstrate the significance of site-specific data.

  4. Analysis of data from test-well sites along the downdip limit of freshwater in the Edwards Aquifer, San Antonio, Texas, 1985-87

    USGS Publications Warehouse

    Groschen, G.E.

    1994-01-01

    A consistent trend in the water quality was not detected in the monitor-well data for July 1986-April 1987. This was caused, in part, by the average to above-average rainfall and by the lack of large withdrawals during the period. The water quality of samples from several of the wells was similar to the water quality determined by a previous study of the area. Geochemistry of the oil- or gas-well brines from downdip in the saline-water zone had slight resemblance to the geochemistry of the water at the downdip limit of freshwater; updip flow of saline water toward the freshwater zone was not indicated.

  5. Methyl Bromide Alternatives for Floriculture Production in a Problem Site

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Successful methyl bromide alternatives must manage a variety of pest problems in floriculture and vegetable production systems including weeds, plant-parasitic nematodes, and soil-borne diseases. Methods that may be successful in some situations may be challenged in sites with unusually heavy pest p...

  6. Petroleum fingerprinting: Effective identification of petroleum products at contaminated sites

    SciTech Connect

    Uhler, A.D.

    1997-07-01

    A critical issue in many environmental liability cases is the successful identification of the parties responsible for petroleum products that contaminate sites or properties. Identification of these parties is critical for owners of petroleum contaminated sites who are seeking to spread liability by identifying previous owners or operators of nearby properties who may be the source of, and thus be responsible for, the petroleum contamination at these sites. This issue is also critical for these potential defendants who will seek to demonstrate that the petroleum products associated with their activities could not be the source of the contamination in question. Finally, the issue is critical in situations where multiple responsible parties seek to equitably allocate among themselves shares of contamination and associated clean-up costs.

  7. Management of Hanford Site non-defense production reactor spent nuclear fuel, Hanford Site, Richland, Washington

    SciTech Connect

    1997-03-01

    The US Department of Energy (DOE) needs to provide radiologically, and industrially safe and cost-effective management of the non-defense production reactor spent nuclear fuel (SNF) at the Hanford Site. The proposed action would place the Hanford Site`s non-defense production reactor SNF in a radiologically- and industrially-safe, and passive storage condition pending final disposition. The proposed action would also reduce operational costs associated with storage of the non-defense production reactor SNF through consolidation of the SNF and through use of passive rather than active storage systems. Environmental, safety and health vulnerabilities associated with existing non-defense production reactor SNF storage facilities have been identified. DOE has determined that additional activities are required to consolidate non-defense production reactor SNF management activities at the Hanford Site, including cost-effective and safe interim storage, prior to final disposition, to enable deactivation of facilities where the SNF is now stored. Cost-effectiveness would be realized: through reduced operational costs associated with passive rather than active storage systems; removal of SNF from areas undergoing deactivation as part of the Hanford Site remediation effort; and eliminating the need to duplicate future transloading facilities at the 200 and 400 Areas. Radiologically- and industrially-safe storage would be enhanced through: (1) removal from aging facilities requiring substantial upgrades to continue safe storage; (2) utilization of passive rather than active storage systems for SNF; and (3) removal of SNF from some storage containers which have a limited remaining design life. No substantial increase in Hanford Site environmental impacts would be expected from the proposed action. Environmental impacts from postulated accident scenarios also were evaluated, and indicated that the risks associated with the proposed action would be small.

  8. SEASONAL EFFECTS ON MICROBIAL TRANSFORMATION RATES OF AN HERBICIDE IN A FRESHWATER STREAM: APPLICATION OF LABORATORY DATA TO A FIELD SITE

    EPA Science Inventory

    Seasonal effects on microbial transformation rates of an herbicide, 2,4-dichlorophenoxyacetic acid butoxyethyl ester (2,4-DBE), in a freshwater stream were investigated using low concentrations (less than 100 micrograms L(-1)) of the herbicide mixed with an inert dye, rhodamine W...

  9. Site selection modeling system for a production facility at Savannah River site

    SciTech Connect

    Shedrow, C.B.; Shedrow, D.M.

    1996-12-31

    The Savannah River site (SRS) is located along the Savannah River in southwestern South Carolina and encompasses an area of {approximately}832 km (198 344 acres). Major land covers include evergreen and deciduous forests, surface water, wetlands, and administrative/industrial areas. Less than 10% of the site`s surface area is developed. Several endangered and threatened species are found on the SRS, including the red-cockaded woodpecker, the southern bald eagle, the wood stork, and the smooth purple coneflower. With the cessation of the Cold War, the traditional defense-related missions at the SRS have been significantly reduced. The implementation of new missions at the SRS will require the utilization of effective siting and prioritization methodologies to ensure the best use of available land resources and protection of the environment. The objective of this paper is to describe the utilization of the Site Selection Modeling System (SSMS) for the selection of potential industrial development sites within the SRS. The SSMS is a raster geographic information system (GIS)-based system that integrates the graphical interface ArcView 2.1 with the GRID modeling functionality of ARC/INFO. The proposed industrial development being sited is a linear accelerator, which will be used for the accelerator production of tritium.

  10. Freshwater macroinvertebrates

    SciTech Connect

    Nalepa, T.F.; Quigley, M.A.

    1980-06-01

    Review papers on the subjects of organic wastes, physical environmental alterations, distribution and habitat requirements, production, food and feeding, periodicity and drift, animal-sediment interactions, and methods dealing with the above are discussed. (DAD)

  11. Impact of freshwater inflow on bacterial abundance and activity in the estuarine system Ria de Aveiro

    NASA Astrophysics Data System (ADS)

    Santos, Luísa; Vaz, Leandro; Marcial Gomes, Newton C.; Vaz, Nuno; Dias, João Miguel; Cunha, Ângela; Almeida, Adelaide

    2014-02-01

    The influence of freshwater flow on bacterial communities in the estuarine system Ria de Aveiro (Portugal) was investigated at two sites differently impacted by river inputs, representative of the marine and brackish water zones of the estuary. Sampling events were clustered based on hydrological features. The hydrodynamic was simulated with a Lagrangian model and related to microbiological parameters. Estuarine bacteria responded to different freshwater regimes developing distinct patterns of abundance and activity at the marine and brackish water zones. A circulation pattern induced by high river inflow produced vertical stratification in the marine zone, promoting a seaward flux of bacterioplankton, and stimulating the import of riverine phytoplankton and particle-attached bacteria to the brackish water zone. Advective transport and resuspension processes contributed to a 3-times increase in abundance of particle-attached bacteria during intense freshwater inputs. Additionally, bacterial activity in the estuary was controlled by inorganic nitrogen, responding to different freshwater inputs, which, in association with different prevailing sources of organic substrates induced significant changes in bacterial production. The dynamic and main controlling factors of bacterial communities are clearly impacted by freshwater inputs. Therefore, significant changes in the recycling of nutrients by microbial activities can be expected from alterations in freshwater inputs either related to global climate change or regional hydrological regimes.

  12. Preliminary obervations on use of ethanol distiller's by-products for polyculture of freshwater prawn (Macrobrachium rosenbergii) and golden shiner (Notemigonus crysoleucas)

    SciTech Connect

    Kohler, C.C.; Lewis, W.M.; Krueger, S.P.

    1983-01-01

    Two major by-products of ethanol distillation, corn distiller's solubles and corn distiller's mash, were evaluated for their potential use as a food source for freshwater prawn (Macrobrachium rosenbergii) and golden shiner (Notemigonus crysoleucas) in mid-western United States. Corn distiller's solubles were not found to be highly toxic to aquatic organisms at concentrations ranging up to 10,000 ppM. However, the high biological oxygen demand of the material requires that single applications not exceed 2000 ppM. Yield trials were conducted over a four month period in five 0.1 ha earthen ponds, located in proximity to an ethanol distillery. Each pond was stocked with 2000 postlarval shrimp (0.02 g mean weight). Three of these ponds were also each stocked with 75 adult golden shiner (27.0 g mean weight). One application of corn distiller's solubles (equivalent to approx. 2000 ppM) and three applications of corn distiller's mash (approx. 5 kg/application) were made over the course of the yield trails (approx. 120 days). No other food or fertilizer was added to the ponds. Survival of shrimp ranged from 34 to 75%. Survival of brood fish exceeded 90%. Mean weight of shrimp at harvest was approximately 12 g, and average production was equivalent to approximately 104 kg ha/sup -1/. Golden shiner reared in the same ponds as shrimp had production rates equivalent to approxmately 130 kg ha/sup -1/. The presence of fish did not appear to impede shrimp production. Although production results of fish and shrimp were encouraging, several factors existed which impeded production; these included: (1) little by-product was applied to ponds because the distillery was undergoing its shakedown period; (2) ponds were new and had minimal natural productivity; (3) grass was not fully established on the watershed and ponds became turbid; and (4) lower than normal temperatures prevailed over much of the growing period. 11 references, 2 figures, 8 tables.

  13. Isotope Production at the Hanford Site in Richland, Washington

    SciTech Connect

    Ammoniums

    1999-06-01

    This report was prepared in response to a request from the Nuclear Energy Research Advisory Committee (NERAC) subcommittee on ''Long-Term Isotope Research and Production Plans.'' The NERAC subcommittee has asked for a reply to a number of questions regarding (1) ''How well does the Department of Energy (DOE) infrastructure sme the need for commercial and medical isotopes?'' and (2) ''What should be the long-term role of the federal government in providing commercial and medical isotopes?' Our report addresses the questions raised by the NERAC subcommittee, and especially the 10 issues that were raised under the first of the above questions (see Appendix). These issues are related to the isotope products offered by the DOE Isotope Production Sites, the capabilities and condition of the facilities used to produce these products, the management of the isotope production programs at DOE laboratories, and the customer service record of the DOE Isotope Production sites. An important component of our report is a description of the Fast Flux Test Facility (FFTF) reactor at the Hbford Site and the future plans for its utilization as a source of radioisotopes needed by nuclear medicine physicians, by researchers, and by customers in the commercial sector. In response to the second question raised by the NERAC subcommittee, it is our firm belief that the supply of isotopes provided by DOE for medical, industrial, and research applications must be strengthened in the near future. Many of the radioisotopes currently used for medical diagnosis and therapy of cancer and other diseases are imported from Canada, Europe, and Asia. This situation places the control of isotope availability, quality, and pricing in the hands of non-U.S. suppliers. It is our opinion that the needs of the U.S. customers for isotopes and isotope products are not being adequately served, and that the DOE infrastructure and facilities devoted to the supply of these products must be improved This perception

  14. Assessing The Ecosystem Service Freshwater Production From An Integrated Water Resources Management Perspective. Case Study: The Tormes Water Resources System (Spain)

    NASA Astrophysics Data System (ADS)

    Momblanch, Andrea; Paredes-Arquiola, Javier; Andreu, Joaquín; Solera, Abel

    2014-05-01

    The Ecosystem Services are defined as the conditions and processes through which natural ecosystems, and the species that make them up, sustain and fulfil human life. A strongly related concept is the Integrated Water Resources Management. It is a process which promotes the coordinated development and management of water, land and related resources in order to maximise the resultant economic and social welfare in an equitable manner without compromising the sustainability of vital ecosystems. From these definitions, it is clear that in order to cover so many water management and ecosystems related aspects the use of integrative models is increasingly necessary. In this study, we propose to link a hydrologic model and a water allocation model in order to assess the Freshwater Production as an Ecosystem Service in anthropised river basins. First, the hydrological model allows determining the volume of water generated by each sub-catchment; that is, the biophysical quantification of the service. This result shows the relevance of each sub-catchment as a source of freshwater and how this could change if the land uses are modified. On the other hand, the water management model allocates the available water resources among the different water uses. Then, it is possible to provide an economic value to the water resources through the use of demand curves, or other economic concepts. With this second model, we are able to obtain the economical quantification of the Ecosystem Service. Besides, the influence of water management and infrastructures on the service provision can be analysed. The methodology is applied to the Tormes Water Resources System, in Spain. The software used are EVALHID and SIMGES, for hydrological and management aspects, respectively. Both models are included in the Decision Support System Shell AQUATOOL for water resources planning and management. A scenario approach is presented to illustrate the potential of the methodology, including the current

  15. Increasing sulfate concentrations result in higher sulfide production and phosphorous mobilization in a shallow eutrophic freshwater lake.

    PubMed

    Chen, Mo; Li, Xiao-Hong; He, Yu-Hong; Song, Na; Cai, Hai-Yuan; Wang, Changhui; Li, Yun-Tao; Chu, Hai-Yan; Krumholz, Lee R; Jiang, He-Long

    2016-06-01

    Increasing sulfate input has been seen as an issue in management of aquatic ecosystems, but its influences on eutrophic freshwater lakes is not clear. In this study, it was observed that increasing sulfate concentration without additional cyanobacterial bloom biomass (CBB) addition did not have an obvious effect on element cycling during 1-year continuous flow mesocosm experiments in which water and sediments were taken from a shallow eutrophic lake with sulfate levels near 1 mM. However, following addition of CBB to mesocosms, sulfate-reducing bacteria (SRB) were observed in the water column, and increasing numbers of SRB in the water column were associated with higher sulfate input. Sulfate amendment (0-70 mg L(-1)) also resulted in a larger amount of total dissolved sulfide (peak values of 5.90 ± 0.36 to 7.60 ± 0.12 mg L(-1)) in the water column and acid volatile sulfide (1081.71 ± 69.91 to 1557.98 ± 41.72 mg kg(-1)) in 0-1 cm surface sediments due to sulfate reduction. During the period of CBB decomposition, increasing sulfate levels in the water column were positively correlated with increasing diffusive phosphate fluxes of 1.23 ± 0.32 to 2.17 ± 0.01 mg m(-2) d(-1) at the water-sediment interface. As increases in sulfide and phosphate release rates deteriorated the water quality/ecosystem and even spurred the occurrence of a black water problem in lakes, the control of sulfate input level should be considered for shallow eutrophic lake management, especially during cyanobacterial bloom periods. PMID:27023925

  16. Cable Bacteria in Freshwater Sediments

    PubMed Central

    Kristiansen, Michael; Frederiksen, Rasmus B.; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and electric fields indicated electron transfer between vertically separated anodic and cathodic half-reactions. Fluorescence in situ hybridization revealed the presence of Desulfobulbaceae filaments. In addition, in situ measurements of oxygen, pH, and electric potential distributions in the waterlogged banks of Giber Å demonstrated the presence of distant electric redox coupling in naturally occurring freshwater sediment. At the same site, filamentous Desulfobulbaceae with cable bacterium morphology were found to be present. Their 16S rRNA gene sequence placed them as a distinct sister group to the known marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary origin of the cable phenotype within Desulfobulbaceae with subsequent diversification into a freshwater and a marine lineage. PMID:26116678

  17. Cable Bacteria in Freshwater Sediments.

    PubMed

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus B; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-09-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and electric fields indicated electron transfer between vertically separated anodic and cathodic half-reactions. Fluorescence in situ hybridization revealed the presence of Desulfobulbaceae filaments. In addition, in situ measurements of oxygen, pH, and electric potential distributions in the waterlogged banks of Giber Å demonstrated the presence of distant electric redox coupling in naturally occurring freshwater sediment. At the same site, filamentous Desulfobulbaceae with cable bacterium morphology were found to be present. Their 16S rRNA gene sequence placed them as a distinct sister group to the known marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary origin of the cable phenotype within Desulfobulbaceae with subsequent diversification into a freshwater and a marine lineage. PMID:26116678

  18. Resource evaluation and site selection for microalgae production systems

    SciTech Connect

    Maxwell, E.L.; Folger, A.G.; Hogg, S.E.

    1985-05-01

    Climate, land, and water resource requirements of microalgae production systems (MPS) were examined relative to construction costs, operating costs, and biomass productivity. The objective was the stratification of the southwestern United States into zones of relative suitability for MPS. Maps of climate (insolation, freeze-free period, precipitation, evaporation, thunderstorm days), land (use/cover, ownership, slope), and water (saline groundwater) resource parameters were obtained. These maps were transformed into digital overlays permitting the cell-by-cell compositing of selected resource parameters to form maps representing relative productivity, make-up water, climate suitability, land suitability, water suitability, and overall suitability. The Southwest was selected for this study because of its high levels of insolation, saline water resources, and large areas of relatively low valued land. The stratification maps cannot be used for the selection of specific sites because of their low resolution (12,455-acre cells). They can be used to guide future resource studies and site selection efforts, however, by limiting these efforts to the most suitable regions. Future efforts should concentrate on saline water resources, for which only limited data are currently available. 13 refs., 44 figs., 5 tabs.

  19. The alpha/beta ocean distinction: A perspective on freshwater fluxes, convection, nutrients and productivity in high-latitude seas

    NASA Astrophysics Data System (ADS)

    Carmack, Eddy C.

    2007-11-01

    Stratification is perhaps the most important attribute of oceans with regards to climate and biology. Two simple aspects of the ocean's climate system appear to have a surprisingly important role in transforming waters that feed the global thermohaline circulation, dominating patterns of biogeochemical flux and establishing macroecological domains. First, largely because of meridional distillation (mainly due to the atmospheric transport of freshwater across the Isthmus of Panama) the North Pacific is fresher than the North Atlantic. Second, largely because of zonal distillation (e.g., warming and evaporation at low latitudes and poleward transport of latent heat and moisture by the atmosphere) the upper layers of subtropical seas are permanently stratified by temperature ( NT2= gαd T/d z>0; here called alpha oceans), while the upper layers of high-latitude seas are permanently stratified by salinity ( NS2= gβd S/d z>0; here called beta oceans). The physical basis for the boundary separating alpha and beta oceans is unclear, but may lie in the thermodynamical equations published by Fofonoff [1961. Energy transformations in the sea. Fisheries Research Board of Canada, Report Series 109, 82pp]. Nevertheless, it is clear that the resulting thermohaline distributions establish a 'downhill journey' of low-salinity (and nutrient-rich) waters from the North Pacific to the Arctic and then into the North Atlantic. The Arctic Ocean—itself—acts a double estuary, whereby waters entering from the North Atlantic become either denser through cooling (negative estuary) or lighter by freshening (positive estuary) as they circulate within the basin and then return to the North Atlantic as a variety of components of the ocean's conveyor. Intermediate and deep waters generally form within cyclonic beta oceans in close proximity to alphas systems. Similar patterns of stratification, nutrients and biogeographical boundaries persist in the Southern Hemisphere. It is thus argued

  20. Methane production and isotopic fingerprinting in ethanol fuel contaminated sites.

    PubMed

    Freitas, Juliana G; Fletcher, Barbara; Aravena, Ramon; Barker, James F

    2010-01-01

    Biodegradation of organic compounds in groundwater can be a significant source of methane in contaminated sites. Methane might accumulate in indoor spaces posing a hazard. The increasing use of ethanol as a gasoline additive is a concern with respect to methane production since it is easily biodegraded and has a high oxygen demand, favoring the development of anaerobic conditions. This study evaluated the use of stable carbon isotopes to distinguish the methane origin between gasoline and ethanol biodegradation, and assessed the occurrence of methane in ethanol fuel contaminated sites. Two microcosm tests were performed under anaerobic conditions: one test using ethanol and the other using toluene as the sole carbon source. The isotopic tool was then applied to seven field sites known to be impacted by ethanol fuels. In the microcosm tests, it was verified that methane from ethanol (δ¹³C = -11.1‰) is more enriched in ¹³C, with δ¹³C values ranging from -20‰ to -30‰, while the methane from toluene (δ¹³C = -28.5‰) had a carbon isotopic signature of -55‰. The field samples had δ¹³C values varying over a wide range (-10‰ to -80‰), and the δ¹³C values allowed the methane source to be clearly identified in five of the seven ethanol/gasoline sites. In the other two sites, methane appears to have been produced from both sources. Both gasoline and ethanol were sources of methane in potentially hazardous concentrations and methane could be produced from organic acids originating from ethanol along the groundwater flow system even after all the ethanol has been completed biodegraded. PMID:20070380

  1. Groundwater modeling of the proposed new production reactor site, Savannah River Site, South Carolina

    SciTech Connect

    Looney, B.B.; Haselow, J.S.; Andersen, P.F.; Spalding, C.P.; Davis, D.H.

    1990-01-05

    This report addresses groundwater modeling performed to support the Environmental Impact Statement (EIS) that is being prepared by the Department of Energy (DOE). The EIS pertains to construction and operation of a new production reactor (NPR) that is under consideration for the Savannah River Site (SRS). Three primary issues are addressed by the modeling analysis: (1) groundwater availability, (2) changes in vertical hydraulic gradients as a result of groundwater pumpage, and (3) migration of potential contaminants from the NPR site. The modeling indicates that the maximum pumpage to be used, 1000 gpm, will induce only minor drawdown across SRS. Pumpage of this magnitude will have a limited effect on the upward gradient from the Cretaceous into the Tertiary near Upper Three Runs Creek. Potentiometric surface maps generated from modeled results indicate that horizontal flow in the water table is either towards Four Mile Creek to the north or to Pen Branch on the south. Particle tracking analysis indicates that the primary flow paths are vertical into the Lower Tertiary Zone, with very little lateral migration. Total travel times from the NPR site to the edge of the model (approximately 3 miles) is on the order of 50 years. The flow direction of water in the Lower Tertiary Zone is relatively well defined due to the regional extent of the flow system. The Pen Branch Fault does not influence contaminant migration for this particular site because it is in the opposite direction of Lower Tertiary Zone groundwater flow. 20 refs., 27 figs., 2 tabs.

  2. Redox potential: An indicator of site productivity in forest management

    NASA Astrophysics Data System (ADS)

    Sajedi, Toktam; Prescott, Cindy; Lavkulich, Les

    2010-05-01

    Redox potential (Eh) is an integrated soil measurement that reflects several environmental conditions in the soil associated with aeration, moisture and carbon (organic matter) dynamics. Its measurement can be related to water table fluctuations, precipitation and landscape gradients, organic matter decomposition rates, nutrient dynamics, biological diversity and plant species distribution. Redox is an excellent indicator of soil biological processes, as it is largely a reflection of microbial activities which to a large extent govern carbon dynamics and nutrient cycling. Redox thus serves as an ecological indicator of site productivity at the ecosystem scale and may be used for management purposes as its magnitude can be altered by activities such as harvesting and drainage. A threshold value of 300 mv has been documented as the critical value below which anaerobic conditions in the soil develop. However, redox measurements and its impacts on ecosystem processes such as nutrient cycling and productivity, especially in forest ecosystems, have not received the attention that this "master" variable deserves, On northern Vancouver Island, Canada, regenerating stands of western redcedar-western hemlock (CH) sites exhibit symptoms of nutrient deficiencies and slow growth, but this phenomenon does not occur on adjacent western hemlock- amabalis fir (HA) sites. We tested the hypothesis that differences in nutrient supply and distribution of plant species was caused by differences in moisture regime and redox potential. Redox potential, pH, soil aeration depth (steel rods), organic matter thickness, bulk density, soil carbon store, plant species distribution and richness were measured at five old-growth and five 10-year-old cutover blocks. Results of investigations confirmed that CH forests were wetter, had redox values lower than the critical 300mv and a shallower aerated zone, compared with adjacent regenerating HA sites. Fifty percent of the CH plots had redox values

  3. Sulfur cycling in freshwater sediments

    NASA Technical Reports Server (NTRS)

    Klug, M. J.

    1985-01-01

    Organic sulfur containing compounds represent greater than 80% of the total sulfur in sediments of eutrophic freshwater lakes. Although sedimentary sulfur is predominantly in the form of organic compounds, more sulfur is transformed by sulfate reduction than by any other process. Rates of sulfate reduction in these sediments average 7 mmol/sq m/day. This rate is 19 times greater than the net rate of production of inorganic sulfur from organic compounds on an annual basis.

  4. Treatment of Dairy Manure Effluent Using Freshwater Algae in Outdoor Pilot-Scale Raceways: Algal Production and Nutrient Recovery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An alternative practice to land spreading of manure effluents is to grow crops of algae on the nitrogen (N) and phosphorus (P) present in these liquid slurries. The objective of this study was to determine how algal productivity, nutrient removal efficiency, and elemental composition of turf algae ...

  5. Trade-offs in plant responses to herbivory influence trophic routes of production in a freshwater wetland.

    PubMed

    Cherry, Julia A; Gough, Laura

    2009-09-01

    Responses of aquatic macrophytes to leaf herbivory may differ from those documented for terrestrial plants, in part, because the potential to maximize growth following herbivory may be limited by the stress of being rooted in flooded, anaerobic sediments. Herbivory on aquatic macrophytes may have ecosystem consequences by altering the allocation of nutrients and production of biomass within individual plants and changing the quality and quantity of aboveground biomass available to consumers or decomposers. To test the effects of leaf herbivory on plant growth and production, herbivory of a dominant macrophyte, Nymphaea odorata, by chrysomelid beetles and crambid moths was controlled during a 2-year field experiment. Plants exposed to herbivory maintained, or tended to increase, biomass and aboveground net primary production relative to controls, which resulted in 1.5 times more aboveground primary production entering the detrital pathway of the wetland. In a complementary greenhouse experiment, the effects of simulated leaf herbivory on total plant responses, including biomass and nutrient allocation, were investigated. Plants in the greenhouse responded to moderate herbivory by maintaining aboveground biomass relative to controls, but this response occurred at the expense of belowground growth. Results of these studies suggest that N. odorata may tolerate moderate levels of herbivory by reallocating biomass and resources aboveground, which in turn influences the quantity, quality and fate of organic matter available to herbivores and decomposers. PMID:19590899

  6. Biological assessment of proposed US Army Corps of Engineers navigation dredging and disposal on freshwater mussels at sites downstream from Cordell Hull Dam, Cumberland River miles 303. 8 to 309. 2

    SciTech Connect

    Jenkinson, J.J.; Hickman, G.D.

    1983-10-01

    Preimpoundment survey data indicate that at least four freshwater mussel species now listed as endangered by the US Fish and Wildlife Service (Dromus dromas, Lampsilis orbiculata, Plethobasus cooperianus and Pleurobema plenum) once occurred in or near CRM 303 to 309. Post impoundment surveys, including this study, indicate the L. orbiculata is widespread but uncommon throughout at least a 40 mile reach of the upper Cumberland River while the other three species persist only as rare old individuals. This survey of potential dredge, disposal and adjacent sites in CRM 305.8 to 309.1 indicated that the mussel fauna consisted of 22 species and was not particularly abundant. Lampsilis orbiculata was found to occur in proposed dredge sites at CRM 305.3, 306.5 and 307.0. The diversity and density of other species at CRM 305.5 suggested that L. orbiculata also may occur at that proposed dredge site. The single potential disposal site where L. orbiculata was found is located at CRM 305.1 to .5. Pleurobema plenum was found only at the proposed dredge site at CRM 307.0. Extensive habitat modification at any of the five dredge or disposal sites where endangered species were found or suspected, could be expected to eliminate resident specimens. Loss of L. orbiculata specimens at these sites would not constitute a substantial impact to the species throughout its range or in this reach of the Cumberland River. Loss of P. plenum at CRM 307.0 would eliminate a few of the surviving specimens of this species in the river. 10 references, 2 figures, 4 tables.

  7. Multi-site production planning in hybrid make-to-stock/make-to-order production environment

    NASA Astrophysics Data System (ADS)

    Rafiei, Hamed; Rabbani, Masoud; Kokabi, Reza

    2014-06-01

    Today competitive environment has enforced practitioners and researchers to pay great attention to issues enhancing both production and marketing competitiveness. To do so, it has been obligatory for the firms to consider production side activities while customer requirements are on the other side of competition. In this regard, hybrid make-to-stock (MTS)/make-to-order (MTO) production systems have revealed outstanding results. This paper addresses multi-site production planning of a hybrid manufacturing firm for the first time in the hybrid systems' body of literature. In this regard, a network of suppliers, manufacturers and customers is considered for which a mixed-integer mathematical model is proposed. Objective function of the proposed mathematical model seeks to maximize profitability of the manufacturing firm. Because of computational complexity of the developed mathematical model, a genetic algorithm is developed upon which numerical experiments are reported in order to show validity and applicability of the proposed model.

  8. Studies on Bioflocculant Production by Arthrobacter sp. Raats, a Freshwater Bacteria Isolated from Tyume River, South Africa

    PubMed Central

    Mabinya, Leonard V.; Cosa, Sekelwa; Nwodo, Uchechukwu; Okoh, Anthony I.

    2012-01-01

    A bioflocculant-producing bacteria was isolated from Tyume River in the Eastern Cape Province, South Africa and identified by 16S rRNA gene nucleotide sequence to have 91% similarity to Arthrobacter sp. 5J12A, and the nucleotide sequence was deposited in GenBank as Arthrobacter sp. Raats (accession number HQ875723). The bacteria produced an extracellular bioflocculant when grown aerobically in a production medium containing glucose as sole carbon source and had an initial pH of 7.0. Influences of carbon, nitrogen and metal ions sources, as well as initial pH on flocculating activity were investigated. The bacteria optimally produced the bioflocullant when lactose and urea were used as sole sources of carbon and nitrogen respectively with flocculating activities of 75.4% and 83.4% respectively. Also, the bacteria produced the bioflocculant optimally when initial pH of the medium was 7.0 (flocculating activity 84%), and when Mg2+ was used as cation (flocculating activity 77%). Composition analyses indicated the bioflocculant to be principally a glycoprotein made up of about 56% protein and 25% total carbohydrate. PMID:22312304

  9. Vegetative community control of freshwater availability: Phoenix Islands case study

    NASA Astrophysics Data System (ADS)

    Engels, M.; Heinse, R.

    2014-12-01

    On small low islands with limited freshwater resources, terrestrial plant communities play a large role in moderating freshwater availability. Freshwater demands of vegetative communities are variable depending on the composition of the community. Hence, changes to community structure from production crop introductions, non-native species invasions, and climate change, may have significant implications for freshwater availability. Understanding how vegetative community changes impact freshwater availability will allow for better management and forecasting of limited freshwater supplies. To better understand these dynamics, we investigated three small tropical atolls in the Phoenix Island Protected Area, Kiribati. Despite their close proximity, these islands receive varying amounts of rainfall, are host to different plant communities and two of the islands have abandoned coconut plantations. Using electromagnetic induction, ground penetrating radar, soil samples, climate and satellite data, we present preliminary estimates of vegetative water demand for different tropical plant communities.

  10. Heavy Metals in the Vegetables Collected from Production Sites

    PubMed Central

    Taghipour, Hassan; Mosaferi, Mohammad

    2013-01-01

    Background: Contamination of vegetable crops (as an important part of people's diet) with heavy metals is a health concern. Therefore, monitoring levels of heavy metals in vegetables can provide useful information for promoting food safety. The present study was carried out in north-west of Iran (Tabriz) on the content of heavy metals in vegetable crops. Methods: Samples of vegetables including kurrat (n=20) (Allium ampeloprasumssp. Persicum), onion (n=20) (Allium cepa) and tomato (n=18) (Lycopersiconesculentum var. esculentum), were collected from production sites in west of Tabriz and analyzed for presence of Cd, Cr, Cu, Ni, Pb and Zn by atomic absorption spectroscopy (AAS) after extraction by aqua regia method (drying, grounding and acid diges­tion). Results: Mean ± SD (mg/kg DW) concentrations of Cd, Cu, Cr, Ni and Zn were 0.32 ± 0.58, 28.86 ± 28.79, 1.75 ± 2.05, 6.37± 5.61 and 58.01 ± 27.45, respec­tively. Cr, Cu and Zn were present in all the samples and the highest concentra­tions were observed in kurrat (leek). Levels of Cd, Cr and Cu were higher than the acceptable limits. There was significant difference in levels of Cr (P<0.05) and Zn (P<0.001) among the studied vegetables. Positive correlation was observed be­tween Cd:Cu (R=0.659, P<0.001) Cr:Ni (R=0.326, P<0.05) and Cr:Zn (R=0.308, P<0.05).   Conclusion: Level of heavy metals in some of the analyzed vegetables, especially kurrat samples, was higher than the standard levels. Considering the possi­ble health outcomes due to the consumption of contaminated vegetables, it is re­quired to take proper actions for avoiding people's chronic exposure. PMID:24688968

  11. Institutional development of freshwater fish stocking in Mexico.

    PubMed

    Ibáñez, A L; Pérez-Ramírez, M; García-Calderón, J L

    2014-12-01

    By using freshwater fish stocking information from the Mexican government, this work described the current situation of the national stocking and its associated fishery policy. There is a lack of effective freshwater stocking programmes as a result of limited fisheries management, unharmonized fisheries regulations and institutional performance. The fry production has decreased from 140 to 20 million in the past 11 years. PMID:25146570

  12. Sediment accretion in tidal freshwater forests and oligohaline marshes of the Waccamaw and Savannah Rivers, USA

    USGS Publications Warehouse

    Ensign, Scott H.; Hupp, Cliff R.; Noe, Gregory B.; Krauss, Ken W.; Stagg, Camille L.

    2014-01-01

    Sediment accretion was measured at four sites in varying stages of forest-to-marsh succession along a fresh-to-oligohaline gradient on the Waccamaw River and its tributary Turkey Creek (Coastal Plain watersheds, South Carolina) and the Savannah River (Piedmont watershed, South Carolina and Georgia). Sites included tidal freshwater forests, moderately salt-impacted forests at the freshwater–oligohaline transition, highly salt-impacted forests, and oligohaline marshes. Sediment accretion was measured by use of feldspar marker pads for 2.5 year; accessory information on wetland inundation, canopy litterfall, herbaceous production, and soil characteristics were also collected. Sediment accretion ranged from 4.5 mm year−1 at moderately salt-impacted forest on the Savannah River to 19.1 mm year−1 at its relict, highly salt-impacted forest downstream. Oligohaline marsh sediment accretion was 1.5–2.5 times greater than in tidal freshwater forests. Overall, there was no significant difference in accretion rate between rivers with contrasting sediment loads. Accretion was significantly higher in hollows than on hummocks in tidal freshwater forests. Organic sediment accretion was similar to autochthonous litter production at all sites, but inorganic sediment constituted the majority of accretion at both marshes and the Savannah River highly salt-impacted forest. A strong correlation between inorganic sediment accumulation and autochthonous litter production indicated a positive feedback between herbaceous plant production and allochthonous sediment deposition. The similarity in rates of sediment accretion and sea level rise in tidal freshwater forests indicates that these habitats may become permanently inundated if the rate of sea level rise increases.

  13. Assessment of ectomycorrhizal biodiversity in Tuber macrosporum productive sites.

    PubMed

    Benucci, Gian Maria Niccolò; Raggi, Lorenzo; Albertini, Emidio; Csorbai, Andrea Gógán; Donnini, Domizia

    2014-05-01

    Tuber macrosporum Vittad. is a truffle with superb organoleptic properties, whose cultivation is still in its infancy. For the first time we have aimed to provide information on ectomycorrhizal communities in natural and cultivated T. macrosporum sites. Ectomycorrhizal morphotypes were identified using ITS nrDNA sequencing and sorted into molecular operational taxonomic unit (MOTU). We detected 16 MOTUs in the T. macrosporum cultivated plantation. Ascomycota were the most abundant (86.4%) with Helvellaceae, Pyronemataceae and Pezizaceae the most common. Twenty-two MOTUs were collected in the natural T. macrosporum site. Basidiomycota morphotypes were plentiful (70.6%) and Thelephoraceae dominated. Each site had different taxa belowground with only T. macrosporum in common, being more abundant in the natural (18.2%) than in the cultivated (14.4%) site. Species richness, Simpson and Shannon diversity indices, taxonomic diversity, distinctness and variation of taxonomic distinctness were lower in the cultivated than in the natural site. PMID:24232503

  14. Davis Pond Freshwater Prediversion Biomonitoring Study: Freshwater Fisheries and Eagles

    USGS Publications Warehouse

    Jenkins, Jill A.; Bourgeois, E. Beth; Jeske, Clint W.

    2008-01-01

    In January 2001, the construction of the Davis Pond freshwater diversion structure was completed by the U.S. Army Corps of Engineers. The diversion of freshwater from the Mississippi River is intended to mitigate saltwater intrusion from the Gulf of Mexico and to lessen the concomitant loss of wetland areas. In addition to the freshwater inflow, Barataria Bay basin would receive nutrients, increased flows of sediments, and water-borne and sediment-bound compounds. The purpose of this biomonitoring study was, therefore, to serve as a baseline for prediversion concentrations of selected contaminants in bald eagle (Haliaeetus leucocephalus) nestlings (hereafter referred to as eaglets), representative freshwater fish, and bivalves. Samples were collected from January through June 2001. Two similarly designed postdiversion studies, as described in the biological monitoring program, are planned. Active bald eagle nests targeted for sampling eaglet blood (n = 6) were generally located southwest and south of the diversion structure. The designated sites for aquatic animal sampling were at Lake Salvador, at Lake Cataouatche, at Bayou Couba, and along the Mississippi River. Aquatic animals representative of eagle prey were collected. Fish were from three different trophic levels and have varying feeding strategies and life histories. These included herbivorous striped mullet (Mugil cephalus), omnivorous blue catfish (Ictalurus furcatus), and carnivorous largemouth bass (Micropterus salmoides). Three individuals per species were collected at each of the four sampling sites. Freshwater Atlantic rangia clams (Rangia cuneata) were collected at the downstream marsh sites, and zebra mussels (Dreissena spp.) were collected on the Mississippi River. The U.S. Geological Survey (USGS) Biomonitoring of Environmental Status and Trends (BEST) protocols served as guides for fish sampling and health assessments. Fish are useful for monitoring aquatic ecosystems because they accumulate

  15. ENERGY CONSERVATION AND PRODUCTION AT WASTE CLEANUP SITES (ISSUE PAPER)

    EPA Science Inventory

    Saving energy used by hazardous waste cleanup remediation systems should interest those people working on waste cleanup sites. Presidential Executive Order 13123, "Greening the Government Through Efficient Energy Management", states that each agency shall strive to expand the us...

  16. Siting Evaluation for Biomass-Ethanol Production in Hawaii

    SciTech Connect

    Kinoshita, C.M.; Zhou, J.

    2000-10-15

    This report examines four Hawaiian islands, Oahu, Hawaii, Maui, and Kauai, to identify three best combinations of potential sites and crops for producing dedicated supplies of biomass for conversion to ethanol. Key technical and economic factors considered in the siting evaluation include land availability (zoning and use), land suitability (agronomic conditions), potential quantities and costs of producing biomass feedstocks, infrastructure (including water and power supplies), transportation, and potential bioresidues to supplement dedicated energy crops.

  17. An empirical test of freshwater vicariance via river capture.

    PubMed

    Burridge, Christopher P; Craw, Dave; Waters, Jonathan M

    2007-05-01

    River capture is a geomorphological process through which stream sections are displaced from one catchment to another, and it may represent a dominant facilitator of interdrainage transfer and cladogenesis in freshwater-limited taxa. However, few studies have been conducted in a manner to explicitly test the biological significance of river capture. Here we present a multispecies phylogeographical analysis to test whether the nonmigratory fish fauna of the Von River (South Island, New Zealand) is the product of a well-documented, Late Quaternary capture of a section of the Oreti River (Southland drainage). Specifically, we predict that nonmigratory fishes of the Von River will exhibit closer genetic affinities with those of Southland, rather than those of the Clutha system, into which the Von River presently drains. Mitochondrial DNA phylogeography (control region and cytochrome b sequence data) and analysis of nuclear orthologues of mtDNA sequences indicate that 'flathead'Galaxias of the Von River (n = 31, three sites) have greatest genetic affinities with those of Southland (Galaxias 'southern', n = 216, 38 sites), rather than with those of the Clutha River (Galaxias sp. 'D', n = 73, 32 sites). Likewise, Von River 'roundhead'Galaxias (n = 52, four sites) have greatest genetic affinities with those of Southland drainages (Galaxias gollumoides, n = 223, 58 sites), rather than with those of the Clutha River (Galaxias pullus, Galaxias anomalus, Galaxias gollumoides of the Nevis tributary; n = 68, 32 sites). These findings are consistent with our predictions that genetic affinities of the nonmigratory fish fauna in the Von River would reflect past, rather than present, drainage connections. Consequently, river capture is responsible for the nonmigratory fish fauna of the Von River. In a broader context, river capture has frequently influenced the distribution of genetic lineages among catchments in New Zealand freshwater-limited fish, and its biogeographical

  18. Resource Evaluation and Site Selection for Microalgae Production in India

    SciTech Connect

    Milbrandt, A.; Jarvis, E.

    2010-09-01

    The study evaluates climate conditions, availability of CO2 and other nutrients, water resources, and land characteristics to identify areas in India suitable for algae production. The purpose is to provide an understanding of the resource potential in India for algae biofuels production and to assist policymakers, investors, and industry developers in their future strategic decisions.

  19. Freshwater Marsh. Habitat Pac.

    ERIC Educational Resources Information Center

    Fish and Wildlife Service (Dept. of Interior), Washington, DC.

    The materials in this educational packet are designed for use with students in grades 4 through 7. They consist of an overview, three lesson plans and student data sheets, and a poster. The overview describes how the freshwater marsh is an important natural resource for plant, animal, and human populations and how the destruction of marshes causes…

  20. Assessment of activation products in the Savannah River Site environment

    SciTech Connect

    Carlton, W.H.; Denham, M.

    1996-07-01

    This document assesses the impact of radioactive activation products released from SRS facilities since the first reactor became operational late in 1953. The isotopes reported here are those whose release resulted in the highest dose to people living near SRS: {sup 32}P, {sup 51}Cr, {sup 60}C, and {sup 65}Zn. Release pathways, emission control features, and annual releases to the aqueous and atmospheric environments are discussed. No single incident has resulted in a major acute release of activation products to the environment. The releases were the result of normal operations of the reactors and separations facilities. Releases declined over the years as better controls were established and production was reduced. The overall radiological impact of SRS activation product atmospheric releases from 1954 through 1994 on the offsite maximally exposed individual can be characterized by a total dose of 0.76 mrem. During the same period, such an individual received a total dose of 14,400 mrem from non-SRS sources of ionizing radiation present in the environment. SRS activation product aqueous releases between 1954 and 1994 resulted in a total dose of 54 mrem to the offsite maximally exposed individual. The impact of SRS activation product releases on offsite populations also has been evaluated.

  1. New Mexico aggregate production sites, 1997-1999

    USGS Publications Warehouse

    Orris, Greta J.

    2000-01-01

    This report presents data, including latitude and longitude, for aggregate sites in New Mexico that were believed to be active in the period 1997-1999. The data are presented in paper form in Part A of this report and as Microsoft Excel 97 and Data Interchange Format (DIF) files in Part B. The work was undertaken as part of the effort to update information for the National Atlas. This compilation includes data from: the files of U.S. Geological Survey (USGS); company contacts; the New Mexico Bureau of Mines and Mineral Resources, New Mexico Bureau of Mine Inspection, and the Mining and Minerals Division of the New Mexico Energy, Minerals and Natural Resources Department (Hatton and others, 1998); the Bureau of Land Management Information; and direct communications with some of the aggregate operators. Additional information on most of the sites is available in Hatton and others (1998).

  2. Bioaccumulation of metals in three freshwater mussel species exposed in situ during and after dredging at a coal ash spill site (Tennessee Valley Authority Kingston Fossil Plant).

    PubMed

    Otter, Ryan R; McKinney, David; Brown, Bobby; Lainer, Susan; Monroe, William; Hubbs, Don; Read, Bob

    2015-06-01

    On December 22, 2008, a dike containing coal fly ash at the Tennessee Valley Authority Kingston Fossil Plant (TN, USA) failed, and within months, dredging operations began to remove ash-contaminated sediments. The purpose of this study was to investigate differences in the bioaccumulation of metals in three mussel species during and after dredging operations. Mussels were caged for approximately 1 year during dredging and after, and then mussel condition index values and As, Cd, Cr, Pb, Ni, Se, Hg, U, Fe, Mg, Al, Sb, Ba, Be, Co, Cu, Mn, Mo, Ag, Sr, Tl, V, and Zn concentrations in soft tissue were determined via inductively coupled plasma-mass spectrometery. Overall, the differences observed in metal bioaccumulation and mussel health suggest that mussels in the immediate downstream area of the dredging site may have been impacted, as evidenced by a significant decrease in mussel condition index values, but that this impact did not result in increased tissue concentrations of metals. PMID:25957195

  3. Are native naiads more tolerant to pollution than exotic freshwater bivalve species? An hypothesis tested using physiological responses of three species transplanted to mercury contaminated sites in the Ebro River (NE, Spain).

    PubMed

    Faria, Melissa; López, Miguel Angel; Díez, Sergi; Barata, Carlos

    2010-11-01

    In the lower Ebro River exist the paradoxical convergence of relatively well preserved river dynamics with the historical presence of a chloralkali plant with a long history of mercury discharges and the recent invasion of foreign bivalves species. Here we performed a comparative study on two alien bivalves, the Zebra mussel and the Asian clam (Dreissena polymorpha and Corbicula fluminea), and one protected species of naiads (Psilunio littoralis), which is the most common species of the freshwater mussel assemblages in this river. Individuals of the three species were transplanted to three sites that included a clean unpolluted upstream site, a contaminated location next to the mercury source and a downstream one. The study focused on digestive gland antioxidant and oxidative stress responses such as antioxidant enzymes, glutathione S transferase, glutathione levels, metallothionein proteins, DNA strand breaks and lipid peroxidation levels. Results evidenced interspecies differences on accumulation levels of mercury, antioxidant defensive systems and oxidative tissue damage. The naiad species, despite of accumulating more mercury showed the greatest antioxidant defensive potential, which was characterized by having high constitutive activities of glutathione S transferase and inducible activities and levels of key antioxidant enzymes and glutathione. Exposed individuals of C. fluminea had moderate levels of metal accumulation, the highest activities of antioxidant enzymes but also high levels of lipid peroxidation. D. polymorpha mussels showed the lowest levels of mercury but the lowest antioxidant responses and consequently the highest levels of oxidative injuries in the DNA and of mortality. Our results support the hypothesis that naiad species might be more tolerant to pollution than exotic species. PMID:20952043

  4. Proceedings of the global climate change and freshwater ecosystems

    SciTech Connect

    Firth, P.; Fisher, S.G.

    1992-01-01

    This book discusses global climate change which is a certainty. The Earth's climate has never remained static for long and the prospect for human-accelerated climate change in the near future appears likely. Freshwater systems are intimately connected to climate in several ways. They may influence, or even drive, global atmospheric processes affecting climate (e.g., biogenic gas emissions from freshwater wetlands). They may be sensitive early indicators of climate change because they integrate the atmospheric and terrestrial events occurring in their catchments. And, of course, they will be affected by climate change. Freshwater hydrological processes, freshwater resources, and freshwater ecosystems have historically responded to climatic shifts and we fully expect that they will continue to do so. Climate-induced changes may include altered water temperatures, runoff, nutrient flux, discharge, flow regime, lake and aquifer levels, water quality, ice cover, suspended load, primary and secondary production, trophic dynamics, organism ranges, and migration patterns.

  5. Productive Observing with a Small Telescope at an Urban Site

    NASA Astrophysics Data System (ADS)

    Mason, Brian D.; Hartkopf, W. I.

    2014-01-01

    In the modern era keeping smaller telescopes in non-optimal sites relevant requires significant preparation and planning. The "Great Equatorial," the largest telescope in the world (1873-1880) at the U.S. Naval Observatory, discovered the two moons of Mars in 1877. Since then, it's primary observing program has been the observation of double stars. While the number of binary stars appropriate for orbital analysis with a 26inch refractor at an urban site is small, the telescope can observe approximately 38,500 of the 127,758 known pairs in the sky. Many of these pairs fall into a class of double we call "neglected," that is, no measures have been obtained in the last ten years or the have never been confirmed. These measures can eventually establish whether the pair is a chance alignment or a bona fide binary star. Whether some of these more tenuous doubles are physical or not has implications for Galactic dynamics. Observations we can make with the 26inch are those which don't need to be made at greater expense at remote observatories with our speckle camera or through collaborations with other astronomers. However, these other observations still need to be made. The breadth of the USNO double star observing program is presented along with new "phase optimizer" software to ascertain when pairs need to be observed to improve the quality of their orbit significantly and with what telescope/technique.

  6. Freshwater savings from marine protein consumption

    NASA Astrophysics Data System (ADS)

    Gephart, Jessica A.; Pace, Michael L.; D'Odorico, Paolo

    2014-01-01

    Marine fisheries provide an essential source of protein for many people around the world. Unlike alternative terrestrial sources of protein, marine fish production requires little to no freshwater inputs. Consuming marine fish protein instead of terrestrial protein therefore represents freshwater savings (equivalent to an avoided water cost) and contributes to a low water footprint diet. These water savings are realized by the producers of alternative protein sources, rather than the consumers of marine protein. This study quantifies freshwater savings from marine fish consumption around the world by estimating the water footprint of replacing marine fish with terrestrial protein based on current consumption patterns. An estimated 7 600 km3 yr-1 of water is used for human food production. Replacing marine protein with terrestrial protein would require an additional 350 km3 yr-1 of water, meaning that marine protein provides current water savings of 4.6%. The importance of these freshwater savings is highly uneven around the globe, with savings ranging from as little as 0 to as much as 50%. The largest savings as a per cent of current water footprints occur in Asia, Oceania, and several coastal African nations. The greatest national water savings from marine fish protein occur in Southeast Asia and the United States. As the human population increases, future water savings from marine fish consumption will be increasingly important to food and water security and depend on sustainable harvest of capture fisheries and low water footprint growth of marine aquaculture.

  7. Detection and genetic profiling of infectious hypodermal and haematopoietic necrosis virus (IHHNV) infections in wild berried freshwater prawn, Macrobrachium rosenbergii collected for hatchery production.

    PubMed

    Hazreen Nita, M K; Kua, B C; Bhassu, S; Othman, R Y

    2012-04-01

    Infectious hypodermal and haematopoietic necrosis virus (IHHNV) has been detected widely in penaeid culture facilities in Asia and the Americas. IHHNV infection on sub-adult and postlarvae of the giant freshwater prawn, Macrobrachium rosenbergii which had caused up to 80% mortalities was first reported in Southeast Taiwan in 2006. In Malaysia, although, there has been no report on IHHNV infections in M. rosenbergii, preliminary work suggests that there is an urgent need to setup a screening protocol for IHHNV for both wild and cultured populations. In this study, polymerase chain reaction based screening was carried out on 30 randomly sampled berried wild M. rosenbergii before and after spawning. All samples did not showed any sign of IHHNV infection. However, the results showed that 20% of the samples were IHHNV positive. Sequence analysis of the amplified band using NCBI-BLAST showed that the putative IHHNV sequence had 98% nucleotide sequence (388 bp) identity with the IHHNV isolate AC-05-005 non-structural protein 1 gene and seven other IHHNV strains in the data bank further affirming the suggestion on the presence of IHHNV in wild freshwater prawn populations in Malaysia. PMID:21755294

  8. In Brief: Europe's freshwater fish threatened

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2007-11-01

    Two hundred of Europe's 522 freshwater fish species are threatened with extinction and 12 are already extinct, according to the Handbook of European Freshwater Fishes, published in collaboration with the World Conservation Union (IUCN) and released on 1 November 2007. IUCN notes that the main threats to fish species stem from development and population growth and include water withdrawals, large dams, and inappropriate fisheries management that has led to overfishing and the introduction of alien species. Authors Maurice Kottelat, former president of the European Ichthyological Society, and Jörg Freyhof, scientist from Leibniz Institute of Freshwater Ecology, noted that fish conservation should be managed by agencies in charge of conservation, and not as a crop by agencies in charge of agriculture. William Darwall, senior program officer with IUCN's Species Program, said the species ``are critical to the freshwater ecosystems upon which we do depend, such as for water purification and flood control.'' For more information, visit the Web site: http://www.iucn.org.

  9. Outside the Box: Site-Specific Productions Put the Audience and the Actors in a New Light.

    ERIC Educational Resources Information Center

    Cantor, Jon

    2002-01-01

    Suggests site-specific theatrical productions can create innovative productions in nontraditional spaces. Discusses the experiences of the author as he directed a site-specific production (Wendy MacLeod's "The Shallow End," set at an indoor pool) and addresses the lessons he learned from it. Includes advice on creating site-specific productions.…

  10. Toward a Functional Definition of Methane Super-Emitters: Application to Natural Gas Production Sites.

    PubMed

    Zavala-Araiza, Daniel; Lyon, David; Alvarez, Ramón A; Palacios, Virginia; Harriss, Robert; Lan, Xin; Talbot, Robert; Hamburg, Steven P

    2015-07-01

    Emissions from natural gas production sites are characterized by skewed distributions, where a small percentage of sites-commonly labeled super-emitters-account for a majority of emissions. A better characterization of super-emitters is needed to operationalize ways to identify them and reduce emissions. We designed a conceptual framework that functionally defines superemitting sites as those with the highest proportional loss rates (methane emitted relative to methane produced). Using this concept, we estimated total methane emissions from natural gas production sites in the Barnett Shale; functionally superemitting sites accounted for roughly three-fourths of total emissions. We discuss the potential to reduce emissions from these sites, under the assumption that sites with high proportional loss rates have excess emissions resulting from abnormal or otherwise avoidable operating conditions, such as malfunctioning equipment. Because the population of functionally superemitting sites is not expected to be static over time, continuous monitoring will likely be necessary to identify them and improve their operation. This work suggests that achieving and maintaining uniformly low emissions across the entire population of production sites will require mitigation steps at a large fraction of sites. PMID:26148555

  11. Acidification of freshwaters

    SciTech Connect

    Cresser, M.S.; Edwards, A.C.

    1987-01-01

    This volume gives an account that draws not only on the main branches of chemistry but also on soil physics, chemistry, hydrology, meteorology, geography, geology, plant physiology, soil microbiology and zoology. The author examine the numerous interacting physical, chemical, and biological, processes that regulate the acidity of freshwaters, a phenomenon that has various causes, including precipitation; acidifying pollutions; and the interaction of plants, soils and water. The relative importance of the different processes is examined.

  12. SMAP L2/L3 Soil Moisture Product Validation using In Situ Based Core Validation Sites

    NASA Astrophysics Data System (ADS)

    Colliander, A.; Jackson, T. J.; Chan, S.; Das, N. N.; Kim, S.; Dunbar, R. S.; Bindlish, R.; Dang, L. B.; Berg, A. A.; Rowlandson, T. L.; Caylor, K. K.; Cosh, M. H.; AlJassar, H. K.; Lopez-baeza, E.; Martínez-Fernández, J.; Gonzales-Zamora, A.; McNairn, H.; Pacheco, A. M.; Moghaddam, M.; Montzka, C.; Notarnicola, C.; Niedrist, G.; Pellarin, T.; Pulliainen, J.; Rautiainen, K.; Ramos, J.; Seyfried, M. S.; Su, Z.; Zeng, Y.; Van der Velde, R.; Temimi, M.; Thibeault, M.; Dorigo, W.; Vreugdenhil, M.; Walker, J.; Wu, X.; Caldwell, T. G.; Spencer, M.; O'Neill, P. E.; Entekhabi, D.; Yueh, S. H.; Njoku, E. G.

    2015-12-01

    NASA's Soil Moisture Active Passive (SMAP) Mission was launched in January 2015. The objective of the mission is global mapping of soil moisture and landscape freeze/thaw state. SMAP utilizes L-band radar and radiometer instruments sharing a rotating 6-meter mesh reflector antenna. Merging of active and passive L-band observations enables an unprecedented combination of accuracy, resolution, global coverage and revisit-time for soil moisture and freeze/thaw retrievals. The primary validation reference of the data products will be ground-based measurements. Well characterized sites with calibrated in situ measurements will be used to determine the quality of the data products; these sites are designated as core validation sites. The mission success criteria will be evaluated with respect to these core site comparisons. Other remote sensing and model-based products will be used as additional resources to expand the spatial and temporal scope of the evaluation. In an effort to ensure the geographic distribution and diversity of conditions of the core validation sites, SMAP has partnered with investigators across the globe. Because different SMAP Level 2 soil moisture products have different spatial scales, the suitability of the various sites for validation of the different products must be done for each site while considering several factors. The main factors are gravimetric calibration of the sensors within a site and determination of a spatial scaling function of the sensor measurements up to the SMAP resolution scales. The mission has been able to utilize the core site measurements since the launch of the satellite because the infrastructure for data transmission and processing was established well before the launch. The validated soil moisture products will be released by May 2016. In this presentation we will show the performance of the beta version of the soil moisture products (released by November 2015) and discuss the status of the validation process.

  13. Restricted-Range Fishes and the Conservation of Brazilian Freshwaters

    PubMed Central

    Nogueira, Cristiano; Buckup, Paulo A.; Menezes, Naercio A.; Oyakawa, Osvaldo T.; Kasecker, Thais P.; Ramos Neto, Mario B.; da Silva, José Maria C.

    2010-01-01

    Background Freshwaters are the most threatened ecosystems on earth. Although recent assessments provide data on global priority regions for freshwater conservation, local scale priorities remain unknown. Refining the scale of global biodiversity assessments (both at terrestrial and freshwater realms) and translating these into conservation priorities on the ground remains a major challenge to biodiversity science, and depends directly on species occurrence data of high taxonomic and geographic resolution. Brazil harbors the richest freshwater ichthyofauna in the world, but knowledge on endemic areas and conservation in Brazilian rivers is still scarce. Methodology/Principal Findings Using data on environmental threats and revised species distribution data we detect and delineate 540 small watershed areas harboring 819 restricted-range fishes in Brazil. Many of these areas are already highly threatened, as 159 (29%) watersheds have lost more than 70% of their original vegetation cover, and only 141 (26%) show significant overlap with formally protected areas or indigenous lands. We detected 220 (40%) critical watersheds overlapping hydroelectric dams or showing both poor formal protection and widespread habitat loss; these sites harbor 344 endemic fish species that may face extinction if no conservation action is in place in the near future. Conclusions/Significance We provide the first analysis of site-scale conservation priorities in the richest freshwater ecosystems of the globe. Our results corroborate the hypothesis that freshwater biodiversity has been neglected in former conservation assessments. The study provides a simple and straightforward method for detecting freshwater priority areas based on endemism and threat, and represents a starting point for integrating freshwater and terrestrial conservation in representative and biogeographically consistent site-scale conservation strategies, that may be scaled-up following naturally linked drainage systems

  14. 76 FR 14101 - Meadwestvaco Corporation, Consumer and Office Products Division, Including On-Site Leased Workers...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-15

    ..., Including On-Site Leased Workers From Pro-Tel People, Sidney, NY; Amended Certification Regarding... Corporation, Consumer and Office Products Division, including on-site leased workers from Pro-Tel People... published in the Federal Register on September 3, 2008 (73 FR 51529). In order to avoid an overlap in...

  15. BACTERIOPLANKTON DYNAMICS IN NORTHERN SAN FRANCISCO BAY: ROLE OF PARTICLE ASSOCIATION AND SEASONAL FRESHWATER FLOW

    EPA Science Inventory

    Bacterioplankton abundance and metabolic characteristics were observed in northern San Francisco Bay, California, during spring and summer 1996 at three sites: Central Bay, Suisun Bay, and the Sacramento River. These sites spanned a salinity gradient from marine to freshwater, an...

  16. Electronic Cigarette Marketing Online: a Multi-Site, Multi-Product Comparison

    PubMed Central

    Sidhu, Anupreet K; Valente, Thomas W

    2015-01-01

    Background Electronic cigarette awareness and use has been increasing rapidly. E-cigarette brands have utilized social networking sites to promote their products, as the growth of the e-cigarette industry has paralleled that of Web 2.0. These online platforms are cost-effective and have unique technological features and user demographics that can be attractive for selective marketing. The popularity of multiple sites also poses a risk of exposure to social networks where e-cigarette brands might not have a presence. Objective To examine the marketing strategies of leading e-cigarette brands on multiple social networking sites, and to identify how affordances of the digital media are used to their advantage. Secondary analyses include determining if any brands are benefitting from site demographics, and exploring cross-site diffusion of marketing content through multi-site users. Methods We collected data from two e-cigarette brands from four social networking sites over approximately 2.5 years. Content analysis is used to search for themes, population targeting, marketing strategies, and cross-site spread of messages. Results Twitter appeared to be the most frequently used social networking site for interacting directly with product users. Facebook supported informational broadcasts, such as announcements regarding political legislation. E-cigarette brands also differed in their approaches to their users, from informal conversations to direct product marketing. Conclusions E-cigarette makers use different strategies to market their product and engage their users. There was no evidence of direct targeting of vulnerable populations, but the affordances of the different sites are exploited to best broadcast context-specific messages. We developed a viable method to study cross-site diffusion, although additional refinement is needed to account for how different types of digital media are used. PMID:27227129

  17. Methane Emissions from Conventional and Unconventional Natural Gas Production Sites in the Marcellus Shale Basin.

    PubMed

    Omara, Mark; Sullivan, Melissa R; Li, Xiang; Subramanian, R; Robinson, Allen L; Presto, Albert A

    2016-02-16

    There is a need for continued assessment of methane (CH4) emissions associated with natural gas (NG) production, especially as recent advancements in horizontal drilling combined with staged hydraulic fracturing technologies have dramatically increased NG production (we refer to these wells as "unconventional" NG wells). In this study, we measured facility-level CH4 emissions rates from the NG production sector in the Marcellus region, and compared CH4 emissions between unconventional NG (UNG) well pad sites and the relatively smaller and older "conventional" NG (CvNG) sites that consist of wells drilled vertically into permeable geologic formations. A top-down tracer-flux CH4 measurement approach utilizing mobile downwind intercepts of CH4, ethane, and tracer (nitrous oxide and acetylene) plumes was performed at 18 CvNG sites (19 individual wells) and 17 UNG sites (88 individual wells). The 17 UNG sites included four sites undergoing completion flowback (FB). The mean facility-level CH4 emission rate among UNG well pad sites in routine production (18.8 kg/h (95% confidence interval (CI) on the mean of 12.0-26.8 kg/h)) was 23 times greater than the mean CH4 emissions from CvNG sites. These differences were attributed, in part, to the large size (based on number of wells and ancillary NG production equipment) and the significantly higher production rate of UNG sites. However, CvNG sites generally had much higher production-normalized CH4 emission rates (median: 11%; range: 0.35-91%) compared to UNG sites (median: 0.13%, range: 0.01-1.2%), likely resulting from a greater prevalence of avoidable process operating conditions (e.g., unresolved equipment maintenance issues). At the regional scale, we estimate that total annual CH4 emissions from 88 500 combined CvNG well pads in Pennsylvania and West Virginia (660 Gg (95% CI: 500 to 800 Gg)) exceeded that from 3390 UNG well pads by 170 Gg, reflecting the large number of CvNG wells and the comparably large fraction of

  18. Stormwater runoff drives viral community composition changes in inland freshwaters

    PubMed Central

    Williamson, Kurt E.; Harris, Jamie V.; Green, Jasmin C.; Rahman, Faraz; Chambers, Randolph M.

    2014-01-01

    Storm events impact freshwater microbial communities by transporting terrestrial viruses and other microbes to freshwater systems, and by potentially resuspending microbes from bottom sediments. The magnitude of these impacts on freshwater ecosystems is unknown and largely unexplored. Field studies carried out at two discrete sites in coastal Virginia (USA) were used to characterize the viral load carried by runoff and to test the hypothesis that terrestrial viruses introduced through stormwater runoff change the composition of freshwater microbial communities. Field data gathered from an agricultural watershed indicated that primary runoff can contain viral densities approximating those of receiving waters. Furthermore, viruses attached to suspended colloids made up a large fraction of the total load, particularly in early stages of the storm. At a second field site (stormwater retention pond), RAPD-PCR profiling showed that the viral community of the pond changed dramatically over the course of two intense storms while relatively little change was observed over similar time scales in the absence of disturbance. Comparisons of planktonic and particle-associated viral communities revealed two completely distinct communities, suggesting that particle-associated viruses represent a potentially large and overlooked portion of aquatic viral abundance and diversity. Our findings show that stormwater runoff can quickly change the composition of freshwater microbial communities. Based on these findings, increased storms in the coastal mid-Atlantic region predicted by most climate change models will likely have important impacts on the structure and function of local freshwater microbial communities. PMID:24672520

  19. Across a macro-ecological gradient forest competition is strongest at the most productive sites.

    PubMed

    Prior, Lynda D; Bowman, David M J S

    2014-01-01

    We tested the hypothesis that the effect of forest basal area on tree growth interacts with macro-ecological gradients of primary productivity, using a large dataset of eucalypt tree growth collected across temperate and sub- tropical mesic Australia. To do this, we derived an index of inter-tree competition based on stand basal area (stand BA) relative to the climatically determined potential basal area. Using linear mixed effects modeling, we found that the main effects of climatic productivity, tree size, and competition explained 26.5% of the deviance in individual tree growth, but adding interactions to the model could explain a further 8.9%. The effect of competition on growth interacts with the gradient of climatic productivity, with negligible effect of competition in low productivity environments, but marked negative effects at the most productive sites. We also found a positive interaction between tree size and stand BA, which was most pronounced in the most productive sites. We interpret these patterns as reflecting intense competition for light amongst maturing trees on more productive sites, and below ground moisture limitation at low productivity sites, which results in open stands with little competition for light. These trends are consistent with the life history and stand development of eucalypt forests: in cool moist environments, light is the most limiting resource, resulting in size-asymmetric competition, while in hot, low rainfall environments are open forests with little competition for light but where the amount of tree regeneration is limited by water availability. PMID:24926304

  20. 75 FR 43565 - Johns Manville; Engineered Products Division, Including On-Site Leased Workers From Volt...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-26

    ... Employment and Training Administration Johns Manville; Engineered Products Division, Including On-Site Leased... reconsideration, I determine that workers of Johns Manville, Engineered Products Division, Spartanburg, South... with Section 223 of the Act, 19 U.S.C. 2273, I make the following certification: All workers of...

  1. Migration of fission products at the Nevada Test Site: Detection with an isotopic tracer

    SciTech Connect

    Thompton, J.L.; Gilmore, J.S. )

    1989-01-01

    Researchers at Los Alamos National Laboratory are studying the migration of fission products away from explosion cavities formed by underground nuclear tests at the Nevada Test Site. In some cases, the isotopic composition of the fission products or activation products associated with a particular test are distinctive and we may identify them many years after the event. In this paper we describe a case in which we used rhodium isotopes to identify the source of radioactive material that had moved some 350 m from the explosion site. 4 refs., 2 figs., 2 tabs.

  2. Effects of pollution on freshwater organisms

    SciTech Connect

    Phipps, G.L.; Harden, M.J.; Leonard, E.N.; Roush, T.H; Spehar, D.L.; Stephan, C.E.; Pickering, Q.H.; Buikema, A.L. Jr.

    1984-06-01

    This review includes subjects in last year's reviews on effects of pollution on freshwater invertebrates and effects of pollution on freshwater fish and amphibians. This review also includes information on the effects of pollution on freshwater plants. 625 references.

  3. Occurrence of triclosan, triclocarban, and Its Lesser Chlorinated Congeners in Minnesota Freshwater Sediments Collected Near Wastewater Treatment Plants

    PubMed Central

    Venkatesan, Arjun K.; Pycke, Benny F.G.; Barber, Larry B.; Lee, Kathy E.; Halden, Rolf U.

    2012-01-01

    The antimicrobial agents triclosan (TCS), triclocarban (TCC) and their associated transformation products are of increasing concern as environmental pollutants due to their potential adverse effects on humans and wildlife, including bioaccumulation and endocrine-disrupting activity. Analysis by tandem mass spectrometry of 24 paired freshwater bed sediment samples (top 10 cm) collected by the U.S. Geological Survey near 12 wastewater treatment plants (WWTPs) in Minnesota revealed TCS and TCC concentrations of up to 85 and 822 ng/g dry weight (dw), respectively. Concentrations of TCS and TCC in bed sediments collected downstream of WWTPs were significantly greater than upstream concentrations in 58% and 42% of the sites, respectively. Dichloro- and non-chlorinated carbanilides (DCC and NCC) were detected in sediments collected at all sites at concentrations of up to 160 and 1.1 ng/g dw, respectively. Overall, antimicrobial concentrations were significantly higher in lakes than in rivers and creeks, with relative abundances decreasing from TCC > TCS > DCC > NCC. This is the first statewide report on the occurrence of TCS, TCC and TCC transformation products in freshwater sediments. Moreover, the results suggest biological or chemical TCC dechlorination products to be ubiquitous in freshwater environments of Minnesota, but whether this transformation occurs in the WWTP or bed sediment remains to be determined. PMID:22742731

  4. Occurrence of triclosan, triclocarban, and its lesser chlorinated congeners in Minnesota freshwater sediments collected near wastewater treatment plants

    USGS Publications Warehouse

    Venkatesan, Arjun K.; Pycke, Benny F.G.; Barber, Larry B.; Lee, Kathy E.; Halden, Rolf U.

    2012-01-01

    The antimicrobial agents triclosan (TCS), triclocarban (TCC) and their associated transformation products are of increasing concern as environmental pollutants due to their potential adverse effects on humans and wildlife, including bioaccumulation and endocrine-disrupting activity. Analysis by tandem mass spectrometry of 24 paired freshwater bed sediment samples (top 10 cm) collected by the U.S. Geological Survey near 12 wastewater treatment plants (WWTPs) in Minnesota revealed TCS and TCC concentrations of up to 85 and 822 ng/g dry weight (dw), respectively. Concentrations of TCS and TCC in bed sediments collected downstream of WWTPs were significantly greater than upstream concentrations in 58% and 42% of the sites, respectively. Dichloro- and non-chlorinated carbanilides (DCC and NCC) were detected in sediments collected at all sites at concentrations of up to 160 and 1.1 ng/g dw, respectively. Overall, antimicrobial concentrations were significantly higher in lakes than in rivers and creeks, with relative abundances decreasing from TCC > TCS > DCC > NCC. This is the first statewide report on the occurrence of TCS, TCC and TCC transformation products in freshwater sediments. Moreover, the results suggest biological or chemical TCC dechlorination products to be ubiquitous in freshwater environments of Minnesota, but whether this transformation occurs in the WWTP or bed sediment remains to be determined.

  5. Phase 1 of the North Site cleanup: Definition of product streams. Volume 1

    SciTech Connect

    Sorini, S.; Merriam, N.

    1994-03-01

    Various materials and equipment have accumulated at the Western Research Institute (WRI) North Site Facility since its commissioning in 1968. This facility was built by the US Bureau of Mines, transferred to the US Energy Research Development Administration (ERDA) in 1976, and transferred once again to the US Department of Energy (DOE) shortly thereafter. In 1983, the North Site Facility became part of WRI. The materials that have accumulated over the years at the site have been stored in drums, tanks, and open piles. They vary from oil shale, tar sand, and coal feedstocks to products and materials associated with in situ simulation and surface process developments associated with these feedstocks. The majority of these materials have been associated with DOE North Site activities and work performed at the North Site under DOE-WRI cooperative agreement contracts. In phase I of the North Site Facility cleanup project, these materials were sampled and evaluated to determine their chemical characteristics for proper disposal or use in accordance with current local, state, and federal regulations. Phase I of the North Site Facility cleanup project involved dividing the stored materials into product streams and dividing each product stream into composite groups. Composite groups contain materials known to be similar in composition, source, and process exposure. For each composite group, materials, which are representative of the composite, were selected for sampling, compositing, and analysis.

  6. Geologic setting of the New Production Reactor within the Savannah River Site

    SciTech Connect

    Price, V.; Fallaw, W.C.; McKinney, J.B.

    1991-12-31

    The geology and hydrology of the reference New Production Reactor (NPR) site at Savannah River Site (SRS) have been summarized using the available information from the NPR site and areas adjacent to the site, particularly the away from reactor spent fuel storage site (AFR site). Lithologic and geophysical logs from wells drilled near the NPR site do not indicate any faults in the upper several hundred feet of the Coastal Plain sediments. However, the Pen Branch Fault is located about 1 mile south of the site and extends into the upper 100 ft of the Coastal Plain sequence. Subsurface voids, resulting from the dissolution of calcareous portions of the sediments, may be present within 200 ft of the surface at the NPR site. The water table is located within 30 to 70 ft of the surface. The NPR site is located on a groundwater divide, and groundwater flow for the shallowest hydraulic zones is predominantly toward local streams. Groundwater flow in deeper Tertiary sediments is north to Upper Three Runs Creek or west to the Savannah River Swamp. Groundwater flow in the Cretaceous sediments is west to the Savannah River.

  7. Arctic freshwater synthesis: Introduction

    NASA Astrophysics Data System (ADS)

    Prowse, T.; Bring, A.; Mârd, J.; Carmack, E.

    2015-11-01

    In response to a joint request from the World Climate Research Program's Climate and Cryosphere Project, the International Arctic Science Committee, and the Arctic Council's Arctic Monitoring and Assessment Program, an updated scientific assessment has been conducted of the Arctic Freshwater System (AFS), entitled the Arctic Freshwater Synthesis (AFSΣ). The major reason for joint request was an increasing concern that changes to the AFS have produced, and could produce even greater, changes to biogeophysical and socioeconomic systems of special importance to northern residents and also produce extra-Arctic climatic effects that will have global consequences. Hence, the key objective of the AFSΣ was to produce an updated, comprehensive, and integrated review of the structure and function of the entire AFS. The AFSΣ was organized around six key thematic areas: atmosphere, oceans, terrestrial hydrology, terrestrial ecology, resources and modeling, and the review of each coauthored by an international group of scientists and published as separate manuscripts in this special issue of Journal of Geophysical Research-Biogeosciences. This AFSΣ—Introduction reviews the motivations for, and foci of, previous studies of the AFS, discusses criteria used to define the domain of the AFS, and details key characteristics of the definition adopted for the AFSΣ.

  8. Sperm in "parhenogenetic" freshwater gastrotrichs.

    PubMed

    Weiss, M J; Levy, D P

    1979-07-20

    Freshwater members of the phylum Gastrotricha have been considered obligate parthenogens. In Lepidodermelia squammata, the species for which there is most evidence for parthenogenesis, sperm have been discovered. This finding will necessitate reexamination of the nature of sexuality and life cycles and of the concept of "species" in freshwater gastrotrichs. PMID:17747043

  9. RECOVERY OF FRESHWATER STORED IN SALINE AQUIFERS IN PENINSULAR FLORIDA.

    USGS Publications Warehouse

    Merritt, Michael L.

    1986-01-01

    Subsurface freshwater storage has been operationally tested at seven sites in central and south Florida. Injection was into a high chloride water aquifer at six sites, and into a high sulfate water aquifer at the seventh. Recovery efficiency has ranged from 0 to 75 percent in high chloride water aquifers, and has exceeded 100 percent in the high sulfate water aquifer. Computer modeling techniques were used to examine the geohydrologic, design, and management factors governing the recovery efficiency of subsurface freshwater storage. The modeling approach permitted many combinations of geohydrologic and operational conditions to be studied at relatively low cost.

  10. Pesticides in Brazilian freshwaters: a critical review.

    PubMed

    Albuquerque, A F; Ribeiro, J S; Kummrow, F; Nogueira, A J A; Montagner, C C; Umbuzeiro, G A

    2016-07-13

    The widespread use of pesticides in agriculture can lead to water contamination and cause adverse effects on non-target organisms. Brazil has been the world's top pesticide market consumer since 2008, with 381 approved pesticides for crop use. This study provides a comprehensive literature review on the occurrence of pesticide residues in Brazilian freshwaters. We searched for information in official agency records and peer-reviewed scientific literature. Risk quotients were calculated to assess the potential risk posed to aquatic life by the individual pesticides based on their levels of water contamination. Studies about the occurrence of pesticides in freshwaters in Brazil are scarce and concentrated in few sampling sites in 5 of the 27 states. Herbicides (21) accounted for the majority of the substances investigated, followed by fungicides (11), insecticides (10) and plant growth regulators (1). Insecticides are the class of major concern. Brazil would benefit from the implementation of a nationwide pesticide freshwater monitoring program to support preventive, remediation and enforcement actions. PMID:27367607

  11. Freshwater diatom influx in intertropical Atlantic: Relationships with continental records from Africa

    NASA Astrophysics Data System (ADS)

    Gasse, Françoise; Stabell, Bjørg; Fourtanier, Elizabeth; van Iperen, Yolanda

    1989-09-01

    Diatom assemblages from modern West African rivers and from lacustrine sediments subjected to deflation represent the present-day sources of continental diatoms to the sea. Diatom productivity in large rivers is high, especially for the genus Melosira. Windblown diatoms derive mainly from the central and northern Sahara (summer dust plume) where saline chloride-water assemblages are widespread, or from the southern edge of the Sahara (winter dust plume) where Melosira-rich assemblages of dilute water predominate. Freshwater diatom peaks in Atlantic cores may reflect (1) phases of increased river influx, correlated with humid episodes on the continent or (2) phases of enhanced deflation and wind transport during arid episodes (the single hypothesis for fine sediments from mid-ocean sites). Genus Melosira dominates the freshwater assemblages of many modern and fossil marine samples, whatever the transport agent is. Therefore, it is not an accurate paleoclimate indicator by itself, but associated taxa may provide information on the environmental and geographical origin of the displaced diatoms. This tentative approach shows that freshwater diatoms in Atlantic cores may be a good tool for reconstructing paleoclimates and for establishing continent-ocean correlations if species analyses are made and if the continental distribution of the taxa encountered is considered.

  12. Neolithic agriculture, freshwater resources and rapid environmental changes on the lower Yangtze, China

    NASA Astrophysics Data System (ADS)

    Qin, Jungan; Taylor, David; Atahan, Pia; Zhang, Xinrong; Wu, Guoxuan; Dodson, John; Zheng, Hongbo; Itzstein-Davey, Freea

    2011-01-01

    Analyses of sedimentary evidence in the form of spores, pollen, freshwater algae, dinoflagellate cysts, phytoliths and charcoal from AMS 14C-dated, Holocene-aged sequences provide an excellent opportunity to examine the responses of Neolithic agriculturalists in the lower Yangtze to changing environments. Evidence from two sites close to the southern margin of the Yangtze delta and separated by what is now Hangzhou Bay attests the critical importance to early attempts at food production of access to freshwater resources. More readily, if episodically, available freshwater resources during the early to mid-Holocene on the Hangjiahu plain may have encouraged an early reliance on rice-based agriculture, which in turn facilitated the accumulation of agricultural surpluses and cultural diversification. Cultural change was relatively attenuated and human population pressures possibly lower on the Ningshao plain, seemingly because of much more profound environmental impacts of variations in local hydrological conditions, and because predominantly saline conditions, associated with rising relative sea level, hampered the early development of irrigated agriculture. The evidence, although largely dating to the early and middle parts of the Holocene, provides a timely warning of the complexity of vulnerability to climate change-induced processes of agriculture, and indeed human activities more generally, on megadeltas in Asia.

  13. Novel reference site approach to prototyping, calibrating, and validating Earth observation data and products

    NASA Astrophysics Data System (ADS)

    Schaepman, M. E.; Morsdorf, F.; Leiterer, R.; Pfeifer, N.; Hollaus, M.; Disney, M.; Lewis, P.; Gastellu-Etchegorry, J.; Brazile, J.; Koetz, B.

    2012-12-01

    Much of global change is driven by feedback mechanisms taking place at spatial and temporal scales that are smaller than those currently incorporated in models. This severely limits our ability to predict, mitigate and adapt to environmental change at local and regional scales. Ideally, global modelling, reference sites and data will gradually converge to spatial and temporal scales where processes at their characteristic length scale can be compared, Ultimately; scale invariant observations and products would be the goal. But because of the inherent nature of a changing environment, spatio-temporal homogeneity of reference sites will remain a main concern. Globally distributed sites with naturally changing homogeneity and biome cover are of fundamental importance to understand potential bias errors in retrieval algorithms, amongst other benefits. We propose a new site concept using a highly detailed description of vegetation based on terrestrial and airborne laser scanning, extensive optical properties measurements as well as airborne imaging spectrometer data acquisition in combination with both, 1D and 3D radiative transfer models. Effects of horizontal and vertical heterogeneities and asymmetrical structure of vegetation and high temporal dynamics can be simulated and used in algorithm development, calibration and validation procedures. The approach allows comparison with heritage algorithms and products, and will support estimates of scale invariance for all spatial, spectral, and temporal dimensions. The site design is further using standards, allowing stage 1 & 2 validation according to CEOS/LPV (Committee on Earth Observation Satellites/ Land Product Validation Subgroup) recommendations as well as supporting the Quality Assurance Framework for Earth Observation (QA4EO) of the ESA/CEOS Cal/Val initiative. We demonstrate feasibility of the approach using the 'Laegeren' site (temperate deciduous forest, with dominant beech trees; 47°28'42.0" N; 8°21'51.8" E

  14. Freshwater withdrawals in Texas, 1985

    USGS Publications Warehouse

    Lurry, Dee L.; Barber, Nancy L.

    1990-01-01

    Freshwater withdrawal data was compiled for the 254 counties in Texas for 1985. Major categories of withdrawal are presented by county on maps of the State. Withdrawals are also shown by source, aquifer, and major river basin. Total freshwater withdrawals in Texas during 1985 were about 20, 100 million gal/day. Surface-water withdrawals were about 12,900 million gal/day or 64% of the total, and groundwater withdrawals were about 7,190 million gal/day or 36% of the total. More water was withdrawn for irrigation than for any other purpose, accounting for 40% of total freshwater withdrawals and for 75% of groundwater withdrawals. (USGS)

  15. 76 FR 14100 - Electrolux Home Products, Inc., Electrolux Major Appliances Division Including On-Site Leased...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-15

    ... 19, 2009 (74 FR 41935). The notice was amended on January 21, 2011 to include on-site leased workers from Per Mar Security. The notice was published in the Federal Register on February 2, 2011 (76 FR 5832... Employment and Training Administration Electrolux Home Products, Inc., Electrolux Major Appliances...

  16. IMPACT OF OIL PRODUCTION RELEASES ON SOME SOIL CHEMICAL PROPERTIES AT THE OSPER SITES

    EPA Science Inventory

    Surface and soil core samples were collected at two field sites in an old oil production area near Skiatook Lake in Oklahoma. The soil samples were analyzed for nitrates, organic matter, total petroleum hydrocarbons, conductivity, chlorides and dehydrogenase activity. Low level...

  17. 77 FR 48550 - Technicolor Creative Services, Post Production Feature Mastering Division Including On-Site...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-14

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF LABOR Employment and Training Administration Technicolor Creative Services, Post Production Feature Mastering Division Including On-Site Leased Workers From Ajilon Professional Staffing and KForce, Hollywood, CA; Notice of Affirmative Determination...

  18. Fast-growing species and sustainability (productivity and site dynamics of three fast-growing species)

    SciTech Connect

    Reddy, A.N.; Sugur, G.V.

    1992-12-31

    Growth of three fast-growing species, raised in a high rainfall zone (2000-2500 mm per annum) has been compared, and the associated site dynamics studies in the Western Ghat area of Karnataka State. Two fast-growing exotics, Acacia auriculiformis and Castuarina equisitifolia, were planted on degraded, open sites at high planting densities (5000 plants ha{sup {minus}1}), and one native fast-growing species. Dendrocalamus strictus, was planted on a good site under seasonal irrigation and wider spacing (500 plants ha{sup {minus}1}). These were studies at the age of 5 years for their comparative productivity, quantity of litter fall and changes in nutrient and microbial status. Among these species, A. auriculiformis recorded the highest total productivity closely followed by D. strictus. However, the MAI after 5 years indicated a higher productivity for D. strictus, when culm production attained harvestable size. C. equisitifolia was a close third. It was also found that D. strictus produced higher biomass at lower planting densities, under better sites and management. The litter fall and changes in nutrient status indicated the highest efficiency in A. auriculiformis, followed by C. equisitifolia. It was concluded that the higher planting density was the major contributing factor; the values were comparatively low for D. strictus mainly owing to a lower stocking density of plants.

  19. Effects of growth conditions on the production of neurotoxin 2,4-diaminobutyric acid (DAB) in Microcystis aeruginosa and its universal presence in diverse cyanobacteria isolated from freshwater in China.

    PubMed

    Fan, Hua; Qiu, Jiangbing; Fan, Lin; Li, Aifeng

    2015-04-01

    Neurotoxins β-N-methylamino-L-alanine (BMAA) and its isomer 2,4-diaminobutyric acid (DAB) have been reported previously in diverse strains of cyanobacteria. In this study, BMAA and DAB were analyzed for two strains of Microcystis aeruginosa incubated with four different levels of phosphate, nitrate, illumination, and temperature, respectively, in order to explore the effects of growth factors on toxin-producing ability of cyanobacteria. Both toxins were also screened in 17 cyanobacterial strains cultured with BG-11 medium and conventional illumination and temperature conditions, and in three field phytoplankton samples collected from different lakes in China. All samples were analyzed using a liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS) system coupled with a hydrophilic interaction liquid chromatography (HILIC) column. Results showed that no BMAA was detected in any of the cyanobacterial strains grown under our laboratory culture conditions, or in any of the field samples. Production of DAB in M. aeruginosa was significantly enhanced by extreme concentrations of nutrient and physical factors. Various concentrations of DAB were also present in most cultured samples (13 of 17) of cyanobacteria and were not species specific. This is the first time to report the production of DAB in M. aeruginosa cultured under alterative conditions in laboratory. Occurrence of DAB in most of the strains examined here means that consideration should be given to the presence of this compound in freshwater environment in China. PMID:25354443

  20. The Architecture of the Qo Site of Cytochrome bc1 Complex Probed by Superoxide Production

    SciTech Connect

    Muller, Florian L.; Roberts, Arthur G.; Bowman, Michael K.); Kramer, David M.

    2003-06-03

    Although several X-ray structures have been solved for the mitochondrial cytochrome (cyt) bc1 complex, none yet shows the position of substrate, ubiquinol, in the quinol oxidase (Qo) site. In the present study, the interaction of molecular oxygen with the reactive intermediate Qo semiquinone is used to probe Qo site. It has been known for some time that partial turnover of the cyt bc1 complex in the presence of antimycin A, a Qi site inhibitor, results in accumulation of a semiquinone at the Qo site, which can reduce O2 to superoxide (O2?-). It was more recently shown that myxothiazol, which binds close to the cyt bL heme in the proximal Qo niche, also induces O2?- production. In this work we show that, in addition to myxothiazol, a number of other proximal Qo inhibitors (including E-b-methoxyacrylate-stilbene, mucidin and famoxadone) also induce O2?- production in isolated yeast cyt bc1 complex, at about 50% the Vmax observed in the presence of antimycin A. We propose that proximal Qo site inhibitors induce O2?- production because they allow formation, but not oxidation of the semiquinone at the distal niche of the Qo site pocket. The apparent Km for ubiquinol at the Qo site in the presence of Qo proximal inhibitors suggests that the distal niche of the Qo pocket can act as a fully independent quinol binding and oxidation site. Together with the X-ray structures these results suggest substrate ubiquinol binds in essentially the same position as stigmatellin with H-bonds between H161 of the Rieske iron-sulfur protein and E272 of the cyt b protein. When modeled in this way, mucidin, and ubiquinol can bind simultaneously to the Qo site with virtually no steric hindrance, whereas progressively bulkier inhibitors show increasing overlap. The fact that partial turnover of the Qo site is possible even with bound proximal Qo site inhibitors is consistent with the participation of two separate functional Qo binding niches, occupied simultaneously or sequentially.

  1. Plutonium production story at the Hanford site: processes and facilities history

    SciTech Connect

    Gerber, M.S., Westinghouse Hanford

    1996-06-20

    This document tells the history of the actual plutonium production process at the Hanford Site. It contains five major sections: Fuel Fabrication Processes, Irradiation of Nuclear Fuel, Spent Fuel Handling, Radiochemical Reprocessing of Irradiated Fuel, and Plutonium Finishing Operations. Within each section the story of the earliest operations is told, along with changes over time until the end of operations. Chemical and physical processes are described, along with the facilities where these processes were carried out. This document is a processes and facilities history. It does not deal with the waste products of plutonium production.

  2. Characterization of the Escherichia coli F factor traY gene product and its binding sites.

    PubMed Central

    Nelson, W C; Morton, B S; Lahue, E E; Matson, S W

    1993-01-01

    The traY gene product (TraYp) from the Escherichia coli F factor has previously been purified and shown to bind a DNA fragment containing the F plasmid oriT region (E. E. Lahue and S. W. Matson, J. Bacteriol. 172:1385-1391, 1990). To determine the precise nucleotide sequence bound by TraYp, DNase I footprinting was performed. The TraYp-binding site is near, but not coincident with, the site that is nicked to initiate conjugative DNA transfer. In addition, a second TraYp binding site, which is coincident with the mRNA start site at the traYI promoter, is described. The Kd for each binding site was determined by a gel mobility shift assay. TraYp exhibits a fivefold higher affinity for the oriT binding site compared with the traYI promoter binding site. Hydrodynamic studies were performed to show that TraYp is a monomer in solution under the conditions used in DNA binding assays. Early genetic experiments implicated the traY gene product in the site- and strand-specific endonuclease activity that nicks at oriT (R. Everett and N. Willetts, J. Mol. Biol. 136:129-150, 1980; S. McIntire and N. Willetts, Mol. Gen. Genet. 178:165-172, 1980). As this activity has recently been ascribed to helicase I, it was of interest to see whether TraYp had any effect on this reaction. Addition of TraYp to nicking reactions catalyzed by helicase I showed no effect on the rate or efficiency of oriT nicking. Roles for TraYp in conjugative DNA transfer and a possible mode of binding to DNA are discussed. Images PMID:8468282

  3. Differential behavior of the sub-sites of cytochrome 450 active site in binding of substrates, and products (implications for coupling/uncoupling).

    PubMed

    Narasimhulu, Shakunthala

    2007-03-01

    The cytochrome P450 catalyzes hydroxylation of many substrates in the presence of O(2) and specific electron transport system. The ternary complex S-Fe(+)O(2) with substrate and O(2) bound to their respective sites on the reduced enzyme is an important intermediate in the formation of the hydroxylating species. Then the active site may be considered as having two sub-sites geared for entirely different types of functionally relevant interactions. The two sites are the substrate binding site, the specific protein residues (Site I), and the L(6) position of the iron (Site II) to which O(2) binds upon reduction. In the ferric enzyme, when substrate binds to Site I, the low spin six-coordinated P450 is converted to the readily reducible high spin five coordinated state. Certain amines and OH compounds, such as products of P450-catalyzed reactions, can bind to Site II resulting in six coordinated inhibited complexes. Then the substrate and product interactions with the two sub-sites can regulate the functional state of the enzyme during catalysis. Product interactions have received very little attention. CYP101 is the only P450 in which X-ray and spectroscopic data on all three structures, the substrate-free, camphor-bound and the 5-exo-OHcamphor-bound are available. The substrate-free CYP101 is low spin and six-coordinated with a water molecule ligated at the L(6) position of the iron. The substrate camphor binds to Site I, and releases the L(6) water despite its inability to bind to this site, indicating that Site I binding can inhibit Site II ligation. The product 5-exo-OHcamphor in addition to binding to Site I, binds to Site II through its -OH group forming Fe-O bond, resulting in the low spin six-coordinated complex. New temperature-jump relaxation kinetic data indicating that Site II ligation inhibits Site I binding are presented. It appears that the Site I and Site II function as interacting sub-sites. The inhibitory allosteric interactions between the two sub-sites

  4. Measurement Sets and Sites Commonly Used for High Spatial Resolution Image Product Characterization

    NASA Technical Reports Server (NTRS)

    Pagnutti, Mary

    2006-01-01

    Scientists within NASA's Applied Sciences Directorate have developed a well-characterized remote sensing Verification & Validation (V&V) site at the John C. Stennis Space Center (SSC). This site has enabled the in-flight characterization of satellite high spatial resolution remote sensing system products form Space Imaging IKONOS, Digital Globe QuickBird, and ORBIMAGE OrbView, as well as advanced multispectral airborne digital camera products. SSC utilizes engineered geodetic targets, edge targets, radiometric tarps, atmospheric monitoring equipment and their Instrument Validation Laboratory to characterize high spatial resolution remote sensing data products. This presentation describes the SSC characterization capabilities and techniques in the visible through near infrared spectrum and examples of calibration results.

  5. TOXICITY OF COPPER-SPIKED SEDIMENTS TO FRESHWATER INVERTEBRATES

    EPA Science Inventory

    Natural freshwater sediments from two Oregon sites were spiked with copper in the laboratory and two static toxicity tests were conducted with series of copper concentrations ranging from 59 to 10,600 mg/kg of dry sediment. Water (800 ml) was added to 1-liter test beakers over th...

  6. High diversity of magnetotactic deltaproteobacteria in a freshwater niche.

    PubMed

    Wang, Yinzhao; Lin, Wei; Li, Jinhua; Pan, Yongxin

    2013-04-01

    Knowledge of the diversity of magnetotactic bacteria in natural environments is crucial for understanding their contribution to various biological and geological processes. Here we report a high diversity of magnetotactic bacteria in a freshwater site. Ten out of 18 operational taxonomic units (OTUs) were affiliated with the Deltaproteobacteria. Some rod-shaped bacteria simultaneously synthesized greigite and magnetite magnetosomes. PMID:23377941

  7. High Diversity of Magnetotactic Deltaproteobacteria in a Freshwater Niche

    PubMed Central

    Wang, Yinzhao; Lin, Wei; Li, Jinhua

    2013-01-01

    Knowledge of the diversity of magnetotactic bacteria in natural environments is crucial for understanding their contribution to various biological and geological processes. Here we report a high diversity of magnetotactic bacteria in a freshwater site. Ten out of 18 operational taxonomic units (OTUs) were affiliated with the Deltaproteobacteria. Some rod-shaped bacteria simultaneously synthesized greigite and magnetite magnetosomes. PMID:23377941

  8. Land Surface Product Validation Using the DOE ARM Southern Great Plains Site

    NASA Astrophysics Data System (ADS)

    Knuteson, R.; Revercomb, H.; Tobin, D.; Osborne, B.

    2003-12-01

    The University of Wisconsin Space Science and Engineering Center (UW-SSEC) is making use of the U.S. Department of Energy Atmospheric Radiation Measurement (DOE ARM) program Southern Great Plains (SGP) site for validation of NASA EOS land surface products. The DOE ARM site covers a 250 km square region that includes most of Oklahoma and southern Kansas. The site is dominated by a mixture of vegetation and bare soil with a vegetation fraction that changes with the growing season. The land use is divided between cattle ranching (permanent pasture) and wheat farming (seasonal). The DOE ARM site provides routine state-of-the-art vertical profile measurements of the atmospheric state. Special radiosonde launches have been conducted by DOE ARM to coincide with overpasses of the NASA Aqua platform. The UW-SSEC has provided ground truth measurements of surface characteristics using a mobile research vehicle (the AERIbago) during several aircraft field campaigns. The UW-SSEC Scanning High-resolution Interferometer Sounder (S-HIS) has provided high altitude observations of the thermal infrared spectrum for comparison to satellite observations. Coincident measurements of ground-based and aircraft observations with AIRS and MODIS satellite observations have been obtained during TX-2001, TX-2002, and IHOP. Preliminary land surface products from AIRS will be compared with MODIS land products and the validation measurements obtained from aircraft and ground-based sensors.

  9. Workbook for prioritizing petroleum industry exploration and production sites for remediation

    SciTech Connect

    White, G.J.

    1998-08-03

    The purpose of this Workbook is to provide a screening-level method for prioritizing petroleum exploration and production sites for remediation that is based on readily available information, but which does not require a full characterization of the sites being evaluated. The process draws heavily from the Canadian National Classification System for Contaminated Sites, and fits into the framework for ecological risk assessment provided in guidance from the US Environmental Protection Agency. Using this approach, scoring guidelines are provided for a number of Evaluation Factors relating to: (1) the contaminants present at the site; (2) the potential exposure pathways for these contaminants; and (3) the potential receptors of those contaminants. The process therefore incorporates a risk-based corrective action (RBCA) framework to estimate the relative threat posed by a site to human health and to ecological systems. Physical (non-toxic) disturbance factors have also been incorporated into the process. It should also be noted that the process described in this Workbook has not yet been field tested at petroleum E and P sites. The first logical step in the field testing of this process is to apply the method at a small number of sites to assess the availability of the information that is needed to score each evaluation factor. Following this evaluation, the Workbook process should be applied at a series of sites to determine the effectiveness of the process at ranking sites according to their relative need for remediation. Upon completion of these tests, the Workbook should be revised to reflect the findings of the field tests.

  10. [Lactobacilli of freshwater fishes].

    PubMed

    Kvasnikov, E I; Kovalenko, N K; Materinskaia, L G

    1977-01-01

    Normal microflora in the intestinal tract of fishes inhabiting fresh-water reservoirs includes lactic bacteria. The number of the bacteria depends on the animal species, the composition of food, the age, and the season. The highest number of these microorganisms (hundreds of millions per gram of the intestinal content) is found in carps. Enterococci are most often encountered in fishes inhabiting ponds: Streptococcus faecalis Andrewes a. Horder, Str. faecium Orla-Jensen, Str. bovis Orla-Jensen. Lactobacilli are more typical of fishes in water reserviors: Lactobacillus plantarum (Orla-Jensen) Bergey et al., L. casei (Orla-Jensen) Hansen a. Lessel, L. casei var. casei, L. casei var. rhamnosus, L. Casei var. alactosus, L. leichmannii (Henneberg) Bergey et al., L. acidophillus (Moro) Hansen a. Mocquot, L. Fermenti Beijerinck, L. cellobiosus Rogosa et al., L. Buchneri (Henneberg) Bergey et al. The content of lactic bacteria varies in water reservoirs; their highest content is found in ooze (tens of thousands per gram). PMID:909475

  11. FROM THE MOUNTAINS TO THE SEA: THE STATE OF MARYLAND'S FRESHWATER STREAMS

    EPA Science Inventory

    The Maryland Biological Stream Survey, conducted by the Maryland Department of Natural Resources, sampled about 1,000 randomly-selected sites on first through third order freshwater streams throughout Maryland from 1995 to 1997. Biota (fish, benthic macroinvertebrates, herpetofau...

  12. Information system of forest growth and productivity by site quality type and elements of forest

    NASA Astrophysics Data System (ADS)

    Khlyustov, V.

    2012-04-01

    Information system of forest growth and productivity by site quality type and elements of forest V.K. Khlustov Head of the Forestry Department of Russian State Agrarian University named after K.A.Timiryazev doctor of agricultural sciences, professor The efficiency of forest management can be improved substantially by development and introduction of principally new models of forest growth and productivity dynamics based on regionalized site specific parameters. Therefore an innovative information system was developed. It describes the current state and gives a forecast for forest stand parameters: growth, structure, commercial and biological productivity depend on type of site quality. In contrast to existing yield tables, the new system has environmental basis: site quality type. The information system contains set of multivariate statistical models and can work at the level of individual trees or at the stand level. The system provides a graphical visualization, as well as export of the emulation results. The System is able to calculate detailed description of any forest stand based on five initial indicators: site quality type, site index, stocking, composition, and tree age by elements of the forest. The results of the model run are following parameters: average diameter and height, top height, number of trees, basal area, growing stock (total, commercial with distribution by size, firewood and residuals), live biomass (stem, bark, branches, foliage). The system also provides the distribution of mentioned above forest stand parameters by tree diameter classes. To predict the future forest stand dynamics the system require in addition the time slot only. Full set of forest parameters mention above will be provided by the System. The most conservative initial parameters (site quality type and site index) can be kept in the form of geo referenced polygons. In this case the system would need only 3 dynamic initial parameters (stocking, composition and age) to

  13. Global impacts of energy demand on the freshwater resources of nations.

    PubMed

    Holland, Robert Alan; Scott, Kate A; Flörke, Martina; Brown, Gareth; Ewers, Robert M; Farmer, Elizabeth; Kapos, Valerie; Muggeridge, Ann; Scharlemann, Jörn P W; Taylor, Gail; Barrett, John; Eigenbrod, Felix

    2015-12-01

    The growing geographic disconnect between consumption of goods, the extraction and processing of resources, and the environmental impacts associated with production activities makes it crucial to factor global trade into sustainability assessments. Using an empirically validated environmentally extended global trade model, we examine the relationship between two key resources underpinning economies and human well--being-energy and freshwater. A comparison of three energy sectors (petroleum, gas, and electricity) reveals that freshwater consumption associated with gas and electricity production is largely confined within the territorial boundaries where demand originates. This finding contrasts with petroleum, which exhibits a varying ratio of territorial to international freshwater consumption, depending on the origin of demand. For example, although the United States and China have similar demand associated with the petroleum sector, international freshwater consumption is three times higher for the former than the latter. Based on mapping patterns of freshwater consumption associated with energy sectors at subnational scales, our analysis also reveals concordance between pressure on freshwater resources associated with energy production and freshwater scarcity in a number of river basins globally. These energy-driven pressures on freshwater resources in areas distant from the origin of energy demand complicate the design of policy to ensure security of fresh water and energy supply. Although much of the debate around energy is focused on greenhouse gas emissions, our findings highlight the need to consider the full range of consequences of energy production when designing policy. PMID:26627262

  14. Global impacts of energy demand on the freshwater resources of nations

    PubMed Central

    Holland, Robert Alan; Scott, Kate A.; Flörke, Martina; Brown, Gareth; Ewers, Robert M.; Farmer, Elizabeth; Kapos, Valerie; Muggeridge, Ann; Taylor, Gail; Barrett, John; Eigenbrod, Felix

    2015-01-01

    The growing geographic disconnect between consumption of goods, the extraction and processing of resources, and the environmental impacts associated with production activities makes it crucial to factor global trade into sustainability assessments. Using an empirically validated environmentally extended global trade model, we examine the relationship between two key resources underpinning economies and human well-being—energy and freshwater. A comparison of three energy sectors (petroleum, gas, and electricity) reveals that freshwater consumption associated with gas and electricity production is largely confined within the territorial boundaries where demand originates. This finding contrasts with petroleum, which exhibits a varying ratio of territorial to international freshwater consumption, depending on the origin of demand. For example, although the United States and China have similar demand associated with the petroleum sector, international freshwater consumption is three times higher for the former than the latter. Based on mapping patterns of freshwater consumption associated with energy sectors at subnational scales, our analysis also reveals concordance between pressure on freshwater resources associated with energy production and freshwater scarcity in a number of river basins globally. These energy-driven pressures on freshwater resources in areas distant from the origin of energy demand complicate the design of policy to ensure security of fresh water and energy supply. Although much of the debate around energy is focused on greenhouse gas emissions, our findings highlight the need to consider the full range of consequences of energy production when designing policy. PMID:26627262

  15. Evaluation of the Main Ceos Pseudo Calibration Sites Using Modis Brdf/albedo Products

    NASA Astrophysics Data System (ADS)

    Kharbouche, Said; Muller, Jan-Peter

    2016-06-01

    This work describes our findings about an evaluation of the stability and the consistency of twenty primary PICSs (Pseudo-Invariant Calibration Sites). We present an analysis of 13 years of 8-daily MODIS products of BRDF parameters and white-sky-albedos (WSA) over the shortwave band. This time series of WSA and BRDFs shows the variation of the "stability" varies significantly from site to site. Using a 10x10 km window size over all the sites, the change in of WSA stability is around 4% but the isotropicity, which is an important element in inter-satellite calibration, can vary from 75% to 98%. Moreover, some PICS, especially, Libya-4 which is one of the PICS which is most employed, has significant and relatively fast changes in wintertime. PICS observations of BRDF/albedo shows that the Libya-4 PICS has the best performance but it is not too far from some sites such as Libya-1 and Mali. This study also reveals that Niger-3 PICS has the longest continuous period of high stability per year, and Sudan has the most isotropic surface. These observations have important implications for the use of these sites.

  16. Effects of different media composition, light intensity and photoperiod on morphology and physiology of freshwater microalgae Ankistrodesmus falcatus--a potential strain for bio-fuel production.

    PubMed

    George, Basil; Pancha, Imran; Desai, Chahana; Chokshi, Kaumeel; Paliwal, Chetan; Ghosh, Tonmoy; Mishra, Sandhya

    2014-11-01

    Media composition, light intensity and photoperiod significantly affect the algal growth and productivity and their optimization is important for the commercialization of microalgae based biofuels. In the present study, effects of different culture medium, light intensity and photoperiod were studied on growth, biomass productivity, and biochemical composition of a fresh water microalgae Ankistrodesmus falcatus in batch culture. The results revealed that A. falcatus could yield more than 35% of total lipid (containing around 65.74% neutral lipid) along with optimal growth (0.20 μ) and biomass productivity (7.9 mg/L/day) in the BG-11 medium under a light intensity of 60 μmol m(-2) s(-1) and 12:12 (Light: Dark) cycle. The highest total lipid yield of 67.2% (containing 72.68% of neutral lipid) was observed in Zarrouk's medium grown culture but with altered cell morphology and ultra-structural changes. PMID:25218209

  17. Ecogeomorphological feedbacks in a tidal freshwater marsh

    NASA Astrophysics Data System (ADS)

    Palinkas, C. M.; Engelhardt, K.

    2013-12-01

    Tidal freshwater marshes are critical components of fluvial and estuarine ecosystems. However, ecogeomorphological feedbacks (i.e., feedbacks between sediment dynamics and the vegetation community) in freshwater marshes have not received as much attention as within their saltwater counterparts. This study evaluates the role of these feedbacks in stabilizing marsh-surface elevation, relative to sea-level rise, in Dyke Marsh Preserve (Potomac River, USA). Specifically, we relate the composition of the vegetation community to current and historical patterns of sedimentation that occur on bimonthly to decadal time scales. Along with a ~3-year time series of bimonthly and seasonal-scale observations, 210Pb (half-life 22.3 y) profiles are used to identify sites with relatively steady sediment accumulation (i.e., stable sediments) and those with numerous deposition/erosion events (i.e., unstable sediments). Differences in the vegetation community (e.g., composition, stem density) and sediment character (e.g., organic content, grain size) among sites in each of these stability categories are examined with statistical techniques and compared to observations of marsh-surface elevation change. The resulting insights are placed into a geomorphological context to assess the potential response of this marsh to rapid global environmental change.

  18. Taking High Conservation Value from Forests to Freshwaters

    NASA Astrophysics Data System (ADS)

    Abell, Robin; Morgan, Siân K.; Morgan, Alexis J.

    2015-07-01

    The high conservation value (HCV) concept, originally developed by the Forest Stewardship Council, has been widely incorporated outside the forestry sector into companies' supply chain assessments and responsible purchasing policies, financial institutions' investment policies, and numerous voluntary commodity standards. Many, if not most, of these newer applications relate to production practices that are likely to affect freshwater systems directly or indirectly, yet there is little guidance as to whether or how HCV can be applied to water bodies. We focus this paper on commodity standards and begin by exploring how prominent standards currently address both HCVs and freshwaters. We then highlight freshwater features of high conservation importance and examine how well those features are captured by the existing HCV framework. We propose a new set of freshwater `elements' for each of the six values and suggest an approach for identifying HCV Areas that takes out-of-fence line impacts into account, thereby spatially extending the scope of existing methods to define HCVs. We argue that virtually any non-marine HCV assessment, regardless of the production sector, should be expanded to include freshwater values, and we suggest how to put those recommendations into practice.

  19. Antioxidant status and Na(+), K (+)-ATPase activity in freshwater fish Carassius auratus exposed to different combustion products of Nafion 117 membrane: an integrated biomarker approach.

    PubMed

    Feng, Mingbao; Wang, Xinghao; Wang, Chao; Qin, Li; Wei, Zhongbo; Wang, Zunyao

    2015-03-01

    Nafion 117 membrane (N117), an important polymer electrolyte membrane (PEM), has been widely applied in numerous chemical technologies. Its increasing production and utilization will inevitably lead to the problem of waste disposal, with incineration as an important method. However, toxicity data of its combustion products on aquatic organisms have been seldom reported. The present study was therefore conducted to investigate the antioxidant response and Na(+), K(+)-ATPase activity in liver of Carassius auratus exposed to different combustion products of N117 for 5, 15, and 30 days. The concentrations of fluorine ion (F(-)) in the aquaria among the exposure durations were analyzed using the ion chromatography system. The results showed that these treatments have the capability to induce oxidative stress and suppress Na(+), K(+)-ATPase activity, as indicated by some significant alterations on these measured toxicity end-points in fish liver. According to the integrated biomarker response (IBR) index, the toxicity intensity of these experimental treatments was tentatively ranked. Taken together, these observations provided some preliminary data on the potential toxicity of the combustion products of N117 on aquatic organisms and could fill the information gaps in the toxicity database of the current-use PEM. PMID:25398218

  20. Screening of three proposed DOE geopressured-geothermal aquifer natural gas project areas for potential conflicting commercial production: Freshwater Bayou, Lake Theriot, and Kaplan, Louisiana

    SciTech Connect

    Knutson, C.F.; Rogers, L.A.

    1982-02-01

    Three proposed DOE geopressured geothermal prospects defined by the Louisiana State University resource assessment group were screened for possible conflict with existing gas production. The analysis used the public records available at the Louisiana Department of Conservation offices in Baton Rouge and structural and statigraphic interpretations made by the L.S.U. resource assessment group. (MHR)

  1. A Simulation Model for Studying Effects of Pollution and Freshwater Inflow on Secondary Productivity in an Ecosystem. Ph.D. Thesis - North Carolina State Univ.

    NASA Technical Reports Server (NTRS)

    Johnson, R. W.

    1974-01-01

    A mathematical model of an ecosystem is developed. Secondary productivity is evaluated in terms of man related and controllable factors. Information from an existing physical parameters model is used as well as pertinent biological measurements. Predictive information of value to estuarine management is presented. Biological, chemical, and physical parameters measured in order to develop models of ecosystems are identified.

  2. Malacofauna of Holocene freshwater calcareous deposits of Lithuania

    NASA Astrophysics Data System (ADS)

    Sanko, Aleksander; Vainorius, Julius; Melešytė, Monika

    2010-12-01

    The malacofauna of freshwater calcareous deposits of Lithuania was studied. Sections of the Mūšos Tyrelis and Pabaliai peatbogs near the town of Šiauliai, as well as Dubičiai section (three sites) in SE Lithuania and Dūkštos in Central Lithuania were investigated. Freshwater calcareous deposits are attributed to three groups of facies - lacustrine, valley-hollow-peatbog and terrestrial. Each group of facies consists of sub-facies (freshwater lime, "gazha" (limno-calcite), peat-tufa, calcareous tufa, "mada") varying the formation conditions, composition and other characteristics. The mollusc fauna in the lacustrine facies group (Mūšos Tyrelis and Pabaliai sections) is represented by lacustrine species containing euryecological freshwater molluscs. Terrestrial and rheophilous species are rare or absent in the lacustrine group. Deposits of valley-hollow-peatbog facies contain shells of euryecological freshwater and lacustrine molluscs together with rheophyl shells, sometimes with abundant terrestrial shells, as was observed in the Dubičiai-4 section. A characteristic feature of the terrestrial facies group deposits is the occurrence of solely terrestrial mollusc shells (Dūkštos section).

  3. Contaminants, water quality, and wildlife mortality on oil production sites in western South Dakota. Interim report

    SciTech Connect

    Henry, C.J.; Ruelle, R.

    1993-04-01

    The objectives of the study were to evaluate oil pits and other hazards at oil production sites to (1) document the magnitude of wildlife mortality due to exposure to oil and other chemicals, (2) determine the physical and toxic effects of oil pit contents on wildlife, and (3) identify methods to prevent sublethal and lethal impacts to wildlife. Pits at oil production sites in Fall River and Harding Counties of western South Dakota were surveyed for wildlife carcasses by searching the shorelines and raking underwater around the pit edges in April, July, and October 1992. In July, composite water and sediment samples were collected from 26 pits, and analyzed for oil and grease. Bioassays were conducted with two life stages of Hyalella azteca and Daphnia magna to determine pit water toxicity. Seed germination tests were conducted using radish seeds exposed to pit water. Oil and poor water quality appeared to be the primary causes of pit liquid toxicity.

  4. Holliday intermediates and reaction by-products in FLP protein-promoted site-specific recombination.

    PubMed Central

    Meyer-Leon, L; Huang, L C; Umlauf, S W; Cox, M M; Inman, R B

    1988-01-01

    Holliday structures are formed and resolved by FLP protein during site-specific recombination. These structures have been isolated and are visualized in both native and partially denatured states by electron microscopy. No single-strand breaks are found within the junction, indicating that the structure results from a reciprocal exchange of strands. These structures have properties consistent with being reaction intermediates. Double-strand cleavage products and "Y structures" are also detected and appear to be by-products of the reaction. The Y structures are three-armed branched molecules with a covalently closed junction located at the FLP recombination target site. Models are discussed, suggesting that both of these novel structures are made by aberrant cleavages during formation and resolution of the Holliday intermediate. Images PMID:3065624

  5. Nutrition Content of Food and Beverage Products on Web Sites Popular With Children

    PubMed Central

    Lingas, Elena O.; Bukofzer, Eliana

    2009-01-01

    We assessed the nutritional quality of branded food and beverage products advertised on 28 Web sites popular with children. Of the 77 advertised products for which nutritional information was available, 49 met Institute of Medicine criteria for foods to avoid, 23 met criteria for foods to neither avoid nor encourage, and 5 met criteria for foods to encourage. There is a need for further research on the nature and extent of food and beverage advertising online to aid policymakers as they assess the impact of this marketing on children. PMID:19443816

  6. Nutrition content of food and beverage products on Web sites popular with children.

    PubMed

    Lingas, Elena O; Dorfman, Lori; Bukofzer, Eliana

    2009-11-01

    We assessed the nutritional quality of branded food and beverage products advertised on 28 Web sites popular with children. Of the 77 advertised products for which nutritional information was available, 49 met Institute of Medicine criteria for foods to avoid, 23 met criteria for foods to neither avoid nor encourage, and 5 met criteria for foods to encourage. There is a need for further research on the nature and extent of food and beverage advertising online to aid policymakers as they assess the impact of this marketing on children. PMID:19443816

  7. Quantitative Site-Specific Phosphoproteomics of Trichoderma reesei Signaling Pathways upon Induction of Hydrolytic Enzyme Production.

    PubMed

    Nguyen, Elizabeth V; Imanishi, Susumu Y; Haapaniemi, Pekka; Yadav, Avinash; Saloheimo, Markku; Corthals, Garry L; Pakula, Tiina M

    2016-02-01

    The filamentous fungus Trichoderma reesei is used for industrial production of secreted enzymes including carbohydrate active enzymes, such as cellulases and hemicellulases. The production of many of these enzymes by T. reesei is influenced by the carbon source it grows on, where the regulation system controlling hydrolase genes involves various signaling pathways. T. reesei was cultivated in the presence of sorbitol, a carbon source that does not induce the production of cellulases and hemicellulases, and then exposed to either sophorose or spent-grain extract, which are efficient inducers of the enzyme production. Specific changes at phosphorylation sites were investigated in relation to the production of cellulases and hemicellulases using an MS-based framework. Proteome-wide phosphorylation following carbon source exchange was investigated in the early stages of induction: 0, 2, 5, and 10 min. The workflow involved sequential trypsin digestion, TiO2 enrichment, and MS analysis using a Q Exactive mass spectrometer. We report on the identification and quantitation of 1721 phosphorylation sites. Investigation of the data revealed a complex signaling network activated upon induction involving components related to light-mediated cellulase induction, osmoregulation, and carbon sensing. Changes in protein phosphorylation were detected in the glycolytic pathway, suggesting an inhibition of glucose catabolism at 10 min after the addition of sophorose and as early as 2 min after the addition of spent-grain extract. Differential phosphorylation of factors related to carbon storage, intracellular trafficking, cytoskeleton, and cellulase gene regulation were also observed. PMID:26689635

  8. Estimating switchgrass productivity in the Great Plains using satellite vegetation index and site environmental variables

    USGS Publications Warehouse

    Gu, Yingxin; Wylie, Bruce K.; Howard, Daniel M.

    2015-01-01

    Switchgrass is being evaluated as a potential feedstock source for cellulosic biofuels and is being cultivated in several regions of the United States. The recent availability of switchgrass land cover maps derived from the National Agricultural Statistics Service cropland data layer for the conterminous United States provides an opportunity to assess the environmental conditions of switchgrass over large areas and across different geographic locations. The main goal of this study is to develop a data-driven multiple regression switchgrass productivity model and identify the optimal climate and environment conditions for the highly productive switchgrass in the Great Plains (GP). Environmental and climate variables used in the study include elevation, soil organic carbon, available water capacity, climate, and seasonal weather. Satellite-derived growing season averaged Normalized Difference Vegetation Index (GSN) was used as a proxy for switchgrass productivity. Multiple regression analyses indicate that there are strong correlations between site environmental variables and switchgrass productivity (r = 0.95). Sufficient precipitation and suitable temperature during the growing season (i.e., not too hot or too cold) are favorable for switchgrass growth. Elevation and soil characteristics (e.g., soil available water capacity) are also an important factor impacting switchgrass productivity. An anticipated switchgrass biomass productivity map for the entire GP based on site environmental and climate conditions and switchgrass productivity model was generated. Highly productive switchgrass areas are mainly located in the eastern part of the GP. Results from this study can help land managers and biofuel plant investors better understand the general environmental and climate conditions influencing switchgrass growth and make optimal land use decisions regarding switchgrass development in the GP.

  9. In-situ subaqueous capping of mercury-contaminated sediments in a fresh-water aquatic system, Part I—Bench-scale microcosm study to assess methylmercury production

    SciTech Connect

    Randall, Paul M.; Fimmen, Ryan; Lal, Vivek; Darlington, Ramona

    2013-08-15

    Bench-scale microcosm experiments were designed to provide a better understanding of the potential for Hg methylation in sediments from an aquatic environment. Experiments were conducted to examine the function of sulfate concentration, lactate concentration, the presence/absence of an aqueous inorganic Hg spike, and the presence/absence of inoculums of Desulfovibrio desulfuricans, a strain of sulfate-reducing bacteria (SRB) commonly found in the natural sediments of aquatic environments. Incubations were analyzed for both the rate and extent of (methylmercury) MeHg production. Methylation rates were estimated by analyzing MeHg and Hg after 2, 7, 14, 28, and 42 days. The production of metabolic byproducts, including dissolved gases as a proxy for metabolic utilization of carbon substrate, was also monitored. In all treatments amended with lactate, sulfate, Hg, and SRB, MeHg was produced (37 ng/g-sediment dry weight) after only 48 h of incubation and reached a maximum sediment concentration of 127 ng/g-sediment dry weight after the 42 day incubation period. Aqueous phase production of MeHg was observed to be 10 ng/L after 2 day, reaching a maximum observed concentration of 32.8 ng/L after 14 days, and declining to 10.8 ng/L at the end of the incubation period (42 day). The results of this study further demonstrates that, in the presence of an organic carbon substrate, sulfate, and the appropriate consortia of microorganisms, sedimentary Hg will be transformed into MeHg through bacterial metabolism. Further, this study provided the basis for evaluation of an in-situ subaqueous capping strategy that may limit (or potentially enhance) MeHg production. -- Highlights: • Hg methylation by SRB is limited by the depletion of sulfate and carbon. • Hg methylation is sensitive to competition by methanogens for carbon substrate. • In high lactate environment, all lactate was utilized in the microcosms within seven days. • In the absence of adequate metabolic fuel, Me

  10. Mechanical challenges to freshwater residency in sharks and rays.

    PubMed

    Gleiss, Adrian C; Potvin, Jean; Keleher, James J; Whitty, Jeff M; Morgan, David L; Goldbogen, Jeremy A

    2015-04-01

    Major transitions between marine and freshwater habitats are relatively infrequent, primarily as a result of major physiological and ecological challenges. Few species of cartilaginous fish have evolved to occupy freshwater habitats. Current thought suggests that the metabolic physiology of sharks has remained a barrier to the diversification of this taxon in freshwater ecosystems. Here, we demonstrate that the physical properties of water provide an additional constraint for this species-rich group to occupy freshwater systems. Using hydromechanical modeling, we show that occurrence in fresh water results in a two- to three-fold increase in negative buoyancy for sharks and rays. This carries the energetic cost of lift production and results in increased buoyancy-dependent mechanical power requirements for swimming and increased optimal swim speeds. The primary source of buoyancy, the lipid-rich liver, offers only limited compensation for increased negative buoyancy as a result of decreasing water density; maintaining the same submerged weight would involve increasing the liver volume by very large amounts: 3- to 4-fold in scenarios where liver density is also reduced to currently observed minimal levels and 8-fold without any changes in liver density. The first data on body density from two species of elasmobranch occurring in freshwater (the bull shark Carcharhinus leucas, Müller and Henle 1839, and the largetooth sawfish Pristis pristis, Linnaeus 1758) support this hypothesis, showing similar liver sizes as marine forms but lower liver densities, but the greatest negative buoyancies of any elasmobranch studied to date. Our data suggest that the mechanical challenges associated with buoyancy control may have hampered the invasion of freshwater habitats in elasmobranchs, highlighting an additional key factor that may govern the predisposition of marine organisms to successfully establish in freshwater habitats. PMID:25573824

  11. Anthropogenic litter in urban freshwater ecosystems: distribution and microbial interactions.

    PubMed

    Hoellein, Timothy; Rojas, Miguel; Pink, Adam; Gasior, Joseph; Kelly, John

    2014-01-01

    Accumulation of anthropogenic litter (i.e. garbage; AL) and its ecosystem effects in marine environments are well documented. Rivers receive AL from terrestrial habitats and represent a major source of AL to marine environments, but AL is rarely studied within freshwater ecosystems. Our objectives were to 1) quantify AL density in urban freshwaters, 2) compare AL abundance among freshwater, terrestrial, and marine ecosystems, and 3) characterize the activity and composition of AL biofilms in freshwater habitats. We quantified AL from the Chicago River and Chicago's Lake Michigan shoreline, and found that AL abundance in Chicago freshwater ecosystems was comparable to previously reported data for marine and terrestrial ecosystems, although AL density and composition differed among habitats. To assess microbial interactions with AL, we incubated AL and natural substrates in 3 freshwater ecosystems, quantified biofilm metabolism as gross primary production (GPP) and community respiration (CR), and characterized biofilm bacterial community composition via high-throughput sequencing of 16S rRNA genes. The main driver of biofilm community composition was incubation location (e.g., river vs pond), but there were some significant differences in biofilm composition and metabolism among substrates. For example, biofilms on organic substrates (cardboard and leaves) had lower GPP than hard substrates (glass, plastic, aluminum and tiles). In addition, bacterial communities on organic substrates were distinct in composition from those on hard substrates, with higher relative abundances of bacteria associated with cellulose decomposition. Finally, we used our results to develop a conceptual diagram designed to unite the study of AL in terrestrial and freshwater environments with the well-established field of marine debris research. We suggest this broad perspective will be useful for future studies which synthesize AL sources, ecosystem effects, and fate across multiple ecosystem

  12. Anthropogenic Litter in Urban Freshwater Ecosystems: Distribution and Microbial Interactions

    PubMed Central

    Hoellein, Timothy; Rojas, Miguel; Pink, Adam; Gasior, Joseph; Kelly, John

    2014-01-01

    Accumulation of anthropogenic litter (i.e. garbage; AL) and its ecosystem effects in marine environments are well documented. Rivers receive AL from terrestrial habitats and represent a major source of AL to marine environments, but AL is rarely studied within freshwater ecosystems. Our objectives were to 1) quantify AL density in urban freshwaters, 2) compare AL abundance among freshwater, terrestrial, and marine ecosystems, and 3) characterize the activity and composition of AL biofilms in freshwater habitats. We quantified AL from the Chicago River and Chicago's Lake Michigan shoreline, and found that AL abundance in Chicago freshwater ecosystems was comparable to previously reported data for marine and terrestrial ecosystems, although AL density and composition differed among habitats. To assess microbial interactions with AL, we incubated AL and natural substrates in 3 freshwater ecosystems, quantified biofilm metabolism as gross primary production (GPP) and community respiration (CR), and characterized biofilm bacterial community composition via high-throughput sequencing of 16S rRNA genes. The main driver of biofilm community composition was incubation location (e.g., river vs pond), but there were some significant differences in biofilm composition and metabolism among substrates. For example, biofilms on organic substrates (cardboard and leaves) had lower GPP than hard substrates (glass, plastic, aluminum and tiles). In addition, bacterial communities on organic substrates were distinct in composition from those on hard substrates, with higher relative abundances of bacteria associated with cellulose decomposition. Finally, we used our results to develop a conceptual diagram designed to unite the study of AL in terrestrial and freshwater environments with the well-established field of marine debris research. We suggest this broad perspective will be useful for future studies which synthesize AL sources, ecosystem effects, and fate across multiple ecosystem

  13. A multi-sites analysis on the ozone effects on Gross Primary Production of European forests.

    PubMed

    Proietti, C; Anav, A; De Marco, A; Sicard, P; Vitale, M

    2016-06-15

    Ozone (O3) is both a greenhouse gas and a secondary air pollutant causing adverse impacts on forests ecosystems at different scales, from cellular to ecosystem level. Specifically, the phytotoxic nature of O3 can impair CO2 assimilation that, in turn affects forest productivity. This study aims to evaluate the effects of tropospheric O3 on Gross Primary Production (GPP) at 37 European forest sites during the time period 2000-2010. Due to the lack of carbon assimilation data at O3 monitoring stations (and vice-versa) this study makes a first attempt to combine high resolution MODIS Gross Primary Production (GPP) estimates and O3 measurement data. Partial Correlations, Anomalies Analysis and the Random Forests Analysis (RFA) were used to quantify the effects of tropospheric O3 concentration and its uptake on GPP and to evaluate the most important factors affecting inter-annual GPP changes. Our results showed, along a North-West/South-East European transect, a negative impact of O3 on GPP ranging from 0.4% to 30%, although a key role of meteorological parameters respect to pollutant variables in affecting GPP was found. In particular, meteorological parameters, namely air temperature (T), soil water content (SWC) and relative humidity (RH) are the most important predictors at 81% of test sites. Moreover, it is interesting to highlight a key role of SWC in the Mediterranean areas (Spanish, Italian and French test sites) confirming that, soil moisture and soil water availability affect vegetation growth and photosynthesis especially in arid or semi-arid ecosystems such as the Mediterranean climate regions. Considering the pivotal role of GPP in the global carbon balance and the O3 ability to reduce primary productivity of the forests, this study can help in assessing the O3 impacts on ecosystem services, including wood production and carbon sequestration. PMID:26971205

  14. Human health risk assessment in restoring safe and productive use of abandoned contaminated sites.

    PubMed

    Wcisło, Eleonora; Bronder, Joachim; Bubak, Anicenta; Rodríguez-Valdés, Eduardo; Gallego, José Luis R

    2016-09-01

    In Europe soil contamination has been recognized as a serious problem. The needs to remediate contaminated sites are not questionable, although the remediation actions are often hindered by their very high financial costs. On the other hand, the abandoned contaminated sites may have the potential for redevelopment and creating conditions appropriate for their productive reuse bringing social, economic and environmental benefits. The main concern associated with the contaminated sites is their potential adverse health impact. Therefore, in the process of contaminated site redevelopment the risk assessment and the subsequent risk management decisions will play a crucial role. The main objective of this study was to illustrate the role of the human health risk assessment (HRA) in supporting site remediation and reuse decisions. To exemplify the significance of the HRA process in this field the Nitrastur site, located in Asturias, Spain was used. Risks resulting from soil contamination with arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), mercury (Hg), zinc (Zn) and lead (Pb) were assessed under three potential future land use patterns: industrial, residential and recreational. The results of the study indicated that soil at the Nitrastur site might pose non-cancer and cancer risks to potential future receptors - industrial workers, residents and recreational users. Arsenic and lead are the main substances responsible for the health risk and the primary drivers of remedial decisions at the site. The highest total cancer risks were observed under the residential scenario, followed in descending order by the recreational and industrial ones. The remedial maps illustrate in which areas remediation activities are required, depending on a given land use pattern. The obtained results may be used to develop, analyse, compare and select the remedial options within the intended land use pattern. They may also be used to support the decisions concerning the

  15. Effects of TiO2 nanoparticles on ROS production and growth inhibition using freshwater green algae pre-exposed to UV irradiation.

    PubMed

    Fu, Ling; Hamzeh, Mahsa; Dodard, Sabine; Zhao, Yuan H; Sunahara, Geoffrey I

    2015-05-01

    This study investigated the possibility that titanium dioxide nanoparticles (nano-TiO2) toxicity in Pseudokirchneriella subcapitata involves reactive oxygen species (ROS) production, using the dichlorodihydrofluorescein (DCF) assay. Algae were exposed to nano-TiO2 under laboratory fluorescent lamps supplemented with UV irradiation for 3h, with or without a UV filter. Results showed that nano-TiO2 increased ROS production in UV-exposed cells, with or without a UV filter (LOEC values were 250 and 10mg/L, respectively). Sublethal effects of nano-TiO2 on UV pre-exposed algae were also examined. Toxicity studies indicated that exposure to nano-TiO2 agglomerates decreased algal growth following 3h pre-exposure to UV, with or without a UV filter (EC50s were 8.7 and 6.3mg/L, respectively). The present study suggests that the growth inhibitory effects of nano-TiO2 in algae occurred at concentrations lower than those that can elevate DCF fluorescence, and that ROS generation is not directly involved with the sublethal effects of nano-TiO2 in algae. PMID:25867689

  16. Evaluating multiple indices of agricultural water use efficiency and productivity to improve comparisons between sites and trends

    NASA Astrophysics Data System (ADS)

    Levy, M. C.

    2012-12-01

    Approximately 70% of global available freshwater supplies are used in the agricultural sector. Increased demands for water to meet growing population food requirements, and expected changes in the reliability of freshwater supplies due to climate change, threaten the sustainability of water supplies worldwide - not only on farms, but in connected cities and industries. Researchers concerned with agricultural water use sustainability use a variety of theoretical and empirical measures of efficiency and productivity to gain insight into the sustainability of agricultural water use. However, definitions of measures, or indices, vary between different natural and political boundaries, across regions, states and nations and between their respective research, industry, and environmental groups. Index development responds to local data availability and local agendas, and there is debate about the validity of various indices. However, real differences in empirical index measures are not well-understood across the multiple disciplines that study agricultural water use, including engineering and hydrology, agronomy, climate and soil sciences, and economics. Nevertheless reliable, accessible, and generalizable indices are required for planners and policymakers to promote sustainable water use systems. This study synthesizes a set of water use efficiency and productivity indices based on academic, industry and government literature in California and Australia, two locations with similarly water-stressed and valuable agricultural industries under pressure to achieve optimal water use efficiency and productivity. Empirical data at the irrigation district level from the California San Joaquin Valley and Murray Darling Basin states of Victoria and New South Wales in Australia are used to compute indices that estimate efficiency, yield productivity, and economic productivity of agricultural water use. Multiple index estimates of same time-series data demonstrate historical spread

  17. Slush hydrogen propellant production, transfer, and expulsion studies at the NASA K-Site Facility

    NASA Technical Reports Server (NTRS)

    Hardy, Terry L.; Whalen, Margaret V.

    1991-01-01

    Slush hydrogen is currently being considered as a fuel for the National AeroSpace Plane (NASP) because it offers the potential for decreased vehicle size and weight. However, no large scale data was available on the production, transfer, and tank pressure control characteristics required to use the fuel for the NASP. Therefore, experiments were conducted at NASA-Lewis K-Site Facility to improve the slush hydrogen data base. Slush hydrogen was produced using the evaporative cooling, or freeze-thaw, technique in batches for approx. 800 gallons. This slush hydrogen was pressure transferred to a 5 ft diameter spherical test tank following production, and flow characteristics were measured during this transfer process. The slush hydrogen in the test tank was pressurized and expelled using a pressurized expulsion technique to obtain information on tank pressure control for the NASP. Results from the production, transfer, pressurization, and pressurized expulsion tests are described.

  18. Slush hydrogen propellant production, transfer, and expulsion studies at the NASA K-Site Facility

    NASA Technical Reports Server (NTRS)

    Hardy, Terry L.; Whalen, Margaret V.

    1991-01-01

    Slush hydrogen is currently being considered as a fuel for the National Aero-Space Plane (NASP) because it offers the potential for decreased vehicle size and weight. However, no large-scale data was available on the production, transfer, and tank pressure control characteristics required to use the fuel for the NASP. Therefore, experiments were conducted at the NASA Lewis Research Center K-Site Facility to improve the slush hydrogen database. Slush hydrogen was produced using the evaporative cooling, or freeze-thaw, technique in batches of about 800 gallons. This slush hydrogen was pressure transferred to a 5 ft diameter spherical test tank following production, and flow characteristics were measured during this transfer process. The slush hydrogen in the test tank was pressurized and expelled using a pressurized expulsion technique to obtain information on tank pressure control for the NASP. Results from the production, transfer, pressurization, and pressurized expulsion tests are described.

  19. Treatment of dairy manure effluent using freshwater algae: algal productivity and recovery of manure nutrients using pilot-scale algal turf scrubbers.

    PubMed

    Mulbry, Walter; Kondrad, Shannon; Pizarro, Carolina; Kebede-Westhead, Elizabeth

    2008-11-01

    Cultivating algae on nitrogen (N) and phosphorus (P) in animal manure effluents presents an alternative to the current practice of land application. The objective of this study was to determine values for productivity, nutrient content, and nutrient recovery using filamentous green algae grown in outdoor raceways at different loading rates of raw and anaerobically digested dairy manure effluent. Algal turf scrubber raceways (30m2 each) were operated in central Maryland for approximately 270 days each year (roughly April 1-December 31) from 2003 to 2006. Algal biomass was harvested every 4-12 days from the raceways after daily additions of manure effluent corresponding to loading rates of 0.3 to 2.5g total N (TN) and 0.08 to 0.42g total P (TP) m(-2)d(-1). Mean algal productivity values increased from approximately 2.5g DW m(-2)d(-1) at the lowest loading rate (0.3g TN m(-2)d(-1)) to 25g DW m(-2)d(-1) at the highest loading rate (2.5g TN m(-2)d(-1)). Mean N and P contents in the dried biomass increased 1.5-2.0-fold with increasing loading rate up to maximums of 7% N and 1% P (dry weight basis). Although variable, algal N and P accounted for roughly 70-90% of input N and P at loading rates below 1g TN, 0.15g TP m(-2)d(-1). N and P recovery rates decreased to 50-80% at higher loading rates. There were no significant differences in algal productivity, algal N and P content, or N and P recovery values from raceways with carbon dioxide supplementation compared to values from raceways without added carbon dioxide. Projected annual operational costs are very high on a per animal basis ($780 per cow). However, within the context of reducing nutrient inputs in sensitive watersheds such as the Chesapeake Bay, projected operational costs of $11 per kgN are well below the costs cited for upgrading existing water treatment plants. PMID:18487042

  20. Toxicity of rotenone to giant river freshwater prawn Macrobrachium rosenbergii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquaculturists have often suffered predation losses in the production of freshwater giant river prawn Macrobrachium rosenbergii due to the presence of wild fish species in culture ponds. The piscicide rotenone is widely used to remove undesirable fish species from ponds. Although evidence in the t...

  1. An easy-to-use tool for the evaluation of leachate production at landfill sites.

    PubMed

    Grugnaletti, Matteo; Pantini, Sara; Verginelli, Iason; Lombardi, Francesco

    2016-09-01

    A simulation program for the evaluation of leachate generation at landfill sites is herein presented. The developed tool is based on a water balance model that accounts for all the key processes influencing leachate generation through analytical and empirical equations. After a short description of the tool, different simulations on four Italian landfill sites are shown. The obtained results revealed that when literature values were assumed for the unknown input parameters, the model provided a rough estimation of the leachate production measured in the field. In this case, indeed, the deviations between observed and predicted data appeared, in some cases, significant. Conversely, by performing a preliminary calibration for some of the unknown input parameters (e.g. initial moisture content of wastes, compression index), in nearly all cases the model performances significantly improved. These results although showed the potential capability of a water balance model to estimate the leachate production at landfill sites also highlighted the intrinsic limitation of a deterministic approach to accurately forecast the leachate production over time. Indeed, parameters such as the initial water content of incoming waste and the compression index, that have a great influence on the leachate production, may exhibit temporal variation due to seasonal changing of weather conditions (e.g. rainfall, air humidity) as well as to seasonal variability in the amount and type of specific waste fractions produced (e.g. yard waste, food, plastics) that make their prediction quite complicated. In this sense, we believe that a tool such as the one proposed in this work that requires a limited number of unknown parameters, can be easier handled to quantify the uncertainties. PMID:27033994

  2. Effects of produced waters at oilfield production sites on the Osage Indian Reservation, northeastern Oklahoma

    USGS Publications Warehouse

    Otton, James K.; Asher-Bolinder, Sigrid; Owen, Douglass E.; Hall, Laurel

    1997-01-01

    The authors conducted limited site surveys in the Wildhorse and Burbank oilfields on the Osage Indian Reservation, northeastern Oklahoma. The purpose was to document salt scarring, erosion, and soil and water salinization, to survey for radioactivity in oilfield equipment, and to determine if trace elements and naturally occurring radioactive materials (NORM) were present in soils affected by oilfield solid waste and produced waters. These surveys were also designed to see if field gamma spectrometry and field soil conductivity measurements were useful in screening for NORM contamination and soil salinity at these sites. Visits to oilfield production sites in the Wildhorse field in June of 1995 and 1996 confirmed the presence of substantial salt scarring, soil salinization, and slight to locally severe erosion. Levels of radioactivity on some oil field equipment, soils, and road surfaces exceed proposed state standards. Radium activities in soils affected by tank sludge and produced waters also locally exceed proposed state standards. Laboratory analyses of samples from two sites show moderate levels of copper, lead, and zinc in brine-affected soils and pipe scale. Several sites showed detectable levels of bromine and iodine, suggesting that these trace elements may be present in sufficient quantity to inhibit plant growth. Surface waters in streams at two sampled sites exceed total dissolved solid limits for drinking waters. At one site in the Wildhorse field, an EM survey showed that saline soils in the upper 6m extend from a surface salt scar downvalley about 150 m. (Photo [95k]: Dead oak trees and partly revegetated salt scar at Site OS95-2 in the Wildhorse field, Osage County, Oklahoma.) In the Burbank field, limited salt scarring and slight erosion occurs in soils at some sites and low to moderate levels of radioactivity were observed in oil field equipment at some sites. The levels of radioactivity and radium observed in some soils and equipment at these

  3. Ultrasound-assisted extraction method for the simultaneous determination of emerging contaminants in freshwater sediments.

    PubMed

    de Sousa, Diana Nara Ribeiro; Grosseli, Guilherme Martins; Mozeto, Antonio Aparecido; Carneiro, Renato Lajarim; Fadini, Pedro Sergio

    2015-10-01

    Sediments are the fate of several emerging organic contaminants, such as pharmaceuticals, personal care products and hormones, and therefore an important subject in environmental monitoring studies. In the present work, a simple and sensitive method was developed, validated and applied for the simultaneous extraction of atenolol, caffeine, carbamazepine, diclofenac, ibuprofen, naproxen, propranolol, triclosan, estrone, 17-β-estradiol and 17-α-ethinylestradiol using ultrasound-assisted extraction from freshwater sediment samples followed by solid-phase extraction clean-up and liquid chromatography with tandem mass spectrometry detection. The solvent type and extraction pH were evaluated to obtain the highest recoveries of the compounds. The best method shows absolute recoveries between 54.0 and 94.4% at 50 ng/g concentration. The method exhibits good precision with relative standard deviation ranging from 1.0-16%. The detection and quantification limits ranged from 0.006-0.067 and 0.016-0.336 ng/g, respectively. The developed method was successfully applied to freshwater sediment samples collected from different sites in Jundiaí River basin of São Paulo State, Brazil. The compounds atenolol, caffeine, propranolol and triclosan were detected in all the sampling sites with concentrations of 13.8, 41.0, 28.5 and 176 ng/g, respectively. PMID:26257164

  4. Siderophore production by actinomycetes isolates from two soil sites in Western Australia.

    PubMed

    Lee, Joanna; Postmaster, Armin; Soon, Hooi Peng; Keast, David; Carson, Kerry C

    2012-04-01

    The actinomycetes are metabolically flexible soil micro-organisms capable of producing a range of compounds of interest, including siderophores. Siderophore production by actinomycetes sampled from two distinct and separate geographical sites in Western Australia were investigated and found to be generally similar in the total percentage of siderophore producers found. The only notable difference was the proportion of isolates producing catechol siderophores with only 3% found in site 1 (from the north-west of Western Australia and reportedly containing 40% magnetite) and 17% in site 2 (a commercial stone fruit orchard in the hills east of Perth with a soil base ranging from sandy loam to laterite). Further detailed characterization of isolates of interest identified a Streptomyces that produced extracellularly excreted enterobactin, the characteristic Enterobacteriaceae siderophore, and also revealed some of the conditions required for enterobactin production. Carriage of the entF gene, which codes for the synthetase responsible for the final assembly of the tri-cyclic structure of enterobactin, was confirmed by PCR in this isolate. Another separate Streptomyces produced a compound that matched the UV/VIS spectra of heterobactin, a siderophore previously only described in Rhodococcus and Nocardia. PMID:22038645

  5. Tunable Molecular MoS2 Edge-Site Mimics for Catalytic Hydrogen Production.

    PubMed

    Garrett, Benjamin R; Polen, Shane M; Click, Kevin A; He, Mingfu; Huang, Zhongjie; Hadad, Christopher M; Wu, Yiying

    2016-04-18

    Molybdenum sulfides represent state-of-the-art, non-platinum electrocatalysts for the hydrogen evolution reaction (HER). According to the Sabatier principle, the hydrogen binding strength to the edge active sites should be neither too strong nor too weak. Therefore, it is of interest to develop a molecular motif that mimics the catalytic sites structurally and possesses tunable electronic properties that influence the hydrogen binding strength. Furthermore, molecular mimics will be important for providing mechanistic insight toward the HER with molybdenum sulfide catalysts. In this work, a modular method to tune the catalytic properties of the S-S bond in MoO(S2)2L2 complexes is described. We studied the homogeneous electrocatalytic hydrogen production performance metrics of three catalysts with different bipyridine substitutions. By varying the electron-donating abilities, we present the first demonstration of using the ligand to tune the catalytic properties of the S-S bond in molecular MoS2 edge-site mimics. This work can shed light on the relationship between the structure and electrocatalytic activity of molecular MoS2 catalysts and thus is of broad importance from catalytic hydrogen production to biological enzyme functions. PMID:27022836

  6. Assessment of microbial processes on gas production at radioactive low-level waste disposal sites

    SciTech Connect

    Weiss, A.J.; Tate, R.L. III; Colombo, P.

    1982-05-01

    Factors controlling gaseous emanations from low level radioactive waste disposal sites are assessed. Importance of gaseous fluxes of methane, carbon dioxide, and possible hydrogen from the site, stems from the inclusion of tritium and/or carbon-14 into the elemental composition of these compounds. In that the primary source of these gases is the biodegradation of organic components of the waste material, primary emphasis of the study involved an examination of the biochemical pathways producing methane, carbon dioxide, and hydrogen, and the environmental parameters controlling the activity of the microbial community involved. Initial examination of the data indicates that the ecosystem is anaerobic. As the result of the complexity of the pathway leading to methane production, factors such as substrate availability, which limit the initial reaction in the sequence, greatly affect the overall rate of methane evolution. Biochemical transformations of methane, hydrogen and carbon dioxide as they pass through the soil profile above the trench are discussed. Results of gas studies performed at three commercial low level radioactive waste disposal sites are reviewed. Methods used to obtain trench and soil gas samples are discussed. Estimates of rates of gas production and amounts released into the atmosphere (by the GASFLOW model) are evaluated. Tritium and carbon-14 gaseous compounds have been measured in these studies; tritiated methane is the major radionuclide species in all disposal trenches studied. The concentration of methane in a typical trench increases with the age of the trench, whereas the concentration of carbon dioxide is similar in all trenches.

  7. Subsurface storage of freshwater in south Florida; a prospectus

    USGS Publications Warehouse

    Merritt, M.L.; Meyer, F.W.; Sonntag, W.H.; Fitzpatrick, D.J.

    1983-01-01

    A method of increasing storage capacity for freshwater in south Florida is to use brackish artesian aquifers as reservoirs. In this way, water deficiencies occurring during the annual dry season can be offset by surplus water obtained during the wet season and injected underground. Most of south Florida is underlain by several deep, confined, carbonate waterbearing zones which might be suitable for freshwater storage. These zones are in the Avon Park, Ocala, Suwannee, Tampa, and Hawthorn Formations. Experimental freshwater injection systems have been operated at five locations with promising, but not fully definitive, results. A determination of the feasibility of freshwater injection at a selected site begins with an assessment of the local geologic suitability. Verification of feasibility, however, requires injection and recovery tests to be performed at the site. Recovery efficiency, a measure of the success of the operation, is the amount of potable water, expressed as a percentage of the volume injected, which can be recovered before its salinity, or the concentration of other chemical constituents present in the native aquifer water, increases to the point that the recovered water is no longer useable. (USGS)

  8. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Paducah Gaseous Diffusion Plant site

    SciTech Connect

    Marmer, G.J.; Dunn, C.P.; Moeller, K.L.; Pfingston, J.M.; Policastro, A.J.; Yuen, C.R.; Cleland, J.H.

    1991-09-01

    Uranium enrichment in the United States has utilized a diffusion process to preferentially enrich the U-235 isotope in the uranium product. The U-AVLIS process is based on electrostatic extraction of photoionized U-235 atoms from an atomic vapor stream created by electron-beam vaporization of uranium metal alloy. The U-235 atoms are ionized when precisely tuned laser light -- of appropriate power, spectral, and temporal characteristics -- illuminates the uranium vapor and selectively photoionizes the U-235 isotope. A programmatic document for use in screening DOE site to locate a U-AVLIS production plant was developed and implemented in two parts. The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. These sites were subjected to a more rigorous and detailed comparative analysis for the purpose of developing a short list of reasonable alternative sites for later environmental examination. This environmental site description (ESD) provides a detailed description of the PGDP site and vicinity suitable for use in an environmental impact statement (EIS). The report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during a site visit. 65 refs., 15 tabs.

  9. PERFORMANCE OF THE SAVANNAH RIVER SITE COULOMETER FOR NEPTUNIUM PROCESSACCOUNTABILITY AND NEPTUNIUM OXIDE PRODUCT CHARACTERIZATION

    SciTech Connect

    Holland, M; Patterson Nuessle, P; Sheldon Nichols, S; Joe Cordaro, J; George Reeves, G

    2008-06-04

    The Savannah River Site's (SRS) H-Area B-Line (HB-Line) nuclear facility is processing neptunium solutions for stabilization as an oxide. The oxide will eventually be reprocessed and fabricated into target material and the 237Np irradiated to produce {sup 238}Pu in support of National Aeronautics and Space Administration space program missions. As part of nuclear materials accountability, solution concentrations were measured using a high-precision controlled-potential coulometer developed and manufactured at the SRS for plutonium accountability measurements. The Savannah River Site Coulometer system and measurement methodology for plutonium meets performance standards in ISO 12183-2005, 'Controlled-Potential Coulometric Assay of Plutonium'. The Department of Energy (DOE) does not produce or supply a neptunium metal certified reference material, which makes qualifying a measurement method and determining accuracy and precision difficult. Testing and performance of the Savannah River Site Coulometer indicates that it can be used to measure neptunium process solutions and dissolved neptunium oxide without purification for material control and accountability purposes. Savannah River Site's Material Control and Accountability organization has accepted the method uncertainty for accountability and product characterization measurements.

  10. Microbial degradation of microcystin in Florida's freshwaters.

    PubMed

    Ramani, A; Rein, K; Shetty, K G; Jayachandran, K

    2012-02-01

    Presence of microcystin (MC), a predominant freshwater algal toxin and a suspected liver carcinogen, in Florida's freshwaters poses serious health threat to humans and aquatic species. Being recalcitrant to conventional physical and chemical water treatment methods, biological methods of MC removal is widely researched. Water samples collected from five sites of Lake Okeechobee (LO) frequently exposed to toxic Microcystis blooms were used as inoculum for enrichment with microcystin LR (MC-LR) supplied as sole C and N source. After 20 days incubation, MC levels were analyzed using high performance liquid chromatography (HPLC). A bacterial consortium consisting of two isolates DC7 and DC8 from the Indian Prairie Canal sample showed over 74% toxin degradation at the end of day 20. Optimal temperature requirement for biodegradation was identified and phosphorus levels did not affect the MC biodegradation. Based on 16S rRNA sequence similarity the isolate DC8 was found to have a match with Microbacterium sp. and the DC7 isolate with Rhizobium gallicum (AY972457). PMID:21611743

  11. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Portsmouth Gaseous Diffusion Plant site

    SciTech Connect

    Marmer, G.J.; Dunn, C.P.; Filley, T.H.; Moeller, K.L.; Pfingston, J.M.; Policastro, A.J.; Cleland, J.H.

    1991-09-01

    Uranium enrichment in the United States has utilized a diffusion process to preferentially enrich the U-235 isotope in the uranium product. In the 1970s, the US Department of Energy (DOE) began investigating more efficient and cost-effective enrichment technologies. In January 1990, the Secretary of Energy approved a plan for the demonstration and deployment of the Uranium Atomic Vapor Laser isotope Separation (U-AVLIS) technology with the near-term goal to provide the necessary information to make a deployment decision by November 1992. Initial facility operation is anticipated for 1999. A programmatic document for use in screening DOE sites to locate a U-AVLIS production plant was developed and implemented in two parts. The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. The final evaluation, which included sensitivity studies, identified the Oak Ridge Gaseous Diffusion Plant (ORGDP) site, the Paducah Gaseous Diffusion Plant (PGDP) site, and the Portsmouth Gaseous Diffusion Plant (PORTS) site as having significant advantages over the other sites considered. This environmental site description (ESD) provides a detailed description of the PORTS site and vicinity suitable for use in an environmental impact statement (EIS). This report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during site visits. The organization of the ESD is as follows. Topics addressed in Sec. 2 include a general site description and the disciplines of geology, water resources, biotic resources, air resources, noise, cultural resources, land use. Socioeconomics, and waste management. Identification of any additional data that would be required for an EIS is presented in Sec. 3.

  12. Mercury in freshwater ecosystems of the Canadian Arctic: recent advances on its cycling and fate.

    PubMed

    Chételat, John; Amyot, Marc; Arp, Paul; Blais, Jules M; Depew, David; Emmerton, Craig A; Evans, Marlene; Gamberg, Mary; Gantner, Nikolaus; Girard, Catherine; Graydon, Jennifer; Kirk, Jane; Lean, David; Lehnherr, Igor; Muir, Derek; Nasr, Mina; Poulain, Alexandre J; Power, Michael; Roach, Pat; Stern, Gary; Swanson, Heidi; van der Velden, Shannon

    2015-03-15

    The Canadian Arctic has vast freshwater resources, and fish are important in the diet of many Northerners. Mercury is a contaminant of concern because of its potential toxicity and elevated bioaccumulation in some fish populations. Over the last decade, significant advances have been made in characterizing the cycling and fate of mercury in these freshwater environments. Large amounts of new data on concentrations, speciation and fluxes of Hg are provided and summarized for water and sediment, which were virtually absent for the Canadian Arctic a decade ago. The biogeochemical processes that control the speciation of mercury remain poorly resolved, including the sites and controls of methylmercury production. Food web studies have examined the roles of Hg uptake, trophic transfer, and diet for Hg bioaccumulation in fish, and, in particular, advances have been made in identifying determinants of mercury levels in lake-dwelling and sea-run forms of Arctic char. In a comparison of common freshwater fish species that were sampled across the Canadian Arctic between 2002 and 2009, no geographic patterns or regional hotspots were evident. Over the last two to four decades, Hg concentrations have increased in some monitored populations of fish in the Mackenzie River Basin while other populations from the Yukon and Nunavut showed no change or a slight decline. The different Hg trends indicate that the drivers of temporal change may be regional or habitat-specific. The Canadian Arctic is undergoing profound environmental change, and preliminary evidence suggests that it may be impacting the cycling and bioaccumulation of mercury. Further research is needed to investigate climate change impacts on the Hg cycle as well as biogeochemical controls of methylmercury production and the processes leading to increasing Hg levels in some fish populations in the Canadian Arctic. PMID:24993511

  13. Inhabitants of the Fresh-Water Community.

    ERIC Educational Resources Information Center

    Jorgensen, Joseph; Schroeder, Marlene

    This learner's guide is designed to assist middle school students in studying freshwater organisms. Following a brief introduction to freshwater ecology, simple line drawings facilitate the identification of plants and animals common to Florida's freshwater ecosystems. Emphasis of the short text which accompanies each illustration is upon the…

  14. Radionuclide concentrations in agricultural products near the Hanford Site, 1982 through 1992

    SciTech Connect

    Antonio, E.J.

    1994-06-01

    The Pacific Northwest Laboratory reviewed monitoring data for agricultural products collected from 1982 through 1992 near the Hanford Site to determine radionuclide concentration trends. While samples were collected and analyzed, and results reported annual in Hanford Site environmental reports, an 11-year data set was reviewed for this report to increase the ability to assess trends and potential Hanford effects. Products reviewed included milk, chicken, eggs, beef, vegetables, fruit, wine, wheat, and alfalfa. To determine which radionuclides were detected sufficiently often to permit analysis for trends and effects, each radionuclide concentration and its associated uncertainty were ratioed. Radionuclides were considered routinely detectable if more than 50% of the ratios were between zero and one. Data for these radionuclides were then analyzed statistically, using analyses of variance. The statistical analyses indicated the following: for the most part, there were no measurable effects for Hanford operations; radionuclide concentrations in all products reviewed remained relatively low when compared to concentrations that would result in a 1-mrem effective dose equivalent to an individual; radionuclide concentrations are decreasing in general; however, {sup 90}Sr concentrations in all media and {sup 129}I in milk increased from 1982 to 1986, then decreased gradually for the remainder of the review period. The {sup 129}I concentrations may be correlated with processing of irradiated reactor fuel at the Plutonium-Uranium Extraction (PUREX) Plant.

  15. Interim Safe Storage of Plutonium Production Reactors at the US DOE Hanford Site - 13438

    SciTech Connect

    Schilperoort, Daryl L.; Faulk, Darrin

    2013-07-01

    Nine plutonium production reactors located on DOE's Hanford Site are being placed into an Interim Safe Storage (ISS) period that extends to 2068. The Environmental Impact Statement (EIS) for ISS [1] was completed in 1993 and proposed a 75-year storage period that began when the EIS was finalized. Remote electronic monitoring of the temperature and water level alarms inside the safe storage enclosure (SSE) with visual inspection inside the SSE every 5 years are the only planned operational activities during this ISS period. At the end of the ISS period, the reactor cores will be removed intact and buried in a landfill on the Hanford Site. The ISS period allows for radioactive decay of isotopes, primarily Co-60 and Cs-137, to reduce the dose exposure during disposal of the reactor cores. Six of the nine reactors have been placed into ISS by having an SSE constructed around the reactor core. (authors)

  16. Inventory of chemicals used at Hanford Site production plants and support operations (1944-1980)

    SciTech Connect

    Klem, M. J.

    1990-04-01

    A complete list of chemicals used in the production facilities and support operations of the US Department of Energy Hanford Site is presented to aid development of plans for characterizing the radioactive liquid chemical wastes stored in the 149 single-shell tanks. The complete chemical list is compared to the list provided by the regulatory agencies to identify hazardous chemicals stored in the single-shell tanks. A reduced list has been developed by others and is used to identify the chemical constituents for analysis in the Waste Characterization Plan for the Hanford Site Single-Shell Tanks. The chemical list is based on chemical process flowsheets, essential material consumption records, letters, reports, and other historical data. 14 refs., 36 tabs.

  17. Influence of extractive solvents on lipid and fatty acids content of edible freshwater algal and seaweed products, the green Microalga Chlorella kessleri and the Cyanobacterium Spirulina platensis.

    PubMed

    Ambrozova, Jarmila Vavra; Misurcova, Ladislava; Vicha, Robert; Machu, Ludmila; Samek, Dusan; Baron, Mojmir; Mlcek, Jiri; Sochor, Jiri; Jurikova, Tunde

    2014-01-01

    Total lipid contents of green (Chlorella pyrenoidosa, C), red (Porphyra tenera, N; Palmaria palmata, D), and brown (Laminaria japonica, K; Eisenia bicyclis, A; Undaria pinnatifida, W, WI; Hizikia fusiformis, H) commercial edible algal and cyanobacterial (Spirulina platensis, S) products, and autotrophically cultivated samples of the green microalga Chlorella kessleri (CK) and the cyanobacterium Spirulina platensis (SP) were determined using a solvent mixture of methanol/chloroform/water (1:2:1, v/v/v, solvent I) and n-hexane (solvent II). Total lipid contents ranged from 0.64% (II) to 18.02% (I) by dry weight and the highest total lipid content was observed in the autotrophically cultivated cyanobacterium Spirulina platensis. Solvent mixture I was found to be more effective than solvent II. Fatty acids were determined by gas chromatography of their methyl esters (% of total FAMEs). Generally, the predominant fatty acids (all results for extractions with solvent mixture I) were saturated palmitic acid (C16:0; 24.64%-65.49%), monounsaturated oleic acid (C18:1(n-9); 2.79%-26.45%), polyunsaturated linoleic acid (C18:2(n-6); 0.71%-36.38%), α-linolenic acid (C18:3(n-3); 0.00%-21.29%), γ-linolenic acid (C18:3(n-6); 1.94%-17.36%), and arachidonic acid (C20:4(n-6); 0.00%-15.37%). The highest content of ω-3 fatty acids (21.29%) was determined in Chlorella pyrenoidosa using solvent I, while conversely, the highest content of ω-6 fatty acids (41.42%) was observed in Chlorella kessleri using the same solvent. PMID:24566307

  18. Evaluation of the Acceptability of Potential Depleted Uranium Hexafluoride Conversion Products at the Envirocare Disposal Site

    SciTech Connect

    Croff, A.G.

    2001-01-11

    The purpose of this report is to review and document the capability of potential products of depleted UF{sub 6} conversion to meet the current waste acceptance criteria and other regulatory requirements for disposal at the facility in Clive, Utah, owned by Envirocare of Utah, Inc. The investigation was conducted by identifying issues potentially related to disposal of depleted uranium (DU) products at Envirocare and conducting an initial analysis of them. Discussions were then held with representatives of Envirocare, the state of Utah (which is a NRC Agreement State and, thus, is the cognizant regulatory authority for Envirocare), and DOE Oak Ridge Operations. Provisional issue resolution was then established based on the analysis and discussions and documented in a draft report. The draft report was then reviewed by those providing information and revisions were made, which resulted in this document. Issues that were examined for resolution were (1) license receipt limits for U isotopes; (2) DU product classification as Class A waste; (3) use of non-DOE disposal sites for disposal of DOE material; (4) historical NRC views; (5) definition of chemical reactivity; (6) presence of mobile radionuclides; and (7) National Environmental Policy Act coverage of disposal. The conclusion of this analysis is that an amendment to the Envirocare license issued on October 5, 2000, has reduced the uncertainties regarding disposal of the DU product at Envirocare to the point that they are now comparable with uncertainties associated with the disposal of the DU product at the Nevada Test Site that were discussed in an earlier report.

  19. Measurements of methane emissions at natural gas production sites in the United States

    PubMed Central

    Allen, David T.; Torres, Vincent M.; Thomas, James; Sullivan, David W.; Harrison, Matthew; Hendler, Al; Herndon, Scott C.; Kolb, Charles E.; Fraser, Matthew P.; Hill, A. Daniel; Lamb, Brian K.; Miskimins, Jennifer; Sawyer, Robert F.; Seinfeld, John H.

    2013-01-01

    Engineering estimates of methane emissions from natural gas production have led to varied projections of national emissions. This work reports direct measurements of methane emissions at 190 onshore natural gas sites in the United States (150 production sites, 27 well completion flowbacks, 9 well unloadings, and 4 workovers). For well completion flowbacks, which clear fractured wells of liquid to allow gas production, methane emissions ranged from 0.01 Mg to 17 Mg (mean = 1.7 Mg; 95% confidence bounds of 0.67–3.3 Mg), compared with an average of 81 Mg per event in the 2011 EPA national emission inventory from April 2013. Emission factors for pneumatic pumps and controllers as well as equipment leaks were both comparable to and higher than estimates in the national inventory. Overall, if emission factors from this work for completion flowbacks, equipment leaks, and pneumatic pumps and controllers are assumed to be representative of national populations and are used to estimate national emissions, total annual emissions from these source categories are calculated to be 957 Gg of methane (with sampling and measurement uncertainties estimated at ±200 Gg). The estimate for comparable source categories in the EPA national inventory is ∼1,200 Gg. Additional measurements of unloadings and workovers are needed to produce national emission estimates for these source categories. The 957 Gg in emissions for completion flowbacks, pneumatics, and equipment leaks, coupled with EPA national inventory estimates for other categories, leads to an estimated 2,300 Gg of methane emissions from natural gas production (0.42% of gross gas production). PMID:24043804

  20. Measurements of methane emissions at natural gas production sites in the United States.

    PubMed

    Allen, David T; Torres, Vincent M; Thomas, James; Sullivan, David W; Harrison, Matthew; Hendler, Al; Herndon, Scott C; Kolb, Charles E; Fraser, Matthew P; Hill, A Daniel; Lamb, Brian K; Miskimins, Jennifer; Sawyer, Robert F; Seinfeld, John H

    2013-10-29

    Engineering estimates of methane emissions from natural gas production have led to varied projections of national emissions. This work reports direct measurements of methane emissions at 190 onshore natural gas sites in the United States (150 production sites, 27 well completion flowbacks, 9 well unloadings, and 4 workovers). For well completion flowbacks, which clear fractured wells of liquid to allow gas production, methane emissions ranged from 0.01 Mg to 17 Mg (mean = 1.7 Mg; 95% confidence bounds of 0.67-3.3 Mg), compared with an average of 81 Mg per event in the 2011 EPA national emission inventory from April 2013. Emission factors for pneumatic pumps and controllers as well as equipment leaks were both comparable to and higher than estimates in the national inventory. Overall, if emission factors from this work for completion flowbacks, equipment leaks, and pneumatic pumps and controllers are assumed to be representative of national populations and are used to estimate national emissions, total annual emissions from these source categories are calculated to be 957 Gg of methane (with sampling and measurement uncertainties estimated at ± 200 Gg). The estimate for comparable source categories in the EPA national inventory is ~1,200 Gg. Additional measurements of unloadings and workovers are needed to produce national emission estimates for these source categories. The 957 Gg in emissions for completion flowbacks, pneumatics, and equipment leaks, coupled with EPA national inventory estimates for other categories, leads to an estimated 2,300 Gg of methane emissions from natural gas production (0.42% of gross gas production). PMID:24043804

  1. Selecting Reliable and Robust Freshwater Macroalgae for Biomass Applications

    PubMed Central

    Lawton, Rebecca J.; de Nys, Rocky; Paul, Nicholas A.

    2013-01-01

    Intensive cultivation of freshwater macroalgae is likely to increase with the development of an algal biofuels industry and algal bioremediation. However, target freshwater macroalgae species suitable for large-scale intensive cultivation have not yet been identified. Therefore, as a first step to identifying target species, we compared the productivity, growth and biochemical composition of three species representative of key freshwater macroalgae genera across a range of cultivation conditions. We then selected a primary target species and assessed its competitive ability against other species over a range of stocking densities. Oedogonium had the highest productivity (8.0 g ash free dry weight m−2 day−1), lowest ash content (3–8%), lowest water content (fresh weigh: dry weight ratio of 3.4), highest carbon content (45%) and highest bioenergy potential (higher heating value 20 MJ/kg) compared to Cladophora and Spirogyra. The higher productivity of Oedogonium relative to Cladophora and Spirogyra was consistent when algae were cultured with and without the addition of CO2 across three aeration treatments. Therefore, Oedogonium was selected as our primary target species. The competitive ability of Oedogonium was assessed by growing it in bi-cultures and polycultures with Cladophora and Spirogyra over a range of stocking densities. Cultures were initially stocked with equal proportions of each species, but after three weeks of growth the proportion of Oedogonium had increased to at least 96% (±7 S.E.) in Oedogonium-Spirogyra bi-cultures, 86% (±16 S.E.) in Oedogonium-Cladophora bi-cultures and 82% (±18 S.E.) in polycultures. The high productivity, bioenergy potential and competitive dominance of Oedogonium make this species an ideal freshwater macroalgal target for large-scale production and a valuable biomass source for bioenergy applications. These results demonstrate that freshwater macroalgae are thus far an under-utilised feedstock with much potential

  2. Modeling the hydrothermal circulation and the hydrogen production at the Rainbow site with Cast3M

    NASA Astrophysics Data System (ADS)

    Perez, F.; Mügler, C.; Charlou, J.; Jean-baptiste, P.

    2012-12-01

    On the Mid-Atlantic Ridge, the Rainbow venting site is described as an ultramafic-hosted active hydrothermal site and releases high fluxes of methane and hydrogen [1, 2]. This behavior has first been interpreted as the result of serpentinization processes. But geochemical reactions involving olivine and plagioclase assemblages, and leading to chlorite, tremolite, talc and magnetite assemblages, could contribute to the observed characteristics of the exiting fluid [2]. The predominance of one of these geochemical reactions or their coexistence strongly depend on the hydrothermal fluid circulation. We developed and validated a 2D/3D numerical model using a Finite Volume method to simulate heat driven fluid flows in the framework of the Cast3M code [3, 4]. We also developed a numerical model for hydrogen production and transport that is based on experimental studies of the serpentinization processes [5-6]. This geochemical model takes into account the exothermic and water-consuming behavior of the serpentinization reaction and it can be coupled to our thermo-hydrogeological model. Our simulations provide temperatures, mass fluxes and venting surface areas very close to those estimated in-situ [7]. We showed that a single-path model [8] was necessary to simulate high values such as the in-situ measured temperatures and estimated water mass fluxes of the Rainbow site [7]. This single-path model will be used to model the production and transport of hydrogen at the Rainbow hydrothermal site. References [1]Charlou et al. (2010) AGU Monograph series. [2]Seyfried et al. (2011) Geochim. Cosmochim. Acta 75, 1574-1593. [3]http://www-cast3m.cea.fr. [4]Martin & Fyfe (1970) Chem. Geol. 6, 185-202. [5] Marcaillou et al. (2011) Earth and Planet. Sci. Lett. 303, 281-290. [6]Malvoisin et al. (2012) JGR, 117, B01104. [7]Perez et al. (2012) submited to Computational Geosciences. [8]Lowell & Germanovich (2004) AGU, Washington DC, USA.

  3. Development of remote sensing based site specific weed management for Midwest mint production

    NASA Astrophysics Data System (ADS)

    Gumz, Mary Saumur Paulson

    Peppermint and spearmint are high value essential oil crops in Indiana, Michigan, and Wisconsin. Although the mints are profitable alternatives to corn and soybeans, mint production efficiency must improve in order to allow industry survival against foreign produced oils and synthetic flavorings. Weed control is the major input cost in mint production and tools to increase efficiency are necessary. Remote sensing-based site-specific weed management offers potential for decreasing weed control costs through simplified weed detection and control from accurate site specific weed and herbicide application maps. This research showed the practicability of remote sensing for weed detection in the mints. Research was designed to compare spectral response curves of field grown mint and weeds, and to use these data to develop spectral vegetation indices for automated weed detection. Viability of remote sensing in mint production was established using unsupervised classification, supervised classification, handheld spectroradiometer readings and spectral vegetation indices (SVIs). Unsupervised classification of multispectral images of peppermint production fields generated crop health maps with 92 and 67% accuracy in meadow and row peppermint, respectively. Supervised classification of multispectral images identified weed infestations with 97% and 85% accuracy for meadow and row peppermint, respectively. Supervised classification showed that peppermint was spectrally distinct from weeds, but the accuracy of these measures was dependent on extensive ground referencing which is impractical and too costly for on-farm use. Handheld spectroradiometer measurements of peppermint, spearmint, and several weeds and crop and weed mixtures were taken over three years from greenhouse grown plants, replicated field plots, and production peppermint and spearmint fields. Results showed that mints have greater near infrared (NIR) and lower green reflectance and a steeper red edge slope than

  4. Chemo- and Site-Selective Derivatizations of Natural Products Enabling Biological Studies

    PubMed Central

    Robles, Omar

    2014-01-01

    Bioactive natural products and derivatives remain an enduring starting point for the discovery of new cellular targets for disease intervention and lead compounds for the development of new therapeutic agents. The former goal is accomplished through the synthesis of bioactive cellular probes from natural products enabling insights into the mechanism of action of these natural products by classical affinity chromatography or more recent proteome profiling methods. However, the direct and selective modification of native natural products for these purposes remains a challenge due to the structural complexity and the wide functional group diversity found in these natural substances. The lack of selective synthetic methods available to directly manipulate unprotected complex small molecules, in particular to perform structure-activity relationship studies and prepare appropriate cellular probes, has recently begun to be addressed benefitting from the broader emerging area of chemoselective synthetic methodology. Thus, new reagents, catalysts and reaction processes are enabling both chemo- and site-selective modifications of complex, native natural products. In this review, we describe selected recent examples of these functionalization strategies in this emerging area. PMID:24468713

  5. Chemo- and site-selective derivatizations of natural products enabling biological studies.

    PubMed

    Robles, Omar; Romo, Daniel

    2014-03-01

    Bioactive natural products and derivatives remain an enduring starting point for the discovery of new cellular targets for disease intervention and lead compounds for the development of new therapeutic agents. The former goal is accomplished through the synthesis of bioactive cellular probes from natural products, enabling insights into the mechanism of action of these natural products by classical affinity chromatography or more recent proteome profiling methods. However, the direct and selective modification of native natural products for these purposes remains a challenge due to the structural complexity and the wide functional group diversity found in these natural substances. The lack of selective synthetic methods available to directly manipulate unprotected complex small molecules, in particular to perform structure-activity relationship studies and prepare appropriate cellular probes, has recently begun to be addressed, benefitting from the broader emerging area of chemoselective synthetic methodology. Thus, new reagents, catalysts and reaction processes are enabling both chemo- and site-selective modifications of complex, native natural products. In this review, we describe selected recent examples of these functionalization strategies in this emerging area. PMID:24468713

  6. Single Pass LiDAR-derived Estimate of Site Productivity in Western Oregon

    NASA Astrophysics Data System (ADS)

    McAdam, E.; Hilker, T.; Waring, R. H.; Sousa, C. H. R. D.; Moura, Y. M.

    2014-12-01

    Accurate estimates of forest growth at different ages are essential to evaluate the effect of a changing climate and to adjust management practices accordingly. Most current approaches are spatially discrete and therefore unable to predict forest growth accurately across landscapes. While airborne LiDAR has been widely used in forestry, it can only estimate growth rates with repeated passes. In contrast, Landsat imagery records disturbances (at 30 m resolution) but is unable to measure changes in growth rates. Historical archives of Landsat imagery provided us a way of knowing when and where even-aged stands of Pseudotsuga menziesii (Douglas-fir) were cut and replanted. Since early growth rates are nearly linear with age, the height of dominant trees recorded in one pass by LiDAR yields a direct measure of growth and likely changes as stands age under recent climatic conditions. Process-based growth models are available to assess possible shifts in the growth rates of stands under a changing climate; the accuracy of such model predictions can be evaluated with additional LiDAR coverage. In this study we use the Physiological Principles Predicting Growth Model (3-PG) to estimate site index at the landscape level to predict site productivity based on the year of stand establishment obtained from Landsat, and one-pass airborne LiDAR measurement of forest height. We are monitoring forest plantations of known ages and with data on their current age we will calculate site index for 60 separate sites across western Oregon. The results of this study will allow us to create updated site index maps for the state of Oregon under varying climate scenarios.

  7. Only low methane production and emission in degraded peat extraction sites after rewetting

    NASA Astrophysics Data System (ADS)

    Agethen, Svenja; Waldemer, Carolin; Knorr, Klaus-Holger

    2015-04-01

    In Central Europe rewetting of bogs after peat extraction is a wide spread technique to halt secondary aerobic decomposition and to reestablish plant species such as Sphagnum spp. and Eriophorum spp. that initialize accumulation of organic carbon in peat. Before extraction, such sites are often used for agriculture causing the aerobic degradation of peat and mobilization of phosphorus, ammonia, and dissolved organic matter (DOM). In nutrient poor ecosystems such as bogs, additional supply of P and N does not only trigger the establishment of uncharacteristic vegetation but also the formation of more labile plant litter and DOM that is readily degradable. Therefore, after rewetting and the development of anoxic conditions especially in initial stages high methane (CH4) emissions are reported for these systems compared to pristine bogs. Regarding the potential of methane production and emissions we investigated three common practices to prepare extraction fields for restoration (years since rewetting): i) Filling of drainage ditches, passive rewetting (1 site, Altendorfer Moor, Stade, NW-Germany, ca. 20 yr.), ii) Removal of upper 30 cm peat layer, removed peat used for construction of polder dikes (2 sites, Königsmoor, Leer, NW-Germany, 2 and 3 yr.), iii) Removal upper peat layer down to 50 cm grown peat, not extracted peat used as polder walls (2 sites, Benthullener Moor, Wardenburg, NW-Germany, 3 and 7 yr.). In each site two vegetated replicate mesocosms (diam. 30 cm, depth 40 cm) were sampled and placed in a greenhouse from May-October 2014 to maintain the water table at surface level. Pore water concentrations of ions, fermentation products and DOM, DOM electron acceptor capacity (EAC), soil gas concentrations of CO2, CH4 and H2, gas fluxes as well as element composition and organic matter quality of DOM and SOM were analyzed. We found out that practice i) with least efforts of nutrient removal in the peat produced the highest CH4 emissions (3.5 mmol m-2 d-1

  8. Validation of Global EO Biophysical Products at JECAM Test Site in Ukraine

    NASA Astrophysics Data System (ADS)

    Skakun, Sergii; Kussul, Nataliia; Kravchenko, Oleksiy; Basarab, Ruslan; Ostapenko, Vadym; Yailymov, Bohdan; Shelestov, Andrii; Kolotii, Andrii; Mironov, Andrii

    Efficient global agriculture monitoring requires appropriate validation of Earth observation (EO) products for different regions and cropping system. This problem is addressed within the Joint Experiment of Crop Assessment and Monitoring (JECAM) initiative which aims to develop monitoring and reporting protocols and best practices for a variety of global agricultural systems. Ukraine is actively involved into JECAM, and a JECAM Ukraine test site was officially established in 2011. The following problems are being solved within JECAM Ukraine: (i) crop identification and crop area estimation [1]; (ii) crop yield forecasting [2]; (iii) EO products validation. The following case study regions were selected for these purposes: (i) the whole Kyiv oblast (28,000 sq. km) indented for crop mapping and acreage estimation; (ii) intensive observation sub-site in Pshenichne which is a research farm from the National University of Life and Environmental Sciences of Ukraine and indented for crop biophysical parameters estimation; (iii) Lviv region for rape-seed identification and crop rotation control; (iv) Crimea region for crop damage assessment due to droughts, and illegial field detection. In 2013, Ukrainian JECAM test site was selected as one of the “Champion User” for the ESA Sentinel-2 for Agriculture project. The test site was observed with SPOT-4 and RapidEye satellites every 5 days. The collected images are then used to simulate Sentinel-2 images for agriculture purposes. JECAM Ukraine is responsible for collecting ground observation data for validation purposes, and is involved in providing user requirements for Sentinel-2 agriculture related products. In particular, three field campaigns to characterize the vegetation biophysical parameters at the Pshenichne test site were carried out: First campaign - 14th to 17th of May 2013; second campaign - 12th to 15th of June 2013; third campaign - 14th to 17th of July 2013. Digital Hemispheric Photographs (DHP) images were

  9. Coherence between woody carbon uptake and net ecosystem productivity at five eddy-covariance sites

    NASA Astrophysics Data System (ADS)

    Babst, F.; Bouriaud, O.; Papale, D.; Gielen, B.; Janssens, I.; Nikinmaa, E.; Ibrom, A.; Wu, J.; Bernhofer, C.; Koestner, B.; Gruenwald, T.; Seufert, G.; Ciais, P.; Frank, D. C.

    2013-12-01

    Forest growth ranks amongst the most important processes that determine the carbon balance of terrestrial ecosystems. Quantifications of forest carbon cycling can be made e.g. using biometric and eddy-covariance (EC) techniques. Both offer different perspectives on carbon uptake and attempts to combine them have been inconsistent and variably successful in the past. This contributes to persistent uncertainties regarding carbon allocation in forest ecosystems and complicates precise vegetation model parameterization. Aiming to reconcile assessments of carbon cycling from biometric and EC techniques, we measured radial tree growth and wood density at five long-term EC stations across Europe. The resulting records were used to calculate annual carbon uptake during above-ground wood formation and compared to monthly and seasonal CO2-flux measurements. Efforts were made to identify i) the time periods when EC and tree-ring data correspond best in different parts of Europe and ii) the fraction of eddy-fluxes which is associated with changes in above-ground woody carbon stocks. Biometric measurements and net ecosystem productivity (NEP) proved largely compatible at seasonal time scales while relationships with gross primary productivity (GPP) were often weaker. Results suggest a partitioning of sequestered carbon mainly used for volume increase (January-June) and a combination of cell-wall thickening and storage (July-September). The inter-annual variability in above-ground woody carbon uptake was significantly linked with absolute productivity ranging between 69-366 g C m-2 y-1 at boreal and temperate sites, thereby accounting for 10-25% of GPP, 15-32% of TER, and 25-80% of NEP. These findings from sites representing the major European climate zones and tree species contribute to improved quantification of above-ground carbon allocation in forests. Furthermore, they refine knowledge on processes driving ecosystem productivity important for e.g. vegetation models and

  10. Inhibitors of ROS production by the ubiquinone-binding site of mitochondrial complex I identified by chemical screening.

    PubMed

    Orr, Adam L; Ashok, Deepthi; Sarantos, Melissa R; Shi, Tong; Hughes, Robert E; Brand, Martin D

    2013-12-01

    Mitochondrial production of reactive oxygen species is often considered an unavoidable consequence of aerobic metabolism and currently cannot be manipulated without perturbing oxidative phosphorylation. Antioxidants are widely used to suppress effects of reactive oxygen species after formation, but they can never fully prevent immediate effects at the sites of production. To identify site-selective inhibitors of mitochondrial superoxide/H2O2 production that do not interfere with mitochondrial energy metabolism, we developed a robust small-molecule screen and secondary profiling strategy. We describe the discovery and characterization of a compound (N-cyclohexyl-4-(4-nitrophenoxy)benzenesulfonamide; CN-POBS) that selectively inhibits superoxide/H2O2 production from the ubiquinone-binding site of complex I (site I(Q)) with no effects on superoxide/H2O2 production from other sites or on oxidative phosphorylation. Structure/activity studies identified a core structure that is important for potency and selectivity for site I(Q). By employing CN-POBS in mitochondria respiring on NADH-generating substrates, we show that site I(Q) does not produce significant amounts of superoxide/H2O2 during forward electron transport on glutamate plus malate. Our screening platform promises to facilitate further discovery of direct modulators of mitochondrially derived oxidative damage and advance our ability to understand and manipulate mitochondrial reactive oxygen species production under both normal and pathological conditions. PMID:23994103

  11. Sound production by dusky grouper Epinephelus marginatus at spawning aggregation sites.

    PubMed

    Bertucci, F; Lejeune, P; Payrot, J; Parmentier, E

    2015-08-01

    Sound production by the dusky grouper Epinephelus marginatus was monitored both in captivity and at two Mediterranean spawning sites during the summers of 2012 and 2013. The results of long-term passive acoustic recordings provide for the first time a description of the sounds produced by E. marginatus. Two types of sounds were mainly recorded and consisted of low-frequency booms that can be produced singly or in series with dominant frequencies below 100 Hz. Recordings in captivity validated these sounds as belonging to E. marginatus and suggested that they may be associated with reproductive displays usually performed during early stages of courtship behaviour. This study also allowed the identification of a third, low-frequency growl-like type of sound typically found in other grouper species. These growls were, however, not recorded in tanks and it is cautiously proposed that they are produced by E. marginatus. Acoustic signals attributed to E. marginatus were produced throughout the spawning season, with a diel pattern showing an increase before dusk, i.e., from 1900 to 2200 hours, before decreasing until the morning. The occurrence of sounds during the spawning season of this species suggests that they are probably involved in social activity occurring close to aggregation sites. Passive acoustics offer a helpful tool to monitor aggregation sites of this emblematic species in order to improve conservation efforts. PMID:26177857

  12. Aerial Surveys of Elevated Hydrocarbon Emissions from Oil and Gas Production Sites.

    PubMed

    Lyon, David R; Alvarez, Ramón A; Zavala-Araiza, Daniel; Brandt, Adam R; Jackson, Robert B; Hamburg, Steven P

    2016-05-01

    Oil and gas (O&G) well pads with high hydrocarbon emission rates may disproportionally contribute to total methane and volatile organic compound (VOC) emissions from the production sector. In turn, these emissions may be missing from most bottom-up emission inventories. We performed helicopter-based infrared camera surveys of more than 8000 O&G well pads in seven U.S. basins to assess the prevalence and distribution of high-emitting hydrocarbon sources (detection threshold ∼ 1-3 g s(-1)). The proportion of sites with such high-emitting sources was 4% nationally but ranged from 1% in the Powder River (Wyoming) to 14% in the Bakken (North Dakota). Emissions were observed three times more frequently at sites in the oil-producing Bakken and oil-producing regions of mixed basins (p < 0.0001, χ(2) test). However, statistical models using basin and well pad characteristics explained 14% or less of the variance in observed emission patterns, indicating that stochastic processes dominate the occurrence of high emissions at individual sites. Over 90% of almost 500 detected sources were from tank vents and hatches. Although tank emissions may be partially attributable to flash gas, observed frequencies in most basins exceed those expected if emissions were effectively captured and controlled, demonstrating that tank emission control systems commonly underperform. Tanks represent a key mitigation opportunity for reducing methane and VOC emissions. PMID:27045743

  13. Processing Tritiated Water at the Savannah Rivver Site: A Production Scale Demonstration

    SciTech Connect

    Sessions, K

    2004-11-04

    The Palladium Membrane Reactor (PMR) process was installed in the Tritium Facilities at the Savannah River Site to perform a production-scale demonstration for the recovery of tritium from tritiated water adsorbed on molecular sieve (zeolite). Unlike the current recovery process that utilizes magnesium, the PMR offers a means to process tritiated water in a more cost effective and environmentally friendly manner. The design and installation of the large-scale PMR process was part of a collaborative effort between the Savannah River Site and Los Alamos National Laboratory. The PMR process operated at the Savannah River Site between May 2001 and April 2003. During the initial phase of operation the PMR processed thirty-four kilograms of tritiated water from the Princeton Plasma Physics Laboratory. The water was processed in fifteen separate batches to yield approximately 34,400 liters (STP) of hydrogen isotopes. Each batch consisted of round-the-clock operations for approximately nine days. In April 2003 the reactor's palladium-silver membrane ruptured resulting in the shutdown of the PMR process. Reactor performance, process performance and operating experiences have been evaluated and documented. A performance comparison between PMR and current magnesium process is also documented.

  14. Automated flow for site definition and CD measurement with a SEM for use in mask production

    NASA Astrophysics Data System (ADS)

    Rotsch, Christian; Haffner, Henning; Ruebekohl, Christian; Buechner, Bettine

    2002-12-01

    The continuous tightening of CD and registration specifications demands most advanced metrology equipment and highly sophisticated logistics and measurement strategies. Not only the smallness of structures but also the increasing number of measurement sites is a challenge. Until recently, CD measurements in mask mass production were done at a handful of different positions using mainly optical microscopy. The measurement locations were usually picked randomly according to the visual image and some general rules that were agreed upon between lithographers and the mask shop. In this paper we describe a flow for SEM based CD measurement in automated production. A new type of instances is introduced solely to provide a simple and effective way for transferring the desired measurement locations from design to a mask shop. Therefore, we use the new CATS features that allow highly automated and flexible off-line preparation of measurement jobs. On the KLA-Tencor 8250-R CD-SEM we furthermore utilize its capability of converting CATS output files into fully functional SEM measurement jobs with large numbers of sites and multiple steps of pattern recognition. A comparison of results obtained with the CATS jobs with those of native SEM jobs proves the consistency of data.

  15. Novel method for the high-throughput production of phosphorylation site-specific monoclonal antibodies.

    PubMed

    Kurosawa, Nobuyuki; Wakata, Yuka; Inobe, Tomonao; Kitamura, Haruki; Yoshioka, Megumi; Matsuzawa, Shun; Kishi, Yoshihiro; Isobe, Masaharu

    2016-01-01

    Threonine phosphorylation accounts for 10% of all phosphorylation sites compared with 0.05% for tyrosine and 90% for serine. Although monoclonal antibody generation for phospho-serine and -tyrosine proteins is progressing, there has been limited success regarding the production of monoclonal antibodies against phospho-threonine proteins. We developed a novel strategy for generating phosphorylation site-specific monoclonal antibodies by cloning immunoglobulin genes from single plasma cells that were fixed, intracellularly stained with fluorescently labeled peptides and sorted without causing RNA degradation. Our high-throughput fluorescence activated cell sorting-based strategy, which targets abundant intracellular immunoglobulin as a tag for fluorescently labeled antigens, greatly increases the sensitivity and specificity of antigen-specific plasma cell isolation, enabling the high-efficiency production of monoclonal antibodies with desired antigen specificity. This approach yielded yet-undescribed guinea pig monoclonal antibodies against threonine 18-phosphorylated p53 and threonine 68-phosphorylated CHK2 with high affinity and specificity. Our method has the potential to allow the generation of monoclonal antibodies against a variety of phosphorylated proteins. PMID:27125496

  16. Methane emissions from process equipment at natural gas production sites in the United States: pneumatic controllers.

    PubMed

    Allen, David T; Pacsi, Adam P; Sullivan, David W; Zavala-Araiza, Daniel; Harrison, Matthew; Keen, Kindal; Fraser, Matthew P; Daniel Hill, A; Sawyer, Robert F; Seinfeld, John H

    2015-01-01

    Emissions from 377 gas actuated (pneumatic) controllers were measured at natural gas production sites and a small number of oil production sites, throughout the United States. A small subset of the devices (19%), with whole gas emission rates in excess of 6 standard cubic feet per hour (scf/h), accounted for 95% of emissions. More than half of the controllers recorded emissions of 0.001 scf/h or less during 15 min of measurement. Pneumatic controllers in level control applications on separators and in compressor applications had higher emission rates than controllers in other types of applications. Regional differences in emissions were observed, with the lowest emissions measured in the Rocky Mountains and the highest emissions in the Gulf Coast. Average methane emissions per controller reported in this work are 17% higher than the average emissions per controller in the 2012 EPA greenhouse gas national emission inventory (2012 GHG NEI, released in 2014); the average of 2.7 controllers per well observed in this work is higher than the 1.0 controllers per well reported in the 2012 GHG NEI. PMID:25488196

  17. Topoisomerase IV, not gyrase, decatenates products of site-specific recombination in Escherichia coli

    PubMed Central

    Zechiedrich, E. Lynn; Khodursky, Arkady B.; Cozzarelli, Nicholas R.

    1997-01-01

    DNA replication and recombination generate intertwined DNA intermediates that must be decatenated for chromosome segregation to occur. We showed recently that topoisomerase IV (topo IV) is the only important decatenase of DNA replication intermediates in bacteria. Earlier results, however, indicated that DNA gyrase has the primary role in unlinking the catenated products of site-specific recombination. To address this discordance, we constructed a set of isogenic strains that enabled us to inhibit selectively with the quinolone norfloxacin topo IV, gyrase, both enzymes, or neither enzyme in vivo. We obtained identical results for the decatenation of the products of two different site-specific recombination enzymes, phage λ integrase and transposon Tn3 resolvase. Norfloxacin blocked decatenation in wild-type strains, but had no effect in strains with drug-resistance mutations in both gyrase and topo IV. When topo IV alone was inhibited, decatenation was almost completely blocked. If gyrase alone were inhibited, most of the catenanes were unlinked. We showed that topo IV is the primary decatenase in vivo and that this function is dependent on the level of DNA supercoiling. We conclude that the role of gyrase in decatenation is to introduce negative supercoils into DNA, which makes better substrates for topo IV. We also discovered that topo IV has an unexpectedly strong DNA relaxation activity that, together with gyrase and topo I, is able to set the supercoiling levels in Escherichia coli. PMID:9334322

  18. Novel method for the high-throughput production of phosphorylation site-specific monoclonal antibodies

    PubMed Central

    Kurosawa, Nobuyuki; Wakata, Yuka; Inobe, Tomonao; Kitamura, Haruki; Yoshioka, Megumi; Matsuzawa, Shun; Kishi, Yoshihiro; Isobe, Masaharu

    2016-01-01

    Threonine phosphorylation accounts for 10% of all phosphorylation sites compared with 0.05% for tyrosine and 90% for serine. Although monoclonal antibody generation for phospho-serine and -tyrosine proteins is progressing, there has been limited success regarding the production of monoclonal antibodies against phospho-threonine proteins. We developed a novel strategy for generating phosphorylation site-specific monoclonal antibodies by cloning immunoglobulin genes from single plasma cells that were fixed, intracellularly stained with fluorescently labeled peptides and sorted without causing RNA degradation. Our high-throughput fluorescence activated cell sorting-based strategy, which targets abundant intracellular immunoglobulin as a tag for fluorescently labeled antigens, greatly increases the sensitivity and specificity of antigen-specific plasma cell isolation, enabling the high-efficiency production of monoclonal antibodies with desired antigen specificity. This approach yielded yet-undescribed guinea pig monoclonal antibodies against threonine 18-phosphorylated p53 and threonine 68-phosphorylated CHK2 with high affinity and specificity. Our method has the potential to allow the generation of monoclonal antibodies against a variety of phosphorylated proteins. PMID:27125496

  19. Excavation on the Moon: Regolith Collection for Oxygen Production and Outpost Site Preparation

    NASA Technical Reports Server (NTRS)

    Caruso, John J.; Spina, Dan C.; Greer, Lawrence C.; John, Wentworth T.; Michele, Clem; Krasowski, Mike J.; Prokop, Norman F.

    2008-01-01

    The development of a robust regolith moving system for lunar and planetary processing and construction is critical to the NASA mission to the Moon and Mars. Oxygen production may require up to 200 metric tons of regolith collection per year; outpost site development may require several times this amount. This paper describes progress in the small vehicle implement development and small excavation system development. Cratos was developed as a platform for the ISRU project to evaluate the performance characteristics of a low center of gravity, small (0.75m x 0.75m x 0.3m), low-power, tracked vehicle performing excavation, load, haul, and dump operations required for lunar ISRU. It was tested on loose sand in a facility capable of producing level and inclined surfaces, and demonstrated the capability to pick up, carry, and dump sand, allowing it to accomplish the delivery of material to a site. Cratos has demonstrated the capability to pick up and deliver simulant to a bury an inflatable habitat, to supply an oxygen production plant, and to build a ramp.

  20. Ancient pottery from archaeological sites in Southern Italy: first evidence of red grape products markers.

    PubMed

    Bianco, Giuliana; Granafei, Sara; Colivicchi, Fabio; Catald, Tommaso; Buchicchio, Alessandro

    2015-01-01

    The chemical analysis of tartaric acid (TA) and syringic acid (SA), as grape product markers in ancient ceramic vessels from the sites of Manduria and Torre di Satriano (southern Italy), was successfully performed. Firstly, the fragmentation behaviour of TA and SA as deprotonated molecules, [M-H](-), obtained by collision-induced dissociation, was investigated. Then, reversed-phase liquid chromatography (RPLC) with electrospray ionization (ESI) in negative ion mode, using a quadrupole linear ion trap in multiple reaction monitoring (MRM), was employed. A binary mobile phase composed of water-acetonitrile with 0.1% (v/v) acetic acid enabled the optimum ESI efficiency of SA, greatly improving its identification when it occurs in trace amounts. Chemical analysis of ancient pottery fragments is a valid method for establishing the existence of preserved organic residues, which is valuable new evidence for the culture and customs of ancient populations, in this case those of southern Italy. The proposed RPLC-ESI-MRM method allowed a systematic investigation of ceramic fragments of both archaeological sites, thus providing positive evidence for the presence of TA and SA as grape product markers in storage vessels dating back to the ninth to third centuries BC. PMID:26353991

  1. Greater Green River Basin production improvement project, Phase 1: Site characterization report

    SciTech Connect

    DeJarnett, B.B.; Krystinik, L.F.; Mead, R.H.; Poe, S.C.

    1996-05-01

    Several tight, naturally-fractured, gas-productive formations in the Greater Green River Basin (GGRB) in Wyoming have been exploited using conventional vertical well technology. Typically, hydraulic fracture treatments must be performed in completing these wells to increase gas production rates to economic levels. However, with the maturation of horizontal drilling technology hydraulic fracture treatments may not be the most effective method for improving gas production from these tight reservoirs. Two of the most prolific tight gas reservoirs in the Green River Basin, the Frontier and the Mesaverde, are candidates for the application of horizontal well completion technology. The objective of the proposed project is to apply the DOE`s technical concept to the Second Frontier Formation on the western flank of the Rock Springs Uplift. Previous industry attempts to produce in commercial quantities from the Second Frontier Formation have been hampered by lack of understanding of both the in-situ natural fracture system and lack of adequate stimulation treatments. The proposed technical approach involves drilling a vertical characterization well to the Second Frontier Formation at a depth of approximately 16,000 ft. from a site located about 18 miles northwest of Rock Springs, Wyoming. Logging, coring, and well testing information from the vertical well will be used to design a hydraulic fracturing treatment and to assess the resulting production performance. Data from the vertical drilling phase will be used to design a 2,500 to 3,000-ft lateral wellbore which will be kicked off from the vertical hole and extend into the blanket marine sandstone bench of the Second Frontier Formation. The trajectory of this wellbore will be designed to intersect the maximum number of natural fractures to maximize production rates. Production testing of the resulting completion will provide an assessment of reserve potential related to horizontal lateral completions.

  2. Pesticide toxicity index for freshwater aquatic organisms

    USGS Publications Warehouse

    Munn, Mark D.; Gilliom, Robert J.

    2001-01-01

    The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is designed to assess current water-quality conditions, changes in water quality over time, and the effects of natural and human factors on water quality for the Nation's streams and ground-water resources. For streams, one of the most difficult parts of the assessment is to link chemical conditions to effects on aquatic biota, particularly for pesticides, which tend to occur in streams as complex mixtures with strong seasonal patterns. A Pesticide Toxicity Index (PTI) was developed that combines pesticide exposure of aquatic biota (measured concentrations of pesticides in stream water) with toxicity estimates (standard endpoints from laboratory bioassays) to produce a single index value for a sample or site. The development of the PTI was limited to pesticide compounds routinely measured in NAWQA studies and to toxicity data readily available from existing databases. Qualifying toxicity data were found for one or more types of test organisms for 75 of the 83 pesticide compounds measured in NAWQA samples, but with a wide range of bioassays per compound (1 to 65). There were a total of 2,824 bioassays for the 75 compounds, including 287 48-hour EC50 values (concentration at which 50 percent of test organisms exhibit a nonlethal response) for freshwater cladocerans, 585 96-hour LC50 values (concentration lethal to 50 percent of test organisms) for freshwater benthic invertebrates, and 1,952 96-hour LC50 values for freshwater fish. The PTI for a particular sample is the sum of toxicity quotients (measured concentration divided by the median toxicity concentration from bioassays) for each detected pesticide. The PTI can be calculated for specific groups of pesticides and for specific taxonomic groups.While the PTI does not determine whether water in a sample is toxic, its values can be used to rank or compare the toxicity of samples or sites on a relative basis for use in further analysis or

  3. Microbiological reduction of Sb(V) in anoxic freshwater sediments.

    PubMed

    Kulp, Thomas R; Miller, Laurence G; Braiotta, Franco; Webb, Samuel M; Kocar, Benjamin D; Blum, Jodi S; Oremland, Ronald S

    2014-01-01

    Microbiological reduction of millimolar concentrations of Sb(V) to Sb(III) was observed in anoxic sediments from two freshwater settings: (1) a Sb- and As-contaminated mine site (Stibnite Mine) in central Idaho and 2) an uncontaminated suburban lake (Searsville Lake) in the San Francisco Bay Area. Rates of Sb(V) reduction in anoxic sediment microcosms and enrichment cultures were enhanced by amendment with lactate or acetate as electron donors but not by H2, and no reduction occurred in sterilized controls. Addition of 2-(14)C-acetate to Stibnite Mine microcosms resulted in the production of (14)CO2 coupled to Sb(V) reduction, suggesting that this process proceeds by a dissimilatory respiratory pathway in those sediments. Antimony(V) reduction in Searsville Lake sediments was not coupled to acetate mineralization and may be associated with Sb-resistance. The microcosms and enrichment cultures also reduced sulfate, and the precipitation of insoluble Sb(III)-sulfide complexes was a major sink for reduced Sb. The reduction of Sb(V) by Stibnite Mine sediments was inhibited by As(V), suggesting that As(V) is a preferred electron acceptor for the indigenous community. These findings indicate a novel pathway for anaerobic microbiological respiration and suggest that communities capable of reducing high concentrations of Sb(V) commonly occur naturally in the environment. PMID:24274659

  4. Microbiological reduction of Sb(V) in anoxic freshwater sediments

    USGS Publications Warehouse

    Oremland, Ronald S.; Kulp, Thomas R.; Miller, Laurence G.; Braiotta, Franco; Webb, Samuel M.; Kocar, Benjamin D; Blum, Jodi S.

    2013-01-01

    Microbiological reduction of millimolar concentrations of Sb(V) to Sb(III) was observed in anoxic sediments from two freshwater settings: (1) a Sb- and As-contaminated mine site (Stibnite Mine) in central Idaho and 2) an uncontaminated suburban lake (Searsville Lake) in the San Francisco Bay Area. Rates of Sb(V) reduction in anoxic sediment microcosms and enrichment cultures were enhanced by amendment with lactate or acetate as electron donors but not by H2, and no reduction occurred in sterilized controls. Addition of 2-14C-acetate to Stibnite Mine microcosms resulted in the production of 14CO2 coupled to Sb(V) reduction, suggesting that this process proceeds by a dissimilatory respiratory pathway in those sediments. Antimony(V) reduction in Searsville Lake sediments was not coupled to acetate mineralization and may be associated with Sb-resistance. The microcosms and enrichment cultures also reduced sulfate, and the precipitation of insoluble Sb(III)-sulfide complexes was a major sink for reduced Sb. The reduction of Sb(V) by Stibnite Mine sediments was inhibited by As(V), suggesting that As(V) is a preferred electron acceptor for the indigenous community. These findings indicate a novel pathway for anaerobic microbiological respiration and suggest that communities capable of reducing high concentrations of Sb(V) commonly occur naturally in the environment.

  5. 2H and 18O Freshwater Isoscapes of Scotland

    NASA Astrophysics Data System (ADS)

    Meier-Augenstein, Wolfram; Hoogewerff, Jurian; Kemp, Helen; Frew, Danny

    2013-04-01

    Scotland's freshwater lochs and reservoirs provide a vital resource for sustaining biodiversity, agriculture, food production as well as for human consumption. Regular monitoring of freshwaters by the Scottish Environment Protection Agency (SEPA) fulfils legislative requirements with regards to water quality but new scientific methods involving stable isotope analysis present an opportunity combining these mandatory monitoring schemes with fundamental research to inform and deliver on current and nascent government policies [1] through gaining a greater understanding of Scottish waters and their importance in the context of climate change, environmental sustainability and food security. For example, 2H and 18O isoscapes of Scottish freshwater could be used to underpin research and its applications in: • Climate change - Using longitudinal changes in the characteristic isotope composition of freshwater lochs and reservoirs as proxy, isoscapes will provide a means to assess if and how changes in temperature and weather patterns might impact on precipitation patterns and amount. • Scottish branding - Location specific stable isotope signatures of Scottish freshwater have the potential to be used as a tool for provenancing and thus protecting premium Scottish produce such as Scottish beef, Scottish soft fruit and Scottish Whisky. During 2011 and 2012, with the support of SEPA more than 110 samples from freshwater lochs and reservoirs were collected from 127 different locations across Scotland including the Highlands and Islands. Here we present the results of this sampling and analysis exercise isotope analyses in form of 2H and 18O isoscapes with an unprecedented grid resolution of 26.5 × 26.5 km (or 16.4 × 16.4 miles). [1] Adaptation Framework - Adapting Our Ways: Managing Scotland's Climate Risk (2009): Scotland's Biodiversity: It's in Your Hands - A strategy for the conservation and enhancement of biodiversity in Scotland (2005); Recipe For Success - Scotland

  6. 75 FR 453 - FLSMidth, Inc., Cement Division, Product Engineering, Including On-Site Leased Workers of Aerotek...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-05

    ... Employment and Training Administration FLSMidth, Inc., Cement Division, Product Engineering, Including On-Site Leased Workers of Aerotek Contract Engineering, Allied Personnel Services, Eastern Engineering... Engineering, and Clarke Consulting, Inc., Bethlehem, PA; Amended Certification Regarding Eligibility To...

  7. Aedes aegypti (Diptera: Culicidae) production from non-residential sites in the Amazonian city of Iquitos, Peru.

    PubMed

    Morrison, A C; Sihuincha, M; Stancil, J D; Zamora, E; Astete, H; Olson, J G; Vidal-Ore, C; Scott, T W

    2006-04-01

    Programmes for the surveillance of Aedes aegypti (L.) often focus on residential areas, ignoring non-residential sites. Between November 2003 and October 2004, pupal/demographic surveys were therefore conducted in non-residential sites in the Peruvian city of Iquitos. The sampled sites included schools, factories, ports, public markets, petrol stations, commercial zones, airports, government buildings, animal-production areas, and recreational areas. Compared with the residential sites that had been surveyed a few years earlier, the non-residential sites generally had fewer pupae/ha, even though pupae were found in a high percentage of the sites investigated. Nonetheless, although <56 pupae/ha were observed in the industrial, commercial, recreational and school sites, the river boats in the ports and the areas in and around public markets sometimes had pupal abundances (of 122-213 pupae/ha) that were comparable with those previously recorded in the residential sites. When the relative production of Ae. aegypti was calculated by container type and characteristic (lidded/lidless, indoors/outdoors, and water-use patterns), no single container category was found to be a major producer of Ae. aegypti, with the exception of flower vases in cemeteries. In general, almost all (97%) of the pupae collected in the non-residential sites came from unlidded containers, although 91% of those collected in river boats came from lidded storage areas. With the exception of lumber mills, plant nurseries and markets (where only 39%-60% of the pupae were collected outdoors), >70% of pupal production was outdoors. In commercial areas, 41% of the pupae came from manually-filled containers, compared with <12% in residential sites. These results indicate that non-residential sites can be highly productive for Ae. aegypti and that the role of such sites in dengue transmission requires further investigation. PMID:16630393

  8. Field experiment on CO2 back-production at the Ketzin pilot site

    NASA Astrophysics Data System (ADS)

    Martens, Sonja; Möller, Fabian; Schmidt-Hattenberger, Cornelia; Streibel, Martin; Szizybalski, Alexandra; Liebscher, Axel

    2015-04-01

    The operational phase of the Ketzin pilot site for geological CO2 storage in Germany started in June 2008 and ended in August 2013. Over the period of approximately five years, a total amount of 67 kt of CO2 was successfully injected into a saline aquifer (Upper Triassic sandstone) at a depth of 630 m - 650 m. The CO2 used was mainly of food grade quality. In addition, 1.5 kt of CO2 from the pilot capture facility "Schwarze Pumpe" (lignite power plant CO2) was used in 2011. At the end of the injection period, 32 t N2 and 613 t CO2 were co-injected during a four-week field test in July and August 2013. In October 2014, a field experiment was carried out at Ketzin with the aim to back-produce parts of the injected CO2 during a two-week period. This experiment addressed two main questions: (i) How do reservoir and wellbore behave during back-production of CO2? and (ii) What is the composition of the CO2 and the co-produced formation fluid? The back-production was carried out through the former injection well. It was conducted continuously over the first week and with an alternating regime including production during day-time and shut-ins during night-time in the second week. During the test, a total amount of 240 t of CO2 and 57 m3 of brine were safely back-produced from the reservoir. Production rates up to 3,200 kg/h - which corresponds to the former highest injection rate - could be tested. Vital monitoring parameters included production rates of CO2 and brine, wellhead and bottomhole pressure and temperature at the production and observation wells and distributed temperature sensing (DTS) along the production well. A permanently installed geoelectrical array was used for crosshole electrical resistivity tomography (ERT) monitoring of the reservoir. Formation fluid and gas samples were collected and analysed. The measured compositions allow studying the geochemical interactions between CO2, formation fluid and rocks under in-situ conditions The field experiment

  9. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Oak Ridge Gaseous Diffusion Plant Site

    SciTech Connect

    Not Available

    1991-09-01

    In January 1990, the Secretary of Energy approved a plan for the demonstration and deployment of the Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) technology, with the near-term goal to provide the necessary information to make a deployment decision by November 1992. The U-AVLIS process is based on electrostatic extraction of photoionized U-235 atoms from an atomic vapor stream created by electron-beam vaporization of uranium metal alloy. A programmatic document for use in screening DOE sites to locate the U-AVLIS production plant was developed and implemented in two parts (Wolsko et al. 1991). The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. These sites were then subjected to a more rigorous and detailed comparative analysis for the purpose of developing a short list of reasonable alternative sites for later environmental examination. This environmental site description (ESD) provides a detailed description of the ORGDP site and vicinity suitable for use in an environmental impact statement (EIS). The report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during a site visit. The organization of the ESD is as follows. Topics addressed in Sec. 2 include a general site description and the disciplines of geology, water resources, biotic resources, air resources, noise, cultural resources, land use, socioeconomics, and waste management. Identification of any additional data that would be required for an EIS is presented in Sec. 3. Following the site description and additional data requirements, Sec. 4 provides a short, qualitative assessment of potential environmental issues. 37 refs., 20 figs., 18 tabs.

  10. Water quality for freshwater fish

    SciTech Connect

    Howells, G. )

    1994-01-01

    This timely and up-to-date volume brings together recent critical reviews on water quality requirements for freshwater fish commissioned by the European Inland Fisheries Advisory Commission, an agency of the United Nations Food and Agriculture Organization. It provides a unique and authoritative source of critically evaluated water quality data concerning the effects of chromium, nickel, aluminum and nitrite on freshwater fish and includes an assessment of the toxicity of mixtures. The reports presented in this volume cover all stages of the life cycle and relevant trophic levels, including aquatic invertebrates and plants and potential bioaccumulation through the food chain. An extensive bibliography is provided for each chapter as well as a glossary of terms and a list of fish species mentioned in the text. This compilation of papers is the definitive reference volume for chemists, biologists, ecologists and toxicologists as well as for water resource managers concerned with management and control of pollution in fresh waters.

  11. Freshwater Biodiversity and Insect Diversification

    PubMed Central

    Dijkstra, Klaas-Douwe B.; Monaghan, Michael T.; Pauls, Steffen U.

    2016-01-01

    Inland waters cover less than one percent of Earth’s surface, but harbor more than six percent of all insect species: nearly 100,000 species from 12 orders spend one or more life stages in freshwater. Little is known about how this remarkable diversity arose, although allopatric speciation and ecological adaptation are thought to be primary mechanisms. Freshwater habitats are exceptionally susceptible to environmental change, and exhibit marked ecological gradients. The amphibiotic lifestyles of aquatic insects result in complex contributions of extinction and allopatric and non-allopatric speciation in species diversification. In contrast to the lack of evolutionary studies, the ecology and habitat preferences of aquatic insects have been intensively studied, in part because of their widespread use as bio-indicators. The combination of phylogenetics with the extensive ecological data provides a promising avenue for future research, making aquatic insects highly suitable models for the study of ecological diversification. PMID:24160433

  12. On-site cellulase production by Trichoderma reesei 3EMS35 mutant and same vessel saccharification and fermentation of acid treated wheat straw for ethanol production

    PubMed Central

    Khokhar, Zia-ullah; Syed, Qurat-ul-Ain; Wu, Jing; Athar, Muhammad Amin

    2014-01-01

    Bioethanol production from lignocellulosic raw materials involves process steps like pre-treatment, enzymatic hydrolysis, fermentation and distillation. In this study, wheat straw was explored as feedstock for on-site cellulase production by T. reesei 3EMS35 mutant, and as a substrate for second generation bioethanol production from baker yeast. Scanning electron microscopy (SEM) and X-ray diffractography (XRD) of untreated wheat straw (UWS) and acid treated wheat straw (TWS) were done to understand the structural organization and changes in the cellulase accessibility and reactivity. The effect of delignification and structural modification for on-site cellulase enzyme production was comparably studied. The efficiency of crude cellulase enzyme for digestion of UWS and TWS and then production of ethanol from TWS was studied using same-vessel saccharification and fermentation (SVSF) technique, both in shaking flasks as well as in fermenters. Two different methods of operation were tested, i.e. the UWSEnz method, where UWS was used for on-site enzyme production, and TWSEnz method where TWS was applied as substrate for cellullase production. Results obtained showed structural modifications in cellulose of TWS due to delignification, removal of wax and change of crystallinity. UWS was better substrate than TWS for cellulase production due to the fact that lignin did not hinder the enzyme production by fungus but acted as a booster. On-site cellulase enzyme produced by T. reesei 3EMS35 mutant hydrolyzed most of cellulose (91 %) in TWS within first 24 hrs. Shake flasks experiments showed that ethanol titers and yields with UWSEnz were 2.9 times higher compared to those obtained with TWSEnz method respectively. Comparatively, titer of ethanol in shake flask experiments was 10 % higher than this obtained in 3 L fermenter with UWSEnz. Outcomes from this investigation clearly demonstrated the potential of on-site cellulase enzyme production and SVSF for ethanol production

  13. Quinoline and derivatives at a tar oil contaminated site: hydroxylated products as indicator for natural attenuation?

    SciTech Connect

    Anne-Kirsten Reineke; Thomas Goeen; Alfred Preiss; Juliane Hollender

    2007-08-01

    LC-MS-MS analysis of groundwater of a tar oil contaminated site (a former coal mine and coking plant in Castrop-Rauxel, Germany) showed the occurrence of the N-heterocycles quinoline and isoquinoline as well as their hydroxylated and hydrogenated metabolites. The concentrations of the hydroxylated compounds, 2(1H)-quinolinone and 1(2H)-isoquinolinone, were significantly higher than those of the nonsubstituted parent compounds. Therefore, exclusive quantification of the parent compounds leads to an underestimation of the amount of N-heterocycles present in the groundwater. Microbial degradation experiments of quinoline and isoquinoline with aquifer material of the site as inocculum showed the formation of hydroxylated and hydrogenated products under sulfate-reducing conditions, the prevailing conditions in the field. However, since analyses of seven tar products showed that these compounds are also primary constituents, their detection in groundwater is found to be a nonsufficient indicator for the occurrence of biological natural attenuation processes. Instead, the ratio of hydroxylated to parent compound (R{sub metabolite}) is proposed as a useful indicator. We found that 65-83% of all groundwater samples showed R{sub metabolite} for 2(1H)-quinolinone, 1(2H)-isoquinolinone, 3,4-dihydro-2(1H)-quinolinone, and 3,4-dihydro-1(2H)-isoquinolinone, which was higher than the highest ratio found in tar products. With respect to the observed partition coefficient between tar oil and water of 3.5 for quinoline and isoquinoline and 0.3 for 2(1H)-quinolinone and 1(2H)-isoquinolinone, the ratio in groundwater would be approximately 10 times higher than the ratio in tar oil. When paying attention to these two parameters, 19-31% of groundwater samples exceed the highest tar oil ratio. This indicates that biological processes take place in the aquifer of the site and R{sub metabolite} is an applicable indicator for natural attenuation. 42 refs., 6 figs., 2 tabs.

  14. Arctic freshwater export: Status, mechanisms, and prospects

    NASA Astrophysics Data System (ADS)

    Haine, Thomas W. N.; Curry, Beth; Gerdes, Rüdiger; Hansen, Edmond; Karcher, Michael; Lee, Craig; Rudels, Bert; Spreen, Gunnar; de Steur, Laura; Stewart, Kial D.; Woodgate, Rebecca

    2015-02-01

    Large freshwater anomalies clearly exist in the Arctic Ocean. For example, liquid freshwater has accumulated in the Beaufort Gyre in the decade of the 2000s compared to 1980-2000, with an extra ≈ 5000 km3 - about 25% - being stored. The sources of freshwater to the Arctic from precipitation and runoff have increased between these periods (most of the evidence comes from models). Despite flux increases from 2001 to 2011, it is uncertain if the marine freshwater source through Bering Strait for the 2000s has changed, as observations in the 1980s and 1990s are incomplete. The marine freshwater fluxes draining the Arctic through Fram and Davis straits are also insignificantly different. In this way, the balance of sources and sinks of freshwater to the Arctic, Canadian Arctic Archipelago (CAA), and Baffin Bay shifted to about 1200 ± 730 km3 yr- 1 freshening the region, on average, during the 2000s. The observed accumulation of liquid freshwater is consistent with this increased supply and the loss of freshwater from sea ice. Coupled climate models project continued freshening of the Arctic during the 21st century, with a total gain of about 50,000 km3 for the Arctic, CAA, and Baffin Bay (an increase of about 50%) by 2100. Understanding of the mechanisms controlling freshwater emphasizes the importance of Arctic surface winds, in addition to the sources of freshwater. The wind can modify the storage, release, and pathways of freshwater on timescales of O(1-10) months. Discharges of excess freshwater through Fram or Davis straits appear possible, triggered by changes in the wind, but are hard to predict. Continued measurement of the fluxes and storage of freshwater is needed to observe changes such as these.

  15. Using a third tone to probe the physiological generation site of distortion product otoacoustic emissions in gerbil

    NASA Astrophysics Data System (ADS)

    Dong, Wei

    2015-12-01

    The generation of distortion product otoacoustic emissions (DPOAEs) has been summarized using a two-mechanism theory consisting of nonlinear distortion and linear coherent reflection. However, the precise generation site in the cochlea is still unclear. The current study in gerbils used a third tone in different cochlear regions to probe the cochlear origin site of DPOAEs. DPOAEs and their intracochlear sources, distortion products (DPs), were simultaneously measured. Our results suggest that the major generation site of DPOAEs evoked by an f2/f1 ratio of 1.25 extends basal to the primary f2 place, which is consistent with notions about the location of the cochlear amplifier.

  16. Mobile measurement of methane and hydrogen sulfide at natural gas production site fence lines in the Texas Barnett Shale.

    PubMed

    Eapi, Gautam R; Sabnis, Madhu S; Sattler, Melanie L

    2014-08-01

    Production of natural gas from shale formations is bringing drilling and production operations to regions of the United States that have seen little or no similar activity in the past, which has generated considerable interest in potential environmental impacts. This study focused on the Barnett Shale Fort Worth Basin in Texas, which saw the number of gas-producing wells grow from 726 in 2001 to 15,870 in 2011. This study aimed to measure fence line concentrations of methane and hydrogen sulfide at natural gas production sites (wells, liquid storage tanks, and associated equipment) in the four core counties of the Barnett Shale (Denton, Johnson, Tarrant, and Wise). A mobile measurement survey was conducted in the vicinity of 4788 wells near 401 lease sites, representing 35% of gas production volume, 31% of wells, and 38% of condensate production volume in the four-county core area. Methane and hydrogen sulfide concentrations were measured using a Picarro G2204 cavity ring-down spectrometer (CRDS). Since the research team did not have access to lease site interiors, measurements were made by driving on roads on the exterior of the lease sites. Over 150 hr of data were collected from March to July 2012. During two sets of drive-by measurements, it was found that 66 sites (16.5%) had methane concentrations > 3 parts per million (ppm) just beyond the fence line. Thirty-two lease sites (8.0%) had hydrogen sulfide concentrations > 4.7 parts per billion (ppb) (odor recognition threshold) just beyond the fence line. Measured concentrations generally did not correlate well with site characteristics (natural gas production volume, number of wells, or condensate production). t tests showed that for two counties, methane concentrations for dry sites were higher than those for wet sites. Follow-up study is recommended to provide more information at sites identified with high levels of methane and hydrogen sulfide. Implications: Information regarding air emissions from shale gas

  17. Methods and apparatus for the on-site production of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Buschmann, Wayne E. (Inventor); James, Patrick I. (Inventor)

    2010-01-01

    Methods, apparatus, and applications for the on-site production of hydrogen peroxide are described. An embodiment of the apparatus comprises at least one anolyte chamber coupled to at least one anode, at least one catholyte chamber, wherein the at least one catholyte chamber is coupled to at least one cathode, at least one anode membrane and at least one cathode membrane, wherein the anode membrane is adjacent to the at least one anode, wherein the cathode membrane is adjacent to the at least one cathode, at least one central chamber disposed between the at least one anolyte chamber and the at least one catholyte chamber. Hydrogen peroxide is produced by reduction of an oxygen-containing gas at the cathode.

  18. Bioremediation demonstration on Kwajalein Island: Site characterization and on-site biotreatability studies

    SciTech Connect

    Siegrist, R.L.; Korte, N.E.; Pickering, D.A. ); Phelps, T.J. )

    1991-09-01

    An environmental study was conducted during February 1991 on Kwajalein Island, a US Army Kwajalein Atoll (USAKA) Base in the Republic of the Marshall Islands (RMI). This study was undertaken for the US Department of Energy (DOE) Hazardous Waste Remedial Actions Program (HAZWRAP) acting in behalf of USAKA. The purpose of the study was to determine if selected locations for new construction on Kwajalein Island were contaminated by petroleum hydrocarbons as suspected and, if so, whether bioremediation appeared to be a feasible technology for environmental restoration. Two different sites were evaluated: (1) the site planned freshwater production facility and (2) a site adjacent to an aboveground diesel fuel storage tank. Within the proposed construction zone for the freshwater production facility (a.k.a desalination plant), total petroleum hydrocarbons (TPH) where either absent or at low levels. Characterization data for another potential construction site adjacent to an aboveground diesel fuel storage tank southeast of the old diesel power plant revealed high concentrations of diesel fuel in the soil and groundwater beneath the site. Results of this investigation indicate that there are petroleum-contaminated soils on Kwajalein Island and bioremediation appears to be a viable environmental restoration technique. Further experimentation and field demonstration are required to determine the design and operating conditions that provide for optimum biodegradation and restoration of the petroleum-contaminated soils. 17 refs., 7 figs., 26 figs.

  19. Bone marrow is a major site of long-term antibody production after acute viral infection.

    PubMed Central

    Slifka, M K; Matloubian, M; Ahmed, R

    1995-01-01

    Antiviral antibody production is often sustained for long periods after resolution of an acute viral infection. Despite extensive documentation of this phenomenon, the mechanisms involved in maintaining long-term antibody production remain poorly defined. As a first step towards understanding the nature of long-term humoral immunity, we examined the anatomical location of antibody-producing cells during acute viral infection. Using the lymphocytic choriomeningitis virus (LCMV) model, we found that after resolution of the acute infection, when antiviral plasma cells in the spleen decline, a population of virus-specific plasma cells appears in the bone marrow and constitutes the major source of long-term antibody production. Following infection of adult mice, LCMV-specific antibody-secreting cells (ASC) peaked in the spleen at 8 days postinfection but were undetectable in the bone marrow at that time. The infection was essentially cleared by 15 days, and the ASC numbers in the spleen rapidly declined while an increasing population of LCMV-specific ASC began to appear in the bone marrow. Compared with the peak response at 8 days postinfection, time points from 30 days to more than 1 year later demonstrated greater-than-10-fold reductions in splenic ASC. In contrast, LCMV-specific plasma cell numbers in the bone marrow remained high and correlated with the high levels of antiviral serum antibody. The presence of LCMV-specific plasma cells in the bone marrow was not due to persistent infection at this site, since the virus was cleared from both the spleen and bone marrow with similar kinetics as determined by infectivity and PCR assays. The immunoglobulin G subclass profile of antibody-secreting cells derived from bone marrow and the spleen correlated with the immunoglobulin G subclass distribution of LCMV-specific antibody in the serum. Upon rechallenge with LCMV, the spleen exhibited a substantial increase in virus-specific plasma cell numbers during the early phase

  20. Variations in egg characteristics of ruffe Gymnocephalus cernua inhabiting brackish and freshwater environments

    NASA Astrophysics Data System (ADS)

    Svirgsden, Roland; Albert, Anu; Rohtla, Mehis; Taal, Imre; Saks, Lauri; Verliin, Aare; Kesler, Martin; Hubel, Kalvi; Vetemaa, Markus; Saat, Toomas

    2015-09-01

    Egg characteristics of teleost fishes are affected by various abiotic and biotic factors. In order to reproduce successfully, freshwater fishes inhabiting brackish environments must alter their reproductive characteristics, including egg properties, to increased osmotic pressure. Ruffe Gymnocephalus cernua was used as a model species to compare egg characteristics between fish populations inhabiting brackish and freshwater environments. Fish from the brackish environment had larger eggs with higher energy content than the individuals originating from freshwater. In freshwater, eggs from the first batch were larger than from the second. Female size correlated positively with egg size in the brackish water population. In freshwater, this correlation was evident only with eggs from the first batch. Only a weak positive correlation was found between fish condition and egg size in females from the brackish water population. Egg size variation did not differ between sites, nor was it correlated with mean egg size or any other maternal traits within populations. These results indicate significant modifications in reproductive strategies between brackish and freshwater ruffe populations. Additionally, results show that at least in freshwater, the first batch of eggs is of the highest quality and therefore more important for reproduction.

  1. Eutrophication of freshwater and marine ecosystems

    USGS Publications Warehouse

    Smith, Val H.; Joye, Samantha B.; Howarth, Robert W.

    2006-01-01

    Initial understanding of the links between nutrients and aquatic productivity originated in Europe in the early 1900s, and our knowledge base has expanded greatly during the past 40 yr. This explosion of eutrophication-related research has made it unequivocally clear that a comprehensive strategy to prevent excessive amounts of nitrogen and phosphorus from entering our waterways is needed to protect our lakes, rivers, and coasts from water quality deterioration. However, despite these very significant advances, cultural eutrophication remains one of the foremost problems for protecting our valuable surface water resources. The papers in this special issue provide a valuable cross section and synthesis of our current understanding of both freshwater and marine eutrophication science. They also serve to identify gaps in our knowledge and will help to guide future research.

  2. The effect of alder forest cover and alder forest conversion on site fertility and productivity

    SciTech Connect

    Van Miegroet, H.; Cole, D.W.; Homann, P.S.

    1988-01-01

    Red alder (Alnus rubra Bong.) is known for its ability to improve the status of soil N through symbiotic N fixation. The objective of this paper is to assess the effect of red alder forests and their removal on soil and solution chemistry and on the growth of trees subsequently established on such sites. This was achieved through a series of paired field comparisons at two locations in Washington, involving similar-aged pure alder and Douglas-fir forests on soils that were essentially the same prior to stand establishment. At Pack Forest alder and Douglas-fir stands on high- and low-productivity sites were subjected to three levels of harvesting: bore only removal, whole tree (aboveground) harvesting, and complete removal of all vegetation and forest floor. The effect of harvesting intensity was examined on nutrient removal with biomass and through leaching, and on subsequent seedling growth. At Thompson Research Center adjacent Douglas-fir and alder forests were harvested, and half of each area was replanted with either Douglas-fir or red alder seedlings, yielding four forest conversion units. Differences in growth patterns, tree nutrient status, and leaching losses between these conversion plots were examined. Compared with adjacent Douglas-fir forests, substantially more N, P, K, and Ca are tied up in aboveground vegetation and on the forest floor of alder forests, and these elements also cycle faster in alder ecosystems primarily due to the deciduous nature of alder.

  3. Natural attenuation of trichloroethene and its degradation products at a lake-shore site.

    PubMed

    An, Youn-Joo; Kampbell, Donald H; Weaver, James W; Wilson, John T; Jeong, Seung-Woo

    2004-08-01

    Subsurface contamination by trichloroethene (TCE) was detected at a Michigan National Priorities List (NPL) site in 1982. The TCE plume resulted from the disposal of spent solvent and other chemicals at an industrial facility located in the eastern shore of Lake Michigan. TCE degradation products of three dichloroethene (DCE) isomers, vinyl chloride (VC) and ethene were present. The plume was depleted of oxygen and methanogenic at certain depths. Transects of the plume were sampled by slotted auger borings the year after the TCE plume was first discovered. Water samples were also taken from lake sediments to a depth of 12 m about 100 m offshore. Later samples were taken along the shoreline of the lake with a hand-driven probe. Later in 1998 water was taken from sediments about 3-m from the shoreline. The average concentration of each chemical and net apparent base coefficient between appropriate pairs of transects between the lower site and lakeshore were calculated. Loss rates were then calculated from an analytical solution of the two-dimensional advective-dispersive-reactive transport equation. Net apparent rate coefficients and a set of coupled reaction rate equations were used to extract the apparent loss coefficients. This study showed the field evidence for natural attenuation of TCE. PMID:15182966

  4. Framework for managing wastes from oil and gas exploration and production (E&P) sites.

    SciTech Connect

    Veil, J. A.; Puder, M. G.; Environmental Science Division

    2007-09-15

    Oil and gas companies operate in many countries around the world. Their exploration and production (E&P) operations generate many kinds of waste that must be carefully and appropriately managed. Some of these wastes are inherently part of the E&P process; examples are drilling wastes and produced water. Other wastes are generic industrial wastes that are not unique to E&P activities, such as painting wastes and scrap metal. Still other wastes are associated with the presence of workers at the site; these include trash, food waste, and laundry wash water. In some host countries, mature environmental regulatory programs are in place that provide for various waste management options on the basis of the characteristics of the wastes and the environmental settings of the sites. In other countries, the waste management requirements and authorized options are stringent, even though the infrastructure to meet the requirements may not be available yet. In some cases, regulations and/or waste management infrastructure do not exist at all. Companies operating in these countries can be confronted with limited and expensive waste management options.

  5. 75 FR 20390 - Senco Brands, Inc., fka Senco Products, Inc., Including the On-Site Leased Workers of Manpower...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-19

    ... published in the Federal Register on January 25, 2010 (75 FR 3930). At the request of the State Agency, the... Employment and Training Administration Senco Brands, Inc., fka Senco Products, Inc., Including the On- Site... December 10, 2009, applicable to workers of Senco Brands, Inc., fka Senco Products, Inc., including the...

  6. Salinity Tolerance of Picochlorum atomus and the Use of Salinity for Contamination Control by the Freshwater Cyanobacterium Pseudanabaena limnetica

    PubMed Central

    von Alvensleben, Nicolas; Stookey, Katherine; Magnusson, Marie; Heimann, Kirsten

    2013-01-01

    Microalgae are ideal candidates for waste-gas and –water remediation. However, salinity often varies between different sites. A cosmopolitan microalga with large salinity tolerance and consistent biochemical profiles would be ideal for standardised cultivation across various remediation sites. The aims of this study were to determine the effects of salinity on Picochlorum atomus growth, biomass productivity, nutrient uptake and biochemical profiles. To determine if target end-products could be manipulated, the effects of 4-day nutrient limitation were also determined. Culture salinity had no effect on growth, biomass productivity, phosphate, nitrate and total nitrogen uptake at 2, 8, 18, 28 and 36 ppt. 11 ppt, however, initiated a significantly higher total nitrogen uptake. While salinity had only minor effects on biochemical composition, nutrient depletion was a major driver for changes in biomass quality, leading to significant increases in total lipid, fatty acid and carbohydrate quantities. Fatty acid composition was also significantly affected by nutrient depletion, with an increased proportion of saturated and mono-unsaturated fatty acids. Having established that P. atomus is a euryhaline microalga, the effects of culture salinity on the development of the freshwater cyanobacterial contaminant Pseudanabaena limnetica were determined. Salinity at 28 and 36 ppt significantly inhibited establishment of P. limnetica in P. atomus cultures. In conclusion, P. atomus can be deployed for bioremediation at sites with highly variable salinities without effects on end-product potential. Nutrient status critically affected biochemical profiles – an important consideration for end-product development by microalgal industries. 28 and 36 ppt slow the establishment of the freshwater cyanobacterium P. limnetica, allowing for harvest of low contaminant containing biomass. PMID:23667639

  7. Periodicity in stem growth and litterfall in tidal freshwater forested wetlands: influence of salinity and drought on nitrogen recycling

    USGS Publications Warehouse

    Cormier, Nicole; Krauss, Ken W.; Conner, William H.

    2013-01-01

    Many tidally influenced freshwater forested wetlands (tidal swamps) along the south Atlantic coast of the USA are currently undergoing dieback and decline. Salinity often drives conversion of tidal swamps to marsh, especially under conditions of regional drought. During this change, alterations in nitrogen (N) uptake from dominant vegetation or timing of N recycling from the canopy during annual litter senescence may help to facilitate marsh encroachment by providing for greater bioavailable N with small increases in salinity. To monitor these changes along with shifts in stand productivity, we established sites along two tidal swamp landscape transects on the lower reaches of the Waccamaw River (South Carolina) and Savannah River (Georgia) representing freshwater (≤0.1 psu), low oligohaline (1.1–1.6 psu), and high oligohaline (2.6–4.1 psu) stands; the latter stands have active marsh encroachment. Aboveground tree productivity was monitored on all sites through monthly litterfall collection and dendrometer band measurements from 2005 to 2009. Litterfall samples were pooled by season and analyzed for total N and carbon (C). On average between the two rivers, freshwater, low oligohaline, and high oligohaline tidal swamps returned 8,126, 3,831, and 1,471 mg N m−2 year−1, respectively, to the forest floor through litterfall, with differences related to total litterfall volume rather than foliar N concentrations. High oligohaline sites were most inconsistent in patterns of foliar N concentrations and N loading from the canopy. Leaf N content generally decreased and foliar C/N generally increased with salinization (excepting one site), with all sites being fairly inefficient in resorbing N from leaves prior to senescence. Stands with higher salinity also had greater flood frequency and duration, lower basal area increments, lower tree densities, higher numbers of dead or dying trees, and much reduced leaf litter fall (103 vs. 624 g m−2 year−1) over the

  8. Viruses of freshwater finfish in the asian-pacific region.

    PubMed

    Sahoo, P K; Goodwin, A E

    2012-09-01

    There has been a tremendous increase in global demand for marine and freshwater fish to meet the protein needs of our expanding human population. However, due to the limited capacity of the wild-capture sector and a levelling of production from capture fisheries, the practice of farming aquatic animals has expanded rapidly to become a major global industry. Aquaculture, particularly freshwater aquaculture is now integral to the economies of many countries. A large number of aquatic animal species are farmed in high density in freshwater, brackish and marine systems, where they are exposed to new environments and potentially new diseases. Further, environmental stress factors, the use of manufactured feeds, and prolific global trade has led to the emergence and spread of new diseases. Viral pathogens, established for decades or newly emerging as disease threats, are particularly challenging since there are few efficacious treatments. Vaccines have been developed for some viral fish pathogens in salmonids, but vaccines are not available for many of the viral pathogens important in Asia. Control and eradication programs are difficult because many viral infections remain latent until adverse environmental conditions, such as overcrowding or poor water quality, trigger the onset of disease. Here, we review the more significant viral pathogens of finfish in the Asia-Pacific including both those with a long history in Asian aquaculture and emerging pathogens including betanodaviruses and koi herpes virus that have caused massive losses in the freshwater aquaculture and ornamental fish industries. PMID:23997433

  9. Transitioning to Zero Freshwater Withdrawal for Thermoelectric Generation

    NASA Astrophysics Data System (ADS)

    Macknick, J.; Tidwell, V. C.; Zemlick, K. M.; Sanchez, J.; Woldeyesus, T.

    2013-12-01

    The electricity sector is the largest withdrawer of freshwater in the United States. The primary demand for water from the electricity sector is for cooling thermoelectric power plants. Droughts and potential changes in water resources resulting from climate change pose important risks to thermoelectric power production in the United States. Power plants can minimize risk in a variety of ways. One method of reducing risk is to move away from dependency on freshwater resources. Here a scoping level analysis is performed to identify the technical tradeoffs and initial cost estimates for retrofitting all existing steam-powered generation to achieve zero freshwater withdrawal. Specifically, the conversion of existing freshwater-cooled plants to dry cooling or a wet cooling system utilizing non-potable water is considered. The least cost alternative is determined for each of the 1,178 freshwater using power plants in the United States. The use of non-potable water resources, such as municipal wastewater and shallow brackish groundwater, is considered based on the availability and proximity of those resources to the power plant, as well as the costs to transport and treat those resources to an acceptable level. The projected increase in levelized cost of electricity due to power plant retrofits ranges roughly from 0.20 to 20/MWh with a median value of 3.53/MWh. With a wholesale price of electricity running about 35/MWh, many retrofits could be accomplished at levels that would add less than 10% to current power plant generation expenses. Such retrofits could alleviate power plant vulnerabilities to thermal discharge limits in times of drought (particularly in the East) and would save 3.2 Mm3/d of freshwater consumption in watersheds with limited water availability (principally in the West). The estimated impact of retrofits on wastewater and brackish water supply is minimal requiring only a fraction of the available resource. Total parasitic energy requirements to

  10. Idaho National Engineering and Environmental Laboratory Site Report on the Production and Use of Recycled Uranium

    SciTech Connect

    L. C. Lewis; D. C. Barg; C. L. Bendixsen; J. P. Henscheid; D. R. Wenzel; B. L. Denning

    2000-09-01

    Recent allegations regarding radiation exposure to radionuclides present in recycled uranium sent to the gaseous diffusion plants prompted the Department of Energy to undertake a system-wide study of recycled uranium. Of particular interest, were the flowpaths from site to site operations and facilities in which exposure to plutonium, neptunium and technetium could occur, and to the workers that could receive a significant radiation dose from handling recycled uranium. The Idaho National Engineering and Environmental Laboratory site report is primarily concerned with two locations. Recycled uranium was produced at the Idaho Chemical Processing Plant where highly enriched uranium was recovered from spent fuel. The other facility is the Specific Manufacturing Facility (SMC) where recycled, depleted uranium is manufactured into shapes for use by their customer. The SMC is a manufacturing facility that uses depleted uranium metal as a raw material that is then rolled and cut into shapes. There are no chemical processes that might concentrate any of the radioactive contaminant species. Recyclable depleted uranium from the SMC facility is sent to a private metallurgical facility for recasting. Analyses on the recast billets indicate that there is no change in the concentrations of transuranics as a result of the recasting process. The Idaho Chemical Processing Plant was built to recover high-enriched uranium from spent nuclear fuel from test reactors. The facility processed diverse types of fuel which required uniquely different fuel dissolution processes. The dissolved fuel was passed through three cycles of solvent extraction which resulted in a concentrated uranyl nitrate product. For the first half of the operating period, the uranium was shipped as the concentrated solution. For the second half of the operating period the uranium solution was thermally converted to granular, uranium trioxide solids. The dose reconstruction project has evaluated work exposure and

  11. Downhole monitoring of biogenic gas production at the Maguelone shallow injection experimental site (Languedoc coastline, France).

    NASA Astrophysics Data System (ADS)

    Abdelghafour, H.; Brondolo, F.; Denchik, N.; Pezard, P. A.

    2014-12-01

    The controllability of CO2 geological storage can ensure the integrity of storage operations, requiring a precise monitoring of reservoir fluids and properties during injection and over time. In this context, deep saline aquifers offer a large capacity of storing CO2, but the accessibility to long term behavior studies remains limited until now. The Maguelone shallow experimental site located near Montpellier (Languedoc, France) provides such an opportunity for the understanding and accuracy of hydrogeophysical monitoring methods. The geology, petrophysic and hydrology of this site have been studied in details in previous studies, revealing the presence of a thin saline aquifer at 13-16 m depth surrounded by clay-rich materials. The site as a whole provides a natural laboratory to study CO2 injection at field scale, shallow depth, hence reasonable costs. The monitoring setup is composed of a series of hydrogeophysical and geochemical methods offering measurements of fluid pore pressure, electrical resistivity, acoustic velocities as well as pH and fluid properties and chemistry. To assess the response of the reservoir during CO2 injection, all measurements need to be compared to a representative baseline. Long after a series of gas injection experiments at Maguelone, fluctuations overtime of reservoir fluids and properties (such as pore fluid pH) were discovered at steady state, demonstrating the natural variability of the site in terms of biogenic gas (H2S, CH4, CO2) production and transfer. For this, a new resistivity baseline had to be constructed for all observatories. From this, the downhole gas saturation was determined versus depth and time from time-lapse resistivity logs analysed on the basis of other logs and laboratory measurements. The Waxman and Smits model (1968) for electrical properties of sand-clay formations was modified to estimate the gas saturation in 4D, to account for surface conductivity and pore connectivity. High frequency logging and

  12. Secondary succession is influenced by belowground insect herbivory on a productive site.

    PubMed

    Schädler, Martin; Jung, Gertraud; Brandl, Roland; Auge, Harald

    2004-01-01

    We investigated the effects of insect herbivory on a plant community of a productive old-field community by applying foliar and soil insecticides in a full factorial design. During the first 3 years of succession, insecticide treatments had only minor effects on total cover abundance and species richness. However, species ranking within the plant community was strongly affected by soil insecticide but not by foliar insecticide. Creeping thistle, Cirsium arvense, dominated the experimental plots with reduced root herbivory, while square-stemmed willow-herb, Epilobium adnatum, dominated the control and the plots with foliar insecticide. When soil insecticide was applied, cover abundance of monocarpic forbs increased and cover abundance of polycarpic herbs decreased compared to the control. However, this effect was due to a few abundant plant species and is not based on a consistent difference between life history groups. Instead, application of soil insecticide promoted persistence of species that established at the start of succession, and suppressed species that established in the following years. We conclude that below-ground herbivory reduces competitive ability of resident species and, thus, facilitates colonization by late-successional species. Hence, soil insects can exert strong top-down effects on the vegetation of productive sites by affecting dominant plant species and altering competitive balances. PMID:14566558

  13. Inversion and classification studies of live-site production-level MetalMapper data sets

    NASA Astrophysics Data System (ADS)

    Shubitidze, F.; Fernández, J. P.; Miller, J.; Keranen, J.; Barrowes, B. E.; Bijamov, A.

    2012-06-01

    This paper illustrates the discrimination performance of a set of advanced models at an actual UXO live site. The suite of methods, which combines the orthonormalized volume magnetic source (ONVMS) model, a data-preprocessing technique based on joint diagonalization (JD), and differential evolution (DE) minimization, among others, was tested at the former Camp Beale in California. The data for the study were collected independently by two UXO production teams from Parsons and CH2M HILL using the MetalMapper (MM) sensor in cued mode; each set of data was also processed independently. Initially all data were inverted using a multi-target version of the combined ONVMS-DE algorithm, which provided intrinsic parameters (the total ONVMS amplitudes) that were then used to perform classification after having been inspected by an expert. Classification of the Parsons data was conducted by a Sky Research production team using a fingerprinting approach; analysis of the CH2M HILL data was performed by a Sky/Dartmouth R&D team using unsupervised clustering. During the classification stage the analysts requested the ground truth for selected anomalies typical of the different clusters; this was then used to classify them using a probability function. This paper reviews the data inversion, processing, and discrimination schemes involving the advanced EMI methods and presents the classification results obtained for both the CH2M HILL and the Parsons data. Independent scoring by the Institute for Defense Analyses reveals superb all-around classification performance.

  14. Hydrogen production by the naked active site of the di-iron hydrogenases in water.

    PubMed

    Zipoli, Federico; Car, Roberto; Cohen, Morrel H; Selloni, Annabella

    2009-10-01

    We explored the reactivity of the active center of the [FeFe]-hydrogenases detached from the enzyme and immersed in acidified water by first-principles Car-Parrinello molecular-dynamics simulations. We focused on the identification of the structures that are stable and metastable in acidified water and on their activity for hydrogen production. Our calculations revealed that the naked active center could be an efficient catalyst provided that electrons are transferred to the cluster. We found that both bridging and terminal isomers are present at equilibrium and that the bridging configuration is essential for efficient hydrogen production. The formation of the hydrogen molecule occurs via sequential protonations of the distal iron and of the N-atom of the S-CH(2)-NH-CH(2)-S chelating group. H(2) desorption does not involve a significant energy barrier, making the process very efficient at room temperature. We established that the bottleneck in the reaction is the direct proton transfer from water to the vacant site of the distal iron. Moreover, we found that even if the terminal isomer is present at the equilibrium, its strong local hydrophobicity prevents poisoning of the cluster. PMID:19737003

  15. Knowledges and abilities catalog for nuclear power plant operators: Savannah River Site (SRS) production reactors

    SciTech Connect

    Not Available

    1990-06-20

    The Knowledges and Abilities Catalog for Nuclear Power Plant Operations: Savannah River Site (SRS) Production Reactors, provides the basis for the development of content-valid certification examinations for Senior Reactor Operators (SROs) and Central Control Room Supervisors (SUP). The position of Shift Technical Engineer (STE) has been included in the catalog for completeness. This new SRS reactor operating shift crew position is held by an individual holding a CCR Supervisor Certification who has received special engineering and technical training. Also, the STE has a Bachelor of Science degree in engineering or a related technical field. The SRS catalog contains approximately 2500 knowledge and ability (K/A) statements for SROs and SUPs at heavy water moderated production reactors. Each K/A statement has been rated for its importance to the safe operation of the plant in a manner ensuring the health and safety of the public. The SRS K/A catalog is presently organized into five major sections: Plant Systems grouped by Safety Function, Plant Wide Generic K/As, Emergency Plant Evolutions, Theory and Components (to be developed).

  16. STABLE NITROGEN ISOTOPES AS INDICATORS OF ANTHOPOGENIC ACTIVITIES IN SMALL FRESHWATER SYSTEMS

    EPA Science Inventory

    Stable nitrogen isotope ratios ( 15N) were measured in fish, mussel, and sediment samples taken from 17 small freshwater sites to examine food chain length and trophic position across sites affected by differing levels of anthropogenic activity. Both shoreline development and fis...

  17. Chemodiversity in Freshwater and Terrestrial Cyanobacteria – a Source for Drug Discovery

    PubMed Central

    Chlipala, George E.; Mo, Shunyan; Orjala, Jimmy

    2011-01-01

    Cyanobacteria are considered a promising source for new pharmaceutical lead compounds and a large number of chemically diverse and bioactive metabolites have been obtained from cyanobacteria over the last few decades. This review highlights the structural diversity of natural products from freshwater and terrestrial cyanobacteria. The review is divided into three areas: cytotoxic metabolites, protease inhibitors, and antimicrobial metabolites. The first section discusses the potent cytotoxins cryptophycin and tolytoxin. The second section covers protease inhibitors from freshwater and terrestrial cyanobacteria and is divided in five subsections according to structural class: aeruginosins, cyanopeptolins, microviridins, anabaenopeptins, and microginins. Structure activity relationships are discussed within each protease inhibitor class. The third section, antimicrobial metabolites from freshwater and terrestrial cyanobacteria, is divided by chemical class in three subsections: alkaloids, peptides and terpenoids. These examples emphasize the structural diversity and drug development potential of natural products from freshwater and terrestrial cyanobacteria. PMID:21561419

  18. Validation of Land Surface Temperature Products and Site Characterisation with Ground Based Radiometric Measurements

    NASA Astrophysics Data System (ADS)

    Goettsche, Frank; Olesen, Folke; Bork-Unkelbach, Annika

    2013-04-01

    Land Surface Temperature (LST) is an important quantity for the energy and water exchange between the earth's surface and the atmosphere and, therefore, an important parameter of many environmental models. LST is derived operationally from several space-borne sensors, e.g. the Moderate Resolution Imaging Spectroradiometer (MODIS) on EOS-Terra and the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard Meteosat Second Generation (MSG) and AVHRR onboard NOAA and EPS satellites. Ground based validation of LST and Land Surface Emissivity (LSE) is largely complicated by the spatial scale mismatch between satellite sensors and ground based sensors: areas observed by ground radiometers usually cover about 10 m2, whereas satellite measurements in the thermal infra-red typically cover between 1 km2 and 100 km2. Therefore, validation sites have to be carefully selected and need to be characterised on the spatial scale of the ground radiometer as well as on the scale of the satellite pixel. The permanent validation station near Gobabeb, Namibia, is one of KIT's four dedicated LST validation stations. Gobabeb is located on vast and flat gravel plains (several 100 km2), which are mainly covered by coarse gravel, sand, and desiccated grass. The plains are highly homogeneous in space and time, which makes them an ideal site for validating a broad range of satellite-derived products. However, for reliable product validation the effect of the small scale variation of surface materials (e.g. dry grass, rock outcrops) and topography needs to be closely characterised. Using a mobile radiometer system, several field experiments were performed during which the radiometer was driven along tracks of 20 km to 40 km length through the gravel plains. The results show a high level of homogeneity and a stable relationship between station LST and LST determined along the tracks from the mobile measurements with a small bias of about 0.4°C. LSEs of the dominant surface cover types at

  19. Estimated freshwater withdrawals in Texas, 1990

    USGS Publications Warehouse

    Lurry, Dee L.

    1994-01-01

    Freshwater withdrawals in Texas during 1990 were estimated as part of the U.S. Geological Survey's National Water Use Information Program. Estimates of freshwater withdrawals were made for five categories of use: irrigation, thermoelectric- power generation, water supply, industrial and mining, and domestic/commercial/livestock. Total freshwater withdrawals for the State were estimated to be 20,100 Mgal/d (million gallons per day). Ground water was estimated to account for 37 percent (7,390 Mgal/d), and surface water was estimated to account for 63 percent (12,700 Mgal/d) of total withdrawals. The largest withdrawals of freshwater were for irrigation purposes.

  20. Late Pleistocene temperature and productivity variations in the Benguela Current System (ODP Leg 175, Site 1082)

    NASA Astrophysics Data System (ADS)

    Wenzel, C.; Rullkötter, J.

    2003-04-01

    Site 1082 (Walvis Basin) is located close to the major upwelling cells along the Southwest African coast with a year-round upwelling activity. Sediment samples spanning the last 770 kyr were investigated to reconstruct the paleoclimatic and paleoceanographic conditions in the Benguela upwelling system off Namibia. Alkenone-derived paleo-sea surface temperatures (calculated from the Uk'37index) roughly follow the 18O variations of planktonic foraminifera. The core shows warmer SST values (18-20°C) during interglacial stages and colder SST values (14-16°C) during glacial stages. Two long-term trends were observed: a decrease in SST values by 1°C from 770 kyr to 450 kyr and an increase in SST values by 2°C for the last 450 kyr. SST values in the northern Benguela System confirm the onset of the dominant 100 ka cycles associated with Northern Hemisphere glaciation over the past 650 kyr. One important result is the observed warming trend in the Benguela Current region over the last 450 kyr. In this period, the trend to warmer sea surface temperatures is more evident during glacials, suggesting a southward migration of the polar and subpolar frontal systems and an intensification of the influence of the warm Agulhas Current on the Benguela Current System during glacial stages 10, 8, 6 and 4. Another possible mechanism that could be responsible for such a warming trend of the eastern South Atlantic is a weakening of the cross-equatorial heat transport from the South to the North Atlantic as a result of a weakening of the thermohaline circulation. The accumulation profile of the alkenones indicates an elevated marine surface productivity may have fluctuated over time due to the upwelling activity in the southeastern Atlantic Ocean. The fluctuations in marine productivity are not related to the glacial-interglacial cycles which exhibit increased productivity during glacials at other locations. The marine biomarker distributions indicate that periods of higher

  1. Freshwater flow from estuarine creeks into northeastern Florida Bay

    USGS Publications Warehouse

    Hittle, Clinton; Patino, Eduardo; Zucker, Mark A.

    2001-01-01

    Water-level, water-velocity, salinity, and temperature data were collected from selected estuarine creeks to compute freshwater flow into northeastern Florida Bay. Calibrated equations for determining mean velocity from acoustic velocity were obtained by developing velocity relations based on direct acoustic measurements, acoustic line velocity, and water level. Three formulas were necessary to describe flow patterns for all monitoring sites, with R2 (coefficient of determination) values ranging from 0.957 to 0.995. Cross-sectional area calculations were limited to the main channel of the creeks and did not include potential areas of overbank flow. Techniques also were used to estimate discharge at noninstrumented sites by establishing discharge relations to nearby instrumented sites. Results of the relation between flows at instrumented and noninstrumented sites varied with R2 values ranging from 0.865 to 0.99. West Highway Creek was used to estimate noninstrumented sites in Long Sound, and Mud Creek was used to estimate East Creek in Little Madeira Bay. Mean monthly flows were used to describe flow patterns and to calculate net flow along the northeastern coastline. Data used in the study were collected from October 1995 through September 1999, which includes the El Nino event of 1998. During this period, about 80 percent of the freshwater flowing into the bay occurred during the wet season (May-October). The mean freshwater discharge for all five instrumented sites during the wet season from 1996 to 1999 is 106 cubic feet per second. The El Nino event caused a substantial increase (654 percent) in mean flows during the dry season (November-April) at the instrumented sites, ranging from 8.5 cubic feet per second in 1996-97 to 55.6 cubic feet per second in 1997-98. Three main flow signatures were identified when comparing flows at all monitoring stations. The most significant was the magnitude of discharges at Trout Creek, which carries about 50 percent of the

  2. Toxicity testing of freshwater sediment collected near freshwater aquaculture facilities in the Maritimes, Canada.

    PubMed

    Lalonde, B A; Garron, C; Ernst, B; Jackman, P

    2013-01-01

    In the Atlantic region of Canada, there are close to 50 land-based freshwater aquaculture facilities, most of which discharge wastewater to freshwater receiving environments. This study was designed to assess the chemical and toxicological characteristics of sediments in those receiving environments. Thirty sediment samples were collected from 3 locations (upstream, outfall and downstream) at seven freshwater aquaculture facilities. Toxicity tests conducted included amphipod growth, amphipod survival and Microtox™. Sediments were also analysed for ammonia/porewater ammonia, redox and sulphide. Porewater ammonia concentration for the amphipod survival test ranged from 0.01 to 42 mg/L at the conclusion of the 14-day survival test. Ammonia concentration in sediment ranged from 0.3-202 μg/g, sulphide concentration ranged from 0.15 to 17.4 μg/g, yet redox ranged from 32 to 594 mV. Microtox™  IC50 values ranged from 108,00 to >164,000 mg/L, yet amphipod survival ranged from 0 to 100%, depending on sampling locations. Amphipod survival was significantly related (P < 0.05) to porewater ammonia (at time = 0 and 14 days) and Microtox™  IC50 was significantly related (P < 0.05) to ammonia, sulphide and redox levels. These results indicate that discharges from some the land-based aquaculture facilities are impacting sediment dwelling benthic invertebrates at the outfall but that impact largely disappears by 100 m downstream. Furthermore those impacts were rarely detected during the early winter season, when biomass production was at the lowest. PMID:23705607

  3. Ecology of tidal freshwater marshes of the United States east coast: a community profile

    SciTech Connect

    Odum, W.E.; Smith, T.J. III; Hoover, J.K.; McIvor, C.C.

    1984-01-01

    Tidal freshwater marshes are a distinctive type of estuarine ecosystem located upstream from tidal saline marshes and downstream from non-tidal freshwater marshes. They are characterized by freshwater or nearly freshwater conditions most of the time, flora and fauna dominated by freshwater species, and daily lunar tidal flushing. This report examines the ecology of this community as it occurs along the Atlantic seaboard from southern New England to northern Florida. This marsh community is heavily influenced by river flow, which maintains freshwater conditions and deposits sediments high in silt and clay. The plant assemblage in tidal freshwater marshes is diverse both in numbers of species and structural plant types. Plant community structure is markedly diverse spatially and seasonally, and reflects the dynamic processing of energy and biomass in the marsh through high productivity, rapid decomposition and seasonal nutrient cycling. The diverse niches in this heterogeneous environment are exploited by a very diverse animal community of as many as 125 species of fish, 102 species of amphibians and reptiles, 280 species of birds, and 46 species of mammals over the community's broad range. Although fewer species are permanent residents or marsh breeders, use of his community for food and cover is high. This use, coupled with the marshes' capacity to be natural buffers and water filters, argue for their high value as natural resources. 349 references, 31 figures, 24 tables.

  4. L-citrulline immunostaining identifies nitric oxide production sites within neurons

    NASA Technical Reports Server (NTRS)

    Martinelli, G. P. T.; Friedrich, V. L. Jr; Holstein, G. R.

    2002-01-01

    The cellular and subcellular localization of L-citrulline was analyzed in the adult rat brain and compared with that of traditional markers for the presence of nitric oxide synthase. Light, transmission electron, and confocal laser scanning microscopy were used to study tissue sections processed for immunocytochemistry employing a monoclonal antibody against L-citrulline or polyclonal anti-neuronal nitric oxide synthase sera, and double immunofluorescence to detect neuronal nitric oxide synthase and L-citrulline co-localization. The results demonstrate that the same CNS regions and cell types are labeled by neuronal nitric oxide synthase polyclonal antisera and L-citrulline monoclonal antibodies, using both immunocytochemistry and immunofluorescence. Short-term pretreatment with a nitric oxide synthase inhibitor reduces L-citrulline immunostaining, but does not affect neuronal nitric oxide synthase immunoreactivity. In the vestibular brainstem, double immunofluorescence studies show that many, but not all, neuronal nitric oxide synthase-positive cells co-express L-citrulline, and that local intracellular patches of intense L-citrulline accumulation are present in some neurons. Conversely, all L-citrulline-labeled neurons co-express neuronal nitric oxide synthase. Cells expressing neuronal nitric oxide synthase alone are interpreted as neurons with the potential to produce nitric oxide under other stimulus conditions, and the subcellular foci of enhanced L-citrulline staining are viewed as intracellular sites of nitric oxide production. This interpretation is supported by ultrastructural observations of subcellular foci with enhanced L-citrulline and/or neuronal nitric oxide synthase staining that are located primarily at postsynaptic densities and portions of the endoplasmic reticulum. We conclude that nitric oxide is produced and released at focal sites within neurons that are identifiable using L-citrulline as a marker. Copyright 2002 IBRO.

  5. ENVIRONMENTAL ASSESSMENT OF OKLAHOMA ABANDONED DRILLING AND PRODUCTION SITES AND ASSOCIATED PUBLIC EDUCATION/OUTREACH ACTIVITIES

    SciTech Connect

    Mike Terry

    2002-03-01

    The U.S. Department of Energy has participated with the Oklahoma Energy Resource Board (OERB) since 1995 by providing grant funding for on-going work in both environmental assessment of abandoned oilfield exploration and production sites and associated public education/outreach activities. The OERB, a state agency created in 1993 by the Oklahoma legislature, administers programs funded by an assessment of one tenth of one percent on all oil and natural gas produced and sold in the state of Oklahoma. Approximately one half of the funds are used to assess and remediate abandoned oilfield sites and the other half are being used to educate about the importance of the oil and natural gas industry and OERB's environmental efforts. Financial participation through grant funding by the U.S. D.O.E. has been $200,000 annually which represents approximately 3 percent of OERB's private funding. Most of OERB's revenues come from an assessment of 1/10th of 1% on the sale of crude and natural gas in Oklahoma. The assessment is considered voluntary in that any interest owner may ask for a refund annually of their contributions to the fund. On average, 95% of the assessment dollars have remained with OERB, which shows tremendous support by the industry. This Final Report summarizes the progress of the three year grant. The purpose of this three-year project was to continue the progress of the OERB to accomplish its environmental and educational objectives and transfer information learned to other organizations and producing states in the industry.

  6. The Hanford Site New Production Reactor (NPR) economic and demographic baseline forecasts

    SciTech Connect

    Cluett, C.; Clark, D.C. ); Pittenger, D.B. )

    1990-08-01

    The objective of this is to present baseline employment and population forecasts for Benton, Franklin, and Yakima Counties. These forecasts will be used in the socioeconomic analysis portion of the New Production Reactor Environmental Impact Statement. Aggregate population figures for the three counties in the study area were developed for high- and low-growth scenarios for the study period 1990 through 2040. Age-sex distributions for the three counties during the study period are also presented. The high and low scenarios were developed using high and low employment projections for the Hanford site. Hanford site employment figures were used as input for the HARC-REMI Economic and Demographic (HED) model to produced baseline employment forecasts for the three counties. These results, in turn, provided input to an integrated three-county demographic model. This model, a fairly standard cohort-component model, formalizes the relationship between employment and migration by using migration to equilibrate differences in labor supply and demand. In the resulting population estimates, age-sex distributions for 1981 show the relatively large work force age groups in Benton County while Yakima County reflects higher proportions of the population in the retirement ages. The 2040 forecasts for all three counties reflect the age effects of relatively constant and low fertility increased longevity, as well as the cumulative effects of the migration assumptions in the model. By 2040 the baby boom population will be 75 years and older, contributing to the higher proportion of population in the upper end age group. The low scenario age composition effects are similar. 13 refs., 5 figs., 9 tabs.

  7. Site Specific Nematode Management—Development and Success in Cotton Production in the United States

    PubMed Central

    Overstreet, C.; McGawley, E. C.; Khalilian, A.; Kirkpatrick, T. L.; Monfort, W. S.; Henderson, W.; Mueller, J. D.

    2014-01-01

    Variability in edaphic factors such as clay content, organic matter, and nutrient availability within individual fields is a major obstacle confronting cotton producers. Adaptation of geospatial technologies such global positioning systems (GPS), yield monitors, autosteering, and the automated on-and-off technology required for site-specific nematicide application has provided growers with additional tools for managing nematodes. Multiple trials in several states were conducted to evaluate this technology in cotton. In a field infested with Meloidogyne spp., both shallow (0 to 0.3 m) and deep (0 to 0.91 m) apparent electrical conductivity (ECa) readings were highly correlated with sand content. Populations of Meloidogyne spp. were present when shallow and deep EC values were less than 30 and 90 mS/m, respectively. Across three years of trials in production fields in which verification strips (adjacent nematicide treated and untreated rows across all soil zones) were established to evaluate crop response to nematicide application, deep EC values from 27.4-m wide transects of verification strips were more predictive of yield response to application of 1,3-dichloropropene than were shallow EC values in one location and both ECa values equally effective at predicting responses at the second location. In 2006, yields from entire verification strips across three soil zones in four production fields showed that nematicide response was greatest in areas with the lowest EC values indicating highest content of sand. In 2008 in Ashley and Mississippi Counties, AR, nematicide treatment by soil zone resulted in 36% and 42% reductions in the amount of nematicide applied relative to whole-field application. In 2007 in Bamberg County, SC, there was a strong positive correlation between increasing population densities of Meloidogyne incognita and increasing sand content. Trials conducted during 2007 and 2009 in South Carolina against Hoplolaimus columbus showed a stepwise response

  8. Draft environmental impact statement siting, construction, and operation of New Production Reactor capacity. Volume 4, Appendices D-R

    SciTech Connect

    1991-04-01

    This Environmental Impact Statement (EIS) assesses the potential environmental impacts, both on a broad programmatic level and on a project-specific level, concerning a proposed action to provide new tritium production capacity to meet the nation`s nuclear defense requirements well into the 21st century. A capacity equivalent to that of about a 3,000-megawatt (thermal) heavy-water reactor was assumed as a reference basis for analysis in this EIS; this is the approximate capacity of the existing production reactors at DOE`s Savannah River Site near Aiken, South Carolina. The EIS programmatic alternatives address Departmental decisions to be made on whether to build new production facilities, whether to build one or more complexes, what size production capacity to provide, and when to provide this capacity. Project-specific impacts for siting, constructing, and operating new production reactor capacity are assessed for three alternative sites: the Hanford Site near Richland, Washington; the Idaho National Engineering Laboratory near Idaho Falls, Idaho; and the Savannah River Site. For each site, the impacts of three reactor technologies (and supporting facilities) are assessed: a heavy-water reactor, a light-water reactor, and a modular high-temperature gas-cooled reactor. Impacts of the no-action alternative also are assessed. The EIS evaluates impacts related to air quality; noise levels; surface water, groundwater, and wetlands; land use; recreation; visual environment; biotic resources; historical, archaeological, and cultural resources; socioeconomics; transportation; waste management; and human health and safety. The EIS describes in detail the potential radioactive releases from new production reactors and support facilities and assesses the potential doses to workers and the general public. This volume contains 15 appendices.

  9. Draft environmental impact statement for the siting, construction, and operation of New Production Reactor capacity. Volume 1, Summary

    SciTech Connect

    Not Available

    1991-04-01

    This Environmental Impact Statement (EIS) assesses the potential environmental impacts, both on a broad programmatic level and on a project-specific level, concerning a proposed action to provide new tritium production capacity to meet the nation`s nuclear defense requirements well into the 21st century. A capacity equivalent to that of about a 3,000-megawatt (thermal) heavy-water reactor was assumed as a reference basis for analysis in this EIS; this is the approximate capacity of the existing production reactors at DOE`s Savannah River Site near Aiken, South Carolina. The EIS programmatic alternatives address Departmental decisions to be made on whether to build new production facilities, whether to build one or more complexes, what size production capacity to provide, and when to provide this capacity. Project-specific impacts for siting, constructing, and operating new production reactor capacity are assessed for three alternative sites: the Hanford Site near Richland, Washington; the Idaho National Engineering Laboratory near Idaho Falls, Idaho; and the Savannah River Site. For each site, the impacts of three reactor technologies (and supporting facilities) are assessed: a heavy-water reactor, a light-water reactor, and a modular high-temperature gas-cooled reactor. Impacts of the no-action alternative also are assessed. The EIS evaluates impacts related to air quality; noise levels; surface water, groundwater, and wetlands; land use; recreation; visual environment; biotic resources; historical, archaeological, and cultural resources; socioeconomics; transportation; waste management; and human health and safety. The EIS describes in detail the potential radioactive releases from new production reactors and support facilities and assesses the potential doses to workers and the general public.

  10. Paradoxical High Productivity in the Eastern Equatorial Pacific Ocean During the Miocene "El Padre", ODP Site 849, and IODP Sites U1337 and U1338

    NASA Astrophysics Data System (ADS)

    Lyle, M. W.; Moore, T. C., Jr.; Ravelo, A. C.; Baldauf, J.; Ford, H. L.; Stepanova, A.; Hertzberg, J. E.

    2015-12-01

    Prior to 4.6 Ma, SST proxy data has identified a 2° SST gradient from east to west across the equatorial Pacific, much smaller than the Holocene E-W gradient near 6°. The reduced Miocene gradient should have significantly reduced atmospheric Walker circulation and reduced the forcing for eastern Pacific upwelling. However, abundant data on biogenic deposition has found that, if anything, eastern equatorial Pacific productivity was higher in the Miocene and was still centered at the equator. The eastern equatorial Pacific is also marked by abrupt order-of-magnitude changes in production that last for 50-200 kyr throughout the middle and late Miocene. The latest (but not largest) of these productivity intervals began abruptly (<5 kyr onset) at 4745 ka at ODP Site 849, then at 0.6°S, and ended more gradually around 4555 ka. The high production interval can be traced as far north as Site U1337 at a paleolatitude of 2.5°N. Much higher relative diatom production occurs near the equator than at sites further north; instead they have high carbonate production, presumably by coccolithophorids. The opal and carbonate distributions will ultimately provide information on plankton response to changes in nutrient delivery. We explore why the equatorial Pacific was more productive in the Miocene than in the late Pliocene and Pleistocene. Since the thermocline was warmer and the SST gradient with depth was more gradual in the Miocene, less wind stress is needed to lift the same nutrient load. Also, under warmer climates the ocean was probably more heterotrophic. Changes in organic carbon burial suggest that plankton decomposed higher in the water column in the Miocene than in the Pleistocene, and there was less cycling of particulate organic matter deep into the ocean interior. Nevertheless, abrupt but long lasting changes in production are a challenge to understand without abrupt dynamic changes in linkages between nutrient reservoirs. In the eastern Pacific the longer term

  11. Forests fuel fish growth in freshwater deltas

    PubMed Central

    Tanentzap, Andrew J.; Szkokan-Emilson, Erik J.; Kielstra, Brian W.; Arts, Michael T.; Yan, Norman D.; Gunn, John M.

    2014-01-01

    Aquatic ecosystems are fuelled by biogeochemical inputs from surrounding lands and within-lake primary production. Disturbances that change these inputs may affect how aquatic ecosystems function and deliver services vital to humans. Here we test, using a forest cover gradient across eight separate catchments, whether disturbances that remove terrestrial biomass lower organic matter inputs into freshwater lakes, thereby reducing food web productivity. We focus on deltas formed at the stream-lake interface where terrestrial-derived particulate material is deposited. We find that organic matter export increases from more forested catchments, enhancing bacterial biomass. This transfers energy upwards through communities of heavier zooplankton, leading to a fourfold increase in weights of planktivorous young-of-the-year fish. At least 34% of fish biomass is supported by terrestrial primary production, increasing to 66% with greater forest cover. Habitat tracers confirm fish were closely associated with individual catchments, demonstrating that watershed protection and restoration increase biomass in critical life-stages of fish. PMID:24915965

  12. Forests fuel fish growth in freshwater deltas.

    PubMed

    Tanentzap, Andrew J; Szkokan-Emilson, Erik J; Kielstra, Brian W; Arts, Michael T; Yan, Norman D; Gunn, John M

    2014-01-01

    Aquatic ecosystems are fuelled by biogeochemical inputs from surrounding lands and within-lake primary production. Disturbances that change these inputs may affect how aquatic ecosystems function and deliver services vital to humans. Here we test, using a forest cover gradient across eight separate catchments, whether disturbances that remove terrestrial biomass lower organic matter inputs into freshwater lakes, thereby reducing food web productivity. We focus on deltas formed at the stream-lake interface where terrestrial-derived particulate material is deposited. We find that organic matter export increases from more forested catchments, enhancing bacterial biomass. This transfers energy upwards through communities of heavier zooplankton, leading to a fourfold increase in weights of planktivorous young-of-the-year fish. At least 34% of fish biomass is supported by terrestrial primary production, increasing to 66% with greater forest cover. Habitat tracers confirm fish were closely associated with individual catchments, demonstrating that watershed protection and restoration increase biomass in critical life-stages of fish. PMID:24915965

  13. Evidence for cold water circulation at DSDP site 395: Isotopes and chemistry of alteration products

    SciTech Connect

    Lawrence, J.R.; Drever, J.I.

    1981-06-10

    A variety of low temperature alteration products occurs in the 573-m-thick section of basaltic rock from Site 395. Carbonate veins, smectities (predominantly saponite), zeolites, goethite, opal, and gypsum, listed in order of decreasing abundance, are present. Values of delta/sup 18/O (SMOW) of calcite veins range from +31.8 to +34.8/sup 0//00, and delta/sup 13/C (PDB) ranges from +2.3 to +4.4/sup 0//00. Apparently the calcite veins were formed at 0--15 /sup 0/C in equilibrium with deep ocean water. Some veins may have formed during glacial periods, when delta/sup 18/O of the deep water was higher than it is presently. The deepest calcite veins were formed in the temperature range 8--15 /sup 0/C. Saponite veins associated with an intrusive dolerite sill (delta/sup 18/O = +9.8 to +24.3%/sub 0/, SMOW) are estimated to have formed in the temperature range 30--160 /sup 0/C. Very extensive circulation (i.e., large water/rock ratios) predominated during alteration of the basalts as evidenced by seawater carbon and sulfur istope ratios in calcite and gypsum and carbon, sulfur and magnesium mass balance considerations.

  14. NATIVE FRESHWATER FISH AND MUSSEL SPECIES RICHNESS

    EPA Science Inventory

    These data represent predicted current distributions of all native freshwater fish and freshwater mussels in the Middle-Atlantic region. The data are available for both 8-digit HUCs and EMAP hexagons and represent total species counts for each spatial unit.

  15. Effects of Pollution on Freshwater Fish.

    ERIC Educational Resources Information Center

    Brungs, W. A.; And Others

    1978-01-01

    Presents a literature review of the effects of pollution on freshwater fish, covering publications of 1976-77. This review includes: (1) water quality; (2) pesticide pollutants; (3) chemical pollutants; (4) miscellaneous pollutants; and (5) physical factors of pollution on freshwater fish. A list of 338 references is also presented. (HM)

  16. Freshwater Ecology. LC Science Tracer Bullet.

    ERIC Educational Resources Information Center

    Niskern, Diana, Comp.

    Freshwater ecosystems include lakes, ponds, streams, rivers, and certain types of wetlands. This literature and resources guide is not intended to be a comprehensive bibliography on freshwater ecology; the guide is designed--as the name of the series implies--to put the reader or student "on target." Other literature guides related to freshwater…

  17. Why are freshwater fish so threatened?

    USGS Publications Warehouse

    Closs, Gerard P.; Angermeier, Paul; Darwall, William R.T.; Balcombe, Stephen R.

    2015-01-01

    Understanding why so many freshwater fish species are threatened requires some understanding of their biology, diversity, distribution, biogeography and ecology, but also some appreciation of the social, economic and political forces that are causing humans to destroy the natural ecosystems upon which we all ultimately depend. To begin to understand the diversity of freshwater fishes, we first need to consider the processes that generated and continue to sustain the diversity of species we see today. Based on an understanding of how freshwater fish diversity is generated and sustained, we consider how vulnerable or resilient various freshwater fishes are to the range of anthropogenic impacts that impinge on freshwater ecosystems. Finally, we discuss how social, political and economic drivers influence human impacts on natural systems, and the changes needed to current models of development that can lead to a sustainable future for humans and the diverse range of freshwater fish species with which we share our planet. The aim of this chapter is to provide an overview of the key issues and threats driving the declines in freshwater fish diversity identified in Chapter 1; subsequent chapters provide more detail on the key issues and address our options for developing a sustainable future for freshwater fishes.

  18. Occurrence of microcystin-producing cyanobacteria in Ugandan freshwater habitats

    PubMed Central

    Okello, William; Portmann, Cyril; Erhard, Marcel; Gademann, Karl; Kurmayer, Rainer

    2011-01-01

    Microcystins (MCs) are cyclic heptapeptides that are the most abundant toxins produced by cyanobacteria in freshwater. The phytoplankton of many freshwater lakes in Eastern Africa is dominated by cyanobacteria. Less is known, however, on the occurrence of MC producers and the production of MCs. Twelve Ugandan freshwater habitats ranging from mesotrophic to hypertrophic conditions were sampled in May and June of 2004 and April of 2008 and were analyzed for their physico-chemical parameters, phytoplankton composition, and MC concentrations. Among the group of the potential MC-producing cyanobacteria, Anabaena (0 - 107 cells ml−1) and Microcystis (103 - 107 cells ml−1) occurred most frequently and dominated in eutrophic systems. A significant linear relationship (n = 31, r2 = 0.38, p < 0.001) between the Microcystis cell numbers and MC concentration (1.3-93 fg of MC cell−1) was observed. Beside [MeAsp3, Mdha7]-MC-RR two new microcystins, [Asp3]-MC-RY and [MeAsp3]-MC-RY were isolated and their constitution assigned by LC-MS2. In order to identify the MC-producing organism in the water samples (i), the conserved aminotransferase domain part of the mcyE gene that is indicative of MC production was amplified by general primers and cloned and sequenced, and (ii), genus-specific primers were used to amplify the mcyE gene of the genera Microcystis, Anabaena, and Planktothrix. Only mcyE genotypes that are indicative of Microcystis sp. were obtained via the environmental cloning approach (337 bp, 96.1%-96.7% similarity to the Microcystis aeruginosa strain PCC7806). Accordingly, only the mcyE primers, which are specific for Microcystis, revealed PCR products. We concluded that Microcystis is the major MC-producer in Ugandan freshwater. PMID:19609871

  19. Impact of freshwater diversion projects on diversity and activity of methanotrophic communities in freshwater wetlands

    NASA Astrophysics Data System (ADS)

    Isaac, J.; Schulz, C. J.; Childers, G. W.

    2009-12-01

    Methanotrophic bacteria are key players in the carbon cycle capable of using methane as a sole carbon and energy source. Methanotrophs are ubiquitous in soil environments and play a key role in decreasing methane flux from anaerobic environments to the atmosphere, reducing the concentration of this greenhouse gas. Wetlands are a particularly important source of methane to the atmosphere, even though methanotrophs can consume the majority of the methane produced. Decreases in methanotrophic activity in wetland environments due to disturbance can have negative impacts with regard to greenhouse gas emissions, especially if the impact is widespread. Currently, several freshwater diversion projects are active and/or scheduled to come online in south Louisiana, delivering freshwater, sediments, and nutrients to coastal wetlands en masse to help combat subsidence and coastal erosion. Along with freshwater, these diversions also deliver other components of the Mississippi River including substantial bicarbonate alkalinity, reactive nitrogen, and sulfate. Analogous to the large scale diversion projects are smaller restoration projects that deliver treated wastewater effluent to wetlands. In particular, the Joyce Wildlife Management Area (JWMA) in southeast Louisiana has been the recipient of ~5 million gallons of treated domestic effluent per day since 2006. Both the composition of the marsh receiving the effluent and the effluent itself have similarities to Mississippi River diversions. We collected pre and post JWMA sediment microbial community DNA and created cloned libraries of genes encoding particulate methane monooxygenase (pmoA) as a proxy for methanotrophic community composition. Water chemistry data was also collected. Shifts in methanotrophic community composition were apparent as well as shifts in water chemistry. The most notable shift in water chemistry was pH, which changed from mildly acidic to slightly alkaline conditions, due to the increased alkalinity of

  20. Freshwater for resilience: a shift in thinking.

    PubMed Central

    Folke, Carl

    2003-01-01

    Humanity shapes freshwater flows and biosphere dynamics from a local to a global scale. Successful management of target resources in the short term tends to alienate the social and economic development process from its ultimate dependence on the life-supporting environment. Freshwater becomes transformed into a resource for optimal management in development, neglecting the multiple functions of freshwater in dynamic landscapes and its fundamental role as the bloodstream of the biosphere. The current tension of these differences in worldview is exemplified through the recent development of modern aquaculture contrasted with examples of catchment-based stewardship of freshwater flows in dynamic landscapes. In particular, the social and institutional dimension of catchment management is highlighted and features of social-ecological systems for resilience building are presented. It is concluded that this broader view of freshwater provides the foundation for hydrosolidarity. PMID:14728796

  1. Paleo-Productivity across the Paleocene-Eocene Thermal Maximum, Walvis Ridge Transect (ODP Sites 1262, 1263, and 1266)

    NASA Astrophysics Data System (ADS)

    Chun, C. O.; Delaney, M. L.; Zachos, J. C.

    2005-12-01

    Walvis Ridge transect (Ocean Drilling Program (ODP) Leg 208) provides the first high-resolution depth-transect of deep-sea sediments recovered from the south Atlantic across the P/E boundary. A geographically restricted depth transect (~ 2.2 km, water depths between 2500 and 4770 m) allows us to constrain the surface waters by assuming marine productivity conditions in the overlying water column are similar across all sites. The sediment record will reveal variations for processes that are water-depth dependent. We use the geochemical tracers; biogenic barium, phosphorus, calcium carbonate, and the redox sensitive trace elements manganese and uranium, to reconstruct nutrient burial, paleoproductivity, and bottom water redox chemistry across the Paleocene-Eocene Thermal Maximum (PETM). We calculate our concentrations on a calcium carbonate-free basis to account for dilution by non-carbonate sediments. Trace metal enrichment factors (EFs) are calculated relative to bulk crustal averages. We chose three sites from the depth transect: the shallowest (Site 1263, 2717 m water depth), an intermediate site (Site 1266, 3798 m water depth), and the deepest site (Site 1262, 4755 m water depth). We sampled each site at a sample resolution of ~ 1-2 kyr for 5 m.y. centered at 55 Ma. Uranium EFs at the shallow site exhibits values ~ 5 pre-event and drop to values near crustal averages during and after the carbon isotope excursion (CIE). No dramatic changes in U EFs across the P/E boundary are recorded at the deep and intermediate sites. Mn EFs range between 2.9 -8.6 prior to the event across all three sites, suggesting an oxygenated depositional environment. At the boundary, Mn EFs drop to crustal averages at all sites, then gradually return to pre-event values, indicating more reducing environments during the CIE, a possible explanation for the benthic extinction event (BEE) observed across this transect. Ba excess and reactive phosphorus exhibit decreased concentrations during

  2. Fine root dynamics in lodgepole pine and white spruce stands along productivity gradients in reclaimed oil sands sites.

    PubMed

    Jamro, Ghulam Murtaza; Chang, Scott X; Naeth, M Anne; Duan, Min; House, Jason

    2015-10-01

    Open-pit mining activities in the oil sands region of Alberta, Canada, create disturbed lands that, by law, must be reclaimed to a land capability equivalent to that existed before the disturbance. Re-establishment of forest cover will be affected by the production and turnover rate of fine roots. However, the relationship between fine root dynamics and tree growth has not been studied in reclaimed oil sands sites. Fine root properties (root length density, mean surface area, total root biomass, and rates of root production, turnover, and decomposition) were assessed from May to October 2011 and 2012 using sequential coring and ingrowth core methods in lodgepole pine (Pinus contorta Dougl.) and white spruce (Picea glauca (Moench.) Voss) stands. The pine and spruce stands were planted on peat mineral soil mix placed over tailings sand and overburden substrates, respectively, in reclaimed oil sands sites in Alberta. We selected stands that form a productivity gradient (low, medium, and high productivities) of each tree species based on differences in tree height and diameter at breast height (DBH) increments. In lodgepole pine stands, fine root length density and fine root production, and turnover rates were in the order of high > medium > low productivity sites and were positively correlated with tree height and DBH and negatively correlated with soil salinity (P < 0.05). In white spruce stands, fine root surface area was the only parameter that increased along the productivity gradient and was negatively correlated with soil compaction. In conclusion, fine root dynamics along the stand productivity gradients were closely linked to stand productivity and were affected by limiting soil properties related to the specific substrate used for reconstructing the reclaimed soil. Understanding the impact of soil properties on fine root dynamics and overall stand productivity will help improve land reclamation outcomes. PMID:26668730

  3. Predator-induced reduction of freshwater carbon dioxide emissions

    NASA Astrophysics Data System (ADS)

    Atwood, Trisha B.; Hammill, Edd; Greig, Hamish S.; Kratina, Pavel; Shurin, Jonathan B.; Srivastava, Diane S.; Richardson, John S.

    2013-03-01

    Predators can influence the exchange of carbon dioxide between ecosystems and the atmosphere by altering ecosystem processes such as decomposition and primary production, according to food web theory. Empirical knowledge of such an effect in freshwater systems is limited, but it has been suggested that predators in odd-numbered food chains suppress freshwater carbon dioxide emissions, and predators in even-numbered food chains enhance emissions. Here, we report experiments in three-tier food chains in experimental ponds, streams and bromeliads in Canada and Costa Rica in the presence or absence of fish (Gasterosteus aculeatus) and invertebrate (Hesperoperla pacifica and Mecistogaster modesta) predators. We monitored carbon dioxide fluxes along with prey and primary producer biomass. We found substantially reduced carbon dioxide emissions in the presence of predators in all systems, despite differences in predator type, hydrology, climatic region, ecological zone and level of in situ primary production. We also observed lower amounts of prey biomass and higher amounts of algal and detrital biomass in the presence of predators. We conclude that predators have the potential to markedly influence carbon dioxide dynamics in freshwater systems.

  4. Genotoxicity monitoring of freshwater environments using caged carp (Cyprinus carpio).

    PubMed

    Klobucar, Göran I V; Stambuk, Anamaria; Pavlica, Mirjana; Sertić Perić, Mirela; Kutuzović Hackenberger, Branimir; Hylland, Ketil

    2010-01-01

    The present study deals with genotoxicity assessment of freshwaters using caged carp (Cyprinus carpio). Carps were transplanted from a fish-farm to three differently polluted sites in eastern Croatia. Two polluted sites were situated in the river Drava, downstream from the cities of Belisće and Osijek, while the reference site was in the Nature Park Kopacki rit, a preserved wetland area with limited anthropogenic influence. Exposure lasted for 3 weeks and was repeated for 3 years (2002-2004). DNA damage was assessed in erythrocytes of the exposed animals by the Comet assay and micronucleus test (MNT). In order to evaluate possible differences in stress responses to polluted water in situ and in aquaria a laboratory exposure was performed with water from the studied location in the second year of the study. Carp from the sites with high anthropogenic influence (Belisće and Osijek) had higher average DNA damage as expressed in both the MNT and Comet assay. Of the two, the Comet assay appeared to be more sensitive following both caging and aquaria exposures. The results from this study suggest that 3 weeks caging exposure of C. carpio may be a useful strategy to monitor for genotoxic agents in freshwater ecosystems. PMID:19626438

  5. A new source of freshwater for Antarctica's coastal waters

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2011-06-01

    Research into submarine groundwater discharge (SGD), predominantly regarding its prevalence as a source of freshwater and nutrients to coastal ecosystems, has recently grown in prominence. Using a new groundwater discharge sensor specifically designed for use in the cold polar ocean, Uemura et al. measured the flows of freshwater streaming through the Antarctic subsurface and into the surrounding coastal waters. The researchers found that SGD rates measured in Lützow-Holm Bay in eastern Antarctica showed important differences from SGD rates measured elsewhere on Earth. At midlatitudes, discharge rates drop with increasing ocean depth, while the Antarctic flows were relatively consistent despite differences in depth among the seven survey sites scattered throughout the bay. In addition, the measured average flow rates, ranging from 0.85 × 10-7 to 9.5 × 10-7 meters per second, were 10-100 times higher than flow rates at similar depths made at midlatitudes. The authors also found that SDG rates oscillated with a period of 12.8 hours, peaking at low tide. Further, the discharge rates roughly tracked the size of the tide, having higher peaks in spring, when tides were strongest. The researchers propose that the most likely source of the freshwater flow is meltwater formed beneath the massive glaciers surrounding the bay. (Geophysical Research Letters, doi:10.1029/2010GL046394, 2011)

  6. 75 FR 41531 - Hewlett Packard (HP) Global Product Development, Working On-Site at General Motors Corporation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-16

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Employment and Training Administration Hewlett Packard (HP) Global Product Development, Working On-Site at General Motors Corporation, Milford, MI; Notice of Revised Termination of Investigation Pursuant to Section 223 of the Trade Act of 1974, as...

  7. Frequent short rest breaks from computer work: effects on productivity and well-being at two field sites.

    PubMed

    Henning, R A; Jacques, P; Kissel, G V; Sullivan, A B; Alteras-Webb, S M

    1997-01-01

    Computer operators at two work sites (n = 73, n = 19) were prompted to take three 30-s and one 3-min break from computer work each hour in addition to conventional rest breaks. Some operators were asked to perform stretching exercises during the short breaks. Mood state and musculoskeletal discomfort were assessed at each work site over a 2- or 3-week baseline period and a 4- or 6-week treatment period, respectively. Operator productivity measures were obtained from company records. Operators complied with about half of the added breaks but favoured 3-min breaks over 30-s breaks. No improvement in productivity or well-being was found at the larger work site. At the smaller work site, productivity, eye, leg and foot comfort all improved when the short breaks included stretching exercises. These results provide evidence that frequent short breaks from continuous computer-mediated work can benefit worker productivity and well-being when the breaks integrate with task demands. PMID:8995049

  8. Online Measurement of Exhaled NO Concentration and Its Production Sites by Fast Non-equilibrium Dilution Ion Mobility Spectrometry

    PubMed Central

    Peng, Liying; Jiang, Dandan; Wang, Zhenxin; Liu, Jiwei; Li, Haiyang

    2016-01-01

    Exhaled nitric oxide (NO) is one of the most promising breath markers for respiratory diseases. Its profile for exhalation and the respiratory NO production sites can provide useful information for medical disease diagnosis and therapeutic procedures. However, the high-level moisture in exhaled gas always leads to the poor selectivity and sensitivity for ion spectrometric techniques. Herein, a method based on fast non-equilibrium dilution ion mobility spectrometry (NED-IMS) was firstly proposed to directly monitor the exhaled NO profile on line. The moisture interference was eliminated by turbulently diluting the original moisture to 21% of the original with the drift gas and dilution gas. Weak enhancement was observed for humid NO response and its limit of detection at 100% relative humidity was down to 0.58 ppb. The NO concentrations at multiple exhalation flow rates were measured, while its respiratory production sites were determined by using two-compartment model (2CM) and Högman and Meriläinen algorithm (HMA). Last but not the least, the NO production sites were analyzed hourly to tentatively investigate the daily physiological process of NO. The results demonstrated the capacity of NED-IMS in the real-time analysis of exhaled NO and its production sites for clinical diagnosis and assessment. PMID:26975333

  9. 78 FR 1252 - CalAmp Wireless Networks Corporation (CWNC), Satellite Products Division, Including On-Site...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-08

    ... December 13, 2011 (76 FR 77556). At the request of the State of Minnesota, the Department reviewed the... Division, Including On-Site Leased Workers From Select Staffing, Oxnard, CA; CalAmp Wireless Networks... Select Staffing, Oxnard, California (TA-W-80,399). The workers are engaged in the production of...

  10. Monitoring Production of Methane and Carbon Dioxide and Consumption of Oxygen at Spills of Gasoline at UST Release Sites

    EPA Science Inventory

    Methane is rarely measured at fuel spill sites, and most commonly the measurements are made on samples of ground water. Many ground water monitoring wells are intentionally screened across the water table. This was done to allow them to sample free product. However, if there is s...

  11. Online Measurement of Exhaled NO Concentration and Its Production Sites by Fast Non-equilibrium Dilution Ion Mobility Spectrometry.

    PubMed

    Peng, Liying; Jiang, Dandan; Wang, Zhenxin; Liu, Jiwei; Li, Haiyang

    2016-01-01

    Exhaled nitric oxide (NO) is one of the most promising breath markers for respiratory diseases. Its profile for exhalation and the respiratory NO production sites can provide useful information for medical disease diagnosis and therapeutic procedures. However, the high-level moisture in exhaled gas always leads to the poor selectivity and sensitivity for ion spectrometric techniques. Herein, a method based on fast non-equilibrium dilution ion mobility spectrometry (NED-IMS) was firstly proposed to directly monitor the exhaled NO profile on line. The moisture interference was eliminated by turbulently diluting the original moisture to 21% of the original with the drift gas and dilution gas. Weak enhancement was observed for humid NO response and its limit of detection at 100% relative humidity was down to 0.58 ppb. The NO concentrations at multiple exhalation flow rates were measured, while its respiratory production sites were determined by using two-compartment model (2CM) and Högman and Meriläinen algorithm (HMA). Last but not the least, the NO production sites were analyzed hourly to tentatively investigate the daily physiological process of NO. The results demonstrated the capacity of NED-IMS in the real-time analysis of exhaled NO and its production sites for clinical diagnosis and assessment. PMID:26975333

  12. 75 FR 57505 - Dell Products LP, Winston-Salem (WS-1) Division, Including On-Site Leased Workers From Adecco...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Employment and Training Administration Dell Products LP, Winston-Salem (WS-1) Division, Including On- Site Leased Workers From Adecco, Spherion, Patriot Staffing, Manpower, Teksystems, APN, ICONMA, Staffing Solutions, South East and OMNI Resources...

  13. Biomass of freshwater turtles: a geographic comparison

    SciTech Connect

    Congdon, J.D.; Greene, J.L.; Gibbons, J.W.

    1986-01-01

    Standing crop biomass of freshwater turtles and minimum annual biomass of egg production were calculated for marsh and farm pond habitats in South Caroling and in Michigan. The species in South Carolina included Chelydra serpentina, Deirochelys reticularia, Kinosternon subrubrum, Pseudemys floridana, P. scripta and Sternotherus odoratus. The species in Michigan were Chelydra serpentina, Chrysemys picta and Emydoidea blandingi. Biomass was also determined for a single species population of P. scripta on a barrier island near Charleston, South Carolina. Population density and biomass of Pseudemys scripta in Green Pond on Capers Island were higher than densities and biomass of the entire six-species community studied on the mainland. In both the farm pond and marsh habitat in South Carolina P. scripta was the numerically dominant species and had the highest biomass. In Michigan, Chrysemys picta was the numerically dominant species; however, the biomass of Chelydra serpentina was higher. The three-species community in Michigan in two marshes (58 kg ha/sup -1/ and 46 kg ha/sup -1/) and farm ponds (23 kg ha/sup -1/) had lower biomasses than did the six-species community in a South Carolina marsh (73 kg/sup -1/). Minimum annual egg production by all species in South Carolina averaged 1.93 kg ha/sup -1/ and in Michigan averaged 2.89 kg ha/sup -1/ of marsh.

  14. Climate-driven uncertainties in modeling terrestrial gross primary production: a site level to global-scale analysis.

    PubMed

    Barman, Rahul; Jain, Atul K; Liang, Miaoling

    2014-05-01

    We used a land surface model to quantify the causes and extents of biases in terrestrial gross primary production (GPP) due to the use of meteorological reanalysis datasets. We first calibrated the model using meteorology and eddy covariance data from 25 flux tower sites ranging from the tropics to the northern high latitudes and subsequently repeated the site simulations using two reanalysis datasets: NCEP/NCAR and CRUNCEP. The results show that at most sites, the reanalysis-driven GPP bias was significantly positive with respect to the observed meteorology-driven simulations. Notably, the absolute GPP bias was highest at the tropical evergreen tree sites, averaging up to ca. 0.45 kg C m(-2)  yr(-1) across sites (ca. 15% of site level GPP). At the northern mid-/high-latitude broadleaf deciduous and the needleleaf evergreen tree sites, the corresponding annual GPP biases were up to 20%. For the nontree sites, average annual biases of up to ca. 20-30% were simulated within savanna, grassland, and shrubland vegetation types. At the tree sites, the biases in short-wave radiation and humidity strongly influenced the GPP biases, while the nontree sites were more affected by biases in factors controlling water stress (precipitation, humidity, and air temperature). In this study, we also discuss the influence of seasonal patterns of meteorological biases on GPP. Finally, using model simulations for the global land surface, we discuss the potential impacts of site-level reanalysis-driven biases on the global estimates of GPP. In a broader context, our results can have important consequences on other terrestrial ecosystem fluxes (e.g., net primary production, net ecosystem production, energy/water fluxes) and reservoirs (e.g., soil carbon stocks). In a complementary study (Barman et al., ), we extend the present analysis for latent and sensible heat fluxes, thus consistently integrating the analysis of climate-driven uncertainties in carbon, energy, and water fluxes

  15. 2007 NWFSC Tidal Freshwater Genetics Results

    SciTech Connect

    David Teel

    2008-03-18

    Genetic Analysis of Juvenile Chinook Salmon for inclusion in 'Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, lower Columbia River, 2007. Final report submitted to the Bonneville Power Administration, Contract DE-AC05-76RLO1830.' Genotypic data were collected for 108 Chinook salmon and used in the genetic stock identification analysis. Results of the mixture analysis are presented in Table 1. Percentage estimates for four genetic stock groups (West Cascade Tributary Fall, Willamette River Spring, Deschutes River Fall, and Upper Columbia River Summer/Fall) ranged from 11% to 43%, all with non-zero lower 95% confidence intervals. Small contributions were also estimated for the West Cascade Tributary Spring (3%) and Snake River Fall (6%) stock groups. Results of individual fish probability assignments were summed by collection date (Figure 1) and site (Figure 2). Assignment probabilities for the most likely stock group for each individual ranged from 0.51 to 1.00 with approximately 60% of the assignments greater than 0.90 (data not shown). Nearly all of the low probability assignments were fish with assignments split between the Deschutes River Fall and Upper Columbia River Summer/Fall groups.

  16. Pathogenic agents in freshwater resources

    NASA Astrophysics Data System (ADS)

    Geldreich, Edwin E.

    1996-02-01

    Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and should not be ignored. The range of infected individuals within a given warm-blooded animal group (humans included) may range from 1 to 25%. Survival times for pathogens in the water environment may range from a few days to as much as a year (Ascaris, Taenia eggs), with infective dose levels varying from one viable cell for several primary pathogenic agents to many thousands of cells for a given opportunistic pathogen.As pathogen detection in water is complex and not readily incorporated into routine monitoring, a surrogate is necessary. In general, indicators of faecal contamination provide a positive correlation with intestinal pathogen occurrences only when appropriate sample volumes are examined by sensitive methodology.Pathways by which pathogens reach susceptible water users include ingestion of contaminated water, body contact with polluted recreational waters and consumption of salad crops irrigated by polluted freshwaters. Major contributors to the spread of various water-borne pathogens are sewage, polluted surface waters and stormwater runoff. All of these contributions are intensified during periods of major floods. Several water-borne case histories are cited as examples of breakdowns in public health protection related to water supply, recreational waters and the consumption of contaminated salad crops. In the long term, water resource management must focus on pollution prevention from point sources of waste discharges and the spread of pathogens in watershed stormwater runoff.

  17. The mesoscale and regional freshwater flux

    NASA Astrophysics Data System (ADS)

    Gordon, A. L.; Giulivi, C. F.

    2012-12-01

    The closer we look at the ocean, with improved instrumentation and models, the less it looks like the familiar 'textbook' view of overly smoothed maps of SST and SSS, with ocean scale circulation gyres, and more of a jumble of a westward parade of mesoscale features. The question arises: what role does the mesoscale play in compensating the air-sea flux of heat and freshwater? Here we focus on the freshwater balance within the salty North Atlantic subtropics regime, where the annual evaporation minus precipitation (E-P) is over 1 m/year. A traditional view is that the required quasi-steady state ocean freshwater inflow is derived from the wind-driven circulation and the associated shallow meridional overturning circulation. Here we evaluate if the mesoscale 'eddy' field, may stir into the subtropical regime a significant share of the needed freshwater. The Voluntary Observing Ships (VOS) data provide an overview of the SSS seasonal cycle of the Atlantic subtropical regime. While E-P is always positive, greater in January-July, minimum in October, the SSS displays a maximum in October, minimum occurs in April. It is hypothesized that the lower SSS of the winter/spring period marks increased winter freshwater flux by meso-scale activity. While the eddy freshwater flux can be estimated from the Rapid thermohaline and velocity data sections near 24.5°N, it is the meridional convergence of the eddy freshwater flux that compensates the regional E-P. We use the SODA output, which assimilates the VOS and Rapid data, to estimate the eddy freshwater flux convergence. Our preliminary assessment is that the eddy flux convergence does play a major role in closing the seasonal freshwater cycle of the North Atlantic surface layer.

  18. Conservation and protection of Georgia's freshwater wetlands

    SciTech Connect

    Turner, M.J.J.

    1989-01-01

    Georgia's freshwater wetlands are a valuable natural resource. Despite this fact, they are vanishing at an alarming rate. One objective of the research presented in this dissertation was to try to determine why freshwater wetlands have been so little esteemed historically that their destruction has until lately drawn little attention. In addition, it was hoped that this research would lead to conclusions about the extent of Georgia's freshwater wetlands and the status of their conservation and protection. A further goal of the study was to generate ideas about how better to protect this resource, and to examine policy issues that must be addressed in association with the problem. Interest in freshwater wetlands is part of a continuum of interests and events associated with environmental awareness that has its roots in the late 1800's and early 1900's. An understanding of the history of the environmental movement and the maturation of environmental philosophy provides needed background against which the issues associated with preservation of freshwater wetlands must be viewed. The first two chapters are thus devoted to an exploration of the history of environmental awareness and activism. In the third chapter, historical material about freshwater wetlands in the, US is presented. The final section is dedicated to a discussion of freshwater wetlands in Georgia. Georgia's boundaries encompass five physiographic provinces. Freshwater wetlands are found in all of these regions, but the type of wetland varies among them. In the northern part of the state, freshwater wetlands are scarce, but in the southern half of the state they are so common as to be considered a dominant feature of the landscape. Among the threats to Georgia's wetlands are urban development, agricultural conversion, impoundment, and pollution.

  19. Relative yields of U-235 fission products measured in a high level radioactive sludge at Savannah River Site

    SciTech Connect

    Bibler, N.E.; Coleman, C.J. ); Kinard, W.F. . Dept. of Chemistry)

    1992-01-01

    This paper presents measurements of the concentrations of 42 of the long-lived U-235 fission products in a high-level radioactive waste sludge stored at Savannah River Site. The 42 fision products make up 98% of the waste sludge. We used inductively coupled plasma-mass spectroscopy for the analysis. The relative yields for most of the fission products are in complete agreement with the known relative yields for the beta decay chains of the two asymmetric branches of the slow neutron fission of U-235. Disagreements can be reconciled based on the chemistry of the fission products in the caustic waste sludges, the neutron fluences in SRS reactors, or interferences in the ICP-MS analyses. This paper presents measurements of the concentrations of 42 (98%) of the long-lived U-235 fission products in a high-level radioactive waste sludge stored at the Savannah River Site. We analyzed the sludge with inductively coupled plasma-mass spectroscopy. The relative yields for most of the fission products agree completely with the known relative vields for the beta decay chains of the two asymmetric: branches of the slow neutron fission of U-235. The chemistry of the fission products in the caustic waste sludges, the neutron fluences in SRS reactors, or interferences in the ICP-MS analyses explain the differences in the measured and calculated results.

  20. Relative yields of U-235 fission products measured in a high level radioactive sludge at Savannah River Site

    SciTech Connect

    Bibler, N.E.; Coleman, C.J.; Kinard, W.F.

    1992-10-01

    This paper presents measurements of the concentrations of 42 of the long-lived U-235 fission products in a high-level radioactive waste sludge stored at Savannah River Site. The 42 fision products make up 98% of the waste sludge. We used inductively coupled plasma-mass spectroscopy for the analysis. The relative yields for most of the fission products are in complete agreement with the known relative yields for the beta decay chains of the two asymmetric branches of the slow neutron fission of U-235. Disagreements can be reconciled based on the chemistry of the fission products in the caustic waste sludges, the neutron fluences in SRS reactors, or interferences in the ICP-MS analyses. This paper presents measurements of the concentrations of 42 (98%) of the long-lived U-235 fission products in a high-level radioactive waste sludge stored at the Savannah River Site. We analyzed the sludge with inductively coupled plasma-mass spectroscopy. The relative yields for most of the fission products agree completely with the known relative vields for the beta decay chains of the two asymmetric: branches of the slow neutron fission of U-235. The chemistry of the fission products in the caustic waste sludges, the neutron fluences in SRS reactors, or interferences in the ICP-MS analyses explain the differences in the measured and calculated results.

  1. Biomass, productivity and density of the seagrass Thalassia testudinum at three sites in Cahuita National Park, Costa Rica.

    PubMed

    Paynter, C K; Cortés, J; Engels, M

    2001-12-01

    The basic ecology of seagrass beds was investigated by comparing biomass, productivity and density of Thalassia testudinum (turtle grass) at three sites: Puerto Vargas, Punta Cahuita and Rio Perezoso, in Cahuita National Park, Limón, Costa Rica, over a two month period (March-April 1999). Above ground biomass, density, and productivity were highest in the Puerto Vargas site while Punta Cahuita had the least non-green above ground biomass was significantly lower in total biomass than Puerto Vargas. Punta Cahuita was distinguished by the largest grain size, a very hard substrate, and shallower water. Rio Perezoso, on the other hand, had extremely fine sediment and lower salinity, while Puerto Vargas was intermediate both in sediment size and environmental conditions. It appears, therefore, that higher biomass and productivity result from a combination of moderate environmental characteristics and an intermediate sediment size. PMID:15264540

  2. Black History, Inc! Investigating the Production of Black History through Walmart's Corporate Web Site

    ERIC Educational Resources Information Center

    King, LaGarrett J.; Brown, Anthony L.

    2012-01-01

    Social and public sites are becoming a popular medium for intellectual consumption of Black history. Given the educational climate in which many students' exposure to Black history may come from outside of schools, the authors examine how Walmart's Black History Month Web site produced simplistic and safe narratives about African American history.

  3. Legend and legacy: Fifty years of defense production at the Hanford Site

    SciTech Connect

    Gerber, M.S.

    1992-09-01

    Today, the Hanford Site is engaged in the largest waste cleanup effort ever undertaken in human history. That in itself makes the endeavor historic and unique. The Hanford Site has been designated the ``flagship`` of Department of Energy (DOE) waste remediation endeavors. And, just as the wartime Hanford Project remains unmatched in history, no counterpart exists for the current waste cleanup enterprise. This report provides a summary of the extensive historical record, however, which does give a partial road map. The science of environmental monitoring pioneered at the Hanford Site, and records of this type are the most complete of any in the world, from private companies or public agencies, for the early years of Site operations. The Hanford Site was unique for establishing a detailed, scientific, and multi-faceted environmental monitoring program.

  4. Potential methane production and oxidation in soil reclamation covers of an oil sands mining site in Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Pum, Lisa; Reichenauer, Thomas; Germida, Jim

    2015-04-01

    Anthropogenic activities create a number of significant greenhouse gases and thus potentially contribute to global warming. Methane production is significant in some agricultural production systems and from wetlands. In soil, methane can be oxidised by methanotrophic bacteria. However, little is known about methane production and oxidation in oil sand reclamation covers. The purpose of this study was to investigate methane production and oxidation potential of tailing sands and six different reclamation layers of oil sands mining sites in Alberta, Canada. Methane production and oxidation potential were investigated in laboratory scale microcosms through continuous headspace analysis using gas chromatography. Samples from a reclamation layer were collected at the Canadian Natural Resources Limited (CNRL) reclamation site at depths of 0-10 cm, 10-20 cm and 20-40 cm in October 2014. In addition, tailing sands provided by Suncor Energy Inc. and soil from a CNRL wetland were studied for methane production. Samples were dried, crushed and sieved to 4 mm, packed into serum bottle microcosms and monitored for eight weeks. Methane production potential was assessed by providing an anoxic environment and by adjusting the samples to a moisture holding capacity of 100 %. Methane oxidation potential was examined by an initial application of 2 vol % methane to the microcosms and by adjusting the samples to a moisture holding capacity of 50 %. Microcosm headspace gas was analysed for methane, carbon dioxide, nitrous oxide and oxygen. All experiments were carried out in triplicates, including controls. SF6 and Helium were used as internal standards to detect potential leaks. Our results show differences for methane production potential between the soil depths, tailing sands and wetlands. Moreover, there were differences in the methane oxidation potential of substrate from the three depths investigated and between the reclamation layers. In conclusion, the present study shows that

  5. Late Holocene climate and land-use impacts on ecology and carbon cycling in Atlantic coastal plain tidal freshwater wetlands

    NASA Astrophysics Data System (ADS)

    Jones, M.; Bernhardt, C. E.

    2013-12-01

    pollen record of the two uppermost sites. Peat accumulation rates increased at all sites after the onset of Colonial land clearance, identified by a slight Ambrosia pollen rise, and likely is explained by both increased sediment deposition and by greater nutrient availability that enhanced wetland productivity and C accumulation. Vegetation changes are recorded in the pollen record following the cessation of rice agriculture at all sites. All sites show declining C accumulation rates during the post-Colonial interval to present. The two degrading middle sites show increased graminoid peat toward present, suggesting a shift from forested swamp to marsh during this post-Colonial interval. This is most apparent today at the lower degrading site, where Taxodium trees are being replaced by an expanding marsh, suggesting sea-level rise is transforming low-lying tidal freshwater swamps to oligohaline marshes as salinity increases. This study demonstrates that vegetation and C accumulation in tidal freshwater wetlands is extremely sensitive to changes in climate and sea level. It is also demonstrates that much of the modern vegetation became established following rice agriculture cessation.

  6. Contamination of the freshwater ecosystem by pesticides

    USGS Publications Warehouse

    Cope, Oliver B.

    1966-01-01

    A large part of our disquieting present-day pesticide problem is intimately tied to the freshwater ecosystem. Economic poisons are used in so many types of terrain to control so many kinds of organisms that almost all lakes and streams are likely to be contaminated. In addition to accidental contamination many pesticides are deliberately applied directly to fresh waters for suppression of aquatic animals or plants. The problem is intensified because of the extreme susceptibility of freshwater organisms. The complexity of freshwater environments and their variety makes it difficult to comprehend the total effect of pesticides.

  7. Field transplantation of the freshwater bivalve Corbicula fluminea along a polymetallic contamination gradient (River Lot, France): 1. Geochemical characteristics of the sampling sites and cadmium and zinc bioccumulation kinetics

    SciTech Connect

    Andres, S.; Baudrimont, M.; Lapaquellerie, Y.; Ribeyre, F.; Maillet, N.; Latouche, C.; Boudou, A.

    1999-11-01

    Specimens of the Asiatic clam Corbicula fluminea were transplanted from a clean lacustrine site to four stations along a polymetallic gradient in the river Lot (France), downstream from an old Zn ore treatment facility. The bivalves were held in benthic cages for a 5-month exposure period, April to September 1996; mollusk growth and metal bioaccumulation kinetics (Cd, Zn) were followed by subsampling the cages at t = 0, 21, 49, 85, 120, and 150 d. Rates of Cd bioaccumulation in the whole soft bodies and in individual organs were greater at the upstream stations located close to the pollution source, but there was no direct proportionality between Cd in the bivalves and in the unfiltered or filtered river water samples. Unlike the case for Cd, rates of Zn bioaccumulation did not reflect the contamination gradient. Marked growth differences were measured among the four stations, reflecting both nutritional differences and changes in the degree of metal contamination; these growth differences produced markedly different trends when metal bioaccumulation was expressed in terms of burdens rather than concentrations.

  8. 40 CFR 35.1605-3 - Publicly owned freshwater lake.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Publicly owned freshwater lake. 35.1605... Owned Freshwater Lakes § 35.1605-3 Publicly owned freshwater lake. A freshwater lake that offers public... maintaining the public access and recreational facilities of this lake or other publicly owned...

  9. 40 CFR 35.1605-3 - Publicly owned freshwater lake.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Publicly owned freshwater lake. 35.1605... Owned Freshwater Lakes § 35.1605-3 Publicly owned freshwater lake. A freshwater lake that offers public... maintaining the public access and recreational facilities of this lake or other publicly owned...

  10. 40 CFR 35.1605-3 - Publicly owned freshwater lake.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Publicly owned freshwater lake. 35.1605... Owned Freshwater Lakes § 35.1605-3 Publicly owned freshwater lake. A freshwater lake that offers public... maintaining the public access and recreational facilities of this lake or other publicly owned...

  11. 40 CFR 35.1605-3 - Publicly owned freshwater lake.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Publicly owned freshwater lake. 35.1605... Owned Freshwater Lakes § 35.1605-3 Publicly owned freshwater lake. A freshwater lake that offers public... maintaining the public access and recreational facilities of this lake or other publicly owned...

  12. 40 CFR 35.1605-3 - Publicly owned freshwater lake.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Publicly owned freshwater lake. 35.1605... Owned Freshwater Lakes § 35.1605-3 Publicly owned freshwater lake. A freshwater lake that offers public... maintaining the public access and recreational facilities of this lake or other publicly owned...

  13. Site-specific analysis of advanced glycation end products in plasma proteins of type 2 diabetes mellitus patients.

    PubMed

    Greifenhagen, Uta; Frolov, Andrej; Blüher, Matthias; Hoffmann, Ralf

    2016-08-01

    Advanced glycation end products (AGEs) are posttranslational modifications formed non-enzymatically from the reaction of carbohydrates and their degradation products with proteins. Accumulation of AGEs is associated with the progression of severe diabetic complications, for example, and elevated tissue levels of AGEs might even predict these pathologies. As AGE formation is often site-specific, mapping of these modification sites may reveal more sensitive and specific markers than the global tissue level. Here, 42 AGE modifications were identified in a bottom-up proteomic approach by tandem mass spectrometry, which corresponded to 36 sites in 22 high to medium abundant proteins in individual plasma samples obtained from type 2 diabetes mellitus (T2DM) patients with long disease duration (>10 years). Major modifications were glarg (11 modification sites) and carboxymethylation (5) of arginine and formylation (8), acetylation (7), and carboxymethylation (7) of lysine residues. Relative quantification of these sites in plasma samples obtained from normoglycemic individuals (n = 47) and patients with T2DM being newly diagnosed (n = 47) or of medium (2-5 years, n = 20) and long disease duration (>10 years, n = 20) did not reveal any significant differences. PMID:27236317

  14. Evaluating Primers for Profiling Anaerobic Ammonia Oxidizing Bacteria within Freshwater Environments

    PubMed Central

    Sonthiphand, Puntipar; Neufeld, Josh D.

    2013-01-01

    Anaerobic ammonia oxidizing (anammox) bacteria play an important role in transforming ammonium to nitrogen gas and contribute to fixed nitrogen losses in freshwater environments. Understanding the diversity and abundance of anammox bacteria requires reliable molecular tools, and these are not yet well established for these important Planctomycetes. To help validate PCR primers for the detection of anammox bacteria within freshwater ecosystems, we analyzed representative positive controls and selected samples from Grand River and groundwater sites, both from Ontario, Canada. The objectives of this study were to identify a suitable anammox denaturing gradient gel electrophoresis (DGGE) fingerprint method by using GC-clamp modifications to existing primers, and to verify the specificity of anammox-specific primers used for DGGE, cloning and qPCR methods. Six primer combinations were tested from four published primer sets (i.e. A438f/A684r, Amx368f/Amx820r, An7f/An1388r, and Pla46/1392r) for both direct and nested PCR amplifications. All PCR products were run subsequently on DGGE gels to compare the resulting patterns. Two anammox-specific primer combinations were also used to generate clone libraries and quantify anammox bacterial 16S rRNA genes with qPCR. The primer set A438f/A684r was highly specific to anammox bacteria, provided reliable DGGE fingerprints and generated a high proportion of anammox-related clones. A second primer set (Amx368f/Amx820r) was anammox specific, based on clone library analysis, but PCR products from different candidate species of anammox bacteria resolved poorly using DGGE analysis. Both DGGE and cloning results revealed that Ca. Brocadia and an uncharacterized anammox bacterial cluster represented the majority of anammox bacteria found in Grand River sediment and groundwater samples, respectively. Together, our results demonstrate that although Amx368f/Amx820r was useful for anammox-specific qPCR and clone library analysis, A438f/A684r

  15. Digital mapping of the Mars Pathfinder landing site: Design, acquisition, and derivation of cartographic products for science applications

    USGS Publications Warehouse

    Gaddis, L.R.; Kirk, R.L.; Johnson, J. R.; Soderblom, L.A.; Ward, A.W.; Barrett, J.; Becker, K.; Decker, T.; Blue, J.; Cook, D.; Eliason, E.; Hare, T.; Howington-Kraus, E.; Isbell, C.; Lee, E.M.; Redding, B.; Sucharski, R.; Sucharski, T.; Smith, P.H.; Britt, D.T.

    1999-01-01

    The Imager for Mars Pathfinder (IMP) acquired more than 16,000 images and provided panoramic views of the surface of Mars at the Mars Pathfinder landing site in Ares Vallis. This paper describes the stereoscopic, multispectral IMP imaging sequences and focuses on their use for digital mapping of the landing site and for deriving cartographic products to support science applications of these data. Two-dimensional cartographic processing of IMP data, as performed via techniques and specialized software developed for ISIS (the U.S.Geological Survey image processing software package), is emphasized. Cartographic processing of IMP data includes ingestion, radiometric correction, establishment of geometric control, coregistration of multiple bands, reprojection, and mosaicking. Photogrammetric processing, an integral part of this cartographic work which utilizes the three-dimensional character of the IMP data, supplements standard processing with geometric control and topographic information [Kirk et al., this issue]. Both cartographic and photogrammetric processing are required for producing seamless image mosaics and for coregistering the multispectral IMP data. Final, controlled IMP cartographic products include spectral cubes, panoramic (360?? azimuthal coverage) and planimetric (top view) maps, and topographic data, to be archived on four CD-ROM volumes. Uncontrolled and semicontrolled versions of these products were used to support geologic characterization of the landing site during the nominal and extended missions. Controlled products have allowed determination of the topography of the landing site and environs out to ???60 m, and these data have been used to unravel the history of large- and small-scale geologic processes which shaped the observed landing site. We conclude by summarizing several lessons learned from cartographic processing of IMP data. Copyright 1999 by the American Geophysical Union.

  16. Digital mapping of the Mars Pathfinder landing site: Design, acquisition, and derivation of cartographic products for science applications

    NASA Astrophysics Data System (ADS)

    Gaddis, L. R.; Kirk, R. L.; Johnson, J. R.; Soderblom, L. A.; Ward, A. W.; Barrett, J.; Becker, K.; Becker, T.; Blue, J.; Cook, D.; Eliason, E.; Hare, T.; Howington-Kraus, E.; Isbell, C.; Lee, E. M.; Redding, B.; Sucharski, R.; Sucharski, T.; Smith, P. H.; Britt, D. T.

    1999-04-01

    The Imager for Mars Pathfinder (IMP) acquired more than 16,000 images and provided panoramic views of the surface of Mars at the Mars Pathfinder landing site in Ares Vallis. This paper describes the stereoscopic, multispectral IMP imaging sequences and focuses on their use for digital mapping of the landing site and for deriving cartographic products to support science applications of these data. Two-dimensional cartographic processing of IMP data, as performed via techniques and specialized software developed for ISIS (the U.S. Geological Survey image processing software package), is emphasized. Cartographic processing of IMP data includes ingestion, radiometric correction, establishment of geometric control, coregistration of multiple bands, reprojection, and mosaicking. Photogrammetric processing, an integral part of this cartographic work which utilizes the three-dimensional character of the IMP data, supplements standard processing with geometric control and topographic information [Kirk et al., this issue]. Both cartographic and photogrammetric processing are required for producing seamless image mosaics and for coregistering the multispectral IMP data. Final, controlled IMP cartographic products include spectral cubes, panoramic (360° azimuthal coverage) and planimetric (top view) maps, and topographic data, to be archived on four CD-ROM volumes. Uncontrolled and semicontrolled versions of these products were used to support geologic characterization of the landing site during the nominal and extended missions. Controlled products have allowed determination of the topography of the landing site and environs out to ~60 m, and these data have been used to unravel the history of large- and small-scale geologic processes which shaped the observed landing site. We conclude by summarizing several lessons learned from cartographic processing of IMP data.

  17. Effects of salinity on freshwater fishes in coastal plain drainages in the southeastern U.S.

    USGS Publications Warehouse

    Peterson, Mark S.; Meador, Michael R.

    1994-01-01

    This review focuses on the influence of salinity on freshwater fishes in coastal rivers and estuaries of the southeastern U.S. Influences of salinity on freshwater fish species can be explained partly through responses evidenced by behavior, physiology, growth, reproduction, and food habits during all aspects of life history. Factors influencing the rate of salinity change affect the community structure and dynamics of freshwater fishes in brackish environments. Our understanding of the relation between salinity and the life history of freshwater fishes is limited because little ecological research has been conducted in low-salinity habitats that we consider an “interface” between freshwater streams and the estuary proper. Much of the available data are descriptive in nature and describe best general patterns, but more specific studies are required to better determine the influence of salinity on freshwater fishes. Improved understanding of the influence of human-induced changes on the productivity and viability of these important systems will require a new research focus.

  18. Reflections in a stock pond: are anthropogenically derived freshwater ecosystems natural, artificial, or something else?

    PubMed

    Crifasi, Robert R

    2005-11-01

    "A skyscraper is as natural as a bird's nest" -Alan Watts. For millennia, people have altered freshwater ecosystems directly through water development and indirectly by global change and surrounding land-use activities. In these altered ecosystems, human impacts can be subtle and are sometimes overlooked by the people who manage them. This article provides two case studies near Boulder, Colorado that demonstrate how perceptions regarding these ecosystems affect their management. These examples are typical of lakes and streams along the Front Range of Colorado that are simultaneously natural and social in origin. Although natural, many of the region's freshwater ecosystems are affected by ongoing ecologic, hydrologic, chemical, and geomorphic modifications produced by human activity. People and nature are both active participants in the production of these freshwater ecosystems. The concept of "hybridity," borrowed from geographers and social scientists, is useful for describing landscapes of natural and social origin. Hybrid freshwater ecosystems are features of the humanized landscape and are derived from deliberate cultural activities, nonhuman physical and biological processes, and incidental anthropogenic disturbance. Our perceptions of "natural" freshwater ecosystems and what definitions we use to describe them influences our view of hybrid systems and, in turn, affects management decisions regarding them. This work stresses the importance of understanding the underlying societal forces and cultural values responsible for the creation of hybrid freshwater ecosystems as a central step in their conservation and management. PMID:16206025

  19. Monitoring NEON terrestrial sites phenology with daily MODIS BRDF/albedo product and landsat data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The MODerate resolution Imaging Spectroradiometer (MODIS) Bidirectional Reflectance Distribution Function (BRDF) and albedo products (MCD43) have already been in production for more than a decade. The standard product makes use of a linear “kernel-driven” RossThick-LiSparse Reciprocal (RTLSR) BRDF m...

  20. Simulation of potential oyster density with variable freshwater inflow (1965-2000) to the Caloosahatchee River Estuary, southwest Florida, USA.

    PubMed

    Buzzelli, Christopher; Doering, Peter H; Wan, Yongshan; Gorman, Patricia; Volety, Aswani

    2013-10-01

    Oyster beds are disappearing worldwide through a combination of over-harvesting, diseases, and salinity alterations in the coastal zone. Sensitivity of oysters to variable discharge and salinity is particularly acute in small sub-tropical estuaries subject to regulated freshwater releases. South Florida has sub-tropical estuaries where watershed flood control sometimes results in excessive freshwater inflow to estuaries during the wet season (May-Oct) and reduced discharge and increased salinities in the dry season (Nov-Apr). The potential to reserve freshwater accumulated during the wet season could offer the capacity to regulate freshwater at different temporal scales, thus optimizing salinity conditions for estuarine biota. The goal of this study was to use simulation modeling to explore the effects of freshwater inflows and salinity on adult oyster survival in the Caloosahatchee River Estuary (CRE) in southwest Florida. Water managers derived three different freshwater inflow scenarios for the CRE based on historical and modified watershed attributes for the time period of 1965-2000. Three different salinity time series were generated from the inflow scenarios at each of three sites in the lower CRE and used to conduct nine different oyster simulations. Overall, the predicted densities of adult oysters in the upstream site were 3-4 times greater in seasons that experienced reduced freshwater inflow (e.g., increased salinity) with oyster density in the lower estuary much less influenced by the inflows. Potential storage of freshwater reduced the frequency of extreme flows in the wet season and helped to maintain minimum inflow in the dry season near the estuarine mouth. Analyses of inflows indicated that discharges ranging from 0 to 1,500 cfs could promote favorable salinities of 10-25 in the lower CRE depending on wet versus dry season climatic conditions. This range of inflows is similar to that derived in other studies of the CRE and emphasizes the value of

  1. Monitoring Production of Methane from Spills of Gasoline at UST Release Sites (Boston, MA)

    EPA Science Inventory

    Anaerobic biodegradation of the BTEX compounds can produce substantial concentrations of methane in ground water at gasoline spill sites. This methane can escape the ground water, move through the unsaturated zone and potentially produce explosive concentrations of methane in c...

  2. Adaptive diversity: hormones and metabolism in freshwaters.

    PubMed

    Laudet, Vincent

    2010-12-01

    Genes underlying the evolution of morphological traits have recently been identified in a number of model species. In the stickleback, the metabolic adaptations to a freshwater habitat have now been linked to a well-known hormonal system. PMID:21145015

  3. EFFECTS OF POLLUTION ON FRESHWATER FISH

    EPA Science Inventory

    An extensive literature review is presented which is concerned with the effects of pollutants (metals, pesticides, detergents, industrial wastes) on freshwater fish; chemical and biological methods for identifying and determining the effects of such pollutants; and the effects of...

  4. Freshwater resources of Big Pine Key, Florida

    USGS Publications Warehouse

    Hanson, Chris E.

    1980-01-01

    The principal freshwater-bearing unit underlying Big Pine Key, Fla, is a layer of oolitic limestone averaging 19 feet in thickness. The freshwater exists in two separate lenses, one in the northern half of the island and one in the southern half. The slightly larger north lens is separated from the south lens by a low-lying land area 1 to 3 feet above mean sea level. The lenses float on saltwater in the aquifer and are affected by tidal fluctuations. The areal and depth configuration of the lenses fluctuate in response to rainfall, evapotranspiration, lateral and vertical losses, and pumpage from local wells. The lenses are not a major source of freshwater. Only a small amount of the freshwater in the lenses can be removed before saltwater intrusion will occur. (USGS)

  5. Local and Regional Economic Benefits from Forest Products Production Activities at the Savannah River Site: 1955-Present

    SciTech Connect

    Teeter, L.; Blake, J.I.

    2002-01-01

    SRS was established in 1951 as a nuclear materials production facility; however, decline in the defense mission budget at SRS has created a major economic impact on the community in the Central Savannah River Area. SRS has been offsetting these effects by producing revenue (80 million dollars to date) from the sale of forest products since 1955 primarily trees, but also pine straw. Revenue has been re-invested into the infrastructure development, restoration and management of natural resources. Total asset value of the forest-land has increased from 21 million to over 500 million dollars in the same period.

  6. Abbreviation of larval development and extension of brood care as key features of the evolution of freshwater Decapoda.

    PubMed

    Vogt, Günter

    2013-02-01

    The transition from marine to freshwater habitats is one of the major steps in the evolution of life. In the decapod crustaceans, four groups have colonized fresh water at different geological times since the Triassic, the freshwater shrimps, freshwater crayfish, freshwater crabs and freshwater anomurans. Some families have even colonized terrestrial habitats via the freshwater route or directly via the sea shore. Since none of these taxa has ever reinvaded its environment of origin the Decapoda appear particularly suitable to investigate life-history adaptations to fresh water. Evolutionary comparison of marine, freshwater and terrestrial decapods suggests that the reduction of egg number, abbreviation of larval development, extension of brood care and lecithotrophy of the first posthatching life stages are key adaptations to fresh water. Marine decapods usually have high numbers of small eggs and develop through a prolonged planktonic larval cycle, whereas the production of small numbers of large eggs, direct development and extended brood care until the juvenile stage is the rule in freshwater crayfish, primary freshwater crabs and aeglid anomurans. The amphidromous freshwater shrimp and freshwater crab species and all terrestrial decapods that invaded land via the sea shore have retained ocean-type planktonic development. Abbreviation of larval development and extension of brood care are interpreted as adaptations to the particularly strong variations of hydrodynamic parameters, physico-chemical factors and phytoplankton availability in freshwater habitats. These life-history changes increase fitness of the offspring and are obviously favoured by natural selection, explaining their multiple origins in fresh water. There is no evidence for their early evolution in the marine ancestors of the extant freshwater groups and a preadaptive role for the conquest of fresh water. The costs of the shift from relative r- to K-strategy in freshwater decapods are traded

  7. Methane cycling in a tidal freshwater swamp

    SciTech Connect

    Megonigal, J.P.; Schlesinger, W.H. )

    1993-06-01

    Previous studies of methanogenesis in a tidal freshwater swamp on the North Carolina coast have found that potential rates of methane production overestimate observed rates of methane flux, especially during summer months. This research investigates three possibilities for the unexplained losses: methane oxidation, lateral export of dissolved methane to the adjacent river, and ebullition. It is possible that each of these sinks increase during the summer. The potential for methane oxidation was demonstrated in intact soil cores incubated for 21 hours under a 0.5% CH[sub 3]F atmosphere. Methane flux increased from 10+/-27 (mean+/-sd) to 60+/-3 mg m[sup [minus]2] d[sup [minus]1] in treated cores; control core fluxes were 15+/-3 and 19+/-3 mg m[sup [minus]2] d[sup [minus]1] over the same periods. Incubations of slightly unsaturated soils with [sup 14]CH[sub 4] confirmed rapid potential rates of methane oxidation.

  8. THERMAL AND WATER SOURCE EFFECTS UPON THE STABILITY OF ENTEROVIRUSES IN SURFACE FRESHWATERS

    EPA Science Inventory

    The long-term survival of three human enterovirus serotypes, coxsackievirus B3, echovirus 7, and poliovirus 1 was examined in samples of surface freshwater collected from five sites of physically different character. hese were an artificial lake created by damming a creek, a smal...

  9. Estimated freshwater withdrawals in Washington, 2010

    USGS Publications Warehouse

    Lane, Ron C.; Welch, Wendy B.

    2015-01-01

    The amount of public- and self-supplied water used for domestic, irrigation, livestock, aquaculture, industrial, mining, and thermoelectric power was estimated for state, county, and eastern and western regions of Washington during calendar year 2010. Withdrawals of freshwater for offstream uses were estimated to be about 4,885 million gallons per day. The total estimated freshwater withdrawals for 2010 was approximately 15 percent less than the 2005 estimate because of decreases in irrigation and thermoelectric power withdrawals.

  10. Future freshwater demands in the Arctic

    NASA Astrophysics Data System (ADS)

    White, D.; Strang, E. T.; Hinzman, L.; Alessa, L.; Kliskey, A.

    2004-12-01

    The overall objective of our research is to understand how humans rely on freshwater at local and regional scales in the Arctic, how these dependencies have changed in the recent past, and how they are likely to change in the future. This study will take place on the Seward Peninsula where climate induced changes in the hydrologic cycle are already being observed. This presentation will describe the human dependencies on freshwater in the Arctic. In particular, we will discuss the effects of inadequate quantity or quality of freshwater on Arctic inhabitants. The freshwater used by humans in the Arctic for drinking, cooking, and washing is derived in many cases from surface water, such as lakes and streams. Since the surface water frozen 6-9 months of the year in the Arctic, communities that rely on rivers and lakes must treat and store large volumes of water for use during winter. The stored water must be heated throughout the winter and distributed on an as-needed basis. Unfortunately, when not enough water can be gathered in the summer or stored in the winter, the entire community may be without freshwater. During these months, water must be collected by individuals from ice, snow, and rain. Collecting water during breakup can be dangerous. River ice is rotten, there is too little snow for snow mobiles, and the tundra is too soft all terrain vehicles. While the state of Alaska and Federal programs are making progress towards developing sustainable water sources for Alaska's Arctic communities, freshwater remains a precious commodity. Communities throughout the Arctic, including Canada and Russia, have similar problems with obtaining and purifying freshwater. As climate induced changes are being observed in the Arctic, the threat to the freshwater resource is now a greater concern than ever. This study is being funded under the NSF Arctic System Science Program, Human Dimensions of the Arctic (OPP-0328686).

  11. Ubiquitin vinyl methyl ester binding orients the misaligned active site of the ubiquitin hydrolase UCHL1 into productive conformation

    SciTech Connect

    Boudreaux, David A.; Maiti, Tushar K.; Davies, Christopher W.; Das, Chittaranjan

    2010-07-06

    Ubiquitin carboxy-terminal hydrolase L1 (UCHL1) is a Parkinson disease-associated, putative cysteine protease found abundantly and selectively expressed in neurons. The crystal structure of apo UCHL1 showed that the active-site residues are not aligned in a canonical form, with the nucleophilic cysteine being 7.7 {angstrom} from the general base histidine, an arrangement consistent with an inactive form of the enzyme. Here we report the crystal structures of the wild type and two Parkinson disease-associated variants of the enzyme, S18Y and I93M, bound to a ubiquitin-based suicide substrate, ubiquitin vinyl methyl ester. These structures reveal that ubiquitin vinyl methyl ester binds primarily at two sites on the enzyme, with its carboxy terminus at the active site and with its amino-terminal {beta}-hairpin at the distal site - a surface-exposed hydrophobic crevice 17 {angstrom} away from the active site. Binding at the distal site initiates a cascade of side-chain movements in the enzyme that starts at a highly conserved, surface-exposed phenylalanine and is relayed to the active site resulting in the reorientation and proximal placement of the general base within 4 {angstrom} of the catalytic cysteine, an arrangement found in productive cysteine proteases. Mutation of the distal-site, surface-exposed phenylalanine to alanine reduces ubiquitin binding and severely impairs the catalytic activity of the enzyme. These results suggest that the activity of UCHL1 may be regulated by its own substrate.

  12. Freshwater Commercial Bycatch: an Understated Conservation Problem

    SciTech Connect

    Raby, Graham D.; Colotelo, Alison HA; Blouin-Demers, Gabriel; Cooke, Steven J.

    2011-04-01

    Commercial fisheries bycatch in marine systems has been regarded as a global conservation concern by environmental groups, scientists, government, and the public for decades. Fortunately, some headway has been made to mitigate the negative impacts of bycatch in marine environments. In a survey of the literature, we found that despite freshwater commercial fisheries yields comprising 11% of the global commercial catch, bycatch research focusing on freshwater commercial fisheries represented only {approx}3% of the total bycatch literature. This paucity of research is particularly alarming given that freshwater animals and habitats are some of the world's most imperiled. The limited inland bycatch literature that does exist includes examples of population declines attributed to commercial bycatch (e.g., freshwater dolphins in the Yangtze River in China) and illustrates that in some systems bycatch can be substantial (e.g., lake trout bycatch in the Laurentian Great Lakes). Encouraging results from the marine realm can serve as models for bycatch research in freshwater, and lead to measurable gains in conservation of freshwater ecosystems. We summarize existing work on inland bycatch in an effort to draw attention to this understated and understudied conservation problem.

  13. Medical costs and lost productivity from health conditions at volatile organic compound-contaminated Superfund sites

    SciTech Connect

    Lybarger, J.A.; Spengler, R.F.; Brown, D.R.; Lee, R.; Vogt, D.P. |; Perhac, R.M. Jr. |

    1998-10-01

    This paper estimates the health costs at Superfund sites for conditions associated with volatile organic compounds (VOCs) in drinking water. Health conditions were identified from published literature and registry information as occurring at excess rates in VOC-exposed populations. These health conditions were: (1) some categories of birth defects, (2) urinary tract disorders, (3) diabetes, (4) eczema and skin conditions, (5) anemia, (6) speech and hearing impairments in children under 10 years of age, and (7) stroke. Excess rates were used to estimate the excess number of cases occurring among the total population living within one-half mile of 258 Superfund sites. These sites had evidence of completed human exposure pathways for VOCs in drinking water. For each type of medical condition, an individual`s expected medical costs, long-term care costs, and lost work time due to illness or premature mortality were estimated. Costs were calculated to be approximately $330 million per year, in the absence of any remediation or public health intervention programs. The results indicate the general magnitude of the economic burden associated with a limited number of contaminants at a portion of all Superfund sites, thus suggesting that the burden would be greater than that estimated in this study if all contaminants at all Superfund sites could be taken into account.

  14. Commissioned Review. Carbon: freshwater plants

    USGS Publications Warehouse

    Keeley, J.E.; Sandquist, D.R.

    1992-01-01

    δ13C values for freshwater aquatic plant matter varies from −11 to −50‰ and is not a clear indicator of photosynthetic pathway as in terrestrial plants. Several factors affect δ13C of aquatic plant matter. These include: (1) The δ13C signature of the source carbon has been observed to range from +1‰ for HCO3− derived from limestone to −30‰ for CO2 derived from respiration. (2) Some plants assimilate HCO3−, which is –7 to –11‰ less negative than CO2. (3) C3, C4, and CAM photosynthetic pathways are present in aquatic plants. (4) Diffusional resistances are orders of magnitude greater in the aquatic environment than in the aerial environment. The greater viscosity of water acts to reduce mixing of the carbon pool in the boundary layer with that of the bulk solution. In effect, many aquatic plants draw from a finite carbon pool, and as in terrestrial plants growing in a closed system, biochemical discrimination is reduced. In standing water, this factor results in most aquatic plants having a δ13C value similar to the source carbon. Using Farquhar's equation and other physiological data, it is possible to use δ13C values to evaluate various parameters affecting photosynthesis, such as limitations imposed by CO2 diffusion and carbon source.

  15. Extended region of nodulation genes in Rhizobium meliloti 1021. II. Nucleotide sequence, transcription start sites and protein products

    SciTech Connect

    Fisher, R.F.; Swanson, J.A.; Mulligan, J.T.; Long, S.R.

    1987-10-01

    The authors have established the DNA sequence and analyzed the transcription and translation products of a series of putative nodulation (nod) genes in Rhizobium meliloti strain 1021. Four loci have been designated nodF, nodE, nodG and nodH. The correlation of transposon insertion positions with phenotypes and open reading frames was confirmed by sequencing the insertion junctions of the transposons. The protein products of these nod genes were visualized by in vitro expression of cloned DNA segments in a R. meliloti transcription-translation system. In addition, the sequence for nodG was substantiated by creating translational fusions in all three reading frames at several points in the sequence; the resulting fusions were expressed in vitro in both E. coli and R. meliloti transcription-translation systems. A DNA segment bearing several open reading frames downstream of nodG corresponds to the putative nod gene mutated in strain nod-216. The transcription start sites of nodF and nodH were mapped by primer extension of RNA from cells induced with the plant flavone, luteolin. Initiation of transcription occurs approximately 25 bp downstream from the conserved sequence designated the nod box, suggesting that this conserved sequence acts as an upstream regulator of inducible nod gene expression. Its distance from the transcription start site is more suggestive of an activator binding site rather than an RNA polymerase binding site.

  16. Numerical studies of gas production from several CH4 hydrate zones at the Mallik site, Mackenzie Delta, Canada

    USGS Publications Warehouse

    Moridis, G.J.; Collett, T.S.; Dallimore, S.R.; Satoh, T.; Hancock, S.; Weatherill, B.

    2004-01-01

    The Mallik site represents an onshore permafrost-associated gas hydrate accumulation in the Mackenzie Delta, Northwest Territories, Canada. A gas hydrate research well was drilled at the site in 1998. The objective of this study is the analysis of various gas production scenarios from five methane hydrate-bearing zones at the Mallik site. In Zone #1, numerical simulations using the EOSHYDR2 model indicated that gas production from hydrates at the Mallik site was possible by depressurizing a thin free gas zone at the base of the hydrate stability field. Horizontal wells appeared to have a slight advantage over vertical wells, while multiwell systems involving a combination of depressurization and thermal stimulation offered superior performance, especially when a hot noncondensible gas was injected. Zone #2, which involved a gas hydrate layer with an underlying aquifer, could yield significant amounts of gas originating entirely from gas hydrates, the volumes of which increased with the production rate. However, large amounts of water were also produced. Zones #3, #4 and #5 were lithologically isolated gas hydrate-bearing deposits with no underlying zones of mobile gas or water. In these zones, thermal stimulation by circulating hot water in the well was used to induce dissociation. Sensitivity studies indicated that the methane release from the hydrate accumulations increased with the gas hydrate saturation, the initial formation temperature, the temperature of the circulating water in the well, and the formation thermal conductivity. Methane production appears to be less sensitive to the specific heat of the rock and of the hydrate, and to the permeability of the formation. ?? 2004 Published by Elsevier B.V.

  17. Transitions in ancient inland freshwater resource management in Sri Lanka affect biota and human populations in and around coastal lagoons.

    PubMed

    Dahdouh-Guebas, F; Hettiarachchi, S; Lo Seen, D; Batelaan, O; Sooriyarachchi, S; Jayatissa, L P; Koedam, N

    2005-03-29

    The increasing anthropogenic pressure on natural environments results in impacts that affect tropical forest areas and their biodiversity. Adverse impacts on terrestrial and oceanic environments often compound in the intertidal area, where mangrove forest ecosystems thrive. In tropical coastal areas of many developing countries where people depend on wood and other mangrove forest products and services, forest degradation leads to socioeconomic problems. At the same time, increasing freshwater needs in these areas are expected to cause additional problems. On the basis of remote sensing and ground truthing complemented by colonial archival material from the Dutch East India Company (1602-1800), we report that changes to the historic system of inland freshwater management have increased dramatically in recent times. Hydrological changes, such as interbasin transfers, have resulted in a qualitative ecological and socioeconomic degradation in three coastal lagoons in southern Sri Lanka. Variations in river hydrology have caused changes in the areas suitable as mangrove habitat and, thus, have resulted in an altered distribution. However, increases in mangrove area can mask the degradation of the site in terms of floristic composition, significance of the species, and biodiversity (this effect is termed "cryptic ecological degradation"). It is important that such changes be carefully monitored to ensure biological and socioeconomic sustainability. PMID:15797030

  18. BOREAS TGB-6 Soil Methane Oxidation and Production from NSA BP and Fen Sites

    NASA Technical Reports Server (NTRS)

    Deck, Bruce; Wahlen, Martin; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study Trace Gas Biogeochemistry (BOREAS TGB-6) team collected soil methane measurements at several sites in the Southern Study Area (SSA) and Northern Study Area (NSA). This data set contains soil methane consumption (bacterial CH4 oxidation) and associated C-13 fractionation effects in samples that were collected at various sites in 1994 and 1996 from enclosures (chambers). Methane C-13 data in soil gas samples from the NSA Young Jack Pine (YJP) and Old Jack Pine (OJP) sites for 1994 and 1996 are also given. Additional data on the isotopic composition of methane (carbon and hydrogen isotopes) produced in the NSA beaver ponds and fen bog in 1993 and 1994 are given as well. The data are stored in tabular ASCII files.

  19. Age-specific productivity and nest site characteristics of Cooper's hawks (Accipiter cooperii)

    USGS Publications Warehouse

    Moore, K.R.; Henny, C.J.

    1984-01-01

    Nesting Cooper's Hawks (Accipiter cooperii) were studied in northeastern Oregon. Second-year (SY) males did not breed, but 22 percent of the breeding females were SY's. Mean clutch size (P = 0.012) and mean number of young fledged per pair that laid eggs (P < 0.10) were lower for SY females than for adult (after second year [ASY}) females; however, an equal percentage of the eggs (excluding a collected sample egg) yielded fledged young for each age class. Stepwise discriminant analysis suggested differences in structural characteristics of the nest site habitat for ASY and SY females, i.e., SY female nest sites were associated with younger successional stages than ASY female nest sites. Nests of both age groups were built in trees with high crown volume, but ASY females utilized mistletoe (Arceuthobium sp.) for nest structures more frequently (P < 0.01) than SY females.

  20. The effect of increasing salinity and forest mortality on soil nitrogen and phosphorus mineralization in tidal freshwater forested wetlands

    USGS Publications Warehouse

    Noe, Gregory B.; Krauss, Ken W.; Lockaby, B. Graeme; Conner, William H.; Hupp, Cliff R.

    2013-01-01

    Tidal freshwater wetlands are sensitive to sea level rise and increased salinity, although little information is known about the impact of salinification on nutrient biogeochemistry in tidal freshwater forested wetlands. We quantified soil nitrogen (N) and phosphorus (P) mineralization using seasonal in situ incubations of modified resin cores along spatial gradients of chronic salinification (from continuously freshwater tidal forest to salt impacted tidal forest to oligohaline marsh) and in hummocks and hollows of the continuously freshwater tidal forest along the blackwater Waccamaw River and alluvial Savannah River. Salinification increased rates of net N and P mineralization fluxes and turnover in tidal freshwater forested wetland soils, most likely through tree stress and senescence (for N) and conversion to oligohaline marsh (for P). Stimulation of N and P mineralization by chronic salinification was apparently unrelated to inputs of sulfate (for N and P) or direct effects of increased soil conductivity (for N). In addition, the tidal wetland soils of the alluvial river mineralized more P relative to N than the blackwater river. Finally, hummocks had much greater nitrification fluxes than hollows at the continuously freshwater tidal forested wetland sites. These findings add to knowledge of the responses of tidal freshwater ecosystems to sea level rise and salinification that is necessary to predict the consequences of state changes in coastal ecosystem structure and function due to global change, including potential impacts on estuarine eutrophication.

  1. A Site-Related Suitability Analysis for the Production of Biomass as a Contribution to Sustainable Regional Land-Use

    NASA Astrophysics Data System (ADS)

    Förster, Michael; Helms, Yvonne; Herberg, Alfred; Köppen, Antje; Kunzmann, Kathrin; Radtke, Dörte; Ross, Lutz; Itzerott, Sibylle

    2008-04-01

    The use of renewable energy in Europe offers the possibility of reducing greenhouse gas emissions, and contributes to energy security and independence. With the reform of the Common Agricultural Policy (CAP) and a variety of recently introduced national directives supporting renewable energy sources in the European Union, the economic attractiveness of bioenergy production has distinctly increased. This article combines an economic evaluation of biomass production with site-related natural conditions of the Havelland region, situated in the north-east area of Germany. Two methods for evaluating site-specific potential biomass yields were compared. For three example biomass crops, evaluations of yield estimations at agricultural lots for site-optimized suitability (SOS) and conventional suitability (CS) were carried out. Both modelling approaches were compared. The results of the GIS modelling indicate that the financial support for increasing the use of renewable energy with the German feed-in system, called Erneuerbare-Energien-Gesetz (EEG), will possibly lead to an increased cultivation of crops with high biomass output. This monocultural orientation of farming practices and the negative effects on the ecosystem could act in opposition to other environmental initiatives of the EU. The outputs of the SOS analysis show that high biomass production could be integrated into environmental policy proposals. Therefore, new EU policy should take modified subsidies into consideration in order to avoid developing conflicts between small-scale changes in landscape ecosystems caused by large-scale transformations in energy policy.

  2. Peak water limits to freshwater withdrawal and use

    PubMed Central

    Gleick, Peter H.; Palaniappan, Meena

    2010-01-01

    Freshwater resources are fundamental for maintaining human health, agricultural production, economic activity as well as critical ecosystem functions. As populations and economies grow, new constraints on water resources are appearing, raising questions about limits to water availability. Such resource questions are not new. The specter of “peak oil”—a peaking and then decline in oil production—has long been predicted and debated. We present here a detailed assessment and definition of three concepts of “peak water”: peak renewable water, peak nonrenewable water, and peak ecological water. These concepts can help hydrologists, water managers, policy makers, and the public understand and manage different water systems more effectively and sustainably. Peak renewable water applies where flow constraints limit total water availability over time. Peak nonrenewable water is observable in groundwater systems where production rates substantially exceed natural recharge rates and where overpumping or contamination leads to a peak of production followed by a decline, similar to more traditional peak-oil curves. Peak “ecological” water is defined as the point beyond which the total costs of ecological disruptions and damages exceed the total value provided by human use of that water. Despite uncertainties in quantifying many of these costs and benefits in consistent ways, more and more watersheds appear to have already passed the point of peak water. Applying these concepts can help shift the way freshwater resources are managed toward more productive, equitable, efficient, and sustainable use. PMID:20498082

  3. Soil Moisture Active and Passive Microwave Products: Intercomparison and Evaluation over a Sahelian Site

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper presents a comparison and an evaluation of five soil moisture products based on satellite-based passive and active microwave measurements. Products are evaluated for 2005-2006 against ground measurements obtained from the soil moisture network deployed in Mali (Sahel) in the framework of ...

  4. Carbon Sources and Sinks in Freshwater and Estuarine Environments of the Arctic Coastal Plain.

    NASA Astrophysics Data System (ADS)

    Lougheed, V.; Tarin, G.; Tweedie, C. E.

    2015-12-01

    The source, fate and transport of terrestrially derived carbon as it moves through multiple landscape components (i.e. groundwater, rivers, ponds, wetlands, lakes, lagoons) on a path from land to sea in permafrost-dominated watersheds is poorly understood. Critical to our understanding of Arctic carbon budgets are small, but numerically abundant watersheds that dominate the landscape of the Alaskan Arctic Coastal Plain (ACP), which appears to be changing rapidly in response to climate warming and other environmental changes. This study was designed to understand the contribution of freshwater ecosystems in the Arctic to regional carbon budgets. pCO2 was logged continually in ponds, lakes and streams sites near Barrow, AK and recorded across transects in Elson Lagoon, a coastal lagoon on the Beaufort coast. Average pCO2 of the pond over 2 weeks in August (1196 μatm) was double that of lakes and streams, and four times higher than Elson Lagoon (216 μatm); thus, the Lagoon was acting as a small sink while the pond was a substantial source of CO2 to the atmosphere. The uptake of CO2 in Elson Lagoon, combined with an oversaturation of O2, may be due to enhanced primary productivity caused by freshwater nutrient inputs. Conversely, pCO2, chlorophyll-a and DOC increased substantially in the pond after a large rain event, suggesting that run-off introduced large amounts of terrestrially-derived carbon from groundwater. Further studies are required to elucidate the fate and transport of carbon in the numerically abundant smaller watersheds of the Arctic.

  5. Developing Terrestrial Trophic Models for Petroleum and Natural Gas Exploration and Production Sites: The Oklahoma Tallgrass Prairie Preserve Example

    SciTech Connect

    Stevenson, M; Coty, J; Stewart, J; Carlsen, T; Callaham, M

    2001-01-26

    This document details procedures to be used when constructing a conceptual terrestrial trophic model for natural gas and oil exploration and production sites. A site conceptual trophic model is intended for use in evaluating ecological impacts of oil and brine releases at E&P sites from a landscape or ecosystem perspective. The terrestrial trophic model protocol was developed using an example site, the Tallgrass Prairie Preserve (TPP) in Oklahoma. The procedure focuses on developing a terrestrial trophic model using information found in the primary literature, and augmented using site-specific research where available. Although the TPP has been the subject of considerable research and public interest since the high-profile reintroduction of bison (Bison bison) in 1993, little formal work has been done to develop a food web for the plant and animal communities found at the preserve. We describe how to divide species into guilds using explicit criteria on the basis of resource use and spatial distribution. For the TPP, sixteen guilds were developed for use in the trophic model, and the relationships among these guilds were analyzed. A brief discussion of the results of this model is provided, along with considerations for its use and areas for further study.

  6. Lessons in divergence and convergence in marine and freshwater iron-oxidizing bacteria

    NASA Astrophysics Data System (ADS)

    Emerson, D.; McBeth, J. M.; Fleming, E. J.; Moyer, C. L.

    2011-12-01

    Lithoautotrophic oxygen-dependent Fe-oxidizing bacteria (FeOB) that grow at circumneutral pH are found in marine and freshwater habitats and play an important role in Fe-transformations. These obligately microaerophilic bacteria form unique biogenic Fe minerals that can become fossilized. Their obligate metabolism suggests they may been present during the late Archaean or early Proterozoic when oxygen was in low abundance and high Fe(II) concentrations existed in the ocean. Phylogenetic analysis indicates that members of the marine FeOB community belong to the Zetaproteobacteria, a novel class of Proteobacteria, whereas dominant freshwater FeOB belong to the class Betaproteobacteria. Despite different evolutionary histories, freshwater and marine strains share remarkable morphological and physiological similarities. As an illustration, this work describes the discovery of a sheathed FeOB that grows as a surface film on thick microbial mats composed of FeOB at hydrothermal vents associated with Loihi Seamount, an active undersea volcano. This uncultivated organism bears striking resemblance to the freshwater sheath forming Fe-oxidizer, Leptothrix ochracea; however by using different culture-independent techniques, including specific fluorescence in-situ hybridization (FISH) probes to the SSU rRNA gene, we show that it is not L. ochracea, but a member of the Zetaproteobacteria. The strong morphological similarities between these organisms likely represent a case of convergent evolution. To further constrain relationships between members of the marine and freshwater groups of FeOB we surveyed four iron mat communities along a salinity gradient, from freshwater to near full strength seawater, in a tidal region of the Sheepscot river in Maine. The mat communities were examined microscopically, and all had abundant evidence for biogenically formed iron oxides. Community DNA was extracted from each site and community composition, as assessed by tagged pyrosequencing of V4

  7. Monitoring Production of Methane from Spills of Gasoline at UST Release Sites.

    EPA Science Inventory

    ORD-362 (Rev 06/10/05) (Webforms v2.4) Abstract: Anaerobic biodegradation of the BTEX compounds can produce substantial concentrations of methane in ground water at gasoline spill sites. This methane can escape the ground water, move through the unsaturated zone and potentiall...

  8. VOLATILE ORGANIC COMPOUNDS AND ISOPRENE OXIDATION PRODUCTS AT A TEMPERATE DECIDUOUS FOREST SITE

    EPA Science Inventory

    Biogenic volatile compounds (BVOCs) and their role in atmospheric oxidant formation were investigated at a forest site near Oak Ridge, Tennessee, as part of the Nashville Southern Oxidants Study (SOS) in July 1995. Of 98 VOCs detected, a major fraction were anthropogenic VOCs suc...

  9. Is there a need for site productivity functions for short-rotation woody crop plantings?

    SciTech Connect

    Downing, M.; Tuskan, G.A.

    1995-07-06

    For over a decade, researchers have used small-scale research plots to assist development and selection of high yielding, pest-resistant clones of fast-growing hardwoods such as hybrid poplar (Populus spp.). Substantial advances have been made in the techniques and criteria for screening species and selecting clones. Data from these research plots indicate that the ultimate performance of selected clones is dependent upon variable factors in the environment. Until now, researchers could only determine the suitability of a given site for such clones, not the actual yield potential of the site. Recently in the north central US, several clones were planted on larger-than-research-scale plots on private land recontracted under the Conservation Reserve Program (CRP). The historical database could not provide a framework which would allow producers to predict the yield potential of a particular clone on a specific site. Through a systematic combination of clonal trials on experimental research-scale plots and operational plantings on 50 to 100 acre agricultural-scale field plots, it may be possible to develop yield functions or site quality equations which would predict biomass yields at rotation for selected clones. Such estimates will (1) reduce the probability of planting failure, (2) allow maximum expression of the genetic potential of selected superior clones, and thus (3) facilitate accurate economic planning for both the producer and conversion facility manager.

  10. Development of Unmanned Aerial Vehicles for Site-Specific Crop Production Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unmanned Aerial Vehicles (UAV) have been developed and applied to support the practice of precision agriculture. Compared to piloted aircrafts, an Unmanned Aerial Vehicle can focus on much smaller crop fields with much lower flight altitude than regular airplanes to perform site-specific management ...

  11. Productivity, mortality, and response to disturbance of nesting Swainson's hawks on the Hanford Site

    SciTech Connect

    Poole, L.D.; Marr, N.V.; McCorquodale, S.M.

    1988-03-01

    The objectives of this study were to characterize Swainson's hawk (Buteo swainson) use of the US Department of Energy (DOE) Hanford Site and to evaluate the potential for engineering and other human activities on the Hanford Site to negatively affect the nesting Swainson's hawk population. Activities associated with the Basalt Waste Isolation Project (BWIP) were used as the primary external stimuli in studying hawk responses to potential human disturbance. Parked and moving vehicles were the most common disturbance sources observed in Swainson's hawk territories. Hawks appeared to be sensitive to disturbance from pedestrians and slow-moving vehicles near nests. Novel stimuli were much more likely to evoke strong responses than were recurring events. Adult hawks reacted more frequently and vigorously than did juveniles. When disturbed, adult hawks usually flew toward the location of the disturbance; juvenile hawks usually flew away from disturbances. Human activity associated with BWIP may have had negative on one pair of nesting Swainson's hawks and may have precluded the use of an additional traditional nesting territory. Negative impacts to nesting Swainson's hawks from human activity could be minimized by confining activities to the non-nesting period or to distances greater than 2.2 km from nest sites. Tree groves and elevated perches, including utility poles, across the Hanford Site are probably critical to the success of nesting Swainson's hawks. Potential mitigation strategies associated with energy research and development activities on the Hanford Site could include provisions for maintenance and establishment of drought-tolerant trees and native vegetation. 22 refs., 5 figs., 3 tabs.

  12. A well system to recover usable water from a freshwater-saltwater aquifer in Puerto Rico

    USGS Publications Warehouse

    Zack, Allen L.

    1988-01-01

    Aquifers in coastal areas of Puerto Rico commonly contain limited quantities of freshwater that occur as a thin layer at the surface of the water table. Many wells have been abandoned because well screens were inadvertently placed in saltwater parts of the aquifer. A scavenger/production well couple that can be installed in an abandoned well, screened in both freshwater and saltwater parts of the aquifer, provides an effective method for extracting freshwater from the well. Withdrawal of a sufficient quantity of water having low chloride concentrations, by use of a well couple, depends on the upward movement of saltwater within the aquifer when the well is pumped. Upward movement of saltwater depends on the relative concentrations of chloride in the borehole and on the distribution of horizontal and vertical hydraulic conductivity of the aquifer. For any well screened in an aquifer that contains both freshwater and saltwater, a family of curves can be constructed to represent all combinations of pumping rates and corresponding chloride loads when the scavenger well and the production well are being pumped simultaneously. The curves permit estimates of optimal withdrawals of freshwater based on the desired pumping rates and the levels of chloride concentration required for each well.

  13. A realistic freshwater forcing protocol for ocean-coupled climate models

    NASA Astrophysics Data System (ADS)

    van den Berk, J.; Drijfhout, S. S.

    2014-09-01

    A high-end scenario of polar ice loss from the Greenland and Antarctic ice sheet is presented with separate projections for different mass-loss sites up to the year 2100. For each large ice sheet three potential sources of freshwater release to the ocean are considered: run-off from surface melt, basal melt through heat exchange with the ocean, and iceberg calving and subsequent mass loss through melt of drifting icebergs. The location and relative magnitude of freshwater forcing due to drifting icebergs is calculated from a separate iceberg drift simulation. We assume fixed annual spatial patterns with magnitudes varying in time. These magnitudes are based on a severe warming scenario based on expert elicitation. The resultant freshwater forcing is applied to a global climate model and the effects on sea-level rise are discussed. The simulations show strong sea level rise on the Antarctic continental shelves. The effect on the Atlantic overturning circulation is very small, however.

  14. Global estimation of freshwater fluxes and freshwater oceanic transport from satellite data

    SciTech Connect

    Gautier, C.; Peterson, P.; Jones, C.

    1996-12-01

    The exchange of moisture and heat fluxes across the ocean-atmosphere interface exerts a strong influence on the oceanic and atmospheric circulations, and therefore on the maintenance of the climate system equilibrium. Observational measurements of these fluxes over large areas of the ocean`s surface are limited by the lack of in-situ data. This paper reports research efforts to estimate the freshwater budget and freshwater oceanic transport using remotely sensed data. Six years (1988--1993) of surface evaporation estimated with satellite and in-situ data re combined with satellite-derived precipitation to compute the freshwater budget and freshwater oceanic transport. The interannual variability of the freshwater budget and oceanic transport eliminates are examined for two contrasting events: the La Nina of 1988--89 and the El Nino condition during 1991--92, one of the longest El Nino episodes on record. Possible implications for future climate change are discussed.

  15. Effects of freshwater petroleum contamination on amphibian hatching and metamorphosis

    SciTech Connect

    Mahaney, P.A. . Dept. of Zoology)

    1994-02-01

    This study examined the effects of freshwater petroleum contamination on amphibian reproduction. The primary objectives were to assess the potential environmental and physiological impacts of runoff petroleum products on amphibians, using the green tree frog (Hyla cinerea) as a target species and engine crankcase oil as a contaminant. Egg hatching success, tadpole growth, and successful metamorphosis were measured in four concentrations of oil. The effects of oil on food source was also studied. Hatching success was not measurably influenced by the presence of oil. Tadpole and alga growth were negatively associated with the presence of oil. No tadpoles from the high concentration of oil treatments successfully metamorphosed.

  16. Assessment of selected fission products in the Savannah River Site environment

    SciTech Connect

    Carlton, W.H.; Denham, M.

    1997-04-01

    Most of the radioactivity produced by the operation of a nuclear reactor results from the fission process, during which the nucleus of a fissionable atom (such as 235U) splits into two or more nuclei, which typically are radioactive. The Radionuclide Assessment Program (RAP) has reported on fission products cesium, strontium, iodine, and technetium. Many other radionuclides are produced by the fission process. Releases of several additional fission products that result in dose to the offsite population are discussed in this publication. They are 95Zr, 95Nb, 103Ru, 106Ru, 141Ce, and 144Ce. This document will discuss the production, release, migration, and dose to humans for each of these selected fission products.

  17. Freshwater Variability in the Arctic Ocean and Subpolar North Atlantic: a Comparison from the 1990s to Present

    NASA Astrophysics Data System (ADS)

    Horn, Myriel; Rabe, Benjamin; Schauer, Ursula

    2016-04-01

    A significant increase in liquid freshwater content has been observed in the Arctic Ocean over the last 20 years, whereas the Arctic sea ice volume shrank significantly. In contrast, the North Atlantic became more saline in recent years. Both regions are of great importance for the global ocean circulation and climate, and salinity changes may have a profound impact on the global climate. We found that for the period between 1992 and 2013, the liquid freshwater content of the subpolar North Atlantic, calculated from objectively mapped in-situ salinity measurements, and the total freshwater content of the Arctic Ocean, i.e. the liquid freshwater content and freshwater stored in sea ice, are significantly negative correlated (r=-0.77). Moreover, the amount of the anomalies are of the same size. Furthermore, the time series hint at multi-decadal oscillations. The highest negative correlation with the total freshwater content of the Arctic Ocean can be found in the Irminger and Labrador Seas, while we observed a positive correlation east of the Mid-Atlantic Ridge at the path of the North Atlantic Current, which is the source of Atlantic Water entering the Arctic Ocean through the Nordic Seas. We suggest a redistribution of freshwater as a response to frequent changes in atmospheric pressure patterns. Under certain conditions the freshwater is re-routed and kept in the Arctic Ocean, while it is released under other conditions. We conclude that decadal scale changes of the freshwater content in the North Atlantic, particularly those in the deep water formation sites like the Labrador Sea, are originating in the Arctic Ocean.

  18. Comparing bioenergy production sites in the Southeastern US regarding ecosystem service supply and demand.

    PubMed

    Meyer, Markus A; Chand, Tanzila; Priess, Joerg A

    2015-01-01

    Biomass for bioenergy is debated for its potential synergies or tradeoffs with other provisioning and regulating ecosystem services (ESS). This biomass may originate from different production systems and may be purposefully grown or obtained from residues. Increased concerns globally about the sustainable production of biomass for bioenergy has resulted in numerous certification schemes focusing on best management practices, mostly operating at the plot/field scale. In this study, we compare the ESS of two watersheds in the southeastern US. We show the ESS tradeoffs and synergies of plantation forestry, i.e., pine poles, and agricultural production, i.e., wheat straw and corn stover, with the counterfactual natural or semi-natural forest in both watersheds. The plantation forestry showed less distinct tradeoffs than did corn and wheat production, i.e., for carbon storage, P and sediment retention, groundwater recharge, and biodiversity. Using indicators of landscape composition and configuration, we showed that landscape planning can affect the overall ESS supply and can partly determine if locally set environmental thresholds are being met. Indicators on landscape composition, configuration and naturalness explained more than 30% of the variation in ESS supply. Landscape elements such as largely connected forest patches or more complex agricultural patches, e.g., mosaics with shrub and grassland patches, may enhance ESS supply in both of the bioenergy production systems. If tradeoffs between biomass production and other ESS are not addressed by landscape planning, it may be reasonable to include rules in certification schemes that require, e.g., the connectivity of natural or semi-natural forest patches in plantation forestry or semi-natural landscape elements in agricultural production systems. Integrating indicators on landscape configuration and composition into certification schemes is particularly relevant considering that certification schemes are governance

  19. Potential restrictions for CO2 sequestration sites due to shale and tight gas production.

    PubMed

    Elliot, T R; Celia, M A

    2012-04-01

    Carbon capture and geological sequestration is the only available technology that both allows continued use of fossil fuels in the power sector and reduces significantly the associated CO(2) emissions. Geological sequestration requires a deep permeable geological formation into which captured CO(2)can be injected, and an overlying impermeable formation, called a caprock, that keeps the buoyant CO(2) within the injection formation. Shale formations typically have very low permeability and are considered to be good caprock formations. Production of natural gas from shale and other tight formations involves fracturing the shale with the explicit objective to greatly increase the permeability of the shale. As such, shale gas production is in direct conflict with the use of shale formations as a caprock barrier to CO(2) migration. We have examined the locations in the United States where deep saline aquifers, suitable for CO(2) sequestration, exist, as well as the locations of gas production from shale and other tight formations. While estimated sequestration capacity for CO(2) sequestration in deep saline aquifers is large, up to 80% of that capacity has areal overlap with potential shale-gas production regions and, therefore, could be adversely affected by shale and tight gas production. Analysis of stationary sources of CO(2) shows a similar effect: about two-thirds of the total emissions from these sources are located within 20 miles of a deep saline aquifer, but shale and tight gas production could affect up to 85% of these sources. These analyses indicate that colocation of deep saline aquifers with shale and tight gas production could significantly affect the sequestration capacity for CCS operations. This suggests that a more comprehensive management strategy for subsurface resource utilization should be developed. PMID:22352312

  20. Comparing Bioenergy Production Sites in the Southeastern US Regarding Ecosystem Service Supply and Demand

    PubMed Central

    Meyer, Markus A.; Chand, Tanzila; Priess, Joerg A.

    2015-01-01

    Biomass for bioenergy is debated for its potential synergies or tradeoffs with other provisioning and regulating ecosystem services (ESS). This biomass may originate from different production systems and may be purposefully grown or obtained from residues. Increased concerns globally about the sustainable production of biomass for bioenergy has resulted in numerous certification schemes focusing on best management practices, mostly operating at the plot/field scale. In this study, we compare the ESS of two watersheds in the southeastern US. We show the ESS tradeoffs and synergies of plantation forestry, i.e., pine poles, and agricultural production, i.e., wheat straw and corn stover, with the counterfactual natural or semi-natural forest in both watersheds. The plantation forestry showed less distinct tradeoffs than did corn and wheat production, i.e., for carbon storage, P and sediment retention, groundwater recharge, and biodiversity. Using indicators of landscape composition and configuration, we showed that landscape planning can affect the overall ESS supply and can partly determine if locally set environmental thresholds are being met. Indicators on landscape composition, configuration and naturalness explained more than 30% of the variation in ESS supply. Landscape elements such as largely connected forest patches or more complex agricultural patches, e.g., mosaics with shrub and grassland patches, may enhance ESS supply in both of the bioenergy production systems. If tradeoffs between biomass production and other ESS are not addressed by landscape planning, it may be reasonable to include rules in certification schemes that require, e.g., the connectivity of natural or semi-natural forest patches in plantation forestry or semi-natural landscape elements in agricultural production systems. Integrating indicators on landscape configuration and composition into certification schemes is particularly relevant considering that certification schemes are governance

  1. The Hawaiian freshwater algae biodiversity survey (2009–2014): systematic and biogeographic trends with an emphasis on the macroalgae

    PubMed Central

    2014-01-01

    Background A remarkable range of environmental conditions is present in the Hawaiian Islands due to their gradients of elevation, rainfall and island age. Despite being well known as a location for the study of evolutionary processes and island biogeography, little is known about the composition of the non-marine algal flora of the archipelago, its degree of endemism, or affinities with other floras. We conducted a biodiversity survey of the non-marine macroalgae of the six largest main Hawaiian Islands using molecular and microscopic assessment techniques. We aimed to evaluate whether endemism or cosmopolitanism better explain freshwater algal distribution patterns, and provide a baseline data set for monitoring future biodiversity changes in the Hawaiian Islands. Results 1,786 aquatic and terrestrial habitats and 1,407 distinct collections of non-marine macroalgae were collected from the islands of Kauai, Oahu, Molokai, Maui, Lanai and Hawaii from the years 2009–2014. Targeted habitats included streams, wet walls, high elevation bogs, taro fields, ditches and flumes, lakes/reservoirs, cave walls and terrestrial areas. Sites that lacked freshwater macroalgae were typically terrestrial or wet wall habitats that were sampled for diatoms and other microalgae. Approximately 50% of the identifications were of green algae, with lesser proportions of diatoms, red algae, cyanobacteria, xanthophytes and euglenoids. 898 DNA sequences were generated representing eight different markers, which enabled an assessment of the number of taxonomic entities for genera collected as part of the survey. Forty-four well-characterized taxa were assessed for global distribution patterns. This analysis revealed no clear biogeographic affinities of the flora, with 27.3% characterized as “cosmopolitan”, 11.4% “endemic”, and 61.3% as intermediate. Conclusions The Hawaiian freshwater algal biodiversity survey represents the first comprehensive effort to characterize the non

  2. The First Detailed 2H and 18O Isoscapes of Freshwater in Scotland

    NASA Astrophysics Data System (ADS)

    Meier-Augenstein, W.; Hoogewerff, J.; Kemp, H. F.; Frew, D.

    2012-04-01

    Scotland's freshwater lochs and reservoirs provide a vital resource for sustaining biodiversity, agriculture, food production as well as for human consumption. Regular monitoring of freshwater quality by the Scottish Environmental Protection Agency (SEPA) fulfils the legislative requirements but new scientific methods involving stable isotope analysis present an opportunity for delivering on current and nascent government policies [1] and gaining a greater understanding of Scottish waters and their importance in the context of climate change, environmental sustainability and the aforementioned functions. In brief, 2H and 18O isoscapes of Scottish freshwater could be used to support fundamental and applied research in: • Climate change - These first ever isoscapes will provide a baseline against which future environmental impact can be assessed due to changes in the characteristic isotope composition of freshwater lochs and reservoirs. • Scottish branding - Location specific stable isotope signatures of Scottish freshwater have the potential to be used as a tool for provenancing and thus protecting premium Scottish produce such as Scottish beef, Scottish berries and Scottish Whisky. During 2011, freshwater samples were collected with the support of SEPA from more than 80 freshwater lochs and reservoirs across Scotland. Here we present the result of the 2H and 18O stable isotope analyses of these water samples together with the first isoscapes generated based on these data. [1] Adaptation Framework - Adapting Our Ways: Managing Scotland's Climate Risk (2009): Scotland's Biodiversity: It's in Your Hands - A strategy for the conservation and enhancement of biodiversity in Scotland (2005); Recipe For Success - Scotland's National Food and Drink Policy (2009); Scottish Planning Policy Environmental Report (2009); Scottish Planning Policy (SPP) 15 Planning for Rural Development (2005); National Planning Policy Guideline (NPPG) 14: Natural Heritage (1999).

  3. Nanoaerosols Including Radon Decay Products in Outdoor and Indoor Air at a Suburban Site

    PubMed Central

    Smerajec, Mateja; Vaupotič, Janja

    2012-01-01

    Nanoaerosols have been monitored inside a kitchen and in the courtyard of a suburban farmhouse. Total number concentration and number size distribution (5–1000 nm) of general aerosol particles, as measured with a Grimm Aerosol SMPS+C 5.400 instrument outdoors, were mainly influenced by solar radiation and use of farming equipment, while, indoors, they were drastically changed by human activity in the kitchen. In contrast, activity concentrations of the short-lived radon decay products 218Po, 214Pb, and 214Bi, both those attached to aerosol particles and those not attached, measured with a Sarad EQF3020-2 device, did not appear to be dependent on these activities, except on opening and closing of the kitchen window. Neither did a large increase in concentration of aerosol particles smaller than 10 or 20 nm, with which the unattached radon products are associated, augment the fraction of the unattached decay products significantly. PMID:22523488

  4. Lipid production and mixotrophic growth features of cyanobacterial strains isolated from various aquatic sites.

    PubMed

    Modiri, Sima; Sharafi, Hakimeh; Alidoust, Leila; Hajfarajollah, Hamidreza; Haghighi, Omid; Azarivand, Aisan; Zamanzadeh, Zahra; Zahiri, Hossein Shahbani; Vali, Hojatollah; Noghabi, Kambiz Akbari

    2015-03-01

    The present study was conducted to determine the potential of five cyanobacteria strains isolated from aquatic zones to induce lipid production. The phylogenetic affiliation of the isolates was determined by 16S rRNA gene sequencing. Amongst the isolates, an efficient cyanobacterium, Synechococcus sp. HS01 showing maximal biomass and lipid productivity, was selected for further studies. In order to compare lipid productivity, the HS01 strain was grown in different media to screen potential significant culture ingredients and to evaluate mixotrophic cultivation. Mixotrophic cultivation of the strain using ostrich oil as a carbon source resulted in the best lipid productivity. GC analysis of fatty acid methyl esters of the selected cyanobacterial strain grown in media supplemented with ostrich oil showed a high content of C16 (palmitoleic acid and palmitic acid) and C18 (linoleic acid, oleic acid and linolenic acid) fatty acids of 42.7 and 42.8 %, respectively. Transmission electron micrographs showed that the HS01 cells exhibited an elongated rod-shaped appearance, either isolated, paired, linearly connected or in small clusters. According to initial experiments, ostrich oil, NaNO3 and NaCl were recognized as potential essential nutrients and selected for optimization of media with the goal of maximizing lipid productivity. A culture optimization technique using the response surface method demonstrated a maximum lipid productivity of 56.5 mg l(-1) day(-1). This value was 2.82-fold higher than that for the control, and was achieved in medium containing 1.12 g l(-1) NaNO3, 1 % (v/v) ostrich oil and 0.09 % (w/v) NaCl. PMID:25575545

  5. Identification of characteristic organic contaminants in wastewaters from modern paper production sites and subsequent tracing in a river.

    PubMed

    Dsikowitzky, Larissa; Botalova, Oxana; Illgut, Sarah; Bosowski, Sylwana; Schwarzbauer, Jan

    2015-12-30

    The paper industry is one of the most significant industrial branches that contributes to water pollution. Recent studies regarding the chemical composition of wastewaters from modern paper production sites are sparse, and organic contaminants originating from this source may remain undetected and uncontrolled. Therefore, for this study, non-target screening analyses of wastewaters from five different paper production sites were performed, including an extended analysis of one facility, for the identification of volatile non-polar to semi-polar organic contaminants. The identified contaminants were also traced in the adjacent river. Several specific agents related to paper production, including photoinitiators, ink and thermal paper constituents, were present in most wastewaters and were therefore considered to be characteristic paper industry contaminants. A couple of contaminants identified in this study are being reported for the first time and might be toxic, but have been neglected in previous studies. Bisphenol A and 2,4,7,9-tetramethyl-5-decyne-4,7-diol were found in untreated wastewaters, treated wastewater and in river water. Bisphenol A was present in river water downstream from where the paper industry discharges at a concentration that was reported to affect the reproduction of gastropods. Thus, our findings imply that paper industry discharges pose a risk to the populations of sensitive macroinvertebrates. PMID:26188868

  6. 76 FR 5832 - Electrolux Home Products, Inc., Electrolux Major Appliances Division, Including On-Site Leased...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-02

    ... Federal Register on August 19, 2009 (74 FR 41935). The workers produce laundry equipment. At the request... Employment and Training Administration Electrolux Home Products, Inc., Electrolux Major Appliances Division... to Apply for Worker Adjustment Assistance on June 25, 2009, applicable to workers of Electrolux...

  7. Development of a method for estimating emissions from oil and gas production sites utilizing remote observations

    EPA Science Inventory

    There is a lack of information on emissions of ozone precursors, hazardous air pollutants, and greenhouse gases from oil and gas production operations, and measurement of these emissions presents many challenges. Assessment is complicated by the fugitive nature ofthe emissions, v...

  8. DIGITAL IMAGE ANALYSIS REPORTS: THE CONVERSION OF EPIC'S TRADITIONAL SITE CHARACTERIZATION PRODUCT

    EPA Science Inventory

    Over the past several years EPIC has been exploring the practicality and cost-effectiveness of providing its traditional hard-copy report product in digital form. This conversion has a number of practical uses including- 1) compatibility for use as data layers in a GIS; 2) transp...

  9. The Potential of Carbonyl Sulfide as a Tracer for Gross Primary Productivity at Flux Tower Sites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Regional/continental scale studies of atmospheric carbonyl sulfide (OCS) seasonal dynamics and leaf level studies of plant OCS uptake have shown a close relationship to CO2 dynamics and uptake, suggesting potential for OCS as a tracer for gross primary productivity (GPP). Canopy CO2 and OCS differen...

  10. Impressions, Improvisations and Compositions: Reframing Children's Text Production in Social Network Sites

    ERIC Educational Resources Information Center

    Dowdall, Clare

    2009-01-01

    Social networking can currently be described as a mainstream youth activity, with almost half of 8-17-year-old children, who have access to the Internet, claiming to participate. As an activity it is of particular interest to literacy educators because it is enacted through the production and consumption of text. However, a growing body of…

  11. Listeria monocytogenes from slaughter plant to fully cooked product – sources, sites and potential for intervention

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Listeria monocytogenes is a human pathogen that has been associated with fully cooked poultry products. This organism is not highly prevalent on live broilers; prevalence tends to increase as carcasses proceed through an initial processing plant. In one study we found no L. monocytogenes on pre-sc...

  12. Z{sup '} production at the LHC in the four-site Higgsless model

    SciTech Connect

    Accomando, Elena; De Curtis, Stefania; Dominici, Daniele; Fedeli, Luca

    2011-01-01

    We study the phenomenology of the neutral gauge sector of the four-site Higgsless model, based on the SU(2){sub L}xSU(2){sub 1}xSU(2){sub 2}xU(1){sub Y} gauge symmetry, at present colliders. The model predicts the existence of two neutral and four charged extra gauge bosons, Z{sub 1,2} and W{sub 1,2}{sup {+-}}. We expand and update a previous study, by concentrating on the neutral sector. We derive new limits on Z{sub 1,2}-boson masses and couplings from recent direct searches at the Tevatron. We moreover estimate the discovery potential at the Tevatron with a project luminosity L=10 fb{sup -1}, and at the 7 TeV LHC with L=1 fb{sup -1}. In contrast to other Higgsless theories characterized by almost fermiophobic extra gauge bosons, the four-site model allows sizable Z{sub 1,2}-boson couplings to standard model fermions. Owing to this feature, we find that in the next 2 years the extra Z{sub 1,2} bosons could be discovered in the favored Drell-Yan channel at the 7 TeV LHC for Z{sub 1,2} masses in the TeV region, depending on model parameters.

  13. Forging the strategic linkage between facilities management and the corporation -- Production of a sites comprehensive plan

    SciTech Connect

    Petersen, T.P.; Williams, J.L.; Reyes, C.M.

    1997-06-01

    In 1996, Sandia National Laboratories (SNL) undertook a major effort to develop, produce, and execute a Sites Comprehensive Plan. Fundamentally, this document is intended to serve as a tool to clarify the strategic link between (1) current and future mission needs and responsibilities, and (2) the condition, capacity, and required amount of facilities space and infrastructure. It documents the Facilities Group`s response to programmatic requests for capability and makes the case for the required facilities investments through integrated master plans that document SNL`s short- and long-range needs. This paper outlines the history and business environment that led to the writing of the plan, the organizations and committees involved, the steps required to develop and produce it, the challenges encountered in selling it, both internally and externally, and the issues involved in executing the proposed actions set forth in the plan. The paper also articulates the benefits gained by Facilities Management (FM) and the corporation, as well as the lessons learned in producing the plan. SNL has concluded that the Sites Comprehensive Plan was a worthwhile effort in terms of retained facilities investment funding, increased awareness of facility needs, and other measures, despite the significant effort and cost required to produce it.

  14. A multi-site approach towards integrating environmental management in the wine production industry.

    PubMed

    Walsdorff, A; van Kraayenburg, M; Barnardt, C A

    2005-01-01

    Nine wineries and a water bottling plant situated in the Franschhoek Valley, South Africa, have decided to lead the way towards creating a safer and more sustainable environment in the Valley. As part of the Vignerons de Franschhoek ECO Association (VFEA), they adopted a multi-site approach and obtained, in December 2003, the first ISO 14001 multi-site certification in South Africa. This proactive approach allows them better overall environmental performances through mutual motivation, information sharing and comparison of practices by the different participating organisations of Franschhoek Valley. At the initiation of the project, the major concerns were associated with a lack of sound environmental management and training of employees. Of particular concern was also the lack of monitoring and measurement of environmental performance key indicators, especially in water consumption and wastewater disposal areas. Although the system is still in its juvenile stage, it already showed some effluent quality improvements through better wastewater management, better control over chemical stores as well as definite improvement in water management and increase in solid wastes recycling. The latter improvements will definitely entail long-term cost savings should the system be continually and properly maintained. It is the intention of the VFEA to create a more environmentally friendly and sustainable Valley by convincing others to be more environmentally responsive and expanding the ISO 14001 principles to other areas of the organisations including the farms, to other wineries and ultimately to the whole Franschhoek Valley. PMID:15771100

  15. Evaluation and Intercomparison of MODIS and GEOV1 Global Leaf Area Index Products over Four Sites in North China

    PubMed Central

    Li, Zhenwang; Tang, Huan; Zhang, Baohui; Yang, Guixia; Xin, Xiaoping

    2015-01-01

    This study investigated the performances of the Moderate Resolution Imaging Spectroradiometer (MODIS) and GEOLAND2 Version 1 (GEOV1) Leaf Area Index (LAI) products using ground measurements and LAI reference maps over four sites in North China for 2011–2013. The Terra + Aqua MODIS and Terra MODIS LAI retrieved by the main algorithm and GEOV1 LAI within the valid range were evaluated and intercompared using LAI reference maps to assess their uncertainty and seasonal variability The results showed that GEOV1 LAI is the most similar product with the LAI reference maps (R2 = 0.78 and RMSE = 0.59). The MODIS products performed well for biomes with low LAI values, but considerable uncertainty arose when the LAI was larger than 3. Terra + Aqua MODIS (R2 = 0.72 and RMSE = 0.68) was slightly more accurate than Terra MODIS (R2 = 0.57 and RMSE = 0.90) for producing slightly more successful observations. Both MODIS and GEOV1 products effectively followed the seasonal trajectory of the reference maps, and GEOV1 exhibited a smoother seasonal trajectory than MODIS. MODIS anomalies mainly occurred during summer and likely occurred because of surface reflectance uncertainty, shorter temporal resolutions and inconsistency between simulated and MODIS surface reflectances. This study suggests that further improvements of the MODIS LAI products should focus on finer algorithm inputs and improved seasonal variation modeling of MODIS observations. Future field work considering finer biome maps and better generation of LAI reference maps is still needed. PMID:25781509

  16. Evaluation and intercomparison of MODIS and GEOV1 global leaf area index products over four sites in North China.

    PubMed

    Li, Zhenwang; Tang, Huan; Zhang, Baohui; Yang, Guixia; Xin, Xiaoping

    2015-01-01

    This study investigated the performances of the Moderate Resolution Imaging Spectroradiometer (MODIS) and GEOLAND2 Version 1 (GEOV1) Leaf Area Index (LAI) products using ground measurements and LAI reference maps over four sites in North China for 2011-2013. The Terra + Aqua MODIS and Terra MODIS LAI retrieved by the main algorithm and GEOV1 LAI within the valid range were evaluated and intercompared using LAI reference maps to assess their uncertainty and seasonal variability The results showed that GEOV1 LAI is the most similar product with the LAI reference maps (R2 = 0.78 and RMSE = 0.59). The MODIS products performed well for biomes with low LAI values, but considerable uncertainty arose when the LAI was larger than 3. Terra + Aqua MODIS (R2 = 0.72 and RMSE = 0.68) was slightly more accurate than Terra MODIS (R2 = 0.57 and RMSE = 0.90) for producing slightly more successful observations. Both MODIS and GEOV1 products effectively followed the seasonal trajectory of the reference maps, and GEOV1 exhibited a smoother seasonal trajectory than MODIS. MODIS anomalies mainly occurred during summer and likely occurred because of surface reflectance uncertainty, shorter temporal resolutions and inconsistency between simulated and MODIS surface reflectances. This study suggests that further improvements of the MODIS LAI products should focus on finer algorithm inputs and improved seasonal variation modeling of MODIS observations. Future field work considering finer biome maps and better generation of LAI reference maps is still needed. PMID:25781509

  17. Effect of salt treatments on survival and consumer acceptance of freshwater prawn, Macrobrachium rosenbergii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Post harvest acclimation of live freshwater prawns to a mixture of water and marine salt increases the consumer acceptability of the finished product. However, the high cost of marine salts prohibits their use in commercial practice. Therefore, the identification of successful, cost effective salt a...

  18. Effects of Pollution on Freshwater Organisms.

    PubMed

    Choudri, B S; Baawain, Mahad

    2016-10-01

    This review includes works published in the general scientific literature during 2015 on the effects of anthropogenic pollutants on freshwater organisms. It begins with two broad sections: research reviews and broad field studies and surveys. This is followed by reviews of research categorized in sections to reflect the pollutant class. These sections include wastewater, stormwater and non-point source pollution, nutrients, sediment cap materials and suspended clays, botanical extracts, surfactants, metals, persistent organic pollutants, pharmaceuticals, endocrine disruptors, pesticides, petroleum hydrocarbons and polycyclic aromatic hydrocarbons (PAHs), ionic liquids, and nanomaterials. The final section includes works describing innovations in the field of freshwater pollution research. PMID:27620107

  19. Khazar Iodine Production Plant Site Remediation in Turkmenistan. NORM Contaminated Waste Repository Establishment - 12398

    SciTech Connect

    Gelbutovskiy, Alexander B.; Cheremisin, Peter I.; Troshev, Alexander V.; Egorov, Alexander J.; Boriskin, Mikhail M.; Bogod, Mikhail A.

    2012-07-01

    Radiation safety provisions for NORM contaminated areas are in use in a number of the former Soviet republics. Some of these areas were formed by absorbed radionuclides at the iodine and bromine extraction sites. As a rule, there are not any plant radiation monitoring systems nor appropriate services to ensure personnel, population and environmental radiation safety. The most hazardous sites are those which are situated in the Caspian Sea coastal zone. The bulk of the accumulated waste is represented by a loose mixture of sand and charcoal, which was basically used as the iodine extraction sorbent. The amounts of these wastes were estimated to be approximately 20,000 metric tons. The waste contamination is mainly composed of Ra-226 (U-238 decay series) and Ra-224, Ra-228 (Th-232 decay series). In 2009, the 'ECOMET-S', a Closed Joint-Stock Company from St. Petersburg, Russian Federation, was authorized by the Turkmenistan government to launch the rehabilitation project. The project includes D and D activities, contaminated areas remediation, collected wastes safe transportation to the repository and its disposal following repository closure. The work at the Khazar chemical plant started in September, 2010. Comprehensive radiological surveys to estimate the waste quantities were carried out in advance. In course of the rehabilitation work at the site of the Khazar chemical plant additional waste quantities (5,000 MT, 10,000 m{sup 3}) were discovered after the sludge was dumped and drained. Disposal volumes for this waste was not provided initially. The additional volume of the construction wastes was required in order to accommodate all the waste to be disposed. For the larger disposal volume the project design enterprise VNIPIET, offered to erect a second wall outside the existing one and this solution was adopted. As of May, 2011, 40,575 m{sup 3} of contaminated waste were collected and disposed safely. This volume represents 96.6% of the initial repository volume

  20. FRESHWATER INFLOWS: WATER FOR HEALTHY ESTUARIES CONFERENCE (MX96476507

    EPA Science Inventory

    The grantee will hold an interstate workshop on Freshwater Inflow issues in the Gulf of Mexico coastal region. The conference will identify water management questions to be addressed regarding providing freshwater inflows to estuaries, update participants on the current scientif...

  1. Subsurface Hybrid Power Options for Oil & Gas Production at Deep Ocean Sites

    SciTech Connect

    Farmer, J C; Haut, R; Jahn, G; Goldman, J; Colvin, J; Karpinski, A; Dobley, A; Halfinger, J; Nagley, S; Wolf, K; Shapiro, A; Doucette, P; Hansen, P; Oke, A; Compton, D; Cobb, M; Kopps, R; Chitwood, J; Spence, W; Remacle, P; Noel, C; Vicic, J; Dee, R

    2010-02-19

    An investment in deep-sea (deep-ocean) hybrid power systems may enable certain off-shore oil and gas exploration and production. Advanced deep-ocean drilling and production operations, locally powered, may provide commercial access to oil and gas reserves otherwise inaccessible. Further, subsea generation of electrical power has the potential of featuring a low carbon output resulting in improved environmental conditions. Such technology therefore, enhances the energy security of the United States in a green and environmentally friendly manner. The objective of this study is to evaluate alternatives and recommend equipment to develop into hybrid energy conversion and storage systems for deep ocean operations. Such power systems will be located on the ocean floor and will be used to power offshore oil and gas exploration and production operations. Such power systems will be located on the oceans floor, and will be used to supply oil and gas exploration activities, as well as drilling operations required to harvest petroleum reserves. The following conceptual hybrid systems have been identified as candidates for powering sub-surface oil and gas production operations: (1) PWR = Pressurized-Water Nuclear Reactor + Lead-Acid Battery; (2) FC1 = Line for Surface O{sub 2} + Well Head Gas + Reformer + PEMFC + Lead-Acid & Li-Ion Batteries; (3) FC2 = Stored O2 + Well Head Gas + Reformer + Fuel Cell + Lead-Acid & Li-Ion Batteries; (4) SV1 = Submersible Vehicle + Stored O{sub 2} + Fuel Cell + Lead-Acid & Li-Ion Batteries; (5) SV2 = Submersible Vehicle + Stored O{sub 2} + Engine or Turbine + Lead-Acid & Li-Ion Batteries; (6) SV3 = Submersible Vehicle + Charge at Docking Station + ZEBRA & Li-Ion Batteries; (7) PWR TEG = PWR + Thermoelectric Generator + Lead-Acid Battery; (8) WELL TEG = Thermoelectric Generator + Well Head Waste Heat + Lead-Acid Battery; (9) GRID = Ocean Floor Electrical Grid + Lead-Acid Battery; and (10) DOC = Deep Ocean Current + Lead-Acid Battery.

  2. Ashes to earth: Coal combustion by-products returned to the mine site

    SciTech Connect

    Power, C.B.

    1997-06-01

    The use of coal in the generation of electricity has grown dramatically in the last twenty years. With increasing demand for energy and deregulation in the utility industry, there is good reason to believe that coal will play an even larger role in meeting future utility fuel needs. This increased use of coal in energy production will create larger amounts of coal combustion by-products (CCBs). Add to the equation the strict limits on power plant emissions of sulfur dioxide the nitrogen oxides brought about by the 1990 Clean Air Act Amendments- and the resultant increased use of scrubbing and other emission control methods- and it is quite possible that the quantities of CCBs will grow at an even faster rate than the increase in the use of coal. Although the list of productive uses for CCBs has expanded considerably, large amounts continue to be disposed each year. According to the American Coal Ash Association, no more than 25 percent of the 90 million tons of CCBs produced in 1994 were put to beneficial use. The remainder must be dealt with in some acceptable fashion. As of 1988, coal-fired electric utilities spent about $800 million per year doing so.

  3. Production and dissolution of nuclear explosive melt glasses at underground test sites in the Pacific Region

    SciTech Connect

    Bourcier, W.L.; Smith, D.K.

    1998-11-06

    From 1975 to 1996 the French detonated 140 underground nuclear explosions beneath the atolls of Mururoa and Fangataufa in the South Pacific; from 1965 to 1971 the United States detonated three high yield nuclear tests beneath Amchitka Island in the Aleutian chain. Approximately 800 metric tons of basalt is melted per kiloton of nuclear yield; almost lo7 metric tons of basalt were melted in these tests. Long-lived and toxic radionuclides are partitioned into the melt glass at the time of explosion and are released by dissolution with seawater under saturated conditions. A glass dissolution model predicts that nuclear melt glasses at these sites will dissolve in lo6 to lo7 yea

  4. The effect of zebra mussel consumption on growth of freshwater drum in Lake Erie

    USGS Publications Warehouse

    French, John R. P., III; Bur, Michael T.

    1996-01-01

    We examined food habits and scale annuli of freshwater drum (Aplodinotus grunniens) from western Lake Erie to determine whether increasing predation on zebra mussels (Dreissena polymorpha) had affected growth of freshwater drum. The volume of zebra mussels in drum guts was greater in older fish. Growth of age classes 3–4, which consumed few zebra mussels, was greater in the most productive year for zebra mussels, July 1990–August 1991, than in three prior years. The total lengths of 5-year-old drum changed little. The mean total length of 6-year-old females has declined since the zebra mussel invaded Lake Erie, even through mussels comprised more than two-thirds of gut samples in these fish. These studies suggest that zebra mussels may not benefit freshwater drum when serving as a staple in the diet. PDF

  5. Variation in freshwater input to the Eastern US coastal ecosystem

    NASA Astrophysics Data System (ADS)

    Feng, D.; Yoon, Y.; Beighley, E., II; Hughes, R.; Kimbro, D.

    2014-12-01

    Phragmites is one of the most invasive plants in North American wetlands. Although its spread in coastal marshes has been linked by independent studies to urbanization, eutrophication, and salinity change, there is good evidence that these factors may interactively determine invasion success and in turn, the ecosystem services provided by marshes. We hypothesize that the invasion of Phragmites is linked to changes in freshwater inputs due to climate and/or land use change. El Nino/Southern Oscillation (ENSO), originating in the sea surface temperature anomalies (warm or cold) in the eastern tropical Pacific Ocean, is a notable and prominent signal in inter-annual climatic variation. Recent studies shows that the probability of strong El Nino events may increase in the future. In this study, we will investigate the teleconnections between freshwater inputs to the coastal zone along the eastern U.S. and ENSO indices, and attempt to explore the predictability of temporal and spatial variation of freshwater inputs based on ENSO conditions. To quantify changes in freshwater input in this region, hydrologic modeling, remote sensing and field measurements are combined. The Hillslope River Routing (HRR) model is used to simulate hourly streamflow from all watersheds from southern Florida to northern Maine draining into the Atlantic Ocean. The modeling effort utilizes satellite precipitation (Tropical Rainfall Measuring Mission Product 3B42v7: 2001-current with a 3-hr temporal resolution and 0.25 degree spatial resolution), land surface temperature and vegetation measures (Moderate Resolution Imaging Spectroradiometer, MODIS, products: 2001-current with a monthly temporal resolution and 0.05 degree spatial resolution). To account for land cover change, annual MODIS land cover data and time varying population statics are merged to estimate annual land cover characteristics for each sub-catchment within the study region. Static datasets for soils and ground elevations are

  6. Toxicological effects of polychlorinated biphenyls (PCBs) on freshwater turtles in the United States.

    PubMed

    Ming-Ch'eng Adams, Clare Isabel; Baker, Joel E; Kjellerup, Birthe V

    2016-07-01

    Prediction of vertebrate health effects originating from persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) has remained a challenge for decades thus making the identification of bioindicators difficult. POPs are predominantly present in soil and sediment, where they adhere to particles due to their hydrophobic characteristics. Animals inhabiting soil and sediment can be exposed to PCBs via dermal exposure while others may obtain PCBs through contaminated trophic interaction. Freshwater turtles can serve as bioindicators due to their strong site fidelity, longevity and varied diet. Previous research observed the health effects of PCBs on turtles such as decreased bone mass, changed sexual development and decreased immune responses through studying both contaminated sites along with laboratory experimentation. Higher deformity rates in juveniles, increased mortality and slower growth have also been observed. Toxicological effects of PCBs vary between species of freshwater turtles and depend on the concertation and configuration of PCB congeners. Evaluation of ecotoxicological effects of PCBs in non-endangered turtles could provide important knowledge about the health effects of endangered turtle species thus inform the design of remediation strategies. In this review, the PCB presence in freshwater turtle habitats and the ecotoxicological effects were investigated with the aim of utilizing the health status to identify areas of focus for freshwater turtle conservation. PMID:27043381

  7. Sediment quality in freshwater impoundments at Savannah National Wildlife Refuge.

    PubMed

    Winger, P V; Lasier, P J

    2004-10-01

    Freshwater impoundments at Savannah National Wildlife Refuge (NWR), South Carolina, provide an important habitat for wildlife species, but degraded sediment quality in the Savannah River downstream of the discharge from two impoundments have caused concern about potential contaminant problems within the impoundments. The quality of sediments from five impoundments (impoundments no. 1, 2, 6, 7, and 17) on the NWR was evaluated using physical and chemical characterization, contaminant concentrations (metals, organochlorine pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons), and toxicity testing. Survival of Hyalella azteca (freshwater amphipod) exposed for 28 days to solid-phase sediments was not significantly different from controls, but growth was significantly decreased at several sites. Survival in 96-hour exposures to sediment pore water was significantly decreased at most sites. Factors contributing to the toxic responses were low pH (3.7 to 4.1), ammonia (20 mg/L), and increased concentrations of cations in the pore water. The excess of simultaneously extracted metals over the acid volatile sulfides in the sediments was also typical of sites displaying decreased sediment quality. Elemental concentrations in pore water were negatively correlated with pH, and the highest concentrations were observed in impoundment no. 7. The acidic nature of the sediment in this impoundment was exacerbated by recent draining, burning, and disking, which allowed oxidation of the previously anoxic wetland sediment. Sediment disturbance and mixing of vegetation into the sediments by disking may also have contributed to the formation of ammonia caused by microbial decomposition of the fragmented organic matter. Contaminants were not detected in sediments from the impoundments, but releases of acidic water with increased levels of sediment cations from the impoundments may have contributed to the degraded sediment conditions previously observed in the river

  8. Sediment quality in freshwater impoundments at Savannah National Wildlife Refuge

    USGS Publications Warehouse

    Winger, P.V.; Lasier, P.J.

    2004-01-01

    Freshwater impoundments at Savannah National Wildlife Refuge (NWR), South Carolina, provide an important habitat for wildlife species, but degraded sediment quality in the Savannah River downstream of the discharge from two impoundments have caused concern about potential contaminant problems within the impoundments. The quality of sediments from five impoundments (impoundments no. 1, 2, 6, 7, and 17) on the NWR was evaluated using physical and chemical characterization, contaminant concentrations (metals, organochlorine pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons), and toxicity testing. Survival of Hyalella azteca (freshwater amphipod) exposed for 28 days to solid-phase sediments was not significantly different from controls, but growth was significantly decreased at several sites. Survival in 96-hour exposures to sediment pore water was significantly decreased at most sites. Factors contributing to the toxic responses were low pH (3.7 to 4.1), ammonia (20 mg/L), and increased concentrations of cations in the pore water. The excess of simultaneously extracted metals over the acid volatile sulfides in the sediments was also typical of sites displaying decreased sediment quality. Elemental concentrations in pore water were negatively correlated with pH, and the highest concentrations were observed in impoundment no. 7. The acidic nature of the sediment in this impoundment was exacerbated by recent draining, burning, and disking, which allowed oxidation of the previously anoxic wetland sediment. Sediment disturbance and mixing of vegetation into the sediments by disking may also have contributed to the formation of ammonia caused by microbial decomposition of the fragmented organic matter. Contaminants were not detected in sediments from the impoundments, but releases of acidic water with increased levels of sediment cations from the impoundments may have contributed to the degraded sediment conditions previously observed in the river

  9. 40 CFR 35.1605-2 - Freshwater lake.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Freshwater lake. 35.1605-2 Section 35... STATE AND LOCAL ASSISTANCE Cooperative Agreements for Protecting and Restoring Publicly Owned Freshwater Lakes § 35.1605-2 Freshwater lake. Any inland pond, reservoir, impoundment, or other similar body...

  10. 40 CFR 35.1605-2 - Freshwater lake.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Freshwater lake. 35.1605-2 Section 35... STATE AND LOCAL ASSISTANCE Cooperative Agreements for Protecting and Restoring Publicly Owned Freshwater Lakes § 35.1605-2 Freshwater lake. Any inland pond, reservoir, impoundment, or other similar body...

  11. 40 CFR 35.1605-2 - Freshwater lake.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Freshwater lake. 35.1605-2 Section 35... STATE AND LOCAL ASSISTANCE Cooperative Agreements for Protecting and Restoring Publicly Owned Freshwater Lakes § 35.1605-2 Freshwater lake. Any inland pond, reservoir, impoundment, or other similar body...

  12. 40 CFR 35.1605-2 - Freshwater lake.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Freshwater lake. 35.1605-2 Section 35... STATE AND LOCAL ASSISTANCE Cooperative Agreements for Protecting and Restoring Publicly Owned Freshwater Lakes § 35.1605-2 Freshwater lake. Any inland pond, reservoir, impoundment, or other similar body...

  13. 40 CFR 35.1605-2 - Freshwater lake.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Freshwater lake. 35.1605-2 Section 35... STATE AND LOCAL ASSISTANCE Cooperative Agreements for Protecting and Restoring Publicly Owned Freshwater Lakes § 35.1605-2 Freshwater lake. Any inland pond, reservoir, impoundment, or other similar body...

  14. Identification of specific organic contaminants in different units of a chemical production site.

    PubMed

    Dsikowitzky, L; Botalova, O; al Sandouk-Lincke, N A; Schwarzbauer, J

    2014-07-01

    Due to the very limited number of studies dealing with the chemical composition of industrial wastewaters, many industrial organic contaminants still escape our view and consequently also our control. We present here the chemical characterization of wastewaters from different units of a chemical complex, thereby contributing to the characterization of industrial pollution sources. The chemicals produced in the investigated complex are widely and intensively used and the synthesis processes are common and applied worldwide. The chemical composition of untreated and treated wastewaters from the chemical complex was investigated by applying a non-target screening which allowed for the identification of 39 organic contaminants. According to their application most of them belonged to four groups: (i) unspecific educts or intermediates of industrial syntheses, (ii) chemicals for the manufacturing of pharmaceuticals, (iii) educts for the synthesis of polymers and resins, and (iv) compounds known as typical constituents of municipal sewage. A number of halogenated compounds with unknown toxicity and with very high molecular diversity belonged to the second group. Although these compounds were completely removed or degraded during wastewater treatment, they could be useful as "alarm indicators" for industrial accidents in pharmaceutical manufacturing units or for malfunctions of wastewater treatment plants. Three potential branch-specific indicators for polymer manufacturing were found in the outflow of the complex. Among all compounds, bisphenol A, which was present in the leachate water of the on-site waste deposit, occurred in the highest concentrations of up to 20 000 μg L(-1). The comparison of contaminant loads in the inflow and outflow of the on-site wastewater treatment facility showed that most contaminants were completely or at least significantly removed or degraded during the treatment, except two alkylthiols, which were enriched during the treatment process

  15. Vacant Lots: Productive Sites for Aedes (Stegomyia) aegypti (Diptera: Culicidae) in Mérida City, México

    PubMed Central

    BAAK-BAAK, CARLOS M.; ARANA-GUARDIA, ROGER; CIGARROA-TOLEDO, NOHEMI; LOROÑO-PINO, MARÍA ALBA; REYES-SOLIS, GUADALUPE; MACHAIN-WILLIAMS, CARLOS; BEATY, BARRY J.; EISEN, LARS; GARCÍA-REJÓN, JULIÁN E.

    2014-01-01

    We assessed the potential for vacant lots and other non-residential settings to serve as source environments for Aedes (Stegomyia) aegypti (L.) in Mérida City, México. Mosquito immatures were collected, during November 2011 – June 2013, from residential premises (n = 156 site visits) and non-residential settings represented by vacant lots (50), parking lots (18), and streets/sidewalks (28). Collections totaled 46,025 mosquito immatures of 13 species. Ae. aegypti was the most commonly encountered species accounting for 81.0% of total immatures, followed by Culex quinquefasciatus Say (12.1%). Site visits to vacant lots (74.0%) were more likely to result in collection of Ae. aegypti immatures that residential premises (35.9%). Tires accounted for 75.5% of Ae. aegypti immatures collected from vacant lots. Our data suggest that vacant lots should be considered for inclusion in mosquito surveillance and control efforts in Mérida City, as they often are located near homes, commonly have abundant vegetation, and frequently harbor accumulations of small and large discarded water-holding containers that we now have demonstrated to serve as development sites for immature mosquitoes. Additionally, we present data for associations of immature production with various container characteristics, such as storage capacity, water quality and physical location in the environment. PMID:24724299

  16. Efficient solid acid catalyst containing Lewis and Brønsted Acid sites for the production of furfurals.

    PubMed

    Mazzotta, Michael G; Gupta, Dinesh; Saha, Basudeb; Patra, Astam K; Bhaumik, Asim; Abu-Omar, Mahdi M

    2014-08-01

    Self-assembled nanoparticulates of porous sulfonated carbonaceous TiO2 material that contain Brønsted and Lewis acidic sites were prepared by a one-pot synthesis method. The material was characterized by XRD, FTIR spectroscopy, NH3 temperature-programmed desorption, pyridine FTIR spectroscopy, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, N2 -sorption, atomic absorbance spectroscopy, and inductively coupled plasma optical emission spectroscopy. The carbonaceous heterogeneous catalyst (Glu-TsOH-Ti) with a Brønsted-to-Lewis acid density ratio of 1.2 and more accessible acid sites was effective to produce 5-hydroxymethylfurfural and furfural from biomass-derived mono- and disaccharides and xylose in a biphasic solvent that comprised water and biorenewable methyltetrahydrofuran. The catalyst was recycled in four consecutive cycles with a total loss of only 3 % activity. Thus, Glu-TsOH-Ti, which contains isomerization and dehydration catalytic sites and is based on a cheap and biorenewable carbon support, is a sustainable catalyst for the production of furfurals, platform chemicals for biofuels and chemicals. PMID:24807741

  17. Vacant lots: productive sites for Aedes (Stegomyia) aegypti (Diptera: Culicidae) in Mérida City, México.

    PubMed

    Baak-Baak, Carlos M; Arana-Guardia, Roger; Cigarroa-Toledo, Nohemi; Loroño-Pino, Maria Alba; Reyes-Solis, Guadalupe; Machain-Williams, Carlos; Beaty, Barry J; Eisen, Lars; García-Rejón, Julián E

    2014-03-01

    We assessed the potential for vacant lots and other nonresidential settings to serve as source environments for Aedes (Stegomyia) aegypti (L.) (Diptera: Culicidae) in Mérida City, México. Mosquito immatures were collected, during November 2011-June 2013, from residential premises (n = 156 site visits) and nonresidential settings represented by vacant lots (50), parking lots (18), and streets or sidewalks (28). Collections totaled 46,025 mosquito immatures of 13 species. Ae. aegypti was the most commonly encountered species accounting for 81.0% of total immatures, followed by Culex quinquefasciatus Say (12.1%). Site visits to vacant lots (74.0%) were more likely to result in collection of Ae. aegypti immatures than residential premises (35.9%). Tires accounted for 75.5% of Ae. aegypti immatures collected from vacant lots. Our data suggest that vacant lots should be considered for inclusion in mosquito surveillance and control efforts in Mérida City, as they often are located near homes, commonly have abundant vegetation, and frequently harbor accumulations of small and large discarded water-holding containers that we now have demonstrated to serve as development sites for immature mosquitoes. In addition, we present data for associations of immature production with various container characteristics, such as storage capacity, water quality, and physical location in the environment. PMID:24724299

  18. Dengue vector management using insecticide treated materials and targeted interventions on productive breeding-sites in Guatemala

    PubMed Central

    2012-01-01

    Background In view of the epidemiological expansion of dengue worldwide and the availability of new tools and strategies particularly for controlling the primary dengue vector Aedes aegypti, an intervention study was set up to test the efficacy, cost and feasibility of a combined approach of insecticide treated materials (ITMs) alone and in combination with appropriate targeted interventions of the most productive vector breeding-sites. Methods The study was conducted as a cluster randomized community trial using “reduction of the vector population” as the main outcome variable. The trial had two arms: 10 intervention clusters (neighborhoods) and 10 control clusters in the town of Poptun Guatemala. Activities included entomological assessments (characteristics of breeding-sites, pupal productivity, Stegomyia indices) at baseline, 6 weeks after the first intervention (coverage of window and exterior doorways made of PermaNet 2.0 netting, factory treated with deltamethrin at 55 mg/m2, and of 200 L drums with similar treated material) and 6 weeks after the second intervention (combination of treated materials and other suitable interventions targeting productive breeding-sites i.e larviciding with Temephos, elimination etc.). The second intervention took place 17 months after the first intervention. The insecticide residual activity and the insecticidal content were also studied at different intervals. Additionally, information about demographic characteristics, cost of the intervention, coverage of houses protected and satisfaction in the population with the interventions was collected. Results At baseline (during the dry season) a variety of productive container types for Aedes pupae were identified: various container types holding >20 L, 200 L drums, washbasins and buckets (producing 83.7% of all pupae). After covering 100% of windows and exterior doorways and a small number of drums (where the commercial cover could be fixed) in 970 study households, tropical

  19. Methane emissions from process equipment at natural gas production sites in the United States: liquid unloadings.

    PubMed

    Allen, David T; Sullivan, David W; Zavala-Araiza, Daniel; Pacsi, Adam P; Harrison, Matthew; Keen, Kindal; Fraser, Matthew P; Daniel Hill, A; Lamb, Brian K; Sawyer, Robert F; Seinfeld, John H

    2015-01-01

    Methane emissions from liquid unloadings were measured at 107 wells in natural gas production regions throughout the United States. Liquid unloadings clear wells of accumulated liquids to increase production, employing a variety of liquid lifting mechanisms. In this work, wells with and without plunger lifts were sampled. Most wells without plunger lifts unload less than 10 times per year with emissions averaging 21,000-35,000 scf methane (0.4-0.7 Mg) per event (95% confidence limits of 10,000-50,000 scf/event). For wells with plunger lifts, emissions averaged 1000-10,000 scf methane (0.02-0.2 Mg) per event (95% confidence limits of 500-12,000 scf/event). Some wells with plunger lifts are automatically triggered and unload thousands of times per year and these wells account for the majority of the emissions from all wells with liquid unloadings. If the data collected in this work are assumed to be representative of national populations, the data suggest that the central estimate of emissions from unloadings (270 Gg/yr, 95% confidence range of 190-400 Gg) are within a few percent of the emissions estimated in the EPA 2012 Greenhouse Gas National Emission Inventory (released in 2014), with emissions dominated by wells with high frequencies of unloadings. PMID:25488307

  20. List of currently classified documents relative to Hanford Production Facilities Operations originated on the Hanford Site between 1961 and 1972

    SciTech Connect

    Not Available

    1993-04-01

    The United States Department of Energy (DOE) has declared that all Hanford plutonium production- and operations-related information generated between 1944 and 1972 is declassified. Any documents found and deemed useful for meeting Hanford Environmental Dose Reconstruction (HEDR) objectives may be declassified with or without deletions in accordance with DOE guidance by Authorized Derivative Declassifiers. The September 1992, letter report, Declassifications Requested by the Technical Steering Panel of Hanford Documents Produced 1944--1960, (PNWD-2024 HEDR UC-707), provides an important milestone toward achieving a complete listing of documents that may be useful to the HEDR Project. The attached listing of approximately 7,000 currently classified Hanford-originated documents relative to Hanford Production Facilities Operations between 1961 and 1972 fulfills TSP Directive 89-3. This list does not include such titles as the Irradiation Processing Department, Chemical Processing Department, and Hanford Laboratory Operations monthly reports generated after 1960 which have been previously declassified with minor deletions and made publicly available. Also Kaiser Engineers Hanford (KEH) Document Control determined that no KEH documents generated between January 1, 1961 and December 31, 1972 are currently classified. Titles which address work for others have not been included because Hanford Site contractors currently having custodial responsibility for these documents do not have the authority to determine whether other than their own staff have on file an appropriate need-to-know. Furthermore, these documents do not normally contain information relative to Hanford Site operations.

  1. Containment of groundwater pollution (methyl tertiary butyl ether and benzene) to protect a drinking-water production site in Belgium

    NASA Astrophysics Data System (ADS)

    Haest, Pieter Jan; Lookman, Richard; van Keer, Ilse; Patyn, Johan; Bronders, Jan; Joris, Marjan; Bellon, Jan; de Smedt, Florimond

    2010-12-01

    The subsurface migration of methyl tertiary butyl ether (MTBE) and benzene towards a drinking-water production site in Belgium was monitored for 9 years. A large gasoline spill at a nearby fuel station had caused a 500-m long and 50-m-wide pollution plume of MTBE (10-30 mg/L) and benzene (2-10 mg/L). In order to prevent any intrusion of pollutants into the drinking-water supply, a conceptual model was used to design a pump-and-treat system that intercepted the gasoline-contaminated groundwater emanating from the spill. The contaminated soil in the spill zone was excavated. A numerical mass transport model was developed to evaluate the ongoing plume containment. The model describes the subsurface MTBE migration and was regularly updated, based on groundwater monitoring data and the measured mass of MTBE extracted with the pump-and-treat system. With continued interception pumping, the MTBE plume can be remediated in 14 years. Without it, MTBE and benzene concentrations up to 600 μg/L could have reached the drinking-water production site and the plume would persist for 9 years longer. Source zone treatment combined with plume interception pumping is a suitable risk-based remediation strategy for the containment of MTBE and benzene groundwater pollution.

  2. Characterization of stored defense production spent nulcear fuel and associated materials at Hanford Site, Richland Washington: Environmental assessment

    SciTech Connect

    1995-03-01

    There are about 2,100 tonnes (2,300 tons) of defense production spent nuclear fuel stored in the 100-K Area Basins located along the south shore of the Columbia River in the northern part of the Hanford Site. Some of the fuel which has been in storage for a number of years is in poor condition and continues to deteriorate. The basins also contain fuel fragments and radioactively contaminated sludge. The DOE needs to characterize defense production spent nuclear fuel and associated materials stored on the Hanford Site. In order to satisfy that need, the Department of Energy (DOE) proposes to select, collect and transport samples of spent nuclear fuel and associated materials to the 327 Building for characterization. As a result of that characterization, modes of interim storage can be determined that would be compatible with the material in its present state and alternative treatment processes could be developed to permit a broader selection of storage modes. Environmental impacts of the proposed action were determined to be limited principally to radiation exposure of workers, which, however, were found to be small. No health effects among workers or the general public would be expected under routine operations. Implementation of the proposed action would not result in any impacts on cultural resources, threatened, endangered and candidate species, air or water quality, socioeconomic conditions, or waste management.

  3. Factors driving changes in freshwater mussel (Bivalvia, Unionida) diversity and distribution in Peninsular Malaysia.

    PubMed

    Zieritz, Alexandra; Lopes-Lima, Manuel; Bogan, Arthur E; Sousa, Ronaldo; Walton, Samuel; Rahim, Khairul Adha A; Wilson, John-James; Ng, Pei-Yin; Froufe, Elsa; McGowan, Suzanne

    2016-11-15

    Freshwater mussels (Bivalvia, Unionida) fulfil important ecosystem functions and are one of the most threatened freshwater taxa globally. Knowledge of freshwater mussel diversity, distribution and ecology in Peninsular Malaysia is extremely poor, and the conservation status of half of the species presumed to occur in the region has yet to be assessed. We conducted the first comprehensive assessment of Peninsular Malaysia's freshwater mussels based on species presence/absence and environmental data collected from 155 sites spanning all major river catchments and diverse habitat types. Through an integrative morphological-molecular approach we recognised nine native and one widespread non-native species, i.e. Sinanodonta woodiana. Two species, i.e. Pilsbryoconcha compressa and Pseudodon cambodjensis, had not been previously recorded from Malaysia, which is likely a result of morphological misidentifications of historical records. Due to their restriction to single river catchments and declining distributions, Hyriopsis bialata, possibly endemic to Peninsular Malaysia, Ensidens ingallsianus, possibly already extinct in the peninsula, and Rectidens sumatrensis, particularly require conservation attention. Equally, the Pahang, the Perak and the north-western river catchments are of particular conservation value due to the presence of a globally unique freshwater mussel fauna. Statistical relationships of 15 water quality parameters and mussel presence/absence identified acidification and nutrient pollution (eutrophication) as the most important anthropogenic factors threatening freshwater mussel diversity in Peninsular Malaysia. These factors can be linked to atmospheric pollution, deforestation, oil-palm plantations and a lack of functioning waste water treatment, and could be mitigated by establishing riparian buffers and improving waste water treatment for rivers running through agricultural and residential land. PMID:27473771

  4. Structure of the E. Coli Bifunctional GlmU Acetyltransferase Active Site with Substrates and Products

    SciTech Connect

    Olsen,L.; Vetting, M.; Roderick, S.

    2007-01-01

    The biosynthesis of UDP-GlcNAc in bacteria is carried out by GlmU, an essential bifunctional uridyltransferase that catalyzes the CoA-dependent acetylation of GlcN-1-PO{sub 4} to form GlcNAc-1-PO{sub 4} and its subsequent condensation with UTP to form pyrophosphate and UDP-GlcNAc. As a metabolite, UDP-GlcNAc is situated at a branch point leading to the biosynthesis of lipopolysaccharide and peptidoglycan. Consequently, GlmU is regarded as an important target for potential antibacterial agents. The crystal structure of the Escherichia coli GlmU acetyltransferase active site has been determined in complexes with acetyl-CoA, CoA/GlcN-1-PO{sub 4}, and desulpho-CoA/GlcNAc-1-PO{sub 4}. These structures reveal the enzyme groups responsible for binding the substrates. A superposition of these complex structures suggests that the 2-amino group of GlcN-1-PO{sub 4} is positioned in proximity to the acetyl-CoA to facilitate direct attack on its thioester by a ternary complex mechanism.

  5. TOXICITY OF SYNTHETIC PYRETHROIDS TO FRESHWATER INVERTEBRATES

    EPA Science Inventory

    This report reviews the laboratory toxicity data on freshwater target and nontarget invertebrate s exposed to pyrethroids and evaluates the state of the data. Early in their development, yrethroids were shown to be highly effective insecticides gainst mosquitoes, blackflies and c...

  6. Mathematical Explorations: Freshwater Scarcity: A Proportional Representation

    ERIC Educational Resources Information Center

    King, Alessandra

    2014-01-01

    Middle school students' mathematical understanding benefits from connecting mathematics to other content areas in the curriculum. This month's activity explores the issue of the scarcity of freshwater, a natural resource (activity sheets are included). This activity concentrates on the critical areas mentioned in the Common Core State…

  7. Freshwater Biological Traits Database (External Review Draft)

    EPA Science Inventory

    This draft report discusses the development of a database of freshwater biological traits. The database combines several existing traits databases into an online format. The database is also augmented with additional traits that are relevant to detecting climate change-related ef...

  8. Toxicity of vanadium to different freshwater organisms

    SciTech Connect

    Beusen, J.M.; Neven, B.

    1987-08-01

    The aim of this study is to determine the acute and subchronic toxicity of vanadium for various species of freshwater fish. The long-term toxicity and the effect of vanadium on the reproduction of Daphnia magna is also evaluated and compared with the toxicity of other metals.

  9. Effects of Pollution on Freshwater Invertebrates.

    ERIC Educational Resources Information Center

    Buikema, A. L., Jr.; Herricks, E. E.

    1978-01-01

    Presents a literature review of the effects of pollution on freshwater invertebrates, covering publications of 1976-77. Some of the areas covered are: (1) toxicant effects on invertebrates; (2) microcosm and community effects, and (3) biological control of aquatic life. A list of 123 references is also presented. (HM)

  10. Tetanus after envenomations caused by freshwater stingrays.

    PubMed

    Torrez, Pasesa P Q; Quiroga, Mariana M; Said, Renato; Abati, Paulo A M; França, Francisco O S

    2015-04-01

    Injuries caused by freshwater stingray are common in several regions of South America, although they are underreported. The riverside inhabitants are the main victims in the Amazonian and Midwest regions of South America. The fishermen are injured mainly in the new focus of colonization of the rivers by freshwater stingrays. With the increasing population in these regions, where freshwater stingrays are found, there has been a significant increase in injuries within the general population. The highest increase occurred among tourists from other regions, where these animals are not known, when visiting these areas. The envenomations from the stingray causes prolonged and intense pain, both local and regionally. Generally these are associated with other local inflammatory manifestations, such as swelling and erythema. The injury often progresses to necrosis and it is considered potentially tetanogenic. A secondary infection is also a frequent local complication and most frequently is caused by Aeromonas species, usually Aeromonas hydrophila. Herein we report the first 2 cases of tetanus after freshwater stingray injuries: a 51-year-old men who had tetanus and recovered without sequel and the second a 67-year-old men who had severe tetanus and a deep, necrotizing soft-tissue infection with sepsis, septic shock and evolution to death. PMID:25576234

  11. FRESHWATER SNAILS (MOLLUSCA: GASTROPODA) OF NORTH AMERICA

    EPA Science Inventory

    Freshwater gastropod mollusks are represented in North America (north of Mexico) by 15 families, 78 genera and, as treated in this manual, 499 species. They are grouped into two large subclasses, the gill-breathing, operculated Prosobranchia and the lung-breathing, non-operculate...

  12. Effects of pollution on freshwater invertebrates

    SciTech Connect

    Buikema

    1982-06-01

    The biological effects of acid rain, chlorination, heavy metals and other forms of pollution on freshwater invertebrates are examined in this review. Several methods for evaluating chronic toxicity to pesticide residues and synthetic fuels components are reviewed. The effects of pollutants is reviewed in detail for cladocera, amphipods, isopods, decapods, aquatic insects, molluscs, worms, and protozoa.(KRM)

  13. Macrophytes: Freshwater Forests of Lakes and Rivers.

    ERIC Educational Resources Information Center

    McDermid, Karla J.; Naiman, Robert J.

    1983-01-01

    Physical, chemical, and biological effects on macrophytes (aquatic plants) on the freshwater ecosystem are discussed. Research questions and issues related to these organisms are also discussed, including adaptations for survival in a wet environment, ecological consequences of large-scale macrophyte eradication, seasonal changes in plant…

  14. 2008 NWFSC Tidal Freshwater Genetics Results

    SciTech Connect

    David Teel

    2009-05-01

    Genetic Analysis of Juvenile Chinook Salmon for inclusion in 'Ecology of Juvenile Salmon in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, Lower Columbia River, 2008. Annual Report to Bonneville Power Administration, Contract DE-AC05-76RL01830.'

  15. Phenanthrene Biodegradation in Freshwater Environments

    PubMed Central

    Sherrill, T. W.; Sayler, G. S.

    1980-01-01

    Phenanthrene, a low-molecular-weight polycyclic aromatic hydrocarbon, was incubated with water samples from various reservoir systems in Tennessee to evaluate the potential for significant polycyclic aromatic hydrocarbon degradation by the indigenous microbial populations. Biodegradation was assessed by comparison of total polycyclic aromatic hydrocarbon substrate recovery in degradation flasks relative to sterile control flasks. During 1977 field studies, the mean phenanthrene biodegradation was approximately 80% after a 4-week incubation. Within a given habitat, 45% of the total variability in phenanthrene biodegradation was attributable to the physical, chemical, and microbiological site characteristics examined. Polycyclic aromatic hydrocarbon degradation was directly related to the historical environmental pollution of the sampling sites examined, the length of biodegradation assessment, temperature, and the molecular size of the polycyclic aromatic hydrocarbon substrate. PMID:16345487

  16. Spatial and overwinter changes in clam populations of San Pablo Bay, a semiarid estuary with highly variable freshwater inflow

    NASA Astrophysics Data System (ADS)

    Poulton, V. K.; Lovvorn, J. R.; Takekawa, J. Y.

    2004-03-01

    In many estuaries worldwide, climate trends together with human diversion of fresh water have dramatically impacted the benthos. Such impacts have sometimes been complicated by exotic species, whose invasion and persistence can be mediated by wide variations in freshwater inflow. Monitoring such changes usually involves periodic samples at a few sites; but sampling that does not recognize variation at a range of spatial and seasonal scales may not reveal important benthic trends. San Pablo Bay, in northern San Francisco Bay, has extreme fluctuations in freshwater inflow. This bay also experienced a major benthic change with introduction of the Asian clam ( Potamocorbula amurensis) in 1986. This species initially displaced the former community, but later appeared to vary in abundance depending on site and freshwater inflow. To investigate such patterns and provide guidelines for research and monitoring, we took 1746 core samples at six sites around San Pablo Bay from 19 October to 17 December 1999 and from 6 March to 19 April 2000. Most biomass consisted of the clams P. amurensis, Macoma balthica and Mya arenaria. Potamocorbula amurensis dominated the benthos at most sites in the fall and recruited a new cohort during winter, while there was weak recruitment in M. balthica and none in M. arenaria. At most but not all sites, densities of P. amurensis and M. arenaria declined dramatically over winter while M. balthica declined only slightly. The dominant clams had patch diameters >5 m at most but not all sites, and some showed inconsistent patch structure at scales of 100-1400 m. In this semiarid estuary with highly variable freshwater inflow, samples for research and monitoring should include multiple sites and seasons, and samples within sites should be ≥5 m apart to account for between-patch variation. Species abundance in winter 1999-2000 appeared to be affected by high freshwater inflows in 1997-1999, while spatial patterns were probably most affected by post

  17. Spatial and overwinter changes in clam populations of San Pablo Bay, a semiarid estuary with highly variable freshwater inflow

    USGS Publications Warehouse

    Poulton, V.K.; Lovvorn, J.R.; Takekawa, J.Y.

    2004-01-01

    In many estuaries worldwide, climate trends together with human diversion of fresh water have dramatically impacted the benthos. Such impacts have sometimes been complicated by exotic species, whose invasion and persistence can be mediated by wide variations in freshwater inflow. Monitoring such changes usually involves periodic samples at a few sites; but sampling that does not recognize variation at a range of spatial and seasonal scales may not reveal important benthic trends. San Pablo Bay, in northern San Francisco Bay, has extreme fluctuations in freshwater inflow. This bay also experienced a major benthic change with introduction of the Asian clam (Potamocorbula amurensis) in 1986. This species initially displaced the former community, but later appeared to vary in abundance depending on site and freshwater inflow. To investigate such patterns and provide guidelines for research and monitoring, we took 1746 core samples at six sites around San Pablo Bay from 19 October to 17 December 1999 and from 6 March to 19 April 2000. Most biomass consisted of the clams P. amurensis, Macoma balthica and Mya arenaria. Potamocorbula amurensis dominated the benthos at most sites in the fall and recruited a new cohort during winter, while there was weak recruitment in M. balthica and none in M. arenaria. At most but not all sites, densities of P. amurensis and M. arenaria declined dramatically over winter while M. balthica declined only slightly. The dominant clams had patch diameters > 5 m at most but not all sites, and some showed inconsistent patch structure at scales of 100-1400 m. In this semiarid estuary with highly variable freshwater inflow, samples for research and monitoring should include multiple sites and seasons, and samples within sites should be ??? 5 m apart to account for between-patch variation. Species abundance in winter 1999-2000 appeared to be affected by high freshwater inflows in 1997-1999, while spatial patterns were probably most affected by post

  18. Computational Prediction of Metabolism: Sites, Products, SAR, P450 Enzyme Dynamics, and Mechanisms

    PubMed Central

    2012-01-01

    Metabolism of xenobiotics remains a central challenge for the discovery and development of drugs, cosmetics, nutritional supplements, and agrochemicals. Metabolic transformations are frequently related to the incidence of toxic effects that may result from the emergence of reactive species, the systemic accumulation of metabolites, or by induction of metabolic pathways. Experimental investigation of the metabolism of small organic molecules is particularly resource demanding; hence, computational methods are of considerable interest to complement experimental approaches. This review provides a broad overview of structure- and ligand-based computational methods for the prediction of xenobiotic metabolism. Current computational approaches to address xenobiotic metabolism are discussed from three major perspectives: (i) prediction of sites of metabolism (SOMs), (ii) elucidation of potential metabolites and their chemical structures, and (iii) prediction of direct and indirect effects of xenobiotics on metabolizing enzymes, where the focus is on the cytochrome P450 (CYP) superfamily of enzymes, the cardinal xenobiotics metabolizing enzymes. For each of these domains, a variety of approaches and their applications are systematically reviewed, including expert systems, data mining approaches, quantitative structure–activity relationships (QSARs), and machine learning-based methods, pharmacophore-based algorithms, shape-focused techniques, molecular interaction fields (MIFs), reactivity-focused techniques, protein–ligand docking, molecular dynamics (MD) simulations, and combinations of methods. Predictive metabolism is a developing area, and there is still enormous potential for improvement. However, it is clear that the combination of rapidly increasing amounts of available ligand- and structure-related experimental data (in particular, quantitative data) with novel and diverse simulation and modeling approaches is accelerating the development of effective tools for

  19. Hydrogen Production Catalyzed by Bidirectional, Biomimetic Models of the [FeFe]-Hydrogenase Active Site.

    PubMed

    Lansing, James C; Camara, James M; Gray, Danielle E; Rauchfuss, Thomas B

    2014-10-27

    Active site mimics of [FeFe]-hydrogenase are shown to be bidirectional catalysts, producing H2 upon treatment with protons and reducing equivalents. This reactivity complements the previously reported oxidation of H2 by these same catalysts in the presence of oxidants. The complex Fe2(adt(Bn))(CO)3(dppv)(PFc*(Et2) ) ([1](0); adt(Bn) = (SCH2)2NBn, dppv = cis-1,2-bis(diphenylphosphino)ethylene, PFc*(Et2) = Et2PCH2C5Me4FeCp*) reacts with excess [H(OEt2)2]BAr(F) 4 (BAr(F) 4 (-) = B(C6H3-3,5-(CF3)2)4 (-)) to give ∼0.5 equiv of H2 and [Fe2(adt(Bn)H)(CO)3(dppv)(PFc*(Et2) )](2+) ([1H](2+)). The species [1H](2+) consists of a ferrocenium ligand, an N-protonated amine, and an Fe(I)Fe(I) core. In the presence of additional reducing equivalents in the form of decamethylferrocene (Fc*), hydrogen evolution is catalytic, albeit slow. The related catalyst Fe2(adt(Bn))(CO)3(dppv)(PMe3) (3) behaves similarly in the presence of Fc*, except that in the absence of excess reducing agent it converts to the catalytically inactive μ-hydride derivative [μ-H3](+). Replacement of the adt in [1](0) with propanedithiolate (pdt) results in a catalytically inactive complex. In the course of synthesizing [FeFe]-hydrogenase mimics, new routes to ferrocenylphosphine ligands and nonamethylferrocene were developed. PMID:25364093

  20. Hydrogen Production Catalyzed by Bidirectional, Biomimetic Models of the [FeFe]-Hydrogenase Active Site

    PubMed Central

    2015-01-01

    Active site mimics of [FeFe]-hydrogenase are shown to be bidirectional catalysts, producing H2 upon treatment with protons and reducing equivalents. This reactivity complements the previously reported oxidation of H2 by these same catalysts in the presence of oxidants. The complex Fe2(adtBn)(CO)3(dppv)(PFc*Et2) ([1]0; adtBn = (SCH2)2NBn, dppv = cis-1,2-bis(diphenylphosphino)ethylene, PFc*Et2 = Et2PCH2C5Me4FeCp*) reacts with excess [H(OEt2)2]BArF4 (BArF4– = B(C6H3-3,5-(CF3)2)4–) to give ∼0.5 equiv of H2 and [Fe2(adtBnH)(CO)3(dppv)(PFc*Et2)]2+ ([1H]2+). The species [1H]2+ consists of a ferrocenium ligand, an N-protonated amine, and an FeIFeI core. In the presence of additional reducing equivalents in the form of decamethylferrocene (Fc*), hydrogen evolution is catalytic, albeit slow. The related catalyst Fe2(adtBn)(CO)3(dppv)(PMe3) (3) behaves similarly in the presence of Fc*, except that in the absence of excess reducing agent it converts to the catalytically inactive μ-hydride derivative [μ-H3]+. Replacement of the adt in [1]0 with propanedithiolate (pdt) results in a catalytically inactive complex. In the course of synthesizing [FeFe]-hydrogenase mimics, new routes to ferrocenylphosphine ligands and nonamethylferrocene were developed. PMID:25364093

  1. Beyond the active site: the impact of the outer coordination sphere on electrocatalysts for hydrogen production and oxidation.

    PubMed

    Ginovska-Pangovska, Bojana; Dutta, Arnab; Reback, Matthew L; Linehan, John C; Shaw, Wendy J

    2014-08-19

    Redox active metalloenzymes play a major role in energy transformation reactions in biological systems. Examples include formate dehydrogenases, nitrogenases, CO dehydrogenase, and hydrogenases. Many of these reactions are also of interest to humans as potential energy storage or utilization reactions for photoelectrochemical, electrolytic, and fuel cell applications. These metalloenzymes consist of redox active metal centers where substrates are activated and undergo transformation to products accompanied by electron and proton transfer to or from the substrate. These active sites are typically buried deep within a protein matrix of the enzyme with channels for proton transport, electron transport, and substrate/product transport between the active site and the surface of the protein. In addition, there are amino acid residues that lie in close proximity to the active site that are thought to play important roles in regulating and enhancing enzyme activity. Directly studying the outer coordination sphere of enzymes can be challenging due to their complexity, and the use of modified molecular catalysts may allow us to provide some insight. There are two fundamentally different approaches to understand these important interactions. The "bottom-up" approach involves building an amino acid or peptide containing outer coordination sphere around a functional molecular catalyst, and the "top-down" approach involves attaching molecular catalyst to a structured protein. Both of these approaches have been undertaken for hydrogenase mimics and are the emphasis of this Account. Our focus has been to utilize amino acid or peptide based scaffolds on an active functional enzyme mimic for H2 oxidation and production, [Ni(P(R)2N(R('))2)2](2+). This "bottom-up" approach has allowed us to evaluate individual functional group and structural contributions to electrocatalysts for H2 oxidation and production. For instance, using amine, ether, and carboxylic acid functionalities in the

  2. Diagnostic extrapolation of gross primary production from flux tower sites to the globe

    NASA Astrophysics Data System (ADS)

    Beer, Christian; Reichstein, Markus; Tomelleri, Enrico; Ciais, Philippe; Jung, Martin; Carvalhais, Nuno; Rödenbeck, Christian; Baldocchi, Dennis; Luyssaert, Sebastiaan; Papale, Dario

    2010-05-01

    The uptake of atmospheric CO2 by plant photosynthesis is the largest global carbon flux and is thought of driving most terrestrial carbon cycle processes. While the photosynthesis processes at the leaf and canopy levels are quite well understood, so far only very crude estimates of its global integral, the Gross Primary Production (GPP) can be found in the literature. Existing estimates have been lacking sound empirical basis. Reasons for such limitations lie in the absence of direct estimates of ecosystem-level GPP and methodological difficulties in scaling local carbon flux measurements to global scale across heterogeneous vegetation. Here, we present global estimates of GPP based on different diagnostic approaches. These up-scaling schemes integrated high-resolution remote sensing products, such as land cover, the fraction of photosynthetically active radiation (fAPAR) and leaf-area index, with carbon flux measurements from the global network of eddy covariance stations (FLUXNET). In addition, meteorological datasets from diverse sources and river runoff observations were used. All the above-mentioned approaches were also capable of estimating uncertainties. With six novel or newly parameterized and highly diverse up-scaling schemes we consistently estimated a global GPP of 122 Pg C y-1. In the quantification of the total uncertainties, we considered uncertainties arising from the measurement technique and data processing (i.e. partitioning into GPP and respiration). Furthermore, we accounted for the uncertainties of drivers and the structural uncertainties of the extrapolation approach. The total propagation led to a global uncertainty of 15 % of the mean value. Although our mean GPP estimate of 122 Pg C y-1 is similar to the previous postulate by Intergovernmental Panel on Climate Change in 2001, we estimated a different variability among ecoregions. The tropics accounted for 32 % of GPP showing a greater importance of tropical ecosystems for the global carbon

  3. Using paleolimnology to track the impacts of early Arctic peoples on freshwater ecosystems from southern Baffin Island, Nunavut

    NASA Astrophysics Data System (ADS)

    Michelutti, Neal; McCleary, Kathryn M.; Antoniades, Dermot; Sutherland, Patricia; Blais, Jules M.; Douglas, Marianne S. V.; Smol, John P.

    2013-09-01

    profiles and diatom assemblages. Due to slow rates of decomposition, nutrients from butchered marine animal bones continue to influence the freshwater sites into which they drain, as evidenced by higher than typical nutrient and production-related water chemistry variables.

  4. In-Situ Hydraulic Conductivities of Soils and Anomalies at a Future Biofuel Production Site

    NASA Astrophysics Data System (ADS)

    Williamson, M. F.; Jackson, C. R.; Hale, J. C.; Sletten, H. R.

    2010-12-01

    Forested hillslopes of the Upper Coastal Plain at the Savannah River Site, SC, feature a shallow clay loam argillic layer with low median saturated hydraulic conductivity. Observations from a grid of shallow, maximum-rise piezometers indicate that perching on this clay layer is common. However, flow measurements from an interflow-interception trench indicate that lateral flow is rare and most soil water percolates through the clay layer. We hypothesize that the lack of frequent lateral flow is due to penetration of the clay layer by roots of pine trees. We used ground penetrating radar (GPR) to map the soil structure and potential anomalies, such as root holes, down to two meters depth at three 10×10-m plots. At each plot, a 1×10-m trench was later back-hoe excavated along a transect that showed the most anomalies on the GPR maps. Each trench was excavated at 0.5-m intervals until the clay layer was reached (two plots were excavated to a final depth of 0.875 m and the third plot was excavated to a final depth of 1.0 m). At each interval, compact constant-head permeameters (CCHPs) were used to measure in-situ hydraulic conductivities in the clay-loam matrix and in any visually apparent anomalies. Conductivity was also estimated using a second 1×10-m transect of CCHP measurements taken within randomly placed augur holes. Additional holes targeted GPR anomalies. The second transect was created in case the back-hoe impacted conductivity readings. High-conductivity anomalies were also visually investigated by excavating with a shovel. Photographs of soil wetness were taken at visually apparent anomalies with a multispectral camera. We discovered that all visually apparent anomalies found are represented on the GPR maps, but that not all of the predicted anomalies on the GPR maps are visually apparent. We discovered that tree root holes create anomalies, but that there were also many conductivity anomalies that could not be visually distinguished from low

  5. Tidal Energy Conversion Installation at an Estuarine Bridge Site: Resource Evaluation and Energy Production Estimate

    NASA Astrophysics Data System (ADS)

    Wosnik, M.; Gagnon, I.; Baldwin, K.; Bell, E.

    2015-12-01

    The "Living Bridge" project aims to create a self-diagnosing, self-reporting "smart bridge" powered by a local renewable energy source, tidal energy - transforming Memorial Bridge, a vertical lift bridge over the tidal Piscataqua River connecting Portsmouth, NH and Kittery, ME, into a living laboratory for researchers, engineers, scientists, and the community. The Living Bridge project includes the installation of a tidal turbine at the Memorial Bridge. The energy converted by the turbine will power structural health monitoring, environmental and underwater instrumentation. Utilizing locally available tidal energy can make bridge operation more sustainable, can "harden" transportation infrastructure against prolonged grid outages and can demonstrate a prototype of an "estuarine bridge of the future". A spatio-temporal tidal energy resource assessment was performed using long term bottom-deployed Acoustic Doppler Current Profilers (ADCP) at two locations: near the planned deployment location in 2013-14 for 123 days and mid-channel in 2007 for 35 days. Data were evaluated to determine the amount of available kinetic energy that can be converted into usable electrical energy on the bridge. Changes in available kinetic energy with ebb/flood and spring/neap tidal cycles and electrical energy demand were analyzed. The target deployment site exhibited significantly more energetic ebb tides than flood tides, which can be explained by the local bathymetry of the tidal estuary. A system model is used to calculate the net energy savings using various tidal generator and battery bank configurations. Different resource evaluation methodologies were also analyzed, e.g., using a representative ADCP "bin" vs. a more refined, turbine-geometry-specific methodology, and using static bin height vs. bin height that move w.r.t. the free surface throughout a tidal cycle (representative of a bottom-fixed or floating turbine deployment, respectively). ADCP operating frequencies and bin

  6. Potential sites of bioactive gibberellin production during reproductive growth in Arabidopsis.

    PubMed

    Hu, Jianhong; Mitchum, Melissa G; Barnaby, Neel; Ayele, Belay T; Ogawa, Mikihiro; Nam, Edward; Lai, Wei-Chu; Hanada, Atsushi; Alonso, Jose M; Ecker, Joseph R; Swain, Stephen M; Yamaguchi, Shinjiro; Kamiya, Yuji; Sun, Tai-Ping

    2008-02-01

    Gibberellin 3-oxidase (GA3ox) catalyzes the final step in the synthesis of bioactive gibberellins (GAs). We examined the expression patterns of all four GA3ox genes in Arabidopsis thaliana by promoter-beta-glucuronidase gene fusions and by quantitative RT-PCR and defined their physiological roles by characterizing single, double, and triple mutants. In developing flowers, GA3ox genes are only expressed in stamen filaments, anthers, and flower receptacles. Mutant plants that lack both GA3ox1 and GA3ox3 functions displayed stamen and petal defects, indicating that these two genes are important for GA production in the flower. Our data suggest that de novo synthesis of active GAs is necessary for stamen development in early flowers and that bioactive GAs made in the stamens and/or flower receptacles are transported to petals to promote their growth. In developing siliques, GA3ox1 is mainly expressed in the replums, funiculi, and the silique receptacles, whereas the other GA3ox genes are only expressed in developing seeds. Active GAs appear to be transported from the seed endosperm to the surrounding maternal tissues where they promote growth. The immediate upregulation of GA3ox1 and GA3ox4 after anthesis suggests that pollination and/or fertilization is a prerequisite for de novo GA biosynthesis in fruit, which in turn promotes initial elongation of the silique. PMID:18310462

  7. Could crop height affect the wind resource at agriculturally productive wind farm sites?

    SciTech Connect

    Vanderwende, Brian; Lundquist, Julie K.

    2015-11-07

    The collocation of cropland and wind turbines in the US Midwest region introduces complex meteorological interactions that could influence both agriculture and wind-power production. Crop management practices may affect the wind resource through alterations of land-surface properties. We use the weather research and forecasting (WRF) model to estimate the impact of crop height variations on the wind resource in the presence of a large turbine array. A hypothetical wind farm consisting of 121 1.8-MW turbines is represented using the WRF model wind-farm parametrization. We represent the impact of selecting soybeans rather than maize by altering the aerodynamic roughness length in a region approximately 65 times larger than that occupied by the turbine array. Roughness lengths of 0.1 and 0.25 m represent the mature soy crop and a mature maize crop, respectively. In all but the most stable atmospheric conditions, statistically significant hub-height wind-speed increases and rotor-layer wind-shear reductions result from switching from maize to soybeans. Based on simulations for the entire month of August 2013, wind-farm energy output increases by 14 %, which would yield a significant monetary gain. Further investigation is required to determine the optimal size, shape, and crop height of the roughness modification to maximize the economic benefit and minimize the cost of such crop-management practices. As a result, these considerations must be balanced by other influences on crop choice such as soil requirements and commodity prices.

  8. Estimating emissions of toxic hydrocarbons from natural gas production sites in the Barnett Shale region

    NASA Astrophysics Data System (ADS)

    Marrero, J. E.; Townsend-Small, A.; Lyon, D. R.; Tsai, T.; Meinardi, S.; Blake, D. R.

    2015-12-01

    Throughout the past decade, shale gas operations have moved closer to urban centers and densely populated areas, contributing to growing public concerns regarding exposure to hazardous air pollutants (HAPs). These HAPs include gases like hexane, 1,3-butadiene and BTEX compounds, which can cause minor health effects from short-term exposure or possibly cancer due to prolonged exposure. During the Barnett Shale Coordinated Campaign in October, 2013, ground-based whole air samples revealed enhancements in several of these toxic volatile organic compounds (VOCs) downwind of natural gas well pads and compressor stations. Two methods were used to estimate the emission rate of several HAPs in the Barnett Shale. The first method utilized CH4 flux measurements derived from the Picarro Mobile Flux Plane (MFP) and taken concurrently with whole air samples, while the second used a CH4 emissions inventory developed for the Barnett Shale region. From these two approaches, the regional emission estimate for benzene (C6H6) ranged from 48 ± 16 to 84 ± 26 kg C6H6 hr-1. A significant regional source of atmospheric benzene is evident, despite measurement uncertainty and limited number of samples. The extent to which these emission rates equate to a larger public health risk is unclear, but is of particular interest as natural gas productions continues to expand.

  9. Could Crop Height Affect the Wind Resource at Agriculturally Productive Wind Farm Sites?

    NASA Astrophysics Data System (ADS)

    Vanderwende, Brian; Lundquist, Julie K.

    2016-03-01

    The collocation of cropland and wind turbines in the US Midwest region introduces complex meteorological interactions that could influence both agriculture and wind-power production. Crop management practices may affect the wind resource through alterations of land-surface properties. We use the weather research and forecasting (WRF) model to estimate the impact of crop height variations on the wind resource in the presence of a large turbine array. A hypothetical wind farm consisting of 121 1.8-MW turbines is represented using the WRF model wind-farm parametrization. We represent the impact of selecting soybeans rather than maize by altering the aerodynamic roughness length in a region approximately 65 times larger than that occupied by the turbine array. Roughness lengths of 0.1 and 0.25 m represent the mature soy crop and a mature maize crop, respectively. In all but the most stable atmospheric conditions, statistically significant hub-height wind-speed increases and rotor-layer wind-shear reductions result from switching from maize to soybeans. Based on simulations for the entire month of August 2013, wind-farm energy output increases by 14 %, which would yield a significant monetary gain. Further investigation is required to determine the optimal size, shape, and crop height of the roughness modification to maximize the economic benefit and minimize the cost of such crop-management practices. These considerations must be balanced by other influences on crop choice such as soil requirements and commodity prices.

  10. Quantification of Hydroxylated Polybrominated Diphenyl Ethers (OH-BDEs), Triclosan, and Related Compounds in Freshwater and Coastal Systems

    PubMed Central

    Kerrigan, Jill F.; Engstrom, Daniel R.; Yee, Donald; Sueper, Charles; Erickson, Paul R.; Grandbois, Matthew; McNeill, Kristopher; Arnold, William A.

    2015-01-01

    Hydroxylated polybrominated diphenyl ethers (OH-BDEs) are a new class of contaminants of emerging concern, but the relative roles of natural and anthropogenic sources remain uncertain. Polybrominated diphenyl ethers (PBDEs) are used as brominated flame retardants, and they are a potential source of OH-BDEs via oxidative transformations. OH-BDEs are also natural products in marine systems. In this study, OH-BDEs were measured in water and sediment of freshwater and coastal systems along with the anthropogenic wastewater-marker compound triclosan and its photoproduct dioxin, 2,8-dichlorodibenzo-p-dioxin. The 6-OH-BDE 47 congener and its brominated dioxin (1,3,7-tribromodibenzo-p-dioxin) photoproduct were the only OH-BDE and brominated dioxin detected in surface sediments from San Francisco Bay, the anthropogenically impacted coastal site, where levels increased along a north-south gradient. Triclosan, 6-OH-BDE 47, 6-OH-BDE 90, 6-OH-BDE 99, and (only once) 6’-OH-BDE 100 were detected in two sediment cores from San Francisco Bay. The occurrence of 6-OH-BDE 47 and 1,3,7-tribromodibenzo-p-dioxin sediments in Point Reyes National Seashore, a marine system with limited anthropogenic impact, was generally lower than in San Francisco Bay surface sediments. OH-BDEs were not detected in freshwater lakes. The spatial and temporal trends of triclosan, 2,8-dichlorodibenzo-p-dioxin, OH-BDEs, and brominated dioxins observed in this study suggest that the dominant source of OH-BDEs in these systems is likely natural production, but their occurrence may be enhanced in San Francisco Bay by anthropogenic activities. PMID:26466159

  11. Quantification of Hydroxylated Polybrominated Diphenyl Ethers (OH-BDEs), Triclosan, and Related Compounds in Freshwater and Coastal Systems.

    PubMed

    Kerrigan, Jill F; Engstrom, Daniel R; Yee, Donald; Sueper, Charles; Erickson, Paul R; Grandbois, Matthew; McNeill, Kristopher; Arnold, William A

    2015-01-01

    Hydroxylated polybrominated diphenyl ethers (OH-BDEs) are a new class of contaminants of emerging concern, but the relative roles of natural and anthropogenic sources remain uncertain. Polybrominated diphenyl ethers (PBDEs) are used as brominated flame retardants, and they are a potential source of OH-BDEs via oxidative transformations. OH-BDEs are also natural products in marine systems. In this study, OH-BDEs were measured in water and sediment of freshwater and coastal systems along with the anthropogenic wastewater-marker compound triclosan and its photoproduct dioxin, 2,8-dichlorodibenzo-p-dioxin. The 6-OH-BDE 47 congener and its brominated dioxin (1,3,7-tribromodibenzo-p-dioxin) photoproduct were the only OH-BDE and brominated dioxin detected in surface sediments from San Francisco Bay, the anthropogenically impacted coastal site, where levels increased along a north-south gradient. Triclosan, 6-OH-BDE 47, 6-OH-BDE 90, 6-OH-BDE 99, and (only once) 6'-OH-BDE 100 were detected in two sediment cores from San Francisco Bay. The occurrence of 6-OH-BDE 47 and 1,3,7-tribromodibenzo-p-dioxin sediments in Point Reyes National Seashore, a marine system with limited anthropogenic impact, was generally lower than in San Francisco Bay surface sediments. OH-BDEs were not detected in freshwater lakes. The spatial and temporal trends of triclosan, 2,8-dichlorodibenzo-p-dioxin, OH-BDEs, and brominated dioxins observed in this study suggest that the dominant source of OH-BDEs in these systems is likely natural production, but their occurrence may be enhanced in San Francisco Bay by anthropogenic activities. PMID:26466159

  12. Persistent Effects of Oil Palm Plantation Agriculture on Freshwater Stream Function in Indonesian Borneo

    NASA Astrophysics Data System (ADS)

    Carlson, K. M.; Curran, L.; Ratnasari, D.

    2012-12-01

    Conversion of forests to agricultural land uses alters freshwater stream ecosystems by changing flows of physical, chemical, and biological stream inputs. In contrast with annual agricultural crops, oil palm agribusiness may have distinctive effects on stream function because these plantations replace existing land cover with 1,000-20,000 ha tree-like monocultures that have 20-30 year rotation cycles. From 2008 to 2012 in Kalimantan (Indonesian Borneo), we measured water temperature, metabolism, and sediment and nutrient loads in four streams draining watersheds dominated (> ~70%) by intact and logged forests, agroforests and agricultural fallows, and young (< 3 y) and mature (> 10 y) oil palm plantations. We find that mean daily stream temperature was elevated 12% at the mature and 8% at the young oil palm site compared to the forest stream (25.5 ± 0.3°C). No clear relationship emerged between land cover type and ecosystem respiration (ER, g O2 m-2 d-1) or gross primary production (GPP, g O2 m-2 d-1). Yet GPP:ER ratios were 600% and 650% greater at young and mature oil palm watersheds, respectively, than the forested watershed (0.020 ± 0.005). Sediment loads (t d-1) across measured water yields (m d-1) were higher in the young oil palm stream compared to all other streams. Total phosphorous, total dissolved phosphorous, and total nitrogen loads for measured water yields were elevated in the agroforest and young oil palm sites compared to the forest site. Our results indicate that oil palm plantation land use alters tropical stream temperature, metabolism, nutrient loads, and sediment loads; moreover, these conditions appear to persist for ≥ 15 years. We discuss the implications of these findings for local human communities and ecosystems.

  13. Quantitative and qualitative assessment of the groundwater system behavior to support Brownfield regeneration of Hunedoara (Romania) former steel production site

    NASA Astrophysics Data System (ADS)

    Gogu, R.; Gaitanaru, D.; Ciugulea, O.; Boukhemacha, M. A.; Bica, I.

    2012-04-01

    Located in the Western part of Romania, the study area is the Hunedoara former steel industry site. The current contamination status of the subsurface shows a real threat due to the contribution of more than 100 years of steel production, ironworks operations, coke products generation, and recovery of recycling materials. Analyses performed in 2007 indicated high contaminations with heavy metals like copper, lead, cadmium, manganese, and chromium. As the contamination of the soil and groundwater severe, brownfield regeneration of this site is essential for a sustainable land management. Intelligent remediation techniques with regard to phytoremediation and soil washing with recycled solutions could be applied. However, these techniques could be correctly chosen and applied if a reliable image of the hydrological, geological, hydrogeological, pedological settings exits and after a deep understanding of the contamination mechanisms. As consequence the development of a groundwater flow and contaminant transport model for this area is compulsory. Hunedoara County has a complex geological structure, made by crystalline-Mesozoic units belonging to Southern Carpathians and by sedimentary-volcanic units of Western Carpathians. The site area is shaped by the presence of alluvial deposits from the Superior Holocene. From the lithologic point of view, covered by a thick layer of clay a sandy formation is located at depths bellow 10 m. The two strata are covering an extended carbonate media. The main aquifer is represented by a groundwater body located under the clay layer. The groundwater table of the superficial aquifer is located at about 10 m depth. The one layer groundwater flow model simulating aquifer behavior covers about 1,2 km2. Its conceptual model relies on a 3D geological model made by using 7 accurate geological cross-sections of the studied domain. Detailed geological data was provided by direct-push core sampling correlated with the penetration time and with

  14. Internet resources for dentistry: computer, Internet, reference, and sites for enhancing personal productivity of the dental professional.

    PubMed

    Guest, G F

    2000-08-15

    At the onset of the new millennium the Internet has become the new standard means of distributing information. In the last two to three years there has been an explosion of e-commerce with hundreds of new web sites being created every minute. For most corporate entities, a web site is as essential as the phone book listing used to be. Twenty years ago technologist directed how computer-based systems were utilized. Now it is the end users of personal computers that have gained expertise and drive the functionality of software applications. The computer, initially invented for mathematical functions, has transitioned from this role to an integrated communications device that provides the portal to the digital world. The Web needs to be used by healthcare professionals, not only for professional activities, but also for instant access to information and services "just when they need it." This will facilitate the longitudinal use of information as society continues to gain better information access skills. With the demand for current "just in time" information and the standards established by Internet protocols, reference sources of information may be maintained in dynamic fashion. News services have been available through the Internet for several years, but now reference materials such as online journals and digital textbooks have become available and have the potential to change the traditional publishing industry. The pace of change should make us consider Will Rogers' advice, "It isn't good enough to be moving in the right direction. If you are not moving fast enough, you can still get run over!" The intent of this article is to complement previous articles on Internet Resources published in this journal, by presenting information about web sites that present information on computer and Internet technologies, reference materials, news information, and information that lets us improve personal productivity. Neither the author, nor the Journal endorses any of the

  15. The effect of animal health products on the formation of injection site lesions in subprimals of experimentally injected beef calves.

    PubMed Central

    Van Donkersgoed, J; Dubeski, P L; VanderKop, M; Aalhus, J L; Bygrove, S; Starr, W N

    2000-01-01

    Two hundred and twenty beef calves were used in an experimental study to determine the occurrence of injection site lesions at slaughter (15 to 18 months of age) following subcutaneous and intramuscular injection of various products into the top hip (top butt), thigh (round), and neck or rib of calves at birth, branding, or weaning. Products tested were: 2 different preparations of selenium; a 2-way, a 7-way, and an 8-way clostridial bacterin; 2 combination 7-way clostridial and Haemophilus somnus bacterins; 2 H. somnus bacterins; 2 different 4-way modified-live viral respiratory vaccines; a 4-way killed viral and H. somnus vaccine; and penicillin, florfenicol, ceftiofur, trimethoprim-sulfa, and tilmicosin. The occurrence of lesions, number of steaks affected with lesions, the trim weight of lesions, the histological class of lesions, and the estimated economic losses are described. Generally, products administered subcutaneously in the neck produced minimal tissue damage and economic losses. Images Figure 1. Figure 2. Figure 3. PMID:10945127

  16. Azoospermia and maturation arrest: malfunction of valves in erect poster of humans leads to hypoxia in sperm production site.

    PubMed

    Gat, Y; Gornish, M; Chakraborty, J; Perlow, A; Levinger, U; Pasqualotto, F

    2010-12-01

    Maturation arrest (MA) of spermatogenesis is diagnosed on histology as interruption of spermatogenesis before the final stage without impairment of Sertoli or Leydig cells. It is considered a condition of irreversible or absolute infertility. Varicocele, which represents impairment in the testicular venous drainage system, has been shown to be a bilateral disease. Malfunction of the valves increase the hydrostatic pressure in the testicular venous system that exceeds the pressure in the arterial system leading to hypoxia in the testicular microcirculation and in the seminiferous tubules, the sperm production site. Sperm production deteriorates, and ultimately progresses to azoospermia. Our prediction was that MA, if genetic factors are excluded, is the final stage of long standing hypoxia. This would indicate that MA is not always an independent disease entity, but may represent progressive process of deterioration of the testicular parenchyma beyond azoospermia. By histology and electron microscopy, our prediction confirmed, at least partially, that MA is associated with degenerative ischaemic changes in the seminiferous tubules. Adequate treatment of bilateral varicocele by microsurgery or super-selective sclerotherapy of the internal spermatic veins including associated network of venous bypasses, vertically oriented, may resume the flow of oxygenated blood. If irreversible damages did not occur and ischaemia is not too long standing, limited sperm production may be restored, at least partially. PMID:21105890

  17. Could crop height affect the wind resource at agriculturally productive wind farm sites?

    DOE PAGESBeta

    Vanderwende, Brian; Lundquist, Julie K.

    2015-11-07

    The collocation of cropland and wind turbines in the US Midwest region introduces complex meteorological interactions that could influence both agriculture and wind-power production. Crop management practices may affect the wind resource through alterations of land-surface properties. We use the weather research and forecasting (WRF) model to estimate the impact of crop height variations on the wind resource in the presence of a large turbine array. A hypothetical wind farm consisting of 121 1.8-MW turbines is represented using the WRF model wind-farm parametrization. We represent the impact of selecting soybeans rather than maize by altering the aerodynamic roughness length inmore » a region approximately 65 times larger than that occupied by the turbine array. Roughness lengths of 0.1 and 0.25 m represent the mature soy crop and a mature maize crop, respectively. In all but the most stable atmospheric conditions, statistically significant hub-height wind-speed increases and rotor-layer wind-shear reductions result from switching from maize to soybeans. Based on simulations for the entire month of August 2013, wind-farm energy output increases by 14 %, which would yield a significant monetary gain. Further investigation is required to determine the optimal size, shape, and crop height of the roughness modification to maximize the economic benefit and minimize the cost of such crop-management practices. As a result, these considerations must be balanced by other influences on crop choice such as soil requirements and commodity prices.« less

  18. Could Crop Roughness Impact the Wind Resource at Agriculturally Productive Wind Farm Sites?

    NASA Astrophysics Data System (ADS)

    Vanderwende, B. J.; Lundquist, J. K.

    2014-12-01

    The high concentration of both large-scale agriculture and wind power production in the United States Midwest region raises new questions concerning the interaction of the two activities. For instance, it is known from internal boundary layer theory that changes in the roughness of the land-surface resulting from crop choices could modify the momentum field aloft. Upward propagation of such an effect might impact the properties of the winds encountered by modern turbines, which typically span a layer from about 40 to 120 meters above the surface. As direct observation of such interaction would require impractical interference in the planting schedules of farmers, we use numerical modeling to quantify the magnitude of crop-roughness effects. To simulate a collocated farm and turbine array, we use version 3.4.1 of the Weather Research and Forecasting model (WRF). The hypothetical farm is inserted near the real location of the 2013 Crop Wind Energy Experiment (CWEX). Reanalyses provide representative initial and boundary conditions. A month-long period spanning August 2013 is used to evaluate the differences in flows above corn (maize) and soybean crops at the mature, reproductive stage. Simulations are performed comparing the flow above each surface regime, both in the absence and presence of a wind farm, which consists of a parameterized 11x11 array of 1.8 MW Vestas V90 turbines. Appreciable differences in rotor-layer wind speeds emerge. The use of soybeans results in an increase in wind speeds and a corresponding reduction in rotor-layer shear when compared to corn. Despite the turbulent nature of flow within a wind farm, high stability reduces the impact of crop roughness on the flow aloft, particularly in the upper portion of the rotor disk. We use these results to estimate the economic impact of crop selection on wind power producers.

  19. Calcium uptake in the skin of a freshwater teleost.

    PubMed

    McCormick, S D; Hasegawa, S; Hirano, T

    1992-04-15

    The skin, particularly the opercular membrane of some teleosts, contains mitochondrion-rich "chloride" cells and has been widely used as a model to study branchial salt-extrusion mechanisms in seawater fish. Skin isolated from the operculum of the freshwater Nile tilapia (Oreochromis niloticus) can transport Ca2+ against an ionic and electrical gradient. Adaptation of Nile tilapia to a low-Ca2+ environment increased the capacity of the opercular membrane to transport Ca2+. The density of mitochondrion-rich cells increased in parallel with Ca2+ transport capacity. The results demonstrate net Ca2+ uptake by vertebrate skin and strongly implicate mitochondrion-rich cells as the site of Ca2+ uptake in fresh water. PMID:1565659

  20. Position of the freshwater-saltwater interface in a coastal confined aquifer

    NASA Astrophysics Data System (ADS)

    Evans, T. B.; White, S. M.; Wilson, A. M.

    2014-12-01

    Delineating the position of the freshwater-saltwater interface is necessary for understanding submarine groundwater discharge and for assessing risks associated with saltwater intrusion, but most studies of the freshwater-saltwater interface focus on shallow surficial aquifers. Groundwater dynamics in coastal aquifers at depths greater than 5 m below land surface have rarely been assessed. The freshwater-saltwater interface in deeper confined aquifers is frequently positioned offshore, where it is difficult to locate or study. Our investigation was located at North Inlet, a wide, intertidal wetland southeast of Georgetown, SC. This site was ideal for studying the freshwater-saltwater interface at the embayment scale because the first major confined aquifer under the wetlands was accessible. Using electrical resistivity tomography, we were able to image the upper 20 to 30 m of sediment, including the first major confined aquifer. At North Inlet a 75 km2 island is bounded by extensive marsh and relict and modern barrier islands extending ~10 km seaward to the Atlantic Ocean. Surface and groundwater salinity throughout the marsh is 35 ppt. In order to get maximum depth penetration, surveys were conducted along dry land on the island and marsh surface with 10 m electrode spacing. Measured apparent resistivity varied in all surveys. A 20 Ohm-m resistivity layer at 25 m depth suggests that freshwater extends 335 m from the mainland. The presence of this freshwater indicates regional groundwater flow under the marsh or high rates of infiltration during precipitation events. Groundwater was saline to brackish (~10 Ohm-m) 1 km further out into the marsh at the next relict beach ridge at depths of 20 to 30 m. These results indicate that embayment scale groundwater flow plays an important role in providing low salinity pore-water to the marsh from beneath. The presence of fresh/brackish groundwater hundreds of meters from the mainland suggests that coastal confined aquifers

  1. Gas monitoring during the CO2 back production field test at the Ketzin pilot site

    NASA Astrophysics Data System (ADS)

    Szizybalski, Alexandra; Zimmer, Martin; Kujawa, Christian; Erzinger, Jörg

    2015-04-01

    The GFZ German Research Centre for Geosciences operates Europe's first on-shore CO2 storage site in Ketzin, a small town near Berlin. From June 2008 until August 2013 about 67 kt of CO2 were injected into Upper Triassic sandstones in 630 to 650 m depth. The injection phase ended with an experiment to evaluate the influence of additives on CO2 storage. During this experiment 32 t N2 and 613 t CO2 were co-injected into the borehole over a period of 25 days followed by the final injection of 66 t pure CO2. At the beginning of the experiment 10,000 l (10 Nm3) Kr were pumped into the borehole, to separate the previous pure CO2 and the CO2-N2 mixture. For the same reason, CO2 with a different isotopic composition (δ13C = -3.4±0.2o instead of δ13C = -30.6±0.4) was used for the first 548 t of the total 613 t. To demonstrate that the stored CO2 is retrievable a field test was carried out in October 2014 during a period of two weeks. Of interest, in this context, is the composition of the back-produced gas which delivers key information on possible interactions between the CO2, formation fluid and rocks. In total 240 t of gas were produced via the former injection well. The flow rates ranged between 800 and 3,200 kg gas/h. The gas was sampled after the gas/water separator and continuously analysed using a mass spectrometer, a gas chromatograph and a photoacoustic sensor, thus covering all gas components and concentrations. In addition, gas samples were collected for stable carbon isotopes investigations in the laboratory. Preliminary results show that the produced gas consists of > 97% CO2 plus mainly N2. The N2 was detected from the beginning, although the injection in 2013 ended with pure CO2. The N2 concentration decreased from about 3% to 1% during the two weeks of the experiment. In addition to these major components CH4, CO and H2 (up to 0.01%) as well as Kr and SF6 (up to 0.001%, both were used as tracers in 2013) were detected. The gas composition of natural

  2. Toxic potential of five freshwater Phormidium species (Cyanoprokaryota).

    PubMed

    Teneva, Ivanka; Dzhambazov, Balik; Koleva, Lyubka; Mladenov, Rumen; Schirmer, Kristin

    2005-05-01

    Among the Cyanoprokaryota (blue-green algae), the genus Phormidium has thus far rarely been studied with respect to toxin production and potentially resulting human and environmental health effects. We here show that five previously unexplored freshwater species of this genus (Ph. bijugatum, Ph. molle, Ph. papyraceum, Ph. uncinatum, Ph. autumnale) are indeed capable of producing bioactive compounds. Phormidium extracts caused weight loss as well as neuro/hepatotoxic symptoms in mice, and in the case of Ph. bijugatum even death. Very low levels of saxitoxins and microcystins, as confirmed by ELISA, were insufficient to explain this toxicity and the differing toxic potencies of the Phormidium species. Qualitative HPLC analyses confirmed different substance patterns and in the future could aid in the separation of fractions for more detailed substance characterisation. The results in vivo were confirmed in vitro using cells of human, mouse and fish. The fish cells responded least sensitive but proved useful in studying the temperature dependence of the toxicity by the Phormidium samples. Further, the human cells were more sensitive than the mouse cells thus suggesting that the former may be a more appropriate choice for studying the impact of Phormidium to man. Among the human cells, two cancer cell lines were more responsive to one of the samples than a normal cell line, thereby indicating a potential anti-tumour activity. Thus, the five freshwater Phormid