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Sample records for elutriation

  1. An elutriation apparatus for macroinvertebrates

    USGS Publications Warehouse

    Worswick, Joseph M.; Barbour, Michael T.

    1974-01-01

    An inexpensive hydropneumatic apparatus screens macroinvertebrates from bottom samples containing silt, mud, or clay. The elutriator, an acrylic cylinder with screened windows, cemented on an upright plastic funnel, retains benthic fauna while the sediment is washed away. The apparatus yields clean samples and has reduced the time required to sort benthos samples by more than 80%.

  2. Isolation of symbiotic dinoflagellates by centrifugal elutriation

    SciTech Connect

    Bird, A.E.; Quinn, R.J.

    1986-01-01

    Centrifugal elutriation, a method combining centripetal liquid flow with centrifugal force, has been used to isolate symbiotic dinoflagellates from a cnidarian host. The elutriated cells were shown to be viable by photosynthetic incorporation of /sup 14/CO/sub 2/ and low release of photosynthetic products into the incubation medium. The level of contamination by clinging debris was low and by host solids was negligible.

  3. Comparison of bulk sediment and sediment elutriate toxicity testing methods

    EPA Science Inventory

    Elutriate bioassays are among numerous methods that exist for assessing the potential toxicity of sediments in aquatic systems. In this study, interlaboratory results were compared from 96-hour Ceriodaphnia dubia and Pimephales promelas static-renewal acute toxicity tests conduct...

  4. Elutriated acid fermentation of municipal primary sludge.

    PubMed

    Ahn, Young Ho; Speece, Richard E

    2006-06-01

    The performance of a novel fermentation process, adopting a sludge blanket type configuration, for higher hydrolysis/acidogenesis of the municipal primary sludge was investigated under batch and semi-continuous conditions with varying pH and temperature. This acid elutriation slurry reactor provided higher system performance with a short HRT (5d) and higher acidogenic effluent quality under pH 9 and thermophilic (55 degrees C) conditions. The hydrolysis of the sludge was revealed to be significantly dependent on seasonal effects for sludge characteristics but with little impact on acidogenesis. Based on the rainy season at the optimal conditions, VFA production and recovery fraction (VFA(COD)/COD) were 0.18 g VFA(COD)/g VSS(COD) and 63%. As byproducts, nitrogen and phosphorus release were measured at 0.006 g N/g VSS(COD) and 0.003 g P/g VSS(COD), respectively. For the mass balance in a full-scale plant (Q=158,880 m(3)/d) based on the rainy season, the VFA and non-VFA (as COD) production were 3110 kg VFA(COD)/d and 1800 kg COD/d, resulting in an increase of organics of 31 mg COD/L and 20mg VFA(COD)/L and nutrients of 0.7 mg N/L and 0.3 mg P/L in the influent sewage. The economical benefit from this process application was estimated to be about 67 dollars per 1000 m(3) of sewage except for energy requirements and also, better benefits can be expected during the dry season. Moreover, the results revealed that the process has various additional advantages such as pathogen-free stabilized solids production, excellent solids control and economical benefits.

  5. In-Tank Elutriation Test Report And Independent Assessment

    SciTech Connect

    Burns, H. H.; Adamson, D. J.; Qureshi, Z. H.; Steeper, T. J.

    2011-04-13

    The Department of Energy (DOE) Office of Environmental Management (EM) funded Technology Development and Deployment (TDD) to solve technical problems associated with waste tank closure for sites such as Hanford Site and Savannah River Site (SRS). One of the tasks supported by this funding at Savannah River National Laboratory (SRNL) and Pacific Northwest Laboratory (PNNL) was In-Tank Elutriation. Elutriation is the process whereby physical separation occurs based on particle size and density. This report satisfies the first phase of Task WP_1.3.1.1 In-Tank Elutriation, which is to assess the feasibility of this method of separation in waste tanks at Hanford Site and SRS. This report includes an analysis of scoping tests performed in the Engineering Development Laboratory of SRNL, analysis of Hanford's inadvertent elutriation, the viability of separation methods such as elutriation and hydrocyclones and recommendations for a path forward. This report will demonstrate that the retrieval of Hanford salt waste tank S-112 very successfully decreased the tank's inventories of radionuclides. Analyses of samples collected from the tank showed that concentrations of the major radionuclides Cs-136 and Sr-90 were decreased by factors of 250 and 6 and their total curie tank inventories decreased by factors of 60,000 and 2000. The total tank curie loading decreased from 300,000 Ci to 55 Ci. The remaining heel was nearly all innocuous gibbsite, Al(OH){sub 3}. However, in the process of tank retrieval approximately 85% of the tank gibbsite was also removed. Significant amounts of money and processing time could be saved if more gibbsite could be left in tanks while still removing nearly all of the radionuclides. There were factors which helped to make the elutriation of Tank S-112 successful which would not necessarily be present in all salt tanks. 1. The gibbsite particles in the tank were surprisingly large, as much as 200 {micro}m. The gibbsite crystals had probably grown in

  6. Elutriation for Cell Cycle Synchronization in Fission Yeast.

    PubMed

    Kume, Kazunori

    2016-01-01

    Cell synchronization is a powerful technique for studying the eukaryotic cell cycle events precisely. The fission yeast is a rod-shaped cell whose growth is coordinated with the cell cycle. Monitoring the cellular growth of fission yeast is a relatively simple way to measure the cell cycle stage of a cell. Here, we describe a detailed method of unperturbed cell synchronization, named centrifugal elutriation, for fission yeast. PMID:26254921

  7. Microplastics elutriation from sandy sediments: A granulometric approach.

    PubMed

    Kedzierski, Mikaël; Le Tilly, Véronique; Bourseau, Patrick; Bellegou, Hervé; César, Guy; Sire, Olivier; Bruzaud, Stéphane

    2016-06-15

    Although relatively easy to extract in the marine environment, microplastics are very difficult to recover when they are trapped in sediments. The elutriation column is one of the best tools currently available for extracting plastics from sediment, but with a high sand recovery yield. This study aims to address the following questions: (i) is it possible to use a sedimentological approach to limit the sand recovery? (ii) does the extraction velocity of the sand and plastic particles vary according to density and granulometry? (iii) what is the relative recovery efficiency obtained for dense polymer particles mixed with marine sand? Based on a new granulometric classification, different plastic particle-size fractions are defined. Their extraction velocities are experimentally determined on particles of sediment and different plastics (PA, PVC). The particle recovery experiments indicate that it is possible to extract >90% of dense plastic particles in cases of negligible sand recovery. PMID:27053014

  8. Microplastics elutriation from sandy sediments: A granulometric approach.

    PubMed

    Kedzierski, Mikaël; Le Tilly, Véronique; Bourseau, Patrick; Bellegou, Hervé; César, Guy; Sire, Olivier; Bruzaud, Stéphane

    2016-06-15

    Although relatively easy to extract in the marine environment, microplastics are very difficult to recover when they are trapped in sediments. The elutriation column is one of the best tools currently available for extracting plastics from sediment, but with a high sand recovery yield. This study aims to address the following questions: (i) is it possible to use a sedimentological approach to limit the sand recovery? (ii) does the extraction velocity of the sand and plastic particles vary according to density and granulometry? (iii) what is the relative recovery efficiency obtained for dense polymer particles mixed with marine sand? Based on a new granulometric classification, different plastic particle-size fractions are defined. Their extraction velocities are experimentally determined on particles of sediment and different plastics (PA, PVC). The particle recovery experiments indicate that it is possible to extract >90% of dense plastic particles in cases of negligible sand recovery.

  9. Structural effects of the bioavailable fraction of pesticides in soil: suitability of elutriate testing.

    PubMed

    Antunes, Sara C; Pereira, Joana L; Cachada, Anabela; Duarte, Armando C; Gonçalves, Fernando; Sousa, José P; Pereira, Ruth

    2010-12-15

    This study focused the ecotoxicological evaluation of four different pesticides (chlorpyrifos, glyphosate, vinclozolin, endosulfan), sprayed into an agricultural soil, using a standard battery of aquatic bioassays for testing of soil elutriates: Vibrio fischeri -Microtox(®); Pseudokirchneriella subcapitata growth inhibition; Daphnia magna acute and chronic toxicity. Despite relevant pesticide residues were recovered from the soil matrix (concentrations higher than 1000 μg kg(-1)), much lower concentrations could be retrieved from elutriates (highest records for endosulfan of ca. 250 ng L(-1)and 1400 ng L(-1); dissolved and particulate concentration, respectively) and little effects were generally found in the bioassays. Lethal effects (D. magna 48 h-EC50 of 36.8%) could be noticed following exposure to the endosulfan elutriate. Elutriates induced no toxicity on V. fischeri; algal growth was generally inhibited at high elutriate dilutions and stimulated at the lower elutriate dilutions; and no overall impairment of D. magna life-history was noticed. Results revealed that cross-contamination during field application, input of organic matter and nutrients by elutriates in test solutions, and choice of test species and endpoints may constrain the ecotoxicological assessment. Suitability of established aquatic bioassay test batteries for these purposes, and questioning on whether direct assays with soil organisms could be more protective tools is discussed.

  10. An interlaboratory comparison of sediment elutriate preparation and toxicity test methods

    EPA Science Inventory

    Elutriate bioassays are among numerous methods that exist for assessing the potential toxicity of sediments in aquatic systems. In this study, interlaboratory results were compared from 96-hour Ceriodaphnia dubia and Pimephales promelas static-renewal acute toxicity tests conduct...

  11. Characterization of bottom-sediment, water, and elutriate chemistry at selected stations at Reelfoot Lake, Tennessee

    USGS Publications Warehouse

    Broshears, R.E.

    1991-01-01

    To better-understand and predict the potential effect of dredging on water quality at Reelfoot Lake, chemical analyses were conducted on samples of lake water, bottom sediment, and elutriate water. Chemical analyses were conducted on samples of lake water, bottom sediment, and elutriate water collected at five stations in the lake during November 1988. Lake water was of the calcium magnesium bicarbonate type with an average dissolved-solids concentration of 120 milligrams per liter. Trace constituents were present in bottom sediments at concentrations representative of their average relative abundance in the earth?s crust. Elutriate waters prepared by mixing bottom sediment and lake water had suspended-solids concentrations as high as 2,000 milligrams per liter which exerted significant oxygen demand Trace constituents in the unfiltered elutriate waters were elevated with respect to lake water; elevated concentrations were attributable to the increased suspended-solids concentrations. Concentrations of total-recoverable copper, lead., and zinc in many elutriate waters exceeded U.S. Environmental Protection Agency?s water-quality criteria for the protection of freshwater aquatic life. The toxicity of elutriate waters, as measured by a 48-hour bioassay with Ceriodaphnia dubia, was low.

  12. Ecological assessment of soil using a soil elutriate and the perennial ryegrass, Lolium perenne

    SciTech Connect

    Lawrence, C.; Meyers-Shone, L.; Duh, D.

    1995-12-31

    A 28-day plant bioassay using the perennial ryegrass, Lolium perenne, was utilized for an ecological assessment of soil from a hazardous waste site. An elutriate of the test soil was prepared and nutrients added, so that the seedlings would have direct exposure via uptake and to control for poor plant growth due to a lack of nutrients or proper soil profile characteristics. Use of an elutriate as the exposure medium assumes that those contaminants that can become waterborne for uptake by plants in the site conditions is the same as those which can be separated from adsorption to soil particulates during elutriate preparation. The ryegrass seeds were planted in a hydroponic system consisting of an upper chamber with an inert soil for a growth matrix and a lower reservoir with the nutrient and soil elutriate. Polyester cords were used to continuously wick the solution up to the inert soil and the chambers were drenched twice daily with the solution in the reservoir. At the conclusion of the study the plants` shoot length and dry weight (biomass) were measured to assess phytotoxicity of constituents in soil. The results of the test plants parameters were statistically compared to control plants to determine if test soil elutriates caused a measurable effect on ryegrass, The results of this plant bioassay provided additional and useful information for assessment of test soil.

  13. Optimization of elutriation device for filtration of microplastic particles from sediment.

    PubMed

    Zhu, X

    2015-03-15

    The increasing presence of plastic pollution in marine ecosystems has become a major concern. In the environment, plastics break down into smaller and smaller pieces of microplastics. Methods of microplastic recovery are needed to reduce the dangers they can pose to a variety of organisms. An elutriation device was manufactured and optimized to achieve maximum microplastic recovery. The parameters flow rate and diameter of elutriation column were varied and their domain of variation was determined. A composite factorial experimental design was generated using MODDE 10.1 and was undergone. The optimal values of flow rate and column diameter were determined to be 385 L h(-1) and 5.06 cm respectively, under constraints, to achieve a maximum feasible microplastics recovery percentage of 50.2%. The elutriation process can be improved through further testing, and can be tested in the field to compare its efficiency to that of manual microplastics filtration.

  14. Recovery of valuable materials from spent NIMH batteries using spouted bed elutriation.

    PubMed

    Tanabe, Eduardo H; Schlemmer, Diego F; Aguiar, Mônica L; Dotto, Guilherme L; Bertuol, Daniel A

    2016-04-15

    In recent years, a great increase in the generation of spent batteries occurred. Then, efficient recycling ways and correct disposal of hazardous wastes are necessary. An alternative to recover the valuable materials from spent NiMH batteries is the spouted bed elutriation. The aim of this study was to apply the mechanical processing (grinding and sieving) followed by spouted bed elutriation to separate the valuable materials present in spent NiMH batteries. The results of the manual characterization showed that about 62 wt.% of the batteries are composed by positive and negative electrodes. After the mechanical separation processes (grinding, sieving and spouted bed elutriation), three different fractions were obtained: 24.21 wt.% of metals, 28.20 wt.% of polymers and 42.00 wt.% of powder (the positive and negative electrodes). It was demonstrated that the different materials present in the spent NiMH batteries can be efficiently separated using a simple and inexpensive mechanical processing.

  15. Bivalve larvae testing of ocean and in-bay sediments using porewater and elutriates

    SciTech Connect

    Griffin, D.; Targgart, L.

    1995-12-31

    Toxicity of marine sediments is commonly tested using bivalve larval tests. The tests are performed on elutriates, which are prepared by mixing the sediment sample with seawater, and allowing the mixture to settle. The supernatant is separated and tested. Test results appeared to vary depending on the grain-size of the sediments. A study was performed to compare the effects of sediment grain-size on elutriate and porewater toxicity using the bivalve larvae test. Sediments were sampled from two sites: one in San Francisco Bay and one off the coast of San Francisco in the open ocean. From each site, two areas were sampled, one that was potentially impacted by a point-source discharge and another that was free from any discharge impacts. The bay sediments were fine-grained, and the ocean sediments were coarse grained. Porewater from each sample was extracted by centrifugation, and elutriates were prepared using a 4:1 sediment: seawater ratio. Each of the porewater and elutriate samples were tested using the ASTM Standard Guide for Conducting Static Acute Toxicity Tests with Saltwater Bivalves. The results show differences in toxicity that appear to be related to sediment grain-size. The results of this study further imply that dredge material test results should be interpreted with caution when fine-grained sediments are tested. Normalization of the results to grain-size may be appropriate.

  16. Analysis of native water, bed material, and elutriate samples of major Louisiana waterways, 1975

    USGS Publications Warehouse

    Demas, Charles R.

    1976-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, conducted a series of elutriate studies in selected reaches of major navigable waterways of Louisiana. As defined by the U.S. Environmental Protection Agency, an elutriate is the supernatant resulting from the vigorous 30-minute shaking of one part bottom sediment from the dredging site with four parts water (vol/vol) collected from the dredging site followed by one hour settling time and appropriate centrifugation and a 0.45-micron filtration. The elutriate studies were initiated to evaluate possible environmental effects of proposed dredging activities in selected reaches of Louisiana waterways. The waterways investigated were the Mississippi River-Gulf Outlet, Breton Sound, Mississippi River downstream from Baton Rouge, Bayou Long, Intracoastal Waterway (east and west of the Harvey Canal), Three Rivers area, Ouachita River, Barataria Bay, Houma Navigation Canal, Atchafalaya Bay (Ship Channel), Berwick Bay, Intracoastal Waterway (Port Allen to Morgan City), Petite Anse area, and Calcasieu River and Ship Channel. The Geological Survey collected 227 samples of native water and bed (bottom) material from 130 different sites. These samples (as well as elutriates prepared from mixtures of native water and bed material) were analyzed for selected metal, pesticide, nutrient, and organic constituents. An additional 116 bed samples collected at 58 sites were analyzed for selected pesticides; and 4 additional native-water samples from 2 sites were analyzed for selected metal pesticide, nutrient, and organic constituents. (Woodard-USGS)

  17. Analyses of native water, bottom material, and elutriate samples of southern Louisiana waterways, 1977-78

    USGS Publications Warehouse

    Dupuy, Alton J.; Couvillion, Nolan P.

    1979-01-01

    From March 1977 to July 1978 the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers conducted a series of elutriate studies to determine water quality in selected reaches of major navigable waterways of southern Louisiana. Sample were collected from the Mississippi River-Gulf Outlet areas; Mississippi River, South Pass; Baptiste Collette Bayou; Tiger Pass area; Baou Long; Bayou Barataria and Barataria Bay Waterway area (gulf section); Bayou Segnette Waterway, Lake Pontchartrain near Tangipahoa River mouth; Bayou Grand Caillou; Bayou la Carpe at Homa; Houma Navigation Canal and Terrebonne Bay; Bayou Boeuf, Bayou Chene, and Baou Black, Atchafalaya River Channel, Atchafalaya Bay; Old River Lock tailbay; Red River below mouth of Black River; Freshwaer Canal; Mermentau River and Lake Arthur Mermentau River outlet; and Calcasieu Ship Channel. The studies were initiated at the request of the U.S. Army Corps of Engineers to evaluate possible environmental effects of proposed dredging activities in those waterways. The U.S. Army Corps of Engineers and U.S. Geological Survey collected 189 samples of native water and 172 samples of bottom (bed) material from 163 different sites. A total of 117 elutriates (Mixtures of native water and bottom material) were prepared. The native water and elutriate samples were analyzed for selected metals, pesticides, nutrients organics, and pysical constituents. Particle-size determinations were made on bottom-material samples. (Kosco-USGS)

  18. Theory and practice of centrifugal elutriation (CE). Factors influencing the separation of human blood cells.

    PubMed

    Figdor, C G; Leemans, J M; Bont, W S; de Vries, J E

    1983-06-01

    Centrifugal elutriation (CE) is currently a widely used preparative cell separation technique. In order to optimize the separation of cells that show only small differences in sedimentation velocity, several conditions that might influence the resolution capacity, such as rotor speed, counterflow, jetstream, cell load, density, and viscosity of the elutriation medium, were analyzed. Experiments carried out with human red blood cells (rbc) indicated that selective losses of rbc from the rotor caused by the jetstream, could be prevented if the separations were carried out at high rotor speeds, as predicted by the theory. In addition, high cell loads (5 X 10(8) rbc) resulted in better separations than low cell loads (5 X 10(7) rbc). Human monocytes were separated into subpopulations that differed only about 0.003 g/mL in density, but have virtually the same size. The separation was carried out either by increasing the density or viscosity of the elutriation medium or by decreasing the rotor speed. In all cases similar results were obtained. These results indicated that under optimal conditions CE can be applied for the separation of cells that differ only slightly in sedimentation velocity. PMID:6197173

  19. Absence of carbonic anhydrase on the surface of red cells suspended in an elutriator

    SciTech Connect

    Dodek, P.; Effros, R.M.

    1986-03-01

    Studies of the carbonic anhydrase activity of intact red cells are complicated by hemolysis, which markedly accelerates catalytic conversion between HCO/sub 2//sup -/ and CO/sub 2/. The authors have reduced this effect to negligible levels by studying red cells suspended with an elutriator. 1.Oml of packed rabbit red cells were introduced in an elutriator chamber which was spun in a centrifuge with a force of 2900G. An isotonic, pH 7.4, 6/sup 0/C, HCO/sub 3//sup -/ Ringer's lactate solution was pumped centripetally through the chamber to keep the cells in suspension. 0.1 ml of the perfusion solution containing /sup 22/Na/sup +/, /sup 36/Cl-, H/sup 14/CO/sub 3//sup -///sup 14/CO/sub 2/ (equilibrated), and /sup 3/H/sub 2/O were injected into the elutriator inflow and 22 samples were collected with a computerized anaerobic collector. Outflow concentrations of each radionuclide were divided by the amounts injected to yield fractional concentrations and upslope areas of indicators were divided by that of /sup 22/Na/sup +/ to yield an index of red cell exchange, R. Under control conditions, R(/sup 14/C) averaged .80 +/- .01 (S.E.). After anion exchange had been blocked with 0.1..mu..M DIDS, R(/sup 14/C) increased to .86 +/- .01. When 100 mg/1 bovine carbonic anhydrase was added R(/sup 1/$C) fell to .78 +/- .01. Subsequent addition of acetazolamide (10/sup -5/) increased R(/sup 14/C) to .86 +/- .01. R(/sup 36/Cl/sup -/) was increased from .91 +/- .02 to .96 +/- .01 after DIDS. These data indicate no detectable carbonic anhydrase activity on red cell surface.

  20. Quality of bottom material and elutriates in the lower Willamette River, Portland Harbor, Oregon

    USGS Publications Warehouse

    Fuhrer, Gregory J.

    1989-01-01

    In October 1983 the U.S. Geological Survey, in cooperation with the U.S. Army Corp of Engineers, collected bottom-material and water samples from Portland Harbor, Oregon to determine concentrations of trace metals and organic compounds in elutriate-test filtrate and bottom material. Of the trace metals examined in bottom material, concentrations of cadmium slightly exceed those of local rocks, whereas lead and zinc exceedance is substantially larger. Of the organochlorine compounds examined in bottom material chlordane, DDD, DDE, DDT, dieldrin, and polychlorinated biphenyls (PCB's) were detected and quantified in at least 30% of the samples tested. A large DDT concentration (2,700 microgram/kilogram) near Doane Lake outlet is indicative of recent contamination. Polychlorinated biphenyls are ubiquitous in bottom sediments; median concentrations are nearly 65 micrograms/kilogram and as large as 550 microgram/kilogram. PCB loading to the Columbia River from Willamette River suspended sediment has been estimated to be 72 kilograms/year, nearly five times the PCB dredge load of 15 kilogram/year. The acid and base-neutral extractable di-n-butyl phthalate and bis (2-ethylhexyl)phthalate occur in sediments of Terminal No. 2 in concentrations as large as 1,965 and 2,200 micrograms/kilogram, respectively. Of the trace metals examined in both standard and oxic elutriate-test filtrate, only copper concentration in an oxic elutriate-test filtrate (19 micrograms/L) exceeded the water quality criteria (5.7 micrograms/L). (USGS)

  1. Analyses of water, core material, and elutriate samples collected near Yazoo City, Mississippi (Yazoo Headwater Project)

    USGS Publications Warehouse

    Leone, Harold L.; Dupuy, Alton J.

    1978-01-01

    Five core-material-sampling sites near Yazoo City, Miss., were chosen by the U.S. Army Corps of Engineers to represent areas of proposed dredging activity. Four receiving-water sites also were selected to represent the water that will contact the proposed dredged material. Chemical and physical analyses were performed upon core material and native-water samples from these sites as well as upon elutriate samples of specific sediment-receiving water systems. The results of these analyses are presented without interpretation. (Woodard-USGS)

  2. Use of population modeling to interpret a 21-day sediment elutriate bioassay with Daphnia magna

    SciTech Connect

    Bridges, T.S.; Gibson, A.B.; Wright, R.B.; Gray, B.R.; Gamble, V.E.

    1994-12-31

    Sediment contamination was evaluated in 17 Great Lakes sediments using a 21-day sediment elutriate bioassay with D. magna. Sediment type had a significant effect on survival at the conclusion of the test, age at first reproduction, the number of broods produced, and the total number of young produced per adult. Sediments producing low survivorship also had negative effects on reproduction. However, a broad range of reproductive responses were found among sediments with high survivorship. To integrate all of these results a stochastic matrix population model was constructed for each of the sediment treatments. Survivorship, age at first reproduction, and total fecundity were all important determinants of population growth. However, modeling results indicated that independent examination of the endpoints measured during the test does not accurately reflect effects at the population level; i.e., no one endpoint appeared to have an overriding effect on population growth. The amount of total suspended solids (TSS) in the elutriates had a strong effect on the reproductive endpoints measured; TSS was negatively correlated with age at first reproduction and positively correlated with per brood fecundity and measures of population growth. Demographic modeling appears to be a useful method for integrating the effects of multiple endpoints and for providing ecologically relevant interpretive guidance.

  3. Liver histological changes and lipid peroxidation in the amphibian Ambystoma mexicanum induced by sediment elutriates from the Lake Xochimilco.

    PubMed

    Ortiz-Ordoñez, Esperanza; López-López, Eugenia; Sedeño-Díaz, Jacinto Elías; Uría, Esther; Morales, Ignacio Andrés; Pérez, María Estela; Shibayama, Mineko

    2016-08-01

    Lacustrine sediments accumulate pollutants that input from the lake watershed and can be released to the water column by sediment resuspension; thus, pollutants can change their bioavailability and exert adverse effects to aquatic biota. Shallow-urban lakes are particularly susceptible to receive pollutants from urban discharges and sediment resuspension. Lake Xochimilco, in Mexico City, an urban-shallow lake, faces multiple problems: urban sprawl, overexploitation of aquifers, drying of springs, discharge of wastewater from treatment plants, and sediment resuspension. The aquatic biota living in this ecosystem is continuously exposed to the release of pollutants from the sediments. We assessed the risk that pollutants released from sediments from Lake Xochimilco, Touristic (TZ) and Agriculture zone (AZ), can exert on a native amphibian species of the lake (Ambystoma mexicanum) through exposure bioassays to sediment elutriates. We evaluate alterations in the amphibian by three approaches: biochemical (level of lipid peroxidation, LPO), cellular (ultrastructure) and the liver histology of A. mexicanum and we compare them with a batch control. Additionally, we assessed heavy metals (Pb, Cd and Hg) in elutriates. Elutriates from TZ showed the highest concentrations of the metals assessed. Organisms exposed to sediment elutriates from either study sites showed higher LPO values than control organisms (p<0.05). Organisms exposed to elutriates from the TZ showed the most conspicuous damages: hepatic vasodilation of sinusoids, capillaries with erythrocytes, leukocyte infiltration and cytoplasmic vacuolation in hepatocytes. The biological responses assessed reflected the risk that faces A. mexicanum when is exposed for prolonged periods to sediment resuspension in Lake Xochimilco.

  4. Liver histological changes and lipid peroxidation in the amphibian Ambystoma mexicanum induced by sediment elutriates from the Lake Xochimilco.

    PubMed

    Ortiz-Ordoñez, Esperanza; López-López, Eugenia; Sedeño-Díaz, Jacinto Elías; Uría, Esther; Morales, Ignacio Andrés; Pérez, María Estela; Shibayama, Mineko

    2016-08-01

    Lacustrine sediments accumulate pollutants that input from the lake watershed and can be released to the water column by sediment resuspension; thus, pollutants can change their bioavailability and exert adverse effects to aquatic biota. Shallow-urban lakes are particularly susceptible to receive pollutants from urban discharges and sediment resuspension. Lake Xochimilco, in Mexico City, an urban-shallow lake, faces multiple problems: urban sprawl, overexploitation of aquifers, drying of springs, discharge of wastewater from treatment plants, and sediment resuspension. The aquatic biota living in this ecosystem is continuously exposed to the release of pollutants from the sediments. We assessed the risk that pollutants released from sediments from Lake Xochimilco, Touristic (TZ) and Agriculture zone (AZ), can exert on a native amphibian species of the lake (Ambystoma mexicanum) through exposure bioassays to sediment elutriates. We evaluate alterations in the amphibian by three approaches: biochemical (level of lipid peroxidation, LPO), cellular (ultrastructure) and the liver histology of A. mexicanum and we compare them with a batch control. Additionally, we assessed heavy metals (Pb, Cd and Hg) in elutriates. Elutriates from TZ showed the highest concentrations of the metals assessed. Organisms exposed to sediment elutriates from either study sites showed higher LPO values than control organisms (p<0.05). Organisms exposed to elutriates from the TZ showed the most conspicuous damages: hepatic vasodilation of sinusoids, capillaries with erythrocytes, leukocyte infiltration and cytoplasmic vacuolation in hepatocytes. The biological responses assessed reflected the risk that faces A. mexicanum when is exposed for prolonged periods to sediment resuspension in Lake Xochimilco. PMID:27521947

  5. Analyses of elutriates, native water, and bottom material in selected rivers and estuaries in western Oregon and Washington

    USGS Publications Warehouse

    Fuhrer, Gregory J.; Rinella, Frank A.

    1983-01-01

    Chemical analyses of elutriates, bottom sediment and water samples for selected metals, nutrients and organic compounds including insecticides and herbicides have been made to provide data to determine short-term water quality conditions associated with dredging operations in rivers and estuaries. Between May and December 1980 data were collected as far south as the Coos River in Western Oregon, as far north as Baker Bay in Southwestern Washington and as far inland as Bonneville Dam on the Columbia River. In an elutriation test, bottom material from a dredging site is mixed with native water and the filtrate is analysed. Elutriation test results showed variability in concentrates of dissolved chemicals as follows: in micrograms per liter (micro g/l), manganese ranged from 0 to 10,000, iron from 10 to 4300, zinc from 1 to 90, and phenols from 9 to 420; in milligrams per liter (mg/l), ammonia as nitrogen ranged from 0.03 to 46 and organic carbon from 0.5 to 45. (USGS)

  6. Particle Size Characterization of Water-Elutriated Libby Amphibole 2000 and RTI International Amosite

    USGS Publications Warehouse

    Lowers, Heather; Bern, Amy M.

    2009-01-01

    This report presents data on particle characterization analyzed by scanning electron microscopy on Libby amphibole collected by the U.S. Geological Survey in 2000 (LA2000) and amosite material collected by RTI International (RTI amosite). The particle characterization data were generated to support a portion of the Libby Action Plan. Prior to analysis, the raw LA2000 and RTI amosite materials were subjected to a preparation step. Each sample was water-elutriated by U.S. Environmental Protection Agency (USEPA) Office of Research and Development, Research Triangle Park using the methods generally described in another published report and then delivered to the U.S. Geological Survey, Denver Microbeam Laboratory for analysis. Data presented here represent analyses performed by the U.S. Geological Survey, Denver Microbeam Laboratory and USEPA National Enforcement Investigations Center. This report consists of two Excel spreadsheet files developed by USEPA, Region 8 Superfund Technical Assistance Unit and describe the particle size characterization of the LA2000 and RTI amosite, respectively. Multiple tabs and data entry cells exist in each spreadsheet and are defined herein.

  7. Analyses of water, core material, and elutriate samples collected near Sicily Island, Louisiana (Sicily Island area levee project)

    USGS Publications Warehouse

    Demcheck, Dennis K.; Dupuy, Alton J.

    1980-01-01

    Samples consisting of composited core material were collected from five areas by the U.S. Army Corps of Engineers and analyzed by the U.S. Geological Survey to provide data on the impact of proposed channel excavation and levee construction in the Sicily Island area, Louisiana. Samples of receiving water from the five areas, selected to represent the water that will contact the proposed dredged material of the levee fill material, also were collected. Chemical and physical analyses were performed on samples of core material and native water and on elutriate samples of specific core material-receiving water mixtures. The results of these analyses are presented without interpretation. (USGS)

  8. Analyses of water, core material, and elutriate samples collected near Galliano, Louisiana: Larose to Golden Meadow, Louisiana, Hurricane Protection Project

    USGS Publications Warehouse

    Leone, Harold L.

    1977-01-01

    Seven core-material-sampling sites were chosen by the U.S. Army Corps of Engineers as possible borrow areas for fill material to be used in levee construction near Galliano La. Four receiving-water sites also were selected to represent the water that will contact the proposed levees. Analyses of selected nutrients, metals, pesticides, and other organic constituents were performed upon these bed-material and native-water samples as well as upon elutriate samples of specific core material-receiving water systems. The results of these analyses are presented without interpretation. (Woodard-USGS)

  9. Analyses of water, core material, and elutriate samples collected near Buras, Louisiana (New Orleans to Venice, Louisiana, Hurricane Protection Project)

    USGS Publications Warehouse

    Leone, Harold A.

    1977-01-01

    Eight core-material-sampling sites were chosen by the U.S. Army Corps of Engineers as possible borrow areas for fill material to be used in levee contruction near Buras, La. Eleven receiving-water sites also were selected to represent the water that will contact the porposed levees. Analyses of selected nutrients, metals, pesticides, and other organic constitutents were performed upon these bed-material and native-water samples as well as upon elutriate samples of specific core material-receiving water systems. The results of these analyses are presented without interpretation. (Woodard-USGS)

  10. Analyses of water, bank material, bottom material, and elutriate samples collected near Belzoni, Mississippi (upper Yazoo projects)

    USGS Publications Warehouse

    Brightbill, David B.; Treadway, Joseph B.

    1980-01-01

    Four core-material-sampling sites and one bottom-material site were chosen by the U.S. Army Corps of Engineers to represent areas of proposed dredging activity along a 24.9-mile reach of the upper Yazoo River. Five receiving-water sites also were selected to represent the water that will contact the proposed dredged material. Chemical and physical analyses were performed upon core or bottom material and native-water (receiving-water) samples from these sites as well as upon elutriate samples of the mixture of sediment and receiving water. The results of these analyses are presented without interpertation. (USGS)

  11. Phosphogypsum as a soil fertilizer: Ecotoxicity of amended soil and elutriates to bacteria, invertebrates, algae and plants.

    PubMed

    Hentati, Olfa; Abrantes, Nelson; Caetano, Ana Luísa; Bouguerra, Sirine; Gonçalves, Fernando; Römbke, Jörg; Pereira, Ruth

    2015-08-30

    Phosphogypsum (PG) is a metal and radionuclide rich-waste produced by the phosphate ore industry, which has been used as soil fertilizer in many parts of the world for several decades. The positive effects of PG in ameliorating some soil properties and increasing crop yields are well documented. More recently concerns are emerging related with the increase of metal/radionuclide residues on soils and crops. However, few studies have focused on the impact of PG applications on soil biota, as well as the contribution to soils with elements in mobile fractions of PG which may affect freshwater species as well. In this context the main aim of this study was to assess the ecotoxicity of soils amended with different percentages of Tunisian phosphogypsum (0.0, 4.9, 7.4, 11.1, 16.6 and 25%) and of elutriates obtained from PG - amended soil (0.0, 6.25, 12.5 and 25% of PG) to a battery of terrestrial (Eisenia andrei, Enchytraeus crypticus, Folsomia candida, Hypoaspis aculeifer, Zea mays, Lactuca sativa) and aquatic species (Vibrio fischeri, Daphnia magna, Raphidocelis subcapitata, Lemna minor). Both for amended soils and elutriates, invertebrates (especially D. magna and E. andrei) were the most sensitive species, displaying acute (immobilization) and chronic (reproduction inhibition) effects, respectively. Despite the presence of some concerning metals in PG and elutriates (e.g., zinc and cadmium), the extremely high levels of calcium found in both test mediums, suggest that this element was the mainly responsible for the ecotoxicological effects observed. Terrestrial and aquatic plants were the most tolerant species, which is in line with studies supporting the application of PG to increase crop yields. Nevertheless, no stimulatory effects on growth were observed for any of the species tested despite the high levels of phosphorus added to soils by PG. Given the importance of soil invertebrates for several soil functions and services, this study gives rise to new serious

  12. Phosphogypsum as a soil fertilizer: Ecotoxicity of amended soil and elutriates to bacteria, invertebrates, algae and plants.

    PubMed

    Hentati, Olfa; Abrantes, Nelson; Caetano, Ana Luísa; Bouguerra, Sirine; Gonçalves, Fernando; Römbke, Jörg; Pereira, Ruth

    2015-08-30

    Phosphogypsum (PG) is a metal and radionuclide rich-waste produced by the phosphate ore industry, which has been used as soil fertilizer in many parts of the world for several decades. The positive effects of PG in ameliorating some soil properties and increasing crop yields are well documented. More recently concerns are emerging related with the increase of metal/radionuclide residues on soils and crops. However, few studies have focused on the impact of PG applications on soil biota, as well as the contribution to soils with elements in mobile fractions of PG which may affect freshwater species as well. In this context the main aim of this study was to assess the ecotoxicity of soils amended with different percentages of Tunisian phosphogypsum (0.0, 4.9, 7.4, 11.1, 16.6 and 25%) and of elutriates obtained from PG - amended soil (0.0, 6.25, 12.5 and 25% of PG) to a battery of terrestrial (Eisenia andrei, Enchytraeus crypticus, Folsomia candida, Hypoaspis aculeifer, Zea mays, Lactuca sativa) and aquatic species (Vibrio fischeri, Daphnia magna, Raphidocelis subcapitata, Lemna minor). Both for amended soils and elutriates, invertebrates (especially D. magna and E. andrei) were the most sensitive species, displaying acute (immobilization) and chronic (reproduction inhibition) effects, respectively. Despite the presence of some concerning metals in PG and elutriates (e.g., zinc and cadmium), the extremely high levels of calcium found in both test mediums, suggest that this element was the mainly responsible for the ecotoxicological effects observed. Terrestrial and aquatic plants were the most tolerant species, which is in line with studies supporting the application of PG to increase crop yields. Nevertheless, no stimulatory effects on growth were observed for any of the species tested despite the high levels of phosphorus added to soils by PG. Given the importance of soil invertebrates for several soil functions and services, this study gives rise to new serious

  13. Accumulation of trace metals in sediments in a Mediterranean Lagoon: Usefulness of metal sediment fractionation and elutriate toxicity assessment.

    PubMed

    Zaaboub, Noureddine; Martins, Maria Virgínia Alves; Dhib, Amel; Béjaoui, Béchir; Galgani, François; El Bour, Monia; Aleya, Lotfi

    2015-12-01

    The authors investigated sediment quality in Bizerte Lagoon (Tunisia) focusing on geochemical characteristics, metal sediment fractionation and elutriate toxicity assessment. Nickel, Cu, Zn, Pb, Cr and Cd partitioning in sediments was studied; accumulation and bioavailability were elucidated using enrichment factors, sequential extractions, redox potential, acid volatile sulfide and biotest procedures in toxicity evaluation. Results revealed an accumulation for Pb and Zn, reaching 99 and 460 mg kg(-1) respectively. In addition, the acid volatile sulfide values were high in both eastern and western lagoon areas, thus affecting metal availability. Mean enrichment factor values for Pb and Zn were 4.8 and 4.9, respectively, with these elements as the main contributors to the lagoon's moderate enrichment level. Toxicity levels were influenced by accumulation of Zn in different surface sediment areas. Core sediments were investigated in areas with the highest metal concentrations; metal fractionation and biotest confirmed that Zn contributes to sediment toxicity. PMID:26412262

  14. Accumulation of trace metals in sediments in a Mediterranean Lagoon: Usefulness of metal sediment fractionation and elutriate toxicity assessment.

    PubMed

    Zaaboub, Noureddine; Martins, Maria Virgínia Alves; Dhib, Amel; Béjaoui, Béchir; Galgani, François; El Bour, Monia; Aleya, Lotfi

    2015-12-01

    The authors investigated sediment quality in Bizerte Lagoon (Tunisia) focusing on geochemical characteristics, metal sediment fractionation and elutriate toxicity assessment. Nickel, Cu, Zn, Pb, Cr and Cd partitioning in sediments was studied; accumulation and bioavailability were elucidated using enrichment factors, sequential extractions, redox potential, acid volatile sulfide and biotest procedures in toxicity evaluation. Results revealed an accumulation for Pb and Zn, reaching 99 and 460 mg kg(-1) respectively. In addition, the acid volatile sulfide values were high in both eastern and western lagoon areas, thus affecting metal availability. Mean enrichment factor values for Pb and Zn were 4.8 and 4.9, respectively, with these elements as the main contributors to the lagoon's moderate enrichment level. Toxicity levels were influenced by accumulation of Zn in different surface sediment areas. Core sediments were investigated in areas with the highest metal concentrations; metal fractionation and biotest confirmed that Zn contributes to sediment toxicity.

  15. Analyses of native water, core material, and elutriate samples collected from the Atchafalaya River and Atchafalaya Bay

    USGS Publications Warehouse

    Demas, Charles R.

    1977-01-01

    During October and November 1976 the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, collected native water and core material from 14 sites along the Atchafalya River in Louisiana (from the head of Whiskey Bay Pilot Channel to American Pass) and 5 sites in Atchafalya Bay for evaluation of possible environmental effects of a proposed channel-enlargement project. Core material from all river sites and one bay site was collected to a depth of 50 feet (15 meters). At the remaining bay sites, samples were collected to a depth of less than 6 inches (15 centimeters) using a pipe dredge. Core material and native water were analyzed (separately and as elutriate samples prepared from mixtures) for selected metals, nutrients, organic compounds, and physical characteristics. No interpretation of the data is given. (Woodard-USGS)

  16. A multidisciplinary approach for assessing the toxicity of marine sediments: analysis of metal content and elutriate bioassays using metal bioavailability and genotoxicity biomarkers.

    PubMed

    Frassinetti, Stefania; Pitzalis, Emanuela; Mascherpa, Marco Carlo; Caltavuturo, Leonardo; Morelli, Elisabetta

    2012-01-01

    The goal of this article is to verify the applicability of two different biological assays for studying a coastal area that is subject to anthropogenic inputs. Phytochelatins in the marine diatom Thalassiosira weissflogii were used as a biomarker of metal bioavailability. The frequency of genetic damage in the sensitive D7 strain of the yeast Saccharomyces cerevisiae was used to estimate the mutagenic potential. Biological assays were carried out using sediment elutriates. Sediments were collected at three selected sites located in the Gulf of Follonica (Tuscany, Italy), during a 2-year sampling period: Cala Violina (reference site) and the mouths of the rivers Pecora and Cornia, named sites V, P and C, respectively. The chemical characterization of each site was determined in terms of metal concentrations (As, Cd, Cr, Cu, Ni, Pb), measured in 11 sediment samples for each site. The results showed that metal concentrations in sediments from sites C and P were 2-10 times higher than the reference values (site V, year 2004). In addition, we found generally higher metal concentrations in the 2007 sediments than in the 2008 ones, including those of site V, due to the occurrence of an unexpected pollution event. This enabled us to obtain a pollution gradient to validate the proposed bioassays. In fact, the bioassays showed a potential biological hazard in the 2007 elutriates. Significant mutagenic effects were found in samples exhibiting higher concentrations of Cd and Cr. The induction of phytochelatins in T. weissflogii correlated positively with the Cd concentration in the elutriates.

  17. Horizontal diffusion elutriation: a new size-separation technique for preparation of rodent-respirable fibers for animal testing.

    PubMed

    Zoitos, Bruce K; Andrejcak, Michael J; Boymel, Paul M; Maxim, L Daniel; Niebo, Ron

    2007-01-01

    Short-and long-term animal experiments are used to examine the toxicology and biopersistence of various types of fibers. In order to ensure an adequate exposure dose for testing, modern experimental protocols specify that the exposure aerosol (in an inhalation test) or the fibers (in an intratracheal instillation [IT] test) must contain at least a minimum concentration of long (> 20 mum) rodent-respirable fibers. As produced and handled, most fibers contain a distribution of diameters and lengths, only some of which are both long and rodent-respirable. Therefore, it is necessary to size-separate the fibers to enrich the proportion of long, rodent-respirable fibers in the material to be tested. This article presents a new and relatively simple method for size separation that avoids some of the difficulties associated with other methods. The method, termed horizontal diffusion elutriation (HDE), is illustrated by size-separating refractory ceramic fiber (RCF) and four polycrystalline alumina (PCA) fibers. PMID:17127641

  18. Toxicity assessment of diesel- and metal-contaminated soils through elutriate and solid phase assays with the slime mold Dictyostelium discoideum.

    PubMed

    Rodríguez-Ruiz, Amaia; Dondero, Francesco; Viarengo, Aldo; Marigómez, Ionan

    2016-06-01

    A suite of organisms from different taxonomical and ecological positions is needed to assess environmentally relevant soil toxicity. A new bioassay based on Dictyostelium is presented that is aimed at integrating slime molds into such a testing framework. Toxicity tests on elutriates and the solid phase developmental cycle assay were successfully applied to a soil spiked with a mixture of Zn, Cd, and diesel fuel freshly prepared (recently contaminated) and after 2 yr of aging. The elutriates of both soils provoked toxic effects, but toxicity was markedly lower in the aged soil. In the D. discoideum developmental cycle assay, both soils affected amoeba viability and aggregation, with fewer multicellular units, smaller fruiting bodies and, overall, inhibition of fruiting body formation. This assay is quick and requires small amounts of test soil, which might facilitate its incorporation into a multispecies multiple-endpoint toxicity bioassay battery suitable for environmental risk assessment in soils. Environ Toxicol Chem 2016;35:1413-1421. © 2015 SETAC.

  19. Toxicity assessment of diesel- and metal-contaminated soils through elutriate and solid phase assays with the slime mold Dictyostelium discoideum.

    PubMed

    Rodríguez-Ruiz, Amaia; Dondero, Francesco; Viarengo, Aldo; Marigómez, Ionan

    2016-06-01

    A suite of organisms from different taxonomical and ecological positions is needed to assess environmentally relevant soil toxicity. A new bioassay based on Dictyostelium is presented that is aimed at integrating slime molds into such a testing framework. Toxicity tests on elutriates and the solid phase developmental cycle assay were successfully applied to a soil spiked with a mixture of Zn, Cd, and diesel fuel freshly prepared (recently contaminated) and after 2 yr of aging. The elutriates of both soils provoked toxic effects, but toxicity was markedly lower in the aged soil. In the D. discoideum developmental cycle assay, both soils affected amoeba viability and aggregation, with fewer multicellular units, smaller fruiting bodies and, overall, inhibition of fruiting body formation. This assay is quick and requires small amounts of test soil, which might facilitate its incorporation into a multispecies multiple-endpoint toxicity bioassay battery suitable for environmental risk assessment in soils. Environ Toxicol Chem 2016;35:1413-1421. © 2015 SETAC. PMID:26450765

  20. Analyses of native water, bottom material, elutriate samples, and dredged material from selected southern Louisiana waterways and selected areas in the Gulf of Mexico, 1979-81

    USGS Publications Warehouse

    Lurry, Dee L.

    1983-01-01

    The U.S. Geological Survey was requested by the U.S. Army Corps of Engineers, New Orleans District, to provide water-quality data to evaluate environmental effects of dredging activities in selected reaches of the Calcasieu River in southwestern Louisiana. Samples were collected from the upper and lower Calcasieu River between January 1980 and March 1981. Thirty-three samples (22 native-water and 11 effluent) were collected from eleven dredging sites. In addition, a series of elutriate studies were conducted between July 1979 and July 1981 to determine water quality as a basis for assessing possible environmental effects of proposed dredging activities in the following areas: Grand Bayou and Martins Canal near Happy Jack, unnamed bayou near Port Sulphur, Grand Bayou and Pipeline Canal near Port Sulphur and Bayou des Plantins near Empire; Mississippi River Gulf Outlet and Inner Harbor Navigation Canal; Southwest Pass; Barataria Bay; Atchafalaya Bay at Eugene Island; Calcasieu Ship Channel. Samples of native water and samples of bottom material were collected from 22 different sites and elutriate (mixtures of native water and bottom material) samples were prepared and analyzed. Four proposed ocean-disposal sites were sampled for bottom material only. Samples were analyzed for selected chemical and biological constituents and physical properties. (USGS)

  1. Analyses of water, core material, and elutriate samples collected near New Orleans, Louisiana (Lake Pontchartrain, Louisiana, and vicinity hurricane protection project)

    USGS Publications Warehouse

    Leone, Harold L.

    1976-01-01

    When a hurricane approaches the New Orleans, Louisiana area, the accompanying tides and heavy rainfall increase the level of water in Lake Borgne, Mississippi Sound, and Lake Pontchartrain and pose a major threat of water damage to the populated areas. During Hurricane Betsy (1965), for example, the level of Lake Pontchartrain rose as much as 13 feet. Nineteen core-material-sampling sites were chosen by the U.S. Army Corps of Engineers as possible borrow areas for fill material to be used in levee construction for flood protection around Lake Pontchartrain. Twenty-three receiving-water sites were also selected to represent the water that will contact the proposed levees. Selected nutrients, metals, pesticides, and other organic constituents were analyzed from bed-material and native-water samples as well as upon elutriate samples of specific core material-receiving water systems. The results of these analyses are presented without interpretation. (Woodard-USGS)

  2. Comparison of whole-sediment, elutriate and pore-water exposures for use in assessing sediment-associated organic contaminants in bioassays

    SciTech Connect

    Harkey, G.A. Clemson Univ., Pendleton, SC ); Landrum, P.F. ); Klaine, S.J. )

    1994-08-01

    Bioassays have frequently been used as tools to simulate exposure of benthos to sediment-associated contaminants in hazard assessments. Due to the problems involved with estimating bioavailability in whole-sediment bioassays, aqueous fractions such as elutriates and pore water have been substituted for whole-sediment exposures. The objective of this research was to compare and evaluate the bioavailability of representative neutral hydrophobic contaminants in whole sediments and in aqueous extracts of whole sediment in simultaneous bioassays, using three representative indicator species, Diporeia spp., Chironomus riparius larvae, and Lumbriculus variegatus. Aqueous extracts of whole sediment did not accurately represent the exposure observed in whole sediment. Generally, the aqueous extracts underexposed organisms compared to whole sediment, even after adjusting accumulation to the fraction of organic carbon in the test media. Accumulation comparisons among whole-sediment, elutriate, and pore-water exposures depended on sampling time. At some sampling times for some contaminants, differences in accumulation between a particular aqueous extract and whole sediment were not significant; however, these similarities were not observed for all species at the particular sampling time. Bioaccumulation and contaminant clearance data suggest that a number of factors such as the indicator species, exposure media, and chemical/physical properties of individual contaminants are responsible for the accumulation differences observed among the tested media. Normalizing bioaccumulation to the amount of organic carbon in a source compartment adjusted for bioavailability differences of only some contaminants. The authors suggest that the bioavailability of contaminants such as those tested cannot be accurately predicted in bioassays that expose organisms to aqueous representations of whole sediment.

  3. Elutriated stem cells derived from the adult bone marrow differentiate into insulin-producing cells in vivo and reverse chemical diabetes.

    PubMed

    Iskovich, Svetlana; Goldenberg-Cohen, Nitza; Stein, Jerry; Yaniv, Isaac; Fabian, Ina; Askenasy, Nadir

    2012-01-01

    An ongoing debate surrounds the existence of stem cells in the adult endowed with capacity to differentiate into multiple lineages. We examined the possibility that adult bone marrow cells participate in recovery from chemical diabetes through neogenesis of insulin-producing cells. Small-sized cells negative for lineage markers derived by counterflow centrifugal elutriation from the bone marrow were transplanted into mice made diabetic with streptozotocin and sublethal irradiation. These cells homed efficiently to the injured islets and contributed to tissue revascularization. Islet-homed CD45-negative donor cells identified by sex chromosomes downregulated GFP, expressed PDX-1 and proinsulin, and converted the hormone precursor to insulin. An estimated 7.6% contribution of newly formed insulin-producing cells to islet cellularity increased serum insulin and stabilized glycemic control starting at 5 weeks post-transplant and persisting for 20 weeks. Newly differentiated cells displayed normal diploid genotype and there was no evidence of fusion between the grafted stem cells or their myeloid progeny and injured β-cells. Considering the extensive functional incorporation of insulin-producing donor cells in the injured islets, we conclude that the adult bone marrow contains a subset of small cells endowed with plastic developmental capacity.

  4. Brucella abortus as a potential vaccine candidate: induction of interleukin-12 secretion and enhanced B7.1 and B7.2 and intercellular adhesion molecule 1 surface expression in elutriated human monocytes stimulated by heat-inactivated B. abortus.

    PubMed Central

    Zaitseva, M; Golding, H; Manischewitz, J; Webb, D; Golding, B

    1996-01-01

    Development of a vaccine which is capable of generating a strong cellular immune response associated with gamma interferon (IFN-gamma) production and cytotoxic T-cell development requires that the immunogen be capable of inducing the secretion of interleukin-12 (IL-12), which is a pivotal factor for the differentiation of Th1 or Tc1 cells. We have previously shown that the heat-inactivated gram-negative bacterium Brucella abortus can induce IFN-gamma secretion by T cells. In the present study, we demonstrate that B. abortus and lipopolysaccharide (LPS) from B. abortus can induce IL-12 p40 mRNA expression and protein secretion by human elutriated monocytes (99% pure). p40 mRNA was detected within 4 h, and p40 protein could be measured at 24 h. This induction was abrogated by anti-CD14 monoclonal antibody, suggesting that monocytes recognize B. abortus via their receptor for LPS. The biological activity of IL-12 secreted by B. abortus-stimulated monocytes was demonstrated by its ability to upregulate IFN-gamma mRNA expression in T cells separated from monocytes and B. abortus by a transwell membrane. The B. abortus-induced IL-12 also enhanced NK cytolytic activity against K562 target cells. B. abortus was shown to rapidly increase the expression of the costimulatory molecules B7.1 and B7.2 and intercellular adhesion molecule 1 on human monocytes. Together, these data indicate that B. abortus can directly activate human monocytes and provide the cytokine milieu which would direct the immune response towards Th1-Tc1 differentiation. PMID:8757841

  5. COPPER UPTAKE BY LOBSTER HEPATOPANCREATIC CELLS ISOLATED BY A CENTRIFUGAL ELUTRIATION TECHNIQUE. (R823068)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  6. A COMPARISON OF BULK SEDIMENT TOXICITY TESTING METHODS AND SEDIMENT ELUTRIATE TOXICITY

    EPA Science Inventory

    Bulk sediment toxicity tests are routinely used to assess the level and extent of contamination in natural sediments. While reliable, these tests can be resource intensive, requiring significant outlays of time and materials. The purpose of this study was to compare the results ...

  7. Recirculating elutriator for extracting gastrointestinal nematode larvae from pasture herbage samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gastrointestinal nematode parasites present an important limitation to ruminant production worldwide. Methods for quantifying infective larvae of GIN on pastures are generally tedious, time-consuming, and require bulky equipment set-ups. This limitation to expedient data collection is a bottleneck...

  8. A CENTRIFUGAL ELUTRIATION METHOD TO ISOLATE AND PURIFY DISTINCT CELL POPULATIONS FROM A HETEROGENEOUS INVERTEBRATE GASTROINTESTINAL ORGAN FOR PHYSIOLOGICAL STUDIES. (R823068)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  9. Comparison of soil toxicity estimates using lettuce seeds and soil ciliates

    SciTech Connect

    Pratt, J.R.; Bowers, N.J.; Beeson, D.; Lewis, M.

    1995-12-31

    Contaminants in soils affect microbes, fungi, animals and plants, yet few tests species are available to assess soil toxicity. Many soil microbes are adapted to grow rapidly after wetting and can be used to assess contaminants in the soil solution. The authors compared the growth of the soil ciliate, Colpoda inflata, to germination and growth of lettuce (Lactuca saliva) seeds exposed to water elutriate from twenty-five soil samples suspected of being toxic. Exposure to full strength elutriate resulted in significant (p < 0.05) reduction in seed germination in 15 of 25 elutriates, five of which produced no germination. Growth (total dry weight) of the seeds that germinated was unaffected. Growth of C. inflata was reduced by more than 70% in 12 of 25 elutriates. All C. inflata were killed following exposure to the same five elutriates that resulted in no seed germination. The ciliate growth test identified three elutriates as toxic that were not identified as toxic by the seed germination test. Conversely, the seed germination test identified seven elutriates as toxic that were not toxic in the ciliate growth test. Stepwise regression using concentrations of nine metals in the soil elutriates indicated that cadmium, copper, and arsenic significantly reduced C. inflata growth (r{sup 2} = 0.77), whereas copper, arsenic, and lead significantly reduced lettuce seed germination (r{sup 2} = 0.61). The plant and microbe models showed different responses, and there was a greater correspondence between elutriate chemistry and ciliate response than in the plant tests.

  10. Thyroid hormone disrupting activities of sediment from the Guanting Reservoir, Beijing, China.

    PubMed

    Li, Jian; Li, Morui; Ren, Shujuan; Feng, Chenglian; Li, Na

    2014-06-15

    In the present study, yeast bioassays were used to evaluate and characterize the thyroid receptor (TR) disrupting activities of the organic extracts and elutriates of the sediments from the Guanting Reservoir, Beijing, China. An accelerated solvent extraction was used to separate the organic extracts, which were subjected to a yeast bioassay. The organic extracts could affect thyroid hormone signaling by decreasing the binding of the thyroid hormone. The TR antagonistic activity equivalents (TEQbio) referring to amiodarone hydrochloride were calculated and the observed TEQbio-organic extracts ranged from 25.4 ± 3.7 to 176.9 ± 18.0 μg/g. Elutriate toxicity tests using the modified yeast bioassay revealed that the elutriates also significantly antagonized the TR, with the TEQbio-elutriates ranging from N.D. to 7.8 ± 0.8 μg/L. To characterize the toxic compounds, elutriates were extracted by using a C18 cartridge or treated with ethylenediaminetetraacetic acid (EDTA, 30 mg/L). The results suggested that the addition of EDTA eliminated over 74.3% of the total effects, and the chemical analysis revealed that heavy metals, some of which exhibited TR disrupting potency, for example Zn and Cd, were detectable with higher concentrations in the elutriates. Thus, the cause(s) of toxicity in the elutriate appear to be partly related to the heavy metals.

  11. 30 CFR 90.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... sampler with a four channel horizontal elutriator developed by the Mining Research Establishment of the..., tunnels, excavations, and other property, real or personal, placed upon, under, or above the surface...

  12. 30 CFR 90.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... sampler with a four channel horizontal elutriator developed by the Mining Research Establishment of the..., tunnels, excavations, and other property, real or personal, placed upon, under, or above the surface...

  13. 30 CFR 90.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... sampler with a four channel horizontal elutriator developed by the Mining Research Establishment of the..., tunnels, excavations, and other property, real or personal, placed upon, under, or above the surface...

  14. Separation of organic ion exchange resins from sludge -- engineering study

    SciTech Connect

    Duncan, J.B.

    1998-08-25

    This engineering study evaluates the use of physical separation technologies to separate organic ion exchange resin from KE Basin sludge prior to nitric acid dissolution. This separation is necessitate to prevent nitration of the organics in the acid dissolver. The technologies under consideration are: screening, sedimentation, elutriation. The recommended approach is to first screen the Sludge and resin 300 microns then subject the 300 microns plus material to elutriation.

  15. Comparative evaluation of soil toxicity using lettuce seeds and soil ciliates

    SciTech Connect

    Bowers, N.; Pratt, J.R.; Beeson, D.; Lewis, M.

    1997-02-01

    The toxicity of elutriates from 25 putatively contaminated soils was evaluated using the standard seed (Lactuca sativa) germination test and a recently developed soil ciliate (Colpoda inflata) growth test. Correspondence in the identification of presence or absence of toxicity in the 25 soil elutriates between the two tests was 60% and concordance in ranking of toxicity between the two tests was significant (p < 0.05) using Spearman`s rank correlation test (r{sub s} = 0.3831). Stepwise multiple regression analysis of toxicity results against soil elutriate chemistry indicated that pH explained the greatest amount of variation in response in both tests, despite high concentrations of several metals in the elutriates. For the germination test, a multiple regression model that included pH and cadmium explained 58.5% of response variation, whereas over 83% of response variation in the ciliate growth test could be explained by pH, copper, and cadmium. Differences in the response of the plant and protozoan models appeared to be due primarily to differences in their sensitivity to elutriate pH. In addition to better correspondence between elutriate chemistry and ciliate response compared to the seed germination test, lower response variability associated with the measure of ciliate growth compared with seed germination provided greater statistical sensitivity for detecting toxic effects.

  16. Toxicological evaluation of the effects of waste-to-energy ash-concrete on two marine species

    SciTech Connect

    Hamilton, K.L.; Nelson, W.G.; Curley, J.L. )

    1993-10-01

    The toxicological effects of waste-to-energy ash-concrete on survivorship, growth, and fecundity (end-point parameters) of Mysidopsis bahia and on survivorship and growth of Menidia beryllina were evaluated with the 7-d static-renewal toxicity test. Leachate and elutriate solutions were prepared from experimental ash-concrete test cylinders constructed from concrete with additions of either bottom ash (mix BA), mixed bottom ash and scrubber residue, or mixed bottom ash and fly ash (60:40%, mix BA:FA). Control experiments with concrete (without ash) and pH (7-9.5) were conducted to assess any toxic effects of the stabilization process. pH did not affect end-point parameters of Mysidopsis bahia or Menidia beryllina. However, the 100% elutriate solution made from concrete reduced survivorship of Mysidopsis bahia. For experiments with ash-concrete test cylinders with the BA mixture, 10-d leachate solution reduced survivorship of Mysidopsis bahia and the 100% elutriate solutions reduced survivorship of Mysidopsis bahia and Manidia beryllina. With the BA:SR mixture, the 100 and 50% elutriate solutions reduced survivorship of Menidia beryllina. The BA:FA 10- and 5-d leachate solutions and the 100, 50, and 25% elutriate solutions reduced survivorship of Menidia beryllina. The BA:FA 10- and 5-d leachate solutions and the 100, 50, 25% elutriate solutions reduced survivorship of Mysidopsis bahia.

  17. Evaluation of the toxicity of two soils from Jales Mine (Portugal) using aquatic bioassays.

    PubMed

    Loureiro, Susana; Ferreira, Abel L G; Soares, Amadeu M V M; Nogueira, António J A

    2005-10-01

    Soil contamination can be one path for streams and groundwater contamination. As a complement of chemical analysis and total contaminants determination, bioassays can provide information on the bioavailable fraction of chemical compounds, focusing on the retention and habitat function of soils. In this study the evaluation of the toxicity of two soils from the abandoned Jales Mine (Portugal) regarded both functions. The buffer capacity of soils was tested with bioassays carried out using the cladoceran Daphnia magna and the marine bacteria Vibrio fischeri. The habitat function of soils was evaluated with the reproduction bioassay with the collembolan Folsomia candida. The Microtox solid-phase test was performed with V. fischeri using soil as test medium, and soil elutriates were extracted to perform the Microtox basic test, and an immobilization and reproduction bioassay with D. magna. The marine bacteria showed high sensitivity to the soil with low heavy metal content (JNC soil) and to JNC soil elutriates, while the soil with highest heavy metal content (JC soil) or soil elutriates exposure did not cause any toxic effect. In the bioassays with D. magna, organisms showed sensitivity to JNC and also to JC soil elutriates. Both mobilization and reproduction features were inhibited. The bioassay with F. candida did not reflect any influence of the contaminants on their reproduction. Although JNC soil presented lower heavy metal contents, elutriates showed different patterns of contamination when compared to JC soil and elutriates, which indicates different retention and buffer capacities between soils. Results obtained in this study underlined the sensitivity and importance of soil elutriate bioassays with aquatic organisms in the evaluation strategy in soil ERA processes.

  18. Evaluation of dredged material proposed for ocean disposal from Buttermilk Channel, New York

    SciTech Connect

    Gardiner, W.W.; Barrows, E.S.; Antrim, L.D; Gruendell, B.D.; Word, J.Q.; Tokos, J.J.S.

    1996-08-01

    Buttermilk Channel was one of seven waterways that was sampled and evaluated for dredging and sediment disposal. Sediment samples were collected and analyses were conducted on sediment core samples. The evaluation of proposed dredged material from the channel included bulk sediment chemical analyses, chemical analyses of site water and elutriate, water column and benthic acute toxicity tests, and bioaccumulation studies. Individual sediment core samples were analyzed for grain size, moisture content, and total organic carbon. A composite sediment samples, representing the entire area proposed for dredging, was analyzed for bulk density, polynuclear aromatic hydrocarbons, and 1,4-dichlorobenzene. Site water and elutriate were analyzed for metals, pesticides, and PCBs.

  19. Settling behaviour of concentrated dispersions and some volcanological applications

    NASA Astrophysics Data System (ADS)

    Druitt, T. H.

    1995-04-01

    Experiments have been carried out on the settling of non-aggregating, poorly sorted aqueous dispersions laced with lowdensity particles in order to gain insight into the sedimentation behaviour of volcaniclastic flows which contain pumice. Two poorly sorted dispersions of silicon carbide particles with continuous size distributions were studied; plastic beads were added as a light component. Experiments were carried out at solids concentrations between 10 and 60 vol%. Dispersions of low concentration generated normally graded deposits in which particles of different densities were in approximate hydraulic equivalence. Above a critical concentration (45 to 60% depending on the grain-size distribution) particle segregation was suppressed, and the dispersion settled to form a virtually ungraded bed. Hindered settling at intermediate concentrations generated normally graded deposits with elutriation pipes, "floating" rafts of plastic, and capping layers of fines elutriated by escaping pore fluid. Buoyancy forces resulted in strong hydraulic inequivalence between light and dense components in the deposits from intermediate concentrations. Two mechanisms of elutriation-pipe growth were observed. At intermediate concentrations, pipes grew progressively upwards in the deposit as the latter aggraded, whereas at high concentrations they nucleated and grew uniformly throughout the whole dispersion. Elutriation pipes form readily during sedimentation of some poorly sorted aqueous dispersions; the presence of elutriation pipes cannot be used alone to distinguish between deposits of epiclastic and pyroclastic flows. Reverse grading of pumice, pumice rafts, elutriation pipes, and layers of elutriated fines should characterise deposits from pumice-rich submarine mass flows. Despite differences in the fluid phase, the experiments also have implications for fluidization mechanisms in pyroclastic flows. Hindered settling of a concentrated, poorly sorted dispersion is a type of self

  20. Separation and characterization of respirable amphibole fibers from Libby, Montana.

    PubMed

    Webber, James S; Blake, David J; Ward, Tony J; Pfau, Jean C

    2008-06-01

    The vermiculite mine in Libby, Montana, was in operation for over 70 yr and was contaminated with asbestos-like amphibole fibers. The mining, processing, and shipping of this vermiculite led to significant fiber inhalation exposure throughout the community, and residents of Libby have developed numerous pulmonary diseases such as lung cancer and mesothelioma. The present study describes the separation of Libby 6-mix into respirable and nonrespirable size fractions by means of aqueous elutriation. The elutriator, designed to separate fibers with aerodynamic diameters smaller than 2.5 microm (respirable) from larger fibers, used an upward flow rate of 3.4 x 10(- 4) cm s(-1). The resultant respirable fraction constituted only 13% of the raw Libby 6-mix mass, and less than 2% of the fibers in the elutriated fraction had aerodynamic diameters exceeding 2.5 microm. Surface area of the elutriated fibers was 5.3 m(- 2) g(-1), compared to 0.53 m(-2) g(-1) for the raw fibers. There were no detectable differences in chemical composition between the larger and smaller fibers. Such harvesting of respirable fractions will allow toxicological studies to be conducted within a controlled laboratory setting, utilizing fiber sizes that may more accurately simulate historical exposure of Libby residents' lungs. Importantly, this work describes a method that allows the use of material enriched in more uniform respirable material than raw Libby 6-mix, making comparisons with other known fiber preparations more valid on a mass basis.

  1. Cellular and inflammatory responses in bronchoalveolar lavage and lungs in rats after intratracheal instillation of Libby amphibole or amosite asbestos

    EPA Science Inventory

    The high incidence of asbestos-related disease in residents of Libby, Montana, is associated with the mining of asbestos-contaminated vermiculite, but the etiology of disease related to Libby amphibole asbestos (LA) exposure is unclear. In this study, water elutriation was used t...

  2. 40 CFR 230.61 - Chemical, biological, and physical evaluation and testing.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... be obtained from bioassays in lieu of chemical tests. (2) Water column effects. (i) Sediments... locations within the sediment. An elutriate test may be used to predict the effect on water quality due to release of contaminants from the sediment to the water column. However, in the case of fill...

  3. 40 CFR 230.61 - Chemical, biological, and physical evaluation and testing.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... be obtained from bioassays in lieu of chemical tests. (2) Water column effects. (i) Sediments... locations within the sediment. An elutriate test may be used to predict the effect on water quality due to release of contaminants from the sediment to the water column. However, in the case of fill...

  4. 40 CFR 230.61 - Chemical, biological, and physical evaluation and testing.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... be obtained from bioassays in lieu of chemical tests. (2) Water column effects. (i) Sediments... locations within the sediment. An elutriate test may be used to predict the effect on water quality due to release of contaminants from the sediment to the water column. However, in the case of fill...

  5. Utilization of a duckweed bioassay to evaluate leaching of heavy metals in smelter contaminated soils

    SciTech Connect

    Youngman, A.L.; Lydy, M.J.; Williams, T.L.

    1998-12-31

    The purpose of this study was to determine whether a duckweed bioassay could be used to evaluate the downward migration of heavy metals in smelter soils. The duckweed bioassay was initially used to evaluate elutriates prepared from samples of smelter soils. These initial tests verified that the elutriates would elicit toxic responses. Elutriate testing was followed with an evaluation of leachate from untreated soil cores or soil cores that had been amended with organic matter either unplanted or planted to a grass-forb seed mixture. There was an inverse linear relationship between heavy-metal concentrations in leachate and NOEC and IC{sub 50} values expressed as percentages among all soil cores. Based on these preliminary duckweed bioassays, there were no differences between soil types or organic amended or non-amended soil, but leachate from vegetated soil cores were less toxic than were leachates from non-vegetated soil cores. Overall, the duckweed bioassays were useful in detecting heavy metal availability in elutriate and leachate samples from smelter soils.

  6. Comparing milled fiber, Quebec ore, and textile factory dust: has another piece of the asbestos puzzle fallen into place?

    PubMed

    Berman, D Wayne

    2010-01-01

    Results of a meta-analysis indicate that the variation in potency factors observed across published epidemiology studies can be substantially reconciled (especially for mesothelioma) by considering the effects of fiber size and mineral type, but that better characterization of historical exposures is needed before improved exposure metrics potentially capable of fully reconciling the disparate potency factors can be evaluated. Therefore, an approach for better characterizing historical exposures, the Modified Elutriator Method (MEM), was evaluated to determine the degree that dusts elutriated using this method adequately mimic dusts generated by processing in a factory. To evaluate this approach, elutriated dusts from Grade 3 milled fiber (the predominant feedstock used at a South Carolina [SC] textile factory) were compared to factory dust collected at the same facility. Elutriated dusts from chrysotile ore were also compared to dusts collected in Quebec mines and mills. Results indicate that despite the substantial variation within each sample set, elutriated dusts from Grade 3 fiber compare favorably to textile dusts and elutriated ore dusts compare to dusts from mines and mills. Given this performance, the MEM was also applied to address the disparity in lung cancer mortality per unit of exposure observed, respectively, among chrysotile miners/millers in Quebec and SC textile workers. Thus, dusts generated by elutriation of stockpiled chrysotile ore (representing mine exposures) and Grade 3 milled fiber (representing textile exposures) were compared. Results indicate that dusts from each sample differ from one another. Despite such variation, however, the dusts are distinct and fibers in Grade 3 dusts are significantly longer than fibers in ore dusts. Moreover, phase-contrast microscopy (PCM) structures in Grade 3 dusts are 100% asbestos and counts of PCM-sized structures are identical, whether viewed by PCM or transmission electron microscope (TEM). In

  7. Relationship between fluid bed aerosol generator operation and the aerosol produced

    SciTech Connect

    Carpenter, R.L.; Yerkes, K.

    1980-12-01

    The relationships between bed operation in a fluid bed aerosol generator and aerosol output were studied. A two-inch diameter fluid bed aerosol generator (FBG) was constructed using stainless steel powder as a fluidizing medium. Fly ash from coal combustion was aerosolized and the influence of FBG operating parameters on aerosol mass median aerodynamic diameter (MMAD), geometric standard deviation (sigma/sub g/) and concentration was examined. In an effort to extend observations on large fluid beds to small beds using fine bed particles, minimum fluidizing velocities and elutriation constant were computed. Although FBG minimum fluidizing velocity agreed well with calculations, FBG elutriation constant did not. The results of this study show that the properties of aerosols produced by a FBG depend on fluid bed height and air flow through the bed after the minimum fluidizing velocity is exceeded.

  8. Results of bulk sediment analysis and bioassay testing on selected sediments from Oakland Inner Harbor and Alcatraz disposal site, San Francisco, California

    SciTech Connect

    Word, J Q; Ward, J A; Woodruff, D L

    1990-09-01

    The Battelle/Marine Sciences Laboratory (MSL) was contracted by the US Army Corps of Engineers, San Francisco District, to perform bulk sediment analysis and oyster larvae bioassays (elutriate) on sediments from Inner Oakland Harbor, California. Analysis of sediment characteristics by MSL indicated elevated priority pollutants, PAHs, pesticides, metals, organotins, and oil and grease concentrations, when compared to Alcatraz Island Dredged Material Disposal Site sediment concentrations. Larvae of the Pacific oyster, Crassostrea gigas, were exposed to seawater collected from the Alcatraz Island Site water, and a series of controls using water and sediments collected from Sequim Bay, Washington. Exposure of larvae to the Alcatraz seawater and the 50% and 100% elutriate concentrations from each Oakland sediment resulted in low survival and a high proportion of abnormal larvae compared to Sequim Bay control exposures. MSL identified that field sample collection, preservation, and storage protocols used by Port of Oakland contractors were inconsistent with standard accepted practices. 23 refs., 10 figs., 40 tabs.

  9. Evaluation of dredged material proposed for ocean disposal from Shark River Project area

    SciTech Connect

    Antrim, L.D.; Gardiner, W.W.; Barrows, E.S.; Borde, A.B.

    1996-09-01

    The objective of the Shark River Project was to evaluate proposed dredged material to determine its suitability for unconfined ocean disposal at the Mud Dump Site. Tests and analyses were conducted on the Shark River sediments. The evaluation of proposed dredged material consisted of bulk sediment chemical and physical analysis, chemical analyses of dredging site water and elutriate, water-column and benthic acute toxicity tests, and bioaccumulation tests. Individual sediment core samples collected from the Shark River were analyzed for grain size, moisture content, and total organic carbon (TOC). One sediment composite was analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl (PCB) congeners, polynuclear aromatic hydrocarbons (PAHs), and 1,4- dichlorobenzene. Dredging site water and elutriate, prepared from suspended-particulate phase (SPP) of the Shark River sediment composite, were analyzed for metals, pesticides, and PCBs. Benthic acute toxicity tests and bioaccumulation tests were performed.

  10. Contribution of ammonia, metals, and nonpolar organic compounds to the toxicity of sediment interstitial water from an Illinois River tributary

    SciTech Connect

    Schubauer-Berigan, M.K.; Ankley, G.T.

    1991-01-01

    Toxicity of Illinois River bulk sediment, sediment interstitial (pore) water and elutriates to the oligochaete Lumbriculus variegatus, fathead minnow (Pimephales promelas) and the amphipod Hyalella azteca was compared to determine the most representative aqueous fraction for toxicity identification evaluation (TIE) studies. Toxicity of pore water corresponded better than elutriates to bulk sediment toxicity. Subsequent TIE procedures conducted with the cladoceran Ceriodaphnia dubia indicated that ammonia, metals and nonpolar organic compounds (nonylphenols, polycyclic aromatic hydrocarbons, benzenes, long-chain hydrocarbons) were responsible for toxicity of the sediment pore water. Results of TIE manipulations also suggested that methods for recovering pore water that include filtration may eliminate, a priori, a major component of the sediment contaminants responsible for toxicity.

  11. Fines in fluidized bed silane pyrolysis

    NASA Technical Reports Server (NTRS)

    Hsu, G.; Hogle, R.; Rohatgi, N.; Morrison, A.

    1984-01-01

    Silicon deposition on silicon seed particles by silane pyrolysis in a fluidized-bed reactor is investigated as a low-cost, high-throughput method to produce high-purity polysilicon for solar-cell applications. Studies of fines, particles 0.1-10 microns diam, initiated from homogeneous decomposition in the reactor were conducted using 2 and 6-in-diam fluidized beds. The studies show functional dependences of fines elutriation on silane feed concentration, temperature, gas velocity, and bubble size. The observation that the fines elutriation is generally below 10 percent of the silicon-in-silane feed is attributed to scavenging by large particles in an environment of less free space for homogeneous nucleation. Preliminary results suggest that, with proper conditions and distributor design, high-silane-concentration (over 50 percent SiH4 in H2) feed may be used.

  12. Endotoxins in baled cottons and airborne dusts in textile mills in the People's Republic of China.

    PubMed Central

    Olenchock, S A; Christiani, D C; Mull, J C; Ye, T T; Lu, P L

    1983-01-01

    Bulk cotton samples and airborne vertical elutriated cotton dusts were obtained from textile mills in Shanghai, People's Republic of China. Analysis of endotoxin contents revealed that baled cottons which were grown in different countries varied in endotoxin contamination. The two textile mills, which operated at similar overall airborne dust levels, differed markedly in the levels of airborne endotoxins. The data suggest that the biological activity or "toxicity" of airborne cotton dusts may not be correlated directly with gravimetric dust levels. PMID:6639029

  13. Fluidized bed boiler feed system

    DOEpatents

    Jones, Brian C.

    1981-01-01

    A fluidized bed boiler feed system for the combustion of pulverized coal. Coal is first screened to separate large from small particles. Large particles of coal are fed directly to the top of the fluidized bed while fine particles are first mixed with recycled char, preheated, and then fed into the interior of the fluidized bed to promote char burnout and to avoid elutriation and carryover.

  14. Water quality, organic chemistry of sediment, and biological conditions of streams near an abandoned wood-preserving plant site at Jackson, Tennessee

    USGS Publications Warehouse

    Bradfield, A.D.; Flexner, N.M.; Webster, D.A.

    1993-01-01

    An investigation of water quality, organic sediment chemistry, and biological conditions of streams near an abandoned wood-preserving plant site at Jackson, Tennessee, was conducted during December 1990. The study was designed to assess the extent of possible contamination of water and biota in the streams from creosote-related discharge originating at this Superfund site. Central Creek, adjacent to the plant, had degraded water quality and biological conditions. Water samples from the most downstream station on Central Creek contained 30 micrograms per liter of pentachlorophenol, which exceeds the State's criterion maximum concentrations of 9 micrograms per liter for fish and aquatic life. Bottom-sediment samples from stations on Central Creek contained concentrations of acenaphthene, napthalene, and phenanthrene ranging from 1,400 to 2,500 micrograms per kilogram. Chronic or acute toxicity resulted during laboratory experiments using test organisms exposed to creosote-related contaminants. Sediment elutriate samples from Central Creek caused slightly to highly toxic effects on Ceriodaphnia dubia. Pimephales promelas, and Photobacterium phosphoreum. Fish-tissue samples from this station contained concentrations of naphthalene. dibenzofuran, fluorene, and phenanthrene ranging from 1.5 to 3.9 micrograms per kilogram Blue-green algae at this station represented about 79 percent of the organisms counted, whereas diatoms accounted for only 11 percent. Benthic invertebrate and fish samples from Central Creek had low diversity and density. Sediment samples from a station on the South Fork Forked Deer River downstream from its confluence with Central Creek contained concentrations of acenaphthene, anthracene, chrysene, fluoranthene, fluorene, pyrere, and phenanthrene ranging from 2,800 to 69,000 micrograms per kilogram. Sediment elutriate samples using water as elutriate from this station contained concentrations of extractable organic compounds ranging from an estimated

  15. Nuclear waste solidification

    DOEpatents

    Bjorklund, William J.

    1977-01-01

    High level liquid waste solidification is achieved on a continuous basis by atomizing the liquid waste and introducing the atomized liquid waste into a reaction chamber including a fluidized, heated inert bed to effect calcination of the atomized waste and removal of the calcined waste by overflow removal and by attrition and elutriation from the reaction chamber, and feeding additional inert bed particles to the fluidized bed to maintain the inert bed composition.

  16. Impurities in pretreated biowaste for co-digestion: A determination approach.

    PubMed

    Jank, Anna; Müller, Wolfgang; Waldhuber, Sebastian; Gerke, Frédéric; Ebner, Christian; Bockreis, Anke

    2016-06-01

    Although the mechanical treatment of source separated organic waste typically includes processing steps to remove impurities like plastic bags, smaller particles like glass, stones or sand are often not sufficiently removed. These particles lead to plant malfunctions, increased equipment abrasion and accumulation in the digester. It is possible to remove these small impurities before or during the fermentation process but this requires additional equipment at the waste treatment facilities. For pretreated biowaste with fairly low concentrations of impurities and small particle sizes no appropriate method was found in literature to determine these particles. Therefore various approaches to develop an appropriate method were tested and finally one method was selected. Sample mass calculation showed that for the determination of impurities >2mm a sample mass of about 6kg is required to receive statistically sound result. Firstly an elutriation step is used to concentrate the impurities in a sinking fraction, still containing some organic material. The elutriated material is then dried. After drying the elutriated material, impurities can be fairly easily sorted manually. The elutriation process is applicable for the determination of impurities >1mm. Due to the difficult manual sorting of particles <2mm and the reduced sample mass required for the determination of particles <2mm, these particles are determined by a different procedure: A sample mass of about 1kg is dried and combusted in a muffle furnace. The remaining ashes are sieved from 2 to 0.06mm. Particles <0.06mm were not considered as impurities. The data regarding the impurities content and particle size distribution in food- and biowaste are required for assessing separation options as well as the behavior of stones or sand in the digester. This allows describing the quality of the pretreated biowaste. Furthermore the need to adopt or improve the existing pretreatment can be identified and the impact to the

  17. An integrated system for synchronous culture of animal cells under controlled conditions.

    PubMed

    Mendoza-Pérez, Elena; Hernández, Vanessa; Palomares, Laura A; Serrato, José A

    2016-01-01

    The cell cycle has fundamental effects on cell cultures and their products. Tools to synchronize cultured cells allow the study of cellular physiology and metabolism at particular cell cycle phases. However, cells are most often arrested by methods that alter their homeostasis and are then cultivated in poorly controlled environments. Cell behavior could then be affected by the synchronization method and culture conditions used, and not just by the particular cell cycle phase under study. Moreover, only a few viable cells are recovered. Here, we designed an integrated system where a large number of cells from a controlled bioreactor culture is separated by centrifugal elutriation at high viabilities. In contrast to current elutriation methods, cells are injected directly from a bioreactor into an injection loop, allowing the introduction of a large number of cells into the separation chamber without stressful centrifugation. A low pulsation peristaltic pump increases the stability of the elutriation chamber. Using this approach, a large number of healthy cells at each cell cycle phase were obtained, allowing their direct inoculation into fully instrumented bioreactors. Hybridoma cells synchronized and cultured in this system behaved as expected for a synchronous culture. PMID:27625207

  18. An integrated system for synchronous culture of animal cells under controlled conditions.

    PubMed

    Mendoza-Pérez, Elena; Hernández, Vanessa; Palomares, Laura A; Serrato, José A

    2016-01-01

    The cell cycle has fundamental effects on cell cultures and their products. Tools to synchronize cultured cells allow the study of cellular physiology and metabolism at particular cell cycle phases. However, cells are most often arrested by methods that alter their homeostasis and are then cultivated in poorly controlled environments. Cell behavior could then be affected by the synchronization method and culture conditions used, and not just by the particular cell cycle phase under study. Moreover, only a few viable cells are recovered. Here, we designed an integrated system where a large number of cells from a controlled bioreactor culture is separated by centrifugal elutriation at high viabilities. In contrast to current elutriation methods, cells are injected directly from a bioreactor into an injection loop, allowing the introduction of a large number of cells into the separation chamber without stressful centrifugation. A low pulsation peristaltic pump increases the stability of the elutriation chamber. Using this approach, a large number of healthy cells at each cell cycle phase were obtained, allowing their direct inoculation into fully instrumented bioreactors. Hybridoma cells synchronized and cultured in this system behaved as expected for a synchronous culture.

  19. Evaluation of the threat of marine CO2 leakage-associated acidification on the toxicity of sediment metals to juvenile bivalves.

    PubMed

    Basallote, M Dolores; Rodríguez-Romero, Araceli; De Orte, Manoela R; Del Valls, T Ángel; Riba, Inmaculada

    2015-09-01

    The effects of the acidification associated with CO2 leakage from sub-seabed geological storage was studied by the evaluation of the short-term effects of CO2-induced acidification on juveniles of the bivalve Ruditapes philippinarum. Laboratory scale experiments were performed using a CO2-bubbling system designed to conduct ecotoxicological assays. The organisms were exposed for 10 days to elutriates of sediments collected in different littoral areas that were subjected to various pH treatments (pH 7.1, 6.6, 6.1). The acute pH-associated effects on the bivalves were observed, and the dissolved metals in the elutriates were measured. The median toxic effect pH was calculated, which ranged from 6.33 to 6.45. The amount of dissolved Zn in the sediment elutriates increased in parallel with the pH reductions and was correlated with the proton concentrations. The pH, the pCO2 and the dissolved metal concentrations (Zn and Fe) were linked with the mortality of the exposed bivalves.

  20. Effect of dissolved organic matter (DOM) of contrasting origins on Cu and Pb speciation and toxicity to Paracentrotus lividus larvae.

    PubMed

    Sánchez-Marín, Paula; Santos-Echeandía, Juan; Nieto-Cid, Mar; Alvarez-Salgado, Xosé Antón; Beiras, Ricardo

    2010-01-31

    Water samples of contrasting origin, including natural seawater, two sediment elutriates and sewage-influenced seawater, were collected and obtained to examine the effect of the dissolved organic matter (DOM) present on metal bioavailability. The carbon content (DOC) and the optical properties (absorbance and fluorescence) of the coloured DOM fraction (CDOM) of these materials were determined. Cu and Pb complexation properties were measured by anodic stripping voltammetry (ASV) and the effect of DOM on Cu and Pb bioavailability was studied by means of the Paracentrotus lividus embryo-larval bioassay. Sediment elutriates and sewage-influenced water (1) were enriched 1.4-1.7 times in DOC; (2) absorbed and reemitted more light; and (3) presented higher Cu complexation capacities (L(Cu)) than the natural seawater used for their preparation. L(Cu) varied from 0.08 microM in natural seawater to 0.3 and 0.5 microM in sediment elutriates and sewage-influenced water, respectively. Differences in DOC, CDOM and Cu complexation capacities were reflected in Cu toxicity. DOM enriched samples presented a Cu EC(50) of 0.64 microM, significantly higher than the Cu EC(50) of natural and artificial seawater, which was 0.38 microM. The protecting effect of DOM on Cu toxicity greatly disappeared when the samples were irradiated with high intensity UV-light. Cu toxicity could be successfully predicted considering ASV-labile Cu concentrations in the samples. Pb complexation by DOM was only detected in the DOM-enriched samples and caused little effect on Pb EC(50). This effect was contrary for both elutriates: one elutriate reduced Pb toxicity in comparison with the control artificial seawater, while the other increased it. UV irradiation of the samples caused a marked increase in Pb toxicity, which correlated with the remaining DOC concentration. DOM parameters were related to Cu speciation and toxicity: good correlations were found between DOC and Cu EC(50), while L(Cu) correlated

  1. Influence of size-fractioning techniques on concentrations of selected trace metals in bottom materials from two streams in northeastern Ohio

    USGS Publications Warehouse

    Koltun, G.F.; Helsel, Dennis R.

    1986-01-01

    Identical stream-bottom material samples, when fractioned to the same size by different techniques, may contains significantly different trace-metal concentrations. Precision of techniques also may differ, which could affect the ability to discriminate between size-fractioned bottom-material samples having different metal concentrations. Bottom-material samples fractioned to less than 0.020 millimeters by means of three common techniques (air elutriation, sieving, and settling) were analyzed for six trace metals to determine whether the technique used to obtain the desired particle-size fraction affects the ability to discriminate between bottom materials having different trace-metal concentrations. In addition, this study attempts to assess whether median trace-metal concentration in size-fractioned bottom materials of identical origin differ depending on the size-fractioning technique used. Finally, this study evaluates the efficiency of the three size-fractioning techniques in terms of time, expense, and effort involved. Bottom-material samples were collected at two sites in northeastern Ohio: One is located in an undeveloped forested basin, and the other is located in a basin having a mixture of industrial and surface-mining land uses. The sites were selected fir their close physical proximity, similar contributing drainage areas, and the likelihood that trace-metal concentrations in the bottom materials would be significantly different. Statistically significant differences in the concentrations of trace metals were detected between bottom-material samples collected at the two sites when the samples had been size-fractioned by means of air elutriation or sieving. Statistical analyses of samples that had been size fractioned by settling in native water were not measurably different in any of the six trace metals analyzed. Results of multiple comparison tests suggest that differences related to size-fractioning technique were evident in median copper, lead, and

  2. The vertical distribution of selected trace metals and organic compounds in bottom materials of the proposed lower Columbia River export channel, Oregon, 1984

    USGS Publications Warehouse

    Fuhrer, Gregory J.; Horowitz, Arthur J.

    1989-01-01

    A proposal to deepen the lower Columbia River navigation channel in Oregon prompted a study of the vertical distribution of selected trace metals and organic compounds in bottom sediments. These data are needed to evaluate the effects of dredging and disposal operations. Elutriation testing of bottom material indicated chemical concentrations as large as 900 ug/L for barium, 6,500 ug/L for manganese, and 14 ug/L for nickel. The amount of oxygen present during elutriation testing of reduced bottom material was shown to have a negligble effect on manganese elutriate-test concentrations, but it did affect barium and iron concentrations. Sediment-associated organochlorine compounds detected in bottom-sediment core samples were as large as 0.1 ug/kg (micrograms/kilogram) for aldrin, 2.0 ug/kg for chlordane, 27 ug/kg for DDD, 5.0 ug/kg for DDE, 0.2 ug/kg for DDT, 0.2 ug/kg for dieldrin, 37 ug/kg for PCB 's 1.0 ug/kg for PCN 's and 1.0 ug/kg for heptachlor epoxide. Concentrations of cadmium, lead, and zinc in selected cores were found to exceed those of local basalts. Concentrations of cadmium, lead, and zinc were as large as 3.6 ug/g, 26 ug/g, and 210 ug/g respectively. Bottom-sediment concentrations of cadmium , chromium, copper, iron, and zinc associated with the less-than-100-micrometer size fraction are larger than those associated with the greater-than-100-micrometer fraction. (USGS)

  3. Bone Marrow Homing Enriches Stem Cells Responsible for Neogenesis of Insulin-Producing Cells, While Radiation Decreases Homing Efficiency.

    PubMed

    Goldenberg-Cohen, Nitza; Iskovich, Svetlana; Askenasy, Nadir

    2015-10-01

    Small-sized adult bone marrow cells isolated by counterflow centrifugal elutriation and depleted of lineage markers (Fr25lin(-)) have the capacity to differentiate into insulin-producing cells and stabilize glycemic control. This study assessed competitive migration of syngeneic stem cells to the bone marrow and islets in a murine model of chemical diabetes. VLA-4 is expressed in ∼ 25% of these cells, whereas CXCR4 is not detected, however, it is transcriptionally upregulated (6-fold). The possibility to enrich stem cells by a bone marrow homing (BM-H) functional assay was assessed in sequential transplants. Fr25lin(-) cells labeled with PKH26 were grafted into primary myeloablated recipients, and mitotically quiescent Fr25lin(-)PKH(bright) cells were sorted from the bone marrow after 2 days. The contribution of bone marrow-homed stem cells was remarkably higher in secondary recipients compared to freshly elutriated cells. The therapeutic efficacy was further increased by omission of irradiation in the secondary recipients, showing a 25-fold enrichment of islet-reconstituting cells by the bone marrow homing assay. Donor cells identified by the green fluorescent protein (GFP) and a genomic marker in sex-mismatched transplants upregulated PDX-1 and produced proinsulin, affirming the capacity of BM-H cells to convert in the injured islets. There was no evidence of transcriptional priming of freshly elutriated subsets to express PDX-1, insulin, and other markers of endocrine progenitors, indicating that the bone marrow harbors stem cells with versatile differentiation capacity. Affinity to the bone marrow can be used to enrich stem cells for pancreatic regeneration, and reciprocally, conditioning reduces the competitive incorporation in the injured islets.

  4. Meiofaunal community analysis by high-throughput sequencing: comparison of extraction, quality filtering, and clustering methods.

    PubMed

    Brannock, Pamela M; Halanych, Kenneth M

    2015-10-01

    Using molecular tools to examine community composition of meiofauna, animals 45μm to 1mm in size living between sediment grains in aquatic environments, is relatively new in comparison to bacterial and archaeal microbial studies. Although high-throughput molecular approaches are starting to be applied to these ccommunities, effectiveness of different approaches for nucleic acid extraction from meiofauna is poorly known and bioinformatic pipelines vary between studies. Given this situation, there is a need for protocols to be developed that promote consistency in sample collection and processing, sequence quality filtering, and Operational Taxonomic Unit (OTU) clustering methods. Herein, we assess different approaches used for DNA extraction (DNA extracted directly from sediment versus elutriated material retained on a 45μm sieve) as well as how different quality filtering methods of sequences and OTU clustering algorithms impact genetic assessment of meiofauna community composition. DNA extracted directly from sediment resulted in higher presence of non-metazoan eukaryotic taxa; in contrast, an elutriation (resuspension with decanting) approach increased meiofauna abundance and enriched metazoan OTUs. In regards to bioinformatics analyses, the number of overall OTUs varied by clustering algorithm, primarily due to the applied method of sequence quality filtering. However, alpha and beta diversity analyses showed similar trends regardless of bioinformatics pipeline utilized. Based on our results, we recommend studies of meiofauna communities first elutriate samples prior to DNA extraction and include multiple biological replicates to account for variation in community-level composition. The quality filtering method should be carefully considered as this step accounted for large discrepancy in the number of OTUs inferred.

  5. Lethal effects on different marine organisms, associated with sediment-seawater acidification deriving from CO2 leakage.

    PubMed

    Basallote, M D; Rodríguez-Romero, A; Blasco, J; DelValls, A; Riba, I

    2011-08-01

    CO(2) leakages during carbon capture and storage in sub-seabed geological structures could produce potential impacts on the marine environment. To study lethal effects on marine organisms attributable to CO(2) seawater acidification, a bubbling CO(2) system was designed enabling a battery of different tests to be conducted, under laboratory conditions, employing various pH treatments (8.0, 7.5, 7.0, 6.5, 6.0, and 5.5). Assays were performed of three exposure routes (seawater, whole sediment, and sediment elutriate). Individuals of the clam (Ruditapes philippinarum) and early-life stages of the gilthead seabream, Sparus aurata, were exposed for 10 days and 72 h, respectively, to acidified clean seawater. S. aurata larvae were also exposed to acidified elutriate samples, and polychaete organisms of the specie Hediste diversicolor and clams R. philippinarum were also exposed for 10 days to estuarine whole sediment. In the fish larvae elutriate test, 100 % mortality was recorded at pH 6.0, after 48 h of exposure. Similar results were obtained in the clam sediment exposure test. In the other organisms, significant mortality (p < 0.05) was observed at pH values lower than 6.0. Very high lethal effects (calculating L[H(+)]50, defined as the H(+) concentration that causes lethal effects in 50 % of the population exposed) were detected in association with the lowest pH treatment for all the species. The implication of these results is that a severe decrease of seawater pH would cause high mortality in marine organisms of several different kinds and life stages. The study addresses the potential risks incurred due to CO(2) leakages in marine environments. PMID:22828884

  6. Ecotoxicological analysis during the removal of carbofuran in fungal bioaugmented matrices.

    PubMed

    Ruíz-Hidalgo, Karla; Masís-Mora, Mario; Barbieri, Edison; Carazo-Rojas, Elizabeth; Rodríguez-Rodríguez, Carlos E

    2016-02-01

    Biomixtures are used for the removal of pesticides from agricultural wastewater. As biomixtures employ high content of lignocellulosic substrates, their bioaugmentation with ligninolytic fungi represents a novel approach for their enhancement. Nonetheless, the decrease in the concentration of the pesticide may result in sublethal concentrations that still affect ecosystems. Two matrices, a microcosm of rice husk (lignocellulosic substrate) bioaugmented with the fungus Trametes versicolor and a biomixture that contained fungally colonized rice husk were used in the degradation of the insecticide/nematicide carbofuran (CFN). Elutriates simulating lixiviates from these matrices were used to assay the ecotoxicological effects at sublethal level over Daphnia magna (Straus) and the fish Oreochromis aureus (Steindachner) and Oncorhynchus mykiss (Walbaum). Elutriates obtained after 30 d of treatment in the rice husk microcosms at dilutions over 2.5% increased the offspring of D. magna as a trade-off stress response, and produced mortality of neonates at dilutions over 5%. Elutriates (dilution 1:200) obtained during a 30 d period did not produce alterations on the oxygen consumption and ammonium excretion of O. mykiss, however these physiological parameters were affected in O. aureus at every time point of treatment, irrespective of the decrease in CFN concentration. When the fungally colonized rice husk was used to prepare a biomixture, where more accelerated degradation is expected, similar alterations on the responses by O. aureus were achieved. Results suggest that despite the good removal of the pesticide, it is necessary to optimize biomixtures to minimize their residual toxicity and potential chronic effects on aquatic life.

  7. Bioassays with terrestrial and aquatic species as monitoring tools of hydrocarbon degradation.

    PubMed

    Bori, Jaume; Vallès, Bettina; Ortega, Lina; Riva, Maria Carme

    2016-09-01

    In this study chemical analyses and ecotoxicity tests were applied for the assessment of a heavily hydrocarbon-contaminated soil prior and after the application of a remediation procedure that consisted in the stimulation of soil autochthonous populations of hydrocarbon degraders in static-ventilated biopiles. Terrestrial bioassays were applied in mixtures of test soils and artificial control soil and studied the survival and reproduction of Eisenia fetida and the avoidance response of E. fetida and Folsomia candida. Effects on aquatic organisms were studied by means of acute tests with Vibrio fischeri, Raphidocelis subcapitata, and Daphnia magna performed on aqueous elutriates from test soils. The bioremediation procedure led to a significant reduction in the concentration of hydrocarbons (from 34264 to 3074 mg kg(-1), i.e., 91 % decrease) and toxicity although bioassays were not able to report a percentage decrease of toxicity as high as the percentage reduction. Sublethal tests proved the most sensitive terrestrial bioassays and avoidance tests with earthworms and springtails showed potential as monitoring tools of hydrocarbon remediation due to their high sensitivity and short duration. The concentrations of hydrocarbons in water extracts from test soils were 130 and 100 μg L(-1) before and after remediation, respectively. Similarly to terrestrial tests, most aquatic bioassays detected a significant reduction in toxicity, which was almost negligible at the end of the treatment. D. magna survival was the most affected by soil elutriates although toxicity to the crustacean was associated to the salinity of the samples rather than to the concentration of hydrocarbons. Ecotoxicity tests with aqueous soil elutriates proved less relevant in the assessment of hydrocarbon-contaminated soils due to the low hydrosolubility of hydrocarbons and the influence of the physicochemical parameters of the aquatic medium.

  8. Ecotoxicological evaluation of the bioleaching treatment of sewage sludges contaminated with heavy metals

    SciTech Connect

    Renoux, A.Y.; Tyagi, R.D.; Paquette, L.; Samson, R.

    1995-12-31

    A new decontamination technology of sewage sludge, the bioleaching of heavy metals, was assessed using ecotoxicity bioassays. Sewage sludges, treated or non-treated, were mixed with a non-contaminated soil used as a negative control at a rate of 1 to 100 g per liter of soil. Aqueous elutriates (TCLP) of the sludges were used for the aqueous bioassays. The bioleaching of metals reduced the toxic effects associated with sludge for most of the bioassays, although the sludge after treatment exhibited an inherent level of toxicity at high loading rates. With respect to seed germination, bioleached sludge was less toxic (EC50 barley: 53 g/L; lettuce: 13.6) than the non-treated (72; 16.8 g/L). The treated sludge stimulated the barley growth at > 5 6 g/L. The non-treated causes an inhibition at 100 g/L. Earthworms survived in up to 56 g/L of bioleached sludge, compared to 32 g/L of the non-treated. The Microtox{reg_sign} EC50s were 4.0% and 8.4% for nontreated and treated sludges respectively. No genotoxicity (SOS Chromotest) in the sludge elutriates was detected, and no significant treatment effects were noticeable using the lettuce root elongation bioassay. The Daphnia magna mortality of the elutriate was increased with sludge treatment. However, the lettuce root elongation and D. magna mortality bioassay results were difficult to interpret due to variability in standard deviations. This study demonstrated that the ecotoxicological battery of bioassays, and particularly direct contact bioassays, can be used to assess sewage sludge remediation technologies.

  9. Ecotoxicological analysis during the removal of carbofuran in fungal bioaugmented matrices.

    PubMed

    Ruíz-Hidalgo, Karla; Masís-Mora, Mario; Barbieri, Edison; Carazo-Rojas, Elizabeth; Rodríguez-Rodríguez, Carlos E

    2016-02-01

    Biomixtures are used for the removal of pesticides from agricultural wastewater. As biomixtures employ high content of lignocellulosic substrates, their bioaugmentation with ligninolytic fungi represents a novel approach for their enhancement. Nonetheless, the decrease in the concentration of the pesticide may result in sublethal concentrations that still affect ecosystems. Two matrices, a microcosm of rice husk (lignocellulosic substrate) bioaugmented with the fungus Trametes versicolor and a biomixture that contained fungally colonized rice husk were used in the degradation of the insecticide/nematicide carbofuran (CFN). Elutriates simulating lixiviates from these matrices were used to assay the ecotoxicological effects at sublethal level over Daphnia magna (Straus) and the fish Oreochromis aureus (Steindachner) and Oncorhynchus mykiss (Walbaum). Elutriates obtained after 30 d of treatment in the rice husk microcosms at dilutions over 2.5% increased the offspring of D. magna as a trade-off stress response, and produced mortality of neonates at dilutions over 5%. Elutriates (dilution 1:200) obtained during a 30 d period did not produce alterations on the oxygen consumption and ammonium excretion of O. mykiss, however these physiological parameters were affected in O. aureus at every time point of treatment, irrespective of the decrease in CFN concentration. When the fungally colonized rice husk was used to prepare a biomixture, where more accelerated degradation is expected, similar alterations on the responses by O. aureus were achieved. Results suggest that despite the good removal of the pesticide, it is necessary to optimize biomixtures to minimize their residual toxicity and potential chronic effects on aquatic life. PMID:26421626

  10. Comparative evaluation of techniques for the manufacturing of dendritic cell-based cancer vaccines

    PubMed Central

    Dohnal, Alexander Michael; Graffi, Sebastian; Witt, Volker; Eichstill, Christina; Wagner, Dagmar; Ul-Haq, Sidrah; Wimmer, Doris; Felzmann, Thomas

    2009-01-01

    Abstract Manufacturing procedures for cellular therapies are continuously improved with particular emphasis on product safety. We previously developed a dendritic cell (DC) cancer vaccine technology platform that uses clinical grade lipopolysaccharide (LPS) and interferon (IFN)-y for the maturation of monocyte derived DCs. DCs are frozen after 6 hrs exposure at a semi-mature stage (smDCs) retaining the capacity to secret interleukin (IL)-12 and thus support cytolytic T-cell responses, which is lost at full maturation. We compared closed systems for monocyte enrichment from leucocyte apheresis products from healthy individuals using plastic adherence, CD14 selection, or CD2/19 depletion with magnetic beads, or counter flow centrifugation (elutriation) using a clinical grade in comparison to a research grade culture medium for the following DC generation. We found that elutriation was superior compared to the other methods showing 36 ± 4% recovery, which was approximately 5-fold higher as the most frequently used adherence protocol (8 ± 1%), and a very good purity (92 ± 5%) of smDCs. Immune phenotype and IL-12 secretion (adherence: 1.4 ± 0.4; selection: 20 ± 0.6; depletion: 1 ±0.5; elutriation: 3.6 ± 1.5 ng/ml) as well as the potency of all DCs to stimulate T cells in an allogeneic mixed leucocyte reaction did not show statistically significant differences. Research grade and clinical grade DC culture media were equally potent and freezing did not impair the functions of smDCs. Finally, we assessed the functional capacity of DC cancer vaccines manufactured for three patients using this optimized procedure thereby demonstrating the feasibility of manufacturing DC cancer vaccines that secret IL-12 (9.4 ± 6.4 ng/ml). We conclude that significant steps were taken here towards clinical grade DC cancer vaccine manufacturing. PMID:18363835

  11. Bioassays with terrestrial and aquatic species as monitoring tools of hydrocarbon degradation.

    PubMed

    Bori, Jaume; Vallès, Bettina; Ortega, Lina; Riva, Maria Carme

    2016-09-01

    In this study chemical analyses and ecotoxicity tests were applied for the assessment of a heavily hydrocarbon-contaminated soil prior and after the application of a remediation procedure that consisted in the stimulation of soil autochthonous populations of hydrocarbon degraders in static-ventilated biopiles. Terrestrial bioassays were applied in mixtures of test soils and artificial control soil and studied the survival and reproduction of Eisenia fetida and the avoidance response of E. fetida and Folsomia candida. Effects on aquatic organisms were studied by means of acute tests with Vibrio fischeri, Raphidocelis subcapitata, and Daphnia magna performed on aqueous elutriates from test soils. The bioremediation procedure led to a significant reduction in the concentration of hydrocarbons (from 34264 to 3074 mg kg(-1), i.e., 91 % decrease) and toxicity although bioassays were not able to report a percentage decrease of toxicity as high as the percentage reduction. Sublethal tests proved the most sensitive terrestrial bioassays and avoidance tests with earthworms and springtails showed potential as monitoring tools of hydrocarbon remediation due to their high sensitivity and short duration. The concentrations of hydrocarbons in water extracts from test soils were 130 and 100 μg L(-1) before and after remediation, respectively. Similarly to terrestrial tests, most aquatic bioassays detected a significant reduction in toxicity, which was almost negligible at the end of the treatment. D. magna survival was the most affected by soil elutriates although toxicity to the crustacean was associated to the salinity of the samples rather than to the concentration of hydrocarbons. Ecotoxicity tests with aqueous soil elutriates proved less relevant in the assessment of hydrocarbon-contaminated soils due to the low hydrosolubility of hydrocarbons and the influence of the physicochemical parameters of the aquatic medium. PMID:27312898

  12. Exploratory and basic fluidized-bed combustion studies. Quarterly report, April-June 1980. [Limestone and dolomite; USA

    SciTech Connect

    Johnson, I.; Myles, K.M.; Swift, W.M.

    1980-12-01

    This work supports the development studies for both atmospheric and pressurized fluidized-bed coal combustion. Laboratory and process development studies are aimed at providing needed information on limestone utilization, removal of particles and alkali metal compounds from the flue gas, control of SO/sub 2/ and trace pollutant emissions, and other aspects of fluidized-bed coal combustion. This report presents information on: (1) the development of a sorbent utilization prediction methodology, (2) studies of factors which affect limestone breakup and elutriation, (3) basic studies of limestone sulfation under combustion conditions, and (4) studies of the kinetics of the hydration of spent limestone.

  13. Simulation of fluidized bed coal combustors

    NASA Technical Reports Server (NTRS)

    Rajan, R.

    1979-01-01

    The many deficiencies of previous work on simulation of fluidized bed combustion (FBC) processes are presented. An attempt is made to reduce these deficiencies, and to formulate a comprehensive FBC model taking into account the following elements: (1) devolatilization of coal and the subsequent combustion of volatiles and residual char; (2) sulfur dioxide capture by limestone; (3) NOx release and reduction of NOx by char; (4) attrition and elutriation of char and limestone; (5) bubble hydrodynamics; (6) solids mixing; (7) heat transfer between gas and solid, and solid and heat exchange surfaces; and (8) freeboard reactions.

  14. Preliminary comparison of theory and experiment for a conical, pressurized-fluidized-bed coal combustor

    NASA Technical Reports Server (NTRS)

    Patch, R. W.

    1979-01-01

    A published model was used for a comparison of theory with an actual combustor burning caking bituminous coal and using limestone to reduce sulfur dioxide emission. Theoretical bed pressure drop was in good agreement with experiment. The burnable carbon elutriated was not in agreement with experiment, at least partly because the exhaust port was apparently below the transport disengaging height. The observed nitrogen oxides emission rate was about half the theoretical value. There was order-or-magnitude agreement of sulfur dioxide emission rates.

  15. Exploratory and basic fluidized-bed combustion studies. Quarterly report, January-March 1980

    SciTech Connect

    Johnson, I.; Myles, K.M.; Swift, W.M.

    1980-12-01

    This work supports development studies for both atmospheric and pressurized fluidized-bed coal combustion. Laboratory and process development studies are aimed at providing needed information on limestone utilization, removal of particulates and alkali metal compounds from the flue gas, control of SO/sub 2/ and trace pollutants emissions, and other aspects of fluidized-bed combustion. This report presents information on: (1) the development of a limestone utilization predictive methodology, (2) studies of particle breakup and elutriation, (3) basic studies on limestone sulfation enhancement by hydration, (4) studies of the kinetics of the hydration process, and (5) an investigation of various hydration process concepts.

  16. Deflocculation of clay suspensions using sodium polyacrylates

    NASA Technical Reports Server (NTRS)

    Jedlicka, P.

    1984-01-01

    Rheological properties of elutriated kaolin suspensions deflocculated by Na polyacrylate (DAC 3 and DAC 4) were studied and compared to those deflocculated by the conventional Na2CO3 water and glass and imported Dispex N40. The deflocculating effect of Na polyacrylate was comparable to that of Dispex N40. The optimum amounts of Na polyacrylate were determined for suspensions based on 5-type kaolin. The Na polyacrylate can be successfully used for decreasing the water content of ceramic slips for casting and spray drying.

  17. Devolatilization and ash comminution of two different sewage sludges under fluidized bed combustion conditions

    SciTech Connect

    Solimene, R.; Urciuolo, M.; Cammarota, A.; Chirone, R.; Salatino, P.; Damonte, G.; Donati, C.; Puglisi, G.

    2010-04-15

    Two different wet sewage sludges have been characterized under fluidized bed combustion conditions with reference to their devolatilization behavior and ash comminution with the aid of different and complementary experimental protocols. Analysis of the devolatilization process allowed to determine the size of fuel particle able to achieve effective lateral spreading of the volatile matter across the cross-section of medium-scale combustors. Primary fragmentation and primary ash particle characterization pointed out the formation of a significant amount of relatively large fragments. The mechanical properties of these fragments have been characterized by means of elutriation/abrasion tests using both quartz and sludge ash beds. (author)

  18. Hybrid fluidized bed combuster

    DOEpatents

    Kantesaria, Prabhudas P.; Matthews, Francis T.

    1982-01-01

    A first atmospheric bubbling fluidized bed furnace is combined with a second turbulent, circulating fluidized bed furnace to produce heat efficiently from crushed solid fuel. The bed of the second furnace receives the smaller sizes of crushed solid fuel, unreacted limestone from the first bed, and elutriated solids extracted from the flu gases of the first bed. The two-stage combustion of crushed solid fuel provides a system with an efficiency greater than available with use of a single furnace of a fluidized bed.

  19. Short term chronic and acute toxicity screening of water and sediment using fathead minnows, daphnids, rotifers (Rotox[reg sign]) and light emitting bacteria (Microtox[reg sign]), Ambient Stream Monitoring, summers of 1990 and 1991

    SciTech Connect

    Moses, J.; Wade, D.C.

    1992-07-01

    Toxicological evaluation of water column and sediment samples from six locations in the Ambient Stream Monitoring fixed station network was initiated in 1986 using short-term chronic bioassay methods. Toxicological evaluation of six additional stations was initiated in 1990. Chronic studies were conducted at one of these new stations and acute screening methods were used at all twelve locations now included in the activity. This report provides results from studies conducted during the summers of 1990 and 1991. The 1990--91 studies evaluated toxicity of stream water and porewater extracted from sediments as test media, whereas previous studies evaluated water and sediment elutriate samples.

  20. Short term chronic and acute toxicity screening of water and sediment using fathead minnows, daphnids, rotifers (Rotox{reg_sign}) and light emitting bacteria (Microtox{reg_sign}), Ambient Stream Monitoring, summers of 1990 and 1991

    SciTech Connect

    Moses, J.; Wade, D.C.

    1992-07-01

    Toxicological evaluation of water column and sediment samples from six locations in the Ambient Stream Monitoring fixed station network was initiated in 1986 using short-term chronic bioassay methods. Toxicological evaluation of six additional stations was initiated in 1990. Chronic studies were conducted at one of these new stations and acute screening methods were used at all twelve locations now included in the activity. This report provides results from studies conducted during the summers of 1990 and 1991. The 1990--91 studies evaluated toxicity of stream water and porewater extracted from sediments as test media, whereas previous studies evaluated water and sediment elutriate samples.

  1. Fluidized Bed Asbestos Sampler Design and Testing

    SciTech Connect

    Karen E. Wright; Barry H. O'Brien

    2007-12-01

    A large number of samples are required to characterize a site contaminated with asbestos from previous mine or other industrial operations. Current methods, such as EPA Region 10’s glovebox method, or the Berman Elutriator method are time consuming and costly primarily because the equipment is difficult to decontaminate between samples. EPA desires a shorter and less costly method for characterizing soil samples for asbestos. The objective of this was to design and test a qualitative asbestos sampler that operates as a fluidized bed. The proposed sampler employs a conical spouted bed to vigorously mix the soil and separate fine particulate including asbestos fibers on filters. The filters are then analyzed using transmission electron microscopy for presence of asbestos. During initial testing of a glass prototype using ASTM 20/30 sand and clay fines as asbestos surrogates, fine particulate adhered to the sides of the glass vessel and the tubing to the collection filter – presumably due to static charge on the fine particulate. This limited the fines recovery to ~5% of the amount added to the sand surrogate. A second prototype was constructed of stainless steel, which improved fines recovery to about 10%. Fines recovery was increased to 15% by either humidifying the inlet air or introducing a voltage probe in the air space above the sample. Since this was not a substantial improvement, testing using the steel prototype proceeded without using these techniques. Final testing of the second prototype using asbestos suggests that the fluidized bed is considerably more sensitive than the Berman elutriator method. Using a sand/tremolite mixture with 0.005% tremolite, the Berman elutriator did not segregate any asbestos structures while the fluidized bed segregated an average of 11.7. The fluidized bed was also able to segregate structures in samples containing asbestos at a 0.0001% concentration, while the Berman elutriator method did not detect any fibers at this

  2. Obtaining growth hormone from calf blood

    NASA Technical Reports Server (NTRS)

    Kalchev, L. A.; Ralchev, K. K.; Nikolov, I. T.

    1979-01-01

    The preparation of a growth hormone from human serum was used for the isolation of the hormone from calf serum. The preparation was biologically active - it increased the quantity of the free fatty acids released in rat plasma by 36.4 percent. Electrophoresis in Veronal buffer, ph 8.6, showed the presence of a single fraction having mobility intermediate between that of alpha and beta globulins. Gel filtration through Sephadex G 100 showed an elutriation curve identical to that obtained by the growth hormone prepared from pituitary glands.

  3. Decontamination of Dissolved Salt Solution from Tank 19F Using Duolite CS-100 and Amberlite IRC-718 Resins

    SciTech Connect

    Lee, L.M.

    2001-10-17

    In this study actual Savannah River Plant liquid supernate solutions were processed to refine and verify these synthetic solution studies. The main objectives were: (1) confirm high decontamination factors (DFs) for cesium-137 and strontium-90 using Duolite CS-100 and Amberlite IRC-718 ion exchange resins, (2) obtain DFs for other minor radioactive isotopes such as plutonium, technetium and ruthenium, (3) provide ion exchange elutriant containing cesium-137, strontium-90 and other radioactive isotopes for ''hot'' melter studies, (4) determine the quality of the decontaminated salt solution, and (5) provide actual decontaminated salt solution for saltcrete development programs.

  4. Prospective ecological risk assessment of sediment resuspension in an estuary.

    PubMed

    Rial, Diego; Beiras, Ricardo

    2012-08-01

    This study assesses potential ecological risk of resuspended sediment in the water column during the construction of a viaduct in the estuary of the Ulla river (Galicia, NW Iberian Peninsula), a shellfish production area. Chemical analyses and toxicity bioassays with elutriates were performed with sediments from the area where the three pillars of the viaduct will be located (CT1, CT2 and CT3) and a reference sediment (A2). Acute toxicity of the elutriate was evaluated in five species of three trophic levels (Isochrysis galbana, Paracentrotus lividus, Mytilus galloprovincialis, Venerupis pullastra and Siriella armata). The sediments of the pillars showed moderate levels of contamination by trace elements (Cu, Cr). Clam and sea urchin embryo-larval toxicity tests showed slightly higher sensitivity than mussel embryo tests, and toxicity was not detected for phytoplankton and mysid bioassays. The predicted no-effect environmental concentration (PNEC) was calculated from the arithmetic mean of the lowest calculated EC(50)s for each sampling site. The predicted environmental concentration (PEC) was estimated from a simple dilution model and the PEC/PNEC ratio was calculated according to different scenarios of resuspension. Negligible ecological risk in the water column is expected during construction of the pillars.

  5. Toxicity assessment through multiple endpoint bioassays in soils posing environmental risk according to regulatory screening values.

    PubMed

    Rodriguez-Ruiz, A; Asensio, V; Zaldibar, B; Soto, M; Marigómez, I

    2014-01-01

    Toxicity profiles of two soils (a brownfield in Legazpi and an abandoned iron mine in Zugaztieta; Basque Country) contaminated with several metals (As, Zn, Pb and Cu in Legazpi; Zn, Pb, Cd and Cu in Zugaztieta) and petroleum hydrocarbons (in Legazpi) were determined using a multi-endpoint bioassay approach. Investigated soils exceeded screening values (SVs) of regulatory policies in force (Basque Country; Europe). Acute and chronic toxicity bioassays were conducted with a selected set of test species (Vibrio fischeri, Dictyostelium discoideum, Lactuca sativa, Raphanus sativus and Eisenia fetida) in combination with chemical analysis of soils and elutriates, as well as with bioaccumulation studies in earthworms. The sensitivity of the test species and the toxicity endpoints varied depending on the soil. It was concluded that whilst Zugaztieta soil showed very little or no toxicity, Legazpi soil was toxic according to almost all the toxicity tests (solid phase Microtox, D. discoideum inhibition of fruiting body formation and developmental cycle solid phase assays, lettuce seed germination and root elongation test, earthworm acute toxicity and reproduction tests, D. discoideum cell viability and replication elutriate assays). Thus, albeit both soils had similar SVs, their ecotoxicological risk, and therefore the need for intervening, was different for each soil as unveiled after toxicity profiling based on multiple endpoint bioassays. Such a toxicity profiling approach is suitable to be applied for scenario-targeted soil risk assessment in those cases where applicable national/regional soil legislation based on SVs demands further toxicity assessment. PMID:24819436

  6. Toxicity assessment through multiple endpoint bioassays in soils posing environmental risk according to regulatory screening values.

    PubMed

    Rodriguez-Ruiz, A; Asensio, V; Zaldibar, B; Soto, M; Marigómez, I

    2014-01-01

    Toxicity profiles of two soils (a brownfield in Legazpi and an abandoned iron mine in Zugaztieta; Basque Country) contaminated with several metals (As, Zn, Pb and Cu in Legazpi; Zn, Pb, Cd and Cu in Zugaztieta) and petroleum hydrocarbons (in Legazpi) were determined using a multi-endpoint bioassay approach. Investigated soils exceeded screening values (SVs) of regulatory policies in force (Basque Country; Europe). Acute and chronic toxicity bioassays were conducted with a selected set of test species (Vibrio fischeri, Dictyostelium discoideum, Lactuca sativa, Raphanus sativus and Eisenia fetida) in combination with chemical analysis of soils and elutriates, as well as with bioaccumulation studies in earthworms. The sensitivity of the test species and the toxicity endpoints varied depending on the soil. It was concluded that whilst Zugaztieta soil showed very little or no toxicity, Legazpi soil was toxic according to almost all the toxicity tests (solid phase Microtox, D. discoideum inhibition of fruiting body formation and developmental cycle solid phase assays, lettuce seed germination and root elongation test, earthworm acute toxicity and reproduction tests, D. discoideum cell viability and replication elutriate assays). Thus, albeit both soils had similar SVs, their ecotoxicological risk, and therefore the need for intervening, was different for each soil as unveiled after toxicity profiling based on multiple endpoint bioassays. Such a toxicity profiling approach is suitable to be applied for scenario-targeted soil risk assessment in those cases where applicable national/regional soil legislation based on SVs demands further toxicity assessment.

  7. Biomass gasification with air in a fluidized bed: Effect of the in-bed use of dolomite under different operation conditions

    SciTech Connect

    Gil, J.; Caballero, M.A.; Martin, J.A.; Aznar, M.P.; Corella, J.

    1999-11-01

    The performance of a biomass gasifier, fluidized-bed type, is improved by in-bed use of calcined dolomite. Tar contents in the raw flue gas below 1 g/m{sub n}{sup 3} are obtained by using a bed with a percentage between 15 and 30 wt% of dolomite (the rest being silica sand). The work is carried out at small pilot-plant scale (10 kg of biomass/h) with equivalence ratios (ER) between 0.20 and 0.35 and temperatures of 800--840 C in the gasifier bed. To replace the eroded and elutriated dolomite (from the gasifier bed), an amount of dolomite (0.40--0.63 mm) is continuously fed, mixed with the biomass at 3 wt%. When the results obtained with in-bed dolomite are compared to the ones gained in a gasifier bed without dolomite, change of the following variables is reported: gas composition and its corresponding heating value, gas and char yields, apparent thermal efficiency, and tar contents. Once the usefulness of the in-bed use of dolomite is established, three main operation variables (ER and temperature of the gasifier bed and freeboard) are studied in the improved gasifier. Carryover of solids from the gasifier also increases when calcined dolomite is used because of its softness. Elutriation rate constants are calculated for several operational parameters.

  8. Application of new technologies to radiation biodosimetry in mammalian systems

    NASA Astrophysics Data System (ADS)

    Sutherland, R. M.; Lord, E. M.; Keng, P. C.

    1986-02-01

    Mononuclear cells from peripheral blood are presently the best candidates for a space radiation biodosimeter for man because they are easily obtained, and are among the most radiosensitive cells in the body. They are, however, members of a highly heterogeneous population of cell subtypes potentially differing in radiosensitivities. To study the cell subpopulation holding the greatest potential for use as a biodosimeter, the cell types must be uniquely identified, and/or separated so that subtle effects on radiosensitive cells are not masked by non-effects on relatively radioresistant cells present in a mixed population. Flow cytometry and centrifugal elutriation are proving to be useful for identifying and separating individual subpopulations from heterogeneous mixtures of cells. Flow cytometry uses fluorescent antibodies to label and sort the cells of interest, while centrifugal elutriation utilizes counterbalanced centrifugal and fluid flow forces to separate cells by size. In combination with two analytical procedures (premature chromosome condensation (PCC) and alkaline elution), these two techniques have been applied to study radiation effects on mononuclear cells from mouse peripheral blood irradiated in vivo, and cell cycle phase specific repair of single-strand breaks in cellular deoxyribonucleic acid (DNA) of the Chinese hamster ovary (CHO) fibroblast cell line irradiated in vitro.

  9. Bioassays on Illinois waterway dredged material. Final report

    SciTech Connect

    Moore, D.W.; Gibson, A.B.; Dillon, T.M.

    1992-12-01

    Sediment from the Illinois Waterway navigation channel is hydraulically dredged by the US Army Engineer District, Rock Island, and placed in the nearshore environment via pipeline. Water returning to the river can have a high-suspended solids load approaching fluid mud consistency. There is a concern that this return water may exceed the State of Illinois water quality standards for ammonia and have adverse effects on aquatic life. To address these concerns, composite sediment samples and site water collected from selected sites in the Illinois Waterway were evaluated in toxicity tests. Acute (48-hr) toxicity tests were conducted with two species, Pimephales promelas (the fathead minnow) and Daphnia magna (a freshwater cladoceran). A chronic (21-day) toxicity test was also conducted using Daphnia magna. Animals were exposed separately to different concentrations of filtered and unfiltered elutriates prepared from Acute, Cadmium, Daphnia magna, Pimephales promela, Ammonia, Chronic, Elutriate, Sediment, Bioassay, Cladoceran, Fathead minnow. Illinois Waterway edged material. Total ammonia concentrations were measured in all tests and the un-ionized fraction was calculated by adjusting for temperature and pH. Tests were conducted at the US Army Engineer Waterways Experiment Station, Vicksburg, MS. In addition, as part of an interlaboratory effort, a 48-hr acute toxicity test with Pimephales pomelas fry was conducted concurrently by the Hygienic Laboratory of the University of Iowa, Des Moines, IA.

  10. Evaluation of dredged material proposed for ocean disposal from Bronx River Project Area, New York

    SciTech Connect

    Gruendell, B.D.; Gardiner, W.W.; Antrim, L.D.; Pinza, M.R.; Barrows, E.S.; Borde, A.B.

    1996-12-01

    The objective of the Bronx River project was to evaluate proposed dredged material from the Bronx River project area in Bronx, New York, to determine its suitability for unconfined ocean disposal at the Mud Dump Site. Bronx River was one of five waterways that the US Army Corps of Engineers-New York District (USAGE-NYD) requested the Battelle Marine Sciences Laboratory (MSL) to sample and to evaluate for dredging and disposal. Sediment samples were submitted for physical and chemical analyses, chemical analyses of dredging site water and elutriate, benthic and water-column acute toxicity tests, and bioaccumulation studies. Fifteen individual sediment core samples collected from the Bronx River project area were analyzed for grain size, moisture content, and total organic carbon (TOC). One composite sediment sample, representing the entire reach of the area proposed for dredging, was analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl (PCB) congeners, polynuclear aromatic hydrocarbons (PAH), and 1,4- dichlorobenzene. Dredging site water and elutriate water, which was prepared from the suspended-particulate phase (SPP) of the Bronx River sediment composite, were analyzed for metals, pesticides, and PCBS.

  11. Evaluation of dredged material proposed for ocean Disposal from Shoal Harbor/Compton Creek Project Area

    SciTech Connect

    Gardiner, W.W.; Borde, A.B.; Nieukirk, S.L.; Barrows, E.S.; Gruendell, B.D.; Word, J.Q.

    1996-10-01

    The objective of the Shoal Harbor/Compton Creek Project was to evaluate proposed dredged material from the Shoal harbor/Compton Creek Project Area in Belford and Monmouth, New Jersey to determine its suitability for unconfined ocean disposal at the Mud Dump Site. This was one of five waterways that the US Army Corps of Engineers- New York District requested the Battelle Marine Sciences Laboratory (MSL) to sample and evaluate for dredging and disposal in May 1995. The evaluation of proposed dredged material from the Shoal Harbor/Compton Creek Project area consisted of bulk chemical analyses, chemical analyses of dredging site water and elutriate, benthic and water-column acute toxicity tests and bioaccumulation studies. Eleven core samples were analyzed or grain size, moisture content, and total organic carbon. Other sediments were evaluated for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl (PCB) congers, polynuclear aromatic hydrocarbons, and 1,4- dichlorobenzene. Dredging site water and elutriate water were analyzed for metals, pesticides, and PCBs.

  12. Evaluation of dredged material proposed for ocean disposal from Westchester Creek project area, New York

    SciTech Connect

    Pinza, M.R.; Gardiner, W.W.; Barrows, E.S.; Borde, A.B.

    1996-11-01

    The objective of the Westchester Creek project was to evaluate proposed dredged material from this area to determine its suitability for unconfined ocean disposal at the Mud Dump Site. Westchester Creek was one of five waterways that the US Army Corps of Engineers- New York District (USACE-NYD) requested the Battelle/Marine Sciences Laboratory (MSL) to sample and evaluate for dredging and disposal in May 1995. The evaluation of proposed dredged material from the Westchester Creek project area consisted of bulk sediment chemical analyses, chemical analyses of dredging site water and elutriate, benthic acute and water-column toxicity tests, and bioaccumulation studies. Thirteen individual sediment core samples were collected from this area and analyzed for grain size, moisture content, and total organic carbon (TOC). One composite sediment sample representing the Westchester Creek area to be dredged, was analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl (PCB) congeners, polynuclear aromatic hydrocarbons (PAHs), and 1,4-dichlorobenzene. Dredging site water and elutriate water, which is prepared from the suspended- particulate phase (SPP) of the Westchester Creek sediment composite, was analyzed for metals, pesticides, and PCBS.

  13. Study of the influence of different organic pollutants on Cu accumulation by Halimione portulacoides

    NASA Astrophysics Data System (ADS)

    Almeida, C. Marisa R.; Claúdia Dias, A.; Mucha, Ana P.; Bordalo, A. A.; Vasconcelos, M. Teresa S. D.

    2009-12-01

    The influence of each of four organic pollutants selected from among those commonly found in coastal areas, 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE), monobutyltin (MBT), Triton X-100 and polycyclic aromatic hydrocarbons (PAHs), on Cu accumulation by Halimione portulacoides was investigated. Experiments were carried out in a laboratory setting, either in hydroponics (sediment elutriate) or in a salt marsh sediment ( Cávado River, NW Portugal) soaked in elutriate. Groups of H. portulacoides were exposed to media for 6 days spiked with 10 mg/L Cu(II) and with one of the selected pollutants, at an environmentally realistic concentration. DDE and MBT did not cause any major change on Cu accumulation by H. portulacoides, whereas PAHs slightly increased accumulation only in hydroponics i.e. in the absence of sediment. On the other hand, the non-ionic surfactant Triton X-100 markedly favoured Cu accumulation on plant roots both in the presence and absence of sediment. The addition of DDE, MBT and Triton X-100 also favoured Cu solubility from sediments. Therefore, the simultaneous presence of pollutants from different nature (inorganic and organic) in the estuarine environment may result in a composition of water column, pore water, sediment or biota different of that expected considering the effect of each individual pollutant.

  14. Chemical contamination and toxicity of sediment from a coastal area receiving industrial effluents in Kuwait.

    PubMed

    Beg, M U; Al-Muzaini, S; Saeed, T; Jacob, P G; Beg, K R; Al-Bahloul, M; Al-Matrouk, K; Al-Obaid, T; Kurian, A

    2001-10-01

    The Shuaiba coastal area (12.5 x 1.5 km) was examined for contamination with total organic carbon, volatile organic matter, total petroleum hydrocarbons, polycyclic aromatic hydrocarbons, cadmium, chromium, copper, lead, nickel, vanadium, and zinc in sediment; their desorption by aqueous elution; and toxicity to aquatic biota. The pollutants were mainly accumulated in the upstream area facing Mina Al-Ahmadi refinery to Shuaiba harbour. Solid-phase Microtox assays showed severe toxicity, and the LC(50) was negatively correlated with most of the chemical parameters, suggesting that toxicity was the function of collective effects of the pollutants present in sediment. Sea water elutriation showed poor desorption of pollutants from sediment, and the elutriates were not found toxic to Microtox and brine shrimp larvae. Whole sediment suspension in sea water reduced the survival of fingerlings in fish bioassays. Action from Shuaiba Area Authority is required to reduce pollutant accumulation in identified depositional area on the Shuaiba coast by facilitating unrestricted water flow in the area and restricting pollutant discharge at source. PMID:11503065

  15. Liquid versus solid phase bioassays for dredged material toxicity assessment.

    PubMed

    Casado-Martínez, M C; Fernández, N; Forja, J M; DelValls, T A

    2007-05-01

    Since 1994 the results of the analyses of key chemical compounds (trace metals, polychlorinated biphenyls and polycyclic aromatic hydrocarbons) and the comparison with the corresponding sediment quality guidelines (SQGs) are used in decision-making for dredged material management in Spain. Nonetheless in the last decades a tiered testing approach is promoted for assessing the physical and chemical characteristics of dredged sediments and their potential biological effects in the environment. Bioassays have been used for sediment toxicity assessment in Spain but few or no experiences are reported on harbour sediments. We studied the incidence of toxicity in the 7 d bioassay using rotifers (Brachionus plicatilis) and the 48 h bioassay using sea urchin (Paracentrotus lividus) embryos over a series of experiments employing 22 different elutriates. The relative performance of this exposure phase was not comparable to data on the 10-d acute toxicity test using the burrowing amphipod Corophium volutator and the polychaete Arenicola marina, carried out on the whole sediments. These results evidence the importance of the exposure route and the test selected in decision-making, as the toxicity registered for the undiluted elutriates was largely due to the different solubility of sediment-bound contaminants. This work and other studies indicate that for many sediments, a complete battery of test is recommended together with physico-chemical analyses to decide whether dredged sediments are suitable for open water disposal or not. PMID:17174396

  16. A comparison of sediment toxicity test methods at three Great Lake Areas of Concern

    USGS Publications Warehouse

    Burton, G. Allen; Ingersoll, Christopher G.; Burnett, LouAnn C.; Henry, Mary; Hinman, Mark L.; Klaine, Stephen J.; Landrum, Peter F.; Ross, Phillipe; Tuchman, Marc

    1996-01-01

    The significance of sediment contamination is often evaluated using sediment toxicity (bioassay) testing. There are relatively few “standardized” test methods for evaluating sediments. Popular sediment toxicity methods examine the extractable water (elutriate), interstitial water, or whole (bulk) sediment phases using test species spanning the aquatic food chain from bacteria to fish. The current study was designed to evaluate which toxicity tests were most useful in evaluations of sediment contamination at three Great Lake Areas of Concern. Responses of 24 different organisms including fish, mayflies, amphipods, midges, cladocerans, rotifers, macrophytes, algae, and bacteria were compared using whole sediment or elutriate toxicity assays. Sediments from several sites in the Buffalo River, Calumet River (Indiana Harbor), and Saginaw River were tested, as part of the U.S. Environmental Protection Agency's (USEPA) Assessment and Remediation of Contaminated Sediments (ARCS) Project. Results indicated several assays to be sensitive to sediment toxicity and able to discriminate between differing levels of toxicity. Many of the assay responses were significantly correlated to other toxicity responses and were similar based on factor analysis. For most applications, a test design consisting of two to three assays should adequately detect sediment toxicity, consisting of various groupings of the following species: Hyalella azteca, Ceriodaphnia dubia, Chironomus riparius, Chironomus tentans, Daphnia magna, Pimephales promelas, Hexagenia bilineata, Diporeia sp., Hydrilla verticillata, or Lemna minor.

  17. Studying S-phase DNA Damage Checkpoints using the Fission Yeast Schizosaccharomyces pombe

    PubMed Central

    Willis, Nicholas; Rhind, Nicholas

    2016-01-01

    Slowing of replication in response to DNA damage is a universal response to DNA damage during S-phase. Originally discovered to be defective in checkpoint mutant cells in metazoans, this S-phase DNA damage checkpoint response has been extensively studied in yeast. Unlike other checkpoints that completely arrest cell cycle, the S-phase DNA damage checkpoint slows but does not completely halt replication in response to DNA damage. An analysis of mutants defective in the slowing response requires a sensitive assay to measure this quantitative effect. The use of centrifugal elutriation to synchronize cells and improved techniques in preparing cells for flow cytometry allow for more sensitive and accurate measurement of cells’ ability to slow replication in the presence of DNA damage. This chapter describes the use of transient cdc10-M17 temperature sensitive allele arrest and release combined with centrifugal elutriation to synchronize cells in G1. The S-phase progression of these cells is then assayed by flow cytometry of isolated nuclei, which allows sensitive determination of replication kinetics. PMID:21870281

  18. Evaluation of dredged material proposed for ocean disposal from Hudson River, New York

    SciTech Connect

    Gardiner, W.W.; Barrows, E.S.; Antrim, L.D.; Gruendell, B.D.; Word, J.Q.; Tokos, J.J.S.

    1996-09-01

    The Hudson River (Federal Project No. 41) was one of seven waterways that the U.S. Army Corps of Engineers-New York District (USACE-NYD) requested the Battelle Marine Sciences Laboratory (MSL) to sample and evaluate for dredging and disposal in March 1994. Sediment samples were collected from the Hudson River. Tests and analyses were conducted on Hudson River sediment core samples. The evaluation of proposed dredged material from the Hudson River included bulk sediment chemical analyses, chemical analyses of site water and elutriate, water-column and benthic acute toxicity tests, and bioaccumulation studies. Individual sediment core samples collected from Hudson River were analyzed for grain size, moisture content, and total organic carbon (TOC). A composite sediment sample, representing the entire area proposed for dredging, was analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl (PCB) congeners, polynuclear aromatic hydrocarbons (PAH), and 1,4-dichlorobenzene. Site water and elutriate water, prepared from the suspended-particulate phase (SPP) of Hudson River sediment, were analyzed for metals, pesticides, and PCBS. Water-column or SPP toxicity tests were performed with three species. Benthic acute toxicity tests were performed. Bioaccumulation tests were also conducted.

  19. Evaluation of dredged material proposed for ocean disposal from South Brother Island Channel, New York

    SciTech Connect

    Barrows, E.S.; Gardiner, W.W.; Antrim, L.D.; Gruendell, B.D.; Word, J.Q.; Tokos, J.J.S.

    1996-09-01

    South Brother Island Channel was one of seven waterways that the US Army Crops of Engineers-New York District requested the Battelle/Marine Sciences Laboratory to sample and evaluate for dredging and disposal. Tests and analyses were conducted on South Brother Island Channel sediment core samples and evaluations were performed. The evaluation of proposed dredged material from South Brother Island Channel included bulk sediment chemical analyses, chemical analyses of site water and elutriate, water-column and benthic acute toxicity tests, and bioaccumulation studies. Individual sediment core samples collected from Souther Brother Island Channel were analyzed for grain size, moisture content, and total organic carbon. a composite sediment sample, representing the entire area proposed for dredging, was analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl congers, polynuclear aromatic hydrocarbons, and 1,4- dichlorobenzene. Site water and elutriate water, prepared from the suspended-particle phase of South Brother Island Channel sediment, were analyzed for metals, pesticides, and PCBs.

  20. Evaluation of dredged material proposed for ocean disposal from Red Hook/Bay Ridge project areas, New York

    SciTech Connect

    Pinza, M.R.; Barrows, E.S.; Borde, A.B.

    1996-09-01

    The objective of the Red HookIBay Ridge project was to evaluate proposed dredged material from these two areas to determine its suitability for unconfined ocean disposal at the Mud Dump Site. Sediment samples were collected from the Red Hook/Bay Ridge project areas. Tests and analyses were conducted. The evaluation of proposed dredged material from the Red Hook/Bay Ridge project areas consisted of bulk sediment chemical analyses, chemical analyses of dredging site water and elutriate, water-column and benthic acute toxicity tests. Twenty-four individual sediment core samples were collected from these two areas and analyzed for grain size, moisture content, and total organic carbon (TOC). Three composite sediment samples, representing Red Hook Channel and the two Bay Ridge Reaches to be dredged, were analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl (PCB) congeners, polynuclear aromatic hydrocarbons (PAH), and 1,4-dichlorobenzene. Dredging site water and elutriate water, which is prepared from the suspended-particulate phase (SPP) of the three Red Hook Bay Ridge sediment composites, were analyzed for metals, pesticides, and PCBS. Benthic acute toxicity tests were performed. Water-column or SPP toxicity tests were performed. Bioaccumulation tests were also conducted.

  1. Phase-specific cytotoxicity in vivo of hydroxyurea on murine fibrosarcoma pulmonary nodules.

    PubMed Central

    Grdina, D. J.

    1982-01-01

    The cytotoxic effects in vivo of hydroxyurea (HU) on murine fibrosarcoma (FSa) cells grown as pulmonary tumours were determined. Tumour cells from 13-day-old nodules were made into suspension and separated on the basis of cell size by centrifugal elutriation. Flow microfluorometry (FMF) was used to determine the cell-cycle parameters and the relative synchrony of the separated populations, as well as the degree of contamination by normal diploid cells in each of the tumour-cell populations. HU cytotoxicity was tested by administering both a single 1 mg/g i.p. dose into mice that had been injected i.v. 20 min earlier with known numbers of synchronized viable FSa cells, and i.p. doses of 1 mg/g each into mice bearing 13-day-old pulmonary nodules. In the latter experiments, animals were killed 1 h after the last dose, and the tumour nodules were excised and made into a single-cell suspension and elutriated. Known numbers of cells from each fraction were injected into recipient mice to determine survival. In both sets of experiments, cell killing by HU correlated with the percentage of S-phase cells. The treatment of 13-day-old pulmonary nodules with 3 doses of HU also depleted the (G2+M) phase tumour cells and increased the heterogeneity between tumour subpopulations, as determined by FMF analysis. PMID:7073937

  2. Assessment of toxicity reduction after metal removal in bioleached sewage sludge.

    PubMed

    Renoux, A Y; Tyagi, R D; Samson, R

    2001-04-01

    Sewage sludge can be applied to land to supply and recycle organic matter and nutrients. Trace elements in sludge, however, may accumulate in the soil with repeated sludge applications. Reducing metal content may therefore reduce the adverse effects of sludge application. The objective of this study was to evaluate the efficiency of bioleaching technology in reducing metal content and toxicity as measured by a battery of terrestrial and liquid-phase bioassays. Sludge-soil mixtures simulating the application of sludge to land were tested by means of terrestrial bioassays, barley (Hordeum vulgare L.) seed germination (5 d) and sprout growth (14 d), lettuce (Lactuca sativa) seed germination (5 d), and worm (Eisenia andrei) mortality (14 d). Liquid-phase bioassays, Microtox (Vibrio fischeri, 15 min), lettuce root elongation (L. sativa, 5 d), cladoceran mortality (Daphnia magna, 48 h), and SOS Chromotest (Escherichia coli) were used after elutriation of the sludge. Comparison of the bioassay results (except for D. magna) before and after treatment demonstrated that this bioleaching process reduced both sludge toxicity and metal content. In addition, lower Cu and Zn concentrations found in barley sprouts following treatment supported the assumption that the bioleaching process, by decreasing metal content and bioavailability, reduced sewage sludge toxicity. This study also emphasized the interest of using ecotoxicological bioassays for testing biosolids. In particular, the terrestrial bioassays after simulation of land application and the Microtox test after sludge elutriation proved to be the most appropriate procedures. PMID:11317888

  3. Synchronization of cells.

    PubMed

    Sonoda, Eiichiro

    2006-01-01

    Synchronization of cells is essential to study cell cycle specific events. If, for example, one suspects that a given DNA repair pathway is used in a particular cell cycle phase, the protocol can be used to enrich cells in each phase of the cell cycle and analyze the cellular response to DNA damage. Synchronization is also useful, when a gene is essential for a particular phase of the cell cycle. If a gene is, for example, essential for mitosis, synchronization of the cells in G1 phase with concomitant inactivation of the gene enables us to study the function of the gene in interphase, and to follow synchronous cell cycle progression to M phase. Two synchronization methods: centrifugal elutriation to enrich G1, S or G2 phase cells and nocodazole-mimocine sequential treatment to enrich cells at the G1/S boundary are described. Centrifugal elutriation can be achieved in less time (0.5-2 h) and with very little physiological stress to the cells whereas synchronization by drugs, such as nocodazole and mimocine, may result in unfavorable side effects.

  4. Combustion rates of chars from high-volatile fuels for FBC application

    SciTech Connect

    Masi, S.; Salatino, P.; Senneca, O.

    1997-12-31

    The fluidized bed combustion of high volatile fuels is often associated with huge occurrence of comminution phenomena. These result into in-bed generation of substantial amounts of carbon fines which further undergo competitive processes of combustion and elutriation. The small size of carbon fines generated by comminution is such that their further combustion is largely controlled by the intrinsic kinetics of carbon oxidation, alone or in combination with intraparticle diffusion. The competition between fine combustion and elutriation strongly affects the efficiency of fixed carbon conversion and calls for thorough characterization of the combustion kinetics and of residence times of fines in a fluidized bed of coarse solids. In this paper a collection of intrinsic combustion kinetic and porosimetric data for chars from three high-volatile fuels suitable for FBC application is presented. Chars from a Refuse Derived Fuel (RDF), a Tyre Derived Fuel (TDF) and a biomass (Robinia Pseudoacacia) are obtained from devolatilization, in fluidized bed, of fuel samples. Thermogravimetric analysis, mercury porosimetry and helium pycnometry are used to characterize the reactivity and the pore structure of the chars. Combustion rates are characterized over a wide range of temperatures (320--850 C) and oxygen partial pressures, covering the entire range of interest in fluidized bed combustion. Analysis of thermogravimetric and porosimetric data is directed to obtaining the parameters (pre-exponential factors, reaction orders, activation energies, intraparticle diffusivities) of combustion kinetic submodels for application in fluidized bed combustor modeling.

  5. The impact of microbial ecology and chemical profile on the enhanced biological phosphorus removal (EBPR) process: a case study of Northern Wastewater Treatment Works, Johannesburg.

    PubMed

    Kamika, Ilunga; Coetzee, Martie; Mamba, Bhekie Brilliance; Msagati, Titus; Momba, Maggy N B

    2014-03-10

    The impact of polyphosphate-accumulating organism (PAO) and glycogen-accumulating organism (GAO) populations as well as of the chemical profile on the performance of Unit-3 (open elutriation tanks) and Unit-5 (covered elutriation tank) of the City of Johannesburg Northern Wastewater Treatment Works was determined. Physicochemical parameters of wastewater samples were measured using standard methods. Bacterial diversity was determined using 16S rRNA gene amplicon pyrosequencing of the variable region V1-3. Results showed soluble COD concentrations from settled sewage for Unit-3 at 192.8 mg COD/L and for Unit-5 at 214.6 mg COD/L, which increased to 301.8 mg COD/L and 411.6 mg COD/L in the overflow from elutriation tanks and decreased to 170.9 mg COD/L and 256.3 mg COD/L at the division boxes, respectively. Both long-chain volatile fatty acids (heptanoic acid, isobutyric acid, 3-methylbutanoic acid, pentanoic acid, 4-methylpentanoic acid, methylheptanoic acid) and short-chain volatile fatty acids (acetic acid, propionic acid, isobutyric acid) were present within concentration ranges of 17.19 mg/L to 54.98 mg/L and 13.64 mg/L to 87.6 mg/L for Unit 3 and 38.61 mg/L to58.85 mg/L and 21.63 mg/L to 92.39 mg/L for Unit 5, respectively. In the secondary settling tanks, the phosphate-removal efficiency in Unit-5 appeared to be slightly higher (0.08 mg P/L) compared to that of Unit-3 (0.11 mg P/L). The average DO concentrations (2.1 mg/L and 2.2 mg/L) as well as the pH values (pH 7 to pH 7.5) were found to be slightly higher in Unit-5 in the aerobic zones. The high presence of PAOs in the bioreactors (Unit-5: Dechloromonas (14.96%), Acinetobacter (6.3%), Zoogloea (4.72%) in the anaerobic zone and Dechloromonas (22.37 %) in the aerobic zone; Unit-3: Dechloromonas (37.25%) in the anaerobic zone and Dechloromonas (23.97%) in the aerobic zone) confirmed the phosphate-removal efficiencies of both units. Negligible GAOs were found in the aerobic zones (Defluviicoccus spp.: 0.33% for

  6. The Impact of Microbial Ecology and Chemical Profile on the Enhanced Biological Phosphorus Removal (EBPR) Process: A Case Study of Northern Wastewater Treatment Works, Johannesburg

    PubMed Central

    Kamika, Ilunga; Coetzee, Martie; Mamba, Bhekie Brilliance; Msagati, Titus; Momba, Maggy N. B.

    2014-01-01

    The impact of polyphosphate-accumulating organism (PAO) and glycogen-accumulating organism (GAO) populations as well as of the chemical profile on the performance of Unit-3 (open elutriation tanks) and Unit-5 (covered elutriation tank) of the City of Johannesburg Northern Wastewater Treatment Works was determined. Physicochemical parameters of wastewater samples were measured using standard methods. Bacterial diversity was determined using 16S rRNA gene amplicon pyrosequencing of the variable region V1-3. Results showed soluble COD concentrations from settled sewage for Unit-3 at 192.8 mg COD/L and for Unit-5 at 214.6 mg COD/L, which increased to 301.8 mg COD/L and 411.6 mg COD/L in the overflow from elutriation tanks and decreased to 170.9 mg COD/L and 256.3 mg COD/L at the division boxes, respectively. Both long-chain volatile fatty acids (heptanoic acid, isobutyric acid, 3-methylbutanoic acid, pentanoic acid, 4-methylpentanoic acid, methylheptanoic acid) and short-chain volatile fatty acids (acetic acid, propionic acid, isobutyric acid) were present within concentration ranges of 17.19 mg/L to 54.98 mg/L and 13.64 mg/L to 87.6 mg/L for Unit 3 and 38.61 mg/L to58.85 mg/L and 21.63 mg/L to 92.39 mg/L for Unit 5, respectively. In the secondary settling tanks, the phosphate-removal efficiency in Unit-5 appeared to be slightly higher (0.08 mg P/L) compared to that of Unit-3 (0.11 mg P/L). The average DO concentrations (2.1 mg/L and 2.2 mg/L) as well as the pH values (pH 7 to pH 7.5) were found to be slightly higher in Unit-5 in the aerobic zones. The high presence of PAOs in the bioreactors (Unit-5: Dechloromonas (14.96%), Acinetobacter (6.3%), Zoogloea (4.72%) in the anaerobic zone and Dechloromonas (22.37 %) in the aerobic zone; Unit-3: Dechloromonas (37.25%) in the anaerobic zone and Dechloromonas (23.97%) in the aerobic zone) confirmed the phosphate-removal efficiencies of both units. Negligible GAOs were found in the aerobic zones (Defluviicoccus spp.: 0.33% for

  7. K Basin sludge/resin bead separation test report

    SciTech Connect

    Squier, D.M.

    1998-08-25

    The K Basin sludge is an accumulation of fuel element corrosion products, organic and inorganic ion exchange materials, canister gasket materials, iron and aluminum corrosion products, sand, dirt and minor amounts of other organic material. The sludge will be collected and treated for storage and eventual disposal. This process will remove the large solid materials by a 1/4 inch screen. The screened material will be subjected to nitric acid in a chemical treatment process. The organic ion exchange resin beads produce undesirable chemical reactions with the nitric acid. The resin beads must be removed from the bulk material and treated by another process. An effective bead separation method must extract 95% of the resin bead mass without entraining more than 5% of the other sludge component mass. The test plan I-INF-2729, ``Organic Ion Exchange Resin Separation Methods Evaluation,`` proposed the evaluation of air lift, hydro cyclone, agitated slurry and elutriation resin bead separation methods. This follows the testing strategy outlined in section 4.1 of BNF-2574, ``Testing Strategy to Support the Development of K Basins Sludge Treatment Process``. Engineering study BNF-3128, ``Separation of Organic Ion Exchange Resins from Sludge,`` Rev. 0, focused the evaluation tests on a method that removed the fine sludge particles by a sieve and then extracted the beads by means of a elutriation column. Ninety-nine percent of the resin beads are larger than 125 microns and 98.5 percent are 300 microns and larger. Particles smaller than 125 microns make up the largest portion of sludge in the K Basins. Eliminating a large part of the sludge`s non-bead component will reduce the quantity that is lifted with the resin beads in the elutriation column. Resin bead particle size distribution measurements are given in Appendix A The Engineering Testing Laboratory conducted measurements of a elutriation column`s ability to extract resin beads from a sieved, non-radioactive sludge

  8. The impact of microbial ecology and chemical profile on the enhanced biological phosphorus removal (EBPR) process: a case study of Northern Wastewater Treatment Works, Johannesburg.

    PubMed

    Kamika, Ilunga; Coetzee, Martie; Mamba, Bhekie Brilliance; Msagati, Titus; Momba, Maggy N B

    2014-03-01

    The impact of polyphosphate-accumulating organism (PAO) and glycogen-accumulating organism (GAO) populations as well as of the chemical profile on the performance of Unit-3 (open elutriation tanks) and Unit-5 (covered elutriation tank) of the City of Johannesburg Northern Wastewater Treatment Works was determined. Physicochemical parameters of wastewater samples were measured using standard methods. Bacterial diversity was determined using 16S rRNA gene amplicon pyrosequencing of the variable region V1-3. Results showed soluble COD concentrations from settled sewage for Unit-3 at 192.8 mg COD/L and for Unit-5 at 214.6 mg COD/L, which increased to 301.8 mg COD/L and 411.6 mg COD/L in the overflow from elutriation tanks and decreased to 170.9 mg COD/L and 256.3 mg COD/L at the division boxes, respectively. Both long-chain volatile fatty acids (heptanoic acid, isobutyric acid, 3-methylbutanoic acid, pentanoic acid, 4-methylpentanoic acid, methylheptanoic acid) and short-chain volatile fatty acids (acetic acid, propionic acid, isobutyric acid) were present within concentration ranges of 17.19 mg/L to 54.98 mg/L and 13.64 mg/L to 87.6 mg/L for Unit 3 and 38.61 mg/L to58.85 mg/L and 21.63 mg/L to 92.39 mg/L for Unit 5, respectively. In the secondary settling tanks, the phosphate-removal efficiency in Unit-5 appeared to be slightly higher (0.08 mg P/L) compared to that of Unit-3 (0.11 mg P/L). The average DO concentrations (2.1 mg/L and 2.2 mg/L) as well as the pH values (pH 7 to pH 7.5) were found to be slightly higher in Unit-5 in the aerobic zones. The high presence of PAOs in the bioreactors (Unit-5: Dechloromonas (14.96%), Acinetobacter (6.3%), Zoogloea (4.72%) in the anaerobic zone and Dechloromonas (22.37 %) in the aerobic zone; Unit-3: Dechloromonas (37.25%) in the anaerobic zone and Dechloromonas (23.97%) in the aerobic zone) confirmed the phosphate-removal efficiencies of both units. Negligible GAOs were found in the aerobic zones (Defluviicoccus spp.: 0.33% for

  9. Assessment of sediment toxicity in the Lagoon of Venice (Italy) using a multi-species set of bioassays.

    PubMed

    Picone, Marco; Bergamin, Martina; Losso, Chiara; Delaney, Eugenia; Arizzi Novelli, Alessandra; Ghirardini, Annamaria Volpi

    2016-01-01

    Within the framework of a Weight of Evidence (WoE) approach, a set of four toxicity bioassays involving the amphipod Corophium volutator (10 d lethality test on whole sediment), the sea urchin Paracentrotus lividus (fertilization and embryo toxicity tests on elutriate) and the pacific oyster Crassostrea gigas (embryo toxicity test on elutriate) was applied to sediments from 10 sampling sites of the Venice Lagoon (Italy). Sediments were collected during three campaigns carried out in May 2004 (spring campaign), October 2004 (autumn campaign) and February 2005 (winter campaign). Toxicity tests were performed on all sediment samples. Sediment grain-size and chemistry were measured during spring and autumn campaigns. This research investigated (i) the ability of toxicity tests in discriminating among sites with different contamination level, (ii) the occurrence of a gradient of effect among sampling sites, (iii) the possible correlation among toxicity tests, sediment chemistry, grain size and organic carbon, and (iv) the possible occurrence of toxicity seasonal variability. Sediment contamination levels were from low to moderate. No acute toxicity toward amphipods was observed, while sea urchin fertilization was affected only in few sites in just a single campaign. Short-term effects on larval development of sea urchin and oyster evidenced a clear spatial trend among sites, with increasing effects along the axis connecting the sea-inlets with the industrial area. The set of bioassays allowed the identification of a spatial gradient of effect, with decreasing toxicity from the industrial area toward the sea-inlets. Multivariate data analysis showed that the malformations of oyster embryos were significantly correlated to the industrial contamination (metals, polynuclear aromatic hydrocarbons, hexachlorobenzene and polychlorinated biphenyls), while sea urchin development to sediment concentrations of As, Cr and organic carbon. Both embryo toxicity tests were

  10. Evaluating aquatic toxicity by visual inspection of thallus color in the green macroalga Ulva: testing a novel bioassay.

    PubMed

    Han, Young-Seok; Brown, Murray T; Park, Gyoung Soo; Han, Taejun

    2007-05-15

    A novel bioassaythat uses visual inspection of reproduction of the aquatic green macroalga Ulva has been developed for testing toxic chemicals. The method employs a technique to quantify percentage reproduction based on thallus color change during the progression of reproduction. The validity of visual inspection as a reliable method was supported by a high test score (80.4) from a test of the ability of 97 first year university students with no biology background to evaluate reproduction by visual observation after 30 min training. The sensitivity of the method was assessed using a reference toxicant (sodium dodecyl sulfate; SDS; EC50 = 7.1 mg x L(-1)), heavy metals Cu (0.063 mg x L(-1)), Cd (0.217 mg x L(-1, Pb (0.840 mg x L(-1)), Zn (0.966 mg x L(-1)), formalin (1.458 mg x L(-1)), diesel fuel (3.7 mL x L(-1)), and is shown to be similar or better than more established aquatic toxicity bioassays. Toxicity data obtained by the Ulva bioassay for elutriates of sludge collected from nine different locations were directly compared with the commercially available Microtox test. Ulva reproduction was significantly inhibited in all elutriates with the greatest and least toxic effects, estimated by toxicity units (TU) observed in elutriates from industrial waste (13.1 TU) and a filtration bed (4.8 TU), whereas values ranging from 1 to 4.5 TU were obtained from the Microtox test, confirming that the Ulva bioassay is more sensitive. Correlation analyses for EC50 data versus the concentrations of toxicants in the sludge indicated a significant relationship between toxicity and four heavy meals (Cd, Cu, Pb, Zn) for the Ulva bioassay but no such correlation was detected by the Microtox test. The new bioassay method is simple to use, easy to interpret, economical, and eco-relevant so would be a valuable addition to aquatic toxicity testing protocols for a wide range of toxicants. Moreover, since Ulva has a wide geographical distribution and species have similar reproductive

  11. Bacterial contamination of cotton as an indicator of respiratory effects among card room workers.

    PubMed Central

    Rylander, R; Imbus, H R; Suh, M W

    1979-01-01

    The influence of the bacterial contamination of cotton dust on the development of pulmonary symptoms has been investigated. The pulmonary function of card room workers in 23 US cotton mills was tested before and after the Monday working shift. A significant relation was found between the delta FEV1.0 decrement and the vertical elutriator dust level in the different mills. An improved correlation was obtained when the number of Gram-negative bacteria cultured from the bale cotton used in the different mills was employed in the exposure description. The results support earlier epidemiological and experimental studies, which demonstrate the importance of the Gram-negative bacteria in the development of pulmonary symptoms among workers in cotton mills. PMID:389278

  12. Bacterial contamination of cotton as an indicator of respiratory effects among card room workers.

    PubMed

    Rylander, R; Imbus, H R; Suh, M W

    1979-11-01

    The influence of the bacterial contamination of cotton dust on the development of pulmonary symptoms has been investigated. The pulmonary function of card room workers in 23 US cotton mills was tested before and after the Monday working shift. A significant relation was found between the delta FEV1.0 decrement and the vertical elutriator dust level in the different mills. An improved correlation was obtained when the number of Gram-negative bacteria cultured from the bale cotton used in the different mills was employed in the exposure description. The results support earlier epidemiological and experimental studies, which demonstrate the importance of the Gram-negative bacteria in the development of pulmonary symptoms among workers in cotton mills.

  13. Evidence of lead biomagnification in invertebrate predators from laboratory and field experiments.

    PubMed

    Rubio-Franchini, Isidoro; Rico-Martínez, Roberto

    2011-07-01

    This report includes atomic absorption data from water column, elutriates and zooplankton that demonstrate that lead biomagnifies at El Niágara reservoir, Mexico. Results include field data (bioaccumulation factors) (BAFs) and laboratory data (bioconcentration factors) (BCFs). Two findings: high BAFs for invertebrate predator like Acanthocyclops robustus, Asplanchna brightwellii, Culex sp. larvae, and Hyalella azteca, compared to grazer species Moina micrura and Simocephalus vetulus; low BCF's found for some predators, suggested that lead biomagnifications were taking place. The presence of Moina micrura in the gut of Asplanchna allowed us to design experiments where A. brightwellii was fed lead-exposed M. micrura neonates. The BAF of Asplanchna was 123,684, BCF was 490. Asplanchna individuals fed exposed Moina had 13.31 times more lead than Asplanchna individuals just exposed 48-h to lead, confirming that lead biomagnification occurs. Results of two fish species showed no lead biomagnification, suggesting that lead biomagnification might be restricted to invertebrate predators.

  14. Technique of leukocyte harvesting and labeling: problems and perspectives

    SciTech Connect

    McAfee, J.G.; Subramanian, G.; Gagne, G.

    1984-04-01

    Mixed leukocyte suspensions obtained after gravity sedimentation of red cells and labeled with /sup 111/In lipophilic chelates are now widely used clinically for abscess localization at many medical centers. So far, labeling with /sup 111/In-oxine or tropolone has been more successful than any /sup 99/mTc method. More sophisticated approaches are available for isolation and labeling of specific leukocyte cell types, to study their migration in vivo. The most significant advances in cell harvesting include newer density gradients for isopyknic centrifugation, centrifugal elutriation, and flow cytometry. Unlike current radioactive agents which label many cell types indiscriminately, more selective ligands are being developed which bind to specific cell surface receptors. These will label certain leukocyte populations or subtypes while not reacting with others, thereby avoiding laborious separation techniques. Monoclonal antibodies against leukocyte cell-surface antigens appear particularly promising as agents for selective cell labeling.

  15. H₂-rich syngas production by fluidized bed gasification of biomass and plastic fuel.

    PubMed

    Ruoppolo, G; Ammendola, P; Chirone, R; Miccio, F

    2012-04-01

    This paper reports the results of gasification tests using a catalytic fluidized bed gasifier to obtain a H(2)-rich stream by feeding different pellets made of wood, biomass/plastic and olive husks to the gasifier. The effects of both the steam supply and an in-bed catalyst on gasifier performance have been investigated. In general, pelletization was an effective pre-treatment for improving the homogeneity of the fuel and the reliability of the feeding devices. The use of biomass/plastic pellets in a catalyst bed yielded good results in terms of the hydrogen concentration (up to 32%vol.), even if an increase in tar production and in the fine/carbon elutriation rate was observed in comparison with wood pellets.

  16. Fluidized bed combustor modeling

    NASA Technical Reports Server (NTRS)

    Horio, M.; Rengarajan, P.; Krishnan, R.; Wen, C. Y.

    1977-01-01

    A general mathematical model for the prediction of performance of a fluidized bed coal combustor (FBC) is developed. The basic elements of the model consist of: (1) hydrodynamics of gas and solids in the combustor; (2) description of gas and solids contacting pattern; (3) kinetics of combustion; and (4) absorption of SO2 by limestone in the bed. The model is capable of calculating the combustion efficiency, axial bed temperature profile, carbon hold-up in the bed, oxygen and SO2 concentrations in the bubble and emulsion phases, sulfur retention efficiency and particulate carry over by elutriation. The effects of bed geometry, excess air, location of heat transfer coils in the bed, calcium to sulfur ratio in the feeds, etc. are examined. The calculated results are compared with experimental data. Agreement between the calculated results and the observed data are satisfactory in most cases. Recommendations to enhance the accuracy of prediction of the model are suggested.

  17. Application of the general model 'biological nutrient removal model no. 1' to upgrade two full-scale WWTPs.

    PubMed

    Ruano, M V; Serralta, J; Ribes, J; Garcia-Usach, F; Bouzas, A; Barat, R; Seco, A; Ferrer, J

    2012-01-01

    In this paper, two practical case studies for upgrading two wastewater treatment plants (WWTPs) using the general model BNRM 1 (Biological Nutrient Removal Model No. 1) are presented. In the first case study, the Tarragona WWTP was upgraded by reducing the phosphorus load to the anaerobic digester in order to minimize the precipitation problems. Phosphorus load reduction was accomplished by mixing the primary sludge and the secondary sludge and by elutriating the mixed sludge. In the second case study, the Alcantarilla WWTP, the nutrient removal was enhanced by maintaining a relatively low dissolved oxygen concentration in Stage A to maintain the acidogenic bacteria activity. The VFA produced in Stage A favour the denitrification process and biological phosphorus removal in Stage B. These case studies demonstrate the benefits of using the general model BNRMI to simulate settling processes and biological processes related to both anaerobic and aerobic bacteria in the same process unit.

  18. Sulfur capture in an atmospheric fluidized-bed combustor

    SciTech Connect

    Baars, D.M.; Hunter, C.A.; Keitelman, E.N.

    1981-06-01

    Sulfur capture in an atmospheric fluidized-bed combustor (AFBC) both with and without recycle of fines elutriated from the bed was studied. Two empirical correlations, one by Babcock and Wilcox and the other by Westinghouse, correlate sulfur capture as a function of the calcium-to-sulfur mole ratio and gas residence time. Both correlations fit the experimental no-recycle results quite well. Of the limestones tested with no recycle, Vulcan Materials exhibits the best sulfur-capture performance. Data collected with Reed limestone indicates that recycle improves sulfur-capture compared with once-through performance. However, there is a decreasing effect on sulfur capture as the recycle rate is increased to large values. At 90% sulfur capture, the fractional reduction of fresh limestone feed attributable to recycle is 24 to 35% over a gas-residence time range of 0.7 to 0.4 s.

  19. Analysis of the Schizosaccharomyces pombe Cell Cycle.

    PubMed

    Hagan, Iain M; Grallert, Agnes; Simanis, Viesturs

    2016-01-01

    Schizosaccharomyces pombe cells are rod shaped, and they grow by tip elongation. Growth ceases during mitosis and cell division; therefore, the length of a septated cell is a direct measure of the timing of mitotic commitment, and the length of a wild-type cell is an indicator of its position in the cell cycle. A large number of documented stage-specific changes can be used as landmarks to characterize cell cycle progression under specific experimental conditions. Conditional mutations can permanently or transiently block the cell cycle at almost any stage. Large, synchronously dividing cell populations, essential for the biochemical analysis of cell cycle events, can be generated by induction synchrony (arrest-release of a cell cycle mutant) or selection synchrony (centrifugal elutriation or lactose-gradient centrifugation). Schizosaccharomyces pombe cell cycle studies routinely combine particular markers, mutants, and synchronization procedures to manipulate the cycle. We describe these techniques and list key landmarks in the fission yeast mitotic cell division cycle.

  20. Methods to assess airborne concentrations of cotton dust.

    PubMed

    Corn, M

    1987-01-01

    Assessment of concentrations of airborne cotton dust in the factory is necessary to determine adherence to applicable Permissible Exposure Limits (PELs) on a day-to-day basis, as well as for investigatory studies of an epidemiological nature. The latter are required on an ongoing basis to determine the adequacy of PELs to prevent disease in the exposed population. A strategy of sampling includes considerations of the numbers of samples to be obtained for statistical validity and the locations of samples. Current practice is to obtain more "personal samples" of exposure wherever possible, but with regard to cotton dust, instrumentation is not available for such sampling. In the U.S., the vertical elutriator is the instrument of choice for determining the concentrations of cotton dust in air. Results are expressed as milligrams of airborne particulate (cotton dust) per cubic meter. PMID:3434562

  1. Evaluation of Dredged Material Proposed for Ocean Disposal from Port Chester, New York

    SciTech Connect

    Barrows, E.S.; Mayhew, H.L.; Word, J.Q.; Tokos, J.J.S.

    1996-08-01

    Port Chester was one of seven waterways that the US Army Corps of Engineers-New York District requested the Battelle Marine Sciences Laboratory to sample and evaluate for dredging and disposal in March 1994. Tests and analyses were conducted on Port Chester sediment core samples. Because the Port Chester area is located on the border between New York and southeast Connecticut, its dredged material may also be considered for disposal at the Central Long Island Sound Disposal Site. The sediment evaluation consisted of bulk sediment chemical analyses, chemical analyses of site water and dredged material elutriate preparations, water-column and benthic acute toxicity tests, and bioaccumulation studies. Individual sediment core samples collected from Port Chester were analyzed for grain size, moisture content, and total organic carbon. In addition, sediment was analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl congers, polynuclear aromatic hydrocarbons and 1,4-dichlorobenzene.

  2. Atomic absorption spectrophotometric and X-ray studies of respirable dusts in Indian coal mines

    SciTech Connect

    Rawat, N.S.; Sinha, J.D.; Sahoo, B.

    1982-01-01

    Quantitative determination of 10 minor and 8 trace elements in respirable coal dust by atomic absorption spectrophotometry is described herein. The coal dust samples were collected in the mine atmosphere during drilling in coal seams. A ''Hexhlet'' appratus specially designed and fitted with a horizontal elutriator was used to collect the respirable coal dust fraction. After destruction of organic matter by wet oxidation and filtering off the clay and silica, iron, calcium, magnesium, sodium, potassium, manganese, zinc, copper, cadmium, and nickel were determined directly in the resulting solution by atomic absorption spectrophotometry. The studies relate to a respiratoy disease-pneumoconiosis-affecting coal mine workers. X-Ray diffraction studies have shown the presence of kaolin, quartz, pirrsonite and beidellite clay minerals in the coal dust.

  3. Behavior of suspended particles in the Changjiang Estuary: Size distribution and trace metal contamination.

    PubMed

    Yao, Qingzhen; Wang, Xiaojing; Jian, Huimin; Chen, Hongtao; Yu, Zhigang

    2016-02-15

    Suspended particulate matter (SPM) samples were collected along a salinity gradient in the Changjiang Estuary in June 2011. A custom-built water elutriation apparatus was used to separate the suspended sediments into five size fractions. The results indicated that Cr and Pb originated from natural weathering processes, whereas Cu, Zn, and Cd originated from other sources. The distribution of most trace metals in different particle sizes increased with decreasing particle size. The contents of Fe/Mn and organic matter were confirmed to play an important role in increasing the level of heavy metal contents. The Cu, Pb, Zn, and Cd contents varied significantly with increasing salinity in the medium-low salinity region, thus indicating the release of Cu, Pb, Zn, and Cd particles. Thus, the transfer of polluted fine particles into the open sea is probably accompanied by release of pollutants into the dissolved compartment, thereby amplifying the potential harmful effects to marine organisms. PMID:26743609

  4. Characterization of the Particle Size Fraction associated with Heavy Metals in Suspended Sediments of the Yellow River

    PubMed Central

    Yao, Qingzhen; Wang, Xiaojing; Jian, Huimin; Chen, Hongtao; Yu, Zhigang

    2015-01-01

    Variations in the concentrations of particulate heavy metals and fluxes into the sea in the Yellow River were examined based on observational and measured data from January 2009 to December 2010. A custom-built water elutriation apparatus was used to separate suspended sediments into five size fractions. Clay and very fine silt is the dominant fraction in most of the suspended sediments, accounting for >40% of the samples. Cu, Pb, Zn, Cr, Fe and Mn are slightly affected by anthropogenic activities, while Cd is moderate affected. The concentrations of heavy metals increased with decrease in particle size. For suspended sediments in the Yellow River, on average 78%–82% of the total heavy metal loading accumulated in the <16 μm fraction. About 43% and 53% of heavy metal in 2009 and 2010 respectively, were readily transported to the Bohai Sea with “truly suspended” particles, which have potentially harmful effects on marine organisms. PMID:26083999

  5. Evidence of lead biomagnification in invertebrate predators from laboratory and field experiments.

    PubMed

    Rubio-Franchini, Isidoro; Rico-Martínez, Roberto

    2011-07-01

    This report includes atomic absorption data from water column, elutriates and zooplankton that demonstrate that lead biomagnifies at El Niágara reservoir, Mexico. Results include field data (bioaccumulation factors) (BAFs) and laboratory data (bioconcentration factors) (BCFs). Two findings: high BAFs for invertebrate predator like Acanthocyclops robustus, Asplanchna brightwellii, Culex sp. larvae, and Hyalella azteca, compared to grazer species Moina micrura and Simocephalus vetulus; low BCF's found for some predators, suggested that lead biomagnifications were taking place. The presence of Moina micrura in the gut of Asplanchna allowed us to design experiments where A. brightwellii was fed lead-exposed M. micrura neonates. The BAF of Asplanchna was 123,684, BCF was 490. Asplanchna individuals fed exposed Moina had 13.31 times more lead than Asplanchna individuals just exposed 48-h to lead, confirming that lead biomagnification occurs. Results of two fish species showed no lead biomagnification, suggesting that lead biomagnification might be restricted to invertebrate predators. PMID:21530032

  6. Assessment of microplastic toxicity to embryonic development of the sea urchin Lytechinus variegatus (Echinodermata: Echinoidea).

    PubMed

    Nobre, C R; Santana, M F M; Maluf, A; Cortez, F S; Cesar, A; Pereira, C D S; Turra, A

    2015-03-15

    Apart from the physiological impacts on marine organisms caused by ingesting microplastics, the toxicity caused by substances leaching from these particles into the environment requires investigation. To understand this potential risk, we evaluated the toxicity of virgin (raw) and beach-stranded plastic pellets to the development of embryos of Lytechinus variegatus, simulating transfers of chemical compounds to interstitial water and water column by assays of pellet-water interface and elutriate, respectively. Both assays showed that virgin pellets had toxic effects, increasing anomalous embryonic development by 58.1% and 66.5%, respectively. The toxicity of stranded pellets was lower than virgin pellets, and was observed only for pellet-water interface assay. These results show that (i) plastic pellets act as a vector of pollutants, especially for plastic additives found on virgin particles; and that (ii) the toxicity of leached chemicals from pellets depends on the exposure pathway and on the environmental compartment in which pellets accumulate. PMID:25662316

  7. Integrated sediment quality assessment in Paranaguá Estuarine System, Southern Brazil.

    PubMed

    Choueri, R B; Cesar, A; Torres, R J; Abessa, D M S; Morais, R D; Pereira, C D S; Nascimento, M R L; Mozeto, A A; Riba, I; DelValls, T A

    2009-10-01

    Sediment quality from Paranaguá Estuarine System (PES), a highly important port and ecological zone, was evaluated by assessing three lines of evidence: (1) sediment physical-chemical characteristics; (2) sediment toxicity (elutriates, sediment-water interface, and whole sediment); and (3) benthic community structure. Results revealed a gradient of increasing degradation of sediments (i.e. higher concentrations of trace metals, higher toxicity, and impoverishment of benthic community structure) towards inner PES. Data integration by principal component analysis (PCA) showed positive correlation between some contaminants (mainly As, Cr, Ni, and Pb) and toxicity in samples collected from stations located in upper estuary and one station placed away from contamination sources. Benthic community structure seems to be affected by both pollution and natural fine characteristics of the sediments, which reinforces the importance of a weight-of-evidence approach to evaluate sediments of PES. PMID:19616298

  8. Utilizing FUCCI reporters to understand pluripotent stem cell biology.

    PubMed

    Singh, Amar M; Trost, Robert; Boward, Benjamin; Dalton, Stephen

    2016-05-15

    The fluorescence ubiquitination cell cycle indicator (FUCCI) system provides a powerful method to evaluate cell cycle mechanisms associated with stem cell self-renewal and cell fate specification. By integrating the FUCCI system into human pluripotent stem cells (hPSCs) it is possible to isolate homogeneous fractions of viable cells representative of all cell cycle phases. This method avoids problems associated with traditional tools used for cell cycle analysis such as synchronizing drugs, elutriation and temperature sensitive mutants. Importantly, FUCCI reporters allow cell cycle events in dynamic systems, such as differentiation, to be evaluated. Initial reports on the FUCCI system focused on its strengths in reporting spatio-temporal aspects of cell cycle events in living cells and developmental models. In this report, we describe approaches that broaden the application of FUCCI reporters in PSCs through incorporation of FACS. This approach allows molecular analysis of the cell cycle in stem cell systems that were not previously possible.

  9. Melting behavior and phase relations of lunar samples

    NASA Technical Reports Server (NTRS)

    Hays, J. F.

    1976-01-01

    An attempt was made to show that feldspar would float during melting. Large anorthite crystals were placed beneath a silicate glass representative of liquid in which plagioclase accumulation is thought to have occurred. In less than 3 hours at 1,300 C, the crystals rose to the top in a Pt crucible 3 cm deep equilibrated in air and in a Mo crucible 1.5 cm deep equilibrated in an H2/CO2 gas stream of log PO2 = -10.9 (below Fe/FeO). These results suggest that lunar crustal formation by feldspar flotation is possible without special recourse to differential sinking of plagioclase versus mafic minerals or selective elutriation of plagioclase.

  10. Environmental impact assessment of tailings dispersal from a uranium mine using toxicity testing protocols

    SciTech Connect

    Rippon, G.D.; Riley, S.J.

    1996-12-01

    Toxicity testing is a means of establishing the environmental risk of uranium tailings release. It is valuable in designing tailings containment structures because it assists in setting acceptable levels of risk of the design. This paper presents details of toxicity tests of the tailings from Ranger Uranium Mine, Northern Territory, Australia. The results suggest that the non-radiological toxicity of the tailings is low. The environmental risk of a tailings release is more likely to be related to the physical impacts of the tailings, including infilling of billabongs and changes in the sedimentology of riparian ecosystems rather than their biogeochemical impact. Two major results were: (1) water from treatment with washed tailing fines was not toxic to Hydra viridissima, and (2) mixtures of washed tailings fines and natural floodplain sediment (overlying water or elutriates) were not toxic to Hydra viridissima or Moinodaphnia macleayi. 33 refs., 4 figs., 3 tabs.

  11. An experimental investigation of gas-particle flows through diffusers in the freeboard region of fluidized beds

    SciTech Connect

    Kale, S.R.; Eaton, J.K.

    1985-09-01

    Results reported in Kale and Eaton showed that very-wide-angle diffusers located in the freeboard above a fluidized bed substantially reduce elutriation--a resul that was contrary to intuition. The present experiment was designed to explain these results. One set of measurements was made with the bed in place and a second set with the bed material removed. The flow structure was drastically altered by the presence of the fluidized bed below the diffuser. A simple analysis suggests that suspended particles in the diffuser flow are responsible for the change in the flow structure. Momentum loss from the gas to the suspended particles reduces the pressure gradient, thereby eliminating the tendency to separate.

  12. Germination and root elongation bioassays in six different plant species for testing Ni contamination in soil.

    PubMed

    Visioli, Giovanna; Conti, Federica D; Gardi, Ciro; Menta, Cristina

    2014-04-01

    In vitro short-term chronic phytotoxicity germination and root elongation test were applied to test the effects of nickel (Ni) in seed germination and root elongation in six plants species: Cucumis sativus (Cucurbitaceae), Lepidium sativum and Brassica nigra (Brassicaceae), Trifolium alexandrinum and Medicago sativa (Fabaceae), Phacelia tanacetifolia (Boraginaceae). A naturally Ni rich soil was used to compare the results obtained. Unlike root elongation, germination was not affected by Ni in any of the six species tested. EC50 values, calculated on the root elongation, showed that Ni toxicity decreases in the following order: P. tanacetifolia > B. nigra > C. sativus > L. sativum > M. sativa > T. alexandrinum. The test conducted using soil elutriate revealed a significantly lower effect in both seed germination and root elongation when compared to the results obtained using untreated soil. Conversely, the test performed on soil confirmed the high sensitivity of C. sativus, P. tanacetifolia and L. sativum to Ni. PMID:24288040

  13. Assessment of microplastic toxicity to embryonic development of the sea urchin Lytechinus variegatus (Echinodermata: Echinoidea).

    PubMed

    Nobre, C R; Santana, M F M; Maluf, A; Cortez, F S; Cesar, A; Pereira, C D S; Turra, A

    2015-03-15

    Apart from the physiological impacts on marine organisms caused by ingesting microplastics, the toxicity caused by substances leaching from these particles into the environment requires investigation. To understand this potential risk, we evaluated the toxicity of virgin (raw) and beach-stranded plastic pellets to the development of embryos of Lytechinus variegatus, simulating transfers of chemical compounds to interstitial water and water column by assays of pellet-water interface and elutriate, respectively. Both assays showed that virgin pellets had toxic effects, increasing anomalous embryonic development by 58.1% and 66.5%, respectively. The toxicity of stranded pellets was lower than virgin pellets, and was observed only for pellet-water interface assay. These results show that (i) plastic pellets act as a vector of pollutants, especially for plastic additives found on virgin particles; and that (ii) the toxicity of leached chemicals from pellets depends on the exposure pathway and on the environmental compartment in which pellets accumulate.

  14. Anion-exchange separation of Pt and Pd using perchloric and hydrochloric acid solutions

    USGS Publications Warehouse

    Petrie, R.K.; Morgan, J.W.

    1982-01-01

    On Biorad Ag-1X8 anion-exchange resin (200-400 mesh), Pd and Pt may be separated from one another by elution with 0.2M HClO4, and 5M HClO4, respectively. If present, Au may be retained by making the elutriants 0.003M in HCl. Alternatively, reduction by H2SO3 enables elution of Pt2+ with 6M HCl before recovery of Pd2+ with 0.2M HClO4??Ir4+ is reduced to Ir3+ by H2SO3 and may be eluted ahead of Pt2+ by 2M HCl. ?? 1982 Akade??miai Kiado??.

  15. Ecotoxicity of selected nano-materials to aquatic organisms.

    PubMed

    Blaise, C; Gagné, F; Férard, J F; Eullaffroy, P

    2008-10-01

    Present knowledge concerning the ecotoxic effects of nano-materials is very limited and merits to be documented more fully. For this purpose, we appraised the toxicity of nine metallic nano-powders (copper zinc iron oxide, nickel zinc iron oxide, yttrium iron oxide, titanium dioxide, strontium ferrite, indium tin oxide, samarium oxide, erbium oxide, and holmium oxide) and of two organic nano- powders (fullerene-C60 and single-walled carbon nanotube or SWCNT). After a simple process where nano-powders (NPs) were prepared in aqueous solution and filtered, they were then bioassayed across several taxonomic groups including decomposers (bacteria), primary producers (micro-algae), as well as primary and secondary consumers (micro-invertebrates and fish). Toxicity data generated on the 11 NPs reflected a wide spectrum of sensitivity that was biological level-, test-, and endpoint-specific. With all acute and chronic tests confounded for these 11 NPs, toxicity responses spanned over three orders of magnitude: >463 mg/L (24 h LC50 of the invertebrate Thamnoplatyurus platyurus for fullerene-C60) / 0.3 mg/L (96 h EC50 of the invertebrate Hydra attenuata for indium tin oxide), that is a ratio of 1543. On the basis of the MARA (Microbial Array for Risk Assessment) assay toxic fingerprint concept, it is intimated that NPs may have different modes of toxic action. When mixed in a 1:1 ratio with a certified reference material (CRM) sediment, two solid phase assays and an elutriate assay, respectively, showed that five NPs (copper zinc iron oxide, samarium oxide, erbium oxide, holmium oxide, and SWCNT) were able to increase both CRM sediment toxicity and its elutriate toxicity. This initial investigation suggests that chemicals emerging from nanotechnology may pose a risk to aquatic life in water column and sediment compartments and that further studies on their adverse effects are to be encouraged.

  16. Investigation of Depth Distribution of Radionuclides in Soil Contaminated by the Fukushima Dai-ichi Nuclear Power Plant Accident

    NASA Astrophysics Data System (ADS)

    Sato, Haruo; Niizato, Tadafumi; Tanaka, Shingo; Abe, Hironobu; Aoki, Kazuhiro

    2014-05-01

    This work was conducted as one of the researches relating to distribution maps of radiation dose rate etc. which the government has promoted as one of the counter-measures to the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011, and the 2nd investigation on the depth distribution of radionuclides (RNs) in soil was conducted after about 1 year from the accident, succeedingly to the 1st investigation which was conducted after about 3 months from the accident. Soil core samples to about 50cm deep were taken at 11 locations in Nihonmatsu-city, Kawamata-town and Namie-town. Sorption-desorption experiments of Cs-137 and I-131, CEC and AEC measurements and mineralogical analyses by XRD were conducted for 3 types of soils (sandy, clayey, organic) and those elutriated components (clay, silt, sand). Radiocaesium (Cs-134 and Cs-137) and Ag-110m were detected at all locations investigated and only at locations where radiation dose rate is high, respectively. Radiocaesium more than 95% and 99% of the inventory distributed within 5cm and 10cm deep in soil in the surface layer (mainly sandy soil), respectively, and distributed within 16cm and 20cm deep in organic soil and soil at locations where are supposed to have been used as farmland, respectively. Radiocaesium tended to extend to deeper parts in soil that organic and clayey soils are the support layer, particularly in organic soil, compared with the 1st investigation. Distribution coefficients of Cs-137 onto organic soil and its elutriated components were also lower than that onto other soils. This is consistent with trend of penetration profile.

  17. Reduced bed agglomeration by co-combustion biomass with peat fuels in a fluidized bed

    SciTech Connect

    Karin Lundholm; Anders Nordin; Marcus Oehman; Dan Bostroem

    2005-12-01

    Fluidized bed combustion is an energy conversion technology that is very suitable for biomass combustion because of its fuel flexibility and low process temperatures. However, agglomeration of bed material may cause severe operating problems. To prevent or at least reduce this, peat has been suggested as an additive to the main fuels. Nevertheless, the characteristics of peat fuels vary and there is limited information of the effect of different peat fuels and of the mechanisms behind the agglomeration prevention. The objectives of the present work were therefore to: (I) quantify the potential positive effect by co-combustion peat with forest fuels in terms of initial agglomeration temperatures; (ii) determine the amount of peat fuel that is needed to significantly reduce the agglomeration tendencies; and, if possible, (iii) elucidate the governing mechanisms. The results showed that all peat fuels prevented agglomeration in the studied interval of 760-1020{sup o}C and even as little as 5% peat fuel was found to have significant effects. The results also indicated that the mechanism of the agglomeration prevention varies between different peat fuels. Possible mechanisms are the minerals in the peat fuel retain alkali, which then is either elutriated up from the bed or captured in the bed; calcium and other refractory elements increase the melting temperature and thereby counteract the melting of alkali; and sulfur reacts with alkali metals and the alkali sulfates is either elutriated up from the bed or prevents agglomeration by increased melting temperature and lowered viscosity. Results from elemental analysis of the coating on bed particles showed that all mixtures with peat fuel resulted in a decreased or unchanged fraction of potassium and an increased fraction of aluminum in the coatings. The results also indicated a complex relationship between the fuel inorganic contents and the agglomeration process. 21 refs., 6 figs., 5 tabs.

  18. Can physiological endpoints improve the sensitivity of assays with plants in the risk assessment of contaminated soils?

    PubMed

    Gavina, Ana; Antunes, Sara C; Pinto, Glória; Claro, Maria Teresa; Santos, Conceição; Gonçalves, Fernando; Pereira, Ruth

    2013-01-01

    Site-specific risk assessment of contaminated areas indicates prior areas for intervention, and provides helpful information for risk managers. This study was conducted in the Ervedosa mine area (Bragança, Portugal), where both underground and open pit exploration of tin and arsenic minerals were performed for about one century (1857-1969). We aimed at obtaining ecotoxicological information with terrestrial and aquatic plant species to integrate in the risk assessment of this mine area. Further we also intended to evaluate if the assessment of other parameters, in standard assays with terrestrial plants, can improve the identification of phytotoxic soils. For this purpose, soil samples were collected on 16 sampling sites distributed along four transects, defined within the mine area, and in one reference site. General soil physical and chemical parameters, total and extractable metal contents were analyzed. Assays were performed for soil elutriates and for the whole soil matrix following standard guidelines for growth inhibition assay with Lemna minor and emergence and seedling growth assay with Zea mays. At the end of the Z. mays assay, relative water content, membrane permeability, leaf area, content of photosynthetic pigments (chlorophylls and carotenoids), malondialdehyde levels, proline content, and chlorophyll fluorescence (Fv/Fm and ΦPSII) parameters were evaluated. In general, the soils near the exploration area revealed high levels of Al, Mn, Fe and Cu. Almost all the soils from transepts C, D and F presented total concentrations of arsenic well above soils screening benchmark values available. Elutriates of several soils from sampling sites near the exploration and ore treatment areas were toxic to L. minor, suggesting that the retention function of these soils was seriously compromised. In Z. mays assay, plant performance parameters (other than those recommended by standard protocols), allowed the identification of more phytotoxic soils. The results

  19. Evaluation of dredged material proposed for ocean disposal from Eastchester Project Area, New York

    SciTech Connect

    Antrim, L.D.; Pinza, M.R.; Barrows, E.S.; Gardiner, W.W.; Tokos, J.J.S.; Gruendell, B.D.; Word, J.Q.

    1996-07-01

    The objective of the Eastchester project (Federal Project [FP] No. 6) was to evaluate proposed dredged material from the Eastchester project area in the Hutchinson River to determine its suitability for unconfined ocean disposal at the Mud Dump Site. Eastchester was one of seven waterways that the U. S. Army Corps of Engineers-New York District (USACE-NYD) requested the Battelle/Marine Sciences Laboratory (MSL) to sample and evaluate for dredging and disposal in March 1994. The evaluation of proposed dredged material from the Eastchester project area consisted of bulk sediment chemical analyses, chemical analyses of dredging site water and elutriate, water- column and benthic acute toxicity tests, and bioaccumulation studies. Eighteen individual sediment core samples collected from the Eastchester project area were analyzed for grain size, moisture content, and total organic carbon (TOC). Two composite sediment samples, representing the upstream and lower reaches of the area proposed for dredging, were analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl (PCB) congeners, polynuclear aromatic hydrocarbons (PAHs), and 1,4- dichlorobenzene. Dredging site water and elutriate water, which is prepared from the suspended-particulate phase (SPP) of the two Eastchester sediment composites, were analyzed for metals, pesticides, and PCBS. An additional 1 1 composite samples were created for the USACE-New England Division (USACE-NED) using the same 18 Eastchester core samples but combined into different composites. These composites were analyzed for metals, chlorinated pesticides, PCB congeners, PAHS, and 1,4-dichlorobenzene. Water-column or SPP toxicity tests were performed along with bioaccumulation tests.

  20. Removal of mercury from powder river basin coal by low-temperature thermal treatment

    SciTech Connect

    Merriam, N.W.

    1993-07-01

    This report describes work conducted at Western Research Institute (WRI) to remove mercury from Powder River Basin (PRB) coal as part of the research performed under Task 2.1, Development and Optimization of a Process for the Production of a Premium Solid Fuel from Western US Coals, of the 1993 Annual Project Plan. In the tests minus 16 mesh PRB coal was fed to a bench-scale fluidized-bed reactor where it was heated by contact with carbon dioxide fluidizing gas. A side stream of the gas from the reactor was passed through traps containing activated carbon where mercury driven from the coal was collected. The feed coal (which contains about 0.062 milligrams of mercury/kilogram of coal), the fines elutriated from the reactor, the activated carbon, and the condensed water from the reactor were analyzed for mercury. The solid products were analyzed using cold vapor atomic adsorption spectroscopy (ASTM D3684) while the water was analyzed using US Environmental Protection Agency (EPA) Method 245.1 which is based upon reduction of mercury to elemental form followed by adsorption at a wave length of 253.7 nanometers. The results of these tests show that about 70 to 80 wt % of the mercury is removed from the coal when the temperature is raised from about 300{degree}F (149{degree}C) to about 550{degree}F (288{degree}C). The remaining 20 wt % of the mercury remains in the char at temperatures up to about 1100{degree}F (593{degree}C). About 0.5 wt % of the mercury in the feed coal is condensed with water recovered from the coal. Nearly all of the mercury driven from the coal remains in the gas stream. Fines elutriated from the reactor contain about the same concentration of mercury as the feed coal.

  1. Toxicological evaluation of sediment samples from Burns Harbor, Porter County, Indiana

    SciTech Connect

    Ward, J.A.; Pinza, M.R.; Barrows, M.E.; Karls, R.K.; Word, J.Q.

    1994-05-01

    The US Army Corps of Engineers (USACE) Chicago District is authorized to maintain the water depths in Burns Harbor at navigable levels. In order to maintain these levels, sediments must be dredged and disposed of at approved disposal sites. To make a 404 (b) 1 open-water disposal evaluation, the dredged sediment may be evaluated through a series of toxicological tests to assess its potential for causing an adverse environmental effect. Battelle/Marine Sciences Laboratory (MSL) was contracted by USACE to perform these freshwater toxicity tests. The tests were designed to simulate conditions that organisms living within an aquatic dredged material disposal site might experience during disposal operations, and included both bedded-sediment (solid-phase) and suspended-sediment (elutriate) tests. Test samples were collected by USACE personnel and composited into three test treatments representing potential dredging areas (Management Units {number_sign}1, {number_sign}2, and {number_sign}3). Four toxicological tests were conducted in support of this program. The solid-phase tests included the amphipod, Hyalella azteca, and the midge, Chironomus tentans. The elutriate tests included the fathead minnow, Pimephales promelas, and the daphnid, Daphnia magna. Testing was conducted following standard procedures provided by USACE which are consistent with ASTM protocols and the Evaluation of Dredged Material Proposed for Discharge in Inland and Near Coastal Waters -- Testing Manual (Draft) Inland Testing Manual (EPA/USACE 1993), known as the ``Draft Inland Testing Manual.`` The suitability of sediment representing the management units for open-water disposal was evaluated following the guidelines contained in the Draft Inland Testing Manual.

  2. Can Physiological Endpoints Improve the Sensitivity of Assays with Plants in the Risk Assessment of Contaminated Soils?

    PubMed Central

    Gavina, Ana; Antunes, Sara C.; Pinto, Glória; Claro, Maria Teresa; Santos, Conceição; Gonçalves, Fernando; Pereira, Ruth

    2013-01-01

    Site-specific risk assessment of contaminated areas indicates prior areas for intervention, and provides helpful information for risk managers. This study was conducted in the Ervedosa mine area (Bragança, Portugal), where both underground and open pit exploration of tin and arsenic minerals were performed for about one century (1857 – 1969). We aimed at obtaining ecotoxicological information with terrestrial and aquatic plant species to integrate in the risk assessment of this mine area. Further we also intended to evaluate if the assessment of other parameters, in standard assays with terrestrial plants, can improve the identification of phytotoxic soils. For this purpose, soil samples were collected on 16 sampling sites distributed along four transects, defined within the mine area, and in one reference site. General soil physical and chemical parameters, total and extractable metal contents were analyzed. Assays were performed for soil elutriates and for the whole soil matrix following standard guidelines for growth inhibition assay with Lemna minor and emergence and seedling growth assay with Zea mays. At the end of the Z. mays assay, relative water content, membrane permeability, leaf area, content of photosynthetic pigments (chlorophylls and carotenoids), malondialdehyde levels, proline content, and chlorophyll fluorescence (Fv/Fm and ΦPSII) parameters were evaluated. In general, the soils near the exploration area revealed high levels of Al, Mn, Fe and Cu. Almost all the soils from transepts C, D and F presented total concentrations of arsenic well above soils screening benchmark values available. Elutriates of several soils from sampling sites near the exploration and ore treatment areas were toxic to L. minor, suggesting that the retention function of these soils was seriously compromised. In Z. mays assay, plant performance parameters (other than those recommended by standard protocols), allowed the identification of more phytotoxic soils. The

  3. A geochemical investigation of fragmentation and physical fractionation in pyroclastic flows from the Soufrière Hills volcano, Montserrat

    NASA Astrophysics Data System (ADS)

    Horwell, C. J.; Braña, L. P.; Sparks, R. S. J.; Murphy, M. D.; Hards, V. L.

    2001-09-01

    Geochemical analysis is used to investigate fragmentation and physical fractionation in pyroclastic flows. Bulk analyses of the matrices (<4 mm) and individual size fractions in pyroclastic flow deposits formed in the eruption of the Soufrière Hills volcano, Montserrat, West Indies are compared with analyses of associated ash fall deposits formed from lofting plumes above the flows, and with bulk lava analyses. Within the flow matrices intermediate grain size fractions (<4 mm to 125 μm) are depleted in the groundmass component of the lava (principally glass and micro-crystalline silica) and enriched in phenocryst components. Fine-grained size fractions (<125 μm) are enriched in groundmass components. Crushing of the lava in the laboratory with analysis of grain size fractions shows the same relationship, but enrichment and depletions are less pronounced. Comparison of the bulk compositions of matrices, ash fall deposits and lava show that the finest fractions, enriched in the groundmass component, have been selectively removed from the flows into the lofting ash plumes. Mass balance calculations indicate that typically about 10% of the mass of the pyroclastic flows are elutriated into lofting ash plumes to form ash fall deposits, which is consistent with data on relative volumes of the deposits. Three factors influence fragmentation and fractionation. First, the initial size distribution of crystals influences fragmentation with phenocrysts resisting break up, whereas fine groundmass minerals (mostly feldspar, glass and micro-crystalline silica) are preferentially fragmented to form the finest ash fractions. Second, the mineral phases and groundmass glass vary in strength so that vesicular glass fragments more rapidly than other silicate minerals. This interpretation is supported by crushing experiments on different rock types. Third, only the finest fractions are elutriated into the lofting ash plume from the pyroclastic flows. Description of the natural size

  4. Gastrin receptors on isolated canine parietal cells

    SciTech Connect

    Soll, A.H.; Amirian, D.A.; Thomas, L.P.; Reedy, T.J.; Elashoff, J.D.

    1984-05-01

    The receptors in the fundic mucosa that mediate gastrin stimulation of acid secretion have been studied. Synthetic human gastrin-17-I (G17) with a leucine substitution in the 15th position ((Leu15)-G17) was iodinated by chloramine T; high saturable binding was found to enzyme-dispersed canine fundic mucosal cells. /sup 127/I-(Leu15)-G17, but not /sup 127/I-G17, retained binding potency and biological activity comparable with uniodinated G17. Fundic mucosal cells were separated by size by using an elutriator rotor, and specific /sup 125/I-(Leu-15)-G17 binding in the larger cell fractions was highly correlated with the distribution of parietal cells. There was, however, specific gastrin binding in the small cell fractions, not accounted for by parietal cells. Using sequential elutriation and stepwise density gradients, highly enriched parietal and chief cell fractions were prepared; /sup 125/I-(Leu15)-G17 binding correlated positively with the parietal cell (r . 0.98) and negatively with chief cell content (r . -0.96). In fractions enriched to 45-65% parietal cells, specific /sup 125/I-(Leu15)-G17 binding was rapid, reaching a steady state at 37 degrees C within 30 min. Dissociation was also rapid, with the rate similar after 100-fold dilution or dilution plus excess pentagastrin. At a tracer concentration from 10 to 30 pM, saturable binding was 7.8 +/- 0.8% per 10(6) cells (mean +/- SE) and binding in the presence of excess pentagastrin accounted for 11% of total binding. G17 and carboxyl terminal octapeptide of cholecystokinin (26-33) were equipotent in displacing tracer binding and in stimulating parietal cell function ((/sup 14/C)aminopyrine accumulation), whereas the tetrapeptide of gastrin (14-17) had a much lower potency. Proglumide inhibited gastrin binding and selectively inhibited gastrin stimulation of parietal cell function.

  5. Progress in pressurized fluidized bed combustion (PFBC) filter cakes and filter cleaning

    SciTech Connect

    Smith, D.H.; Grimm, U.; Haddad, G.J.; VanOsdol, J.; Ferer, M.V.

    1996-12-31

    The Pressurized Fluidized Bed Combustion (PFBC) program of the US Department of Energy includes a Second Generation technology with a goal of 45% net efficiency and an Advanced Cycle technology with an efficiency greater than 50%. Both technologies require filtration, at temperatures in excess of 700 C, of fine particles of coal ash and spent and unreacted sorbent from the hot-gas stream. The authors have developed and tested physically realistic equations that allow real-time determination of filter-cake thicknesses from on-line measurements of tube-sheet pressure drops and gas and particle flow rates, and laboratory measurements of filter-cake porosities. The models also accommodate changes of cake-strengths and cleaning produced by changes in particle-size distributions before filtration (e.g., as produced by cyclone detuning). The degree of agglomeration in filter cakes strongly depends on chemical reactions, diffusion, and neck formation, which in turn depend on the operating temperature and frequency of filter-cleaning. When a dolomitic sorbent is used with a filter-vessel temperature of {approximately}700 C, capture of SO{sub 2} by sulfation of MgO (elutriated from the combustor) occurs in the filter cakes. Sulfation reactions produce bonding between particles and thus agglomeration. Agglomeration also can occur by sintering of MgSO{sub 4} or of CaSO{sub 4}; the latter compound also is elutriated from the combustor. However, the end-product produced by sulfation in the filter cakes of the Tidd PFBC demonstration plant was not MgSO{sub 4}, but Mg{sub 2}Ca(SO{sub 4}){sub 3}. The amounts of this compound and the rate at which it was produced also have been determined for the Tidd filter unit.

  6. Attrition and changes in size distribution of lime sorbents during fluidization in a circulating fluidized bed absorber. Double quarterly report, January 1--August 31, 1993

    SciTech Connect

    Lee, Sang-Kwun; Keener, T.C.; Cook, J.L.; Khang, Soon Jai

    1993-12-31

    The experimental data of lime sorbent attrition obtained from attriton tests in a circulating fluidized bed absorber (CFBA) are represented. The results are interpreted as both the weight-based attrition rate and size-based attrition rate. The weight-based attrition rate constants are obtained from a modified second-order attrition model, incorporating a minimum fluidization weight, W{sub min}, and excess velocity. Furthermore, this minimum fluidization weight, or W{sub min} was found to be a function of both particle size and velocity. A plot of the natural log of the overall weight-based attrition rate constants (ln K{sub a}) for Lime 1 (903 MMD) at superficial gas velocities of 2 m/s, 2.35 m/s, and 2.69 m/s and for Lime 2 (1764 MMD) at superficial gas velocities of 2 m/s, 3 m/s, 4 m/s and 5 m/s versus the energy term, 1/(U-U{sub mf}){sup 2}, yielded a linear relationship. And, a regression coefficient of 0.9386 for the linear regression confirms that K{sub a} may be expressed in Arrhenius form. In addition, an unsteady state population model is represented to predict the changes in size distribution of bed materials during fluidization. The unsteady state population model was verified experimentally and the solid size distribution predicted by the model agreed well with the corresponding experimental size distributions. The model may be applicable for the batch and continuous operations of fluidized beds in which the solids size reduction is predominantly resulted from attritions and elutriations. Such significance of the mechanical attrition and elutriation is frequently seen in a fast fluidized bed as well as in a circulating fluidized bed.

  7. Generation rates and emission factors of particulate matter and particle-bound polycyclic aromatic hydrocarbons of incense sticks.

    PubMed

    Lung, Shih-Chun Candice; Hu, Shu-Chuan

    2003-02-01

    The generation rates and emission factors of particulate matter and associated polycyclic aromatic hydrocarbons (PAHs) from incense burning were assessed in a laboratory setting. The differences among different segments of the same stick, among different sticks of the same kind of incense, and between two kinds of manually made Chih-Chen incense sticks (A and B) were evaluated. Joss sticks were burned inside a 44 cm long elutriator; personal environmental monitors fitted into the top of the elutriator were used to take PM2.5 and PM10 samples of incense smoke. Samples were analyzed for PAHs by gas chromatography-flame ionization Detector. It was found that particle and associated PAHs were generated approximately at 561 microg/min (geometric standard deviation (GSD) = 1.1) and 0.56 microg/min (GSD = 1.1) from Incense A, and at 661 microg/min (GSD = 1.7) and 0.46 microg/min (GSD = 1.3) from Incense B, respectively. One gram of Incense A emitted about 19.8 mg (GSD = 1.1) particulate matter and 17.1 microg (GSD = 1.2) particulate-phase PAHs, while one gram of Incense B produced around 43.6 mg (GSD = 1.1) of particles and 25.2 microg (GSD = 1.2) of particle-bound PAHs. There were significant differences in emissions between Incenses A and B, although they belong to the same class of incense. A 10-20% variability in emissions was observed in the main part of the manually produced stick, and a larger variation was found at both tips of the combustible part.

  8. Can physiological endpoints improve the sensitivity of assays with plants in the risk assessment of contaminated soils?

    PubMed

    Gavina, Ana; Antunes, Sara C; Pinto, Glória; Claro, Maria Teresa; Santos, Conceição; Gonçalves, Fernando; Pereira, Ruth

    2013-01-01

    Site-specific risk assessment of contaminated areas indicates prior areas for intervention, and provides helpful information for risk managers. This study was conducted in the Ervedosa mine area (Bragança, Portugal), where both underground and open pit exploration of tin and arsenic minerals were performed for about one century (1857-1969). We aimed at obtaining ecotoxicological information with terrestrial and aquatic plant species to integrate in the risk assessment of this mine area. Further we also intended to evaluate if the assessment of other parameters, in standard assays with terrestrial plants, can improve the identification of phytotoxic soils. For this purpose, soil samples were collected on 16 sampling sites distributed along four transects, defined within the mine area, and in one reference site. General soil physical and chemical parameters, total and extractable metal contents were analyzed. Assays were performed for soil elutriates and for the whole soil matrix following standard guidelines for growth inhibition assay with Lemna minor and emergence and seedling growth assay with Zea mays. At the end of the Z. mays assay, relative water content, membrane permeability, leaf area, content of photosynthetic pigments (chlorophylls and carotenoids), malondialdehyde levels, proline content, and chlorophyll fluorescence (Fv/Fm and ΦPSII) parameters were evaluated. In general, the soils near the exploration area revealed high levels of Al, Mn, Fe and Cu. Almost all the soils from transepts C, D and F presented total concentrations of arsenic well above soils screening benchmark values available. Elutriates of several soils from sampling sites near the exploration and ore treatment areas were toxic to L. minor, suggesting that the retention function of these soils was seriously compromised. In Z. mays assay, plant performance parameters (other than those recommended by standard protocols), allowed the identification of more phytotoxic soils. The results

  9. Flow-permeability feedbacks and the development of segregation pipes in volcanic materials

    NASA Astrophysics Data System (ADS)

    Rust, Alison

    2014-05-01

    Flow and transformation in volcanic porous media is important for the segregation of melts and aqueous fluids from magmas as well as elutriation of fine ash from pyroclastic flows and vents. The general topic will be discussed in the framework of understanding sets of vertical pipes found in two very different types of volcanic deposits: 1) vesicular (bubbly) cylinders in basalt lava flows and 2) gas escape pipes in pyroclastic flow deposits. In both cases the cylinders can be explained by a flow-permeability feedback where perturbations in porosity and thus permeability cause locally higher flow speeds that in turn locally increase the permeability. For vesicular cylinders in lava flows, the porous medium is a framework of crystals within the magma. Above a critical crystallinity, which depends on the shape and size distribution of the crystals, the crystals form a touching framework. As the water-saturated magma continues to cool, it crystallizes anhydrous minerals, resulting in the exsolution of water vapour bubbles that can drive flow of bubbly melt through the crystal network. It is common to find sets of vertical cylinders of bubby melt in solidified lava flows, with compositions that match the residual melt from 35-50% crystallization of the host basalt. These cylinders resemble chimneys in experiments of crystallising ammonium chloride solution that are explained by reactive flow with porous medium convection. The Rayleigh number for the magmatic case is too low for convection but the growth of steam bubbles as the magma crystallizes induces pore fluid flow up through the permeable crystal pile even if there is no convective instability. This bubble-growth-driven upward flow is reactive and can lead to channelization because of a feedback between velocity and permeability. For the gas escape pipes in pyroclastic flows, the porous medium is a very poorly sorted granular material composed of fragments of solid magma with a huge range of grain sizes from ash

  10. Guidelines for the processing and quality assurance of benthic invertebrate samples collected as part of the National Water-Quality Assessment Program

    USGS Publications Warehouse

    Cuffney, T.F.; Gurtz, M.E.; Meador, M.R.

    1993-01-01

    Benthic invertebrate samples are collected as part of the U.S. Geological Survey's National Water-Quality Assessment Program. This is a perennial, multidisciplinary program that integrates biological, physical, and chemical indicators of water quality to evaluate status and trends and to develop an understanding of the factors controlling observed water quality. The Program examines water quality in 60 study units (coupled ground- and surface-water systems) that encompass most of the conterminous United States and parts of Alaska and Hawaii. Study-unit teams collect and process qualitative and semi-quantitative invertebrate samples according to standardized procedures. These samples are processed (elutriated and subsampled) in the field to produce as many as four sample components: large-rare, main-body, elutriate, and split. Each sample component is preserved in 10-percent formalin, and two components, large-rare and main-body, are sent to contract laboratories for further processing. The large-rare component is composed of large invertebrates that are removed from the sample matrix during field processing and placed in one or more containers. The main-body sample component consists of the remaining sample materials (sediment, detritus, and invertebrates) and is subsampled in the field to achieve a volume of 750 milliliters or less. The remaining two sample components, elutriate and split, are used for quality-assurance and quality-control purposes. Contract laboratories are used to identify and quantify invertebrates from the large-rare and main-body sample components according to the procedures and guidelines specified within this document. These guidelines allow the use of subsampling techniques to reduce the volume of sample material processed and to facilitate identifications. These processing procedures and techniques may be modified if the modifications provide equal or greater levels of accuracy and precision. The intent of sample processing is to

  11. Methods for Isolation and Purification of Murine Liver Sinusoidal Endothelial Cells: A Systematic Review.

    PubMed

    Meyer, Jeremy; Gonelle-Gispert, Carmen; Morel, Philippe; Bühler, Léo

    2016-01-01

    To study the biological functions of liver sinusoidal endothelial cells (LSEC) and to identify their interplay with blood or liver cells, techniques allowing for the isolation and purification of LSEC have been developed over the last decades. The objective of the present review is to summarize and to compare the efficiency of existing methods for isolating murine LSEC. Toward this end, the MEDLINE database was searched for all original articles describing LSEC isolation from rat and mouse livers. Out of the 489 publications identified, 23 reported the main steps and outcomes of the procedure and were included in our review. Here, we report and analyse the technical details of the essential steps of the techniques used for LSEC isolation. The correlations between the prevalence of some steps and the efficiency of LSEC isolation were also identified. We found that centrifugal elutriation, selective adherence and, more recently, magnetic-activated cell sorting were used for LSEC purification. Centrifugal elutriation procured high yields of pure LSEC (for rats 30-141.9 million cells for 85-98% purities; for mice 9-9.25 million cells for >95% purities), but the use of this method remained limited due to its high technical requirements. Selective adherence showed inconsistent results in terms of cell yields and purities in rats (5-100 million cells for 73.7-95% purities). In contrast, magnetic-activated cell sorting allowed for the isolation of highly pure LSEC, but overall lower cell yields were reported (for rats 10.7 million cells with 97.6% purity; for mice 0.5-9 million cells with 90-98% purities). Notably, the controversies regarding the accuracy of several phenotypic markers for LSEC should be considered and their use for both magnetic sorting and characterization remain doubtful. It appears that more effort is needed to refine and standardize the procedure for LSEC isolation, with a focus on the identification of specific antigens. Such a procedure is required

  12. Methods for Isolation and Purification of Murine Liver Sinusoidal Endothelial Cells: A Systematic Review.

    PubMed

    Meyer, Jeremy; Gonelle-Gispert, Carmen; Morel, Philippe; Bühler, Léo

    2016-01-01

    To study the biological functions of liver sinusoidal endothelial cells (LSEC) and to identify their interplay with blood or liver cells, techniques allowing for the isolation and purification of LSEC have been developed over the last decades. The objective of the present review is to summarize and to compare the efficiency of existing methods for isolating murine LSEC. Toward this end, the MEDLINE database was searched for all original articles describing LSEC isolation from rat and mouse livers. Out of the 489 publications identified, 23 reported the main steps and outcomes of the procedure and were included in our review. Here, we report and analyse the technical details of the essential steps of the techniques used for LSEC isolation. The correlations between the prevalence of some steps and the efficiency of LSEC isolation were also identified. We found that centrifugal elutriation, selective adherence and, more recently, magnetic-activated cell sorting were used for LSEC purification. Centrifugal elutriation procured high yields of pure LSEC (for rats 30-141.9 million cells for 85-98% purities; for mice 9-9.25 million cells for >95% purities), but the use of this method remained limited due to its high technical requirements. Selective adherence showed inconsistent results in terms of cell yields and purities in rats (5-100 million cells for 73.7-95% purities). In contrast, magnetic-activated cell sorting allowed for the isolation of highly pure LSEC, but overall lower cell yields were reported (for rats 10.7 million cells with 97.6% purity; for mice 0.5-9 million cells with 90-98% purities). Notably, the controversies regarding the accuracy of several phenotypic markers for LSEC should be considered and their use for both magnetic sorting and characterization remain doubtful. It appears that more effort is needed to refine and standardize the procedure for LSEC isolation, with a focus on the identification of specific antigens. Such a procedure is required

  13. Methods for Isolation and Purification of Murine Liver Sinusoidal Endothelial Cells: A Systematic Review

    PubMed Central

    Meyer, Jeremy; Gonelle-Gispert, Carmen; Morel, Philippe; Bühler, Léo

    2016-01-01

    To study the biological functions of liver sinusoidal endothelial cells (LSEC) and to identify their interplay with blood or liver cells, techniques allowing for the isolation and purification of LSEC have been developed over the last decades. The objective of the present review is to summarize and to compare the efficiency of existing methods for isolating murine LSEC. Toward this end, the MEDLINE database was searched for all original articles describing LSEC isolation from rat and mouse livers. Out of the 489 publications identified, 23 reported the main steps and outcomes of the procedure and were included in our review. Here, we report and analyse the technical details of the essential steps of the techniques used for LSEC isolation. The correlations between the prevalence of some steps and the efficiency of LSEC isolation were also identified. We found that centrifugal elutriation, selective adherence and, more recently, magnetic-activated cell sorting were used for LSEC purification. Centrifugal elutriation procured high yields of pure LSEC (for rats 30–141.9 million cells for 85–98% purities; for mice 9–9.25 million cells for >95% purities), but the use of this method remained limited due to its high technical requirements. Selective adherence showed inconsistent results in terms of cell yields and purities in rats (5–100 million cells for 73.7–95% purities). In contrast, magnetic-activated cell sorting allowed for the isolation of highly pure LSEC, but overall lower cell yields were reported (for rats 10.7 million cells with 97.6% purity; for mice 0.5–9 million cells with 90–98% purities). Notably, the controversies regarding the accuracy of several phenotypic markers for LSEC should be considered and their use for both magnetic sorting and characterization remain doubtful. It appears that more effort is needed to refine and standardize the procedure for LSEC isolation, with a focus on the identification of specific antigens. Such a procedure

  14. Experimental investigation into the incineration of wool scouring sludges in a novel rotating fluidised bed.

    PubMed

    Wong, W Y; Lu, Y; Nasserzadeh, V S; Swithenbank, J; Shaw, T; Madden, M

    2000-04-01

    The main purpose of this research was to investigate the possibility of incineration of wool scouring sludges in a novel vertical axis rotating fluidized bed (RFB). A small-scale RFB was designed and constructed with an internal diameter (ID) of 200 mm and height of 50 mm to carry out the experiments. In phase one of the experiments, a cold test was conducted to investigate the fluidization performance of the RFB, which eventually led to the optimisation of the operating parameters, i.e., sand particle size, rotation speed and bed loading (bed thickness) which ensures complete fluidization and minimum particle elutriation. Sand particle size of 0.5 to 0.6 mm, rotation speed of 200 to 400 rpm and bed loading of 1 kg (equivalent to bed thickness of 27 mm) were found optimal. These information generated were useful for the second phase of the experiments, which was the hot test, in investigating the possibility of incinerating wool scouring sludges in the RFB. Nine wool sludges from different process routes generated from the wool scouring industries were analysed for their compositions. Most of these sludges were highly moist, had high volatile matter and high ash content with low level of fixed carbon. These characteristics made incineration difficult. Hence, the effect of varying the moisture content, rotation speed and sludge feed rate on the incineration of the three selected sludges were studied in the hot test. With 5% support methane, all sludges with a maximum moisture up to 70% as-received could be successfully burned in the RFB at rotating speeds of 200 and 300 rpm. The combustion was found to be intense with a high efficiency due to the good turbulence and mixing in the RFB. The combustion gases produced, i.e., CO, CO(2) and NO(x) were reasonably low due to the high combustion intensity and efficiency. To study the dynamics of the bed and freeboard region in the RFB, the velocity flow field was simulated using a computational fluid dynamics (CFD) model to

  15. Cyclin-like accumulation and loss of the putative kinetochore motor CENP-E results from coupling continuous synthesis with specific degradation at the end of mitosis

    PubMed Central

    1994-01-01

    CENP-E is a kinesin-like protein that binds to kinetochores through the early stages of mitosis, but after initiation of anaphase, it relocalizes to the overlapping microtubules in the midzone, ultimately concentration in the developing midbody. By immunoblotting of cells separated at various positions in the cell cycle using centrifugal elutriation, we show that CENP-E levels increase progressively across the cycle peaking at approximately 22,000 molecules/cell early in mitosis, followed by an abrupt (> 10 fold) loss at the end of mitosis. Pulse-labeling with [35S]methionine reveals that beyond a twofold increase in synthesis between G1 and G2, interphase accumulation results primarily from stabilization of CENP-E during S and G2. Despite localizing in the midbody during normal cell division, CENP-E loss at the end of mitosis is independent of cytokinesis, since complete blockage of division with cytochalasin has no affect on CENP-E loss at the M/G1 transition. Thus, like mitotic cyclins, CENP-E accumulation peaks before cell division, and it is specifically degraded at the end of mitosis. However, CENP-E degradation kinetically follows proteolysis of cyclin B in anaphase. Combined with cyclin A destruction before the end of metaphase, degradation of as yet unidentified components at the metaphase/anaphase transition, and cyclin B degradation at or after the anaphase transition, CENP-E destruction defines a fourth point in a mitotic cascade of timed proteolysis. PMID:8207059

  16. Steaming of cotton to prevent byssinosis—a plant study

    PubMed Central

    Imbus, Harold R.; Suh, Moon W.

    1974-01-01

    Imbus, H. R. and Suh, M. W. (1974).British Journal of Industrial Medicine,31, 209-219. Steaming of cotton to prevent byssinosis—a plant study. Pulmonary function tests, respiratory questionnaires, and dust measurements were made in a cotton spinning plant during the processing of steamed cotton and after its discontinuance. During steaming the average drop in FEV1 (Δ FEV1) from the beginning to six hours into the work shift was 19 ml, and after steaming was discontinued 62 ml. In addition, the FEV1 measurements, before work on the first day of the work week, were 60 to 100 ml higher during the time of steaming. The improvement in Δ FEV1 with steaming was much greater for males than for females. Improvement was greatest in the higher dust areas, namely, opening, picking, blending, and carding, and less in spinning, winding, and twisting. Questionnaire results did not reveal any significant difference in the incidence of symptoms of byssinosis during the two periods, the reasons for which are not clear. There was an approximately 30% reduction in elutriated and total dust. PMID:4415886

  17. Mesenchymal precursor cells in the blood of normal individuals.

    PubMed

    Zvaifler, N J; Marinova-Mutafchieva, L; Adams, G; Edwards, C J; Moss, J; Burger, J A; Maini, R N

    2000-01-01

    STATEMENT OF FINDINGS: Mesenchymal precursor cells found in the blood (BMPCs) of normal persons adhere to plastic and glass and proliferate logarithmically in DMEM-20% fetal calf serum (FCS) without growth factors. They form cells with fibroblast-like and stromal morphology, which is not affected by eliminating CD34, CD3, or CD14 cells. Osteogenic supplements (dexamethasone, ascorbic acid, and beta-glycerophosphate) added to the culture inhibited fibroblast formation, and BMPCs assumed the cuboidal shape of osteoblasts. After 5 days in supplemented medium, the elutriated cells displayed alkaline phosphatase (AP), and the addition of bone morphogenetic protein (BMP)2 (1 ng) doubled AP production (P < 0.04). Two weeks later, 30% of the cells were very large and reacted with anti-osteocalcin antibody. The same cultures also contained sudanophlic adipocytes and multinucleated giant cells that stained for tartrate-resistant acid phosphatase (TRAP) and vitronectin receptors. Cultured BMPCs immunostain with antibodies to vimentin, type I collagen, and BMP receptors, heterodimeric structures expressed on mesenchymal lineage cells. In addition, BMPCs stain with anti-CD105 (endoglin), a putative marker for bone-marrow mesenchymal stem cells (MSCs). PMID:11056678

  18. [Phosphorus forms of the suspended particulate matter in the Yellow River downstream during water and sediment regulation 2008].

    PubMed

    Wei, Jun-Feng; Chen, Hong-Tao; Liu, Yue-Liang; Shan, Kai; Yao, Qing-Zhen; He, Hui-Jun; Yu, Zhi-Gang

    2011-02-01

    Suspended particulate matter samples were collected from Lijin Station on the Yellow River during the 2008 water and sediment regulation. Using water elutriation method, samples were physically separated according to grain size, and phosphorus forms were detected by the improved SEDEX technology. Results show that authigenic apatite phosphorus and organic phosphorus are the dominant forms of the particulate phosphorus. During water and sediment regulation, concentrations of total particulate phosphorus, loosely adsorbed phosphorus, organic phosphorus and refractory phosphorus are lower than those in other time of the year, while the concentration of detrital fluorapatite phosphorus is higher than that in other time. Grain size is the primary variable in the determination of the content of various particulate phosphorus forms. In fine particles, loosely adsorbed phosphorus, organic phosphorus and refractory phosphorus concentrations are high, while detrital fluorapatite phosphorus concentration is high in coarse particles. About 28.3% of the total particulate phosphorus is in the form of bio-available phosphorus, of which organic phosphorus is the major component. During the water and sediment regulation, the fluxes of sediment, particulate phosphorus and particulate bio-available phosphorus are 6.63 x 10(7) t, 3.42 x 10(4) t, and 8.30 x 10(3) t, which are 83.2%, 78.6%, and 80.2% each of the total fluxes in 2008.

  19. Acute lung function response to cotton dust in atopic and non-atopic individuals.

    PubMed Central

    Sepulveda, M J; Castellan, R M; Hankinson, J L; Cocke, J B

    1984-01-01

    Acute spirometric responses to inhaled cotton dust were examined in a population of 226 healthy, non-asthmatic adults whose atopic status had been evaluated by skin prick tests to 10 common environmental allergens. Exposure to cotton dust occurred in model cardrooms where elutriated dust levels were carefully controlled (1.02 mg/m3). Atopy, defined as positive prick tests to at least two allergens, was observed in 26% of subjects. Significant forced expiratory volume in one second (FEV1) decrements occurred after exposure to cotton dust independent of atopic status (p less than 0.001). The mean FEV1 decline in atopic subjects, however, was significantly greater than in non-atopic subjects (p less than 0.05). Degree of atopy, as measured by number of positive skin tests, also exhibited a significant association with cotton induced decrements in FEV1 (p less than 0.05). These data suggest that atopy may be an important determinant of the magnitude of the acute pulmonary response to cotton dust. This may reflect the non-specific airways hyperresponsiveness that has been described in non-asthmatic, atopic individuals. PMID:6498112

  20. Study on the property of the production for Fengdongyan kiln in Early Ming dynasty by INAA and EDXRF

    NASA Astrophysics Data System (ADS)

    Li, L.; Huang, Y.; Sun, H. Y.; Yan, L. T.; Feng, S. L.; Xu, Q.; Feng, X. Q.

    2016-08-01

    A lot of official wares carved "Guan" or the dragon patterns were excavated on the strata of Ming dynasty of the Fengdongyan kiln site at Dayao County. The imperial porcelain was fired in Hongwu and Yongle eras. However, the emergence of this imperial porcelain has triggered academic debate about the property of Fengdongyan kiln in the Early Ming dynasty. Based on the differences of the official kiln management, some scholars have determined that the property of the production for this kiln was the civilian kiln. According to the historical textural records and typology, others preliminary confirmed that Fengdongyan kiln was the official kiln. In this paper, the elemental compositions of body and glaze in imperial and civilian porcelain are study by INAA and EDXRF for determining the property of the production for this kiln in Early Ming dynasty. After the processing of experimental data by geochemical analysis and principal component analysis, the result show that the raw materials for making body and glaze in imperial porcelain are similar with those of the civilian porcelain and the degrees of elutriation for body can be slightly different in HW-M period of Ming dynasty. The analytical results support the view that the Fengdongyan kiln is civilian not official.

  1. Microbiological community analysis of vermicompost tea and its influence on the growth of vegetables and cereals.

    PubMed

    Fritz, J I; Franke-Whittle, I H; Haindl, S; Insam, H; Braun, R

    2012-07-01

    Vermicompost, the digestion product of organic material by earthworms, has been widely reported to have a more positive effect on plant growth and plant health than conventional compost. A study was conducted to investigate the effects of different vermicompost elutriates (aerated compost teas) on soils and plant growth. The teas were analyzed by chemical, microbiological, and molecular methods accompanied by plant growth tests at laboratory and field scale. The number of microorganisms in the teas increased during the extraction process and was affected by substrate addition. The vermicompost tea found to increase plant growth best under laboratory tests was applied to cereals (wheat and barley) and vegetables (Raphanus sativus, Rucola selvatica, and Pisum sativum) in a field study. The results revealed no effects of tea application on plant yield; however, sensoric tests indicated an improvement in crop quality. The soils from laboratory and field studies were investigated to detect possible microbial or chemical changes. The results indicated that minor changes to the soil microbial community occurred following tea application by foliar spray in both the laboratory-scale and field-scale experiments. PMID:22712623

  2. Development of a solid waste fired fluidized boiler, phase 1

    NASA Astrophysics Data System (ADS)

    Preuit, L. C.

    1982-02-01

    Tests were conducted to develop solid waste fired fluid bed boiler (FBB) technology. The fluid bed facility incorporates water tubes for heat extraction and can burn over seven tons of refuse derived fuel per day. Municipal solid waste from surrounding communities is shredded and air classified to remove inerts and recoverable materials. Current and past work shows that a fluid bed boiler will be able to operate at excess air levels well below those presently required by conventional grate-type waste fired boilers, and with comparable or superior combustion efficiencies. Tests were conducted to investigate: the range of process conditions over which satisfactory operation can be maintained; suppression of acid gas emissions; recycle of elutriated fines back to the fluid bed; and fuel technology. In previous testing, operation was stable while firing refuse derived fuel for the duration of a 300-hour test. No agglomeration of bed material or slag formation was experienced. Low excess air, low exhaust gas emissions, and constant bed temperature demonstrated feasibility of steam generation from fluid bed combustion.

  3. Radionuclide Leaching from Organic Ion Exchange Resin

    SciTech Connect

    Delegard, C.H.; Rinehart, D.E.

    1999-04-02

    Laboratory tests were performed to examine the efficacy of leach treatments for decontaminating organic ion exchange resins (OIER), which have been found in a number of samples retrieved from K East Basin sludge. Based on process records, the OIER found in the K Basins is a mixed-bet strong acid/strong base material marketed as Purolite{trademark} NRW-037. Radionuclides sorbed or associated with the OIER can restrict its disposal to the Environmental Restoration Disposal Facility (ERDF). The need for testing to support development of a treatment process for K Basin sludge has been described in Section 4.2 of ''Testing Strategy to Support the Development of K Basins Sludge Treatment Process'' (Flament 1998). To help understand the effects of anticipated OIER elutriation and washing, tests were performed with well-rinsed OIER material from K East Basin floor sludge (sample H-08 BEAD G) and with well-rinsed OIER having approximately 5% added K East canister composite sludge (sample KECOMP). The rinsed resin-bearing material also contained the inorganic ion exchanger Zeolon-900{trademark}, a zeolite primarily composed of the mineral mordenite. The zeolite was estimated to comprise 27 weight percent of the dry H-08 BEAD G material.

  4. Lime-based sorbents for high-temperature CO2 capture--a review of sorbent modification methods.

    PubMed

    Manovic, Vasilije; Anthony, Edward J

    2010-08-01

    This paper presents a review of the research on CO(2) capture by lime-based looping cycles undertaken at CanmetENERGY's (Ottawa, Canada) research laboratories. This is a new and very promising technology that may help in mitigation of global warming and climate change caused primarily by the use of fossil fuels. The intensity of the anticipated changes urgently requires solutions such as more cost-effective technologies for CO(2) capture. This new technology is based on the use of lime-based sorbents in a dual fluidized bed combustion (FBC) reactor which contains a carbonator-a unit for CO(2) capture, and a calciner-a unit for CaO regeneration. However, even though natural materials are cheap and abundant and very good candidates as solid CO(2) carriers, their performance in a practical system still shows significant limitations. These limitations include rapid loss of activity during the capture cycles, which is a result of sintering, attrition, and consequent elutriation from FBC reactors. Therefore, research on sorbent performance is critical and this paper reviews some of the promising ways to overcome these shortcomings. It is shown that reactivation by steam/water, thermal pre-treatment, and doping simultaneously with sorbent reforming and pelletization are promising potential solutions to reduce the loss of activity of these sorbents over multiple cycles of use.

  5. Synchronization of mammalian cell cultures by serum deprivation.

    PubMed

    Langan, Thomas J; Chou, Richard C

    2011-01-01

    Mammalian cells are amenable to study the regulation of cell cycle progression in vitro by shifting them into the same phase of the cycle. Procedures to arrest cultured cells in specific phases of the cell cycle may be termed in vitro synchronization. The procedure described here was developed for the study of primary astrocytes and a glioma cell line, but is applicable to other mammalian cells. Its application allows astrocytes to reenter the cell cycle from a state of quiescence (G(0)), and then, under carefully defined experimental conditions, to move together into subsequent phases such as the G(1) and S phases. A number of methods have been established to synchronize mammalian cell cultures, which include physical separation by centrifugal elutriation and mitotic shake off or chemically induced cell cycle arrest. Yet, there are intrinsic limitations associated with these methods. In the present protocol, we describe a simple, reliable, and reversible procedure to synchronize astrocyte and glioma cultures from newborn rat brain by serum deprivation. The procedure is similar, and generally applicable, to other mammalian cells. This protocol consists essentially of two parts: (1) proliferation of astrocytes under optimal conditions in vitro until reaching desired confluence; and (2) synchronization of cultures by serum downshift and arrested in the G(0) phase of the cell cycle. This procedure has been extended to the examination of cell cycle control in astroglioma cells and astrocytes from injured adult brain. It has also been employed in precursor cloning studies in developmental biology, suggesting wide applicability.

  6. In vitro synchronization of mammalian astrocytic cultures by serum deprivation.

    PubMed

    Chou, Richard C; Langan, Thomas J

    2003-07-01

    The study of the regulation of cell division cycle in vitro requires cell cultures growing in the same phase of the cycle. The procedure by which cells are arrested in specific phases of the cell cycle is termed synchronization. Synchronization is particularly important in the study of astrocyte biology, as its application allows astrocytes to re-enter the cell cycle from a state of quiescence (G(0)), and, under carefully defined experimental conditions, move together into subsequent phases such as the G(1) and S phases. A number of methods have been established to synchronize mammalian cell cultures, including centrifugal elutriation, mitotic shake-off, and chemically induced cell cycle arrest. Yet there are intrinsic limitations associated with these methods. In the present protocol, we describe a simple, reliable, and reversible procedure to synchronize astrocytic cultures from newborn rat brains by serum deprivation. This protocol consists essentially of two parts: (1) proliferation of astrocytes under optimal conditions in vitro until reaching desired confluence; and (2) synchronization of cultures by serum down-shift and arrested in the G(0) phase of the cell cycle. This procedure has recently been extended toward the study of cell cycle control in astroglioma cells and astrocytes from injured adult brains. Since it was also employed in recent precursor cloning studies in developmental biology, this procedure will certainly find increasing use in future research.

  7. A novel method for extraction of a proteinous coagulant from Plantago ovata seeds for water treatment purposes.

    PubMed

    Ramavandi, Bahman; Hashemi, Seyedenayat; Kafaei, Raheleh

    2015-01-01

    Several chemicals have been applied in the process of coagulant extraction from herbal seeds, and the best extraction has been obtained in the presence of KCl or NaNO3[1-3], and NaCl [4]. However, the main challenge posed to these methods of coagulant extraction is their relatively low efficiency for water treatment purposes and the formation of dissolved organic matter during the treatment process. In these methods the salts, which have a one-valance metal (Na(+) and K(+)), are deposited in the internal structure and the pore of the coagulant, and may be useful for the coagulation/flocculation process. In this research, we found that modified methods produced more dense protein. Therefore, the modified procedure was better than the older one for removal of turbidity and harness from the contaminated water. Here we describe a method where: •According to the Hardy-Schulze rule, we applied the Fe(3+) ions instead of Na(+) and K(+) for the extraction of protein from Plantago ovata seeds.•The method was narrowed to extract protein by ethanol (defatting) and ammonium acetate and CM-Sepharose (protein extraction).•Two consecutive elutriations of crude extract was directly performed using 0.025-M FeCl3 and 0.05-M FeCl3 according to the basis of the ion-exchange processes. PMID:26150999

  8. Chemistry and toxicity of sediments from San Diego Bay, including a biomarker (P450 RGS) response

    SciTech Connect

    Anderson, J.W.; Newton, F.C.; Hardin, J.; Tukey, R.H.; Richter, K.E.

    1996-12-31

    Thirty sediment samples were collected from the vicinity of the Naval Docking Facility in San Diego Bay and used to conduct bioassays with amphipods, oyster larvae, Microtox, and a new rapid screening test called the cytochrome P450 Reporter Gene System (RGS). This RGS cell line, from a human liver cancer cell, has been engineered to produce luciferase, when the CYP1A1 gene on the chromosome is induced by toxic and carcinogenic organics (dioxin, coplanar PCBs, PAHs). Elutriates were tested with both Microtox and oyster larvae, and organic extracts of sediments were tested with Microtox and the P450 RGS assay. Chemical analyses included total organic carbon (TOC), and acid volatile sulfides (AVS) along with a wide range of metals and organic chemicals. The simultaneously extracted metals (SEM) to AVS ratio was compared to the toxic response of oyster larvae and amphipods. Along each of the piers sampled, contaminant concentrations decreased with distance from shore. A correlation matrix analysis of all biological and chemical data was conducted. The strongest correlation between a chemical measurement and a biological response was that of total PAH versus the P450 RGS response. The use of P450 RGS as a screening tool to assess the relative risk of contaminants on sediments is biologically meaningful, and is a rapid and inexpensive means of determining which samples require complete chemical characterization.

  9. Lime-Based Sorbents for High-Temperature CO2 Capture—A Review of Sorbent Modification Methods

    PubMed Central

    Manovic, Vasilije; Anthony, Edward J.

    2010-01-01

    This paper presents a review of the research on CO2 capture by lime-based looping cycles undertaken at CanmetENERGY’s (Ottawa, Canada) research laboratories. This is a new and very promising technology that may help in mitigation of global warming and climate change caused primarily by the use of fossil fuels. The intensity of the anticipated changes urgently requires solutions such as more cost-effective technologies for CO2 capture. This new technology is based on the use of lime-based sorbents in a dual fluidized bed combustion (FBC) reactor which contains a carbonator—a unit for CO2 capture, and a calciner—a unit for CaO regeneration. However, even though natural materials are cheap and abundant and very good candidates as solid CO2 carriers, their performance in a practical system still shows significant limitations. These limitations include rapid loss of activity during the capture cycles, which is a result of sintering, attrition, and consequent elutriation from FBC reactors. Therefore, research on sorbent performance is critical and this paper reviews some of the promising ways to overcome these shortcomings. It is shown that reactivation by steam/water, thermal pre-treatment, and doping simultaneously with sorbent reforming and pelletization are promising potential solutions to reduce the loss of activity of these sorbents over multiple cycles of use. PMID:20948952

  10. A novel method for extraction of a proteinous coagulant from Plantago ovata seeds for water treatment purposes

    PubMed Central

    Ramavandi, Bahman; Hashemi, Seyedenayat; Kafaei, Raheleh

    2015-01-01

    Several chemicals have been applied in the process of coagulant extraction from herbal seeds, and the best extraction has been obtained in the presence of KCl or NaNO3[1], [2], [3], and NaCl [4]. However, the main challenge posed to these methods of coagulant extraction is their relatively low efficiency for water treatment purposes and the formation of dissolved organic matter during the treatment process. In these methods the salts, which have a one-valance metal (Na+ and K+), are deposited in the internal structure and the pore of the coagulant, and may be useful for the coagulation/flocculation process. In this research, we found that modified methods produced more dense protein. Therefore, the modified procedure was better than the older one for removal of turbidity and harness from the contaminated water. Here we describe a method where: • According to the Hardy–Schulze rule, we applied the Fe3+ ions instead of Na+ and K+ for the extraction of protein from Plantago ovata seeds. • The method was narrowed to extract protein by ethanol (defatting) and ammonium acetate and CM-Sepharose (protein extraction). • Two consecutive elutriations of crude extract was directly performed using 0.025-M FeCl3 and 0.05-M FeCl3 according to the basis of the ion-exchange processes. PMID:26150999

  11. Experimental and predicted approaches for biomass gasification with enriched air-steam in a fluidised bed.

    PubMed

    Fu, Qirang; Huang, Yaji; Niu, Miaomiao; Yang, Gaoqiang; Shao, Zhiwei

    2014-10-01

    Thermo-chemical gasification of sawdust refuse-derived fuel was performed on a bench-scale fluidised bed gasifier with enriched air and steam as fluidising and oxidising agents. Dolomite as a natural mineral catalyst was used as bed material to reform tars and hydrocarbons. A series of experiments were carried out under typical operating conditions for gasification, as reported in the article. A modified equilibrium model, based on equilibrium constants, was developed to predict the gasification process. The sensitivity analysis of operating parameters, such as the fluidisation velocity, oxygen percentage of the enriched air and steam to biomass ratios on the produced gas composition, lower heating value, carbon conversion and cold gas efficiency was investigated. The results showed that the predicted syngas composition was in better agreement with the experimental data compared with the original equilibrium model. The higher fluidisation velocity enhanced gas-solid mixing, heat and mass transfers, and carbon fines elutriation, simultaneously. With the increase of oxygen percentage from 21% to 45%, the lower heating value of syngas increased from 5.52 MJ m(-3) to 7.75 MJ m(-3) and cold gas efficiency from 49.09% to 61.39%. The introduction of steam improved gas quality, but a higher steam to biomass ratio could decrease carbon conversion and gasification efficiency owing to a low steam temperature. The optimal value of steam to biomass ratio in this work was 1.0. PMID:25265865

  12. Liver injury in hypervitaminosis A: Evidence for activation of Kupffer cell function

    SciTech Connect

    Sim, W.L.W.

    1988-01-01

    The most important and novel finding of this work was enhanced liver Kupffer cell phagocytic and metabolic function by hypervitaminosis A. An animal model of hypervitaminosis A was developed in male Sprague-Dawley rats gavaged with 250,000 I.U. retinol/kg body weight/day for 3 weeks. Presence of hypervitaminosis A was indicated by characteristic changes in the fur coat, presence of brittle bones and spontaneous fractures and a significant increase in plasma and liver concentrations of retinyl palmitate while retinol levels remained the same as in controls. Hypervitaminosis A did not cause severe liver abnormalities as reflected by normal plasma glutamate pyruvate transaminase activity and bilirubin. The main change was a marked increase in size of the fat or Vitamin A storing cells. Measurement of clearance from blood of indocyanine green and {sup 99m}Tc-disofenin indicated this hepatocyte function was normal. Kupffer cell phagocytic function was enhanced in hypervitaminosis A as determined by clearance from blood of {sup 99m}Tc-sulfur colloid. In vitro, there was also evidence that treatment with high doses of Vitamin A activated or enhanced Kupffer cell function. Kupffer cells from control and Vitamin A treated rats were isolated by enzymatic dispersion, purified by centrifugal elutriation, and placed in culture. Activation was indicated by (1) increased phagocytosis of {sup 51}Cr-labeled opsonized sheep red blood cells (2) enhanced release of superoxide anion and (3) enhanced production of tumor cytolytic factor by Kupffer cells from Vitamin A treated rats.

  13. Optimum design and operation of primary sludge fermentation schemes for volatile fatty acids production.

    PubMed

    Chanona, J; Ribes, J; Seco, A; Ferrer, J

    2006-01-01

    This paper presents a model-knowledge based algorithm for optimising the primary sludge fermentation process design and operation. This is a recently used method to obtain the volatile fatty acids (VFA), needed to improve biological nutrient removal processes, directly from the raw wastewater. The proposed algorithm consists in a heuristic reasoning algorithm based on the expert knowledge of the process. Only effluent VFA and the sludge blanket height (SBH) have to be set as design criteria, and the optimisation algorithm obtains the minimum return sludge and waste sludge flow rates which fulfil those design criteria. A pilot plant fed with municipal raw wastewater was operated in order to obtain experimental results supporting the developed algorithm groundwork. The experimental results indicate that when SBH was increased, higher solids retention time was obtained in the settler and VFA production increased. Higher recirculation flow-rates resulted in higher VFA production too. Finally, the developed algorithm has been tested by simulating different design conditions with very good results. It has been able to find the optimal operation conditions in all cases on which preset design conditions could be achieved. Furthermore, this is a general algorithm that can be applied to any fermentation-elutriation scheme with or without fermentation reactor.

  14. Replication Factor C3 of Schizosaccharomyces pombe, a Small Subunit of Replication Factor C Complex, Plays a Role in Both Replication and Damage Checkpoints

    PubMed Central

    Shimada, Midori; Okuzaki, Daisuke; Tanaka, Seiji; Tougan, Takahiro; Tamai, Katsuyuki K.; Shimoda, Chikashi; Nojima, Hiroshi

    1999-01-01

    We report here the isolation and functional analysis of the rfc3+ gene of Schizosaccharomyces pombe, which encodes the third subunit of replication factor C (RFC3). Because the rfc3+ gene was essential for growth, we isolated temperature-sensitive mutants. One of the mutants, rfc3-1, showed aberrant mitosis with fragmented or unevenly separated chromosomes at the restrictive temperature. In this mutant protein, arginine 216 was replaced by tryptophan. Pulsed-field gel electrophoresis suggested that rfc3-1 cells had defects in DNA replication. rfc3-1 cells were sensitive to hydroxyurea, methanesulfonate (MMS), and gamma and UV irradiation even at the permissive temperature, and the viabilities after these treatments were decreased. Using cells synchronized in early G2 by centrifugal elutriation, we found that the replication checkpoint triggered by hydroxyurea and the DNA damage checkpoint caused by MMS and gamma irradiation were impaired in rfc3-1 cells. Association of Rfc3 and Rad17 in vivo and a significant reduction of the phosphorylated form of Chk1 in rfc3-1 cells after treatments with MMS and gamma or UV irradiation suggested that the checkpoint signal emitted by Rfc3 is linked to the downstream checkpoint machinery via Rad17 and Chk1. From these results, we conclude that rfc3+ is required not only for DNA replication but also for replication and damage checkpoint controls, probably functioning as a checkpoint sensor. PMID:10588638

  15. Replication factor C3 of Schizosaccharomyces pombe, a small subunit of replication factor C complex, plays a role in both replication and damage checkpoints.

    PubMed

    Shimada, M; Okuzaki, D; Tanaka, S; Tougan, T; Tamai, K K; Shimoda, C; Nojima, H

    1999-12-01

    We report here the isolation and functional analysis of the rfc3(+) gene of Schizosaccharomyces pombe, which encodes the third subunit of replication factor C (RFC3). Because the rfc3(+) gene was essential for growth, we isolated temperature-sensitive mutants. One of the mutants, rfc3-1, showed aberrant mitosis with fragmented or unevenly separated chromosomes at the restrictive temperature. In this mutant protein, arginine 216 was replaced by tryptophan. Pulsed-field gel electrophoresis suggested that rfc3-1 cells had defects in DNA replication. rfc3-1 cells were sensitive to hydroxyurea, methanesulfonate (MMS), and gamma and UV irradiation even at the permissive temperature, and the viabilities after these treatments were decreased. Using cells synchronized in early G2 by centrifugal elutriation, we found that the replication checkpoint triggered by hydroxyurea and the DNA damage checkpoint caused by MMS and gamma irradiation were impaired in rfc3-1 cells. Association of Rfc3 and Rad17 in vivo and a significant reduction of the phosphorylated form of Chk1 in rfc3-1 cells after treatments with MMS and gamma or UV irradiation suggested that the checkpoint signal emitted by Rfc3 is linked to the downstream checkpoint machinery via Rad17 and Chk1. From these results, we conclude that rfc3(+) is required not only for DNA replication but also for replication and damage checkpoint controls, probably functioning as a checkpoint sensor. PMID:10588638

  16. Analysis of the Schizosaccharomyces pombe Cell Cycle.

    PubMed

    Hagan, Iain M; Grallert, Agnes; Simanis, Viesturs

    2016-01-01

    Schizosaccharomyces pombe cells are rod shaped, and they grow by tip elongation. Growth ceases during mitosis and cell division; therefore, the length of a septated cell is a direct measure of the timing of mitotic commitment, and the length of a wild-type cell is an indicator of its position in the cell cycle. A large number of documented stage-specific changes can be used as landmarks to characterize cell cycle progression under specific experimental conditions. Conditional mutations can permanently or transiently block the cell cycle at almost any stage. Large, synchronously dividing cell populations, essential for the biochemical analysis of cell cycle events, can be generated by induction synchrony (arrest-release of a cell cycle mutant) or selection synchrony (centrifugal elutriation or lactose-gradient centrifugation). Schizosaccharomyces pombe cell cycle studies routinely combine particular markers, mutants, and synchronization procedures to manipulate the cycle. We describe these techniques and list key landmarks in the fission yeast mitotic cell division cycle. PMID:27587785

  17. Characterization of chemical waste site contamination and its extent using bioassays

    SciTech Connect

    Thomas, J.M.; Callahan, C.A.; Cline, J.F.; Greene, J.C.; McShane, M.C.; Miller, W.E.; Peterson, S.A.; Simpson, J.C.; Skalski, J.R.

    1984-12-01

    Bioassays were used in a three-phase research project to assess the comparative sensitivity of test organisms to known chemicals, determine if the chemical components in field soil and water samples containing unknown contaminants could be inferred from our laboratory studies using known chemicals, and to investigate kriging (a relatively new statistical mapping technique) and bioassays as methods to define the areal extent of chemical contamination. The algal assay generally was most sensitive to samples of pure chemicals, soil elutriates and water from eight sites with known chemical contamination. Bioassays of nine samples of unknown chemical composition from the Rocky Mountain Arsenal (RMA) site showed that a lettuce seed soil contact phytoassay was most sensitive. In general, our bioassays can be used to broadly identify toxic components of contaminated soil. Nearly pure compounds of insecticides and herbicides were less toxic in the sensitive bioassays than were the counterpart commercial formulations. This finding indicates that chemical analysis alone may fail to correctly rate the severity of environmental toxicity. Finally, we used the lettuce seed phytoassay and kriging techniques in a field study at RMA to demonstrate the feasibility of mapping contamination to aid in cleanup decisions. 25 references, 9 figures, 9 tables.

  18. Fluidized-bed reactor modeling for production of silicon by silane pyrolysis

    NASA Technical Reports Server (NTRS)

    Dudukovic, M. P.; Ramachandran, P. A.; Lai, S.

    1986-01-01

    An ideal backmixed reactor model (CSTR) and a fluidized bed bubbling reactor model (FBBR) were developed for silane pyrolysis. Silane decomposition is assumed to occur via two pathways: homogeneous decomposition and heterogeneous chemical vapor deposition (CVD). Both models account for homogeneous and heterogeneous silane decomposition, homogeneous nucleation, coagulation and growth by diffusion of fines, scavenging of fines by large particles, elutriation of fines and CVD growth of large seed particles. At present the models do not account for attrition. The preliminary comparison of the model predictions with experimental results shows reasonable agreement. The CSTR model with no adjustable parameter yields a lower bound on fines formed and upper estimate on production rates. The FBBR model overpredicts the formation of fines but could be matched to experimental data by adjusting the unkown jet emulsion exchange efficients. The models clearly indicate that in order to suppress the formation of fines (smoke) good gas-solid contacting in the grid region must be achieved and the formation of the bubbles suppressed.

  19. Viable seed banks under grazing and exclosure conditions in montane mesic grasslands of Argentina

    NASA Astrophysics Data System (ADS)

    Loydi, Alejandro; Zalba, Sergio M.; Distel, Roberto A.

    2012-08-01

    Grazing by large herbivores affects the composition of established vegetation and seed banks. Montane Pampas grasslands are highly productive and have evolved with the influence of grazing by native herbivores. Thus we proposed, firstly that grazing by feral horses would increase seed bank diversity, without changing seed density in grazed areas and secondly that there is a greater similarity between the seed bank and aboveground vegetation in exclosure areas. The study area is located in sub-humid montane grassland in mid-eastern Argentina. Sampling took place at the beginning and end of summer in 2008 and 2009, in three one-year-old exclosures and grazed areas. Soil and litter samples were collected and established vegetation cover was visually recorded in every area. Each sample was elutriated and sieved. Seed composition was recorded using a dissecting microscope. Seed density and species richness of the samples was analyzed using ANOVA and species composition was analyzed by multivariate analysis. Grazing reduces the seed density and richness of grasses, but forb species are not affected. The seed density of grasses increases in soil samples at the end of summer, while the density of forb species does not change. Similarity between the established vegetation and the seed bank was low. Grazing affects seed bank composition which could limit restoration time after the removal of herbivores. However, grass seed availability increases considerably during a short period after exclosure establishment, showing high potential for recovery in sub-humid grasslands.

  20. An assessment of injury to sediments and sediment-dwelling organisms in the Grand Calumet River and Indiana Harbor Area of Concern, USA

    USGS Publications Warehouse

    MacDonald, D.D.; Ingersoll, C.G.; Smorong, D.E.; Lindskoog, R.A.; Sparks, D.W.; Smith, J.R.; Simon, T.P.; Hanacek, M.A.

    2002-01-01

    This article is the first in a series of three that describe the results of a Natural Resource Damage Assessment (NRDA) conducted in the Grand Calumet River and Indiana Harbor Area of Concern (IHAOC). The assessment area is located in northwest Indiana and was divided into nine reaches to facilitate the assessment. This component of the NRDA was undertaken to determine if sediments and sediment-dwelling organisms have been injured due to exposure to contaminants that have accumulated in sediments as a result of discharges of oil or releases of other hazardous substances from industrial, municipal, and nonpoint sources. To support this assessment, information was compiled on the chemical composition of sediment and pore water; on the toxicity of whole sediments, pore water, and elutriates; and on the status of benthic invertebrate communities. The data on each of these indicators were compared to regionally relevant benchmarks to assess the presence and extent of injury to surface water resources (i.e., sediments) or biological resources (i.e., sediment-dwelling organisms). The results of this assessment indicate that sediment injury has occurred throughout the assessment area, with up to four distinct lines of evidence demonstrating injury within the various reaches. The primary contaminants of concern (i.e., those substances that are present at concentrations that are sufficient to cause or substantially contribute to sediment injury) include metals, polycyclic aromatic hydrocarbons, and total polychlorinated biphenyls.

  1. Improved silicon nitride for advanced heat engines

    NASA Technical Reports Server (NTRS)

    Yeh, H. C.; Wimmer, J. M.; Huang, H. H.; Rorabaugh, M. E.; Schienle, J.; Styhr, K. H.

    1985-01-01

    The AiResearch Casting Company baseline silicon nitride (92 percent GTE SN-502 Si sub 3 N sub 4 plus 6 percent Y sub 2 O sub 3 plus 2 percent Al sub 2 O sub 3) was characterized with methods that included chemical analysis, oxygen content determination, electrophoresis, particle size distribution analysis, surface area determination, and analysis of the degree of agglomeration and maximum particle size of elutriated powder. Test bars were injection molded and processed through sintering at 0.68 MPa (100 psi) of nitrogen. The as-sintered test bars were evaluated by X-ray phase analysis, room and elevated temperature modulus of rupture strength, Weibull modulus, stress rupture, strength after oxidation, fracture origins, microstructure, and density from quantities of samples sufficiently large to generate statistically valid results. A series of small test matrices were conducted to study the effects and interactions of processing parameters which included raw materials, binder systems, binder removal cycles, injection molding temperatures, particle size distribution, sintering additives, and sintering cycle parameters.

  2. A study of the short-term retention and clearance of inhaled asbestos by rats, using U.I.C.C. standard reference samples.

    PubMed

    Middleton, A P; Beckett, S T; Davis, J M

    1975-09-01

    Rats have been dosed over a 6-week period with U.I.C.C. standard reference samples of amosite, crocidolite and chrysotile A, each at three concentrations: 1,5 and 10 mg/m3. Mass concentrations in the exposure chambers were monitored daily. Because the M.R.E. gravimetric sampler was found to undersample some of these dusts at high concentrations, a sampler with a vertical elutriator was developed. Data on other physical parameters of the dust clouds were also obtained and it was found that the fibre number (greater than 5 micron in length) vs. mass correlation varied markedly between asbestos varieties. After dusting, the rats were sacrificed in five batches over a period of 4 months. The lungs of some animals were retained for pathological examination. This did not reveal any fibrosis although large numbers of fibres were visible, mostly within alveolar macrophages. The remaining lungs were analysed for their asbestos contents by a method based upon infrared spectrophotometry. The clearance data confirm earlier published reports that for rats dosed at similar mass concentrations of chrysotile and amphibole, those dosed with chrysotile retain considerably less dust in their lungs. The data also suggest that the retention and clearance of amphibole abestos may be dose related. Some mathematical treatment of the clearance data has been undertaken.

  3. Substrate inhibition and control for high rate biogas production

    SciTech Connect

    Shin, H.S.

    1982-01-01

    This research addresses a critical aspect of the technical feasibility of biogas recovery with poultry manure using anaerobic digestion, namely, inhibition and toxicity factors limiting methane generation under high rate conditions. The research was designed to identify the limiting factors and to examine alternative pretreatment and in situ control methods for the anaerobic digestion of poultry manure as an energy producing system. Biogas production was indicated by the daily gas volume produced per unit digester capacity. Enhanced biogas generation from the anaerobic digester systems using poultry manure was studied in laboratory- and pilot-scale digester operations. It was found that ammonia nitrogen concentration above 4000 mg/l was inhibitory to biogas production. Pretreatment of the manure by elutriation was effective for decreasing inhibitory/toxic conditions. Increased gas production resulted without an indication of serious inhibition by increased volatile acids, indicating a limitation of available carbon sources. For poultry manure digestion, the optimum pH range was 7.1 to 7.6. Annual costs for pretreatment/biogas systems for 10,000, 30,000 and 50,000 birds were estimated and compared with annual surplus energy produced. The economic break-even point was achieved in digesters for greater than 30,000 birds. Capital cost of the digester system was estimated to be $18,300 with annual costs around $4000. It is anticipated that the digester system could be economically applied to smaller farms as energy costs increase.

  4. Stratification of yeast cells during chronological aging by size points to the role of trehalose in cell vitality.

    PubMed

    Svenkrtova, Andrea; Belicova, Lenka; Volejnikova, Andrea; Sigler, Karel; Jazwinski, S Michal; Pichova, Alena

    2016-04-01

    Cells of the budding yeast Saccharomyces cerevisiae undergo a process akin to differentiation during prolonged culture without medium replenishment. Various methods have been used to separate and determine the potential role and fate of the different cell species. We have stratified chronologically-aged yeast cultures into cells of different sizes, using centrifugal elutriation, and characterized these subpopulations physiologically. We distinguish two extreme cell types, very small (XS) and very large (L) cells. L cells display higher viability based on two separate criteria. They respire much more actively, but produce lower levels of reactive oxygen species (ROS). L cells are capable of dividing, albeit slowly, giving rise to XS cells which do not divide. L cells are more resistant to osmotic stress and they have higher trehalose content, a storage carbohydrate often connected to stress resistance. Depletion of trehalose by deletion of TPS2 does not affect the vital characteristics of L cells, but it improves some of these characteristics in XS cells. Therefore, we propose that the response of L and XS cells to the trehalose produced in the former differs in a way that lowers the vitality of the latter. We compare our XS- and L-fraction cell characteristics with those of cells isolated from stationary cultures by others based on density. This comparison suggests that the cells have some similarities but also differences that may prove useful in addressing whether it is the segregation or the response to trehalose that may play the predominant role in cell division from stationary culture.

  5. Development of a simple fluidized-bed coal combustion model for the assessment of a pressurized fluidized-bed combustion system for electrical power generation

    SciTech Connect

    Saxena, S.C.; Turek, D.G.

    1980-07-01

    This report summarizes the state-of-the-art in the mathematical modeling of fluidized-bed coal combustors with the goal of evolving a general framework which will be appropriate for developing a system model for the fluidized-bed coal combustion and power generation technology. Consequently, no attempt is made to generate a functional model, but instead a very simple model is proposed as a first step. The model considers all the essential ingredients of coal combustion and sulfur absorption in fluidized-bed reactors. These are coal devolatilization, char combustion in a bed of dolomite or calcium carbonate, sulfur retention in the fluidized-bed elutriation from the bed, and heat removal by cooling tubes imbedded in the bed. The model is presented and a numerical scheme is proposed which will permit the calculation of bed temperature, coal combustion efficiency, sulfur retention, flue gas composition, and overflow from the bed. Numerical results are presented in which the dependence of the various combustion and operating parameters is examined.

  6. The 1989-1990 eruptions of Redoubt Volcano: an introduction

    USGS Publications Warehouse

    Miller, T.P.; Chouet, B.A.

    1994-01-01

    Redoubt Volcano, located on the west side of Cook Inlet in south-central Alaska, erupted explosively on over 20 separate occasions between December 14, 1989 and April 21, 1990. Fourteen lava domes were emplaced in the summit area, thirteen of which were subsequently destroyed. The eruption caused economic losses estimated at over $160,000,000 making this the second most costly eruption in U.S. history. This economic impact provided the impetus for a integrated comprehensive account of an erupting volcano using both modern and classical research and modern techniques which in turn led to advances in eruption monitoring and interpretation. Research on such topics as dome formation and collapse and the resulting pyroclastic flows, elutriated ash, lightning, tephra, and flooding was blended with the rapid communication of associated hazards to a large user group. The seismology successes in predicting and monitoring eruption dynamics were due in part to (1) the recognition of long-period seismic events as indicators of the readiness of the volcano to erupt, and (2) to the development of new tools that allowed the seismicity to be assessed instantaneously. Integrated studies of the petrology of erupted products and volatile content over time gave clues as to the progress of the eruption towards completion. ?? 1994.

  7. Genotoxicity and endocrine-disruption potentials of sediment near an oil spill site: two years after the Hebei Spirit oil spill.

    PubMed

    Ji, Kyunghee; Seo, Jihyeon; Liu, Xiaoshan; Lee, Jinyoung; Lee, Sangwoo; Lee, Woojin; Park, Jeongim; Khim, Jong Seong; Hong, Seongjin; Choi, Yeyong; Shim, Won Joon; Takeda, Shunichi; Giesy, John P; Choi, Kyungho

    2011-09-01

    The Hebei Spirit oil spill episode (December 7, 2007) has affected the western coastal area of South Korea; however, there is limited information on the potential toxicity of the oil spill to the ecosystem or humans. The potential toxicity of sediments collected from the affected area (n = 22) 2 years after the spill was evaluated. Acute lethal toxicity tests using Vibrio fischeri and Moina macrocopa and tests for genotoxicity and alteration of steroidogenesis using chicken DT40 cells and H295R cells, respectively, were conducted. Both crude and weathered oil extracts were evaluated in order to link the observed toxicity in the sediment extracts to the oil spill. Whereas toxicity to bacteria and daphnids was observed in only two elutriate samples, 10 of the 22 sediment extracts showed genotoxic potential in DT40 cells. The mechanisms of genotoxicity involved nucleotide excision repair (XPA(-/)), homologous recombination (RAD54(-/-)), and translesion synthesis pathways (REV3(-/-)). In addition, nine sediment extracts caused significantly greater production of E2 in H295R cells, and significant up-regulation of CYP19, CYP11B2, and 3βHSD2 by sediment extracts was observed. The pattern of toxicities observed in both crude and weathered oil samples was similar to that observed in the sediment extracts. The genotoxicicity and endocrine-disruption potential of the sediment extracts suggest a need for long-term followup for such toxicity in humans and wildlife in this area. PMID:21786741

  8. Validation of a FBC model for co-firing of hazelnut shell with lignite against experimental data

    SciTech Connect

    Kulah, Gorkem

    2010-07-15

    Performance of a comprehensive system model extended for modelling of co-firing of lignite and biomass was assessed by applying it to METU 0.3 MW{sub t} Atmospheric Bubbling Fluidized Bed Combustor co-firing lignite with hazelnut shell and validating its predictions against on-line temperature and concentration measurements of O{sub 2}, CO{sub 2}, CO, SO{sub 2} and NO along the same test rig fired with lignite only, lignite with limestone addition and lignite with biomass and limestone addition. The system model accounts for hydrodynamics; volatiles release and combustion, char combustion, particle size distribution for lignite and biomass; entrainment; elutriation; sulfur retention and NO formation and reduction, and is based on conservation equations for energy and chemical species. Special attention was paid to different devolatilization characteristics of lignite and biomass. A volatiles release model based on a particle movement model and a devolatilization kinetic model were incorporated into the system model separately for both fuels. Kinetic parameters for devolatilization were determined via thermogravimetric analysis. Predicted and measured temperatures and concentrations of gaseous species along the combustor were found to be in good agreement. Introduction of biomass to lignite was found to decrease SO{sub 2} emissions but did not affect NO emissions significantly. The system model proposed in this study proves to be a useful tool in qualitatively and quantitatively simulating the processes taking place in a bubbling fluidized bed combustor burning lignite with biomass. (author)

  9. Sediment toxicity assessment in the Lagoon of Venice (Italy) using Paracentrotus lividus (Echinodermata: Echinoidea) fertilization and embryo bioassays.

    PubMed

    Volpi Ghirardini, A; Arizzi Novelli, A; Tagliapietra, D

    2005-09-01

    The capacity of two toxicity bioassays (fertilization and embryo toxicity tests) to discriminate sediment toxicity using the sea urchin Paracentrotus lividus was tested in five stations with different levels of pollution in the Lagoon of Venice. Two stations were located in estuarine sites, two in the industrial zone, and one in a site at the top of our quality gradient (reference). Elutriate was chosen as sediment matrix to assess the potential effects of bioavailable pollutants in the water column as a consequence of sediment resuspension (dredging and dumping, fishing gear, etc.). An experimental design based on Quality Assurance/Quality Control procedures (QA/QC) was adopted in order to set the methodological basis for an effective use of these bioassays in monitoring programs. Results revealed both higher embriotoxicity than spermiotoxicity in all stations and the efficacy of combined use of both toxicity bioassays in discriminating differing pollution/bioavailability between stations and periods. The good representativeness of the integrated sampling scheme and the standardization of all experimental phases yielded high precision of results. Clear Toxicity Fingerprints were evidenced for the investigated sites through the combined use of both bioassays. A good fit between ecotoxicological data and chemical contamination levels was found, except for unnatural sediment texture. PMID:16019068

  10. Direct-contact heat exchanger for swirling countercurrent flow of hot gas and finely divided solids: A parametric study

    NASA Astrophysics Data System (ADS)

    Bell, K. J.; Arman, B.

    1991-06-01

    A vertically oriented solid-to-gas direct-contact heat exchanger (DCHX) has been proposed for heat recovery in high temperature plants that process finely divided solids. The flows are countercurrent, with the inlet gas flow entering on the centerline and swirling strongly. Swirling enhances heat transfer and centrifuges the solid particles from the center to the wall in order to minimize entrainment and permit gravity separation. A computer program was written to calculate particle trajectories and heat transfer rates (and, therefore, temperature profiles) for gas and solid phases. The flow model considers interactions between the particles and the flow field of the gas. The results of the computer program showed that the introduction of swirl significantly reduced the vertical distance required to achieve a given thermal efficiency. The countercurrent flow arrangement achieves high thermal efficiency in one contacting stage, unlike existing cocurrent suspension preheater systems, which require four or five stages. The practical application of this design to the cement industry appears unlikely, because very low gas velocities and correspondingly large areas of cross-sectional flow are required to prevent elutriation of the 74 micron particles required for the chemical reactions. The computer program can be modified for spray-dryer applications by the addition of mass transfer terms and a spray-formation model. In addition, the concept of a swirling flow heat exchanger may be applicable to other processes in which larger and heavier particles are used.

  11. Lead-, cadmium-, and arsenic-induced DNA damage in rat germinal cells.

    PubMed

    Nava-Hernández, Martha P; Hauad-Marroquín, Leticia A; Bassol-Mayagoitia, Susana; García-Arenas, Guadalupe; Mercado-Hernández, Roberto; Echávarri-Guzmán, Miguel A; Cerda-Flores, Ricardo M

    2009-05-01

    Toxic agents can interfere with the male reproductive system at many targets. One of the major unresolved questions concerning male infertility is identification of its molecular origins. Clinical and animal studies indicate that abnormalities of spermatogenesis result from exposure to three toxic metals (lead acetate, cadmium chloride, and arsenic trioxide), but the effects on primary spermatocyte DNA of the male rat after chronic exposure to these metals have not been identified. The aims of this study were to analyze, in three independent experiments, the DNA damage induced by lead (Pb), cadmium (Cd), and arsenic (As) in rat germinal cells during three time periods, and to determine the relationship between DNA damage and blood Pb, blood Cd, and urine As levels. For lead acetate and cadmium chloride experiments, blood was collected by cardiac puncture, while for arsenic trioxide a 24-h urine sample was collected. Afterward, the animals were sacrificed by decapitation. Pachytene spermatocytes from rat testes were purified by trypsin digestion followed by centrifugal elutriation. After establishment of cell purity and viability, DNA damage (tail length) was measured employing a single cell gel/comet assay. Significant DNA damage was found in primary spermatocytes from rats with chronic exposure (13 weeks) to toxic metals. In conclusion, these findings indicate that exposure to toxic metals affects primary spermatocyte DNA and are suggestive of possible direct testicular toxicity. PMID:19388847

  12. Fluidized-bed reactor modeling for production of silicon by silane pyrolysis

    NASA Astrophysics Data System (ADS)

    Dudukovic, M. P.; Ramachandran, P. A.; Lai, S.

    1986-02-01

    An ideal backmixed reactor model (CSTR) and a fluidized bed bubbling reactor model (FBBR) were developed for silane pyrolysis. Silane decomposition is assumed to occur via two pathways: homogeneous decomposition and heterogeneous chemical vapor deposition (CVD). Both models account for homogeneous and heterogeneous silane decomposition, homogeneous nucleation, coagulation and growth by diffusion of fines, scavenging of fines by large particles, elutriation of fines and CVD growth of large seed particles. At present the models do not account for attrition. The preliminary comparison of the model predictions with experimental results shows reasonable agreement. The CSTR model with no adjustable parameter yields a lower bound on fines formed and upper estimate on production rates. The FBBR model overpredicts the formation of fines but could be matched to experimental data by adjusting the unkown jet emulsion exchange efficients. The models clearly indicate that in order to suppress the formation of fines (smoke) good gas-solid contacting in the grid region must be achieved and the formation of the bubbles suppressed.

  13. Tennessee Valley Authority atmospheric fluidized-bed combustor simulation interim annual report, January 1-December 31, 1979

    SciTech Connect

    Wells, J.W.; Krishnan, R.P.

    1980-10-01

    This report contains a detailed description of the work performed during 1979 for the Tennessee Valley Authority in support of the TVA Fluidized-Bed Combustor (FBC) Demonstration Plant Program. The work was carried out under task 4, modeling and simulation of atmospheric fluidized-bed combustor (AFBC) systems. The overall objective of this task is to develop a steady-state mathematical model with the capability of predicting trends in bed performance under various feed and operating conditions. As part of this effort, three predictive subprograms (subcodes) were developed during 1979: (1) bubble-growth subcode, (2) sorbent-coal ash elutriation and attrition subcode, and (3) coal combustion subcode. These codes, which are currently being tested with experimental data, are capable of predicting how some of the important operating variables in the AFBC affect its performance. After testing against field data, these subcodes will be incorporated into an overall AFBC system code, which was developed earlier at ORNL for analysis of the Department of Energy (DOE) Component Test and Integration Unit (CTIU) at Morgantown, West Virginia. In addition to these predictive subcodes, the overall system code previously developed for the CTIU is described. The material balance is closed, based on vendor-supplied data. This balance is then used to predict the heat transfer characteristics of the surfaces (submerged and freeboard) in the AFBC. Existing correlations for heat transfer in AFBC are used in the code along with thermophysical properties of the various streams.

  14. TELEOST FISH (Solea solea): A NOVEL MODEL FOR ECOTOXICOLOGICAL ASSAY OF CONTAMINATED SEDIMENTS

    PubMed Central

    Ribecco, C; Hardiman, G; Sásik, R; Vittori, S; Carnevali, O

    2012-01-01

    Chemical analysis of sediment is not indicative of the downstream biological effects on aquatic organisms. In this study, the biological effects of sediment were examined using: Teleost fish, (Solea solea), Artemia and rotifers. Although chemicals levels were below the limits permissible by Italian law, S. solea juveniles exposed to sediment (0.3% w/v) for 96 hours, revealed significant induction in the expression levels of HSP70, ERα, TRα, RXRα, PPARα, β, CYP4501A1 and CYP3A mRNAs, suggesting the utility of this species as a novel biosensor. The bio-toxicity of the sediment was further validated by exposing Artemia and rotifers to concentrations of elutriate (derived from the sediment) from 10 to 100 % v/v (with a 50% mortality rate). These results suggest that sediment defined as moderately contaminated, solely on the basis of the chemical profile, may in fact cause harmful effects to aquatic organisms. This study highlights the need for biological approaches in the establishment of sediment toxicity levels. PMID:22217502

  15. The remedial investigation of marine sediment at the United Heckathorn Superfund site

    SciTech Connect

    White, P.J.; Kohn, N.P.; Gardiner, W.W.; Word, J.Q.

    1994-02-01

    The former United Heckathom site in Richmond, California, was used to process and package chlorinated pesticides from the 1940s to the mid-1960s. These activities resulted in the contamination of upland soils and marine sediment in the adjacent waterways. Battelle/Marine Sciences Laboratory (MSL) was requested by USEPA to conduct a remedial investigation and feasibility study (RI/FS). of the marine portion of the site. The objectives of this RI are to determine the extent of pesticide contamination in inner Richmond Harbor, estimate the total volume of contaminated sediment, characterize the subsurface geology; characterize the biological effects of contaminated sediment; and characterize the quality of effluent derived from dewatered sediment through treatability testing. Sediment cores were collected from 53 stations. Vertical subsamples from each sediment core were analyzed for chlorinated pesticides. Sediment from selected cores was also analyzed for other contaminants. Younger Bay Mud (YBM) sediment from multiple stations was mixed to form composite samples representing various segments of the study area. These composites were used for solid-phase toxicity and bioaccumulation tests, and the preparation of liquid-phase samples for treatability testing. The probable quality of effluent produced by dewatering sediment was evaluated by chemical and toxicological testing of suspended-particulate-phase (SPP) and elutriate samples.

  16. The vitronectin receptor (alpha v beta 3) is implicated, in cooperation with P-selectin and platelet-activating factor, in the adhesion of monocytes to activated endothelial cells.

    PubMed Central

    Murphy, J F; Bordet, J C; Wyler, B; Rissoan, M C; Chomarat, P; Defrance, T; Miossec, P; McGregor, J L

    1994-01-01

    In this study we have investigated the presence on endothelial cells of potential glycoprotein receptors, other than P-selectin, which are involved in the adhesion of monocytes at the early stages of activation. We report that the majority of cells binding to thrombin-activated endothelial cells from a peripheral blood mononuclear cell (PBMC) preparation are monocytes. The adhesion of PBMC to thrombin-activated, but not resting, endothelial cells was inhibited (66%) by a monoclonal antibody (mAb) directed against alpha v beta 3. Elutriated monocytes or a monocytic cell line (U937) were also inhibited by this antibody, its F(ab)'2 fragments and three other anti-(alpha v beta 3) mAbs. alpha v beta 3 isolated from endothelial-cell lysates significantly inhibited the adhesion of monocytes and U937 cells to endothelial cells. A peptide motif (RGDF) known to interact with alpha v beta 3 inhibited U937 cell adhesion to activated endothelial cells by 53%. Finally, an anti-(P-selectin) mAb (LYP20) or a platelet-activating factor (PAF)-receptor antagonist (WEB 2086) inhibited monocyte adhesion to activated endothelial cells. This study shows for the first time that alpha v beta 3 is implicated, in addition to P-selectin and PAF, in the adhesion of monocytes to activated endothelial cells. PMID:7528011

  17. Exploratory studies of extended storage of apheresis platelets in a platelet additive solution (PAS).

    PubMed

    Slichter, Sherrill J; Corson, Jill; Jones, Mary Kay; Christoffel, Todd; Pellham, Esther; Bailey, S Lawrence; Bolgiano, Doug

    2014-01-01

    To evaluate the poststorage viability of apheresis platelets stored for up to 18 days in 80% platelet additive solution (PAS)/20% plasma, 117 healthy subjects donated platelets using the Haemonetics MCS+, COBE Spectra (Spectra), or Trima Accel (Trima) systems. Control platelets from the same subjects were compared with their stored test PAS platelets by radiolabeling their stored and control platelets with either (51)chromium or (111)indium. Trima platelets met Food and Drug Administration poststorage platelet viability criteria for only 7 days vs almost 13 days for Haemonetics platelets; ie, platelet recoveries after these storage times averaged 44 ± 3% vs 49 ± 3% and survivals were 5.4 ± 0.3 vs 4.6 ± 0.3 days, respectively. The differences in storage duration are likely related to both the collection system and the storage bag. The Spectra and Trima platelets were hyperconcentrated during collection, and PAS was added, whereas the Haemonetics platelets were elutriated with PAS, which may have resulted in less collection injury. When Spectra and Trima platelets were stored in Haemonetics' bags, poststorage viability was significantly improved. Platelet viability is better maintained in vitro than in vivo, allowing substantial increases in platelet storage times. However, implementation will require resolution of potential bacterial overgrowth during storage.

  18. AFRRI (Armed Forces Radiobiology Research Institute) reports, January-March 1985. Technical report

    SciTech Connect

    Not Available

    1985-01-01

    This volume contains AFRRI Scientific Reports SR85-1 through 85-16, and Contract Report CR85-1, for Jan-Mar, 1985. Scientific reports included in this volume follow: Isolation of cellular membranes from rat mast cells; Effect of proteases on the Beta thromboglobulin radioimmunoassay; Effect of gamma irradiation on the healing of gastric biopsy sites in monkeys; Calcium- and voltage-activated potassium channels in human macrophages; Radiation abrogation of myelopoietic inhibitors found in thymus-conditioned medium; Cell proliferation kinetics analyzed with BrdU and near-UV light treatment; Special techniques for the separation of hemopoietic cells. Elutriation; Hematopoietic colony-forming cells from mice after wound trauma; The macrophage colony-forming cell; Early kinetics of Ca/sup 2 +/ fluxes and histamine release in rat mast cells stimulated with compound 48/80; Hexose regulation of sodium-hexose transport in LLC-PK1 epithelia: The nature of the signal; Plasma histamine and hemodynamic responses following administration of nalbuphine and morphine; Actions of ethanol on voltage-sensitive sodium channels: Effects on neurotoxin-stimulated sodium uptake in synaptosomes; Soluble polyglycans enhance recovery from cobalt-60-induced hemopoietic injury; Effects of pre- and post-irradiation glucan treatment on pluripotent stem cells, granulocyte, macrophage and erythroid progenitor cells, and hemopoietic stromal cells; Alterations in gastric mucus secretion in rhesus monkeys after exposure to ionizing radiation.

  19. Methods Development for Blood Borne Macrophage Carriage of Nanoformulated Antiretroviral Drugs

    PubMed Central

    Roy, Upal; Martinez-Skinner, Andrea; McMillan, JoEllyn; Gendelman, Howard E.

    2010-01-01

    Nanoformulated drugs can improve pharmacodynamics and bioavailability while serving also to reduce drug toxicities for antiretroviral (ART) medicines. To this end, our laboratory has applied the principles of nanomedicine to simplify ART regimens and as such reduce toxicities while improving compliance and drug pharmacokinetics. Simple and reliable methods for manufacturing nanoformulated ART (nanoART) are shown. Particles of pure drug are encapsulated by a thin layer of surfactant lipid coating and produced by fractionating larger drug crystals into smaller ones by either wet milling or high-pressure homogenization. In an alternative method free drug is suspended in a droplet of a polymer. Herein, drug is dissolved within a polymer then agitated by ultrasonication until individual nanosized droplets are formed. Dynamic light scattering and microscopic examination characterize the physical properties of the particles (particle size, charge and shape). Their biologic properties (cell uptake and retention, cytotoxicity and antiretroviral efficacy) are determined with human monocyte-derived macrophages (MDM). MDM are derived from human peripheral blood monocytes isolated from leukopacks using centrifugal elutriation for purification. Such blood-borne macrophages may be used as cellular transporters for nanoART distribution to human immunodeficiency virus (HIV) infected organs. We posit that the repackaging of clinically available antiretroviral medications into nanoparticles for HIV-1 treatments may improve compliance and positively affect disease outcomes. PMID:21178968

  20. Discrepancy between tissue factor activity and tissue factor expression in endotoxin-induced monocytes is associated with apoptosis and necrosis.

    PubMed

    Henriksson, Carola E; Klingenberg, Olav; Ovstebø, Reidun; Joø, Gun-Britt; Westvik, Ase-Brit; Kierulf, Peter

    2005-12-01

    Tissue factor (TF), the main initiator of blood coagulation, contributes to the manifestation of disseminated intravascular coagulation following septic shock in meningococcal infection. Since a direct relationship between disease severity and lipopolysaccharide (LPS) concentration in the circulation has been shown, we hypothesized that the procoagulant and cytotoxic effects of endotoxin also in vitro were related to its concentration. In vitro studies, however, have frequently used much higher LPS concentrations than those observed in clinical samples. Using elutriation-purified human monocytes, we observed that LPS up to 1000 ng/ml exerted a concentration-dependent increase in TF activity (tenase activity, fibrin formation in plasma). Although there was a dose-dependent increase in TF activity, there was not a concomitant increase in TF expression at LPS concentrations above 1 ng/ml (flow cytometry, Western blotting, TF mRNA). Flow cytometry revealed that this discrepancy between TF activity and TF expression at endotoxin concentrations above 1 ng/ml, coincided with an LPS dose-dependent increase in cell surface phosphatidylserine (PS), considered to promote coagulation. The increased PS expression was associated with an increased number of 7-AAD-positive cells indicating cell death. We conclude that enhancement of monocyte procoagulant activity in vitro by high concentrations of LPS may result from increased PS exposure due to apoptosis and necrosis. Therefore, the LPS concentrations used to examine monocyte procoagulant activity in vitro, should be carefully chosen.

  1. Are WWTPs effluents responsible for acute toxicity? Seasonal variations of sediment quality at the Bay of Cádiz (SW, Spain).

    PubMed

    Maranho, L A; Garrido-Pérez, M C; Baena-Nogueras, R M; Lara-Martín, P A; Antón-Martín, R; DelValls, T A; Martín-Díaz, M L

    2015-03-01

    Adverse effects of wastewater treatment plants (WWTPs) on sediment quality at the Bay of Cádiz (SW, Spain) were evaluated by a battery of acute bioassays and chemical contamination. Five sites directly affected by WWTPs effluents and one control site were chosen. Results evidenced clear deterioration of ecological sediment quality parameters and possible effects on aquatic communities towards WWTPs areas. Acute toxicity and chemical contamination varied significantly across the studied sites and differed between winter and summer seasons. The Bay of Cádiz is contaminated by PAHs, metals, detergents (SAS) and pharmaceutical products. Principal Component Analyses indicated metals, SAS and pharmaceutical products as the major environmental stresses. Sea-urchin embryo-larval and microalgae growth rate were the most sensitive bioassays to evaluate resuspension of contaminants (elutriate) from bulk sediment. Amphipods mortality and Microtox(®) solid phase test bioassays were recommended to evaluate bulk sediment quality. Therefore, the use of multiple-bioassays, sensitive to sediment pollution, may provide complementary information to diagnose environmental factors that can impair aquatic communities. The battery of bioassays is recommended to assess and monitor marine sediments directly affected by a mixture of contaminants released from WWTPs. PMID:25410810

  2. In situ fluidization for peat bed rupture, and preliminary economic analysis

    NASA Astrophysics Data System (ADS)

    Niven, R. K.; Khalili, N.

    2002-11-01

    This study concerns in situ fluidization (ISF), a new remediation method with potential application to the remediation of NAPL and heavy metal contaminants, by their release from the fluidized zone generated by a water jet. The present study examines the effect of ISF on layers of peat, of significance owing to its role as an important NAPL and metal contaminant trap. Once trapped, such contaminants are not readily accessible by most remedial methods, due to the low permeability and diffusivity of the peat. A simple tank experiment is used to demonstrate rupture of a peat layer by ISF, with removal of the peat as elutriated fines and segregated peat chunks. The application of ISF in the field is then examined by three field trials in uncontaminated sands, in both saturated and unsaturated conditions. Fluidized depths of up to 1.9 m in the saturated zone (with refusal on a peat layer) and 2.5 m in the unsaturated zone (no refusal) were attained, using a 1.9-m-long, 50 mm diameter jet operated at 5-13 l s -1. Pulses of dark turbidity and shell fragments in the effluent indicated the rupture of peat and shelly layers. The experiments demonstrate the hydraulic viability of ISF in the field, and its ability to remove peat-based contaminants. The issues of appropriate jet design and water generation during ISF are discussed, followed by a preliminary economic analysis of ISF relative to existing remediation methods.

  3. Modelacio de sedimentadors en plantes de tractament d'aigues residuals. Aplicacio al proces de fermentacio - elutracio de fangs primaris

    NASA Astrophysics Data System (ADS)

    Ribes Bertomeu, Josep

    the development and validation of a general settling model that allows simulating the main settling operations taking place in a WWTP, considering both primary and secondary settlers and thickeners. It consists in a one-dimensional model based on the flux theory of Kynch and the double-exponential settling function of Takacs that takes into account flocculation, hindered settling and compression processes. The model has been applied to simulation of settlers and thickeners by means of splitting the system into several horizontal layers, all of them considered as completely mixed reactors which are interconnected by mass flux obtained from the settling model. In order to simulate the conversion processes taking place during sedimentation, the general quality model BNRM1 has been added, and it has been proposed an iterative procedure for solving the equations for each layer in which the settler has been divided. The settling flux model validation, along with the quality model, has been carried out by applying them to a simulation of primary sludge fermentation - elutriation process. This process has been studied on a pilot plant located in the Carraixet WWTP in Alboraia (Valencia). In order to simulate the observed decrease in solids separation efficiency in the studied fermentation - elutriation process, the quality model has been modified with the addition of a new process called "disintegration of complex particulate material". This process influences the settleability of the sludge because it is considered that the disintegrated solids become non-settleable solids. This modification implies the addition of two new kinetic parameters (the specific disintegration velocity for volatile particulate material and the specific disintegration velocity for non volatile particulate material). However, the settling parameter that represents the non-settleable fraction of total suspended solids is eliminated from the model and it has been transformed into an experimental

  4. Microbiological community analysis of vermicompost tea and its influence on the growth of vegetables and cereals.

    PubMed

    Fritz, J I; Franke-Whittle, I H; Haindl, S; Insam, H; Braun, R

    2012-07-01

    Vermicompost, the digestion product of organic material by earthworms, has been widely reported to have a more positive effect on plant growth and plant health than conventional compost. A study was conducted to investigate the effects of different vermicompost elutriates (aerated compost teas) on soils and plant growth. The teas were analyzed by chemical, microbiological, and molecular methods accompanied by plant growth tests at laboratory and field scale. The number of microorganisms in the teas increased during the extraction process and was affected by substrate addition. The vermicompost tea found to increase plant growth best under laboratory tests was applied to cereals (wheat and barley) and vegetables (Raphanus sativus, Rucola selvatica, and Pisum sativum) in a field study. The results revealed no effects of tea application on plant yield; however, sensoric tests indicated an improvement in crop quality. The soils from laboratory and field studies were investigated to detect possible microbial or chemical changes. The results indicated that minor changes to the soil microbial community occurred following tea application by foliar spray in both the laboratory-scale and field-scale experiments.

  5. A proteomic chronology of gene expression through the cell cycle in human myeloid leukemia cells

    PubMed Central

    Ly, Tony; Ahmad, Yasmeen; Shlien, Adam; Soroka, Dominique; Mills, Allie; Emanuele, Michael J; Stratton, Michael R; Lamond, Angus I

    2014-01-01

    Technological advances have enabled the analysis of cellular protein and RNA levels with unprecedented depth and sensitivity, allowing for an unbiased re-evaluation of gene regulation during fundamental biological processes. Here, we have chronicled the dynamics of protein and mRNA expression levels across a minimally perturbed cell cycle in human myeloid leukemia cells using centrifugal elutriation combined with mass spectrometry-based proteomics and RNA-Seq, avoiding artificial synchronization procedures. We identify myeloid-specific gene expression and variations in protein abundance, isoform expression and phosphorylation at different cell cycle stages. We dissect the relationship between protein and mRNA levels for both bulk gene expression and for over ∼6000 genes individually across the cell cycle, revealing complex, gene-specific patterns. This data set, one of the deepest surveys to date of gene expression in human cells, is presented in an online, searchable database, the Encyclopedia of Proteome Dynamics (http://www.peptracker.com/epd/). DOI: http://dx.doi.org/10.7554/eLife.01630.001 PMID:24596151

  6. Nitrification processes in scrubbing liquid of an exhaust air treatment system of a large-scale pig housing facility.

    PubMed

    Haneke, J; Siemers, V; Van den Weghe, H F A

    2011-01-01

    The use of multi-staged exhaust air treatment systems is an effective method of substantially reducing the emission of ammonia, dust particles and odorous substances. Wet filter walls are able to absorb large amounts of ammonia when scrubbing fluid containing sulphuric acid is used. In addition, due to their large surface areas and the permanent supply of oxygen and nutrients, wet filter walls provide a basis for the development of biofilms containing nitrogen-converting bacteria. Cyclic nitrification processes could be observed in a two-stage exhaust air treatment system, which had been converted to function as a regulated process control system (elutriation at κ = 20 mS cm(-1); pH 6.5-6.8). With this system, the sulphuric acid requirement was periodically reduced every 6-8 weeks to less than 1 kg H(2)SO(4) per fattening place and year. There was an increased formation of nitrous oxide gas during nitrification after the wet filter stage. Electron-microscopic images of the biofilm growing on the wet filter wall showed aggregates of possible ammonium-oxidising and nitrite-oxidising bacteria.

  7. Fabrication and Testing of Active and Adaptive Cyanate Ester Composite Mirrors

    NASA Technical Reports Server (NTRS)

    Bennett, H. E.

    2004-01-01

    The objective of the NASA/Bennett Optical Research Inc. (BOR) NAS8-02008 Phase II Program, which also incorporated ideas developed under the earlier NASA NAS8-01035 Phase 1 Program, was to develop a large mirror fabrication and test facility with emphasis on producing large, light weight active and adaptive optics. A principle objective was to develop mandrels on which to make large composite graphite-filled cyanate ester mirrors, Deliverables were two of these superpolished lightweight active/adaptive optic composite mirrors, one 12" (approx.1/3 meter) in diameter and one 22" (approx.1/2 meter) in diameter. In addition optical superpolishers for mandrels up to 1.2 meters in diameter, test instruments for determining optical figure and scattered light, novel design actuators for making the composite mirrors both active and adaptive, and passive and active means for measuring actuator performance were developed at BOR. We are now installing a superpolisher capable of producing 3 meter diameter mirror/mandrels. All polishers utilize the principle of centrifugal elutriation and produce superpolished mandrels with surface microroughnesses under 1 nm rms.

  8. Mass Fluxes Attending the Palagonitization of Sideromelane in Hyaloclastites From the HSDP-2 Core Hole

    NASA Astrophysics Data System (ADS)

    Walton, A.; Schiffman, P.; Macpherson, G. L.; Santee, S.

    2001-12-01

    Isovolumetric conversion of sideromelane to gel palagonitized glass releases components to solution because the latter is hydrated and less dense. In hyaloclastites from the HSDP-2 core, development of gel palagonitized glass is accompanied by the precipitation of secondary minerals, chiefly smectite, phillipsite, and chabazite, but also thaumasite, apophyllite, gyrolite, and gypsum. We have calculated mass balance among these major phases using a combination of electron microprobe analyses (for major elements) and laser ablation microprobe-inductively coupled mass spectrometry (for trace elements), in conjunction with density determinations and petrographic point counts. Our reconnaissance data indicate that most major elements are elutriated from sideromelane during conversion to gel palagonitized glass, except FeO which remains constant, and TiO2 which is somewhat enriched (by more than passive accumulation) in the gel palagonitized glass. Conversely, precipitation of secondary cements in pores requires addition of major elements to the whole rock, chiefly SiO2, Al2O3, K2O, MgO, and MnO. One unexpected initial result is that the REE patterns of sideromelane and associated gel palagonitized glasses are nearly identical. Differences in absolute abundances reflect change in density.

  9. Interactions between salt marsh plants and Cu nanoparticles - Effects on metal uptake and phytoremediation processes.

    PubMed

    Andreotti, Federico; Mucha, Ana Paula; Caetano, Cátia; Rodrigues, Paula; Rocha Gomes, Carlos; Almeida, C Marisa R

    2015-10-01

    The increased use of metallic nanoparticles (NPs) raises the probability of finding NPs in the environment. A lot of information exists already regarding interactions between plants and metals, but information regarding interactions between metallic NPs and plants, including salt marsh plants, is still lacking. This work aimed to study interactions between CuO NPs and the salt marsh plants Halimione portulacoides and Phragmites australis. In addition, the potential of these plants for phytoremediation of Cu NPs was evaluated. Plants were exposed for 8 days to sediment elutriate solution doped either with CuO or with ionic Cu. Afterwards, total metal concentrations were determined in plant tissues. Both plants accumulated Cu in their roots, but this accumulation was 4 to 10 times lower when the metal was added in NP form. For P. australis, metal translocation occurred when the metal was added either in ionic or in NP form, but for H. portulacoides no metal translocation was observed when NPs were added to the medium. Therefore, interactions between plants and NPs differ with the plant species. These facts should be taken in consideration when applying these plants for phytoremediation of contaminated sediments in estuaries, as the environmental management of these very important ecological areas can be affected.

  10. Endocytosis of heat-denatured albumin by cultured rat Kupffer cells

    SciTech Connect

    Brouwer, A.; Knook, D.L.

    1982-10-01

    Purified Kupffer cells were obtained by centrifugal elutriation of sinusoidal cells isolated by pronase treatment of the rat liver. The endocytosis of radioactively labeled heat-aggregated colloidal albumin (CA /sup 125/I) was investigated in maintenance cultures of the purified Kupffer cells. The endocytic capacity of the cells was studied during 4 days of culture. Maximum uptake was observed after 24 hr of culture, with a gradual decline during the following days. When the uptake was measured after incubation with increasing concentrations of CA /sup 125/I, a saturation effect was observed. This finding and the observed high rate of uptake are strong indications that receptor sites on the cell membrane are involved in the mechanism of endocytosis. The uptake of CA /sup 125/I by Kupffer cells was inhibited by the metabolic inhibitors fluoride and antimycin A, indicating that endocytosis of CA /sup 125/I is dependent on energy derived from both glycolysis and mitochondrial respiration. The mechanism of internalization may also require the action of microfilaments as well as intact microtubules, since both cytochalasin B and colchicine inhibited the uptake of CA /sup 125/I. The intracellular degradation of CA /sup 125/I by Kupffer cells was strongly inhibited by chloroquine but not by colchicine. The degradation of ingested CA /sup 125/I occurred within the Kupffer cell lysosomes.

  11. Impact of solids management on nutrient ratios for in-line wastewater prefermenters.

    PubMed

    Rössle, W H; Pretorius, W A

    2001-01-01

    The full-scale evaluation of in-line prefermentation effects on wastewater nutrient ratios was performed under three different sludge operating conditions, with regards to sludge elutriation rates (0.7, 2.2 and 3.7 kg dry sludge/m3 raw sewage) and the corresponding sludge ages (17.3, 2.5 and 7.5 days). At all three operating conditions the TKN/COD ratio increased (64, 46 and 20% respectively), with an average ratio of 0.057 mg N/mg COD in the raw sewage increasing to 0.082 mg N/mg COD in the settled sewage. These ratio increases can limit the use and performance of certain biological nutrient removal process configurations. This study has further highlighted the importance to counterbalance fermentation, thickening and solids removal requirements in a single tank in-line prefermenter. The minimum suspended solids removal (33%) was achieved at the lowest settled sludge solids content (4.3%), against a corresponding maximum volatile fatty acid generation rate (5.7 mg VFA/l/h). The total solids and volatile fatty acid concentration profiles down the prefermenter tank depth were determined at a high sludge blanket level condition. It was demonstrated that the accumulated constituent mass inventory increase was about constant throughout the water and sludge layers respectively under such operational conditions. PMID:11548024

  12. Silicon production in a fluidized bed reactor

    NASA Technical Reports Server (NTRS)

    Rohatgi, N. K.

    1986-01-01

    Part of the development effort of the JPL in-house technology involved in the Flat-Plate Solar Array (FSA) Project was the investigation of a low-cost process to produce semiconductor-grade silicon for terrestrial photovoltaic cell applications. The process selected was based on pyrolysis of silane in a fluidized-bed reactor (FBR). Following initial investigations involving 1- and 2-in. diameter reactors, a 6-in. diameter, engineering-scale FBR was constructed to establish reactor performance, mechanism of silicon deposition, product morphology, and product purity. The overall mass balance for all experiments indicates that more than 90% of the total silicon fed into the reactor is deposited on silicon seed particles and the remaining 10% becomes elutriated fines. Silicon production rates were demonstrated of 1.5 kg/h at 30% silane concentration and 3.5 kg/h at 80% silane concentration. The mechanism of silicon deposition is described by a six-path process: heterogeneous deposition, homogeneous decomposition, coalescence, coagulation, scavenging, and heterogeneous growth on fines. The bulk of the growth silicon layer appears to be made up of small diameter particles. This product morphology lends support to the concept of the scavenging of homogeneously nucleated silicon.

  13. Profile of toxic response to sediments using whole-animal and in vitro submitochondrial particle (SMP) assays

    SciTech Connect

    Bettermann, A.D.; Dorofi, J.C.; Lazorchak, J.M.

    1996-03-01

    A rapid bioassay for monitoring acute toxicity of wastewater, ground water, and soil and sediment extracts using submitochondrial particles (SMP) has been developed. The assay utilizes the mitochondrial electron transfer enzyme complex, present in all eukaryotic cells. Prior developmental work with pure chemicals chosen from the US Environmental Protection Agency`s (EPA) priority pollutant list documented order-of-magnitude predictability between the bioassay response and whole-organism tests (e.g., fathead minnow). Recent work has adapted the assay for analysis of uncharacterized environmental samples, including stormwater runoff, landfill leachate, and soil and sediment extracts. A feasibility study was performed to determine whether the SMP assay could detect toxicity in samples previously assessed for toxicity to amphipods. Acute toxicity tests using Hyalella azteca were performed on 30 sediment samples from Colorado`s Arkansas River, Eagle River, and Chalk Creek watersheds, all of which have been directly or indirectly affected by heavy metal mine tailings and drainage. In parallel, two SMP assay protocols designed to differentiate between modes of toxicity were performed on elutriate samples from 23 of the above sites. The results from analysis of the sediments differed widely in the nature and degree of test responses. Significant correlation was found between the responses of the SMP electron transfer protocol and the whole-organisms assay, and between the responses of the SMP electron transfer protocol and levels of zinc and sulfur, as determined by inductively coupled plasma spectroscopy.

  14. Status and applications of echinoid (phylum echinodermata) toxicity test methods

    SciTech Connect

    Bay, S.; Burgess, R.; Nacci, D.

    1993-01-01

    The use of echinoderms for toxicity testing has focused primarily on sea urchins and sand dollars (Strongylocentrotus purpuratus, Arbacia punctulata, Lytechinus pictus, and Dendraster excentricus, for example). The status and relative sensitivity of various test methods are described. The most frequently used test methods consist of short-term exposures of sea urchin sperm or embryos; these tests can be easily conducted at all times of the year by using species with complementary spawning cycles or laboratory conditioned populations of a single species. Data from reference toxicant and effluent toxicity tests are summarized. Information on the precision and sensitivity of echinoid test methods are limited and preclude rigorous comparisons with other test methods. The available data indicate that the sensitivity and precision of these methods are comparable to short-term chronic methods for other marine invertebrates and fish. Recent application of the sperm test in toxicity identification evaluations (TIEs) and studies of effluent toxicity decay and sediment toxicity illustrate the versatility of this rapid (10 to 60 min exposure) test method. Embryo tests typically use a 48 to 96 h exposure period and measure the occurrence of embryo malformations. Most recent applications of the embryo test have been for the assessment of sediment elutriate toxicity. Adult echinoderms are not frequently used to assess effluent or receiving water toxicity. Recent studies have had success in using the adult life stage of urchins and sand dollars to assess the effects of contaminated sediment on growth, behavior, and bioaccumulation.

  15. Changes in the activities of key enzymes of glycolysis during the cell cycle in yeast: a rectification.

    PubMed

    de Koning, W; Groeneveld, K; Oehlen, L J; Berden, J A; van Dam, K

    1991-04-01

    Activities of glycolytic enzymes were determined in elutriation fractionated cultures of Saccharomyces cerevisiae grown on different carbon sources. Almost pure fractions of single cells at the G1 state of cell division were obtained for some of the growth conditions tested, whereas other stages were enriched in particular fractions. Specific activities of glucose-6-phosphate dehydrogenase and alcohol dehydrogenase were found to be constant during the cell cycle, as reported by van Doorn et al. (1988a), Journal of Bacteriology 170, 4808-4815, and (1988b), Journal of General Microbiology 134, 785-790. In contrast to the earlier reports, the activities of hexokinase, phosphofructokinase, pyruvate kinase and trehalase were also constant in different states of the cell cycle. For hexokinase and phosphofructokinase it was shown that the apparent specific activity in a cell-free extract strongly diminished when extracts contained less that 0.5-1 mg protein ml-1. In the experiments of van Doorn et al. (1988a) the protein content of the outer fractions was up to 20 times lower than that of the central fractions, suggesting an alternative explanation for the observed changes in enzyme activities during the cell cycle. Therefore, we want to rectify the observations presented by van Doorn et al. (1988a), and conclude that the activities of the glycolytic enzymes do not vary greatly during the cell cycle of S. cervisiae. PMID:1856683

  16. The Dtk receptor tyrosine kinase, which binds protein S, is expressed during hematopoiesis.

    PubMed

    Crosier, P S; Freeman, S A; Orlic, D; Bodine, D M; Crosier, K E

    1996-02-01

    Dtk (Tyro 3/Sky/Rse/Brt/Tif) belongs to a recently recognized subfamily of receptor tyrosine kinases that also includes Ufo (Axl/Ark) and Mer (Eyk). Ligands for Dtk and Ufo have been identified as protein S and the related molecule Gas6, respectively. This study examined expression of Dtk during ontogeny of the hematopoietic system and compared the pattern of expression with that of Ufo. Both receptors were abundantly expressed in differentiating embryonic stem cells, yolk sac blood islands, para-aortic splanchnopleural mesoderm, fractionated AA4+ fetal liver cells, and fetal thymus from day 14 until birth. Although Ufo was expressed at moderate levels in adult bone marrow, expression of Dtk in this tissue was barely detectable. In adult bone marrow subpopulations fractionated using counterflow centrifugal elutriation, immunomagnetic bead selection for lineage-depletion and FACS sorting for c-kit expression, very low levels of Dtk and/or Ufo were detected in some cell fractions. These results suggest that Dtk and Ufo are likely to be involved in the regulation of hematopoiesis, particularly during the embryonic stages of blood cell development.

  17. Computational and Experimental Studies of Fluidized Beds for Biomass Gasification

    NASA Astrophysics Data System (ADS)

    Battaglia, Francine; Deza, Mirka; Franka, Nathan; Heindel, Theodore

    2007-11-01

    Fluidized bed gasifiers can convert feedstocks with low-carbon content into valuable products such as ethanol. Understanding fluidized bed hydrodynamics is important for reactor design and avoiding issues such as agglomeration or defluidization of the bed. In particular, biomass gasification is not well characterized and is the focus of this work. Glass beads or sand particles are typically used as bed materials due to their high sphericity and uniform properties. X-ray imaging will be used to visualize these complex flows and alternative bed materials will be considered to increase X-ray penetration and resolution to enhance flow visualization. Furthermore, computational modeling of fluidized beds can be used to predict operation of biomass gasifiers after extensive validation with experimental data. The hydrodynamics will be modeled assuming each phase behaves as interpenetrating continua using an Eulerian model and each solid phase is characterized by a particle diameter and density so that segregation and elutriation can be described. The simulations will model the cold-flow fluidized bed experiment, and consider factors such as sphericity of the particles, and calibration of drag coefficients. Hydrodynamic results from the simulations will be qualitatively and quantitatively compared to X-ray flow visualization studies of a similar bed.

  18. Generation of leukotrienes by purified human lung mast cells.

    PubMed Central

    MacGlashan, D W; Schleimer, R P; Peters, S P; Schulman, E S; Adams, G K; Newball, H H; Lichtenstein, L M

    1982-01-01

    Although mediator release from mast cells and basophils plays a central role in the pathogenesis of human allergic disease, biochemical studies have been restricted to rat peritoneal mast cells and basophilic leukemia cells because they could be easily purified. We have used two new techniques of cell separation to purify human lung mast cells to 98% homogeneity. Lung cell suspensions were obtained by dispersion of chopped lung tissue with proteolytic enzymes. Mast cells were then purified from the suspensions by countercurrent centrifugal elutriation and affinity chromatography. The purified mast cells released both histamine and slow-reacting substance of anaphylaxis (SRS-A) (leukotriene C and D) during stimulation with goat anti-human IgE antibody. Moreover, these preparations were able to generate significant quantities of SRS-A (32 +/- 7 x 10(-17) LTD mole-equivalents/mast cell) at all stages of purification, indicating that a secondary cell is not necessary for the antigen-induced release of SRS. Images PMID:7119113

  19. Fate of gamma-interferon-activated killer blood monocytes adoptively transferred into the abdominal cavity of patients with peritoneal carcinomatosis

    SciTech Connect

    Stevenson, H.C.; Keenan, A.M.; Woodhouse, C.; Ottow, R.T.; Miller, P.; Steller, E.P.; Foon, K.A.; Abrams, P.G.; Beman, J.; Larson, S.M.

    1987-11-15

    Five patients with colorectal cancer widely metastatic to peritoneal surfaces have been treated i.p. with infusions of autologous blood monocytes made cytotoxic by in vitro incubation with human gamma-interferon. The monocytes were purified by a combination of cytapheresis and counter-current centrifugal elutriation procedures; each week approximately 350 million activated monocytes were given to patients as adoptive immunotherapy by a single i.p. instillation. On the eighth cycle of treatment the trafficking of i.p. infused blood monocytes was studied in two patients by prelabeling the cells with /sup 111/In. These activated cells became distributed widely within the peritoneal cavity. Two and 5 days after infusion their position within the peritoneum had not changed. When peritoneal specimens were obtained 36 h after /sup 111/In-labeled monocyte infusion, labeled monocytes were demonstrated to be associated with the serosal surfaces by autoradiographic analysis. Scintiscanning structures outside the abdominal cavity revealed that /sup 111/In-labeled monocytes infused i.p. did not traffic to other organs during the 5 days of the study. We conclude that i.p. adoptive transfer of autologous killer blood monocytes is an effective way of delivering these cytotoxic cells to sites of tumor burden on peritoneal surfaces in these cancer patients.

  20. Results of chemical, toxicological, and bioaccumulation evaluations of dioxins, furans, and guaicol/organic acids in sediments from the Grays Harbor/Chehalis River area

    SciTech Connect

    Word, J.Q.; Ward, J.A.; Squires, A.L.

    1990-09-01

    The Battelle/Marine Sciences Laboratory (MSL) was requested by the US Army Corps of Engineers (USACE), Seattle District, to assist in planning and conducting sampling, toxicological tests, and chemistry evaluations on sediment samples collected from the Chehalis River in Grays Harbor, Washington. The objectives of the study were to investigate the toxicity and biological effects of sediments that might potentially contain dioxins, furans, and organic acids, as a result of industrial practices in the Grays Harbor area, on sensitive marine species. In addition to the toxicological tests conducted using standard bioassays, sediment chemistry tests were performed to determine levels of selected chemicals, and elutriates of sediments were tested chemically and biologically to determine contaminant mobility in water. Also, bioaccumulation measurements were made to determine chemical mobility in animal tissue. A joint task group, including representatives from the USACE, Washington Department of Ecology (WDOE), Washington Department of Natural Resources (WDNR), Washington Department of Fisheries (WDOF), and Region 9 of the US Environmental Protection Agency (USEPA) participated in designing the testing program and reviewing data produced by MSL. The results of this analysis will be included in a supplemental Environmental Assessment (EA) prepared by the USACE for the Grays Harbor Dredging Program, beginning in early 1990. 13 refs., 5 figs., 8 tabs.

  1. Experimental and predicted approaches for biomass gasification with enriched air-steam in a fluidised bed.

    PubMed

    Fu, Qirang; Huang, Yaji; Niu, Miaomiao; Yang, Gaoqiang; Shao, Zhiwei

    2014-10-01

    Thermo-chemical gasification of sawdust refuse-derived fuel was performed on a bench-scale fluidised bed gasifier with enriched air and steam as fluidising and oxidising agents. Dolomite as a natural mineral catalyst was used as bed material to reform tars and hydrocarbons. A series of experiments were carried out under typical operating conditions for gasification, as reported in the article. A modified equilibrium model, based on equilibrium constants, was developed to predict the gasification process. The sensitivity analysis of operating parameters, such as the fluidisation velocity, oxygen percentage of the enriched air and steam to biomass ratios on the produced gas composition, lower heating value, carbon conversion and cold gas efficiency was investigated. The results showed that the predicted syngas composition was in better agreement with the experimental data compared with the original equilibrium model. The higher fluidisation velocity enhanced gas-solid mixing, heat and mass transfers, and carbon fines elutriation, simultaneously. With the increase of oxygen percentage from 21% to 45%, the lower heating value of syngas increased from 5.52 MJ m(-3) to 7.75 MJ m(-3) and cold gas efficiency from 49.09% to 61.39%. The introduction of steam improved gas quality, but a higher steam to biomass ratio could decrease carbon conversion and gasification efficiency owing to a low steam temperature. The optimal value of steam to biomass ratio in this work was 1.0.

  2. A Novel System to Generate WTC Dust Particles for Inhalation Exposures

    PubMed Central

    Vaughan, Joshua M.; Garrett, Brittany; Prophete, Colette; Horton, Lori; Sisco, Maureen; Soukup, Joleen M.; Zelikoff, Judith; Ghio, Andrew; Peltier, Richard E.; Asgharian, Bahman; Chen, Lung-Chi; Cohen, Mitchell D.

    2014-01-01

    First Responders (FR) present at Ground Zero within the first 72-hr after the WTC (World Trade Center) collapse have progressively exhibited significant respiratory injury. The majority (>96%) of WTC dusts were >10 μm and no studies have examined potential health effects of this size fraction. This study sought to develop a system to generate and deliver supercoarse (10–53 μm) WTC particles to a rat model in a manner that mimicked FR exposure scenarios. A modified Fishing Line generator was integrated onto an intratracheal inhalation (ITIH) system that allowed for a bypassing of the nasal passages so as to mimic FR exposures. Dust concentrations were measured gravimetrically; particle size distribution was measured via elutriation. Results indicate that the system could produce dusts with 23 μm MMAD at levels up to ≥ 1200 mg/m3. To validate system utility, F344 rats were exposed for 2-hr to ≈100 mg WTC dust/m3. Exposed rats had significantly increased lung weight and levels of select tracer metals 1-hr post-exposure. Using this system, it is now possible to conduct relevant inhalation exposures to determine adverse WTC dusts impacts on the respiratory system. Furthermore, this novel integrated Fishing Line-ITIH system could potentially be used in the analyses of a wide spectrum of other dusts/pollutants of sizes previously untested or delivered to the lungs in ways that did not reflect realistic exposure scenarios. PMID:24220216

  3. Biostimulation of the autochthonous bacterial community and bioaugmentation of selected bacterial strains for the depletion of Polycyclic Aromatic Hydrocarbons in a historically contaminated soil

    NASA Astrophysics Data System (ADS)

    DiGregorio, Simona; Ruffini Castglione, Monica; Gentini, Alessandro; Lorenzi, Roberto

    2015-04-01

    Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic contaminants causing hazards to organisms including humans. The objective of the study was (1) to validate the biostimulation of the autochthonous bacterial population by the amendment of lignocellulosic matrices inoculated with white rot fungi, to be exploited for the depletion of PAHs (5687 ppm) in a historical contaminated soil. (2) to validate the isolation of autochthonous bacterial strains capable to use PAHs as sole carbon source and their massive bioaugmentation for PAH depletion in a historical contaminated soil. The validation has been performed at mesocosm and pilot scale (7 tons of soil in a biopile). The two approaches end up with the complete depletion of the PAHs. A genotoxicological assessment of the process and of the soil at the end of the process of decontamination has been performed. The process of soil decontamination showed an increase in the genotoxicity of either the soil and the deriving elutriates. The bioaugmetation of selected bacterial strains determined the complete detoxification of the decontaminated soil after 21 weeks. The microbial ecology of the system during the process of decontamination has been monitored.

  4. Characterization of hydrodynamics and solids mixing in fluidized beds involving biomass

    NASA Astrophysics Data System (ADS)

    Fotovat, Farzam

    of biomass particles at U=0.36 m/s and U=0.64 m/s. In this regard, an active biomass particle is tracked for a long period of time and its instantaneous position is recorded. The acquired data is then processed to achieve the time-averaged concentration profile of biomass particles. This profile represents the segregation of biomass particles, which tend to accumulate in the upper levels of the bed. Changes in the fraction of biomass with increasing gas velocity are inferred from the local changes of the time-averaged pressure drop values at the top of the bed. To determine the parameters affecting the movement and segregation of biomass particles, their circulatory motion is also scrutinized using the RPT data. The circulation of biomass is impeded when the load of biomass rises at U=0.36 m/s, resulting in a more pronounced segregation of sand and biomass. The opposite trend is observed at U=0.64 m/s. This prompts a more uniform distribution of particles along the bed and brings about a higher degree of mixing. The average rise velocity of biomass is 0.2 times the bubble velocity, regardless of the biomass load or fluidization velocity. A one-dimensional model is proposed to predict the volume fraction of biomass along the bed. Some of the terms of this model are linked to the fluidizing behavior of biomass particles as deduced from the RPT findings. The fluidization of sand and cylindrical biomass particles is also simulated using the BARRACUDA CPFD software, which is based on the Lagrangian-Eulerian approach. Simulation and experimental results are compared in order to evaluate the capability of the numerical approach to predict the bubbling characteristics of the sand-biomass mixture for systems differing in composition and fluidization velocity. The last part of this thesis is devoted to the separation of the main components of the shredded bulky waste. A step-wise process has been developed based on the elutriation and density segregation techniques. After

  5. Long Focal Length Large Mirror Fabrication System

    NASA Technical Reports Server (NTRS)

    Bennett, H. E.

    2003-01-01

    The goals of this ambitious program are (1) to develop systems to make large superpolished optical mirrors, (2) to develop low scatter polishing techniques using centrifugal elutriation, (3) to develop a means of measuring scatter at any point on the mirror, (4) to polish a Hindle sphere to measure the optical figure of a one meter diameter convex mandrel, and (5) to fabricate low scatter, large adaptive optic graphite filled, cyanate ester replica transfer mirrors using these mandrels. Deliverables are a 30 cm diameter superpolished composite AO mirror. We fabricated a 1/3rd meter superpolished zerodur flat mandrel and with the support of our major subcontractor, Composite Mirror Applications Inc (CMA) we have demonstrated a 30 cm lightweight cyanate ester mirror with an rms microroughness between 0.6 and 0.8 nm and 8 faceplate influence function of 5 cm. The influence function was chosen to be comparable to the atmospheric correlation coefficient r(sub 0) which is about 5 cm at sea level. There was no print-thru of the graphite fibers in the cyanate ester surface (the bane of many previous efforts to use cyanate ester mirrors). Our subcontractor has devised a means for developing a 30-50 nm thick layer of graphite free pure ester resin on the surface of the mirrors. This graphite fiber filled material has a thermal expansion coefficient in the 10(exp -8) centimeter per Kelvin range (the same range of expansion coefficient as Zerodur and ULE glasses) and does not take up water and swell, so it is a nearly ideal mirror material in these areas. Unfortunately for these 0.8mm thick faceplates, the number of plies is not enough to result in isometric coverage. Isolated figure irregularities can appear, making it necessary to go to thicker faceplates. The influence function will then only approximate the length of r(sub 0), at higher altitudes or longer wavelengths. The influence function goes as the cube of the thickness, so we are now making a faceplate optimized for

  6. Dissolution-replacement textures in Hopi Buttes diatreme deposits indicate that primary deposits had a fine-ash matrix

    NASA Astrophysics Data System (ADS)

    Lefebvre, N.; White, J. D.

    2013-12-01

    Textural studies of diatreme deposits are important for interpretation of eruption processes. High primary porosities, are inferred for some southern African kimberlite diatreme deposits, with subsequent addition of pore-filling cements. Where cement in diatreme deposits is interpreted to reflect primary void space, a range of 20-50 vol% porosity is implied, and has been inferred to reflect mechanical processes, specifically fluidization, which elutriate fines from the system during eruption. We have studied the texture of unbedded lower-diatreme deposits at Standing Rocks West, in the Hopi Buttes volcanic field. The interstitial material now comprises varied proportions of matrix and cement. Non-cemented pore space is rare, and there does not appear to be a relationship between the presence of cement vs. matrix and lithofacies or units within the diatreme. The matrix consists of juvenile pyroclasts, sandstone, siltstone and mudstone lithic clasts, detrital quartz grains, and single clinopyroxene, olivine and spinel crystals. In most lapilli tuff, juvenile clasts can be resolved to sizes less than 1 μm, and are typically the dominant matrix component. At least six different cement types are apparent, but the cemented deposits show similar textural relationships. The most common paragenetic sequence, seen in rocks throughout the lower diatreme deposit is, from texturally older to younger, an early phyllosilicate, a later phyllosilicate, calcite, and zeolite. There is evidence for dissolution: 1. Matrix and cement are unevenly distributed on a mm- to cm-scale, and where matrix is low to absent, the framework clast distribution within the cement remains similar and is still poorly sorted. 2. Cement cross-cuts pyroclasts, especially those that are smaller and glassier, resulting in skeletal pyroclast remnants. 3. Where interstitial material is dominantly cement, matrix is preserved locally within pyroclast embayments and around coarser clasts, especially where they

  7. Vitrification of human monocytes.

    PubMed

    Takahashi, T; Hirsh, A; Erbe, E F; Bross, J B; Steere, R L; Williams, R J

    1986-04-01

    Human monocytes purified from peripheral blood by counterflow centrifugal elutriation were cryopreserved in a vitreous state at 1 atm pressure. The vitrification solution was Hanks' balanced salt solution (HBSS) containing (w/v) 20.5% Me2SO, 15.5% acetamide, 10% propylene glycol, and 6% polyethylene glycol. Fifteen milliliters of this solution was added dropwise to 1 ml of a concentrated monocyte suspension at 0 degrees C. Of this, 0.8 ml was drawn into silicone tubing and rapidly cooled to liquid nitrogen temperature, stored for various periods, and rapidly warmed in an ice bath. The vitrification solution was removed by slow addition of HBSS containing 20% fetal calf serum. The numerical cell recovery was about 92% and most of these retained normal phagocytic and chemotactic ability. Differential scanning calorimeter records of the solution show a glass transition at -115 degrees C during cooling and warming, but no evidence of ice formation during cooling. Devitrification occurs at about -70 degrees C during warming at rates as rapid as 80 degrees C/min. The amount of devitrification is dependent upon the warming rate. Freeze-fracture freeze-etch electron microscope observations revealed no ice either intra- or extracellularly in samples rapidly cooled to liquid nitrogen temperatures except for small amounts in some cellular organelles. However, if these cell suspensions were warmed rapidly to -70 degrees C and then held for 5 min, allowing devitrification to occur, the preparation contained significant amounts of both intra- and extracellular ice. Biological data showed that this devitrification was associated with severe loss of cell function. PMID:3698640

  8. Behavior of different phosphorus species in suspended particulate matter in the Changjiang estuary

    NASA Astrophysics Data System (ADS)

    He, Huijun; Chen, Hongtao; Yao, Qingzhen; Qin, Yanwen; Mi, Tiezhu; Yu, Zhigang

    2009-11-01

    Suspended particulate matter (SPM) collected in the Changjiang (Yangtze River) estuary in June 2006 was separated into five fractions via water elutriation: clay-very fine silt (<8 µm), fine silt (8-16 µm), medium silt (16-32 µm), coarse silt (32-63 µm) and sand (>63 µm). The SPM and fractionated particles were sequentially analyzed by a modified SEDEX sequential extraction method to obtain six species of phosphorus: exchangeable or loosely-sorbed P, organic P, Fe-bound P, authigenic P, detrital P and refractory P. The results indicated that all particulate phosphorus species except for detrital P were negatively correlated to particle size; a high detrital P content was found in coarse silt and very coarse silt. From the inside of the river mouth to the gate of the river mouth, organic P, Fe-bound P and refractory P in the suspended particles decreased and a higher amount of exchangeable P appeared around the gate of the river mouth. From the gate of the river mouth to the sea, exchangeable P and organic P in suspended particles increased distinctly. The total particulate P flux into the estuary from the Changjiang River was about 45.45×108 µmol/s during sampling. Of this, about 8.27×108 µmol/s was associated with the “truly suspended” fraction. The bio-available particulate P flux was about 13.58×108 µmol/s. Of this, about 4.24×108 µmol/s was transported by “truly suspended” particles.

  9. Recovery and Longevity of Egg Masses of Meloidogyne incognita during Simulated Winter Survival

    PubMed Central

    Starr, J. L.

    1993-01-01

    Effects of soil matrix potential on longevity of egg masses of Meloidogyne incognita were determined during simulated winter conditions. Egg masses were recovered from isolated root fragments incubated in field soil at matrix potentials of -0.1, -0.3, -1.0, and -4.0 bars throughout winter survival periods of 10 weeks for tomato roots and 12 weeks for cotton roots. Egg masses were more superficial on cotton roots than on tomato roots and were more easily dislodged from cotton roots during recovery of root fragments by elutriation. The rate of decline in numbers of eggs and J2 per egg mass was greater in wet as compared to dry soils (P = 0.01), with the relationship between numbers of eggs and J2 per egg mass and time being best described by quadratic models. Percentage hatch of recovered eggs declines linearly with time at soil matrix potentials of -0.1 and -0.3 bars, but at -1.0 and -4.0 bars the percentage hatch of recovered eggs increased before declining. Effects of soil matrix potential on numbers of eggs per egg mass and percentage hatch of recovered eggs were consistent with previous reports that low soil moisture inhibits egg hatch before affecting egg development. Estimations of egg population densities during winter survival periods will be affected by ability to recover infected root fragments from the soil without dislodging associated egg masses. There is a need for procedures for extraction of egg masses not attached to roots from the soil. PMID:19279764

  10. The status of toxicity tests with sediment in Brazil

    SciTech Connect

    Araujo, R.P.A.

    1995-12-31

    The earliest studies in Brazil aiming to evaluate sediment quality through toxicity tests started in the beginning of the 80`s. These were developed by the Environmental Sanitation Agency of Sao Paulo State (CETESB) in Cubatao River and Billings Reservoir, which are located in industrialized and populous regions. Elutriate phase sediment toxicity tests were run with Daphnia similis. In the Cubatao River Basin the combination of toxicity, chemistry data and benthic community structure provided clear indications of sites with different levels of pollution. At this time there was a consensus that the study of a complex compartment such as sediment needed improvements in sampling and analysis procedures. Only in the 90`s the investigations involving sediment toxicity assessment were resumed by CETESB, and it was clear that integrative studies were needed in order to make environmental quality assessment. This kind of studies were conducted by CETESB in some highly polluted areas of Sao Paulo State, Ceriodaphnia dubia and Photobacterium phosphoreum interstitial water tests and Hyalella sp whole sediment tests were run, and the results correlated with several sediment organic and inorganic contaminants. The Sediment Quality Triad proposed by Chapman was applied in one of these studies. This approach was extremely useful in interpreting the data. At the same time marine sediment toxicity tests were developed by CETESB in collaboration with Sao Paulo University, and tests were run with the amphipods Tiburonella viscana, Battyporeiapus bisetosus; tanaidacean Kalliapseudes shubarti and the echinoderm Lytechinus variegatus. The embryo test with L. variegatus was the most adequate in these studies. Nowadays there are other groups in some universities developing sediment toxicity tests with Hyalella and Chironomus in response to a growing concern in Brazil to establish adequate sediment quality assessment guidelines.

  11. Spatial distribution of trace elements and ecotoxicity of bottom sediments in Rybnik reservoir, Silesian-Poland.

    PubMed

    Baran, Agnieszka; Tarnawski, Marek; Koniarz, Tomasz

    2016-09-01

    The aim of study was to integrate chemical analyses and toxicity bioassays in order to assess the environmental risk connected with the presence of trace elements in the sediments. This study examined the ecological significance of trace elements in bottom sediments by applying a set of complementary sediment quality assessment methods sediment quality guidelines (SQGs) (mean probable effect concentration quotient (PECQ)), potential ecological risk index (PERI), contamination degree (C d) and two bioassays: the bacterial luminescence inhibition test with Vibrio fischeri on sediment elutriates and the direct contact test with the ostracod crustacean Heterocypris incongruens. The samples were collected from 50 stations of Rybnik reservoir. The reservoir is a region with enormous concentration of industry, mainly hard coal mining, electric power industry, and transportation. Despite the high diversity in metal concentration in the sediments, the spatial distribution of trace elements in the sediments was very similar. Moreover, the strong positive correlations between individual pairs of trace elements indicate that they may derive from a similar source and move together. According to mean PECQs, 68 % of the samples were potentially non-toxic and 32 % of the samples were potentially toxic. PERI values suggested that 70 % of the sediment sampling sites exhibited low ecological risk from metal pollution while 24 % of the samples had severe and serious risk. Based on our combined evaluation, we believe that Cd and Cu in the sediment samples frequently caused adverse biological effects. Higher toxic responses were observed in the Microtox test than in the Ostracodtoxkit test. All the sediment samples were found toxic to V. fischeri, and 96 % of the samples had effect percentages >50 %. For H. incongruens, 12 % of the sediments were not toxic and 44 % had effect percentages >50 %. In order to perform a complex assessment of the environmental impact of metal

  12. BENZO[a]PYRENE DIOL EPOXIDE PERTURBATION OF CELL CYCLE KINETICS OF SYNCHRONIZED MOUSE LIVER EPITHELIAL CELLS

    SciTech Connect

    Pearlman, A.L.; Navsky, B.N.; Bartholomew, J.C

    1980-07-01

    A cell cycle synchronization system is described for the analysis of the perturbation of cell cycle kinetics and the cycle-phase specificity of chemicals and other agents. We used the system to study the effects of ({+-})r-7, t-8-dihydroxy-t-9, 10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BaP diol epoxide) upon the cell cycle of mouse liver epithelial cells(NMuLi). BaP diol epoxide(0.6 uM) was added to replated cultures of NMuLi cells that had been synchronized in various stages of the cell cycle by centrifugal elutriation. DNA histograms were obtained by flow cytometry as a function of time after replating. The data were analyzed by a computer modeling routine and reduced to a few graphs illustrating the 'net effects' of the BaP diol epoxide relative to controls. BaP diol epoxide slowed S-phase traversal in all samples relative to their respective control. Traversal through G{sub 2}M was also slowed by at least 50%. BaP diol epoxide had no apparent effect upon G{sub 1} traversal by cycling cells, but delayed the recruitment of quiescent G{sub 0} cells by about 2 hrs. The methods described constitute a powerful new approach for probing the cell cycle effects of a wide variety of agents. The present system appears to be extremely sensitive and capable of characterizing the action of agents on each phase of the cell cycle. The methods are automatable and would allow for the assay and possible differential characterization of mutagens and carcinogens.

  13. Radon (222Rn) in ground water of fractured rocks: A diffusion/ion exchange model

    USGS Publications Warehouse

    Wood, W.W.; Kraemer, T.F.; Shapiro, A.

    2004-01-01

    Ground waters from fractured igneous and high-grade sialic metamorphic rocks frequently have elevated activity of dissolved radon (222Rn). A chemically based model is proposed whereby radium (226Ra) from the decay of uranium (238U) diffuses through the primary porosity of the rock to the water-transmitting fracture where it is sorbed on weathering products. Sorption of 226Ra on the fracture surface maintains an activity gradient in the rock matrix, ensuring a continuous supply of 226Ra to fracture surfaces. As a result of the relatively long half-life of 226Ra (1601 years), significant activity can accumulate on fracture surfaces. The proximity of this sorbed 226Ra to the active ground water flow system allows its decay progeny 222Rn to enter directly into the water. Laboratory analyses of primary porosity and diffusion coefficients of the rock matrix, radon emanation, and ion exchange at fracture surfaces are consistent with the requirements of a diffusion/ion- exchange model. A dipole-brine injection/withdrawal experiment conducted between bedrock boreholes in the high-grade metamorphic and granite rocks at the Hubbard Brook Experimental Forest, Grafton County, New Hampshire, United States (42??56???N, 71??43???W) shows a large activity of 226Ra exchanged from fracture surfaces by a magnesium brine. The 226Ra activity removed by the exchange process is 34 times greater than that of 238U activity. These observations are consistent with the diffusion/ion-exchange model. Elutriate isotopic ratios of 223Ra/226Ra and 238U/226Ra are also consistent with the proposed chemically based diffusion/ion-exchange model.

  14. Bed hydrodynamics and heat transfer to tubes in the freeboard region of a pressurized fluidized-bed coal combustor

    SciTech Connect

    Sellakumar, K.M.

    1988-01-01

    Various modes of Pressurized Fluidized Bed Combustor part-load operation are analyzed. Bed change is considered to be the most effective of these methods. The need to understand the variation in heat absorption by exposed in-bed tubes immediately above the reducing or increasing bed height has resulted in the pursuit for a clearer understanding of the particle concentration profile and heat transfer mechanisms to the referred tubes. Bubble characteristics in a PFBC with internals are studied in depth. A model for gas flow through dense and bubble phases is developed. Model results are compared with the limited experimental results available in literature. For both atmospheric and pressurized fluidized bed combustors, the deviation from the two phase theory is highlighted; and this simple model approach has evolved a procedure to quantify gas flows in different streams which was thus far available only qualitatively. The dense phase velocity is found to be much more than the minimum fluidization velocity. A theoretical model for particle efflux from the bed top surface has been evolved. An empirical model has also been developed for elutriant flux above the Transport Disengagement Height, the concentration of fines in the efflux material, superficial velocity in the freeboard, and mean particle terminal velocity have appeared to be the major factors influencing the carry over. The model developed using the data form a smaller rectangular rest rig was tested satisfactorily with the limited data from a larger as well as a similar size circular unit. If the particulate loading profile above the bed surface is known, then the heat transfer to the heat exchanger surfaces may be obtained from the available correlations.

  15. Extensive soft-sediment deformation and peperite formation at the base of a rhyolite lava: Owyhee Mountains, SW Idaho, USA

    NASA Astrophysics Data System (ADS)

    McLean, Charlotte E.; Brown, David J.; Rawcliffe, Heather J.

    2016-06-01

    In the Northern Owyhee Mountains (SW Idaho), a >200-m-thick flow of the Miocene Jump Creek Rhyolite was erupted on to a sequence of tuffs, lapilli tuffs, breccias and lacustrine siltstones of the Sucker Creek Formation. The rhyolite lava flowed over steep palaeotopography, resulting in the forceful emplacement of lava into poorly consolidated sediments. The lava invaded this sequence, liquefying and mobilising the sediment, propagating sediment subvertically in large metre-scale fluidal diapirs and sediment injectites. The heat and the overlying pressure of the thick Jump Creek Rhyolite extensively liquefied and mobilised the sediment resulting in the homogenization of the Sucker Creek Formation units, and the formation of metre-scale loading structures (simple and pendulous load casts, detached pseudonodules). Density contrasts between the semi-molten rhyolite and liquefied sediment produced highly fluidal Rayleigh-Taylor structures. Local fluidisation formed peperite at the margins of the lava and elutriation structures in the disrupted sediment. The result is a 30-40-m zone beneath the rhyolite lava of extremely deformed stratigraphy. Brittle failure and folding is recorded in more consolidated sediments, indicating a differential response to loading due to the consolidation state of the sediments. The lava-sediment interaction is interpreted as being a function of (1) the poorly consolidated nature of the sediments, (2) the thickness and heat retention of the rhyolite lava, (3) the density contrast between the lava and the sediment and (4) the forceful emplacement of the lava. This study demonstrates how large lava bodies have the potential to extensively disrupt sediments and form significant lateral and vertical discontinuities that complicate volcanic facies architecture.

  16. Scenario-targeted toxicity assessment through multiple endpoint bioassays in a soil posing unacceptable environmental risk according to regulatory screening values.

    PubMed

    Rodriguez-Ruiz, A; Etxebarria, J; Boatti, L; Marigómez, I

    2015-09-01

    Lanestosa is a chronically polluted site (derelict mine) where the soil (Lanestosa (LA) soil) exceeds screening values (SVs) of regulatory policies in force (Basque Country; Europe) for Zn, Pb and Cd. A scenario-targeted toxicity assessment was carried out on the basis of a multi-endpoint bioassay approach. Acute and chronic toxicity bioassays were conducted with selected test species (Vibrio fischeri, Dictyostelium discoideum, Lactuca sativa, Raphanus sativus and Eisenia fetida) in combination with chemical analysis of soils and elutriates and with bioaccumulation studies in earthworms. Besides, the toxicity profile was compared with that of the mine runoff (RO) soil and of a fresh artificially polluted soil (LAAPS) resembling LA soil pollutant profile. Extractability studies in LA soil revealed that Pb, Zn and Cd were highly available for exchange and/or release into the environment. Indeed, Pb and Zn were accumulated in earthworms and LA soil resulted to be toxic. Soil respiration, V. fischeri, vegetative and developmental cycles of D. discoideum and survival and juvenile production of E. fetida were severely affected. These results confirmed that LA soil had unacceptable environmental risk and demanded intervention. In contrast, although Pb and Zn concentrations in RO soil revealed also unacceptable risk, both metal extractability and toxicity were much lower than in LA soil. Thus, within the polluted site, the need for intervention varied between areas that posed dissimilar risk. Besides, since LAAPS, with a high exchangeable metal fraction, was the most toxic, ageing under in situ natural conditions seemingly contributed to attenuate LA soil risk. As a whole, combining multi-endpoint bioassays with scenario-targeted analysis (including leaching and ageing) provides reliable risk assessment in soils posing unacceptable environmental risk according to SVs, which is useful to optimise the required intervention measures.

  17. Purified murine granulocyte/macrophage progenitor cells express a high-affinity receptor for recombinant murine granulocyte/macrophage colony-stimulating factor

    SciTech Connect

    Williams, D.E.; Bicknell, D.C.; Park, L.S.; Straneva, J.E.; Cooper, S.; Broxmeyer, H.E.

    1988-01-01

    Purified recombinant murine granulocyte/macrophage colony-stimulating factor (GM-CSF) was labeled with /sup 125/I and used to examine the GM-CSF receptor on unfractionated normal murine bone marrow cells, casein-induced peritoneal exudate cells, and highly purified murine granulocyte/macrophage progenitor cells (CFU-GM). CFU-GM were isolated from cyclophosphamide-treated mice by Ficoll-Hypaque density centrifugation followed by counterflow centrifugal elutriation. The resulting population had a cloning efficiency of 62-99% in cultures containing conditioned medium from pokeweed mitogen-stimulated spleen cells and 55-86% in the presence of a plateau concentration of purified recombinant murine GM-CSF. Equilibrium binding studies with /sup 125/I-labeled GM-CSF showed that normal bone marrow cells, casein-induced peritoneal exudate cells, and purified CFU-GM had a single class of high-affinity receptor. Affinity crosslinking studies demonstrated that /sup 125/I-labeled GM-CSF bound specifically to two species of M/sub r/ 180,000 and 70,000 on CFU-GM, normal bone marrow cells, and peritoneal exudate cells. The M/sub r/ 70,000 species is thought to be a proteolytic fragment of the intact M/sub r/ 180,000 receptor. The present studies indicate that the GM-CSF receptor expressed on CFU-GM and mature myeloid cells are structurally similar. In addition, the number of GM-CSF receptors on CFU-GM is twice the average number of receptors on casein-induced mature myeloid cells, suggesting that receptor number may decrease as CFU-GM mature.

  18. Identification, localization and developmental studies of rat prepro thyrotropin-releasing hormone mRNA in the testis.

    PubMed

    Feng, P; Gu, J; Kim, U J; Carnell, N E; Wilber, J F

    1993-02-01

    Thyrotropin-releasing hormone (TRH) plays the central regulatory role in the hypothalamic-pituitary-thyroid axis, but is also present in many extra-hypothalamic loci. The adult rat testis has been identified previously as a source of hypothalamic neuropeptides including TRH. To investigate whether the TRH gene is transcribed in testis, the identification and localization of prepro(pp) TRH mRNA and TRH were studied. Northern blot analyses of ppTRH mRNA in the adult rat testis showed a 2.0 kb band, hybridized with a ppTRH cRNA probe. This band was 0.4 kb greater than the 1.6 kb hypothalamic band. The concentration of ppTRH mRNA in the adult testis was approximately 13% of that found in the hypothalamus. Developmental studies of testicular ppTRH mRNA revealed that no ppTRH mRNA could be detected at the earliest stage (day 8). However, hybridization signals were detected on day 20 and increased progressively on days 35, 45 and 70 by 5.8, 6.4, and 9.8-fold, respectively. In addition, ppTRH mRNA was determined in Leydig cells by Northern analyses of elutriated testicular cell fractions. TRH was also measured in the rat testes at different developmental stages by RIA. TRH concentrations paralleled ppTRH mRNA during development. TRH was localized to Leydig cells by immunohistochemistry. These results indicate that ppTRH mRNA and TRH are present in the rat testis, especially in the Leydig cells. The changes of ppTRH gene expression and the concentration of TRH in the rat testis are developmentally dependent. TRH may function as a new paracrine or autocrine regulator of testicular function.

  19. Evaluation of Dredged Material Proposed for Ocean Disposal from Federal Projects in New York and New Jersey and the Military Ocean Terminal (MOTBY)

    SciTech Connect

    Barrows, E.S.; Antrim, L.D.; Pinza, M.R.; Gardiner, W.W.; Kohn, N.P.; Gruendell, B.D.; Mayhew, H.L.; Word, J.Q.; Rosman, L.B.

    1996-08-01

    The U.S. Army Corps of Engineers (USACE) is authorized by Section 103 of the Marine Protection, Research, and Sanctuaries Act of 1972 (MPRSA), Public Law 92-532, and by the Clean Water Act of 1972 (CWA) and Amendments of 1977 to permit, evaluate, and regulate the disposal of dredged material in ocean waters to minimize adverse environmental effects. Compliance with the regulations of the MPRSA calls for physical and biological testing of sediment proposed for dredging prior to its disposal in ocean waters. The testing required by the MPRSA criteria is conducted under a testing manual developed by the USACE and the U.S. Environmental Protection Agency (EPA), Evaluation of Dredged Material Proposed for Ocean Disposal (Testing Manual), commonly referred to as the `Green Book.` Testing protocols in the Green Book include bulk sediment analysis, grain size analysis, elutriate testing, and biological testing. The biological testing includes bioassays for acute toxicity as well as analysis to determine bioaccumulation of certain contaminants by marine organisms. The objective of the USACE-NYD Federal Projects Program was to evaluate sediment proposed for dredging and unconfined ocean disposal at the Mud Dump Site. The results of analytical measurements and bioassays performed on the test sediments were compared with analyses of sediment from the Mud Dump Reference Site to determine whether the test sediments were acutely toxic to marine organisms or resulted in statistically significantly greater bioaccumulation of contaminants in marine organisms, relative to the reference sediment. Testing for the federal project areas was performed according to the requirements.

  20. Activation of "synthetic ambient" aerosols - Relation to chemical composition of particles <100 nm

    NASA Astrophysics Data System (ADS)

    Burkart, J.; Hitzenberger, R.; Reischl, G.; Bauer, H.; Leder, K.; Puxbaum, H.

    2012-07-01

    Cloud condensation nuclei (CCN) are an important fraction of atmospheric aerosols because of their role in cloud formation. Experimental studies focus either on direct field measurements of complex ambient aerosols or laboratory investigations on well defined aerosols produced from single substances or substance mixtures. In this study, we focussed on the ultrafine aerosol because in terms of number concentration, the majority of the CCN are expected to have sizes in this range. A field study was performed from July 2007 to October 2008 to investigate the activation behaviour of the atmospheric aerosol in Vienna (Burkart et al., 2011). Filter samples of the aerosol <0.1 μm aerodynamic equivalent diameter were collected, elutriated and used to generate "synthetic ambient" aerosol in a nebulizer. Chemical analyses of the ultrafine water soluble material were also performed. The CCN properties of the "synthetic ambient" aerosol were obtained using the University of Vienna CCN counter (Giebl et al., 2002; Dusek et al., 2006b) at a nominal supersaturation (SS) of 0.5%. Activation diameters dact ranged from 54.5 nm to 66 nm, were larger than dact of typical single inorganic salts and showed no seasonal pattern in contrast to the fraction of water soluble organic carbon (WSOC), which ranged from 44% in spring to 15% in winter. The average hygroscopicity parameter κ (Petters and Kreidenweis, 2007) obtained from the activation curves ranged from 0.20 to 0.30 (average 0.24), which was significantly lower than κchem calculated from the chemical composition (0.43 ± 0.07).

  1. Stratification of yeast cells during chronological aging by size points to the role of trehalose in cell vitality.

    PubMed

    Svenkrtova, Andrea; Belicova, Lenka; Volejnikova, Andrea; Sigler, Karel; Jazwinski, S Michal; Pichova, Alena

    2016-04-01

    Cells of the budding yeast Saccharomyces cerevisiae undergo a process akin to differentiation during prolonged culture without medium replenishment. Various methods have been used to separate and determine the potential role and fate of the different cell species. We have stratified chronologically-aged yeast cultures into cells of different sizes, using centrifugal elutriation, and characterized these subpopulations physiologically. We distinguish two extreme cell types, very small (XS) and very large (L) cells. L cells display higher viability based on two separate criteria. They respire much more actively, but produce lower levels of reactive oxygen species (ROS). L cells are capable of dividing, albeit slowly, giving rise to XS cells which do not divide. L cells are more resistant to osmotic stress and they have higher trehalose content, a storage carbohydrate often connected to stress resistance. Depletion of trehalose by deletion of TPS2 does not affect the vital characteristics of L cells, but it improves some of these characteristics in XS cells. Therefore, we propose that the response of L and XS cells to the trehalose produced in the former differs in a way that lowers the vitality of the latter. We compare our XS- and L-fraction cell characteristics with those of cells isolated from stationary cultures by others based on density. This comparison suggests that the cells have some similarities but also differences that may prove useful in addressing whether it is the segregation or the response to trehalose that may play the predominant role in cell division from stationary culture. PMID:26614086

  2. Cell Cycle-Dependent Mechanisms Underlie Vincristine-Induced Death of Primary Acute Lymphoblastic Leukemia Cells.

    PubMed

    Kothari, Anisha; Hittelman, Walter N; Chambers, Timothy C

    2016-06-15

    Microtubule-targeting agents (MTA), such as the taxanes and vinca alkaloids, are used to treat a variety of cancers due to their ability to perturb microtubule dynamics. In cell culture, MTAs exert their anticancer effects primarily by causing mitotic arrest and cell death. However, accumulating indirect evidence suggests that MTAs may exert their cytotoxicity in human tumors by interfering with interphase microtubules. In this study, we sought to develop and characterize an experimental system in which to test the hypothesis that MTAs induce cell death during interphase. Primary adult acute lymphoblastic leukemia (ALL) cells treated with vincristine only weakly exhibited colocalization between mitotic and apoptotic markers and major characteristics of mitotic death, such as an increase in cells with 4N DNA content before the appearance of cells with <2N DNA content, suggesting a mixed response. Therefore, we separated ALL cells into distinct phases of the cell cycle by centrifugal elutriation, labeled cells with 5-ethynyl-2'-deoxyuridine (EdU), and then treated each population with vincristine. Cells isolated during G1 underwent cell death without evidence of EdU uptake, indicating that the cytotoxic effects of vincristine took place during G1 Conversely, cells isolated during S or G2-M phases underwent death following mitotic arrest. Thus, vincristine induces distinct death programs in primary ALL cells depending on cell-cycle phase, and cells in G1 are particularly susceptible to perturbation of interphase microtubules. Primary ALL cells may therefore provide a powerful model system in which to study the multimodal mechanisms underlying MTA-induced cell death. Cancer Res; 76(12); 3553-61. ©2016 AACR. PMID:27197148

  3. Hepatic lipase is localized at the parenchymal cell microvilli in rat liver.

    PubMed Central

    Breedveld, B; Schoonderwoerd, K; Verhoeven, A J; Willemsen, R; Jansen, H

    1997-01-01

    Hepatic lipase (HL) is thought to be located at the vascular endothelium in the liver. However, it has also been implicated in the binding and internalization of chylomicron remnants in the parenchymal cells. In view of this apparent discrepancy between localization and function, we re-investigated the localization of HL in rat liver using biochemical and immunohistochemical techniques. The binding of HL to endothelial cells was studied in primary cultures of rat liver endothelial cells. Endothelial cells bound HL in a saturable manner with high affinity. However, the binding capacity accounted for at most 1% of the total HL activity present in the whole liver. These results contrasted with earlier studies, in which non-parenchymal cell (NPC) preparations had been found to bind HL with a high capacity. To study HL binding to the different components of the NPC preparations, we separated endothelial cells, Kupffer cells and blebs by counterflow elutriation. Kupffer cells and endothelial cells showed a relatively low HL-binding capacity. In contrast, the blebs, representing parenchymal-cell-derived material, had a high HL-binding capacity (33 m-units/mg of protein) and accounted for more than 80% of the total HL binding in the NPC preparation. In contrast with endothelial and Kupffer cells, the HL-binding capacity of parenchymal cells could account for almost all the HL activity found in the whole liver. These data strongly suggest that HL binding occurs at parenchymal liver cells. To confirm this conclusion in situ, we studied HL localization by immunocytochemical techniques. Using immunofluorescence, we confirmed the sinusoidal localization of HL. Immunoelectron microscopy demonstrated that virtually all HL was located at the microvilli of parenchymal liver cells, with a minor amount at the endothelium. We conclude that, in rat liver, HL is localized at the microvilli of parenchymal cells. PMID:9020876

  4. Bioassays and selected chemical analysis of biocide-free antifouling coatings.

    PubMed

    Watermann, B T; Daehne, B; Sievers, S; Dannenberg, R; Overbeke, J C; Klijnstra, J W; Heemken, O

    2005-09-01

    Over the years several types of biocide-free antifouling paints have entered the market. The prohibition of biocidal antifouling paints in special areas of some European countries such as Sweden, Denmark and Germany has favoured the introduction of these paints to the market. Several types of biocide-free antifouling paints were subjected to bioassays and selected chemical analysis of leachate and incorporated substances. Both non-eroding coatings (silicones, fibre coats, epoxies, polyurethane, polyvinyl) and eroding coatings (SPCs, ablative) were tested to exclude the presence of active biocides and dangerous compounds. The paints were subjected to the luminescent bacteria test and the cypris larvae settlement assay, the latter delivering information on toxicity as well as on efficacy. The following chemical analyses of selected compounds of dry-film were performed: The results of the bioassays indicated that none of the coatings analysed contained leachable biocides. Nevertheless, some products contained or leached dangerous compounds. The analyses revealed leaching of nonylphenol (up to 74.7 ng/cm2/d after 48 h) and bisphenol A (up to 2.77 ng/cm2/d after 24 h) from epoxy resins used as substitutes for antifouling paints. The heavy metal, zinc, was measured in dry paint film in quantities up to 576,000 ppm in erodable coatings, not incorporated as a biocide but to control the rate of erosion. Values for TBT in silicone elutriates were mostly below the detection limit of 0.005 mg/kg. Values for DBT ranged between <0.005 and 6.28 mg/kg, deriving from catalysts used as curing agents. Some biocide-free paints contained leachable, toxic and dangerous compounds in the dry film, some of which may act as substitutes for biocides or are incorporated as plasticizers or catalysts. Implications to environmental requirements and legislation are discussed. PMID:15878605

  5. Human very small embryonic-like cells generate skeletal structures, in vivo.

    PubMed

    Havens, Aaron M; Shiozawa, Yusuke; Jung, Younghun; Sun, Hongli; Wang, Jincheng; McGee, Samantha; Mishra, Anjali; Taichman, L Susan; Danciu, Theodora; Jiang, Yajuan; Yavanian, Gregory; Leary, Elizabeth; Krebsbach, Paul H; Rodgerson, Denis; Taichman, Russell S

    2013-02-15

    Human very small embryonic-like (hVSEL) cells are a resident population of multipotent stem cells in the bone marrow involved in the turnover and regeneration of tissues. The levels of VSEL cells in blood are greatly increased in response to injury, and they have been shown to repair injured tissues. Adult hVSEL cells, SSEA-4(+)/CD133(+)/CXCR4(+)/Lin(-)/CD45(-), express the pluripotency markers (Oct-4 and Nanog) and may be able to differentiate into cells from all 3 germ lineages. hVSEL cells isolated from blood by apheresis following granulocyte-colony-stimulating factor mobilization were fractionated and enriched by elutriation and fluorescence activated cell sorting. Collagen sponge scaffolds containing 2,000-30,000 hVSEL cells were implanted into cranial defects generated in SCID mice. Analysis by microcomputed tomography showed that a cell population containing VSEL cells produced mineralized tissue within the cranial defects compared with controls at 3 months. Histologic studies showed significant bone formation and cellular organization within the defects compared with cellular or scaffold controls alone. Antibodies to human leukocyte antigens demonstrated that the newly generated tissues were of human origin. Moreover, human osteocalcin was identified circulating in the peripheral blood. There was evidence that some level of hVSEL cells migrated away from the defect site, using quantitative real-time polymerase chain reaction to detect for human-specific Alu sequences. This study demonstrates that hVSEL cells are able to generate human bone tissue in a mouse model of skeletal repair. These studies lay the foundation for future cell-based regenerative therapies for osseous and connective tissue disorders, including trauma and degenerative conditions, such as osteoporosis, fracture repair, and neoplastic repair.

  6. Rate and topography of peptidoglycan synthesis during cell division in Escherichia coli: Concept of a leading edge

    SciTech Connect

    Wientjes, F.B.; Nanninga, N. )

    1989-06-01

    The rate at which the peptidoglycan of Escherichia coli is synthesized during the division cycle was studied with two methods. One method involved synchronization of E. coli MC4100 lysA cultures by centrifugal elutriation and subsequent pulse-labeling of the synchronously growing cultures with (meso-{sup 3}H)diaminopimelic acid (({sup 3}H)Dap). The second method was autoradiography of cells pulse-labeled with ({sup 3}H)Dap. It was found that the peptidoglycan is synthesized at a more or less exponentially increasing rate during the division cycle with a slight acceleration in this rate as the cells start to constrict. Apparently, polar cap formation requires synthesis of extra surface components, presumably to accommodate for a change in the surface-to-volume ratio. Furthermore, it was found that the pool size of Dap was constant during the division cycle. Close analysis of the topography of ({sup 3}H)Dap incorporation at the constriction site revealed that constriction proceeded by synthesis of peptidoglycan at the leading edge of the invaginating cell envelope. During constriction, no reallocation of incorporation occurred, i.e., the incorporation at the leading edge remained high throughout the process of constriction. Impairment of penicillin-binding protein 3 by mutation or by the specific {beta}-lactam antibiotic furazlocillin did not affect ({sup 3}H)Dap incorporation during initiation of constriction. However, the incorporation at the constriction site was inhibited in later stages of the constriction process. It is concluded that during division at least two peptidoglycan-synthesizing systems are operating sequentially.

  7. Sediment and water toxicity evaluations for the Clinch River ecological risk assessment

    SciTech Connect

    Gonzalez, A.M.; Phipps, T.L.; Kszos, L.A.

    1995-12-31

    The sediment and surface water at three sites in the Clinch River and six sites in Poplar Creek were evaluated by means of toxicity tests with aquatic organisms. The results of these tests were used as one of the lines of evidence in an assessment of ecological risk due to contaminants, transported from the Oak Ridge Reservation, to the off-site sediment and water environment. Results from a suite of six whole sediment, elutriate and pore water toxicity tests were summarized in terms of survival (Hyalella azteca, Daphnia magna, Anodonta imbecillis, Ceriodaphnia dubia), fecundity (Daphnia magna) or light output reduction (Microtox{reg_sign}). Results from the water toxicity tests were summarized in terms of reduction in survival or fecundity of C. dubia, and survival or growth of Pimephales promelas. Toxicity test results (covering a period of about 1 6 months) showed little difference between reference site media and media from sites of concern. They also showed no strong spatial or temporal response pattern. These results are further supported by the presence of indigenous Chironomus and Hexagenia spp. in the sediment samples. Toxicity results will be discussed with respect to three issues. Two criteria were used to define significant differences between reference sites and sites of concern: a difference of 20%, and statistical significance at a = 0.05. Secondly, the relevance of comparing mean responses to control vs. reference site will be discussed. Lastly, toxicity results are consistent with site characterization information which suggest that contaminants of concern in sediment are buried under clean sediment, effectively isolating the material from potential human or ecological exposure.

  8. Give reverse-air fabric filters a closer look

    SciTech Connect

    Jensen, R.M.

    1995-02-01

    Although use of reverse-air filters dominates in operating US utility power stations, pulse-jet designs seem to be getting the lion`s share of attention for new and retrofit plants. This article examines key technical advantages of reverse-air designs that are becoming lost in the current debate. Control of particulate emissions continues to be an area of growing concern for operators of coal-fired powerplants, especially as it relates to air toxics and fine particulates. That concern has led to greater scrutiny of the devices used to control those emissions. Regarding the fabric-filter option, reverse-air (RA) designs have operated reliably at large utility units, but now face a strong challenge from pulse-jet (PJ) designs--which are more popular with operators of independent-power-producer, waste-to-energy, and other small solid-fuel-fired units. Both RA and PJ designs can adequately meet the particulate emissions requirements for large coal-fired units when properly applied. The wholesale shift by electric utilities from RA to PJ fabric filters--at least in discussion if not actual projects--is apparent but may be short-sighted. The oft-stated reason--that RA fabric filters can only handle a face velocity one-half that of PJ, resulting in higher cost for the RA option--is too simplistic. The many design and operating characteristics that distinguish the two should be thoroughly reviewed before blanket acceptance of PJ technology. Some of the technical areas reviewed here are level of commercial design experience, bag life, pressure drop, bag replacement procedure, cleaning cycles, particle elutriation, submicron-particle floaters, residual-cake preservation, and particle re-entrainment.

  9. Application of a toxicity test battery integrated index for a first screening of the ecotoxicological threat posed by ports and harbors in the southern Adriatic Sea (Italy).

    PubMed

    Manzo, Sonia; Schiavo, Simona; Aleksi, Pellumb; Tabaku, Afrim

    2014-11-01

    Ports and harbors may represent a threat for coastal ecosystems due to pollutant inputs, especially those derived from maritime activities. In this study, we report a first assessment of the ecotoxicological threat posed by six ports and harbors of opposite coastal regions, Apulia and Albania, in the southern Adriatic Sea (Italy). A bioassay battery consisting of four different species representing different trophic levels, algae Dunaliella tertiolecta, bacteria Vibrio fischeri, crustacean Artemia salina, and echinoids Paracentrotus lividus, has been used to assess sediment elutriates, pore waters, and sediment suspensions. Two different approaches of toxicity data integration, worst case and integrated index, have been used to determine the most appropriate procedure for the investigated sites. All sites with the worst case approach showed high toxicity levels. The chronic test with algae was the most sensitive identifying the highest effects in the battery. This effect can be attributable to contaminants derived from antifouling paints. The sediments, evaluated with V. fischeri test, often showed toxicity not found in the aqueous matrices of the same sites and that can be mainly linked to organic compounds. The test battery used in this study allowed us to perform a preliminary screening of the ecotoxicological risk of the studied area. In fact, the species utilized for toxicity tests responded differently to the investigated samples, showing different sensitivity. The test battery integrated index did not allow highlighting the differences among the sites and showed a general high ecotoxicological risk. A larger number of tests with higher sensitivity together with a tailored attribution of weights to endpoints and matrices will improve the final site evaluation.

  10. Myeloid-derived suppressor cells impair the quality of dendritic cell vaccines.

    PubMed

    Poschke, I; Mao, Y; Adamson, L; Salazar-Onfray, F; Masucci, G; Kiessling, R

    2012-06-01

    Myeloid-derived suppressor cells (MDSC) are important regulators of the immune system and key players in tumor-induced suppression of T-cell responses. CD14+HLA-DR-/low MDSC have been detected in a great number of malignancies, including melanoma. MDSC are known to be impaired in their ability to differentiate along the myeloid lineage, e.g., into dendritic cells (DC). This is a concern for utilization of monocyte-derived DC for vaccination of patients with melanoma or other cancers exhibiting accumulation of CD14+ MDSC. When producing DC according to standard operating procedures of two currently ongoing clinical trials, we found that MDSC co-purified with monocytes isolated by elutriation. MDSC frequencies did not affect yield or viability of the produced DC, but induced a dose-dependent decrease in DC maturation, ability to take up antigen, migrate and induce T-cell IFNγ production. Changes in DC characteristics were most notable when 'pathological' frequencies of >50% CD14+HLA-DR- cells were present in the starting culture. The impaired DC quality could not be explained by altered cytokine production or increased oxidative stress in the cultures. Tracking of HLA-DR- cells throughout the culture period revealed that the observed changes were partially due to the impaired maturation and functionality of the originally HLA-DR- population, but also to their negative effects on HLA-DR+ cells. In conclusion, MDSC could be induced to differentiate into DC but, due to the impairment of overall DC vaccine quality when >50% HLA-DR- cells were present in the starting culture, their removal could be advisable.

  11. Radon (222Rn) in ground water of fractured rocks: a diffusion/ion exchange model.

    PubMed

    Wood, Warren W; Kraemer, Thomas F; Shapiro, Allen

    2004-01-01

    Ground waters from fractured igneous and high-grade sialic metamorphic rocks frequently have elevated activity of dissolved radon (222Rn). A chemically based model is proposed whereby radium (226Ra) from the decay of uranium (238U) diffuses through the primary porosity of the rock to the water-transmitting fracture where it is sorbed on weathering products. Sorption of 226Ra on the fracture surface maintains an activity gradient in the rock matrix, ensuring a continuous supply of 226Ra to fracture surfaces. As a result of the relatively long half-life of 226Ra (1601 years), significant activity can accumulate on fracture surfaces. The proximity of this sorbed 226Ra to the active ground water flow system allows its decay progeny 222Rn to enter directly into the water. Laboratory analyses of primary porosity and diffusion coefficients of the rock matrix, radon emanation, and ion exchange at fracture surfaces are consistent with the requirements of a diffusion/ion-exchange model. A dipole-brine injection/withdrawal experiment conducted between bedrock boreholes in the high-grade metamorphic and granite rocks at the Hubbard Brook Experimental Forest, Grafton County, New Hampshire, United States (42 degrees 56'N, 71 degrees 43'W) shows a large activity of 226Ra exchanged from fracture surfaces by a magnesium brine. The 226Ra activity removed by the exchange process is 34 times greater than that of 238U activity. These observations are consistent with the diffusion/ion-exchange model. Elutriate isotopic ratios of 223Ra/226Ra and 238U/226Ra are also consistent with the proposed chemically based diffusion/ion-exchange model. PMID:15318778

  12. Tumor necrosis factor alpha and interleukin-1 alpha stimulate late shedding of p75 TNF receptors but not p55 TNF receptors from human monocytes.

    PubMed

    Joyce, D A; Steer, J H

    1995-11-01

    Soluble receptors for TNF (sTNF-R) are present at elevated concentrations in the synovial fluid of patients with rheumatoid arthritis. They are presumably released by cells of the synovial membrane, including the monocyte-derived synovial macrophages. Cytokines from the synovium, including IL-1 and TNF-alpha, may stimulate release. We therefore examined the release of sTNF-R from monocytes exposed to IL-1 and TNF-alpha. Elutriator-purified human blood monocytes spontaneously released both the p75 and the p55 sTNF-R (1011 +/- 199 and 177 +/- 20 pg/10(6) cells, respectively, mean +/- SEM) during 48 h of in vitro culture. TNF-alpha and IL-1 alpha induced time- and concentration-dependent increases in the release of sTNF-R75 from monocytes, but neither had a measurable effect on the release of sTNF-R55. The release of sTNF-R75 was inhibited by cycloheximide. Neither lymphocytes nor polymorphonuclear leukocytes (PMN) released measurable sTNF-R spontaneously or in response to stimulation with IL-1 alpha, but TNF-alpha stimulated the release of small amounts of sTNF-R75 by PMN. The timing, cycloheximide sensitivity, and selectivity of stimulated release of TNF-R75 by monocytes are consistent with previous observations on other cell types of late (8-20 h) increased synthesis and turnover of cell surface TNF-R75, but not TNF-R55, after stimulation with TNF-alpha or IL-1. These observations help to explain why elevated levels of sTNF-R in synovial fluid coexist with enhanced expression of cell surface TNF-R on synovial macrophages in rheumatoid arthritis. PMID:8590306

  13. Assessment of sediment contamination at Great Lakes Areas of Concern: the ARCS Program Toxicity-Chemistry Work Group strategy

    USGS Publications Warehouse

    Ross, P.E.; Burton, G.A.; Crecelius, E.A.; Filkins, J. C.; Giesy, J.P.; Ingersoll, C.G.; Landrum, P.F.; Mac, M.J.; Murphy, T.J.; Rathbun, J. E.; Smith, V. E.; Tatem, H. E.; Taylor, R.W.

    1992-01-01

    In response to a mandate in Section 118(c)(3) of the Water Quality Act of 1987, a program called Assessment and Remediation of Contaminated Sediments (ARCS) was established. Four technical work groups were formed. This paper details the research strategy of the Toxicity-Chemistry Work Group.The Work Group's general objectives are to develop survey methods and to map the degree of contamination and toxicity in bottom sediments at three study areas, which will serve as guidance for future surveys at other locations. A related objective is to use the data base that will be generated to calculate sediment quality concentrations by several methods. The information needed to achieve these goals will be collected in a series of field surveys at three areas: Saginaw Bay (MI), Grand Calumet River (IN), and Buffalo River (NY). Assessments of the extent of contamination and potential adverse effects of contaminants in sediment at each of these locations will be conducted by collecting samples for physical characterization, toxicity testing, mutagenicity testing, chemical analyses, and fish bioaccumulation assays. Fish populations will be assessed for tumors and external abnormalities, and benthic community structure will be analyzed. A mapping approach will use low-cost indicator parameters at a large number of stations, and will extrapolate by correlation from traditional chemical and biological studies at a smaller number of locations. Sediment toxicity testing includes elutriate, pore water and whole sediment bioassays in a three-tiered framework. In addition to the regular series of toxicity tests at primary mater stations, some stations are selected for a more extensive suite of tests.

  14. Estimation of total discharged mass from the phreatic eruption of Ontake Volcano, central Japan, on September 27, 2014

    NASA Astrophysics Data System (ADS)

    Takarada, Shinji; Oikawa, Teruki; Furukawa, Ryuta; Hoshizumi, Hideo; Itoh, Jun'ichi; Geshi, Nobuo; Miyagi, Isoji

    2016-08-01

    The total mass discharged by the phreatic eruption of Ontake Volcano, central Japan, on September 27, 2014, was estimated using several methods. The estimated discharged mass was 1.2 × 106 t (segment integration method), 8.9 × 105 t (Pyle's exponential method), and varied from 8.6 × 103 to 2.5 × 106 t (Hayakawa's single isopach method). The segment integration and Pyle's exponential methods gave similar values. The single isopach method, however, gave a wide range of results depending on which contour was used. Therefore, the total discharged mass of the 2014 eruption is estimated at between 8.9 × 105 and 1.2 × 106 t. More than 90 % of the total mass accumulated within the proximal area. This shows how important it is to include a proximal area field survey for the total mass estimation of phreatic eruptions. A detailed isopleth mass distribution map was prepared covering as far as 85 km from the source. The main ash-fall dispersal was ENE in the proximal and medial areas and E in the distal area. The secondary distribution lobes also extended to the S and NW proximally, reflecting the effects of elutriation ash and surge deposits from pyroclastic density currents during the phreatic eruption. The total discharged mass of the 1979 phreatic eruption was also calculated for comparison. The resulting volume of 1.9 × 106 t (using the segment integration method) indicates that it was about 1.6-2.1 times larger than the 2014 eruption. The estimated average discharged mass flux rate of the 2014 eruption was 1.7 × 108 kg/h and for the 1979 eruption was 1.0 × 108 kg/h. One of the possible reasons for the higher flux rate of the 2014 eruption is the occurrence of pyroclastic density currents at the summit area.

  15. Early and delayed effects of naturally occurring asbestos on serum biomarkers of inflammation and metabolism.

    PubMed

    Kodavanti, Urmila P; Andrews, Debora; Schladweiler, Mette C; Gavett, Stephen H; Dodd, Darol E; Cyphert, Jaime M

    2014-01-01

    Studies recently showed that intratracheal (IT) instillation of Libby amphibole (LA) increases circulating acute-phase proteins (APP; α-2 macroglobulin, A2M; and α-1 acid glycoprotein, AGP) and inflammatory biomarkers (osteopontin and lipocalin) in rats. In this study, objectives were to (1) compare changes in biomarkers of rats after instillation of different naturally occurring asbestos (NOA) minerals including LA, Sumas Mountain chrysotile (SM), El Dorado Hills tremolite (ED), and Ontario ferroactinolite cleavage fragments (ON), and (2) examine biomarkers after subchronic LA or amosite inhalation exposure. Rat-respirable fractions (aerodynamic diameter approximately 2.5 μm) prepared by water elutriation were delivered via a single IT instillation at doses of 0, 0.5, and 1.5 mg/rat in male F344 rats. Nose-only inhalation exposures were performed at 0, 1, 3.3, and 10 mg/m(3) for LA and at 3.3 mg /m(3) for amosite, 6h/d, 5 d/wk for 13 wk. Inflammation, metabolic syndrome, and cancer biomarkers were analyzed in the serum for up to 18 mo. IT instillation of some asbestos materials significantly increased serum AGP and A2M but to a varying degree (SM = LA > ON = ED). Numerical increases in interleukin (IL)-6 and osteopontin occurred in rats instilled with SM. SM and ED also elevated leptin and insulin at 15 mo, suggesting potential metabolic effects. LA inhalation tended to raise A2M at d 1 but not cytokines. Serum mesothelin appeared to elevate after 18 mo of LA inhalation. These results suggest that the lung injury induced by high levels of asbestos materials may be associated with systemic inflammatory changes and predisposition to insulin resistance.

  16. Measuring and modeling solids movement in a large, cold fluidized bed test facility. Second quarterly report, January 1, 1980-March 31, 1980

    SciTech Connect

    Fitzgerald, T. J.; Mrazek, R. V.; Crane, S. D.

    1980-03-01

    The plume model is developed to represent a tube-filled AFBC with large particles, in which air-entrained coal enters in a number of feed ports from below. It assumes that the volatiles are rapidly released from the coal at the feed entry ports to rise as plumes of combustible vapors. Graphs have been prepared to display the predictions of this model for narrow size cuts of a typical coal feed. For a feed of wide size distribution, use these single size charts and properly sum. The lowest carbon efficiency always comes with an intermediate size of feed coal, not with very large or very small feed sizes. Thus the coal feed to the AFBC should try to avoid this critical size. The plume behavior, whether it breaks the surface of the bed, the temperature jump above the bed, concentration variations across the bed, etc., are all governed by one dimensionless group HD/u/sub 0/L/sub 2//sup 2/, which depends primarily on the spacing of feed ports in the bed. For a given coal feed, the carbon efficiency depends only on superficial gas velocity in the bed, the excess air, and elutriation rate constant. A special case and simplification of this model views the coal as being uniformly distributed all over the bed before the volatiles are released. Here analysis is very much simpler, not involving plumes and no volatiles leaving the bed. This plumeless model should reasonably represent AFBC using large feed particles, introduced across the top of the bed and then rapidly mixed by large scale convective flow of solids. The analysis shows that, even in beds with plumes, the simpler plumeless model can be used with negligible error to calculate carbon efficiency; for volatile efficiency, temperature jumps and composition variations across the bed, the complete plume model must be used.

  17. Radon (222Rn) in ground water of fractured rocks: a diffusion/ion exchange model.

    PubMed

    Wood, Warren W; Kraemer, Thomas F; Shapiro, Allen

    2004-01-01

    Ground waters from fractured igneous and high-grade sialic metamorphic rocks frequently have elevated activity of dissolved radon (222Rn). A chemically based model is proposed whereby radium (226Ra) from the decay of uranium (238U) diffuses through the primary porosity of the rock to the water-transmitting fracture where it is sorbed on weathering products. Sorption of 226Ra on the fracture surface maintains an activity gradient in the rock matrix, ensuring a continuous supply of 226Ra to fracture surfaces. As a result of the relatively long half-life of 226Ra (1601 years), significant activity can accumulate on fracture surfaces. The proximity of this sorbed 226Ra to the active ground water flow system allows its decay progeny 222Rn to enter directly into the water. Laboratory analyses of primary porosity and diffusion coefficients of the rock matrix, radon emanation, and ion exchange at fracture surfaces are consistent with the requirements of a diffusion/ion-exchange model. A dipole-brine injection/withdrawal experiment conducted between bedrock boreholes in the high-grade metamorphic and granite rocks at the Hubbard Brook Experimental Forest, Grafton County, New Hampshire, United States (42 degrees 56'N, 71 degrees 43'W) shows a large activity of 226Ra exchanged from fracture surfaces by a magnesium brine. The 226Ra activity removed by the exchange process is 34 times greater than that of 238U activity. These observations are consistent with the diffusion/ion-exchange model. Elutriate isotopic ratios of 223Ra/226Ra and 238U/226Ra are also consistent with the proposed chemically based diffusion/ion-exchange model.

  18. Reburning Characteristics of Residual Carbon in Fly Ash from CFB Boilers

    NASA Astrophysics Data System (ADS)

    Zhang, S. H.; Luo, H. H.; Chen, H. P.; Yang, H. P.; Wang, X. H.

    The content of residual carbon in fly ash of CFB boilers is a litter high especially when low-grade coal, such as lean coal, anthracite coal, gangue, etc. is in service, which greatly influences the efficiency of boilers and fly ash further disposal. Reburn of fly ash through collection, recirculation in CFB furnace or external combustor is a possibly effective strategy to decrease the carbon content, mainly depending on the residual carbon reactivity. In this work, the combustion properties of residual carbon in fly ash and corresponding original coal from large commercial CFB boilers (Kaifeng (440t/h), and Fenyi (410t/h), all in china) are comparably investigated through experiments. The residual carbon involved was firstly extracted and enriched from fly ash by means of floating elutriation to mitigate the influence of ash and minerals on the combustion behavior of residual carbon. Then, the combustion characteristic of two residual carbons and the original coal particles was analyzed with thermogravimetric analyzer (TGA, STA409C from Nestch, Germany). It was observed that the ignition temperature of the residual carbon is much higher than that of original coal sample, and the combustion reactivity of residual carbon is not only dependent on the original coal property, but also the operating conditions. The influence of oxygen content and heating rate was also studied in TGA. The O2 concentration is set as 20%, 30%, 40% and 70% respectively in O2/N2 gas mixture with the flow rate of 100ml/min. It was found that higher oxygen content is favor for decreasing ignition temperature, accelerating the combustion rate of residual carbon. And about 40% of oxygen concentration is experimentally suggested as an optimal value when oxygen-enriched combustion is put into practice for decreasing residual carbon content of fly ash in CFB boilers.

  19. Purified CD34+ Lin- Thy+ stem cells do not contain clonal myeloma cells.

    PubMed

    Gazitt, Y; Reading, C C; Hoffman, R; Wickrema, A; Vesole, D H; Jagannath, S; Condino, J; Lee, B; Barlogie, B; Tricot, G

    1995-07-01

    High-dose therapy with autologous marrow or peripheral blood stem cell (PBSC) rescue has been extensively applied in the treatment of multiple myeloma (MM) patients during the past 10 years resulting in improved event-free and overall survival when compared with standard chemotherapy. However, relapses are common and cure is unlikely in the majority of patients. Because both bone marrow and PBSCs are contaminated with myeloma cells it is conceivable that relapse after autotransplantation originates at least in part from autografted tumor cells. In this study, mobilized PBSCs were examined for the presence of myeloma cells based on immunophenotyping and sensitive polymerase chain reaction (PCR)-based techniques. In addition, CD34+ Lin- Thy+ stem cells were purified from mobilized PBSC harvests of 10 MM patients by sequentially using counterflow elutriation centrifugation, treatment with phenylalanine methylester, and flow sorting, using 5-parameter gating (propidium iodide, forward scatter, side scatter, CD34+ v Lin- and CD34+ v Thy+). Virtually all mobilized unsorted PBSC preparations contained myeloma cells in sufficient quantities (range, < 0.01 to > 10%) potentially causing a disease relapse. Stem cell purification led to an overall enrichment by about 50-fold in all 10 patients; approximately 90% of the final cell population expressed CD34+ Lin- Thy+ with no evidence of myeloma cell contamination based on flow cytometric analysis of CD38bright cells (< 0.1%). Quantitative PCR amplification of patient-specific complementarity determining region III (CDRIII) DNA sequences showed depletion of clonal B cells by 2.7 to 7.3 logs, with the highest log reduction noted in the samples initially containing the most tumor cells. Our results show that purification of CD34+ Lin- Thy+ cells depletes myeloma cells to undetectable levels from up to 10% present in unsorted PBSCs, thus offering a tool to investigate whether MM relapse after autotransplantation can be reduced

  20. Pilot plant testing of IGT`s two-stage fluidized-bed/cyclonic agglomerating combustor

    SciTech Connect

    Rehmat, A.; Mensinger, M.C.; Richardson, T.L.

    1993-12-31

    The Institute of Gas Technology (IGT) is conducting a multi-year experimental program to develop and test, through pilot-scale operation, IGT`s two-stage fluidized-bed/cyclonic agglomerating combustor (AGGCOM). The AGGCOM process is based on combining the fluidized-bed agglomeration and gasification technology with the cyclonic combustion technology, both of which have been developed at IGT over many years. AGGCOM is a unique and extremely flexible combustor that can operate over a wide range of conditions in the fluidized-bed first stage from low temperature (desorption) to high temperature (agglomeration), including gasification of high-energy-content wastes. The ACCCOM combustor can easily and efficiently destroy solid, liquid, and gaseous organic wastes, while isolating solid inorganic contaminants within an essentially non-leachable glassy matrix, suitable for disposal in ordinary landfills. Fines elutriated from the first stage are captured by a high-efficiency cyclone and returned to the fluidized bed for ultimate incorporation into the agglomerates. Intense mixing in the second-stage cyclonic combustor ensures high destruction and removal efficiencies (DRE) for organic compounds that may be present in the feed material. This paper presents an overview of the experimental development of the AGGCOM process and progress made to date in designing, constructing, and operating the 6-ton/day AGGCOM pilot plant. Results of the bench-scale tests conducted to determine the operating conditions necessary to agglomerate a soil were presented at the 1991 Incineration Conference. On-site construction of the AGGCOM pilot plant was initiated in August 1992 and completed at the end of March 1993, with shakedown testing following immediately thereafter. The initial tests in the AGGCOM pilot plant will focus on the integrated operation of both stages of the combustor and will be conducted with ``clean`` topsoil.

  1. Polycyclic aromatic hydrocarbon-contaminated soils: bioaugmentation of autochthonous bacteria and toxicological assessment of the bioremediation process by means of Vicia faba L.

    PubMed

    Ruffini Castiglione, Monica; Giorgetti, Lucia; Becarelli, Simone; Siracusa, Giovanna; Lorenzi, Roberto; Di Gregorio, Simona

    2016-04-01

    Two bacterial strains, Achromobacter sp. (ACH01) and Sphingomonas sp. (SPH01), were isolated from a heavily polycyclic aromatic hydrocarbon (PAH)-contaminated soil (5431.3 ± 102.3 ppm) for their capacity to use a mixture of anthracene, pyrene, phenanthrene and fluorene as sole carbon sources for growth and for the capacity to produce biosurfactants. The two strains were exploited for bioaugmentation in a biopile pilot plant to increase the bioavailability and the degradation of the residual PAH contamination (99.5 ± 7.1 ppm) reached after 9 months of treatment. The denaturing gel gradient electrophoresis (DGGE) profile of the microbial ecology of the soil during the experimentation showed that the bioaugmentation approach was successful in terms of permanence of the two strains in the soil in treatment. The bioaugmentation of the two bacterial isolates positively correlated with the PAH depletion that reached 7.9 ± 2 ppm value in 2 months of treatment. The PAH depletion was assessed by the loss of the phyto-genotoxicity of soil elutriates on the model plant Vicia faba L., toxicological assessment adopted also to determine the minimum length of the decontamination process for obtaining both the depletion of the PAH contamination and the detoxification of the soil at the end of the process. The intermediate phases of the bioremediation process were the most significant in terms of toxicity, inducing genotoxic effects and selective DNA fragmentation in the stem cell niche of the root tip. The selective DNA fragmentation can be related to the selective induction of cell death of mutant stem cells that can compromise offsprings.

  2. A novel system to generate WTC dust particles for inhalation exposures.

    PubMed

    Vaughan, Joshua M; Garrett, Brittany J; Prophete, Colette; Horton, Lori; Sisco, Maureen; Soukup, Joleen M; Zelikoff, Judith T; Ghio, Andrew; Peltier, Richard E; Asgharian, Bahman; Chen, Lung-Chi; Cohen, Mitchell D

    2014-01-01

    First responders (FRs) present at Ground Zero within the critical first 72 h after the World Trade Center (WTC) collapse have progressively exhibited significant respiratory injury. The majority (>96%) of WTC dusts were >10 μm and no studies have examined potential health effects of this size fraction. This study sought to develop a system to generate and deliver supercoarse (10-53 μm) WTC particles to a rat model in a manner that mimicked FR exposure scenarios. A modified Fishing Line generator was integrated onto an intratracheal inhalation (ITIH) system that allowed for a bypassing of the nasal passages so as to mimic FR exposures. Dust concentrations were measured gravimetrically; particle size distribution was measured via elutriation. Results indicate that the system could produce dusts with 23 μm mass median aerodynamic diameter (MMAD) at levels up to ≥1200 mg/m(3). To validate system utility, F344 rats were exposed for 2 h to ≈100 mg WTC dust/m(3). Exposed rats had significantly increased lung weight and levels of select tracer metals 1 h after exposure. Using this system, it is now possible to conduct relevant inhalation exposures to determine adverse WTC dusts impacts on the respiratory system. Furthermore, this novel integrated Fishing Line-ITIH system could potentially be used in the analyses of a wide spectrum of other dusts/pollutants of sizes previously untested or delivered to the lungs in ways that did not reflect realistic exposure scenarios. PMID:24220216

  3. In-duct removal of mercury from coal-fired power plant flue gas by activated carbon: assessment of entrained flow versus wall surface contributions

    SciTech Connect

    Scala, F.; Chirone, R.; Lancia, A.

    2008-12-15

    In-duct mercury capture efficiency by activated carbon from coal-combustion flue gas was investigated. To this end, elemental mercury capture experiments were conducted at 100 C in a purposely designed 65-mm ID labscale pyrex apparatus operated as an entrained flow reactor. Gas residence times were varied between 0.7 and 2.0 s. Commercial-powdered activated carbon was continuously injected in the reactor and both mercury concentration and carbon elutriation rate were followed at the outlet. Transient mercury concentration profiles at the outlet showed that steady-state conditions were reached in a time interval of 15-20 min, much longer than the gas residence time in the reactor. Results indicate that the influence of the walls is non-negligible in determining the residence time of fine carbon particles in the adsorption zone, because of surface deposition and/or the establishment of a fluid-dynamic boundary layer near the walls. Total mercury capture efficiencies of 20-50% were obtained with carbon injection rates in the range 0.07-0.25 g/min. However, only a fraction of this capture was attributable to free-flowing carbon particles, a significant contribution coming from activated carbon staying near the reactor walls. Entrained bed experiments at lab-scale conditions are probably not properly representative of full-scale conditions, where the influence of wall interactions is lower. Moreover, previously reported entrained flow lab-scale mercury capture data should be reconsidered by taking into account the influence of particle-wall interactions.

  4. Cotton dust and endotoxin exposure-response relationships in cotton textile workers

    SciTech Connect

    Kennedy, S.M.; Christiani, D.C.; Eisen, E.A.; Wegman, D.H.; Greaves, I.A.; Olenchock, S.A.; Ye, T.T.; Lu, P.L.

    1987-01-01

    Endotoxin exposure has been implicated in the etiology of lung disease in cotton workers. We investigated this potential relationship in 443 cotton workers from 2 factories in Shanghai and 439 control subjects from a nearby silk mill. A respiratory questionnaire was administered and pre- and postshift forced expiratory volume (FVC) and flow in one second (FEV1) were determined for each worker. Multiple area air samples were analyzed for total elutriated dust concentration (range: 0.15 to 2.5 mg/m3) and endotoxin (range: 0.002 to 0.55 microgram U.S. Reference Endotoxin/m3). The cotton worker population was stratified by current and cumulative dust or endotoxin exposure. Groups were compared for FEV1, FVC, FEV1/FVC%, % change in FEV1 over the shift (delta FEV1%), and prevalences of chronic bronchitis and byssinosis, and linear and logistic regression models were constructed. No dose-response relationships were demonstrated comparing dust concentration to any pulmonary function or symptom variable. A dose-response trend was seen with the current endotoxin level and FEV1, delta FEV1%, and the prevalence of byssinosis and chronic bronchitis, except for the highest exposure level group in which a reversal of the trend was seen. The regression coefficients for current endotoxin exposure were significant (p less than 0.05) in the models for FEV1 and chronic bronchitis but not in the models for delta FEV1% (i.e., acute change in FEV1) or byssinosis prevalence. The coefficient for dust level was never significant in the models.

  5. Tumor recognition and lytic competence of IL-2-activated lymphocytes: regulation of both antibody-independent and -dependent cellular cytotoxicity via P75 IL-2 receptor.

    PubMed

    Lagoo-Deenadayalan, S; Lagoo, A S; Hardy, K J; Grimm, E A

    1992-08-01

    Fc receptor-positive lymphocytes (FcR+) contain lymphokine-activated killer cell (LAK) precursors that in response to IL-2 develop potent antitumor cytotoxicity. These FcR+ cells are also capable of antibody-dependent cytotoxicity (ADCC), which can be detected using fresh human peripheral blood lymphocytes (PBL) directed to murine targets, however, PBL-mediated ADCC to human tumors usually is very low, requiring a stimulation of the PBL, which also can be accomplished with IL-2. Using human melanoma tumor target cells, with and without the 14G2a monoclonal antibody, we examined in parallel the role of p75 IL-2 receptor for regulation of the induction of both LAK and ADCC forms of antitumor cytotoxicity. Enrichment of FcR+ cells from fresh peripheral blood by elutriation and flow cytometry, followed by varying periods of IL-2 culture, revealed a differential kinetics of activation. ADCC was detectable after PBL exposure to IL-2 for as short as the 4 h cytotoxicity assay, while LAK activation required more than 24 h of exposure. Elimination of the FcR+ cells by magnetic bead depletion from large granular lymphocyte populations (LGL) resulted in a loss of both LAK and ADCC. Addition of antibody known to block the binding of IL-2 to the p75 molecule of the IL-2 receptor complex (Mik-beta 1) to activation cultures at zero time resulted in abrogation of both cytotoxicities. These results suggest that differentiation and maturation of the ADCC effectors occurs in response to IL-2 via the p75 molecule, as also does LAK activation.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1420599

  6. Quantitative shape measurements of distal volcanic ash

    NASA Astrophysics Data System (ADS)

    Riley, Colleen M.; Rose, William I.; Bluth, Gregg J. S.

    2003-10-01

    Large-scale volcanic eruptions produce fine ash (<200 μm) which has a long atmospheric residence time (1 hour or more) and can be transported great distances from the volcanic source, thus, becoming a hazard to aircraft and public health. Ash particles have irregular shapes, so data on particle shape, size, and terminal velocities are needed to understand how the irregular-shaped particles affect transport processes and radiative transfer measurements. In this study, a methodology was developed to characterize particle shapes, sizes, and terminal velocities for three ash samples of different compositions. The shape and size of 2500 particles from (1) distal fallout (˜100 km) of the 14 October 1974 Fuego eruption (basaltic), (2) the secondary maxima (˜250 km) of the 18 August 1992 Spurr eruption (andesitic), and (3) the Miocene Ash Hollow member, Nebraska (rhyolitic) were measured using image analysis techniques. Samples were sorted into 10 to 19 terminal velocity groups (0.6-59.0 cm/s) using an air elutriation device. Grain-size distributions for the samples were measured using laser diffraction. Aspect ratio, feret diameter, and perimeter measurements were found to be the most useful descriptors of how particle shape affects terminal velocity. These measurement values show particle shape differs greatly from a sphere (commonly used in models and algorithms). The diameters of ash particles were 10-120% larger than ideal spheres at the same terminal velocity, indicating that irregular particle shape greatly increases drag. Gas-adsorption derived surface areas are 1 to 2 orders of magnitude higher than calculated surface areas based on measured dimensions and simple geometry, indicating that particle shapes are highly irregular. Correction factors for surface area were derived from the ash sample measurements so that surface areas calculated by assuming spherical particle shapes can be corrected to reflect more realistic values.

  7. Antioxidant response of Phragmites australis to Cu and Cd contamination.

    PubMed

    Rocha, A Cristina S; Almeida, C Marisa R; Basto, M Clara P; Vasconcelos, M Teresa S D

    2014-11-01

    Metals are known to induce oxidative stress in plant cells. Antioxidant thiolic compounds are known to play an important role in plants׳ defence mechanisms against metal toxicity but, regarding salt marsh plants, their role is still very poorly understood. In this work, the involvement of non-protein thiols (NPT), such as cysteine (Cys), reduced glutathione (GSH), oxidised glutathione (GSSG) and total acid-soluble SH compounds (total thiols), in the tolerance mechanisms of the marsh plant Phragmites australis against Cu and Cd toxicity was assessed. Specimens of this plant, freshly harvested in an estuarine salt marsh, were exposed, for 7 days, to rhizosediment soaked with the respective elutriate contaminated with Cu (0, 10 and 100 mg/L) or Cd (0, 1, 10 mg/L). In terms of NPT production, Cu and Cd contamination induced different responses in P. australis. The content of Cys increased in plant tissue after plant exposure to Cu, whereas Cd contamination led to a decrease in GSSG levels. In general, metal contamination did not cause a significant variation on GSH levels. Both metals influenced, to some extent, the production of other thiolic compounds. Despite the accumulation of considerable amounts of Cu and Cd in belowground tissues, no visible toxicity signs were observed. So, antioxidant thiolic compounds were probably involved in the mechanisms used by P. australis to alleviate metal toxicity. As P. australis is considered suitable for phytostabilising metal-contaminated sediments, understanding its tolerance mechanisms to toxic metals is important to optimise the conditions for applying this plant in phytoremediation procedures.

  8. Computational fluid dynamic modeling of fluidized-bed polymerization reactors

    SciTech Connect

    Rokkam, Ram

    2012-01-01

    Polyethylene is one of the most widely used plastics, and over 60 million tons are produced worldwide every year. Polyethylene is obtained by the catalytic polymerization of ethylene in gas and liquid phase reactors. The gas phase processes are more advantageous, and use fluidized-bed reactors for production of polyethylene. Since they operate so close to the melting point of the polymer, agglomeration is an operational concern in all slurry and gas polymerization processes. Electrostatics and hot spot formation are the main factors that contribute to agglomeration in gas-phase processes. Electrostatic charges in gas phase polymerization fluidized bed reactors are known to influence the bed hydrodynamics, particle elutriation, bubble size, bubble shape etc. Accumulation of electrostatic charges in the fluidized-bed can lead to operational issues. In this work a first-principles electrostatic model is developed and coupled with a multi-fluid computational fluid dynamic (CFD) model to understand the effect of electrostatics on the dynamics of a fluidized-bed. The multi-fluid CFD model for gas-particle flow is based on the kinetic theory of granular flows closures. The electrostatic model is developed based on a fixed, size-dependent charge for each type of particle (catalyst, polymer, polymer fines) phase. The combined CFD model is first verified using simple test cases, validated with experiments and applied to a pilot-scale polymerization fluidized-bed reactor. The CFD model reproduced qualitative trends in particle segregation and entrainment due to electrostatic charges observed in experiments. For the scale up of fluidized bed reactor, filtered models are developed and implemented on pilot scale reactor.

  9. Rapid screening for soil ecotoxicity with a battery of luminescent bacteria tests.

    PubMed

    Heinlaan, Margit; Kahru, Anne; Kasemets, Kaja; Kurvet, Imbi; Waterlot, Cristophe; Sepp, Kalev; Dubourguier, Henri-Charles; Douay, Francis

    2007-03-01

    A bacterial test battery, involving i) Microtox, an aquatic test, ii) the Flash assay, a soil-suspension test (with Vibrio fischeri as the test organism), and iii) the Metal Detector assay, a semi-specific aquatic test for heavy metals (with recombinant luminescent Escherichia coli), was used in a combined toxicological and chemical hazard assessment of Estonian soils sampled from a former Soviet military airfield (13 samples) and from traffic-influenced roadsides (5 samples). The soils showed slightly elevated levels of total petroleum hydrocarbons (TPH), but not of heavy metals. In most of the samples, the levels of TPH did not exceed the Estonian permitted limit values set for residential areas. Toxicity testing was performed on both fresh and dried soils, after aqueous extraction for 1 hour and 24 hours. The toxicity results obtained with the Microtox test did not significantly differ in all of the sample treatment schemes; however, it appeared that the drying and sieving of the soils increased the bioavailability of toxicants, probably due to an enlarged reactive soil surface area. According to chemical analysis of the soils and the data from the Microtox test and the Metal Detector assay (performed on aqueous elutriates of the soils), these soils would not be considered to be hazardous. In contrast, the Flash assay performed on soil-water suspensions of dried soils, showed that most of the soils were toxic and thus probably contained undetermined particle-bound bioavailable toxicants. The photobacterial toxicity test (the Flash assay) can be recommended for the rapid screening of soils, as it is sensitive, cheap and inexpensive, and provides valuable information on particle-bound bioavailable toxicants, useful for complementing a chemical analysis and for assessing the risks originating from polluted soils. PMID:17411358

  10. In vitro systems for exposure of lung cells to NO2 and O3.

    PubMed

    Rasmussen, R E

    1984-01-01

    In vitro studies of the effects of NO2 and O3 require development of methods for separation and culture of those lung cells that experience in vivo exposure, and also the design and construction of systems for controlled exposure of the cells to known concentrations of the gases. Separation of lung cell types has been accomplished by enzymatic dispersal of lung tissue and centrifugation of the mixed cells on media of various densities in order to separate the cells on the basis of buoyant density or sedimentation rate. The application of centrifugal elutriation has enabled separation of type II alveolar cells and Clara cells with a high degree of purity. Alveolar macrophages and endothelial cells have also been obtained in good yield. Exposure of cultured cells to test atmospheres requires precise control of pollutant levels, close contact of cells and gas without an intervening layer of medium, capability for prolonged exposure, and maintenance of sterile conditions, so that recovered cells can be cultured further or studied for other biological activity. Systems which meet these criteria include roller bottle cultures, petri dish cultures on rocker platforms, cell cultures on cellulose filters fed by perfusion of medium from the side opposite the cells, and cells grown in dishes with gas-permeable film bottoms. Systems that rely on solution of the gases in the overlaying medium do not resemble exposure conditions in vivo, and may not be suitable for studying effects of the poorly soluble oxidant gases. The cell exposure systems have not been used extensively for studies of the effects of pollutants on freshly isolated specific lung cell types. Such studies should be encouraged.

  11. Screening of binders for pelletization of CaO-based sorbents for CO{sub 2} capture

    SciTech Connect

    Vasilije Manovic; Edward J. Anthony

    2009-09-15

    CaO-based CO{sub 2} looping cycle technology is a promising method for separation of CO{sub 2} from flue gas and syngas at high temperatures. The process of CO{sub 2} capture is expected to take place in fluidized-bed combustion (FBC) systems, which implies significant attrition and elutriation of the solid sorbent. Hence, both reactivation of spent sorbent and preparation of modified CaO-based sorbent may be required to maximize the performance of the sorbent. We present initial results on the screening of suitable binders for pelletization. Two types of bentonite (Na- and Ca-bentonite) and four types of commercial calcium aluminate cements (CA-14, CA-25, Secar 51, and Secar 80) were investigated here, with a primary focus of maintaining a high CO{sub 2}-capture capacity over 30-35 cycles. The tests were carried out using a thermogravimetric analyzer (TGA), and the results showed that the presence of bentonites led to faster decay in activity as a result of the formation of calcium-silica compounds with low melting points, which leads to enhanced sintering. This is confirmed by scanning electron microscopy (SEM) and also X-ray diffraction (XRD), which showed the presence of spurrite (Ca{sub 5}(SiO{sub 4}){sub 2}CO{sub 3}) as the dominant compound in the pellet after this series of cycles. Better results were obtained with no binder, i.e., by hydration of lime, where Ca(OH){sub 2} plays the role of the binder. Promising results were obtained also with calcium aluminate cements, where no effect of sintering because of the presence of these binders was noticed. Thus, on the basis of this study, the use of calcium aluminate cements for pelletization of CaO-based sorbent is recommended. 39 refs., 9 figs., 2 tabs.

  12. Contrasting effects of inflammatory stimuli on neutrophil and monocyte adherence to endothelial cells.

    PubMed

    Kamp, D W; Bauer, K D; Knap, A; Dunn, M M

    1989-08-01

    Leukocyte adherence to endothelial cells (EC) is an important early event in inflammatory responses, which are often characterized by a predominance of either neutrophils (PMN) or monocytes. However, there is little information concerning the molecular events important in leukocyte adherence to EC. Intracellular activation of protein kinase C and the calcium-second messenger system leads to the stimulation of a number of important functions in PMN and monocytes. We compared the effects of members of these pathways on human PMN and monocyte adherence to cultured bovine aortic EC. We observed that phorbol myristate acetate, phorbol, 12,13-dibutyrate, L-alpha-1-oleoyl-2-acetoyl-sn-3-glycerol, and ionomycin each induced significant dose-dependent increases in PMN adherence to EC monolayers. In contrast, similar concentrations of each of these agents induced significant decreases in EC adherence of monocytes enriched by countercurrent centrifugal elutriation. Separate experiments determined that the differences in PMN and monocyte adherence to EC were not related to differences in oxidant production because 1) phorbol myristate acetate and L-alpha-1-oleoyl-2-acetoyl-sn-3-glycerol caused similar marked increases in both PMN and monocyte superoxide anion and hydrogen peroxide production and 2) ionomycin, which had opposing effects on PMN and monocyte adherence, had no effect on PMN and monocyte superoxide anion or hydrogen peroxide release. We conclude that activators of protein kinase C and the Ca-second messenger pathway have opposite effects on PMN and monocyte adherence to EC and that these effects are mediated by O2 radical-independent mechanisms.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Distribution of Components in Ion Exchange Materials Taken from the K East Basin and Leaching of Ion Exchange Materials by Nitric/Hydrofluoric Acid and Nitric/Oxalic Acid

    SciTech Connect

    Delegard, C.H.; Rinehart, D.E.; Hoopes, F.V.

    1999-04-02

    Laboratory tests were performed to examine the efficacy of mixed nitric/hydrofluoric acid followed by mixed nitric/oxalic acid leach treatments to decontaminate ion exchange materials that have been found in a number of samples retrieved from K East (KE)Basin sludge. The ion exchange materials contain organic ion exchange resins and zeolite inorganic ion exchange material. Based on process records, the ion exchange resins found in the K Basins is a mixed-bed, strong acid/strong base material marketed as Purolite NRW-037. The zeolite material is Zeolon-900, a granular material composed of the mineral mordenite. Radionuclides sorbed or associated with the ion exchange material can restrict its disposal to the Environmental Restoration Disposal Facility (ERDF). The need for testing to support development of a treatment process for K Basin sludge has been described in Section 4.2 of ''Testing Strategy to Support the Development of K Basins Sludge Treatment Process'' (Flament 1998). Elutriation and washing steps are designed to remove the organic resins from the K Basin sludge. To help understand the effects of the anticipated separation steps, tests were performed with well-rinsed ion exchange (IX) material from KE Basin floor sludge (sample H-08 BEAD G) and with well-rinsed IX having small quantities of added KE canister composite sludge (sample KECOMP). Tests also were performed to determine the relative quantities of organic and inorganic IX materials present in the H-08 K Basin sludge material. Based on chemical analyses of the separated fractions, the rinsed and dry IX material H-08 BEAD G was found to contain 36 weight percent inorganic material (primarily zeolite). The as-received (unrinsed) and dried H-08 material was estimated to contain 45 weight percent inorganic material.

  14. Polycyclic aromatic hydrocarbon-contaminated soils: bioaugmentation of autochthonous bacteria and toxicological assessment of the bioremediation process by means of Vicia faba L.

    PubMed

    Ruffini Castiglione, Monica; Giorgetti, Lucia; Becarelli, Simone; Siracusa, Giovanna; Lorenzi, Roberto; Di Gregorio, Simona

    2016-04-01

    Two bacterial strains, Achromobacter sp. (ACH01) and Sphingomonas sp. (SPH01), were isolated from a heavily polycyclic aromatic hydrocarbon (PAH)-contaminated soil (5431.3 ± 102.3 ppm) for their capacity to use a mixture of anthracene, pyrene, phenanthrene and fluorene as sole carbon sources for growth and for the capacity to produce biosurfactants. The two strains were exploited for bioaugmentation in a biopile pilot plant to increase the bioavailability and the degradation of the residual PAH contamination (99.5 ± 7.1 ppm) reached after 9 months of treatment. The denaturing gel gradient electrophoresis (DGGE) profile of the microbial ecology of the soil during the experimentation showed that the bioaugmentation approach was successful in terms of permanence of the two strains in the soil in treatment. The bioaugmentation of the two bacterial isolates positively correlated with the PAH depletion that reached 7.9 ± 2 ppm value in 2 months of treatment. The PAH depletion was assessed by the loss of the phyto-genotoxicity of soil elutriates on the model plant Vicia faba L., toxicological assessment adopted also to determine the minimum length of the decontamination process for obtaining both the depletion of the PAH contamination and the detoxification of the soil at the end of the process. The intermediate phases of the bioremediation process were the most significant in terms of toxicity, inducing genotoxic effects and selective DNA fragmentation in the stem cell niche of the root tip. The selective DNA fragmentation can be related to the selective induction of cell death of mutant stem cells that can compromise offsprings. PMID:26769476

  15. Comet Assay on Daphnia magna in eco-genotoxicity testing.

    PubMed

    Pellegri, Valerio; Gorbi, Gessica; Buschini, Annamaria

    2014-10-01

    Detection of potentially hazardous compounds in water bodies is a priority in environmental risk assessment. For the evaluation and monitoring of water quality, a series of methodologies may be applied. Among them, the worldwide used toxicity tests with organisms of the genus Daphnia is one of the most powerful. In recent years, some attempts were made to utilize Daphnia magna in genotoxicity testing as many of the new environmental contaminants are described as DNA-damaging agents in aquatic organisms. The aim of this research was to develop a highly standardized protocol of the Comet Assay adapted for D. magna, especially regarding the isolation of cells derived from the same tissue (haemolymph) from newborn organisms exposed in vivo. Several methods for haemolymph extraction and different Comet Assay parameters were compared. Electrophoretic conditions were adapted in order to obtain minimum DNA migration in cells derived from untreated organisms and, at the same time, maximum sensitivity in specimens treated with known genotoxicants (CdCl2 and H2O2). Additional tests were performed to investigate if life-history traits of the cladoceran (such as the age of adult organisms that provide newborns, the clutch size of origin, the number of generations reared in standard conditions) and the water composition as well, might influence the response of the assay. This study confirms the potential application of the Comet Assay in D. magna for assessing genotoxic loads in aqueous solution. The newly developed protocol could integrate the acute toxicity bioassay, thus expanding the possibility of using this model species in freshwater monitoring (waters, sediment and soil elutriates) and is in line with the spirit of the EU Water Framework Directive in reducing the number of bioassays that involve medium-sized species.

  16. Cell Cycle-Dependent Mechanisms Underlie Vincristine-Induced Death of Primary Acute Lymphoblastic Leukemia Cells.

    PubMed

    Kothari, Anisha; Hittelman, Walter N; Chambers, Timothy C

    2016-06-15

    Microtubule-targeting agents (MTA), such as the taxanes and vinca alkaloids, are used to treat a variety of cancers due to their ability to perturb microtubule dynamics. In cell culture, MTAs exert their anticancer effects primarily by causing mitotic arrest and cell death. However, accumulating indirect evidence suggests that MTAs may exert their cytotoxicity in human tumors by interfering with interphase microtubules. In this study, we sought to develop and characterize an experimental system in which to test the hypothesis that MTAs induce cell death during interphase. Primary adult acute lymphoblastic leukemia (ALL) cells treated with vincristine only weakly exhibited colocalization between mitotic and apoptotic markers and major characteristics of mitotic death, such as an increase in cells with 4N DNA content before the appearance of cells with <2N DNA content, suggesting a mixed response. Therefore, we separated ALL cells into distinct phases of the cell cycle by centrifugal elutriation, labeled cells with 5-ethynyl-2'-deoxyuridine (EdU), and then treated each population with vincristine. Cells isolated during G1 underwent cell death without evidence of EdU uptake, indicating that the cytotoxic effects of vincristine took place during G1 Conversely, cells isolated during S or G2-M phases underwent death following mitotic arrest. Thus, vincristine induces distinct death programs in primary ALL cells depending on cell-cycle phase, and cells in G1 are particularly susceptible to perturbation of interphase microtubules. Primary ALL cells may therefore provide a powerful model system in which to study the multimodal mechanisms underlying MTA-induced cell death. Cancer Res; 76(12); 3553-61. ©2016 AACR.

  17. Emplacement of the Cabezo María lamproite volcano (Miocene, SE Spain)

    NASA Astrophysics Data System (ADS)

    Gernon, Thomas M.; Spence, Samuel; Trueman, Clive N.; Taylor, Rex N.; Rohling, Eelco; J. Hatter, Stuart; Harding, Ian C.

    2015-06-01

    Lamproite volcanoes are uncommon in the geological record but are exceptionally well preserved in the Betic Cordilleras of SE Spain, where they erupted during the Late Miocene (Tortonian to Messinian stages). The parent melts are thought to have been channelled through major lithospheric faults to erupt at or near the faulted margins of Neogene sedimentary basins. Lamproite magmas are thought to be relatively CO2-poor (<1 wt %) and are typically characterised by an effusive eruption style and the development of lava lakes and scoria cones. Cabezo María is a relatively small (˜550 m diameter) lamproite volcano that was emplaced within the shallow-water marine-influenced Vera Basin. The lamproites are compositionally similar to those of the Roman Province and generally less potassic (K2O<5 wt%) than other (ultra-) potassic rocks in SE Spain (e.g. Cancarix, Fortuna). The initial eruption stages were dominated by explosive magma-water interactions and the formation of peperites. These are characterised by angular fragments of glassy lamproite lavas (and isolated lobes) incorporated in sediments, locally showing the effects of thermal metamorphism. Further, elutriation pipes and `jigsaw-fit' textures are observed in the peperites. The lavas and peperites are overlain by outward-dipping well-stratified scoria deposits defining part of a cinder cone, which is inferred to have emerged above sea level. Steep internal contacts with inward-dipping, structureless breccias likely represent the inner wall deposits of a central conduit. The deposits are cross-cut by late-stage dykes, which supplied fissure eruptions of geochemically similar lavas capping the scoria cone. The transition from explosive to effusive behaviour may reflect the decreased availability of water, possibly due to downward migration of the feeder conduit below the level of water-saturated sediments.

  18. Evaluation of toxicity of polluted marine sediments from Bahia Salina Cruz, Mexico.

    PubMed

    Gonzalez-Lozano, Maria Cristina; Mendez-Rodriguez, Lia C; Maeda-Martinez, Alejandro M; Murugan, Gopal; Vazquez-Botello, Alfonso

    2010-01-01

    Bahia Salina Cruz, Oaxaca, Mexico is a major center of oil and refined product distribution on the Mexican Pacific coast. From the start of oil industry operations in 1979, negative effects from discharges of treated effluents in the bay have been a constant concern for local communities. We analyzed 28 surface sediment samples obtained in June, 2002 to evaluate the level of toxicity in the littoral zone, port-harbor, and La Ventosa estuary in Bahia Salina Cruz. The extractable organic matter concentration was high (1,213 to 7,505 micro g g(-1)) in 5 of 7 stations from the port and harbor, whereas it was low in 12 of 16 stations in the littoral zone (36 to 98 micro g g(-1)). The total aromatic hydrocarbon concentration was highest (57 to 142 micro g g(-1)) in the port and harbor compared to the La Ventosa estuary and the littoral zone. Among the heavy metals analyzed, cadmium exceeded the effects range-low values associated with adverse biological effects. The geo-accumulation index of sediments was moderate to strong contamination at 5 stations in the nonlittoral and 6 stations in the littoral zone. The enrichment of lead, zinc, and cadmium at 5 stations from the littoral, port, and harbor suggest that these metals are of anthropogenic origin. Bioassay tests of elutriates of sediments on nauplii of Artemia franciscana and Artemia sp. showed that the port and harbor were more toxic than the La Ventosa estuary and the coastal zone. The Microtox test (Vibrio fischeri) did not show a similar response with the solid phase of the sediments. The results of this study indicate that the high levels of organic content and metals in the sediments of port-harbor and the La Ventosa estuary are mainly caused by anthropogenic activities.

  19. Human Very Small Embryonic-Like Cells Generate Skeletal Structures, In Vivo

    PubMed Central

    Havens, Aaron M.; Shiozawa, Yusuke; Jung, Younghun; Sun, Hongli; Wang, Jincheng; McGee, Samantha; Mishra, Anjali; Taichman, L. Susan; Danciu, Theodora; Jiang, Yajuan; Yavanian, Gregory; Leary, Elizabeth; Krebsbach, Paul H.; Rodgerson, Denis

    2013-01-01

    Human very small embryonic-like (hVSEL) cells are a resident population of multipotent stem cells in the bone marrow involved in the turnover and regeneration of tissues. The levels of VSEL cells in blood are greatly increased in response to injury, and they have been shown to repair injured tissues. Adult hVSEL cells, SSEA-4+/CD133+/CXCR4+/Lin−/CD45−, express the pluripotency markers (Oct-4 and Nanog) and may be able to differentiate into cells from all 3 germ lineages. hVSEL cells isolated from blood by apheresis following granulocyte–colony-stimulating factor mobilization were fractionated and enriched by elutriation and fluorescence activated cell sorting. Collagen sponge scaffolds containing 2,000–30,000 hVSEL cells were implanted into cranial defects generated in SCID mice. Analysis by microcomputed tomography showed that a cell population containing VSEL cells produced mineralized tissue within the cranial defects compared with controls at 3 months. Histologic studies showed significant bone formation and cellular organization within the defects compared with cellular or scaffold controls alone. Antibodies to human leukocyte antigens demonstrated that the newly generated tissues were of human origin. Moreover, human osteocalcin was identified circulating in the peripheral blood. There was evidence that some level of hVSEL cells migrated away from the defect site, using quantitative real-time polymerase chain reaction to detect for human-specific Alu sequences. This study demonstrates that hVSEL cells are able to generate human bone tissue in a mouse model of skeletal repair. These studies lay the foundation for future cell-based regenerative therapies for osseous and connective tissue disorders, including trauma and degenerative conditions, such as osteoporosis, fracture repair, and neoplastic repair. PMID:23020187

  20. Combustion studies of high moisture content waste in a fluidised bed.

    PubMed

    Suksankraisorn, K; Patumsawad, S; Fungtammasan, B

    2003-01-01

    The combustion of three high moisture content waste materials in a fluidised bed combustor has been investigated and a comparison with co-firing of these materials with coal in the same combustor has been made. Waste materials burnt were olive oil waste, municipal solid waste and potato, which is representative of vegetable waste. Mixtures of up to 20% mass concentration water in the waste were fed to the combustor. Above that value the moisture content was too high to sustain combustion without addition of coal. Measurements of CO, NOx, SO2 temperatures were made and the carbon combustion efficiency evaluated. Co-firing with coal resulted in markedly higher combustion efficiencies with an increase of approximately 10-80% when burning the simulated MSW. However, this was much lower than the value of 93% when coal was burnt on its own. It was also much lower than the value obtained, average 90%, when co-firing potato and olive oil waste with coal and there was little difference in the combustion efficiency between the two types of waste and with increasing moisture content. It was concluded that the high ash content of the simulated MSW 26%, compared with 5% in the other two waste materials resulted in slower burning and consequently the char particles were elutriated from the bed without being fully burnt. In term of gaseous emissions during co-combustion, CO emission is relatively insensitive to change in waste fraction. While emission of SO2 can be reduced as the waste fraction increases as a result of fuel-S dilution. But in terms of percent fuel-S converted, it is actually increased by increasing waste fraction. Emissions of NO and N2O increase slightly with MSW fraction.

  1. Bioaccumulation of toxicants in the zebra mussel, Dreissena polymorpha, at the Times Beach Confined Disposal Facility, Buffalo, New York.

    PubMed

    Roper, J M; Cherry, D S; Simmers, J W; Tatem, H E

    1996-01-01

    This study consisted of a site characterization followed by biomonitoring the zebra mussel, Dreissena polymorpha, at the Times Beach Confined Disposal Facility (CDF), located in Buffalo, New York. Concentrations of selected contaminants, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and metals -arsenic (As), chromium (Cr), barium (Ba), mercury (Hg), cadmium (Cd), lead (Pb), selenium (Se) and silver (Ag)-were at or below detection limits in the water column. Sediment contaminant concentrations, recorded as dry weight, were as high as 549 mg/kg for total PAHs, 9 mg/kg for PCB Aroclor 1248 and 54, 99, 6, 355, 637 and 16 mg/kg for the metals As, Ba, Cd, Cr, Pb and Hg, respectively. To predict contaminant bioavailability, elutriate and whole sediment toxicity tests were performed utilizing the cladoceran, Daphnia magna. Whole sediment tests indicated significant impact. Control survival was 84%, while sediment treatment had survival ranging from 1 to 7%. Mean control reproduction was 86.8 neonates, whereas treatment reproduction ranged from 1.4 to 9.0. Zebra mussels placed both in the water column (Upper) and at the sediment level (Lower) survived the 34-day exposure. Contaminants that significantly accumulated in zebra mussel tissue (wet wt mg/kg) were total PAHs (6.58), fluoranthene (1.23), pyrene (1.08), chrysene (0.98), benzo(a)anthracene (0.60), PCB Aroclor 1248 (1.64), As (0.97), Cr (2.87) and Ba (7.00). Accumulation of these contaminants in zebra mussel tissue represent a potentially realistic hazard to organisms (i.e. fish and birds) that feed on them.

  2. Validation of Microtox as a first screening tool for waste classification.

    PubMed

    Weltens, R; Deprez, K; Michiels, L

    2014-12-01

    The Waste Framework Directive (WFD; 2008/98/EG) describes how waste materials are to be classified as hazardous or not. For complex waste materials chemical analyses are often not conclusive and the WFD provides the possibility to assess the hazardous properties by testing on the waste materials directly. As a methodology WFD refers to the protocols described in the CLP regulation (regulation on Classification, Labeling and Packaging of chemicals) but the toxicity tests on mammals are not acceptable for waste materials. The DISCRISET project was initiated to investigate the suitability of alternative toxicity tests that are already in use in pharmaceutical applications, for the toxicological hazard assessment of complex waste materials. Results indicated that Microtox was a good candidate as a first screening test in a tiered approached hazard assessment. This is now further validated in the present study. The toxic responses measured in Microtox were compared to biological responses in other bioassays for both organic and inorganic fractions of the wastes. Both fractions contribute to the toxic load of waste samples. Results show that the Microtox test is indeed a good and practical screening tool for the organic fraction. A screening threshold (ST) of 5 geq/l as the EC50 value in Microtox is proposed as this ST allows to recognize highly toxic samples in the screening test. The data presented here show that the Microtox toxicity response at this ST is not only predictive for acute toxicity in other organisms but also for sub lethal toxic effects of the organic fraction. This limit value has to be further validated. For the inorganic fraction no specific biotest can be recommended as a screening test, but the use of direct toxicity assessment is also preferable for this fraction as metal speciation is an important issue to define the toxic load of elutriate fractions. A battery of 3 tests (Microtox, Daphnia and Algae) for direct toxicity assessment of this

  3. Development of a cytokine-producing immortalized murine Kupffer cell line.

    PubMed

    Wang, Zheng-Yu; Burlak, Christopher; Klaunig, James E; Kamendulis, Lisa M

    2014-12-01

    Kupffer cells (KC) play a critical role in both liver physiology and the pathogenesis of various liver diseases. Isolated primary KC have a limited lifespan in culture, and due to the relatively low number obtained, limit their study in vitro. Here, a cytokine-producing immortalized KC (ImKC) line was established from transgenic mice that express the thermolabile mutant tsA58 of the Simian virus 40 large T antigen under the control of the H-2k(b) promoter. Primary KC were obtained using a three step procedure: liver perfusion, centrifugal elutriation, and sorting for F4/80⁺ cells. ImKC were identified within the small-intermediate population of KC that maintained stable expression of F4/80, and the surface antigens CD11b, CD14 and TLR4. ImKC grow at IFNγ-independent manner at 37°C and exhibited a doubling time of ∼24 h when cultured in RPMI 1640 with 5% FBS. Our observations indicate that both activation of telomerase and expression of P53 are markedly increased, suggesting that enhanced telomerase activity and P53 expression may contribute to the immortalization of this cell population. ImKC cells maintained a high capacity to phagocytose FITC-latex beads, and bind/phagocytose erythrocytes. In addition, similar to primary KC, ImKC responded to stimulation with lipopolysaccharide (LPS: 0.1-1μg/ml) by upregulating mRNA levels of TNFα (23-fold), IL-6 (28-fold), and IL-1β (1459-fold), as measured by qRT-PCR. Protein levels of TNFα and IL-6 were also increased, 10-fold and 12-fold, respectively. Reactive oxygen species (ROS) and nitric oxide (NO) production were significantly enhanced in ImKC following an LPS challenge. Furthermore, LPS elicited a marked increase in mitogen activated protein kinase (MAPK) phospho-(ERK1/2, JNK) and NF-κB p50 with decreased IκBα in ImKC, as assessed by Western blot. Collectively, these results demonstrate that the ImKC line retains critical characteristics of primary KC, and thus provides a useful tool to assess the role of

  4. Pressurized fluidized bed combustion second-generation system research and development. Technical progress for Phase 2 and Phase 3, October 1, 1997--September 30, 1998

    SciTech Connect

    Robertson, A.; Horazak, D.; Newby, R.; Rehmat, A.; White, J.

    1998-10-01

    When DOE funds were exhausted in March 1995, all Phase 2 activities were placed on hold. In February 1996 a detailed cost estimate was submitted to the DOE for completing the two remaining Phase 2 Multi Annular Swirl Burner (MASB) topping combustor test burns; in August 1996 release was received from METC to proceed with these tests. The first test (Test Campaign No.3) will be conducted to: (1) test the MASB at proposed demonstration plant full to minimum loading operating conditions; (2) identify the lower oxygen limit of the MASB; and (3) demonstrate natural gas to carbonizer fuel gas switching. The Livingston Phase 3 Pilot Plant was last operated under contract DE-AC21-86MC21023 in September 1995 for seven days in an integrated carbonizer-CPFBC configuration. In May, 1996, the pilot plant was transferred to Contract DE-AC22-95PC95143 to allow testing in support of the High Performance Power Systems (HIPPS) Program. The HIPPS Program required modifications to the pilot plant and the following changes were incorporated: (1) installation of a dense phase transport system for loading pulverized coal into the feed system lock hopper directly from a pneumatic transport truck; (2) removal of the char transfer pipe between the char collecting hopper and the CPFBC to allow carbonizer only operation; (3) installation of a lock hopper directly under the char collecting hopper to facilitate char removal from the process, the hopper vent gases exhaust to the carbonizer baghouse filter and the depressured char is transferred via nitrogen to the CPFBC baghouse for dumping into drums; (4) removal of the carbonizer cyclone and top of bed overflow drain line; all material elutriated from the carbonizer bed will thus be removed by the 22-element Westinghouse ceramic candle filter; (5) replacement of the carbonizer continuous bottom bed drain (screw feeder) with a batch-type drain removal system; and (6) installation of a mass spectrometer that draws sample gas via a steam jacketed

  5. Role of Water and Ice in Ash Aggregation: Constraints from the Upper Scoriae 1 Deposit, Santorini, Greece.

    NASA Astrophysics Data System (ADS)

    Durant, A. J.; Ernst, G. G.

    2001-12-01

    Volcanic eruption clouds can disperse ash over large areas, posing hazards on the ground and for air traffic. One distant goal is to develop much needed risk models of ash fallout. This however, is hindered by incompletely understood aspects, one of which is ash aggregation and especially the role of liquid water and ice. We analysed accretionary lapilli-rich fall deposits from Santorini, interpreted here to have formed from eruption clouds elutriated from energetic base surges rich in water, which condensed and froze during rise while interacting with ash. Investigation methods included fieldwork, hand sample binocular microscopy, lapilli and particle size analysis, SEM, EPMA and basic modelling of aggregate settling. Field data indicate both ductile and brittle deformation of aggregates during deposition. Lapilli size distributions peak sharply at 2.5 mm with few aggregates ~10 mm, but most <4.5 mm. Lapilli display a volumetrically-dominant, poorly sorted, coarse-grained core and a thin, fine-grained rim. Particle size distributions in the core and rim peak at 45-70 microns and 10-30 microns (MALVERN and SEM data), with a sharp grain size break. This is consistent with growth by wet collection where aggregate size is limited by `drop break-up'. Fine ash rims imply freezing halts wet accretion, and lapilli >4.5 mm indicate accretion proceeds similar to hailstone growth. Insights from hailstone studies and experiments of Gilbert & Lane (1994) suggest that a liquid skin is needed to aggregate fine rim ash, thus constraining rimming processes to approximately 5-8 km asl. Multiple fine rims indicate recycling of frozen accretionary lapilli. Close association of fine vesiculated ash and large lapilli (i.e. contrasting Vt) in the deposit suggests that fallout of lapilli and mud rain was coeval, perhaps due to a settling-driven instability at the umbrella base. A new conceptual model accounting for all data observations is summarised. The new constraints will be useful

  6. Murine pulmonary responses after sub-chronic exposure to aluminum oxide-based nanowhiskers

    PubMed Central

    2012-01-01

    Background Aluminum oxide-based nanowhiskers (AO nanowhiskers) have been used in manufacturing processes as catalyst supports, flame retardants, adsorbents, or in ceramic, metal and plastic composite materials. They are classified as high aspect ratio nanomaterials. Our aim was to assess in vivo toxicity of inhaled AO nanowhisker aerosols. Methods Primary dimensions of AO nanowhiskers specified by manufacturer were 2–4 nm x 2800 nm. The aluminum content found in this nanomaterial was 30% [mixed phase material containing Al(OH)3 and AlOOH]. Male mice (C57Bl/6 J) were exposed to AO nanowhiskers for 4 hrs/day, 5 days/wk for 2 or 4 wks in a dynamic whole body exposure chamber. The whiskers were aerosolized with an acoustical dry aerosol generator that included a grounded metal elutriator and a venturi aspirator to enhance deagglomeration. Average concentration of aerosol in the chamber was 3.3 ± 0.6 mg/m3 and the mobility diameter was 150 ± 1.6 nm. Both groups of mice (2 or 4 wks exposure) were necropsied immediately after the last exposure. Aluminum content in the lung, heart, liver, and spleen was determined. Pulmonary toxicity assessment was performed by evaluation of bronchoalveolar lavage (BAL) fluid (enumeration of total and differential cells, total protein, activity of lactate dehydrogenase [LDH] and cytokines), blood (total and differential cell counts), lung histopathology and pulmonary mechanics. Results Following exposure, mean Al content of lungs was 0.25, 8.10 and 15.37 μg/g lung (dry wt) respectively for sham, 2 wk and 4 wk exposure groups. The number of total cells and macrophages in BAL fluid was 2-times higher in animals exposed for 2 wks and 6-times higher in mice exposed for 4 wks, compared to shams (p < 0.01, p < 0.001, respectively). However no neutrophilic inflammation in BAL fluid was found and neutrophils were below 1% in all groups. No significant differences were found in total protein, activity of LDH, or

  7. Validation of Microtox as a first screening tool for waste classification.

    PubMed

    Weltens, R; Deprez, K; Michiels, L

    2014-12-01

    The Waste Framework Directive (WFD; 2008/98/EG) describes how waste materials are to be classified as hazardous or not. For complex waste materials chemical analyses are often not conclusive and the WFD provides the possibility to assess the hazardous properties by testing on the waste materials directly. As a methodology WFD refers to the protocols described in the CLP regulation (regulation on Classification, Labeling and Packaging of chemicals) but the toxicity tests on mammals are not acceptable for waste materials. The DISCRISET project was initiated to investigate the suitability of alternative toxicity tests that are already in use in pharmaceutical applications, for the toxicological hazard assessment of complex waste materials. Results indicated that Microtox was a good candidate as a first screening test in a tiered approached hazard assessment. This is now further validated in the present study. The toxic responses measured in Microtox were compared to biological responses in other bioassays for both organic and inorganic fractions of the wastes. Both fractions contribute to the toxic load of waste samples. Results show that the Microtox test is indeed a good and practical screening tool for the organic fraction. A screening threshold (ST) of 5 geq/l as the EC50 value in Microtox is proposed as this ST allows to recognize highly toxic samples in the screening test. The data presented here show that the Microtox toxicity response at this ST is not only predictive for acute toxicity in other organisms but also for sub lethal toxic effects of the organic fraction. This limit value has to be further validated. For the inorganic fraction no specific biotest can be recommended as a screening test, but the use of direct toxicity assessment is also preferable for this fraction as metal speciation is an important issue to define the toxic load of elutriate fractions. A battery of 3 tests (Microtox, Daphnia and Algae) for direct toxicity assessment of this

  8. A multidisciplinary effort to assign realistic source parameters to models of volcanic ash-cloud transport and dispersion during eruptions

    NASA Astrophysics Data System (ADS)

    Mastin, L. G.; Guffanti, M.; Servranckx, R.; Webley, P.; Barsotti, S.; Dean, K.; Durant, A.; Ewert, J. W.; Neri, A.; Rose, W. I.; Schneider, D.; Siebert, L.; Stunder, B.; Swanson, G.; Tupper, A.; Volentik, A.; Waythomas, C. F.

    2009-09-01

    During volcanic eruptions, volcanic ash transport and dispersion models (VATDs) are used to forecast the location and movement of ash clouds over hours to days in order to define hazards to aircraft and to communities downwind. Those models use input parameters, called "eruption source parameters", such as plume height H, mass eruption rate Ṁ, duration D, and the mass fraction m63 of erupted debris finer than about 4ϕ or 63 μm, which can remain in the cloud for many hours or days. Observational constraints on the value of such parameters are frequently unavailable in the first minutes or hours after an eruption is detected. Moreover, observed plume height may change during an eruption, requiring rapid assignment of new parameters. This paper reports on a group effort to improve the accuracy of source parameters used by VATDs in the early hours of an eruption. We do so by first compiling a list of eruptions for which these parameters are well constrained, and then using these data to review and update previously studied parameter relationships. We find that the existing scatter in plots of H versus Ṁ yields an uncertainty within the 50% confidence interval of plus or minus a factor of four in eruption rate for a given plume height. This scatter is not clearly attributable to biases in measurement techniques or to well-recognized processes such as elutriation from pyroclastic flows. Sparse data on total grain-size distribution suggest that the mass fraction of fine debris m63 could vary by nearly two orders of magnitude between small basaltic eruptions (˜ 0.01) and large silicic ones (> 0.5). We classify eleven eruption types; four types each for different sizes of silicic and mafic eruptions; submarine eruptions; "brief" or Vulcanian eruptions; and eruptions that generate co-ignimbrite or co-pyroclastic flow plumes. For each eruption type we assign source parameters. We then assign a characteristic eruption type to each of the world's ˜ 1500 Holocene

  9. A multidisciplinary effort to assign realistic source parameters to models of volcanic ash-cloud transport and dispersion during eruptions

    USGS Publications Warehouse

    Mastin, L.G.; Guffanti, M.; Servranckx, R.; Webley, P.; Barsotti, S.; Dean, K.; Durant, A.; Ewert, J.W.; Neri, A.; Rose, William I.; Schneider, D.; Siebert, L.; Stunder, B.; Swanson, G.; Tupper, A.; Volentik, A.; Waythomas, C.F.

    2009-01-01

    During volcanic eruptions, volcanic ash transport and dispersion models (VATDs) are used to forecast the location and movement of ash clouds over hours to days in order to define hazards to aircraft and to communities downwind. Those models use input parameters, called "eruption source parameters", such as plume height H, mass eruption rate ???, duration D, and the mass fraction m63 of erupted debris finer than about 4??{symbol} or 63????m, which can remain in the cloud for many hours or days. Observational constraints on the value of such parameters are frequently unavailable in the first minutes or hours after an eruption is detected. Moreover, observed plume height may change during an eruption, requiring rapid assignment of new parameters. This paper reports on a group effort to improve the accuracy of source parameters used by VATDs in the early hours of an eruption. We do so by first compiling a list of eruptions for which these parameters are well constrained, and then using these data to review and update previously studied parameter relationships. We find that the existing scatter in plots of H versus ??? yields an uncertainty within the 50% confidence interval of plus or minus a factor of four in eruption rate for a given plume height. This scatter is not clearly attributable to biases in measurement techniques or to well-recognized processes such as elutriation from pyroclastic flows. Sparse data on total grain-size distribution suggest that the mass fraction of fine debris m63 could vary by nearly two orders of magnitude between small basaltic eruptions (??? 0.01) and large silicic ones (> 0.5). We classify eleven eruption types; four types each for different sizes of silicic and mafic eruptions; submarine eruptions; "brief" or Vulcanian eruptions; and eruptions that generate co-ignimbrite or co-pyroclastic flow plumes. For each eruption type we assign source parameters. We then assign a characteristic eruption type to each of the world's ??? 1500

  10. Effects of aqueous soil-biochar extracts on representative aquatic organisms: a first evaluation

    NASA Astrophysics Data System (ADS)

    Bastos, A. C.; Abrantes, N.; Prodana, M.; Verheijen, F.; Keizer, J. J.; Soares, A. M. V. M.; Loureiro, S.

    2012-04-01

    Increasing considerations of biochar application to soils has raised concerns over implications to overall environmental quality, associated to some of its components. The heterogeneity of biochar composition is well documented in relation to co-existing chemical species, as a function of feedstock and pyrolysis conditions. Robust ecotoxicology studies with focus on bioavailable biochar components in soil remain scarce and have only started to emerge. This pilot study provides an insight into the potential ecotoxicological effects of aqueous extracts of biochar-amended soil on a range of aquatic organisms (Vibrio fischeri, Pseudokirchneriella subcapitata and Daphnia magna), using a battery of standard aquatic bioassays. The use of such bioassays in environmental risk assessment of soil-biochar elutriates is here suggested as a crucial tool, to bridge the gap between biochar's 'inert' fraction in soil and that bioavailable to edaphic organisms. Aqueous extracts were obtained from LUFA 2.2 standard soil (control) and following amendment with pine biochar at common field application rates (80 ton ha-1). Acute exposure to soil-biochar extracts allowed estimating toxicity parameters and developing dose-response curves for all tested species, through well-established methodological guidelines. The bioluminescent bacteria V. fischeri showed negligible EC50 (effect concentration corresponding to 50% luminescence decline) values in the MICROTOX® basic test (independent of exposure time), suggesting low susceptibility to soil-biochar extracts. Mild toxicity was also observed in the microalgae P. subcapitata growth inhibition test, where significant deleterious effects on growth rate occurred only at the highest (100%) extract concentration (p<0.05). Among the tested species, toxicity was generally more marked in the primary consumer D. magna, with an EC50 (effect concentration corresponding to 50% immobilisation) of 2.95%. The pattern and extent of observed effects were

  11. What is the role of pyroclastic density currents in volcanic ash aggregation? Perspectives from a phreatoplinian eruption deposit, New Zealand

    NASA Astrophysics Data System (ADS)

    Van Eaton, A. R.; Wilson, C. J.

    2012-12-01

    This study documents the processes and products of volcanic ash aggregation within individual phases of the 25.4 ka Oruanui super-eruption from Taupo volcano, New Zealand. Textural and stratigraphic relationships of aggregates are examined in seven of the ten erupted units, which range from relatively dry styles of eruption and deposition (fall units 2, 5) to mixed (units 6, 7, 8) and dominantly wet (unit 3). Aggregate structures and grain size distributions shift abruptly over vertical scales of cm to dm within and between eruptive units, providing diagnostic features that identify deposits emplaced as vertical fallout or pyroclastic density currents (PDCs). The six categories of ash aggregates documented here are used to infer distinct volcanic and meteorological interactions in the eruption cloud related to dispersal characteristics and mode of emplacement. Our field observations support the notion that deposits bearing matrix-supported accretionary lapilli with complex internal layering and abundant rim fragments are associated with emplacement of PDCs. However, on the basis of grain size distributions and field relationships, it is inferred that these types of ash aggregates formed their ultrafine (<10 μm ash) outer layers in the overriding fine ash cloud elutriated from PDCs, not during transport within the basal portion of ground-hugging currents. The propagation of voluminous PDCs beneath an overriding buoyant plume - whether coignimbrite or vent-derived in origin - is proposed to generate the observed, concentrically layered accretionary lapilli by producing wedge-like updrafts of convectively unstable, ash-laden air. The apparent coarsening of mean grain size with distance from source, which is observed in the aggregate-bearing fall deposits, reflects a combination of multi-level plume transport and preferential scavenging of fine ash <250 μm. Proximal fallout and melting of ice in the clouds was likely to have contributed a key source of liquid water

  12. The A.D. 1835 eruption of Volcán Cosigüina, Nicaragua: A guide for assessing local volcanic hazards

    USGS Publications Warehouse

    Scott, William E.; Gardner, Cynthia A.; Devoli, Graziella; Alvarez, Antonio

    2006-01-01

    The January 1835 eruption of Volcán Cosigüina in northwestern Nicaragua was one of the largest and most explosive in Central America since Spanish colonization. We report on the results of reconnaissance stratigraphic studies and laboratory work aimed at better defining the distribution and character of deposits emplaced by the eruption as a means of developing a preliminary hazards assessment for future eruptions. On the lower flanks of the volcano, a basal tephra-fall deposit comprises either ash and fine lithic lapilli or, locally, dacitic pumice. An overlying tephra-fall deposit forms an extensive blanket of brown to gray andesitic scoria that is 35–60 cm thick at 5–10 km from the summit-caldera rim, except southwest of the volcano, where it is considerably thinner. The scoria fall produced the most voluminous deposit of the eruption and underlies pyroclastic-surge and -flow deposits that chiefly comprise gray andesitic scoria. In northern and southeastern sectors of the volcano, these flowage deposits form broad fans and valley fills that locally reach the Gulf of Fonseca. An arcuate ridge 2 km west of the caldera rim and a low ridge east of the caldera deflected pyroclastic flows northward and southeastward. Pyroclastic flows did not reach the lower west and southwest flanks, which instead received thick, fine-grained, accretionary-lapilli–rich ashfall deposits that probably derived chiefly from ash clouds elutriated from pyroclastic flows. We estimate the total bulk volume of erupted deposits to be ∼6 km3. Following the eruption, lahars inundated large portions of the lower flanks, and erosion of deposits and creation of new channels triggered rapid alluviation. Pre-1835 eruptions are poorly dated; however, scoria-fall, pyroclastic-flow, and lahar deposits record a penultimate eruption of smaller magnitude than that of 1835. It occurred a few centuries earlier—perhaps in the fifteenth century. An undated sequence of thick tephra-fall deposits on

  13. The influence of slope-angle ratio on the dynamics of granular flows: insights from laboratory experiments

    NASA Astrophysics Data System (ADS)

    Sulpizio, R.; Castioni, D.; Rodriguez-Sedano, L. A.; Sarocchi, D.; Lucchi, F.

    2016-11-01

    Laboratory experiments on granular flows using natural material were carried out in order to investigate the behaviour of granular flows passing over a break in slope. Sensors in the depositional area recorded the flow kinematics, while video footage permitted reconstruction of the deposit formation, which allowed investigation of the deposit shape as a function of the change in slope. We defined the slope-angle ratio as the proportion between slope angle in the depositional area and that of the channel. When the granular flow encounters the break in slope part of the flow front forms a bouncing clast zone due to elastic impact with the expansion box floor. During this process, part of the kinetic energy of the dense granular flow is transferred to elutriating fine ash, which subsequently forms turbulent ash cloud accompanying the granular flow until it comes to rest. Morphometric analysis of the deposits shows that they are all elliptical, with an almost constant minor axis and a variable major axis. The almost constant value of the minor axis relates to the spreading angle of flow at the end of the channel, which resembles the basal friction angle of the material. The variation of the major axis is interpreted to relate to the effect of competing inertial and frictional forces. This effect also reflects the partitioning of centripetal and tangential velocities, which changes as the flow passes over the break in slope. After normalization, morphometric data provided empirical relationships that highlight the dependence of runout from the product of slope-angle ratio and the difference in height between granular material release and deposit. The empirical relationships were tested against the runouts of hot avalanches formed during the 1944 ad eruption at Vesuvius, with differences among actual and calculated values are between 1.7 and 15 %. Velocity measurements of laboratory granular flows record deceleration paths at different breaks in slope. When normalized

  14. Calculation of Decompression Rates for the Initial Explosive Phase of the 2010 Merapi Eruption

    NASA Astrophysics Data System (ADS)

    Matthews, E.; Genareau, K. D.

    2015-12-01

    The 2010 eruption of Merapi (Java, Indonesia) initiated with an uncharacteristic explosion, followed by rapid lava dome growth and collapse, all of which generated deadly pyroclastic density currents (PDCs). PDC samples from the initial explosion on October 26th were collected from several locations surrounding the edifice. Plagioclase phenocrysts represent the primary component of the dominant ash mode due to the elutriation of the finer ash fraction during PDC transport. Secondary electron images of 45 phenocrysts were taken using the scanning electron microscope (SEM) to examine preserved glass coatings on phenocrysts, which represent the interstitial melt within the magma at the point of fragmentation. Using these images, the bubble number densities (BNDs) were determined, and the decompression rate meter of Toramaru (2006) was used to calculate the decompression rate during the initial explosion of the 2010 Merapi eruption. Calculated decompression rates range from 6.08x10^7 Pa/s to 1.4x10^8 Pa/s. Decompression rates have shown to correlate with eruption column height; therefore Merapi's rates should be similar to those of other Vulcanian explosions, because the eruption column was 8-9 km in height. The decompression rates acquired for Merapi using Toramaru's BND meter are higher than the rates calculated with other methods such as microlite number density and extension cracks in crystals. Sakurajima volcano (Japan) experienced decompression rates from 7.0 × 10^3 to 7.8 × 10^4 Pa/s during the later phase of the fall 2011 Vulcanian explosions. Plinian explosions, such as at the 1991 eruption of Mt. Pinatubo and the 1980 eruption of St. Helens had much higher column heights compared to the initial 2010 Merapi explosion; 35 km, 19 km, and 8-9 km, respectively, but decompression rates in a comparative range (10^8 Pa/s). Higher decompression rates during the 2010 initial explosion at Merapi likely resulted from increased overpressure in the shallow conduit, the

  15. Fluidized bed combustion of pelletized biomass and waste-derived fuels

    SciTech Connect

    Chirone, R.; Scala, F.; Solimene, R.; Salatino, P.; Urciuolo, M.

    2008-10-15

    The fluidized bed combustion of three pelletized biogenic fuels (sewage sludge, wood, and straw) has been investigated with a combination of experimental techniques. The fuels have been characterized from the standpoints of patterns and rates of fuel devolatilization and char burnout, extent of attrition and fragmentation, and their relevance to the fuel particle size distribution and the amount and size distribution of primary ash particles. Results highlight differences and similarities among the three fuels tested. The fuels were all characterized by limited primary fragmentation and relatively long devolatilization times, as compared with the time scale of particle dispersion away from the fuel feeding ports in practical FBC. Both features are favorable to effective lateral distribution of volatile matter across the combustor cross section. The three fuels exhibited distinctively different char conversion patterns. The high-ash pelletized sludge burned according to the shrinking core conversion pattern with negligible occurrence of secondary fragmentation. The low-ash pelletized wood burned according to the shrinking particle conversion pattern with extensive occurrence of secondary fragmentation. The medium-ash pelletized straw yielded char particles with a hollow structure, resembling big cenospheres, characterized by a coherent inorganic outer layer strong enough to prevent particle fragmentation. Inert bed particles were permanently attached to the hollow pellets as they were incorporated into ash melts. Carbon elutriation rates were very small for all the fuels tested. For pelletized sludge and straw, this was mostly due to the shielding effect of the coherent ash skeleton. For the wood pellet, carbon attrition was extensive, but was largely counterbalanced by effective afterburning due to the large intrinsic reactivity of attrited char fines. The impact of carbon attrition on combustion efficiency was negligible for all the fuels tested. The size

  16. Development of lightweight mirror elements for the Euro50 mirrors

    NASA Astrophysics Data System (ADS)

    Bennett, Harold E.; Romeo, Robert C.; Shaffer, Joseph J.; Chen, Peter C.

    2004-07-01

    New, very large telescopes with apertures of 30, 50, and 100 meters are being proposed by the astronomical community. Superpolished or ultrapolished mirrors with low scattered light levels and the use of adaptive optics for near-diffraction-limited performance would make such large telescopes a turning point in astronomy. The secondary mirror for the Euro50 will be a four meter adaptive optic made of a low expansion graphite-filled cyanate ester resin composite produced using a replica transfer technique. We have made three 1/3rd meter diameter prototype composite adaptive optic mirrors of this cyanate ester composite material. Because of the embedded graphite fibers, the composite material has a measured expansion coefficient in the 10-8 range, as has Zerodur or ULE glass. It is very much lighter, more rugged and more economical than Zerodur or ULE, and can be fabricated in weeks, not months. The Zerodur mandrels upon which these replica transfer mirrors are made are superpolished using centrifugal elutriation, so the replica surface has an rms roughness of 0.6 to 0.8 nm. It thus scatters about an order of magnitude less light than typical conventionally polished astronomical mirrors. In adaptive optic mirrors with sub-mm thick faceplates the number of plies used is insufficient to produce an isotropic surface. For mirrors 2 mm thick, with more plies, the surfaces are isotropic, and the slight astigmatism sometimes resulting from the mesh in the ply can be corrected by actuators to make them attractive mirrors. They must be supported to maintain a good optical figure over a meter diameter mirror. The support requirement may be met by using a new type of mechanical/piezoelectric actuator adjustable to a fraction of a wavelength. The mechanical actuators have a coarse adjust of over an mm and a fine adjust of less than a wavelength of light. They can be used in series with a novel type of piezoelectric actuator for final static adjustment. The low voltage, up to 2

  17. Genotoxicity assessment of suspended particulate matter in the Elbe river: comparison of Salmonella microsome test, arabinose resistance test, and umu-test.

    PubMed

    Vahl, H H; Karbe, L; Westendorf, J

    1997-11-27

    This study evaluates the applicability of three bacterial short-term genotoxicity test systems to aquatic suspended particulate matter of the Elbe river. This material was sampled in sedimentation vessels after deposition periods of one month. It was extracted in a Soxhlet apparatus with toluene and methanol. Aqueous elutriates were prepared additionally. A solid phase method was developed that enables to incubate bacteria in contact with the particulate material. The test battery consists of two mutagenicity assays (the Ames-test and the Ara-test) and an SOS induction assay (the umu-test). Both mutagenicity assays came to nearly the same assessment of the samples of particulate matter of the Elbe. The quantitative response, however, was higher in the Ara-test. The particulate river material generally induced lower genotoxic potencies in the umu-test than in the mutagenicity assays. This lead to a completely different outcome of the umu-test; 29 out of 35 mutagenic samples were not SOS inducing. No quantitative or rank correlations between the concentrations of anthropogenic contaminants (PAHs, chlorinated hydrocarbons and metals) and the observed effects could be established on a 90% confidence limit. However, there is obvious correspondence between more contaminated regions of the river system and mutagenic effects (Ames- and Ara-test) in the samples from this region, as well as correspondence between low contaminated regions and the absence of mutagenicity. For this reason, the mutagenicity assays appear more favourable to describe the anthropogenic contamination with genotoxins in complex mixtures than the umu-test. The authors recommend the Ara-test for a first genotoxicity screening of complex environmental mixtures. This forward mutagenicity assay is advantageous due to higher effects and lower costs compared to the Ames-test. The development and use of a solid phase version of Ames- and Ara-test revealed the occurrence of a major part of particle

  18. Assessment of injury to fish and wildlife resources in the Grand Calumet River and Indiana Harbor Area of Concern, USA

    USGS Publications Warehouse

    MacDonald, D.D.; Ingersoll, C.G.; Smorong, D.E.; Lindskoog, R.A.; Sparks, D.W.; Smith, J.R.; Simon, T.P.; Hanacek, M.A.

    2002-01-01

    This article is the second in a series of three that describes the results of a Natural Resource Damage Assessment (NRDA) conducted in the Grand Calumet River and Indiana Harbor Area of Concern (IHAOC). The assessment area is located in northwest Indiana and was divided into nine reaches to facilitate the assessment. This component of the NRDA was undertaken to determine if fish and wildlife resources have been injured due to exposure to contaminants that are associated with discharges of oil or releases of other hazardous substances. To support this assessment, information was compiled on the chemical composition of sediment and tissues; on the toxicity of whole sediments, pore water, and elutriates to fish; on the status of fish communities; and on fish health. The data on each of these indicators were compared to regionally relevant benchmarks to assess the presence and extent of injury to fish and wildlife resources. The results of this assessment indicate that injury to fish and wildlife resources has occurred throughout the assessment area, with up to five distinct lines of evidence demonstrating injury within the various reaches. Based on the frequency of exceedance of the benchmarks for assessing sediment and tissue chemistry data, total polychlorinated biphenyls is the primary bioaccumulative contaminant of concern in the assessment area. It is important to note, however, that this assessment was restricted by the availability of published bioaccumulation-based sediment quality guidelines, tissue residue guidelines, and other benchmarks of sediment quality conditions. The availability of chemistry data for tissues also restricted this assessment in certain reaches of the assessment area. Furthermore, insufficient information was located to facilitate identification of the substances that are causing or substantially contributing to effects on fish (i.e., sediment toxicity, impaired fish health, or impaired fish community structure). Therefore, substances

  19. Inducible nucleotide excision repair (NER) of UV-induced cyclobutane pyrimidine dimers in the cell cycle of the budding yeast Saccharomyces cerevisiae: evidence that inducible NER is confined to the G1 phase of the mitotic cell cycle.

    PubMed

    Scott, A D; Waters, R

    1997-03-18

    We previously reported on an inducible component of nucleotide excision repair in Saccharomyces cerevisiae that is controlled by the RAD16 gene. Here we describe a study of this event at the MAT alpha and HML alpha mating-type loci and on the transcribed (TS) and nontranscribed (NTS) strands of the RAD16 gene. Events were examined at various stages of the mitotic cycle in cells synchronised by centrifugal elutriation. Repair of cyclobutane pyrimidine dimers (CPDs) following a single UV dose does not vary significantly in different stages of the mitotic cell cycle. CPDs are removed more rapidly from the transcriptionally active MAT alpha locus than from the silent HML alpha locus, and the TS of RAD16 is repaired faster than the NTS in all stages of the cycle following a single UV irradiation. Enhanced excision of CPDs at MAT alpha and HML alpha can be induced only in the G1 and early S stages of the cell cycle. Here prior irradiation of cells with 25 J/m2 enhances the removal of CPDs following a second UV dose of 70 J/m2. The level of enhancement of repair does not differ significantly between MAT alpha and HML alpha in G1. Enhanced removal of CPDs is absent when cells receive the inducing dose in late S or G2/M. Repair of CPDs in both strands of RAD16 is similarly enhanced only if cells receive the initial irradiation in G1 and early S. The level of enhanced removal of CPDs is not significantly different in the TS and NTS of RAD16 either in asynchronous cells or in cells preirradiated in G1 and early S. It has been shown by others that UV-induced expression of RAD16 remains at high levels if cells are held in G1 by treatment with alpha factor. Therefore the increase in RAD16 transcript levels in G1 may be responsible for the ability to enhance NER solely in this stage of the cell cycle.

  20. Interactions of dimethyl sulfoxide and granulocyte-macrophage colony-stimulating factor on the cell cycle kinetics and phosphoproteins of G1-enriched HL-60 cells: evidence of early effects on lamin B phosphorylation.

    PubMed

    Brennan, J K; Lee, K S; Frazel, M A; Keng, P C; Young, D A

    1991-03-01

    We have found that GM-CSF and DMSO have antagonistic effects on the proliferation but not maturation of asynchronously growing HL-60 cells such that growth in the presence of both more closely resembles normal hematopoiesis (Brennan et al., J. Cell Physiol. 132:246, 1987). Studies were undertaken to determine whether or not the agents affected the same mitogenic pathway and locus in the cell cycle. HL-60 populations containing at least 90% G1 cells were obtained by centrifugal elutriation, exposed to 100 u/ml recombinant human GM-CSF and/or 0-1.25% DMSO, and phosphoprotein changes quantified on autoradiograms of [32P]-orthophosphate-labeled cell proteins separated by giant 2-D gel electrophoresis. Results were correlated with 1) intracellular pH, determined by measurement of BCECF fluorescence; 2) [32P]-orthophosphate uptake; 3) cell cycle progression, determined by flow quantitation of DNA content in mithramycin or propidium iodide-stained cells; and 4) growth, determined by cell volume and concentration. GM-CSF stimulated and DMSO inhibited the GM-CSF-stimulated phosphorylation of 1 protein (approximately 65 kDa, p.i. 5.6) within 2 min of exposure. These effects were sustained through G1, not associated with changes in intracellular pH, and preceded similar antagonistic effects on phosphate uptake (15-30 minutes), cell volume change (16-24 hr), and cell concentration increase (28-32 hr). GM-CSF accelerated and DMSO inhibited G1 to S transit with the most marked antagonism observed in the second cycle following synchronization (28 to 40 hrs). Cell maturation (morphology, NBT reduction) was dominated by DMSO and not antagonized by GM-CSF. We have identified p65 as the nuclear intermediate filament protein, lamin B, on the basis of its locus on gels and its binding of a monoclonal antibody to intermediate filaments and antiserum to human lamin B on immunoblots. These studies suggest that at least part of the GM-CSF-DMSO antagonism is exerted through the same

  1. Development of a Low-Cost Particulate Matter Monitor

    SciTech Connect

    White, Richard M.; Apte, Michael G.; Gundel, Lara A.; Black, Justin

    2008-08-01

    We describe a small, inexpensive portable monitor for airborne particulates, composed of the following elements: a. A simple size-selective inlet (vertical elutriator) that permits only particles below a pre-set diameter to pass and enter the measurement section; b. A measurement section in which passing particles are deposited thermophoretically on a micro-fabricated resonant piezoelectric mass sensor; c. An optical characterization module co-located with the mass sensor module that directs infrared and ultraviolet beams through the deposit. The emergent optical beams are detected by a photodiode. The optical absorption of the deposit can be measured in order to characterize the deposit, and determine how much is due to diesel exhaust and/or environmental tobacco smoke; and d. A small pump that moves air through the device, which may also be operated in a passive mode. The component modules were designed by the project team, and fabricated at UCB andLBNL. Testing and validation were performed in a room-sized environmental chamber at LBNL in to which was added either environmental tobacco smoke (ETS, produced by a cigarette smoking machine) or diesel exhaust (from a conventional diesel engine). Two pilot field tests in a dwelling compared the monitor with existing aerosol instruments during exposure to infiltrated ambient air to which cigarette smoke, diesel exhaust, wood smoke and cooking fumes were added. The limit of detection (LOD) derived from statistical analysis of field data is 18 mu g m-3, at the 99percent confidence level. The monitor weighs less than 120 g and has a volume of roughly 250 cm3. Power consumption is approximately 100 milliwatts. During this study, the optical component of the device was not fully implemented and has been left for future efforts. Suggested improvements in the current prototype include use of integrated thermal correction, reconfiguration of the resonator for increased particle collection area, increased thermophoretic

  2. Experimental methods to determine inhalability and personal sampler performance for aerosols in ultra-low windspeed environments.

    PubMed

    Schmees, Darrah K; Wu, Yi-Hsuan; Vincent, James H

    2008-12-01

    Most previous experiments of aerosol inhalability as it relates to particle aerodynamic diameter were conducted in wind tunnels for windspeeds greater than 0.5 m s(-1). While that body of work was used to establish an inhalable aerosol convention, results from studies in calm air chambers (for essentially zero windspeed) are being discussed as the basis of a modified criterion. Meanwhile, however, information is lacking for windspeeds in the intermediate range, which--it so happens--pertain to most actual workplaces. With this in mind, we have developed a new experimental system to assess inhalability and personal sampler performance for aerosols with particle aerodynamic diameter within the range from 6 to 90 microm for ultra-low windspeed environments from about 0.1 to 0.5 m s(-1). In this range of conditions for particle size and windspeed, controlled aerosol experiments are very difficult to perform, most notably with respect to the problem of achieving uniform spatial distributions of both test aerosols and air velocity. In the work reported in this paper, we have addressed these difficulties in a new, custom-designed experimental facility. It is a novel wind tunnel design that provides stable and controllable low-turbulence air movement, and allows for the delivery of test aerosol to the working section both from upstream (as in conventional wind tunnel experiments) and from above (as in calm air studies). In this system, losses by elutriation of particles that are being convected in the horizontal aerosol flow are compensated by particles entering from above by gravitational settling. An important feature of the new facility is the life-size, breathing mannequin that contains physical means to achieve any combination of mouth and nasal inspiration and expiration, and allows any desired relevant breathing flowrate and pattern by means of an external computer-controlled breathing simulator. Special steps were taken in the detailed design to ensure that

  3. The perfect ash-storm: large-scale Pyroclastic Density Current experiments reveal highly mobile, self-fluidising and air-cushioned flow transport regime

    NASA Astrophysics Data System (ADS)

    Lube, G.; Cronin, S. J.; Breard, E.; Valentine, G.; Bursik, M. I.; Hort, M. K.; Freundt, A.

    2013-12-01

    -solids concentrations of 1-5 vol%. The front shows a brief phase of negative pore pressure due to the entrainment and upward elutriation of ambient air inside this front. It is immediately followed by the fine-ash rich and highly impermeable main flow body. Passage of the flow body is accompanied by strongly increasing pore-pressures of 1-3 kPa that almost fully supports the weight of the entire underflow - depicting flow-induced fluidisation of the main flow part. The remainder of the flow body shows further increases in pore-pressure aside with strong reductions in flow mass. This suggests the occurrence of zones of air-cushions forming at the base of the underflow that largely aid its inviscid runout. This sequence is repeated during arrival and passage of up to three more flow pulses. The low-permeability deposits maintain high internal gas pore pressures for several minutes after emplacement, before sudden deaeration, settling and gas loss is caused by fracturing. Flow-induced fluidisation and basal air-cushioning provide key processes behind the enigmatic long runout behaviour of dense PDCs.

  4. Generation and Characterization of Nanoaerosols Using a Portable Scanning Mobility Particle Sizer and Electron Microscopy

    NASA Astrophysics Data System (ADS)

    Marty, Adam J.

    The purpose of this research is to demonstrate the ability to generate and characterize a nanometer sized aerosol using solutions, suspensions, and a bulk nanopowder, and to research the viability of using an acoustic dry aerosol generator/elutriator (ADAGE) to aerosolize a bulk nanopowder into a nanometer sized aerosol. The research compares the results from a portable scanning mobility particle sizer (SMPS) to the more traditional method of counting and sizing particles on a filter sample using scanning electron microscopy (SEM). Sodium chloride aerosol was used for the comparisons. The sputter coating thickness, a conductive coating necessary for SEM, was measured on different sizes of polystyrene latex spheres (PSLS). Aluminum oxide powder was aerosolized using an ADAGE and several different support membranes and sound frequency combinations were explored. A portable SMPS was used to determine the size distributions of the generated aerosols. Polycarbonate membrane (PCM) filter samples were collected for subsequent SEM analysis. The particle size distributions were determined from photographs of the membrane filters. SMPS data and membrane samples were collected simultaneously. The sputter coating thicknesses on four different sizes of PSLS, range 57 nanometers (nm) to 220 nm, were measured using transmission electron microscopy and the results from the SEM and SMPS were compared after accounting for the sputter coating thickness. Aluminum oxide nanopowder (20 nm) was aerosolized using a modified ADAGE technique. Four different support membranes and four different sound frequencies were tested with the ADAGE. The aerosol was collected onto PCM filters and the samples were examined using SEM. The results indicate that the SMPS and SEM distributions were log-normally distributed with a median diameter of approximately 42 nm and 55 nm, respectively, and geometric standard deviations (GSD) of approximately 1.6 and 1.7, respectively. The two methods yielded similar

  5. DEVELOPMENT OF PRESSURIZED CIRCULATING FLUIDIZED BED PARTIAL GASIFICATION MODULE (PGM)

    SciTech Connect

    Unknown

    2001-07-10

    sequestration of stack gas carbon dioxide gases for a 100% reduction in greenhouse gas emissions. The amount of syngas and char produced by the PGM can be tailored to fit the production objectives of the overall plant, i.e., power generation, clean liquid fuel production, chemicals production, etc. Hence, PGM is a robust building block that offers all the advantages of coal gasification but in a more user friendly form; it is also fuel flexible in that it can use alternative fuels such as biomass, sewerage sludge, etc. The PGM consists of a pressurized circulating fluidized bed (PCFB) reactor together with a recycle cyclone and a particulate removing barrier filter. Coal, air, steam, and possibly sand are fed to the bottom of the PCFB reactor and establish a relatively dense bed of coal/char in the bottom section. As these constituents react, a hot syngas is produced which conveys the solids residue vertically up through the reactor and into the recycle cyclone. Solids elutriated from the dense bed and contained in the syngas are collected in the cyclone and drain via a dipleg back to the dense bed at the bottom of the PCFB reactor. This recycle loop of hot solids acts as a thermal flywheel and promotes efficient solid-gas chemical reaction.

  6. Sedimentological processes in a scarp-controlled rocky shoreline to upper continental slope environment, as revealed by unusual sedimentary features in the Neogene Coquimbo Formation, north-central Chile

    NASA Astrophysics Data System (ADS)

    Le Roux, J. P.; Gómez, Carolina; Fenner, Juliane; Middleton, Heather

    2004-03-01

    Exceptionally good outcrops of Miocene to Pliocene deposits in the vicinity of submarine Paleozoic basement scarps at Carrizalillo, north of La Serena, reveal a wealth of sedimentary features not commonly observed. The most proximal facies consist of rock fall and coarse-grained debris flow deposits directly abutting the basement wall from which they originated. Angular basement clasts are mixed with well-rounded cobbles, which probably formed as a basal gravel on a wave-cut platform at the beginning of marine flooding, subsequently accumulated at the scarp edge and were incorporated into the debris when the latter collapsed. The poor sorting, inverse grading, and protruding cobbles and boulders are classical debris flow features, with good clast imbrication indicating a laminar shearing action. A medial facies is represented by secondary channels running parallel to the major scarp about 1 km downslope of the first locality. In the largest channel, megaflutes at the base indicate the passage of highly turbulent, nondepositing flows eroding the soft, silty substrate. In the deepest, central part of the channel, a pebbly coquina shows horizontal and trough cross-stratification, with most of the bivalves oriented convex side up. Meter-scale rip-up clasts of the underlying siltstone are also present, indicating turbulent flow with a density sufficiently high to retard settling. The coquina is interpreted as a detachment deposit resulting from a hydroplaning debris flow along the central part of the channel, where the velocity and rate of pore pressure decay were highest. This deposit is overlain by fining upward, massive to horizontally stratified sandstone very similar in texture and composition to the matrix of the debris flow, suggesting its formation by surface transformation and elutriation of the latter. Along the channel margin, a basal centimeter-scale sandstone layer is virtually unaffected by the megaflute topography and clearly represents a subsequent event

  7. Vent Processes and Deposits of a Hiatus in a Violent Eruption: Quilotoa Volcano, Ecuador

    NASA Astrophysics Data System (ADS)

    Best, J. A.; Bustillos, J.; Ort, M. H.; Cashman, K. V.; Mothes, P. A.; di Muro, A.; Rosi, M.

    2010-12-01

    , with the simultaneous milling of the weakened material producing the orange dust. We interpret the dense vitric lapilli ≥ -2.0 φ of U2c as being from an explosion through a lava dome, and thus they indicate that the eruption was continuous from U2c through U3. Our current hypothesis is that, as the U1 eruption ended, magma stalled deep in the conduit and degassed hot acidic gas that streamed through the material clogging the vent. This elutriated vitric material that eventually formed a cap on the system. As the U3 magma began its ascent, gas flux increased, leading to explosions that gradually removed the vitric cap and deposited the vitric U2a. Then, more continuous gas streaming led to the development of a pulsatory eruption column that carried hot crystals and vitric grains from the vent clog into a convecting column and eventual deposition as U2b fallout, which was then followed by the establishment of the U3 eruption column.

  8. Vent Processes and Deposits of a Hiatus in a Violent Eruption: Quilotoa Volcano, Ecuador

    NASA Astrophysics Data System (ADS)

    Best, J. A.; Bustillos, J.; Ort, M. H.; Cashman, K. V.; Mothes, P. A.; di Muro, A.; Rosi, M.

    2009-12-01

    high proportion of stained fragments in U2b requires a different, possibly hydrothermal, source. We interpret the lava lapilli of U2c and U3 as being from a single explosion, perhaps the opening of a new vent, and thus they indicate that the eruption was continuous from U2b through U3. Our current hypothesis is that, as the U1 eruption ended, acidic gas streamed through the material clogging the vent. This elutriated vitric material that eventually formed a cap on the system. As the U3 magma began its ascent, gas flux increased, leading to explosions that gradually removed the vitric cap and depositing the vitric U2a. Then, more continuous gas streaming led to the development of an pulsatory eruption column that carried the hot stained crystals and lithic fragments into a convecting column and eventual deposition as fallout of U2b, which was then followed by the establishment of the U3 eruption column.

  9. Characterizing toxicity of metal-contaminated sediments from mining areas

    USGS Publications Warehouse

    Besser, John M.; Brumbaugh, William G.; Ingersoll, Christopher G.

    2015-01-01

    This paper reviews methods for testing the toxicity of metals associated with freshwater sediments, linking toxic effects with metal exposure and bioavailability, and developing sediment quality guidelines. The most broadly applicable approach for characterizing metal toxicity is whole-sediment toxicity testing, which attempts to simulate natural exposure conditions in the laboratory. Standard methods for whole-sediment testing can be adapted to test a wide variety of taxa. Chronic sediment tests that characterize effects on multiple endpoints (e.g., survival, growth, and reproduction) can be highly sensitive indicators of adverse effects on resident invertebrate taxa. Methods for testing of aqueous phases (pore water, overlying water, or elutriates) are used less frequently. Analysis of sediment toxicity data focuses on statistical comparisons between responses in sediments from the study area and responses in one or more uncontaminated reference sediments. For large or complex study areas, a greater number of reference sediments is recommended to reliably define the normal range of responses in uncontaminated sediments – the ‘reference envelope’. Data on metal concentrations and effects on test organisms across a gradient of contamination may allow development of concentration-response models, which estimate metal concentrations associated with specified levels of toxic effects (e.g. 20% effect concentration or EC20). Comparisons of toxic effects in laboratory tests with measures of impacts on resident benthic invertebrate communities can help document causal relationships between metal contamination and biological effects. Total or total-recoverable metal concentrations in sediments are the most common measure of metal contamination in sediments, but metal concentrations in labile sediment fractions (e.g., determined as part of selective sediment extraction protocols) may better represent metal bioavailability. Metals released by the weak-acid extraction

  10. The vadose zone as a geoindicator of environmental change and groundwater quality in water-scarce areas

    NASA Astrophysics Data System (ADS)

    Edmunds, W. M.; Baba Goni, I.; Gaye, C. B.; Jin, L.

    2013-12-01

    Inert and reactive tracers in moisture profiles provide considerable potential for the vadose zone to be used as an indicator of rapid environmental change. This indicator is particularly applicable in areas of water stress where long term (decade to century) scale records may be found in deep unsaturated zones in low rainfall areas and provide insights into recent recharge, climate variation and water-rock interactions which generate groundwater quality. Unsaturated zone Cl records obtained by elutriation of moisture are used widely for estimating recharge and water balance studies; isotope profiles (3H, δ2H, δ18O) from total water extraction procedures are used for investigation of residence times and hydrological processes. Apart from water taken using lysimeters, little work has been conducted directly on the geochemistry of pore fluids. This is mainly due to the difficulties of extraction of moisture from unsaturated material with low water contents (typically 2-6 wt%) and since dilution methods can create artifacts. Using immiscible liquid displacement techniques it is now possible to directly investigate the geochemistry of moisture from unsaturated zone materials. Profiles up to 35m from Quaternary sediments from dryland areas of the African Sahel (Nigeria, Senegal) as well as Inner Mongolia, China are used to illustrate the breadth of information obtainable from vadose zone profiles. Using pH, major and trace elements and comparing with isotopic data, a better understanding is gained of timescales of water movement, aquifer recharge, environmental records and climate history as well as water-rock interaction and contaminant behaviour. The usefulness of tritium as residence time indicator has now expired following cessation of atmospheric thermonuclear testing and through radioactive decay. Providing the rainfall Cl, moisture contents and bulk densities of the sediments are known, then Cl accumulation can be substituted to estimate timescales. Profiles

  11. Comprehensive and systematic MC-ICP-MS/TIMS isotopic characterization of USGS Standards

    NASA Astrophysics Data System (ADS)

    Mahoney, J. B.; Weis, D.; Keiffer, B.; Hanano, D.; Williams, G.; Pretorius, W.; Barling, J.; Scoates, J.; Friedman, R.; Goolaerts, A.; Mattielli, N.; Maerschalk, C.

    2003-12-01

    The Pacific Centre for Isotopic and Geochemical Research (PCIGR) at the University of British Columbia has undertaken a systematic analysis of isotopic (Nd, Sr, Hf, Pb) composition and concentration of a broad compositional range of United States Geological Survey standards, including basalt (BCR-1, 2; BHVO-1, 2; BIR-1), dunite (DNC-1), andesite (AGV-1, 2), rhyolite (RGM-1, 2), syenite (STM-1, 2) and granite (G-2). USGS rock standards are geochemically well-characterized, but there is no systematic methodology nor database for radiogenic isotopic analyses, even for the widely used BCR-I. This investigation represents the first comprehensive, systematic analysis of the isotopic concentration and composition of USGS standards, and will provide an important database for the isotopic community. The wide range of equipment at PCIGR, including a Nu MC-ICPMS, a Triton TIMS, and an ElementII HR-ICPMS, permits a rigorous assessment and comparison of precision and accuracy in isotopic analyses. Our separation technique involves an HF/HNO3 dissolution in Teflon bombs, standard cation exchange elutriation for Sr and REE separation, and HDEHP Teflon columns for Nd separation. Samples are unspiked, and elemental concentration is determined by HR-ICPMS. Isotopic composition is determined by both thermal ionization mass spectrometry (Sr, Nd) and by multi-collector inductively coupled plasma mass spectrometry (Nd, Hf, Pb). Replicate runs of La Jolla Nd standard demonstrate excellent agreement between MC-ICPMS (143Nd/144Nd=0.511846+/-14 [n=100]) and TIMS (0.511850+/-16 [n=67]). Replicate analyses of strontium standard NBS987 yield 86Sr/87Sr values of 0.710256+/-15 [n=130]. Neodymium isotopic analyses (143Nd/144Nd values and Sm/Nd ratios) of previously characterized standards, such as BCR-1 (143Nd/144Nd=0.512623+/-2 [Nu; n=2]; 0.512627+/-8 [Triton; n=8]; Sm/Nd=0.1389) and BHVO-1 (0.512972+/-5 [Nu; n=2]; 0.512973+/-6 [Triton; n=14]; 0.1522-0.1532) are within error of published values

  12. Altering recharge dynamics through woody vegetation removal: a study on the Carrizo-Wilcox aquifer of south Texas

    NASA Astrophysics Data System (ADS)

    Mattox, A. M.

    2011-12-01

    initial steps to determining if ground water recharge may be increased through brush management. Rooting depth and volumetric water content were determined in the Chacon clay loam, Webb sandy loam and Antosa-Bobillo loamy sands. Two soil cores were taken to depths of 2 m in each of the 1/4 acre plots in each of the treated and untreated plots for a total of 54 cores. Rooting depths were determined through a combination of hydro-pneumatic root elutriation, comparison of soil water profiles in treated and untreated plots, as well as stem and soil water isotope analysis. Initial data indicates hydraulic redistribution is occurring in the loamy sand as well as the clay loam soils. Neutron probe measurements suggest that vegetation may be facilitating the movement of water into deeper soil horizons in the clay loam soils. In addition to improving our understanding of the relationships between vegetation structure and vadose zone hydrology, our results will be useful for managing water resources under increasing demand, climate change, and varied priorities for entities tasked with managing water resources.

  13. Integrated Waste Treatment Unit (IWTU) Input Coal Analyses and Off-Gass Filter (OGF) Content Analyses

    SciTech Connect

    Jantzen, Carol M.; Missimer, David M.; Guenther, Chris P.; Shekhawat, Dushyant; VanEssendelft, Dirk T.; Means, Nicholas C.

    2015-04-23

    in process piping and materials, in excessive off-gas absorbent loading, and in undesired process emissions. The ash content of the coal is important as the ash adds to the DMR and other vessel products which affect the final waste product mass and composition. The amount and composition of the ash also affects the reaction kinetics. Thus ash content and composition contributes to the mass balance. In addition, sodium, potassium, calcium, sulfur, and maybe silica and alumina in the ash may contribute to wall-scale formation. Sodium, potassium, and alumina in the ash will be overwhelmed by the sodium, potassium, and alumina from the feed but the impact from the other ash components needs to be quantified. A maximum coal particle size is specified so the feed system does not plug and a minimum particle size is specified to prevent excess elutriation from the DMR to the Process Gas Filter (PGF). A vendor specification was used to procure the calcined coal for IWTU processing. While the vendor supplied a composite analysis for the 22 tons of coal (Appendix A), this study compares independent analyses of the coal performed at the Savannah River National Laboratory (SRNL) and at the National Energy Technology Laboratory (NETL). Three supersacks a were sampled at three different heights within the sack in order to determine within bag variability and between bag variability of the coal. These analyses were also compared to the vendor’s composite analyses and to the coal specification. These analyses were also compared to historic data on Bestac coal analyses that had been performed at Hazen Research Inc. (HRI) between 2004-2011.

  14. Unusual gravitational failures on lava domes of Tatun Volcanic Group, Northern Taiwan.

    NASA Astrophysics Data System (ADS)

    Belousov, Alexander; Belousova, Marina; Chen, Chang-Hwa; Zellmer, Georg

    2010-05-01

    Tatun Volcanic Group of Northern Taiwan was formed mainly during the Pleistocene - Early Holocene. Most of the volcanoes are represented by andesitic lava domes of moderate sizes: heights up to 400 m (absolute altitudes 800-1100 m a.s.l.), base diameters up to 2 km, and volumes up to 0.3 km³. Many of the domes have broadly opened (0.5-1.0 km across and up to 140° wide), shallow-incised horseshoe-shaped scars formed by gravitational collapses. The failure planes did not intersect the volcanic conduits, and the scars were not filled by younger volcanic edifices: most of the collapses occurred a long time after the eruptions had ceased. The largest collapse, with a volume 0.1 km³, occurred at eastern part of Datun lava dome. Specific feature of the collapse was that the rear slide blocks did not travel far from the source; they stopped high inside the collapse scar, forming multiple narrow toreva blocks descending downslope. The leading slide blocks formed a low mobile debris avalanche (L~5 km; H~1 km; H/L~0.2). The deposit is composed mainly of block facies. The age of the collapse is older than 24,000 yrs, because the related debris avalanche deposit is covered by a younger debris avalanche deposit of Siaoguanyin volcano having calibrated 14C age 22,600-23,780 BP. The Siaoguanyin debris avalanche was formed as a result of collapse of southern part of a small flank dome. Specific feature of the resulted avalanche - it was hot during deposition. The deposit contains carbonized wood; andesite boulders within the deposit frequently have radial cooling joints, and in rare cases "bread-crust" surfaces. The paucity of fine fractions in the deposit can be connected with elutriation of fines into the convective cloud when the hot avalanche travelled downslope. However in several locations the deposit is represented by typical avalanche blocks surrounded by heterolithologic mixed facies containing abundant clasts of Miocene sandstone (picked up from the substrate). Thus

  15. Lunar Airborne Dust Toxicity Hazard Assessments (Invited)

    NASA Astrophysics Data System (ADS)

    Cooper, B. L.; McKay, D. S.; Taylor, L. A.; Wallace, W. T.; James, J.; Riofrio, L.; Gonzalez, C. P.

    2009-12-01

    was developed for this task. The dust separation system includes a fluidized bed, an elutriation flask, and a cyclone. The product dust is collected on a membrane filter with 0.45 micrometer pore size. Collection and separation efficiencies, and particle size distribution measurements of the material retained in the various components are tracked as development and tests proceed. Calculations show that respirable-sized particles, if released in a habitat, would remain suspended in the air for extended periods of time. Without active dust control, most of this fine dust would end up in the crew’s lungs. Dust exposure standards, similar to those established for quartz on Earth, will determine the design, mass, power, and cost of dust control systems incorporated into lunar habitats and pressurized rovers.

  16. Epidermal growth factor and gonadotropin-releasing hormone stimulate proliferation of enriched population of gonadotropes.

    PubMed

    Childs, G V; Unabia, G

    2001-02-01

    Recent studies of epidermal growth factor (EGF) receptors on gonadotropes show that they appear early in the estrous cycle on immature gonadotropes, most of which could be identified by LH messenger RNA only. As diestrous gonadotropes translate the messenger RNAs, the percentages of LH and FSH cells with EGF receptors increase to reach a peak during proestrus. To learn more about the function of EGF in gonadotrope regulation, parallel studies of its mitogenic potential were conducted. To test this in a cell growth assay, we initially developed a protocol for enrichment of gonadotropes by counterflow centrifugation (elutriation). Analysis of immunolabeled cells in the enriched fraction showed that the population contained 90-95% cells with LH and/or FSH antigens. Less than 4% have TSH or PRL antigens, and less than 7% have ACTH antigens. About 15% of the enriched population expressed GH antigens in male rats and nearly 30% of the population express GH in females. This agrees with the known hormone storage overlap between these cells, especially in proestrous female rats. The MTT cell growth/cell death assay was then used to test the mitogenic potential of EGF, GnRH, and activin. This assay showed a linear relationship between plated cell numbers and optical density of the media after the MTT reaction was run. The enriched gonadotropes were plated in 96-microwell trays and grown for 3-4 days in the presence of defined media alone (no serum), or defined media containing 0.5-10 ng/ml EGF, 0.5-1 nM GnRH, 60 ng/ml activin or two of these factors. In all of the 12 experiments, each of the factors stimulated a 3- to 10-fold increase in optical density values, depending on the dose of the stimulating factor. The effects of any two factors were not additive. Because the MTT assays do not discriminate between mitogenic effects and enhanced cell survival, a second group of tests was run with mixed cultures of pituitary cells from diestrous female rats. These cells were