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Sample records for elutriation

  1. Synchronization of Mammalian Cells and Nuclei by Centrifugal Elutriation.

    PubMed

    Banfalvi, Gaspar

    2017-01-01

    Synchronized populations of large numbers of cells can be obtained by centrifugal elutriation on the basis of sedimentation properties of small round particles, with minimal perturbation of cellular functions. The physical characteristics of cell size and sedimentation velocity are operative in the technique of centrifugal elutriation also known as counterstreaming centrifugation. The elutriator is an advanced device for increasing the sedimentation rate to yield enhanced resolution of cell separation. A random population of cells is introduced into the elutriation chamber of an elutriator rotor running in a specially designed centrifuge. By increasing step-by-step the flow rate of the elutriation fluid, successive populations of relatively homogeneous cell size can be removed from the elutriation chamber and used as synchronized subpopulations. For cell synchronization by centrifugal elutriation, early log S phase cell populations are most suitable where most of the cells are in G1 and S phase (>80 %). Apoptotic cells can be found in the early elutriation fractions belonging to the sub-Go window. Protocols for the synchronization of nuclei of murine pre-B cells and high-resolution centrifugal elutriation of CHO cells are given. The verification of purity and cell cycle positions of cells in elutriated fractions includes the measurement of DNA synthesis by [(3)H]-thymidine incorporation and DNA content by propidium iodide flow cytometry.

  2. 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...

  3. 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

  4. Nitrate destruction in an elutriated fluid-bed calciner

    SciTech Connect

    Cowan, R.G.; Cash, R.J.; Owen, T.J.; Shook, G.E.

    1987-09-01

    Nitrate destruction was demonstrated using an elutriated fluid-bed calciner process developed for nuclear fuel mixed-oxide conversion. Testing was directed to treatment of sodium nitrate, a major waste component at the Hanford Site. One test was also performed with copper nitrate. All tests produced low concentrations of NO/sub x/ in the offgas. The chemistry developed for uranium and plutonium nitrate appears to apply to other metal nitrates. The copper nitrate test was successful, with over 90% of the nitrate converted to elemental nitrogen and water and with recovery of a granular, free-flowing copper product. Tests with sodium nitrate were not successful due to fusion of sodium carbonate in the calciner bed and plugging of the calciner. Further development of the elutriated fluid-bed system would be required to process high sodium nitrate waste solutions.

  5. 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.

  6. 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...

  7. CELL CYCLE SYNCHRONIZATION OF MOUSE LIVER EPITHELIAL CELLS BY ELUTRIATION CENTRIFUGATION

    SciTech Connect

    Pearlman, Andrew L.; Bartholomew, James C.

    1980-06-01

    Detailed methods are described for the sorting and cell cycle synchronization by means of centrifugal elutriation of an established mouse liver epithelial cell line(NMuLi). In a comparison between three different elutriation media and between two different temperatures(4° and 20° C), the NMuLi cells were found to be most reproducibly sorted in the cell cycle when run in growth medium in the absence of serum and at the lower temperature. Under these conditions. and using decrements of rotor speed calculated from an empirically derived algorithm as described in the text an initially asynchronous population (38% G{sub 1}, 36% S, and 28% G{sub 2}M) was sorted into fractions enriched to 60% G{sub 1}, 75% S, and 50% G{sub 2}M. Of the cells loaded into the rotor, 30% were lost in the elutriation process, and about 20% recovered as aggregates. The remainder appeared in the various synchronized fractions. Epithelial cells sorted in this manner demonstrated no loss of viability, and upon replating showed significant movement in the cell cycle by 6 hrs post elutriation. The degree of synchronous movement through the cell cycle achieved by elutriation depended on the part of the cell cycle from which the original elutriated fraction came. Cells collected as late S and G{sub 2}M moved through the cell cycle with the tightest sychrony.

  8. 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.

  9. 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.

  10. 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.

  11. Review of Dredging Elutriate Application Factors: Relevance to Acute-to-Chronic Protection, Contaminant, and Endpoint Specificity

    DTIC Science & Technology

    2015-07-01

    Particularly, use of the default AF is overly conservative when high levels of nonpersistent chemicals such as ammonia are present in elutriate... ammonia toxicity and the development toxicity test endpoint. DISCLAIMER: The contents of this report are not to be used for advertising, publication, or...Importance of ammonia in determining elutriate toxicity results ............................................. 6 Development toxicity tests and use of

  12. 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.

  13. 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)

  14. Application of spouted bed elutriation in the recycling of lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Bertuol, Daniel A.; Toniasso, Camila; Jiménez, Bernardo M.; Meili, Lucas; Dotto, Guilherme L.; Tanabe, Eduardo H.; Aguiar, Mônica L.

    2015-02-01

    The growing environmental concern, associated with the continuous increase in electronic equipment production, has induced the development of new technologies to recycle the large number of spent batteries generated in recent years. The amount of spent lithium-ion batteries (LIBs) tends to grow over the next years. These batteries are composed by valuable metals, such as Li, Co, Cu and Al, which can be recovered. Thus, the present work is carried out in two main steps: In the first step, a characterization of the LIBs is performed. Batteries from different brands and models are dismantled and their components characterized regarding to the chemical composition and main phases. In the second step, a sample of LIBs is shredded and the different materials present are separated by spouted bed elutriation. The results show that spouted bed elutriation is a simple and inexpensive way to obtain the separation of the different materials (polymers, metals, active electrode materials) present in spent LIBs.

  15. 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)

  16. Chemical analyses of elutriates, native water, and bottom material from the Chetco, Rogue, and Columbia rivers in western Oregon

    USGS Publications Warehouse

    Fuhrer, Gregory J.

    1984-01-01

    Chemical analyses of elutriates, bottom sediment, and water samples for selected metals, nutrients and organic compounds including insecticides, herbicides, and acid/neutral extractables have been made to provide data to determine short-term water-quality conditions associated with dredging operations in rivers and estuaries. Between April and August 1982, data were collected from the Chetco and Rogue River estuaries in southwestern Oregon, and from the mouth of the Columbia River in the northwestern Oregon to Cathlamet Bay, 18.2 miles upstream. In an elutriation test, bottom materials from a potential dredge site are mixed with native water - collected from either a dredge or disposal site - and the liquid portion of the mixture is removed, filtered, and chemically analyzed. Presented in this report are chemical and physical analyses of elutriates, native water, and bottom material for selected metals, ammonia, organic carbon, pesticides, particle size, and gas chromatographic/mass spectrometric semi-quantitative organic scans. Elutriate and bottom-material samples were screened specifically for phenolic compounds, particularly the chlorinated phenols; phenol was the only compound identified. Elutriate-test results showed variability for selected trace-metal concentrations of dissolved chemicals as follows: in micrograms per liter, arsenic ranged from < 1 to 15, cadmium from 1 to 210, copper from < 1 to 13, chromium from < 1 to 5, and nickel from 2 to 18. Results of computations to determine the amount of a constituent associated with bottom material and interstitial water and subsequently released (dissolved) into the elutriate-test native-mixing water are presented for selected trace metals. The highest elutriate-test release was 35 percent for manganese; the second highest, 5 percent for cadmium. All other computed releases were less than or equal to 1 percent. (USGS)

  17. Regulation of hydrogen ion secretion in rat gastric mucosal parietal cells isolated by centrifugal elutriation

    SciTech Connect

    Thompson, W.J.; Black, E.W.; Strada, S.J.

    1986-03-01

    To study the second messengers, cyclic AMP (cA) and calcium as regulators of gastric acid secretion, the authors have developed a method to isolate and enrich parietal cells (PC) from rat gastric mucosa by centrifugal elutriation. After mucosal dispersion with Pronase/EDTA in KRB buffer containing glucose and albumin, cells are elutriated with a four step washout procedure. The PC fraction is 60-80% pure with 95% viability and yields of 40-60%. PC cells are used to identify calcium/calmodulin and cA-mediated protein phosphorylations. CA level is measured with a solid phase radioimmunoassay using sample acetylation and hydrogen ion production is determined indirectly by /sup 14/C-aminopyrine (AP) accumulation. PC-rich (PCR) and PC-poor (PCP) fractions show similar basal cA content (380 fmol/million cells) but have markedly different responses to secretagogues in both rate and magnitude. AP and cA correlate with stimulation induced by forskolin (F) and histamine (H) but not carbachol. F increases cA 14 fold linearly for 60 min in PCP and 180 fold in PCR. H gives a weak 1 fold cA increase in PCP with little change in AP, but shows a 10 fold increase in cA and an 8 fold increase in AP in PCR. No changes in cA are observed with carbachol induced AP accumulation. These data support the role of cA in regulation of acid secretion and demonstrate the utility of centrifugal elutriation as a method to obtain parietal cells from rat gastric mucosa.

  18. 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)

  19. Modelling of an activated primary settling tank including the fermentation process and VFA elutriation.

    PubMed

    Ribes, J; Ferrer, J; Bouzas, A; Seco, A

    2002-10-01

    A complete model of a primary settler including both sedimentation and biological processes is presented. It is a one-dimensional model based on the solids flux concept and the conservation of mass that uses the Takács model for the settling velocity, which is corrected by a compression function in the lower layers. The biological model is based on the ASM2 and enlarged with the fermentation model proposed by this research group. The settler was split in ten layers and the flux terms in the mass balance for each layer is obtained by means of the settling model. A pilot plant has been operated to study the primary sludge fermentation and volatile fatty acids (VFA) elutriation in a primary settler tank. The model has been tested with pilot plant experimental data with very good results. It has been able to simulate the VFA production in the settler and their elutriation with the influent wastewater for all the studied experiments. The developed model is easily applicable to secondary settlers and thickeners, also taking into account biological activity inside them.

  20. 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.

  1. 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.

  2. Trace element accumulation and elutriate toxicity in surface sediment in northern Tunisia (Tunis Gulf, southern Mediterranean).

    PubMed

    Oueslati, Walid; Zaaboub, Noureddine; Helali, Mohamed Amine; Ennouri, Rym; Martins, Maria Virgínia Alves; Dhib, Amel; Galgani, Francois; El Bour, Monia; Added, Ayed; Aleya, Lotfi

    2017-03-15

    Metal concentrations in sediments were investigated in the Gulf of Tunis, Tunisia, in relation to anthropic activities along the Mejerda River and Ghar El Melh Lagoon, with effluents discharged into the gulf. Distribution of grain size showed that the silty fraction is dominant with 53%, while sand and clay averages are 34 and 12% respectively. Zn concentration increased in the vicinity of the Mejerda River while Pb was at its highest levels at the outlet of Ghar El Mehl Lagoon. Sediment elutriate toxicity, as measured by oyster embryo bioassays, ranged from 10 to 45% abnormalities after 24h, but no relation was found between metal concentration and sediment toxicity. The AVS fraction that represents monosulfide concentrations in the sediment was higher in the central part of the gulf than in the coastal zone. The results reveal the influence of AVS, TOC and grain size on metal speciation and sediment toxicity.

  3. 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)

  4. Modified anaerobic digestion elutriated phased treatment for the anaerobic co-digestion of sewage sludge and food wastewater.

    PubMed

    Mo, Kyung; Lee, Wonbae; Kim, Moonil

    2017-02-01

    A modified anaerobic digestion elutriated phased treatment (MADEPT) process was developed for investigating anaerobic co-digestion of sewage sludge and food wastewater. The anaerobic digestion elutriated phased treatment (ADEPT) process is similar to a two-phase system, however, in which the effluent from a methanogenic reactor recycles into an acidogenic reactor to elutriate mainly dissolved organics. Although ADEPT could reduce reactor volume significantly, the unsolubilized solids should be wasted from the system. The MADEPT process combines thermo-alkali solubilization with ADEPT to improve anaerobic performance and to minimize the sludge disposal. It was determined that the optimal volume mixing ratio of sewage sludge and food wastewater was 4 : 1 for the anaerobic co-digestion. The removal efficiencies of total chemical oxygen demand, volatile solids, and volatile suspended solids in the MADEPT process were 73%, 70%, and 64%, respectively. However, those in the ADEPT process were only 48%, 37%, and 40%, respectively, at the same hydraulic retention time (HRT) of 7 days. The gas production of MADEPT was two times higher than that of ADEPT. The thermo-alkali solubilization increased the concentration of dissolved organics so that they could be effectively degraded in a short HRT, implying that MADEPT could improve the performance of ADEPT in anaerobic co-digestion.

  5. GHRP-6 in heifer and cow adenohypophisial cells separated by elutriation.

    PubMed

    Rico, M; Lorenzo, M T; Pazo, J A; Vega, F V; De la Cruz, L F

    1999-03-01

    Previous studies have reported that the growth hormone (GH)-releasing peptide (GHRP-6), a synthetic Met-enkephalin peptide analog, stimulates GH release in vivo in a variety of species, including bovine. In the present study, the in vitro effects of GHRP-6 on bovine somatotropes separated by elutriation were analyzed as well as its interactions with the GH-releasing hormone (GHRH). The administration of GHRP-6 at doses from 10(-8) M to 10(-5) M stimulated GH release, and also 10(-9) M in cow pituitary cells, and produced maximal stimulation at 10(-6) M. The effects of GHRP-6 (10(-6) M) on GH release were shown at 1, 2, 3 and 4-h incubation (p < 0.05), except for heifer pituitary cells at 1-h incubation (p > 0.05). The GH releasing effects of either GHRH alone or GHRH+GHRP-6 were significantly more potent than that of GHRP-6 alone (p < 0.05). Contrary to what occurred in rat pituitary cells, the combined administration of 10(-6) M GHRP-6 with 10(-8) M GHRH did not result in a synergist action of GH release. Although the additive effect was significant when compared with GHRH alone (p < 0.05). The results demonstrate the existence of differences in the effect of GHRH+GHRP-6 on bovine somatotropes. These differences may reflect the physiological importance of distinct cell subpopulation, like the mammosomatotroph cells.

  6. Separation of high and low metastatic subpopulations from solid tumors by centrifugal elutriation.

    PubMed

    Onoda, J M; Nelson, K K; Grossi, I M; Umbarger, L A; Taylor, J D; Honn, K V

    1988-02-01

    We have isolated from murine solid tumors (B16a) subpopulations of cells possessing high and low metastatic potential. Tumors were dispersed by collagenase treatment. The resulting heterogeneous population of cells (i.e., viable and non-viable tumor cells and host cells) were separated by centrifugal elutriation. Four of the fractions (100, 180, 260, 340) contained tumor cells of high viability (greater than 95%) and high purity (less than 1% host cell contamination). The four fractions were characterized by flow cytometry and found to differ in distribution of cells in G1, S and G2. The cell populations were also found to differ in metastatic potential as determined by their ability to form lung colonies following intravenous injection. The 340 fraction was approximately 5-fold more metastatic than the 100 fraction. We also observed that cells from the 100 fraction failed to induce platelet aggregation whereas cells from the 340 fraction induced significant platelet aggregation. These observations demonstrate that cells of B16a tumors are heterogeneous for phenotypic characteristics (i.e., metastatic potential; platelet aggregation, etc.) and that their ability to induce platelet aggregation is positively correlated with metastatic potential.

  7. 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.

  8. 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)

  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, 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)

  11. Impact assessment of dredging to remove coal fly ash at the Tennessee Valley Authority Kingston Fossil plant using fathead minnow elutriate exposures.

    PubMed

    Stanley, Jacob K; Kennedy, Alan J; Bednar, Anthony J; Chappell, Mark A; Seiter, Jennifer M; Averett, Daniel E; Steevens, Jeffery A

    2013-04-01

    On December 22, 2008, failure of an earthen containment structure resulted in the release of approximately 4.1 million m(3) of coal fly ash into the Emory River and the surrounding area from the Tennessee Valley Authority Kingston Fossil Plant near Kingston, Tennessee, USA. The purpose of the present study was to assess the potential of dredging activities performed to remove the fly ash from the river to result in increased risk to pelagic fish, with special consideration of mobilization of metals. Elutriates were created using two sources of fly ash by bubbling with air over 10 d. This elutriate preparation method was designed to represent worst-case conditions for oxidation, metal release, and dissolution. Larval and juvenile Pimephales promelas underwent 10-d exposures to these elutriates. Larval end points included survival and biomass, and juvenile end points included survival, length, biomass, liver somatic index, and bioaccumulation. No significant toxicity was observed. Bioaccumulation of metals in juveniles was found to be primarily attributable to metals associated with particles in the gut. Results suggest little potential for toxicity to related fish species due to fly ash removal dredging activities given the extreme conditions represented by the elutriates in the present study.

  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. 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)

  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. Toxicity assessment of water and sediment elutriates from fixed-station ambient water quality network stations, 1986, 1987, 1988, and 1989

    SciTech Connect

    Moses, J.; Wade, D.C.

    1991-02-01

    Toxicity biomonitoring of water column and sediment toxicity was conducted at six fixed network stations from 1986 through 1989. Stations were located on the Holston River, Bear Creek (Pickwick Reservoir), Hiwassee River, Emory River, Nolichucky River, and French Broad River at locations chosen to represent those sub-basins. Tests evaluated acute and chronic responses of larval fathead minnow survival and growth and Ceriodaphnia survival and reproduction to water and sediment elutriates collected from these sites. Samples were collected once each year during summer. Neither water nor sediment elutriates from the French Broad River were toxic during the study period. Water column toxicity (chronic) occurred in Bear Creek in 1986 and in the Nolichucky River in 1987. Sediment elutriate toxicity occurred once during the study period in the Emory (1987) and Nolichucky (1988) Rivers. Sediments from the Holston and Hiwassee Rivers were toxic two times each. Hiwassee River sediment exhibited >1.3 chronic toxicity units in 1987 and 1989 (were toxic at the lowest dilution tested). Holston River sediment toxicity occurred during the most recent two years of testing. Results from the Holston and Hiwassee Rivers may indicate a toxics problem in the sub-basin. No acute toxicity occurred during the study. 4 refs., 2 tabs.

  16. 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)

  17. The effects of elutriates from PAH and heavy metal polluted sediments on Crassostrea gigas (Thunberg) embryogenesis, larval growth and bio-accumulation by the larvae of pollutants from sedimentary origin.

    PubMed

    Geffard, Olivier; Budzinski, Hélène; His, Edouard

    2002-12-01

    The release, bio-availability and toxicity of contaminants, when sediments are resuspended have been examined, studying concurrently their effects on the embryogenesis and on the larval growth of the Crassostrea gigas larvae and their bio-accumulation in those organisms. Three characteristic sediments have been selected (one contaminated by PAHs, a second by heavy metals and the last by the both pollutants). The organisms were directly exposed to elutriates obtained from each sediment or fed on algae (Isochrysis galbana) contaminated with the same elutriates. The elutriates used in this study show contamination levels similar to those observed in some polluted coastal and estuary environments. The larval growth test has appeared to be more sensitive that the embryotoxicity test. The biological effects and the contaminant bio-accumulation were more pronounced when larvae were directly exposed to different elutriates. In the case of PAHs, the contamination of algae was sufficient to lead to effect on the larval growth of the Crassostrea gigas. In all cases, a fraction of contaminants adsorbed on suspended particles was bio-available and accumulated by the larvae. This study has shown that resuspending polluted sediments constitutes a threat to pelagic organisms and than the C. gigas larval growth may be proposed as a test to protect the most sensitive areas.

  18. Comparison of human monocytes isolated by elutriation and adherence suggests that heterogeneity may reflect a continuum of maturation/activation states.

    PubMed Central

    Dransfield, I; Corcoran, D; Partridge, L J; Hogg, N; Burton, D R

    1988-01-01

    Monocytes are heterogeneous both in terms of physical properties and in their functional capacity. Isolation of monocytes from peripheral blood may perturb the observed heterogeneity for purified cell preparations. To explore this possibility we examined monocytes prepared by two techniques, counter-flow centrifugation elutriation (CCE) and fibronectin adherence, in terms of cell-surface molecule expression and several physical properties. Although such cells would be expected to represent dissimilar cross-sections of the total monocyte population, they were found to have similar cell-surface antigenic profiles. Observed differences in levels of expression of several molecules (CR1, CR3 and the antigen recognized by LP9 antibody) were found to be a temperature-related phenomenon. These results indicate that monocytes are not divisible into 'subpopulations' on the basis of cell-surface molecule expression and suggest that heterogeneity of monocytes may reflect the presence in the circulation of a continuum of maturational/activation states. PMID:3350583

  19. Specific binding of sup 125 I-rErythropoietin to Friend polycythemia virus-transformed erythroleukemia cells purified by centrifugal elutriation

    SciTech Connect

    Correa, P.N.; Bard, V.; Axelrad, A.A. )

    1990-01-01

    We have used countercurrent centrifugal elutriation (CCE) to determine the distribution of cells with respect to cell volume and buoyant density for an erythroleukemia cell line (JG6) transformed by the polycythemia strain of Friend virus (FV-P), and to determine the effect of inducing the cells to differentiate with dimethylsulfoxide (DMSO) on this distribution. CCE made it possible to obtain suspensions of modal JG6 populations virtually free of dead cells and uniform with respect to volume and buoyant density. These modal populations were assayed for specific binding of erythropoietin (Epo). Between 500 and 550 Epo receptors per cell were detected. These belonged to a single class having a dissociation constant of 0.36 nM. DMSO induction of differentiation of the JG6 cells had no effect on the number of Epo receptors expressed.

  20. 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)

  1. 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.

  2. 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.

  3. Toxicity profiling of marine surface sediments: A case study using rapid screening bioassays of exhaustive total extracts, elutriates and passive sampler extracts.

    PubMed

    Vethaak, A Dick; Hamers, Timo; Martínez-Gómez, Concepción; Kamstra, Jorke H; de Weert, Jasperien; Leonards, Pim E G; Smedes, Foppe

    2017-03-01

    This study was carried out in the framework of the ICON project (Integrated Assessment of Contaminant Impacts on the North Sea) (Hylland et al., 2015) and aimed (1) to evaluate the toxicity of marine sediments using a battery of rapid toxicity bioassays, and; (2) to explore the applicability and data interpretation of in vitro toxicity profiling of sediment extracts obtained from ex situ passive sampling. Sediment samples were collected at 12 selected (estuarine, coastal, offshore) sites in the North Sea, Icelandic waters (as reference sites), south-western Baltic Sea and western Mediterranean during autumn 2008. Organic extracts using a mild non-destructive clean-up procedure were prepared from total sediment and silicone passive samplers and tested with five in vitro bioassays: DR-Luc bioassay, ER-Luc bioassay, AR-EcoScreen bioassay, transthyretin (TTR) binding assay, and Vibrio fischeri bioluminescence bioassay. In vitro toxicity profiling of total sediment and silicone passive sampler extracts showed the presence of multiple organic contaminations by arylhydrocarbon receptor agonists (e.g. polycyclic aromatic hydrocarbons) and endocrine-active compounds, as well as non-specific toxicity caused by organic contaminants, at virtually all sampling sites. In vitro responses to total sediment extracts from coastal/estuarine sites were significantly different from those in offshore sites (p < 0.05). Several bioassays of passive sampler extracts showed highest activity in some offshore sediment samples. Impact on embryogenesis success and larval growth in undiluted sediment elutriates was shown at some sites using the in vivo sea urchin embryo test. The observed toxicity profiles could only partially be explained by the chemical target analysis, indicating the presence of unknown or unanalysed biologically-active compounds in the sediments. In vitro bioassay testing with silicone passive sampler extracts of sediments is a promising tool to assess the toxic

  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. 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 ...

  6. 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...

  7. Results of Sediment Sampling and Elutriate Testing at the Proposed Desoto Shallow Water Habitat Project Site

    DTIC Science & Technology

    2013-08-01

    Chlordane 2.4 0.0043 ----- DDT 1.1 0.001 ----- DDD 0.6 0.0031 0.0031 DDE 1,050 0.0022 0.0022 Dieldrin 0.24 0.00054 0.00054 Endosulfan (Alpha) 0.22 0.056...9.9 Alpha-BHC (alpha-Lindane) 0.4 5.1 DDD 0.7 9.9 Beta-BHC (beta-Lindane) 1.0 5.1 DDT 1.0 9.9 Delta-BHC (delta-Lindane) 1.8 5.1 Methoxychlor 1.2... DDT 0.004 0.1 Delta-BHC (delta-Lindane) 0.014 0.05 Methoxychlor 0.005 0.5 Gamma-BHC (gamma-Lindane) 0.035 0.05 Aldrin 0.008 0.5 Gamma-Chlordane

  8. 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...

  9. Elutriation of bone marrow delineates two distinct natural suppressor cell populations.

    PubMed

    Noga, S J; Fischer, A C; Horwitz, L R; Donnenberg, A D; Wagner, J E; Hess, A D

    1990-01-01

    It appears that part of the confusion surrounding the lineage of NS cells could be due, in part, to the presence of more than one cell population in normal BM. Whether other cell populations exist in other organ compartments, or can be induced, is presently unknown. This is of particular interest in allogeneic BMT where various lymphocyte depletion techniques have been employed to reduce the incidence of AGVHD. When CCE is used for depletion, the NS lymphocyte component is entirely removed. Since the incidence of AGVHD is significantly reduced with CCE lymphocyte-depleted rat and human BM, it appears that this subpopulation need not be present to abrogate AGVHD. Quite surprisingly, preliminary studies in rats indicates that this lymphocyte subpopulation may actually induce acute syngeneic GVHD (Fischer et al., 1989). That a cell(s) in the clonogenic compartment has the ability to suppress or down-regulate a variety of immune responses is not altogether surprising. This cell is better thought of as an auto-regulatory cell which has the ability to control the cellular interactions in its immediate micro-environment. Indeed, R/O NSCA can be augmented by GM-CSF, IL-3, and CsA (NoGa et al., 1988a). In vitro, this cell differentiates into the mono-myeloid series using a variety of stimulatory agents and can acquire tumoricidal activity. The ability to express NSCA is lost however, being present only during a brief window of early maturation. Only IL-3 can sustain NSCA in culture.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Results of Sediment Sampling and Elutriate Testing at the Proposed Indian Cave State Park Shallow Water Habitat Project Site

    DTIC Science & Technology

    2013-08-01

    DDT 1.1 0.001 ----- DDD 0.6 0.0031 0.0031 DDE 1,050 0.0022 0.0022 Dieldrin 0.24 0.00054 0.00054 Endosulfan (Alpha) 0.22 0.056...Limit (g/kg) Reporting Limit (g/kg) DDE 0.8 9.9 Alpha-BHC (alpha-Lindane) 0.4 5.1 DDD 0.7 9.9 Beta-BHC (beta-Lindane) 1.0 5.1 DDT 1.0 9.9 Delta...BHC (beta-Lindane) 0.009 0.05 DDT 0.004 0.1 Delta-BHC (delta-Lindane) 0.014 0.05 Methoxychlor 0.005 0.5 Gamma-BHC (gamma-Lindane) 0.035 0.05 Aldrin

  11. Results of Sediment Sampling and Elutriate Testing at the Proposed Middle Decatur Shallow Water Habitat Project Site

    DTIC Science & Technology

    2013-07-01

    µg/L) Aldrin 3 0.0005 0.0005 BHC 100 0.414 0.414 BHC (Alpha) ----- 0.049 0.049 BHC (Beta) ----- 0.17 0.17 Chlordane 2.4 0.0043 ----- DDT 1.1...9.9 Beta-BHC (beta-Lindane) 1.0 5.1 DDT 1.0 9.9 Delta-BHC (delta-Lindane) 1.8 5.1 Methoxychlor 1.2 5.1 Gamma-BHC (gamma-Lindane) 0.6 5.1 Aldrin...alpha-Lindane) 0.009 0.05 DDD 0.005 0.1 Beta-BHC (beta-Lindane) 0.009 0.05 DDT 0.004 0.1 Delta-BHC (delta-Lindane) 0.014 0.05 Methoxychlor 0.005

  12. Results of Sediment Sampling and Elutriate Testing at the Proposed Wilson Island Shallow Water Habitat Project Site

    DTIC Science & Technology

    2013-08-01

    Aldrin 3 0.0005 0.0005 BHC 100 0.414 0.414 BHC (Alpha) ----- 0.049 0.049 BHC (Beta) ----- 0.17 0.17 Chlordane 2.4 0.0043 ----- DDT 1.1 0.001...Beta-BHC (beta-Lindane) 1.0 5.1 DDT 1.0 9.9 Delta-BHC (delta-Lindane) 1.8 5.1 Methoxychlor 1.2 5.1 Gamma-BHC (gamma-Lindane) 0.6 5.1 Aldrin 0.7...µg/l) DDE 0.005 0.1 Alpha-BHC (alpha-Lindane) 0.009 0.05 DDD 0.005 0.1 Beta-BHC (beta-Lindane) 0.009 0.05 DDT 0.004 0.1 Delta-BHC (delta-Lindane

  13. Results of Sediment Sampling and Elutriate Testing at the Proposed Middle Decatur Revetment Shallow Water Habitat Project Site

    DTIC Science & Technology

    2014-07-01

    Detection Limit (µg/kg) Reporting Limit (µg/kg) DDE 0.8 9.9 Alpha-BHC (alpha-Lindane) 0.4 5.1 DDD 0.7 9.9 Beta-BHC (beta-Lindane) 1.0 5.1 DDT 1.0...DDD 0.005 0.1 Beta-BHC (beta-Lindane) 0.009 0.05 DDT 0.004 0.1 Delta-BHC (delta-Lindane) 0.014 0.05 Methoxychlor 0.005 0.5 Gamma-BHC (gamma-Lindane...20-May-14 1401161-01 MDR-S1 8-May-14 9:30 AM 0 -10 Composite 4,4’- DDT ɘ.009 ug/kg U EPA 8081 496.524 0.009 10 20-May-14 1401161-01 MDR-S1 8-May-14 9

  14. Results of Sediment Sampling and Elutriate Testing at the Proposed Little Sioux Bend Shallow Water Habitat Project Site

    DTIC Science & Technology

    2013-04-01

    5 2.2 Section 303( d ) Impaired Waters Listings...advisory has recently been removed based on recent fish tissue sampling (NDEQ, 2012). 2.2 Section 303( d ) Impaired Waters Listings Section 303( d ) of...the Federal CWA requires States to evaluate water quality conditions in designated waterbodies, and list as impaired (i.e. 303( d ) list) any

  15. Results of Sediment Sampling and Elutriate Testing at the Proposed Glovers Point Shallow Water Habitat Project Site

    DTIC Science & Technology

    2013-04-01

    5 2.2 Section 303( d ) Impaired Waters Listings...2.2 Section 303( d ) Impaired Waters Listings Section 303( d ) of the Federal CWA requires States to evaluate water quality conditions in...designated waterbodies, and list as impaired (i.e. 303( d ) list) any waterbodies not meeting water quality 6 standards. As appropriate, States must

  16. 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...

  17. 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.

  18. Bioassays on Illinois Waterway Dredged Material.

    DTIC Science & Technology

    1992-12-01

    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

  19. 30 CFR 90.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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...

  20. 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...

  1. 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...

  2. 30 CFR 90.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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...

  3. 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...

  4. Toxicity evaluation of natural samples from the vicinity of rice fields using two trophic levels.

    PubMed

    Marques, Catarina R; Pereira, Ruth; Gonçalves, Fernando

    2011-09-01

    An ecotoxicological screening of environmental samples collected in the vicinity of rice fields followed a combination of physical and chemical measurements and chronic bioassays with two freshwater trophic levels (microalgae: Pseudokirchneriella subcapitata and Chlorella vulgaris; daphnids: Daphnia longispina and Daphnia magna). As so, water and sediment/soil elutriate samples were obtained from three sites: (1) in a canal reach crossing a protected wetland upstream, (2) in a canal reach surrounded by rice fields and (3) in a rice paddy. The sampling was performed before and during the rice culture. During the rice cropping, the whole system quality decreased comparatively to the situation before that period (e.g. nutrient overload, the presence of pesticides in elutriates from sites L2 and L3). This was reinforced by a significant inhibition of both microalgae growth, especially under elutriates. Contrary, the life-history traits of daphnids were significantly stimulated with increasing concentrations of water and elutriates, for both sampling periods.

  5. Evaluation of Proposed U.S. Environmental Protection Agency Dredged Material Bioassays Using Great Lakes Sediments.

    DTIC Science & Technology

    1994-11-01

    1755. Oris, J. T., and Bailer, A. J. (1993). "Statistical analysis of the Ceriodaphnia toxicity test: Sample size determination for reproductive ...considered sublethal end points such as growth and reproduction , and examined chronic effects of sus- pended sediments (e.g., 21-day elutriate...survival and growth) and elutriate tests using Pimephales promelas (7-day survival and growth) and Daphnia magna (21-day survival and reproduction

  6. 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.

  7. 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.

  8. Impact of contaminated-sediment resuspension on phytoplankton in the Biguglia lagoon (Corsica, Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Lafabrie, Céline; Garrido, Marie; Leboulanger, Christophe; Cecchi, Philippe; Grégori, Gérald; Pasqualini, Vanina; Pringault, Olivier

    2013-09-01

    In shallow human-impacted systems, sediment resuspension events can result in pulsed exposures of pelagic organisms to multiple contaminants. Here, we examined the impact of the resuspension of contaminated sediment on phytoplankton in the Biguglia lagoon (Corsica, Mediterranean Sea), by conducting an in situ microcosm experiment over a 96-h period. Natural phytoplankton was exposed to elutriates prepared from a contaminated-sediment resuspension simulating process, and its functional and structural responses were compared with those of non-exposed phytoplankton. The elutriates displayed moderate multiple contamination by trace metals and PAHs. Our results show that elutriate exposure induced both functional and structural phytoplankton changes. Elutriates strongly stimulated phytoplankton growth after 24 h of exposure. They also enhanced phytoplankton photosynthetic performance during the first hours of exposure (up to 48 h), before reducing it toward the end of the experiment. Elutriates were also found to slightly stimulate Bacillariophyceae and conversely to slightly inhibit Dinophyceae in the short term. Additionally, they were found to stimulate phycocyanin-rich picocyanobacteria in the short term (8-48 h) before inhibiting it in the longer term (72-96 h), and to inhibit eukaryotic nanophytoplankton in the short term (8-48 h) before stimulating it in the longer term (72-96 h). Sediment resuspensions are thus likely to have significant effects on the global dynamics and functions of phytoplankton in contaminated coastal environments.

  9. A new activated primary tank developed for recovering carbon source and its application.

    PubMed

    Jin, Pengkang; Wang, Xianbao; Zhang, Qionghua; Wang, Xiaochang; Ngo, Huu Hao; Yang, Lei

    2016-01-01

    A novel activated primary tank process (APT) was developed for recovering carbon source by fermentation and elutriation of primary sludge. The effects of solids retention time (SRT), elutriation intensity (G) and return sludge ratio (RSR) on this recovery were evaluated in a pilot scale reactor. Results indicated that SRT significantly influenced carbon source recovery, and mechanical elutriation could promote soluble COD (SCOD) and VFA yields. The optimal conditions of APT were SRT=5d, G=152s(-1) and RSR=10%, SCOD and VFA production were 57.0mg/L and 21.7mg/L. Particulate organic matter in sludge was converted into SCOD and VFAs as fermentative bacteria were significantly enriched in APT. Moreover, the APT process was applied in a wastewater treatment plant to solve the problem of insufficient carbon source. The outcomes demonstrated that influent SCOD of biological tank increased by 31.1%, which improved the efficiency of removing nitrogen and phosphorus.

  10. 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.

  11. Particulate Formation from a Copper Oxide-Based Oxygen Carrier in Chemical Looping Combustion for CO2 Capture

    EPA Science Inventory

    Attrition behavior and particle loss of a copper oxide-based oxygen carrier from a methane chemical looping combustion (CLC) process was investigated in a fluidized bed reactor. The aerodynamic diameters of most elutriated particulates, after passing through a horizontal settling...

  12. Consequences of contaminant mixture on the dynamics and functional diversity of bacterioplankton in a southwestern Mediterranean coastal ecosystem.

    PubMed

    Pringault, Olivier; Lafabrie, Céline; Avezac, Murielle; Bancon-Montigny, Chrystelle; Carre, Claire; Chalghaf, Mohamed; Delpoux, Sophie; Duvivier, Adrien; Elbaz-Poulichet, Françoise; Gonzalez, Catherine; Got, Patrice; Leboulanger, Christophe; Spinelli, Sylvie; Hlaili, Asma Sakka; Bouvy, Marc

    2016-02-01

    Contamination of coastal environments is often due to a complex mixture of pollutants, sometimes in trace levels, that may have significant effects on diversity and function of organisms. The aim of this study was to evaluate the short-term dynamics of bacterioplankton exposed to natural and artificial mixtures of contaminants. Bacterial communities from a southwestern Mediterranean ecosystem, lagoon and the bay (offshore) of Bizerte were exposed to i) elutriate from resuspension of contaminated sediment, and ii) an artificial mixture of metals and herbicides mimicking the contamination observed during sediment resuspension. Elutriate incubation as well as artificial spiking induced strong enrichments in nutrients (up to 18 times), metals (up to six times) and herbicides (up to 20 times) relative to the in situ concentrations in the offshore station, whereas the increases in contaminants were less marked in the lagoon station. In the offshore waters, the artificial mixture of pollutants provoked a strong inhibition of bacterial abundance, production and respiration and significant modifications of the potential functional diversity of bacterioplankton with a strong decrease of the carbohydrate utilization. In contrast, incubation with elutriate resulted in a stimulation of bacterial activities and abundances, suggesting that the toxic effects of pollutants were modified by the increase in nutrient and DOM concentrations due to the sediment resuspension. The effects of elutriate and the artificial mixture of pollutants on bacterial dynamics and the functional diversity were less marked in the lagoon waters, than in offshore waters, suggesting a relative tolerance of lagoon bacteria against contaminants.

  13. 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...

  14. Effects of anthracene, pyrene and benzo[a]pyrene spiking and sewage sludge compost amendment on soil ecotoxicity during a bioremediation process.

    PubMed

    Hamdi, Helmi; Manusadzianas, Levonas; Aoyama, Isao; Jedidi, Naceur

    2006-11-01

    The fate of spiked anthracene, pyrene and benzo[a]pyrene in soil with or without sewage sludge compost was assessed during a 6-month bioremediation process simulating landfarming. Bioassays and physico-chemical analyses were employed to monitor toxicity change in soil samples and elutriates through ten sampling campaigns. Pearson product-moment correlation coefficient was determined to measure the strength of relationship between bioassays and physico-chemical analyses. The PAH dissipation in soil was enhanced after the first water addition, and the remaining amounts at the end of the experiment were positively correlated to the number of benzene rings and the presence of sewage sludge compost. Toxicity of soil elutriates to Daphnia magna was evident at early stages, originating exclusively from sewage sludge compost amendment. The lettuce root elongation was continuously inhibited by elutriates for all the treatments including control soil, probably due to high salinity or to unaddressed leachable phytotoxic compounds that were present in the experimental soil. The newly developed direct solid-phase chronic toxicity test using ostracod (Heterocypris incongruens) succeeded in evaluating the soil-bound PAH toxicity, as PAHs could not be detected in elutriates.

  15. Characteristics of fluidized-packed beds

    NASA Technical Reports Server (NTRS)

    Gabor, J. D.; Mecham, W. J.

    1968-01-01

    Study of fluidized-packed bed includes investigation of heat transfer, solids-gas mixing, and elutriation characteristics. A fluidized-packed bed is a system involving the fluidization of small particles in the voids of a packed bed of larger nonfluidized particles.

  16. 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

  17. Electronic scraps - Recovering of valuable materials from parallel wire cables

    SciTech Connect

    Pinheiro Bezerra de Araujo, Mishene Christie; Pinto Chaves, Arthur; Crocce Romano Espinosa, Denise; Tenorio, Jorge Alberto Soares

    2008-11-15

    Every year, the number of discarded electro-electronic products is increasing. For this reason recycling is needed, to avoid wasting non-renewable natural resources. The objective of this work is to study the recycling of materials from parallel wire cable through unit operations of mineral processing. Parallel wire cables are basically composed of polymer and copper. The following unit operations were tested: grinding, size classification, dense medium separation, electrostatic separation, scrubbing, panning, and elutriation. It was observed that the operations used obtained copper and PVC concentrates with a low degree of cross contamination. It was concluded that total liberation of the materials was accomplished after grinding to less than 3 mm, using a cage mill. Separation using panning and elutriation presented the best results in terms of recovery and cross contamination.

  18. 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.

  19. Identification of the toxic constituents of sediments in a Brazilian subtropical estuary.

    PubMed

    Poleza, Fernanda; Souza, Rafael C; Resgalla, Charrid

    2014-03-15

    Phase 1 of the TIE method was applied to samples of elutriates from sediments of the Itajaí-Açu estuary and adjacent coastal region in southern Brazil. Embryo-larval toxicity assays were used with the sea urchin Arbacia lixula in samples of raw elutriate, and treated with Ulva fasciata, EDTA and sodium thiosulfate. Inside the estuary, ammonia was responsible for more than 40% of the toxicity in both the dredged and undredged regions. A toxicity gradient was observed, between the estuary and the coastal region, with an increase in the importance of metals for the latter. Temporally, there is strong evidence of the influence of dredging and disposal of sediments in the contamination of the coastal dumping site. The results indicating that this area presents limitations in its saturation capacity. Chemical analysis indicated the metal Cu is probably responsible for the toxicity of the sediments observed, without the interference of ammonia.

  20. Electronic scraps--recovering of valuable materials from parallel wire cables.

    PubMed

    de Araújo, Mishene Christie Pinheiro Bezerra; Chaves, Arthur Pinto; Espinosa, Denise Crocce Romano; Tenório, Jorge Alberto Soares

    2008-11-01

    Every year, the number of discarded electro-electronic products is increasing. For this reason recycling is needed, to avoid wasting non-renewable natural resources. The objective of this work is to study the recycling of materials from parallel wire cable through unit operations of mineral processing. Parallel wire cables are basically composed of polymer and copper. The following unit operations were tested: grinding, size classification, dense medium separation, electrostatic separation, scrubbing, panning, and elutriation. It was observed that the operations used obtained copper and PVC concentrates with a low degree of cross contamination. It was concluded that total liberation of the materials was accomplished after grinding to less than 3 mm, using a cage mill. Separation using panning and elutriation presented the best results in terms of recovery and cross contamination.

  1. 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.

  2. Metal mobility and toxicity to microalgae associated with acidification of sediments: CO2 and acid comparison.

    PubMed

    De Orte, M R; Lombardi, A T; Sarmiento, A M; Basallote, M D; Rodriguez-Romero, A; Riba, I; Del Valls, A

    2014-05-01

    The injection and storage of CO2 into marine geological formations has been suggested as a mitigation measure to prevent global warming. However, storage leaks are possible resulting in several effects in the ecosystem. Laboratory-scale experiments were performed to evaluate the effects of CO2 leakage on the fate of metals and on the growth of the microalgae Phaeodactylum tricornutum. Metal contaminated sediments were collected and submitted to acidification by means of CO2 injection or by adding HCl. Sediments elutriate were prepared to perform toxicity tests. The results showed that sediment acidification enhanced the release of metals to elutriates. Iron and zinc were the metals most influenced by this process and their concentration increased greatly with pH decreases. Diatom growth was inhibited by both processes: acidification and the presence of metals. Data obtained is this study is useful to calculate the potential risk of CCS activities to the marine environment.

  3. [Assessment of measured respirable dust sampler penetration and the sampling convention for work environment measurement].

    PubMed

    Myojo, Toshihiko

    2005-11-01

    The relationship between dust size and penetration for a static horizontal elutriator (Sibata C-30) was measured in calm air. The elutriator as a low-volume air sampler is widely used as a dust size classifier in work environment measurements. The actual penetrations were compared with the theoretical models of the sampler and with sampling convention for respirable dust in work environment measurement. The sampling convention was recently introduced into the Japanese standard for work environment measurement and is based on the ISO 7708 respirable dust convention. The bias of sampled masses from the respirable dust was calculated for two flow rates of the sampler, i.e., 50% cut sizes of 4 microm and 5 microm, from measured penetration curves. The bias of the sampler was overestimated in the 5 microm, 50% cut condition and underestimated in the 4 microm, 50% cut condition for most workplace sampling situations.

  4. 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.

  5. 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.

  6. 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

  7. Toxicity assessment of reference and natural freshwater sediments with the LuminoTox assay.

    PubMed

    Dellamatrice, P M; Monteiro, R T R; Blaise, C; Slabbert, J L; Gagné, F; Alleau, S

    2006-08-01

    We examined the possibility of adapting the LuminoTox, a recently-commercialized bioanalytical testing procedure initially developed for aqueous samples, to assess the toxic potential of sediments. This portable fluorescent biosensor uses photosynthetic enzyme complexes (PECs) to rapidly measure photosynthetic efficiency. LuminoTox testing of 14 CRM (Certified Reference Material) sediments was first undertaken with (1) a "solid phase assay" (Lum-SPA) in which PECs are in intimate contact with sediment slurries for a 15 min exposure period and (2) an elutriate assay (Lum-ELU) in which PECs are exposed for 15 min to sediment water elutriates. CRM sediment toxicity data were then compared with those generated with the Microtox Solid Phase Assay (Mic-SPA). A significant correlation (P < 0.05) was shown to exist between Lum-SPA and Mic-SPA, indicating that both tests display a similar toxicity response pattern for CRM sediments having differing contaminant profiles. The sediment elutriate Lum-ELU assay displayed toxicity responses (i.e. measurable IC20s) for eight of the 14 CRM sediments, suggesting that it is capable of determining the presence of sediment contaminants that are readily soluble in an aqueous elutriate. Lum-SPA and Mic-SPA bioassays were further conducted on 12 natural freshwater sediments and their toxicity responses were more weakly, yet significantly, correlated. Finally, Lum-SPA testing undertaken with increasing mixtures of kaolin clay confirmed that its toxicity responses, in a manner similar to those reported for the Mic-SPA assay, are also subject to the influence of grain size. While further studies will be required to more fully understand the relationship between Lum-SPA assay responses and the physicochemical makeup of sediments (e.g., grain size, combined presence of natural and anthropogenic contaminants), these preliminary results suggest that LuminoTox testing could be a useful screen to assess the toxic potential of solid media.

  8. Effects of Dredged Materials on Zooplankton.

    DTIC Science & Technology

    1984-06-01

    VI. Biology of Acartia clausi and A. tonsa. Bull. Bingham Oceanogr. Coll., 15: 156-7 . "b Darby, 0. A., R. W. Alden III, J. H. Rule, C. H. Blair...block number) Elutriate bioassays with Acartia tonsa suggest that sediments from the Southern Branch lower reaches could significantly impact the...REFERENCES ..................................................... 15 -’ LIST OF TABLES Table 1 Multiple regression table for Acartia tonsa survival

  9. 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

  10. 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.

  11. Plow Shop Pond Supplemental Investigation Work Plan

    DTIC Science & Technology

    1994-09-01

    Ceriodaphnia dubia to sediment elutriate, and Chironomus tentans and Hyallella azteca to whole sediment. Twenty-two short-term chronic toxicity tests with C...in the proposed short-term chronic test include survival, growth, and reproduction . Twenty-two sediment samples for screening level bioassay will be...collected concurrently and from the same locations as the sediment samples collected for3 analytical chemical analyses. Ceriodaphnia dubia or water

  12. 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

  13. Field Evaluations of the Quality of Effluent from Confined Dredged Material Disposal Areas. Long-Term Effects of Dredging Operations Program.

    DTIC Science & Technology

    1988-02-01

    acknowledged. This work was performed under the general supervison of Dr. Raymond L. Montgomery, Chief, EED, and Dr. John Harrison, Chief, EL. Managers of the...material discharge under Section 404 of the Clean Water Act. The Corps of Engineers has recently developed modified elutriate testing procedures for...ABSTRACT (Continued). showed that all five disposal areas were very efficient in retaining suspended solids. The relative retention of contaminants

  14. 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.

  15. Trinity River Bottom Sediment Reconnaissance Study. Phase I. Plan of Work.

    DTIC Science & Technology

    1976-11-30

    5B Proposed Corps of Engineers Lock and Dam CRM = Corps River Mile Experiment Station, Corps of Engineers*; and Approved EPA Analytical Methods for...Appendix A, Approved EPA Analytical Methods for Dredged or Fill Material, (Undated). iv doe&- made on water and sediment samples. Chemical analysis will be...Distillation-Nesslerization) ...... ............. 74 Total Kjeldahl Nitrogen in Water and in Elutriate .... 74 Ammonia Nitrogen in Bottom Sediment

  16. Summary of Available Guidance and Best Practices for Determining Suitability of Dredged Material for Beneficial Uses

    DTIC Science & Technology

    2007-11-01

    Kjeldahl Nitrogen EPA-CRL-468 21. Ammonium Nitrogen EPA-CRL-324 22. Nitrate-nitrogen EPA-SW846-9200 23. Nitrite-nitrogen EPA-SW846-9200 24. Total...USEPA (1993) utilized Elutriate Toxicity Tests, Whole Sediment Toxicity Tests, Benthic Community Structure, Mutagenicity Assays , and Genotoxicity... Assays to assess Indiana Harbor, Buffalo River, and Saginaw River sediment samples. This collection of documents lacks the comprehensive

  17. 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.

  18. The effects of ocean acidification and a carbon dioxide capture and storage leak on the early life stages of the marine mussel Perna perna (Linneaus, 1758) and metal bioavailability.

    PubMed

    Szalaj, D; De Orte, M R; Goulding, T A; Medeiros, I D; DelValls, T A; Cesar, A

    2017-01-01

    The study assesses the effects of carbon dioxide capture and storage (CCS) leaks and ocean acidification (OA) on the metal bioavailability and reproduction of the mytilid Perna perna. In laboratory-scale experiments, CCS leakage scenarios (pH 7.0, 6.5, 6.0) and one OA (pH 7.6) scenario were tested using metal-contaminated sediment elutriates and seawater from Santos Bay. The OA treatment did not have an effect on fertilisation, while significant effects were observed in larval-development bioassays where only 16 to 27 % of larva developed normally. In treatments that simulated CO2 leaks, when compared with control, fertilisation success gradually decreased and no larva developed to the D-shaped stage. A fall in pH increased the bioavailability of metals to marine mussels. Larva shell size was significantly affected by both elutriates when compared with seawater; moreover, a significant difference occurred at pH 6.5 between elutriates in the fertilisation bioassay.

  19. Hydropower reservoirs: cytotoxic and genotoxic assessment using the Allium cepa root model.

    PubMed

    Rambo, Cassiano Lazarotto; Zanotelli, Patrícia; Dalegrave, Daniela; De Nez, Dinara; Szczepanik, Jozimar; Carazek, Fábio; Franscescon, Francini; Rosemberg, Denis Broock; Siebel, Anna Maria; Magro, Jacir Dal

    2017-02-17

    Hydropower offers a reliable source of electricity in several countries, and Brazil supplies its energy needs almost entirely through hydropower plants. Nevertheless, hydropower plants comprise large buildings and water reservoirs and dams, resulting in huge ecological disruptions. Here, we analyzed the impact of four hydropower reservoirs construction in metals and pesticides incidence and the cytotoxic and genotoxic potential of sediment elutriate of rivers from southern Brazil. Our analyses have evidenced the elevated incidence of different metals (lead, iron, cadmium, and chrome) and pesticides (methyl parathion, atrazine, and 2,4-dichlorophenoxyacetic acid). We showed that Allium cepa exposed to sediment elutriates did not change the seed germination rate and mitotic index. However, roots from Allium cepa exposed to reservoirs sediment elutriates showed increased occurrence of chromosomal aberrations and nuclear abnormalities. Therefore, the results obtained in our study indicate that sediment from reservoirs present elevated concentration of metals and pesticides and a significant genotoxic potential. Taken together, our data support that hydropower reservoirs represent an environmental scenario that could impact surrounding wildlife and population.

  20. Combination of Cobe AutoPBSC and Gambro Elutra as a platform for monocyte enrichment in dendritic cell (DC) therapy: clinical study.

    PubMed

    Chen, Ying; Hoecker, Paul; Zeng, Jia; Dettke, Markus

    2008-01-01

    Monocytes are a common source for generating dendritic cells (DCs). The aim of the present study was to evaluate the efficiency of a platform for monocyte collection and enrichment in a clinical setting. The platform was based on the combination of two semiautomated devices; the Cobe Spectra Auto PBSC for mononuclear cells (MNC) collection followed by counterflow elutriation for monocyte enrichment (Gambro BCT Elutra). Twenty-four patients with various types of epithelial cancer participated in the study. MNC collections were first performed as large volume leukapheresis (LVL). Subsequently, MNC products were processed with an elutriation system for monocyte isolation. LVL resulted in the collection of MNC at a median of 8.1 x 10(9) cells, containing of 31.4% monocytes. A similar efficacy was also shown in patients with lower peripheral blood counts. Elutriation of the MNC product with the Cobe Elutra device resulted in the enrichment of monocytes at a median of 2.7 x 10(9) cells, with a recovery of 80.2% and a purity of 90.7%. These monocytes were then successfully developed into DCs for clinical therapy after in vitro manipulation. These data suggest that the combination of the Cobe Spectra Auto PBSC and the Gambro BCT Elutra is an effective platform for monocyte enrichment in clinical practice according to GCP standards and GMP guidelines, and can be easily implemented in the clinical routine under current DC protocols.

  1. Two distinct mechanisms mediate the involvement of bone marrow cells in islet remodeling: neogenesis of insulin-producing cells and support of islet recovery.

    PubMed

    Iskovich, Svetlana; Goldenberg-Cohen, Nitza; Sadikov, Tamila; Yaniv, Isaac; Stein, Jerry; Askenasy, Nadir

    2015-01-01

    We have recently reported that small-sized bone marrow cells (BMCs) isolated by counterflow centrifugal elutriation and depleted of lineage markers (Fr25lin(-)) have the capacity to differentiate and contribute to regeneration of injured islets. In this study, we assess some of the characteristics of these cells compared to elutriated hematopoietic progenitors (R/O) and whole BMCs in a murine model of streptozotocin-induced chemical diabetes. The GFP(bright)CD45(+) progeny of whole BMCs and R/O progenitors progressively infiltrate the pancreas with evolution of donor chimerism; are found at islet perimeter, vascular, and ductal walls; and have a modest impact on islet recovery from injury. In contrast, Fr25lin(-) cells incorporate in the islets, convert to GFP(dim)CD45(-)PDX-1(+) phenotypes, produce proinsulin, and secrete insulin with significant contribution to stabilization of glucose homeostasis. The elutriated Fr25lin(-) cells express low levels of CD45 and are negative for SCA-1 and c-kit, as removal of cells expressing these markers did not impair conversion to produce insulin. BMCs mediate two synergistic mechanisms that contribute to islet recovery from injury: support of islet remodeling by hematopoietic cells and neogenesis of insulin-producing cells from stem cells.

  2. Proteomic analysis of the response to cell cycle arrests in human myeloid leukemia cells

    PubMed Central

    Ly, Tony; Endo, Aki; Lamond, Angus I

    2015-01-01

    Abstract Previously, we analyzed protein abundance changes across a ‘minimally perturbed’ cell cycle by using centrifugal elutriation to differentially enrich distinct cell cycle phases in human NB4 cells (Ly et al., 2014). In this study, we compare data from elutriated cells with NB4 cells arrested at comparable phases using serum starvation, hydroxyurea, or RO-3306. While elutriated and arrested cells have similar patterns of DNA content and cyclin expression, a large fraction of the proteome changes detected in arrested cells are found to reflect arrest-specific responses (i.e., starvation, DNA damage, CDK1 inhibition), rather than physiological cell cycle regulation. For example, we show most cells arrested in G2 by CDK1 inhibition express abnormally high levels of replication and origin licensing factors and are likely poised for genome re-replication. The protein data are available in the Encyclopedia of Proteome Dynamics (http://www.peptracker.com/epd/), an online, searchable resource. DOI: http://dx.doi.org/10.7554/eLife.04534.001 PMID:25555159

  3. 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.

  4. Toxicity of sediments near an aluminum smelter on the St. Lawrence river to aquatic organisms

    SciTech Connect

    Metcalfe-Smith, J.L.; Sirota, G.R.; Holtze, K.E.; Reid, J.J.

    1994-12-31

    Under a US EPA Superfund Administrative Order, over 50,000 cu yds of bottom sediments contaminated with fluoride, cyanide, PCBs, PAHs and Al will be dredged from the St. Lawrence River near the Reynolds Metals plant at Massena, NY in 1994. The purpose of this study was to determine the toxicity of these sediments to aquatic organisms and the potential for remobilizing sediment-bound contaminants into the water column during dredging. Sediment was collected from 7 sites along a gradient from the outfall in October 1993. Sediment from the most contaminated site ``B2`` (1,500 {mu}g/g fluoride, 30 {mu}g/g cyanide, 450 {mu}g/g PCBs, 3,500 {mu}g/g PAHs, 90,000 {mu}g/g Al), caused complete mortality of mayflies, Hexagenia limbata, and avoidance, considerable weight loss and some mortality in fathead minnows, Pimephales promelas, after 21 d exposure. Mortality was not observed at other sites, but growth of both organisms decreased with increasing contamination. LOECs of B2 elutriate were 13% for survival and reproduction of Ceriodaphnia dubia, and 6% for survival and 1.5% for growth of larval fatheads. Elutriates of other sediments were nontoxic. TIE testing suggested organic contaminants as the primary toxicants. Over 2,000 cu yds of sediment are highly toxic and 18,000 cu yds somewhat toxic. Toxicity of B2 elutriate shows that contaminants enter the water column when sediments are disturbed and may harm indigenous biota.

  5. Dependence of Cu, Pb and Zn remobilization on physicochemical properties of marine sediments.

    PubMed

    Durán, Iria; Sánchez-Marín, Paula; Beiras, Ricardo

    2012-06-01

    The resuspension of 65 marine sediments was simulated in the laboratory with elutriates from 30 different sites from the north coast of Spain. The partitioning of Cu, Pb and Zn between sediment and elutriate was studied as a function of different physicochemical characteristics of the sediment: organic matter (OM), fine fraction (FF), redox potential and acid volatile sulfides (AVS). Mean remobilization factors (RF) -calculated as metal concentration in the elutriate (μg/L) divided by metal concentration in the sediment (μg/g dry weight)- were 0.072 for Cu, 0.012 for Pb and 0.071 for Zn. Remobilization of Pb was significantly lower than that of Cu and Zn. Although AVS, OM and FF presented a strong intercorrelation, OM explained great part of the variability on Cu and Pb remobilization while AVS did it for Zn. A multiple regression model considering both OM and AVS explained slightly better the remobilization of Pb and Cu, but not that of Zn.

  6. Bioluminescent Vibrio fischeri Assays in the Assessment of Seasonal and Spatial Patterns in Toxicity of Contaminated River Sediments

    PubMed Central

    Jarque, Sergio; Masner, Petr; Klánová, Jana; Prokeš, Roman; Bláha, Ludek

    2016-01-01

    Several bacteria-based assays, notably Vibrio fischeri luminescence assays, are often used as environmental monitoring tool for toxicity in sediments that may serve as both sinks and secondary source of contamination in aquatic ecosystems. In this study, we used 30-s kinetic bioassays based on V. fischeri to evaluate the toxicity associated to sediments from five localities with different contamination inputs (Morava River and its tributary Drevnice River in the south-eastern part of the Czech Republic). Toxicity assessed as half maximal inhibitory concentration (IC50) over the course of a year-long sampling was compared in bottom sediments and freshly trapped particulate material. Standard approach based on testing of aqueous elutriates was compared with toxicity of whole sediments (contact suspension toxicity). Bottom sediments showed lower toxicity compared to freshly trapped suspended materials in all cases. On the other hand, standardized elutriates induced generally weaker effects than suspended sediments likely due to losses during the extraction process. Toxicity generally increased during winter reaching maximum peaks in early spring months in all five sites. Total organic carbon (TOC) was found to be highly correlated with toxic effects. Toxicity from sites with direct industrial and agricultural water inputs also correlated with concentrations of metals, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs). Single time point sampling followed by the extraction and testing of elutriates, do not truly reflect the spatial and temporal variability in natural sediments and may lead to underestimation of ecotoxic risks. PMID:27872614

  7. 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 contain 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 concentrations 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 for 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

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. Cyclic-radiation response of murine fibrosarcoma cells grown as pulmonary nodules

    SciTech Connect

    Grdina, D.J.; Hunter, N.

    1982-10-01

    The radiation age response of murine fibrosarcoma (FSa) cells grown as pulmonary nodules in C/sub 3/Hf/Kam mice was determined. FSa cells were irradiated in vivo either with 10 Gy as 14 day-old lung tumors (i.e., artificial macrometastases) prior to cell separation or with 5 Gy as single cells trapped in the lungs of recipient mice (i.e., artificial micrometastases) following cell separation and synchronization by centrifugal elutriation. Flow microfluorometry (FMF) was used to determine cell-cycle parameters and the relative synchrony of the separated populations, as well as the percent contamination of normal diploid cells in each of the tumor cell populations. Tumor populations containing up to 90% G/sub 1/, 60% S-, and 75% G/sub 2/+M-phase tumor cells were obtained. Cell clonogenicity, determined using a lung colony assay, ranged from 0.7 to 6% for control FSa cells from the various elutriator fractions. The radiation sensitivity of these separated cell populations varied by a factor of 6, regardless of whether the cells were irradiated as artificial micro or macro-metastases. In each experiment, tumor populations most enriched in s-phase cells exhibited the greatest radiation sensitivity. To confirm that these populations were highly enriched in S-phase cells and to demonstrate that they were more radiosensitive than FSa cells in other parts of the cell cycle, the elutriated tumor populations were exposed to either suicide labeling by high specific activity tritiated thymidine or hydroxyurea. The resultant age response curves were qualitatively similar to those obtained following irradiation and reflected the S-phase sensitivity of FSa cells to these agents.

  13. 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)

  14. Toxicity of metal-contaminated sediments from Keswick Reservoir, California, USA

    SciTech Connect

    Finlayson, B.; Fujimura, R.; Huang, Z.Z.

    2000-02-01

    Keswick Reservoir, California, USA, receives metal-laden acid-mine drainage (AMD) from the abandoned Iron Mountain Mine. Mixing of the AMD with reservoir water causes precipitation and deposition of metal-rich sludge in the reservoir. Hydroelectric generation activities can scour the sediments and mobilize trace metals cadmium, copper, and zinc into the water column, thus creating potentially toxic conditions to fish and aquatic invertebrates. Sediment samples collected from Keswick Reservoir in 1993 and 1994 were analyzed for acid-volatile sulfides and for simultaneously extractable metals (SEM), and whole sediments and sediment elutriates were tested for toxicity to rainbow trout (Oncorhynchus mykiss), amphipods (Hyalella azteca), and cladocerans (Ceriodaphnia dubia). Acid-volatile sulfide concentrations in the sediments were low (<10 {micro}mol/g H{sub 2}S), indicating that dissolved metals in the sediment pore water were not limited by sulfide. The SEM concentrations were generally high (up to 11 {micro}g/g Cd, 4,800 {micro}g/g Cu, and 1,600 {micro}g/g Zn, dry weight) in the sediments. Whole sediments and 20% w/w sediment elutriates from 16 sites were tested for toxicity. Low survival (as low as 0{degree}) in whole sediments was generally associated with copper and zinc, and to a lesser extent cadmium, concentrations that exceeded probable effect level values for freshwater sediments; survival also may have been influenced by low pH and alkalinity conditions. Low survival (as low as 0%) in sediment elutriates was also generally associated with higher concentrations of dissolved zinc. Further study is required to formulate sediment cleanup levels that are protective of fish and wildlife. Source control in the Iron Mountain Mine drainage will eventually significantly lessen the production of sediments.

  15. 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

  16. 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.

  17. Types of gas fluidization of cohesive granular materials

    NASA Astrophysics Data System (ADS)

    Valverde, Jose Manuel; Castellanos, Antonio

    2007-03-01

    Some years ago it was shown that gas-fluidized powders may transit from solidlike to fluidlike fluidization prior to bubbling, shedding light on a long-standing controversy on the nature of “homogeneous” fluidization. In this paper it is shown that some gas-fluidized powders may also transit from the fluidlike regime to elutriation, with full suppression of the bubbling regime. We provide a diagram that can be used to predict these types of fluidization exhibited by cohesive powders based on simple phenomenological equations in which particle aggregation due to attractive forces is a key ingredient.

  18. Mesenchymal precursor cells in the blood of normal individuals

    PubMed Central

    Zvaifler, Nathan J; Marinova-Mutafchieva, Lilla; Adams, Gill; Edwards, Christopher J; Moss, Jill; Burger, Jan A; Maini, Ravinder N

    2000-01-01

    Introduction: Adult human bone marrow contains a minority population of MSCs that contribute to the regeneration of tissues such as bone, cartilage, muscle, ligaments, tendons, fat, and stroma. Evidence that these MSCs are pluripotent, rather than being a mixture of committed progenitor cells each with a restricted potential, includes their rapid proliferation in culture, a characteristic morphology, the presence of typical marker proteins, and their consistent differentiation into various mesenchymal lineages. These attributes are maintained through multiple passages and are identifiable in individual stem cells. Aims: Since stem cells are present in both the bone marrow and other tissues, we thought it possible that cells with a similar appearance and pluripotent mesenchymal potential would be present in the blood. We applied techniques used successfully with marrow MSCs to identify similar cells in elutriation fractions of normal human blood. Methods: BMPCs were elutriated by diluting the buffy coats from 500 ml of anticoagulant-treated, platelet-depleted blood 1:4 in RPMI-1640 medium (RPMI) and layering 25-ml portions over 20 ml of Lymphoprep™. These samples were centrifuged at 2000 rpm for 20 min. The leukocyte-rich interface cells were collected, made up to 20 ml in RPMI, and separated by density-gradient centrifugation. The interface cells, now depleted of red blood cells, were collected, resuspended in 50 ml of sterile RMPI and 5% heat-inactivated FCS, and introduced into the sample line of the flow system of a Beckman JE-50 cell elutriator charged with elutriation buffer. The chamber was centrifuged at 25 000 rpm at 10°C and the flow rate adjusted to 12 ml/min. After about 150 ml had been collected, the flow rate was increased by 1 ml/min. Fractions nos. 1-6 (flow rates of 12-16 ml/min) contained most of the lymphocytes. Monocytes usually appeared in fractions 6 or 7 (as determined by flow cytometric analysis in a fluorescence-activated cell sorter

  19. Environmental Assessment/Section 404(b) Evaluation and Finding of no Significant Impact for the Main-Tenance Dredging of the Black Rock Harbor-Cedar Creek Federal Navigation Channel, Bridgeport, Connecticut.

    DTIC Science & Technology

    1982-07-01

    permits. The fill was placed intermittently since the early 1970’s and is part of an ongoing sand and gravel operation on this property and will...create a channel 18 feet deep for access to 0 & G’s shoreline property . The material will be dredged with a mechanical bucket dredge and will be disposed...Elutriate From , Water Sample Sediment Sample Water Sample Sediment Sample Watn EW-1-79 PE-1-79 EW-2-79 PE-2-79 E; Test Property Nitrite Nitrogen (N

  20. Changes in expression of murine alpha- and beta-globin genes during development

    SciTech Connect

    Popp, R.A.; D'Surney, S.J.; Wawrzyniak, C.J.

    1986-09-30

    Polyacrylamide gel isoelectric focusing was used to separate the multiple embryonic and adult hemoglobins in order to determine the relative amounts of the a1 and a/sup 2/ gene products in fetal mice of the Hba/sup c/ and Hba/sup g2/ haplotypes. In addition, centrifugal elutriation was used to separte the nucleated and non-nucleated red cells in order to determine the relative amounts of the b1/sup s2/ and b2/sup s/ gene products in each subpopulation of erythryocytes in fetal mice of the Hbb/sup s2/ haplotype. 22 refs., 2 figs.

  1. 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.

  2. 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.

  3. A non-optical real-time particle fallout monitor

    NASA Technical Reports Server (NTRS)

    Chuan, Raymond L.; Bowers, William D.

    1990-01-01

    The paper describes a size-selective fallout monitor that can be employed to assess the degradation of sensitive optical surfaces as well as facilitate the analysis of particle types. The device combines a vertical elutriator and a quartz crystal microbalance, and only particles greater than a specific size can pass through an upward laminar flow generated in the device. The larger particles cause a frequency shift in the crystal oscillator, thereby permitting the measurement of the fallout associated with the contamination of optical instruments.

  4. 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.

  5. 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.

  6. 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.

  7. Types of gas fluidization of cohesive granular materials.

    PubMed

    Valverde, Jose Manuel; Castellanos, Antonio

    2007-03-01

    Some years ago it was shown that gas-fluidized powders may transit from solid-like to fluid-like fluidization prior to bubbling, shedding light on a long-standing controversy on the nature of "homogeneous" fluidization. In this paper it is shown that some gas-fluidized powders may also transit from the fluid-like regime to elutriation, with full suppression of the bubbling regime. We provide a diagram that can be used to predict these types of fluidization exhibited by cohesive powders based on simple phenomenological equations in which particle aggregation due to attractive forces is a key ingredient.

  8. Trinity River Bottom Sediment Reconnaissance Study. Phase I. Plan of Work. Appendices,

    DTIC Science & Technology

    1976-11-30

    J-6 Nitrogen, Total Kjeldahl in Water and Standard Elutriate. . . . J-11 Nitrogen, Amonia in Bottom Sediments...Phosphate Buffer Solution pH 7.4: Dissolve 14.3 g anhydrous potassium dihydrogen phosphate, KH2 PO4 . and 68.8 g anhydrous dipotassium hydrogen phosphate...K2 HP0 4 , and dilute 1 liter with ammonia-free water. 3. 3 Boric Acid Solution: Dissolve 20 g anhydrous boric acid H 3BO 3 in ammonia-free water and

  9. 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.

  10. Sources and properties of natural organic matter (NOM) in water along the Dongjiang River (the Source of Hong Kong's drinking water) and toxicological assay of its chlorination by-products.

    PubMed

    Liang, Y; Hong, H C; Dong, L H; Lan, C Y; Han, B P; Wong, M H

    2008-05-01

    The Dongjiang River is the major source of the drinking water supply for Hong Kong and also other parts of the Pearl River Delta in China, and the deterioration in the water quality of this river and the excessive levels of trihalomethanes (THMs) in the tap water of some districts in Hong Kong have become a matter of public concern. The main objective of the present study is to investigate the distribution patterns of natural organic matter (NOM) and their association with THM production in the Dongjiang River. We examined the physicochemical and biological properties of the river water and the corresponding sediment elutriate collected from four sampling sites along the Dongjiang River from upstream to downstream and chlorination experiments were conducted. Algal bioassays were performed in order to test the chlorination effects. The results showed that: (1) upstream NOM was derived from terrestrial input, while that at mid- and downstream was most likely derived from phytoplankton; (2) phytoplankton is a major contributor to NOM in the sediments, whereas sediments seem to be the site for major microbial degradation of NOM, biogeochemical recycling of nutrients and a potential NOM pool for the overlaying water during sediment resuspension; (3) dissolved organic carbon (DOC) in surface water is a good indicator for THM production, whereas ultraviolet (UV) absorbance at 254 nm (UV(254)) is a better predictor for THM formation in the elutriates; (4) the bioassay results showed that toxic compounds other than THMs in the chlorinated water are the major factors causing algal growth inhibition.

  11. 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.

  12. 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.

  13. 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.

  14. Response of peripheral blood leucocytes to mitogenic factor(s) in porcine seminal plasma.

    PubMed

    Kovacs, D P; Tekpetey, F R; Armstrong, D T

    1994-04-01

    Porcine seminal plasma (PSP) contains a potent mitogenic substance capable of causing proliferation and extensive agglutination in cultured porcine peripheral blood leucocytes (PBL). In order to determine the specific leucocyte cell population affected by this mitogen, lymphocyte, monocyte and polymorphonuclear (PMN)-enriched cell fractions were separated from PBL and treated with increasing concentrations of PSP (1-8%, v/v). For monocyte cell populations enriched through elutriation and adherence to plastic, cell proliferation in response to PSP treatment was consistently higher than PSP-treated unfractionated PBL. Monocyte-depleted PBL and lymphocyte populations enriched through elutriation demonstrated a decrease in proliferation compared to PSP-treated unfractionated PBL. PMN populations separated from PBL by discontinuous Percoll gradient centrifugation were unresponsive to PSP. Agglutination was observed for the unfractionated PBL and each enriched cell population. These results demonstrate that PSP contains a potent mitogen which induces proliferation in monocyte-enriched cell populations and may reflect the potential of PSP to act as an immune regulator in the uterine environment during early embryo development and implantation.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  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 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.

  1. 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.

  2. 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.

  3. Chronic toxicity of tire and road wear particles to water- and sediment-dwelling organisms.

    PubMed

    Panko, Julie M; Kreider, Marisa L; McAtee, Britt L; Marwood, Christopher

    2013-01-01

    Tire and road wear particles (TRWP) consist of a complex mixture of rubber, and pavement released from tires during use on road surfaces. Subsequent transport of the TRWP into freshwater sediments has raised some concern about the potential adverse effects on aquatic organisms. Previous studies have shown some potential for toxicity for tread particles, however, toxicity studies of TRWP collected from a road simulator system revealed no acute toxicity to green algae, daphnids, or fathead minnows at concentrations up to 10,000 mg/kg under conditions representative of receiving water bodies. In this study, the chronic toxicity of TRWP was evaluated in four aquatic species. Test animals were exposed to whole sediment spiked with TRWP at concentrations up to 10,000 mg/kg sediment or elutriates from spiked sediment. Exposure to TRWP spiked sediment caused mild growth inhibition in Chironomus dilutus but had no adverse effect on growth or reproduction in Hyalella azteca. Exposure to TRWP elutriates resulted in slightly diminished survival in larval Pimephales promelas but had no adverse effect on growth or reproduction in Ceriodaphnia dubia. No other endpoints in these species were affected. These results, together with previous studies demonstrating no acute toxicity of TRWP, indicate that under typical exposure conditions TRWP in sediments pose a low risk of toxicity to aquatic organisms.

  4. 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.

  5. 5-Fluorouracil-radiation interactions in human colon adenocarcinoma cells

    SciTech Connect

    Buchholz, D.J.; Lepek, K.J.; Rich, T.A.

    1995-07-15

    The purpose of this investigation was to determine the effect of cellular proliferation and cell cycle stage on the ability of postirradiation 5-fluorouracil (5-FU) to radiosensitize cultured human colon adenocarcinoma Clone A cells. Cell survival curves were generated for irradiated: (a) log- and plateau-phase Clone A cells; and (b) Clone A cells separated by centrifugal elutriation into the various phases of the cell cycle; with and without postirradiation treatment with 100 {mu}g/ml 5-FU. Postirradiation treatment with 5-FU sensitized proliferating cells to a greater degree than it sensitized cells growing in plateau phase. The {beta} component of cell kill in log-phase cells was increased by a factor of 1.5 with a sensitizer enhancement ratio of 1.21 at the 0.01 survival level. Plateau-phase cells showed less radiosensitization (sensitizer enhancement ratio of 1.13 at the 0.01 survival level); however, there was a mild increase in both {alpha} and {beta} kill in plateau-phase cells. Elutriated G{sub 1} cells were the most radiosensitive, independent of treatment with 5-FU. The phase of the cell cycle had little effect on the ability of fluorouracil to radiosensitize Clone A cells. Proliferating cells are more susceptible to radiosensitization with 5-FU than plateau-phase cells are, but this effect appears to be independent of the phase of the cell cycle. 18 refs., 4 figs., 3 tabs.

  6. Dissolution of resin acids, retene and wood sterols from contaminated lake sediments.

    PubMed

    Meriläinen, Päivi; Lahdelma, Ilpo; Oikari, Laura; Hyötyläinen, Tarja; Oikari, Aimo

    2006-10-01

    The dissolution potency of hydrophobic resin acids (RAs), retene and wood sterols from sediments was studied. These wood extractives and their metabolites are sorbed from pulp and paper mill effluents to downstream sediments. With harmful components like these, sediments can pose a hazard to the aquatic environment. Therefore, sediment elutriates with water were produced under variable conditions (agitation rate and efficiency, time), and concentrations of the dissoluted compounds were analyzed. Both naturally contaminated field sediments and artificially spiked sediments were studied. By vigorous agitation RAs can be released fast from the sediment matrix and equilibrium reached within 3 days. Compared to RAs, desorption of retene from lake sediment was slower and did not completely reach equilibrium in 23 days. Sterols spiked to pristine sediment with a 33-day contact time desorbed faster than those associated authentically with industrial sediment of from a contaminated lake. Simulating the water turbulence adjacent to a sediment surface by low and high rate of agitation in the laboratory, an increase in the mixing rate after 43-day elutriation suddenly released a high amount of wood sterols. The results indicate wide variation between hazardous chemicals in their tendency to dissolution from sediment solids. Erosion and hydrology adjacent to the sediment surface, as well as risks from dredging activities of sediments, may expose lake biota to bioactive chemicals.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. Temporal order of gene replication in Chinese hamster ovary cells.

    PubMed Central

    Taljanidisz, J; Popowski, J; Sarkar, N

    1989-01-01

    To investigate the molecular basis of the regulatory mechanisms responsible for the orderly replication of the mammalian genome, we have developed an experimental system by which the replication order of various genes can be defined with relative ease and precision. Exponentially growing CHO-K1 cells were separated into populations representing various stages of the cell cycle by centrifugal elutriation and analyzed for cell cycle status flow cytometry. The replication of specific genes in each elutriated fraction was measured by labeling with 5-mercuri-dCTP and [3H]dTPP under conditions of optimal DNA synthesis after cell permeabilization with lysolecithin. Newly synthesized mercurated DNA from each elutriated fraction was purified by affinity chromatography on thiol-agarose and replicated with the large fragment of Escherichia coli DNA polymerase I by using [alpha-32P]dATP and random primers. The 32P-labeled DNA representative of various stages of the cell cycle was then hybridized with dot blots of plasmid DNA containing specific cloned genes. From these results, it was possible to deduce the nuclear DNA content at the time each specific gene replicated during S phase (C value). The C values of 29 genes, which included single-copy genes, multifamily genes, oncogenes, and repetitive sequences, were determined and found to be distributed over the entire S phase. Of the 28 genes studied, 19 had been examined by others using in vivo labeling techniques, with results which agreed with the replication pattern observed in this study. The replication times of nine other genes are described here for the first time. Our method of analysis is sensitive enough to determine the replication time of single-copy genes. The replication times of various genes and their levels of expression in exponentially growing CHO cells were compared. Although there was a general correlation between transcriptional activity and replication in the first half of S phase, examination of specific

  12. 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

  13. 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

  14. Dynamics and Deposits of Coignimbrite Plumes

    NASA Astrophysics Data System (ADS)

    Engwell, Samantha; de'Michieli Vitturi, Mattia; Esposti Ongaro, Tomaso; Neri, Augusto

    2014-05-01

    Fine ash in the atmosphere poses a significant hazard, with potentially disastrous consequences for aviation and, on deposition, health and infrastructure. Fine-grained particles form a large proportion of ejecta in Plinian volcanic clouds. However, another common, but poorly studied phenomena exists whereby large amounts of fine ash are injected into the atmosphere. Coignimbrite plumes form as material is elutriated from the top of pyroclastic density currents. The ash in these plumes is considerably finer grained than that in Plinian plumes and can be distributed over thousands of kilometres in the atmosphere. Despite their significance, very little is known regarding coignimbrite plume formation and dispersion, predominantly due to the poor preservation of resultant deposits. As a result, consequences of coignimbrite plume formation are usually overlooked when conducting hazard and risk analysis. In this study, deposit characteristics and numerical models of plumes are combined to investigate the conditions required for coignimbrite plume formation. Coignimbrite deposits from the Campanian Ignimbrite eruption (Magnitude 7.7, 39 ka) are well sorted and very fine, with a mode of between 30 and 50 microns, and a significant component of respirable ash (less than 10 microns). Analogous distributions are found for coignimbrite deposits from Tungurahua 2006 and Volcan de Colima (2004-2006), amongst others, regardless of magnitude, type or chemistry of eruption. These results indicate that elutriation processes are the dominant control on coignimbrite grainsize distribution. To further investigate elutriation and coignimbrite plume dynamics, the numerical plume model of Bursik (2001) is applied. Model sensitivity analysis demonstrates that neutral buoyancy conditions (required for the formation of the plume) are controlled by a balance between temperature and gas mass flux in the upper most parts of the pyroclastic density current. In addition, results emphasize the

  15. 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??.

  16. 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.

  17. Replication of alpha and beta globin DNA sequences occurs during early S phase in murine erythroleukemia cells.

    PubMed Central

    Epner, E; Rifkind, R A; Marks, P A

    1981-01-01

    Murine erythroleukemia cells (MELC) can be induced to express the characteristics of erythroid differentiation by a variety of agents. Previous studies indicate that an action of inducer, occurring during early S phase, may be critical to the expression of differentiated characteristics such as initiation of accumulation of newly synthesized alpha and beta globin mRNAs. In this investigation, the time of replication of globin genes in MELC was studied. DNA was isolated from synchronous populations of cells obtained by centrifugal elutriation. Newly replicated DNA sequences were prepared from synchronized cells cultured for 1 1/2 hr with 5-bromodeoxyuridine; bromodeoxyuridine-containing DNA was isolated by CsCl gradient centrifugation. By employing cloned probes for hybridization to newly synthesized DNA, it was found that alpha and beta globin gene sequences are replicated early in S phase, while ribosomal RNA gene sequences are replicated to about the same extent in early, middle, and late S phases. PMID:6942415

  18. The mandibular condylar growth center: separation and characterization of the cellular elements.

    PubMed

    Landesberg, R; Proctor, R L; Rosier, R N; Puzas, J E

    1995-01-01

    The developing mandibular condylar growth center consists of a number of histologically distinct cell types. There is an increase in cell volume that takes place from the condylar surface layer through the center of ossification, resulting in a disorganized, irregular cellular pattern. Consequently, the isolation and separation of the different cells from this tissue is difficult using standard methodologies. Countercurrent centrifugal elutriation, whereby cells are separated on the basis of size, was applied to bovine mandibular condylar growth center cells. The cell volume, alkaline phosphatase content, proteoglycan synthesis, and type X collagen synthesis all showed a positive correlation with increasing cell size. The largest cells had characteristics that are consistent with hypertrophic chondrocytes; the smallest cells, on the other hand, had many fibroblastic characteristics.

  19. Are antifouling paint particles a continuous source of toxic chemicals to the marine environment?

    PubMed

    Soroldoni, Sanye; Abreu, Fiamma; Castro, Ítalo Braga; Duarte, Fabio Andrei; Pinho, Grasiela Lopes Leães

    2017-05-15

    Antifouling paint particles (APPs) are generated during periodical maintenance of boat hulls. Chemical composition and toxicity (either chronic or acute) of APPs found in the sediment was evaluated using the epibenthic copepod Nitokra sp. The APPs analyzed showed the presence of high levels of metals such as Cu (234,247±268μgg(-1)), Zn (112,404±845μgg(-1)) and the booster biocide DCOIT (0.13μgg(-1)). Even at low concentrations (as from 5mgg(-1) of APPs by mass of sediment) a significantly decrease in the fecundity was observed in laboratory tests. When the sediment was disturbed in elutriate test, a LC50 of 0.14% for APPs was found. This study was the first assessment of toxicity associated with the presence of APPs in sediment to benthic organisms, and it calls attention to the need of improving regulations in boatyards and marina areas.

  20. 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.

  1. Comparative performances of eggs and embryos of sea urchin (Paracentrotus lividus) in toxicity bioassays used for assessment of marine sediment quality.

    PubMed

    Khosrovyan, A; Rodríguez-Romero, A; Salamanca, M J; Del Valls, T A; Riba, I; Serrano, F

    2013-05-15

    The potential toxicity of sediments from various ports was assessed by means of two different liquid-phase toxicity bioassays (acute and chronic) with embryos and eggs of sea urchin Paracentrotus lividus. Performances of embryos and eggs of P. lividus in these bioassays were compared for their interchangeable applicability in integrated sediment quality assessment. The obtained endpoints (percentages of normally developed plutei and fertilized eggs) were linked to physical and chemical properties of sediments and demonstrated dependence on sediment contamination. The endpoints in the two bioassays were strongly correlated and generally exhibited similar tendency throughout the samples. Therein, embryos demonstrated higher sensitivity to elutriate exposure, compared to eggs. It was concluded that these tests could be used interchangeably for testing toxicity of marine sediments. Preferential use of any of the bioassays can be determined by the discriminatory capacity of the test or vulnerability consideration of the test subject to the surrounding conditions.

  2. 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.

  3. 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.

  4. Assessment of coastal marine pollution in Galicia (NW Iberian Peninsula); metal concentrations in seawater, sediments and mussels (Mytilus galloprovincialis) versus embryo-larval bioassays using Paracentrotus lividus and Ciona intestinalis.

    PubMed

    Beiras, R; Bellas, J; Fernández, N; Lorenzo, J I; Cobelo-García, A

    2003-10-01

    Sediments from three Galician Rias were tested for toxicity using sea-urchin and ascidian sediment elutriate embryo-larval bioassays. Trace metal contents in seawater, sediments and mussels were also determined and subjected to multidimensional scaling methods which grouped stations according to chemical contamination. High metal contents were found in seawater, sediments and mussels from the Ria of Pontevedra, and moderate levels were detected in the Ria of Vigo and Ria of Arousa. The results revealed that samples assessed as toxic, according to the sea-urchin and ascidian embryo-larval bioassays, were among the most polluted by trace metals. A good agreement was reported between ordination plots resulting from applying multidimensional scaling to the chemical data, and the results of the biological endpoints tested.

  5. 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.

  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.

  7. New techniques for the detection of microplastics in sediments and field collected organisms.

    PubMed

    Claessens, Michiel; Van Cauwenberghe, Lisbeth; Vandegehuchte, Michiel B; Janssen, Colin R

    2013-05-15

    Microplastics have been reported in marine environments worldwide. Accurate assessment of quantity and type is therefore needed. Here, we propose new techniques for extracting microplastics from sediment and invertebrate tissue. The method developed for sediments involves a volume reduction of the sample by elutriation, followed by density separation using a high density NaI solution. Comparison of this methods' efficiency to that of a widely used technique indicated that the new method has a considerably higher extraction efficiency. For fibres and granules an increase of 23% and 39% was noted, extraction efficiency of PVC increased by 100%. The second method aimed at extracting microplastics from animal tissues based on chemical digestion. Extraction of microspheres yielded high efficiencies (94-98%). For fibres, efficiencies were highly variable (0-98%), depending on polymer type. The use of these two techniques will result in a more complete assessment of marine microplastic concentrations.

  8. Exposure to cotton dust in an experimental cardroom.

    PubMed Central

    Haglind, P; Rylander, R

    1984-01-01

    Changes in respiratory function (FEV1) and polymorphonuclear neutrophils (PMN) on nasal epithelium were studied in 68 students and 39 cotton mill workers in an experimental cardroom. The exposure was characterised by the vertical elutriator dust and endotoxin levels. A dose related decrease was found for FEV1 which was more pronounced in smoking workers. The thresholds for no FEV1 reaction were 0.58 mg/m3 dust and 0.17 micrograms/m3 endotoxin for students and 0.43 mg/m3 and 0.08 micrograms/m3 for smoking workers. The PMN increased in most of the experiments but no dose response relationship could be shown. In experiments with smoking workers or when washed cotton was carded a better correlation was obtained between FEV1 decrease and endotoxin levels than for dust levels. PMID:6743581

  9. 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.

  10. 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

  11. 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.

  12. Environmental assessment of physical/chemical impacts related to the dredging and disposal of spoil from the proposed trench tube crossing of the Anacostia River

    NASA Astrophysics Data System (ADS)

    Pine, F. W.; Yost, J. C.; Saul, S. W.; Wood, S. G.

    1981-03-01

    Environmental sampling and testing was conducted to identify specified chemical pollutants in river-bottom material to be dredged during construction of the Metro subway tube tunnel crossing of the Anacostia River. Constituent concentrations is sediments, elutriates, and surface waters at the site and defined and compared with federal, state, and District of Columbia criteria and guidelines to identify potential problem areas and to evaluate potential chemical and physical impacts of dredging and spoil disposal. The results indicate sediment-bound concentrations of chlordane, DDT and PCBs which fail to meet federal criteria. High surface water concentrations of iron and mercury were identified which would prevent regulatory compliances of dredging operations for these constituents. It was concluded that the dredging would be minimal. Potential impacts upon groundwater were identified, bur further analyses of hydrogeology at the proposed disposal sites would be needed to define the potential for problems.

  13. Sludge management modeling to enhance P-recovery as struvite in wastewater treatment plants.

    PubMed

    Martí, N; Barat, R; Seco, A; Pastor, L; Bouzas, A

    2017-03-15

    Interest in phosphorus (P) recovery and reuse has increased in recent years as supplies of P are declining. After use, most of the P remains in wastewater, making Wastewater Treatment Plants (WWTPs) a vital part of P recycling. In this work, a new sludge management operation was studied by modeling in order to recover P in the form of struvite and minimize operating problems due to uncontrolled P precipitation in WWTPs. During the study, intensive analytical campaigns were carried out on the water and sludge lines. The results identified the anaerobic digester as a "hot spot" of uncontrolled P precipitation (9.5 gP/kg sludge) and highlighted possible operating problems due to the accumulation of precipitates. A new sludge line management strategy was simulated therefore using DESASS(©) software, consisting of the elutriation of the mixed sludge in the mixing chamber, to reduce uncontrolled P precipitation and to obtain a P-rich stream (primary thickener supernatant) to be used in a crystallization process. The key operating parameters were found to be: the elutriation flow from the mixing chamber to the primary thickener, the digestion flow and the sludge blanket height of the primary thickener, with optimized values between 70 and 80 m(3)/d, 90-100 m(3)/d and 1.4-1.5 m, respectively. Under these operating conditions, the preliminary results showed that P concentration in the primary thickener overflow significantly increased (from 38 to 100 mg PO4-P/L), which shows that this stream is suitable for use in a subsequent crystallization reactor to recover P in the form of struvite.

  14. Functionally impaired, hypertrophic ECL cells accumulate vacuoles and lipofuscin bodies. An ultrastructural study of ECL cells isolated from hypergastrinemic rats.

    PubMed

    Zhao, C M; Bakke, I; Tostrup-Skogaker, N; Waldum, H L; Håkanson, R; Chen, D

    2001-03-01

    ECL cells in the oxyntic mucosa of stomach control gastric acid secretion by mobilizing histamine in response to gastrin. They respond to gastrin also with hypertrophy and hyperplasia. ECL cells exhibit functional impairment upon long-term gastrin stimulation. The impairment is manifested in a gradual decline of the activity of the histamine-forming enzyme per individual ECL cell and in a failure of gastrin to mobilize histamine. The mechanism behind this impairment is unknown. In the present study, rats were treated with the proton pump inhibitor pantoprazole for 45 days to induce sustained hypergastrinemia. The ECL cells were isolated from normogastrinemic and hypergastrinemic rats and size-separated from other mucosal cells by the elutriation technique. The total ECL cell number was twofold higher in hypergastrinemic rats than in normogastrinemic rats, and most of the cells appeared in elutriation fractions where large cells predominate. The ECL cells of the different fractions were analyzed by quantitative electron microscopy. Normal-sized ECL cells from hypergastrinemic rats displayed a reduced number of secretory vesicles (probably because of degranulation) compared with normal-sized ECL cells from normogastrinemic rats. Hypertrophic ECL cells from hypergastrinemic rats had an unchanged number of secretory vesicles, supporting the view that such cells fail to respond to gastrin with degranulation. Although both normal-sized and hypertrophic ECL cells from hypergastrinemic rats contained vacuoles, those in the hypertrophic ECL cells were larger and more numerous. In addition, hypertrophic ECL cells were found to contain numerous, prominent lipofuscin bodies which are the presumed end product of crinophagia. Conceivably therefore, large vacuoles and lipofuscin bodies cause functional impairment of the hypertrophic ECL cells.

  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. Filtration of nano-particles by a gas-solid fluidized bed.

    PubMed

    Liu, Kuang-Yu; Wey, Ming-Yen

    2007-08-17

    The filtration of 80 nm SiO2 and Al(2)O(3) particles in a gas stream using fluidized beds was studied. Silica sand and activated carbon (A.C.) were adopted as bed materials to filtrate 80 nm SiO2 and Al(2)O(3) particles. The collected particles were elutriated from the fluidized bed, so the filtration was a dynamic process and the variations of the removal efficiency with time were studied. Experimental results showed that the filtrations of 80 nm SiO2 and Al(2)O(3) particles with a bed material of silica sand were not dynamic processes but the filtration by A.C. was. The removal efficiencies for SiO2 and Al(2)O(3) particles using silica sand as bed material were held steady and found to be equal, between 86 and 93%. A.C. is considered to be more efficient than silica sand because it has a high specific surface area. However, the experimental data yield conflicting results. The removal efficiency of Al(2)O(3) particles fell from 92% initially to 80% at the end of test-a little lower than that obtained by filtration using silica sand. A higher voidage of A.C. than silica sand weakens the removal of nanoparticles since the diffusion mechanism dominates. The removal efficiency of SiO2 by A.C. decayed from 83 to 40% with time passed. The huge differences between the filtration efficiency of SiO2 and that of Al(2)O(3) particles by A.C. was associated with the extensive segregation of SiO2 and A.C. particles, which caused more SiO2 particles to move to the top of the bed, where they were elutriated. The weak inter-particle force for SiO2 decreased the removal efficiency also.

  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. 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.

  19. 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

  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. 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.

  2. Primitive stem cells derived from bone marrow express glial and neuronal markers and support revascularization in injured retina exposed to ischemic and mechanical damage.

    PubMed

    Goldenberg-Cohen, Nitza; Avraham-Lubin, Bat-Chen R; Sadikov, Tamilla; Goldstein, Ronald S; Askenasy, Nadir

    2012-06-10

    Ischemic or mechanical injury to the optic nerve is an irreversible cause of vision loss, associated with limited regeneration and poor response to neuroprotective agents. The aim of this study was to assess the capacity of adult bone marrow cells to participate in retinal regeneration following the induction of anterior ischemic optic neuropathy (AION) and optic nerve crush (ONC) in a rodent model. The small-sized subset of cells isolated by elutriation and lineage depletion (Fr25lin(-)) was found to be negative for the neuroglial markers nestin and glial fibrillary acidic protein (GFAP). Syngeneic donor cells, identified by genomic marker in sex-mismatched transplants and green fluorescent protein, incorporated into the injured retina (AION and ONC) at a frequency of 0.35%-0.45% after intravenous infusion and 1.8%-2% after intravitreous implantation. Perivascular cells with astrocytic morphology expressing GFAP and vimentin were of the predominant lineage that engrafted after AION injury; 10%-18% of the donor cells incorporated in the retinal ganglion cell layer and expressed NeuN, Thy-1, neurofilament, and beta-tubulin III. The Fr25lin(-) cells displayed an excellent capacity to migrate to sites of tissue disruption and developed coordinated site-specific morphological and phenotypic neural and glial markers. In addition to cellular reconstitution of the injured retinal layers, these cells contributed to endothelial revascularization and apparently supported remodeling by secretion of insulin-like growth factor-1. These results suggest that elutriated autologous adult bone marrow-derived stem cells may serve as an accessible source for cellular reconstitution of the retina following injury.

  3. 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.

  4. Marked Dependence on Growth State of Backup Pathways of NHEJ

    SciTech Connect

    Windhofer, Frank; Wu Wenqi; Wang, Minli; Singh, Satyendra K.; Saha, Janapriya; Rosidi, Bustanur; Iliakis, George . E-mail: Georg.Iliakis@uk-essen.de

    2007-08-01

    Purpose: Backup pathways of nonhomologous end joining (B-NHEJ) enable cells to repair DNA double-strand breaks (DSBs) when DNA-PK-dependent NHEJ (D-NHEJ) is compromised. Recent evidence implicates growth signaling in the regulation of D-NHEJ. This study was intended to determine whether the ability to repair DSBs by B-NHEJ also depends on growth state. Methods and Materials: LIG4 {sup -/-} and wild type (WT) mouse embryo fibroblasts (MEFs) were used. Repair of DSBs was measured by pulsed-field agarose gel electrophoresis. G1 cells were selected by centrifugal elutriation. A plasmid assay was used to measure DNA end-joining activity in whole cell extracts. Results: Wild-type MEFs efficiently repaired DSBs by D-NHEJ in either the exponential or plateau phase of growth. Because of their defect in ligase IV, which compromises D-NHEJ, LIG4 {sup -/-} MEFs showed reduced repair capacity but were slowly able to rejoin a large proportion of DSBs via B-NHEJ. B-NHEJ was markedly reduced in the plateau phase of growth or at high radiation doses. Elutriated G1 cells from exponentially growing or plateau-phase LIG4 {sup -/-} cultures showed a response similar to nonelutriated cells, ruling out that the effect simply reflects redistribution in the cell cycle. An in vitro assay, gauging the activity of B-NHEJ, showed a reduction in DNA end joining during the plateau phase that could be corrected by recombinant DNA ligase III{alpha}. Conclusions: Suppression of growth signaling markedly compromises DSB repair by B-NHEJ. This effect is associated with a reduction in DNA ligase III mediated DNA end joining.

  5. Variation in peperite textures associated with differing host-sediment properties

    NASA Astrophysics Data System (ADS)

    Busby-Spera, Cathy J.; White, James D. L.

    1987-12-01

    Peperites formed by mixing of magma and wet sediment are well exposed along Punta China, Baja California, Mexico, where two sills intrude a section of lava flows, limestones, and volcaniclastic rocks. Irregular lobes and dikes extend from the sills several meters into host sediments, including highly comminuted flow top breccias (lithic lapilli tuff breccias) and shelly micrites, whereas intrusive contacts with lava flows are sharp and planar. Where one sill intruded both coarse-grained volcaniclastic rock and fine-grained limestone, textural differences between the hosts produced strikingly different styles of peperite. Blocky masses of the basaltic intrusions up to 1 m in size were dispersed for distances up to 3 m into host lithic lapilli tuff breccias; the blocks consequently underwent in situ fragmentation as they were rapidly quenched. The high degree of dispersion resulted from steam explosions as the magma enveloped pockets of water in the coarse-grained permeable host. Elutriation of fine-grained material from vertical pipes in tuff breccia above the lower sill provides evidence for meter-scale fluidization of the host. The contact zone between the basaltic magma and the shelly micrite host resembles a mixture of two viscous, immiscible fluids (fluidal peperite). Intrusion occurred behind a stable vapor film which entrained lime mud particles and carried them off “grain by grain” as magma advanced into the host. Thin-section-scale elutriation pipes formed. Microglobular peperite represents a “frozen” example of a fuel-coolant interaction (FCI) between basaltic magma and fluidized micrite host. The intimate intermixing of magma and host at the submillimeter level is attributed to fluid instabilities developed along the magma-vapor-host interface. Such intimate intermixing of magma and water-bearing fragmental debris is commonly a precursory step toward explosive hydrovolcanism.

  6. Characterization of toxicants in urban road dust by Toxicity Identification Evaluation using ostracod Heterocypris incongruens direct contact test.

    PubMed

    Khanal, Rajendra; Furumai, Hiroaki; Nakajima, Fumiyuki

    2015-10-15

    The current study involves characterization of organic compounds, heavy metals, and ammonia as potential toxicants in one arterial road (St. 3) and two highway (St. 7 and 8) urban road dust (URD) collected in Tokyo, Japan. URD toxicity was evaluated by Toxicity Identification Evaluation using the ostracod Heterocypris incongruens direct contact test. URDs were treated with resins (10% XAD-4, 20% SIR-300 and 20% SIR-600) to determine the reduction in mortality after treatment. The mortality of ostracods exposed to St. 3 URD (baseline 80%) was significantly (p<0.05) reduced to 0% and 47% after XAD-4 and SIR-300 treatment respectively. This reduction led us to suspect hydrophobic organic compounds and heavy metals as potential toxicants. Subsequent elution of the recovered XAD-4 with polar (methanol, acetone) and non-polar (dichloromethane) solvents confirmed the dominance of relatively polar hydrophobic organic toxicants. The dissolved concentration of Cu and Zn after SIR-300 treatment exceeded the 50% lethal concentration (LC50) for ostracods, which led us to suspect Cu and Zn as other probable toxicants. The concentration of Zn in a SIR-300 acidic elutriate, recovered after the termination of toxicity test, confirmed Zn as one of the toxicants in St. 3. The baseline mortality (100%) of St. 7 was significantly reduced (23%) by SIR-300 treatment. This indicated the presence of heavy metals as the probable toxicant. However, the concentration of dissolved heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in the overlying water was below previously reported LC50 values for each metal in St. 7. Recovery of Zn concentrations exceeding the LC50 in the St. 7 SIR-300 elutriate led us to suspect a dietary exposure route of Zn to the ostracod during the direct contact test. The overall results indicate that the toxicant types can vary widely depending on the road sampled.

  7. 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

  8. Comparative study of different exposure routes on the biotransformation and genotoxicity of PAHs in the flatfish species, Scophthalmus maximus.

    PubMed

    Le Dû-Lacoste, Marie; Akcha, Farida; Dévier, Marie-Hélène; Morin, Bénédicte; Burgeot, Thierry; Budzinski, Hélène

    2013-02-01

    In this study, laboratory experiments were carried out in order to come to a better understanding of the fate of polycyclic aromatic hydrocarbons (PAHs) in the marine environment and especially on their bioaccumulation, biotransformation and genotoxic effects in fish. Juveniles of turbot (Scophthalmus maximus) were exposed to PAHs through different routes via (1) a mixture of dissolved PAHs, (2) a PAH-polluted sediment and (3) an oil fuel elutriate. Fish were exposed 4 days followed by a 6-day depuration period. In each experiment, PAH concentrations in the seawater of the tanks were analysed regularly by gas chromatography coupled with mass spectrometry. Muscle and liver samples were also analysed for parent PAH levels and PAH bioconcentration factors were calculated. Biotransformation was evaluated by measuring the levels of PAH metabolites in fish bile. Genotoxicity was assessed by the alkaline comet assay. Regardless of exposure route, the parent PAH concentrations in the liver and muscle showed a peak level 1 day after the beginning of the exposure, followed by a decrease up to the background level towards the end of the experiment, except for the exposure to dissolved PAHs for which levels were relatively low throughout the study. As a consequence, no bioaccumulation was observed in fish tissues at the end of the experiment. In contrast, regardless of exposure routes, a rapid production of biliary metabolites was observed throughout the whole exposure experiment. This was especially true for 1-hydroxypyrene, the major metabolite of pyrene. After 6 days of recovery in clean water, a significant decrease in the total metabolite concentrations occurred in bile. Fish exposed through either route displayed a significant increase in DNA strand breaks after 4 days of exposure, and significant correlations were observed between the level of biliary PAH metabolites and the level of DNA lesions in fish erythrocytes. Overall results indicate that exposure to either a

  9. Changes in the ecological properties of organic wastes during their biological treatment.

    PubMed

    Kuryntseva, P; Galitskaya, P; Selivanovskaya, S

    2016-12-01

    Organic wastes, such as the organic fractions of municipal solid waste (OFMSW) or sewage sludge (SS), have become a serious environmental problem in Russia as well as in other countries. The use of these wastes as soil amendments allows their negative impact on the environment to be minimized. However, before these wastes can be used, they need to be treated appropriately in order to decrease their level of hazard. In this study, composting of raw SS, OFMSW, a mixture of these two wastes (OFMSW+SS) at a ratio 1:2 as well as the anaerobically digested variants of these wastes (SSd, OFMSWd and OFMSWd+SSd) mixed with oiled sawdust was performed. Composting was conducted in the containers containing 20kg of the wastes. The results of three elutriate bioassays (with water flea Daphnia magna, infusoria Paramecium caudatum and radish plant, Raphanus sativus) and one contact bioassay (with oat plant Avena sativa) were used to indirectly estimate changes in the hazardous properties of the biological treatments. Besides, Corg, Ntot content and pH were analyzed in the process of composting. Within the study stability tests to determine maturation process completion were not carried out. It was revealed, that in the process of anaerobic pretreatment for 15days, the toxicity increased by a mean of 1.3-, 1.9- and 1.1-fold for OFMSW, SS and OFMSW+SS, respectively. During composting, the toxicity level of these pretreated samples decreased more rapidly as compared with those which were not pretreated. As a result, the toxicity levels of the elutriates from the final composts made of pretreated wastes OFMSW, SS and OFMSW+SS were three-, two- and 17-fold lower for D. magna and 15-, 21- and 12-fold lower for P. caudatum. As follows from phytotoxicity estimations, composts from digested substrates became mature on the 60th day and had a stimulation effect on the plants after the 90th day of incubation. For the composts prepared from raw substrates, a significantly longer period was

  10. Fine ash enrichment of fall deposits from explosive eruptions by co-PF ash: nature, significance and implications

    NASA Astrophysics Data System (ADS)

    Eychenne, Julia; Engwell, Samantha; Cashman, Katharine; Rust, Alison; Durant, Adam; Le Pennec, Jean-Luc

    2014-05-01

    Most highly explosive volcanic eruptions (Violent Strombolian, Subplinian to Plinian) are accompanied by the emplacement of pyroclastic flows (PF) and consequently the formation of co-pyroclastic flow (co-PF) elutriation plumes (Campanian Ignimbrite (39 ka BP), Pinatubo (15 June, 1991), Mount St Helens (18 May, 1980), Tungurahua (16 August 2006)). Similar to explosive plumes (i.e. produced at the vent), co-PF plumes can rise through the atmosphere to high altitudes (one of the 18 May, 1980 Mount St Helens co-PF plumes rose up to 30 km a.s.l.) and be transported downwind great distances (more than 2000 km for the Campanian Ignimbrite). Detailed analyses of the componentry and the morphology of the ash fractions (<90 µm) of Mount St Helens (18 May 1980) fall deposit and Tungurahua (16 August 2006) fall and co-PF deposits have been carried out in order to describe the nature of the ash entrained in co-PF plumes and to advance our understanding of the secondary fragmentation mechanisms leading to the formation of elutriated ash. The componentry distribution of the 18 May 1980 Mount St Helens fall deposit samples indicates that a substantial amount of the distal ash (> 150 km from the vent) comprises edifice-derived particles which were produced during the early stage of the eruption (blast and consecutive landslides) and consequently transported in co-PF plumes. Detailed grain size analyses of the August 2006 Tungurahua and Campanian Ignimbrite fall and co-PF deposits, along with a thorough compilation of published data from well constrained explosive eruptions, provide strong evidence that the fine ash enrichment of fall deposits from magmatic eruptions is related to synchronous sedimentation of co-PF ash. These data allow us to demonstrate the significant impact of fine ash incorporation on the physical characteristics of fall deposits (isopach shapes, grain size, density, volume, etc.) and hence on the determination of the style, magnitude and intensity of

  11. More on the dynamics of dust generation: the effects of mixing and sanding chrysotile, calcium carbonate, and other components on the characteristics of joint-compound dusts.

    PubMed

    Berman, D Wayne; Brorby, Gregory P; Sheehan, Patrick J; Bogen, Kenneth T; Holm, Stewart E

    2012-08-01

    An ongoing research effort designed to reconstruct the character of historical exposures associated with use of chrysotile-containing joint compounds naturally raised questions concerning how the character (e.g. particle size distributions) of dusts generated from use of recreated materials compares to dusts from similar materials manufactured historically. This also provided an opportunity to further explore the relative degree that the characteristics of dusts generated from a bulk material are mediated by the properties of the bulk material versus the mechanical processes applied to the bulk material by which the dust is generated. In the current study, the characteristics of dusts generated from a recreated ready mix and recreated dry mix were compared to each other, to dusts from a historical dry mix, and to dusts from the commercial chrysotile fiber (JM 7RF3) used in the recreated materials. The effect of sanding on the character of dusts generated from these materials was also explored. Dusts from the dry materials studied were generated and captured for analysis in a dust generator-elutriator. The recreated and historical joint compounds were also prepared, applied to drywall, and sanded inside sealed bags so that the particles produced from sanding could be introduced into the elutriator and captured for analysis. Comparisons of fiber size distributions in dusts from these materials suggest that dust from commercial fiber is different from dusts generated from the joint compounds, which are mixtures, and the differences persist whether the materials are sanded or not. Differences were also observed between sanded recreated ready mix and either the recreated dry mix or a historical dry mix, again whether sanded or not. In all cases, however, such differences disappeared when variances obtained from surrogate data were used to better represent the 'irreducible variation' of these materials. Even using the smaller study-specific variances, no differences were

  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. 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

    2000-04-03

    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

  14. Experiments on chemical looping combustion of coal with a NiO based oxygen carrier

    SciTech Connect

    Shen, Laihong; Wu, Jiahua; Xiao, Jun

    2009-03-15

    A chemical looping combustion process for coal using interconnected fluidized beds with inherent separation of CO{sub 2} is proposed in this paper. The configuration comprises a high velocity fluidized bed as an air reactor, a cyclone, and a spout-fluid bed as a fuel reactor. The high velocity fluidized bed is directly connected to the spout-fluid bed through the cyclone. Gas composition of both fuel reactor and air reactor, carbon content of fly ash in the fuel reactor, carbon conversion efficiency and CO{sub 2} capture efficiency were investigated experimentally. The results showed that coal gasification was the main factor which controlled the contents of CO and CH{sub 4} concentrations in the flue gas of the fuel reactor, carbon conversion efficiency in the process of chemical looping combustion of coal with NiO-based oxygen carrier in the interconnected fluidized beds. Carbon conversion efficiency reached only 92.8% even when the fuel reactor temperature was high up to 970 C. There was an inherent carbon loss in the process of chemical looping combustion of coal in the interconnected fluidized beds. The inherent carbon loss was due to an easy elutriation of fine char particles from the freeboard of the spout-fluid bed, which was inevitable in this kind of fluidized bed reactor. Further improvement of carbon conversion efficiency could be achieved by means of a circulation of fine particles elutriation into the spout-fluid bed or the high velocity fluidized bed. CO{sub 2} capture efficiency reached to its equilibrium of 80% at the fuel reactor temperature of 960 C. The inherent loss of CO{sub 2} capture efficiency was due to bypassing of gases from the fuel reactor to the air reactor, and the product of residual char burnt with air in the air reactor. Further experiments should be performed for a relatively long-time period to investigate the effects of ash and sulfur in coal on the reactivity of nickel-based oxygen carrier in the continuous CLC reactor

  15. Ash aggregation during the 11 February 2010 partial dome collapse of the Soufrière Hills Volcano, Montserrat

    NASA Astrophysics Data System (ADS)

    Burns, F. A.; Bonadonna, C.; Pioli, L.; Cole, P. D.; Stinton, A.

    2017-04-01

    On 11 February 2010, Soufrière Hills Volcano, Montserrat, underwent a partial dome collapse ( 50 × 106 m3) and a short-lived Vulcanian explosion towards the end. Three main pyroclastic units were identified N and NE of the volcano: dome-collapse pyroclastic density current (PDC) deposits, fountain-collapse PDC deposits formed by the Vulcanian explosion, and tephra-fallout deposits associated with elutriation from the dome-collapse and fountain-collapse PDCs (i.e. co-PDC fallout deposit). The fallout associated with the Vulcanian explosion was mostly dispersed E and SE by high altitude winds. All units N and NE of the volcano contain variable amounts and types of particle aggregates, although the co-PDC fallout deposit is associated with the largest abundance (i.e. up to 24 wt%). The size of aggregates found in the co-PDC fallout deposit increases with distance from the volcano and proximity to the sea, reaching a maximum diameter of 12 mm about 500 m from the coast. The internal grain size of all aggregates have nearly identical distributions (with Mdϕ ≈ 4-5), with particles in the size categories > 3 ϕ (i.e. < 250 μm) being distributed in similar proportions within the aggregates but in different proportions within distinct internal layers. In fact, most aggregates are characterized by a coarse grained central core occupying the main part of the aggregate, coated by a thin layer of finer ash (single-layer aggregates), while others have one or two additional layers accreted over the core (multiple-layer aggregates). Calculated aggregate porosity and settling velocity vary between 0.3 and 0.5 and 11-21 m s- 1, respectively. The aggregate size shows a clear correlation with both the core size and the size of the largest particles found in the core. The large abundance of aggregates in the co-PDC fallout deposits suggests that the buoyant plumes elutriated above PDCs represent an optimal environment for the formation (particle collision) and development

  16. 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.

  17. 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.

  18. 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.

  19. Separating mixed waste plastics in a flotation column

    SciTech Connect

    Biddulph, M.W.; Chow, P.S.; Cloke, M.

    1996-12-31

    This paper describes efforts to develop a continuous separation technique for mixed waste plastics to facilitate subsequent recycling. Selective wetting of the surfaces is used as the separating criterion, and Critical Surface Tension values for various commercial plastic materials have been determined. This has demonstrated the feasibility of the technique. Although the technique has been applied using solvent systems, the method investigated here is the use of surface active agents. Previously batch systems have been reported, but the development of a continuous process requires a much better understanding of dynamic surface tension effects. Detailed studies of the effects of air bubble size and particle size have been made using very high speed video techniques. From these observations, the collision behavior of a bubble against the plastic surface was found to be markedly affected by bubble size, impact velocity, roughness of surface and the surface tension of the surfactant solution, and permanent adhesion to the surface required a contact time for film thinning, rupturing and forming the contact angle. The experiments demonstrated the desirability of small bubbles and low impact velocities. Recovery was influenced significantly by particle size. Actual separations have been achieved in a bench top apparatus, and extended to a water elutriator 4.3 metres in height and 15 cm diameter. A mathematical model has been fitted to the behavior of particles in the column, and the effective axial diffusivity is quite similar to the {open_quotes}free stream{close_quotes} single fluid values. 10 refs., 7 figs.

  20. Genome-Wide Screen for Haploinsufficient Cell Size Genes in the Opportunistic Yeast Candida albicans

    PubMed Central

    Chaillot, Julien; Cook, Michael A.; Corbeil, Jacques; Sellam, Adnane

    2016-01-01

    One of the most critical but still poorly understood aspects of eukaryotic cell proliferation is the basis for commitment to cell division in late G1 phase, called Start in yeast and the Restriction Point in metazoans. In all species, a critical cell size threshold coordinates cell growth with cell division and thereby establishes a homeostatic cell size. While a comprehensive survey of cell size genetic determinism has been performed in the saprophytic yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, very little is known in pathogenic fungi. As a number of critical Start regulators are haploinsufficient for cell size, we applied a quantitative analysis of the size phenome, using elutriation-barcode sequencing methodology, to 5639 barcoded heterozygous deletion strains of the opportunistic yeast Candida albicans. Our screen identified conserved known regulators and biological processes required to maintain size homeostasis in the opportunistic yeast C. albicans. We also identified novel C. albicans-specific size genes and provided a conceptual framework for future mechanistic studies. Interestingly, some of the size genes identified were required for fungal pathogenicity suggesting that cell size homeostasis may be elemental to C. albicans fitness or virulence inside the host. PMID:28040776

  1. Sediment acute toxicity testing utilizing short-term bioassays

    SciTech Connect

    Campbell, M.G.

    1991-01-01

    The purpose of this study was to investigate the usefulness of two new bioassays for acute toxicity assessments of sediments. A bacterial bioassay based on inhibition of alpha-glucosidase biosynthesis in Bacillus licheniformis and a 48-hour lethality bioassay employing the benthic cladoceran, Chydorus sphaericus. were evaluated by direct comparisons with standard bioassays, using sediment samples collected from various sites in Florida. This study showed that the bioassay based on inhibition of alpha-glucosidase biosynthesis in Bacillus licheniformis was useful in the acute toxicity screening of sediment elutriates. In regards to Escambia County, Florida samples, the assay was comparable with the Microtox assay and was especially sensitive for samples containing metals. To determine an appropriate procedure for assessing hydrophobic contaminants of sediments in the B. licheniformis bioassay, two extracting procedures were compared. Based on the responses in the Microtox bioassay, shaking sediment samples in methylene chloride produced extracts that were significantly higher in toxicity than extracts obtained by sonication for eight of the ten sediment samples tested. Comparisons of methanol and dimethyl sulfoxide (DMSO) as exchange solvents revealed that there was generally no significant difference between these solvents in terms of toxicity in the Microtox assay. Solvent extracts prepared by shaking and exchanged into methanol showed lower toxicity in the B. licheniformis bioassay than in the Microtox assay. Observed sediment toxicity in both bioassays was expressed in terms of the equivalent dry weight concentration of sediment causing 50% inhibition of the assay organism.

  2. An integrated approach to the toxicity assessment of Irish marine sediments: validation of established marine bioassays for the monitoring of Irish marine sediments.

    PubMed

    Macken, Ailbhe; Giltrap, Michelle; Foley, Barry; McGovern, Evin; McHugh, Brendan; Davoren, Maria

    2008-10-01

    This paper describes the ecotoxicological evaluation of marine sediments from three sites around Ireland representative of a range of contaminant burdens. A comprehensive assessment of potential sediment toxicity requires the consideration of multiple exposure phases. In addition to the evaluation of multi-exposure phases the use of a battery of multi-trophic test species has been advocated by a number of researchers as testing of single or few organisms may not detect toxicants with a specific mode of action. The Microtox solid phase test (SPT) and the 10-d acute amphipod test with Corophium volutator were used to assess whole sediment toxicity. Porewater and elutriates were assessed with the Microtox acute test, the marine prasinophyte Tetraselmis suecica, and the marine copepod Tisbe battagliai. Solvent extracts were assayed with the Microtox and T. battagliai acute tests. Alexandra Basin was identified as the most toxic site according to all tests, except the Microtox SPT which identified the Dunmore East site as being more toxic. However, it was not possible to correlate the observed ecotoxicological effects with a specific and/or class of contaminants based on sediment chemistry alone. Therefore porewaters found to elicit significant toxicity (Dunmore East and Alexandra Basin) with the test battery were selected for further TIE assessment with T. battalgiai and the Microtox system. The results of this study have important implications for risk assessment in estuarine and coastal waters in Ireland, where, at present the monitoring of sediment and water quality is predominantly reliant on chemical analysis alone.

  3. 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.

  4. 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

  5. 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.

  6. Potential for chemical transport beneath a storm-runoff recharge (retention) basin for an industrial catchment in Fresno, California

    USGS Publications Warehouse

    Schroeder, R.A.

    1995-01-01

    A wide variety of chemicals from urban runoff were found at elevated concentrations in sediment that accumulated in a storm-runoff recharge basin in an industrial part of the city of Fresno. The chemicals include as many as 20 inorganic elements and about the same number of organic compounds, primarily organochlorine pesticides and polycyclic aromatic hydrocarbons. Most of these contaminants were found to be sorbed to the upper 4 centimeters of sediment, which also is the maximum depth to which atmospheric lead-210 penetrated. None of the contaminants were detected above background concentrations in the sediment at depths greater than 16 centimeters. In shallow sediment, zinc is the inorganic element that showed the greatest enrichment; its concentration was 38 times higher in surface sediment (0-1 centimeter) than in deeper strata (below 16 centi- meters). Organic carbon enrichment in the surface sediment was nearly 1,000 times. Although batch- elutriation experiments demonstrated the potential for leaching of contaminants attached to sediments, a sharp decrease in concentrations with increasing sediment depth, and the extremely low level of contaminants in two monitor wells adjacent to the basin, confirmed the absence of contaminant transport to the water table. Continued long-term protection for ground water is afforded by an approximately 8-meter-thick unsaturated zone beneath the basin. On the basis of its hundredfold-higher concentration in the recharge pond then in ground water, zinc is indicated as the most sensitive surrogate for monitoring possible ground-water degradation by inorganic cations.

  7. 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.

  8. Steric stabilization of microspheres with grafted polyethylene oxide reduces phagocytosis by rat Kupffer cells in vitro.

    PubMed

    Harper, G R; Davies, M C; Davis, S S; Tadros, T F; Taylor, D C; Irving, M P; Waters, J A

    1991-09-01

    Sterically stabilized polyethylene oxide-polystyrene copolymer microspheres, (PS-PEO) and charge stabilized polystyrene (PS) microspheres of similar size (1 micron) were prepared in order to compare their uptake by cultured rat Kupffer cells isolated by centrifugal elutriation. The uptake of the sterically stabilized particles was found to be much less than that for the charge stabilized control. The uptake of microspheres stabilized with covalently grafted PEO was lower or equivalent to that of control microspheres stabilized by the adsorption of the non-ionic PEO-polypropylene oxide (PPO-PEO) surfactant Poloxamer 238 or Methoxy-PEO. Phagocytic uptake by Kupffer cells at low and body temperature (8 degrees C and 37 degrees C) demonstrated that PS-PEO particles showed both low adherence and low metabolic uptake. The adsorption of PEO, as Poloxamer 238, to particles with covalently attached or grafted PEO resulted in a synergistic reduction in uptake that was greater than the individual effects of grafting and adsorption alone (P less than or equal to 0.001). It is suggested that this combination produces a more effective steric barrier on the particle surface with the Poloxamer adsorbing to the surface between the grafted PEO chains. The relevance to drug targeting/carrier systems is discussed.

  9. Histamine-stimulated phosphorylation of gastric parietal cell proteins

    SciTech Connect

    Chew, C.S.; Brown, M.R.

    1987-05-01

    Parietal cells from rabbit gastric mucosa respond to histamine with increased HCl secretion. Histamine also increases cAMP and activates cAMP-dependent protein kinase(s) in these cells. cAMP analogues and forskolin appear to mimic these effects. More recently histamine and forskolin but not cAMP-stimulated increases in (Ca/sup 2 +/)/sub i/ have been detected in parietal cells enriched to 98 +/- 2% (n=10) purity using a combined Nycodenz density gradient/centrifugal elutriation technique. In the present experiments parietal cells were loaded with /sup 32/P to label ATP pools then stimulated with histamine or chlorophenylthio-cAMP plus the H/sub 2/ receptor antagonist, cimetidine. Total cell extracts were separated via 2D-gel electrophoresis and analyzed with a Masscomp computer and PDQuest software. Results indicate that histamine stimulates phosphorylation of at least two proteins with molecular weights 49 and 33 kDa and respective pI's of 6.4 and 6.0. Changes in phosphorylation are detected within 1 min of stimulation and remain elevated for at least 15 min. No change in specific activity of samples was detected during this time. A third protein also showed increased phosphorylation but the response appeared more transient. They conclude that histamine increases phosphorylation of several parietal cell proteins via a cAMP-dependent mechanism. The relationship between changes in phosphorylation and onset of HCl secretion remains to be determined.

  10. 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.

  11. The use of cryopreserved sea urchin embryos (Paracentrotus lividus) in marine quality assessment.

    PubMed

    Paredes, E; Bellas, J

    2015-06-01

    We have established for first time an ecotoxicological bioassay using cryopreserved sea urchin embryos (Paracentotus lividus) and provided a comparison to the already standardized sea urchin embryo-larval bioassay, using selected (organic and inorganic) pollutants and sediment elutriates from 4 different locations from Ria de Vigo harbour (Galicia, NW Iberian Peninsula). A cryopreservation protocol was designed in order to enable the successful cryopreservation and cryobanking of gametes and embryos to be used for marine quality assessment and ensure the accessibility to high quality reproductive material all year round, as an option to conditioning adults for out of season reproduction. The calculated EC50 using the cryopreserved blastula was 53.7 μg L(-1) for copper, 81.0 μg L(-1) for lead, 300.6 μg L(-1) for BP-3 and 300.6 μg L(-1) for 4-MBC. The sensitivity of the classic sea urchin embryo-larval bioassay was compared with the bioassay conducted with cryopreserved blastula. The results showed that the use of cryopreserved blastula bioassay allows detecting lower concentrations of pollutants in comparison with the classic bioassay.

  12. 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.

  13. Chromatin Association of Human Origin Recognition Complex, Cdc6, and Minichromosome Maintenance Proteins during the Cell Cycle: Assembly of Prereplication Complexes in Late Mitosis

    PubMed Central

    Méndez, Juan; Stillman, Bruce

    2000-01-01

    Evidence obtained from studies with yeast and Xenopus indicate that the initiation of DNA replication is a multistep process. The origin recognition complex (ORC), Cdc6p, and minichromosome maintenance (MCM) proteins are required for establishing prereplication complexes, upon which initiation is triggered by the activation of cyclin-dependent kinases and the Dbf4p-dependent kinase Cdc7p. The identification of human homologues of these replication proteins allows investigation of S-phase regulation in mammalian cells. Using centrifugal elutriation of several human cell lines, we demonstrate that whereas human Orc2 (hOrc2p) and hMcm proteins are present throughout the cell cycle, hCdc6p levels vary, being very low in early G1 and accumulating until cells enter mitosis. hCdc6p can be polyubiquitinated in vivo, and it is stabilized by proteasome inhibitors. Similar to the case for hOrc2p, a significant fraction of hCdc6p is present on chromatin throughout the cell cycle, whereas hMcm proteins alternate between soluble and chromatin-bound forms. Loading of hMcm proteins onto chromatin occurs in late mitosis concomitant with the destruction of cyclin B, indicating that the mitotic kinase activity inhibits prereplication complex formation in human cells. PMID:11046155

  14. Circulating megakaryocytes: delivery of large numbers of intact, mature megakaryocytes to the lungs.

    PubMed

    Levine, R F; Eldor, A; Shoff, P K; Kirwin, S; Tenza, D; Cramer, E M

    1993-10-01

    To determine the locus of platelet production, we sought to determine if sufficient megakaryocytes reach the lungs in a state that could produce platelets. Elutriation was used to isolate megakaryocytes from blood reaching and leaving the lungs of 20 patients undergoing routine cardiac catheterizations. A mean of 5.0 intact megakaryocytes/ml were found in pulmonary artery blood, compared to only 0.5 megakaryocytes/ml, with partial cytoplasmic content, in aortic samples. The megakaryocytes in central venous and aortic samples were all mature. The identity of these cells as megakaryocytes, their maturity and normal morphology were confirmed by standard and immunoelectron microscopy. Cardiac outputs were obtained for each patient at the time of blood sampling, allowing an extrapolation that 40 x 10(6) intact, mature megakaryocytes were being delivered to the lungs every day in the average patient, compared to only 4.0 x 10(6) partially spent megakaryocytes exiting the lungs daily. About 98% of megakaryocyte cytoplasm reaching the lungs did not exit as recognizable megakaryocytes or fragments. The number and state of the megakaryocytes apparently filtered in the lungs is consistent with the hypothesis that megakaryocytes may shed platelets within the pulmonary microvasculature, which may be the primary site of platelet production.

  15. The Redox Status of Cancer Cells Supports Mechanisms behind the Warburg Effect

    PubMed Central

    da Veiga Moreira, Jorgelindo; Hamraz, Minoo; Abolhassani, Mohammad; Bigan, Erwan; Pérès, Sabine; Paulevé, Loïc; Levy Nogueira, Marcel; Steyaert, Jean-Marc; Schwartz, Laurent

    2016-01-01

    To better understand the energetic status of proliferating cells, we have measured the intracellular pH (pHi) and concentrations of key metabolites, such as adenosine triphosphate (ATP), nicotinamide adenine dinucleotide (NAD), and nicotinamide adenine dinucleotide phosphate (NADP) in normal and cancer cells, extracted from fresh human colon tissues. Cells were sorted by elutriation and segregated in different phases of the cell cycle (G0/G1/S/G2/M) in order to study their redox (NAD, NADP) and bioenergetic (ATP, pHi) status. Our results show that the average ATP concentration over the cell cycle is higher and the pHi is globally more acidic in normal proliferating cells. The NAD+/NADH and NADP+/NADPH redox ratios are, respectively, five times and ten times higher in cancer cells compared to the normal cell population. These energetic differences in normal and cancer cells may explain the well-described mechanisms behind the Warburg effect. Oscillations in ATP concentration, pHi, NAD+/NADH, and NADP+/NADPH ratios over one cell cycle are reported and the hypothesis addressed. We also investigated the mitochondrial membrane potential (MMP) of human and mice normal and cancer cell lines. A drastic decrease of the MMP is reported in cancer cell lines compared to their normal counterparts. Altogether, these results strongly support the high throughput aerobic glycolysis, or Warburg effect, observed in cancer cells. PMID:27706102

  16. 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.

  17. Pollutant Concentrations and Toxic Effects on the Red Alga Ceramium tenuicorne of Sediments from Natural Harbors and Small Boat Harbors on the West Coast of Sweden.

    PubMed

    Eklund, Britta; Hansson, Tomas; Bengtsson, Henrik; Eriksson Wiklund, Ann-Kristin

    2016-04-01

    This investigation set out to analyze the toxicity of surface sediments in a number of natural harbors and small boat harbors on the west coast of Sweden. This was done with the growth inhibition method with Ceramium tenuicorne. Also, concentrations of copper (Cu), lead (Pb), zinc (Zn), irgarol, organotin compounds, and polycyclic aromatic hydrocarbons (PAHs) in the sediments were analyzed. The small boat harbors were heavily polluted by Cu, Zn, butyltins, and PAHs, and to a lesser extent by Pb. The Cu, Pb, Zn, and butyltins probably originated from their past and/or present use in antifouling paints, whereas the PAHs probably had multiple sources, including boat motor exhausts. The measured toxicity of the sediment was generally related to their Cu, Zn, and butyltin content, although other toxic substances than those analyzed here probably contributed to the toxicity in some of the harbors. The natural harbor sediments contained less pollutants and were less toxic than the small boat harbor sediments. Nevertheless, our data indicate that the boating pressure today may be high enough to produce toxic effects even in natural harbors in pristine areas. The strongest relationship between toxicity and the major pollutants was obtained when the sediment toxicity was expressed as gram wet weight per liter compared with gram dry weight per liter and gram total organic carbon per liter. Hence, for pollutants that can be elutriated with natural sea water, sediment toxicity expressed as gram wet weight per liter appears preferable.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

    2014-01-09

    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.

  3. Comprehensive Identification of Cell Cycle–regulated Genes of the Yeast Saccharomyces cerevisiae by Microarray HybridizationD⃞

    PubMed Central

    Spellman, Paul T.; Sherlock, Gavin; Zhang, Michael Q.; Iyer, Vishwanath R.; Anders, Kirk; Eisen, Michael B.; Brown, Patrick O.; Botstein, David; Futcher, Bruce

    1998-01-01

    We sought to create a comprehensive catalog of yeast genes whose transcript levels vary periodically within the cell cycle. To this end, we used DNA microarrays and samples from yeast cultures synchronized by three independent methods: α factor arrest, elutriation, and arrest of a cdc15 temperature-sensitive mutant. Using periodicity and correlation algorithms, we identified 800 genes that meet an objective minimum criterion for cell cycle regulation. In separate experiments, designed to examine the effects of inducing either the G1 cyclin Cln3p or the B-type cyclin Clb2p, we found that the mRNA levels of more than half of these 800 genes respond to one or both of these cyclins. Furthermore, we analyzed our set of cell cycle–regulated genes for known and new promoter elements and show that several known elements (or variations thereof) contain information predictive of cell cycle regulation. A full description and complete data sets are available at http://cellcycle-www.stanford.edu PMID:9843569

  4. Integrative assessment of marine pollution in Galician estuaries using sediment chemistry, mussel bioaccumulation, and embryo-larval toxicity bioassays.

    PubMed

    Beiras, R; Fernández, N; Bellas, J; Besada, V; González-Quijano, A; Nunes, T

    2003-08-01

    An integrative assessment of environmental quality was carried out in selected sites along the Galician coast (NW Iberian Peninsula) combining analytical chemistry of seawater and sediments, bioaccumulation in the marine mussel, and embryo-larval sediment toxicity bioassays, in order to link biological and chemical criteria for the assessment of coastal pollution. Maximum values of Hg and Cu in seawater, sediment and mussels, were found in the inner part of Ria of Pontevedra, while maximum levels of organics (polychlorinated biphenyls, hexachlorobenzene and aldrin) were found in mussels from A Coruña. Outstanding values of Cu, Pb and Zn have been found in seawater and sediment from a single site, P3, which also was the most toxic in the embryo-larval bioassays performed with four different phyla of marine organisms: mollusks, echinoderms, arthropods and chordates. Sediment quality effects range-median values provided a valuable reference to predict biological effects from sediment chemistry data, while effects range-low values were too conservative. Sediment toxicity could also be predicted by using a toxic-unit model based on published EC50 values for trace metals and mobilization factors independently obtained from measurements of metal contents in sediments and their elutriates. When chemical and toxicological data are independently used to arrange sampling sites by using non-metric multidimensional scaling, a remarkable degree of concordance between both types of configurations could be observed.

  5. 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.

  6. Discrimination of hot versus cold avalanche deposits: Implications for hazard assessment at Mount Meager, B.C.

    NASA Astrophysics Data System (ADS)

    Stewart, M. L.; Russell, J. K.; Hickson, C. J.

    The surficial deposits surrounding the Mount Meager volcanic complex include numerous avalanche deposits. These deposits share many attributes: (a) they are nearly monolithologic and comprise mainly intermediate volcanic rock clasts, (b) they lack internal structure, and (c) they are very poorly sorted. Despite these similarities, the avalanche deposits represent two distinct processes. Mass wasting of the Mount Meager volcanic edifice has produced cold rock avalanche deposits, whereas gravitational collapse of active lava domes and flows has produced hot block and ash avalanche deposits. The ability to discriminate between these "hot" and "cold" avalanche deposits is a critical component in the assessment of hazards in volcanic terranes. Hot block and ash avalanche deposits can be distinguished by the presence of radially-oriented joints, breadcrust textures, and incipient welding, which are features indicative of high emplacement temperatures. Conversely, rock avalanche deposits resulting from mass wasting events may be distinguished by the presence of clasts that preserve pre-depositional weathering and jointing surfaces. Volcanic avalanches are mechanically similar to rock avalanches but pose a greater hazard due to high temperatures, increased fluidization from degassing and the potential to decouple highly mobile elutriated ash clouds. The increasing use of hazardous regions such as the Lillooet River valley requires more reliable risk assessment in order to minimize losses from future hazardous events.

  7. Environmental assessment of the compounds from creosote-treated pilings in marine environment

    SciTech Connect

    Jop, K.M.; Butala, J.H.; Webb, D.A.; Wade, T.L.

    1995-12-31

    A comprehensive ecological risk assessment was conducted to evaluate the environmental impact of creosote-treated pilings in the marine environment at Moss Landing Harbor, Moss Landing, California. The chemical composition of creosote is critical to its fate and effects in the environment. Therefore, a multiple-stage methodology utilizing column gas chromatography with mass spectrometer detector was used for the identification and quantification of polycyclic aromatic hydrocarbons (PAHs) in neat creosote and environmental samples. The risk assessment of 46 PAHs (water soluble fraction) in the marine environment was based on bioaccumulation studies with caged mussels Mytilus californianus and a testing program with the surface sheen, water column, sediment elutriate, pore waters and bulk sediment. Water samples were evaluated using 7-day chronic exposures with Mysidopsis bahia, while bulk sediments were evaluated with 10-day tests with Ampelisca abdita. Testing program included exposure to normal and UV fluorescent lights. The results of this environmental assessment program allow to characterize the extent and magnitude of toxicity of PAHs released from creosote treated pilings and the risk associated with using creosote in marine environment.

  8. 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

  9. Relevance of density, size and DNA content of tumour cells to the lung colony assay.

    PubMed Central

    Grdina, D. J.; Hittelman, W. N.; White, R. A.; Meistrich, M. L.

    1977-01-01

    Mouse fibrosarcoma tumours were dissociated and divided into subpopulations of viable cells by centrifugation in linear density gradients of Renografin. Two of these subpopulations, designated Band 2 and Band 4, differed in their clonogenic ability in lung colony assay. The less dense Band 2 cells were significantly more clonogenic than the Band 4 cells (2.9 percent vs 1.4 percent respectively). Each band was further separated on the basis of cell size by centrifugal elutriation. Each size class of cells comprising Band 2 showed higher clonogenic ability than the corresponding size class in Band 4. Thus cell size differences were not responsible for the clonogenic differences between these bands. To determine whether cell-cycle distribution of the tumour cells was responsible for differences in cloning efficiency, flow microfluorometric and premature chromosome condensation methods were utilized. The unseparated and Band 4 populations showed a higher percentage of cells in S and G2 than did the Band 2 populations, but many of the S and G2 tumour cells showed extensive chromosome damage. From this study we conclude that the increased clonogenic ability of the lighter tumour cells is not due to differences in cell size or cell-cycle parameters. Images Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:563726

  10. 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.

  11. 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.

  12. Ecotoxicological effects of sediments from Mar Piccolo, South Italy: toxicity testing with organisms from different trophic levels.

    PubMed

    Costa, Elisa; Piazza, Veronica; Gambardella, Chiara; Moresco, Roberto; Prato, Ermelinda; Biandolino, Francesca; Cassin, Daniele; Botter, Margherita; Maurizio, Daniela; D'Adamo, Raffaele; Fabbrocini, Adele; Faimali, Marco; Garaventa, Francesca

    2016-07-01

    The Mar Piccolo of Taranto (Ionian Sea, Southern Italy) is a semi-enclosed and strongly polluted basin. For decades, it has been subjected to different anthropogenic impacts. These stressors caused severe sediments contamination with high concentration of different pollutants (PAHs, PCB, heavy metals). In order to assess the current status of sediments contamination, an ecotoxicological investigation combined with chemical analysis (heavy metals, PAH, and PCB) has been performed. In order to derive ecologically relevant conclusions, a multiorganisms and multiend-points approach has been applied, exposing organisms from different trophic levels to elutriate and whole sediment. The battery of bioassays consists of a microalgal growth inhibition test (Dunaliella tertiolecta), acute and sublethal assays (end-points: mortality, immobilization and swimming speed alteration) on crustaceans larvae and juveniles, and rotifers (Amphibalanus amphitrite, Artemia salina, Corophium insidiosum and Brachionus plicatilis), and embryotoxicity test on echinoderms (Paracentrotus lividus). Considering the high levels of sediment contamination highlighted from chemical analysis, an unexpected very low toxic effect was observed, even considering the sublethal end-point (larval swimming speed alteration). The results of this study suggest a very complex contaminants dynamic in the Mar Piccolo sediments that, despite a strong level of contamination, seems to not affect in a proportional manner the biological compartment.

  13. Phagocytes in cell suspensions of human colon mucosa.

    PubMed Central

    Beeken, W; Northwood, I; Beliveau, C; Gump, D

    1987-01-01

    Because little is known of the phagocytes of the human colon we enumerated these cells in mucosal suspensions and studied their phagocytic activity. Phagocyte rich suspensions were made by EDTA collagenase dissociation followed by elutriation centrifugation. Phagocytosis was evaluated by measuring cellular radioactivity after incubation of phagocytes with 3H-adenine labelled E coli ON2 and checked microscopically. Dissociation of normal mucosa from colorectal neoplasms yielded means of 1.9 X 10(6) eosinophils, 1.4 X 10(6) macrophages and 2 X 10(5) neutrophils per gram of mucosa. Visually normal mucosa of inflammatory states yielded 2.2 X 10(6) eosinophils, 2.3 X 10(6) macrophages and 7 X 10(5) neutrophils per gram of mucosa. Phagocyte rich suspensions of normal mucosa from tumour patients phagocytosed 21.8% of a pool of opsonised tritiated E coli ON2 and by microscopy 100% of mucosal neutrophils ingested bacteria, 83% of eosinophils were phagocytic, and 53% of macrophages contained bacteria. These results suggest that in the human colonic mucosa, the eosinophil is more abundant than the macrophage and the per cent of those cells exhibiting phagocytosis is intermediate between that of the macrophage and the neutrophil. Thus these three types of cells are actively phagocytic and share the potential for a major role in host defence against invasive enteric bacteria. PMID:3666566

  14. Ecotoxicity monitoring of hydrocarbon-contaminated soil during bioremediation: a case study.

    PubMed

    Hubálek, Tomás; Vosáhlová, Simona; Matejů, Vít; Kovácová, Nora; Novotný, Cenek

    2007-01-01

    The ecotoxicity of hydrocarbon-contaminated soil originating from a brownfield site was evaluated during a 17-month biodegradation pilot test. The initial concentration of total petroleum hydrocarbons (TPHs) in the soil was 6380 microg/g dry weight. An amount of 200 kg soil was inoculated with 1.5 L of the bacterial preparation GEM-100 containing Pseudomonas sp. and Acinetobacter sp. strains (5.3 x 10(10) CFU.mL(-1)) adapted to diesel fuel. The concentration of TPHs in the soil decreased by 65.5% after bioremediation. Different organisms such as the bacterium Vibrio fischeri, terrestrial plants Sinapis alba, Lactuca sativa, and Hordeum vulgare, the water plant Lemna minor, the earthworm Eisenia fetida, and the crustacean Heterocypris incongruens were used for ecotoxicity evaluation. The highest toxicity was detected in the first period of bioremediation. However, certain toxic effects were detectable during the whole bioremediation process. The contact tests with plants, earthworms, and crustaceans were the most sensitive of all of the bioassays. Therefore, the contact tests performed directly on soil samples were shown to be a better tool for ecotoxicity evaluation of hydrocarbon-contaminated soil than the tests performed on soil elutriates. The ecotoxicity measured by the responses of the tests did not always correlate with the decrease in TPH concentrations in the soil during bioremediation.

  15. 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.

  16. 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

  17. Characterization of the natural suppressor cell population in adult rat bone marrow.

    PubMed

    Noga, S J; Wagner, J E; Horwitz, L R; Donnenberg, A D; Santos, G W; Hess, A D

    1988-03-01

    Natural suppressor cell activity (NSCA) has been ascribed to a subset of cells present in human and murine hematopoietic tissues which can suppress a variety of lymphocyte responses without MHC restriction. We investigated NSCA in lymphocyte-depleted rat bone marrow (BM) which is used as a model for prevention of graft vs host disease (GVHD) following allogeneic BM transplantation (BMT). The T-cell depleted fraction obtained after elutriation contained higher levels of NSCA than the unseparated BM. Further separation of this graft fraction by discontinuous Percoll gradient centrifugation revealed high levels of radiosensitive NSCA in the low density (less than 1.070) fraction which represented 0.5% of the original BM population. These cells were of blast morphology, stained intensely with a dansylated derivative of cyclosporine A (dans CsA) and weakly expressed macrophage/granulocyte antigens and non-specific esterase (NSE). These cells were initially non-adherent but proliferated in culture to produce intensely NSE positive, adherent, phagocytic cells of macrophage morphology. We conclude that the highly suppressive, radiosensitive cell present in rat BM may be of early progenitor or monocyte lineage. The grafting of natural suppressor (NS) cells and progenitor cells may affect graft/host immunoregulation and their characterization may provide insight into GVH biology and graft rejection.

  18. Influence of starch on microalgal biomass recovery, settleability and biogas production.

    PubMed

    Gutiérrez, Raquel; Ferrer, Ivet; García, Joan; Uggetti, Enrica

    2015-06-01

    In the context of wastewater treatment with microalgae cultures, coagulation-flocculation followed by sedimentation is one of the suitable options for microalgae harvesting. This process is enabled by the addition of chemicals (e.g. iron). However, in a biorefinery perspective, it is important to avoid possible contamination of downstream products caused by chemicals addition. The aim of this study was to evaluate the effect of potato starch as flocculant for microalgal biomass coagulation-flocculation and sedimentation. The optimal flocculant dose (25mg/L) was determined with jar tests. Such a concentration led to more than 95% biomass recovery (turbidity<9NTU). The settleability of flocs was studied using an elutriation apparatus measuring the settling velocities distribution. This test underlined the positive effect of starch on the biomass settling velocity, increasing to >70% the percentage of particles with settling velocities >6.5m/h. Finally, biochemical methane potential tests showed that starch biodegradation increased the biogas production from harvested biomass.

  19. 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.

  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. T Cell Receptor-induced Activation and Apoptosis In Cycling Human T Cells Occur throughout the Cell Cycle

    PubMed Central

    Karas, Michael; Zaks, Tal Z.; JL, Liu; LeRoith, Derek

    1999-01-01

    Previous studies have found conflicting associations between susceptibility to activation-induced cell death and the cell cycle in T cells. However, most of the studies used potentially toxic pharmacological agents for cell cycle synchronization. A panel of human melanoma tumor-reactive T cell lines, a CD8+ HER-2/neu-reactive T cell clone, and the leukemic T cell line Jurkat were separated by centrifugal elutriation. Fractions enriched for the G0–G1, S, and G2–M phases of the cell cycle were assayed for T cell receptor-mediated activation as measured by intracellular Ca2+ flux, cytolytic recognition of tumor targets, and induction of Fas ligand mRNA. Susceptibility to apoptosis induced by recombinant Fas ligand and activation-induced cell death were also studied. None of the parameters studied was specific to a certain phase of the cell cycle, leading us to conclude that in nontransformed human T cells, both activation and apoptosis through T cell receptor activation can occur in all phases of the cell cycle. PMID:10588669

  2. Magnetic fabrics of the Miocene ignimbrites from West-Cameroon: Implications for pyroclastic flow source and sedimentation

    NASA Astrophysics Data System (ADS)

    Gountié Dedzo, M.; Nédélec, A.; Nono, A.; Njanko, T.; Font, E.; Kamgang, P.; Njonfang, E.; Launeau, P.

    2011-06-01

    The Miocene ignimbrites of Mounts Bambouto and Bamenda located in the central part of Cameroon Volcanic Line are generally made of welded and non-welded massive lapilli tuff and lithic breccias. These discontinuous deposits cover a total area of 180 km 2 with thickness ranging from 25 to 200 m. The different facies contain several lithic fragments of mainly trachytic nature. The devitrified matrix of the welded ignimbrites is constituted by sanidine, anorthoclase, quartz, plagioclase, clinopyroxene, biotite, Fe-Ti oxides and devitrified fiammes. Anisotropy of magnetic susceptibility (AMS) is used to characterize magnetic fabrics and to provide an estimate of flow direction of each ignimbrite sheet. Magnetic mineralogy results from different flow units show that titanomagnetite, titanohematite, maghemite and goethite with grain size ranging from coarse MD to very fine SP are the main magnetic carriers of these ignimbrites. Inferred transport directions based on the AMS data and field indicators show that Bambouto caldera is the source of main pyroclastic deposits of Mount Bambouto. In southwestern Mount Bamenda, Santa-Mbu caldera or Bambouto caldera constituted the probable emission center of Mbengwi, Bamenda and Mbu ignimbrite sheets, whereas magnetic fabrics of Bambili, Sabga and Big Babanki ignimbrites demonstrate that these deposits were emitted from a northeastern source, namely Oku vent in Mount Oku. A small number of subvertical AMS fabrics correspond to rocks possibly modified by an elutriation process.

  3. 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.

  4. Response of a salt marsh microbial community to antibiotic contamination.

    PubMed

    Fernandes, Joana P; Almeida, C Marisa R; Basto, M Clara P; Mucha, Ana P

    2015-11-01

    Salt marsh plants and associated microorganisms can have an important role in contaminant removal from estuaries, through bioremediation processes. Nevertheless, the interaction between emerging contaminants, namely antibiotics, and plant-microorganism associations in estuarine environment are still scarcely known. In this vein, the aim of the present study was to evaluate, in controlled conditions, the response of a salt marsh plant-microorganism association to a contamination with a veterinary antibiotic. For that a salt marsh plant (Phragmites australis) and its respective rhizosediment were collected in a temperate estuary (Lima estuary, NW Portugal) and exposed for 7 days to enrofloxacin (ENR) under different nutritional conditions in sediment elutriates. Response was evaluated in terms of ENR removal and changes in microbial community structure (evaluated by ARISA) and abundance (estimated by DAPI). In general, no significant changes were observed in microbial abundance. Changes in bacterial richness and diversity were observed but only in unplanted systems. However, multivariate analysis of ARISA profiles showed significant effect of both the presence of plant and type of treatment on the microbial community structure, with significant differences among all treatment groups. In addition, plants and associated microorganisms presented a potential for antibiotic removal that, although highly dependent on their nutritional status, can be a valuable asset to recover impacted areas such as estuarine ones.

  5. 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.

  6. 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

  7. Determination of volatile fatty acids in wastewater by solvent extraction and gas chromatography

    NASA Astrophysics Data System (ADS)

    Mkhize, Nontando T.; Msagati, Titus A. M.; Mamba, Bhekie B.; Momba, Maggy

    The purpose of this study was to develop a liquid-liquid extraction method for the analysis of volatile fatty acids collected at the elutriation units of Unit 3, 4 and 5 at Johannesburg Water-Northern Works Wastewater Treatment Plant. Liquid-liquid extraction (LLE) method employing dichloromethane (DCM) and methyl-tert-butyl-ether (MTBE) as extracting solvents was used during the quantitative analysis of volatile fatty acids namely acetic, propionic, butyric, isobutyric, valeric, isovaleric and heptanoic acid. The detection of the extracts was by gas chromatography coupled to a mass spectrometer operating under electron ionization mode (GC-EI-MS). The results showed that MTBE was a better extraction solvent than DCM as it gave much higher recoveries (>5 folds). On the other hand, the overall reactor performance for all the three units in the period when the samples were collected, which was measured by the ratio of propionic to acetic acid was good since the ratio o did not exceed 1.4 with the exception of the samples collected on the 3rd of October where the ratio exceeded 1.4 significantly. The concentration of acetic acid, another indicator for the reactor performance in all three units was way below 800 mg/L thus the digester balance was on par.

  8. Particulate Formation from a Copper Oxide-Based Oxygen ...

    EPA Pesticide Factsheets

    Attrition behavior and particle loss of a copper oxide-based oxygen carrier from a methane chemical looping combustion (CLC) process was investigated in a fluidized bed reactor. The aerodynamic diameters of most elutriated particulates, after passing through a horizontal settling duct, range between 2 and 5 μm. A notable number of submicron particulates are also identified. Oxygen carrier attrition was observed to lead to increased CuO loss resulting from the chemical looping reactions, i.e., Cu is enriched in small particles generated primarily from fragmentation in the size range of 10-75 μm. Cyclic reduction and oxidation reactions in CLC have been determined to weaken the oxygen carrier particles, resulting in increased particulate emission rates when compared to oxygen carriers without redox reactions. The generation rate for particulates < 10 μm was found to decrease with progressive cycles over as-prepared oxygen carrier particles and then reach a steady state. The surface of the oxygen carrier is also found to be coarsened due to a Kirkendall effect, which also explains the enrichment of Cu on particle surfaces and in small particles. As a result, it is important to collect and reprocess small particles generated from chemical looping processes to reduce oxygen carrier loss. The redox reactions associated with chemical looping combustion play an important role in particle attrition in the fluidized bed. Reaction-induced local stresses, due to the r

  9. 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.

  10. Two sites on P-selectin (the lectin and epidermal growth factor-like domains) are involved in the adhesion of monocytes to thrombin-activated endothelial cells.

    PubMed Central

    Murphy, J F; McGregor, J L

    1994-01-01

    P-selectin, also known as GMP-140, PADGEM or CD62, is expressed on the surface of thrombin-activated platelets and endothelial cells (EC). It is a member of the selectin family of adhesion molecules that regulate leucocyte interactions with the blood vessel wall. In this study we have found that peptides derived from both the lectin (residues 19-34 and 51-61) and epidermal growth factor (EGF)-like (residues 127-139) domains inhibit the adhesion of peripheral blood mononuclear cells (PBMC), elutriated monocytes and a monocytic cell line (U937) to thrombin-activated EC. This inhibition occurred in a concentration-dependent manner and the peptide most active at the lowest concentrations was the one derived from the EGF-like motif (127-139). The scrambled forms of these peptides, identical in amino acid composition to the authentic peptides but with altered sequences, were not inhibitory. Thrombin-activated platelets supported adhesion of U937 cells and this adhesion was dramatically inhibited by the two peptides derived from the lectin-like domain (residues 19-34 and 51-61). All three peptides, when conjugated to BSA and coated on plastic plates, mediated U937 cell adhesion. This study shows, for the first time, that two sites on P-selectin, the lectin and EGF-like domains, are involved in the adhesion of monocytes to thrombin-activated EC. PMID:7526845

  11. An S-phase specific release from a transcriptional block regulates the expression of mouse ribonucleotide reductase R2 subunit.

    PubMed Central

    Björklund, S; Skogman, E; Thelander, L

    1992-01-01

    Ribonucleotide reductase (RR) activity in mammalian cells is closely linked to DNA synthesis. The RR enzyme is composed of two non-identical subunits, proteins R1 and R2. Both proteins are required for holoenzyme activity, which is regulated by S-phase specific de novo synthesis and breakdown of the R2 subunit. In quiescent cells stimulated to proliferate and in elutriated cell populations enriched in the various cell cycle phases the R2 protein levels are correlated to R2 mRNA levels that are low in G0/G1-phase cells but increase dramatically at the G1/S border. Using an R2 promoter-luciferase reporter gene construct we demonstrate an unexpected early activation of the R2 promoter as cells pass from quiescence to proliferation. However, due to a transcriptional block, this promoter activation only results in very short R2 transcripts until cells enter the S-phase, when full-length R2 transcripts start to appear. The position for the transcriptional block was localized to a nucleotide sequence approximately 87 bp downstream from the first exon/intron boundary by S1 nuclease mapping of R2 transcripts from modified in vitro nuclear run-on experiments. These results identify blocking of transcription as a mechanism to control cell cycle regulated gene expression. Images PMID:1464320

  12. 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.

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

    PubMed

    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 1 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.

  14. 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.

  15. 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

  16. The Performance of Available Approaches for Quantifying Airborne Exposure to Asbestos Generated from Natural Deposits

    NASA Astrophysics Data System (ADS)

    Berman, D.

    2012-12-01

    General options for quantifying airborne (exposure) concentrations to asbestos include (1) direct measurement, (2) simulation, and (3) emission/dispersion modeling (of measured asbestos concentrations in the source material). Suitable options for particular applications depend on whether one is evaluating current or future and short-term episodic or long-term average exposures. Moreover, because the character and the magnitude of exposure must both be determined for many applications, methods suitable for air- or bulk-phase measurements must exhibit appropriate performance. After all, it is only when we understand precisely what exposure estimates represent that we can interpret them meaningfully. What is known about the suitability and performance of various options for quantifying asbestos exposures generated from natural deposits will be reviewed in this talk with particular emphasis on an approach in which emission and dispersion of asbestos-containing dusts are modeled from bulk-phase measurements collected using the modified elutriator method (a method designed explicitly for this particular application).

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

    PubMed

    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.

  18. Particulate Formation from a Copper Oxide-Based Oxygen Carrier in Chemical Looping Combustion for CO2 Capture.

    PubMed

    He, Feng; Linak, William P; Deng, Shuang; Li, Fanxing

    2017-02-21

    Attrition behavior and particle loss of a copper oxide-based oxygen carrier from a methane chemical looping combustion (CLC) process was investigated in a fluidized bed reactor. The aerodynamic diameters of most elutriated particulates, after passing through a horizontal settling duct, range between 2 and 5 μm. A notable number of submicrometer particulates are also identified. Oxygen carrier attrition was observed to lead to increased CuO loss resulting from the chemical looping reactions, i.e., Cu is enriched in small particles generated primarily from fragmentation in the size range of 10-75 μm. Cyclic reduction and oxidation reactions in CLC have been determined to weaken the oxygen carrier particles, resulting in increased particulate emission rates when compared to those of oxygen carriers without redox reactions. The generation rate for particulates <10 μm was found to decrease with progressive cycles over as-prepared oxygen carrier particles and then reach a steady state. The surface of the oxygen carrier is also found to be coarsened due to a Kirkendall effect, which also explains the enrichment of Cu on particle surfaces and in small particles.

  19. 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.

  20. Nematode Assemblages in Native Plant Communities of Molokai, Hawaii

    PubMed Central

    Bernard, E. C.; Schmitt, D. P.

    2005-01-01

    Four native plant community types (in decreasing elevation: montane bog, rain forest, wet mesic forest, drier forest) on Molokai were sampled for nematodes. Six samples of 10 cores each were gathered from each community. Nematodes were extracted from 200 cm³ soil by elutriation. All extracted nematodes were counted and identified to species-level taxa. Sixty-seven species were identified among the four plant communities; only eight species occurred in all four communities. Species diversity and evenness were greater in the rain forest and mesic forest than in the bog and the drier forest, but the drier forest and mesic forest had similar species communities. The bog nematode community was not similar to the other three sites. In a presence/absence cluster analysis, all six bog sample assemblages clustered together. The rain forest samples also clustered together but were associated with the mesic forest sample closest to the rain forest edge. Of 11 nematode orders collected, Tylenchida accounted for 40% to 73% of all individuals, followed by Dorylaimida (5% to 17%). Diplogasterida were absent. No plant-parasitic nematodes of known Hawaiian agricultural importance or occurrence were collected in these native plant communities. Calculated nematode densities (76,000 to 321,300/m²) were comparable to those reported for some other Pacific tropical forests. PMID:19262867

  1. Evidence that ferritin is associated with light production in the mucus of the marine worm Chaetopterus

    PubMed Central

    Rawat, Renu; Deheyn, Dimitri D.

    2016-01-01

    The blue glow of the mucus from Chaetopterus involves a photoprotein, iron and flavins. Identity and respective role of these components remain, however, largely unresolved today, likely because of viscosity issues and inhibition of this system by oxidizers conventionally used to track bioluminescence activity. Here, we used gentle centrifugation to obtain a mucus supernatant showing no inhibition to oxidizers, allowing for further analysis. We applied conventional chromatographic techniques to isolate major proteins associated with light emission. Luminescence ability of elutriate fractions was tested with hydrogen peroxide to track photoprotein and/or protein-bound chromophore. Fractions producing light contained few major proteins, one with similarity to ferritin. Addition to the mucus of elements with inhibitory/potentiary effect on ferritin ferroxidase activity induced corresponding changes in light production, emphasizing the possible role of ferritin in the worm bioluminescence. DNA of the protein was cloned, sequenced, and expressed, confirming its identity to a Chaetopterus Ferritin (ChF). Both ferric and ferrous iron were found in the mucus, indicating the occurrence of both oxidase and reductase activity. Biochemical analysis showed ChF has strong ferroxidase activity, which could be a source of biological iron and catalytic energy for the worm bioluminescence when coupled to a reduction process with flavins. PMID:27830745

  2. 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

  3. Generation of a conditionally immortalized myeloid progenitor cell line requiring the presence of both interleukin-3 and stem cell factor to survive and proliferate.

    PubMed

    Lee, Candy; Evans, Caroline A; Spooncer, Elaine; Pierce, Andrew; Mottram, Rachel; Whetton, Anthony D

    2003-09-01

    The H-2Kappab temperature-sensitive (ts) A58 transgenic (Immorto) mouse has been used previously to generate conditionally immortalized cells from a number of tissues. The present study aimed to investigate characteristics of primitive myeloid precursor cells derived from H-2Kappab-tsA58 bone marrow. Cell populations were enriched for granulocyte/macrophage progenitors by centrifugal elutriation, and were cultured in the presence and absence of cytokines at the permissive and restrictive temperatures for the A58 oncogene. Cells derived from H-2Kappab-tsA58 mice required both A58 activation and the growth factors, stem cell factor (SCF) and interleukin-3 (IL-3), for long-term cell survival and growth; cells were maintained for > 300 d in culture under these conditions. IL-3- and SCF-dependent clonal cell lines were derived with a phenotype (lin-, Sca-1+, CD34+, ER-MP 58+, ER-MP 12+, ER-MP 20-) characteristic of primitive myeloid progenitors. These cells differentiated on addition of granulocyte/macrophage colony-stimulating factor (GM-CSF) or macrophage colony-stimulating factor (M-CSF) and acquired mature cell morphology with some upregulation of differentiation markers. In conclusion, the A58 oncogene can immortalize haemopoietic progenitor cells. These cells require two cytokines for growth, IL-3 and SCF; as such, they constitute a useful resource for the study of synergistic interactions between growth factors. The ability to develop monocytic cell characteristics also permits the investigation of cytokine-mediated early haemopoietic progenitor cell development.

  4. Uncoordinated expression of fibrinogen compared with thrombospondin and von Willebrand factor in maturing human megakaryocytes.

    PubMed

    Cramer, E M; Debili, N; Martin, J F; Gladwin, A M; Breton-Gorius, J; Harrison, P; Savidge, G F; Vainchenker, W

    1989-04-01

    The localization of three known alpha-granule proteins, thrombospondin (TSP), von Willebrand factor (vWF), and fibrinogen (Fg) has been studied in human megakaryocytes (MK) by immunofluorescence and immunoelectron microscopy. For this study, highly purified populations of MK were prepared from human bone marrow either by counterflow centrifugal elutriation or by cell culture from normal subjects and from two patients with megakaryoblastic leukemia. In normal bone marrow immature MK, TSP, and vWF were observed in the Golgi-associated vesicles and in small immature alpha-granules; in mature MK, they were found in the matrix of the mature large alpha-granules. Surprisingly, Fg was detected neither in the Golgi area, nor in the small precursors of alpha-granules; it was only found in the mature alpha-granules but this labeling was generally weaker than in blood platelets. In order to confirm these differences between the expression of Fg and vWF or TSP additional studies were performed on cultured maturing MK: immunofluorescent and ultrastructural immunogold labeling confirmed that vWF appeared early in the maturation while the same immature MK were negative for Fg. In the late maturation stage, the three proteins were detected in the alpha-granules. In order to know whether Fg was lately synthesized or endocytosed from the outside medium, normal MK were grown in the presence of either normal or afibrinogenemic plasma, and normal serum. Fg was detected only in the alpha-granules of MK grown in normal plasma. Similar results were observed with malignant MK, whose maturation was independent of the culture conditions. In conclusion, this study brings immunocytochemical evidence that vWF and TSP are synthesized by immature MK, whereas Fg appears later in the MK alpha-granules and its expression is dependent of the presence of an exogenous Fg source.

  5. Monocyte to Macrophage Differentiation Goes along with Modulation of the Plasmalogen Pattern through Transcriptional Regulation

    PubMed Central

    Wallner, Stefan; Grandl, Margot; Konovalova, Tatiana; Sigrüner, Alexander; Kopf, Thomas; Peer, Markus; Orsó, Evelyn; Liebisch, Gerhard; Schmitz, Gerd

    2014-01-01

    Background Dysregulation of monocyte-macrophage differentiation is a hallmark of vascular and metabolic diseases and associated with persistent low grade inflammation. Plasmalogens represent ether lipids that play a role in diabesity and previous data show diminished plasmalogen levels in obese subjects. We therefore analyzed transcriptomic and lipidomic changes during monocyte-macrophage differentiation in vitro using a bioinformatic approach. Methods Elutriated monocytes from 13 healthy donors were differentiated in vitro to macrophages using rhM-CSF under serum-free conditions. Samples were taken on days 0, 1, 4 and 5 and analyzed for their lipidomic and transcriptomic profiles. Results Gene expression analysis showed strong regulation of lipidome-related transcripts. Enzymes involved in fatty acid desaturation and elongation were increasingly expressed, peroxisomal and ER stress related genes were induced. Total plasmalogen levels remained unchanged, while the PE plasmalogen species pattern became more similar to circulating granulocytes, showing decreases in PUFA and increases in MUFA. A partial least squares discriminant analysis (PLS/DA) revealed that PE plasmalogens discriminate the stage of monocyte-derived macrophage differentiation. Partial correlation analysis could predict novel potential key nodes including DOCK1, PDK4, GNPTAB and FAM126A that might be involved in regulating lipid and especially plasmalogen homeostasis during differentiation. An in silico transcription analysis of lipid related regulation revealed known motifs such as PPAR-gamma and KLF4 as well as novel candidates such as NFY, RNF96 and Zinc-finger proteins. Conclusion Monocyte to macrophage differentiation goes along with profound changes in the lipid-related transcriptome. This leads to an induction of fatty-acid desaturation and elongation. In their PE-plasmalogen profile macrophages become more similar to granulocytes than monocytes, indicating terminal phagocytic differentiation

  6. Atmospheric fluidized bed combustion of municipal solid waste: test program results

    SciTech Connect

    Preuit, L C; Wilson, K B

    1980-05-01

    Air classified municipal solid waste (MSW) was fired in an atmospheric fluidized bed combustor at low excess air to simulate boiler conditions. The 7 ft/sup 2/ combustor at Combustion Power Company's energy laboratory in Menlo Park, CA, incorporates water tubes for heat extraction and recycles elutriated particles to the bed. System operation was stable while firing processed MSW for the duration of a 300-h test. Low excess air, low exhaust gas emissions, and constant bed temperature demonstrated feasibility of steam generation from fluidized bed combustion of MSW. During the 300-h test, combustion efficiency averaged 99%. Excess air was typically 44% while an average bed temperature of 1400/sup 0/F and an average superficial gas velocity of 4.6 fps were maintained. Typical exhaust emission levels were 30 ppM SO/sub 2/, 160 ppM NO/sub x/, 200 ppM CO, and 25 ppM hydrocarbons. No agglomeration of bed material or detrimental change in fluidization properties was experienced. A conceptual design study of a full scale plant to be located at Stanford University was based on process conditions from the 300-h test. The plant would produce 250,000 lb/hr steam at the maximum firing rate of 1000 tons per day (TPD) processed MSW. The average 800 TPD firing rate would utilize approximately 1200 TPD raw MSW from surrounding communities. The Stanford Solid Waste energy Program was aimed at development of a MSW-fired fluidized bed boiler and cogeneration plant to supply most of the energy needs of Stanford University.

  7. 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.

  8. Transcriptomes of purified gastric ECL and parietal cells: identification of a novel pathway regulating acid secretion.

    PubMed

    Lambrecht, Nils W G; Yakubov, Iskandar; Zer, Cindy; Sachs, George

    2006-03-13

    The gastric entero-chromaffin-like (ECL) cell plays a key regulatory role in peripheral regulation of acid secretion due to the release of histamine that stimulates acid secretion by the parietal cell. Studies in intact animals, gastric glands, and isolated cells after short-term culture have shown expression of stimulatory CCK2 and PAC1 and inhibitory SST2 and Gal1 receptors as well as histidine decarboxylase. However, the pattern of its gene expression as a neuroendocrine cell has not been explored. Comparison of gene expression by 95% pure ECL cells obtained by density gradient, elutriation, and fluorescence-assisted cell sorting with isolates of the intact fundic gastric epithelium (i.e., "subtractive hybridization") identified a variety of additional expressed gene families characteristic of this neuroendocrine cell. These include genes 1) involved in neuropeptide synthesis and secretory vesicle exocytosis, 2) involved in control of inflammation, 3) implicated in healing of the epithelium, 4) encoding inhibitory Gi protein-coupled receptors, 5) playing a role in neuroendocrine regulation of food intake, and 6) encoding proteins likely involved in maintenance of circadian rhythm, in addition to the ECL cell-specific genes histidine decarboxylase and monoamine transporter. Particularly, the inhibitory apelin receptor gene, APJ, was highly expressed in the ECL cell preparation. Because parietal cells express apelin, immunohistochemical and functional studies showed that there is an inhibitory feed back loop between the parietal and ECL cell during gastrin stimulation, providing evidence for a novel pathway of downregulation of acid secretion due to interaction between these two cell types.

  9. 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.

  10. 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.

  11. Bulk enrichment of transplantable hemopoietic stem cell subsets from lipopolysaccharide-stimulated murine spleen

    SciTech Connect

    Ploemacher, R.E.; Brons, R.H.; Leenen, P.J.

    1987-02-01

    Counterflow centrifugal elutriation (CCE) in combination with density flotation centrifugation and fluorescence-activated cell sorting on wheat-germ agglutinin-FITC(WGA)-binding cells within the light-scatter ''blast window'' were used consecutively to enrich pluripotent hemopoietic stem cells (HSC) in bulk from lipopolysaccharide-stimulated mouse spleen. The medium-to-strong WGA + ve fraction contained 3.10(6) cells isolated from 3-4 X 10(9) spleen cells, with an average of 126% day-12 CFU-S and 65% day-8 CFU-S as calculated on the basis of their seeding fraction, suggesting that virtually all cells represented in vivo macroscopic colony formers. In view of the large differences reported elsewhere between stem cell subsets differing in reconstitutive capacity and secondary stem cell generation ability, we also studied various isolated cell fractions with respect to spleen colony formation, radioprotective ability, and spleen- and marrow- repopulating ability. Day-8 and day-12 CFU-S copurified when isolated by CCE. Cells from a fraction with high affinity for WGA were most highly enriched for their radioprotective ability (RPA) and their ability to repopulate the cellularity of the spleen and femur of irradiated recipients. This fraction contained virtually pure day-12 CFU-S. However, the ability to generate secondary day-12 CFU-S and CFU-GM in irradiated organs was enriched most in the medium WGA + ve cell fraction. MRA and SRA, according to the latter criteria, could therefore be partly separated from day-12 CFU-S and RPA on the basis of affinity for WGA. The data strongly suggest that at least part of all day-12 CFU-S have a high potential to proliferate and differentiate into mature progeny, but a relatively low self-renewal ability, and may therefore not be representative of the genuine stem cell.

  12. Isolation of hemopoietic stem cell subsets from murine bone marrow: I. Radioprotective ability of purified cell suspensions differing in the proportion of day-7 and day-12 CFU-S

    SciTech Connect

    Ploemacher, R.E.; Brons, N.H.

    1988-01-01

    We have studied the ability of bone marrow cell suspensions greatly differing in the relative proportion of day-7 and day-12 spleen colony-forming units (CFU-S) to rescue mice from radiation-inflicted death, and to repopulate the irradiated bone marrow and spleen with nucleated cells. Counterflow centrifugal elutriation in combination with removal of adherent cells and fluorescence-activated cell sorting on differences in wheat germ agglutinin (WGA)-fluorescein isothiocyanate (FITC) affinity and light scatter properties were used consecutively to enrich large numbers of hemopoietic stem cells from mouse bone marrow. Enrichments of 50- to 200-fold have been achieved for day-12 CFU-S and radioprotective ability (RPA), permitting 50% of lethally irradiated mice to survive over a period of 30 days with as few as 50-80 donor cells. The ratio of day-7 and day-12 CFU-S in the various suspensions could be significantly modulated on the basis of their WGA binding and perpendicular light scatter characteristics. This finding enabled us to investigate the properties of day-7 and day-12 CFU-S with respect to their RPA. We found a highly significant log/log relationship between enrichment factors for (1) RPA, (2) the number of day-12 CFU-S, and (3) spleen cellularity as measured on day 13. In addition, similar numbers of sorted and unfractionated day-12 CFU-S were required to obtain the same level of protection. Enrichment for RPA was significantly less related to either the number of day-7 CFU-S injected, or the bone marrow cellularity of the irradiated mice on day 13.

  13. Isolation of hemopoietic stem cell subsets from murine bone marrow: II. Evidence for an early precursor of day-12 CFU-S and cells associated with radioprotective ability

    SciTech Connect

    Ploemacher, R.E.; Brons, N.H.

    1988-01-01

    Counterflow centrifugal elutriation (CCE) in combination with plastic adherence and fluorescence-activated cell sorting were used consecutively to enrich functionally different subpopulations of pluripotent hemopoietic stem cells (HSC) from mouse bone marrow. The nonadherent CCE fractions were labeled with wheat germ agglutinin (WGA)-fluorescein isothiocyanate (FITC) and sorted according to differences in fluorescence within various windows on the basis of forward (FLS) and perpendicular (PLS) light scatter. The sorted cells were then assayed for their (1) in vivo colony-forming ability (day-7 and day-12 spleen colony-forming units (CFU-S)), (2) radioprotective ability (RPA; 30-day survival), and (3) their ability to repopulate the bone marrow or spleen over a 13-day period with day-12 CFU-S, granulocyte-macrophage colony-forming units (CFU-GM), nucleated cells, or cells associated with RPA. The highest incidence of day-12 CFU-S and cells with RPA was obtained by sorting the most WGA-positive cells with relatively high PLS (enrichment, 50- to 200-fold), lowering the effective dose (ED 50/30) to an average of 80 cells. The separative procedure enabled hemopoietic stem cells that repopulate both bone marrow and spleen with secondary RPA cells, CFU-S-12, and CFU-GM to be enriched and separated from part of the RPA cells, CFU-S-12, and cells that reconstitute the cellularity of bone marrow and spleen. These data suggest that cells generating both day-12 CFU-S and RPA cells differ from day-12 CFU-S and RPA cells themselves on the basis of PLS characteristics and affinity for WGA. Such early stem cells have also been detected in sorted fractions meeting the FLS/PLS characteristics of lymphocytes.

  14. Multiple Sponsor Support for Core Facilities: Effective Communication and Collaboration

    PubMed Central

    Colmenares, Clemencia

    2013-01-01

    The Lerner Research Institute's core services support all investigators at Cleveland Clinic, including a group of nearly 200 research faculty and their teams, as well as clinical research groups who need access to our centralized technologies. We offer approximately 20 different types of services and instruments ranging from preparation of media and cell lines to genomics and proteomics resources. Services are also available to the greater Cleveland scientific community, with selected cores open to “external” (i.e. non-Cleveland) users as long as capacity permits. Beyond the expected technical and scientific expertise, LRI researchers rely on the cores heavily for education and advice on emerging methodologies and research trends. Core structure is kept flexible by design; annual evaluations of the demand, cost-effectiveness, staffing, and customer satisfaction for each core guide decisions about continued operation or restructuring. The LRI cores are supported in part by the Cleveland Translational Science Collaborative, by the Case Comprehensive Cancer Center, and by multiple PPGs to individual investigators. Resolution of differences in objectives, policies, direction, reporting, and allowable practices among funding sources requires constant, highly effective communication. To this end, we have found that a seemingly pedestrian approach – frequent meetings, scrupulous meeting attendance and insightful, diplomatic selection of meeting participants and agendas – when used consistently and inclusively, has proven effective in resolving most conflicts and generating compromises. In the best of cases, this enlightened cooperativity can result in development of services beyond the standard core fare, such as the development of a service to distribute highly purified, elutriated human peripheral blood cells, made possible by the Clinical Research Unit Core Laboratory in collaboration with 2 PPGs and with the TTR component of the CTSC. Management of ongoing

  15. 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.

  16. Lead and PAHs contamination of an old shooting range: A case study with a holistic approach.

    PubMed

    Rodríguez-Seijo, A; Cachada, A; Gavina, A; Duarte, A C; Vega, F A; Andrade, M L; Pereira, R

    2017-01-01

    Soil pollution at firing ranges is an issue of growing importance, due to the accumulation in soils of contaminants derived from ammunition and clay targets. The concentration of Pb and PAHs was determined in five soils of an abandoned shooting range in Galicia (northwest Spain), and an ecotoxicological characterization was performed in order to obtain an assessment of risks. Therefore, the retention capacity of soils was assessed using test organisms of different trophic levels, and the role of soils as habitat for soil invertebrates was assessed by reproduction tests and bioaccumulation assays with earthworms. The sum of 15 PAHs ranged between 38 and 360mgkg(-1), which exceed, together with Pb (160-720mgkg(-1)), the Galician generic reference value for urban and sporting field soils. Bioaccumulation in E. andrei showed contents up to 104,000μgPbkg(-1)dw, and up to 645μgPAHskg(-1)fw. High contents of Pb and PAHs in soil samples and in Eisenia andrei whole body, caused a reduction in the number of juveniles produced, whereas, Vibrio fischeri, Raphidocelis subcapitata and Daphnia magna displayed a slight toxic response to the soil elutriates tested. Therefore, the function of these soils to retain contaminants seemed not compromised, probably due to the high organic matter content and pH values, which are weakly acidic. The habitat function was affected, indicating that soil solution is not the only route of exposure to contaminants to E. andrei. The integration of chemical and ecotoxicological lines of evidence give rise to high risks values, restricting the use of these areas, and pointing for risks to surrounding ecosystems due to possible trophic transferences. The calculation of risks using the chemical and ecotoxicological data, required by Spanish legislation, could be a good approach to communicate with those responsible and/or involved in the management of contaminated sites.

  17. 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

  18. Up-regulation of survivin by the E2A-HLF chimera is indispensable for the survival of t(17;19)-positive leukemia cells.

    PubMed

    Okuya, Mayuko; Kurosawa, Hidemitsu; Kikuchi, Jiro; Furukawa, Yusuke; Matsui, Hirotaka; Aki, Daisuke; Matsunaga, Takayuki; Inukai, Takeshi; Goto, Hiroaki; Altura, Rachel A; Sugita, Kenich; Arisaka, Osamu; Look, A Thomas; Inaba, Toshiya

    2010-01-15

    The E2A-HLF fusion transcription factor generated by t(17;19)(q22;p13) translocation is found in a small subset of pro-B cell acute lymphoblastic leukemias (ALLs) and promotes leukemogenesis by substituting for the antiapoptotic function of cytokines. Here we show that t(17;19)+ ALL cells express Survivin at high levels and that a dominant negative mutant of E2A-HLF suppresses Survivin expression. Forced expression of E2A-HLF in t(17;19)(-) leukemia cells up-regulated Survivin expression, suggesting that Survivin is a downstream target of E2A-HLF. Analysis using a counterflow centrifugal elutriator revealed that t(17;19)+ ALL cells express Survivin throughout the cell cycle. Reporter assays revealed that E2A-HLF induces survivin expression at the transcriptional level likely through indirect down-regulation of a cell cycle-dependent cis element in the promoter region. Down-regulation of Survivin function by a dominant negative mutant of Survivin or reduction of Survivin expression induced massive apoptosis throughout the cell cycle in t(17;19)+ cells mainly through caspase-independent pathways involving translocation of apoptosis-inducing factor (AIF) from mitochondria to the nucleus. AIF knockdown conferred resistance to apoptosis caused by down-regulation of Survivin function. These data indicated that reversal of AIF translocation by Survivin, which is induced by E2A-HLF throughout the cell cycle, is one of the key mechanisms in the protection of t(17;19)+ leukemia cells from apoptosis.

  19. Late Miocene ignimbrites at the southern Puna-northern Sierras Pampeanas border (˜27°S): Stratigraphic correlation

    NASA Astrophysics Data System (ADS)

    Montero-López, Carolina; Guzmán, Silvina; Barrios, Fabiola

    2015-10-01

    New field observations and petrographic and geochemical data of pyroclastic deposits exposed along the Las Papas valley (border between southern Puna and northern Sierras Pampeanas, Argentina) and further north, lead us to propose a new stratigraphic correlation and classification of the late Miocene volcanism in this area. We redefine the Las Papas, Las Juntas, Aguada Alumbrera and Rosada ignimbrites and define the Agua Caliente and Del Medio ignimbrites. The whole set of ignimbrites are rhyolites and less frequently dacites of calc-alkaline affinity. In the present contribution we divide ignimbrites into the Agua Negra and Rincón groups, based mainly on their geochemical signature. The Agua Negra Group is formed by the Las Papas and Las Juntas ignimbrites, indurated and welded, lithic-rich, with crystal-poor pumices and crystal-rich matrix. The Rincón Group comprises the Agua Caliente, Aguada Alumbrera, Rosada and Del Medio ignimbrites, with variable welding degrees, lithic and crystal content. The greater enrichment of crystals in the matrix in comparison with the crystal content in pumices indicates significant elutriation during flow transport and thus volume estimations are to be considered lower bounds for the actual erupted volume. The total minimum estimated volume for the ignimbrites of the Agua Negra and Rincón groups is 2.8 km3 (2.3 km3 DRE). Field relationships and new analytical data indicate that the different acid ignimbrites that crop out in this small area are related to at least two different magma chambers. The widespread Quaternary volcanism in this area covers the older deposits, thus making it difficult to recognize the volcanic centers that produced these late Miocene ignimbrites.

  20. 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.

  1. 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.

  2. 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.

  3. Primary culture of secretagogue-responsive parietal cells from rabbit gastric mucosa

    SciTech Connect

    Chew, C.S.; Ljungstroem, M.S.; Smolka, A.; Brown, M.R.

    1989-01-01

    A new procedure for isolation and primary culture of gastric parietal cells is described. Parietal cells from rabbit gastric mucosa are enriched to greater than 95% purity by combining a Nycodenz gradient separation with centrifugal elutriation. Cells are plated on the basement membrane matrix, Matrigel, and maintained in culture for at least 1 wk. Parietal cells cultured in this manner remain differentiated, cross-react with monoclonal H+-K+-ATPase antibodies, and respond to histamine, gastrin, and cholinergic stimulation with increased acid production as measured by accumulation of the weak base, (/sup 14/C)aminopyrine. When stimulated, cultured cells undergo ultrastructural changes in which intracellular canaliculi expand and numerous microvilli are observed. These ultrastructural changes are similar to those previously found to occur in vivo and in acutely isolated parietal cells. Morphological transformations in living cells can also be observed with differential interference contrast optics in the light microscope. After histamine stimulation, intracellular canaliculi gradually expand to form large vacuolar spaces. When the H2 receptor antagonist, cimetidine, is added to histamine-stimulated cells, these vacuoles gradually disappear. The ability to maintain hormonally responsive parietal cells in primary culture should make it possible to study direct, long-term effects of a variety of agonists and antagonists on parietal cell secretory-related activity. These cultured cells should also prove to be useful for the study of calcium transients, ion fluxes, and intracellular pH as related to acid secretion in single cells, particularly since morphological transformations can be used to monitor physiological responses at the same time within the same cell.

  4. 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.

  5. 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.

  6. 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.

  7. Modulation of Sertoli cell secretory function by rat round spermatid protein(s).

    PubMed

    Onoda, M; Djakiew, D

    1990-10-01

    The influence of rat round spermatid protein(s) (RSP) on protein synthesis and secretory function of Sertoli cells was used in the bicameral chamber system. Round spermatids (RS) were purified from 90-day-old rats by centrifugal elutriation. RS were incubated in a supplement-enriched culture medium that lacked exogenous proteins. The RS-conditioned media were dialysed and lyophilized to obtain RSP. Most de novo protein synthesized under basal conditions by Sertoli cells (18-day-old) was secreted into the apical chamber (apical/basal ratio: 3.42). Follicle-stimulating hormone (FSH, 100 ng/ml) stimulated total protein secretion from Sertoli cells by a factor of 1.54. The RSP (100 micrograms/ml) stimulated total protein secretion from Sertoli cells by a factor of 2.33. The enhancement of total Sertoli cell protein secretion by FSH and RSP additively increased by a factor of 2.82. The combined effect of FSH and RSP on total protein secretion from Sertoli cells was dose dependent and saturated at approximately 200 micrograms/ml of RSP. Polarity of total protein secretion from Sertoli cells (apical/basal ratio: 3.42) was stimulated by RSP predominantly in the apical direction (apical/basal ratio: 8.48). The modulation of radiolabeled Sertoli cell secretory proteins (ceruloplasmin, CP; sulfated glycoprotein-2, SGP-2; testins and transferrin, Tf) by cold (non-labeled) RSP was investigated by immunoprecipitation followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The secretion of CP, SGP-2 and Tf was stimulated in a dose-dependent manner by the addition of RSP up to a saturating concentration of between 200 and 300 micrograms/ml, whereas the secretion of Sertoli cell testins did not reach saturation at 300 micrograms/ml RSP. These results indicate that FSH and RSP independently modulate Sertoli cell protein secretion, and that Sertoli cell secretory proteins may differentially respond to RSP stimulation.

  8. Pachytene spermatocyte protein(s) stimulate Sertoli cells grown in bicameral chambers: dose-dependent secretion of ceruloplasmin, sulfated glycoprotein-1, sulfated glycoprotein-2, and transferrin.

    PubMed

    Onoda, M; Djakiew, D

    1991-03-01

    Interactions between pachytene spermatocytes and Sertoli cells were investigated using the bicameral culture chamber system. Pachytene spermatocytes were isolated from adult rats with a purity in excess of 90% by centrifugal elutriation. The pachytene spermatocytes were cultured in a defined media and pachytene spermatocyte protein prepared from the conditioned media by dialysis and lyophilization. This pachytene spermatocyte protein was reconstituted at various concentrations and incubated with confluent epithelial sheets of immature Sertoli cells cultured in bicameral chambers. Pachytene spermatocyte protein stimulated secretion of total [35S]methionine-labeled protein from Sertoli cells in a dose-dependent manner predominantly in an apical direction. This stimulatory effect of pachytene spermatocyte protein was domain specific from the apical surface of Sertoli cells, and seemed specific for secretion because total intracellular protein did not increase under the influence of pachytene spermatocyte protein. Pachytene spermatocyte protein and follicle-stimulating hormone additively stimulated Sertoli cell secretion. The physicochemical characteristics of the stimulatory pachytene spermatocyte protein are indicative of heat stability, whereas the stimulatory pachytene spermatocyte protein exhibit acid, dithiothreitol and trypsin sensitivity, and partial urea sensitivity. Furthermore, Sertoli cell secretion of ceruloplasmin, sulfated glycoprotein-1, sulfated glycoprotein-2, and transferrin in response to various concentrations of pachytene spermatocyte protein were determined by immunoprecipitate of these [35S]methionine-labeled proteins with polyclonal antibodies. Maximal stimulation of ceruloplasmin and sulfated glycoprotein-1 secretion from Sertoli cells was observed at a dose of 50 micrograms/ml pachytene spermatocyte protein, whereas maximal stimulation of sulfated glycoprotein-2 and transferrin secretion from Sertoli cells was observed at a dose of 100

  9. A 29,000 M(r) protein derived from round spermatids regulates Sertoli cell secretion.

    PubMed

    Onoda, M; Djakiew, D

    1993-05-01

    Within the last decade it has become accepted that germ cells can modulate Sertoli cell function in a paracrine interactive manner during the regulation of spermatogenesis. In this context, we undertook to identify a specific factor in round spermatid conditioned media that could stimulate Sertoli cell secretory function. Rat round spermatids isolated by centrifugal elutriation were cultured and the concentrated conditioned media were fractionated by Sephacryl S-200 gel filtration column chromatography. The biological activity of the fractionated round spermatid protein was assessed as stimulation of total protein and transferrin secretion from Sertoli cells that had been isolated from 18-day-old immature rat testes. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the gel-filtration fractions showed two predominant proteins of 29,000 and 24,500 molecular weight which coexisted in the fractions containing the greatest biological activity. These two proteins were transferred to a nitrocellulose membrane and excised to raise polyclonal antibodies. Western blot analysis of the 29,000 M(r) protein demonstrated that it specifically occurred in round spermatid conditioned media, whereas no immunoreactive band was observed in either the conditioned media or cell lysates of other testicular cell types such as primary spermatocytes, Sertoli cells and peritubular myoid cells. Following subcellular fractionation of round spermatids by differential centrifugation, the 29,000 M(r) protein was detected by Western blots specifically in the cytosolic fraction of round spermatids, and was absent from the nuclear, mitochondrial, lysosomal and microsomal fractions. The antibody did recognize a few higher molecular bands in the cytosolic fraction which may represent precursor forms of the 29,000 M(r) protein.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Role of soluble factors and three-dimensional culture in in vitro differentiation of intestinal macrophages

    PubMed Central

    Spoettl, Tanja; Hausmann, Martin; Menzel, Katrin; Piberger, Heidi; Herfarth, Hans; Schoelmerich, Juergen; Bataille, Frauke; Rogler, Gerhard

    2007-01-01

    AIM: To examine the factor(s) involved in differentiation of intestinal macrophages (IMACs) using a recently established in vitro model. METHODS: To test whether soluble or membrane bound factors induce IMAC-differentiation, freshly elutriated monocytes (MO) were incubated with conditioned media or cell membranes of intestinal epithelial cells (IEC) or cultured with IEC in transwell systems. To determine the importance of an active migration of MO, three-dimensional aggregates from a 1:1-mixture of MO and IEC were examined by immunohistochemistry and flow cytometry. Apoptosis was examined by caspase-3 Western blots. Extracellular matrix production in differentiation models was compared by immunohistochemistry. RESULTS: IMAC differentiation was observed in a complex three-dimensional co-culture model (multicellular spheroid, MCS) with IEC after migration of MO into the spheroids. By co-culture of MO with conditioned media or membrane preparations of IEC no IMAC differentiation was induced. Co-culture of MO with IEC in transwell-cultures, with the two cell populations separated by a membrane also did not result in intestinal-like differentiation of MO. In contrast to IEC-spheroids with immigrating MO in mixed MCS of IEC and MO only a small subpopulation of MO was able to survive the seven day culture period. CONCLUSION: Intestinal-like differentiation of MO in vitro is only induced in the complex three-dimensional MCS model after immigration of MO indicating a role of cell-matrix and/or cell-cell interactions during the differentiation of IMACs. PMID:17373737

  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.

  12. 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.

  13. 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.

  14. 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.

  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. Sumas Mountain chrysotile induces greater lung fibrosis in Fischer344 rats than Libby amphibole, El Dorado tremolite, and Ontario ferroactinolite.

    PubMed

    Cyphert, Jaime M; Nyska, Abraham; Mahoney, Ron K; Schladweiler, Mette C; Kodavanti, Urmila P; Gavett, Stephen H

    2012-12-01

    The physical properties of different types of asbestos may strongly affect health outcomes in exposed individuals. This study was designed to provide understanding of the comparative toxicity of naturally occurring asbestos (NOA) fibers including Libby amphibole (LA), Sumas Mountain chrysotile (SM), El Dorado tremolite (ED), and Ontario ferroactinolite (ON) cleavage fragments. Rat-respirable fractions (PM₂.₅) were prepared by water elutriation. Surface area was greater for SM (64.1 m²/g) than all other samples (range: 14.1-16.2 m²/g), whereas mean lengths and aspect ratios (ARs) for LA and SM were comparable and greater than ED and ON. Samples were delivered via a single intratracheal (IT) instillation at doses of 0.5 and 1.5mg/rat. One day post-IT instillation, low-dose NOA exposure resulted in a 3- to 4-fold increase in bronchoalveolar lavage fluid (BALF) cellularity compared with dispersion media (DM) controls, whereas high-dose exposure had a more severe effect on lung inflammation which varied by source. Although inducing less neutrophilic inflammation than ON and ED, exposure to either LA or SM resulted in a greater degree of acute lung injury. Three months post-IT instillation, most BALF parameters had returned to control levels, whereas the development of fibrosis persisted and was greatest in SM-exposed rats (SM > LA > ON > ED). These data demonstrate that fiber length and higher AR are directly correlated with the severity of fibrosis and that, in the rat, exposure to SM is more fibrogenic than LA which suggests that there may be cause for concern for people at risk of being exposed to NOA from the Sumas Mountain landslide.

  17. Simple and Efficient Technique for the Preparation of Testicular Cell Suspensions

    PubMed Central

    Rodríguez-Casuriaga, Rosana; Folle, Gustavo A.; Santiñaque, Federico; López-Carro, Beatriz; Geisinger, Adriana

    2013-01-01

    Mammalian testes are very complex organs that contain over 30 different cell types, including somatic testicular cells and different stages of germline cells. This heterogeneity is an important drawback concerning the study of the bases of mammalian spermatogenesis, as pure or enriched cell populations in certain stages of sperm development are needed for most molecular analyses1. Various strategies such as Staput2,3, centrifugal elutriation1, and flow cytometry (FC)4,5 have been employed to obtain enriched or purified testicular cell populations in order to enable differential gene expression studies. It is required that cells are in suspension for most enrichment/ purification approaches. Ideally, the cell suspension will be representative of the original tissue, have a high proportion of viable cells and few multinucleates - which tend to form because of the syncytial nature of the seminiferous epithelium6,7 - and lack cell clumps1 . Previous reports had evidenced that testicular cell suspensions prepared by an exclusively mechanical method clumped more easily than trypsinized ones1 . On the other hand, enzymatic treatments with RNAses and/or disaggregating enzymes like trypsin and collagenase lead to specific macromolecules degradation, which is undesirable for certain downstream applications. The ideal process should be as short as possible and involve minimal manipulation, so as to achieve a good preservation of macromolecules of interest such as mRNAs. Current protocols for the preparation of cell suspensions from solid tissues are usually time-consuming, highly operator-dependent, and may selectively damage certain cell types1,8 . The protocol presented here combines the advantages of a highly reproducible and extremely brief mechanical disaggregation with the absence of enzymatic treatment, leading to good quality cell suspensions that can be used for flow cytometric analysis and sorting4, and ulterior gene expression studies9 . PMID:23963251

  18. 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.

  19. 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.

  20. 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.

  1. Separation of spermatogenic cell types using STA-PUT velocity sedimentation.

    PubMed

    Bryant, Jessica M; Meyer-Ficca, Mirella L; Dang, Vanessa M; Berger, Shelley L; Meyer, Ralph G

    2013-10-09

    Mammalian spermatogenesis is a complex differentiation process that occurs in several stages in the seminiferous tubules of the testes. Currently, there is no reliable cell culture system allowing for spermatogenic differentiation in vitro, and most biological studies of spermatogenic cells require tissue harvest from animal models like the mouse and rat. Because the testis contains numerous cell types--both non-spermatogenic (Leydig, Sertoli, myeloid, and epithelial cells) and spermatogenic (spermatogonia, spermatocytes, round spermatids, condensing spermatids and spermatozoa)--studies of the biological mechanisms involved in spermatogenesis require the isolation and enrichment of these different cell types. The STA-PUT method allows for the separation of a heterogeneous population of cells--in this case, from the testes--through a linear BSA gradient. Individual cell types sediment with different sedimentation velocity according to cell size, and fractions enriched for different cell types can be collected and utilized in further analyses. While the STA-PUT method does not result in highly pure fractions of cell types, e.g. as can be obtained with certain cell sorting methods, it does provide a much higher yield of total cells in each fraction (~1 x 10(8) cells/spermatogenic cell type from a starting population of 7-8 x 10(8) cells). This high yield method requires only specialized glassware and can be performed in any cold room or large refrigerator, making it an ideal method for labs that have limited access to specialized equipment like a fluorescence activated cell sorter (FACS) or elutriator.

  2. 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.

  3. Environmental assessment of creosote-treated pilings in the marine environment

    SciTech Connect

    Butala, J.H.; Webb, D.A.; Jop, K.M.; Putt, A.E.

    1995-12-31

    A comprehensive ecological risk assessment was conducted to evaluate the environmental impact of creosote-treated pilings in the marine environment at Moss Landing Harbor, Moss Landing, California. Four areas of investigation comprising the risk assessment were (1) evaluation of environmental conditions around existing creosote-treated pilings (2) investigating effects related to restoration of pilings (3) assessing creosote migration into surrounding environment, one year after pile-driving and (4) confirmation of creosote toxicity in laboratory studies. Biological and chemical evaluation of the impact of creosote-treated pilings was conducted on surface sheen, water column and sediment samples collected at Moss Landing Harbor. Water samples (surface sheen, water column and sediment pore water) were evaluated using short-term chronic exposures with Mysidopsis bahia, while bulk sediment samples were evaluated with 10-day sediment toxicity tests with Ampelisca abdita. Samples of surface, column water and sediment were analyzed for the constituents of creosote by GC mass spectrometry. In addition, a sample of neat material used to preserve treated pilings represented a reference for the polyaromatic hydrocarbons. Verification of organism response and analyses of field collected samples was performed by conducting 10-day A. abdita sediment and 7-day M. bahia elutriate exposures with creosote applied to clean sediment collected at Moss Landing, Evaluations were also performed to determine the effects of photoinduced toxicity on test organisms exposed to PAHs. The biological and analytical results of the field and laboratory exposures are being used to evaluate and determine risk of creosote-treated pilings on the marine environment.

  4. 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.

  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. Fine Ash Aggregation Processes Observed In Volcanic Plumes

    NASA Astrophysics Data System (ADS)

    Rinkleff, P. G.

    2012-12-01

    Fine airborne volcanic ash was collected during the eruptions of Augustine in 2006, Pavlof in 2007, and Redoubt in 2009 using Davis Rotating Unit for Measurement (DRUM) inertial cascade impactors to observe atmospheric volcanic ash aggregation. Aerosol ash collection by DRUM sampler preserved particle morphologies and compositions that are altered or destroyed by deposition. DRUM samples were analyzed by Scanning Electron Microscopy with Energy Dispersive Spectroscopy to determine particle size, shape, and composition. Ash particles were observed as single grains, ash aggregates, and hybrid ash/marine aerosol aggregates. Single grain ash occurred as single angular silicate shards and likely formed under ash and marine aerosol limited conditions. Ash aggregates occurred as loosely consolidated silicate ash clumps in pyroclastic flow elutriation plumes and were found in a discrete aerodynamic size range between 2.5-1.15 μm. Ash aggregates likely formed in fine ash-rich conditions which resulted from clast milling in flows that also generated abundant electrostatic particle charge. Hybrid ash/marine aerosol aggregates were composed of silicate ash and sea salt with non-sea salt sulfates. The mass concentration of sulfate did not vary systematically with ash which indicated that the sulfate source was not necessarily volcanic. Hybrid ash was common in all samples and likely formed when downward mixing ash mingled with upward mixing sea salt and non-sea salt sulfate aerosol.EM image of ash aggregates with individual ash grains. EM image with EDS element maps of hybrid ash/marine aerosol aggregates. Si is present with marine Cl and S.

  7. Specific inhibition by prostaglandins E2 and I2 of histamine-stimulated [14C]aminopyrine accumulation and cyclic adenosine monophosphate generation by isolated canine parietal cells.

    PubMed Central

    Soll, A H

    1980-01-01

    The effects of prostaglandins E2 and I2 on accumulation of [14C]aminopyrine and the generation of cyclic AMP by fractions of dispersed canine gastric mucosal cells, enriched in their content of parietal cells, have been studied. The parietal cell content of the fractions was enriched to between 43 and 70% using an elutriator rotor. The accumulation of [14C]aminopyrine was used as the index of parietal cell response to stimulation. Prostaglandin E2 (PGE2, 0.1 nM-0.1 mM) inhibited histamine stimulated aminopyrine uptake but did not block the response to carbachol, gastrin, or dibuturyl cyclic AMP. PGE2 did, however, inhibit aminopyrine uptake stimulated by carbachol and gastrin when the response to these agents was potentiated by histamine. PGE2 (0.1 NM-0.1 mM) inhibited histamine-stimulated cyclic AMP production in a dose-dependent fashion with maximal inhibition at 1 microM PGE2. Prostacyclin also inhibited both histamine-stimulated aminopyrine accumulation and histamine-stimulated cyclic AMP production. In the absence of added histamine, PGE2 in concentrations above 1 microM and prostacyclin in concentrations above 10 microM stimulated cyclic AMP production, probably by acting on the nonparietal cells as shown in previous studies. These present data are consistent with the hypothesis that prostaglandins E2 and I2 inhibit the response of isolated parietal cells to histamine by specifically blocking histamine-stimulated cyclic AMP production. PMID:6154063

  8. 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.

  9. 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).

  10. Geochemical stability of chromium in sediments from the lower Hackensack River, New Jersey.

    PubMed

    Magar, Victor S; Martello, Linda; Southworth, Barbara; Fuchsman, Phyllis; Sorensen, Mary; Wenning, Richard J

    2008-05-01

    Elevated levels of chromium, partly attributable to historical disposal of chromite ore processing residue, are present in sediment along the eastern shore of the lower Hackensack River near the confluence with Newark Bay. Due to anaerobic conditions in the sediment, the chromium is in the form of Cr(III), which poses no unacceptable risks to human health or to the river ecology. However, as water quality conditions have improved since the 1970s, aerobic conditions have become increasingly prevalent in the overlying water column. If these conditions result in oxidation of Cr(III) to Cr(VI), either under quiescent conditions or during severe weather or anthropogenic scouring events, the potential for adverse ecological effects due to biological exposures to Cr(VI) is possible, though the reaction kinetics associated with oxidation of Cr(III) to Cr(VI) are unfavorable. To investigate the stability of Cr(III) in Hackensack River sediments exposed to oxic conditions, sediment suspension and oxidation experiments and intertidal sediment exposure experiments that exposed the sediments to oxic conditions were conducted. Results revealed no detectable concentrations of Cr(VI), and thus no measurable potential for total chromium oxidation to Cr(VI). Furthermore, total chromium released from sediment to elutriate water in the oxidation and suspension experiments ranged from below detection (<0.01 mg/L) to 0.18 mg/L, below the freshwater National Recommended Water Quality Criteria (NRWQC) of 0.57 mg/L for Cr(III). These results support conclusions of a stable, in situ geochemical environment in sediments in the lower Hackensack River with respect to chromium. Results showed that chemicals other than Cr(VI), including copper, lead, mercury, zinc, and PCBs, were released at levels that may pose a potential for adverse ecological effects.

  11. Cell cycle regulation of a mouse histone H4 gene requires the H4 promoter.

    PubMed Central

    Seiler-Tuyns, A; Paterson, B M

    1987-01-01

    The mouse histone H4 gene, when stably transformed into L cells on the PSV2gpt shuttle vector, is cell cycle regulated in parallel with the endogenous H4 genes. This was determined in exponentially growing pools of transformants fractionated into cell cycle-specific stages by centrifugal elutriation, a method for purifying cells at each stage of the cell cycle without the use of treatments that arrest growth. Linker additions in the 5' noncoding region of the H4 RNA or in the coding region of the gene did not affect the cell cycle-regulated expression of the modified H4 gene even though the overall level of expression was altered. However, replacing the H4 promoter with the human alpha-2 globin promoter, so that the histone transcript produced by the chimeric gene remains essentially unchanged, resulted in the constitutive expression of H4 mRNA during all phases of the cell cycle with no net increase in H4 mRNA levels during the G1-to-S transition. From these results we conclude that all the information necessary for the cell cycle-regulated expression of the H4 gene is contained in the 5.2-kilobase subclone used in these studies with 228 nucleotides of 5'-flanking DNA and that the increase in H4 mRNA during the G1-to-S transition in the cell cycle is mediated by the H4 promoter and not by the increased stability of the H4 RNA. Images PMID:3561406

  12. Comparison of the structure and cell cycle expression of mRNAs encoded by two histone H3-H4 loci in Saccharomyces cerevisiae.

    PubMed Central

    Cross, S L; Smith, M M

    1988-01-01

    The haploid genome of Saccharomyces cerevisiae contains two nonallelic sets of histone H3 and H4 gene pairs, termed the copy I and copy II loci. The structures of the mRNA transcripts from each of these four genes were examined by nuclease protection and primer extension mapping. For each gene, several species of mRNAs were identified that differed in the lengths of their 5' and 3' untranslated regions. The cell cycle accumulation pattern of the H3 and H4 mRNAs was determined in cells from early-exponential-growth cultures fractionated by centrifugal elutriation. The RNA transcripts from all four genes were regulated with the cell division cycle, and transcripts from the nonallelic gene copies showed tight temporal coordination. Cell cycle regulation did not depend on selection of a particular histone mRNA transcript since the ratio of the multiple species from each gene remained the same across the division cycle. Quantitative measurements showed significant differences in the amounts of mRNA expressed from the two nonallelic gene sets. The mRNAs from the copy II H3 and H4 genes were five to seven times more abundant than the mRNAs from the copy I genes. There was no dosage compensation in the steady-state levels of mRNA when either set of genes was deleted. In particular, there was no increase in the amount of copy I H3 or H4 transcripts in cells in which the high-abundance copy II genes were deleted. Images PMID:3280973

  13. 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.

  14. 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.

  15. 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.

  16. Pulmonary inflammatory and fibrotic responses in Fischer 344 rats after intratracheal instillation exposure to Libby amphibole.

    PubMed

    Padilla-Carlin, Danielle J; Schladweiler, Mette C J; Shannahan, Jonathan H; Kodavanti, Urmila P; Nyska, Abraham; Burgoon, Lyle D; Gavett, Stephen H

    2011-01-01

    Increased incidences of asbestosis have been reported in workers from Libby, MT, associated with exposures to amphibole-contaminated vermiculite. In this study pulmonary and histopathological changes were investigated following Libby amphibole (LA) exposure in a rat model. Rat respirable fractions of LA and amosite (aerodynamic diameter <2.5 μm) were prepared by water elutriation. Male F344 rats were exposed to single doses of either saline (SAL), amosite (0.65 mg/rat), or LA (0.65 or 6.5 mg/rat) by intratracheal instillation. At times from 1 d to 3 mo after exposure, bronchoalveolar lavage (BAL) was performed and right and left lungs were removed for reverse-transcription polymerase chain reaction (RT-PCR) and histopathological analysis, respectively. Data indicated that 0.65 mg amosite resulted in a higher degree of pulmonary injury, inflammation, and fibrotic events than LA at the same mass dose. Exposure to either amosite or high dose LA resulted in higher levels of cellular permeability and injury, inflammatory enzymes, and iron binding proteins in both BAL fluid and lung tissue at most time points when compared to SAL controls. However, mRNA expression for some growth factors (e.g., platelet-derived growth factor [PDGF]-A and transforming growth factor [TGF]-1β), which contribute to fibrosis, were downregulated at several time points. Furthermore, histopathological examination showed notable thickening of interstitial areas surrounding the alveolar ducts and terminal bronchioles. On a mass dose basis, amosite produced a greater acute and persistent lung injury for at least 3 mo after exposure. However, further testing and analysis of LA are needed with regard to the dose metric to fully evaluate its potential fibrogenicity and carcinogenicity.

  17. Byssinosis in Guangzhou, China.

    PubMed Central

    Jiang, C Q; Lam, T H; Kong, C; Cui, C A; Huang, H K; Chen, D C; He, J M; Xian, P Z; Chen, Y H

    1995-01-01

    OBJECTIVES--To study the prevalence of byssinosis and other respiratory abnormalities in workers exposed to cotton dust in Guangzhou in two factories that processed purely cotton. METHODS--All the 1320 workers exposed were included. The controls were 1306 workers with no history of occupational dust exposure. Total dust and inhalable dust were measured by Chinese total dust sampler and American vertical elutriator respectively. A World Health Organisation questionnaire was used. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were measured by a Vitalograph spirometer. RESULTS--The median inhalable dust concentrations ranged from 0.41 to 1.51 mg/m3 and median total dust concentrations from 3.04 to 12.32 mg/m3. The prevalence of respiratory abnormalities in the cotton workers were (a) typical Monday symptoms 9.0%; (b) FEV1 fall by > or = 5% after a shift 16.8%; (c) FEV1 fall by > or = 10% after a shift 4.2%; (d) FEV1 < 80% predicted 6.1%; (e) FEV1/FVC < 75% 4.0%; (f) cough or phlegm 18.2%; (g) chronic bronchitis 10.9%; and (h) byssinosis, defined by (a) plus (b) 1.7%. With the exception of (d), most of the prevalences increased with increasing age, duration of exposure, and cumulative inhalable dust exposure. No increasing trends of respiratory abnormalities were found for current total dust, inhalable dust, and cumulative total dust concentrations. Compared with controls, after adjustment for sex and smoking, with the exception of (d), all the pooled relative risks of respiratory abnormalities were raised for cotton exposure. CONCLUSION--It is concluded that cumulative inhalable cotton is likely to be the cause of byssinotic symptoms, acute lung function decrements, cough, or phlegm, and chronic bronchitis. PMID:7795743

  18. Risk factors for lymphoproliferative disorders after allogeneic hematopoietic cell transplantation.

    PubMed

    Landgren, Ola; Gilbert, Ethel S; Rizzo, J Douglas; Socié, Gérard; Banks, Peter M; Sobocinski, Kathleen A; Horowitz, Mary M; Jaffe, Elaine S; Kingma, Douglas W; Travis, Lois B; Flowers, Mary E; Martin, Paul J; Deeg, H Joachim; Curtis, Rochelle E

    2009-05-14

    We evaluated 26 901 patients who underwent allogeneic hematopoietic cell transplantation (HCT) at 271 centers worldwide to define patterns of posttransplantation lymphoproliferative disorders (PTLDs). PTLDs developed in 127 recipients, with 105 (83%) cases occurring within 1 year after transplantation. In multivariate analyses, we confirmed that PTLD risks were strongly associated (P < .001) with T-cell depletion of the donor marrow, antithymocyte globulin (ATG) use, and unrelated or HLA-mismatched grafts (URD/HLA mismatch). Significant associations were also confirmed for acute and chronic graft-versus-host disease. The increased risk associated with URD/HLA-mismatched donors (RR = 3.8) was limited to patients with T-cell depletion or ATG use (P = .004). New findings were elevated risks for age 50 years or older at transplantation (RR = 5.1; P < .001) and second transplantation (RR = 3.5; P < .001). Lower risks were found for T-cell depletion methods that remove both T and B cells (alemtuzumab and elutriation, RR = 3.1; P = .025) compared with other methods (RR = 9.4; P = .005 for difference). The cumulative incidence of PTLDs was low (0.2%) among 21 686 patients with no major risk factors, but increased to 1.1%, 3.6%, and 8.1% with 1, 2, and more than 3 major risk factors, respectively. Our findings identify subgroups of patients who underwent allogeneic HCT at elevated risk of PTLDs for whom prospective monitoring of Epstein-Barr virus activation and early treatment intervention may be particularly beneficial.

  19. Stability of solid-phase selenium species in fly ash after prolonged submersion in a natural river system.

    PubMed

    Chappell, Mark A; Seiter, Jennifer M; Bednar, Anthony J; Price, Cynthia L; Averett, Daniel; Lafferty, Brandon; Tappero, Ryan; Stanley, Jacob S; Kennedy, Alan J; Steevens, Jeffery A; Zhou, Pingheng; Morikawa, Eizi; Merchan, Gregory; Roy, Amitava

    2014-01-01

    Selenium (Se) chemistry can be very complex in the natural environment, exhibiting different valence states (-2, 0, +4, +6) representing multiple inorganic, methylated, or complexed forms. Since redox associated shifts among most of known Se species can occur at environmentally relevant conditions, it is important to identify these species in order to assess their potential toxicity to organisms. In June of 2009, researchers from the US Army Engineer Research & Development Center (ERDC) conducted investigations of the fly ash spilled 6 months previously into the Emory River at the TVA Kingston Fossil Plant, TN. Ash samples were collected on site from both the original ash pile (that did not move during the levee failure), from the spill zone (including the Emory River), and from the ash recovery ditch (ARD) containing ash removed during dredging cleanup operations. The purpose of this work was to determine the state of Se in the spilled fly ash and to assess its potential for transformation and resultant chemical stability from its prolonged submersion in the river and subsequent dredging. Sequential chemical extractions suggested that the river environment shifted Se distribution toward organic/sulfide species. Speciation studies by bulk XANES analysis on fly ash samples showed that a substantial portion of the Se in the original ash pile had transformed from inorganic selenite to a mixture of Se sulfide and reduced (organo)selenium (Se(-II)) species over the 6-month period. μ-XRF mapping data showed that significant trends in the co-location of Se domains with sulfur and ash heavy metals. Ten-d extended elutriate tests (EETs) that were bubbled continuously with atmospheric air to simulate worst-case oxidizing conditions during dredging showed no discernible change in the speciation of fly ash selenium. The enhanced stability of the organo- and sulfide-selenium species coincided with the mixture of the ash material with humic materials in the river, corresponding

  20. 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.

  1. Respiratory disease in a textile factory in Nicaragua.

    PubMed

    Velazquez, A M; Christiani, D C; McConnell, R; Eisen, E A; Wilcox, M

    1991-01-01

    This is the first epidemiologic study conducted in a textile mill in Nicaragua using techniques and diagnostic criteria similar to those used in the United States and England. The prevalence of byssinosis and nonspecific respiratory symptoms were studied in 194 workers in a cotton mill in Managua. Limited environmental sampling, performed using a vertical elutriator in yarn preparation and weaving areas, indicated that exposures were similar to those reported in other parts of the developing world. A modified translated version of the Medical Research Council respiratory questionnaire was administered. Pulmonary function tests were performed before and after the Monday workshift to measure across-shift change in ventilatory function. The prevalence of byssinosis was 5.9% and all the cases occurred among exposed women. Nonspecific respiratory symptoms were also more prevalent among exposed workers. After adjusting for age, gender, smoking habit, and work tenure, the exposure odds ratios for usual cough and usual phlegm were 3.3 and 2.2, respectively. The association between exposure and across-shift decrement in FEV1 was not significant. Byssinotic workers, however, had greater decrements in FEV1% than those without byssinosis: 5.5% versus 1.8%. A consistent gender effect was observed in which both exposed and unexposed women were found to have greater across-shift decrements in FEV1 than men. The gender difference existed among long-term workers as well as workers who had been employed less than 2 years. Results are related to cotton dust exposure, as has been documented elsewhere. The poorer health status of the women in this study population deserves follow-up.

  2. Longitudinal pulmonary functional loss in cotton textile workers: A 5-year follow-up study

    PubMed Central

    Kahraman, Hasan; Sucakli, Mustafa Haki; Kilic, Talat; Celik, Mustafa; Koksal, Nurhan; Ekerbicer, Hasan Cetin

    2013-01-01

    Background Occupational exposure to cotton dust causes several diseases affecting the lungs, but only limited information is available on effects of long-term exposure. In this study, we aimed to evaluate longitudinal changes in selected parameters of pulmonary function in textile workers. Material/Methods This prospective cohort study began with 196 textile workers in 2006 and was completed in 2011 with 49 workers. We used standardized tests for pulmonary function on participants on the first day of the workweek in June of 2006 and 2011. Environmental samples of cotton dust were gathered with a vertical elutriator. Loss of pulmonary function was assessed based on gender and smoking status. Results The mean number of years participants worked in the textile factory was 7.61±1.83 years, and the mean age was 35.3+5.8 years. The annual FEV1 loss of all workers was 53.2 ml, giving a ratio of annual FEV1 loss to baseline FEV1 of 1.4%. Pulmonary function parameters of all participants in 2011 were significantly lower than those in 2006 (for all, p<0.05). In both surveys, pulmonary function in current smokers was lower, but this difference was not significant (p>0.05). Conclusions This study provides the first data on pulmonary functional loss in Turkish textile workers and supports the findings of other cohort studies that workers with long-term exposure to cotton dust may lose some pulmonary function. The ratio of annual FEV1 loss to baseline FEV1 appears to be a more accurate and comparable method than annual FEV1 loss for evaluating pulmonary functional loss. PMID:24346118

  3. Solid waste management of a chemical-looping combustion plant using Cu-based oxygen carriers.

    PubMed

    García-Labiano, Francisco; Gayán, Pilar; Adánez, Juan; De Diego, Luis F; Forero, Carmen R

    2007-08-15

    Waste management generated from a Chemical-Looping Combustion (CLC) plant using copper-based materials is analyzed by two ways: the recovery and recycling of the used material and the disposal of the waste. A copper recovery process coupled to the CLC plant is proposed to avoid the loss of active material generated by elutriation from the system. Solid residues obtained from a 10 kWth CLC prototype operated during 100 h with a CuO-Al2O3 oxygen carrier prepared by impregnation were used as raw material in the recovery process. Recovering efficiencies of approximately 80% were obtained in the process, where the final products were an eluate of Cu(NO3)2 and a solid. The eluate was used for preparation of new oxygen carriers by impregnation, which exhibited high reactivity for reduction and oxidation reactions as well as adequate physical and chemical properties to be used in a CLC plant. The proposed recovery process largely decreases the amount of natural resources (Cu and Al203) employed in a CLC power plant as well as the waste generated in the process. To determine the stability of the different solid streams during deposition in a landfill, these were characterized with respect to their leaching behavior according to the European Union normative. The solid residue finally obtained in the CLC plant coupled to the recovery process (composed by Al2O3 and CuAl2O4) can be classified as a stable nonreactive hazardous waste acceptable at landfills for nonhazardous wastes.

  4. 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

  5. Fas transduces dual apoptotic and trophic signals in hematopoietic progenitors.

    PubMed

    Pearl-Yafe, Michal; Stein, Jerry; Yolcu, Esma S; Farkas, Daniel L; Shirwan, Haval; Yaniv, Isaac; Askenasy, Nadir

    2007-12-01

    Stem cells and progenitors are often required to realize their differentiation potential in hostile microenvironments. The Fas/Fas ligand (FasL) interaction is a major effector pathway of apoptosis, which negatively regulates the expansion of differentiated hematopoietic cells. The involvement of this molecular interaction in the function of hematopoietic stem and progenitor cells is not well understood. In the murine syngeneic transplant setting, both Fas and FasL are acutely upregulated in bone marrow-homed donor cells; however, the Fas(+) cells are largely insensitive to FasL-induced apoptosis. In heterogeneous populations of lineage-negative (lin(-)) bone marrow cells and progenitors isolated by counterflow centrifugal elutriation, trimerization of the Fas receptor enhanced the clonogenic activity. Inhibition of caspases 3 and 8 did not affect the trophic signals mediated by Fas, yet it efficiently blocked the apoptotic pathways. Fas-mediated tropism appears to be of physiological significance, as pre-exposure of donor cells to FasL improved the radioprotective qualities of hematopoietic progenitors, resulting in superior survival of myeloablated hosts. Under these conditions, the activity of long-term reconstituting cells was not affected, as determined in sequential secondary and tertiary transplants. Dual caspase-independent tropic and caspase-dependent apoptotic signaling place the Fas receptor at an important junction of activation and death. This regulatory mechanism of hematopoietic homeostasis activates progenitors to promote the recovery from aplasia and converts into a negative regulator in distal stages of cell differentiation. Disclosure of potential conflicts of interest is found at the end of this article.

  6. 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.

  7. 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.

  8. PACAP regulation of secretion and proliferation of pure populations of gastric ECL cells.

    PubMed

    Oh, David S; Lieu, Sandy N; Yamaguchi, Dean J; Tachiki, Ken; Lambrecht, Nils; Ohning, Gordon V; Sachs, George; Germano, Patrizia M; Pisegna, Joseph R

    2005-01-01

    The gastric enterochromaffin-like (ECL) cell plays a major role in the regulation of gastric acid secretion. We have previously described that Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) is present on myenteric neurons in the rat and colocalizes with its high-affinity receptor, PAC1, expressed on the surface of gastric ECL cells. The study of ECL cell physiology has been hampered by the inability to isolate and purify ECL cells to homogeneity. Density gradient elutriation alone yields only 65-70% purity of ECL cells. In the present study, we used fluorescence-activated cell sorting (FACS) with a novel fluorescent ligand, Fluor-PACAP-38, for isolating pure ECL cells. FACS was used to isolate ECL cells based on their relatively small size, low density, and ability to bind the fluorescent ligand Fluor-PACAP-38. The sorted cells were unambiguously identified as ECL cells by immunohistochemical analysis using anti-PACAP type-I (PAC1), anti-histidine decarboxylase (HDC), and anti-somatostatin antibodies. Further confocal microscopy demonstrated that Fluor-PACAP-38, a ligand with a higher affinity for PAC1, bound to extracellular receptors of these FACS-purified cells. FACS yielded an average of 2 million ECL cells/4 rat stomachs, and >99% of the sorted cells were positive for PAC1 receptor and HDC expression. The absence of immunohistochemical staining for somatostatin indicated lack of contamination by gastric D cells, which are similar in size and shape to the ECL cells. Internalization of PACAP receptors and a rapid Ca2+ response in purified ECL cells were observed upon PACAP activation, suggesting that these cells are viable and biologically active. These ECL cells demonstrated a dose-dependent stimulation of proliferation in response to PACAP, with a maximum of 30% proliferation at a concentration of 10-7 M. Microarray studies were perfor med to confirm the expression of genes specific for ECL cells. These results demonstrate that rat gastric ECL

  9. Anaesthetic agents inhibit gastrin-stimulated but not basal histamine release from rat stomach ECL cells.

    PubMed

    Norlén, P; Kitano, M; Lindström, E; Håkanson, R

    2000-06-01

    By mobilizing histamine in response to gastrin, the ECL cells in the oxyntic mucosa play a key role in the control of the parietal cells and hence of gastric acid secretion. General anaesthesia suppresses basal and gastrin- and histamine-stimulated acid secretion. The present study examines if the effect of anaesthesia on basal and gastrin-stimulated acid secretion is associated with suppressed ECL-cell histamine secretion. A microdialysis probe was implanted in the submucosa of the ventral aspect of the acid-producing part of the stomach (32 rats). Three days later, ECL-cell histamine mobilization was monitored 2 h before and 4 h after the start of intravenous infusion of gastrin (5 nmol kg(-1) h(-1)). The rats were either conscious or anaesthetized. Four commonly used anaesthetic agents were given 1 h before the start of the experiments by intraperitoneal injection: chloral hydrate (300 mg kg(-1)), pentobarbitone (40 mg kg(-1)), urethane (1.5 g kg(-1)) and a mixture of fluanisone/fentanyl/midazolam (15/0.5/7.5 mg kg(-1)). In a parallel series of experiments, basal- and gastrin-induced acid secretion was monitored in six conscious and 25 anaesthetized (see above) chronic gastric fistula rats. All anaesthetic agents lowered gastrin-stimulated acid secretion; also the basal acid output was reduced (fluanisone/fentanyl/midazolam was an exception). Anaesthesia reduced gastrin-stimulated but not basal histamine release by 55 - 80%. The reduction in gastrin-induced acid response (70 - 95%) was strongly correlated to the reduction in gastrin-induced histamine mobilization. The correlation is in line with the view that the reduced acid response to gastrin reflects impaired histamine mobilization. Rat stomach ECL cells were purified by counter-flow elutriation. Gastrin-evoked histamine mobilization from the isolated ECL cells was determined in the absence or presence of anaesthetic agents in the medium. With the exception of urethane, they inhibited gastrin

  10. Isolated rat stomach ECL cells generate prostaglandin E(2) in response to interleukin-1 beta, tumor necrosis factor-alpha and bradykinin.

    PubMed

    Lindström, E; Lerner, U H; Håkanson, R

    2001-03-30

    The ECL cells control parietal cells by releasing histamine in their immediate vicinity. Gastrin and pituitary adenylate cyclase-activating peptide (PACAP) stimulate histamine secretion from isolated ECL cells, while somatostatin and galanin inhibit stimulated secretion. Prostaglandin E2 and related prostaglandins likewise suppress ECL-cell histamine secretion. Conceivably, that is how they inhibit acid secretion. In the present study, we examined if prostaglandin E2 can be generated by isolated ECL cells. Rat stomach ECL cells were purified (>90% purity) by counterflow elutriation and gradient centrifugation and cultured for 48 h. ECL cell stimulants (gastrin and PACAP) and inflammatory agents (interleukin-1 beta, tumor necrosis factor-alpha and bradykinin) were tested for their ability to induce prostaglandin E2 accumulation (24-h incubation), measured by radioimmunoassay. Gastrin and PACAP did not affect prostaglandin E2 accumulation but interleukin-1 beta (300 pg/ml), tumor necrosis factor-alpha (10 ng/ml) and bradykinin (1 microM) induced a 2- to 3-fold increase in the amount of prostaglandin E2 accumulated. While the combination of interleukin-1 beta and bradykinin induced a 9-fold increase, the combination interleukin-1 beta+tumor necrosis factor-alpha and bradykinin + tumor necrosis factor-alpha induced additive effects only. The combination of interleukin-1 beta + tumor necrosis factor-alpha + bradykinin did not induce a greater effect than interleukin-1 beta + bradykinin. The effect of interleukin-1 beta + bradykinin was abolished by adding 10 nM hydrocortisone (suppressing phospholipase A2 and cyclooxygenase) or 1 microM indomethacin (inhibiting cyclooxygenase). Incubating ECL cells in the presence of interleukin-1 beta+bradykinin for 24 h reduced their ability to secrete histamine in response to gastrin. The inhibitory effect was reversed by 1 microM indomethacin. Also, increasing the concentrations of hydrocortisone in the medium resulted in an

  11. Toxicity of sediments from around a North Sea oil platform: are metals or hydrocarbons responsible for ecological impacts?

    PubMed

    Grant, Alastair; Briggs, Andrew D

    2002-02-01

    Discharges of contaminated drill cuttings have caused appreciable ecological change of the benthos adjacent to many oil and gas platforms in the North Sea. Many platforms have large piles of cuttings lying beneath them and these probably present the greatest potential hazard to the environment during platform decommissioning and removal. There is, however, a lack of consensus on which aspects of drill cuttings are responsible for the adverse ecological effects. This hinders risk assessment of management options. Here we report data on the toxicity of sediments from around the North West Hutton platform to the amphipod Corophium volutator, the polychaete Arenicola marina and the Microtox" acute test system. Sediment was acutely toxic to Corophium out as far as 600 m from the platform. Sediment from 100 m from the platform remained acutely toxic to Corophium when 3% contaminated sediment was mixed with clean sediment. A 10% dilution of this sediment also inhibited Arenicola feeding almost completely. Sediment elutriates did not inhibit Microtox light output, but organics extracted by dichloromethane were very toxic. Fifteen minute EC50 values were as low as 0.25 mg ml(-1) and were strongly correlated with hydrocarbon concentrations. Metal concentrations in whole sediments were correlated with their toxicity to Corophium but the relationship was much weaker when data on dilutions were included. Except at sites immediately adjacent to the platform, metal concentrations were well below ERL values from the literature, so were too low to explain sediment toxicity. Toxicity of sediments to Corophium was closely correlated with their hydrocarbon content, even when tests on dilutions were included in the analysis. We conclude that hydrocarbons are the most significant cause of toxicity in these sediments contaminated with oil based drill cuttings and that polar organics, sulphide. ammonia and other water soluble substances are of much lower significance. Applying OSPAR

  12. Extracellular calcium and cholinergic stimulation of isolated canine parietal cells.

    PubMed Central

    Soll, A H

    1981-01-01

    The role of calcium gating in cholinergic stimulation of the function of parietal cells was studied using cells isolated from canine fundic mucosa by treatment with collagenase and EDTA and enriched by velocity separation in an elutriator rotor. Monitoring the accumulation of [14C[ aminopyrine as an index of parietal cell response, stimulation by carbachol, but not by histamine, was highly dependent upon the concentration of extracellular calcium. Incubation of parietal cells in 0-.1 mM calcium, rather than the usual 1.8 mM concentration, reduced the response to 100 microM carbachol by 92 +/- 2%, whereas histamine stimulation was impaired by 28 +/- 5%. A similar reduction in extracellular calcium suppressed the response to gastrin (100 nM) by 67 +/- 7%. The impairment of cholinergic stimulation found at low extracellular calcium concentrations was rapidly reversed with the readdition of calcium. Lanthanum, which blocks calcium movement across membranes, caused a similar pattern of effects on secretagogue stimulation of aminopyrine accumulation, with 100 microM lanthanum suppressing carbachol stimulation by 83 +/- 2%. This concentration of lanthanum suppressed gastrin stimulation by 40 +/- 7% and histamine stimulation by only 12 +/- 9%. Carbachol, but not histamine nor gastrin, stimulated 45Ca++ uptake. The magnitude of carbachol-stimulated calcium uptake correlated with the parietal cell content of the fractions examined (r = 0.88), and was dose responsive over carbachol concentrations from 1 microM to 1 mM. Atropine (100 nM) caused surmountable inhibition, and these effects of carbachol and atropine on calcium uptake correlated with their effects on oxygen consumption (r = 0.93) and [14C]-aminopyrine accumulation (r = 0.90). Cells preloaded with 45Ca++ lost cellular calcium in a time-dependent fashion; however, this rate of egress was not accelerated by treatment with histamine, gastrin, or carbachol, thus failing to implicate mobilization of intracellular calcium

  13. 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

  14. 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

  15. 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

  16. Effects of slope on the formation of dunes in dilute, turbulent pyroclastic currents: May 18th, 1980 Mt. St. Helens eruption

    NASA Astrophysics Data System (ADS)

    Bendana, Sylvana; Brand, Brittany D.; Self, Stephen

    2014-05-01

    The flanks of Mt St Helens volcano (MSH) are draped with thin, cross-stratified and stratified pyroclastic density current (PDC) deposits. These are known as the proximal bedded deposits produced during the May 18th, 1980 eruption of MSH. While the concentrated portions of the afternoon PDCs followed deep topographic drainages down the steep flanks of the volcano, the dilute overriding cloud partially decoupled to develop fully dilute, turbulent PDCs on the flanks of the volcano (Beeson, D.L. 1988. Proximal Flank Facies of the May 18, 1980 Ignimbrite: Mt. St. Helens, Washington.). The deposits along the flank thus vary greatly from those found in the pumice plain, which are generally thick, massive, poorly-sorted, block-rich deposits associated with the more concentrated portions of the flow (Brand et al, accepted. Dynamics of pyroclastic density currents: Conditions that promote substrate erosion and self-channelization - Mount St Helens, Washington (USA). JVGR). We explore the influence of topography on the formation of these dilute currents and influence of slope on the currents transport and depositional mechanisms. The deposits on steeper slopes (>15°) are fines depleted relative to the proximal bedded deposits on shallower slopes (<15°). Bedform amplitude and wavelength increase with increasing slope, as does the occurrence of regressive dunes. Increasing slope causes an increase in flow velocity and thus an increase in flow turbulence. The fines depleted deposits suggest that fine ash elutriation is more efficient in flows with stronger turbulence. The longer wavelength and amplitudes suggest that bedform morphology is directly related to flow velocity, an important finding since the controls on bedform wavelength and amplitude in density stratified flows remains poorly constrained. The occurrence of regressive dunes, often interpreted as high flow-regime bedforms, on steeper slopes relative to progressive dunes on shallower slopes further attests to the

  17. Germ cell mitogenic activity is associated with nerve growth factor-like protein(s).

    PubMed

    Onoda, M; Pflug, B; Djakiew, D

    1991-12-01

    The mitogenicity of germ cell proteins released from round spermatids (RS) and pachytene spermatocytes (PS) was investigated. Germ cells were isolated by centrifugal elutriation from 90-day-old rat testes and incubated in a supplement enriched culture media that lacked exogenous proteins. The conditioned culture media of RS and PS were dialysed/concentrated and lyophilized to prepare RS protein (RSP) and PS protein (PSP). Mitogenic activity of RSP and PSP was determined by 3H-thymidine incorporation into Swiss 3T3 fibroblasts. RSP and PSP stimulated 3H-thymidine incorporation by fibroblasts in a dose-dependent manner. At a higher concentration of RSP (300 micrograms/ml), fibroblast proliferation was stimulated from 6- to 20-fold of control cultures, whereas PSP (300 micrograms/ml) stimulated fibroblast proliferation 2.5-fold of control cultures. Since RSP exhibited substantially greater mitogenic activity than PSP we further investigated the RSP mitogenic substance(s) by immunoneutralization with antibodies against several growth factors. The mitogenic activity of RSP was significantly reduced by treatment with nerve growth factor (NGF) antibody, while neither the treatment of RSP with acidic fibroblast growth factor (aFGF) antibody, nor basic fibroblast growth factor (bFGF) antibody significantly modified the mitogenic activity of RSP. Interestingly, murine NGF-beta, recombinant human NGF-beta, and bovine serum albumin (BSA) did not exhibit mitogenic activity on 3T3 fibroblasts. Nevertheless, the presence of a NGF-like protein in RS and PS was confirmed by indirect immunofluorescence staining with a murine NGF antibody. Subsequently, a Western blot analysis with the NGF antibody identified two immunoreactive bands of 41 +/- 2 kDa and 51 +/- 1 kDa in both RSP and PSP under reduced conditions. These germ cell NGF-like proteins were apparently different from similarly prepared murine and human NGFs (13 kDa) in their molecular weight. Furthermore, neurite outgrowth

  18. 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

  19. High frequency of donor chimerism after allogeneic transplantation of CD34+-selected peripheral blood cells.

    PubMed

    Briones, J; Urbano-Ispizua, A; Lawler, M; Rozman, C; Gardiner, N; Marín, P; Salgado, C; Féliz, P; McCann, S; Montserrat, E

    1998-05-01

    Ex vivo T cell depletion of allogeneic grafts is associated with a high (up to 80%) rate of mixed chimerism (MC) posttransplantation. The number of transplanted progenitor cells is an important factor in achieving complete donor chimerism in the T cell depletion setting. Use of granulocyte colony-stimulating factor (G-CSF) peripheral blood allografts allows the administration of large numbers of CD34+ cells. We studied the chimeric status of 13 patients who received allogeneic CD34+-selected peripheral blood progenitor cell transplants (allo-PBPCTs/CD34+) from HLA-identical sibling donors. Patients were conditioned with cyclophosphamide (120 mg/kg) and total-body irradiation (13 Gy in four fractions). Apheresis products were T cell-depleted by the immunoadsorption avidin-biotin method. The median number of CD34+ and CD3+ cells infused was 2.8x10(6)/kg (range 1.9-8.6x10(6)/kg) and 0.4x10(6)/kg (range 0.3-1x10(6)/kg), respectively. Molecular analysis of the engraftment was performed using polymerase chain reaction (PCR) amplification of highly polymorphic short tandem repeat (PCR-STR) sequences in peripheral blood samples. MC was detected in two (15%) of 13 patients. These two patients relapsed at 8 and 10 months after transplant, respectively. The remaining 11 patients showed complete donor chimerism and were in clinical remission after a maximum follow-up period of 24 months (range 6-24 months). These results were compared with those obtained in 10 patients who were treated with T cell-depleted bone marrow transplantation by means of elutriation and who received the same conditioning treatment and similar amounts of CD3+ cells (median 0.45x10(6)/kg; not significant) but a lower number of CD34+ cells (median 0.8x10(6)/kg; p = 0.001). MC was documented in six of 10 patients (60%), which was significantly higher than in the allo-PBPCT/CD34+ group (p = 0.04). We conclude that a high frequency of complete donor chimerism is achieved in patients receiving allo-PBPCT/CD34

  20. oxLDL and eLDL Induced Membrane Microdomains in Human Macrophages

    PubMed Central

    Wallner, Stefan; Grandl, Margot; Liebisch, Gerhard; Peer, Markus; Orsó, Evelyn; Sigrüner, Alexander; Sobota, Andrzej; Schmitz, Gerd

    2016-01-01

    Background Extravasation of macrophages and formation of lipid-laden foam cells are key events in the development and progression of atherosclerosis. The degradation of atherogenic lipoproteins subsequently leads to alterations in cellular lipid metabolism that influence inflammatory signaling. Especially sphingolipids and ceramides are known to be involved in these processes. We therefore analyzed monocyte derived macrophages during differentiation and after loading with enzymatically (eLDL) and oxidatively (oxLDL) modified low-density lipoproteins (LDL). Methods Primary human monocytes were isolated from healthy, normolipidemic blood donors using leukapheresis and counterflow elutriation. On the fourth day of MCSF-induced differentiation eLDL (40 μg/ml) or oxLDL (80 μg/ml) were added for 48h. Lipid species were analyzed by quantitative tandem mass spectrometry. Taqman qPCR was performed to investigate transcriptional changes in enzymes involved in sphingolipid metabolism. Furthermore, membrane lipids were studied using flow cytometry and confocal microscopy. Results MCSF dependent phagocytic differentiation of blood monocytes had only minor effects on the sphingolipid composition. Levels of total sphingomyelin and total ceramide remained unchanged, while lactosylceramides, cholesterylesters and free cholesterol decreased. At the species level most ceramide species showed a reduction upon phagocytic differentiation. Loading with eLDL preferentially increased cellular cholesterol while loading with oxLDL increased cellular ceramide content. Activation of the salvage pathway with a higher mRNA expression of acid and neutral sphingomyelinase, neutral sphingomyelinase activation associated factor and glucosylceramidase as well as increased surface expression of SMPD1 were identified as potentially underlying mechanisms. Moreover, flow-cytometric analysis revealed a higher cell-surface-expression of ceramide, lactosylceramide (CDw17), globotriaosylceramide (CD77

  1. Modulation of hematopoiesis via alpha 1-adrenergic receptors on bone marrow cells.

    PubMed

    Maestroni, G J; Conti, A

    1994-03-01

    We have recently demonstrated that adrenergic agents can affect hematopoiesis after syngeneic bone marrow transplantation in mice. In particular, chemical sympathectomy by 6-hydroxydopamine (6-OHDA) and/or administration of the alpha 1-adrenergic antagonist prazosin were shown to increase the concentration of blood granulocytes, platelets, and bone marrow colony-forming units-granulocyte/macrophage (CFU-GM), and to induce a granulocytic hyperplasia of the spleen. Here we show that prazosin can also enhance myelopoiesis and platelet formation in normal mice. Furthermore, noradrenaline and the alpha 1-adrenergic agonist methoxamine could directly inhibit the in vitro growth of GM-CFU. The effect of noradrenaline was counteracted by prazosin and by other alpha-adrenergic antagonists such as phentolamine and yohimbine, in the following order of potency: prazosin > phentolamine > yohimbine. In line with these results, we were able to demonstrate that 3H-prazosin binds specifically to both bone marrow cell membranes and intact bone marrow cells. Scatchard analysis of the binding to intact cells revealed the presence of two binding sites. A kd of 0.98 +/- 0.32 nM and a B max of 5 +/- 2.9 fM/2 x 10(6) cells characterized the higher affinity site, while the lower affinity site displayed a kd of 55.9 +/- 8.2 nM and a B max of 44 +/- 7.7 fM/mg protein. These saturation studies, together with competition experiments to evaluate the ability of various adrenergic compounds to displace 3H-prazosin binding, classified the higher affinity site as an alpha 1-adrenergic receptor. The remaining low affinity binding site remains to be characterized. Furthermore, separation of bone marrow cells by counterflow centrifugal elutriation (CCE) showed that the high-affinity binding is due to a lymphoid/stem cell fraction with no blasts and no GM-CFU progenitors. The low-affinity site was apparent on the rotor-off fraction, which was enriched with GM-CFU progenitor cells. These findings

  2. 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

  3. Multiparticle simulation of collapsing volcanic columns and pyroclastic flow

    NASA Astrophysics Data System (ADS)

    Neri, Augusto; Esposti Ongaro, Tomaso; Macedonio, Giovanni; Gidaspow, Dimitri

    2003-04-01

    -particle collisions in the basal layer of the flow, whereas particle dispersal in the suspension current and ascending plumes is determined by the gas-particle drag. Simulations performed with a different grain-size distribution at the vent indicate that a fine-grained mixture produces a thicker and more mobile current, a larger runout distance, and a greater elutriated mass than the coarse-grained mixture.

  4. Pharmacological analysis of CCK2 receptor antagonists using isolated rat stomach ECL cells

    PubMed Central

    Lindström, Erik; Björkqvist, Maria; Håkanson, Rolf

    1999-01-01

    Gastrin stimulates rat stomach ECL cells to secrete histamine and pacreastatin, a chromogranin A (CGA)-derived peptide. The present report describes the effect of nine cholecystokinin2 (CCK2) receptor antagonists and one CCK1 receptor antagonist on the gastrin-evoked secretion of pancreastatin from isolated ECL cells.The CCK2 receptor antagonists comprised three benzodiazepine derivatives L-740,093, YM022 and YF476, one ureidoacetamide compound RP73870, one benzimidazole compound JB 93182, one ureidoindoline compound AG041R and three tryptophan dipeptoids PD 134308 (CI988), PD135158 and PD 136450. The CCK1 receptor antagonist was devazepide.A preparation of well-functioning ECL cells (∼80% purity) was prepared from rat oxyntic mucosa using counter-flow elutriation. The cells were cultured for 48 h in the presence of 0.1 nM gastrin; they were then washed and incubated with antagonist alone or with various concentrations of antagonist plus 10 nM gastrin (a maximally effective concentration) for 30 min. Gastrin dose-response curves were constructed in the absence or presence of increasing concentrations of antagonist. The amount of pancreastatin secreted was determined by radioimmunoassay.The gastrin-evoked secretion of pancreastatin was inhibited in a dose-dependent manner. YM022, AG041R and YF476 had IC50 values of 0.5, 2.2 and 2.7 nM respectively. L-740,093, JB93182 and RP73870 had IC50 values of 7.8, 9.3 and 9.8 nM, while PD135158, PD136450 and PD134308 had IC50 values of 76, 135 and 145 nM. The CCK1 receptor antagonist devazepide was a poor CCK2 receptor antagonist with an IC50 of about 800 nM.YM022, YF476 and AG041R were chosen for further analysis. YM022 and YF476 shifted the gastrin dose-response curve to the right in a manner suggesting competitive antagonism, while the effects of AG041R could not be explained by simple competitive antagonism. pKB values were 11.3 for YM022, 10.8 for YF476 and the apparent pKB for AG041R was 10.4. PMID

  5. 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

  6. Effects of adherence, activation and distinct serum proteins on the in vitro human monocyte maturation process.

    PubMed

    Akiyama, Y; Griffith, R; Miller, P; Stevenson, G W; Lund, S; Kanapa, D J; Stevenson, H C

    1988-03-01

    Elutriator-purified human monocytes were cultured in a serum-free (SF) medium, and various serum proteins and functional activating agents were assessed for their effects on the in vitro maturation of human monocytes to macrophages. Following 3 days of suspension culture in Teflon labware, 60% of the monocytes were easily recovered. When varying concentrations of human AB serum (HuAB) were employed, human monocyte maturation progressed rapidly; the kinetics of this maturation process during cell suspension culture were very similar to the pattern observed following adherence culture. In contrast, when SF medium was employed, a marked retardation of the monocyte maturation process was observed; this could not be attributed to any changes in cell recovery and/or viability. Thus, cells could be maintained in their monocytoid form for 3 days when cultured in SF medium. When HuAB was added after 3 days of culture, human monocyte maturation into macrophages proceeded at a normal rate. We attempted to characterize certain of the serum protein(s) found in HuAB which promoted the monocyte maturation process. Human immunoglobulin G (IgG) was found to be the most potent serum protein in increasing 5'-N activity and decreasing peroxidase activity of suspension cultured monocytes. Immunoglobulin M (IgM) and albumin (Alb) were shown not to have significant monocyte maturation activity. Heat-treated human gamma globulin and IgG purified by high-performance liquid chromatography (HPLC) were shown to have patterns identical with that of untreated HGG and IgG with regard to promoting monocyte maturation; F(ab')2 was not an active maturation promoter, indicating the need for an intact Fc portion of the IgG molecule. Fibrinogen and fibronectin also had maturation promoting activity. Finally, addition of the potent monocyte functional activators, muramyl dipeptide (MDP), polyriboinosinic:polyribocytidilic acid (Poly I:C), and lipopolysaccharide (LPS) had no effect on the monocyte

  7. 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

  8. Development of an automated closed system for generation of human lymphokine-activated killer (LAK) cells for use in adoptive immunotherapy.

    PubMed

    Muul, L M; Nason-Burchenal, K; Carter, C S; Cullis, H; Slavin, D; Hyatt, C; Director, E P; Leitman, S F; Klein, H G; Rosenberg, S A

    1987-08-03

    Immunotherapy utilizing the adoptive transfer of lymphokine-activated killer (LAK) cells in conjunction with recombinant interleukin-2 (IL-2) can mediate tumor regression in some patients with advanced cancer. The activation of large numbers of LAK cells was performed in roller bottles in a research laboratory setting and required meticulous aseptic technique, at least one skilled technician per patient and one laminar flow hood per patient. To reduce the complexity and expense of LAK cell generation for human immunotherapy trials we have developed a closed-system automated procedure using a continuous flow blood cell separator. PBL were obtained by standard apheresis techniques. Platelets and plasma were elutriated using countercentrifugal flow of saline in the cell separator machine. The washed PBL were underlaid with Ficoll-Hypaque (FH) in the original separation bag. Lymphocytes were then flushed into a collection bag where they were concentrated and washed with 2 liters of saline. Mean recovery from the automated FH technique was 54.6 +/- 4.3% compared to 62.3 +/- 4.0% using manual methods in 50 ml tubes (P greater than 0.05). Cells were diluted in the collection bag with RPMI 1640 +/- 2% human AB serum and could be dispensed in an automated fashion to polyolefin bags via a sample port with 1000-1500 U/ml IL-2. After 3-4 days of culture in 5% CO2 at 37 degrees C, activated cells from the bags were harvested and washed in a closed system using the continuous flow cell separator. Cell yield from the harvest was 79.2 +/- 5.4% in the automated system compared to 64.9 +/- 5.0% in the standard procedure using manual harvest of roller bottles (P less than 0.01). Lytic capacity of the cells against fresh human tumor in a 4 h 51Cr release assay was equivalent in cells processed either by the automated or the conventional manual method. The advantages of a closed system include decreased potential for microbial contamination and reduced labor and capital equipment costs

  9. Effects of Irrigation and Verticillium dahliae on Cauliflower Root and Shoot Growth Dynamics.

    PubMed

    Xiao, C L; Subbarao, K V

    2000-09-01

    ABSTRACT Cauliflower root and plant growth and Verticillium wilt development were evaluated under different moisture regimes in the presence or absence of V. dahliae. Treatments included two main plots (V. dahliae-infested and fumigated), two subplots (furrow and subsurface drip irrigation), and three sub-subplots (deficit, moderate, and excessive regimes) that were arranged in a split-split-plot design in the field. Soil cores with roots were periodically sampled at 5 and 25 cm distance from plants. Total roots in each soil core were extracted with a hydropneumatic root elutriator, and root length from each sample was determined with a digital image analysis system. Incidence and severity of Verticillium wilt, plant height, number of leaves, and dry weights of leaves and roots were determined on 10 plants sampled at 7- to 10-day intervals 1 month after cauliflower transplanting and continued until harvest. To evaluate the effects of Verticillium wilt-induced stress on cauliflower plants, stomatal resistance was measured in upper healthy and lower (or diseased) leaves. Root length density at 5 and 25 cm from plant was significantly (P < 0.05) higher in subsurface drip than in furrow irrigation. Root length density was significantly higher in excessive irrigation regime than in the other regimes. Concomitantly, there was higher wilt incidence and severity in excessive and moderate regimes than deficit regime regardless of the irrigation method. Plant height was affected by irrigation methods and deficit regime. Neither the method of irrigation nor the quantity of water affected the other variables. Stomatal resistance in lower diseased leaves was significantly higher in infested than in fumigated plots but it was not in the upper healthy leaves. In this study, cauliflower yield was not affected by V. dahliae and irrigation method, but the deficit irrigation regime resulted in reduced yield even though it suppressed wilt in cauliflower. Thus, higher moisture levels

  10. 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

  11. 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

  12. Cryptic chemotactic activity of fibronectin for human monocytes resides in the 120-kDa fibroblastic cell-binding fragment.

    PubMed

    Clark, R A; Wikner, N E; Doherty, D E; Norris, D A

    1988-08-25

    Monocytes and lymphocytes form a second wave of infiltrating blood leukocytes in areas of tissue injury. The mechanisms for monocyte accumulation at these sites are not completely understood. Recently, however, fragments from extracellular matrix proteins including collagen, elastin, and fibronectin have been shown to induce monocyte chemotaxis. In this report we demonstrate that chemotactic activity for human monocytes is expressed when a 120-kDa fragment containing the RGDS cell-binding peptide is released from intact fibronectin or from larger fibronectin fragments. Monocytes, either from mononuclear cell Ficoll-Hypaque preparations (10-20% monocytes, 89-90% lymphocytes) or from elutriation preparations (95% monocytes, 5% lymphocytes), but not lymphocytes, migrated toward 120-kDa fragment preparations (10(-7) M) in blind-end chambers when the cells were separated from the chemoattractant by a 5-micron pore polycarbonate filter either alone or overlying a 0.45-micron pore nitrocellulose filter. Neutrophils migrated toward zymosan-activated serum but not toward 10(-5)-10(-8) M concentrations of the 120-kDa fragment. Intact fibronectin had no chemotactic activity for human monocytes. Fibronectin was isolated from citrated human plasma by sequential gelatin-Sepharose affinity and DEAE ion-exchange chromatography in the presence of buffers containing 1 mM phenylmethylsulfonyl fluoride to prevent fragmentation. Controlled enzymatic digestion with thermolysin cleaved fibronectin into 30 kDa fibrin, 45 kDa collagen, and 150/160-kDa cell and heparin domains. Upon prolonged digestion, purified 150/160-kDa fragments were cleaved into 120-kDa cell and 30/40-kDa heparin-binding fragments. Even though the intact fibronectin molecule, the 150/160-kDa fragments, and the 120-kDa fragment, have cell binding activity for Chinese hamster ovary fibroblasts, only the 120-kDa fragment expressed chemotactic activity for human monocytes. Thus, the 120-kDa fibroblastic cell

  13. November 16th 2006 Lateral Collapse of South-East Crater on Mount Etna Volcano and Hazard Implication

    NASA Astrophysics Data System (ADS)

    Norini, G.; Andronico, D.; de Beni, E.; Polacci, M.; Grieco, F.

    2007-05-01

    On November 16th 2006 a sector collapse affected the unstable eastern flank of the South-East Crater (SEC) on Mount Etna Volcano. The SEC is located on the Etna volcano summit and is an active steep cone formed by alternated scoria deposits and lava flows traversed by numerous fractures. The collapse occurred during an eruptive event and was probably triggered by effusive and explosive activity on the SEC. The resulting debris avalanche involved both altered and fresh materials, including an active lava flow. The collapse produced a debris avalanche deposit emplaced on the eastern flank of the volcano, extending up to 1.1 km from the source. The deposit is formed by superimposed flow units, suggesting that it is the result of at least two discrete events, the total volume is estimated in the order of 300,000-500,000 m3. A block-facies and a matrix-facies were recognized in the field. The former is composed by blocks up to 1 meters in dimension and has maximum thickness of 4-5 meters. The matrix-facies is mainly composed by a convection-driven flow deposit consisted of fine ash produced by elutriation during emplacement of the block-facies, maximum observed thickness is 30 cm. The reconstruction of the event has been supported by numerical simulations that were executed using TITAN2D, a modeling software for granular avalanches and landslides developed by GMFG at Buffalo. This approach is also useful to estimate the area that would be affected by an eventual similar event that could interest the SEC. The area affected by the lateral collapse of the SEC is a small portion of the summit area of Mount Etna, but the fact that no one was killed or injured should be considered fortuitous. This because the summit and adjacent areas of the volcano are usually visited by several people, especially tourists, not prepared to face this type of events, which was never observed and described during the recent activity of Mount Etna. The collapse of November 16th 2006 underscores

  14. Prostaglandins inhibit secretion of histamine and pancreastatin from isolated rat stomach ECL cells

    PubMed Central

    Lindström, Erik; Håkanson, Rolf

    1998-01-01

    The present study examines the effect of naturally occurring prostanoids and prostaglandin (PG) congeners on gastrin- and pituitary adenylate cyclase-activating peptide (PACAP)-evoked histamine and pancreastatin secretion from isolated rat stomach ECL cells. ECL cells (75–85% purity) were isolated from rat stomach using pronase digestion followed by repeated counter-flow elutriation and cultured for 48 h before secretion experiments. The release of histamine and pancreastatin was determined by radioimmunoassay. None of the PGs tested stimulated the release of either histamine or pancreastatin. PGE1 and PGE2 inhibited both gastrin- and PACAP-evoked histamine and pancreastatin secretion (IC50=1–2×10−10 M). Most other naturally occuring prostanoids and PG congeners had no or little inhibitory effect. The PGE analogues misoprostol and sulprostone were more potent (IC50=0.9×10−11 M and 2×10−11 M respectively) than PGE1 and PGE2. The rank order of potency was misoprostol>sulprostone>PGE1=PGE2, suggesting the involvement of the so-called EP3 receptor. The effects of PGs on the stomach ECL cells may be direct or indirect, for instance through the stimulated release of somatostatin from contaminating D cells (2–3%). However, the amount of somatostatin in the cell culture after 48 h was below the limit of detection, and somatostatin immunoneutralization did not prevent misoprostol from inhibiting secretion from the ECL cells. The misoprostol-induced inhibition was reversed by pertussis toxin suggesting the involvement of G-protein subunits Gα0 and/or Gαi. In view of the potency by which PGE1, PGE2, misoprostol and sulprostone inhibited the stimulated release of histamine and pancreastatin, we suggest that the ECL cells represent a primary target for prostaglandins acting via an EP3 receptor in the oxyntic mucosa. The results suggest that the clinically useful effect of misoprostol as an anti-ulcer drug reflects its ability to inhibit stomach ECL

  15. 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

  16. 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

  17. 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.

  18. Dynamics of pyroclastic density currents: Conditions that promote substrate erosion and self-channelization - Mount St Helens, Washington (USA)

    NASA Astrophysics Data System (ADS)

    Brand, Brittany D.; Mackaman-Lofland, Chelsea; Pollock, Nicholas M.; Bendaña, Sylvana; Dawson, Blaine; Wichgers, Pamela

    2014-04-01

    The May 18th, 1980 eruption of Mount St. Helens (MSH) produced multiple pyroclastic density currents (PDCs), burying the area north of the volcano under 10s of meters of deposits. Detailed measurements of recently exposed strata from these PDCs provide substantial insight into the dynamics of concentrated currents including inferences on particle-particle interactions, current mobility due to sedimentation fluidization and internal pore pressure, particle support mechanisms, the influence of surface roughness and the conditions that promote substrate erosion and self-channelization. Four primary flow units are identified along the extensive drainage system north of the volcano. Each flow unit has intricate vertical and lateral facies changes and complex cross-cutting relationships away from source. Each flow unit is an accumulation from an unsteady but locally sustained PDC or an amalgamation of several PDC pulses. The PDCs associated with Units I and II likely occurred during the pre-climactic, waxing phase of the eruption. These currents flowed around and filled in the hummocky topography, leaving the massive to diffusely-stratified deposits of Units I and II. The deposits of both Units I and II are generally more massive in low lying areas and more stratified in areas of high surface roughness, suggesting that surface roughness enhanced basal shear stress within the flow boundary. Units III and IV are associated with the climactic phase of the eruption, which produced the most voluminous and wide-spread PDCs. Both flow units are characteristically massive and enriched in vent-derived lithic blocks. These currents flowed over and around the debris avalanche deposits, as evidenced by the erosion of blocks from the hummocks. Unit III is massive, poorly sorted, and shows little to no evidence of elutriation or segregation of lithics and pumice, suggesting a highly concentrated current where size-density segregation was suppressed. Unit IV shows similar depositional

  19. Dynamics of pyroclastic density currents: Conditions that promote substrate erosion and self-channelization - Mount St Helens, Washington (Invited)

    NASA Astrophysics Data System (ADS)

    Brand, B. D.; Pollock, N. M.; Mackaman-Lofland, C. A.; Bendana, S.

    2013-12-01

    elutriation or segregation of lithics and pumice, suggesting a highly concentrated current where size-density segregation was suppressed. Unit IV shows similar depositional features but typically has a basal lithic region, is variably fines-depleted and contains pumice lobes, suggesting density segregation in a less concentrated current relative to Unit III. Deep, erosive channels cut by the Unit III current and thick lithic levee deposits within Unit IV occur in an area where debris avalanche relief is limited, suggesting self-channelization developed as a function of internal flow dynamics. Finally, the combination of thick, massive deposits with a high percentage of fine ash within Unit III and in the medial-distal depositional regions of Units II-IV suggests the PDCs developed and maintained a high internal pore pressure during transport and deposition. Thus the most important results of this work include our ability to understand the role of internal pore pressure on current mobility, the influence of self-channelization on carrying capacity of the currents and the influence of surface roughness on substrate erosion. These observations have critical consequences for understanding the flow dynamics and hazard potential of PDCs.

  20. Air entrainment and the dynamics of volcanic jets and plumes

    NASA Astrophysics Data System (ADS)

    Mastin, L. G.; Solovitz, S.

    2008-12-01

    vectors. In our experiments, the jet starts impulsively by developing a mushroom-shaped head, whose base is surrounded by inward- and upward-oriented vectors that indicate concentrated air engulfment. For steady flow, vectors in ambient air near the jet base are directed horizontally inward; but as the horizontal distance from the jet margin increases from ~0.5 to 5 jet diameters, vector orientation becomes steeply upward. The large vertical component of air velocity suggests that the presence of a crater or other topography may affect air entrainment. Also, upward air movement may accentuate the entrainment into the jet of fine debris elutriated from pyroclastic flows on the volcano's flanks.

  1. 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.

  2. A Weeks-Long Hiatus During the Quilotoa 800 BP VEI 6 Eruption

    NASA Astrophysics Data System (ADS)

    Ort, M. H.; Cashman, K. V.; Best, J. A.; Mothes, P. A.; Bustillos, J.; di Muro, A.; Rosi, M.; Ruscitto, D. M.; Hall, M. L.

    2009-12-01

    hiatus and led directly into the U3 eruption. We suggest that the vitric-rich U2A and crystal-rich U2B material were separated and concentrated in the uppermost conduit during this hiatus by gas streaming from deep non-erupted magma that was decompressed during the U1 eruption. Preliminary FTIR melt inclusion analyses in U1-U2A quartz and plagioclase crystals indicate high magmatic H2O (5.9-6.2 wt%), consistent with a deep magma chamber, but U2B and lower U3 quartz MIs have 3.6-3.9% H2O. With no caldera collapse to reduce the system volume as eruption continued, the U1 eruption stalled, perhaps when the vesiculation front lowered to the point where volatiles and magma separated during ascent. Vigorous degassing, as observed at Mt. Pinatubo (July-August 1991), elutriated vitric material and left crystals and lithic fragments. Gas blasts (U2A) removed the vitric cap and continuous gas streaming through hot crystals produced the crystal fallout (U2B). U2 was probably created by an increase in gas flux related to ascent of a new magma batch (U3).

  3. 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.

  4. 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

  5. Conversion of 5(10)-oestrene-3 beta,17 beta-diol to 19-nor-4-ene-3-ketosteroids by luteal cells in vitro: possible involvement of the 3 beta-hydroxysteroid dehydrogenase/isomerase.

    PubMed

    Lee, C M; Tekpetey, F R; Armstrong, D T; Khalil, M W

    1991-05-01

    We have previously suggested that in porcine granulosa cells, a putative intermediate, 5(10)-oestrene-3,17-dione is involved in 4-oestrene-3,17-dione (19-norandrostenedione; 19-norA) and 4-oestren-17 beta-ol-3-one (19-nortestosterone: 19-norT) formation from C19 aromatizable androgens. In this study, luteal cells prepared from porcine, bovine and rat corpora lutea by centrifugal elutriation were used as a source of 3 beta-hydroxysteroid dehydrogenase/isomerase in order to investigate the role of this enzyme in the biosynthesis of 19-norsteroids. Small porcine luteal cells made mainly 19-norT and large porcine luteal cells 19-norA from 5(10)-oestrene-3 beta,17 beta-diol, the reduced product of the putative intermediate 5(10)-oestrene-3,17-dione. However, neither small nor large cells metabolized androstenedione to 19-norsteroids. Serum and serum plus LH significantly stimulated formation of both 19-norA and 19-norT from 5(10)-oestrene-3 beta,17 beta-diol, compared with controls. Inhibitors of the 3 beta-hydroxysteroid dehydrogenase/isomerase (trilostane and cyanoketone) significantly reduced formation of 19-norT in small porcine luteal cells and 19-norA in large porcine luteal cells, although they were effective at different concentrations in each cell type. In parallel incubations, formation of [4-14C]androstenedione from added [4-14C]dehydroepiandrosterone was also inhibited by cyanoketone in both small and large porcine luteal cells in a dose-dependent manner; however, trilostane (up to 100 mumol/l) did not inhibit androstenedione formation in large porcine luteal cells. In addition, the decrease in progesterone synthesis induced by trilostane and cyanoketone (100 mumol/l each) was accompanied by a parallel accumulation of pregnenolone in both cell types. These results suggest that 3 beta-hydroxysteroid dehydrogenase/isomerase, or a closely related enzyme, present in small and large porcine luteal cells can convert added 5(10)-3 beta-hydroxysteroids into 19-nor-4

  6. 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.

  7. 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