Use of halophytes to remove carbon from the atmosphere: Results of a demonstration experiment. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glenn, E.; Olsen, M.; Frye, R.

1994-01-01

The project examined the feasibility of using salt-tolerant plants, halophytes, to sequester large quantities of C from the atmosphere and enhance food production in desert regions of the world by using seawater and other saline water sources for irrigation. Field experiments using 40 ppt seawater in a coastal desert site in Mexico recorded biomass yields of 16.7--34.0 t ha{sup {minus}1} yr{sup {minus}1} and C yields of 5.4--10.1 t ha{sup {minus}1} yr{sup {minus}1}for the best candidate species in the genera Atriplex, Batis, Salicornia, Suaeda and Sesuvium. These yields are comparable to high-yielding forestry and agricultural biomass crops. Irrigation requirements and othermore » costs of production were within the range of conventional crops as well. Laboratory and field experiments showed that seawater had an inhibitory effect on the decomposition of halophyte biomass in soil; hence, a strategy for C sequestration in desert soil was proposed, in which halophyte crop by-products would be returned to the soil to store C while the harvested portions would be used for oilseeds and animal feed.« less

Poromechanical response of naturally fractured sorbing media

NASA Astrophysics Data System (ADS)

Kumar, Hemant

The injection of CO2 in coal seams has been utilized for enhanced gas recovery and potential CO2 sequestration in unmineable coal seams. It is advantageous because as it enhances the production and significant volumes of CO2 may be stored simultaneously. The key issues for enhanced gas recovery and geologic sequestration of CO2 include (1) Injectivity prediction: The chemical and physical processes initiated by the injection of CO2 in the coal seam leads to permeability/porosity changes (2) Up scaling: Development of full scale coupled reservoir model which may predict the enhanced production, associated permeability changes and quantity of sequestered CO2. (3) Reservoir Stimulation: The coalbeds are often fractured and proppants are placed into the fractures to prevent the permeability reduction but the permeability evolution in such cases is poorly understood. These issues are largely governed by dynamic coupling of adsorption, fluid exchange, transport, water content, stress regime, fracture geometry and physiomechanical changes in coals which are triggered by CO 2 injection. The understanding of complex interactions in coal has been investigated through laboratory experiments and full reservoir scale models are developed to answer key issues. (Abstract shortened by ProQuest.).

Migration rates and formation injectivity to determine containment time scales of sequestered carbon dioxide

USGS Publications Warehouse

Burke, Lauri

2012-01-01

Additionally, this research establishes a methodology to calculate the injectivity of a target formation. Because injectivity describes the pressure increase due to the introduction of fluids into a formation, the relevant application of injectivity is to determine the pressure increase, due to an injection volume and flow rate, that will induce fractures in the reservoir rocks. This quantity is defined mathematically as the maximum pressure differential between the hydrostatic gradient and the fracture gradient of the target formation. Injectivity is mathematically related to the maximum pressure differential of the formation, and can be used to determine the upper limit for the pressure increase that an injection target can withstand before fracturing.

Potential of global croplands and bioenergy crops for climate change mitigation through deployment for enhanced weathering.

PubMed

Kantola, Ilsa B; Masters, Michael D; Beerling, David J; Long, Stephen P; DeLucia, Evan H

2017-04-01

Conventional row crop agriculture for both food and fuel is a source of carbon dioxide (CO 2 ) and nitrous oxide (N 2 O) to the atmosphere, and intensifying production on agricultural land increases the potential for soil C loss and soil acidification due to fertilizer use. Enhanced weathering (EW) in agricultural soils-applying crushed silicate rock as a soil amendment-is a method for combating global climate change while increasing nutrient availability to plants. EW uses land that is already producing food and fuel to sequester carbon (C), and reduces N 2 O loss through pH buffering. As biofuel use increases, EW in bioenergy crops offers the opportunity to sequester CO 2 while reducing fossil fuel combustion. Uncertainties remain in the long-term effects and global implications of large-scale efforts to directly manipulate Earth's atmospheric CO 2 composition, but EW in agricultural lands is an opportunity to employ these soils to sequester atmospheric C while benefitting crop production and the global climate. © 2017 The Author(s).

Scattering and sequestering of blow-up moduli in local string models

NASA Astrophysics Data System (ADS)

Conlon, Joseph P.; Witkowski, Lukas T.

2011-12-01

We study the scattering and sequestering of blow-up fields - either local to or distant from a visible matter sector - through a CFT computation of the dependence of physical Yukawa couplings on the blow-up moduli. For a visible sector of D3-branes on orbifold singularities we compute the disk correlator left< {tau_s^{{(1)}}tau_s^{{(2)}}...tau_s^{{(n)}}ψ ψ φ } rightrangle between orbifold blow-up moduli and matter Yukawa couplings. For n = 1 we determine the full quantum and classical correlator. This result has the correct factorisation onto lower 3-point functions and also passes numerous other consistency checks. For n > 1 we show that the structure of picture-changing applied to the twist operators establishes the sequestering of distant blow-up moduli at disk level to all orders in α'. We explain how these results are relevant to suppressing soft terms to scales parametrically below the gravitino mass. By giving vevs to the blow-up fields we can move into the smooth limit and thereby derive CFT results for the smooth Swiss-cheese Calabi-Yaus that appear in the Large Volume Scenario.

Use of the semipermeable membrane device as an in situ sampler of waterborne bioavailable PCDD and PCDF residues at sub-parts-per-quadrillion concentrations

USGS Publications Warehouse

Lebo, Jon A.; Gale, Robert W.; Petty, Jimmie D.; Tillitt, Donald E.; Huckins, James N.; Meadows, John C.; Orazio, Carl E.; Echols, Kathy R.; Schroeder, Dennis J.; Inmon, Lloyd E.

1995-01-01

Semipermeable membrane devices (SPMDs) were used to passively sample aqueous polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in Bayou Meto, AR. The two sites were upstream and downstream from the confluence with a tributary that delivers PCDDs and PCDFs to the Bayou. Following dialysis, cleanup, and fractionation, four replicate 17-9 SPMD samples from each site were analyzed by GUMS, and four were evaluated by H411E bioassay. Traces of only OCDD and HpCDDs were detected in samples from the upstream site. The four samples from below the tributary contained averages of 1550 ± 80 pg of 2,3,7,8-TCDD, 1640 ± 80 pg of 2,3,7,8-TCDF, and lesser quantities of other congeners. The TCDD equivalents obtained by bioassay of replicate SPMD samples agreed well with results obtained by GC/MS. The quantities of 2,3,7,8- TCDD and 2,3,7,8-TCDF sequestered by SPMDs at the downstream site were used to estimate the aqueous concentrations for both compounds as 2 pg/L.

Histochemical evidence for the differential surface labeling, uptake, and intracellular transport of a colloidal gold-labeled insulin complex by normal human blood cells.

PubMed

Ackerman, G A; Wolken, K W

1981-10-01

A colloidal gold-labeled insulin-bovine serum albumin (GIA) reagent has been developed for the ultrastructural visualization of insulin binding sites on the cell surface and for tracing the pathway of intracellular insulin translocation. When applied to normal human blood cells, it was demonstrated by both visual inspection and quantitative analysis that the extent of surface labeling, as well as the rate and degree of internalization of the insulin complex, was directly related to cell type. Further, the pathway of insulin (GIA) transport via round vesicles and by tubulo-vesicles and saccules and its subsequent fate in the hemic cells was also related to cell variety. Monocytes followed by neutrophils bound the greatest amount of labeled insulin. The majority of lymphocytes bound and internalized little GIA, however, between 5-10% of the lymphocytes were found to bind considerable quantities of GIA. Erythrocytes rarely bound the labeled insulin complex, while platelets were noted to sequester large quantities of the GIA within their extracellular canalicular system. GIA uptake by the various types of leukocytic cells appeared to occur primarily by micropinocytosis and by the direct opening of cytoplasmic tubulo-vesicles and saccules onto the cell surface in regions directly underlying surface-bound GIA. Control procedures, viz., competitive inhibition of GIA labeling using an excess of unlabeled insulin in the incubation medium, preincubation of the GIA reagent with an antibody directed toward porcine insulin, and the incorporation of 125I-insulin into the GIA reagent, indicated the specificity and selectivity of the GIA histochemical procedure for the localization of insulin binding sites.

Quasifixed points from scalar sequestering and the little hierarchy problem in supersymmetry

NASA Astrophysics Data System (ADS)

Martin, Stephen P.

2018-02-01

In supersymmetric models with scalar sequestering, superconformal strong dynamics in the hidden sector suppresses the low-energy couplings of mass dimension 2, compared to the squares of the dimension-1 parameters. Taking into account restrictions on the anomalous dimensions in superconformal theories, I point out that the interplay between the hidden and visible sector renormalizations gives rise to quasifixed point running for the supersymmetric Standard Model squared mass parameters, rather than driving them to 0. The extent to which this dynamics can ameliorate the little hierarchy problem in supersymmetry is studied. Models of this type in which the gaugino masses do not unify are arguably more natural, and are certainly more likely to be accessible, eventually, to the Large Hadron Collider.

Radioimmunoassays of hidden viral antigens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neurath, A.R.; Strick, N.; Baker, L.

1982-07-01

Antigens corresponding to infectious agents may be present in biological specimens only in a cryptic form bound to antibodies and, thus, may elude detection. We describe a solid-phase technique for separation of antigens from antibodies. Immune complexes are precipitated from serum by polyethylene glycol, dissociated with NaSCN, and adsorbed onto nitrocellulose or polystyrene supports. Antigens remain topographically separated from antibodies after removal of NaSCN and can be detected with radiolabeled antibodies. Genomes from viruses immobilized on nitrocellulose can be identified by nucleic acid hybridization. Nanogram quantities of sequestered hepatitis B surface and core antigens and picogram amounts of hepatitis Bmore » virus DNA were detected. Antibody-bound adenovirus, herpesvirus, and measles virus antigens were discerned by the procedure.« less

Assessing ocean alkalinity for carbon sequestration

NASA Astrophysics Data System (ADS)

Renforth, Phil; Henderson, Gideon

2017-09-01

Over the coming century humanity may need to find reservoirs to store several trillions of tons of carbon dioxide (CO2) emitted from fossil fuel combustion, which would otherwise cause dangerous climate change if it were left in the atmosphere. Carbon storage in the ocean as bicarbonate ions (by increasing ocean alkalinity) has received very little attention. Yet recent work suggests sufficient capacity to sequester copious quantities of CO2. It may be possible to sequester hundreds of billions to trillions of tons of C without surpassing postindustrial average carbonate saturation states in the surface ocean. When globally distributed, the impact of elevated alkalinity is potentially small and may help ameliorate the effects of ocean acidification. However, the local impact around addition sites may be more acute but is specific to the mineral and technology. The alkalinity of the ocean increases naturally because of rock weathering in which >1.5 mol of carbon are removed from the atmosphere for every mole of magnesium or calcium dissolved from silicate minerals (e.g., wollastonite, olivine, and anorthite) and 0.5 mol for carbonate minerals (e.g., calcite and dolomite). These processes are responsible for naturally sequestering 0.5 billion tons of CO2 per year. Alkalinity is reduced in the ocean through carbonate mineral precipitation, which is almost exclusively formed from biological activity. Most of the previous work on the biological response to changes in carbonate chemistry have focused on acidifying conditions. More research is required to understand carbonate precipitation at elevated alkalinity to constrain the longevity of carbon storage. A range of technologies have been proposed to increase ocean alkalinity (accelerated weathering of limestone, enhanced weathering, electrochemical promoted weathering, and ocean liming), the cost of which may be comparable to alternative carbon sequestration proposals (e.g., $20-100 tCO2-1). There are still many unanswered technical, environmental, social, and ethical questions, but the scale of the carbon sequestration challenge warrants research to address these.

Aggregation of ALS-linked FUS mutant sequesters RNA binding proteins and impairs RNA granules formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takanashi, Keisuke; Yamaguchi, Atsushi, E-mail: atsyama@restaff.chiba-u.jp

Highlights: • Aggregation of ALS-linked FUS mutant sequesters ALS-associated RNA-binding proteins (FUS wt, hnRNP A1, and hnRNP A2). • Aggregation of ALS-linked FUS mutant sequesters SMN1 in the detergent-insoluble fraction. • Aggregation of ALS-linked FUS mutant reduced the number of speckles in the nucleus. • Overproduced ALS-linked FUS mutant reduced the number of processing-bodies (PBs). - Abstract: Protein aggregate/inclusion is one of hallmarks for neurodegenerative disorders including amyotrophic lateral sclerosis (ALS). FUS/TLS, one of causative genes for familial ALS, encodes a multifunctional DNA/RNA binding protein predominantly localized in the nucleus. C-terminal mutations in FUS/TLS cause the retention and the inclusionmore » of FUS/TLS mutants in the cytoplasm. In the present study, we examined the effects of ALS-linked FUS mutants on ALS-associated RNA binding proteins and RNA granules. FUS C-terminal mutants were diffusely mislocalized in the cytoplasm as small granules in transiently transfected SH-SY5Y cells, whereas large aggregates were spontaneously formed in ∼10% of those cells. hnRNP A1, hnRNP A2, and SMN1 as well as FUS wild type were assembled into stress granules under stress conditions, and these were also recruited to FUS mutant-derived spontaneous aggregates in the cytoplasm. These aggregates stalled poly(A) mRNAs and sequestered SMN1 in the detergent insoluble fraction, which also reduced the number of nuclear oligo(dT)-positive foci (speckles) in FISH (fluorescence in situ hybridization) assay. In addition, the number of P-bodies was decreased in cells harboring cytoplasmic granules of FUS P525L. These findings raise the possibility that ALS-linked C-terminal FUS mutants could sequester a variety of RNA binding proteins and mRNAs in the cytoplasmic aggregates, which could disrupt various aspects of RNA equilibrium and biogenesis.« less

PLANTS AS BIO-MONITORS FOR 137CS, 238PU, 239, 240PU AND 40K AT THE SAVANNAH RIVER SITE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caldwell, E.; Duff, M.; Ferguson, C.

2010-12-16

The nuclear fuel cycle generates a considerable amount of radioactive waste, which often includes nuclear fission products, such as strontium-90 ({sup 90}Sr) and cesium-137 ({sup 137}Cs), and actinides such as uranium (U) and plutonium (Pu). When released into the environment, large quantities of these radionuclides can present considerable problems to man and biota due to their radioactive nature and, in some cases as with the actinides, their chemical toxicity. Radionuclides are expected to decay at a known rate. Yet, research has shown the rate of elimination from an ecosystem to differ from the decay rate due to physical, chemical andmore » biological processes that remove the contaminant or reduce its biological availability. Knowledge regarding the rate by which a contaminant is eliminated from an ecosystem (ecological half-life) is important for evaluating the duration and potential severity of risk. To better understand a contaminants impact on an environment, consideration should be given to plants. As primary producers, they represent an important mode of contamination transfer from sediments and soils into the food chain. Contaminants that are chemically and/or physically sequestered in a media are less likely to be bio-available to plants and therefore an ecosystem.« less

Cis-Acting Pathways Selectively Enforce the Non-Immunogenicity of Shed Placental Antigen for Maternal CD8 T Cells

PubMed Central

Tay, Chin-Siean; Tagliani, Elisa; Collins, Mary K.; Erlebacher, Adrian

2013-01-01

Maternal immune tolerance towards the fetus and placenta is thought to be established in part by pathways that attenuate T cell priming to antigens released from the placenta into maternal blood. These pathways remain largely undefined and their existence, at face value, seems incompatible with a mother's need to maintain a functional immune system during pregnancy. A particular conundrum is evident if we consider that maternal antigen presenting cells, activated in order to prime T cells to pathogen-derived antigens, would also have the capacity to prime T cells to co-ingested placental antigens. Here, we address this paradox using a transgenic system in which placental membranes are tagged with a strong surrogate antigen (ovalbumin). We find that although a remarkably large quantity of acellular ovalbumin-containing placental material is released into maternal blood, splenic CD8 T cells in pregnant mice bearing unmanipulated T cell repertoires are not primed to ovalbumin even if the mice are intravenously injected with adjuvants. This failure was largely independent of regulatory T cells, and instead was linked to the intrinsic characteristics of the released material that rendered it selectively non-immunogenic, potentially by sequestering it from CD8α+ dendritic cells. The release of ovalbumin-containing placental material into maternal blood thus had no discernable impact on CD8 T cell priming to soluble ovalbumin injected intravenously during pregnancy, nor did it induce long-term tolerance to ovalbumin. Together, these results outline a major pathway governing the maternal immune response to the placenta, and suggest how tolerance to placental antigens can be maintained systemically without being detrimental to host defense. PMID:24391885

Expression of an Arabidopsis sodium/proton antiporter gene (AtNHX1)in peanut to improve salt tolerance

USDA-ARS?s Scientific Manuscript database

Salinity is a major environmental stress that affects agricultural productivity worldwide. One approach to improving salt tolerance in crops is through high expression of the Arabidopsis gene AtNHX1, which encodes a vacuolar sodium/proton antiporter that sequesters excess sodium ion into the large i...

Magnitude and Mechanism of Siderophore-Mediated Competition at Low Iron Solubility in the Pseudomonas aeruginosa Pyochelin System.

PubMed

Schiessl, Konstanze T; Janssen, Elisabeth M-L; Kraemer, Stephan M; McNeill, Kristopher; Ackermann, Martin

2017-01-01

A central question in microbial ecology is whether microbial interactions are predominantly cooperative or competitive. The secretion of siderophores, microbial iron chelators, is a model system for cooperative interactions. However, siderophores have also been shown to mediate competition by sequestering available iron and making it unavailable to competitors. The details of how siderophores mediate competition are not well understood, especially considering the complex distribution of iron phases in the environment. One pertinent question is whether sequestering iron through siderophores can indeed be effective in natural conditions; many natural environments are characterized by large pools of precipitated iron, and it is conceivable that any soluble iron that is sequestered by siderophores is replenished by the dissolution of these precipitated iron sources. Our goal here was to address this issue, and investigate the magnitude and mechanism of siderophore-mediated competition in the presence of precipitated iron. We combined experimental work with thermodynamic modeling, using Pseudomonas aeruginosa as a model system and ferrihydrite precipitates as the iron source with low solubility. Our experiments show that competitive growth inhibition by the siderophore pyochelin is indeed efficient, and that inhibition of a competitor can even have a stronger growth-promoting effect than solubilization of precipitated iron. Based on the results of our thermodynamic models we conclude that the observed inhibition of a competitor is effective because sequestered iron is only very slowly replenished by the dissolution of precipitated iron. Our research highlights the importance of competitive benefits mediated by siderophores, and underlines that the dynamics of siderophore production and uptake in environmental communities could be a signature of competitive, not just cooperative, dynamics.

A review of mineral carbonation technologies to sequester CO2.

PubMed

Sanna, A; Uibu, M; Caramanna, G; Kuusik, R; Maroto-Valer, M M

2014-12-07

Carbon dioxide (CO2) capture and sequestration includes a portfolio of technologies that can potentially sequester billions of tonnes of CO2 per year. Mineral carbonation (MC) is emerging as a potential CCS technology solution to sequester CO2 from smaller/medium emitters, where geological sequestration is not a viable option. In MC processes, CO2 is chemically reacted with calcium- and/or magnesium-containing materials to form stable carbonates. This work investigates the current advancement in the proposed MC technologies and the role they can play in decreasing the overall cost of this CO2 sequestration route. In situ mineral carbonation is a very promising option in terms of resources available and enhanced security, but the technology is still in its infancy and transport and storage costs are still higher than geological storage in sedimentary basins ($17 instead of $8 per tCO2). Ex situ mineral carbonation has been demonstrated on pilot and demonstration scales. However, its application is currently limited by its high costs, which range from $50 to $300 per tCO2 sequestered. Energy use, the reaction rate and material handling are the key factors hindering the success of this technology. The value of the products seems central to render MC economically viable in the same way as conventional CCS seems profitable only when combined with EOR. Large scale projects such as the Skyonic process can help in reducing the knowledge gaps on MC fundamentals and provide accurate costing and data on processes integration and comparison. The literature to date indicates that in the coming decades MC can play an important role in decarbonising the power and industrial sector.

Sevelamer and other anion-exchange resins in the prevention and treatment of hyperphosphataemia in chronic renal failure.

PubMed

Wrong, Oliver; Harland, Clive

2007-01-01

Sevelamer, or more precisely 'sevelamer hydrochloride', is a weakly basic anion-exchange resin in the chloride form that was introduced in 1997 for the treatment of the hyperphosphataemia of patients with end-stage renal failure, usually those on long-term haemodialysis. The rationale for this therapy was that sevelamer would sequester phosphate within the gastrointestinal tract, so preventing its absorption and enhancing its faecal excretion. Over the succeeding years, large numbers of patients have been treated with sevelamer, and it has fulfilled expectations in helping to control the hyperphosphataemia of end-stage renal failure. However, it is only one of many anion-exchange resins that could be used for this purpose, some of which are currently available for clinical use and are much less costly than sevelamer. Theoretical considerations suggest that some of these other resins might be at least as efficient as sevelamer in sequestering phosphate in the gastrointestinal tract. Neither sevelamer, nor any of these other agents, has been submitted to a proper metabolic balance study to measure the amount of phosphate sequestered by the resin in the bowel, and without this information it is impossible to judge which is the ideal resin for this purpose. Copyright 2007 S. Karger AG, Basel.

Review of the pyrolysis platform for coproducing bio-oil and biochar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laird, David A.; Brown, Robert C.; Amonette, James E.

2009-09-01

Pyrolysis is a relatively simple, inexpensive, and robust thermochemical technology for transforming biomass into bio-oil, biochar, and syngas. The robust nature of the pyrolysis technology, which allows considerable flexibility in both the type and quality of the biomass feedstock, combined with a distributed network of small pyrolysis plants, would be compatible with existing agriculture and forestry infrastructure. Bio-oil can be used as a fuel in existing industrial boilers. Biochar can be used with existing infrastructure as a replacement for pulverized coal; however, use of biochar as a soil amendment results in significant environmental and agronomic benefits. Soil application of biocharmore » is a means of sequestering large amounts of C and may have other greenhouse gas benefits. Preliminary reports of the impact of soil biochar applications on crop yields indicate that biochar quality is very important. Biochar is an effective adsorbent for both nutrients and organic contaminants, hence the presence of biochar in soils has been shown to improve water quality in column leaching and field lysimeter studies and it is anticipated to do the same for agricultural watersheds. The pyrolysis platform for producing bio-oil and biochar from biomass appears to be a practical, effective, and environmentally sustainable means of producing large quantities of renewable bioenergy while simultaneously reducing emissions of greenhouse gases. At the present time, the pyrolysis platform is economically marginal because markets for bio-oil and biochar are highly competitive. However, if the USA adopts a program for controlling greenhouse gases, the pyrolysis platform would be highly competitive.« less

Ecosystem Carbon Storage in Alpine Grassland on the Qinghai Plateau

PubMed Central

Liu, Shuli; Zhang, Fawei; Du, Yangong; Guo, Xiaowei; Lin, Li; Li, Yikang; Li, Qian; Cao, Guangmin

2016-01-01

The alpine grassland ecosystem can sequester a large quantity of carbon, yet its significance remains controversial owing to large uncertainties in the relative contributions of climate factors and grazing intensity. In this study we surveyed 115 sites to measure ecosystem carbon storage (both biomass and soil) in alpine grassland over the Qinghai Plateau during the peak growing season in 2011 and 2012. Our results revealed three key findings. (1) Total biomass carbon density ranged from 0.04 for alpine steppe to 2.80 kg C m-2 for alpine meadow. Median soil organic carbon (SOC) density was estimated to be 16.43 kg C m-2 in alpine grassland. Total ecosystem carbon density varied across sites and grassland types, from 1.95 to 28.56 kg C m-2. (2) Based on the median estimate, the total carbon storage of alpine grassland on the Qinghai Plateau was 5.14 Pg, of which 94% (4.85 Pg) was soil organic carbon. (3) Overall, we found that ecosystem carbon density was affected by both climate and grazing, but to different extents. Temperature and precipitation interaction significantly affected AGB carbon density in winter pasture, BGB carbon density in alpine meadow, and SOC density in alpine steppe. On the other hand, grazing intensity affected AGB carbon density in summer pasture, SOC density in alpine meadow and ecosystem carbon density in alpine grassland. Our results indicate that grazing intensity was the primary contributing factor controlling carbon storage at the sites tested and should be the primary consideration when accurately estimating the carbon storage in alpine grassland. PMID:27494253

Ecosystem Carbon Storage in Alpine Grassland on the Qinghai Plateau.

PubMed

Liu, Shuli; Zhang, Fawei; Du, Yangong; Guo, Xiaowei; Lin, Li; Li, Yikang; Li, Qian; Cao, Guangmin

2016-01-01

The alpine grassland ecosystem can sequester a large quantity of carbon, yet its significance remains controversial owing to large uncertainties in the relative contributions of climate factors and grazing intensity. In this study we surveyed 115 sites to measure ecosystem carbon storage (both biomass and soil) in alpine grassland over the Qinghai Plateau during the peak growing season in 2011 and 2012. Our results revealed three key findings. (1) Total biomass carbon density ranged from 0.04 for alpine steppe to 2.80 kg C m-2 for alpine meadow. Median soil organic carbon (SOC) density was estimated to be 16.43 kg C m-2 in alpine grassland. Total ecosystem carbon density varied across sites and grassland types, from 1.95 to 28.56 kg C m-2. (2) Based on the median estimate, the total carbon storage of alpine grassland on the Qinghai Plateau was 5.14 Pg, of which 94% (4.85 Pg) was soil organic carbon. (3) Overall, we found that ecosystem carbon density was affected by both climate and grazing, but to different extents. Temperature and precipitation interaction significantly affected AGB carbon density in winter pasture, BGB carbon density in alpine meadow, and SOC density in alpine steppe. On the other hand, grazing intensity affected AGB carbon density in summer pasture, SOC density in alpine meadow and ecosystem carbon density in alpine grassland. Our results indicate that grazing intensity was the primary contributing factor controlling carbon storage at the sites tested and should be the primary consideration when accurately estimating the carbon storage in alpine grassland.

Assessing the 100-Year Climate Change Mitigation Potential of Large-Scale Tropical Forest Restoration Under the Bonn Challenge

NASA Astrophysics Data System (ADS)

Wheeler, C. E.; Mitchard, E. T.; Lewis, S. L.

2017-12-01

Restoring degraded and deforested tropical lands to sequester carbon is widely considered to offer substantial climate change mitigation opportunities, if conducted over large spatial scales. Despite this assertion, explicit estimates of how much carbon could be sequestered because of large-scale restoration are rare and have large uncertainties. This is principally due to the many different characteristics of land available for restoration, and different potential restoration activities, which together cause very different rates of carbon sequestration. For different restoration pathways: natural regeneration of degraded and secondary forest, timber plantations and agroforestry, we estimate carbon sequestration rates from the published literature. Then based on tropical restoration commitments made under the Bonn challenge and using carbon density maps, these carbon sequestration rates were used to predict total pan-tropical carbon sequestration to 2100. Restoration of degraded or secondary forest via natural regeneration offers the greatest carbon sequestration potential, considerably exceeding the carbon captured by either timber plantations or agroforestry. This is predominantly due to naturally regenerating forests representing a more permanent store of carbon in comparison to timber plantations and agroforestry land-use options, which, due to their rotational nature, result in the sequential return of carbon to the atmosphere. If the Bonn Challenge is to achieve its ambition of providing substantial climate change mitigation from restoration it must incorporate large areas of natural regeneration back to an intact forest state, otherwise it stands to be a missed opportunity in helping meet the Paris climate change goals.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mouser, Paula J.; N'Guessan, A. Lucie; Qafoku, Nikolla

The capacity for subsurface sediments to sequester metal contaminants, such as uranium (U), and retain them after bioremediation efforts are completed is critical to site stewardship. Sediments enriched in natural organic matter are capable of sequestering significant quantities of U, but may also serve as sources to the aquifer, contributing to plume persistence. Two types of sediments were compared to better understand the mechanisms contributing to the sequestration and release of U in the presence of organic matter. Artificially bioreduced sediments were retrieved from a field experimental plot previously stimulated with acetate while naturally bioreduced sediments were collected from amore » location enriched in organic matter but never subject to acetate amendment. Batch incubations demonstrated that the artificially bioreduced sediments were primed to rapidly remove uranium from the groundwater whereas naturally bioreduced sediments initially released a sizeable portion of sediment U before U(VI)-removal commenced. Column experiments confirmed that U release persisted for 65 pore volumes in naturally bioreduced sediments, demonstrating the sink-source behavior of this sediment. Acetate addition to artificially bioreduced sediments shifted the microbial community from one dominated by sulfate-reducing bacteria within Desulfobacteraceae to the iron-reducing family Geobacteraceae and Firmicutes during U(VI) reduction. In contrast, initial Geobacteraceae communities innaturally reduced sediments were replaced by clone sequences with similarity to opportunistic Pseudomonas spp. during U release, while U(VI) removal occurred concurrent with enrichment of Firmicutes. These investigations stress the importance of characterizing zones with heterogeneous carbon pools at U contaminated sites prior to the determination of a remedial strategy.« less

CO2 Extraction from Ambient Air Using Alkali-Metal Hydroxide Solutions Derived from Concrete Waste and Steel Slag

NASA Astrophysics Data System (ADS)

Stolaroff, J. K.; Lowry, G. V.; Keith, D. W.

2003-12-01

To mitigate global climate change, deep reductions in CO2 emissions are required in the coming decades. Carbon sequestration will play a crucial role in this reduction. Early adoption of carbon sequestration in low-cost niche markets will help develop the technology and experience required for large-scale deployment. One such niche may be the use of alkali metals from industrial waste streams to form carbonate minerals, a safe and stable means of sequestering carbon. In this research, the potential of using two industrial waste streams---concrete and steel slag---for sequestering carbon is assessed. The scheme is outlined as follows: Ca and Mg are leached with water from a finely ground bed of steel slag or concrete. The resulting solution is sprayed through air, capturing CO2 and forming solid carbonates, and collected. The feasibility of this scheme is explored with a combination of experiments, theoretical calculations, cost accounting, and literature review. The dissolution kinetics of steel slag and concrete as a function of particle size and pH is examined. In stirred batch reactors, the majority of Ca which dissolved did so within the first hour, yielding between 50 and 250 (mg; Ca)/(g; slag) and between 10 and 30 (mg; Ca)/(g; concrete). The kinetics of dissolution are thus taken to be sufficiently fast to support the type of scheme described above. As proof-of-concept, further experiments were performed where water was dripped slowly through a stagnant column of slag or concrete and collected at the bottom. Leachate Ca concentrations in the range of 15 mM were achieved --- sufficient to support the scheme. Using basic physical principles and numerical methods, the quantity of CO2 captured by falling droplets is estimated. Proportion of water loss and required pumping energy is similarly estimated. The results indicate that sprays are capable of capturing CO2 from the air and that the water and energy requirements are tractable. An example system for enacting the scheme is presented, along with capital and operational cost estimates. The system is found to be profitable for carbon credits above \\5/ton; C. Many findings in this research apply to a more general set of systems which capture CO_2$ from the air for sequestration. The metal-hydroxide solution in these systems is regenerated on site, allowing application of this scheme on as large a scale as needed. Implications of this study's findings for these more general carbon-capture systems is discussed.

Agroforestry: working trees for sequestering carbon on agricultural lands

Treesearch

M.M. Schoeneberger

2008-01-01

Agroforestry is an appealing option for sequestering carbon on agricultural lands because it can sequester significant amounts of carbon while leaving the bulk of the land in agricultural production. Simultaneously, it can help landowners and society address many other issues facing these lands, such as economic diversification, biodiversity, and water quality....

Agroforestry-working trees for sequestering carbon on ag-lands

Treesearch

Michele M. Schoeneberger

2005-01-01

Agroforestry is an appealing option for sequestering carbon on agricultural lands because it can sequester significant amounts of carbon whle leaving the bulk of the land in agricultural production. Simultaneously, it can help landowners and society address many other issues, such as economic diversification, biodiversity, and water quality, facing these lands....

The SEQUEST Family Tree

NASA Astrophysics Data System (ADS)

Tabb, David L.

2015-11-01

Since its introduction in 1994, SEQUEST has gained many important new capabilities, and a host of successor algorithms have built upon its successes. This Account and Perspective maps the evolution of this important tool and charts the relationships among contributions to the SEQUEST legacy. Many of the changes represented improvements in computing speed by clusters and graphics cards. Mass spectrometry innovations in mass accuracy and activation methods led to shifts in fragment modeling and scoring strategies. These changes, as well as the movement of laboratories and lab members, have led to great diversity among the members of the SEQUEST family.

Melanosomal sequestration of cytotoxic drugs contributes to the intractability of malignant melanomas

PubMed Central

Chen, Kevin G.; Valencia, Julio C.; Lai, Barry; Zhang, Guofeng; Paterson, Jill K.; Rouzaud, François; Berens, Werner; Wincovitch, Stephen M.; Garfield, Susan H.; Leapman, Richard D.; Hearing, Vincent J.; Gottesman, Michael M.

2006-01-01

Multidrug resistance mechanisms underlying the intractability of malignant melanomas remain largely unknown. In this study, we demonstrate that the development of multidrug resistance in melanomas involves subcellular sequestration of intracellular cytotoxic drugs such as cis-diaminedichloroplatinum II (cisplatin; CDDP). CDDP is initially sequestered in subcellular organelles such as melanosomes, which significantly reduces its nuclear localization when compared with nonmelanoma/KB-3-1 epidermoid carcinoma cells. The melanosomal accumulation of CDDP remarkably modulates melanogenesis through a pronounced increase in tyrosinase activity. The altered melanogenesis manifested an ≈8-fold increase in both intracellular pigmentation and extracellular transport of melanosomes containing CDDP. Thus, our experiments provide evidence that melanosomes contribute to the refractory properties of melanoma cells by sequestering cytotoxic drugs and increasing melanosome-mediated drug export. Preventing melanosomal sequestration of cytotoxic drugs by inhibiting the functions of melanosomes may have great potential as an approach to improving the chemosensitivity of melanoma cells. PMID:16777967

Carbon pool and biomass dynamics associated with deforestation, land use, and agricultural abandonment in the neotropics.

PubMed

Kauffman, J Boone; Hughes, R Flint; Heider, Chris

2009-07-01

Current rates of deforestation and the resulting C emissions in the tropics exceed those of secondary forest regrowth and C sequestration. Changing land-use strategies that would maintain standing forests may be among the least expensive of climate change mitigation options. Further, secondary tropical forests have been suggested to have great value for their potential to sequester atmospheric C. These options require an understanding of and capability to quantify C dynamics at landscape scales. Because of the diversity of physical and biotic features of tropical forests as well as approaches and intensities of land uses within the neotropics, there are tremendous differences in the capacity of different landscapes to store and sequester C. Major gaps in our current knowledge include quantification of C pools, rates and patterns of biomass loss following land-cover change, and quantification of the C storage potential of secondary forests following abandonment. In this paper we present a synthesis and further analyses from recent studies that describe C pools, patterns of C decline associated with land use, and rates of C accumulation following secondary-forest establishment--all information necessary for climate-change mitigation options. Ecosystem C pools of Neotropical primary forests minimally range from approximately 141 to 571 Mg/ha, demonstrating tremendous differences in the capacity of different forests to store C. Most of the losses in C and nutrient pools associated with conversion occur when fires are set to remove the slashed forest to prepare sites for crop or pasture establishment. Fires burning slashed primary forests have been found to result in C losses of 62-80% of prefire aboveground pools in dry (deciduous) forest landscapes and 29-57% in wet (evergreen) forest landscapes. Carbon emissions equivalent to the aboveground primary-forest pool arise from repeated fires occurring in the first 4 to 10 years following conversion. Feedbacks of climate change, land-cover change, and increasing habitat fragmentation may result in increases of both the area burned and the total quantity of biomass consumed per unit area by fire. These effects may well limit the capacity for future tropical forests to sequester C and nutrients.

Phytotransformation of TNT and distribution of metabolic products in Myriophyllum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vanderford, M.; Hughes, J.

Recent investigations indicate that 2,4,6-trinitrotoluene (TNT) disappears from solution in the presence of aquatic macrophytes. Studies using (U) {sup 14}C TNT were conducted to monitor the fate of TNT and its transformation products in Myriophyllum aquaticum. Plants were exposed to TNT solution for several days and destructively sampled at the end of that time. Data for live plants were compared with those for heat killed controls and axenic Myriophyllum systems. Distribution of radiolabel was analyzed in the root, stem and leaf tissue of Myriophyllum directly by incineration of plant tissue and capture of {sup 14}CO{sub 2}. Tissues were also extractedmore » with methanol and subjected to scintillation analysis. Plant extracts were examined by HPLC for TNT and its known reduction products. A complete mass balance analysis was performed for the system. Significant differences in distribution of {sup 14}C were noted between the live and killed plants. For live plants, the majority of {sup 14}C associated with the plant was sequestered in the roots and was largely unextractable. Extracts of stem and leaf were lower in total {sup 14}C content, but the radiolabel was more extractable from these tissues. In the extracted fractions, TNT and monoamino transformation products were detected, but not in stoichiometric quantities. Investigations are currently underway to identify the extractable products of plant associated TNT transformation.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malhotra, Vivak

The USA is embarking upon tackling the serious environmental challenges posed to the world by greenhouse gases, especially carbon dioxide (CO2). The dimension of the problem is daunting. In fact, according to the Energy Information Agency, nearly 6 billion metric tons of CO2 were produced in the USA in 2007 with coal-burning power plants contributing about 2 billion metric tons. To mitigate the concerns associated with CO2 emission, geological sequestration holds promise. Among the potential geological storage sites, unmineable coal seams and shale formations in particular show promise because of the probability of methane recovery while sequestering the CO2. However.more » the success of large-scale sequestration of CO2 in coal and shale would hinge on a thorough understanding of CO2's interactions with host reservoirs. An important parameter for successful storage of CO2 reservoirs would be whether the pressurized CO2 would remain invariant in coal and shale formations under reasonable internal and/or external perturbations. Recent research has brought to the fore the potential of induced seismicity, which may result in caprock compromise. Therefore, to evaluate the potential risks involved in sequestering CO2 in Illinois bituminous coal seams and shale, we studied: (i) the mechanical behavior of Murphysboro (Illinois) and Houchin Creek (Illinois) coals, (ii) thermodynamic behavior of Illinois bituminous coal at - 100oC ≤ T ≤ 300oC, (iii) how high pressure CO2 (up to 20.7 MPa) modifies the viscosity of the host, (iv) the rate of emission of CO2 from Illinois bituminous coal and shale cores if the cores, which were pressurized with high pressure (≤ 20.7 MPa) CO2, were exposed to an atmospheric pressure, simulating the development of leakage pathways, (v) whether there are any fractions of CO2 stored in these hosts which are resistance to emission by simply exposing the cores to atmospheric pressure, and (vi) how compressive shockwaves applied to the coal and shale cores, which were pressurized with high pressure CO2, determine the fate of sequestered CO2 in these cores. Our results suggested that Illinois bituminous coal in its unperturbed state, i.e., when not pressurized with CO2, showed large variations in the mechanical properties. Modulus varied from 0.7 GPa to 3.4 GPa even though samples were extracted from a single large chunk of coal. We did not observe any glass transition for Illinois bituminous coal at - 100oC ≤ T ≤ 300oC, however, when the coal was pressurized with CO2 at ambient ≤ P ≤ 20.7 MPa, the viscosity of the coal decreased and inversely scaled with the CO2 pressure. The decrease in viscosity as a function of pressure could pose CO2 injection problems for coal as lower viscosity would allow the solid coal to flow to plug the fractures, fissures, and cleats. Our experiments also showed a very small fraction of CO2 was absorbed in coal; and when CO2 pressurized coals were exposed to atmospheric conditions, the loss of CO2 from coals was massive. Half of the sequestered gas from the coal cores was lost in less than 20 minutes. Our shockwave experiments on Illinois bituminous coal, New Albany shale (Illinois), Devonian shale (Ohio), and Utica shale (Ohio) presented clear evidence that the significant emission of the sequestered CO2 from these formations cannot be discounted during seismic activity, especially if caprock is compromised. It is argued that additional shockwave studies, both compressive and transverse, would be required for successfully mapping the risks associated with sequestering high pressure CO2 in coal and shale formations.« less

Non-Reductive Strategies for U Sequestration: Natural Analogues and Practical Application

NASA Astrophysics Data System (ADS)

Maher, K.; Bethke, C. M.; Massey, M. S.

2011-12-01

A number of strategies have been proposed for the in situ remediation of U contaminated zones, including bioreduction, permeable reactive barriers, and incorporation into secondary phases such as phosphates. An alternative approach is to sequester U within amorphous Si phases such as opaline silica. We have investigated the isotopic and major element composition and structure of naturally occurring U-rich opaline silica in semi-arid soil environments across the western United States. These phases constitute a large natural reservoir of sequestered U. By combining these observations with geochemical considerations, we propose a remedial strategy for sequestering U in amorphous silica. The U-rich opal occurs as laminations, veins, and coatings on clasts in soils developed on a range of parent materials. U-rich opal deposits are also found as speleothems in caves, as silica-rich spring deposits, and as cavity fillings and hydrothermal veins in volcanic tuffs. Measurements of U, Th and Pb isotopes reveal the age of the opaline silica, demonstrating the long-term stability of U sequestration in open chemical environments. The isotopic data also suggest that opaline silica will retain the majority of the initial U over millions of years. U in naturally occurring opal generally ranges between 200 to 1000 ppm. In contrast, co-existing calcite contains less than 100 ppb U. From pore water chemistry, the distribution coefficient for U incorporation into opaline silica is approximately 20, whereas the coefficient for calcite is typically between 0.2 and 1. X-ray absorption spectroscopy investigations confirm that hexavalent U is incorporated in amorphous silica as the UO22+ ion. Coexisting Fe-oxides provide a further sink for sequestering UO22+ from the pore water. However, preliminary calculations suggest that incorporation of U into amorphous silica may be a dominant mechanism for isolating UO22+from groundwater over long time scales. Nature's mechanism for sequestering UO22+ from the environment might be profitably incorporated into groundwater remediation strategies. We consider a remedial strategy in which Na2SiO3 is amended into the subsurface. The silicate flood reacts with the surface acidity in the sediments to lower pH and precipitate amorphous silica. Hexavalent uranium is partitioned strongly into the silica, as well as complexed with the sediment surfaces.

Reforestation can sequester two petagrams of carbon in US topsoils in a century

Treesearch

Lucas E. Nave; Grant M. Domke; Kathryn L. Hofmeister; Umakant Mishra; Charles H. Perry; Brian F. Walters; Christopher W. Swanston

2018-01-01

Soils are Earth’s largest terrestrial carbon (C) pool, and their responsiveness to land use and management make them appealing targets for strategies to enhance C sequestration. Numerous studies have identified practices that increase soil C, but their inferences are often based on limited data extrapolated over large areas. Here, we combine 15,000 observations from...

Aboveground tree growth varies with belowground carbon allocation in a tropical rainforest environment

Treesearch

J.W. Raich; D.A. Clark; L. Schwendenmann; Tana Wood

2014-01-01

Young secondary forests and plantations in the moist tropics often have rapid rates of biomass accumulation and thus sequester large amounts of carbon. Here, we compare results from mature forest and nearby 15–20 year old tree plantations in lowland Costa Rica to evaluate differences in allocation of carbon to aboveground production and root systems. We found that the...

Evaluation of Populus and Salix continuously irrigated with landfill leachate I. Genotype-specific elemental phytoremediation

Treesearch

Ronald S., Jr. Zalesny; Edmund O. Bauer

2007-01-01

There is a need for the identification and selection of specific tree genotypes that can sequester elements from contaminated soils, with elevated rates of uptake. We irrigated Populus (DN17, DN182, DN34, NM2, NM6) and Salix (94003, 94012, S287, S566, SX61) genotypes planted in large soil-filled containers with landfill leachate or...

The role of old forests and big trees in forest carbon sequestration in the Pacific Northwest

Treesearch

Andrew N. Gray

2015-01-01

Forest ecosystems are an important component of the global carbon (C) cycle. Recent research has indicated that large trees in general, and old-growth forests in particular, sequester substantial amounts of C annually. C sequestration rates are thought to peak and decline with stand age but the timing and controls are not well-understood. The objectives of this study...

Modeling the influence of coupled mass transfer processes on mass flux downgradient of heterogeneous DNAPL source zones

NASA Astrophysics Data System (ADS)

Yang, Lurong; Wang, Xinyu; Mendoza-Sanchez, Itza; Abriola, Linda M.

2018-04-01

Sequestered mass in low permeability zones has been increasingly recognized as an important source of organic chemical contamination that acts to sustain downgradient plume concentrations above regulated levels. However, few modeling studies have investigated the influence of this sequestered mass and associated (coupled) mass transfer processes on plume persistence in complex dense nonaqueous phase liquid (DNAPL) source zones. This paper employs a multiphase flow and transport simulator (a modified version of the modular transport simulator MT3DMS) to explore the two- and three-dimensional evolution of source zone mass distribution and near-source plume persistence for two ensembles of highly heterogeneous DNAPL source zone realizations. Simulations reveal the strong influence of subsurface heterogeneity on the complexity of DNAPL and sequestered (immobile/sorbed) mass distribution. Small zones of entrapped DNAPL are shown to serve as a persistent source of low concentration plumes, difficult to distinguish from other (sorbed and immobile dissolved) sequestered mass sources. Results suggest that the presence of DNAPL tends to control plume longevity in the near-source area; for the examined scenarios, a substantial fraction (43.3-99.2%) of plume life was sustained by DNAPL dissolution processes. The presence of sorptive media and the extent of sorption non-ideality are shown to greatly affect predictions of near-source plume persistence following DNAPL depletion, with plume persistence varying one to two orders of magnitude with the selected sorption model. Results demonstrate the importance of sorption-controlled back diffusion from low permeability zones and reveal the importance of selecting the appropriate sorption model for accurate prediction of plume longevity. Large discrepancies for both DNAPL depletion time and plume longevity were observed between 2-D and 3-D model simulations. Differences between 2- and 3-D predictions increased in the presence of sorption, especially for the case of non-ideal sorption, demonstrating the limitations of employing 2-D predictions for field-scale modeling.

The role of impact events play in redistributing and sequestering water on Early Mars

NASA Astrophysics Data System (ADS)

Osinski, G.; Tornabene, L. L.

2017-12-01

Impact cratering is one of the most fundamental geological process in the Solar System. Several workers have considered the effect that impact events may have had on the climate of Early Mars. The proposed effects range from impact-induced precipitation to the production of runaway stable climates to the impact delivery of climatically active gases. The role of impact events in forming hydrated minerals has been touched upon but remains debated. In this contribution, we focus on the role that impact events may have played in redistributing and sequestering water on Early Mars; a record that may still be preserved in the Noachian crust. It has been previously proposed that the sequestration of significant quantities of water may have occurred within various hydrated minerals, in particular clays, in the martian crust. There is undoubtedly no single origin for clay-bearing rocks on Mars and the purpose of this contribution is not to review all the possible formation mechanisms. What we do propose, however, is that it is theoretically possible for impact events to create all known occurrences of clays on Mars. We show that clays can form within and around impact craters in two main ways: through the solid-state devitrification of hydrous impact melts and/or impact-generated hydrothermal alteration. Neither of these mechanisms requires a warmer or wetter climate scenario on Early Mars. Notwithstanding the original origin of clays, any clays may be widely redistributed over the Martian surface in the ejecta deposits of large impact craters. However, ejecta deposits are much more complex than commonly thought, with evidence in many instances for two different types of ejecta deposits around martian craters. The first is a ballistic ejecta layer that is low-shock, melt-poor and low-temperature; it will likely not induce the formation of new clays through the mechanisms described above, but could redistribute pre-impact clays over 100's and 1000's of km over the martian surface. Overlying ballistic ejecta deposits is a second ejecta type that is more melt-rich and higher temperature and that has been shown (on Earth) to form new primary clays and other hydrated minerals. This potential to form clays in situ many 100's of km away from the source crater in melt-rich ejecta deposits should be considered in any study of the Noachian crust.

Explosion Hazards Associated with Spills of Large Quantities of Hazardous Materials. Phase I

DTIC Science & Technology

1974-10-01

quantities of hazardous material such as liquified natural gas ( LNG ), liquified petroleum gils (LPG), or ethylene. The principal results are (1) a...associated with spills of large quantities of hazardous material such as liquified natural gas ( LNG ), liquified petroleum gas (LPG), or ethylene. The...liquified natural gas ( LNG ). Unfortunately, as the quantity of material shipped at one time increases, so does the potential hazard associated with

Halite as a Methane Sequestration Host: A Possible Explanation for Periodic Methane Release on Mars, and a Surface-accessible Source of Ancient Martian Carbon

NASA Technical Reports Server (NTRS)

Fries, M. D.; Steele, Andrew; Hynek, B. M.

2015-01-01

We present the hypothesis that halite may play a role in methane sequestration on the martian surface. In terrestrial examples, halite deposits sequester large volumes of methane and chloromethane. Also, examples of chloromethane-bearing, approximately 4.5 Ga old halite from the Monahans meteorite show that this system is very stable unless the halite is damaged. On Mars, methane may be generated from carbonaceous material trapped in ancient halite deposits and sequestered. The methane may be released by damaging its halite host; either by aqueous alteration, aeolian abrasion, heating, or impact shock. Such a scenario may help to explain the appearance of short-lived releases of methane on the martian surface. The methane may be of either biogenic or abiogenic origin. If this scenario plays a significant role on Mars, then martian halite deposits may contain samples of organic compounds dating to the ancient desiccation of the planet, accessible at the surface for future sample return missions.

Na+/K+-ATPase resistance and cardenolide sequestration: basal adaptations to host plant toxins in the milkweed bugs (Hemiptera: Lygaeidae: Lygaeinae)

PubMed Central

Bramer, Christiane; Dobler, Susanne; Deckert, Jürgen; Stemmer, Michael; Petschenka, Georg

2015-01-01

Despite sequestration of toxins being a common coevolutionary response to plant defence in phytophagous insects, the macroevolution of the traits involved is largely unaddressed. Using a phylogenetic approach comprising species from four continents, we analysed the ability to sequester toxic cardenolides in the hemipteran subfamily Lygaeinae, which is widely associated with cardenolide-producing Apocynaceae. In addition, we analysed cardenolide resistance of their Na+/K+-ATPases, the molecular target of cardenolides. Our data indicate that cardenolide sequestration and cardenolide-resistant Na+/K+-ATPase are basal adaptations in the Lygaeinae. In two species that shifted to non-apocynaceous hosts, the ability to sequester was secondarily reduced, yet Na+/K+-ATPase resistance was maintained. We suggest that both traits evolved together and represent major coevolutionary adaptations responsible for the evolutionary success of lygaeine bugs. Moreover, specialization on cardenolides was not an evolutionary dead end, but enabled this insect lineage to host shift to cardenolide-producing plants from distantly related families. PMID:25808891

Melanosomal sequestration of cytotoxic drugs contributes to the intractability of malignant melanomas

NASA Astrophysics Data System (ADS)

Chen, Kevin G.; Valencia, Julio C.; Lai, Barry; Zhang, Guofeng; Paterson, Jill K.; Rouzaud, François; Berens, Werner; Wincovitch, Stephen M.; Garfield, Susan H.; Leapman, Richard D.; Hearing, Vincent J.; Gottesman, Michael M.

2006-06-01

Multidrug resistance mechanisms underlying the intractability of malignant melanomas remain largely unknown. In this study, we demonstrate that the development of multidrug resistance in melanomas involves subcellular sequestration of intracellular cytotoxic drugs such as cis-diaminedichloroplatinum II (cisplatin; CDDP). CDDP is initially sequestered in subcellular organelles such as melanosomes, which significantly reduces its nuclear localization when compared with nonmelanoma/KB-3-1 epidermoid carcinoma cells. The melanosomal accumulation of CDDP remarkably modulates melanogenesis through a pronounced increase in tyrosinase activity. The altered melanogenesis manifested an 8-fold increase in both intracellular pigmentation and extracellular transport of melanosomes containing CDDP. Thus, our experiments provide evidence that melanosomes contribute to the refractory properties of melanoma cells by sequestering cytotoxic drugs and increasing melanosome-mediated drug export. Preventing melanosomal sequestration of cytotoxic drugs by inhibiting the functions of melanosomes may have great potential as an approach to improving the chemosensitivity of melanoma cells. cancer | melanosomes | skin | tumor therapy | multidrug resistance

Entrapment of viral capsids in nuclear PML cages is an intrinsic antiviral host defense against varicella-zoster virus.

PubMed

Reichelt, Mike; Wang, Li; Sommer, Marvin; Perrino, John; Nour, Adel M; Sen, Nandini; Baiker, Armin; Zerboni, Leigh; Arvin, Ann M

2011-02-03

The herpesviruses, like most other DNA viruses, replicate in the host cell nucleus. Subnuclear domains known as promyelocytic leukemia protein nuclear bodies (PML-NBs), or ND10 bodies, have been implicated in restricting early herpesviral gene expression. These viruses have evolved countermeasures to disperse PML-NBs, as shown in cells infected in vitro, but information about the fate of PML-NBs and their functions in herpesvirus infected cells in vivo is limited. Varicella-zoster virus (VZV) is an alphaherpesvirus with tropism for skin, lymphocytes and sensory ganglia, where it establishes latency. Here, we identify large PML-NBs that sequester newly assembled nucleocapsids (NC) in neurons and satellite cells of human dorsal root ganglia (DRG) and skin cells infected with VZV in vivo. Quantitative immuno-electron microscopy revealed that these distinctive nuclear bodies consisted of PML fibers forming spherical cages that enclosed mature and immature VZV NCs. Of six PML isoforms, only PML IV promoted the sequestration of NCs. PML IV significantly inhibited viral infection and interacted with the ORF23 capsid surface protein, which was identified as a target for PML-mediated NC sequestration. The unique PML IV C-terminal domain was required for both capsid entrapment and antiviral activity. Similar large PML-NBs, termed clastosomes, sequester aberrant polyglutamine (polyQ) proteins, such as Huntingtin (Htt), in several neurodegenerative disorders. We found that PML IV cages co-sequester HttQ72 and ORF23 protein in VZV infected cells. Our data show that PML cages contribute to the intrinsic antiviral defense by sensing and entrapping VZV nucleocapsids, thereby preventing their nuclear egress and inhibiting formation of infectious virus particles. The efficient sequestration of virion capsids in PML cages appears to be the outcome of a basic cytoprotective function of this distinctive category of PML-NBs in sensing and safely containing nuclear aggregates of aberrant proteins.

Comments on Economides and Ehlig-Economides,"Sequestering carbon dioxide in a closed underground volume," SPE 124430, October 2009

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oldenburg, Curt; Pruess, Karsten; Birkholzer, Jens

The paper examines the pressure increase resulting from injection of CO2 into a 1D radial system with closed boundaries. The finding is that unacceptably high pressures are obtained when only 1% or less of the pore volume is occupied by injected CO2. These results are used to make the general conclusion that large-scale CCS is not feasible.

The Potential for Carbon Sequestration in the United States

DTIC Science & Technology

2007-09-01

Potential of U.S. Cropland to Sequester Carbon and Mitigate the Greenhouse Effect (Ann Arbor, Mich.: Ann Arbor Press, 1998), pp. 18–21; R.F. Follett and...others, The Potential of U.S. Grazing Land to Sequester Carbon and Mitigate the Greenhouse Effect (Boca Raton, Fla.: CRC Press, 2001), pp. 401–430... the Greenhouse Effect , pp. 18–21; R. Lal and others, “Managing U.S. Cropland to Sequester Carbon in Soil,” Journal of Soil and Water Conservation

Large-scale database searching using tandem mass spectra: looking up the answer in the back of the book.

PubMed

Sadygov, Rovshan G; Cociorva, Daniel; Yates, John R

2004-12-01

Database searching is an essential element of large-scale proteomics. Because these methods are widely used, it is important to understand the rationale of the algorithms. Most algorithms are based on concepts first developed in SEQUEST and PeptideSearch. Four basic approaches are used to determine a match between a spectrum and sequence: descriptive, interpretative, stochastic and probability-based matching. We review the basic concepts used by most search algorithms, the computational modeling of peptide identification and current challenges and limitations of this approach for protein identification.

Measurement of carbon for carbon sequestration and site monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Madhavi Z; Wullschleger, Stan D; Garten Jr, Charles T

A 2 to 6 degree C increase in global temperature by 2050 has been predicted due to the production of greenhouse gases that is directly linked to human activities. This has encouraged an increase in the international efforts on ways to reduce anthropogenic emissions of greenhouse gases particularly carbon dioxide (CO{sub 2}) as evidence for the link between atmospheric greenhouse gases and climate change has been established. Suggestion that soils and vegetation could be managed to increase their uptake and storage of CO{sub 2}, and thus become 'land carbon sinks' is an incentive for scientists to undertake the ability tomore » measure and quantify the carbon in soils and vegetation to establish base-line quantities present at this time. The verification of the permanence of these carbon sinks has raised some concern regarding the accuracy of their long-term existence. Out of the total percentage of carbon that is potentially sequestered in the terrestrial land mass, only 25% of that is sequestered above ground and almost 75% is hypothesized to be sequestered underground. Soil is composed of solids, liquids, and gases which is similar to a three-phase system. The gross chemical composition of soil organic carbon (SOC) consists of 65% humic substances that are amorphous, dark-colored, complex, polyelectrolyte-like materials that range in molecular weight from a few hundred to several thousand Daltons. The very complex structure of humic and fulvic acid makes it difficult to obtain a spectral signature for all soils in general. The humic acids of different soils have been observed to have polymeric structure, appearing as rings, chains and clusters as seen in electron microscope observations. The humification processes of the soils will decide the sizes of their macromolecules that range from 60-500 angstroms. The percentage of the humus that occurs in the light brown soils is much lower than the humus present in dark brown soils. The humus of forest soils is characterized by a high content of fulvic acids while the humus of peat and grassland soils is high in humic acids. Similarly it is well known that the amount of carbon present in forest soils is lower than the amount present in grassland soils.« less

Nutrient sequestration in Aquitaine lakes (SW France) limits nutrient flux to the coastal zone

NASA Astrophysics Data System (ADS)

Buquet, Damien; Anschutz, Pierre; Charbonnier, Céline; Rapin, Anne; Sinays, Rémy; Canredon, Axel; Bujan, Stéphane; Poirier, Dominique

2017-12-01

Oligotrophic coastal zones are disappearing from increased nutrient loading. The quantity of nutrients reaching the coast is determined not only by their original source (e.g. fertilizers used in agriculture, waste water discharges) and the land use, but also by the pathways through which nutrients are cycled from the source to the river mouth. In particular, lakes sequester nutrients and, hence, reduce downstream transfer of nutrients to coastal environments. Here, we quantify the impact of Aquitaine great lakes on the fluxes of dissolved macro-nutrients (N, P, Si) to the Bay of Biscay. For that, we have measured nutrient concentrations and fluxes in 2014 upstream and downstream lakes of Lacanau and Carcans-Hourtin, which belongs to the catchment of the Arcachon Bay, which is the largest coastal lagoon of the Bay of Biscay French coast. Data were compared to values obtained from the Leyre river, the main freshwater and nutrient source for the lagoon. Results show that processes in lakes greatly limit nutrient flux to the lagoon compared to fluxes from Leyre river, although the watershed is similar in terms of land cover. In lakes, phosphorus and silicon are trapped for long term in the sediment, silicon as amorphous biogenic silica and phosphorus as organic P and P associated with Fe-oxides. Nitrogen that enters lakes mostly as nitrate is used for primary production. N is mineralized in the sediment; a fraction diffuses as ammonium. N2 production through benthic denitrification extracts only 10% of dissolved inorganic nitrogen from the aquatic system. The main part is sequestered in organic-rich sediment that accumulates below 5 m depth in both lakes.

A small quantity of sodium arsenite will kill large cull hardwoods

Treesearch

Francis M. Rushmore

1956-01-01

Although it is well known that sodium arsenite is an effective silvicide, forestry literature contains little information about the minimum quantities of this chemical that are required to kill large cull trees. Such information would be of value because if small quantities of a chemical will produce satisfactory results, small holes or frills in the tree will hold it...

Development of a Charged-Particle Accumulator Using an RF Confinement Method

DTIC Science & Technology

2007-03-12

antiparticles (antiprotons and positrons), and to produce a large quantity of antimatter . Antihydrogen atoms have recently been produced using Penning...ultimate goal is to trap a large number of antiparticles and to produce a large quantity of antimatter . 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF

Sequestration, tissue distribution and developmental transmission of cyanogenic glucosides in a specialist insect herbivore.

PubMed

Zagrobelny, Mika; Olsen, Carl Erik; Pentzold, Stefan; Fürstenberg-Hägg, Joel; Jørgensen, Kirsten; Bak, Søren; Møller, Birger Lindberg; Motawia, Mohammed Saddik

2014-01-01

Considering the staggering diversity of bioactive natural products present in plants, insects are only able to sequester a small number of phytochemicals from their food plants. The mechanisms of how only some phytochemicals are sequestered and how the sequestration process takes place remains largely unknown. In this study the model system of Zygaena filipendulae (Lepidoptera) and their food plant Lotus corniculatus is used to advance the knowledge of insect sequestration. Z. filipendulae larvae are dependent on sequestration of the cyanogenic glucosides linamarin and lotaustralin from their food plant, and have a much lower fitness if reared on plants without these compounds. This study investigates the fate of the cyanogenic glucosides during ingestion, sequestration in the larvae, and in the course of insect ontogeny. To this purpose, double-labeled linamarin and lotaustralin were chemically synthesized carrying two stable isotopes, a (2)H labeled aglucone and a (13)C labeled glucose moiety. In addition, a small amount of (14)C was incorporated into the glucose residue. The isotope-labeled compounds were applied onto cyanogenic L. corniculatus leaves that were subsequently presented to the Z. filipendulae larvae. Following ingestion by the larvae, the destiny of the isotope labeled cyanogenic glucosides was monitored in different tissues of larvae and adults at selected time points, using radio-TLC and LC-MS analyses. It was shown that sequestered compounds are taken up intact, contrary to earlier hypotheses where it was suggested that the compounds would have to be hydrolyzed before transport across the gut. The uptake from the larval gut was highly stereo selective as the β-glucosides were retained while the α-glucosides were excreted and recovered in the frass. Sequestered compounds were rapidly distributed into all analyzed tissues of the larval body, partly retained throughout metamorphosis and transferred into the adult insect where they were distributed to all tissues. During subsequent mating, isotope labeled cyanogenic glucosides were transferred from the male to the female in the nuptial gift. Copyright © 2013 Elsevier Ltd. All rights reserved.

Modeling the transformation of atmospheric CO2 into microalgal biomass.

PubMed

Hasan, Mohammed Fahad; Vogt, Frank

2017-10-23

Marine phytoplankton acts as a considerable sink of atmospheric CO 2 as it sequesters large quantities of this greenhouse gas for biomass production. To assess microalgae's counterbalancing of global warming, the quantities of CO 2 they fix need to be determined. For this task, it is mandatory to understand which environmental and physiological parameters govern this transformation from atmospheric CO 2 to microalgal biomass. However, experimental analyses are challenging as it has been found that the chemical environment has a major impact on the physiological properties of the microalgae cells (diameter typ. 5-20 μm). Moreover, the cells can only chemically interact with their immediate vicinity and thus compound sequestration needs to be studied on a microscopic spatial scale. Due to these reasons, computer simulations are a more promising approach than the experimental studies. Modeling software has been developed that describes the dissolution of atmospheric CO 2 into oceans followed by the formation of HCO 3 - which is then transported to individual microalgae cells. The second portion of this model describes the competition of different cell species for this HCO 3 - , a nutrient, as well as its uptake and utilization for cell production. Two microalgae species, i.e. Dunaliella salina and Nannochloropsis oculata, were cultured individually and in a competition situation under different atmospheric CO 2 conditions. It is shown that this novel model's predictions of biomass production are in very good agreement with the experimental flow cytometry results. After model validation, it has been applied to long-term prediction of phytoplankton generation. These investigations were motivated by the question whether or not cell production slows down as cultures grow. This is of relevance as a reduced cell production rate means that the increase in a culture's CO 2 -sinking capacity slows down as well. One implication resulting from this is that an increase in anthropogenic CO 2 may not be counterbalanced by an increase in phytoplankton production. Modeling studies have found that for several different atmospheric CO 2 levels provided to single-species cultures as well as to species in competing scenarios the cell production rate does slow down over time.

The deep permafrost carbon pool of the Yedoma region in Siberia and Alaska

PubMed Central

Strauss, Jens; Schirrmeister, Lutz; Grosse, Guido; Wetterich, Sebastian; Ulrich, Mathias; Herzschuh, Ulrike; Hubberten, Hans-Wolfgang

2013-01-01

[1] Estimates for circumpolar permafrost organic carbon (OC) storage suggest that this pool contains twice the amount of current atmospheric carbon. The Yedoma region sequestered substantial quantities of OC and is unique because its deep OC, which was incorporated into permafrost during ice age conditions. Rapid inclusion of labile organic matter into permafrost halted decomposition and resulted in a deep long-term sink. We show that the deep frozen OC in the Yedoma region consists of two distinct major subreservoirs: Yedoma deposits (late Pleistocene ice- and organic-rich silty sediments) and deposits formed in thaw-lake basins (generalized as thermokarst deposits). We quantified the OC pool based on field data and extrapolation using geospatial data sets to 83 + 61/−57 Gt for Yedoma deposits and to 128 + 99/−96 Gt for thermokarst deposits. The total Yedoma region 211 + 160/−153 Gt is a substantial amount of thaw-vulnerable OC that must be accounted for in global models. PMID:26074633

Deciphering ocean carbon in a changing world

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moran, Mary Ann; Kujawinski, Elizabeth B.; Stubbins, Aron

Dissolved organic matter (DOM) in the oceans is one of the largest pools of reduced carbon on Earth, comparable in size to the atmospheric CO 2 reservoir. The cycling of DOM over short and long time scales has profound impacts on the quantity of carbon sequestered in the oceans and the foundations of the food webs that support ocean life. At the heart of this cycle lie molecular-level relationships between the individual molecules in DOM and the members of the ocean microbiome that produce and consume them. In the past, these connections have defied clear definition and study because bothmore » DOM and microbial communities consist of many thousands of individual components. Emerging tools in analytical chemistry, microbiology and informatics are breaking down the barriers to a fuller appreciation of these connections. Furthermore, we highlight questions that are being addressed using this new toolkit and consider how these advances are transforming our understanding of some of the most important reactions of the marine carbon cycle.« less

Biochar composts and composites.

PubMed

Ekebafe, Marian Osazoduwa; Ekebafe, Lawrence Olu; Ugbesia, Stella Omozee

2015-01-01

Research has shown that the carbon content of wastes decreases during composting with an increase in the nitrogen content. This indicates that the increased microbial activity in the process results in an increased mineralisation rate of organic nitrogen. A formula containing biochar in the form of terra preta, biochar bokashi, biochar glomalin, biochar hydrogel and biochar mokusaku-eki could further enhance the stability of the system and its effectiveness as a soil ameliorant. It could increase the cation exchange capacity, reuse crop residue, reduce runoff, reduce watering, reduce the quantity of fertiliser increase crop yield, build and multiply soil biodiversity, strengthen and rebuild our soil food web, sequester atmospheric carbon in a carbon negative process, increase soil pH, restructure poor soils, and reduce carbon dioxide/methane/ nitrous oxide/ammonia emissions from gardens and fields. This paper considers these claims and also the wider environmental implications of the adoption of these processes. The intention of this overview is not just to summarise current knowledge of the subject, but also to identify gaps in knowledge that require further research.

Deciphering ocean carbon in a changing world

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moran, Mary Ann; Kujawinski, Elizabeth B.; Stubbins, Aron

2016-03-07

Dissolved organic matter (DOM) in the oceans is one of the largest pools of reduced carbon on Earth, comparable in size to the atmospheric CO2 reservoir. The cycling of DOM over short and long time scales has profound impacts on the quantity of carbon sequestered in the oceans and the foundations of the food webs that support ocean life. At the heart of this cycle lie molecular-level relationships between the individual molecules in DOM and the members of the ocean microbiome that produce and consume them. In the past, these connections have defied clear definition and study because both DOMmore » and microbial communities consist of many thousands of individual components. Emerging tools in analytical chemistry, microbiology and informatics are breaking down the barriers to a fuller appreciation of these connections. Here we highlight questions that are being addressed using this new toolkit and consider how these advances are transforming our understanding of some of the most important reactions of the marine carbon cycle.« less

Deciphering ocean carbon in a changing world

DOE PAGES

Moran, Mary Ann; Kujawinski, Elizabeth B.; Stubbins, Aron; ...

2016-03-07

Dissolved organic matter (DOM) in the oceans is one of the largest pools of reduced carbon on Earth, comparable in size to the atmospheric CO 2 reservoir. The cycling of DOM over short and long time scales has profound impacts on the quantity of carbon sequestered in the oceans and the foundations of the food webs that support ocean life. At the heart of this cycle lie molecular-level relationships between the individual molecules in DOM and the members of the ocean microbiome that produce and consume them. In the past, these connections have defied clear definition and study because bothmore » DOM and microbial communities consist of many thousands of individual components. Emerging tools in analytical chemistry, microbiology and informatics are breaking down the barriers to a fuller appreciation of these connections. Furthermore, we highlight questions that are being addressed using this new toolkit and consider how these advances are transforming our understanding of some of the most important reactions of the marine carbon cycle.« less

Elution of Uranium and Transition Metals from Amidoxime-Based Polymer Adsorbents for Sequestering Uranium from Seawater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Horng-Bin; Kuo, Li-Jung; Wai, Chien M.

2015-11-30

High-surface-area amidoxime and carboxylic acid grafted polymer adsorbents developed at Oak Ridge National Laboratory were tested for sequestering uranium in a flowing seawater flume system at the PNNL-Marine Sciences Laboratory. FTIR spectra indicate that a KOH conditioning process is necessary to remove the proton from the carboxylic acid and make the sorbent effective for sequestering uranium from seawater. The alkaline conditioning process also converts the amidoxime groups to carboxylate groups in the adsorbent. Both Na 2CO 3-H 2O 2 and hydrochloric acid elution methods can remove ~95% of the uranium sequestered by the adsorbent after 42 days of exposure inmore » real seawater. The Na 2CO 3-H 2O 2 elution method is more selective for uranium than conventional acid elution. Iron and vanadium are the two major transition metals competing with uranium for adsorption to the amidoxime-based adsorbents in real seawater.« less

Influence of seasonal variation and anthropogenic activity on phosphorus cycling and retention in mangrove sediments: A case study in China

NASA Astrophysics Data System (ADS)

Jiang, Shan; Lu, Haoliang; Liu, Jingchun; Lin, Yushan; Dai, Minyue; Yan, Chongling

2018-03-01

Mangroves are known for sequestering and storing large quantities of phosphorus (P) within their sediments. In the present study, the sediment P cycle (including phosphatase activity intensity, total sedimentary P, P fractions distinguished by a sequential extraction method, as well as diffusion-adsorption processes) in a mangrove swamp in a subtropical estuary in China was studied. In the spring, the acid phosphatase activity varied between 1.3 and 1.9 units in the four sites in the estuary. The activity of alkaline phosphatase varied from 0.8 to 1.4 units. The total sedimentary P ranged from 821 to 1689 mg kg-1 with a dominance of redox-sensitive (Fe/Al bound) P. In the autumn, activities of both phosphatases and the total sediment P amount increased, probably due to enhanced inputs of organic matter and Fe oxides. In addition to seasonal variation, P in the mangrove sediment was influenced by anthropogenic activities. In particular, redox-sensitive P decreased significantly while phosphatase activity increased in the site that was flushed with aquaculture pond effluents. In contrast, sediment P enrichment was observed in the site that received domestic sewage. Both sources of anthropogenic P increased the eutrophication risk of the mangrove sediment because of a decrease in the amount of P adsorption and an enhancement of P release via diffusion. Diesel contamination due to the presence of a dock depressed phosphatase activity in the surficial sediment. The overlap between seasonal rhythm and human influences may introduce significant variations in P cycling, which warrants further attention from coastal management.

Put a Coalatom in Your Tank: The Compelling Case for a Marriage of Coal and Nuclear Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Penfield, Scott R. Jr.; Bolthrunis, Charles O.

2006-07-01

Increasing costs and security concerns with present fossil energy sources, plus environmental concerns related to CO{sub 2} emissions and the emergence of new technologies in the energy and transportation sectors set the stage for a marriage of convenience between coal and nuclear energy. As the price of oil continues to increase and supply becomes increasingly constrained, coal offers a secure domestic alternative to foreign oil as a source of liquid fuels. However, conventional technologies for converting coal to liquid fuels produce large quantities of CO{sub 2} that must be released or sequestered. Advanced nuclear technologies, particularly the High-Temperature Gas-Cooled Reactormore » (HTGR), have the potential to produce hydrogen via water splitting; however, the transportation and storage of hydrogen are significant barriers to the 'Holy Grail', the Hydrogen Economy. In a coal/nuclear marriage, the hydrogen and oxygen provided by nuclear energy are joined with coal as a source of carbon to provide liquid fuels with negligible CO{sub 2} release from the process. In combination with emerging hybrid vehicles, fuels based on a coal/nuclear marriage promise stable prices, increased domestic security and a reduction in CO{sub 2} emissions without the need to completely replace our transportation fuels infrastructure. The intent of this paper is to outline the technical basis for the above points and to show that process energy applications of nuclear energy can provide the basis for answering some of the tougher questions related to energy and the environment. (authors)« less

The Genome Sequence of the Leaf-Cutter Ant Atta cephalotes Reveals Insights into Its Obligate Symbiotic Lifestyle

PubMed Central

Suen, Garret; Holt, Carson; Abouheif, Ehab; Bornberg-Bauer, Erich; Bouffard, Pascal; Caldera, Eric J.; Cash, Elizabeth; Cavanaugh, Amy; Denas, Olgert; Elhaik, Eran; Favé, Marie-Julie; Gadau, Jürgen; Gibson, Joshua D.; Graur, Dan; Grubbs, Kirk J.; Hagen, Darren E.; Harkins, Timothy T.; Helmkampf, Martin; Hu, Hao; Johnson, Brian R.; Kim, Jay; Marsh, Sarah E.; Moeller, Joseph A.; Muñoz-Torres, Mónica C.; Murphy, Marguerite C.; Naughton, Meredith C.; Nigam, Surabhi; Overson, Rick; Rajakumar, Rajendhran; Reese, Justin T.; Scott, Jarrod J.; Smith, Chris R.; Tao, Shu; Tsutsui, Neil D.; Viljakainen, Lumi; Wissler, Lothar; Yandell, Mark D.; Zimmer, Fabian; Taylor, James; Slater, Steven C.; Clifton, Sandra W.; Warren, Wesley C.; Elsik, Christine G.; Smith, Christopher D.; Weinstock, George M.; Gerardo, Nicole M.; Currie, Cameron R.

2011-01-01

Leaf-cutter ants are one of the most important herbivorous insects in the Neotropics, harvesting vast quantities of fresh leaf material. The ants use leaves to cultivate a fungus that serves as the colony's primary food source. This obligate ant-fungus mutualism is one of the few occurrences of farming by non-humans and likely facilitated the formation of their massive colonies. Mature leaf-cutter ant colonies contain millions of workers ranging in size from small garden tenders to large soldiers, resulting in one of the most complex polymorphic caste systems within ants. To begin uncovering the genomic underpinnings of this system, we sequenced the genome of Atta cephalotes using 454 pyrosequencing. One prediction from this ant's lifestyle is that it has undergone genetic modifications that reflect its obligate dependence on the fungus for nutrients. Analysis of this genome sequence is consistent with this hypothesis, as we find evidence for reductions in genes related to nutrient acquisition. These include extensive reductions in serine proteases (which are likely unnecessary because proteolysis is not a primary mechanism used to process nutrients obtained from the fungus), a loss of genes involved in arginine biosynthesis (suggesting that this amino acid is obtained from the fungus), and the absence of a hexamerin (which sequesters amino acids during larval development in other insects). Following recent reports of genome sequences from other insects that engage in symbioses with beneficial microbes, the A. cephalotes genome provides new insights into the symbiotic lifestyle of this ant and advances our understanding of host–microbe symbioses. PMID:21347285

Enhanced terrestrial weathering/runoff and surface ocean carbonate production during the recovery stages of the Paleocene-Eocene thermal maximum

NASA Astrophysics Data System (ADS)

Kelly, D. Clay; Zachos, James C.; Bralower, Timothy J.; Schellenberg, Stephen A.

2005-12-01

The carbonate saturation profile of the oceans shoaled markedly during a transient global warming event known as the Paleocene-Eocene thermal maximum (PETM) (circa 55 Ma). The rapid release of large quantities of carbon into the ocean-atmosphere system is believed to have triggered this intense episode of dissolution along with a negative carbon isotope excursion (CIE). The brevity (120-220 kyr) of the PETM reflects the rapid enhancement of negative feedback mechanisms within Earth's exogenic carbon cycle that served the dual function of buffering ocean pH and reducing atmospheric greenhouse gas levels. Detailed study of the PETM stratigraphy from Ocean Drilling Program Site 690 (Weddell Sea) reveals that the CIE recovery period, which postdates the CIE onset by ˜80 kyr, is represented by an expanded (˜2.5 m thick) interval containing a unique planktic foraminiferal assemblage strongly diluted by coccolithophore carbonate. Collectively, the micropaleontological and sedimentological changes preserved within the CIE recovery interval reflect a transient state when ocean-atmosphere chemistry fostered prolific coccolithophore blooms that suppressed the local lysocline to relatively deeper depths. A prominent peak in the abundance of the clay mineral kaolinite is associated with the CIE recovery interval, indicating that continental weathering/runoff intensified at this time as well (Robert and Kennett, 1994). Such parallel stratigraphic changes are generally consonant with the hypothesis that enhanced continental weathering/runoff and carbonate precipitation helped sequester carbon during the PETM recovery period (e.g., Dickens et al., 1997; Zachos et al., 2005).

Native Soil Charcoal as a Model for Designing Biochar for Carbon Sequestration

EPA Science Inventory

Under changing climate a variety of mechanisms for removing carbon from the atmosphere and sequestering it elsewhere are being considered to reduce the forcing of the atmosphere. Amending soils with biochar has been proposed as one long-term means of sequestering carbon originat...

β-CD-dextran polymer for efficient sequestration of cholesterol from phospholipid bilayers: Mechanistic and safe-toxicity investigations.

PubMed

Stelzl, Dominik; Nielsen, Thorbjørn Terndrup; Hansen, Terkel; di Cagno, Massimiliano

2015-12-30

The aim of this work was to investigate the suitability of β-cyclodextrin-dextran (BCD-dextran) polymer as cholesterol sequestering agent in vitro. For this purpose, BCD-dextran-cholesterol complexation was studied by phase solubility studies as well as with a specifically designed in vitro model based on giant unilamellar vesicles (GUVs) to evaluate the ability of this polymer to sequestrate cholesterol from phospholipid bilayers. Cholesterol-sequestering ability of BCD-dextran was also investigated on different cell lines relevant for the hematopoietic system and results were correlated to cells toxicity. BCD-dextran polymer was capable of extracting significant amount of cholesterol from phospholipid bilayers and to a higher extent in comparison to available β-cyclodextrins (BCDs). The ability of BCD-dextran in sequestering cholesterol resulted also very high on cell lines relevant for the hematopoietic system. Moreover, BCD-dextran resulted less toxic on cell cultures due to higher selectivity in sequestering cholesterol in comparison to MBCD (that sequestrated also significant amounts of cholesteryl esters). In conclusion, BCD-dextran resulted an extremely efficient cholesterol-sequestering agent and BCD-dextran resulted more selective to cholesterol extraction in comparison to other BCDs (therefore of lower cytotoxicity). This phenomenon might play a key role to develop an efficient treatment for hypercholesterolemia based on cholesterol segregation. Copyright © 2015 Elsevier B.V. All rights reserved.

40 CFR 273.37 - Response to releases.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 273.37 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Large Quantity Handlers of Universal Waste § 273.37... of universal wastes and other residues from universal wastes. (b) A large quantity handler of...

40 CFR 273.38 - Off-site shipments.

Code of Federal Regulations, 2012 CFR

2012-07-01

....38 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Large Quantity Handlers of Universal Waste § 273.38 Off-site shipments. (a) A large quantity handler of universal waste is prohibited from sending or...

40 CFR 273.38 - Off-site shipments.

Code of Federal Regulations, 2011 CFR

2011-07-01

....38 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Large Quantity Handlers of Universal Waste § 273.38 Off-site shipments. (a) A large quantity handler of universal waste is prohibited from sending or...

40 CFR 273.38 - Off-site shipments.

Code of Federal Regulations, 2010 CFR

2010-07-01

....38 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Large Quantity Handlers of Universal Waste § 273.38 Off-site shipments. (a) A large quantity handler of universal waste is prohibited from sending or...

40 CFR 273.38 - Off-site shipments.

Code of Federal Regulations, 2014 CFR

2014-07-01

....38 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Large Quantity Handlers of Universal Waste § 273.38 Off-site shipments. (a) A large quantity handler of universal waste is prohibited from sending or...

40 CFR 273.38 - Off-site shipments.

Code of Federal Regulations, 2013 CFR

2013-07-01

....38 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Large Quantity Handlers of Universal Waste § 273.38 Off-site shipments. (a) A large quantity handler of universal waste is prohibited from sending or...

Ability of Bruton's Tyrosine Kinase Inhibitors to Sequester Y551 and Prevent Phosphorylation Determines Potency for Inhibition of Fc Receptor but not B-Cell Receptor Signaling.

PubMed

Bender, Andrew T; Gardberg, Anna; Pereira, Albertina; Johnson, Theresa; Wu, Yin; Grenningloh, Roland; Head, Jared; Morandi, Federica; Haselmayer, Philipp; Liu-Bujalski, Lesley

2017-03-01

Bruton's tyrosine kinase (Btk) is expressed in a variety of hematopoietic cells. Btk has been demonstrated to regulate signaling downstream of the B-cell receptor (BCR), Fc receptors (FcRs), and toll-like receptors. It has become an attractive drug target because its inhibition may provide significant efficacy by simultaneously blocking multiple disease mechanisms. Consequently, a large number of Btk inhibitors have been developed. These compounds have diverse binding modes, and both reversible and irreversible inhibitors have been developed. Reported herein, we have tested nine Btk inhibitors and characterized on a molecular level how their interactions with Btk define their ability to block different signaling pathways. By solving the crystal structures of Btk inhibitors bound to the enzyme, we discovered that the compounds can be classified by their ability to trigger sequestration of Btk residue Y551. In cells, we found that sequestration of Y551 renders it inaccessible for phosphorylation. The ability to sequester Y551 was an important determinant of potency against FcεR signaling as Y551 sequestering compounds were more potent for inhibiting basophils and mast cells. This result was true for the inhibition of FcγR signaling as well. In contrast, Y551 sequestration was less a factor in determining potency against BCR signaling. We also found that Btk activity is regulated differentially in basophils and B cells. These results elucidate important determinants for Btk inhibitor potency against different signaling pathways and provide insight for designing new compounds with a broader inhibitory profile that will likely result in greater efficacy. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Measuring the decomposition of organic carbon sequestered by salt marsh sediment

NASA Astrophysics Data System (ADS)

Light, T.; Mctigue, N.; Currin, C.

2016-12-01

As atmospheric carbon dioxide concentrations continue to rise, salt marshes are increasingly being recognized as a natural carbon sink, for large amounts of organic carbon are sequestered by salt marsh sediments. However, little is known regarding the fate of this "blue carbon" after salt marsh sediment is disturbed via erosion or lost due to sea level rise. This investigation explored novel methodologies for determining the lability of carbon sequestered by salt marsh sediment. Sediment cores were collected from a Spartina alterniflora-dominated marsh in Camp Lejeune, NC, and elemental analysis revealed that the upper 76 cm of sediment at the site contains a total carbon stock of 28.4 kg /m2. Sediment ranging from 251-545 years old, as determined through radiocarbon dating, was incubated under sub-aerial and aqueous conditions for 18 days and 25 days respectively. Carbon dioxide flux measurements revealed that shallower sediment organic matter decomposed more rapidly than deeper sediment in sub-aerial incubations, but decomposition was fairly slow in both treatments. No significant organic matter decomposition was observed in the aqueous incubations, as revealed by analyses of organic carbon remaining after the incubation period. The aqueous incubation included a treatment that had been "primed" with highly labile yeast extract, but no significant priming effect was observed over 25 days. While further investigation on the fate of this sediment carbon is needed, these preliminary findings indicate that salt marshes facilitate long-term carbon sequestration even after disturbances. This in turn supports the argument for mitigating anthropogenic carbon dioxide emissions through salt marsh restoration, and supports a policy of preserving and conserving coastal wetlands for this valuable ecosystem service.

Dietary alkaloid sequestration in a poison frog: an experimental test of alkaloid uptake in Melanophryniscus stelzneri (Bufonidae).

PubMed

Hantak, Maggie M; Grant, Taran; Reinsch, Sherri; McGinnity, Dale; Loring, Marjorie; Toyooka, Naoki; Saporito, Ralph A

2013-12-01

Several lineages of brightly colored anurans independently evolved the ability to secrete alkaloid-containing defensive chemicals from granular glands in the skin. These species, collectively referred to as 'poison frogs,' form a polyphyletic assemblage that includes some species of Dendrobatidae, Mantellidae, Myobatrachidae, Bufonidae, and Eleutherodactylidae. The ability to sequester alkaloids from dietary arthropods has been demonstrated experimentally in most poison frog lineages but not in bufonid or eleutherodactylid poison frogs. As with other poison frogs, species of the genus Melanophryniscus (Bufonidae) consume large numbers of mites and ants, suggesting they might also sequester defensive alkaloids from dietary sources. To test this hypothesis, fruit flies dusted with alkaloid/nutritional supplement powder were fed to individual Melanophryniscus stelzneri in two experiments. In the first experiment, the alkaloids 5,8-disubstituted indolizidine 235B' and decahydroquinoline were administered to three individuals for 104 days. In the second experiment, the alkaloids 3,5-disubstituted indolizidine 239Q and decahydroquinoline were given to three frogs for 153 days. Control frogs were fed fruit flies dusted only with nutritional supplement. Gas chromatography/mass spectrometry analyses revealed that skin secretions of all experimental frogs contained alkaloids, whereas those of all control frogs lacked alkaloids. Uptake of decahydroquinoline was greater than uptake of 5,8-disubstituted indolizidine, and uptake of 3,5-disubstituted indolizidine was greater than uptake of decahydroquinoline, suggesting greater uptake efficiency of certain alkaloids. Frogs in the second experiment accumulated a greater amount of alkaloid, which corresponds to the longer duration and greater number of alkaloid-dusted fruit flies that were consumed. These findings provide the first experimental evidence that bufonid poison frogs sequester alkaloid-based defenses from dietary sources.

Conservation agricultural management to sequester soil organic carbon

USDA-ARS?s Scientific Manuscript database

Storing carbon (C) in soil as organic matter is not only a viable strategy to sequester CO2 from the atmosphere, but is vital for improving the quality, fertility, and functioning of soil. This presentation describes relevant management approaches to avoid land degradation and foster soil organic C ...

Uranium Sequestration During Biostimulated Reduction and In Response to the Return of Oxic Conditions In Shallow Aquifers

USGS Publications Warehouse

Fuller, Christopher C.; Johnson, Kelly J.; Akstin, Katherine; Singer, David M.; Yabusaki, Steven B.; Fang, Yilin; Fuhrmann, M.

2015-01-01

A proposed approach for groundwater remediation of uranium contamination is to generate reducing conditions by stimulating the growth of microbial populations through injection of electron donor compounds into the subsurface. Sufficiently reducing conditions will result in reduction of soluble hexavalent uranium, U(VI), and precipitation of the less soluble +4 oxidation state uranium, U(IV). This process is termed biostimulated reduction. A key issue in the remediation of uranium (U) contamination in aquifers by biostimulated reduction is the long term stability of the sequestered uranium. Three flow-through column experiments using aquifer sediment were used to evaluate the remobilization of bioreduced U sequestered under conditions in which biostimulation extended well into sulfate reduction to enhance precipitation of reduced sulfur phases such as iron sulfides. One column received added ferrous iron, Fe(II), increasing production of iron sulfides, to test their effect on remobilization of the sequestered uranium, either by serving as a redox buffer by competing for dissolved oxygen, or by armoring the reduced uranium. During biostimulation of the ambient microbial population with acetate, dissolved uranium was lowered by a factor of 2.5 or more with continued removal for over 110 days of biostimulation, well after the onset of sulfate reduction at ~30 days. Sequestered uranium was essentially all U(IV) resulting from the formation of nano-particulate uraninite that coated sediment grains to a thickness of a few 10’s of microns, sometimes in association with S and Fe. A multicomponent biogeochemical reactive transport model simulation of column effluents during biostimulation was generally able to describe the acetate oxidation, iron, sulfate, and uranium reduction for all three columns using parameters derived from simulations of field scale biostimulation experiments. Columns were eluted with artificial groundwater at equilibrium with atmospheric oxygen to simulate the upper limit of dissolved oxygen in recharge water. Overall about 9% of total uranium removed from solution during biostimulation was remobilized. Release of U during oxic elution was a continuous process over 140 days with dissolved uranium concentrations about 0.2 and 0.8 aM for columns with and without ferrous iron addition, respectively. Uranium remaining on the sediment was in the reduced form. The prolonged period of biostimulation and concomitant sulfate reduction appears to limit the rate of U(IV) oxidative remobilization in contrast to a large release observed for columns in previous studies that did not undergo sulfate reduction. Although continued sulfate reduction may cause decreased permeability from precipitation of iron sulfide, the greater apparent stability of the sequestered U(IV) provided by the sustained biostimulation should be considered in design of field scale remediation efforts. Remobilization of uranium following biostimulated reduction should be tested further at the field scale.

Legacy effects of grassland management on soil carbon to depth.

PubMed

Ward, Susan E; Smart, Simon M; Quirk, Helen; Tallowin, Jerry R B; Mortimer, Simon R; Shiel, Robert S; Wilby, Andrew; Bardgett, Richard D

2016-08-01

The importance of managing land to optimize carbon sequestration for climate change mitigation is widely recognized, with grasslands being identified as having the potential to sequester additional carbon. However, most soil carbon inventories only consider surface soils, and most large-scale surveys group ecosystems into broad habitats without considering management intensity. Consequently, little is known about the quantity of deep soil carbon and its sensitivity to management. From a nationwide survey of grassland soils to 1 m depth, we show that carbon in grassland soils is vulnerable to management and that these management effects can be detected to considerable depth down the soil profile, albeit at decreasing significance with depth. Carbon concentrations in soil decreased as management intensity increased, but greatest soil carbon stocks (accounting for bulk density differences), were at intermediate levels of management. Our study also highlights the considerable amounts of carbon in subsurface soil below 30 cm, which is missed by standard carbon inventories. We estimate grassland soil carbon in Great Britain to be 2097 Tg C to a depth of 1 m, with ~60% of this carbon being below 30 cm. Total stocks of soil carbon (t ha(-1) ) to 1 m depth were 10.7% greater at intermediate relative to intensive management, which equates to 10.1 t ha(-1) in surface soils (0-30 cm), and 13.7 t ha(-1) in soils from 30 to 100 cm depth. Our findings highlight the existence of substantial carbon stocks at depth in grassland soils that are sensitive to management. This is of high relevance globally, given the extent of land cover and large stocks of carbon held in temperate managed grasslands. Our findings have implications for the future management of grasslands for carbon storage and climate mitigation, and for global carbon models which do not currently account for changes in soil carbon to depth with management. © 2016 John Wiley & Sons Ltd.

Transthyretin Sequesters Amyloid β Protein and Prevents Amyloid Formation

NASA Astrophysics Data System (ADS)

Schwarzman, Alexander L.; Gregori, Luisa; Vitek, Michael P.; Lyubski, Sergey; Strittmatter, Warren J.; Enghilde, Jan J.; Bhasin, Ramaninder; Silverman, Josh; Weisgraber, Karl H.; Coyle, Patricia K.; Zagorski, Michael G.; Talafous, Joseph; Eisenberg, Moises; Saunders, Ann M.; Roses, Allen D.; Goldgaber, Dmitry

1994-08-01

The cardinal pathological features of Alzheimer disease are depositions of aggregated amyloid β protein (Aβ) in the brain and cerebrovasculature. However, the Aβ is found in a soluble form in cerebrospinal fluid in healthy individuals and patients with Alzheimer disease. We postulate that sequestration of Aβ precludes amyloid formation. Failure to sequester Aβ in Alzheimer disease may result in amyloidosis. When we added Aβ to cerebrospinal fluid of patients and controls it was rapidly sequestered into stable complexes with transthyretin. Complexes with apolipoprotein E, which has been shown to bind Aβ in vitro, were not observed in cerebrospinal fluid. Additional in vitro studies showed that both purified transthyretin and apolipoprotein E prevent amyloid formation.

Large-scale preparation of plasmid DNA.

PubMed

Heilig, J S; Elbing, K L; Brent, R

2001-05-01

Although the need for large quantities of plasmid DNA has diminished as techniques for manipulating small quantities of DNA have improved, occasionally large amounts of high-quality plasmid DNA are desired. This unit describes the preparation of milligram quantities of highly purified plasmid DNA. The first part of the unit describes three methods for preparing crude lysates enriched in plasmid DNA from bacterial cells grown in liquid culture: alkaline lysis, boiling, and Triton lysis. The second part describes four methods for purifying plasmid DNA in such lysates away from contaminating RNA and protein: CsCl/ethidium bromide density gradient centrifugation, polyethylene glycol (PEG) precipitation, anion-exchange chromatography, and size-exclusion chromatography.

40 CFR 273.33 - Waste management.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Waste management. 273.33 Section 273...) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Large Quantity Handlers of Universal Waste § 273.33 Waste management. (a) Universal waste batteries. A large quantity handler of universal waste must manage...

A Mouse Click Away: Internet Resources for Students in Crisis in Geographically Isolated or Self-Sequestered Communities

ERIC Educational Resources Information Center

Gary, Juneau Mahan

2010-01-01

The impact, incidence, prevalence, and severity of violence and trauma adversely affect students academically, behaviorally, emotionally, and socially. For students residing in geographically isolated or self-sequestered communities, trauma may be exacerbated when school counselors may be unprepared to respond effectively and timely because…

Process for sequestering carbon dioxide and sulfur dioxide

DOEpatents

Maroto-Valer, M Mercedes [State College, PA; Zhang, Yinzhi [State College, PA; Kuchta, Matthew E [State College, PA; Andresen, John M [State College, PA; Fauth, Dan J [Pittsburgh, PA

2009-10-20

A process for sequestering carbon dioxide, which includes reacting a silicate based material with an acid to form a suspension, and combining the suspension with carbon dioxide to create active carbonation of the silicate-based material, and thereafter producing a metal salt, silica and regenerating the acid in the liquid phase of the suspension.

Can greening of aquaculture sequester blue carbon?

PubMed

Ahmed, Nesar; Bunting, Stuart W; Glaser, Marion; Flaherty, Mark S; Diana, James S

2017-05-01

Globally, blue carbon (i.e., carbon in coastal and marine ecosystems) emissions have been seriously augmented due to the devastating effects of anthropogenic pressures on coastal ecosystems including mangrove swamps, salt marshes, and seagrass meadows. The greening of aquaculture, however, including an ecosystem approach to Integrated Aquaculture-Agriculture (IAA) and Integrated Multi-Trophic Aquaculture (IMTA) could play a significant role in reversing this trend, enhancing coastal ecosystems, and sequestering blue carbon. Ponds within IAA farming systems sequester more carbon per unit area than conventional fish ponds, natural lakes, and inland seas. The translocation of shrimp culture from mangrove swamps to offshore IMTA could reduce mangrove loss, reverse blue carbon emissions, and in turn increase storage of blue carbon through restoration of mangroves. Moreover, offshore IMTA may create a barrier to trawl fishing which in turn could help restore seagrasses and further enhance blue carbon sequestration. Seaweed and shellfish culture within IMTA could also help to sequester more blue carbon. The greening of aquaculture could face several challenges that need to be addressed in order to realize substantial benefits from enhanced blue carbon sequestration and eventually contribute to global climate change mitigation.

Nitrogen Deposition: A Component of Global Change Analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norby, Richard J.

1997-12-31

The global cycles of carbon and nitrogen are being perturbed by human activities that increase the transfer from large pools of nonreactive forms of the elements to reactive forms that are essential to the functioning of the terrestrial biosphere. The cycles are closely linked at all scales, and global change analyses must consider carbon and nitrogen cycles together. The increasing amount of nitrogen originating from fossil fuel combustion and deposited to terrestrial ecosystems as nitrogen oxides could increase the capacity of ecosystems to sequester carbon thereby removing some of the excess carbon dioxide from the atmosphere and slowing the developmentmore » of greenhouse warming. Several global and ecosystem models have calculated the amount of carbon sequestration that can be attributed to nitrogen deposition based on assumptions about the allocation of nitrogen among ecosystem components with different carbon-nitrogen ratios. They support the premise that nitrogen deposition is responsible for a an increasing terrestrial carbon sink since industrialization began, but there are large uncertainties related to the continued capacity of ecosystems to retain exogenous nitrogen. Whether terrestrial ecosystems continue to sequester additional carbon will depend in part on their response to increasing atmospheric carbon dioxide concentrations, which is widely thought to be constrained by limited nitrogen availability. Ecosystem models generally support the conclusion that the responses of ecosystems to increasing concentrations of carbon dioxide will be larger, and the range of possible responses will be wider, in ecosystems with increased nitrogen inputs originating as atmospheric deposition.« less

Uncertainty In Greenhouse Gas Emissions On Carbon Sequestration In Coastal and Freshwater Wetlands of the Mississippi River Delta: A Subsiding Coastline as a Proxy for Future Global Sea Level

NASA Astrophysics Data System (ADS)

White, J. R.; DeLaune, R. D.; Roy, E. D.; Corstanje, R.

2014-12-01

The highly visible phenomenon of wetland loss in coastal Louisiana (LA) is examined through the prism of carbon accumulation, wetland loss and greenhouse gas (GHG) emissions. The Mississippi River Deltaic region experiences higher relative sea level rise due to coupled subsidence and eustatic sea level rise allowing this region to serve as a proxy for future projected golbal sea level rise. Carbon storage or sequestration in rapidly subsiding LA coastal marsh soils is based on vertical marsh accretion and areal change data. While coastal marshes sequester significant amount of carbon through vertical accretion, large amounts of carbon, previously sequested in the soil profile is lost through annual deterioration of these coastal marshes as well as through GHG emissions. Efforts are underway in Louisiana to access the carbon credit market in order to provide significant funding for coastal restoration projects. However, there is very large uncertainty on GHG emission rates related to both marsh type and temporal (daily and seasonal) effects. Very little data currently exists which addresses this uncertainty which can significantly affect the carbon credit value of a particular wetland system. We provide an analysis of GHG emission rates for coastal freshwater, brackish and and salt marshes compared to the net soil carbon sequestration rate. Results demonstrate that there is very high uncertainty on GHG emissions which can substantially alter the carbon credit value of a particular wetland system.

The role of protected areas in land use/land cover change and the carbon cycle in the conterminous United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Xiaoliang; Zhou, Yuyu; Liu, Yaling

Protected areas (PAs) cover about 22% of the conterminous United States. Understanding their role on historical land use and land cover change (LULCC) and on the carbon cycle is essential to provide guidance for environmental policies. In this study, we compiled historical LULCC and PAs data to explore these interactions within the terrestrial ecosystem model (TEM). We found that intensive LULCC occurred in the conterminous United States from 1700 to 2005. More than 3 million km2 of forest, grassland and shrublands were converted into agricultural lands, which caused 10,607 Tg C release from land ecosystems to atmosphere. PAs had experiencedmore » little LULCC as they were generally established in the 20th century after most of the agricultural expansion had occurred. PAs initially acted as a carbon source due to land use legacies, but their accumulated carbon budget switched to a carbon sink in the 1960s, sequestering an estimated 1,642 Tg C over 1700–2005, or 13.4% of carbon losses in non-PAs. We also find that PAs maintain larger carbon stocks and continue sequestering carbon in recent years (2001–2005), but at a lower rate due to increased heterotrophic respiration as well as lower productivity associated to aging ecosystems. It is essential to continue efforts to maintain resilient, biodiverse ecosystems and avoid large-scale disturbances that would release large amounts of carbon in PAs.« less

Organic Carbon Burial Rates in Mangrove Soils Along Florida's Coast from Tampa Bay to Biscayne National Park

NASA Astrophysics Data System (ADS)

Smoak, J. M.; Breithaupt, J. L.; Moyer, R. P.; Sanders, C. J.; Proctor, M. R.; Jacobs, J. A.; Chappel, A. R.; Comparetto, K. R.

2016-12-01

Mangrove forests provide a range of valuable ecosystem services including sequestering organic carbon (OC) in their soils at rates much greater on a per area basis than those found in other types of forests. This restricts a large quantity of OC to a relatively small area along tropical and sub-tropical coastal margins, where dramatic climate-driven impacts are expected. Hence this small yet highly-vulnerable area will have a disproportionally large impact on global carbon cycling. One of the fundamental climate-related questions in mangrove systems is whether their soils will continue to function as a globally significant OC sink or become a source as previously buried OC is oxidized and returned to the atmosphere. While changes to precipitation, temperature, cyclone activity, etc. may influence this sink capacity, it is accelerating sea-level rise (SLR) that is of greatest immediate concern because if mangrove peat formation fails to keep pace then all ecosystem services, including carbon burial, will collapse. Mangroves that receive minimal terrigenous sediments (such as those in South Florida) are largely dependent on the rate of OC accumulation as a key contributor to accretion. To investigate these processes, we measured OC burial and accretion rates over the last 100 years (via 210Pb dating) from sites in Tampa Bay, Charlotte Harbor, Ten Thousand Islands, Everglades National Park, Biscayne National Park, and the Lower Florida Keys. The mean 100-year burial rate over all sites is 119 ± 33 (SD) g m-2 yr-1 which is lower than the global mean. Mean accretion rates were found to match (within error) the relatively modest average SLR over the last 100 years, but rates may not have kept pace with the substantially higher SLR in the last decade. This investigation contributes to establishing regional-scale Blue Carbon budgets, and examines how OC burial in mangroves has changed over the last 100 years. This improved understanding of past mangrove OC burial response coupled with future projections of climate change allows for better projections of future carbon cycling and budgets in coastal systems.

75 FR 5120 - United States, et al. v. Stericycle, Inc., et al.; Proposed Final Judgment and Competitive Impact...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-01

... services for Large Quantity Generator (``LQG'') customers in the states of Kansas, Missouri, Nebraska, and...; Oklahoma City, Oklahoma; Omaha, Nebraska; and Booneville, Missouri; LQG customer contracts associated with... collection and treatment services for large quantity generator (``LQG'') customers. The resulting combination...

Substrate prediction of Ixodes ricinus salivary lipocalins differentially expressed during Borrelia afzelii infection

NASA Astrophysics Data System (ADS)

Valdés, James J.; Cabezas-Cruz, Alejandro; Sima, Radek; Butterill, Philip T.; Růžek, Daniel; Nuttall, Patricia A.

2016-09-01

Evolution has provided ticks with an arsenal of bioactive saliva molecules that counteract host defense mechanisms. This salivary pharmacopoeia enables blood-feeding while enabling pathogen transmission. High-throughput sequencing of tick salivary glands has thus become a major focus, revealing large expansion within protein encoding gene families. Among these are lipocalins, ubiquitous barrel-shaped proteins that sequester small, typically hydrophobic molecules. This study was initiated by mining the Ixodes ricinus salivary gland transcriptome for specific, uncharacterized lipocalins: three were identified. Differential expression of these I. ricinus lipocalins during feeding at distinct developmental stages and in response to Borrelia afzelii infection suggests a role in transmission of this Lyme disease spirochete. A phylogenetic analysis using 803 sequences places the three I. ricinus lipocalins with tick lipocalins that sequester monoamines, leukotrienes and fatty acids. Both structural analysis and biophysical simulations generated robust predictions showing these I. ricinus lipocalins have the potential to bind monoamines similar to other tick species previously reported. The multidisciplinary approach employed in this study characterized unique lipocalins that play a role in tick blood-feeding and transmission of the most important tick-borne pathogen in North America and Eurasia.

Photoprotection in sequestered plastids of sea slugs and respective algal sources

PubMed Central

Cruz, Sónia; Cartaxana, Paulo; Newcomer, Rebecca; Dionísio, Gisela; Calado, Ricardo; Serôdio, João; Pelletreau, Karen N.; Rumpho, Mary E.

2015-01-01

Some sea slugs are capable of retaining functional sequestered chloroplasts (kleptoplasts) for variable periods of time. The mechanisms supporting the maintenance of these organelles in animal hosts are still largely unknown. Non-photochemical quenching (NPQ) and the occurrence of a xanthophyll cycle were investigated in the sea slugs Elysia viridis and E. chlorotica using chlorophyll fluorescence measurements and pigment analysis. The photoprotective capacity of kleptoplasts was compared to that observed in their respective algal source, Codium tomentosum and Vaucheria litorea. A functional xanthophyll cycle and a rapidly reversible NPQ component were found in V. litorea and E. chlorotica but not in C. tomentosum and E. viridis. To our knowledge, this is the first report of the absence of a functional xanthophyll cycle in a green macroalgae. The absence of a functional xanthophyll cycle in C. tomentosum could contribute to the premature loss of photosynthetic activity and relatively short-term retention of kleptoplasts in E. viridis. On the contrary, E. chlorotica displays one of the longest functional examples of kleptoplasty known so far. We speculate that different efficiencies of photoprotection and repair mechanisms of algal food sources play a role in the longevity of photosynthetic activity in kleptoplasts retained by sea slugs. PMID:25601025

Design of a perfluorocarbon tracer based monitoring network to support monitoring verification and accounting of sequestered CO2

NASA Astrophysics Data System (ADS)

Watson, T.; Sullivan, T.

2013-05-01

The levels of CO2 in the atmosphere have been growing since the beginning of the industrial revolution. The current level is 391 ppm. If there are no efforts to mitigate CO2 emissions, the levels will rise to 750 ppm by 2100. Geologic carbon sequestration is one strategy that may be used to begin to reduce emissions. Sequestration will not be effective unless reservoir leak rates are significantly less than 1%. There must be rigorous monitoring protocols in place to ensure sequestration projects meet regulatory and environmental goals. Monitoring for CO2 leakage directly is difficult because of the large background levels and variability of CO2 in the atmosphere. Using tracers to tag the sequestered CO2 can mitigate some of the difficulties of direct measurement but a tracer monitoring network and the levels of tagging need to be carefully designed. Simple diffusion and dispersion models are used to predict the surface and atmospheric concentrations that would be seen by a network monitoring a sequestration site. Levels of tracer necessary to detect leaks from 0.01 to 1% are presented and suggestions for effective monitoring and protection of global tracer utility are presented.

Genetically modified Medicago truncatula lacking calcium oxalate has increased calcium bioavailability and partially rescues vitamin D receptor knockout mice phenotypes

USDA-ARS?s Scientific Manuscript database

How the distribution and sequestered form of plant macro/micro-nutrients influence their bioavailability, and ultimately impact human health, is poorly understood. The legume Medicago truncatula has a portion of its tissue calcium sequestered in the form of the calcium oxalate crystal, which reduces...

Meeting global policy commitments carbon sequestration and southern pine forests

Treesearch

Kurt H. Johnsen; David N. Wear; R. Oren; R.O. Teskey; Felipe Sanchez; Rodney E. Will; John Butnor; D. Markewitz; D. Richter; T. Rials; H.L. Allen; J. Seiler; D. Ellsworth; Christopher Maier; G. Katul; P.M. Dougherty

2001-01-01

In managed forests, the amount of carbon further sequestered will be determined by (1) the increased amount of carbon in standing biomass (resulting from land-use changes and increased productivity); (2) the amount of recalcitrant carbon remaining below ground at the end of rotations; and (3) the amount of carbon sequestered in products created from harvested wood....

Quantity discounts on a virtual good: The results of a massive pricing experiment at King Digital Entertainment

PubMed Central

Levitt, Steven D.; List, John A.; Neckermann, Susanne; Nelson, David

2016-01-01

We report on a natural field experiment on quantity discounts involving more than 14 million consumers. Implementing price reductions ranging from 9–70% for large purchases, we found remarkably little impact on revenue, either positively or negatively. There was virtually no increase in the quantity of customers making a purchase; all the observed changes occurred for customers who already were buyers. We found evidence that infrequent purchasers are more responsive to discounts than frequent purchasers. There was some evidence of habit formation when prices returned to pre-experiment levels. There also was some evidence that consumers contemplating small purchases are discouraged by the presence of extreme quantity discounts for large purchases. PMID:27382146

Differential Regulation of Angiogenesis using Degradable VEGF-Binding Microspheres

PubMed Central

Belair, David G.; Miller, Michael J.; Wang, Shoujian; Darjatmokon, Soesiawati R.; Binder, Bernard Y.K.; Sheibani, Nader; Murphy, William L.

2016-01-01

Vascular endothelial growth factor (VEGF) spatial and temporal activity must be tightly controlled during angiogenesis to form perfusable vasculature in a healing wound. The native extracellular matrix (ECM) regulates growth factor activity locally via sequestering, and researchers have used ECM-mimicking approaches to regulate the activity of VEGF in cell culture and in vivo. However, the impact of dynamic, affinity-mediated growth factor sequestering has not been explored in detail with biomaterials. Here, we sought to modulate VEGF activity dynamically over time using poly(ethylene glycol) microspheres containing VEGF-binding peptides (VBPs) and exhibiting varying degradation rates. The degradation rate of VBP microspheres conferred a differential ability to up- or down-regulate VEGF activity in culture with primary human endothelial cells. VBP microspheres with fast-degrading crosslinks reduced VEGF activity and signaling, while VBP microspheres with no inherent degradability sequestered and promoted VEGF activity in culture with endothelial cells. VBP microspheres with degradable crosslinks significantly reduced neovascularization in vivo, but neither non-degradable VBP microspheres nor bolus delivery of soluble VBP reduced neovascularization. The covalent incorporation of VBP to degradable microspheres was required to reduce neovascularization in a mouse model of choroidal neovascularization in vivo, which demonstrates a potential clinical application of degradable VBP microspheres to reduce pathological angiogenesis. The results herein highlight the ability to modulate the activity of a sequestered growth factor by changing the crosslinker identity within PEG hydrogel microspheres. The insights gained here may instruct the design and translation of affinity-based growth factor sequestering biomaterials for regenerative medicine applications. PMID:27061268

Carbon sequestration in forests as a national policy issue

Treesearch

Linda S. Heath; Linda A. Joyce

1997-01-01

The United States' 1993 Climate Change Action Plan called upon the forestry sector to sequester an additional 10 million metric tons/yr by the year 2000. Forests are currently sequestering carbon and may provide opportunities to mitigate fossil fuel emissions in the near-term until fossil fuel emissions can be reduced. Using the analysis of carbon budgets based on...

Forest carbon benefits, costs and leakage effects of carbon reserve scenarios in the United States

Treesearch

Prakash Nepal; Peter J. Ince; Kenneth E. Skog; Sun J. Chang

2013-01-01

This study evaluated the potential effectiveness of future carbon reserve scenarios, where U.S. forest landowners would hypothetically be paid to sequester carbon on their timberland and forego timber harvests for 100 years. Scenarios featured direct payments to landowners of $0 (baseline), $5, $10, or $15 per metric ton of additional forest carbon sequestered on the...

Aligning ecology and markets in the forest carbon cycle

Treesearch

Matthew D. Hurteau; Bruce A. Hungate; George W. Koch; Malcolm P. North; Gordon R Smith

2013-01-01

A forest carbon (C) offset is a quantifiable unit of C that is commonly developed at the local or regional project scale and is designed to counterbalance anthropogenic C emissions by sequestering C in trees. In capand- trade programs, forest offsets have market value if the sequestered C is additional (more than would have occurred in the absence of the project) and...

Elution of uranium and transition metals from amidoxime-based polymer adsorbents for sequestering uranium from seawater

DOE PAGES

Pan, Horng-Bin; Kuo, Li-Jung; Miyamoto, Naomi; ...

2015-11-30

High-surface-area amidoxime and carboxylic acid grafted polymer adsorbents developed at Oak Ridge National Laboratory were tested for sequestering uranium in a flowing seawater flume system at the PNNL-Marine Sciences Laboratory. FTIR spectra indicate that a KOH conditioning process is necessary to remove the proton from the carboxylic acid and make the sorbent effective for sequestering uranium from seawater. The alkaline conditioning process also converts the amidoxime groups to carboxylate groups in the adsorbent. Both Na 2CO 3 H 2O 2 and hydrochloric acid elution methods can remove ~95% of the uranium sequestered by the adsorbent after 42 days of exposuremore » in real seawater. The Na 2CO 3 H 2O 2 elution method is more selective for uranium than conventional acid elution. Iron and vanadium are the two major transition metals competing with uranium for adsorption to the amidoxime-based adsorbents in real seawater. Tiron (4,5-Dihydroxy-1,3-benzenedisulfonic acid disodium salt, 1 M) can remove iron from the adsorbent very effectively at pH around 7. The coordination between vanadium (V) and amidoxime is also discussed based on our 51V NMR data.« less

In-situ observation for growth of hierarchical metal-organic frameworks and their self-sequestering mechanism for gas storage

NASA Astrophysics Data System (ADS)

Hyo Park, Jung; Min Choi, Kyung; Joon Jeon, Hyung; Jung Choi, Yoon; Ku Kang, Jeung

2015-07-01

Although structures with the single functional constructions and micropores were demonstrated to capture many different molecules such as carbon dioxide, methane, and hydrogen with high capacities at low temperatures, their feeble interactions still limit practical applications at room temperature. Herein, we report in-situ growth observation of hierarchical pores in pomegranate metal-organic frameworks (pmg-MOFs) and their self-sequestering storage mechanism, not observed for pristine MOFs. Direct observation of hierarchical pores inside the pmg-MOF was evident by in-situ growth X-ray measurements while self-sequestering storage mechanism was revealed by in-situ gas sorption X-ray analysis and molecular dynamics simulations. The results show that meso/macropores are created at the early stage of crystal growth and then enclosed by micropore crystalline shells, where hierarchical pores are networking under self-sequestering mechanism to give enhanced gas storage. This pmg-MOF gives higher CO2 (39%) and CH4 (14%) storage capacity than pristine MOF at room temperature, in addition to fast kinetics with robust capacity retention during gas sorption cycles, thus giving the clue to control dynamic behaviors of gas adsorption.

Human APC sequesters beta-catenin even in the absence of GSK-3beta in a Drosophila model.

PubMed

Rao, P R; Makhijani, K; Shashidhara, L S

2008-04-10

There have been conflicting reports on the requirement of GSK-3beta-mediated phosphorylation of the tumor suppressor adenomatous polyposis coli (APC) vis-à-vis its ability to bind and degrade beta-catenin. Using a unique combination of loss of function for Shaggy/GSK-3beta and a gain of function for human APC in Drosophila, we show that misexpressed human APC (hAPC) can still sequester Armadillo/beta-catenin. In addition, human APC could suppress gain of Wnt/Wingless phenotypes associated with loss of Shaggy/GSK-3beta activity, suggesting that sequestered Armadillo/beta-catenin is non-functional. Based on these studies, we propose that binding per se of beta-catenin by APC does not require phosphorylation by GSK-3beta.

Growing Large Quantities of Containerized Seedlings

Treesearch

Tim Pittman

2002-01-01

The sowing of large quantities of longleaf pine (Pinus palustris Mill.) seed into trays depends on the quality of the seed and the timing of seed sowing. This can be accomplished with mechanization. Seed quality is accomplished by using a gravity table. Tray filling can be accomplished by using a ribbon-type soil mixer and an automated tray-filling...

An effective and simple procedure to isolate abundant quantities of biologically active chemopreventive lunasin-protease inhibitor concentrate (LPIC) from soybean

USDA-ARS?s Scientific Manuscript database

Lunasin is a 5-kDa soybean bioactive peptide with demonstrated anti-cancer and anti-inflammatory properties. The use of lunasin as a chemopreventive agent in large-scale animal studies and human clinical trials is hampered by the paucity of large quantities of lunasin. Recently, purification methods...

The system-wide economics of a carbon dioxide capture, utilization, and storage network: Texas Gulf Coast with pure CO2-EOR flood

NASA Astrophysics Data System (ADS)

King, Carey W.; Gülen, Gürcan; Cohen, Stuart M.; Nuñez-Lopez, Vanessa

2013-09-01

This letter compares several bounding cases for understanding the economic viability of capturing large quantities of anthropogenic CO2 from coal-fired power generators within the Electric Reliability Council of Texas electric grid and using it for pure CO2 enhanced oil recovery (EOR) in the onshore coastal region of Texas along the Gulf of Mexico. All captured CO2 in excess of that needed for EOR is sequestered in saline formations at the same geographic locations as the oil reservoirs but at a different depth. We analyze the extraction of oil from the same set of ten reservoirs within 20- and five-year time frames to describe how the scale of the carbon dioxide capture, utilization, and storage (CCUS) network changes to meet the rate of CO2 demand for oil recovery. Our analysis shows that there is a negative system-wide net present value (NPV) for all modeled scenarios. The system comes close to breakeven economics when capturing CO2 from three coal-fired power plants to produce oil via CO2-EOR over 20 years and assuming no CO2 emissions penalty. The NPV drops when we consider a larger network to produce oil more quickly (21 coal-fired generators with CO2 capture to produce 80% of the oil within five years). Upon applying a CO2 emissions penalty of 602009/tCO2 to fossil fuel emissions to ensure that coal-fired power plants with CO2 capture remain in baseload operation, the system economics drop significantly. We show near profitability for the cash flow of the EOR operations only; however, this situation requires relatively cheap electricity prices during operation.

Organic carbon storage change in China's urban landfills from 1978-2014

NASA Astrophysics Data System (ADS)

Ge, Shidong; Zhao, Shuqing

2017-10-01

China has produced increasingly large quantities of waste associated with its accelerated urbanization and economic development and deposited these wastes into landfills, potentially sequestering carbon. However, the magnitude of the carbon storage in China’s urban landfills and its spatial and temporal change remain unclear. Here, we estimate the total amount of organic carbon (OC) stored in China's urban landfills between 1978 and 2014 using a first order organic matter decomposition model and data compiled from literature review and statistical yearbooks. Our results show that total OC stored in China’s urban landfills increased nearly 68-fold from the 1970s to the 2010s, and reached 225.2-264.5 Tg C (95% confidence interval, hereafter) in 2014. Construction waste was the largest OC pool (128.4-157.5 Tg C) in 2014, followed by household waste (67.7-83.8 Tg C), and sewage sludge was the least (19.7-34.1 Tg C). Carbon stored in urban landfills accounts for more than 10% of the country’s carbon stocks in urban ecosystems. The annual increase (i.e. sequestration rate) of OC in urban landfills in the 2010s (25.1 ± 4.3 Tg C yr-1, mean ± 2SD, hereafter) is equivalent to 1% of China's carbon emissions from fossil fuel combustion and cement production during the same period, but represents about 9% of the total terrestrial carbon sequestration in the country. Our study clearly indicates that OC dynamics in landfills should not be neglected in regional to national carbon cycle studies as landfills not only account for a substantial part of the carbon stored in urban ecosystems but also have a respectable contribution to national carbon sequestration.

Organic carbon storage change in China's urban landfills from 1978 to 2014

NASA Astrophysics Data System (ADS)

Ge, S.; Zhao, S.

2017-12-01

China has produced increasingly large quantities of waste associated with her accelerated urbanization and economic development and deposited these wastes into landfills potentially sequestering carbon. However, the magnitude of the carbon storage in China's urban landfills and its spatial and temporal change remain unclear. Here, we estimate the total amount of organic carbon (OC) stored in China's urban landfills between 1978 and 2014 using a first order organic matter decomposition model and data compiled from literature review and statistical yearbooks. Our results show that total OC stored in China's urban landfills increased nearly 68 folds from the 1970s to the 2010s, and reached 225.2 - 264.5 Tg C (95% confidence interval, hereafter) in 2014. Construction waste was the largest OC pool (128.4 - 157.5 Tg C) in 2014, followed by household waste (67.7 - 83.8 Tg C), and sewage sludge was the least (19.7 - 34.1 Tg C). Carbon stored in urban landfills accounts for more than 10% of the country's carbon stocks in urban ecosystems. The annual increase (i.e., sequestration rate) of OC in urban landfills in the 2010s (25.1 ± 4.3 Tg C yr-1, mean±2SD, hereafter) is equivalent to 1% of China's carbon emissions from fossil fuel combustion and cement production during the same period, but represents about 9% of the total terrestrial carbon sequestration in the country. Our study clearly indicates that OC dynamics in landfills should not be neglected in regional to national carbon cycle studies as landfills not only account for a substantial part of the carbon stored in urban ecosystems but also contribute respectably to national carbon sequestration.

Naive CD8 T-Cells Initiate Spontaneous Autoimmunity to a Sequestered Model Antigen of the Central Nervous System

ERIC Educational Resources Information Center

Na, Shin-Young; Cao, Yi; Toben, Catherine; Nitschke, Lars; Stadelmann, Christine; Gold, Ralf; Schimpl, Anneliese; Hunig, Thomas

2008-01-01

In multiple sclerosis, CD8 T-cells are thought play a key pathogenetic role, but mechanistic evidence from rodent models is limited. Here, we have tested the encephalitogenic potential of CD8 T-cells specific for the model antigen ovalbumin (OVA) sequestered in oligodendrocytes as a cytosolic molecule. We show that in these "ODC-OVA" mice, the…

Economic Analysis of Planting Forests on Rice Lands in Texas: Sequestering Carbon and Avoiding Methane Production

NASA Astrophysics Data System (ADS)

Kronrad, G. D.; Huang, C.

2005-12-01

Global climate change is predicted due to increases in greenhouse gasses (i.e. CO2, CH4, CFCs, N2O, O3) in the atmosphere caused by human activities. The atmospheric concentration of methane (CH4), which absorbs and retains heat 21 times more effectively than CO2, has increased. Anaerobic bacterial activity in rice paddies constitutes one of major emission sources of CH4. The rice fields of Texas, for example, accounted for an annual CH4 emission of between 1.1 and 1.6 million tons of CO2 equivalent between 1990 and 2000. Converting marginal rice fields to forests plantations will remove CO2 from the atmosphere, sequester carbon in the forests and prevent the production of CH4. Therefore, carbon credits can be claimed for the carbon sequestered and the avoidance of CH4 production. Analyses were conducted to calculate the amount of carbon sequestered and methane avoided, and the profitability, measured in net present worth (NPW), of managing loblolly pine plantation for 1) timber production only, 2) the dual products of timber products and carbon credits in forests planted on marginal agricultural and unused pastureland and 3) the dual products of timber and carbon storage in forests planted on marginal rice lands. Calculations were performed using three discount rates, three site qualities and five prices for carbon credits. The results indicate that on average quality land, using a discount rate of 8 percent, forests planted on marginal agricultural and unused pastureland earn a NPW of 346 per acre from timber production only; a NPW of 438 per acre from timber and carbon credits (54.4 tons of carbon sequestered), assuming carbon is worth 10 per ton, during one rotation (32 years). The profitability of forest management increases due to the inclusion of carbon credits. The profitability of planting forests on marginal rice fields is even higher, earning a NPW of 566 per acre from timber and carbon credits (54.4 tons of C sequestered and 33.3 tons of C emission avoided).

Biennial Hazardous Waste Report

EPA Pesticide Factsheets

Federal regulations require large quantity generators to submit a report (EPA form 8700-13A/B) every two years regarding the nature, quantities and disposition of hazardous waste generated at their facility.

Morphine sulfate and naltrexone hydrochloride extended-release capsules: naltrexone release, pharmacodynamics, and tolerability.

PubMed

Johnson, Franklin; Setnik, Beatrice

2011-01-01

Morphine sulfate and naltrexone hydrochloride extended-release capsules (EMBEDA, King Pharmaceuticals, Inc., Bristol, TN), indicated for management of chronic, moderate-to-severe pain, contain pellets of extended-release morphine sulfate with a sequestered naltrexone core (MS-sNT). Taken as directed, morphine provides analgesia while naltrexone remains sequestered; if tampered with by crushing, naltrexone is released to mitigate morphine-induced euphoric effects. While it is necessary to establish that formulations intended to reduce attractiveness for abuse are successful in doing so, it is also necessary to demonstrate that product therapeutic integrity is maintained for patients. Data were reviewed from 3 studies to determine: 1) the quantity of naltrexone released when MS-sNT pellets are crushed (MS-sNTC) for at least 2 minutes with mortar and pestle); 2) the extent to which the naltrexone released upon crushing mitigated morphine-induced subjective effects; and 3) whether sequestered naltrexone precipitates opioid withdrawal when MS-sNT is taken as directed. The naltrexone bioavailability study compared naltrexone release from MS-sNTC with that from whole intact MS-sNT capsules (MS-sNTW) and an equal naltrexone solution (NS) dose. Equivalent bioavailability was established if 90% confidence intervals (CIs) for geometric mean ratios (maximum plasma naltrexone concentration [Cmax] and area under the concentration-time curve extrapolated to infinity [AUC∞]) fell between 80% and 125%. The oral pharmacodynamic study assessed drug liking and euphoria and pharmacokinetic properties of MS-sNTC and MS-sNTW compared with morphine sulfate solution (MSS) and placebo. The 12-month, open-label (OL) safety study evaluated safety of MS-sNT administered orally as directed in patients with chronic, moderate-to-severe pain. Safety assessments included withdrawal symptoms based on the Clinical Opiate Withdrawal Scale (COWS). Naltrexone from MS-sNTC met criteria for equivalent bioavailability to NS. Although morphine relative bioavailability was similar for MS-sNTC and MSS, mean peak (Emax) visual analog scale (VAS) scores for drug liking and Cole/Addiction Research Center Inventory Stimulation-Euphoria were significantly reduced for MS-sNTC vs MSS (p < 0.001). In these 2 studies, a total of 6 participants had one measurement of plasma naltrexone after MS-sNTW that was above the lower limit of quantification. In the OL safety study, 72/93 participants (77%) had no quantifiable naltrexone concentrations. There was neither evidence of naltrexone accumulation for any participant nor any significant correlation with MS-sNT dose, age, or sex. Of 4 participants with the highest naltrexone concentrations, none had COWS scores consistent with moderate opioid withdrawal symptoms. Only 5 participants had COWS scores consistent with moderate opioid withdrawal; all 5 had not taken MS-sNT as directed. Study populations may not be fully representative of patients receiving opioid therapy for the management of chronic, moderate-to-severe pain and of opioid abusers. When MS-sNT capsules are crushed, all of the sequestered naltrexone (relative to oral NS) is released and immediately available to mitigate morphine-induced effects. When MS-sNT was crushed, the naltrexone released abated drug liking and euphoria relative to that from an equal dose of immediate-release morphine from MSS administration in a majority of participants. Naltrexone concentrations were low over a period of 12 months without evidence of accumulation, and there were no observable opioid withdrawal symptoms when MS-sNT was taken as directed.

Discovery of Newer Therapeutic Leads for Prostate Cancer

DTIC Science & Technology

2009-06-01

promising plant extracts and then prepare large-scale quantities of the plant extracts using supercritical fluid extraction techniques and use this...quantities of the plant extracts using supercritical fluid extraction techniques. Large scale plant collections were conducted for 14 of the top 20...material for bioassay-guided fractionation of the biologically active constituents using modern chromatography techniques. The chemical structures of

Geology and occurrence of ground water in Lyon County, Minnesota

USGS Publications Warehouse

Rodis, Harry G.

1963-01-01

Large quantities of ground water are available from melt-water channels in the county. Moderate quantities, adequate for domestic and small industrial needs, are available from many of the small isolated deposits of sand and gravel in the till. Small quantities of ground water, adequate only for domestic supply, generally can be obtained from Cretaceous sandstone.

Quantity Representation in Children and Rhesus Monkeys: Linear Versus Logarithmic Scales

ERIC Educational Resources Information Center

Beran, Michael J.; Johnson-Pynn, Julie S.; Ready, Christopher

2008-01-01

The performances of 4- and 5-year-olds and rhesus monkeys were compared using a computerized task for quantity assessment. Participants first learned two quantity anchor values and then responded to intermediate values by classifying them as similar to either the large anchor or the small anchor. Of primary interest was an assessment of where the…

Soil carbon stocks in Sarawak, Malaysia.

PubMed

Padmanabhan, E; Eswaran, H; Reich, P F

2013-11-01

The relationship between greenhouse gas emission and climate change has led to research to identify and manage the natural sources and sinks of the gases. CO2, CH4, and N2O have an anthropic source and of these CO2 is the least effective in trapping long wave radiation. Soil carbon sequestration can best be described as a process of removing carbon dioxide from the atmosphere and relocating into soils in a form that is not readily released back into the atmosphere. The purpose of this study is to estimate carbon stocks available under current conditions in Sarawak, Malaysia. SOC estimates are made for a standard depth of 100 cm unless the soil by definition is less than this depth, as in the case of lithic subgroups. Among the mineral soils, Inceptisols tend to generally have the highest carbon contents (about 25 kg m(-2) m(-1)), while Oxisols and Ultisols rate second (about 10-15 kg m(-2) m(-1)). The Oxisols store a good amount of carbon because of an appreciable time-frame to sequester carbon and possibly lower decomposition rates for the organic carbon that is found at 1m depths. Wet soils such as peatlands tend to store significant amounts of carbon. The highest values estimated for such soils are about 114 kg m(-2) m(-1). Such appreciable amounts can also be found in the Aquepts. In conclusion, it is pertinent to recognize that degradation of the carbon pool, just like desertification, is a real process and that this irreversible process must be addressed immediately. Therefore, appropriate soil management practices should be instituted to sequester large masses of soil carbon on an annual basis. This knowledge can be used effectively to formulate strategies to prevent forest fires and clearing: two processes that can quickly release sequestered carbon to the atmosphere in an almost irreversible manner. Copyright © 2013 Elsevier B.V. All rights reserved.

Organic carbon stocks and sequestration rates of forest soils in Germany.

PubMed

Grüneberg, Erik; Ziche, Daniel; Wellbrock, Nicole

2014-08-01

The National Forest Soil Inventory (NFSI) provides the Greenhouse Gas Reporting in Germany with a quantitative assessment of organic carbon (C) stocks and changes in forest soils. Carbon stocks of the organic layer and the mineral topsoil (30 cm) were estimated on the basis of ca. 1.800 plots sampled from 1987 to 1992 and resampled from 2006 to 2008 on a nationwide grid of 8 × 8 km. Organic layer C stock estimates were attributed to surveyed forest stands and CORINE land cover data. Mineral soil C stock estimates were linked with the distribution of dominant soil types according to the Soil Map of Germany (1 : 1 000 000) and subsequently related to the forest area. It appears that the C pool of the organic layer was largely depending on tree species and parent material, whereas the C pool of the mineral soil varied among soil groups. We identified the organic layer C pool as stable although C was significantly sequestered under coniferous forest at lowland sites. The mineral soils, however, sequestered 0.41 Mg C ha(-1) yr(-1) . Carbon pool changes were supposed to depend on stand age and forest transformation as well as an enhanced biomass input. Carbon stock changes were clearly attributed to parent material and soil groups as sandy soils sequestered higher amounts of C, whereas clayey and calcareous soils showed small gains and in some cases even losses of soil C. We further showed that the largest part of the overall sample variance was not explained by fine-earth stock variances, rather by the C concentrations variance. The applied uncertainty analyses in this study link the variability of strata with measurement errors. In accordance to other studies for Central Europe, the results showed that the applied method enabled a reliable nationwide quantification of the soil C pool development for a certain period. © 2014 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Organic carbon stocks and sequestration rates of forest soils in Germany

PubMed Central

Grüneberg, Erik; Ziche, Daniel; Wellbrock, Nicole

2014-01-01

The National Forest Soil Inventory (NFSI) provides the Greenhouse Gas Reporting in Germany with a quantitative assessment of organic carbon (C) stocks and changes in forest soils. Carbon stocks of the organic layer and the mineral topsoil (30 cm) were estimated on the basis of ca. 1.800 plots sampled from 1987 to 1992 and resampled from 2006 to 2008 on a nationwide grid of 8 × 8 km. Organic layer C stock estimates were attributed to surveyed forest stands and CORINE land cover data. Mineral soil C stock estimates were linked with the distribution of dominant soil types according to the Soil Map of Germany (1 : 1 000 000) and subsequently related to the forest area. It appears that the C pool of the organic layer was largely depending on tree species and parent material, whereas the C pool of the mineral soil varied among soil groups. We identified the organic layer C pool as stable although C was significantly sequestered under coniferous forest at lowland sites. The mineral soils, however, sequestered 0.41 Mg C ha−1 yr−1. Carbon pool changes were supposed to depend on stand age and forest transformation as well as an enhanced biomass input. Carbon stock changes were clearly attributed to parent material and soil groups as sandy soils sequestered higher amounts of C, whereas clayey and calcareous soils showed small gains and in some cases even losses of soil C. We further showed that the largest part of the overall sample variance was not explained by fine-earth stock variances, rather by the C concentrations variance. The applied uncertainty analyses in this study link the variability of strata with measurement errors. In accordance to other studies for Central Europe, the results showed that the applied method enabled a reliable nationwide quantification of the soil C pool development for a certain period. PMID:24616061

Milkweed butterfly resistance to plant toxins is linked to sequestration, not coping with a toxic diet.

PubMed

Petschenka, Georg; Agrawal, Anurag A

2015-11-07

Insect resistance to plant toxins is widely assumed to have evolved in response to using defended plants as a dietary resource. We tested this hypothesis in the milkweed butterflies (Danaini) which have progressively evolved higher levels of resistance to cardenolide toxins based on amino acid substitutions of their cellular sodium-potassium pump (Na(+)/K(+)-ATPase). Using chemical, physiological and caterpillar growth assays on diverse milkweeds (Asclepias spp.) and isolated cardenolides, we show that resistant Na(+)/K(+)-ATPases are not necessary to cope with dietary cardenolides. By contrast, sequestration of cardenolides in the body (as a defence against predators) is associated with the three levels of Na(+)/K(+)-ATPase resistance. To estimate the potential physiological burden of cardenolide sequestration without Na(+)/K(+)-ATPase adaptations, we applied haemolymph of sequestering species on isolated Na(+)/K(+)-ATPase of sequestering and non-sequestering species. Haemolymph cardenolides dramatically impair non-adapted Na(+)/K(+)-ATPase, but had systematically reduced effects on Na(+)/K(+)-ATPase of sequestering species. Our data indicate that major adaptations to plant toxins may be evolutionarily linked to sequestration, and may not necessarily be a means to eat toxic plants. Na(+)/K(+)-ATPase adaptations thus were a potential mechanism through which predators spurred the coevolutionary arms race between plants and insects. © 2015 The Author(s).

Milkweed butterfly resistance to plant toxins is linked to sequestration, not coping with a toxic diet

PubMed Central

Petschenka, Georg; Agrawal, Anurag A.

2015-01-01

Insect resistance to plant toxins is widely assumed to have evolved in response to using defended plants as a dietary resource. We tested this hypothesis in the milkweed butterflies (Danaini) which have progressively evolved higher levels of resistance to cardenolide toxins based on amino acid substitutions of their cellular sodium–potassium pump (Na+/K+-ATPase). Using chemical, physiological and caterpillar growth assays on diverse milkweeds (Asclepias spp.) and isolated cardenolides, we show that resistant Na+/K+-ATPases are not necessary to cope with dietary cardenolides. By contrast, sequestration of cardenolides in the body (as a defence against predators) is associated with the three levels of Na+/K+-ATPase resistance. To estimate the potential physiological burden of cardenolide sequestration without Na+/K+-ATPase adaptations, we applied haemolymph of sequestering species on isolated Na+/K+-ATPase of sequestering and non-sequestering species. Haemolymph cardenolides dramatically impair non-adapted Na+/K+-ATPase, but had systematically reduced effects on Na+/K+-ATPase of sequestering species. Our data indicate that major adaptations to plant toxins may be evolutionarily linked to sequestration, and may not necessarily be a means to eat toxic plants. Na+/K+-ATPase adaptations thus were a potential mechanism through which predators spurred the coevolutionary arms race between plants and insects. PMID:26538594

Invasive alien pests threaten the carbon stored in Europe's forests.

PubMed

Seidl, Rupert; Klonner, Günther; Rammer, Werner; Essl, Franz; Moreno, Adam; Neumann, Mathias; Dullinger, Stefan

2018-04-24

Forests mitigate climate change by sequestering large amounts of carbon (C). However, forest C storage is not permanent, and large pulses of tree mortality can thwart climate mitigation efforts. Forest pests are increasingly redistributed around the globe. Yet, the potential future impact of invasive alien pests on the forest C cycle remains uncertain. Here we show that large parts of Europe could be invaded by five detrimental alien pests already under current climate. Climate change increases the potential range of alien pests particularly in Northern and Eastern Europe. We estimate the live C at risk from a potential future invasion as 1027 Tg C (10% of the European total), with a C recovery time of 34 years. We show that the impact of introduced pests could be as severe as the current natural disturbance regime in Europe, calling for increased efforts to halt the introduction and spread of invasive alien species.

Plastid-bearing sea slugs fix CO2 in the light but do not require photosynthesis to survive

PubMed Central

Christa, Gregor; Zimorski, Verena; Woehle, Christian; Tielens, Aloysius G. M.; Wägele, Heike; Martin, William F.; Gould, Sven B.

2014-01-01

Several sacoglossan sea slugs (Plakobranchoidea) feed upon plastids of large unicellular algae. Four species—called long-term retention (LtR) species—are known to sequester ingested plastids within specialized cells of the digestive gland. There, the stolen plastids (kleptoplasts) remain photosynthetically active for several months, during which time LtR species can survive without additional food uptake. Kleptoplast longevity has long been puzzling, because the slugs do not sequester algal nuclei that could support photosystem maintenance. It is widely assumed that the slugs survive starvation by means of kleptoplast photosynthesis, yet direct evidence to support that view is lacking. We show that two LtR plakobranchids, Elysia timida and Plakobranchus ocellatus, incorporate 14CO2 into acid-stable products 60- and 64-fold more rapidly in the light than in the dark, respectively. Despite this light-dependent CO2 fixation ability, light is, surprisingly, not essential for the slugs to survive starvation. LtR animals survived several months of starvation (i) in complete darkness and (ii) in the light in the presence of the photosynthesis inhibitor monolinuron, all while not losing weight faster than the control animals. Contrary to current views, sacoglossan kleptoplasts seem to be slowly digested food reserves, not a source of solar power. PMID:24258718

Engineering of vault nanocapsules with enzymatic and fluorescent properties

PubMed Central

Kickhoefer, Valerie A.; Garcia, Yvette; Mikyas, Yeshi; Johansson, Erik; Zhou, Jing C.; Raval-Fernandes, Sujna; Minoofar, Payam; Zink, Jeffrey I.; Dunn, Bruce; Stewart, Phoebe L.; Rome, Leonard H.

2005-01-01

One of the central issues facing the emerging field of nanotechnology is cellular compatibility. Nanoparticles have been proposed for diagnostic and therapeutic applications, including drug delivery, gene therapy, biological sensors, and controlled catalysis. Viruses, liposomes, peptides, and synthetic and natural polymers have been engineered for these applications, yet significant limitations continue to prevent their use. Avoidance of the body's natural immune system, lack of targeting specificity, and the inability to control packaging and release are remaining obstacles. We have explored the use of a naturally occurring cellular nanoparticle known as the vault, which is named for its morphology with multiple arches reminiscent of cathedral ceilings. Vaults are 13-MDa ribonucleoprotein particles with an internal cavity large enough to sequester hundreds of proteins. Here, we report a strategy to target and sequester biologically active materials within the vault cavity. Attachment of a vault-targeting peptide to two proteins, luciferase and a variant of GFP, resulted in their sequestration within the vault cavity. The targeted proteins confer enzymatic and fluorescent properties on the recombinant vaults, both of which can be detected by their emission of light. The modified vaults are compatible with living cells. The ability to engineer vault particles with designed properties and functionalities represents an important step toward development of a biocompatible nanocapsule. PMID:15753293

Engineering of vault nanocapsules with enzymatic and fluorescent properties.

PubMed

Kickhoefer, Valerie A; Garcia, Yvette; Mikyas, Yeshi; Johansson, Erik; Zhou, Jing C; Raval-Fernandes, Sujna; Minoofar, Payam; Zink, Jeffrey I; Dunn, Bruce; Stewart, Phoebe L; Rome, Leonard H

2005-03-22

One of the central issues facing the emerging field of nanotechnology is cellular compatibility. Nanoparticles have been proposed for diagnostic and therapeutic applications, including drug delivery, gene therapy, biological sensors, and controlled catalysis. Viruses, liposomes, peptides, and synthetic and natural polymers have been engineered for these applications, yet significant limitations continue to prevent their use. Avoidance of the body's natural immune system, lack of targeting specificity, and the inability to control packaging and release are remaining obstacles. We have explored the use of a naturally occurring cellular nanoparticle known as the vault, which is named for its morphology with multiple arches reminiscent of cathedral ceilings. Vaults are 13-MDa ribonucleoprotein particles with an internal cavity large enough to sequester hundreds of proteins. Here, we report a strategy to target and sequester biologically active materials within the vault cavity. Attachment of a vault-targeting peptide to two proteins, luciferase and a variant of GFP, resulted in their sequestration within the vault cavity. The targeted proteins confer enzymatic and fluorescent properties on the recombinant vaults, both of which can be detected by their emission of light. The modified vaults are compatible with living cells. The ability to engineer vault particles with designed properties and functionalities represents an important step toward development of a biocompatible nanocapsule.

Sequestering the Gravitino: Neutralino Dark Matter in Gauge Mediation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Craig, Nathaniel J.; /Stanford U., Dept. Phys.; Green, Daniel

2008-08-15

In conventional models of gauge-mediated supersymmetry breaking, the lightest supersymmetric particle (LSP) is invariably the gravitino. However, if the supersymmetry breaking sector is strongly coupled, conformal sequestering may raise the mass of the gravitino relative to the remaining soft supersymmetry-breaking masses. In this letter, we demonstrate that such conformal dynamics in gauge-mediated theories may give rise to satisfactory neutralino dark matter while simultaneously solving the flavor and {mu}/B{mu} problems.

Pharmacokinetic Models for the Elimination of Drinking Water Contaminants from the Body,

DTIC Science & Technology

1990-03-01

that are sequestered in the bones (lead, barium), in certain soft tissues such as the kidney ( cadmium ), and in the adipose tissue (DDT...slow" component (sequestered in 3 bone or in adipose tissue ). Finally, much more attention must be given to differences among I individuals and among...lead from bone, effectively reducing the half-life. Fasting or starvation can mobilize toxicants 3 stored in adipose tissue . Competition for enzyme

Genome Sequence of Carbon Dioxide-Sequestering Serratia sp. Strain ISTD04 Isolated from Marble Mining Rocks.

PubMed

Kumar, Manish; Gazara, Rajesh Kumar; Verma, Sandhya; Kumar, Madan; Verma, Praveen Kumar; Thakur, Indu Shekhar

2016-10-20

The Serratia sp. strain ISTD04 has been identified as a carbon dioxide (CO 2 )-sequestering bacterium isolated from marble mining rocks in the Umra area, Rajasthan, India. This strain grows chemolithotrophically on media that contain sodium bicarbonate (NaHCO 3 ) as the sole carbon source. Here, we report the genome sequence of 5.07 Mb Serratia sp. ISTD04. Copyright © 2016 Kumar et al.

Budget Issues: Effects of the Fiscal Year 1990 Sequester on the Department of Education. Fact Sheet for the Chairman, Committee on the Budget, House of Representatives.

ERIC Educational Resources Information Center

General Accounting Office, Washington, DC.

The Balanced Budget and Emergency Deficit Control Act of 1985, as amended, establishes deficit targets to lead to a balanced unified budget by fiscal year 1993. If the Office of Management and Budget projects a deficit in excess of the target amount plus $10 billion, the President must issue a sequester order to reduce budget resources…

An étude on global vacuum energy sequester

DOE PAGES

D’Amico, Guido; Kaloper, Nemanja; Padilla, Antonio; ...

2017-09-18

Recently two of the authors proposed a mechanism of vacuum energy sequester as a means of protecting the observable cosmological constant from quantum radiative corrections. The original proposal was based on using global Lagrange multipliers, but later a local formulation was provided. Subsequently other interesting claims of a different non-local approach to the cosmological constant problem were made, based again on global Lagrange multipliers. We examine some of these proposals and find their mutual relationship. We explain that the proposals which do not treat the cosmological constant counterterm as a dynamical variable require fine tunings to have acceptable solutions. Furthermore,more » the counterterm often needs to be retuned at every order in the loop expansion to cancel the radiative corrections to the cosmological constant, just like in standard GR. These observations are an important reminder of just how the proposal of vacuum energy sequester avoids such problems.« less

Dissociation of the Tubulin-sequestering and Microtubule Catastrophe-promoting Activities of Oncoprotein 18/Stathmin

PubMed Central

Howell, Bonnie; Larsson, Niklas; Gullberg, Martin; Cassimeris, Lynne

1999-01-01

Oncoprotein 18/stathmin (Op18) has been identified recently as a protein that destabilizes microtubules, but the mechanism of destabilization is currently controversial. Based on in vitro microtubule assembly assays, evidence has been presented supporting conflicting destabilization models of either tubulin sequestration or promotion of microtubule catastrophes. We found that Op18 can destabilize microtubules by both of these mechanisms and that these activities can be dissociated by changing pH. At pH 6.8, Op18 slowed microtubule elongation and increased catastrophes at both plus and minus ends, consistent with a tubulin-sequestering activity. In contrast, at pH 7.5, Op18 promoted microtubule catastrophes, particularly at plus ends, with little effect on elongation rates at either microtubule end. Dissociation of tubulin-sequestering and catastrophe-promoting activities of Op18 was further demonstrated by analysis of truncated Op18 derivatives. Lack of a C-terminal region of Op18 (aa 100–147) resulted in a truncated protein that lost sequestering activity at pH 6.8 but retained catastrophe-promoting activity. In contrast, lack of an N-terminal region of Op18 (aa 5–25) resulted in a truncated protein that still sequestered tubulin at pH 6.8 but was unable to promote catastrophes at pH 7.5. At pH 6.8, both the full length and the N-terminal–truncated Op18 bound tubulin, whereas truncation at the C-terminus resulted in a pronounced decrease in tubulin binding. Based on these results, and a previous study documenting a pH-dependent change in binding affinity between Op18 and tubulin, it is likely that tubulin sequestering observed at lower pH resulted from the relatively tight interaction between Op18 and tubulin and that this tight binding requires the C-terminus of Op18; however, under conditions in which Op18 binds weakly to tubulin (pH 7.5), Op18 stimulated catastrophes without altering tubulin subunit association or dissociation rates, and Op18 did not depolymerize microtubules capped with guanylyl (α, β)-methylene diphosphonate–tubulin subunits. We hypothesize that weak binding between Op18 and tubulin results in free Op18, which is available to interact with microtubule ends and thereby promote catastrophes by a mechanism that likely involves GTP hydrolysis. PMID:9880330

Quantity and Quality of Computer Use and Academic Achievement: Evidence from a Large-Scale International Test Program

ERIC Educational Resources Information Center

Cheema, Jehanzeb R.; Zhang, Bo

2013-01-01

This study looked at the effect of both quantity and quality of computer use on achievement. The Program for International Student Assessment (PISA) 2003 student survey comprising of 4,356 students (boys, n = 2,129; girls, n = 2,227) was used to predict academic achievement from quantity and quality of computer use while controlling for…

The National Shipbuilding Research Program. Trailer Mounted Water Recovery and Reuse System

DTIC Science & Technology

2000-11-30

surfactants, and stabilize oil emulsions. • Sequestering or chelating agents bind problematic ions such as calcium or iron, which tend to form deposits on...cleaned parts. • Wetting/emulsifying agents (surfactants) help remove oil from dirty parts and stabilize the removed oil, preventing it from redepositing...neutralized; • The metal-loading can overcome the sequestering agents ’ capacity to keep the metals in solution; and • Oil and grease, if held in the emulsified

Agroforestry: a sustainable environmental practice for carbon sequestration under the climate change scenarios-a review.

PubMed

Abbas, Farhat; Hammad, Hafiz Mohkum; Fahad, Shah; Cerdà, Artemi; Rizwan, Muhammad; Farhad, Wajid; Ehsan, Sana; Bakhat, Hafiz Faiq

2017-04-01

Agroforestry is a sustainable land use system with a promising potential to sequester atmospheric carbon into soil. This system of land use distinguishes itself from the other systems, such as sole crop cultivation and afforestation on croplands only through its potential to sequester higher amounts of carbon (in the above- and belowground tree biomass) than the aforementioned two systems. According to Kyoto protocol, agroforestry is recognized as an afforestation activity that, in addition to sequestering carbon dioxide (CO 2 ) to soil, conserves biodiversity, protects cropland, works as a windbreak, and provides food and feed to human and livestock, pollen for honey bees, wood for fuel, and timber for shelters construction. Agroforestry is more attractive as a land use practice for the farming community worldwide instead of cropland and forestland management systems. This practice is a win-win situation for the farming community and for the environmental sustainability. This review presents agroforestry potential to counter the increasing concentration of atmospheric CO 2 by sequestering it in above- and belowground biomass. The role of agroforestry in climate change mitigation worldwide might be recognized to its full potential by overcoming various financial, technical, and institutional barriers. Carbon sequestration in soil by various agricultural systems can be simulated by various models but literature lacks reports on validated models to quantify the agroforestry potential for carbon sequestration.

Enhancement of Terrestrial Carbon Sinks through the Reclamation of Abandoned Mined Lands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gary Kronrad

2004-10-31

This project will determine the optimal forest management method to employ for each of the major commercial tree species so that profitability of timber production only or the combination of timber production and carbon sequestration is maximized. The goal of this project is to achieve DOE's long-term cost goal of sequestering carbon at $10 or less per ton. Because the potential of a forest ecosystem to sequester carbon depends on the species, site quality and management regimes utilized, this project will determine how to optimize carbon sequestration by determining how to optimally manage each species, given a range of sitemore » qualities and economic variables. This project also will determine the effects of a carbon credit market on the method and profitability of forest management, the cost of sequestering carbon, and the amount of carbon that can be sequestered. Information from this project will be used to produce user-friendly manuals which will contain economic and biological data for each of the species. These manuals will inform landowners and forest managers how to manage forests for timber and/or carbon credits, how to maximize financial returns, how much money can be earned, and how much carbon can be stored. Manuals will be disseminated through state and federal agricultural extension services and the forest service of each state, and will be published in forest landowner magazines.« less

Enhancement of Terrestrial Carbon Sinks through the Reclamation of Abandoned Mined Lands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gary Kronrad

2006-01-31

This project will determine the optimal forest management method to employ for each of the major commercial tree species so that profitability of timber production only or the combination of timber production and carbon sequestration is maximized. The goal of this project is to achieve DOE's long-term cost goal of sequestering carbon at $10 or less per ton. Because the potential of a forest ecosystem to sequester carbon depends on the species, site quality and management regimes utilized, this project will determine how to optimize carbon sequestration by determining how to optimally manage each species, given a range of sitemore » qualities and economic variables. This project also will determine the effects of a carbon credit market on the method and profitability of forest management, the cost of sequestering carbon, and the amount of carbon that can be sequestered. Information from this project will be used to produce user-friendly manuals which will contain economic and biological data for each of the species. These manuals will inform landowners and forest managers how to manage forests for timber and/or carbon credits, how to maximize financial returns, how much money can be earned, and how much carbon can be stored. Manuals will be disseminated through state and federal agricultural extension services and the forest service of each state, and will be published in forest landowner magazines.« less

Enhancement of Terrestrial Carbon Sinks through the Reclamation of Abandoned Mined Lands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gary Kronrad

2005-04-30

This project will determine the optimal forest management method to employ for each of the major commercial tree species so that profitability of timber production only or the combination of timber production and carbon sequestration is maximized. The goal of this project is to achieve DOE's long-term cost goal of sequestering carbon at $10 or less per ton. Because the potential of a forest ecosystem to sequester carbon depends on the species, site quality and management regimes utilized, this project will determine how to optimize carbon sequestration by determining how to optimally manage each species, given a range of sitemore » qualities and economic variables. This project also will determine the effects of a carbon credit market on the method and profitability of forest management, the cost of sequestering carbon, and the amount of carbon that can be sequestered. Information from this project will be used to produce user-friendly manuals which will contain economic and biological data for each of the species. These manuals will inform landowners and forest managers how to manage forests for timber and/or carbon credits, how to maximize financial returns, how much money can be earned, and how much carbon can be stored. Manuals will be disseminated through state and federal agricultural extension services and the forest service of each state, and will be published in forest landowner magazines.« less

Enhancement of Terrestrial Carbon Sinks throught the Reclamation of Abandoned Mined Lands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gary Kronrad

2006-06-30

This project will determine the optimal forest management method to employ for each of the major commercial tree species so that profitability of timber production only or the combination of timber production and carbon sequestration is maximized. The goal of this project is to achieve DOE's long-term cost goal of sequestering carbon at $10 or less per ton. Because the potential of a forest ecosystem to sequester carbon depends on the species, site quality and management regimes utilized, this project will determine how to optimize carbon sequestration by determining how to optimally manage each species, given a range of sitemore » qualities and economic variables. This project also will determine the effects of a carbon credit market on the method and profitability of forest management, the cost of sequestering carbon, and the amount of carbon that can be sequestered. Information from this project will be used to produce user-friendly manuals which will contain economic and biological data for each of the species. These manuals will inform landowners and forest managers how to manage forests for timber and/or carbon credits, how to maximize financial returns, how much money can be earned, and how much carbon can be stored. Manuals will be disseminated through state and federal agricultural extension services and the forest service of each state, and will be published in forest landowner magazines.« less

Negative Emissions Technology

NASA Astrophysics Data System (ADS)

Day, Danny

2006-04-01

Although `negative emissions' of carbon dioxide need not, in principle, involve use of biological processes to draw carbon out of the atmosphere, such `agricultural' sequestration' is the only known way to remove carbon from the atmosphere on time scales comparable to the time scale for anthropogenic increases in carbon emissions. In order to maintain the `negative emissions' the biomass must be used in such a way that the resulting carbon dioxide is separated and permanently sequestered. Two options for sequestration are in the topsoil and via geologic carbon sequestration. The former has multiple benefits, but the latter also is needed. Thus, although geologic carbon sequestration is viewed skeptically by some environmentalists as simply a way to keep using fossil fuels---it may be a key part of reversing accelerating climate forcing if rapid climate change is beginning to occur. I will first review the general approach of agricultural sequestration combined with use of resulting biofuels in a way that permits carbon separation and then geologic sequestration as a negative emissions technology. Then I discuss the process that is the focus of my company---the EPRIDA cycle. If deployed at a sufficiently large scale, it could reverse the increase in CO2 concentrations. I also estimate of benefits --carbon and other---of large scale deployment of negative emissions technologies. For example, using the EPRIDA cycle by planting and soil sequestering carbon in an area abut In 3X the size of Texas would remove the amount of carbon that is being accumulated worldwide each year. In addition to the atmospheric carbon removal, the EPRIDA approach also counters the depletion of carbon in the soil---increasing topsoil and its fertility; reduces the excess nitrogen in the water by eliminating the need for ammonium nitrate fertilizer and reduces fossil fuel reliance by providing biofuel and avoiding natural gas based fertilizer production.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doug Cathro

The Lake Charles CCS Project is a large-scale industrial carbon capture and sequestration (CCS) project which will demonstrate advanced technologies that capture and sequester carbon dioxide (CO{sub 2}) emissions from industrial sources into underground formations. Specifically the Lake Charles CCS Project will accelerate commercialization of large-scale CO{sub 2} storage from industrial sources by leveraging synergy between a proposed petroleum coke to chemicals plant (the LCC Gasification Project) and the largest integrated anthropogenic CO{sub 2} capture, transport, and monitored sequestration program in the U.S. Gulf Coast Region. The Lake Charles CCS Project will promote the expansion of EOR in Texas andmore » Louisiana and supply greater energy security by expanding domestic energy supplies. The capture, compression, pipeline, injection, and monitoring infrastructure will continue to sequester CO{sub 2} for many years after the completion of the term of the DOE agreement. The objectives of this project are expected to be fulfilled by working through two distinct phases. The overall objective of Phase 1 was to develop a fully definitive project basis for a competitive Renewal Application process to proceed into Phase 2 - Design, Construction and Operations. Phase 1 includes the studies attached hereto that will establish: the engineering design basis for the capture, compression and transportation of CO{sub 2} from the LCC Gasification Project, and the criteria and specifications for a monitoring, verification and accounting (MVA) plan at the Hastings oil field in Texas. The overall objective of Phase 2, provided a successful competitive down-selection, is to execute design, construction and operations of three capital projects: (1) the CO{sub 2} capture and compression equipment, (2) a Connector Pipeline from the LLC Gasification Project to the Green Pipeline owned by Denbury and an affiliate of Denbury, and (3) a comprehensive MVA system at the Hastings oil field.« less

A thermal and chemical degradation approach to decipher pristane and phytane precursors in sedimentary organic matter

USGS Publications Warehouse

Koopmans, M.P.; Rijpstra, W.I.C.; Klapwijk, M.M.; De Leeuw, J. W.; Lewan, M.D.; Sinninghe, Damste J.S.

1999-01-01

A thermal and chemical degradation approach was followed to determine the precursors of pristane (Pr) and phytane (Ph) in samples from the Gessoso-solfifera, Ghareb and Green River Formations. Hydrous pyrolysis of these samples yields large amounts of Pr and Ph carbon skeletons, indicating that their precursors are predominantly sequestered in high-molecular-weight fractions. However, chemical degradation of the polar fraction and the kerogen of the unheated samples generally does not release large amounts of Pr and Ph. Additional information on the precursors of Pr and Ph is obtained from flash pyrolysis analyses of kerogens and residues after hydrous pyrolysis and after chemical degradation. Multiple precursors for Pr and Ph are recognised in these three samples. The main increase of the Pr/Ph ratio with increasing maturation temperature, which is associated with strongly increasing amounts of Pr and Ph, is probably due to the higher amount of precursors of Pr compared to Ph, and not to the different timing of generation of Pr and Ph.A thermal and chemical degradation approach was followed to determine the precursors of pristane (Pr) and phytane (Ph) in samples from the Gessoso-solfifera, Ghareb and Green River Formations. Hydrous pyrolysis of these samples yields large amounts of Pr and Ph carbon skeletons, indicating that their precursors are predominantly sequestered in high-molecular-weight fractions. However, chemical degradation of the polar fraction and the kerogen of the unheated samples generally does not release large amounts of Pr and Ph. Additional information on the precursors of Pr and Ph is obtained from flash pyrolysis analyses of kerogens and residues after hydrous pyrolysis and after chemical degradation. Multiple precursors for Pr and Ph are recognised in these three samples. The main increase of the Pr/Ph ratio with increasing maturation temperature, which is associated with strongly increasing amounts of Pr and Ph, is probably due to the higher amount of precursors of Pr compared to Ph, and not to the different timing of generation of Pr and Ph.

A Review of distribution and quantity of lingering subsurface oil from the Exxon Valdez Oil Spill

NASA Astrophysics Data System (ADS)

Nixon, Zachary; Michel, Jacqueline

2018-01-01

Remaining lingering subsurface oil residues from the Exxon Valdez oil spill (EVOS) are, at present, patchily distributed across the geologically complex and spatially extensive shorelines of Prince William Sound and the Gulf of Alaska. We review and synthesize previous literature describing the causal geomorphic and physical mechanisms for persistence of oil in the intertidal subsurface sediments of these areas. We also summarize previous sampling and modeling efforts, and refine previously presented models with additional data to characterize the present-day linear and areal spatial extent, and quantity of lingering subsurface oil. In the weeks after the spill in March of 1989, approximately 17,750 t of oil were stranded along impacted shorelines, and by October of 1992, only 2% of the mass of spilled oil was estimated to remain in intertidal areas. We estimate that lingering subsurface residues, generally between 5 and 20 cm thick and sequestered below 10-20 cm of clean sediment, are present over 30 ha of intertidal area, along 11.4 km of shoreline, and represent approximately 227 t or 0.6% of the total mass of spilled oil. These residues are typically located in finer-grained sand and gravel sediments, often under an armor of cobble- or boulder-sized clasts, in areas with limited groundwater flow and porosity. Persistence of these residues is correlated with heavy initial oil loading together with localized sheltering from physical disturbance such as wave energy within the beach face. While no longer generally bioavailable and increasingly chemically weathered, present removal rates for these remaining subsurface oil residues have slowed to nearly zero. The only remaining plausible removal mechanisms will operate over time scales of decades.

Unleashing Empirical Equations with "Nonlinear Fitting" and "GUM Tree Calculator"

NASA Astrophysics Data System (ADS)

Lovell-Smith, J. W.; Saunders, P.; Feistel, R.

2017-10-01

Empirical equations having large numbers of fitted parameters, such as the international standard reference equations published by the International Association for the Properties of Water and Steam (IAPWS), which form the basis of the "Thermodynamic Equation of Seawater—2010" (TEOS-10), provide the means to calculate many quantities very accurately. The parameters of these equations are found by least-squares fitting to large bodies of measurement data. However, the usefulness of these equations is limited since uncertainties are not readily available for most of the quantities able to be calculated, the covariance of the measurement data is not considered, and further propagation of the uncertainty in the calculated result is restricted since the covariance of calculated quantities is unknown. In this paper, we present two tools developed at MSL that are particularly useful in unleashing the full power of such empirical equations. "Nonlinear Fitting" enables propagation of the covariance of the measurement data into the parameters using generalized least-squares methods. The parameter covariance then may be published along with the equations. Then, when using these large, complex equations, "GUM Tree Calculator" enables the simultaneous calculation of any derived quantity and its uncertainty, by automatic propagation of the parameter covariance into the calculated quantity. We demonstrate these tools in exploratory work to determine and propagate uncertainties associated with the IAPWS-95 parameters.

Seismic Monitoring at the Decatur, IL, Geologic Carbon Dioxide Sequestration Site

NASA Astrophysics Data System (ADS)

Hickman, S. H.; Kaven, J. O.; McGarr, A.; Walter, S. R.; Ellsworth, W. L.; Svitek, J. F.; Burke, L. A.

2014-12-01

The viability of carbon capture and storage (CCS) depends on safely sequestering large quantities of carbon dioxide over geologic time scales. One concern is the potential for induced seismicity. We report on seismic monitoring by the U.S. Geological Survey (USGS) at a CCS demonstration site in Decatur, IL. This is the first (and to date only) CCS project in the U.S. to inject large volumes of CO2 into an extensive undisturbed saline reservoir, and thus serves as an important test for future industrial-scale CCS projects. At Decatur, supercritical CO2 is injected at 2.1 km depth into the Mt. Simon Sandstone, which directly overlies granitic basement. The primary sealing cap is the Eau Claire Shale at a depth of about 1.5 km. The Illinois State Geological Survey (ISGS) manages the ongoing Illinois Basin - Decatur Project, a three-year project beginning in November 2011 during which CO2 is injected at an average rate of 1000 metric tons/day. Archer Daniels Midland (ADM) manages the nearby Illinois Industrial Carbon Capture and Storage project, which, pending permit approval, plans to inject 3000 metric tons/day for five years. The USGS seismic network was installed starting in July 2013 and consists of 12 stations, three of which include borehole sensors at depths of 150 m. The aperture of this network is roughly 8 km, centered on the injection well. A one-dimensional velocity model was derived from a vertical seismic profile survey acquired by ADM and the ISGS to a depth of 2.2 km, tied into acoustic logs from a deep observation well and the USGS borehole stations. This model was used together with absolute and double-difference techniques to locate seismic events. These events group into two clusters: 0.4 to 1.0 km NE and 1.8 to 2.6 km WNW from the injection well, with moment magnitudes ranging from -0.8 to 1.1. Most of these events are in the granitic basement, well below the cap rock, and are unlikely to have compromised the integrity of the seal.

Zero-gravity quantity gaging system

NASA Technical Reports Server (NTRS)

1989-01-01

The Zero-Gravity Quantity Gaging System program is a technology development effort funded by NASA-LeRC and contracted by NASA-JSC to develop and evaluate zero-gravity quantity gaging system concepts suitable for application to large, on-orbit cryogenic oxygen and hydrogen tankage. The contract effective date was 28 May 1985. During performance of the program, 18 potential quantity gaging approaches were investigated for their merit and suitability for gaging two-phase cryogenic oxygen and hydrogen in zero-gravity conditions. These approaches were subjected to a comprehensive trade study and selection process, which found that the RF modal quantity gaging approach was the most suitable for both liquid oxygen and liquid hydrogen applications. This selection was made with NASA-JSC concurrence.

Combining Search Engines for Comparative Proteomics

PubMed Central

Tabb, David

2012-01-01

Many proteomics laboratories have found spectral counting to be an ideal way to recognize biomarkers that differentiate cohorts of samples. This approach assumes that proteins that differ in quantity between samples will generate different numbers of identifiable tandem mass spectra. Increasingly, researchers are employing multiple search engines to maximize the identifications generated from data collections. This talk evaluates four strategies to combine information from multiple search engines in comparative proteomics. The “Count Sum” model pools the spectra across search engines. The “Vote Counting” model combines the judgments from each search engine by protein. Two other models employ parametric and non-parametric analyses of protein-specific p-values from different search engines. We evaluated the four strategies in two different data sets. The ABRF iPRG 2009 study generated five LC-MS/MS analyses of “red” E. coli and five analyses of “yellow” E. coli. NCI CPTAC Study 6 generated five concentrations of Sigma UPS1 spiked into a yeast background. All data were identified with X!Tandem, Sequest, MyriMatch, and TagRecon. For both sample types, “Vote Counting” appeared to manage the diverse identification sets most effectively, yielding heightened discrimination as more search engines were added.

Study of Polyolefines Waste Thermo-Destruction in Large Laboratory and in Industrial Installations

DTIC Science & Technology

2014-12-15

coke ”–waste after thermo-destruction carried out on the module No 2 showed an content to 46.1% of ash [20]. This ash content indicates a very large... coke (post-production waste) from the wastes thermo-destruction on 2 modules of vertical modular installation for thermo-destruction of used polymer...of receivedwaste water, the quantity of received coke , the quantity of gaseous product in periods of carrying out installation work before (first

Accelerated weathering of limestone for CO2 mitigation: Opportunities for the stone and cement industries

USGS Publications Warehouse

Langer, William H.; San, Juan A.; Rau, Greg H.; Caldeira, Ken

2009-01-01

Large amounts of limestone fines co-produced during the processing of crushed limestone may be useful in the sequestration of carbon dioxide (CO2). Accelerated weathering of limestone (AWL) is proposed as a low-tech method to capture and sequester CO2 from fossil fuel-fired power plants and other point sources such as cement manufacturing. AWL reactants are readily available, inexpensive and environmentally benign. Waste CO2 is hydrated with water to produce carbonic acid. This reacts with and is neutralized by limestone fines, thus converting CO2 gas to dissolved calcium bicarbonate.

Human Calprotectin Is an Iron-Sequestering Host-Defense Protein

PubMed Central

Nakashige, Toshiki G.; Zhang, Bo; Krebs, Carsten; Nolan, Elizabeth M.

2015-01-01

Human calprotectin (CP) is a metal-chelating antimicrobial protein of the innate immune response. The current working model states that CP sequesters manganese and zinc from pathogens. We report the discovery that CP chelates iron and deprives bacteria of this essential nutrient. Elemental analysis of CP-treated growth medium establishes that CP reduces the concentrations of manganese, iron, and zinc. Microbial growth studies reveal that iron depletion by CP contributes to the growth inhibition of bacterial pathogens. Biochemical investigations demonstrate that CP coordinates Fe(II) at an unusual hexahistidine motif, and the Mössbauer spectrum of 57Fe(II)-bound CP is consistent with coordination of high-spin Fe(II) at this site (δ = 1.20 mm/s, ΔEQ = 1.78 mm/s). In the presence of Ca(II), CP turns on its iron-sequestering function and exhibits sub-picomolar affinity for Fe(II). Our findings expand the biological coordination chemistry of iron and support a previously unappreciated role for CP in mammalian iron homeostasis. PMID:26302479

Proton-driven amide bond-cleavage pathways of gas-phase peptide ions lacking mobile protons.

PubMed

Bythell, Benjamin J; Suhai, Sándor; Somogyi, Arpád; Paizs, Béla

2009-10-07

The mobile proton model (Dongre, A. R., Jones, J. L., Somogyi, A. and Wysocki, V. H. J. Am. Chem. Soc. 1996, 118 , 8365-8374) of peptide fragmentation states that the ionizing protons play a critical role in the gas-phase fragmentation of protonated peptides upon collision-induced dissociation (CID). The model distinguishes two classes of peptide ions, those with or without easily mobilizable protons. For the former class mild excitation leads to proton transfer reactions which populate amide nitrogen protonation sites. This enables facile amide bond cleavage and thus the formation of b and y sequence ions. In contrast, the latter class of peptide ions contains strongly basic functionalities which sequester the ionizing protons, thereby often hindering formation of sequence ions. Here we describe the proton-driven amide bond cleavages necessary to produce b and y ions from peptide ions lacking easily mobilizable protons. We show that this important class of peptide ions fragments by different means from those with easily mobilizable protons. We present three new amide bond cleavage mechanisms which involve salt-bridge, anhydride, and imine enol intermediates, respectively. All three new mechanisms are less energetically demanding than the classical oxazolone b(n)-y(m) pathway. These mechanisms offer an explanation for the formation of b and y ions from peptide ions with sequestered ionizing protons which are routinely fragmented in large-scale proteomics experiments.

Nano Sponges for Drug Delivery and Medicinal Applications

NASA Technical Reports Server (NTRS)

Tour, James M.; Lucente-Schultz, Rebecca; Leonard, Ashley; Kosynkin, Dimitry V.; Price, Brandi Katherine; Hudson, Jared L.; Conyers, Jodie L., Jr.; Moore, Valerie C.; Casscells, S. Ward; Myers, Jeffrey N.;

Host Shifts from Lamiales to Brassicaceae in the Sawfly Genus Athalia

PubMed Central

Opitz, Sebastian E. W.; Boevé, Jean-Luc; Nagy, Zoltán Tamás; Sonet, Gontran; Koch, Frank; Müller, Caroline

2012-01-01

Plant chemistry can be a key driver of host shifts in herbivores. Several species in the sawfly genus Athalia are important economic pests on Brassicaceae, whereas other Athalia species are specialized on Lamiales. These host plants have glucosides in common, which are sequestered by larvae. To disentangle the possible direction of host shifts in this genus, we examined the sequestration specificity and feeding deterrence of iridoid glucosides (IGs) and glucosinolates (GSs) in larvae of five species which either naturally sequester IGs from their hosts within the Plantaginaceae (Lamiales) or GSs from Brassicaceae, respectively. Furthermore, adults were tested for feeding stimulation by a neo-clerodane diterpenoid which occurs in Lamiales. Larvae of the Plantaginaceae-feeders did not sequester artificially administered p-hydroxybenzylGS and were more deterred by GSs than Brassicaceae-feeders were by IGs. In contrast, larvae of Brassicaceae-feeders were able to sequester artificially administered catalpol (IG), which points to an ancestral association with Lamiales. In line with this finding, adults of all tested species were stimulated by the neo-clerodane diterpenoid. Finally, in a phylogenetic tree inferred from genetic marker sequences of 21 Athalia species, the sister species of all remaining 20 Athalia species also turned out to be a Lamiales-feeder. Fundamental physiological pre-adaptations, such as the establishment of a glucoside transporter, and mechanisms to circumvent activation of glucosides by glucosidases are therefore necessary prerequisites for successful host shifts between Lamiales and Brassicaceae. PMID:22485146

Localization of Defensive Chemicals in Two Congeneric Butterflies (Euphydryas, Nymphalidae).

PubMed

Mason, Peri A; Deane Bowers, M

2017-05-01

Many insect species sequester compounds acquired from their host plants for defense against natural enemies. The distribution of these compounds is likely to affect both their efficacy as defenses, and their costs. In this study we examined the distribution of sequestered iridoid glycosides (IGs) in two congeneric species of nymphalid butterfly, Euphydryas anicia and E. phaeton, and found that the pattern of localization of IGs differed between the two species. Although IG concentrations were quite high in the heads of both species, the relative concentrations in wings and abdomens differed substantially. Euphydryas anicia had relatively high IG concentrations in their abdomens and low IG concentrations in their wings, whereas the reverse was true in E. phaeton. We interpret these results in light of two current hypotheses regarding where sequestered chemicals should be localized: that they should be found in wings, which would allow non-lethal sampling by predators; and that their distribution is constrained by the distribution of tissue types to which sequestered compounds bind. We also offer the third hypothesis, that costs of storage may differ among body parts, and that the localization of compounds may reflect a cost-reduction strategy. Results from E. phaeton were consistent with all three of these non-mutually exclusive hypotheses, whereas results from E. anicia were only consistent with the notion that tissue bias among body parts plays a role in IG distribution. The finding that these two congeneric butterflies exhibit different patterns of IG localization suggests that they have been shaped by different selection regimes.

EVALUATING THE ACCOTINK CREEK RESTORATION PROJECT FOR IMPROVING WATER QUALITY, IN-STREAM HABITAT, AND BANK STABILITY

EPA Science Inventory

Increased urbanization results in a larger percentage of connected impervious areas and can contribute large quantities of stormwater runoff and significant quantities of debris and pollutants (e.g., litter, oils, microorganisms, sediments, nutrients, organic matter, and heavy me...

The production of multiprotein complexes in insect cells using the baculovirus expression system.

PubMed

Abdulrahman, Wassim; Radu, Laura; Garzoni, Frederic; Kolesnikova, Olga; Gupta, Kapil; Osz-Papai, Judit; Berger, Imre; Poterszman, Arnaud

2015-01-01

The production of a homogeneous protein sample in sufficient quantities is an essential prerequisite not only for structural investigations but represents also a rate-limiting step for many functional studies. In the cell, a large fraction of eukaryotic proteins exists as large multicomponent assemblies with many subunits, which act in concert to catalyze specific activities. Many of these complexes cannot be obtained from endogenous source material, so recombinant expression and reconstitution are then required to overcome this bottleneck. This chapter describes current strategies and protocols for the efficient production of multiprotein complexes in large quantities and of high quality, using the baculovirus/insect cell expression system.

The plasma separation process as a pre-cursor for large scale radioisotope production

NASA Astrophysics Data System (ADS)

Stevenson, Nigel R.

2001-07-01

Radioisotope production generally employs either accelerators or reactors to convert stable (usually enriched) isotopes into the desired product species. Radioisotopes have applications in industry, environmental sciences, and most significantly in medicine. The production of many potentially useful radioisotopes is significantly hindered by the lack of availability or by the high cost of key enriched stable isotopes. To try and meet this demand, certain niche enrichment processes have been developed and commercialized. Calutrons, centrifuges, and laser separation processes are some of the devices and techniques being employed to produce large quantities of selective enriched stable isotopes. Nevertheless, the list of enriched stable isotopes in sufficient quantities remains rather limited and this continues to restrict the availability of many radioisotopes that otherwise could have a significant impact on society. The Plasma Separation Process is a newly available commercial technique for producing large quantities of a wide range of enriched isotopes and thereby holds promise of being able to open the door to producing new and exciting applications of radioisotopes in the future.

Rapid Ovary Mass-Isolation (ROMi) to Obtain Large Quantities of Drosophila Egg Chambers for Fluorescent In Situ Hybridization.

PubMed

Jambor, Helena; Mejstrik, Pavel; Tomancak, Pavel

2016-01-01

Isolation of large quantities of tissue from organisms is essential for many techniques such as genome-wide screens and biochemistry. However, obtaining large quantities of tissues or cells is often the rate-limiting step when working in vivo. Here, we present a rapid method that allows the isolation of intact, single egg chambers at various developmental stages from ovaries of adult female Drosophila flies. The isolated egg chambers are amenable for a variety of procedures such as fluorescent in situ hybridization, RNA isolation, extract preparation, or immunostaining. Isolation of egg chambers from adult flies can be completed in 5 min and results, depending on the input amount of flies, in several milliliters of material. The isolated egg chambers are then further processed depending on the exact requirements of the subsequent application. We describe high-throughput in situ hybridization in 96-well plates as example application for the mass-isolated egg chambers.

Quantity, Revisited: An Object-Oriented Reusable Class

NASA Technical Reports Server (NTRS)

Funston, Monica Gayle; Gerstle, Walter; Panthaki, Malcolm

1998-01-01

"Quantity", a prototype implementation of an object-oriented class, was developed for two reasons: to help engineers and scientists manipulate the many types of quantities encountered during routine analysis, and to create a reusable software component to for large domain-specific applications. From being used as a stand-alone application to being incorporated into an existing computational mechanics toolkit, "Quantity" appears to be a useful and powerful object. "Quantity" has been designed to maintain the full engineering meaning of values with respect to units and coordinate systems. A value is a scalar, vector, tensor, or matrix, each of which is composed of Value Components, each of which may be an integer, floating point number, fuzzy number, etc., and its associated physical unit. Operations such as coordinate transformation and arithmetic operations are handled by member functions of "Quantity". The prototype has successfully tested such characteristics as maintaining a numeric value, an associated unit, and an annotation. In this paper we further explore the design of "Quantity", with particular attention to coordinate systems.

Variability and Maintenance of Turbulence in the Very Stable Boundary Layer

NASA Astrophysics Data System (ADS)

Mahrt, Larry

2010-04-01

The relationship of turbulence quantities to mean flow quantities, such as the Richardson number, degenerates substantially for strong stability, at least in those studies that do not place restrictions on minimum turbulence or non-stationarity. This study examines the large variability of the turbulence for very stable conditions by analyzing four months of turbulence data from a site with short grass. Brief comparisons are made with three additional sites, one over short grass on flat terrain and two with tall vegetation in complex terrain. For very stable conditions, any dependence of the turbulence quantities on the mean wind speed or bulk Richardson number becomes masked by large scatter, as found in some previous studies. The large variability of the turbulence quantities is due to random variations and other physical influences not represented by the bulk Richardson number. There is no critical Richardson number above which the turbulence vanishes. For very stable conditions, the record-averaged vertical velocity variance and the drag coefficient increase with the strength of the submeso motions (wave motions, solitary waves, horizontal modes and numerous more complex signatures). The submeso motions are on time scales of minutes and not normally considered part of the mean flow. The generation of turbulence by such unpredictable motions appears to preclude universal similarity theory for predicting the surface stress for very stable conditions. Large variation of the stress direction with respect to the wind direction for the very stable regime is also examined. Needed additional work is noted.

EVALUATING THE ACCOTINK CREEK URBAN STREAM RESTORATION PROJECT FOR IMPROVING WATER QUALITY, IN-STREAM HABITAT, AND BANK STABILITY

EPA Science Inventory

Increased urbanization results in a larger percentage of connected impervious areas and can contribute large quantities of stormwater runoff and significant quantities of debris and pollutants (e.g., litter, oils, microorganisms, sediments, nutrients, organic matter, and heavy me...

Influence of pre-injection control parameters on main-injection fuel quantity for an electronically controlled double-valve fuel injection system of diesel engine

NASA Astrophysics Data System (ADS)

Song, Enzhe; Fan, Liyun; Chen, Chao; Dong, Quan; Ma, Xiuzhen; Bai, Yun

2013-09-01

A simulation model of an electronically controlled two solenoid valve fuel injection system for a diesel engine is established in the AMESim environment. The accuracy of the model is validated through comparison with experimental data. The influence of pre-injection control parameters on main-injection quantity under different control modes is analyzed. In the spill control valve mode, main-injection fuel quantity decreases gradually and then reaches a stable level because of the increase in multi-injection dwell time. In the needle control valve mode, main-injection fuel quantity increases with rising multi-injection dwell time; this effect becomes more obvious at high-speed revolutions and large main-injection pulse widths. Pre-injection pulse width has no obvious influence on main-injection quantity under the two control modes; the variation in main-injection quantity is in the range of 1 mm3.

Do Social Conditions Affect Capuchin Monkeys' (Cebus apella) Choices in a Quantity Judgment Task?

PubMed

Beran, Michael J; Perdue, Bonnie M; Parrish, Audrey E; Evans, Theodore A

2012-01-01

Beran et al. (2012) reported that capuchin monkeys closely matched the performance of humans in a quantity judgment test in which information was incomplete but a judgment still had to be made. In each test session, subjects first made quantity judgments between two known options. Then, they made choices where only one option was visible. Both humans and capuchin monkeys were guided by past outcomes, as they shifted from selecting a known option to selecting an unknown option at the point at which the known option went from being more than the average rate of return to less than the average rate of return from earlier choices in the test session. Here, we expanded this assessment of what guides quantity judgment choice behavior in the face of incomplete information to include manipulations to the unselected quantity. We manipulated the unchosen set in two ways: first, we showed the monkeys what they did not get (the unchosen set), anticipating that "losses" would weigh heavily on subsequent trials in which the same known quantity was presented. Second, we sometimes gave the unchosen set to another monkey, anticipating that this social manipulation might influence the risk-taking responses of the focal monkey when faced with incomplete information. However, neither manipulation caused difficulty for the monkeys who instead continued to use the rational strategy of choosing known sets when they were as large as or larger than the average rate of return in the session, and choosing the unknown (riskier) set when the known set was not sufficiently large. As in past experiments, this was true across a variety of daily ranges of quantities, indicating that monkeys were not using some absolute quantity as a threshold for selecting (or not) the known set, but instead continued to use the daily average rate of return to determine when to choose the known versus the unknown quantity.

Nebulization Reflux Concentrator

NASA Technical Reports Server (NTRS)

Cofer, Wesley R., III; Collins, V. G.

1986-01-01

Nebulization reflux concentrator extracts and concentrates trace quantities of water-soluble gases for subsequent chemical analysis. Hydrophobic membrane and nebulizing nozzles form scrubber for removing trace quantities of soluble gases or other contaminants from atmosphere. Although hydrophobic membrane virtually blocks all transport of droplets, it offers little resistance to gas flow; hence, device permits relatively large volumes of gas scrubbed efficiently with very small volumes of liquid. This means analyzable quantities of contaminants concentrate in extracting solutions in much shorter times than with conventional techniques.

Soluble forms of polyQ-expanded huntingtin rather than large aggregates cause endoplasmic reticulum stress

NASA Astrophysics Data System (ADS)

Leitman, Julia; Ulrich Hartl, F.; Lederkremer, Gerardo Z.

2013-11-01

In Huntington’s disease, as in other neurodegenerative diseases, it was initially thought that insoluble protein aggregates are the toxic species. However, growing evidence implicates soluble oligomeric polyglutamine-expanded huntingtin in cytotoxicity. Here we show that pathogenic huntingtin inhibits endoplasmic reticulum (ER)-associated degradation and induces ER stress before its aggregation into visible inclusions. All three branches of the unfolded protein response are activated. ER stress can be compensated by overexpression of p97/VCP, suggesting its sequestration by pathogenic huntingtin as a main cause. Stress correlates with the presence of huntingtin oligomers and is independent of continual huntingtin synthesis. Stress levels, measured in striatal neurons, are stabilized but only slowly subside on huntingtin aggregation into inclusions. Our results can be explained by the constant conversion of huntingtin monomers to toxic oligomers; large aggregates sequester the former, precluding further conversion, whereas pre-existing toxic oligomers are only gradually depleted.

Protection against heavy metal toxicity by mucous and scales in fish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coello, W.F.; Khan, M.A.Q.

1995-12-31

Fingerlings of three freshwater fish species showed differences in susceptibility to lethality of 250 mg/L lead suspension or lead nitrate solution in water. Among these the large mouth bass Micropterus salmoides seemed to be more tolerant than green sunfish Lepomis cyanellus and goldfish Carassius auratus. Mucous from large mouth bass, when added to jars containing lead, lowered the toxicity of lead to sunfish and goldfish. Adding scales, especially if these were pretreated with an alkaline solution of cysteine and glycine, made all these species become tolerant to otherwise lethal concentrations of lead nitrate. The scales and mucous together buffered themore » acidity of lead nitrate and mercuric nitrate solution and sequestered hydrogen ions and lead and mercury from water and then settled to the bottom of jars. Scales of younger fingerling were more efficient than those of older ones.« less

Identification and subsequent phosphorylation of sequestered partially processed caseins in the lactating guinea-pig mammary gland.

PubMed Central

Boulton, A P; Pascall, J C; Craig, R K

1984-01-01

Golgi and endoplasmic-reticulum fractions were prepared from the lactating guinea-pig mammary gland. The endoplasmic-reticulum fraction was highly active in the processing and sequestration of milk-protein primary translation products. Explants from the lactating gland in organ culture were used to identify milk-protein intermediates present in the secretory pathway, and the timing of the events leading to their post-translational modification. With [35S]methionine, the milk proteins labelled after a short pulse (3 min) were represented by the partially processed (but not phosphorylated) caseins and alpha-lactalbumin sequestered within membrane-bound vesicles. After a 30 min labelling period, higher-Mr caseins with electrophoretic mobilities identical with those of the phosphorylated caseins isolated from milk were identified in the incubation medium, and sequestered within membrane-bound vesicles. Pulse-chase experiments established a precursor-product relationship between these forms. Secretion is apparent approx. 30 min after sequestration. Caseins are highly phosphorylated; removal of the phosphate residues with acid phosphatase results in proteins with increased electrophoretic mobility, similar to those of the partially processed early casein intermediates found sequestered in explants after a 3 min pulse with [35S]methionine, and those sequestered within microsomal membranes after mRNA-directed cell-free protein synthesis. A comparison of the proteins labelled during both short (5 min) and long (30 min) pulses with [35S]methionine and [32P]Pi shows that, in contrast with the 35S-labelled caseins, those labelled with [32P]Pi exhibit only electrophoretic mobilities identical with those of the mature caseins isolated from milk and those identified after long labelling periods with [35S]methionine. No phosphorylated early intermediate forms of caseins were identified. We conclude that the synthesis and post-translational modification of guinea-pig caseins occurs in two stages, (i) an early event involving synthesis and sequestration within the endoplasmic reticulum, an event that involves signal-peptide removal, followed (ii) 10-20 min later by phosphorylation at a different point in the secretory pathway, probably in the Golgi complex. Secretion of the phosphorylated caseins occurs 10-20 min later. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. PMID:6477529

The multiple strategies of an insect herbivore to overcome plant cyanogenic glucoside defence.

PubMed

Pentzold, Stefan; Zagrobelny, Mika; Roelsgaard, Pernille Sølvhøj; Møller, Birger Lindberg; Bak, Søren

2014-01-01

Cyanogenic glucosides (CNglcs) are widespread plant defence compounds that release toxic hydrogen cyanide by plant β-glucosidase activity after tissue damage. Specialised insect herbivores have evolved counter strategies and some sequester CNglcs, but the underlying mechanisms to keep CNglcs intact during feeding and digestion are unknown. We show that CNglc-sequestering Zygaena filipendulae larvae combine behavioural, morphological, physiological and biochemical strategies at different time points during feeding and digestion to avoid toxic hydrolysis of the CNglcs present in their Lotus food plant, i.e. cyanogenesis. We found that a high feeding rate limits the time for plant β-glucosidases to hydrolyse CNglcs. Larvae performed leaf-snipping, a minimal disruptive feeding mode that prevents mixing of plant β-glucosidases and CNglcs. Saliva extracts did not inhibit plant cyanogenesis. However, a highly alkaline midgut lumen inhibited the activity of ingested plant β-glucosidases significantly. Moreover, insect β-glucosidases from the saliva and gut tissue did not hydrolyse the CNglcs present in Lotus. The strategies disclosed may also be used by other insect species to overcome CNglc-based plant defence and to sequester these compounds intact.

HIV internalization into oral and genital epithelial cells by endocytosis and macropinocytosis leads to viral sequestration in the vesicles

PubMed Central

Yasen, Aizezi; Herrera, Rossana; Rosbe, Kristina; Lien, Kathy; Tugizov, Sharof M.

2018-01-01

Recently, we showed that HIV-1 is sequestered, i.e., trapped, in the intracellular vesicles of oral and genital epithelial cells. Here, we investigated the mechanisms of HIV-1 sequestration in vesicles of polarized tonsil, foreskin and cervical epithelial cells. HIV-1 internalization into epithelial cells is initiated by multiple entry pathways, including clathrin-, caveolin/lipid raft-associated endocytosis and macropinocytosis. Inhibition of HIV-1 attachment to galactosylceramide and heparan sulfate proteoglycans, and virus endocytosis and macropinocytosis reduced HIV-1 sequestration by 30–40%. T-cell immunoglobulin and mucin domain 1 (TIM-1) were expressed on the apical surface of polarized tonsil, cervical and foreskin epithelial cells. However, TIM-1-associated HIV-1 macropinocytosis and sequestration were detected mostly in tonsil epithelial cells. Sequestered HIV-1 was resistant to trypsin, pronase, and soluble CD4, indicating that the sequestered virus was intracellular. Inhibition of HIV-1 intraepithelial sequestration and elimination of vesicles containing virus in the mucosal epithelium may help in the prevention of HIV-1 mucosal transmission. PMID:29277006

Assessing the impact of changes in climate and CO2 on potential carbon sequestration in agricultural soils

NASA Astrophysics Data System (ADS)

Jain, Atul K.; West, Tristram O.; Yang, Xiaojuan; Post, Wilfred M.

2005-10-01

Changes in soil management can potentially increase the accumulation of soil organic carbon (SOC), thereby sequestering CO2 from the atmosphere. However, the amount of carbon sequestered in soils can be augmented or lessened due to changes in climate and atmospheric CO2 concentration. The purpose of this paper is to study the influence of climate and CO2 feedbacks on soil carbon sequestration using a terrestrial carbon cycle model. Model simulations consist of observed adoption rates of no-tillage practices on croplands in the U.S. and Canada between 1981-2000. Model results indicate potential sequestration rates between 0.4-0.6 MgC/ha/yr in the Midwestern U.S. with decreasing rates towards the western, dryer regions of the U.S. It is estimated here that changes in climate and CO2 between 1981-2000 could be responsible for an additional soil carbon sequestration of 42 Tg. This is 5% of the soil carbon estimated to be potentially sequestered as the result of conversion to no-tillage in the U.S. and Canada.

Federal land management, carbon sequestration, and climate change in the Southeastern U.S.: a case study with fort benning

USGS Publications Warehouse

Zhao, S.; Liu, S.; Li, Z.; Sohl, Terry L.

2010-01-01

Land use activities can have a major impact on the temporal trendsandspatialpatternsofregionalland-atmosphereexchange of carbon. Federal lands generally have substantially different land management strategies from surrounding areas, and the carbon consequences have rarely been quantified and assessed. Using the Fort Benning Installation as a case study, we used the General Ensemble biogeochemical Modeling System (GEMS) to simulate and compare ecosystem carbon sequestration between the U.S. Army's Fort Benning and surrounding areas from 1992 to 2050. Our results indicate that the military installation sequestered more carbon than surrounding areas from 1992 to 2007 (76.7 vs 18.5 g C m-2 yr-1), and is projected to continue sequestering more carbon from 2008 to 2050 (75.7 vs 25.6 g C m-2 yr-1), mostly because of the proactive management approaches adopted on military training lands. Our results suggest that federal lands might play a positive and important role in sequestering and conserving atmospheric carbon because some anthropogenic disturbances (e.g., urbanization, forest harvesting, and agriculture) can be minimized or prevented on federal lands

Poor sequestration of toxic host plant cardenolides and their rapid loss in the milkweed butterfly Danaus chrysippus (Lepidoptera: Nymphalidae: Danainae: Danaini).

PubMed

Mebs, Dietrich; Wunder, Cora; Toennes, Stefan W

2017-06-01

Butterflies of the genus Danaus are known to sequester toxic cardenolides from milkweed host plants (Apocynaceae). In particular, Danaus plexippus efficiently sequesters and stores these compounds, whereas D. chrysippus, is considered to poorly sequester cardenolides. To estimate its sequestration capability compared with that of D. plexippus, larvae of both species were jointly reared on Asclepias curassavica and the major cardenolides of the host plant, calotropin and calactin, were analyzed in adults sampled at different time intervals after eclosion. Both cardenolides were detected in body and wings of D. plexippus. Whereas the calotropin-concentration remained constant over a period of 24 days, that of calactin steadily decreased. In the body, but not in the wings of D. chrysippus, calactin only was detected in low amounts, which was then almost completely lost during the following 8 days after eclosion, suggesting that in contrast to D. plexippus, cardenolides seem to be less important for that butterfly's defence against predators. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biodegradation of organic sulfur compounds in crude oils from Oman

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koopmans, M.P.; Sinninghe Damste, J.S.; Leeuw, J.W. de

1996-10-01

Five closely related crude oils from Oman, showing various degrees of biodegradation ranging from non-biodegraded to severely biodegraded, were quantitatively investigated for free and sulfur-bound hydrocarbons. Hydrocarbons sequestered in the alkylsulfide fraction and the polar fraction were analysed after Raney Ni desulfurisation and subsequent hydrogenation. With increasing degree of biodegradation, pristane (Pr), phytane (Ph) and a series of mid-chain methyl alkanes are enriched relative to the n-alkanes, as evidenced by increased Pr/n-C{sub 17} and Ph/n-C{sub 18} ratios. In the severely biodegraded oil no free n-alkanes, mid-chain alkanes or isoprenoid alkanes could be detected. Sterane and hopane distributions, however, remain unchangedmore » throughout the biodegradation series. Hydrocarbons sequestered in the alkylsulfide fraction (i.e. n-alkanes, mid-chain methyl alkanes, Pr and Ph) are biodegraded at lower rates than the corresponding hydrocarbons in the saturated hydrocarbon fraction. Similar hydrocarbons sequestered in the polar fraction are biodegraded at even lower rates. These results suggest that hydrocarbons bound by a higher amount of sulfur links are biodegraded at a lower rate.« less

An assessment of potential weather effects due to operation of the Space Orbiting Light Augmentation Reflector Energy System (SOLARES)

NASA Technical Reports Server (NTRS)

Allen, N. C.

1978-01-01

Implementation of SOLARES will input large quantities of heat continuously into a stationary location on the Earth's surface. The quantity of heat released by each of the SOlARES ground receivers, having a reflector orbit height of 6378 km, exceeds by 30 times that released by large power parks which were studied in detail. Using atmospheric models, estimates are presented for the local weather effects, the synoptic scale effects, and the global scale effects from such intense thermal radiation.

Effect of indirect non-thermal plasma on particle size distribution and composition of diesel engine particles

NASA Astrophysics Data System (ADS)

Linbo, GU; Yixi, CAI; Yunxi, SHI; Jing, WANG; Xiaoyu, PU; Jing, TIAN; Runlin, FAN

2017-11-01

To explore the effect of the gas source flow rate on the actual diesel exhaust particulate matter (PM), a test bench for diesel engine exhaust purification was constructed, using indirect non-thermal plasma technology. The effects of different gas source flow rates on the quantity concentration, composition, and apparent activation energy of PM were investigated, using an engine exhaust particle sizer and a thermo-gravimetric analyzer. The results show that when the gas source flow rate was large, not only the maximum peak quantity concentrations of particles had a large drop, but also the peak quantity concentrations shifted to smaller particle sizes from 100 nm to 80 nm. When the gas source flow rate was 10 L min-1, the total quantity concentration greatly decreased where the removal rate of particles was 79.2%, and the variation of the different mode particle proportion was obvious. Non-thermal plasma (NTP) improved the oxidation ability of volatile matter as well as that of solid carbon. However, the NTP gas source rate had little effects on oxidation activity of volatile matter, while it strongly influenced the oxidation activity of solid carbon. Considering the quantity concentration and oxidation activity of particles, a gas source flow rate of 10 L min-1 was more appropriate for the purification of particles.

Reexamination of the calculation of two-center, two-electron integrals over Slater-type orbitals. II. Neumann expansion of the exchange integrals

NASA Astrophysics Data System (ADS)

Lesiuk, Michał; Moszynski, Robert

2014-12-01

In this paper we consider the calculation of two-center exchange integrals over Slater-type orbitals (STOs). We apply the Neumann expansion of the Coulomb interaction potential and consider calculation of all basic quantities which appear in the resulting expression. Analytical closed-form equations for all auxiliary quantities have already been known but they suffer from large digital erosion when some of the parameters are large or small. We derive two differential equations which are obeyed by the most difficult basic integrals. Taking them as a starting point, useful series expansions for small parameter values or asymptotic expansions for large parameter values are systematically derived. The resulting expansions replace the corresponding analytical expressions when the latter introduce significant cancellations. Additionally, we reconsider numerical integration of some necessary quantities and present a new way to calculate the integrand with a controlled precision. All proposed methods are combined to lead to a general, stable algorithm. We perform extensive numerical tests of the introduced expressions to verify their validity and usefulness. Advances reported here provide methodology to compute two-electron exchange integrals over STOs for a broad range of the nonlinear parameters and large angular momenta.

Amorphous areas in the cytoplasm of Dendrobium tepal cells

PubMed Central

van Doorn, Wouter G.; Kirasak, Kanjana; Ketsa, Saichol

2013-01-01

In Dendrobium flowers some tepal mesophyll cells showed cytoplasmic areas devoid of large organelles. Such amorphous areas comprised up to about 40% of the cross-section of a cell. The areas were not bound by a membrane. The origin of these areas is not known. We show data suggesting that they can be formed from vesicle-like organelles. The data imply that these organelles and other material become degraded inside the cytoplasm. This can be regarded as a form of autophagy. The amorphous areas became surrounded by small vacuoles, vesicles or double membranes. These seemed to merge and thereby sequester the areas. Degradation of the amorphous areas therefore seemed to involve macroautophagy. PMID:23823702

Electromagnetic Biostimulation of Living Cultures for Biotechnology, Biofuel and Bioenergy Applications

PubMed Central

Hunt, Ryan W.; Zavalin, Andrey; Bhatnagar, Ashish; Chinnasamy, Senthil; Das, Keshav C.

2009-01-01

The surge of interest in bioenergy has been marked with increasing efforts in research and development to identify new sources of biomass and to incorporate cutting-edge biotechnology to improve efficiency and increase yields. It is evident that various microorganisms will play an integral role in the development of this newly emerging industry, such as yeast for ethanol and Escherichia coli for fine chemical fermentation. However, it appears that microalgae have become the most promising prospect for biomass production due to their ability to grow fast, produce large quantities of lipids, carbohydrates and proteins, thrive in poor quality waters, sequester and recycle carbon dioxide from industrial flue gases and remove pollutants from industrial, agricultural and municipal wastewaters. In an attempt to better understand and manipulate microorganisms for optimum production capacity, many researchers have investigated alternative methods for stimulating their growth and metabolic behavior. One such novel approach is the use of electromagnetic fields for the stimulation of growth and metabolic cascades and controlling biochemical pathways. An effort has been made in this review to consolidate the information on the current status of biostimulation research to enhance microbial growth and metabolism using electromagnetic fields. It summarizes information on the biostimulatory effects on growth and other biological processes to obtain insight regarding factors and dosages that lead to the stimulation and also what kind of processes have been reportedly affected. Diverse mechanistic theories and explanations for biological effects of electromagnetic fields on intra and extracellular environment have been discussed. The foundations of biophysical interactions such as bioelectromagnetic and biophotonic communication and organization within living systems are expounded with special consideration for spatiotemporal aspects of electromagnetic topology, leading to the potential of multipolar electromagnetic systems. The future direction for the use of biostimulation using bioelectromagnetic, biophotonic and electrochemical methods have been proposed for biotechnology industries in general with emphasis on an holistic biofuel system encompassing production of algal biomass, its processing and conversion to biofuel. PMID:20057958

Carbon sequestration efficiency of organic amendments in a long-term experiment on a vertisol in Huang-Huai-Hai Plain, China.

PubMed

Hua, Keke; Wang, Daozhong; Guo, Xisheng; Guo, Zibin

2014-01-01

Soil organic carbon (SOC) sequestration is important for improving soil fertility of cropland and for the mitigation of greenhouse gas emissions to the atmosphere. The efficiency of SOC sequestration depends on the quantity and quality of the organic matter, soil type, and climate. Little is known about the SOC sequestration efficiency of organic amendments in Vertisols. Thus, we conducted the research based on 29 years (1982-2011) of long-term fertilization experiment with a no fertilizer control and five fertilization regimes: CK (control, no fertilizer), NPK (mineral NPK fertilizers alone), NPK+1/2W (mineral NPK fertilizers combined with half the amount of wheat straw), NPK+W (mineral NPK fertilizers combined with full the amount of wheat straw), NPK+PM (mineral NPK fertilizers combined with pig manure) and NPK+CM (mineral NPK fertilizers combined cattle manure). Total mean annual C inputs were 0.45, 1.55, 2.66, 3.71, 4.68 and 6.56 ton/ha/yr for CK, NPK, NPKW1/2, NPKW, NPKPM and NPKCM, respectively. Mean SOC sequestration rate was 0.20 ton/ha/yr in the NPK treatment, and 0.39, 0.50, 0.51 and 0.97 ton/ha/yr in the NPKW1/2, NPKW, NPKPM, and NPKCM treatments, respectively. A linear relationship was observed between annual C input and SOC sequestration rate (SOCsequestration rate  = 0.16 Cinput -0.10, R = 0.95, P<0.01), suggesting a C sequestration efficiency of 16%. The Vertisol required an annual C input of 0.63 ton/ha/yr to maintain the initial SOC level. Moreover, the C sequestration efficiencies of wheat straw, pig manure and cattle manure were 17%, 11% and 17%, respectively. The results indicate that the Vertisol has a large potential to sequester SOC with a high efficiency, and applying cattle manure or wheat straw is a recommendable SOC sequestration practice in Vertisols.

Carbon Sequestration Efficiency of Organic Amendments in a Long-Term Experiment on a Vertisol in Huang-Huai-Hai Plain, China

PubMed Central

Hua, Keke; Wang, Daozhong; Guo, Xisheng; Guo, Zibin

2014-01-01

Soil organic carbon (SOC) sequestration is important for improving soil fertility of cropland and for the mitigation of greenhouse gas emissions to the atmosphere. The efficiency of SOC sequestration depends on the quantity and quality of the organic matter, soil type, and climate. Little is known about the SOC sequestration efficiency of organic amendments in Vertisols. Thus, we conducted the research based on 29 years (1982–2011) of long-term fertilization experiment with a no fertilizer control and five fertilization regimes: CK (control, no fertilizer), NPK (mineral NPK fertilizers alone), NPK+1/2W (mineral NPK fertilizers combined with half the amount of wheat straw), NPK+W (mineral NPK fertilizers combined with full the amount of wheat straw), NPK+PM (mineral NPK fertilizers combined with pig manure) and NPK+CM (mineral NPK fertilizers combined cattle manure). Total mean annual C inputs were 0.45, 1.55, 2.66, 3.71, 4.68 and 6.56 ton/ha/yr for CK, NPK, NPKW1/2, NPKW, NPKPM and NPKCM, respectively. Mean SOC sequestration rate was 0.20 ton/ha/yr in the NPK treatment, and 0.39, 0.50, 0.51 and 0.97 ton/ha/yr in the NPKW1/2, NPKW, NPKPM, and NPKCM treatments, respectively. A linear relationship was observed between annual C input and SOC sequestration rate (SOCsequestration rate  = 0.16 Cinput –0.10, R = 0.95, P<0.01), suggesting a C sequestration efficiency of 16%. The Vertisol required an annual C input of 0.63 ton/ha/yr to maintain the initial SOC level. Moreover, the C sequestration efficiencies of wheat straw, pig manure and cattle manure were 17%, 11% and 17%, respectively. The results indicate that the Vertisol has a large potential to sequester SOC with a high efficiency, and applying cattle manure or wheat straw is a recommendable SOC sequestration practice in Vertisols. PMID:25265095

Effects of a Storm-Surge Related Salinity Decrease on Greenhouse Gas Emissions in Tidal Salt Marsh Mesocosms

NASA Astrophysics Data System (ADS)

Capooci, M.; Barba, J.; Seyfferth, A.; Vargas, R.

2017-12-01

Salt marshes, along with mangrove forests and seagrass beds, are capable of sequestering large quantities of carbon. Additionally, salt marshes are resilient ecosystems, capable of quickly recovering from disturbances. However, very little is known about how carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and ammonia (NH3) fluxes from wetland soils, in addition to pore water chemistry, change with a disturbance event such as a storm surge. Using soil mesocosms from St. Jones Reserve, a National Estuarine Research Reserve, and site-specific water salinity data, we conducted a laboratory experiment that recreated the changes in salinity associated with a storm event and compared them to soils flooded with the mean annual salinity of the St. Jones River. Control and treatment were done in triplicate. We controlled for variations in temperature (set at 21°C) and all cores maintained similar flooded conditions. Treatment included a decrease in salinity based on historic values during storm events (i.e. Hurricane Joaquin). Greenhouse gas (GHG; CO2, CH4, N2O, NH3) emissions were measured hourly using automated chambers. Pore water was collected every day to every other day and analyzed for a variety of parameters, including Fe2+, S2-, SO42-, and NO3-. Auxiliary measurements, such as soil temperature, moisture, and oxygen levels, in addition to pore water salinity, were also taken to ensure that proper conditions were maintained. We found significant increases in CO2, CH4, and N2O emissions when comparing the treatment (lowered salinity) to the control. We found also differences in pore water chemistry between treatment phases, particularly in Fe2+. The results of this experiment have implications for GHG dynamics in salt marsh ecosystems, showcasing the need to measure GHG emissions during and after storm events. This study provides insights into how changes in salinity affect GHG emissions in salt marshes, as well as how ecosystem dynamics respond to a disturbance.

Excess single-stranded DNA inhibits meiotic double-strand break repair.

PubMed

Johnson, Rebecca; Borde, Valérie; Neale, Matthew J; Bishop-Bailey, Anna; North, Matthew; Harris, Sheila; Nicolas, Alain; Goldman, Alastair S H

2007-11-01

During meiosis, self-inflicted DNA double-strand breaks (DSBs) are created by the protein Spo11 and repaired by homologous recombination leading to gene conversions and crossovers. Crossover formation is vital for the segregation of homologous chromosomes during the first meiotic division and requires the RecA orthologue, Dmc1. We analyzed repair during meiosis of site-specific DSBs created by another nuclease, VMA1-derived endonuclease (VDE), in cells lacking Dmc1 strand-exchange protein. Turnover and resection of the VDE-DSBs was assessed in two different reporter cassettes that can repair using flanking direct repeat sequences, thereby obviating the need for a Dmc1-dependent DNA strand invasion step. Access of the single-strand binding complex replication protein A, which is normally used in all modes of DSB repair, was checked in chromatin immunoprecipitation experiments, using antibody against Rfa1. Repair of the VDE-DSBs was severely inhibited in dmc1Delta cells, a defect that was associated with a reduction in the long tract resection required to initiate single-strand annealing between the flanking repeat sequences. Mutants that either reduce Spo11-DSB formation or abolish resection at Spo11-DSBs rescued the repair block. We also found that a replication protein A component, Rfa1, does not accumulate to expected levels at unrepaired single-stranded DNA (ssDNA) in dmc1Delta cells. The requirement of Dmc1 for VDE-DSB repair using flanking repeats appears to be caused by the accumulation of large quantities of ssDNA that accumulate at Spo11-DSBs when Dmc1 is absent. We propose that these resected DSBs sequester both resection machinery and ssDNA binding proteins, which in wild-type cells would normally be recycled as Spo11-DSBs repair. The implication is that repair proteins are in limited supply, and this could reflect an underlying mechanism for regulating DSB repair in wild-type cells, providing protection from potentially harmful effects of overabundant repair proteins.

Excess Single-Stranded DNA Inhibits Meiotic Double-Strand Break Repair

PubMed Central

Bishop-Bailey, Anna; North, Matthew; Harris, Sheila; Nicolas, Alain; Goldman, Alastair S. H

2007-01-01

During meiosis, self-inflicted DNA double-strand breaks (DSBs) are created by the protein Spo11 and repaired by homologous recombination leading to gene conversions and crossovers. Crossover formation is vital for the segregation of homologous chromosomes during the first meiotic division and requires the RecA orthologue, Dmc1.We analyzed repair during meiosis of site-specific DSBs created by another nuclease, VMA1-derived endonuclease (VDE), in cells lacking Dmc1 strand-exchange protein. Turnover and resection of the VDE-DSBs was assessed in two different reporter cassettes that can repair using flanking direct repeat sequences, thereby obviating the need for a Dmc1-dependent DNA strand invasion step. Access of the single-strand binding complex replication protein A, which is normally used in all modes of DSB repair, was checked in chromatin immunoprecipitation experiments, using antibody against Rfa1. Repair of the VDE-DSBs was severely inhibited in dmc1Δ cells, a defect that was associated with a reduction in the long tract resection required to initiate single-strand annealing between the flanking repeat sequences. Mutants that either reduce Spo11-DSB formation or abolish resection at Spo11-DSBs rescued the repair block. We also found that a replication protein A component, Rfa1, does not accumulate to expected levels at unrepaired single-stranded DNA (ssDNA) in dmc1Δ cells. The requirement of Dmc1 for VDE-DSB repair using flanking repeats appears to be caused by the accumulation of large quantities of ssDNA that accumulate at Spo11-DSBs when Dmc1 is absent. We propose that these resected DSBs sequester both resection machinery and ssDNA binding proteins, which in wild-type cells would normally be recycled as Spo11-DSBs repair. The implication is that repair proteins are in limited supply, and this could reflect an underlying mechanism for regulating DSB repair in wild-type cells, providing protection from potentially harmful effects of overabundant repair proteins. PMID:18081428

Impacts of crop rotations on soil organic carbon sequestration

NASA Astrophysics Data System (ADS)

Gobin, Anne; Vos, Johan; Joris, Ingeborg; Van De Vreken, Philippe

2013-04-01

Agricultural land use and crop rotations can greatly affect the amount of carbon sequestered in the soil. We developed a framework for modelling the impacts of crop rotations on soil carbon sequestration at the field scale with test case Flanders. A crop rotation geo-database was constructed covering 10 years of crop rotation in Flanders using the IACS parcel registration (Integrated Administration and Control System) to elicit the most common crop rotation on major soil types in Flanders. In order to simulate the impact of crop cover on carbon sequestration, the Roth-C model was adapted to Flanders' environment and coupled to common crop rotations extracted from the IACS geodatabases and statistical databases on crop yield. Crop allometric models were used to calculate crop residues from common crops in Flanders and subsequently derive stable organic matter fluxes to the soil (REGSOM). The REGSOM model was coupled to Roth-C model was run for 30 years and for all combinations of seven main arable crops, two common catch crops and two common dosages of organic manure. The common crops are winter wheat, winter barley, sugar beet, potato, grain maize, silage maize and winter rapeseed; the catch crops are yellow mustard and Italian ryegrass; the manure dosages are 35 ton/ha cattle slurry and 22 ton/ha pig slurry. Four common soils were simulated: sand, loam, sandy loam and clay. In total more than 2.4 million simulations were made with monthly output of carbon content for 30 years. Results demonstrate that crop cover dynamics influence carbon sequestration for a very large percentage. For the same rotations carbon sequestration is highest on clay soils and lowest on sandy soils. Crop residues of grain maize and winter wheat followed by catch crops contribute largely to the total carbon sequestered. This implies that agricultural policies that impact on agricultural land management influence soil carbon sequestration for a large percentage. The framework is therefore suited for further scenario analysis and impact assessment in order to support agri-environmental policy decisions.

Testing of transition-region models: Test cases and data

NASA Technical Reports Server (NTRS)

Singer, Bart A.; Dinavahi, Surya; Iyer, Venkit

1991-01-01

Mean flow quantities in the laminar turbulent transition region and in the fully turbulent region are predicted with different models incorporated into a 3-D boundary layer code. The predicted quantities are compared with experimental data for a large number of different flows and the suitability of the models for each flow is evaluated.

Large-scale generation of cell-derived nanovesicles

NASA Astrophysics Data System (ADS)

Jo, W.; Kim, J.; Yoon, J.; Jeong, D.; Cho, S.; Jeong, H.; Yoon, Y. J.; Kim, S. C.; Gho, Y. S.; Park, J.

2014-09-01

Exosomes are enclosed compartments that are released from cells and that can transport biological contents for the purpose of intercellular communications. Research into exosomes is hindered by their rarity. In this article, we introduce a device that uses centrifugal force and a filter with micro-sized pores to generate a large quantity of cell-derived nanovesicles. The device has a simple polycarbonate structure to hold the filter, and operates in a common centrifuge. Nanovesicles are similar in size and membrane structure to exosomes. Nanovesicles contain intracellular RNAs ranging from microRNA to mRNA, intracellular proteins, and plasma membrane proteins. The quantity of nanovesicles produced using the device is 250 times the quantity of naturally secreted exosomes. Also, the quantity of intracellular contents in nanovesicles is twice that in exosomes. Nanovesicles generated from murine embryonic stem cells can transfer RNAs to target cells. Therefore, this novel device and the nanovesicles that it generates are expected to be used in exosome-related research, and can be applied in various applications such as drug delivery and cell-based therapy.

Climate change and peak demand for electricity: Evaluating policies for reducing peak demand under different climate change scenarios

NASA Astrophysics Data System (ADS)

Anthony, Abigail Walker

This research focuses on the relative advantages and disadvantages of using price-based and quantity-based controls for electricity markets. It also presents a detailed analysis of one specific approach to quantity based controls: the SmartAC program implemented in Stockton, California. Finally, the research forecasts electricity demand under various climate scenarios, and estimates potential cost savings that could result from a direct quantity control program over the next 50 years in each scenario. The traditional approach to dealing with the problem of peak demand for electricity is to invest in a large stock of excess capital that is rarely used, thereby greatly increasing production costs. Because this approach has proved so expensive, there has been a focus on identifying alternative approaches for dealing with peak demand problems. This research focuses on two approaches: price based approaches, such as real time pricing, and quantity based approaches, whereby the utility directly controls at least some elements of electricity used by consumers. This research suggests that well-designed policies for reducing peak demand might include both price and quantity controls. In theory, sufficiently high peak prices occurring during periods of peak demand and/or low supply can cause the quantity of electricity demanded to decline until demand is in balance with system capacity, potentially reducing the total amount of generation capacity needed to meet demand and helping meet electricity demand at the lowest cost. However, consumers need to be well informed about real-time prices for the pricing strategy to work as well as theory suggests. While this might be an appropriate assumption for large industrial and commercial users who have potentially large economic incentives, there is not yet enough research on whether households will fully understand and respond to real-time prices. Thus, while real-time pricing can be an effective tool for addressing the peak load problems, pricing approaches are not well suited to ensure system reliability. This research shows that direct quantity controls are better suited for avoiding catastrophic failure that results when demand exceeds supply capacity.

Regional myocardial oxygen tension: 19F MRI of sequestered perfluorocarbon.

PubMed

Shukla, H P; Mason, R P; Bansal, N; Antich, P P

1996-06-01

A novel noninvasive method of measuring local myocardial oxygen tension (pO2) in the perfused rat heart using 19F MRI is demonstrated. Tissue pO2 was determined on the basis of the 19F spin-lattice relaxation rate (R1) of perflubron (perfluorooctyl bromide) sequestered in the heart after IV infusion of an emulsion. Spectroscopic measurement of R1 was previously used to measure a global weighted average of oxygen status. 19F MRI now provides 3D spatial resolution indicating local cardiac pO2 under normally perfused, globally ischemic, and regionally ischemic conditions.

Application of sensitivity-analysis techniques to the calculation of topological quantities

NASA Astrophysics Data System (ADS)

Gilchrist, Stuart

2017-08-01

Magnetic reconnection in the corona occurs preferentially at sites where the magnetic connectivity is either discontinuous or has a large spatial gradient. Hence there is a general interest in computing quantities (like the squashing factor) that characterize the gradient in the field-line mapping function. Here we present an algorithm for calculating certain (quasi)topological quantities using mathematical techniques from the field of ``sensitivity-analysis''. The method is based on the calculation of a three dimensional field-line mapping Jacobian from which all the present topological quantities of interest can be derived. We will present the algorithm and the details of a publicly available set of libraries that implement the algorithm.

Evaluation of a Class of Simple and Effective Uncertainty Methods for Sparse Samples of Random Variables and Functions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romero, Vicente; Bonney, Matthew; Schroeder, Benjamin

When very few samples of a random quantity are available from a source distribution of unknown shape, it is usually not possible to accurately infer the exact distribution from which the data samples come. Under-estimation of important quantities such as response variance and failure probabilities can result. For many engineering purposes, including design and risk analysis, we attempt to avoid under-estimation with a strategy to conservatively estimate (bound) these types of quantities -- without being overly conservative -- when only a few samples of a random quantity are available from model predictions or replicate experiments. This report examines a classmore » of related sparse-data uncertainty representation and inference approaches that are relatively simple, inexpensive, and effective. Tradeoffs between the methods' conservatism, reliability, and risk versus number of data samples (cost) are quantified with multi-attribute metrics use d to assess method performance for conservative estimation of two representative quantities: central 95% of response; and 10 -4 probability of exceeding a response threshold in a tail of the distribution. Each method's performance is characterized with 10,000 random trials on a large number of diverse and challenging distributions. The best method and number of samples to use in a given circumstance depends on the uncertainty quantity to be estimated, the PDF character, and the desired reliability of bounding the true value. On the basis of this large data base and study, a strategy is proposed for selecting the method and number of samples for attaining reasonable credibility levels in bounding these types of quantities when sparse samples of random variables or functions are available from experiments or simulations.« less

How tobacco companies have used package quantity for consumer targeting.

PubMed

Persoskie, Alexander; Donaldson, Elisabeth A; Ryant, Chase

2018-05-31

Package quantity refers to the number of cigarettes or amount of other tobacco product in a package. Many countries restrict minimum cigarette package quantities to avoid low-cost packs that may lower barriers to youth smoking. We reviewed Truth Tobacco Industry Documents to understand tobacco companies' rationales for introducing new package quantities, including companies' expectations and research regarding how package quantity may influence consumer behaviour. A snowball sampling method (phase 1), a static search string (phase 2) and a follow-up snowball search (phase 3) identified 216 documents, mostly from the 1980s and 1990s, concerning cigarettes (200), roll-your-own tobacco (9), smokeless tobacco (6) and 'smokeless cigarettes' (1). Companies introduced small and large packages to motivate brand-switching and continued use among current users when faced with low market share or threats such as tax-induced price increases or competitors' use of price promotions. Companies developed and evaluated package quantities for specific brands and consumer segments. Large packages offered value-for-money and matched long-term, heavy users' consumption rates. Small packages were cheaper, matched consumption rates of newer and lighter users, and increased products' novelty, ease of carrying and perceived freshness. Some users also preferred small packages as a way to try to limit consumption or quit. Industry documents speculated about many potential effects of package quantity on appeal and use, depending on brand and consumer segment. The search was non-exhaustive, and we could not assess the quality of much of the research or other information on which the documents relied. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Key role of symbiotic dinitrogen fixation in tropical forest secondary succession

NASA Astrophysics Data System (ADS)

Batterman, Sarah A.; Hedin, Lars O.; van Breugel, Michiel; Ransijn, Johannes; Craven, Dylan J.; Hall, Jefferson S.

2013-10-01

Forests contribute a significant portion of the land carbon sink, but their ability to sequester CO2 may be constrained by nitrogen, a major plant-limiting nutrient. Many tropical forests possess tree species capable of fixing atmospheric dinitrogen (N2), but it is unclear whether this functional group can supply the nitrogen needed as forests recover from disturbance or previous land use, or expand in response to rising CO2 (refs 6, 8). Here we identify a powerful feedback mechanism in which N2 fixation can overcome ecosystem-scale deficiencies in nitrogen that emerge during periods of rapid biomass accumulation in tropical forests. Over a 300-year chronosequence in Panama, N2-fixing tree species accumulated carbon up to nine times faster per individual than their non-fixing neighbours (greatest difference in youngest forests), and showed species-specific differences in the amount and timing of fixation. As a result of fast growth and high fixation, fixers provided a large fraction of the nitrogen needed to support net forest growth (50,000kg carbon per hectare) in the first 12years. A key element of ecosystem functional diversity was ensured by the presence of different N2-fixing tree species across the entire forest age sequence. These findings show that symbiotic N2 fixation can have a central role in nitrogen cycling during tropical forest stand development, with potentially important implications for the ability of tropical forests to sequester CO2.

Key role of symbiotic dinitrogen fixation in tropical forest secondary succession.

PubMed

Batterman, Sarah A; Hedin, Lars O; van Breugel, Michiel; Ransijn, Johannes; Craven, Dylan J; Hall, Jefferson S

2013-10-10

Forests contribute a significant portion of the land carbon sink, but their ability to sequester CO2 may be constrained by nitrogen, a major plant-limiting nutrient. Many tropical forests possess tree species capable of fixing atmospheric dinitrogen (N2), but it is unclear whether this functional group can supply the nitrogen needed as forests recover from disturbance or previous land use, or expand in response to rising CO2 (refs 6, 8). Here we identify a powerful feedback mechanism in which N2 fixation can overcome ecosystem-scale deficiencies in nitrogen that emerge during periods of rapid biomass accumulation in tropical forests. Over a 300-year chronosequence in Panama, N2-fixing tree species accumulated carbon up to nine times faster per individual than their non-fixing neighbours (greatest difference in youngest forests), and showed species-specific differences in the amount and timing of fixation. As a result of fast growth and high fixation, fixers provided a large fraction of the nitrogen needed to support net forest growth (50,000 kg carbon per hectare) in the first 12 years. A key element of ecosystem functional diversity was ensured by the presence of different N2-fixing tree species across the entire forest age sequence. These findings show that symbiotic N2 fixation can have a central role in nitrogen cycling during tropical forest stand development, with potentially important implications for the ability of tropical forests to sequester CO2.

UBF-binding site arrays form pseudo-NORs and sequester the RNA polymerase I transcription machinery

PubMed Central

Mais, Christine; Wright, Jane E.; Prieto, José-Luis; Raggett, Samantha L.; McStay, Brian

2005-01-01

Human ribosomal genes (rDNA) are located in nucleolar organizer regions (NORs) on the short arms of acrocentric chromosomes. Metaphase NORs that were transcriptionally active in the previous cell cycle appear as prominent chromosomal features termed secondary constrictions that are achromatic in chromosome banding and positive in silver staining. The architectural RNA polymerase I (pol I) transcription factor UBF binds extensively across rDNA throughout the cell cycle. To determine if UBF binding underpins NOR structure, we integrated large arrays of heterologous UBF-binding sequences at ectopic sites on human chromosomes. These arrays efficiently recruit UBF even to sites outside the nucleolus and, during metaphase, form novel silver stainable secondary constrictions, termed pseudo-NORs, morphologically similar to NORs. We demonstrate for the first time that in addition to UBF the other components of the pol I machinery are found associated with sequences across the entire human rDNA repeat. Remarkably, a significant fraction of these same pol I factors are sequestered by pseudo-NORs independent of both transcription and nucleoli. Because of the heterologous nature of the sequence employed, we infer that sequestration is mediated primarily by protein–protein interactions with UBF. These results suggest that extensive binding of UBF is responsible for formation and maintenance of the secondary constriction at active NORs. Furthermore, we propose that UBF mediates recruitment of the pol I machinery to nucleoli independently of promoter elements. PMID:15598984

Structure of the DBL3X-DBL4ε region of the VAR2CSA placental malaria vaccine candidate: insight into DBL domain interactions

PubMed Central

Gangnard, Stéphane; Lewit-Bentley, Anita; Dechavanne, Sébastien; Srivastava, Anand; Amirat, Faroudja; Bentley, Graham A.; Gamain, Benoît

2015-01-01

The human malaria parasite, Plasmodium falciparum, is able to evade spleen-mediated clearing from blood stream by sequestering in peripheral organs. This is due to the adhesive properties conferred by the P. falciparum Erythrocyte Membrane Protein 1 (PfEMP1) family exported by the parasite to the surface of infected erythrocytes. Expression of the VAR2CSA variant of PfEMP1 leads to pregnancy-associated malaria, which occurs when infected erythrocytes massively sequester in the placenta by binding to low-sulfated Chondroitin Sulfate A (CSA) present in the intervillous spaces. VAR2CSA is a 350 kDa protein that carries six Duffy-Binding Like (DBL) domains, one Cysteine-rich Inter-Domain Regions (CIDR) and several inter-domain regions. In the present paper, we report for the first time the crystal structure at 2.9 Å of a VAR2CSA double domain, DBL3X-DBL4ε, from the FCR3 strain. DBL3X and DBL4ε share a large contact interface formed by residues that are invariant or highly conserved in VAR2CSA variants, which suggests that these two central DBL domains (DBL3X-DBL4ε) contribute significantly to the structuring of the functional VAR2CSA extracellular region. We have also examined the antigenicity of peptides corresponding to exposed loop regions of the DBL4ε structure. PMID:26450557

Property of Fluctuations of Sales Quantities by Product Category in Convenience Stores.

PubMed

Fukunaga, Gaku; Takayasu, Hideki; Takayasu, Misako

2016-01-01

The ability to ascertain the extent of product sale fluctuations for each store and locality is indispensable to inventory management. This study analyzed POS data from 158 convenience stores in Kawasaki City, Kanagawa Prefecture, Japan and found a power scaling law between the mean and standard deviation of product sales quantities for several product categories. For the statistical domains of low sales quantities, the power index was 1/2; for large sales quantities, the power index was 1, so called Taylor's law holds. The value of sales quantities with changing power indixes differed according to product category. We derived a Poissonian compound distribution model taking into account fluctuations in customer numbers to show that the scaling law could be explained theoretically for most of items. We also examined why the scaling law did not hold in some exceptional cases.

The impact of extreme drought on the biofuel feedstock production

NASA Astrophysics Data System (ADS)

hussain, M.; Zeri, M.; Bernacchi, C.

2013-12-01

Miscanthus (Miscanthus x giganteus) and Switchgrass (Panicum virgatum) have been identified as the primary targets for second-generation cellulosic biofuel crops. Prairie managed for biomass is also considered as one of the alternative to conventional biofuel and promised to provide ecosystem services, including carbon sequestration. These perennial grasses possess a number of traits that make them desirable biofuel crops and can be cultivated on marginal lands or interspersed with maize and soybean in the Corn Belt region. The U.S. Corn Belt region is the world's most productive and expansive maize-growing region, approximately 20% of the world's harvested corn hectares are found in 12 Corn Belt states. The introduction of a second generation cellulosic biofuels for biomass production in a landscape dominated by a grain crop (maize) has potential implications on the carbon and water cycles of the region. This issue is further intensified by the uncertainty in the response of the vegetation to the climate change induced drought periods, as was seen during the extreme droughts of 2011 and 2012 in the Midwest. The 2011 and 2012 growing seasons were considered driest since the 1932 dust bowl period; temperatures exceeded 3.0 °C above the 50- year mean and precipitation deficit reached 50 %. The major objective of this study was to evaluate the drought responses (2011 and 2012) of corn and perennial species at large scale, and to determine the seasonability of carbon and water fluxes in the response of controlling factors. We measured net CO2 ecosystem exchange (NEE) and water fluxes of maize-maize-soybean, and perennial species such as miscanthus, switchgrass and mixture of prairie grasses, using eddy covariance in the University of Illinois energy farm at Urbana, IL. The data presented here were for 5 years (2008- 2012). In the first two years, higher NEE in maize led to large CO2 sequestration. NEE however, decreased in dry years, particularly in 2012. On the other hand, miscanthus, switchgrass, and to a lesser extent, prairie showed higher NEE and gross primary production (GPP) - a partitioned NEE component - than maize during 2012. Although miscanthus uses more water relative to maize (consumed 30 % more water), Net Ecosystem Carbon Balance (NECB) results show that it provides the greatest net benefits of sequestering atmospheric CO2 during drought. Our findings highlight the important role of perennial species in sustaining productivity and sequestering CO2 during drought, as compared to maize. We conclude that changing land use from row crops to perennial species will result in more sequestered carbon, even with drought stress, and will be more resilient to prolonged dry periods.

A Functional Model for Management of Large Scale Assessments.

ERIC Educational Resources Information Center

Banta, Trudy W.; And Others

This functional model for managing large-scale program evaluations was developed and validated in connection with the assessment of Tennessee's Nutrition Education and Training Program. Management of such a large-scale assessment requires the development of a structure for the organization; distribution and recovery of large quantities of…

Chemical Waste Management for the Conditionally Exempt Small Quantity Generator

NASA Astrophysics Data System (ADS)

Zimmer, Steven W.

1999-06-01

Management of hazardous chemical wastes generated as a part of the curriculum poses a significant task for the individual responsible for maintaining compliance with all rules and regulations from the Environmental Protection Agency and the Department of Transportation while maintaining the principles of OSHA's Lab Standard and the Hazard Communication Standard. For schools that generate relatively small quantities of waste, an individual can effectively manage the waste program without becoming overly burdened by the EPA regulations required for those generating large quantities of waste, if given the necessary support from the institution.

Uptake and subcellular distributions of cadmium and selenium in transplanted aquatic insect larvae.

PubMed

Rosabal, Maikel; Ponton, Dominic E; Campbell, Peter G C; Hare, Landis

2014-11-04

We transplanted larvae of the phantom midge Chaoborus punctipennis from a lake having lower concentrations of Cd and Se (Lake Dasserat) to a more contaminated lake (Lake Dufault) located near a metal smelter in Rouyn-Noranda, Quebec. Transplanted individuals were held in mesh mesocosms for up to 16 days where they were fed with indigenous contaminated zooplankton. Larval Cd and Se burdens increased over time, and came to equal those measured in indigenous C. punctipennis from contaminated Lake Dufault. Larval Se burdens increased steadily, whereas those of Cd showed an initial lag phase that we explain by a change in the efficiency with which this insect assimilated Cd from its prey. We measured Cd and Se in subcellular fractions and found that larvae sequestered the majority (60%) of the incoming Cd in a detoxified fraction containing metal-binding proteins, whereas a minority of this nonessential metal was in sensitive fractions (20%). In contrast, a much higher proportion of the essential element Se (40%) was apportioned to metabolically active sensitive fractions. Larvae took up equimolar quantities of these elements over the course of the experiment. Likewise, Cd and Se concentrations in wild larvae were equimolar, which suggests that they are exposed to equimolar bioavailable concentrations of these elements in our study lakes.

Rocks Here Sequester Some of Mars Early Atmosphere

NASA Image and Video Library

2015-09-02

This view combines information from two instruments on NASA's Mars Reconnaissance Orbiter to map color-coded composition over the shape of the ground in a small portion of the Nili Fossae plains region of Mars' northern hemisphere. This site is part of the largest known carbonate-rich deposit on Mars. In the color coding used for this map, green indicates a carbonate-rich composition, brown indicates olivine-rich sands, and purple indicates basaltic composition. Carbon dioxide from the atmosphere on early Mars reacted with surface rocks to form carbonate, thinning the atmosphere by sequestering the carbon in the rocks. An analysis of the amount of carbon contained in Nili Fossae plains estimated the total at no more than twice the amount of carbon in the modern atmosphere of Mars, which is mostly carbon dioxide. That is much more than in all other known carbonate on Mars, but far short of enough to explain how Mars could have had a thick enough atmosphere to keep surface water from freezing during a period when rivers were cutting extensive valley networks on the Red Planet. Other possible explanations for the change from an era with rivers to dry modern Mars are being investigated. This image covers an area approximately 1.4 miles (2.3 kilometers) wide. A scale bar indicates 500 meters (1,640 feet). The full extent of the carbonate-containing deposit in the region is at least as large as Delaware and perhaps as large as Arizona. The color coding is from data acquired by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), in observation FRT0000C968 made on Sept. 19, 2008. The base map showing land shapes is from the High Resolution Imaging Science Experiment (HiRISE) camera. It is one product from HiRISE observation ESP_010351_2020, made July 20, 2013. http://photojournal.jpl.nasa.gov/catalog/PIA19817

Phytoremediation: using green plants to clean up contaminate soil, groundwater, and wastewater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Negri, M.C.; Hinchman, R.R.; Gatliff, E.G.

1996-07-01

Phytoremediation, an emerging cleanup technology for contaminated soils, groundwater, and wastewater that is both low-tech and low-cost, is defined as the engineered use of green plants (including grasses, forbs, and woody species) to remove, contain, or render harmless such environmental contaminants as heavy metals, trace elements, organic compounds and radioactive compounds in soil or water. Our research includes a successful field demonstration of a plant bioreactor for processing the salty wastewater from petroleum wells; the demonstration is currently under way at a natural gas well site in Oklahoma, in cooperation with Devon Energy Corporation. A greenhouse experiment on zinc uptakemore » in hybrid poplar (Populus sp.) was initiated in 1995. These experiments are being conducted to confirm and extend field data indicating high levels of zinc (4,200 ppm) in leaves of hybrid poplar growing as a cleanup system at a site with zinc contamination in the root zone of some of the trees. Analyses of soil water from experimental pots that had received several doses of zinc indicated that the zinc was totally sequestered by the plants in about 4 hours during a single pass through the root system. The data also showed concentrations of sequestered metal of >38,000 ppm Zn in the dry root tissue. These levels of sequestered zinc exceed the levels found in either roots or tops of many of the known ``hyperaccumulator`` species. Because the roots sequester most of the contaminant taken up in most plants, a major objective of this program is to determine the feasibility of root harvesting as a method to maximize the removal of contaminants from soils. Available techniques and equipment for harvesting plant roots, including young tree roots, are being evaluated and modified as necessary for use with phytoremediation plants.« less

A Directory of Human Performance Models for System Design (Defence Research Group Panel 8 on the Defence Applications of Human and Bio-Medical Sciences)

DTIC Science & Technology

1992-12-27

quantities, but they are not continuously dependent on these quantities. This pure open-loop programmed-control-like behaviour is called precognitive . Like...and largely accomplished by the precognitive action and then may be completed with compeisatory eor-reducuon operations. 304. A quasilinear or

Variation of organic matter quantity and quality in streams at Critical Zone Observatory watersheds

Treesearch

Matthew P. Miller; Elizabeth W. Boyer; Diane M. McKnight; Michael G. Brown; Rachel S. Gabor; Carolyn Hunsaker; Lidiia Iavorivska; Shreeram Inamdar; Dale W. Johnson; Louis A. Kaplan; Henry Lin; William H. McDowell; Julia N. Perdrial

2016-01-01

The quantity and chemical composition of dissolved organic matter (DOM) in surface waters influence ecosystem processes and anthropogenic use of freshwater. However, despite the importance of understanding spatial and temporal patterns in DOM, measures of DOM quality are not routinely included as part of large-scale ecosystem monitoring programs and variations in...

A cost-effective protocol for the over-expression and purification of fully-functional and more stable Erwinia chrisanthemi ligand-gated ion channel

PubMed Central

Elberson, Benjamin W.; Whisenant, Ty E.; Cortes, D. Marien; Cuello, Luis G.

2017-01-01

The Erwinia chrisanthemi ligand-gated ion channel, ELIC, is considered an excellent structural and functional surrogate for the whole pentameric ligand-gated ion channel family. Despite its simplicity, ELIC is structurally capable of undergoing ligand-dependent activation and a concomitant desensitization process. To determine at the molecular level the structural changes underlying ELIC’s function, it is desirable to produce large quantities of protein. This protein should be properly folded, fully-functional and amenable to structural determinations. In the current paper, we report a completely new protocol for the expression and purification of milligram quantities of fully-functional, more stable and crystallizable ELIC. The use of an autoinduction media and inexpensive detergents during ELIC extraction, in addition to the high-quality and large quantity of the purified channel, are the highlights of this improved biochemical protocol. PMID:28279818

Large-scale purification of 90Sr from nuclear waste materials for production of 90Y, a therapeutic medical radioisotope.

PubMed

Wester, Dennis W; Steele, Richard T; Rinehart, Donald E; DesChane, Jaquetta R; Carson, Katharine J; Rapko, Brian M; Tenforde, Thomas S

2003-07-01

A major limitation on the supply of the short-lived medical isotope 90Y (t1/2 = 64 h) is the available quantity of highly purified 90Sr generator material. A radiochemical production campaign was therefore undertaken to purify 1,500 Ci of 90Sr that had been isolated from fission waste materials. A series of alkaline precipitation steps removed all detectable traces of 137Cs, alpha emitters, and uranium and transuranic elements. Technical obstacles such as the buildup of gas pressure generated upon mixing large quantities of acid with solid 90Sr carbonate were overcome through safety features incorporated into the custom-built equipment used for 90Sr purification. Methods are described for analyzing the chemical and radiochemical purity of the final product and for accurately determining by gravimetry the quantities of 90Sr immobilized on stainless steel filters for future use.

The molecular characteristics of pyrogenic organic materials and their aqueous leachates

NASA Astrophysics Data System (ADS)

Wozniak, A. S.; Hatcher, P.; Mitra, S.; Bostick, K. W.; Zimmerman, A. R.

2016-12-01

Pyrogenic organic matter (Py-OM), or black carbon, is known to impact soil chemistry, pollutant transport, regional and global carbon cycling, and climate. Py-OM is incorporated into soils via atmospheric deposition (e.g., from biomass, fossil fuel combustion) or direct applications by humans (e.g., biochars applied for agricultural production). Due to its presumed refractory and immobile nature, soil Py-OM is thought to be efficiently buried, sequestering atmospheric CO2. However, tracers of dissolved Py-OM (Py-DOM) have been detected in appreciable quantities in riverine, estuarine, and oceanic waters suggesting that Py-OM is more mobile in the environment than expected. The molecular characteristics of Py-OM are likely to be a controlling factor in the quantities and impacts of Py-DOM released to aqueous systems. Yet, little is known about the detailed molecular composition of these materials, let alone how those molecular characteristics vary with combustion conditions or are altered by environmental processes. Here, we examine oak and grass Py-OM (combusted over a range of temperatures), natural Py-OM (chars aged in the environment for variable lengths of time), and their Py-DOM leachates via nuclear magnetic resonance spectroscopy (NMR) and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Multi-CP 13C NMR analyses of Py-OM materials and 1H NMR analyses of corresponding Py-DOM leachates reveal that Py-OM combustion temperature, environmental exposure, and molecular characteristics are reflected in Py-DOM quantities and characteristics. The relative amounts of aromatic C in Py-OM 1) decreases with environmental exposure, the relative oxygen-content in both Py-OM and Py-DOM, and the amount of Py-DOC released per g of Py-OC but 2) is positively correlated with combustion temperature and the relative contributions of acetate and aliphatic hydrogens (CH2) in Py-DOM. Preliminary FTICR-MS analyses show Py-DOM produced from oak at 400 °C to have lost carbohydrate-like compounds found in 250 °C Py-DOM and to contain an abundance of oxygenated aromatic compounds. Oak combusted at 650 °C produces Py-DOM characterized by high H/C, low O/C compounds. The results from this work will improve our understanding of Py-OM transport within and between terrestrial and aqueous systems.

Large scale EMF in current sheets induced by tearing modes

NASA Astrophysics Data System (ADS)

Mizerski, Krzysztof A.

2018-02-01

An extension of the analysis of resistive instabilities of a sheet pinch from a famous work by Furth et al (1963 Phys. Fluids 6 459) is presented here, to study the mean electromotive force (EMF) generated by the developing instability. In a Cartesian configuration and in the presence of a current sheet first the boundary layer technique is used to obtain global, matched asymptotic solutions for the velocity and magnetic field and then the solutions are used to calculate the large-scale EMF in the system. It is reported, that in the bulk the curl of the mean EMF is linear in {{j}}0\\cdot {{B}}0, a simple pseudo-scalar quantity constructed from the large-scale quantities.

Non-symbolic arithmetic in adults and young children.

PubMed

Barth, Hilary; La Mont, Kristen; Lipton, Jennifer; Dehaene, Stanislas; Kanwisher, Nancy; Spelke, Elizabeth

2006-01-01

Five experiments investigated whether adults and preschool children can perform simple arithmetic calculations on non-symbolic numerosities. Previous research has demonstrated that human adults, human infants, and non-human animals can process numerical quantities through approximate representations of their magnitudes. Here we consider whether these non-symbolic numerical representations might serve as a building block of uniquely human, learned mathematics. Both adults and children with no training in arithmetic successfully performed approximate arithmetic on large sets of elements. Success at these tasks did not depend on non-numerical continuous quantities, modality-specific quantity information, the adoption of alternative non-arithmetic strategies, or learned symbolic arithmetic knowledge. Abstract numerical quantity representations therefore are computationally functional and may provide a foundation for formal mathematics.

Property of Fluctuations of Sales Quantities by Product Category in Convenience Stores

PubMed Central

Fukunaga, Gaku; Takayasu, Hideki; Takayasu, Misako

2016-01-01

The ability to ascertain the extent of product sale fluctuations for each store and locality is indispensable to inventory management. This study analyzed POS data from 158 convenience stores in Kawasaki City, Kanagawa Prefecture, Japan and found a power scaling law between the mean and standard deviation of product sales quantities for several product categories. For the statistical domains of low sales quantities, the power index was 1/2; for large sales quantities, the power index was 1, so called Taylor’s law holds. The value of sales quantities with changing power indixes differed according to product category. We derived a Poissonian compound distribution model taking into account fluctuations in customer numbers to show that the scaling law could be explained theoretically for most of items. We also examined why the scaling law did not hold in some exceptional cases. PMID:27310915

Method of detecting leakage from geologic formations used to sequester CO.sub.2

DOEpatents

White, Curt [Pittsburgh, PA; Wells, Arthur [Bridgeville, PA; Diehl, J Rodney [Pittsburgh, PA; Strazisar, Brian [Venetia, PA

2010-04-27

The invention provides methods for the measurement of carbon dioxide leakage from sequestration reservoirs. Tracer moieties are injected along with carbon dioxide into geological formations. Leakage is monitored by gas chromatographic analyses of absorbents. The invention also provides a process for the early leak detection of possible carbon dioxide leakage from sequestration reservoirs by measuring methane (CH.sub.4), ethane (C.sub.2H.sub.6), propane (C.sub.3H.sub.8), and/or radon (Rn) leakage rates from the reservoirs. The invention further provides a method for branding sequestered carbon dioxide using perfluorcarbon tracers (PFTs) to show ownership.

Novel endotoxin-sequestering compounds with terephthalaldehyde-bis-guanylhydrazone scaffolds.

PubMed

Khownium, Kriangsak; Wood, Stewart J; Miller, Kelly A; Balakrishna, Rajalakshmi; Nguyen, Thuan B; Kimbrell, Matthew R; Georg, Gunda I; David, Sunil A

2006-03-01

We have shown that lipopolyamines bind to the lipid A moiety of lipopolysaccharide, a constituent of Gram-negative bacterial membranes, and neutralize its toxicity in animal models of endotoxic shock. In an effort to identify non-polyamine scaffolds with similar endotoxin-recognizing features, we had observed an unusually high frequency of hits containing guanylhydrazone scaffolds in high-throughput screens. We now describe the syntheses and preliminary structure-activity relationships in a homologous series of bis-guanylhydrazone compounds decorated with hydrophobic functionalities. These first-generation compounds bind and neutralize lipopolysaccharide with a potency comparable to that of polymyxin B, a peptide antibiotic known to sequester LPS.

Silicone wristbands as personal passive samplers.

PubMed

O'Connell, Steven G; Kincl, Laurel D; Anderson, Kim A

2014-03-18

Active-sampling approaches are commonly used for personal monitoring, but are limited by energy usage and data that may not represent an individual's exposure or bioavailable concentrations. Current passive techniques often involve extensive preparation, or are developed for only a small number of targeted compounds. In this work, we present a novel application for measuring bioavailable exposure with silicone wristbands as personal passive samplers. Laboratory methodology affecting precleaning, infusion, and extraction were developed from commercially available silicone, and chromatographic background interference was reduced after solvent cleanup with good extraction efficiency (>96%). After finalizing laboratory methods, 49 compounds were sequestered during an ambient deployment which encompassed a diverse set of compounds including polycyclic aromatic hydrocarbons (PAHs), consumer products, personal care products, pesticides, phthalates, and other industrial compounds ranging in log K(ow) from -0.07 (caffeine) to 9.49 (tris(2-ethylhexyl) phosphate). In two hot asphalt occupational settings, silicone personal samplers sequestered 25 PAHs during 8- and 40-h exposures, as well as 2 oxygenated-PAHs (benzofluorenone and fluorenone) suggesting temporal sensitivity over a single work day or week (p < 0.05, power =0.85). Additionally, the amount of PAH sequestered differed between worksites (p < 0.05, power = 0.99), suggesting spatial sensitivity using this novel application.

Classification of CO2 Geologic Storage: Resource and Capacity

USGS Publications Warehouse

Frailey, S.M.; Finley, R.J.

2009-01-01

The use of the term capacity to describe possible geologic storage implies a realistic or likely volume of CO2 to be sequestered. Poor data quantity and quality may lead to very high uncertainty in the storage estimate. Use of the term "storage resource" alleviates the implied certainty of the term "storage capacity". This is especially important to non- scientists (e.g. policy makers) because "capacity" is commonly used to describe the very specific and more certain quantities such as volume of a gas tank or a hotel's overnight guest limit. Resource is a term used in the classification of oil and gas accumulations to infer lesser certainty in the commercial production of oil and gas. Likewise for CO2 sequestration, a suspected porous and permeable zone can be classified as a resource, but capacity can only be estimated after a well is drilled into the formation and a relatively higher degree of economic and regulatory certainty is established. Storage capacity estimates are lower risk or higher certainty compared to storage resource estimates. In the oil and gas industry, prospective resource and contingent resource are used for estimates with less data and certainty. Oil and gas reserves are classified as Proved and Unproved, and by analogy, capacity can be classified similarly. The highest degree of certainty for an oil or gas accumulation is Proved, Developed Producing (PDP) Reserves. For CO2 sequestration this could be Proved Developed Injecting (PDI) Capacity. A geologic sequestration storage classification system is developed by analogy to that used by the oil and gas industry. When a CO2 sequestration industry emerges, storage resource and capacity estimates will be considered a company asset and consequently regulated by the Securities and Exchange Commission. Additionally, storage accounting and auditing protocols will be required to confirm projected storage estimates and assignment of credits from actual injection. An example illustrates the use of these terms and how storage classification changes as new data become available. ?? 2009 Elsevier Ltd. All rights reserved.

Iron Binding at Specific Sites within the Octameric HbpS Protects Streptomycetes from Iron-Mediated Oxidative Stress

PubMed Central

Wedderhoff, Ina; Kursula, Inari; Groves, Matthew R.; Ortiz de Orué Lucana, Darío

2013-01-01

The soil bacterium Streptomyces reticuli secretes the octameric protein HbpS that acts as a sensory component of the redox-signalling pathway HbpS-SenS-SenR. This system modulates a genetic response on iron- and haem-mediated oxidative stress. Moreover, HbpS alone provides this bacterium with a defence mechanism to the presence of high concentrations of iron ions and haem. While the protection against haem has been related to its haem-binding and haem-degrading activity, the interaction with iron has not been studied in detail. In this work, we biochemically analyzed the iron-binding activity of a set of generated HbpS mutant proteins and present evidence showing the involvement of one internal and two exposed D/EXXE motifs in binding of high quantities of ferrous iron, with the internal E78XXE81 displaying the tightest binding. We additionally show that HbpS is able to oxidize ferrous to ferric iron ions. Based on the crystal structure of both the wild-type and the mutant HbpS-D78XXD81, we conclude that the local arrangement of the side chains from the glutamates in E78XXE81 within the octameric assembly is a pre-requisite for interaction with iron. The data obtained led us to propose that the exposed and the internal motif build a highly specific route that is involved in the transport of high quantities of iron ions into the core of the HbpS octamer. Furthermore, physiological studies using Streptomyces transformants secreting either wild-type or HbpS mutant proteins and different redox-cycling compounds led us to conclude that the iron-sequestering activity of HbpS protects these soil bacteria from the hazardous side effects of peroxide- and iron-based oxidative stress. PMID:24013686

Estimation of post-Katrina debris volume: An example from coastal Mississippi: Chapter 3E in Science and the storms-the USGS response to the hurricanes of 2005

USGS Publications Warehouse

Hansen, Mark; Howd, Peter; Sallenger, Asbury; Wright, C. Wayne; Lillycrop, Jeff

2007-01-01

Hurricane Katrina severely impacted coastal Mississippi, creating large quantities of building and vegetation debris. This paper summarizes techniques to estimate vegetation and nonvegetation debris quantities from light detection and ranging (lidar) data and presents debris volume results for Harrison County, Miss.

7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

Code of Federal Regulations, 2014 CFR

2014-01-01

... quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required under... seeds. (b) Seed consigned to a seed cleaning or processing establishment, for cleaning or processing for... pertaining to such seed show that it is “Seed for processing,” or, if the seed is in containers and in...

7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

Code of Federal Regulations, 2012 CFR

2012-01-01

... quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required under... seeds. (b) Seed consigned to a seed cleaning or processing establishment, for cleaning or processing for... pertaining to such seed show that it is “Seed for processing,” or, if the seed is in containers and in...

7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

Code of Federal Regulations, 2011 CFR

2011-01-01

... quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required under... seeds. (b) Seed consigned to a seed cleaning or processing establishment, for cleaning or processing for... pertaining to such seed show that it is “Seed for processing,” or, if the seed is in containers and in...

7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

Code of Federal Regulations, 2010 CFR

2010-01-01

... quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required under... seeds. (b) Seed consigned to a seed cleaning or processing establishment, for cleaning or processing for... pertaining to such seed show that it is “Seed for processing,” or, if the seed is in containers and in...

7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

Code of Federal Regulations, 2013 CFR

2013-01-01

... quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required under... seeds. (b) Seed consigned to a seed cleaning or processing establishment, for cleaning or processing for... pertaining to such seed show that it is “Seed for processing,” or, if the seed is in containers and in...

A Kinetic Study Using Evaporation of Different Types of Hand-Rub Sanitizers

ERIC Educational Resources Information Center

Pinhas, Allan R.

2010-01-01

Alcohol-based hand-rub sanitizers are the types of products that hospital professionals use very often. These sanitizers can be classified into two major groups: those that contain a large quantity of thickener, and thus are a gel, and those that contain a small quantity of thickener, and thus remain a liquid. In an effort to create a laboratory…

Ecosystem carbon stocks of mangroves across broad environmental gradients in West-Central Africa: Global and regional comparisons.

PubMed

Kauffman, J Boone; Bhomia, Rupesh K

2017-01-01

Globally, it is recognized that blue carbon ecosystems, especially mangroves, often sequester large quantities of carbon and are of interest for inclusion in climate change mitigation strategies. While 19% of the world's mangroves are in Africa, they are among the least investigated of all blue carbon ecosystems. We quantified total ecosystem carbon stocks in 33 different mangrove stands along the Atlantic coast of West-Central Africa from Senegal to Southern Gabon spanning large gradients of latitude, soil properties, porewater salinity, and precipitation. Mangrove structure ranged from low and dense stands that were <1m in height and >35,000 trees ha-1 to tall and open stands >40m in height and <100 ha-1. Tremendous variation in ecosystem carbon (C) stocks was measured ranging from 154 to 1,484 Mg C ha-1. The mean total ecosystem carbon stock for all mangroves of West-Central Africa was 799 Mg C ha-1. Soils comprised an average of 86% of the total carbon stock. The greatest carbon stocks were found in the tall mangroves of Liberia and Gabon North with a mean >1,000 Mg C ha-1. The lowest carbon stocks were found in the low mangroves of the semiarid region of Senegal (463 Mg C ha-1) and in mangroves on coarse-textured soils in Gabon South (541 Mg C ha-1). At the scale of the entirety of West-Central Africa, total ecosystem carbon stocks were poorly correlated to aboveground ecosystem carbon pools, precipitation, latitude and soil salinity (r2 = ≤0.07 for all parameters). Based upon a sample of 158 sites from Africa, Asia and Latin America that were sampled in a similar manner to this study, the global mean of carbon stocks for mangroves is 885 Mg C ha-1. The ecosystem carbon stocks of mangroves for West-Central Africa are slightly lower than those of Latin America (940 Mg C ha-1) and Asia (1049 Mg C ha-1) but substantially higher than the default Intergovernmental Panel on Climate Change (IPCC) values for mangroves (511 Mg C ha-1). This study provides an improved estimation of default estimates (Tier 1 values) of mangroves for Asia, Latin America, and West Central Africa.

The origin of volatiles in the Earth's mantle

NASA Astrophysics Data System (ADS)

Hier-Majumder, Saswata; Hirschmann, Marc M.

2017-08-01

The Earth's deep interior contains significant reservoirs of volatiles such as H, C, and N. Due to the incompatible nature of these volatile species, it has been difficult to reconcile their storage in the residual mantle immediately following crystallization of the terrestrial magma ocean (MO). As the magma ocean freezes, it is commonly assumed that very small amounts of melt are retained in the residual mantle, limiting the trapped volatile concentration in the primordial mantle. In this article, we show that inefficient melt drainage out of the freezing front can retain large amounts of volatiles hosted in the trapped melt in the residual mantle while creating a thick early atmosphere. Using a two-phase flow model, we demonstrate that compaction within the moving freezing front is inefficient over time scales characteristic of magma ocean solidification. We employ a scaling relation between the trapped melt fraction, the rate of compaction, and the rate of freezing in our magma ocean evolution model. For cosmochemically plausible fractions of volatiles delivered during the later stages of accretion, our calculations suggest that up to 77% of total H2O and 12% of CO2 could have been trapped in the mantle during magma ocean crystallization. The assumption of a constant trapped melt fraction underestimates the mass of volatiles in the residual mantle by more than an order of magnitude.