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Sample records for freshwater production sites

  1. 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.

  2. 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...

  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. 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...

  6. 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...

  7. 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...

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

    USDA-ARS?s Scientific Manuscript database

    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. ...

  9. 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

  10. Microarray (phylochip) analysis of freshwater pathogens at several sites along the Northern German coast transecting both estuarine and freshwaters.

    PubMed

    Baudart, Julia; Guillebault, Delphine; Mielke, Erik; Meyer, Thomas; Tandon, Neeraj; Fischer, Sabine; Weigel, Wilfried; Medlin, Linda K

    2017-01-01

    Monitoring the quality of drinking water is an important issue for public health. Two of the main objectives of the European Project μAQUA were (i) the development of specific probes to detect and quantify pathogens in drinking water and (ii) the design of standardized sampling programs of water from different sources in Europe in order to obtain sufficient material for downstream analysis. Our phylochip contains barcodes that specifically identify freshwater pathogens for enabling the detection of organisms that can be risks for human health. Monitoring for organisms with molecular tools is rapid, more accurate and more reliable than traditional methods. Rapid detection means that mitigation strategies come into play faster with less harm to the community and to humans. Samples were collected from several waters in France, Germany, Ireland, Italy and Turkey over 2 years. We present microarray results for the presence of freshwater pathogens from brackish and freshwater sites in Northern Germany, and cyanobacterial cell numbers inferred from these sites. In a companion study from the same samples, cyanobacterial toxins were analyzed using two methods and those sites with highest toxin values also had highest cell numbers as inferred from this microarray study.

  11. Production of phthalate esters by nuisance freshwater algae and cyanobacteria.

    PubMed

    Babu, Bakthavachalam; Wu, Jiunn-Tzong

    2010-10-01

    Phthalate esters are widely distributed pollutants which originate from synthetic plasticizer and are known to act as toxicants as well as environmental pheromones in the aquatic ecosystems. From investigating sixteen species of freshwater algae and cyanobacteria we revealed that some of them were capable of producing either di(n-butyl)phthalate (DBP) or mono(2-ethylhexyl)phthalate (MEHP) or both. These phthalate esters would be released into the environment under stress conditions. The incubation of the cells in culture medium containing NaH(13)CO(3) confirmed that both phthalates were de novo synthesized by the studied cells. This study suggested that the nuisance freshwater micro-algae and cyanobacteria growing in eutrophic waters might affect the aquatic ecosystem via the production of these phthalate esters.

  12. 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

  13. Renal mucous production in Australian freshwater plotosid and ariid catfishes.

    PubMed

    Kelly, E; Gibson-Kueh, S

    2017-01-01

    This study reports the presence of large mucous cells lining the large renal collecting ducts and opisthonephric ducts of the Australian freshwater catfishes Tandanus tandanus and Tandanus tropicanus. Histologic examination of the renal tissue from four other species of Australian freshwater catfishes suggests that this feature is unique to the two species of Tandanus studied. The potential functions of renal mucous secretion in T. tandanus and T. tropicanus are discussed. © 2016 The Fisheries Society of the British Isles.

  14. Spatial isolation favours the divergence in microcystin net production by Microcystis in Ugandan freshwater lakes.

    PubMed

    Okello, William; Ostermaier, Veronika; Portmann, Cyril; Gademann, Karl; Kurmayer, Rainer

    2010-05-01

    It is generally agreed that the hepatotoxic microcystins (MCs) are the most abundant toxins produced by cyanobacteria in freshwater. In various freshwater lakes in East Africa MC-producing Microcystis has been reported to dominate the phytoplankton, however the regulation of MC production is poorly understood. From May 2007 to April 2008 the Microcystis abundance, the absolute and relative abundance of the mcyB genotype indicative of MC production and the MC concentrations were recorded monthly in five freshwater lakes in Uganda: (1) in a crater lake (Lake Saka), (2) in three shallow lakes (Lake Mburo, George, Edward), (3) in Lake Victoria (Murchison Bay, Napoleon Gulf). During the whole study period Microcystis was abundant or dominated the phytoplankton. In all samples mcyB-containing cells of Microcystis were found and on average comprised 20+/-2% (SE) of the total population. The proportion of the mcyB genotype differed significantly between the sampling sites, and while the highest mcyB proportions were recorded in Lake Saka (37+/-3%), the lowest proportion was recorded in Lake George (1.4+/-0.2%). Consequently Microcystis from Lake George had the lowest MC cell quotas (0.03-1.24 fg MC cell(-1)) and resulted in the lowest MC concentrations (0-0.5 microg L(-1)) while Microcystis from Lake Saka consistently showed maximum MC cell quotas (14-144 fg cell(-1)) and the highest MC concentrations (0.5-10.2 microg L(-1)). Over the whole study period the average MC content per Microcystis cell depended linearly on the proportion of the mcyB genotype of Microcystis. It is concluded that Microcystis populations differ consistently and independently of the season in mcyB genotype proportion between lakes resulting in population-specific differences in the average MC content per cell.

  15. Use of ethanol production by-products for producing microalgae, tilapia, and freshwater prawns

    SciTech Connect

    Behrends, L.L.; Kingsley, J.B.; Price, A.H. III

    1983-01-01

    By-products from fermentation of grains to alcohol are highly valued as feed supplements for beef and dairy cattle, swine, and poultry. The quantity of wet distillers by-products (stillage) from fuel alcohol production is expected to increase greatly. Unlike dried distillers by-products, wet distillers by-products have generally been abandoned as feed supplements for livestock because of high water content, cost of handling, and storage problems. Using wet distillers by-products as a fertilizer or feed supplement in aquatic production systems appears promising. Two experiments were conducted to determine relationships between stillage application rates and production of microalgae and yields of tilapia (fish) and freshwater prawns (shrimp). Dissolved oxygen concentrations and several other water quality parameters were also monitored. 19 refs., 3 figs., 17 tabs.

  16. Food Production and Freshwater Use within Planetary Boundaries

    NASA Astrophysics Data System (ADS)

    Gerten, D.; Jägermeyr, J.; Heck, V.

    2016-12-01

    The concept of planetary boundaries (PBs) defines guardrails for 9 earth system processes that should not be transgressed by human activity to avoid undermining of earth system resilience. In addition to the scientific challenge of better (e.g. spatially explicit) estimations of PBs themselves, there is a need for assessing opportunities for humankind to stay within these guardrails - while still achieving societal goals such as producing sufficient food for a growing world population. This presentation provides study results (simulations with the LPJmL biosphere model) concerned with a new definition of the PB for human freshwater use in particular, and it addresses the question by how much food production could be increased through more effective water management while respecting this PB. Specifically, we represent this PB in more detail than in its provisional first iteration, i.e. based on spatially explicit estimations of rivers' environmental flow requirements, EFRs (with three different methods on a global 0.5° grid). A key finding is that present human water withdrawals already harm many river stretches around the world, as their EFRs are being tapped; this involves 950 km3/yr (39%) of irrigation water use and a further 226 km3/yr (22%) water use by other sectors. But, improved agricultural water management - here, a moderate upgrade of irrigation systems - could, if implemented across all irrigated regions along with policies to sustain EFRs, fully compensate for these production losses at global scale, albeit not everywhere. The overall, simulated potential of improved on-farm water management - also including measures of water harvesting and avoidance of evaporation in rainfed systems - is a 40% increase in global production. This highlights tremendous opportunities to produce more food without further compromising water systems, also buffering potential future climate change impacts. Finally, the presentation broadens the scope by considering further

  17. 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

  18. 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.

  19. Experimental study of a sustainable hybrid system for thermoelectric generation and freshwater production

    NASA Astrophysics Data System (ADS)

    de Souza, Gabriel Fernandes; Tan, Lippong; Singh, Baljit; Ding, Lai Chet; Date, Abhijit

    2017-04-01

    The paper presents a sustainable hybrid system, which is capable of generating electricity and producing freshwater from seawater using low grade heat source. This proposed system uses low grade heat that can be supplied from solar radiation, industrial waste heat or any other waste heat sources where the temperature is less than 150°C. The concept behind this system uses the Seebeck effect for thermoelectricity generation via incorporating the low boiling point of seawater under sub-atmospheric ambient pressure. A lab-test prototype of the proposed system was built and experimentally tested in RMIT University. The prototype utilised four commercial available thermoelectric generators (Bi2Te3) and a vacuum vessel to achieve the simultaneous production of electricity and freshwater. The temperature profiles, thermoelectric powers and freshwater productions were determined at several levels of salinity to study the influence of different salt concentrations. The theoretical description of system design and experimental results were analysed and discussed in detailed. The experiment results showed that 0.75W of thermoelectricity and 404g of freshwater were produced using inputs of 150W of simulated waste heat and 500g of 3% saline water. The proposed hybrid concept has demonstrated the potential to become the future sustainable system for electricity and freshwater productions.

  20. 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.

  1. 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.

  2. 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...

  3. 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...

  4. 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.

  5. Using thermophilic anaerobic digestate effluent to replace freshwater for bioethanol production.

    PubMed

    Gao, Tiejun; Li, Xiaomei

    2011-01-01

    The possibility of using anaerobic digestate effluent (ADE) to replace freshwater and nutrients for bioethanol production was explored. The ethanol concentration yielded from ADE and post-centrifuged ADE supernatant was 79.60±1.75 g/L and 78.33±1.66 g/L, respectively, with a 24% dry mass (DM) of soft wheat. Ethanol production was enhanced in ADE by as much as 18% in comparison to the production in freshwater (66.61±0.28 g/L, p<0.01). Without yeast nutrients, ADE fermentation yielded an ethanol concentration of 81.10±2.87 g/L, which was significantly higher than that in freshwater fermentation (59.67±1.79 g/L). Analysis showed that ADE contained rich nitrogen, proteins and minerals. After one-step distillation, the ethanol concentration attained was 700.05±46.20 g/L in ADE as compared to 622.79±32.22 g/L in freshwater (p<0.05).

  6. 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...

  7. 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

    2013-05-07

    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.

  8. 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.

  9. Biocrude yield and productivity from the hydrothermal liquefaction of marine and freshwater green macroalgae.

    PubMed

    Neveux, N; Yuen, A K L; Jazrawi, C; Magnusson, M; Haynes, B S; Masters, A F; Montoya, A; Paul, N A; Maschmeyer, T; de Nys, R

    2014-03-01

    Six species of marine and freshwater green macroalgae were cultivated in outdoor tanks and subsequently converted to biocrude through hydrothermal liquefaction (HTL) in a batch reactor. The influence of the biochemical composition of biomass on biocrude yield and composition was assessed. The freshwater macroalgae Oedogonium afforded the highest biocrude yield of all six species at 26.2%, dry weight (dw). Derbesia (19.7%dw) produced the highest biocrude yield for the marine species followed by Ulva (18.7%dw). In contrast to significantly different yields across species, the biocrudes elemental profiles were remarkably similar with higher heating values of 33-34MJkg(-1). Biocrude productivity was highest for marine Derbesia (2.4gm(-2)d(-1)) and Ulva (2.1gm(-2)d(-1)), and for freshwater Oedogonium (1.3gm(-2)d(-1)). These species were therefore identified as suitable feedstocks for scale-up and further HTL studies based on biocrude productivity, as a function of biomass productivity and the yield of biomass conversion to biocrude.

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

    PubMed

    Hoover, 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; Pfleger, Brian F

    2011-07-01

    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 microorganisms. 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.

  11. 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

  12. The importance of environmental quality and catch potential to fishing site selection by freshwater anglers in Mississippi

    USGS Publications Warehouse

    Schramm, H.L.; Gerard, P.D.; Gill, D.A.

    2003-01-01

    We measured the importance of 24 fishing site attributes to Mississippi freshwater anglers. Factor analysis identified four multiattribute factors as important in the selection of fishing location: CLEAN ENVIRONMENT CATCH, COST AND HARVEST and AMENITIES AND SAFETY. In general, the importance of site selection factors differed little among anglers grouped by preferred type of fish, preferred fishing location (lakes and reservoirs, rivers and streams, ponds, or reservoir tailwaters), usual manner of fishing (engine-powered boat, nonpowered boat, or shore), or change in fishing frequency. COST AND HARVEST was more important to anglers with high harvest orientations. We found low correlations between site selection factor importance scores and angler age, fishing frequency, fishing expenditures, or fishing motivation factors. We suggest that the general lack of differences in site selection factors among angler groups indicates that management strategies to improve fishing site attributes should benefit all angler groups. Clean fishing environments and awareness of the availability of desired sport fishes were "very" or "extremely" important to fishing site selection by more than 70% of Mississippi freshwater anglers and should be priority management objectives.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Nutrient removal and biodiesel production by integration of freshwater algae cultivation with piggery wastewater treatment.

    PubMed

    Zhu, Liandong; Wang, Zhongming; Shu, Qing; Takala, Josu; Hiltunen, Erkki; Feng, Pingzhong; Yuan, Zhenhong

    2013-09-01

    An integrated approach, which combined freshwater microalgae Chlorella zofingiensis cultivation with piggery wastewater treatment, was investigated in the present study. The characteristics of algal growth, lipid and biodiesel production, and nutrient removal were examined by using tubular bubble column photobioreactors to cultivate C. zofingiensis in piggery wastewater with six different concentrations. Pollutants in piggery wastewater were efficiently removed among all the treatments. The specific growth rate and biomass productivity were different among all the cultures. As the initial nutrient concentration increased, the lipid content of C. zofingiensis decreased. The differences in lipid and biodiesel productivity of C. zofingiensis among all the treatments mainly resulted from the differences in biomass productivity. It is worthy of note that the diluted piggery wastewater with 1900 mg L(-1) COD provided an optimal nutrient concentration for C. zofingiensis cultivation, where the advantageous nutrient removal and the highest productivities of biomass, lipid and biodiesel were presented. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. 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.

  19. 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)

  20. 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.

  1. 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.

  2. Benthic bacterial and fungal productivity and carbon turnover in a freshwater marsh.

    PubMed

    Buesing, Nanna; Gessner, Mark O

    2006-01-01

    Heterotrophic bacteria and fungi are widely recognized as crucial mediators of carbon, nutrient, and energy flow in ecosystems, yet information on their total annual production in benthic habitats is lacking. To assess the significance of annual microbial production in a structurally complex system, we measured production rates of bacteria and fungi over an annual cycle in four aerobic habitats of a littoral freshwater marsh. Production rates of fungi in plant litter were substantial (0.2 to 2.4 mg C g(-1) C) but were clearly outweighed by those of bacteria (2.6 to 18.8 mg C g(-1) C) throughout the year. This indicates that bacteria represent the most actively growing microorganisms on marsh plant litter in submerged conditions, a finding that contrasts strikingly with results from both standing dead shoots of marsh plants and submerged plant litter decaying in streams. Concomitant measurements of microbial respiration (1.5 to 15.3 mg C-CO2 g(-1) of plant litter C day(-1)) point to high microbial growth efficiencies on the plant litter, averaging 45.5%. The submerged plant litter layer together with the thin aerobic sediment layer underneath (average depth of 5 mm) contributed the bulk of microbial production per square meter of marsh surface (99%), whereas bacterial production in the marsh water column and epiphytic biofilms was negligible. The magnitude of the combined production in these compartments (approximately 1,490 g C m(-2) year(-1)) highlights the importance of carbon flows through microbial biomass, to the extent that even massive primary productivity of the marsh plants (603 g C m(-2) year(-1)) and subsidiary carbon sources (approximately 330 g C m(-2) year(-1)) were insufficient to meet the microbial carbon demand. These findings suggest that littoral freshwater marshes are genuine hot spots of aerobic microbial carbon transformations, which may act as net organic carbon importers from adjacent systems and, in turn, emit large amounts of CO2 (here

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

    PubMed Central

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

    2016-01-01

    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

  4. 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.

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

    USGS Publications Warehouse

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

    2016-01-01

    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.

  6. 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

  7. 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

  8. Site history and edaphic features override the influence of plant species on microbial communities in restored tidal freshwater wetlands.

    PubMed

    Prasse, Christine E; Baldwin, Andrew H; Yarwood, Stephanie A

    2015-05-15

    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.

  9. Influence of temperature and nutrient content on lipid production in freshwater microalgae cultures.

    PubMed

    Bohnenberger, Juliana E; Crossetti, Luciane O

    2014-09-01

    The production of biomass by microalgae is considered a clean alternative compared to other plant crops that require large areas for cultivation and that generate environmental impacts. This study evaluated the influence of temperature and nutrients on lipid contents of cultured species of freshwater microalgae, with a view toward using these lipids for biodiesel production. Two strains of Monoraphidium contortum, a culture containing Chlorella vulgaris and Desmodesmus quadricauda and another strain of Microcystis aeruginosa were maintained in the laboratory for six days, in five culture media: modified ASM-1 (control, with high concentrations of phosphate and nitrate; phosphorus-deficient; non-limiting phosphate; nitrogen-deficient; and non-limiting nitrate). The cultures were then exposed to temperatures of 13°C, 25°C (control) and 37°C for eight days (n=3). Lipids were extracted by the cold-solvent (methanol and chloroform) method. On average, the highest total lipid yields were observed when the strains were maintained at 13°C and in the non-limiting nitrate medium. The lipid percentage varied depending on the concentration of algal biomass. This study showed that manipulation of controlling factors can increase the lipid concentration, optimizing the total production in order to use this raw material for biodiesel.

  10. 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.

  11. 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.

  12. 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.

  13. 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...

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

    Treesearch

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

    2015-01-01

    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...

  15. 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...

  16. 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.

  17. 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

  18. Spermatogenic cycle length and sperm production in the freshwater turtle Kinosternon scorpioides.

    PubMed

    Sousa, Alana Lislea; Campos-Junior, Paulo Henrique Almeida; Costa, Guilherme Mattos Jardim; de França, Luiz Renato

    2014-02-01

    Kinosternon scorpioides is a Brazilian freshwater turtle that belongs to the class Reptilia, encompassing almost 10,000 species. Nevertheless, very little is known about the testicular quantitative parameters, particularly those related to spermatogenesis, in this vertebrate class. Our main objectives were to investigate in detail the structure and function of the testis in K. scorpioides, particularly the aspects related to spermatogenic cycle length and Sertoli cell (SC) and spermatogenic efficiencies. Nine sexually mature turtles were examined, and intraperitoneal bromodeoxyuridine injections were administered to estimate duration of spermatogenesis. Based on the acrosome development in spermatids and the overall germ cell associations, 10 stages of the seminiferous epithelium cycle were characterized. Similar to birds, humans, and some primate species, several stages were observed per seminiferous tubule cross-sections. One spermatogenic cycle and the entire spermatogenic process lasted, respectively, 12 and 53 days. The SC efficiency (number of round spermatids per SC) and daily sperm production per gram of testis were, respectively, 20 and 40 million spermatids. As established for mammals, our findings suggest that SC efficiency is also a critical determinant of sperm production in reptiles. To our knowledge, this is the first study to investigate the kinetics of spermatogenesis and testis function in any reptilian species. Besides allowing a better understanding of reproductive biology in reptiles, these data will be useful in comparative studies. Moreover, these results could provide the basis for investigations related to the evaluation of spermatogonial stem cell physiology niche in Kinosternon scorpioides.

  19. 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.

  20. 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.

  1. 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.

  2. 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).

  3. Freshwater influences on productivity, retention, and export in the northern California Current System (Invited)

    NASA Astrophysics Data System (ADS)

    Banas, N. S.; Hickey, B. M.

    2010-12-01

    The U.S. Pacific Northwest coastal ecosystem is, like other highly productive eastern boundary systems, fueled primarily by the upwelling of deep oceanic nutrients, and it has traditionally been assumed that the strength and fate of biological production was regulated primarily by alongcoast wind stress. Here we synthesize results from three recent large programs (NSF RISE, NOAA ECOHAB PNW, and NSF/NOAA PNWTOX) to describe the variety of ways in which river plume dynamics and estuarine circulation complicate this picture. First, the Fraser River and other rivers of the inland Salish Sea amplify primary prodution on the regional scale not only by directly supplying a modest load of terrestrial nutrients, but also, more important, by driving a persistent estuarine circulation in the Strait of Juan de Fuca that approximately doubles the provision of oceanic nutrients to the shelf. Second, the increased stratification associated with the Columbia River plume increases cross-shelf export on the regional scale, such that 10-20% of total primary production is shifted from the inner shelf to the outer shelf and slope, where carbon export in the vertical sense is likely to be much more efficient. Finally, both river systems increase retention in the alongcoast direction--the Salish Sea outflow through the formation of the persistent Juan de Fuca eddy, and the Columbia River plume by amplifying the surface-layer response to intervals of downwelling winds--leading to older plankton communities and increased transfer to higer trophic levels. These freshwater-driven mechanisms suggest alternate lines of connection between global climate forcing and regional carbon export, beyond the traditional focus on the coastal wind field.

  4. 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.

  5. 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.

  6. 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. © 2013 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  7. 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

  8. Benthic bacterial production and protozoan predation in a silty freshwater environment.

    PubMed

    Wieltschnig, C; Fischer, U R; Kirschner, A K T; Velimirov, B

    2003-07-01

    The interrelation of heterotrophic bacteria with bacterivorous protists has been widely studied in pelagic environments, but data on benthic habitats, especially in freshwater systems, are still scarce. We present a seasonal study focusing on bacterivory by heterotrophic nanoflagellates (HNF) and ciliates in the silty sediment of a temperate macrophyte-dominated oxbow lake. From January 2001 to February 2002 we monitored the standing stock of bacteria and protozoa, bacterial secondary production (BSP, (3)H-thymidine, and (14)C-leucine incorporation), and grazing rates of HNF and ciliates on bacteria (FLB uptake) in the oxic sediment of the investigated system. BSP ranged from 470 to 4050 micro g C L(-1) wet sediment h(-1). The bacterial compartment turned out to be highly dynamic, indicated by population doubling times (0.6-10.0 d), which were comparable to those in the water column of the investigated system. Yet, the control mechanisms acting upon the bacterial population led to a relative constancy of bacterial standing stock during a year. Ingestion rates of protozoan grazers were 0-20.0 bacteria HNF(-1) h(-1) and 0-97.6 bacteria ciliate(-1) h(-1). HNF and ciliates together cropped 0-14 (mean 4)% of BSP, indicating that they did not significantly contribute to benthic bacterial mortality during any period of the year. The low impact of protozoan grazing was due to the low numbers of HNF and ciliates in relation to bacteria (1.8-3.5 x 10(4) bacteria HNF(-1), 0.9-3.1 x 10(6) bacteria ciliate(-1)). Thus, grazing by HNF and ciliates could be ruled out as a parameter regulating bacterial standing stock or production in the sediment of the investigated system, but the factors responsible for the limitation of benthic protistan densities and the fate of benthic BSP remained unclear.

  9. 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.

  10. 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

  11. Effects of ultraviolet radiation on the productivity and composition of freshwater phytoplankton communities.

    PubMed

    Harrison, Joel W; Smith, Ralph E H

    2009-09-01

    The net influence of ultraviolet radiation (UVR; 280-400 nm) on freshwater phytoplankton communities depends on the photon flux density, duration, and spectral quality of exposure and the UVR sensitivity of the assemblage in terms of photosynthetic impairment, biochemical composition, and nutrient assimilation mechanisms. Such effects are mitigated to varying degrees by photoacclimation and selective adaptation at the community level. Variation in UVR penetration among lakes is considerable, largely due to differences in chromophoric dissolved organic matter concentrations. Documented losses of areal daily primary production in lakes due to UVR range from negligible (2.5%) to appreciable (26%). UVR has the potential to alter algal biochemical composition and therefore indirectly affect higher trophic levels. There is evidence that algal nutritional status can influence UVR sensitivity, and that UVR can inhibit uptake and assimilation of inorganic nutrients, but results have been inconsistent. Taxonomic variability in susceptibility to the effects of UVR exists, and likely reflects variation in cell size and shape, concentrations of photoprotective pigments, and capacity to repair UVR photodamage. Suggestions for future research include: (1) resolution of taxon-specific UVR responses by way of single-cell techniques (e.g. enzyme-labelled fluorescence assays, microscope-based variable fluorometers) and (2) systematic comparative studies to link UVR exposure in natural habitats to community responses using the biological weighting function modelling approach. A more robust understanding of how sensitivity to UVR varies according to taxon and habitat is needed if predictions of its role in ecosystem functioning, particularly in connection with climate change, are to be meaningful.

  12. Ecoenzymatic stoichiometry in relation to productivity for freshwater biofilm and plankton communities.

    PubMed

    Sinsabaugh, Robert L; Van Horn, David J; Shah, Jennifer J Follstad; Findlay, Stuart

    2010-11-01

    The degradation of detrital organic matter and assimilation of carbon (C), nitrogen (N), and phosphorus (P) by heterotrophic microbial communities is mediated by enzymes released into the environment (ecoenzymes). For the attached microbial communities of soils and freshwater sediments, the activities of β-glucosidase, β-N-acetylglucosaminidase, leucine aminopeptidase, and phosphatase show consistent stoichiometric patterns. To determine whether similar constraints apply to planktonic communities, we assembled data from nine studies that include measurements of these enzyme activities along with microbial productivity. By normalizing enzyme activity to productivity, we directly compared the ecoenzymatic stoichiometry of aquatic biofilm and bacterioplankton communities. The relationships between β-glucosidase and α-glucosidase and β-glucosidase and β-N-acetylglucosaminidase were statistically indistinguishable for the two community types, while the relationships between β-glucosidase and phosphatase and β-glucosidase and leucine aminopeptidase significantly differed. For β-glucosidase vs. phosphatase, the differences in slope (biofilm 0.65, plankton 1.05) corresponded with differences in the mean elemental C:P ratio of microbial biomass (60 and 106, respectively). For β-glucosidase vs. leucine aminopeptidase, differences in slope (0.80 and 1.02) did not correspond to differences in the mean elemental C:N of biomass (8.6 and 6.6). β-N-Acetylglucosaminidase activity in biofilms was significantly greater than that of plankton, suggesting that aminosaccharides were a relatively more important N source for biofilms, perhaps because fungi are more abundant. The slopes of β-glucosidase vs. (β-N-acetylglucosaminidase + leucine aminopeptidase) regressions (biofilm 1.07, plankton 0.94) corresponded more closely to the estimated difference in mean biomass C:N. Despite major differences in physical structure and trophic organization, biofilm and plankton

  13. Access the toxic effect of the antibiotic cefradine and its UV light degradation products on two freshwater algae.

    PubMed

    Chen, J Q; Guo, R X

    2012-03-30

    Two common freshwater algae Microcystis aeruginosa and Scenedesmus obliquus were employed as test organism to evaluate the toxic effects of the widely used antibiotic, cefradine. In general, cefradine had significantly toxic effect on population growth and chlorophyll-a accumulation of two algae and the cyanophyceae was more sensitive than the chlorophyceae. In addition, cefradine UV light degraded products had adverse effect on M. aeruginosa's growth and chlorophyll-a accumulation. In comparison, even if S. obliquus had growth ability when exposed to cefradine UV light-degradation products, the algal photosynthesis function was also disrupted.

  14. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. 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

    2013-08-06

    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.

  16. 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)

  17. 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)

  18. 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

  19. 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

  20. Freshwater algae competition and correlation between their growth and microcystin production.

    PubMed

    Álvarez, Xana; Valero, Enrique; Cancela, Ángeles; Sánchez, Ángel

    2016-11-01

    There are some different freshwater algae in Eutrophic reservoirs which bloom with specific environmental conditions, and some of them are cyanobacteria. In this investigation, we have cultivated microalgae present in natural water samples from a eutrophic reservoir. Variations in temperature and light were evaluated, as well as the competition among different green algae and cyanobacteria. There were three different freshwater algae growing together, Scenedesmus sp., Kirchneriella sp. and Microcystis aeruginosa, this cyanobacterium was the algae that reached the highest development and growth during the culture. While the algae grew, the concentration of toxin (microcystin-LR) increased until it reached the highest levels at 570 μg g(-1). Blooms occurred at temperatures of 28 ± 1.5 °C and light cycles of longer hours of light than dark. This took place during the summer months, from June to September (in the study area). At temperatures below 18 °C, algae did not grow. Blooms were reproduced to a laboratory scale in different conditions in order to understand the development of freshwater algae, as well as to help decision-making about water supply from that reservoir.

  1. Single dietary amino acids control resting egg production and affect population growth of a key freshwater herbivore.

    PubMed

    Koch, Ulrike; Martin-Creuzburg, Dominik; Grossart, Hans-Peter; Straile, Dietmar

    2011-12-01

    The enormous success of the genus Daphnia in freshwater ecosystems is at least partially due to their cyclical parthenogenetic life cycle, in which asexual and sexual reproduction alternate periodically. This temporal change between reproductive strategies allows for (1) rapid population growth via subitaneously developing eggs when environmental conditions are appropriate and (2) the maintenance of genetic diversity via sexual reproduction and the production of resting eggs when environmental conditions deteriorate. We show here that dietary amino acids are involved in triggering the switch between reproductive modes in Daphnia pulex. Supplementation experiments demonstrate that specific dietary amino acids, in particular arginine and histidine, avert crowding-induced resting egg production, enhance subitaneous reproduction by increasing algal food quality and, as a combined effect of both processes, increase population growth rates. These findings suggest that the availability of single dietary amino acids potentially affects the seasonal dynamics and long-term persistence of Daphnia populations in the field, which may have consequences for the efficiency of carbon transfer and thus the trophic structure of freshwater food webs.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. Contribution of coexisting sulfate and iron reducing bacteria to methylmercury production in freshwater river sediments.

    PubMed

    Yu, Ri-Qing; Flanders, J R; Mack, E Erin; Turner, Ralph; Mirza, M Bilal; Barkay, Tamar

    2012-03-06

    We investigated microbial methylmercury (CH(3)Hg) production in sediments from the South River (SR), VA, an ecosystem contaminated with industrial mercury (Hg). Potential Hg methylation rates in samples collected at nine sites were low in late spring and significantly higher in late summer. Demethylation of (14)CH(3)Hg was dominated by (14)CH(4) production in spring, but switched to producing mostly (14)CO(2) in the summer. Fine-grained sediments originating from the erosion of river banks had the highest CH(3)Hg concentrations and were potential hot spots for both methylation and demethylation activities. Sequencing of 16S rRNA genes of cDNA recovered from sediment RNA extracts indicated that at least three groups of sulfate-reducing bacteria (SRB) and one group of iron-reducing bacteria (IRB), potential Hg methylators, were active in SR sediments. SRB were confirmed as a methylating guild by amendment experiments showing significant sulfate stimulation and molybdate inhibition of methylation in SR sediments. The addition of low levels of amorphous iron(III) oxyhydroxide significantly stimulated methylation rates, suggesting a role for IRB in CH(3)Hg synthesis. Overall, our studies suggest that coexisting SRB and IRB populations in river sediments contribute to Hg methylation, possibly by temporally and spatially separated processes.

  8. 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.

  9. 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.

  10. Increased production of outer membrane vesicles by cultured freshwater bacteria in response to ultraviolet radiation.

    PubMed

    Gamalier, Juliana P; Silva, Thiago P; Zarantonello, Victor; Dias, Felipe F; Melo, Rossana C N

    2017-01-01

    Secretion of membrane vesicles is an important biological process of both eukaryotic and prokaryotic cells. This process has been characterized in pathogenic bacteria, but is less clear in non-pathogenic bacteria from aquatic ecosystems. Here, we investigated, for the first time, the process of formation of outer membranes vesicles (OMVs), nanoscale vesicles extruded from the outer membrane (OM) of gram-negative bacteria, in cultures of freshwater bacteria after exposure or not to ultraviolet radiation (UVR) as an environmental stressor. Non-axenic cultures of freshwater bacteria isolated from a Brazilian aquatic ecosystem (Funil reservoir) were exposed or not to UVR (UVA+UVB) over a 3h period, during which cell density, viability and ultrastructure were analyzed. First, we showed that UVR induce bacterial death. UVR triggered significant negative effect on cell density after 3h of UVR treatment. This decrease was directly associated with cell death as revealed by a cell viability fluorescent probe that enables the distinction of live/dead bacteria. Transmission electron microscopy (TEM) revealed changes indicative of cell death after 3h of UVR exposure, with significant increase of damaged cells compared to the control group. Second, we demonstrated that gram-negative bacteria release OMVs during normal growth and after UVR exposure. OMVs were clearly identified as round, membrane-bound vesicles budding off from the bacterial OM as isolated or clustered vesicles or free in the extracellular medium. Remarkably, quantitative TEM analyses showed that bacteria respond to UVR with increased formation of OMVs. Moreover, while OMVs numbers per intact or damaged cell did not differ in the untreated group, UVR led to a higher vesiculation by bacteria in process of death. This means that degenerating bacteria release OMVs before lysis and that this secretion might be an adaptive/protective response to rapid changes in environmental conditions such as UV radiation. Copyright

  11. Effects of three pharmaceutical and personal care products on natural freshwater algal assemblages.

    PubMed

    Wilson, Brittan A; Smith, Val H; deNoyelles, Frank; Larive, Cynthia K

    2003-05-01

    Treated wastewaters in the United States contain detectable quantities of surfactants, antibiotics, and other types of antimicrobial chemicals contained in pharmaceutical and personal-care products (PPCPs) that are released into stream ecosystems. The degradation characteristics of many of these chemicals are not yet known, nor are the chemical properties of their byproducts. They also are not currently mandated for removal under the U.S. Clean Water Act. Three representative PPCPs were individually tested in this study using a series of laboratory dilution bioassays: Ciprofloxacin (an antibiotic), Triclosan (an antimicrobial agent), and Tergitol NP 10 (a surfactant), to determine their effects on natural algal communities sampled both upstream and downstream of the Olathe, KS wastewater treatment plant (WWTP). There were no significant treatment effects on algal community growth rates during the exponential phase of growth, but significant differences were observed in the final biomass yields (p < 0.001). All three compounds caused marked shifts in the community structure of suspended and attached algae at both the upstream and downstream sites (p < 0.05). Increasing the concentrations of all three compounds over a 3 orders of magnitude range also caused a consistent decline in final algal genus richness in the bioassays. Our results suggest that these three PPCPs may potentially influence both the structure and the function of algal communities in stream ecosystems receiving WWTP effluents. These changes could result in shifts in both the nutrient processing capacity and the natural food web structure of these streams.

  12. Content of some metals in mean tissue of salt-water and fresh-water fish and in their products.

    PubMed

    Krełowska-Kułas, M

    1995-01-01

    The main goal of this work was to determine the concentration of some metals in meat tissue of salt-water and fresh-water fish and in their products. These studies refer to 13 species of fish most often eaten in Poland, caught in 1992. Fish (samples) for testing and examination were taken from each species once every month during the term of 6 months. The lead content in tested fish and their products did not exceed the set limits (0.6 mg Pb/kg), which were exceeded only in preserve from oyster. The average content of cadmium in flounder, Alaska pollack, Baltic herring, pickled herring pieces and in preserves with shrimp, crab and oyster exceeded the set limits (0.05 mg Cd/kg). The copper and zinc content in tested fish and their products is also within the set domestic limits (10.0 mg Cu/kg and 50.0 mg Zn/kg). The iron (3.6-24.2 mg/kg), magnesium (170-380 mg/kg) and manganese (0.12-0.31 mg/kg) contents in muscle tissue of the tested fish and their products seem to be typical. The presence of absolutely toxic metals (lead and cadmium) in some species of fish and their products points to extreme contamination of water environment by those metals.

  13. Maintaining site productivity during biofuel harvest operations

    Treesearch

    Deborah Page-Dumoese; Mark Kimsey

    2012-01-01

    Demand for forest biomass for bioenergy production and other uses is expected to increase to four times the current level in the next one to five years. The search for alternative energy sources, including forest bioenergy, increases pressure on the productive capacity of our western forestlands. The questions are: Can forest soils in the western U.S. support more...

  14. Seasonal variability of estuarine dynamics due to freshwater discharge and its influence on biological productivity in Yeongsan River Estuary, Korea.

    PubMed

    Kim, Yong Hoon; Hong, Seongjin; Song, Yong Sik; Lee, Hyojin; Kim, Hae-Cheol; Ryu, Jongseong; Park, Jinsoon; Kwon, Bong-Oh; Lee, Chang-Hee; Khim, Jong Seong

    2017-08-01

    In order to evaluate water quality and biological productivity, observation data sets were collected and analyzed in Yeongsan River Estuary, Korea. We also set up a numerical model to resolve hydrodynamics and fate of water quality variables in the system. Results show that most of nutrients loading are trapped in the lake and higher concentrations of nutrients and organic matters (OM) are present only inside of the artificial sea dike. There exist episodial discharges at the dam, which coincide mostly with rainfall events during summer monsoon periods. During this discharge event, lower salinity and higher suspended solids, nutrients, and OM are observed in surface layer of the estuarine section. Hydrodynamic model results show that circulation in the estuarine section is governed by freshwater discharge from the lake, resulting in an enhanced two-layer estuarine circulation being dominated, during and after the freshwater is discharged. Such two-layer estuarine circulation combined with higher concentration of nutrients in the surface layer results in that outfluxes of nutrients in the surface layer dominate over the influxes in the bottom layer during summer high precipitation periods. Meanwhile, numerical dye experiment results show that the discharged water with elevated nutrients levels have a short residence time (∼5-10 days) in the estuarine section. Due to this fast flushing rate, excessive nutrient loadings are not used to produce biological matters in the estuarine section. This limited biological productivity, characterized by seaward side of the artificial sea dike, makes Yeongsan estuarine system excluded from acting as an active carbon sink. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  16. Nitrogen removal and production within transient storage zones in a freshwater tidal environment, Delaware, U.S.A.

    NASA Astrophysics Data System (ADS)

    Barnes, R. T.; Bray, S. N.; Sawyer, A. H.; Wallace, C.

    2015-12-01

    Groundwater and surface water flow through riparian aquifer soils and streambed sediment provides opportunities for microbial communities to transform water chemistry, particularly for nitrogen (N). The efficiency of NO3- removal is generally thought to decrease from headwaters to coasts but is poorly constrained near coasts, particularly within tidal freshwater zones (TFZs). High resolution geochemical sampling of reactive and conservative species in White Clay Creek, reveals hotspots of nitrogen removal and production within the stream bed and riparian aquifer. Nitrate removal was greatest in streambed sediments with removal rates decreasing with average stream depth. In addition, nitrate removal occurred within the riparian aquifer at the well 2 m from the stream bank. In contrast, nitrate production was highest in the riparian aquifer (4-13 m from the stream channel). Removal and production are related to the ratio of dissolved organic carbon to nitrate in the pore water, with production occurring when ratios are less than 7 and removal or uptake dominating at ratios greater than 7. Furthermore, nitrogen processes vary more in space than time (i.e. over the tidal cycle); suggesting that nitrogen cycling is driven in large part by substrate chemistry.

  17. 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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Spermatozoa Production by Triploid Males in the New Zealand Freshwater Snail Potamopyrgus antipodarum.

    PubMed

    Soper, D M; Neiman, M; Savytskyy, O P; Zolan, M E; Lively, C M

    2013-09-01

    Asexual lineages derived from dioecious taxa are typically assumed to be all female. Even so, asexual females from a variety of animal taxa occasionally produce males. The existence of these males sets the stage for potential gene flow across asexual lineages as well as between sexual and asexual lineages. A recent study showed that asexual triploid female Potamopyrgus antipodarum, a New Zealand freshwater snail often used as a model to study sexual reproduction, occasionally produce triploid male offspring. Here, we show that these triploid male P. antipodarum 1) have testes that produce morphologically normal sperm, 2) make larger sperm cells that contain more nuclear DNA than the sperm produced by diploid sexual males, and 3) produce sperm that range in DNA content from haploid to diploid, and are often aneuploid. Analysis of meiotic chromosomes of triploid males showed that aberrant pairing during prophase I likely accounts for the high variation in DNA content among sperm. These results indicate that triploid male P. antipodarum produce sperm, but the extent to which these sperm are able to fertilize female ova remains unclear. Our results also suggest that the general assumption of sterility in triploid males should be more closely examined in other species in which such males are occasionally produced.

  19. Methane production in Dutch freshwater sediments: No substantial contribution by ciliates

    SciTech Connect

    Hoek, A.H.A.M. van; Hackstein, J.H.P.; Drift, C. vd

    1996-12-31

    Methanogenesis, the presence of ciliates, and a number of biotic and abiotic parameters were monitored over the course of a year in four different freshwater sediments near Nijmegen, The Netherlands. All sample places exhibited substantial biotic and abiotic differences. Whereas three of the sample places contained several species of ciliates, one location was devoid of substantial numbers of anaerobic protozoa. This location had the highest content of photosynthetic organisms, the lowest conductivity and lacked all kinds of ciliates. The degrees of pollution and the amounts of organic material present in the four sediments differed substantially. The annual course of the in situ temperature of the sediments was comparable, and neither superficial freezing of the sample places nor elevated summer temperatures caused dramatic variations in the methanogenic potential of the sediments. Direct counts of ciliates, their removal by electromigration, and the selective killing of protozoa by heat shock allowed the authors to calculate the contribution by the anaerobic ciliates to the methane emissions. In all three sediments that contained substantial amounts of ciliates, the contribution by these protozoa was less than 5--10%. Only during one exceptional month, the contribution by ciliates raised to 25% of the methane emissions.

  20. Hydrogen Production from Remote Power Sites

    SciTech Connect

    Mezzina, A.; Grimes, G.; Reeves, R.; Wiley, R.

    1980-02-01

    The basic concept for adopting small existing dams to hydrogen production entails the energy conversion steps: hydropower-to-shaft-power via a hydraulic turbine; shaft-power-to-electrical power via a generator; and electrical power-to-hydrogen (and oxygen) via a water electrolyzer. The resource availability is discussed. The concept implementation in Potsdan, New York is mentioned.

  1. 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

  2. The antimicrobial triclocarban stimulates embryo production in the freshwater mudsnail Potamopyrgus antipodarum.

    PubMed

    Giudice, Ben D; Young, Thomas M

    2010-04-01

    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 microg/L dissolved TCC and were removed and dissected, and embryos contained within the brood pouch were counted and classified as shelled or unshelled after two and four weeks of exposure. After four weeks, environmentally relevant TCC concentrations of 1.6 to 10.5 microg/L resulted in statistically significant increases in the number of unshelled embryos, whereas 0.2, 1.6, and 10.5 microg/L exposures significantly increased numbers of shelled embryos. The lowest observed effect concentration (LOEC) was 0.2 microg/L, the no observed effect concentration (NOEC) was 0.05 microg/L; the 10% effective concentration (EC10) and the median effective concentration (EC50) for unshelled effects were 0.5 microg/L and 2.5 microg/L, respectively. Given the widespread occurrence of TCC in the environment and the 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 endocrine-disrupting chemicals (EDCs) is both qualitatively and quantitatively similar to risk from existing classes of EDCs.

  3. 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)

  4. The role of abiotic factors and pesticide levels on enzymatic activity in the freshwater mussel Anodonta cygnea at three different exposure sites.

    PubMed

    Robillard, Sophie; Beauchamp, Guy; Laulier, Marc

    2003-05-01

    Natural variation in abiotic factors, such as temperature and pH, probably influence the activity of enzymes used as potential biomarkers in bivalve mollusks to assess environmental contamination in the field. Changes in levels of an enzymatic biomarker may thus merely reflect natural variation in the annual physiological cycle of a species rather than exposure to contaminants. To investigate this issue, we documented the relationship between pesticide levels in water and three different enzymatic biomarkers over 1 year in enclosed populations of the freshwater unionid mussel Anodonta cygnea at three different sites of exposure. We considered the natural variation in temperature, pH and dissolved oxygen over the year and across the different sites as a potential correlate of enzymatic activity to disentangle the relative contribution of abiotic factors and pesticide levels. Pesticide levels varied among the three sites and over the course of the year. Catalase (CAT) and acetylcholinesterase activity (AChE) varied as a function of abiotic factors but showed no relation to pesticide levels. Glutathione S-transferase (GST) activity was also related to abiotic factors but also decreased with increases in total pesticide levels. The lack of activity induction or inhibition by pesticides and the natural variation in abiotic factors among sites and across time limits the use of CAT and AChE to assess environmental contamination in this species.

  5. Converting Maturing Nuclear Sites to Integrated Power Production Islands

    DOE PAGES

    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

  6. 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...

  7. 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...

  8. The sites and topology of mitochondrial superoxide production

    PubMed Central

    Brand, Martin D.

    2010-01-01

    Mitochondrial superoxide production is an important source of reactive oxygen species in cells, and may cause or contribute to ageing and the diseases of ageing. Seven major sites of superoxide production in mammalian mitochondria are known and widely accepted. In descending order of maximum capacity they are the ubiquinone binding sites in complex I (site IQ) and complex III (site IIIQo), glycerol 3-phosphate dehydrogenase, the flavin in complex I (site IF), the electron transferring flavoprotein:Q oxidoreductase (ETFQOR) of fatty acid beta oxidation, and pyruvate and 2-oxoglutarate dehydrogenases. None of these sites is fully characterized and for some we only have sketchy information. The topology of the sites is important because it determines whether or not a site will produce superoxide in the mitochondrial matrix and be able to damage mitochondrial DNA. All sites produce superoxide in the matrix; site IIIQo and glycerol 3-phosphate dehydrogenase also produce superoxide to the intermembrane space. The relative contribution of each site to mitochondrial reactive oxygen species generation in the absence of electron transport inhibitors is unknown in isolated mitochondria, in cells or in vivo, and may vary considerably with species, tissue, substrate, energy demand and oxygen tension. PMID:20064600

  9. 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.

  10. 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

  11. Effects of marine and freshwater macroalgae on in vitro total gas and methane production.

    PubMed

    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 x 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.

  12. 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...

  13. 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...

  14. Mass Flux Calculations Show Strong Allochthonous Support of Freshwater Zooplankton Production Is Unlikely

    PubMed Central

    Brett, Michael T.; Arhonditsis, George B.; Chandra, Sudeep; Kainz, Martin J.

    2012-01-01

    Many studies have concluded terrestrial carbon inputs contribute 20–70% of the carbon supporting zooplankton and fish production in lakes. Conversely, it is also known that terrestrial carbon inputs are of very low nutritional quality and phytoplankton are strongly preferentially utilized by zooplankton. Because of its low quality, substantial terrestrial support of zooplankton production in lakes is only conceivable when terrigenous organic matter inputs are much larger than algal production. We conducted a quantitative analysis of terrestrial carbon mass influx and algal primary production estimates for oligo/mesotrophic lakes (i.e., TP≤20 µg L−1). In keeping with the principle of mass conservation, only the flux of terrestrial carbon retained within lakes can be utilized by zooplankton. Our field data compilation showed the median (inter-quartile range) terrestrial particulate organic carbon (t-POC), available dissolved organic carbon (t-DOC) inputs, and in-lake bacterial and algal production were 11 (8–17), 34 (11–78), 74 (37–165), and 253 (115–546) mg C m−2 d−1, respectively. Despite the widespread view that terrestrial inputs dominate the carbon flux of many lakes, our analysis indicates algal production is a factor 4–7 greater than the available flux of allochthonous basal resources in low productivity lakes. Lakes with high loading of t-DOC also have high hydraulic flushing rates. Because t-DOC is processed, i.e., mineralized or lost to the sediments, in lakes at ≈0.1% d−1, in systems with the highest t-DOC inputs (i.e., 1000 mg m−2 d−1) a median of 98% of the t-DOC flux is advected and therefore is not available to support zooplankton production. Further, advection is the primary fate of t-DOC in lakes with hydraulic retention times <3 years. When taking into account the availability and quality of terrestrial and autochthonous fluxes, this analysis indicates ≈95–99% of aquatic herbivore production is supported by in

  15. 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.

  16. 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.

  17. A review of current knowledge on toxic benthic freshwater cyanobacteria--ecology, toxin production and risk management.

    PubMed

    Catherine, Quiblier; Susanna, Wood; Isidora, Echenique-Subiabre; Mark, Heath; Aurélie, Villeneuve; Jean-François, Humbert

    2013-10-01

    Benthic cyanobacteria are found globally in plethora of environments. Although they have received less attention than their planktonic freshwater counterparts, it is now well established that they produce toxins and reports of their involvement in animal poisonings have increased markedly during the last decade. Most of the known cyanotoxins have been identified from benthic cyanobacteria including: the hepatotoxic microcystins, nodularins and cylindrospermopsins, the neurotoxic saxitoxins, anatoxin-a and homoanatoxin-a and dermatotoxins, such as lyngbyatoxin. In most countries, observations of toxic benthic cyanobacteria are fragmented, descriptive and in response to animal toxicosis events. Only a limited number of long-term studies have aimed to understand why benthic proliferations occur, and/or how toxin production is regulated. These studies have shown that benthic cyanobacterial blooms are commonly a mixture of toxic and non-toxic genotypes and that toxin concentrations can be highly variable spatially and temporally. Physiochemical parameters responsible for benthic proliferation vary among habitat type with physical disturbance (e.g., flow regimes, wave action) and nutrients commonly identified as important. As climatic conditions change and anthropogenic pressures on waterways increase, it seems likely that the prevalence of blooms of benthic cyanobacteria will increase. In this article we review current knowledge on benthic cyanobacteria: ecology, toxin-producing species, variables that regulate toxin production and bloom formation, their impact on aquatic and terrestrial organisms and current monitoring and management strategies. We suggest research needs that will assist in filling knowledge gaps and ultimately allow more robust monitoring and management protocols to be developed.

  18. 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)

  19. 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)

  20. Production and release of selenocyanate by different green freshwater algae in environmental and laboratory samples.

    PubMed

    LeBlanc, Kelly L; Smith, Matthew S; Wallschläger, Dirk

    2012-06-05

    In a previous study, selenocyanate was tentatively identified as a biotransformation product when green algae were exposed to environmentally relevant concentrations of selenate. In this follow-up study, we confirm conclusively the presence of selenocyanate in Chlorella vulgaris culture medium by electrospray mass spectrometry, based on selenium's known isotopic pattern. We also demonstrate that the observed phenomenon extends to other green algae (Chlorella kesslerii and Scenedesmus obliquus) and at least one species of blue-green algae (Synechococcus leopoliensis). Further laboratory experiments show that selenocyanate production by algae is enhanced by addition of nitrate, which appears to serve as a source of cyanide produced in the algae. Ultimately, this biotransformation process was confirmed in field experiments where trace amounts of selenocyanate (0.215 ± 0.010 ppb) were observed in a eutrophic, selenium-impacted river with massive algal blooms, which consisted of filamentous green algae (Cladophora genus) and blue-green algae (Anabaena genus). Selenocyanate abundance was low despite elevated selenium concentrations, apparently due to suppression of selenate uptake by sulfate, and insufficient nitrogen concentrations. Finally, trace levels of several other unidentified selenium-containing compounds were observed in these river water samples; preliminary suggestions for their identities include thioselenate and small organic Se species.

  1. 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.

  2. UV-B affects photosynthesis, ROS production and motility of the freshwater flagellate, Euglena agilis Carter.

    PubMed

    Kottuparambil, Sreejith; Shin, Woongghi; Brown, Murray T; Han, Taejun

    2012-10-15

    The effects of ultraviolet B (UV-B; 295-320 nm) radiation on certain vital physiological (photosynthesis), biochemical (production of reactive oxygen species - ROS) and behavioral (motility and orientation) characteristics were investigated in the unicellular photoautotroph, Euglena agilis Carter. The photosynthetic performance of E. agilis was recorded after exposure of between 15 and 60 min followed by a period of recovery lasting 6-24h under dim light (5-10 μmol photons m(-2) s(-1)). The maximum quantum yield of PS II (F(v)/F(m)) was reduced to 65% and 14% of initial values immediately following 15 and 30 min UV-B exposure, but recovered to 100 and 86% of the initials, respectively. Values of rETR(max) in E. agilis exposed to 15 min UV-B were similar to those of the initials, but a 30 min UV exposure resulted in 75% reduction of rETR(max) with only a 43% recovery as compared with the initial after 24h recovery. After a 60 min UV-B exposure, there were no Chl a fluorescence signals, and hence no F(v)/F(m) or rETR(max). A UV dose-dependent increase in DCFH-DA fluorescence was found in E. agilis cells, reflecting an increase in ROS production. After exposures to UV-B for between 15 and 60 min, the percentages of motile cells in the population decreased to 76, 39 and 15%, respectively. Following 24h in dim light, the percentage of motile cells increased to between 66% and 95% of the initial value. The velocity of non-irradiated cells was 60 μm s(-1), which decreased to 16-35 μm s(-1) immediately following exposure for 15-60 min. After periods of time in dim light (6, 12 and 24h) velocities had recovered to between 44 and 81% of the initial value. In untreated controls, the r-value was 0.23, indicating random movement of E. agilis, but it increased to 0.35 and 0.72 after exposure to UV-B for 30 and 60 min, respectively. There was a tendency towards vertical downward movement of cells proportional to the duration of exposure. The compactness of E. agilis decreased

  3. 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

  4. Utilization of Site-Specific Recombination in Biopharmaceutical Production.

    PubMed

    Ahmadi, Maryam; Damavandi, Narges; Akbari Eidgahi, 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.

  5. Phytochelatin production in freshwater algae Stigeoclonium in response to heavy metals contained in mining water; effects of some environmental factors.

    PubMed

    Pawlik-Skowrońska, B

    2001-05-01

    Production of phytochelatins (PC) in two freshwater, filamentous green algae of the genus Stigeoclonium, in response to heavy metals contained in mining water was studied. Stigeoclonium sp. grown abundantly in ditches with the mining water (southern Poland) accumulated high amounts of heavy metals. The other studied alga Stigeoclonium tenue Kütz. was isolated from unpolluted lake water in the Netherlands. Both algae exposed to the heavy metal mixture (17 microM; mainly zinc) contained in the hard, alkaline (pH 8.2) mining water produced similar amounts of phytochelatins (PC2 and PC3): 500-600 nmol SH g(-1) dry weight. After water acidification to pH 6.8, a > 2-fold increase of the total phytochelatin level as well as the appearance of longer chain peptide PC4 in the cells of both algae was observed. The concentration of labile forms of zinc in the acidified mining water was four times as high as that in the alkaline water. The heavy metal mixture (17 microM) in non-complexing solution of pH 6.8 caused a comparable phytochelatin production in both Stigeoclonium strains as the same mixture present in the acidified mining water. However, in the non-complexing solution of pH 8.2, the metal mixture induced in algae more PCs than at pH 6.8. A positive effect of bicarbonate enrichment in the solution on the PC production in S. tenue was also observed. Stigeoclonium sp. exposed to high concentrations (10 microM) of individual metals (Zn, Pb and Cd available as free cations) synthesised much higher amounts of phytochelatins (PC2-PC4) than in response to the metal mixture contained in the mining water. The order of PC induction by the studied metals in the Stigeoclonium sp. was Cd > Pb > Zn. Addition of suspended solid matter to the heavy metal solution resulted in essential quantitative changes in phytochelatins in algal cells; a considerable decrease of PC2, PC3 and PC4 levels was observed. The PC production in algae of the genus Stigeoclonium exposed to the heavy metal

  6. A method for evaluating effects of toxic chemicals on the productivity of freshwater ecosystems.

    PubMed

    Crossland, N O

    1988-12-01

    The finding that trout apparently consumed more invertebrates than were produced in the Horokiwi stream has been described as "Allen's paradox." One explanation for this is that invertebrate sampling techniques underestimate the standing crop. If so, trout growth might be a relatively sensitive indicator of the effects of toxic chemicals on the productivity of experimental ponds. In a replicated pond experiment, methyl parathion was applied at concentrations toxic to invertebrates but not to fish. Three 50-m3 ponds were treated at 40 micrograms liter-1 and three at 10 micrograms liter-1, and there were three untreated controls. Each pond was stocked with eight small, individually marked rainbow trout. The fish were removed by electrofishing 3 weeks after treatment. Mean growth rate of fish in control ponds was 6.3% per day, 4.3% per day in ponds treated with 10 micrograms liter-1, and 3.7% per day in ponds treated with 40 micrograms liter-1. Effects were significant at the 1% level. The standing crop of invertebrates was apparently insufficient to support the growth of the fish, an indication that the active, predatory rainbow trout is more efficient at sampling invertebrates than standard limnological procedures.

  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.

  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. 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.

  10. Maximization of cell growth and lipid production of freshwater microalga Chlorella vulgaris by enrichment technique for biodiesel production.

    PubMed

    Wong, Y K; Ho, Y H; Ho, K C; Leung, H M; Yung, K K L

    2017-04-01

    Chlorella vulgaris was cultivated under limitation and starvation and under controlled conditions using different concentrations of nitrate (NaNO3) and phosphate (K2HPO4 and KH2PO4) chemicals in modified Bold basal medium (BBM). The biomass and lipid production responses to different media were examined in terms of optical density, cell density, dry biomass, and lipid productivity. In the 12-day batch culture period, the highest biomass productivity obtained was 72.083 mg L(-1) day(-1) under BBM - NcontrolPlimited condition. The highest lipid content, lipid concentration, and lipid productivity obtained were 53.202 %, 287.291 mg/L, and 23.449 mg L(-1) day(-1) under BBM - NControlPDeprivation condition, respectively. Nitrogen had a major effect in the biomass concentration of C. vulgaris, while no significant effect was found for phosphorus. Nitrogen and phosphorus starvation was found to be the strategy affecting the lipid accumulation and affected the lipid composition of C. vulgaris cultures.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Potential Impacts of Electric Power Production Utilizing Natural Gas, Renewables and Carbon Capture and Sequestration on U.S. Freshwater Resources

    SciTech Connect

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

    2013-07-16

    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 Mm3/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 Mm3/d of water savings.

  18. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. 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.

  20. Ash cap influences on site productivity and fertilizer response in forests of the Inland Northwest

    Treesearch

    Mariann T. Garrison-Johnston; Peter G. Mika; Dan L. Miller; Phil Cannon; Leonard R. Johnson

    2007-01-01

    Data from 139 research sites throughout the Inland Northwest were analyzed for effects of ash cap on site productivity, nutrient availability and fertilization response. Stand productivity and nitrogen (N) fertilizer response were greater on sites with ash cap than on sites without. Where ash was present, depth of ash had no effect on site productivity or N fertilizer...

  1. 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

  2. Forest Soil Productivity on the Southern Long-Term Soil Productivity Sites at Age 5

    Treesearch

    D. Andrew Scott; Allan E. Tiarks; Felipe G. Sanchez; Michael Elliott-Smith; Rick Stagg

    2004-01-01

    Forest management operations have the potential to reduce soil productivity through organic matter and nutrient removal and soil compaction. We measured pine volume, bulk density, and soil and foliar nitrogen and phosphorus at age 5 on the 13 southern Long-Term Soil Productivity study sites. The treatments were organic matter removal [bole only (BO), whole tree (WT),...

  3. 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

  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. 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.

  6. 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

  7. Marine incursion: the freshwater herring of Lake Tanganyika are the product of a marine invasion into west Africa.

    PubMed

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

    2008-04-23

    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.

  8. Reducing Freshwater Toxicity while Maintaining Weed Control, Profits, And Productivity: Effects of Increased Crop Rotation Diversity and Reduced Herbicide Usage.

    PubMed

    Hunt, Natalie D; Hill, Jason D; Liebman, Matt

    2017-02-07

    Increasing crop rotation diversity while reducing herbicide applications may maintain effective weed control while reducing freshwater toxicity. To test this hypothesis, we applied the model USEtox 2.0 to data from a long-term Iowa field experiment that included three crop rotation systems: a 2-year corn-soybean sequence, a 3-year corn-soybean-oat/red clover sequence, and 4-year corn-soybean-oat/alfalfa-alfalfa sequence. Corn and soybean in each rotation were managed with conventional or low-herbicide regimes. Oat, red clover, and alfalfa were not treated with herbicides. Data from 2008-2015 showed that use of the low-herbicide regime reduced freshwater toxicity loads by 81-96%, and that use of the more diverse rotations reduced toxicity and system dependence on herbicides by 25-51%. Mean weed biomass in corn and soybean was <25 kg ha(-1) in all rotation × herbicide combinations except the low-herbicide 3-year rotation, which contained ∼110 kg ha(-1) of weed biomass. Corn and soybean yields and net returns were as high or higher for the 3- and 4-year rotations managed with the low-herbicide regime as for the conventional-herbicide 2-year rotation. These results indicate that certain forms of cropping system diversification and alternative weed management strategies can maintain yield, profit, and weed suppression while delivering enhanced environmental performance.

  9. 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

  10. Hydrogen production from small hyropower sites. Final report

    SciTech Connect

    Not Available

    1980-04-01

    A synergistic relationship was not found to exist between low-head hydropower and electrolytic hydrogen production. The storageability of hydrogen was expected to mitigate problems of hydrogen generation variability associated with the use of low-head hydropower as the power source. The expense of gaseous hydrogen storage equipment effectively eliminates storage as a means to decouple hydrogen demand and power/hydrogen production. From the opposite perspective, the availability of a low and stable cost of power from low-head hydro was expected to improve the competitiveness of electrolysis. In actuality, the results indicated that hydroelectric power from small dams would be comparatively expensive by current grid power standards (mid-1979). Electrolysis, in the capacity range considered here, is less sensitive to the cost of the power than originally presumed. Other costs including depreciation and capital related charges are more significant. Due to power generation variability, sole reliance on low-head hydropower to provide electricity to the cells would reduce the utilization of the hydrogen production investment, resulting in an increase in unit production costs. These factors were paramount in the Air Products recommendation to discontinue the study before continuing to more detailed stages of analysis, including an analysis of a site specific facility and the construction of a demonstration facility. Another major factor was the unavailability of a pipeline hydrogen supply situation which, because of lower distribution and capital costs, could have been commercially viable. An unfavorable judgment on the combined facility should not be misinterpreted and extended to the component systems. Although a detailed analysis of the individual prospects for electrolysis and low-head hydropower was beyond the study scope, the reader will realize, as the study is reviewed, that each is worthy of individual consideration.

  11. Boulder Distributions at Legacy Landing Sites: Assessing Regolith Production Rates and Landing Site Hazards

    NASA Technical Reports Server (NTRS)

    Watkins, R. N.; Jolliff, B. L.; Lawrence, S. J.; Hayne, P. O.; Ghent, R. R.

    2017-01-01

    Understanding how the distribution of boulders on the lunar surface changes over time is key to understanding small-scale erosion processes and the rate at which rocks become regolith. Boulders degrade over time, primarily as a result of micrometeorite bombardment so their residence time at the surface can inform the rate at which rocks become regolith or become buried within regolith. Because of the gradual degradation of exposed boulders, we expect that the boulder population around an impact crater will decrease as crater age increases. Boulder distributions around craters of varying ages are needed to understand regolith production rates, and Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) images provide one of the best tools for conducting these studies. Using NAC images to assess how the distribution of boulders varies as a function of crater age provides key constraints for boulder erosion processes. Boulders also represent a potential hazard that must be addressed in the planning of future lunar landings. A boulder under a landing leg can contribute to deck tilt, and boulders can damage spacecraft during landing. Using orbital data to characterize boulder populations at locations where landers have safely touched down (Apollo, Luna, Surveyor, Chang'e-3) provides validation for landed mission hazard avoidance planning. Additionally, counting boulders at legacy landing sites is useful because: 1) LROC has extensive coverage of these sites at high resolutions (approximately 0.5 meters per pixel). 2) Returned samples from craters at these sites have been radiometrically dated, allowing assessment of how boulder distributions vary as a function of crater age. 3) Surface photos at these sites can be used to correlate with remote sensing measurements.

  12. An approach for siting poplar energy production systems to increase productivity and associated ecosystem services

    Treesearch

    R.S. Jr. Zalesny; D.M. Donner; D.R. Coyle; W.L. Headlee; R.B. Hall

    2010-01-01

    Short rotation woody crops (SRWC) such as Populus species and hybrids (i.e., poplars) are renewable energy feedstocks that are vital to reducing our dependence on non-renewable and foreign sources of energy used for heat, power, and transportation fuels. Highly productive poplars grown primarily on marginal agricultural sites are an important...

  13. Mechanisms and sites for astrophysical gamma ray line production

    NASA Technical Reports Server (NTRS)

    Ramaty, R.

    1978-01-01

    The production of gamma ray lines and estimates of line fluxes resulting from nuclear deexcitations, positron annihilation, and electron capture at various astrophysical sites are discussed. Supernova and nova explosions synthesize long-lived radioactive isotopes and eject them into space where they produce observable gamma ray lines by decaying into excited levels of daughter nuclei or by emitting positrons. Energetic charged particles in the interstellar medium, in supernova remants, in solar or stellar flares, and possibly in the vicinity of compact objects, produce gamma-ray lines by inelastic collisions which either excite nuclear levels or produce positrons and neutrons. Energetic particles can result from acceleration in time-varying magnetic fields (solar flares) or from gravitational accretion onto neutron stars and black holes. Electromagnetic processes in the strong magnetic fields of pulsars can produce positron-electron pairs, with line emission resulting from positron annihilation. Deexcitations of quantized states in strong magnetic fields can also produce lines.

  14. Freshwater Fish Communities

    EPA Science Inventory

    Freshwater fish are ecologically important in stream ecosystems, and they provide people with significant food, recreation, and conservation value as biological indicator of freshwater streams. Historically, the streams and rivers of southern New England supported moderately dive...

  15. 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.

  16. Marginal sites in for biomass production - case study sites in northern Greece. Obstacles and solutions

    NASA Astrophysics Data System (ADS)

    Kiourtsis, Fotios; Keramitzis, Dimitris; Papatheodorou, Ioannis; Tsoulakaki, Dimitra; Gontzaridou, Marina; Lampetsou, Eugenia; Fragkiskakis, Nikitas; Gerwin, Werner; Repmann, Frank; Baumgarten, Wibke

    2017-04-01

    In 2016, D.A.M.T, the Hellenic Forest Service for northern Greece (Macedonia and Thrace Regions), with the support of BTU Cottbus-Senftenberg Reseach Center Landscape Development and Mining Landscapes experts and following common standard protocols of the SEEMLA project, established three plots, in the northeastern part of Greece, in Rodopi prefecture (main forest species for biomass production: Pinus Nigra, Pinus Brutia and Robinia Pseudacacia). Nearby productive ecosystems (including forests etc.) or successional sites will be used as references for estimating the potentials of MagL. Further existing plantations of energy crops on similar MagL, will be used to assess potential crop yields. These plots represent different types of marginal lands, they were specifically selected for SEEMLA purposes (reliable and sustainable exploitation of biomass) and are entirely different from other inventories, used for typical forest operations in Greece. The main differences are:  an intensively studied core area,  Soil Quality Rating (SQR) method measurements,  Soil Classification Maps - parameters estimation (land capability classes and landforms),  tightly spaced plantations (1,5 m x 1,5 m),  cropping systems,  shorter rotations and  the need for special forest management study. The combination of these requirements with the soil conditions of the area has created significant issues on plots establishment and accurate recording of supply chain stages. Main expected SEEMLA impacts are: • provide a substantial amount of EU energy needs from marginal/degraded land, • avoidance of land use conflicts by strengthening the ability to use MagL for biomass production for energy, • reduction of EU-wide greenhouse gas, • mitigation of conflicts regarding sustainability and biodiversity for the utilization of MagL for biomass production, • growth of plantations of bioenergy carriers from MagL at competitive costs, • expansion of economic opportunities

  17. 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.

  18. 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.

  19. 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

  20. Sites of amyloid SAA mRNA production

    SciTech Connect

    Meek, R.L.; Benditt, E.P.

    1986-03-01

    To investigate possible extrahepatic sites of SAA production, male BALB/c mice were given a single 0.5 ml injection of either 10% casein or lipopolysaccharide (LPS; 100 mg/ml). Twenty hours after injection, RNA was extracted from liver, kidney, adrenal, testis, brain, spleen, skeletal muscle, heart, lung and small intestine. Northern blots of total RNA were hybridized with nick-translated /sup 32/P-labeled cDNA probes (length approximately 150 base pairs) corresponding to an homologous region of the three known SAA genes. Both casein and LPS elevated the mRNA in liver to about 200-fold above control levels; mRNA was elevated in adrenals from O to approximately 2% of liver. mRNA in some other tissues responded only to LPS injection: levels in kidney reached 15% of liver; pituitary, testis and brain reached 0.02 to 0.5% of liver; no apoSAA mRNA was detected in heart, skeletal muscle, lung, spleen or small intestine. Thus, some organs other than liver appear to have operational genes for apoSAA. The expression of apoSAA genes in different tissues is shared with other apoproteins; it remains to be seen whether all three or only selected genes are transcribed and translated in different tissues.

  1. Stimulated embryo production as a parameter of estrogenic exposure via sediments in the freshwater mudsnail Potamopyrgus antipodarum.

    PubMed

    Duft, Martina; Schulte-Oehlmann, Ulrike; Weltje, Lennart; Tillmann, Michaela; Oehlmann, Jörg

    2003-09-10

    The effects of three suspected endocrine disrupting chemicals, the xeno-estrogens bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-n-nonylphenol (NP), were investigated in a whole-sediment biotest with the freshwater mudsnail Potamopyrgus antipodarum (Gastropoda, Prosobranchia). Artificial sediments were spiked with five nominal concentrations (six for NP), ranging from 1-300 microg/kg dry weight (1-1000 microg/kg for NP). After 2, 4 and 8 weeks of exposure, the responses of the test species were analysed. P. antipodarum exhibited a distinct increase in the number of embryos sheltered in its brood pouch in a time- and concentration-dependent manner in comparison to the solvent control sediment for BPA and OP. The number of "new", still unshelled embryos turned out to be the most sensitive parameter. The lowest observed effect concentration (LOEC) was equivalent to the lowest administered concentration (1 microg/kg for each test compound) for most parameters after 8 weeks of exposure. The calculation of effect concentrations resulted in even lower values for BPA (unshelled embryos after 2 weeks: EC(10) 0.22 microg BPA/kg, EC(50) 24.5 microg BPA/kg; after 4 weeks: EC(10) 0.19 microg BPA/kg, EC(50) 5.67 microg BPA/kg) and OP (unshelled embryos after 4 weeks: EC(10) 4 ng OP/kg, EC(50) 0.07 microg OP/kg). For NP, there was no clear concentration-dependent response, and therefore, no EC(10) or EC(50) could be estimated, but the data suggest an inverted u-shape type of curve. The LOEC in the experiments with NP was 10 microg/kg. Our results indicate that P. antipodarum is highly sensitive to the tested endocrine disruptors at environmentally relevant concentrations. Furthermore, the biotest with P. antipodarum is a useful tool for the identification of sediment-bound pollutants and for the assessment of sediment quality.

  2. The potential ecotoxicological impact of pharmaceutical and personal care products on humans and freshwater, based on USEtox™ characterization factors. A Spanish case study of toxicity impact scores.

    PubMed

    Ortiz de García, Sheyla; García-Encina, Pedro A; Irusta-Mata, Rubén

    2017-12-31

    Pharmaceutical and personal care products (PPCPs) are being increasingly included in Life Cycle Assessment studies (LCAs) since they have brought into evidence both human and ecological adverse effects due to their presence in different environmental compartments, wastewater facilities and industry. Therefore, the main goal of this research was to estimate the characterization factors (CFs) of 27 PPCPs widely used worldwide in order to incorporate their values into Life Cycle Impact Assessment studies (LCIA) or to generate a toxicity impact score ranking. Physicochemical properties, degradation rates, bioaccumulation, ecotoxicity and human health effects were collected from experimental data, recognized databases or estimated using EPI Suite™ and the USEtox™ software, and were subsequently used for estimating CFs. In addition, a Spanish toxicity impact score ranking was carried out for 49 PPCPs using the 27 newly calculated CFs, and 22 CFs already available in the literature, besides the data related to the occurrence of PPCPs in the environment in Spain. It has been highlighted that emissions into the continental freshwater compartment showed the highest CFs values for human effects (ranging from 10(-9) to 10(-3)Cases·kg(-1)), followed by emissions into the air (10(-9) to 10(-5)Cases·kg(-1)), soil (10(-11) to 10(5)Cases·kg(-1)) and seawater (10(-12) to 10(-4)Cases·kg(-1)). CFs regarding the affectation of freshwater aquatic environments were the highest of those proceeding from emissions into continental freshwater (between 1 to 10(4)PAF·m(3)·day·kgemission(-1)) due to the direct contact between the source of emission and the compartment affected, followed by soil (among 10(-1) to 10(4)PAF·m(3)·day·kgemission(-1)), and air (among 10(-2) to 10(4)PAF·m(3)·day·kgemission(-1)) while the lowest were the CFs of continental seawater (among 10(-28) to 10(-3)PAF·m(3)·day·kgemission(-1)). Freshwater aquatic ecotoxicological CFs are much higher than human

  3. 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. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  4. 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

  5. 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

  6. Rat heart: A site of oxytocin production and action

    PubMed Central

    Jankowski, Marek; Hajjar, Fadi; Kawas, Sausan Al; Mukaddam-Daher, Suhayla; Hoffman, Gloria; McCann, Samuel M.; Gutkowska, Jolanta

    1998-01-01

    We report here that the rat heart is a site of oxytocin (OT) synthesis and release. Oxytocin was detected in all four chambers of the heart. The highest OT concentration was in the right atrium (2128 ± 114 pg/mg protein), which was 19-fold higher than in rat uterus but 3.3-fold lower than in the hypothalamus. OT concentrations were significantly greater in the right and left atria than in the corresponding ventricles. Furthermore, OT was released into the effluent of isolated, perfused rat heart (34.5 ± 4.7 pg/min) and into the medium of cultured atrial myocytes. Reverse-phase HPLC purification of the heart extracts and heart perfusates revealed a main peak identical with the retention time of synthetic OT. Southern blots of reverse transcription–PCR products from rat heart revealed gene expression of specific OT mRNA. OT immunostaining likewise was found in atrial myocytes and fibroblasts, and the intensity of positive stains from OT receptors paralleled the atrial natriuretic peptide stores. Our findings suggest that heart OT is structurally identical, and therefore derived from, the same gene as the OT that is primarily found in the hypothalamus. Thus, the heart synthesizes and processes a biologically active form of OT. The presence of OT and OT receptor in all of the heart’s chambers suggests an autocrine and/or paracrine role for the peptide. Our finding of abundant OT receptor in atrial myocytes supports our hypothesis that OT, directly and/or via atrial natriuretic peptide release, can regulate the force of cardiac contraction. PMID:9826739

  7. Rat heart: a site of oxytocin production and action.

    PubMed

    Jankowski, M; Hajjar, F; Kawas, S A; Mukaddam-Daher, S; Hoffman, G; McCann, S M; Gutkowska, J

    1998-11-24

    We report here that the rat heart is a site of oxytocin (OT) synthesis and release. Oxytocin was detected in all four chambers of the heart. The highest OT concentration was in the right atrium (2128 +/- 114 pg/mg protein), which was 19-fold higher than in rat uterus but 3.3-fold lower than in the hypothalamus. OT concentrations were significantly greater in the right and left atria than in the corresponding ventricles. Furthermore, OT was released into the effluent of isolated, perfused rat heart (34.5 +/- 4.7 pg/min) and into the medium of cultured atrial myocytes. Reverse-phase HPLC purification of the heart extracts and heart perfusates revealed a main peak identical with the retention time of synthetic OT. Southern blots of reverse transcription-PCR products from rat heart revealed gene expression of specific OT mRNA. OT immunostaining likewise was found in atrial myocytes and fibroblasts, and the intensity of positive stains from OT receptors paralleled the atrial natriuretic peptide stores. Our findings suggest that heart OT is structurally identical, and therefore derived from, the same gene as the OT that is primarily found in the hypothalamus. Thus, the heart synthesizes and processes a biologically active form of OT. The presence of OT and OT receptor in all of the heart's chambers suggests an autocrine and/or paracrine role for the peptide. Our finding of abundant OT receptor in atrial myocytes supports our hypothesis that OT, directly and/or via atrial natriuretic peptide release, can regulate the force of cardiac contraction.

  8. Testing tree indicator species for classifying site productivity in southern Appalachian hardwood stands

    Treesearch

    W. Henry McNab; David L. Loftis; R.M. Shefield

    2002-01-01

    Composite indices of site moisture and fertility regimes, site variables, and individual tree species were tested for their relationship with site productivity on forest survey plots in the southern Appalachian Mountains. Mew annual basal area increment was significantly associated with the fertility index and site variables including elevation, slope gradient, and...

  9. 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

    assessed possible influx of contaminants with the freshwater diversion, contaminant levels in fishes and bivalves in this study were generally lower, yet three nontoxic inorganic elements in Davis Pond fish samples exhibited ranges of concentrations that were more than two times higher than did those from Caernarvon. Levels in bivalves were different between diversions but about equal in the numbers of trace elements showing high levels per location. Contaminant values were compared to those listed in various literature and agency sources, both regional and national, including the National Contaminant Biomonitoring Program (NCBP), in which the 85th percentile and above represents what is considered to be an elevated contaminant concentration and cause for concern. Generally, bivalves were at the high end of their ranges for both organic and inorganic contaminants. In this study, OCs were detectable in 67 percent of fish from the Mississippi River site, ranging from 0.15 to 1.09 μg/g wet weight (ww) or fresh weight (fw), and in 11 percent of the fish from the marsh sites, ranging from 0.06 to 0.612 μg/g ww. Bivalves from the Mississippi River had OC levels of 0.096 μg/g ww, whereas none were detectable in bivalves at the marsh sites. In this study, p,p’-dichlorodiphenyldichloroethylene (p,p’-DDE) (a biodegradation product of DDT [dichlorodiphenyl trichloroethane]) and total PCBs were the most frequently detected OCs and were primarily from the Mississippi River. For total OC content, using adjusted least squares means, some significant interactions were noted between fish species and sites. PAHs were detected in aquatic animals at all sites (range of 0.017–17.534 μg/g ww), as were AHs (range of 0.423–4.549 μg/g ww); the highest levels of PAHs and AHs were found in bivalves from the Mississippi River. When analysis of variance (α = 0.05) was performed with data from aquatic animals, there were only two significant relationships between PAHs, AHs, and OCs

  10. Urbanization and the Level of Microplastic Ingestion by Fish: A Comparison of Freshwater Sunfish (Centrarchidae) from the Brazos River watershed, and Pinfish (Sparidae), from the Brazos Estuary and Inshore Marine Sites, Texas, USA

    NASA Astrophysics Data System (ADS)

    Rieper, K. B.; Peters, C. A.; Bratton, S. P.

    2016-02-01

    While previous research has documented ingestion of macro- and microplastics by aquatic fauna in both freshwater and marine ecosystems, relatively little is known of the environmental and ecological factors influencing the entry and diffusion of plastics and artificial polymers into aquatic foodwebs. Microplastics are defined as 50 μm to 5 mm in length. This study utilized stomach content analysis to compare the level of microplastic artificial polymer ingestion for fish collected from the Brazos River watershed, Brazos estuary, and inshore coastal waters of Texas, USA, in areas with varying levels of urbanization. We collected 318 bluegill (Lepomis macrochirus) and 118 longear sunfish (Lepomis megalotis) at 14 freshwater locales, and 11 samples of 298 pinfish (Lagodon rhomboides) at 6 saltwater locales. Sunfish averaged 12.6 cm in length, and pinfish averaged 14.9 cm. Sunfish averaged .807 microplastics per fish, and pinfish averaged 1.09. The maximum percentage for pinfish with microplastics present per sample (frequency) was 77%, compared to 75% for sunfish. Mean frequencies per sample were also similar: 45% for sunfish and 47% for pinfish. The Brazos River collections, however, had a greater percentage with frequencies of <.30 (42%) for sunfish, versus 9% for pinfish. Sample sites in the center of urbanized zones, including downtown Waco and Galveston, TX, had the greatest frequencies of ingestion, while sites upstream of Waco, TX, had the least. For pinfish, the mean stomach weight per sample was significantly positively correlated (p=.01) to both the percent of individuals ingesting microplastics (cc=.742) and the mean number of plastic particles ingested per fish (cc=.697). The majority of the microplastics were thread shaped, with blue and grey the dominant colors. Comparison with presence of natural food items suggests microplastic ingestion is predominantly incidental for these sentinel fish species.

  11. 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.

  12. Composition of beer by 1H NMR spectroscopy: effects of brewing site and date of production.

    PubMed

    Almeida, Cláudia; Duarte, Iola F; Barros, António; Rodrigues, João; Spraul, Manfred; Gil, Ana M

    2006-02-08

    A principal component analysis (PCA) of 1H NMR spectra of beers differing in production site (A, B, C) and date is described, to obtain information about composition variability. First, lactic and pyruvic acids contents were found to vary significantly between production sites, good reproducibility between dates being found for site A but not for sites B and C beers. Second, site B beers were clearly distinguished by the predominance of linear dextrins, while A and C beers were richer in branched dextrins. Carbohydrate reproducibility between dates is poorer for site C with dextrin branching degree varying significantly. Finally, all production sites were successfully distinguished by their contents in adenosine/inosine, uridine, tyrosine/tyrosol, and 2-phenylethanol, reproducibility between dates being again poorer for site C. Interpretation of the above compositional differences is discussed in terms of the biochemistry taking place during brewing, and possible applications of the method in brewing process control are envisaged.

  13. 77 FR 48550 - Technicolor Creative Services, Post Production Feature Mastering Division Including On-Site...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-14

    ... Employment and Training Administration Technicolor Creative Services, Post Production Feature Mastering... Feature Mastering Division, Hollywood, California (subject firm). The worker group also included on-site... related to post-production services for films. The initial investigation resulted in a...

  14. 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.

  15. 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.

  16. Switchgrass nitrogen response and estimated production costs on diverse sites

    USDA-ARS?s Scientific Manuscript database

    Switchgrass (Panicum virgatum L.) has been the principal perennial herbaceous crop investigated for bioenergy production in North America given its high production potential, relatively low input requirements, and potential suitability for use on marginal lands. Few large trials have determined swit...

  17. Linking climate, gross primary productivity, and site index across forests of the western United States

    Treesearch

    Aaron R. Weiskittel; Nicholas L. Crookston; Philip J. Radtke

    2011-01-01

    Assessing forest productivity is important for developing effective management regimes and predicting future growth. Despite some important limitations, the most common means for quantifying forest stand-level potential productivity is site index (SI). Another measure of productivity is gross primary production (GPP). In this paper, SI is compared with GPP estimates...

  18. Site-level evaluation of satellite-based global terrestrial gross primary production and net primary production monitoring.

    Treesearch

    David P. Turner; William D. Ritts; Warren B. Cohen; Thomas K. Maeirsperger; Stith T. Gower; Al A. Kirschbaum; Steve W. Runnings; Maosheng Zhaos; Steven C. Wofsy; Allison L. Dunn; Beverly E. Law; John L. Campbell; Walter C. Oechel; Hyo Jung Kwon; Tilden P. Meyers; Eric E. Small; Shirley A. Kurc; John A. Gamon

    2005-01-01

    Operational monitoring of global terrestrial gross primary production (GPP) and net primary production (NPP) is now underway using imagery from the satellite-borne Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Evaluation of MODIS GPP and NPP products will require site-level studies across a range of biomes, with close attention to numerous scaling...

  19. Is there a better metric than site index to indicate the productivity of forested lands?

    Treesearch

    Maria E. Blanco Martin; Michael Hoppus; Andrew Lister; James A. Westfall

    2009-01-01

    The Forest Service, U.S. Department of Agriculture's Forest Inventory and Analysis (FIA) program selects site trees for each plot that are used to measure site productivity. The ability of a site to produce wood volume is indicated indirectly by comparing total tree height with tree age. This comparison assumes that the rate of height growth is strongly related to...

  20. Water and Nutrient Effects on Loblolly Pine Production and Stand Development on a Sandhill Site

    Treesearch

    H.L. Allen; T. J. Albaugh; Kurt H. Johnsen

    2002-01-01

    During the last decade, it has become apparent that production rates of pine plantations in the southeastern United States are far below levels that are biologically and economically optimal. By managing genetic and site resource effectively, production rates should exceed 350 ft3/ acre/year on most sites. In effort to better understand the...

  1. Fisheries indicators, freshwater

    USGS Publications Warehouse

    Kwak, Thomas J.

    2010-01-01

    Freshwater fisheries exist among diverse ecosystems and fauna, provide societal benefits, and are influenced by human activities. Fisheries scientists assess the status and sustainability of fisheries by multiple approaches, including abundance and condition indices, population parameters, community indices, modeling, and surveys of habitat and human dimensions. The future sustainability of freshwater fisheries is limited not by available methods but by society’s will.

  2. Introduction to Energy Conservation and Production at Waste Cleanup Sites

    EPA Pesticide Factsheets

    This issue paper, prepared by EPA's Engineering Forum under the Technical Support Project, provides an overview on the considerations for energy conservation and production during the design and (O&M) phases of waste cleanup projects.

  3. 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.

  4. 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).

  5. On-Site Construction Productivity Improvement Through Total Quality Management

    DTIC Science & Technology

    1991-12-01

    abnormality if 3 out of 7 or 4 out of 10 points lie within zones drawn as follows: (1) Zone next to the central line when a line is drawn between both the... Joeseph M., Juran on Plannnina for Oualitv. New York: The Free Press, 1988. Oglesby, Clarkson H., Parker, Henry W., and Howell, Gregory A... 10 Figure 1-3 Juran’s Triple Role Concept for On-Site Construction Activity Process ........................ 16

  6. Tracking salinity intrusions in a coastal forested freshwater wetland system

    Treesearch

    Anand D. Jayakaran; Thomas M. Williams; William H. Conner

    2016-01-01

    Coastal forested freshwater wetlands are sentinel sites for salinity intrusions associated with large, tidally influenced, storm-driven or drought-induced incursions of estuarine waters into freshwater ecosystems. These incursions may also be exacerbated by rising sea levels associated with climate change.

  7. Studies on bioflocculant production by Arthrobacter sp. Raats, a freshwater bacteria isolated from Tyume River, South Africa.

    PubMed

    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 Mg(2+) 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.

  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. Substrate and/or substrate-driven changes in the abundance of methanogenic archaea cause seasonal variation of methane production potential in species-specific freshwater wetlands.

    PubMed

    Liu, Deyan; Ding, Weixin; Yuan, Junji; Xiang, Jian; Lin, Yongxin

    2014-05-01

    There are large temporal and spatial variations of methane (CH4) emissions from natural wetlands. To understand temporal changes of CH4 production potential (MPP), soil samples were collected from a permanently inundated Carex lasiocarpa marsh and a summer inundated Calamagrostis angustifolia marsh over the period from June to October of 2011. MPP, dissolved organic carbon (DOC) concentration, abundance and community structure of methanogenic archaea were assessed. In the C. lasiocarpa marsh, DOC concentration, MPP and the methanogen population showed similar seasonal variations and maximal values in September. MPP and DOC in the C. angustifolia marsh exhibited seasonal variations and values peaked during August, while the methanogen population decreased with plant growth. Methanogen abundance correlated significantly (P = 0.02) with DOC only for the C. lasiocarpa marsh. During the sampling period, the dominant methanogens were the Methanosaetaceae and Zoige cluster I (ZC-Ι) in the C. angustifolia marsh, and Methanomicrobiales and ZC-Ι in the C. lasiocarpa marsh. MPP correlated significantly (P = 0.04) with DOC and methanogen population in the C. lasiocarpa marsh but only with DOC in the C. angustifolia marsh. Addition of C. lasiocarpa litter enhanced MPP more effectively than addition of C. angustifolia litter, indicating that temporal variation of substrates is controlled by litter deposition in the C. lasiocarpa marsh while living plant matter is more important in the C. angustifolia marsh. This study indicated that there was no apparent shift in the dominant types of methanogen during the growth season in the species-specific freshwater wetlands. Temporal variation of MPP is controlled by substrates and substrate-driven changes in the abundance of methanogenic archaea in the C. lasiocarpa marsh, while MPP depends only on substrate availability derived from root exudates or soil organic matter in the C. angustifolia marsh.

  10. Site Management and Productivity in Tropical Forest Plantations

    Treesearch

    A. Tiarks; E.K.S. Nambiar; C. Cossalter

    1998-01-01

    Tropical countries are expanding plantation forestry to develop sustainable woodproduction systems. Much of this is based on short rotations of exotic species. These systems require large capital investments, represent intensive land use and increase the demands on the soil. To develop options for maintaining or increasing productivity a partner-project was initiated...

  11. Salting our freshwater lakes.

    PubMed

    Dugan, Hilary A; Bartlett, Sarah L; Burke, Samantha M; Doubek, Jonathan P; Krivak-Tetley, Flora E; Skaff, Nicholas K; Summers, Jamie C; Farrell, Kaitlin J; McCullough, Ian M; Morales-Williams, Ana M; Roberts, Derek C; Ouyang, Zutao; Scordo, Facundo; Hanson, Paul C; Weathers, Kathleen C

    2017-04-10

    The highest densities of lakes on Earth are in north temperate ecosystems, where increasing urbanization and associated chloride runoff can salinize freshwaters and threaten lake water quality and the many ecosystem services lakes provide. However, the extent to which lake salinity may be changing at broad spatial scales remains unknown, leading us to first identify spatial patterns and then investigate the drivers of these patterns. Significant decadal trends in lake salinization were identified using a dataset of long-term chloride concentrations from 371 North American lakes. Landscape and climate metrics calculated for each site demonstrated that impervious land cover was a strong predictor of chloride trends in Northeast and Midwest North American lakes. As little as 1% impervious land cover surrounding a lake increased the likelihood of long-term salinization. Considering that 27% of large lakes in the United States have >1% impervious land cover around their perimeters, the potential for steady and long-term salinization of these aquatic systems is high. This study predicts that many lakes will exceed the aquatic life threshold criterion for chronic chloride exposure (230 mg L(-1)), stipulated by the US Environmental Protection Agency (EPA), in the next 50 y if current trends continue.

  12. Salting our freshwater lakes

    PubMed Central

    Bartlett, Sarah L.; Burke, Samantha M.; Doubek, Jonathan P.; Krivak-Tetley, Flora E.; Skaff, Nicholas K.; Summers, Jamie C.; Farrell, Kaitlin J.; McCullough, Ian M.; Morales-Williams, Ana M.; Roberts, Derek C.; Ouyang, Zutao; Scordo, Facundo; Hanson, Paul C.; Weathers, Kathleen C.

    2017-01-01

    The highest densities of lakes on Earth are in north temperate ecosystems, where increasing urbanization and associated chloride runoff can salinize freshwaters and threaten lake water quality and the many ecosystem services lakes provide. However, the extent to which lake salinity may be changing at broad spatial scales remains unknown, leading us to first identify spatial patterns and then investigate the drivers of these patterns. Significant decadal trends in lake salinization were identified using a dataset of long-term chloride concentrations from 371 North American lakes. Landscape and climate metrics calculated for each site demonstrated that impervious land cover was a strong predictor of chloride trends in Northeast and Midwest North American lakes. As little as 1% impervious land cover surrounding a lake increased the likelihood of long-term salinization. Considering that 27% of large lakes in the United States have >1% impervious land cover around their perimeters, the potential for steady and long-term salinization of these aquatic systems is high. This study predicts that many lakes will exceed the aquatic life threshold criterion for chronic chloride exposure (230 mg L−1), stipulated by the US Environmental Protection Agency (EPA), in the next 50 y if current trends continue. PMID:28396392

  13. Freshwater mussels of Florida

    USGS Publications Warehouse

    Williams, James D.; Butler, Robert S.; Warren, Gary L.; Johnson, Nathan A.

    2014-01-01

    An exhaustive guide to all aspects of the freshwater mussel fauna in Florida,Freshwater Mussels of Florida covers the ecology, biology, distribution, and conservation of the many species of bivalve mollusks in the Sunshine State. In the past three decades, researchers, the public, businesses that depend on wildlife, and policy makers have given more attention to the threatened natural diversity of the Southeast, including freshwater mussels. This compendium meets the increasingly urgent need to catalog this imperiled group of aquatic organisms in the United States.

  14. 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

    2015-07-07

    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.

  15. 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.

  16. Freshwater Harmful Algal Blooms

    EPA Pesticide Factsheets

    EPA is seeking regular and early career applications proposing innovative research on the prediction, prevention, control and mitigation of freshwater HABs as well as the drivers, life cycle patterns, and fate of and effects from from less-common, less

  17. Effects of severe drought on freshwater mussel assemblages

    Treesearch

    Wendell Hagg; Jr. Warren Melvin L.

    2008-01-01

    We examined changes in freshwater mussel abundance and species composition at eight sites in Alabama and Mississippi in response to a severe drought in 2000. Five small-stream sites in Bankhead National Forest were heavily impacted by drought; one site dried almost completely, and four sites experienced total or near cessation of flow but retained water in their...

  18. 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.

  19. The freshwater biodiversity crisis.

    PubMed

    Brautigam, A

    1999-01-01

    This article concerns the threat on freshwater ecosystems, which harbor a disproportionate amount of the world's biodiversity. In many parts of the world, freshwater ecosystems are already degraded from a range of human activities, including water extraction, pollution and physical alteration. The data that showed a biodiversity crisis in ecosystems included species loss and breakdown of the ecological processes and resources. Furthermore, several case studies were cited to illustrate the status of freshwater diversity. Numerous reasons for freshwater biodiversity loss were mentioned, which included pollution from pesticides and agricultural and mine run-off, and physical alteration through channelization and impoundments that affected the hydrology and benthic habitat. Despite the successful establishment of institutions to conserve water birds and wetland habitats, there was a lower priority for conservation of freshwater biodiversity in terms of species and habitats. This bias has had important and serious implications for allocation of resources to increase the knowledge and understanding of freshwater ecosystems, as well as for the adequacy of impact assessments for development projects affecting them.

  20. Partial Updating of TSCA Inventory DataBase; Production and Site Reports; Final Rule

    EPA Pesticide Factsheets

    A partial updating of the TSCA inventory database. The final rule requires manufacturers and importers of certain chemical substances included on the TSCA Chemical Substances Inventory to report current data on the production volume, plant site, etc.

  1. Synthetic Minor NSR Permit: BP America Production Company - Treating Site #8 Central Delivery Point

    EPA Pesticide Factsheets

    This page contains the response to public comments and the final synthetic minor NSR permit for the BP America Production Company, Treating Site #8 Central Delivery Point, located on the Southern Ute Indian Reservation in La Plata County, CO.

  2. 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.

  3. Validation of SMAP surface soil moisture products with core validation sites

    USDA-ARS?s Scientific Manuscript database

    The NASA Soil Moisture Active Passive (SMAP) mission has utilized a set of core validation sites as the primary methodology in assessing the soil moisture retrieval algorithm performance. Those sites provide well-calibrated in situ soil moisture measurements within SMAP product grid pixels for diver...

  4. Productivity of a large-wheeled skidder and roller chopper for preparing sites.

    Treesearch

    Edwin S. Miyata; Helmuth M. Steinhilb; Glenn D. Mroz; Lynne A. Coyer

    1983-01-01

    Discusses the results of a field test of a Pettibone Master 1500 skidder and Flecor Corporation SS812 roller chopper for site preparation work in Wisconsin. Includes cost, productivity, and effectiveness of site preparation on 23.4 acres (9.47 ha).

  5. SOIL PRODUCTIVITY AT TWO NORTH DAKOTA SITES DIFFERING IN TOPSOIL QUALITY AND PROFILE STRUCTURE

    USDA-ARS?s Scientific Manuscript database

    Soil and land productivity depends on the interaction of topsoil quality, profile structure, and landform character. Crop sequence experiments were performed under no-tillage at two sites by growing crops in strips one year, and in perpendicular strips the following year. The two sites (hereafter re...

  6. Vole preference of bilberry along gradients of simulated moose density and site productivity.

    PubMed

    Pedersen, Simen; Andreassen, Harry P; Persson, Inga-Lill; Julkunen-Tiitto, Riitta; Danell, Kjell; Skarpe, Christina

    2011-12-01

    Browsing by large herbivores might either increase or decrease preference for the plant by other herbivores, depending on the plant response. Using a cafeteria test, we studied the preference by root voles (Microtus oeconomus [Pallas, 1776]) for bilberry (Vaccinium myrtillus L.) previously subjected to 4 levels of simulated moose (Alces alces [Linnaeus, 1758]) density. The different levels of moose density were simulated at population densities relevant for Fennoscandian conditions, in exclosures situated along a site productivity gradient. We expected: (i) voles to prefer bilberry from high productivity sites over low productivity sites; (ii) voles to prefer browsed bilberry, if plants allocate resources to compensatory growth or to avoid browsed bilberry if plants allocate resources to defense; (iii) these effects to increase with increasing simulated moose density; and (iv) the concentration of plant chemicals and the plant morphology to explain vole preference. Specifically, we predicted that voles would prefer: (i) plants with high nitrogen content; (ii) plants with low content of defensive substances; and (iii) tall plants with long shoots. Voles preferred bilberry from the high productivity sites compared to the low productivity sites. We also found an interaction between site productivity and simulated moose density, where voles preferred unbrowsed plants at low productivity sites and intermediate levels of browsing at high productivity sites. There was no effect of plant chemistry or morphology on vole preference. We conclude that moose browsing impacts the food preference of voles. With the current high densities of moose in Fennoscandia, this could potentially influence vole food selection and population dynamics over large geographical areas.

  7. Acorn Production on the Missouri Ozark Forest Ecosystem Project Study Sites: Pre-treatment Data

    Treesearch

    Larry D. Vangilder

    1997-01-01

    In the pre-treatment phase of a study to determine if even- and uneven-aged forest management affects the production of acorns on the Missourt Forest Ecosystem Project (MOFEP) study sites, acorn production was measured on the nine study sites by randomly placing from 2 to 6 plots in each of four ecological land type (ELT) groupings (N=130 plots). A split-plot...

  8. Accumulation characteristics of soluble algal products (SAP) by a freshwater microalga Scenedesmus sp. LX1 during batch cultivation for biofuel production.

    PubMed

    Yu, Yin; Hu, Hong-Ying; Li, Xin; Wu, Yin-Hu; Zhang, Xue; Jia, Sheng-Lan

    2012-04-01

    Algae cultivation is the essential basis for microalgal biofuel production. Soluble algal products (SAP) are significant obstacle to large-scale, high-cell-density cultivation processes. SAP accumulation during batch cultivation of Scenedesmus sp. LX1 (a unique strain accumulating lipid substantially while growing fast under low-nutrient conditions) with different initial nitrogen concentrations (7.4-34.0mgNL(-1)) was investigated. The SAP content varied in the range of 3.4-17.4mgDOCL(-1) at stationary phase, with average yield per cell of 0.5-2.5pgDOCcell(-1). High SAP accumulation up to 15.2-17.4mgDOCL(-1) were observed with initial nitrogen above 20.2mgNL(-1). The maximum SAP production rate per unit culture volume (r(SAP)) was 2.6mgDOC(Ld)(-1) and that per cell (ν(SAP)) was 1.5pgDOC(celld)(-1). The r(SAP) increased with cell growth rate and decreased with cell density linearly. The SAP accumulation was majorly due to the release of growth-associated products.

  9. Influence of environmental ammonia on the production of nitric oxide and expression of inducible nitric oxide synthase in the freshwater air-breathing catfish (Heteropneustes fossilis).

    PubMed

    Choudhury, Mahua G; Saha, Nirmalendu

    2012-07-15

    Nitric oxide (NO) is a highly versatile and unique ubiquitous signaling molecule, and is known to play diverse physiological functions in mammals including those of adaptation to various stresses. The present study reports on the influence of exposure to high external ammonia (HEA) on the production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS), that produces NO from l-arginine in the freshwater air-breathing catfish (Heteropneustes fossilis), which is reported to tolerate a very HEA. Some levels of NO were found to be present in all the tissues and also in plasma of control fish, which further enhanced significantly in fishes treated with high concentrations of environmental ammonia (25 and 50 mM ammonium chloride) for 7 days, accompanied by more efflux of NO from the perfused liver. This was accomplished by the induction of iNOS activity in different tissues of fish exposed to HEA, which otherwise was not detectable in control fish. Exposure to 25 mM ammonium chloride also led to a significant expression of iNOS protein in different tissues, followed by further increase at 50mM ammonium chloride. Further, there was an increase in the expression of iNOS mRNA in ammonia-treated fish, thus suggesting that the expression of iNOS gene under hyper-ammonia stress was probably regulated at the transcriptional level. Immunocytochemical analysis indicated that the expression of iNOS in different tissues was zonal specific and not expressed uniformly throughout the organ. Hyper-ammonia stress also led to activation and nuclear translocation of nuclear factor κB (NFκB) in hepatic cells. These results suggest that the activation of iNOS gene under hyper-ammonia stress was probably mediated through the activation of one of the major transcription factors, the NFκB. This is the first report of ammonia-induced expression of iNOS gene, iNOS protein expression leading to more generation of NO under hyper-ammonia stress in any teleosts

  10. 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.

  11. Oviposition by African malaria vector mosquitoes. II. Effects of site tone, water type and conspecific immatures on target selection by freshwater Anopheles gambiae Giles, sensu lato.

    PubMed

    McCrae, A W

    1984-06-01

    Females of Anopheles gambiae s. lat., most of which would have been A. gambiae s. str., were collected from houses in coastal Kenya and tested for their oviposition preferences using Petri dishes in large laboratory cages with lighting equivalent to weak moonlight. Significantly more eggs were laid overnight in water over black than over paler tones, and this difference increased as contrast with the surrounding floor was increased. Direct observation revealed that over white targets, females oviposited from a settled posture, whereas over black targets they did so from flight. The influence on this behaviour of target darkness (tone) overrode that of cage size or target size. In tests which yielded markedly fewer eggs in sea water than in tap water, no significant difference was detected when cage floors were either black or white, although a black floor might have resulted in significantly greater discrimination against sea water had more tests been conducted. All further testing was done over black cage floors. Turbid water from a natural development site received more eggs than distilled, tap or swamp water, even though the turbid water appeared paler than the others. The females did not discriminate between rearing water and tap water, or tap water with and without pupae, but the presence of larvae was repellent. Turbid water from a development site thus seemed to possess an arrestant property which overrode selection favouring darker targets, and which was not derived from prior presence of conspecific immatures. It is suggested that for A. gambiae, oviposition from a settled posture is a response to sub-optimal stimuli, possibly indicating conditions under which oviposition would not occur in nature, and hence why cage experiments using white targets have in the past yielded confusing results.

  12. 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

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

    PubMed

    Chu, Kar-Hai; Sidhu, Anupreet K; Valente, Thomas W

    2015-01-01

    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. 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. 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. 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. 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.

  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. 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

  16. 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.

  17. 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

    ...., Cement Division, Product Engineering, Including On-Site Leased Workers of Aerotek Contract Engineering..., applicable to workers of FLSmidth, Inc., Cement Division, Product Engineering, including on-site leased...-site leased workers from Clarke Consulting, Inc. were also employed on-site at FLSmidth, Inc.,...

  18. 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

    ... to Apply for Worker Adjustment Assistance on December 22, 2010, applicable to workers of MeadWestvaco... assistance was issued for all workers of MeadWestvaco, Consumer and Office Products Division, Sidney, New... workers of MeadWestvaco Corporation, Consumer and Office Products Division, including on-site...

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

    PubMed Central

    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. Field trials of Growmate humic products in Central and South America: benefits of networked sites.

    USDA-ARS?s Scientific Manuscript database

    The effectiveness of humic products as crop and soil amendments deserves further study but remains in dispute. Broad-based evidence for their performance could be gained through coordinated networks of sites that evaluate humic products under diverse soil and weather conditions and for several crop...

  1. 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.

  2. 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...

  3. 77 FR 61383 - Freshwater Crawfish Tail Meat From the People's Republic of China: Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-09

    ... International Trade Administration Freshwater Crawfish Tail Meat From the People's Republic of China... administrative review of the antidumping duty order on freshwater crawfish tail meat from the People's Republic... order is freshwater crawfish tail meat. The product is currently classified in the Harmonized...

  4. Records of River Variation in the Shells of Freshwater Bivalves

    NASA Astrophysics Data System (ADS)

    Carroll, M.; Romanek, C.

    2005-12-01

    The skeletons of hard-shelled invertebrates such as corals and bivalves are commonly used in marine settings as archives of environmental information. They are less commonly used in freshwater settings where variability in water chemistry makes it more difficult to calibrate chemical proxies such as the Sr:Ca in a shell. Our objective is to evaluate whether trace element concentrations in freshwater bivalve shells contain information on environmental conditions. Multiple elements (Ba, Cu, Mn and Sr) were analyzed within the shells of modern bivalves from four streams on DOE's Savannah River Site in S.C. Laser Ablation ICP-MS was used to measure elemental concentrations across five aragonitic shells from each site. These elements were chosen because they are present in detectable concentrations (ppm) in the shell and they have been suggested as useful proxies for temperature, rainfall, productivity and pollution. Results were compared to historical monthly site records of water chemistry and chemical analyses of water samples collected from the streams where the clams were found. The average shell concentrations of Sr and Mn were significantly different between sites and increased proportionally to water concentration. This was not observed for Ba and Cu. For example, the Ba concentrations of shells collected at a site downstream of a lake were higher than those for shells from stream sites with significantly higher dissolved Ba concentrations. Copper was only detected at dark growth lines with the number of lines and shell material between them varying between shells within the same stream. Intrashell profiles of Ba, Sr and Mn concentrations exhibited cyclical variation. The magnitude of cyclical variation for Mn and Sr within a shell corresponds with the annual variation in monthly water sample concentrations. Again, this pattern was not observed for Ba, especially in shells from the site downstream of a lake. This supports suggestions that particulate organic

  5. 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.

  6. Age- and size-specific patterns of heavy metals in the organs of freshwater fish Abramis brama L. populating a low-contaminated site.

    PubMed

    Farkas, Anna; Salánki, János; Specziár, András

    2003-03-01

    Concentrations of cadmium, copper, mercury, lead and zinc were determined by atomic absorption spectrophotometry in the muscle, gill and liver of bream Abramis brama L. to study the relationship between the heavy metal load of fish and their age and size, and the seasonal variation of pollutant loads. Fish were collected from the Western basin of Lake Balaton (Hungary) in October 1999 and May 2000. The average metal concentrations of different organs varied in the following ranges: Cd 0.42-2.10; Cu 1.77-56.2; Hg 0.01-0.19; Pb 0.44-3.24; Zn 10.9-82.5 microg g(-1) dry weight. The highest Cd, Cu, Pb and Zn concentrations were detected in the gill or liver of fish, whereas the highest Hg concentrations were measured in the muscle. In the liver of bream for cadmium, copper and mercury the Pearson correlation analysis revealed positive associations related to age and size (length, net weight), as well as for the mercury load of all three investigated organs. In the muscle and gill the copper, lead and zinc concentrations, similarly to the lead and zinc concentrations of the liver, the associations related to age and size were negative. The correlations between the heavy metal concentrations of organs and the individual condition factors of fish samples proved to have opposite trends compared to those related to the age and size of fish. The seasonal variations in the heavy metal load of bream could be attributed rather to the seasonal change in the condition factor of fish than to variations in the pollutant load of the site.

  7. 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.

  8. 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.

  9. Site-directed mutagenesis of the Anabaena sp. strain PCC 7120 nitrogenase active site to increase photobiological hydrogen production.

    PubMed

    Masukawa, Hajime; Inoue, Kazuhito; Sakurai, Hidehiro; Wolk, C Peter; Hausinger, Robert P

    2010-10-01

    Cyanobacteria use sunlight and water to produce hydrogen gas (H₂), which is potentially useful as a clean and renewable biofuel. Photobiological H₂ arises primarily as an inevitable by-product of N₂ fixation by nitrogenase, an oxygen-labile enzyme typically containing an iron-molybdenum cofactor (FeMo-co) active site. In Anabaena sp. strain 7120, the enzyme is localized to the microaerobic environment of heterocysts, a highly differentiated subset of the filamentous cells. In an effort to increase H₂ production by this strain, six nitrogenase amino acid residues predicted to reside within 5 Å of the FeMo-co were mutated in an attempt to direct electron flow selectively toward proton reduction in the presence of N₂. Most of the 49 variants examined were deficient in N₂-fixing growth and exhibited decreases in their in vivo rates of acetylene reduction. Of greater interest, several variants examined under an N₂ atmosphere significantly increased their in vivo rates of H₂ production, approximating rates equivalent to those under an Ar atmosphere, and accumulated high levels of H₂ compared to the reference strains. These results demonstrate the feasibility of engineering cyanobacterial strains for enhanced photobiological production of H₂ in an aerobic, nitrogen-containing environment.

  10. Identification and chemical characterization of specific organic indicators in the effluents from chemical production sites.

    PubMed

    Botalova, Oxana; Schwarzbauer, Jan; al Sandouk, Nadia

    2011-06-01

    The structural diversity of the wastewater composition was described by the use of detailed non-target screening analyses of industrial effluents from chemical production sites. Determination of the indicative organic compounds acting as potential molecular indicators for industrial emissions from chemical production industries has been possible due to (i) detailed characterisation of industrial contaminants and identification of compounds with high source specificity, (ii) quantitative determination of the organic constituents in the industrial effluents and (iii) the review of their industrial applications. The determination of potential site-specific markers and industrial molecular indicators corresponding to certain production processes (production of starting materials for manufacturing paper and printing inks, powder coatings as well as epichlorohydrin production) was performed in this work. The results of this study allowed significant contributions to the chemical characterisation of industrial contaminants and isolation of indicators that can act as representatives of industrial effluents in the aquatic environment.

  11. Productivity of forests of the United States and its relation to soil and site factors and management practices: a review.

    Treesearch

    C.C. Grier; K.M. Lee; N.M. [and others]. Nadkarni

    1989-01-01

    Data on net primary biological productivity of United States forests are summarized by geographic region. Site factors influencing productivity are reviewed. This paper is a review of existing literature in the productivity of various forest regions of the United States, the influence of site factors on forest productivity, and the impact of various...

  12. IUFRO Symposium on forest site and continuous productivity: Seattle, Washington, August 22-28, 1982.

    Treesearch

    Russell Ballard; Stanley P. Gessel

    1983-01-01

    This Symposium was planned by members of the IUFRO Site Group (S1.02) as part of their on-going activities to facilitate the worldwide exchange of ideas among individual research workers and to promote the dissemination of research results in the area of forest site productivity. The Symposium consisted of three days of indoor sessions followed by a 2-1/2-day field...

  13. Stability of single dispersed silver nanoparticles in natural and synthetic freshwaters: Effects of dissolved oxygen.

    PubMed

    Zou, Xiaoyan; Li, Penghui; Lou, Jie; Fu, Xiaoyan; Zhang, Hongwu

    2017-11-01

    Silver nanoparticles (AgNPs) are increasingly used in various commercial products. This increased use raises ecological concerns because of the large release of AgNPs into the environment. Once released, the local water chemistry has the potential to influence the environmental fates and behaviors of AgNPs. The impacts of dissolved oxygen and natural organic matter (NOM) on the dissolution and stability of AgNPs were investigated in synthetic and natural freshwaters for 7 days. In synthetic freshwater, the aggregation of AgNPs occurred due to the compression of the electric double layer, accompanied by the dissolution of AgNPs. However, once oxygen was removed, the highest dissolved Ag (Agdis) concentration decreased from 356.5 μg/L to 272.1 μg/L, the pH of the AgNP suspensions increased from less than 7.6 to more than 8.4, and AgNPs were regenerated by the reduction of released Ag(+) by citrate. The addition of NOM mitigated aggregation, inhibited oxidative dissolution and induced the transformation of AgNPs into Ag2S due to the formation of NOM-adsorbed layers, the reduction of Ag(+) by NOM, and the high affinity of sulfur-enriched species in NOM for Ag. Likewise, in oxygen-depleted natural freshwaters, the inhibition of oxidative dissolution was obtained in comparison with oxygenated freshwaters, showing a decrease in the maximum Agdis concentration from 137.6 and 57.0 μg/L to 83.3 and 42.4 μg/L from two natural freshwater sites. Our results suggested that aggregation and dissolution of AgNPs in aquatic environments depend on the chemical composition, where oxygen-depleted freshwaters more significantly increase the colloidal stability. In comparison with oxic conditions, anoxic conditions were more favorable to the regeneration of AgNPs by reducing species (e.g., citrate and NOM) and enhanced the stability of nanoparticles. This indicates that some AgNPs will be more stable for long periods in oxygen-deprived freshwaters, and pose more serious

  14. Validation of SMAP Surface Soil Moisture Products with Core Validation Sites

    NASA Technical Reports Server (NTRS)

    Colliander, A.; Jackson, T. J.; Bindlish, R.; Chan, S.; Das, N.; Kim, S. B.; Cosh, M. H.; Dunbar, R. S.; Dang, L.; Pashaian, L.; hide

    2017-01-01

    The NASA Soil Moisture Active Passive (SMAP) mission has utilized a set of core validation sites as the primary methodology in assessing the soil moisture retrieval algorithm performance. Those sites provide well calibrated in situ soil moisture measurements within SMAP product grid pixels for diverse conditions and locations.The estimation of the average soil moisture within the SMAP product grid pixels based on in situ measurements is more reliable when location specific calibration of the sensors has been performed and there is adequate replication over the spatial domain, with an up-scaling function based on analysis using independent estimates of the soil moisture distribution. SMAP fulfilled these requirements through a collaborative CalVal Partner program.This paper presents the results from 34 candidate core validation sites for the first eleven months of the SMAP mission. As a result of the screening of the sites prior to the availability of SMAP data, out of the 34 candidate sites 18 sites fulfilled all the requirements at one of the resolution scales (at least). The rest of the sites are used as secondary information in algorithm evaluation. The results indicate that the SMAP radiometer-based soil moisture data product meets its expected performance of 0.04 cu m/cu m volumetric soil moisture (unbiased root mean square error); the combined radar-radiometer product is close to its expected performance of 0.04 cu m/cu m, and the radar-based product meets its target accuracy of 0.06 cu m/cu m (the lengths of the combined and radar-based products are truncated to about 10 weeks because of the SMAP radar failure). Upon completing the intensive CalVal phase of the mission the SMAP project will continue to enhance the products in the primary and extended geographic domains, in co-operation with the CalVal Partners, by continuing the comparisons over the existing core validation sites and inclusion of candidate sites that can address shortcomings.

  15. Shared Opportunities on Institutional Lands: On-Site Food Production, Its Benefits, Barriers, and Opportunities.

    PubMed

    Knezevic, Irena; Mount, Phil; Clement, Chantal

    2016-10-01

    This article outlines preliminary findings of a 3-year project that explored on-site food production on institutional properties, primarily healthcare facilities. There are growing pressures on healthcare facilities to improve their food offerings and incorporate food gardens into their health programs. While several healthcare facilities produce food on-site, there are few studies that explore opportunities, capacities, and institutional barriers related to on-site food production. The study employed mixed methods including historical review, case studies, surveys, interviews, pilot garden projects, and Geographic Information System mapping. The number of participating institutions varied by method. Benefits associated with on-site food production can be health, economic, environmental, and social. There are also institutional barriers including administrative roadblocks, perceived obstacles, and the difficulty in quantitatively, measuring the qualitatively documented benefits. The benefits of food gardens far outweigh the challenges. On-site food production has tremendous potential to improve nutrition for staff and patients, offer healing spaces, better connect institutions with the communities in which they are located, and provide the long-professed benefits of gardening for all involved-from therapeutic benefits and outdoor physical activities to developing skills and social relationships in ways that few other activities do. © The Author(s) 2016.

  16. 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…

  17. 75 FR 38127 - Visteon Systems, LLC North Penn Plant Electronics Products Group Including On-Site Leased Workers...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-01

    ... Employment and Training Administration Visteon Systems, LLC North Penn Plant Electronics Products Group Including On-Site Leased Workers From Ryder Integrated Logistics and Including On-Site Workers From Span... Systems, LLC, North Penn Plant, Electronics Products Group, including on-site leased workers from...

  18. Growth and development of ponderosa pine on sites of contrasting productivities: relative importance of stand density and shrub competition effects

    Treesearch

    Jianwei Zhang; William W. Oliver; Matt D. Busse

    2006-01-01

    Effects of stand density and shrub competition on growth and development were compared across a gradient of study sites. Challenge, the most productive site, is located in the foothills of the Sierra Nevada, northern California. Pringle Falls is of intermediate productivity in the rain shadow of the central Oregon Cascades. Trough Springs Ridge is the poorest site...

  19. Sites of Superoxide and Hydrogen Peroxide Production by Muscle Mitochondria Assessed ex Vivo under Conditions Mimicking Rest and Exercise*

    PubMed Central

    Goncalves, Renata L. S.; Quinlan, Casey L.; Perevoshchikova, Irina V.; Hey-Mogensen, Martin; Brand, Martin D.

    2015-01-01

    The sites and rates of mitochondrial production of superoxide and H2O2 in vivo are not yet defined. At least 10 different mitochondrial sites can generate these species. Each site has a different maximum capacity (e.g. the outer quinol site in complex III (site IIIQo) has a very high capacity in rat skeletal muscle mitochondria, whereas the flavin site in complex I (site IF) has a very low capacity). The maximum capacities can greatly exceed the actual rates observed in the absence of electron transport chain inhibitors, so maximum capacities are a poor guide to actual rates. Here, we use new approaches to measure the rates at which different mitochondrial sites produce superoxide/H2O2 using isolated muscle mitochondria incubated in media mimicking the cytoplasmic substrate and effector mix of skeletal muscle during rest and exercise. We find that four or five sites dominate during rest in this ex vivo system. Remarkably, the quinol site in complex I (site IQ) and the flavin site in complex II (site IIF) each account for about a quarter of the total measured rate of H2O2 production. Site IF, site IIIQo, and perhaps site EF in the β-oxidation pathway account for most of the remainder. Under conditions mimicking mild and intense aerobic exercise, total production is much less, and the low capacity site IF dominates. These results give novel insights into which mitochondrial sites may produce superoxide/H2O2 in vivo. PMID:25389297

  20. POP-contaminated sites from HCH production in Sabiñánigo, Spain.

    PubMed

    Fernández, J; Arjol, M A; Cacho, C

    2013-04-01

    In 2009, hexachlorocyclohexane (HCH) isomers (α-HCH, β-HCH, and γ-HCH [lindane]) were listed as persistent organic pollutants (POP) in the Stockholm Convention. Accordingly, the legacy of HCH/lindane production with the associated large HCH waste deposits has become recognized as an issue of global concern and is addressed in the implementation of the Convention. The current paper gives an overview of the major contaminated sites from lindane production of the INQUINOSA Company. This company operated from 1975 to 1988 in the city of Sabiñánigo, Spain. HCH production resulted in the production of approximately 115,000 tonnes of waste isomers which were mainly dumped in two unlined landfills. These two landfill sites, together with the former production site, are recognized sources of environmental pollution. Assessment and remediation activities at these sites are described. A dense nonaqueous phase liquid (DNAPL) contaminated inter alia with HCH isomers, benzene, chlorobenzenes, and chlorophenols as the main contaminants and an associated contaminated groundwater plume have been discovered at both landfill/dumpsites and at the former production site. The approximately 4,000 t of DNAPLs constitute a serious risk for the environment due to the proximity of the Gállego River. Since 2004, more than 20 tonnes of this DNAPL has been extracted using "pump and treat" techniques. The Aragon Regional Government and the Spanish Environmental Ministry are taking action, focusing on the treatment of DNAPL and on the transfer of the large quantities of solid POP wastes to a new landfill. A range of laboratory tests has been performed in order to plan the aquifer remediation.

  1. 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.

  2. 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...

  3. Longleaf pine cone production in relation to site index, stand age, and stand density

    Treesearch

    Thomas Croker

    1973-01-01

    Few cones were produced in stands less than 30 years old. In stands 30 to 70 years in age, production seemed best at timber densities of about 30 square feet of basal area per acre, and tended to increase with increasing site index.

  4. 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...

  5. Algorithms for Estimating Learning Opportunity and Productivity Impact at Clerkship Sites.

    ERIC Educational Resources Information Center

    Carter, Jean T.; Draugalis, JoLaine R.; Slack, Marion K.; Cox, Emily R.

    1998-01-01

    A study estimated and compared consequences of pharmacy clerkship placements (learning opportunities) to estimates of clerkship training costs (site impact productivity). A learning opportunity algorithm rank-ordered student activities for involvement level, completeness of experience, completeness of experiential learning cycle, and performance…

  6. Expanding site productivity research to sustain non-timber forest functions

    Treesearch

    D. Andrew Scott; James A. Burger; Barbara Crane

    2006-01-01

    Southern forests produce multiple products and services including timber, wildlife habitat, species bio- and genetic divenity, water quality and control, waste remediation, recreation, and carbon sequestration. All of these benefits must be produced in a sustainable manner to meet today's societal needs without compromising future needs. A forest site is...

  7. A topographic index to quantify the effect of mesoscale and form on site productivity

    Treesearch

    W. Henry McNab

    1992-01-01

    Landform is related to environmental factorsthat affectsite productivity in mountainous areas. I devised a simple index of landform and tested this index as a predictor of site index ín the Blue Ridge physiographic province. The landform index is the mean of eight slope gradients from plot center to skyline. A preliminary test indicated that the index was...

  8. Using Shelterwood Harvests and Prescribed Fire to Regenerate Oak Stands on Productive Upland Sites

    Treesearch

    Patrick H. Brose; David H. van Lear; Roderick Cooper

    1999-01-01

    Regenerating oak stands on productive upland sites in the Piedmont region is a major problem because of intense competition from yellow-poplar. As a potential solution to this problem, we tested the hypothesis that a shelterwood harvest of an oak-dominated stand. followed several years later by a prescribed fire, would adequately regeneraie the stand. Three oak-...

  9. A Shelterwood-Burn Technique for Regenerating Productive Upland Oak Sites in the Piedmont Region

    Treesearch

    Patrick H. Brose; David H. van Lear; Patrick D. Keyser

    1999-01-01

    Regenerating oak stands on productive uplandsires is widely recognized byforesters as a major problem in hardwood management. Recent research indicates that oak regeneration is more resistant to surface fires than its primary competitors on these sites if burning occurs 3 to 5 yr after a partial overstory harvest. This combination of cutting followed by fire (...

  10. Site productivity - current estimates, change, and possible enhancements for the Northern Research Station

    Treesearch

    Scott A. Pugh

    2012-01-01

    Site productivity (SP) is the inherent capacity to grow crops of industrial wood. SP identifies the potential growth in cubic feet/acre/year and is based on the culmination of mean annual increment of fully stocked natural stands. Changes in SP were summarized for timberland and the associated effects on net growth and removal estimates were investigated using data...

  11. 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.

  12. 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.

  13. An approach for siting poplar energy production systems to increase productivity and associated ecosystem services

    Treesearch

    Ronald S. Zalesny; Deahn M. Donner; David R. Coyle; William L. Headlee

    2012-01-01

    Short rotation woody crops such as Populus spp. and their hybrids (i.e., poplars) are a significant component of the total biofuels and bioenergy feedstock resource in the USA. Production of these dedicated energy crops may result in large-scale land conversion, which leads to questions about their economic, logistic, and ecologic feasibility. To...

  14. Methane-limited methanotrophy in tidal freshwater swamps

    NASA Astrophysics Data System (ADS)

    Megonigal, J. Patrick; Schlesinger, William. H.

    2002-12-01

    We investigated the relationship between CH4 production and oxidation in two tidal freshwater wetland forests in order to determine whether CH4 oxidation efficiency was limited by O2 or CH4. Methane oxidation was measured in situ over a 16-month period with bi-monthly applications of the inhibitor CH3F. Oxidation consumed 52 ± 10 and 81 ± 9% of diffusive CH4 emissions on the two sites. Methane oxidation rates were linearly related to gross CH4 emissions on both sites (r2 = 0.96), demonstrating the process was CH4-limited. This interpretation is consistent with the fact that the apparent activation energies for the potential CH4 production and oxidation differed by <4 kJ mol-1. Apparent activation energies calculated from field emissions data were also similar for the two processes. The high CH4 oxidation efficiency on these sites may be attributed to relatively low rates of methane production, a deep oxidizing zone (5-10 cm), and low cover of understory vegetation capable of CH4 transport. If our results are typical of forested wetlands, CH4 oxidation efficiency in forested wetlands will not change in response to soil warming.

  15. 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.

  16. 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.

  17. Identification and quantification of bovine protein lactosylation sites in different milk products.

    PubMed

    Milkovska-Stamenova, Sanja; Hoffmann, Ralf

    2016-02-16

    The microbiological safety of milk is typically guaranteed by thermal treatments, such as pasteurization and ultra high temperature (UHT) treatment, whereas infant formula (IF) is often produced at even harsher conditions including a drying process. Thermal treatments have raised concerns, as they may denature proteins and initiate protein modifications. Previous studies identified already many lactosylation sites in milk and showed that the lactosylation degree of some proteins correlates to thermal treatment conditions. Here, we studied the glycation degrees of 124 lactosylation sites in 28 bovine milk proteins in raw milk, three brands of pasteurized milk, three brands of UHT milk, and five brands of IF. Whereas, the glycation degree of many lactosylation sites increased from raw milk, to pasteurized milk, UHT milk, and IF, several modification sites showed a different behavior indicating that global measures do not correctly reflect the reactivity of distinct sites. Interestingly, the glycation degrees varied considerably among the brands of UHT milk and IF indicating that specific production processes of a company have to be considered and not only the classification of milk as pasteurized or UHT. Thus, proper adjustments of the technical processes should allow reducing the lactosylation levels in both UHT milk and IF. It is well established that thermal treatment of milk triggers protein modifications, such as lactosylation of lysine residues in several proteins, although the extent of lactosylation has not been quantitatively compared for a broad panel of protein lactosylation sites among different commercial products. The current study extends previous reports by relatively quantifying 124 confirmed lactosylation sites in 28 bovine milk proteins including several low abundant proteins. Whereas, glycation is generally assumed to be an unspecific chemical reaction with the modification degrees depending on the protein and sugar concentrations, we could show

  18. Food chains in freshwaters.

    PubMed

    Sabo, John L; Finlay, Jacques C; Post, David M

    2009-04-01

    There are three hypothesized controls on food-chain length (FCL): energy supply (or "resource availability"), ecosystem size and disturbance (or "environmental variation"). In this article, the evidence for controls on FCL in freshwater ecosystems is evaluated. First, the various ways FCL can be measured are defined. Food-chain length typically is estimated as (1) connectance-based FCL--an average connectance between basal resources and top consumers, (2) functional FCL--by experimental determination of functionally significant effects of a top predator on lower trophic-level biomass patterns, and (3) realized FCL--an average connectance measure weighted by energy flow between basal consumers and the consumer occupying the maximum trophic position in the food web. Second, all evidence for relationships between the three hypothetical controls and FCL in freshwater ecosystems are evaluated. The review includes studies from streams, lakes, ponds, wetlands, phytotelmata, and experimental containers. Surprisingly, few studies of FCL in freshwaters that test the same suite of controls using the same methods are found. Equally compelling results arise from case studies based on functional, realized, and connectance-based measures of FCL. Third, 10 rules of thumb that could increase similarity of future studies, thereby facilitating synthesis across systems, are suggested. Fourth, it is discussed how FCL influences the concentration of contaminants in large-bodied animals (many of which are consumed by humans) as well as the efficacy of biocontrol applications in agriculture. Finally, there is a discussion of the potential relationships between global climate change, hydrology, and FCL in freshwaters.

  19. 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.

  20. 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...

  1. 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...

  2. Innovations in Site Characterization: Streamlining Cleanup at Vapor Intrusion and Product Removal Sites Using the Triad Approach: Hartford Plume Site, Hartford, Illinois

    EPA Pesticide Factsheets

    The Hartford Plume Site case study provides a detailed example of the strategies and technologies used at the site that are available to environmental practitioners to use at large and small hydrocarbon sites.

  3. 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

  4. Restricted-range fishes and the conservation of Brazilian freshwaters.

    PubMed

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

    2010-06-30

    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. 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. 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. Proper management (e. g. forestry code enforcement, landscape

  5. 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.

  6. Remediation of cyanide-contaminated industrial sites through woody biomass production

    NASA Astrophysics Data System (ADS)

    Dimitrova, Tsvetelina; Repmann, Frank; Freese, Dirk

    2017-04-01

    Due to the unfavourable chemical and physical soil quality parameters and the potential presence of contaminants, former industrial sites can hardly be utilized as arable land and can thus be classified as marginal areas. Still, as far as possible, they can effectively be used for the production of alternative energy, including the cultivation of fast growing trees. Apart from being a source of bioenergy, trees might facilitate the stabilization, remedation, contaminant extraction and degradation and, not on the last place, to enhance soil quality improvement on former industrial areas. This process is known as phytoremediation and has successfully been applied on industrial sites of various organic and inorganic contamination. The former manufactured gas plant site ( 2500 m2) "ehemalige Leuchtgasanstalt" Cottbus, contaminated, among others, with iron cyanides undergoes phytoremediation with simultaneous biomass production since 2011. The project "Biomass-Remediation" is fully financed by the German Railways JSC. A dense (23700 stems/ha), mixed cover of willow (Salix caprea), poplar (Populus maximowicii Henry x Populus trichocarpa Torr. et Gray (Hybrid 275)) and black locust (Robinia pseudoaccacia) trees has been planted on the site. Throughout the five years of remediation, a successful long-term stabilization of the site has been achieved as a result of the nearly outright established tree stock and the dense planting. Annual monitoring of the cyanide levels in the leaf tissue of the trees on the site and results from greenhouse experiments indicate the ability of all tree species to extract and transport the cyanide from the soil. Additonally, the greenhouse experiments suggest that the willows might be able, although not to a full extent, to detoxify the contaminant by splitting the CN moiety. The contaminated biomass material might easily be dealt with through regular harvests and subsequent incineration. Phytoremediation with simultaneous biomass production

  7. Loblolly pine ( Pinus taeda L.) productivity 23 years after wet site harvesting and site preparation in the lower Atlantic Coastal Plain

    Treesearch

    Charles M. Neaves; W. Michael Aust; M. Chad Bolding; Scott M. Barrett; Carl C. Trettin; Eric Vance

    2017-01-01

    Ground based timber harvesting on wet sites has been linked to alteration of soil properties that may result in reduced long term site productivity. Following Hurricane Hugo in the fall of 1989, numerous salvage logging operations were conducted under high soil moisture conditions to reduce wildfire risk and salvage timber within the Francis Marion National Forest in...

  8. 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

  9. The production rate of cosmogenic 10Be at the Koefels rockslide site, Austria

    NASA Astrophysics Data System (ADS)

    Ivy-Ochs, Susan; Kerschner, Hanns; Kober, Florian; Salcher, Bernhard; Christl, Marcus; Schluechter, Christian

    2017-04-01

    The Koefels rockslide, with a volume of 2-3 km3, involved sliding of predominantly orthogneiss (granitic and augen gneiss) from the Schartle ridge on the west side of Ötztal eastward into the mouth of Horlachtal. The dating of compressed wood fragments found in a tunnel built for a later abandoned waterworks project in the 1960s indicated an early Holocene age. In the 1990s we initiated a study to use the Koefels rockslide as a calibration site for cosmogenic 10Be and 26Al production rates. As the Koefels production rates were markedly higher than those from other sites, the Koefels site was not included in the final CRONUS-Earth calibration data set (Borchers et al. 2016). We discuss a re-assessment of the geomorphological interpretation of the 27 boulder and bedrock 10Be exposure dates, nine of which were previously published. In light of recent dating of further buried wood pieces to 9527-9498 yr ago (Nicolussi et al. 2015), we present the 10Be production rate calculated based on the Koefels data. Borchers B. et al. 2016. Geological calibration of spallation production rates in the CRONUS-Earth project. Quaternary Geochronology 31: 188-198. Nicolussi K. et al. 2015. Precise radiocarbon dating of the giant Köfels landslide (Eastern Alps, Austria). Geomorphology 243: 87-91.

  10. 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.

  11. Complete spatiotemporal freshwater flux budget for a major Greenland glacier-fjord system

    NASA Astrophysics Data System (ADS)

    Moon, Twila; Sutherland, David; Carroll, Dustin; Kehrl, Laura; Straneo, Fiamma; Felikson, Denis

    2017-04-01

    Freshwater flux from ice sheet mass loss raises global sea level, influences large-scale ocean circulation and stratification, and affects biological systems. Freshwater flux in glacial fjords comes from several sources: ice sheet surface melt discharged subglacially at the glacial termini, terrestrial runoff, submarine terminus melt, and melt from icebergs throughout the fjord (here, including icebergs, bergy bits, and melánge). Melt from icebergs is poorly constrained; previous efforts use limited-footprint satellite images and fail to distinguish iceberg freshwater flux from other melt sources. We have developed a new method, combining in situ and remote sensing observations with a parameterized iceberg melt model and climate reanalysis data, to calculate freshwater flux from icebergs and create a spatiotemporally complete fjord freshwater budget. Here, we apply this method to Sermilik Fjord, a major glacier-fjord system in southeast Greenland. We generate complete freshwater budgets for summer and winter periods during 2008-2013 as well as mean monthly estimates of iceberg freshwater flux over a full year. Along with this enhanced understanding of iceberg freshwater flux across time, our estimates also spatially resolve meltwater flux across the full water depth of the fjord. We find that more than 70% of iceberg melt production occurs below 10 m depth. We also compare iceberg melt flux to other freshwater sources, demonstrating that iceberg melt dominates freshwater production. Our work provides the first calculation of iceberg freshwater flux across the full fjord water depth, estimates the first complete freshwater budget for a major Greenland glacier-fjord system, and provides monthly to interannual comparisons across freshwater sources. Ultimately, these results provide a path forward in accurately representing freshwater flux, including iceberg melt production, in large-scale climate models.

  12. 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

  13. Protein Arginine Methyltransferase Product Specificity Is Mediated by Distinct Active-site Architectures.

    PubMed

    Jain, Kanishk; Warmack, Rebeccah A; Debler, Erik W; Hadjikyriacou, Andrea; Stavropoulos, Peter; Clarke, Steven G

    2016-08-26

    In the family of protein arginine methyltransferases (PRMTs) that predominantly generate either asymmetric or symmetric dimethylarginine (SDMA), PRMT7 is unique in producing solely monomethylarginine (MMA) products. The type of methylation on histones and other proteins dictates changes in gene expression, and numerous studies have linked altered profiles of methyl marks with disease phenotypes. Given the importance of specific inhibitor development, it is crucial to understand the mechanisms by which PRMT product specificity is conferred. We have focused our attention on active-site residues of PRMT7 from the protozoan Trypanosoma brucei We have designed 26 single and double mutations in the active site, including residues in the Glu-Xaa8-Glu (double E) loop and the Met-Gln-Trp sequence of the canonical Thr-His-Trp (THW) loop known to interact with the methyl-accepting substrate arginine. Analysis of the reaction products by high resolution cation exchange chromatography combined with the knowledge of PRMT crystal structures suggests a model where the size of two distinct subregions in the active site determines PRMT7 product specificity. A dual mutation of Glu-181 to Asp in the double E loop and Gln-329 to Ala in the canonical THW loop enables the enzyme to produce SDMA. Consistent with our model, the mutation of Cys-431 to His in the THW loop of human PRMT9 shifts its product specificity from SDMA toward MMA. Together with previous results, these findings provide a structural basis and a general model for product specificity in PRMTs, which will be useful for the rational design of specific PRMT inhibitors. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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

    2016-02-05

    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.

  20. 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.

  1. Field study of nitrous oxide production with in situ aeration in a closed landfill site.

    PubMed

    Nag, Mitali; Shimaoka, Takayuki; Nakayama, Hirofumi; Komiya, Teppei; Xiaoli, Chai

    2016-03-01

    Nitrous oxide (N(2)O) has gained considerable attention as a contributor to global warming and depilation of stratospheric ozone layer. Landfill is one of the high emitters of greenhouse gas such as methane and N(2)O during the biodegradation of solid waste. Landfill aeration has been attracted increasing attention worldwide for fast, controlled and sustainable conversion of landfills into a biological stabilized condition, however landfill aeration impel N(2)O emission with ammonia removal. N(2)O originates from the biodegradation, or the combustion of nitrogen-containing solid waste during the microbial process of nitrification and denitrification. During these two processes, formation of N(2)O as a by-product from nitrification, or as an intermediate product of denitrification. In this study, air was injected into a closed landfill site and investigated the major N(2)O production factors and correlations established between them. The in-situ aeration experiment was carried out by three sets of gas collection pipes along with temperature probes were installed at three different distances of one, two and three meter away from the aeration point; named points A-C, respectively. Each set of pipes consisted of three different pipes at three different depths of 0.0, 0.75 and 1.5 m from the bottom of the cover soil. Landfill gases composition was monitored weekly and gas samples were collected for analysis of nitrous oxide concentrations. It was evaluated that temperatures within the range of 30-40°C with high oxygen content led to higher generation of nitrous oxide with high aeration rate. Lower O(2) content can infuse N(2)O production during nitrification and high O(2) inhibit denitrification which would affect N(2)O production. The findings provide insights concerning the production potentials of N(2)O in an aerated landfill that may help to minimize with appropriate control of the operational parameters and biological reactions of N turnover. Investigation of

  2. The effect of preoperative skin preparation products on surgical site infection.

    PubMed

    Young, Heather L; Reese, Sara; Knepper, Bryan; Miller, Amber; Mauffrey, Cyril; Price, Connie S

    2014-12-01

    Skin preparation products contribute to surgical site infection (SSI) prevention. In a case-control study, diabetes was associated with increased SSI (adjusted odds ratio [OR], 5.74 [95% confidence interval (CI), 1.22-27.0]), while the use of chlorhexidine gluconate (CHG) plus isopropyl alcohol versus CHG alone was found to be protective (adjusted OR, 2.64 [95% CI, 1.12-6.20]).

  3. Freshwater biota and rising pCO2?

    PubMed

    Hasler, Caleb T; Butman, David; Jeffrey, Jennifer D; Suski, Cory D

    2016-01-01

    Rising atmospheric carbon dioxide (CO2) has caused a suite of environmental issues, however, little is known about how the partial pressure of CO2 (pCO2) in freshwater will be affected by climate change. Freshwater pCO2 varies across systems and is controlled by a diverse array of factors, making it difficult to make predictions about future levels of pCO2. Recent evidence suggests that increasing levels of atmospheric CO2 may directly increase freshwater pCO2 levels in lakes, but rising atmospheric CO2 may also indirectly impact freshwater pCO2 levels in a variety of systems by affecting other contributing factors such as soil respiration, terrestrial productivity and climate regimes. Although future freshwater pCO2 levels remain uncertain, studies have considered the potential impacts of changes to pCO2 levels on freshwater biota. Studies to date have focused on impacts of elevated pCO2 on plankton and macrophytes, and have shown that phytoplankton nutritional quality is reduced, plankton community structure is altered, photosynthesis rates increase and macrophyte distribution shifts with increasing pCO2. However, a number of key knowledge gaps remain and gaining a better understanding of how freshwater pCO2 levels are regulated and how these levels may impact biota, will be important for predicting future responses to climate change.

  4. The Fall River Long-Term Site Productivity study in coastal Washington: site characteristics, methods, and biomass and carbon and nitrogen stores before and after harvest.

    Treesearch

    Adrian Ares; Thomas A. Terry; Kathryn B. Piatek; Robert B. Harrison; Richard E. Miller; Barry L. Flaming; ChristopherW. Licata; Brian D. Strahm; Constance A. Harrington; Rodney Meade; Harry W. Anderson; Leslie C. Brodie; Joseph M. Kraft

    2007-01-01

    The Fall River research site in coastal Washington is an affiliate installation of the North American Long-Term Soil Productivity (LTSP) network, which constitutes one of the world’s largest coordinated research programs addressing forest management impacts on sustained productivity. Overall goals of the Fall River study are to assess effects of biomass removals, soil...

  5. Productivity of tree swallows (Tachycineta bicolor) exposed to PCBs at the Kalamazoo River superfund site.

    PubMed

    Neigh, Arianne M; Zwiernik, Matthew J; MacCarroll, Monica A; Newsted, John L; Blankenship, Alan L; Jones, Paul D; Kay, Denise P; Giesy, John P

    2006-03-01

    A 123-km stretch of the Kalamazoo River in Michigan, was designated a Superfund site in 1990 due to historical releases of effluent containing polychlorinated biphenyl (PCB)-contaminated paper waste. Risk to bird species in the river ecosystem was evaluated using the tree swallow (Tachycineta bicolor) as a monitor for possible effects due to PCB exposure at two nesting locations, one in the Superfund site and one in an upstream reference location that is less contaminated with PCBs. In 2 of the 3 years of the study, clutch size at the contaminated location was 3.7 +/- 1.4 and 4.8 +/- 0.73 eggs per nest (mean +/- SD), which was significantly less than the clutch size at the reference location (5.0 +/- 1.1 and 5.3 +/- 1.1 eggs per nest). However, there were no statistically significant differences in fledging success, predicted brood size, predicted number of fledglings, or growth of nestlings between the Kalamazoo River Superfund site and an upstream reference location with lesser concentrations of PCBs in the sediments and riparian soils. Productivity and hatching success comparisons between these same sites were also not significantly different; however, the power of these conclusions was less (p < .10). The reduction in clutch size at the co-contaminated location could not be attributed to PCBs due to a number of confounding factors, including Co-cocontaminants, habitat structure, and food availability. Other reproductive parameters were not significantly impaired, and the size of the newly established colony at the Kalamazoo River Superfund site continued to grow over the period of the study. These site-specific observations, combined with multiple lines of evidence approach that considered results reported for the effects of both total PCBs and 2,3,7,8 tetrachlorodibenzo-p-dioxin equivalents (TEQ) on tree swallows at other locations, suggest that there were no significant population-level effects of PCBs on tree swallows at the Kalamazoo River Superfund site.

  6. Site-adapted cultivation of bioenergy crops - a strategy towards a greener and innovative feedstock production

    NASA Astrophysics Data System (ADS)

    Ruf, Thorsten; Emmerling, Christoph

    2017-04-01

    Cultivation of bioenergy crops is of increasing interest to produce valuable feedstocks e.g. for anaerobic digestion. In the past decade, the focus was primarily set to cultivation of the most economic viable crop, namely maize. In Germany for example, the cultivation area of maize was expanded from approx. 200,000 ha in 2006 to 800,000 ha in 2015. However, this process initiated a scientific and public discussion about the sustainability of intense maize cultivation. Concerns addressed in this context are depletion of soil organic matter, soil erosion and compaction as well as losses of (agro-)biodiversity. However, from a soil science perspective, several problems arise from not site-adapted cultivation of maize. In contrast, the cultivation of perennial bioenergy crops may provide a valuable opportunity to preserve or even enhance soil fertility and agrobiodiversity without limiting economic efficiency. Several perennial energy crops, with various requirements regarding stand conditions, allow a beneficial selection of the most suitable species for a respective location. The study aimed to provide a first step towards a more strategic planning of bioenergy crop cultivation with respect to spatial arrangement, distribution and connectivity of sites on a regional scale. The identification of pedological site characteristics is a crucial step in this process. With the study presented, we tried to derive site information that allow for an assessment of the suitability for specific energy crops. Our idea is to design a multifunctional landscape with a coexistence of sites with reduced management for soil protection and highly productive site. By a site adapted cultivation of perennial energy plants in sensitive areas, a complex, heterogeneous landscape could be reached.

  7. 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.

  8. Mapping shallow underground features that influence site-specific agricultural production

    NASA Astrophysics Data System (ADS)

    Freeland, Robert S.; Yoder, Ronald E.; Ammons, John T.

    1998-10-01

    Modern agricultural production practices are rapidly evolving in the United States of America (USA). These new production practices present significant applications for nonintrusive subsurface imaging. One such imaging technology is GPR, and it is now being incorporated within site-specific agriculture in the detection of soil horizons, perched water (episaturation), fragipans, hydrological preferential flow paths, and soil compaction. These features traditionally have been mapped by soil scientists using intrusive measurements (e.g., soil augers, soil pits, coring tools). Rather than developing a tool for soil mapping, our studies are targeting the identification, dimensioning, and position of subsurface features that directly influence agricultural productivity. It is foreseen that this information will allow for an increase in agricultural efficiency through infield machinery automation, and it will also greatly enhance development of highly efficient crop production strategies. The field sensing methodologies that we have developed using existing geophysical technologies are highly dependent upon both the soil and site characteristics due to seasonal variations. The GPR applications presented herein were conducted primarily in a region of loess soil that extends east of the Mississippi River into western Tennessee. GPR studies were also conducted in central Tennessee on the Cumberland Plateau within a region of shallow, sandy loam soils. Additional studies were conducted on the karst area of central Kentucky. Although targeting site-specific agriculture, our results and procedures may benefit the traditional users of GPR technology. We suggest that large-scale agricultural applications of the technology would be enhanced by integrating global positioning (GPS) technology in future hardware and software products.

  9. 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.

  10. 75 FR 28297 - Ovonic Energy Products Including On-Site Leased Workers From PDSI Springboro, OH; Amended...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-20

    ... related energy storage systems. New information shows that workers leased from PDSI were employed on-site... Employment and Training Administration Ovonic Energy Products Including On-Site Leased Workers From PDSI..., applicable to workers of Ovonic Energy Products, Springboro, Ohio. The notice was published in the...

  11. 76 FR 62451 - Avon Products, Inc., Including On-Site Leased Workers From Spherion/Source Right, Springdale...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-07

    ... to TA-W-73,095 is hereby issued as follows: ``All workers of Avon Products, Inc., including on-site... Employment and Training Administration Avon Products, Inc., Including On-Site Leased Workers From Spherion/Source Right, Springdale, Ohio; Amended Certification Regarding Eligibility To Apply for...

  12. 76 FR 62452 - Avon Products, Inc. Including On-Site Leased Workers From Spherion/Source Right, Springdale, OH...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-07

    ...-site at the Springdale, Ohio location of Avon Products. The amended notice applicable to TA-W-73,095 is... Employment and Training Administration Avon Products, Inc. Including On-Site Leased Workers From Spherion/Source Right, Springdale, OH; Amended Certification Regarding Eligibility To Apply for Worker...

  13. 78 FR 48467 - Delphi Automotive Systems, LLC, Products and Service Solutions Division, Including On-Site Leased...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-08

    ... Division, Including On-Site Leased Workers From Bartech Workforce Management, Kokomo, Indiana; Amended... workers of Delphi Automotive Systems, LLC, Product and Service Solutions Division, Original Equipment... of ] Delphi Automotive Systems, LLC, Product and Service Solutions Division, including on-site leased...

  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. A Cross-Site Evaluation of Alternative FPAR Products for Use in Diagnostic Carbon Flux Models

    NASA Astrophysics Data System (ADS)

    Turner, D. P.; Ritts, D.; Nightingale, J.; Wharton, S.; Vickers, D.

    2007-12-01

    Input requirements for diagnostic carbon flux models include estimates of FPAR (the fraction of incident photosynthetically active radiation that is absorbed by the canopy). These estimates are available from a variety of satellite-borne sensors, but in their raw form may contain significant artifacts associated primarily with clouds. In this study we evaluated the sensitivity of simulated gross primary production (GPP), ecosystem respiration (Re), and net ecosystem production (NEP) to alternative formulations of FPAR from the MODIS sensor. These alternatives included the original product (FPARorig), a version based on filling and interpolation (FPARntsg), and a version with a smoothing based on the TIMESAT algorithm (FPARts). Estimates of daily GPP, Re, and NEP from multiple eddy covariance flux towers over multiple years were assembled as reference data. In almost all cases, model output based on FPARntsg and FPARts reduced bias on an annual basis and RMSE for daily values relative to model runs using FPARorig. At a wet conifer site, FPARts maintained the highest and most consistent FPAR, a pattern consistent with the dense coniferous forest canopy there. Limitations of FPARts were apparent at a grassland site with an abrupt fall off in greenness associated with onset of the dry season. Model effectiveness in capturing the interannual variation in NEP was also enhanced in many cases with the adjusted FPAR products.

  16. 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.

  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. MEASUREMENT AND PREDICTION OF RADIOLYTIC HYDROGEN PRODUCTION IN DEFENSE WASTE PROCESSING SLURRIES AT SAVANNAH RIVER SITE

    SciTech Connect

    Bibler, N; John Pareizs, J; Terri Fellinger, T; Cj Bannochie, C

    2007-01-10

    This paper presents results of measurements and predictions of radiolytic hydrogen production rates from two actual process slurries in the Defense Waste Processing Facility (DWPF) at Savannah River Site (SRS). Hydrogen is a flammable gas and its production in nuclear facilities can be a safety hazard if not mitigated. Measurements were made in the Shielded Cells of Savannah River National Laboratory (SRNL) using a sample of Sludge Batch 3 (SB3) currently being processed by the DWPF. Predictions were made using published values for rates of radiolytic reactions producing H{sub 2} in aqueous solutions and the measured radionuclide and chemical compositions of the two slurries. The agreement between measured and predicted results for nine experiments ranged from complete agreement to 24% difference. This agreement indicates that if the composition of the slurry being processed is known, the rate of radiolytic hydrogen production can be reasonably estimated.

  19. 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.

  20. Bi-polar freshwater flux see-saw anomalies impacting the north atlantic thermohaline circulation

    NASA Astrophysics Data System (ADS)

    Harrison, M.

    2016-02-01

    We present three scenarios using a global 1/8 degree eddy-permitting ocean, land and sea-ice general circulation model forced with hourly MERRA GEOS-5 atmospheric data from 1992-2014. In all cases, dense water production in the northern Labrador and Norwegian Seas is fairly well represented during the first decade of the simulation. In the reference case, after the turn of the century, surface haloclines pervade these dense water formation regions, and the overturning of deep North Atlantic watermasses becomes unrealistically weak. In a second case, we attempted to de-stabilize the overturning circulation by reducing precipitation North of 40N. The AMOC index at this latitude increases by roughly 23% for a 15% decrease in net North Atlantic freshwater forcing. A freshwater flux adjustment is used in order to maintain model sea-ice concentrations closer to observations. Of the 0.54 Sv of Atlantic freshwater forcing between 40N and Bering Strait in the reference simulation , 27% is externally applied in order to insulate sea-ice from warmer underlying watermasses, mainly on the continental shelves. In a third experiment, static Antarctic ice shelves are thermodynamically coupled to the ocean. Meltwater injection, in ice shelf cavities, facilitates sea-ice production on nearby continental shelves. The amount of external freshwater required to maintain warm season Antarctic sea-ice reduces by 26% to 0.17 Sv in the presence of a time-average meltwater contribution of 0.06 Sv. Significant changes occur on most high-latitude shelf regions, including in the North Atlantic. Inter-hemispheric propagation of coastally-trapped anomalies results in increased ventilation near deepwater formation sites in the Norwegian and Labrador Seas, and a roughly 20% increase in time-average AMOC strength at 40N, relative to the reference case, for a less than 10% increase in freshwater forcing south of 60S. These case studies demonstrate strong oceanic teleconections between the poles, as

  1. 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.

  2. Effect of Parathion-Methyl on Amazonian Fish and Freshwater Invertebrates: A Comparison of Sensitivity with Temperate Data

    PubMed Central

    Geber-Corrêa, Rachel; Campos, Paola S.; Garcia, Marcos V. B.; Waichman, Andrea V.; van den Brink, Paul J.

    2009-01-01

    Parathion-methyl is an organophosphorous insecticide that is widely used in agricultural production sites in the Amazon. The use of this pesticide might pose a potential risk for the biodiversity and abundance of fish and invertebrate species inhabiting aquatic ecosystems adjacent to the agricultural fields. Due to a lack of toxicity data for Amazonian species, safe environmental concentrations used to predict the ecological risks of parathion-methyl in the Amazon are based on tests performed with temperate species, although it is unknown whether the sensitivity of temperate species is representative for those of Amazonian endemic species. To address this issue, the acute toxic effect (LC50–96 h) of parathion-methyl was assessed on seven fish and five freshwater invertebrate species endemic to the Amazon. These data were used to compare their pesticide sensitivity with toxicity data for temperate species collected from the literature. The interspecies sensitivity was compared using the Species Sensitivity Distribution (SSD) concept. The results of this study suggest that Amazonian species are no more, or less, sensitive to parathion-methyl than their temperate counterparts, with LC50 values ranging from 2900 to 7270 μg/L for fish and from 0.3 to 319 μg/L for freshwater arthropods. Consequently, this evaluation supports the initial use of toxicity data of temperate fish and freshwater invertebrate species for assessing the effects of parathion-methyl on Amazonian freshwater ecosystems. PMID:19847472

  3. 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.

  4. 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

  5. Economics of plant production on marginal sites in the state Mecklenburg-Vorpommern

    NASA Astrophysics Data System (ADS)

    Ziesemer, Andrea; Andreas, Gurgel; Ines, Bull

    2017-04-01

    Marginal sites are defined by economics. It is not possible to produce any profit there under given conditions of markets and policy even when management is optimized. In the state Mecklenburg-Vorpommern, a portion of nearly 20 % of arable land is characterized by such conditions. There are often to find sandy sites below 28 soil points with low storage capacity and irregular water supply. Animal husbandry as a type of agricultural upgrading has a more important role in the south and southwest of the state than in the regions with better soil quality. The percentage of Maize was already in 2003 twice as high in the regions with more marginal sites. After implementation of the Renewable Energy Act many enterprises started built biogas plants. In 2010, the portion of maize was raised to 20 %. The increase of Maize was combined with a reduction of growing other fodder crops, rye and also by reducing set-aside areas. The scale of the cash crops Rape (16%), Wheat (15 %) and barley (9 %) stayed the same. The yields and production processes of several selected farms in Mecklenburg-Vorpommern were analyzed for the years 2011 to 2016. The farms reached 6.6 tons per hectare of wheat and 6.1 tons per hectare of barley on soils below 28 soil points. Hybrid rye achieved 5.4 tons per hectare and rape 3.0. Maize was especially dependent on water supply and made between 30 and 35 tons per hectare. The big problem in these regions is caused by high production costs in cropping. More than a half of the costs is required for seeds, fertilization and crop protection. However, the remaining revenues are not adequate for paying work and fix costs as an evaluation of farms in Mecklenburg-Vorpommern shows. It is not a valid option to set more land that is arable aside in regions with much marginal sites because cropping is a strategic investment there. Therefore, it is important to make effort on crop rotations and optimization of production intensities to decrease costs per unit and to

  6. Coccolithophore export production during the last deglaciation at ODP Site 1089 (Southern Ocean)

    NASA Astrophysics Data System (ADS)

    Balestrieri, Chiara; Ziveri, Patrizia; Mortyn, Peter Graham; Fornaciari, Eliana; Agnini, Claudia

    2017-04-01

    In order to assess the Southern Ocean carbonate budget change during the last deglaciation we evaluated the significance of calcification changes observed in calcareous nannofossil assemblages. In particular, we analysed coccolithophore assemblages from TNO57-21, a site survey core drilled as part of ODP Site 1089 (40°57'S; 9°53'E, 4620 m water depth), over the last 25 ky in the Subantarctic South Atlantic. This region is characterized by strong hydrographic gradients and ODP Site 1089 is optimally located in order to monitor the evolution of the Subtropical Front and Subpolar Front and the Agulhas Current (Flores et al., 2003) through time. The mean sedimentation rate is in the range of 15-20 cm/kyr, and the recovery of coccolith-bearing sediments provides a powerful tool to study deep-sea carbonate export production at high-resolution. Much of the CO2 drawdown from the atmosphere has been proposed to be stored into the deep ocean but evidence for increased carbon storage are still elusive (Martínez- Botí et al., 2015). Here, we present data on the Florisphaera profunda index and CaCO3 concentrations per gram of dry sediment, which were used to intepret the productivity trend during the last 25 kyr. These data clearly show a decrease in carbonate production throughout the last deglaciation. Moreover, we have calculated the Calcidiscus leptoporus-Emiliania huxleyi dissolution index (CEX'), which suggests a strong link between increasing coccolith dissolution and the evolution of the bottom water mass dynamics during Termination 1 (TI). Finally, mass estimations of the coccolith carbonate allow us to assess the role of each species as carbonate producers across this time span. These results reveal that during the last 25 ky the productivity was influenced by the mid-latitude westerlies, the study site was bathed by different bottom water masses, and was affected by a shoaling of the lysocline during T1 and the Holocene. References Flores J-A., Marino M., Sierro

  7. Biology and ecology of higher Diptera from freshwater wetlands.

    PubMed

    Keiper, Joe B; Walton, William E; Foote, Benjamin A

    2002-01-01

    Although studies of freshwater entomofauna frequently do not include the biodiversity and ecological roles of higher Diptera, cyclorraphous flies are often numerous and species rich in wetlands. Seventeen families are commonly found in freshwater wetlands, with Ephydridae, Chloropidae, Sciomyzidae, Sphaeroceridae, and Scathophagidae being among the most important in terms of population size and species richness. Difficulty with sampling cryptic larval habitats and species identification challenges may account for the exclusion of acalyptrate and other dipterans from wetlands ecology studies. Large populations are facilitated by the high productivity of freshwater wetlands and the high intrinsic rate of increase characteristic of many species. Higher dipterans exist in all freshwater wetland types, are microhabitat selective, and play significant roles in food webs. The varied strategies for food acquisition and patterns of spatial and temporal distribution limit ecological overlap among the higher Diptera.

  8. 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.

  9. 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.

  10. 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.

  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. 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.

  13. 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.

  14. 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

  15. Comparison of SeaWiFS, MODIS and MERIS radiometric products at a coastal site

    NASA Astrophysics Data System (ADS)

    Zibordi, G.; Mélin, F.; Berthon, J.-F.

    2006-03-01

    SeaWiFS, MODIS and MERIS remote sensing radiometric products were assessed using in situ data collected at a coastal site in the northern Adriatic Sea from May 2002 to September 2005. The analysis was restricted to satellite and in situ data taken within one hour interval to minimize the effects of temporal variability of atmosphere and seawater around the measurement site. The comparison of SeaWiFS and MODIS normalized water-leaving radiances with in situ values showed averages of relative percent difference varying from 0% to -9% in the 443-555 nm spectral range. Higher values ranging from +15 to +42% were observed for the MERIS data in the equivalent spectral range (i.e., 443-560 nm).

  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. 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)

  18. 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).

  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. 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.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. Alkynol natural products target ALDH2 in cancer cells by irreversible binding to the active site.

    PubMed

    Heydenreuter, Wolfgang; Kunold, Elena; Sieber, Stephan A

    2015-11-11

    Falcarinol and stipudiol are natural products with potent anti-cancer activity found in several vegetables. Here, we use a chemical proteomic strategy to identify ALDH2 as a molecular target of falcarinol in cancer cells and confirm enzyme inhibition via covalent alkylation of the active site. Furthermore, the synthesis of stipudiol led to the observation that ALDH2 exhibits preference for alkynol-based binders. Inhibition of ALDH2 impairs detoxification of reactive aldehydes and limits oxidative stress response, two crucial pathways for cellular viability.

  6. The potential of carbonyl sulfide as a proxy for gross primary production at flux tower sites

    NASA Astrophysics Data System (ADS)

    Blonquist, J. Mark, Jr.

    Seasonal dynamics of atmospheric carbonyl sulfide (OCS) at regional and continental scales and plant OCS exchange at the leaf level have shown a close relationship with those for CO2. CO2 has both sinks and sources within terrestrial ecosystems, but the primary terrestrial exchange for OCS is thought to be leaf uptake, suggesting potential for OCS uptake as a proxy for gross primary production (GPP). The utility of OCS uptake as a GPP proxy in micrometeorological studies of biosphere-atmosphere CO2 exchange was explored by applying theoretical concepts from earlier OCS studies to estimate GPP. Measured net ecosystem exchange (NEE) was partitioned using the ratio of measured vertical mole fraction gradients of OCS and CO2. At the Harvard Forest AmeriFlux site, measured CO2 and OCS vertical gradients were correlated, and were related to NEE and GPP, respectively. Estimates of GPP from OCS-based NEE partitioning were similar to those from established regression techniques, providing evidence that OCS uptake can potentially serve as a GPP proxy. Measured vertical CO 2 mole fraction gradients at five other AmeriFlux sites were used to project anticipated vertical OCS mole fraction gradients to provide indication of potential OCS signal magnitudes at sites where no OCS measurements were made. Projected OCS gradients at sites with short canopies were greater than those in forests, including measured OCS gradients at Harvard Forest, indicating greater potential for OCS uptake as a GPP proxy at these sites. This exploratory study suggests that continued investigation of linkages between OCS and GPP is warranted.

  7. 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.

  8. Increase in D-tagatose production rate by site-directed mutagenesis of L-arabinose isomerase from Geobacillus thermodenitrificans.

    PubMed

    Oh, Hyo-Jung; Kim, Hye-Jung; Oh, Deok-Kun

    2006-02-01

    Among single-site mutations of L-arabinose isomerase derived from Geobacillus thermodenitrificans, two mutants were produced having the lowest and highest activities of D-tagatose production. Site-directed mutagenesis at these sites showed that the aromatic ring at amino acid 164 and the size of amino acid 475 were important for D-tagatose production. Among double-site mutations, one mutant converted D-galactose into D-tagatose with a yield of 58% whereas the wild type gave 46% D-tagatose conversion after 300 min at 65 degrees C.

  9. 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

    ... 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 on... Cincinnati, Ohio location of Senco Brands, Inc., fka Senco Products, Inc. The Department has determined that...

  10. Identifying the most productive breeding sites for malaria mosquitoes in The Gambia

    PubMed Central

    Fillinger, Ulrike; Sombroek, Heleen; Majambere, Silas; van Loon, Emiel; Takken, Willem; Lindsay, Steven W

    2009-01-01

    Background Ideally larval control activities should be targeted at sites that generate the most adult vectors, thereby reducing operational costs. Despite the plethora of potential mosquito breeding sites found in the floodplains of the Gambia River, about 150 km from its mouth, during the rainy season, only a small proportion are colonized by anophelines on any day. This study aimed to determine the characteristics of larval habitats most frequently and most densely populated by anopheline larvae and to estimate the numbers of adults produced in different habitats. Methods A case-control design was used to identify characteristics of sites with or without mosquitoes. Sites were surveyed for their physical water properties and invertebrate fauna. The characteristics of 83 sites with anopheline larvae (cases) and 75 sites without (controls) were collected between June and November 2005. Weekly adult productivity was estimated with emergence traps in water-bodies commonly containing larvae. Results The presence of anopheline larvae was associated with high invertebrate diversity (Odds Ratio, OR 11.69, 95% CI 5.61–24.34, p < 0.001), the presence of emergent vegetation (OR 2.83, 95% CI 1.35–5.95, p = 0.006), and algae (at borderline significance; OR 1.87, 95% CI 0.96–3.618, p = 0.065). The density of larvae was reduced in sites that were larger than 100 m in perimeter (OR 0.151; 95% CI 0.060–0.381, p < 0.001), where water was tidal (OR 0.232; 95% CI 0.101–0.533, p = 0.001), vegetation shaded over 25% of the habitat (OR 0.352; 95% CI 0.136–0.911, p = 0.031) and water conductivity was above 2,000 μS/cm (OR 0.458; 95% CI 0.220–0.990, p = 0.048). Pools produced the highest numbers of Anopheles gambiae adults compared with rice fields, floodwater areas close to the edge of the floodplain or close to the river, and stream fringes. Pools were characterized by high water temperature and turbidity, low conductivity, increased presence of algae, and absence of

  11. 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

  12. 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

  13. Response of structures to energetic events for the Savannah River Site production reactors probabilistic risk assessment

    SciTech Connect

    Santa Cruz, S.M.; Smith, D.C.; Yau, W.F.

    1992-10-01

    The response of structures to energetic events postulated to arise in a probabilistic risk assessment (PRA) of a Savannah River Site (SRS) production reactor is addressed. Energetic events that arise in PRAs can damage structures and therefore have a significant influence on subsequent accident progression. Consequently, the structural response is important to the calculated risk of operating a plant. Difficulties are encountered, however, in the analysis of structural response of components to energetic loadings. First, the analysis of energetic events often does not provide well-defined static or dynamic loads acting on the structures. Secondly, risk assessments, by their nature, address a wide range of events that are not necessarily precisely defined. This paper describes an approach taken to develop the structural analysis required to support the PRA of the SRS production reactor, that overcomes these difficulties.

  14. Response of structures to energetic events for the Savannah River Site production reactors probabilistic risk assessment

    SciTech Connect

    Santa Cruz, S.M.; Smith, D.C. ); Yau, W.F. )

    1992-01-01

    The response of structures to energetic events postulated to arise in a probabilistic risk assessment (PRA) of a Savannah River Site (SRS) production reactor is addressed. Energetic events that arise in PRAs can damage structures and therefore have a significant influence on subsequent accident progression. Consequently, the structural response is important to the calculated risk of operating a plant. Difficulties are encountered, however, in the analysis of structural response of components to energetic loadings. First, the analysis of energetic events often does not provide well-defined static or dynamic loads acting on the structures. Secondly, risk assessments, by their nature, address a wide range of events that are not necessarily precisely defined. This paper describes an approach taken to develop the structural analysis required to support the PRA of the SRS production reactor, that overcomes these difficulties.

  15. Systematic method for oxidation pond conversion for the production of site specific energy sources

    SciTech Connect

    Werner, E.; Rodriguez, T.

    1981-01-01

    Primary sources of solar derived biomass (sugarcane, wood, and aquatic plants), are of considerable future importance as energy producing substrates. The waste products of agriculture and husbandry represent a viable and potentially significant energy source, also. Solar energy, produced photosynthetically, is available not only by combustion or conversion of plant materials, but also by utilizing metabolic products of succeeding trophic levels. Animal wastes, produced in massive quantities from dairy, swine, and poultry operations, can be converted to energy by the relatively simple and well understood technology of bioconversion, or anaerobic digestion. Currently, the principle method for disposal of these wastes is by oxidation ponds, solving neither environmental nor energy problems. Conversion, in situ of farm oxidation ponds to anaerobic digestion systems, can be easily and economically achieved resulting in development of small site specific decentralized energy sources (methane); simultaneously resolving a rapidly growing environmental and social problem.

  16. Production rates of 36Cl in basalts from the calibration site of Fuerteventura, Canary Islands

    NASA Astrophysics Data System (ADS)

    Mai, K.

    2009-09-01

    Age determination based on cosmogenic nuclides is an important tool to investigate landscape development and age relations of geologically very young materials. The aim of this study is to contribute data to establish age determination of the basis of cosmogenic 36Cl production as a generally reliable method. 36Cl is a radionuclide that is in situ produced by cosmic radiation at the earth surface. It is formed by spallation from Ca, K, Ti, and Fe, by thermal neutron capture in 35Cl, and by muogenic production from Ca and K. The concentration of the cosmogenic nuclide provides a measure of the exposure age of the surface, but also of the exposure history which may include periods of burial or erosion. Several factors such as the geographic position of the site, the topographic shielding of the surrounding hillside and the sample thickness or sampling depth influence the effective amount of radiation hitting the surface and are taken into account by applying appropriate scaling factors. Basalt samples from the mid-latitude, low altitude calibration site of Fuerteventura, Canary Islands were collected and the production rates of 36Cl were determined. Geologically young samples covering an age range of approximately 50 to 400 ka could be collected from a number of flows, which suit the time span that can be covered with 36Cl age determination. The age was independently determined with the 40Ar/39Ar method. From nine lava flows 7 or 8 samples were collected whose surface structures indicated as little erosion as possible. ICP and XRF measurements proved that the basalts were very similar in chemical composition. The preparation of the AMS samples followed generally the procedure established by Stone et al. (1996b). The measurements were performed at the AMS facility at the University of Utrecht. From the results of the measurements total chlorine concentrations the amount of 36Cl, and the production rates were deduced. The high variability of the production rates for

  17. 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.

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

    PubMed Central

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

    2013-01-01

    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 IQ) 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 IQ. By employing CN-POBS in mitochondria respiring on NADH-generating substrates, we show that site IQ 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 in both normal and pathological conditions. PMID:23994103

  19. 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

    2016-05-03

    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.

  20. 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. © 2015 The Fisheries Society of the British Isles.

  1. Protein carbonylation sites in bovine raw milk and processed milk products.

    PubMed

    Milkovska-Stamenova, Sanja; Mnatsakanyan, Ruzanna; Hoffmann, Ralf

    2017-08-15

    During thermal treatment of milk, proteins are oxidized, which may reduce the nutritional value of milk, abolish protein functions supporting human health, especially important for newborns, and yield potentially harmful products. The side chains of several amino acids can be oxidized to reactive carbonyls, which are often used to monitor oxidative stress in organisms. Here we mapped protein carbonylation sites in raw milk and different brands of pasteurized, ultra high temperature (UHT) treated milk, and infant formulas (IFs) after digesting the precipitated proteins with trypsin. Reactive carbonyls were derivatized with O-(biotinylcarbazoylmethyl)hydroxylamine to enrich the modified peptides by avidin-biotin affinity chromatography and analyze them by nanoRP-UPLC-ESI-MS. Overall, 53 unique carbonylated peptides (37 carbonylation sites, 15 proteins) were identified. Most carbonyls were derived from dicarbonyls (mainly glyoxal). The number of carbonylation sites increased with the harsher processing from raw milk (4) to pasteurized (16) and UHT milk (16) and to IF (24). Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Testing the EOS MODIS Gross Primary Production algorithm for 2001 at flux tower sites

    NASA Astrophysics Data System (ADS)

    Running, S. W.

    2002-05-01

    The MODIS dataset for vegetation variables has been analyzed for all of 2001 over 29 fluxtower sites in North and South America, Africa and Australia. Seven by seven pixel arrays centered over each fluxtower were extracted from the global MODIS dataset for each 8-day period of the year. These sites represent an array of biome types including temperate and boreal evergreen needleleaf forests, tropical and temperate broadleaf deciduous forests, grasslands, savannah and croplands The Enhanced Vegetation Index (EVI), Leaf Area Index (LAI), Fraction Absorbed Photosynthetically Active Radiation (FPAR). And Gross Primary Production (GPP) were simultaneously evaluated for accurate characterization of the growing season dynamics for each site, and magnitude of the computed biophysical variables. Results show that spring-time phenological timing is well defined by all of these variables. Leaf area index and FPAR appear to be correct in most biomes, but look to be overestimated in some biomes. GPP is underestimated in croplands, but appears accurate in grasslands and forests. Continuation of field validation plans, and improvements in these algorithms for next generation of MODIS processing will be discussed.

  3. 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.

  4. 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.

  5. Protein products obtained by site-preferred partial crosslinking in protein crystals and "liberated" by redissolution.

    PubMed

    Buch, Michal; Wine, Yariv; Dror, Yael; Rosenheck, Sonia; Lebendiker, Mario; Giordano, Rita; Leal, Ricardo M F; Popov, Alexander N; Freeman, Amihay; Frolow, Felix

    2014-07-01

    The use of protein crystals as a source of nanoscale biotemplates has attracted growing interest in recent years owing to their inherent internal order. As these crystals are vulnerable to environmental changes, potential applications require their stabilization by chemical crosslinking. We have previously shown that such intermolecular chemical crosslinking reactions occurring within protein crystals are not random events, but start at preferred crosslinking sites imposed by the alignment of protein molecules and their packing within the crystalline lattice. Here we propose a new working hypothesis and demonstrate its feasibility in enabling us to extricate homogeneous populations of single protein molecules that display chemical point mutations or of dimers that show homogeneous chemical crosslinking, and that have the potential for isolation of higher structures. Characterization of the crosslinking mechanism and its end products opens the way to the potential retrieval of such specific modified/intermolecular crosslinked products simply by effecting partial crosslinking at identified preferred sites, followed by time-controlled arrest of the crosslinking reaction and dissolution of the crystals by medium exchange complemented by chromatographic purification. © 2014 Wiley Periodicals, Inc.

  6. 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

  7. Compositional and physicochemical changes in waste materials and biogas production across 7 landfill sites in UK.

    PubMed

    Frank, R R; Cipullo, S; Garcia, J; Davies, S; Wagland, S T; Villa, R; Trois, C; Coulon, F

    2017-05-01

    The aim of this study was to evaluate the spatial distribution of the paper and fines across seven landfill sites (LFS) and assess the relationship between waste physicochemical properties and biogas production. Physicochemical analysis of the waste samples demonstrated that there were no clear trends in the spatial distribution of total solids (TS), moisture content (MC) and waste organic strength (VS) across all LFS. There was however noticeable difference between samples from the same landfill site. The effect of landfill age on waste physicochemical properties showed no clear relationship, thus, providing evidence that waste remains dormant and non-degraded for long periods of time. Landfill age was however directly correlated with the biochemical methane potential (BMP) of waste; with the highest BMP obtained from the most recent LFS. BMP was also correlated with depth as the average methane production decreased linearly with increasing depth. There was also a high degree of correlation between the Enzymatic Hydrolysis Test (EHT) and BMP test results, which motivates its potential use as an alternative to the BMP test method. Further to this, there were also positive correlations between MC and VS, VS and biogas volume and biogas volume and CH4 content. Outcomes of this work can be used to inform waste degradation and methane enhancement strategies for improving recovery of methane from landfills. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. 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

    2016-04-29

    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.

  9. 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

  10. 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

    2015-01-06

    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.

  11. 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.

  12. 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.

  13. Late Pleistocene-Holocene phytoplankton productivity in the Gulf of Alaska, IODP Site U1419

    NASA Astrophysics Data System (ADS)

    LeVay, L. J.; Romero, O. E.; McClymont, E.; Müller, J.; Penkrot, M. L.; Jaeger, J. M.; Mix, A.; Walczak, M.

    2016-12-01

    The modern Gulf of Alaska (GoA) is a high-nutrient, low-chlorophyll region that is iron-limited; however, the coastal region of Alaska is macronutrient-limited. Vertical mixing of these shallow coastal and deep basinal waters produce high seasonal productivity across the shelf. Previous studies on the Alaskan shelf showed that productivity varied across the Pleistocene-Holocene transition, likely related to climate and sea level change that brought nutrients from estuaries into the Gulf. Here we explore an extended record through the Late Pleistocene-Holocene to reconstruct the productivity of phytoplankton groups in the GoA and to understand the impact of glacial/interglacial climates on primary production and nutrient availability near the shelf. International Ocean Discovery Program (IODP) Site U1419 was cored during Expedition 341 on the upper continental slope in the GoA. A high-resolution sedimentary sequence was recovered that records Late Pleistocene-Holocene glacial and paleoceanographic dynamics. Both calcareous nannoplankton and diatoms are well-represented at Site U1419. Very few studies have explored the competition of these two phytoplankton groups in the geologic record. Because calcareous nannoplankton and diatoms favor differing nutrient conditions, changes in their abundance can aid in reconstructing shifts in primary productivity as well as the causes, such as stratification or nutrient limitation. We present a multi-proxy record, including the group and species abundance of diatoms and calcareous nannoplankton, biogenic bulk components content, alkenone-based sea surface temperatures, and XRF core scanning elemental composition, which is used to interpret fluctuations in phytoplankton and identify the underlying causes. Initial results show the group abundance of nannoplankton and diatoms fluctuates greatly and appears to covary. Calcareous nannoplankton abundance increases with sea surface temperature and is related to higher alkenone

  14. Air pathway effects of nuclear materials production at the Hanford Site, 1983 to 1992

    SciTech Connect

    Patton, G.W.; Cooper, A.T.

    1993-10-01

    This report describes the air pathway effects of Hanford Site operations from 1983 to 1992 on the local environment by summarizing the air concentrations of selected radionuclides at both onsite and offsite locations, comparing trends in environment concentrations to changing facility emissions, and briefly describing trends in the radiological dose to the hypothetical maximally exposed member of the public. The years 1983 to 1992 represent the last Hanford Site plutonium production campaign, and this report deals mainly with the air pathway effects from the 200 Areas, in which the major contributors to radiological emissions were located. An additional purpose for report was to review the environmental data for a long period of time to provide insight not available in an annual report format. The sampling and analytical systems used by the Surface Environmental Surveillance Project (SESP) to collect air samples during the period of this report were sufficiently sensitive to observe locally elevated concentrations of selected radionuclides near onsite source of emission as well as observing elevated levels, compared to distant locations, of some radionuclides at the down wind perimeter. The US DOE Derived Concentration Guides (DCGs) for airborne radionuclides were not exceeded for any air sample collected during 1983 to 1992, with annual average concentrations of all radionuclides at the downwind perimeter being considerably below the DCG values. Air emissions at the Hanford Site during the period of this report were dominated by releases from the PUREX Plant, with {sup 85}Kr being the major release on a curie basis and {sup 129}I being the major release on a radiological dose basis. The estimated potential radiological dose from Hanford Site point source emissions to the hypothetical maximally exposed individual (MEI) ranged from 0. 02 to 0.22 mrem/yr (effective dose equivalent), which is well below the DOE radiation limit to the public of 100 mrem/yr.

  15. [Current status of illegal trade in pharmaceutical products on Internet auction sites in Japan and responses of site administrators to such transactions].

    PubMed

    Ohtani, Hisakazu; Imaoka, Ayuko; Akiyoshi, Takeshi

    2015-01-01

    In Japan, it is illegal to sell pharmaceuticals on Internet auction sites, although a considerable number of pharmaceuticals are listed on such sites. We investigated the current situation regarding the illegal trade in pharmaceuticals on Japanese Internet auction sites and the responses of site administrators to such transactions. We searched for pharmaceuticals and "gray" items that were suspected of being pharmaceuticals on Yahoo-oku! (Yahoo! Auctions, Japan) over a 37-day period and then submitted violation reports indicating that selling pharmaceuticals is illegal or that the description of an item was insufficient. The reports were directed to the site administrators and forwarded to the sellers. One hundred and six pharmaceutical products and 34 gray items were identified during the study period. After the submission of the violation reports, only 28 of the pharmaceutical products and one of the gray items were deleted by the administrator, while 18 of the pharmaceutical products and 7 of the gray items were withdrawn by their sellers. However, 41 pharmaceuticals and 20 gray items were sold. Most of the gray items were listed using characteristic terms or abbreviations without photographic images. More than 70% of the identified pharmaceuticals had a contraindication(s) other than hypersensitivity. In conclusion, the illegal trade in pharmaceuticals on Internet auction sites remains a serious problem in Japan, and the responses of site administrators to such transactions are inadequate. The government and pharmaceutical industry may have to take measures such as providing public and administrative guidance to stop the illegal trade in pharmaceuticals on the Internet.

  16. Production and use of DDT containing antifouling paint resulted in high DDTs residue in three paint factory sites and two shipyard sites, China.

    PubMed

    Xin, Jia; Liu, Xiang; Liu, Wei; Jiang, Lu; Wang, Jihua; Niu, Jia

    2011-06-01

    This study provides the first intensive investigation of Dichlorodiphenyltrichloroethanes (DDT) distribution in typical paint factories and shipyards in China where DDT containing antifouling paint were mass produced and used respectively. DDTs were analyzed in soil, sludge and sediment samples collected from three major paint factories and two shipyards. The results showed that the total DDTs concentrations detected in paint factory and shipyard sites ranged from 0.06 to 8387.24 mg kg(-1). In comparison with paint factory sites, the shipyard sites were much more seriously contaminated. However, for both kinds of sites, the DDTs level was found to be largely affected by history and capacity of production and use of DDT containing antifouling paint. (DDE+DDD)/DDT ratios indicated that DDT containing antifouling paint could serve as important fresh input sources for DDTs. It can be seen that most samples in shipyards were in ranges where heavy contamination and potential ecological risk were identified.

  17. 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.

  18. 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.

  19. Mapping upland hardwood site quality and productivity with GIS and FIA in the Blue Ridge of North Carolina

    Treesearch

    Claudia A. Cotton; Stephen R. Prisley; Thomas R. Fox

    2009-01-01

    The forested ecosystems of the southern Appalachians are some of the most diverse in North America due to the variability in climate, soils, and geologic parent material coupled with the complex topography found throughout the region. These same characteristics cause stands of upland hardwoods to be extremely variable with regard to site quality and productivity. Site...

  20. 75 FR 28657 - Dell Products LP-Parmer North Location, a Subsidiary of Dell, Inc., Including On-Site Leased...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ...., Including On-Site Leased Workers From Belcan Services Group, Hawkins Associates, Inc., Integrated Human Capital, MagRabbit, Manpower and Spherion Corporation; Round Rock, TX; Dell Products LP--Parmer North One...., including on-site leased workers from Belcan Services Group, Hawkins Associates Inc., Integrated...

  1. 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.

  2. 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...

  3. 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...

  4. Methane Detection for Oil and Gas Production Sites Using Portable Dual-Comb Spectrometry

    NASA Astrophysics Data System (ADS)

    Coburn, Sean; Wright, Robert; Cossel, Kevin C.; Truong, Gar-Wing; Baumann, Esther; Coddington, Ian; Newbury, Nathan R.; Alden, Caroline; Ghosh, Subhomoy; Prasad, Kuldeep; Rieker, Greg B.

    2016-06-01

    Considerable uncertainty exists regarding the contribution of oil and gas operations to anthropogenic emissions of atmospheric methane. Additionally, new proposed EPA regulations on volatile organic compound (VOC) emissions from oil and gas production facilities have been expanded to include methane, making this a topic of growing importance to the oil and gas industry as well as regulators. In order to gain a better understanding of emissions, reliable techniques that enable long-term monitoring of entire production facilities are needed. Recent advances in the development of compact and robust fiber frequency combs are enabling the use of this powerful spectroscopic tool outside of the laboratory. Here we characterize and demonstrate a dual comb spectrometer (DCS) system with the potential to locate and size methane leaks from oil and gas production sites over extended periods of time. The DCS operates over kilometer scale open paths, and the path integrated methane measurements will ultimately be coupled with an atmospheric inversion utilizing local meteorology and a high resolution fluid dynamics simulation to determine leak location and also derive a leak rate. High instrument precision is needed in order to accurately perform the measurement inversion on the highly varying methane background, thus the DCS system has been fully optimized for the detection of atmospheric methane in the methane absorption region around 180-184 THz.

  5. Characterization of Aedes aegypti (Diptera: Culcidae) production sites in urban Nicaragua.

    PubMed

    Hammond, Samantha N; Gordon, Aubree L; Lugo, Emperatriz del C; Moreno, Gilberto; Kuan, Guillermina M; López, María M; López, Josefa D; Delgado, Marco A; Valle, Sonia I; Espinoza, Perla M; Harris, Eva

    2007-09-01

    To characterize the production patterns of the dengue virus vector Aedes aegypti (L.) (Diptera: Culcidae), pupal surveys were conducted in selected neighborhoods of two major cities in Nicaragua. In León, 833 houses were visited in July and September 2003, corresponding to the beginning and middle of the dengue season; in Managua, 1,365 homes were visited in July 2003. In total, 7,607 containers were characterized, of which 11% were positive for Ae. aegypti larvae and 4% for pupae. In addition to barrels, potted plants and superficial water on tarps and in puddles were identified as highly productive sites. Univariate and multivariate analysis revealed frequency of container use, use of a lid, and rainwater filling as key variables affecting pupal positivity. Importantly, this survey demonstrated the risk associated with the presence of lids, the limited temporal efficacy of temephos, and the lack of association of water availability with risky water storage practices. Finally, we introduce the concept of an efficiency value and an accompanying graphical display system that can facilitate development of targeted pupal control strategies. These data underscore the importance of entomological surveillance of pupal productivity to gather information from which to derive streamlined, efficient, and effective vector control measures to reduce the density of Aedes mosquito larvae and pupae and thus the risk for dengue.

  6. 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.

  7. 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)

  8. 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.

  9. Genotoxicity monitoring of freshwater environments using caged crayfish (Astacus leptodactylus).

    PubMed

    Klobučar, Göran I V; Malev, Olga; Šrut, Maja; Štambuk, Anamaria; Lorenzon, Simonetta; Cvetković, Želimira; Ferrero, Enrico A; Maguire, Ivana

    2012-03-01

    Genotoxicity of freshwater pollution was assessed by measuring DNA damage in haemocytes of caged freshwater crayfish Astacus leptodactylus by the means of Comet assay and micronucleus test, integrated with the measurements of physiological (total protein concentration) and immunological (total haemocyte count) haemolymph parameters as biomarkers of undergone stress. Crayfish were collected at the reference site (River Mrežnica) and exposed in cages for 1 week at three polluted sites along the Sava River (Zagreb, Sisak, Krapje). The long term pollution status of these locations was confirmed by chemical analyses of sediments. Statistically significant increase in DNA damage measured by the Comet assay was observed at all three polluted sites comparing to the crayfish from reference site. In addition, native crayfish from the mildly polluted site (Krapje) cage-exposed on another polluted site (Zagreb) showed lower DNA damage than crayfish from the reference site exposed at the same location indicating adaptation and acclimatisation of crayfish to lower levels of pollution. Micronuclei induction showed similar gradient of DNA damage as Comet assay, but did not reach the statistical significance. Observed increase in total haemocyte count and total protein content in crayfish from polluted environments in the Sava River also confirmed stress caused by exposure to pollution. The results of this study have proved the applicability of caging exposure of freshwater crayfish A. leptodactylus in environmental genotoxicity monitoring using Comet assay and micronucleus test.

  10. MPL-Net data products available at co-located AERONET sites and field experiment locations

    NASA Astrophysics Data System (ADS)

    Welton, E. J.; Campbell, J. R.; Berkoff, T. A.

    2002-05-01

    Micro-pulse lidar (MPL) systems are small, eye-safe lidars capable of profiling the vertical distribution of aerosol and cloud layers. There are now over 20 MPL systems around the world, and they have been used in numerous field experiments. A new project was started at NASA Goddard Space Flight Center in 2000. The new project, MPL-Net, is a coordinated network of long-time MPL sites. The network also supports a limited number of field experiments each year. Most MPL-Net sites and field locations are co-located with AERONET sunphotometers. At these locations, the AERONET and MPL-Net data are combined together to provide both column and vertically resolved aerosol and cloud measurements. The MPL-Net project coordinates the maintenance and repair for all instruments in the network. In addition, data is archived and processed by the project using common, standardized algorithms that have been developed and utilized over the past 10 years. These procedures ensure that stable, calibrated MPL systems are operating at sites and that the data quality remains high. Rigorous uncertainty calculations are performed on all MPL-Net data products. Automated, real-time level 1.0 data processing algorithms have been developed and are operational. Level 1.0 algorithms are used to process the raw MPL data into the form of range corrected, uncalibrated lidar signals. Automated, real-time level 1.5 algorithms have also been developed and are now operational. Level 1.5 algorithms are used to calibrate the MPL systems, determine cloud and aerosol layer heights, and calculate the optical depth and extinction profile of the aerosol boundary layer. The co-located AERONET sunphotometer provides the aerosol optical depth, which is used as a constraint to solve for the extinction-to-backscatter ratio and the aerosol extinction profile. Browse images and data files are available on the MPL-Net web-site. An overview of the processing algorithms and initial results from selected sites and field

  11. The Potential of Carbonyl Sulfide as a Tracer for Gross Primary Productivity at Flux Tower Sites

    NASA Astrophysics Data System (ADS)

    Blonquist, J.; Montzka, S. A.; Yakir, D.; Desai, A. R.; Dragoni, D.; Griffis, T. J.; Monson, R. K.; Munger, J. W.; Scott, R. L.; Bowling, D. R.

    2010-12-01

    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 differences (mole fraction within canopy minus that above canopy) at a temperate deciduous forest (Harvard Forest AmeriFlux site) were analyzed relative to net ecosystem exchange (NEE) and GPP, respectively. Canopy CO2 and OCS vertical gradients (CO2 and OCS differences divided by within and above canopy measurement height differences) were used to calculate ecosystem relative uptake (ERU; relative canopy OCS gradient divided by relative canopy CO2 gradient, where relative gradients are gradients normalized by above canopy mole fractions), from which GPP was estimated using an equation that assumes OCS follows the same physical pathway as CO2 into plant leaves and where GPP / NEE was proportional to OCS gradient / CO2 gradient. Additionally, canopy CO2 differences from five other AmeriFlux sites were analyzed, and OCS differences were projected from these differences (via an assumed ERU) to further evaluate OCS as a potential GPP tracer. At Harvard Forest, canopy CO2 differences were related to NEE (y = 0.041x + 0.046, r2 = 0.14, P < 0.025) and OCS differences were related to GPP (y = 0.43x - 2.0, r2 = 0.18, P < 0.1), indicating the influence of canopy uptake on canopy differences. Relative canopy OCS and CO2 gradients were linearly correlated (slope = 4.4, intercept = -0.00028, r2 = 0.69, P < 0.025), indicating CO2 and OCS dynamics were likely controlled by similar mechanisms. Estimates of GPP derived from OCS and from temperature-based NEE partitioning showed a strong linear relationship (slope = 1.2, intercept = 3.1, r2 = 0.99, P < 0.0005), indicating the potential of OCS as a GPP tracer. As with Harvard Forest, canopy CO2 differences at the other AmeriFlux sites were related

  12. Heterogeneity of Alkane Chain Length in Freshwater and Marine Cyanobacteria

    PubMed Central

    Shakeel, Tabinda; Fatma, Zia; Fatma, Tasneem; Yazdani, Syed Shams

    2015-01-01

    The potential utilization of cyanobacteria for the biological production of alkanes represents an exceptional system for the next generation of biofuels. Here, we analyzed a diverse group of freshwater and marine cyanobacterial isolates from Indian culture collections for their ability to produce both alkanes and alkenes. Among the 50 cyanobacterial isolates screened, 32 isolates; 14 freshwater and 18 marine isolates; produced predominantly alkanes. The GC-MS/MS profiles revealed a higher percentage of pentadecane and heptadecane production for marine and freshwater strains, respectively. Oscillatoria species were found to be the highest producers of alkanes. Among the freshwater isolates, Oscillatoria CCC305 produced the maximum alkane level with 0.43 μg/mg dry cell weight, while Oscillatoria formosa BDU30603 was the highest producer among the marine isolates with 0.13 μg/mg dry cell weight. Culturing these strains under different media compositions showed that the alkane chain length was not influenced by the growth medium but was rather an inherent property of the strains. Analysis of the cellular fatty acid content indicated the presence of predominantly C16 chain length fatty acids in marine strains, while the proportion of C18 chain length fatty acids increased in the majority of freshwater strains. These results correlated with alkane chain length specificity of marine and freshwater isolates indicating that alkane chain lengths may be primarily determined by the fatty acid synthesis pathway. Moreover, the phylogenetic analysis showed clustering of pentadecane-producing marine strains that was distinct from heptadecane-producing freshwater strains strongly suggesting a close association between alkane chain length and the cyanobacteria habitat. PMID:25853127

  13. 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

  14. 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.

  15. Rhamnolipid production with indigenous Pseudomonas aeruginosa EM1 isolated from oil-contaminated site.

    PubMed

    Wu, Jane-Yii; Yeh, Kuei-Ling; Lu, Wei-Bin; Lin, Chung-Liang; Chang, Jo-Shu

    2008-03-01

    Rhamnolipid is one of the most effective and commonly used biosurfactant with wide industrial applications. Systematic strategies were applied to improve rhamnolipid (RL) production with a newly isolated indigenous strain Pseudomonas aeruginosa EM1 originating from an oil-contaminated site located in southern Taiwan. Seven carbon substrates and four nitrogen sources were examined for their effects on RL production. In addition, the effect of carbon to nitrogen (C/N) ratio on RL production was also studied. Single-factor experiments show that the most favorable carbon sources for RL production were glucose and glycerol (both at 40 g/L), giving a RL yield of 7.5 and 4.9 g/L, respectively. Meanwhile, sodium nitrate appeared to be the preferable nitrogen source, resulting in a RL production of 8.6g/L. Using NaNO(3) as the nitrogen source, an optimal C/N ratio of 26 and 52 was obtained for glucose- and glycerol-based culture, respectively. To further optimize the composition of fermentation medium, twenty experiments were designed by response surface methodology (RSM) to explore the favorable concentration of three critical components in the medium (i.e., glucose, glycerol, and NaNO(3)). The RSM analysis gave an optimal concentration of 30.5, 18.1, and 4.9 g/L for glucose, glycerol, and NaNO(3), respectively, predicting a maximum RL yield of 12.6 g/L, which is 47% higher than the best yield (8.6 g/L) obtained from preliminary selection tests and single factor experiments (glucose and NaNO(3) as the carbon and nitrogen source). The NMR and mass spectrometry analysis show that the purified RL product contained L-rhamnosyl-beta-hydroxydecanoyl-beta-hydroxydecanoate (RL1) and L-rhamnosyl L-rhamnosyl-beta-hydroxydecanoyl-beta-hydroxydecanoate (RL2). Meanwhile, HPLC analysis indicates that the molar ratio of RL1 and RL2 in the purified rhamnolipid product was ca. 1:1.

  16. 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.

  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. 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

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

    PubMed

    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

  20. 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

  1. AATSR land surface temperature product algorithm verification over a WATERMED site

    NASA Astrophysics Data System (ADS)

    Noyes, E. J.; Sòria, G.; Sobrino, J. A.; Remedios, J. J.; Llewellyn-Jones, D. T.; Corlett, G. K.

    A new operational Land Surface Temperature (LST) product generated from data acquired by the Advanced Along-Track Scanning Radiometer (AATSR) provides the opportunity to measure LST on a global scale with a spatial resolution of 1 km2. The target accuracy of the product, which utilises nadir data from the AATSR thermal channels at 11 and 12 μm, is 2.5 K for daytime retrievals and 1.0 K at night. We present the results of an experiment where the performance of the algorithm has been assessed for one daytime and one night time overpass occurring over the WATERMED field site near Marrakech, Morocco, on 05 March 2003. Top of atmosphere (TOA) brightness temperatures (BTs) are simulated for 12 pixels from each overpass using a radiative transfer model, with the LST product and independent emissivity values and atmospheric data as inputs. We have estimated the error in the LST product over this biome for this set of conditions by applying the operational AATSR LST retrieval algorithm to the modelled BTs and comparing the results with the original AATSR LSTs input into the model. An average bias of -1.00 K (standard deviation 0.07 K) for the daytime data, and -1.74 K (standard deviation 0.02 K) for the night time data is obtained, which indicates that the algorithm is yielding an LST that is too cold under these conditions. While these results are within specification for daytime retrievals, this suggests that the target accuracy of 1.0 K at night is not being met within this biome.

  2. 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.

  3. Toxicity of DEDGN (Diethyleneglycol Dinitrate), Synthetic-HC Smoke Combustion Products, Solvent Yellow 33 and Solvent Green 3 to Freshwater Aquatic Organisms.

    DTIC Science & Technology

    1987-01-15

    APR edition may be used untl exhausted.SEUIYC.SFATOOPT45AG All other editwmn are obsoet. SCRT QASFCnNO HSP ~ % % %" 9ECUNY CaASIICAION Of rWS PAug 19...Cont’d) Diethyleneglycol Zinc chloride dinitrate Lead chloride Synthetic-HC smoke Cadmium chloride combustion products Arsenic chloride HCL Carbon ...tested as a group, they exhibited only minimal toxicity to Daphnia magna (Table 13; Figure 5). Carbon tetrachloride does not appear to be acutely toxic

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

    PubMed

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

    2013-08-01

    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 (37ng/g-sediment dry weight) after only 48h of incubation and reached a maximum sediment concentration of 127ng/g-sediment dry weight after the 42 day incubation period. Aqueous phase production of MeHg was observed to be 10ng/L after 2 day, reaching a maximum observed concentration of 32.8ng/L after 14 days, and declining to 10.8ng/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.

  5. 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.

  6. Influence of site index on the relationship between forest net primary productivity and stand age

    PubMed Central

    Yu, Ying; Chen, Jing M.; Yang, Xiguang; Fan, Wenyi; Li, Mingze; He, Liming

    2017-01-01

    Previous studies show that forest net primary productivity (NPP) varies pronouncedly with stand age, and these variations play a crucial role in determining forest carbon sinks or sources at regional scales. Some forest carbon cycling models, eg. InTEC (The integrated terrestrial ecosystem C-budget model), calculates annual forest NPP in the long term according to normalized NPP-age relationships and the reference forest NPP at a given age. Therefore, the accurate NPP-age relationship is important for forest NPP estimation. In this study, NPP at various stand ages for twelve major forest stand types in Heilongjiang Province in northeast China is derived from yield tables with consideration of the total biomass increment and foliage and fine-root turnovers. Similar to previous studies, our results also show that forest NPP increases quickly at young ages, reaches the maximum value at middle age (10–40 years old), and then decreases to a relative stable level at old ages. However, we additionally found that forests under better site conditions have faster growth rates in young ages and steeper declines after reaching the maximum. Therefore, when the NPP-age curves for different site indices are normalized against the maximum value of each curve, there are significant differences among them. These differences have implications on the methodology for estimating the spatial distribution of forest carbon sources and sinks. PMID:28493995

  7. Site-specific DICER and DROSHA RNA products control the DNA-damage response.

    PubMed

    Francia, Sofia; Michelini, Flavia; Saxena, Alka; Tang, Dave; de Hoon, Michiel; Anelli, Viviana; Mione, Marina; Carninci, Piero; d'Adda di Fagagna, Fabrizio

    2012-08-09

    Non-coding RNAs (ncRNAs) are involved in an increasingly recognized number of cellular events. Some ncRNAs are processed by DICER and DROSHA RNases to give rise to small double-stranded RNAs involved in RNA interference (RNAi). The DNA-damage response (DDR) is a signalling pathway that originates from a DNA lesion and arrests cell proliferation3. So far, DICER and DROSHA RNA products have not been reported to control DDR activation. Here we show, in human, mouse and zebrafish, that DICER and DROSHA, but not downstream elements of the RNAi pathway, are necessary to activate the DDR upon exogenous DNA damage and oncogene-induced genotoxic stress, as studied by DDR foci formation and by checkpoint assays. DDR foci are sensitive to RNase A treatment, and DICER- and DROSHA-dependent RNA products are required to restore DDR foci in RNase-A-treated cells. Through RNA deep sequencing and the study of DDR activation at a single inducible DNA double-strand break, we demonstrate that DDR foci formation requires site-specific DICER- and DROSHA-dependent small RNAs, named DDRNAs, which act in a MRE11–RAD50–NBS1-complex-dependent manner (MRE11 also known as MRE11A; NBS1 also known as NBN). DDRNAs, either chemically synthesized or in vitro generated by DICER cleavage, are sufficient to restore the DDR in RNase-A-treated cells, also in the absence of other cellular RNAs. Our results describe an unanticipated direct role of a novel class of ncRNAs in the control of DDR activation at sites of DNA damage.

  8. 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

  9. Sea surface freshwater flux estimates from GECCO, HOAPS and NCEP

    NASA Astrophysics Data System (ADS)

    Romanova, V.; Köhl, A.; Stammer, D.; Klepp, C.; Andersson, A.; Bakan, S.

    2010-08-01

    Surface net freshwater flux fields, estimated from the GECCO ocean state estimation effort over the 50 yr period 1951-2001, are compared to purely satellite-based HOAPS freshwater flux estimates and to the NCEP atmospheric re-analysis net surface freshwater flux fields to assess the quality of all flux products and to improve our understanding of the time-mean surface freshwater flux distribution as well as its temporal variability. Surface flux fields are adjusted by the GECCO state estimation procedure together with initial temperature and salinity conditions so that the model simulation becomes consistent with ocean observations. The entirely independent HOAPS net surface freshwater flux fields result from the difference between SSM/I based precipitation estimates and fields of evaporation resulting from a bulk aerodynamic approach using SSM/I data and the Pathfinder SST. All three products agree well on a global scale. However, overall GECCO seems to have moved away from the NCEP/NCAR first guess surface fluxes and is often closer to the HOAPS data set. This holds for the time mean as well as for the seasonal cycle.

  10. 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.

  11. Taking high conservation value from forests to freshwaters.

    PubMed

    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.

  12. Fungi in freshwaters: ecology, physiology and biochemical potential.

    PubMed

    Krauss, Gerd-Joachim; Solé, Magali; Krauss, Gudrun; Schlosser, Dietmar; Wesenberg, Dirk; Bärlocher, Felix

    2011-07-01

    Research on freshwater fungi has concentrated on their role in plant litter decomposition in streams. Higher fungi dominate over bacteria in terms of biomass, production and enzymatic substrate degradation. Microscopy-based studies suggest the prevalence of aquatic hyphomycetes, characterized by tetraradiate or sigmoid spores. Molecular studies have consistently demonstrated the presence of other fungal groups, whose contributions to decomposition are largely unknown. Molecular methods will allow quantification of these and other microorganisms. The ability of aquatic hyphomycetes to withstand or mitigate anthropogenic stresses is becoming increasingly important. Metal avoidance and tolerance in freshwater fungi implicate a sophisticated network of mechanisms involving external and intracellular detoxification. Examining adaptive responses under metal stress will unravel the dynamics of biochemical processes and their ecological consequences. Freshwater fungi can metabolize organic xenobiotics. For many such compounds, terrestrial fungal activity is characterized by cometabolic biotransformations involving initial attack by intracellular and extracellular oxidative enzymes, further metabolization of the primary oxidation products via conjugate formation and a considerable versatility as to the range of metabolized pollutants. The same capabilities occur in freshwater fungi. This suggests a largely ignored role of these organisms in attenuating pollutant loads in freshwaters and their potential use in environmental biotechnology. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  13. Energy trade-offs between intensive biomass utilization, site productivity loss, and ameliorative treatments in loblolly pine plantations

    Treesearch

    D. Andrew Scott; Thomas J. Dean

    2006-01-01

    Loblolly pine plantations are the most important source of forest products in the US and the slash remaining after conventional harvest represents a significant potential source of bioenergy. However, slash removal in intensive harvests might, under some circumstances, reduce site productivity by reducing soil organic matter and associated nutrients. Two complimentary...

  14. Groundwater Exploration in Freshwater/Saline Layered Aquifers - Southern Bangladesh.

    NASA Astrophysics Data System (ADS)

    McKelvey, P. A.; Rahman, M.

    2001-05-01

    A major urban water supply and sanitation project is being implemented in the southern coastal districts of Bangladesh, by the Governments of Bangladesh and Denmark (DPHE/DANIDA). Due to the poor quality and reliability of surface water in the coastal districts, the source for these schemes will be groundwater. However, the abstraction of large quantities of water is complicated by the fact that the shallow aquifers are thin and of poor hydraulic quality. In addition, there is saline water underlying the shallow aquifer and, in recent years, arsenic has been discovered in many shallow wells throughout Bangladesh. Over the majority of the coastal districts, a thick freshwater sand underlies the saline aquifers, at depths below 200 m. This freshwater unit is bounded by thick clays which protect it from overlying and underlying saline water. The deep aquifer has been exploited in some of the project towns but in a few areas no freshwater aquifers had been located. An exploration programme was undertaken in each of these towns to prove the location of the freshwater sands and to help plan the location and depth of production well drilling. The first exploration stage was to locate any existing deep hand pumped wells and to carry out a water quality survey. Generally, this was sufficient to prove the existence of a thick freshwater aquifer. However, exact well depths and geological data were usually lacking and an exploration well was usually required. In three of the project towns, no deep aquifers had been exploited by existing hand pumped wells and geophysical surveys were undertaken to identify the locations of freshwater aquifers. These surveys comprised resistivity sounding both within the towns and in outlying areas within a feasible pumping distance. In two cases, freshwater aquifers were inferred from the geophysical surveys and exploration drilling was undertaken to prove the resource. Exploration drilling was undertaken by local contractors using hand

  15. Impacts of Climate and UV Change on Arctic Freshwater Ecosystems

    NASA Astrophysics Data System (ADS)

    Wrona, F. J.; Prowse, T. D.; Reist, J. D.

    2004-05-01

    An overview is provided of the key findings of the Arctic Climate Impact Assessment (ACIA), which is an international project of the Arctic Council and the International Arctic Science Committee (IASC), to evaluate and synthesize knowledge on climate variability, climate change, and increased ultraviolet radiation and their consequences. Predicted changes in climate and UV in the Arctic are expected to have far-reaching impacts on the hydrology and ecology of freshwater ecosystems. Key effects include changes in the distribution, abundance and ecology of aquatic species in various trophic levels, dramatic alterations in the physical environment that makes up their habitat, changes to the chemical properties of that environment, and alterations to the processes that act on and within freshwater ecosystems. Interactions of climatic variables, such as temperature and precipitation, with freshwater ecosystems are highly complex and hence can be propagated through ecosystems in ways that are often difficult to predict. This is partly because of our still relatively poor understanding of the structure and function of arctic freshwater systems and their basic interrelationships with climate and other environmental variables, as well as by a paucity of long-term freshwater monitoring sites and integrated hydro-ecological research programs in the Arctic. Predictions of hydro-ecological impacts are further complicated by synergistic and cumulative effects.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Floristic composition, biomass, and aboveground net plant production in grazed and protected sites in a mountain grassland of central Argentina

    NASA Astrophysics Data System (ADS)

    Pucheta, Eduardo; Cabido, Marcelo; Díaz, Sandra; Funes, Guillermo

    1998-04-01

    Changes in plant community composition, diversity, aboveground biomass, and aboveground net primary production (ANPP) of different plant growth-forms were assessed in sites protected from livestock grazing for 2, 4, and 15 years, and in a heavily-grazed site. Species richness was maximum at the grazed site and decreased significantly after 4 years of protection. Diversity decreased significantly only after 15 years of protection. No alien or weedy species were found at grazed or protected sites. Grazing exclusion produced a shift from grazing-tolerant or grazing-avoiding species with a graminoid or prostrate growth-form to taller species with a tall tussock growth-form. Grazing produced a 33% decrease in standing biomass but little change in ANPP when compared to the site protected from grazing for 2 years, but important changes in both biomass and ANPP respect to the sites protected for 4 and 15 years. Consumption was near 35% of ANPP.

  2. 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.

  3. Ceramic microreactors for on-site hydrogen production from high temperature steam reforming of propane.

    PubMed

    Christian, Michael Mitchell; Kenis, Paul J A

    2006-10-01

    The steam reforming of hydrocarbon fuels is a promising method for the production of hydrogen for portable electrical power sources. A suitable reactor for this application, however, must be compatible with temperatures above 800 degrees C to avoid coking of the catalytic structures during the reforming process. Here, ceramic microreactors comprising high surface area, tailored macroporous SiC porous monoliths coated with ruthenium (Ru) catalyst and integrated within high-density alumina reactor housings were used for the steam reforming of propane into hydrogen at temperatures between 800 and 1000 degrees C. We characterized these microreactors by studying C3H8 conversion, H2 selectivity, and product stream composition as a function of the total inlet flow rate, steam-to-carbon ratio (S/C), and temperature. As much as 18.2 sccm H2, or 3.3 x 104 sccm H2 per cm3 of monolith volume, was obtained from a 3.5 sccm entering stream of C3H8 at a S/C of 1.095 and temperatures greater than 900 degrees C. Operating at a S/C close to 1 reduces the energy required to heat excess steam to the reaction temperature and improves the overall thermal efficiency of the fuel processor. Kinetic analysis using a power law model showed reaction orders of 0.50 and -0.23 with respect to propane and steam, respectively, indicating that the rate limiting step in the steam reforming reaction is the dissociative adsorption of propane on the Ru catalyst. The performance of the microreactor was not affected after exposure to more than 15 thermal cycles at temperatures as high as 1000 degrees C, and no catalyst deactivation was observed after more than 120 h of continuous operation at 800 degrees C, making these ceramic microreactors promising for efficient on-site hydrogen production from hydrocarbons for use in polymer electrolyte membrane (PEM) fuel cells.

  4. Feasibility of various carbon sources and plant materials in enhancing the growth and biomass productivity of the freshwater microalgae Monoraphidium griffithii NS16.

    PubMed

    Yee, Willy

    2015-11-01

    In order to assess the feasibility of various carbon sources and plant materials in increasing the growth rate and biomass productivity of Monoraphidium griffithii, ten carbon sources as well as six plant materials were tested in mixotrophic cultures with or without aeration. It was found that glucose, fructose, maltose, sodium acetate and mannitol were potential carbon sources for growth enhancement of M. griffithii. Supplementation of culture medium with these carbon sources resulted in approximately 1-4-fold increase in cell density compared to control in a small scale culture. In a larger scale mixotrophic culture with aeration, 0.05% mannitol and 0.1% fructose resulted in a decent 1-1.5-fold increase in final cell density, approximately 2-fold increase in growth rate and 0.5-1-fold increase in dry biomass weight. Findings from this study suggests that glucose, fructose, maltose and mannitol were potential organic carbon sources for mixotrophic culture of M. griffithii.

  5. The relative risk and its distribution of endocrine disrupting chemicals, pharmaceuticals and personal care products to freshwater organisms in the Bohai Rim, China.

    PubMed

    Zhang, Meng; Shi, Yajuan; Lu, Yonglong; Johnson, Andrew C; Sarvajayakesavalu, Suriyanarayanan; Liu, Zhaoyang; Su, Chao; Zhang, Yueqing; Juergens, Monika D; Jin, Xiaowei

    2017-07-15

    In this study, the risks to aquatic organisms posed by 12 commonly detected pharmaceuticals and personal care products (PPCPs) and endocrine disrupting chemicals (EDCs) that are extensively used in Bohai coastal region of China were examined. These were linear alkylbenzene sulfonate (LAS), nonylphenol (NP), diethylhexyl phthalate (DEHP), norfloxacin (NOR), sulfamethoxazole (SMX), erythromycin (ERY), bisphenol A (BPA), ofloxacin (OFL), carbamazepine (CBZ), naproxen (NPX), atenolol (ATL) and metoprolol (MET). Their relative risk was ranked based on the proximity between the medians of the reported effect concentrations and measured river or lake water concentrations. The surfactants (LAS) and endocrine disrupting chemicals NP (a breakdown product of the surfactant nonylphenol polyethoxylate) and DEHP (a plasticizer) were identified as posing the greatest risk from this range of chemicals. LAS had a hundred-fold higher risk than any of the pharmaceuticals. The highest risk ranked pharmaceuticals were all antibiotics. Zinc (Zn) and mercury (Hg) were added to the comparison as representative heavy metals. Zn posed a risk higher than all the organics. The risk posed by Hg was less than the surfactants but greater than the selected pharmaceuticals. Whereas LAS and DEHP could cause harmful effects to all the wildlife groups, NP and BPA posed the greatest risk to fish. Antibiotics showed the highest risk to algae. Spatial and temporal distributions of PPCPs and EDCs were conducted for risk identification, source analysis and seasonal change exploration. Municipal sewage effluent linked to urban areas was considered to be the major source of pharmaceuticals. With regard to seasonal influence the risk posed by LAS to the aquatic organisms was significantly affected by wet and dry seasonal change. The dilution effects were the common feature of LAS and ERY risks. The difference in LAS and ERY risk patterns along the rivers was mainly affected by the elimination process

  6. A soil-site evaluation index of productivity in intensively managed Pinus radiata (D. Don) plantations in South Australia.

    PubMed

    Hollingsworth, I D; Boardman, R; Fitzpatrick, R W

    1996-01-01

    A limiting-factor, environmental model for radiata pine (Pinus radiata (D. Don)) has been developed using landform and soil morphological features that influence site productivity. The model focuses on soil and landscape constraints to productivity and predicts the native productivity of land and tree species. It permits the integration of land-use objectives for a catchment through forest management and use of silvicultural practices which increase productivity. The soil site evaluation index (SSEI) is an index of forest productivity found when silviculture extends only to the minimum amount of site disturbance needed to establish a plantation of radiata pine. The impacts of intensive silvicultural practices were deducted from the 'Site Quality' productivity survey rating to calculate the unimproved yield class (uYC). We calculated SSEI by range standardising uYC values from 0 to 1. SSEI was correlated with the environmental factors in a regression tree model using readily available analytical software. The model accurately predicts unimproved forest productivity from observed soil horizon and land surface properties. The environmental constraints in low lying areas relate to waterlogging, soil sodicity and gravel content. In elevated areas, plant available water storage, rock weathering, landform, ironstone gravel and aspect are recognised factors for pine growth.

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. 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.

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

    PubMed

    Martinelli, G P T; Friedrich, V L; 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

  13. 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.

  14. 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.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  16. 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.

  17. Site specific nematode management-development and success in cotton production in the United States.

    PubMed

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

    2014-12-01

    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

  18. 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

  19. 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)

  20. 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. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  1. 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

  2. Could Crop Height Impact the Wind Resource at Agriculturally Productive Wind Farm Sites?

    NASA Astrophysics Data System (ADS)

    Vanderwende, B. J.; Lundquist, J. K.

    2013-12-01

    The agriculture-intensive United States Midwest and Great Plains regions feature some of the best wind resources in the nation. Collocation of cropland and wind turbines introduces complex meteorological interactions that could affect both agriculture and wind power production. Crop management practices may modify the wind resource through alterations of land-surface properties. In this study, we used 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. We parameterized a hypothetical array of 121 1.8 MW turbines at the site of the 2011 Crop/Wind-energy Experiment field campaign using the WRF wind farm parameterization. We estimated the impact of crop choices on power production by altering the aerodynamic roughness length in a region approximately 65 times larger than that occupied by the turbine array. Roughness lengths of 10 cm and 25 cm represent a mature soy crop and a mature corn crop respectively. Results suggest that the presence of the mature corn crop reduces hub-height wind speeds and increases rotor-layer wind shear, even in the presence of a large wind farm which itself modifies the flow. During the night, the influence of the surface was dependent on the boundary layer stability, with strong stability inhibiting the surface drag from modifying the wind resource aloft. 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.

  3. Current implementation of site-specific technologies in U.S. cotton production

    NASA Astrophysics Data System (ADS)

    Barnes, Edward M.

    2004-11-01

    The initial adoption of site-specific management for cotton production was slower than by commodities grown in the mid-west. Part of the delayed adoption can be explained by the lack of functional cotton yield monitors. Now that yield monitors are commercially available, cotton producers are beginning to find many applications for geospatial technologies. The emphasis of this paper is on applications that are being implemented at some level on commercial farms. Traditional grid-based soil sampling has found some use for pre-plant application of fertilizer, and soil conductivity mapping has been used to apply variable rate soil amendments in the west. During the growing season, vegetation indices such as the normalized difference vegetation index (NDVI) have been used as a tool to direct scouting for insect infestations. The scouting information and NDVI are combined to create variable rate insecticide application maps. A catalyst to this approach has been the recent development of aerial variable rate application technology. In some production regions, it is necessary to control cotton's vegetative development rate with plant growth regulators (PGRs). Vegetation indices are very useful for defining areas of the field where PGRs are needed. Research is also being conducted on the use of imagery for the development of defoliation application maps before harvest. In the short-term, simple vegetation indices can meet many of management information needs for cotton when combined with directed scouting of the field. However, to be ultimately successful, dependable and frequent sources of imagery will be required. Near-real time delivery is essential, as a majority of the management decisions are often made on a daily basis. Most producer-based applications of these data have been from airborne platforms managed by local image providers where flexible image acquisition schedules are possible.

  4. Photochemical dihydrogen production using an analogue of the active site of [NiFe] hydrogenase.

    PubMed

    Summers, Peter A; Dawson, Joe; Ghiotto, Fabio; Hanson-Heine, Magnus W D; Vuong, Khuong Q; Davies, E Stephen; Sun, Xue-Z; Besley, Nicholas A; McMaster, Jonathan; George, Michael W; Schröder, Martin

    2014-05-05

    Photoproduction of dihydrogen (H2) by a low molecular weight analogue of the active site of [NiFe] hydrogenase has been investigated by reduction of the [NiFe2] cluster, 1, by a photosensitier PS (PS = [ReCl(CO)3(bpy)] or [Ru(bpy)3][PF6]2). Reductive quenching of the (3)MLCT excited state of the photosensitizer by NEt3 or N(CH2CH2OH)3 (TEOA) generates PS(•-), and subsequent intermolecular electron transfer to 1 produces the reduced anionic form of 1. Time-resolved infrared spectroscopy (TRIR) has been used to probe the intermediates throughout the reduction of 1 and subsequent photocatalytic H2 production from [HTEOA][BF4], which was monitored by gas chromatography. Two structural isomers of the reduced form of 1 (1a(•-) and 1b(•-)) were detected by Fourier transform infrared spectroscopy (FTIR) in both CH3CN and DMF (dimethylformamide), while only 1a(•-) was detected in CH2Cl2. Structures for these intermediates are proposed from the results of density functional theory calculations and FTIR spectroscopy. 1a(•-) is assigned to a similar structure to 1 with six terminal carbonyl ligands, while calculations suggest that in 1b(•-) two of the carbonyl groups bridge the Fe centers, consistent with the peak observed at 1714 cm(-1) in the FTIR spectrum for 1b(•-) in CH3CN, assigned to a ν(CO) stretching vibration. Formation of 1a(•-) and 1b(•-) and production of H2 was studied in CH3CN, DMF, and CH2Cl2. Although the more catalytically active species (1a(•-) or 1b(•-)) could not be determined, photocatalysis was observed only in CH3CN and DMF.

  5. Molecular Study of the Effects of Chemical Processing on Heterogeneous Ice Nucleation: Role of Active Sites and Product Formation

    NASA Astrophysics Data System (ADS)

    Sihvonen, S.; Schill, G. P.; Murphy, K. A.; Mueller, K.; Tolbert, M. A.; Freedman, M. A.

    2014-12-01

    Mineral dust aerosol is the largest global source of ice nuclei, but the identity of the active sites for nucleation is unknown. During atmospheric transport, mineral dust aerosol can encounter and react with sulfuric acid, which affects the ice nucleation activity either due to changes to reactive surface sites or product formation. In this study, we reacted two types of clays found in mineral dust, kaolinite and montmorillonite, with sulfuric acid. Variation in the mineral due to acid treatment was separated from product formation through rinsing techniques. The samples were subsequently reacted with a probe molecule, (3,3,3-trifluoropropyl)dimethylchlorosilane, that selectively binds to edge hydroxyl groups that are bonded to a silicon atom with three bridging oxygens. Hydroxyl groups are considered potential active sites, because they can hydrogen bond with water and facilitate ice nucleation. Attachment to these sites was quantified by 19F magic angle spinning nuclear magnetic resonance (MAS NMR) of the 19F atoms on the probe molecule, which provided a direct correlation of the number of hydroxyl groups. Our results indicate that the number of edge-site hydroxyl groups increases with exposure to acid. Ice nucleation measurements indicate that the sulfuric acid-treated mineral is less ice active than the untreated mineral. Surprisingly, no difference between the nucleation activity of the untreated mineral and acid-treated, rinsed mineral is observed. As a result, we hypothesize that once a critical density of active sites is reached for ice nucleation, there is no further change in nucleation activity despite a continued increase in active sites. We additionally propose that the reduced activity of the acid-treated mineral is due to product formation that blocks active sites on the mineral, rather than changes to active sites.

  6. 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.

  7. 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.

  8. Allochthonous carbon is a major regulator to bacterial growth and community composition in subarctic freshwaters

    PubMed Central

    Roiha, Toni; Peura, Sari; Cusson, Mathieu; Rautio, Milla

    2016-01-01

    In the subarctic region, climate warming and permafrost thaw are leading to emergence of ponds and to an increase in mobility of catchment carbon. As carbon of terrestrial origin is increasing in subarctic freshwaters the resource pool supporting their microbial communities and metabolism is changing, with consequences to overall aquatic productivity. By sampling different subarctic water bodies for a one complete year we show how terrestrial and algal carbon compounds vary in a range of freshwaters and how differential organic carbon quality is linked to bacterial metabolism and community composition. We show that terrestrial drainage and associated nutrients supported higher bacterial growth in ponds and river mouths that were influenced by fresh terrestrial carbon than in large lakes with carbon from algal production. Bacterial diversity, however, was lower at sites influenced by terrestrial carbon inputs. Bacterial community composition was highly variable among different water bodies and especially influenced by concentrations of dissolved organic carbon (DOC), fulvic acids, proteins and nutrients. Furthermore, a distinct preference was found for terrestrial vs. algal carbon among certain bacterial tribes. The results highlight the contribution of the numerous ponds to cycling of terrestrial carbon in the changing subarctic and arctic regions. PMID:27686416

  9. Allochthonous carbon is a major regulator to bacterial growth and community composition in subarctic freshwaters.

    PubMed

    Roiha, Toni; Peura, Sari; Cusson, Mathieu; Rautio, Milla

    2016-09-30

    In the subarctic region, climate warming and permafrost thaw are leading to emergence of ponds and to an increase in mobility of catchment carbon. As carbon of terrestrial origin is increasing in subarctic freshwaters the resource pool supporting their microbial communities and metabolism is changing, with consequences to overall aquatic productivity. By sampling different subarctic water bodies for a one complete year we show how terrestrial and algal carbon compounds vary in a range of freshwaters and how differential organic carbon quality is linked to bacterial metabolism and community composition. We show that terrestrial drainage and associated nutrients supported higher bacterial growth in ponds and river mouths that were influenced by fresh terrestrial carbon than in large lakes with carbon from algal production. Bacterial diversity, however, was lower at sites influenced by terrestrial carbon inputs. Bacterial community composition was highly variable among different water bodies and especially influenced by concentrations of dissolved organic carbon (DOC), fulvic acids, proteins and nutrients. Furthermore, a distinct preference was found for terrestrial vs. algal carbon among certain bacterial tribes. The results highlight the contribution of the numerous ponds to cycling of terrestrial carbon in the changing subarctic and arctic regions.

  10. Allochthonous carbon is a major regulator to bacterial growth and community composition in subarctic freshwaters

    NASA Astrophysics Data System (ADS)

    Roiha, Toni; Peura, Sari; Cusson, Mathieu; Rautio, Milla

    2016-09-01

    In the subarctic region, climate warming and permafrost thaw are leading to emergence of ponds and to an increase in mobility of catchment carbon. As carbon of terrestrial origin is increasing in subarctic freshwaters the resource pool supporting their microbial communities and metabolism is changing, with consequences to overall aquatic productivity. By sampling different subarctic water bodies for a one complete year we show how terrestrial and algal carbon compounds vary in a range of freshwaters and how differential organic carbon quality is linked to bacterial metabolism and community composition. We show that terrestrial drainage and associated nutrients supported higher bacterial growth in ponds and river mouths that were influenced by fresh terrestrial carbon than in large lakes with carbon from algal production. Bacterial diversity, however, was lower at sites influenced by terrestrial carbon inputs. Bacterial community composition was highly variable among different water bodies and especially influenced by concentrations of dissolved organic carbon (DOC), fulvic acids, proteins and nutrients. Furthermore, a distinct preference was found for terrestrial vs. algal carbon among certain bacterial tribes. The results highlight the contribution of the numerous ponds to cycling of terrestrial carbon in the changing subarctic and arctic regions.

  11. The spatial distribution of human exposure to PCBs around a former production site in Slovakia

    PubMed Central

    Wimmerová, Soňa; Watson, Alan; Drobná, Beata; Šovčíková, Eva; Weber, Roland; Lancz, Kinga; Patayová, Henrieta; Richterová, Denisa; Koštiaková, Vladimíra; Jurečková, Dana; Závacký, Pavol; Strémy, Maximilián; Jusko, Todd A.; Murínová, L'ubica Palkovičová; Hertz-Picciotto, Irva; Trnovec, Tomáš

    2015-01-01

    We evaluated concentrations of 15 PCB congeners in blood serum of 2,047 adults, 431 8-9-years old children and 1,134 mother-child pairs born in 2001-2003. These subjects were long-standing residents living up to 70 km (to the north) and up to 50 km (to the south) of the former Chemko Strážske PCB production facility in the Michalovce district of Slovakia. We plotted serum concentration against distance from the plant both with and without consideration of the direction of their homes from the site. The decrease in exposure with distance could be described by an exponential function which was dependent on direction and climatic parameters. By kriging we created maps depicting predicted isoconcentration contours for sex- and age-adjusted serum concentration of ΣPCBs for the same group of children, adults and mothers. The principle of our risk analysis was to relate serum concentration data, reflecting PCB body burden, using the critical concentrations established by the French Agency for Food, Environmental and Occupational Health & Safety (ANSES 2010) as thresholds below which the probability of effects on health is regarded as negligible. We conclude that 10 years ago around 200,000 residents were at risk in this densely populated area. Exposure has since decreased but the mechanism for this has not yet been studied. PMID:26250810

  12. Evaluation of radcal gamma thermometers for in-core monitoring of Savannah River Site production reactors

    SciTech Connect

    McCulloch, R.W.; Crowley, J.L.; Croft, W.D.

    1991-12-31

    The Savannah River Site (SRS) recently obtained a quantity of Radcal Gamma Thermometer Assemblies (RGTAs) for in-core monitoring of local power in their production reactors. The RGTAs, manufactured by DELTA M Corporation in Oak Ridge, Tennessee, contained seven Self Calibrating Gamma Thermometer (SCGT) sensors within a 7.26 mm diameter, 3.06 m length with a total length of 5.6 m. All RGTAs contained an isolated segmented heater cable for in-situ calibration. Each SCGT sensor was subjected to a 40 point calibration at discrete power levels from 0.5 to 6 watts per gram (w/g) under both joule and cable power. Calibration equations were developed from this to predict reactor power at each sensor. Additionally three units were calibrated at combined joule and cable heating conditions from 0.5 to 2.5 w/g cable and 0.5 to 6 w/g joule. A statistical analysis of all data was used to derive prediction equations that enable SRS engineers to precisely track any changes in sensor calibration throughout the lifetime of the instruments. This paper presents the detailed configuration of the 36 units manufactured for SRS, reviews the calibration results, and discusses the utility and accuracy of the statistically derived prediction equations for in-situ calibration.

  13. Evaluation of radcal gamma thermometers for in-core monitoring of Savannah River Site production reactors

    SciTech Connect

    McCulloch, R.W.; Crowley, J.L. ); Croft, W.D. )

    1991-01-01

    The Savannah River Site (SRS) recently obtained a quantity of Radcal Gamma Thermometer Assemblies (RGTAs) for in-core monitoring of local power in their production reactors. The RGTAs, manufactured by DELTA M Corporation in Oak Ridge, Tennessee, contained seven Self Calibrating Gamma Thermometer (SCGT) sensors within a 7.26 mm diameter, 3.06 m length with a total length of 5.6 m. All RGTAs contained an isolated segmented heater cable for in-situ calibration. Each SCGT sensor was subjected to a 40 point calibration at discrete power levels from 0.5 to 6 watts per gram (w/g) under both joule and cable power. Calibration equations were developed from this to predict reactor power at each sensor. Additionally three units were calibrated at combined joule and cable heating conditions from 0.5 to 2.5 w/g cable and 0.5 to 6 w/g joule. A statistical analysis of all data was used to derive prediction equations that enable SRS engineers to precisely track any changes in sensor calibration throughout the lifetime of the instruments. This paper presents the detailed configuration of the 36 units manufactured for SRS, reviews the calibration results, and discusses the utility and accuracy of the statistically derived prediction equations for in-situ calibration.

  14. 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

    ..., Including On-Site Leased Workers From Per Mar Security, Webster City, IA; Amended Certification Regarding... company reports that workers leased from Per Mar Security were employed ] on-site at the Webster City... is amending this certification to include workers leased from Per Mar Security working on-site at the...

  15. Productivity and soil properties 45 years after timber harvest and mechanical site preparation in western Montana

    Treesearch

    Luke M. Cerise; Deborah S. Page-Dumroese; Paul McDaniel; Cole Mayn; Robert. Heinse

    2013-01-01

    Site preparation following timber harvests is widely used to increase seedling establishment postharvest. Historically, dozer piling and ripping were the most common forms of site preparation in the Intermountain West. Less commonly, terracing of hill slopes was another form of site preparation on the Bitterroot National Forest in western Montana from 1961-1970 on...

  16. 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

  17. Selecting reliable and robust freshwater macroalgae for biomass applications.

    PubMed

    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

  18. Assessment of SMAP L2/L3 Soil Moisture Products using In Situ Based Core Validation Sites

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

    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 a rotating 6-meter mesh reflector antenna to make measurements with its L-band radiometer. The mission included an L-band radar that experienced a failure in July 2015. While the radar was working, the merger of active and passive L-band observations enabled production of soil moisture at a higher spatial resolution (<10 km) than using the radiometer measurements alone. The primary validation reference of the data products are ground-based measurements. Well characterized sites with calibrated in situ measurements have been used to determine the quality of the data products; these sites are designated as core validation sites. The mission success criteria has been evaluated with respect to these core site comparisons. Other remote sensing and model-based products have been used as complimentary resources to expand the spatial and temporal scope of the evaluation. In an effort to ensure the geographic distribution and diversity of conditions captured by the core validation sites, SMAP partnered with investigators across the globe. Because different SMAP Level 2 and 3 soil moisture products have different spatial scales, the suitability of the various sites for validation of the different products was assessed based on the consideration of several factors. The main factors were the availability of a geographically distributed network consisting of multiple points, gravimetric calibration of the in situ sensors within a site, determination of a spatial scaling function of the sensor measurements up to the SMAP resolution scales, and timely accessibility of the data. 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

  19. El Nino Southern Oscillation (ENSO) enhances CO2 exchange rates in freshwater marsh ecosystems in the Florida Everglades

    Treesearch

    Sparkle L. Malone; Christina L. Staudhammer; Steven F. Oberbauer; Paulo Olivas; Michael G. Ryan; Jessica L. Schedlbauer; Henry W. Loescher; Gregory Starr

    2014-01-01

    This research examines the relationships between El Nino Southern Oscillation (ENSO), water level, precipitation patterns and carbon dioxide (CO2) exchange rates in the freshwater wetland ecosystems of the Florida Everglades. Data was obtained over a 5-year study period (2009–2013) from two freshwater marsh sites located in Everglades National Park that differ...

  20. Thiols in a Connecticut Stratified Freshwater Lake

    NASA Astrophysics Data System (ADS)

    Hu, H.; Mylon, S. E.; Benoit, G.

    2003-12-01

    Thiols are an important class of dissolved reduced sulfur (DRS) species in aquatic environments. They are generally formed from biological processes or during diagenesis of biogenic matter. Thiols can affect the biogeochemistry of B-type metals as they form strong complexes that influence trace metal speciation, bioavailability and toxicity. While current literature focuses on the biogeochemistry of thiols in marine systems, little is known about the biogeochemistry of thiols in oxic freshwaters. We chose to study thiols in Linsley Pond a stratified freshwater lake that has been extensively studied by Hutchinson. Our goals were to identify and quantify the range of thiols present throughout this small lake. Additionally, we hoped to discern the environmental factors that influence the production and distribution of thiols in the water column, and to evaluate importance of thiols in trace metal speciation. To identify and quantify various thiols in freshwaters, we adopted a sensitive and selective analytical method, which involves precolumn fluorometric labeling coupled to high performance liquid chromatography and sensitive fluorescence detection. Using this method, our analytical detection limit is below one nanomolar. Among others, two thiol species were observed in Linsley Pond: 3-mercaptopropionic acid (3-MPA) and glutathione (GSH). 3-MPA exists in both oxic and anoxic water layers at nanomolar levels, and increases from surface to bottom. GSH is only detected in subsurface layer and co-varies with Chl a, indicating possible biological sources of GSH in these layers. There is a third, unidentified thiol species which is currently under investigation. The unidentified thiol species appears only in anoxic lake waters, and tests indicate that it is not PC2 (phytochelatin with 2 glutamic acid-cysteine units). Throughout the water column, concentrations of all three thiols are greater in whole water samples than in the dissolved phase (0.45 um).

  1. 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…

  2. 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…

  3. Current status of parasitic ciliates Chilodonella spp. (Phyllopharyngea: Chilodonellidae) in freshwater fish aquaculture.

    PubMed

    Bastos Gomes, G; Jerry, D R; Miller, T L; Hutson, K S

    2016-07-30

    Freshwater fish farming contributes to more than two-thirds of global aquaculture production. Parasitic ciliates are one of the largest causes of production loss in freshwater farmed fishes, with species from the genus Chilodonella being particularly problematic. While Chilodonella spp. include 'free-living' fauna, some species are involved in mortality events of fish, particularly in high-density aquaculture. Indeed, chilodonellosis causes major productivity losses in over 16 species of farmed freshwater fishes in more than 14 countries. Traditionally, Chilodonella species are identified based on morphological features; however, the genus comprises yet uncharacterized cryptic species, which indicates the necessity for molecular diagnostic methods. This review synthesizes current knowledge on the biology, ecology and geographic distribution of harmful Chilodonella spp. and examines pathological signs, diagnostic methods and treatments. Recent advances in molecular diagnostics and the ability to culture Chilodonella spp. in vitro will enable the development of preventative management practices and sustained freshwater fish aquaculture production.

  4. Freshwater sculpins: phylogenetics to ecology

    Treesearch

    Susan B. Adams; David A. Schmetterling

    2007-01-01

    Freshwater sculpins (Cottidae) are a diverse and ecologically important component of cool- and coldwater ecosystems throughout the northern hemisphere. More than 60 sculpin species occur in a variety of habitats, and sculpin distributions range from highly localized to widespread. Despite the frequently high biomass of sculpins and their numerous ecosystem functions,...

  5. 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

  6. Evaluation of net ecosystem production (2000-2008) for potential grassland biofuel feedstock sites in the Greater Platte River Basin

    NASA Astrophysics Data System (ADS)

    Gu, Y.; Wylie, B. K.; Zhang, L.

    2011-12-01

    Net Ecosystem Production (NEP) is a measure of net carbon accumulation by ecosystems and is an important variable for assessing and understanding the terrestrial carbon cycle and global climate change. We developed a 9-year (2000-2008) time series of NEP data for grasslands within the Great Plains based on flux tower observations, satellite remote sensing, biophysical and climate conditions, and weather data. In this study, we assessed a 9-year time series of NEP in the Greater Platte River Basin to investigate the historical trends of carbon flux (i.e., NEP) for sites possibly suitable for biofuel expansion (productive grasslands) and sites not suitable for biofuel expansion (less productive or degraded grasslands). The suitability of sites was identified using our dynamic modeling of ecosystem performance method. The average annual NEP for sites that were suitable for biofuel feedstock production was from 71 to 169 g C m-2 year-1 during 2000-2008, indicating a strong carbon sink (i.e., more carbon is stored than released) in these areas. The average annual NEP for sites that were not suitable for biofuel feedstock production was from -47 to 69 g C m-2 year-1 during 2000-2008, showing a weak carbon source or a weak carbon sink in these areas. The 9-year accumulated NEP was 200 g C m-2 for the non-suitable areas (a weak carbon sink) and 1166 g C m-2 for the suitable areas (a strong carbon sink). These results demonstrate that our dynamic modeling of ecosystem performance method can identify sites desirable for biofuel feedstock development. Results from this study provide useful information for land managers and decision makers to make optimal land use decisions regarding biofuel feedstock development and sustainability.

  7. 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.

  8. Spatial Upscaling of Long-term In Situ LAI Measurements from Global Network Sites for Validation of Remotely Sensed Products

    NASA Astrophysics Data System (ADS)

    Xu, B.; Jing, L.; Qinhuo, L.; Zeng, Y.; Yin, G.; Fan, W.; Zhao, J.

    2015-12-01

    Leaf area index (LAI) is a key parameter in terrestrial ecosystem models, and a series of global LAI products have been derived from satellite data. To effectively apply these LAI products, it is necessary to evaluate their accuracy reasonablely. The long-term LAI measurements from the global network sites are an important supplement to the product validation dataset. However, the spatial scale mismatch between the site measurement and the pixel grid hinders the utilization of these measurements in LAI product validation. In this study, a pragmatic approach based on the Bayesian linear regression between long-term LAI measurements and high-resolution images is presented for upscaling the point-scale measurements to the pixel-scale. The algorithm was evaluated using high-resolution LAI reference maps provided by the VALERI project at the Järvselja site and was implemented to upscale the long-term LAI measurements at the global network sites. Results indicate that the spatial scaling algorithm can reduce the root mean square error (RMSE) from 0.42 before upscaling to 0.21 after upscaling compared with the aggregated LAI reference maps at the pixel-scale. Meanwhile, the algorithm shows better reliability and robustness than the ordinary least square (OLS) method for upscaling some LAI measurements acquired at specific dates without high-resolution images. The upscaled LAI measurements were employed to validate three global LAI products, including MODIS, GLASS and GEOV1. Results indicate that (i) GLASS and GEOV1 show consistent temporal profiles over most sites, while MODIS exhibits temporal instability over a few forest sites. The RMSE of seasonality between products and upscaled LAI measurement is 0.25-1.72 for MODIS, 0.17-1.29 for GLASS and 0.36-1.35 for GEOV1 along with different sites. (ii) The uncertainty for products varies over different months. The lowest and highest uncertainty for MODIS are 0.67 in March and 1.53 in August, for GLASS are 0.67 in November

  9. 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.

    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 2-14C-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.

  10. 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.

  11. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    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.

  13. 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...

  14. A model-data comparison of gross primary productivity: Results from the North American Carbon Program site synthesis

    Treesearch

    Kevin Schaefer; Christopher R. Schwalm; Chris Williams; M. Altaf Arain; Alan Barr; Jing M. Chen; Kenneth J. Davis; Dimitre Dimitrov; Timothy W. Hilton; David Y. Hollinger; Elyn Humphreys; Benjamin Poulter; Brett M. Raczka; Andrew D. Richardson; Alok Sahoo; Peter Thornton; Rodrigo Vargas; Hans Verbeeck; Ryan Anderson; Ian Baker; T. Andrew Black; Paul Bolstad; Jiquan Chen; Peter S. Curtis; Ankur R. Desai; Michael Dietze; Danilo Dragoni; Christopher Gough; Robert F. Grant; Lianhong Gu; Atul Jain; Chris Kucharik; Beverly Law; Shuguang Liu; Erandathie Lokipitiya; Hank A. Margolis; Roser Matamala; J. Harry McCaughey; Russ Monson; J. William Munger; Walter Oechel; Changhui Peng; David T. Price; Dan Ricciuto; William J. Riley; Nigel Roulet; Hanqin Tian; Christina Tonitto; Margaret Torn; Ensheng Weng; Xiaolu Zhou

    2012-01-01

    Accurately simulating gross primary productivity (GPP) in terrestrial ecosystem models is critical because errors in simulated GPP propagate through the model to introduce additional errors in simulated biomass and other fluxes. We evaluated simulated, daily average GPP from 26 models against estimated GPP at 39 eddy covariance flux tower sites across the United States...

  15. 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...

  16. 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...

  17. Preliminary Evaluation of Methods for Classifying Forest Site Productivity Based on Species Composition in Western North Carolina

    Treesearch

    W. Henry McNab; F. Thomas Lloyd; David L. Loftis

    2002-01-01

    The species indicator approach to forest site classification was evaluated for 210 relatively undisturbed plots established by the USDA Forest Service Forest Inventory and Analysis uni (FIA) in western North Carolina. Plots were classified by low, medium, and high levels of productivity based on 10-year individual tree basal area increment data standardized for initial...

  18. 10. Freiburger Symposium 2011 der SCG-Division Industrielle Chemie Technology Progress, Success Key for our Production Sites.

    PubMed

    Naef, Olivier

    2012-01-01

    This short paper presents the abstracts of the different presentations during 10. Freiburger Symposium 2011 der SCG-Division Industrielle Chemie: Technology Progress, Success key for our production sites held Thursday and Friday, September 29 and 30, 2011 at the Ecole d'ingénieurs et d'architectes de Fribourg (Switzerland).

  19. 78 FR 1252 - CalAmp Wireless Networks Corporation (CWNC), Satellite Products Division, Including On-Site...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-08

    ... 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 converter... Select Staffing, Oxnard, California (TA-W-80,399) and CalAmp Wireless Networks Corporation...

  20. 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

  1. 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

  2. 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

  3. 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

  4. Spatial covariation between freshwater and terrestrial ecosystem services.

    PubMed

    Holland, Robert A; Eigenbrod, Felix; Armsworth, Paul R; Anderson, Barbara J; Thomas, Chris D; Heinemeyer, Andreas; Gillings, Simon; Roy, David B; Gaston, Kevin J

    2011-09-01

    To inform the design and implementation of land-use policies that consider the variety of goods and services people derive from ecosystems, it is essential to understand spatial patterns of individual services, how multiple services relate to each other, and how these relationships vary across spatial scales and localities. Despite the importance of freshwater as a determinant of regional economic and human demographic patterns, there are surprisingly few studies that map the provision of a range of services associated with the quality of the aquatic environment. Here we examine relationships between indicators of riverine water and associated habitat quality, freshwater biodiversity, three terrestrial ecosystem services, and terrestrial biodiversity across England and Wales. The results indicate strong associations between our indicators of freshwater services. However, a comparison of these indicators of freshwater services with other ecosystem services (carbon storage, agricultural production, recreation) and biodiversity of species of conservation concern in the surrounding terrestrial landscape shows no clear relationships. While there are potential policy "win-wins" for the protection of multiple services shown by associations between indicators of freshwater services and carbon storage in upland areas of Britain, the other ecosystem services showed either negative or no relationships with the indicators of freshwater services. We also consider the influence that spatial scale has on these relationships using River Basin Districts. Our results indicate that relationships between indicators of services can change dramatically depending on the societal pressures and other regional conditions. Thus, the delivery of multiple ecosystem services requires the development of regional strategies, or of national strategies that take account of regional variation.

  5. Freshwater bacteria release methane as a byproduct of phosphorus acquisition.

    PubMed

    Yao, Mengyin; Henny, Cynthia; Maresca, Julia A

    2016-09-30

    Freshwater lakes emit large amounts of methane, some of which is produced in oxic surface waters. Two potential pathways for aerobic methane production exist: methanogenesis in oxygenated water, which has been observed in some lakes, or demethylation of small organic molecules. Although methane is produced via demethylation in oxic marine environments, this mechanism of methane release has not yet been demonstrated in freshwater systems. Genes related to the C-P lyase pathway, which cleaves C-P bonds in phosphonate compounds, were found in a metagenomic survey of the surface water of Lake Matano, which is chronically P-starved and methane-rich. We demonstrate that four bacterial isolates from Lake Matano obtain P from methylphosphonate and release methane, and that this activity is repressed by phosphate. We further demonstrate that expression of phnJ, which encodes the enzyme that releases methane, is higher in the presence of methylphosphonate and lower when both methylphosphonate and phosphate are added. This gene is also found in most of the metagenomic data sets from freshwater environments. These experiments link methylphosphonate degradation and methane production with gene expression and phosphate availability in freshwater organisms, and suggest that some of the excess methane in the Lake Matano surface water, and in other methane-rich lakes, may be produced by P-starved bacteria. Methane is an important greenhouse gas, and contributes substantially to global warming. Although freshwater environments are known to release methane into the atmosphere, estimates of the amount of methane emitted by freshwater lakes vary from 8 to 73 Tg per year. Methane emissions are difficult to predict in part because the source of the methane can vary: it is the end product of the energy-conserving pathway in methanogenic archaea, which predominantly live in anoxic sediments or waters, but have also been identified in some oxic freshwater environments. More recently

  6. 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.

  7. 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

    ... Including On-Site Leased Workers From Per Mar Security and Nussbaum Transportation; Webster City, IA... from Per Mar Security. The notice was published in the Federal Register on February 2, 2011 (76 FR 5832...-site leased workers from Per Mar Security and Nussbaum Transportation, Webster City, Iowa, who...

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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