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Sample records for diversity enhances remediation

  1. Surfactant-enhanced aquifier remediation

    SciTech Connect

    Fountain, J.C.

    1996-12-31

    Surfactants can be used to rapidly remove NAPL from contaminated aquifers. They are effective for virtually any organic contaminant. Use in LNAPL contaminated sites requires adequate hydraulic conductivity and control of flow using either hydraulic or physical methods. The presence of DNAPL requires consideration of vertical mobility; a competent confining layer (aquitard) is required if additional aquifers are present at greater depths. Surfactant processes, whether based upon mobilization or solubilization, can be effective at mass removal, but cannot be expected to provide resortation to drinking water standards. The fraction of mass removal, and the cost of remediation using surfactants are dependent upon a sites hydrogeology. Both minimization of cost and maximization of NAPL removal requires detailed characterization of sites contaminant distribution and hydrogeology. Assessment of the feasibility of surfactant-enhanced remediation is dependent upon a detailed site characterization.

  2. SIMULATION OF SURFACTANT-ENHANCED AQUIFER REMEDIATION

    EPA Science Inventory

    Surfactant-enhanced aquifer remediation (SEAR) is currently under active investigation as one of the most promising alternatives to conventional pump-and-treat remediation for aquifers contaminated by dense nonaqueous phase organic liquids. An existing three-dimensional finite-di...

  3. SIMULATION OF SURFACTANT-ENHANCED AQUIFER REMEDIATION

    EPA Science Inventory

    Surfactant-enhanced aquifer remediation (SEAR) is currently under active investigation as one of the most promising alternatives to conventional pump-and-treat remediation for aquifers contaminated by dense nonaqueous phase organic liquids. An existing three-dimensional finite-di...

  4. Simulation of surfactant-enhanced aquifer remediation

    NASA Astrophysics Data System (ADS)

    Brown, Chris L.; Pope, Gary A.; Abriola, Linda M.; Sepehrnoori, Kamy

    1994-11-01

    Surfactant-enhanced aquifer remediation (SEAR) is currently under active investigation as one of the most promising alternatives to conventional pump-and-treat remediation for aquifers contaminated by dense nonaqueous phase organic liquids. An existing three-dimensional finite-difference enhanced oil recovery simulator is adapted to model the SEAR process. This simulator incorporates the complex chemistry and multiphase transport behavior of surfactant/water/organic mixtures in permeable media. Model governing equations and parameter requirements are discussed, and simulations are employed to illustrate some important issues potentially affecting SEAR performance at the field scale. Simulations suggest that the total time for remediation could be reduced by more than an order of magnitude over conventional remediation approaches by employing SEAR. The assumptions, approximations, and conditions required to achieve such a favorable result are identified, and the importance of modeling as a quantitative tool for the assessment of SEAR is highlighted.

  5. GROUND WATER REMEDIATION RESEARCH: ENHANCED BIOREMEDIATION AND MONITORED NATURAL ATTENUATION

    EPA Science Inventory

    An overview of ground water remediation research conducted at the Subsurface Protection and Remediation Division is provided. The focus of the overview is on Enhanced Bioremediation and Monitored Natural Attenuation research for the remediation of organic and inorganic contamina...

  6. GROUND WATER REMEDIATION RESEARCH: ENHANCED BIOREMEDIATION AND MONITORED NATURAL ATTENUATION

    EPA Science Inventory

    An overview of ground water remediation research conducted at the Subsurface Protection and Remediation Division is provided. The focus of the overview is on Enhanced Bioremediation and Monitored Natural Attenuation research for the remediation of organic and inorganic contamina...

  7. ENHANCED REMEDIATION DEMONSTRATIONS AT HILL AFB: INTRODUCTION

    EPA Science Inventory

    Nine enhanced aquifer remediation technologies were demonstrated side-by-side at a Hill Air Force Base Chemical Disposal Pit/Fire Training Area site. The demonstrations were performed inside 3 x 5 m cells isolated from the surrounding shallow aquifer by steel piling. The site w...

  8. ENHANCED REMEDIATION DEMONSTRATIONS AT HILL AFB: INTRODUCTION

    EPA Science Inventory

    Nine enhanced aquifer remediation technologies were demonstrated side-by-side at a Hill Air Force Base Chemical Disposal Pit/Fire Training Area site. The demonstrations were performed inside 3 x 5 m cells isolated from the surrounding shallow aquifer by steel piling. The site w...

  9. Acoustically enhanced remediation, Phase 2: Technology scaling

    SciTech Connect

    Iovenitti, J.L.; Hill, D.G.; Rynne, T.M.; Spadaro, J.F.; Hutchinson, W.; Illangasakere, T.

    1996-12-31

    Weiss Associates is conducting the following three phase program investigating the in-situ application of acoustically enhanced remediation (AER) of contaminated unconsolidated soil and ground water under both saturated and unsaturated conditions: Phase I-- laboratory scale parametric investigation; Phase II--technology Scaling; and Phase III--large scale field tests. AER addresses the need for NAPL (either lighter or denser than water: LNAPL or DNAPL, respectively) in high and low permeability sediments, and the remediation of other types of subsurface contaminants (e.g., metals, radionuclides) in low permeability soils. This program has been placed in the U.S. Department of Energy`s (DOE`s) DNAPL product. Phase I indicated that AER could be used to effectively remediate NAPL in high permeability soil, and that removal of NAPL from low permeability soil could be increased since the water flux through these soils was significantly increased. Phase II, Technology Scaling, the subject of this paper, focused on (1) evaluating the characteristics of an AER field deployment system, (2) developing DNAPL flow and transport performance data under acoustic excitation, (3) predicting the effect of acoustic remediation in three-dimensional unconsolidated hydrogeologic conditions, (4) conducting an engineering analysis of acoustical sources, and (5) identifying candidate field site(s) for large-scale field testing of the technology.

  10. Simulation of surfactant-enhanced aquifer remediation

    SciTech Connect

    Brown, C.L.; Pope, G.A.; Sepehrnoori, K.; Abriola, L.M.

    1994-11-01

    This paper demonstrates that surfactant-enhanced aquifer remediation (SEAR) can be modeled in two and three dimensions using a finite-difference simulator and incorporating realistic heterogenieties in aquifer properties and complex surfactant chemistry based upon a multicomponent, multiphase compositional description of the experimental chemistry. The presented simulations provide significant new insights into the SEAR process. The effectiveness of SEAR is sensitive to many variables including the initial infiltration rate of DNAPL, the natural hydraulic gradient, well locations, well pumping and injection rates, aquifer heterogenieties, and properties such as cappillary pressure, relative permeability, and surfactant chemistry. In this paper a comprehensive model for SEAR is presented and applied to explore the potential performance of this technology on an aquifer scale. This study illustrates the value of modeling in SEAR design, how this modeling can be accomplished, what information is necessary, and what kinds of results modeling can be expected to produce.

  11. Enhanced Remedial Amendment Delivery to Low Permeability Zones in Subsurface Remediation

    NASA Astrophysics Data System (ADS)

    Zhong, L.; Oostrom, M.; Wietsma, T.; Cantrell, K.

    2006-12-01

    Heterogeneity is often encountered in subsurface contamination characterization and remediation. Low- permeability zones are typically bypassed when remedial fluids are injected into subsurface heterogeneous aquifer systems. Therefore, contaminants in the bypassed areas may not be contacted by the amendments in the remedial fluid, which may significantly prolong the remediation operations. An experimental and numerical study has been completed to demonstrate the capability of Mobility-Controlled Flood (MCF) technology to enhance the remedial amendments delivery to the lower permeability zones. This technology, developed in the petroleum industry, has been demonstrated to significantly improve the sweeping efficiency in heterogeneous petroleum reservoirs. Xanthan gum, a water-soluble bio-polymer, was used to modify the viscosity of the amendment-added remedial solutions. Surfactants and (poly)phosphate were the remedial amendments for non-aqueous phase liquid (NAPL) and uranium remediation, respectively. Batch and column experiments were conducted to select the polymer-amendment solutions. The enhanced delivery of the remedial solutions was demonstrated in two- dimensional (2-D) flow cell experiments, packed with heterogeneous systems, as a function of polymer concentration and injection flow rate. The STOMP (Subsurface Transport Over Multiple Phases) simulator was modified to include polymer-induced shear thinning effects. The results clearly show that the MCF technology is capable of enhancing the delivery of remedial amendments to subsurface lower permeability zones. The enhanced delivery significantly improved the NAPL removal from these zones and the sweeping efficiency on a heterogeneous system was remarkably increased when a polymer fluid was applied. MCF technology is also able to stabilize the fluid displacing front when there is a density difference between the fluids. The modified STOMP simulator was able to predict the experimental observed fluid

  12. Electrokinetic soil remediation: Advances and process enhancement

    SciTech Connect

    Hodko, D.; Franaszczuk, K.; Rogers, T.D.

    1995-12-31

    Electrokinetic remediation is an in situ emerging technology that offers potential cost and process benefits for contaminated soil treatment. The innovative approach under development at Lynntech, Inc. is based on the application of nonhomogeneous pulsed DC or AC electric fields with the objective to maximize rates of contaminant removal. The process combines several DC and AC electrokinetic phenomena occurring in soil when pulsed electric fields are applied across the electrodes positioned in the soil and utilize them for an enhanced contaminant removal from soil. Removal of contaminants is achieved by: (i) electroosmotic pore fluid flow; (ii) electromigration of anionic and cationic contaminants towards electrode wells, where they can be removed by electrodeposition, and, (iii) dielectrophoretically induced pore fluid flow and migration of charged and noncharged contaminants through the soil. Successful combination of DC and AC electrokinetic phenomena in soil presents a basis for an enhanced electrokinetic process for removal of both charged and noncharged contaminants from soil. The process utilizes an electrochemically produced acid in the anode well which propagates through the soil and solubilizes heavy metal ions in the pore fluid. An appropriate leachant. which depends on the type of soil and heavy metal contaminant, is electrokinetically delivered and distributed in soil to further enhance solubilization and mobilization of heavy metal contaminants through the soil. It can be efficiently combined with other existing in situ contaminated soil treatment processes, e.g. bioremediation, soil extraction and soil washing. A field scale study is initiated in 1995 and preliminary results will be described.

  13. Chemical Enhancements to Pump-and-Treat Remediation

    EPA Pesticide Factsheets

    The intent of this document is to explore the use of chemical enhancement to improve groundwater remediation efficiencies using pump-and-treat technologies, and point out arenas of contamination where such techniques are not practical.

  14. SURFACTANT ENHANCED AQUIFER REMEDIATION WITH SURFACTANT REGENERATION/REUSE

    EPA Science Inventory

    A demonstration of surfactant-enhanced aquifer remediation was conducted during the spring of 1999 at Marine Corps Base, Camp LeJeune, NC. A PCE-DNAPL zone was identified and delineated by extensive soil sampling in 1997, and was further characteized by a partitioning interwell t...

  15. DEMONSTRATION BULLETIN STEAM ENHANCED REMEDIATION STEAM TECH ENVIRONMENTAL SERVICES, INC.

    EPA Science Inventory

    Steam Enhanced Remediation is a process in which steam is injected into the subsurface to recover volatile and semivolatile organic contaminants. It has been applied successfully to recover contaminants from soil and aquifers and at a fractured granite site. This SITE demonstra...

  16. DEMONSTRATION BULLETIN STEAM ENHANCED REMEDIATION STEAM TECH ENVIRONMENTAL SERVICES, INC.

    EPA Science Inventory

    Steam Enhanced Remediation is a process in which steam is injected into the subsurface to recover volatile and semivolatile organic contaminants. It has been applied successfully to recover contaminants from soil and aquifers and at a fractured granite site. This SITE demonstra...

  17. Decontamination formulation with additive for enhanced mold remediation

    DOEpatents

    Tucker, Mark D.; Irvine, Kevin; Berger, Paul; Comstock, Robert

    2010-02-16

    Decontamination formulations with an additive for enhancing mold remediation. The formulations include a solubilizing agent (e.g., a cationic surfactant), a reactive compound (e.g., hydrogen peroxide), a carbonate or bicarbonate salt, a water-soluble bleaching activator (e.g., propylene glycol diacetate or glycerol diacetate), a mold remediation enhancer containing Fe or Mn, and water. The concentration of Fe.sup.2+ or Mn.sup.2+ ions in the aqueous mixture is in the range of about 0.0001% to about 0.001%. The enhanced formulations can be delivered, for example, as a foam, spray, liquid, fog, mist, or aerosol for neutralization of chemical compounds, and for killing certain biological compounds or agents and mold spores, on contaminated surfaces and materials.

  18. Microemulsion-enhanced remediation of soils contaminated with organochlorine pesticides.

    PubMed

    Zhang, Yanlin; Wong, Jonathan W C; Zhao, Zhenyong; Selvam, Ammaiyappan

    2011-12-01

    Soil contaminated by organic pollutants, especially chlorinated aromatic compounds such as DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane), is an environmental concern because of the strong sorption of organochlorine pesticide onto the soil matrix and persistence in the environment. The remediation of organochlorine pesticide contaminated soils through microemulsion is an innovative technology to expedite this process. The remediation efficiency was evaluated by batch experiments through studying the desorption of DDT and hexachlorocyclohexane (y-HCH) and sorption of microemulsion composed of Triton X-100, 1-pentanol and linseed oil in the soil-surfactant-water suspension system. The reduction of desorption efficiency caused by the sorption loss of microemulsion components onto the soil could be corrected by the appropriate adjustment of C/S (Cosurfactant/Surfactant) and O/S (Oil/Surfactant) ratio. The C/S and O/S ratios of 1:2 and 3:20 were suitable to desorb DDT and gamma-HCH from the studied soils because of the lower sorption of Triton X-100 onto the soil. Inorganic salts added in microemulsion increased the pesticides desorption efficiency of pesticides and calcium chloride has a stronger ability to enhance the desorption of DDT than sodium chloride. From the remediation perspective, the balance of surfactant or cosurfactant sorbed to soil and desorption efficiency should be taken into consideration to enhance the remediation of soils contaminated by organochlorine pesticides.

  19. Sustainable Remediation for Enhanced NAPL Recovery from Groundwater

    NASA Astrophysics Data System (ADS)

    Javaher, M.

    2012-12-01

    Sustainable remediation relates to the achievement of balance between environmental, social, and economic elements throughout the remedial lifecycle. A significant contributor to this balance is the use of green and sustainable technologies which minimize environmental impacts, while maximizing social and economic benefits of remedial implementation. To this end, a patented mobile vapor energy generation (VEG) technology has been developed targeting variable applications, including onsite soil remediation for unrestricted reuse and enhanced non-aqueous phase liquid (NAPL) recover at the water table. At the core of the mobile VEG technology is a compact, high efficiency vapor generator, which utilizes recycled water and propane within an entirely enclosed system to generate steam as high as 1100°F. Operating within a fully enclosed system and capturing all heat that is generated within this portable system, the VEG technology eliminates all emissions to the atmosphere and yields an undetected carbon footprint with resulting carbon dioxide concentrations that are below ambient levels. Introduction of the steam to the subsurface via existing wells results in a desired change in the NAPL viscosity and the interfacial tension at the soil, water, NAPL interface; in turn, this results in mobilization and capture of the otherwise trapped, weathered NAPL. Approved by the California Air Resources Control Board (and underlying Air Quality Management Districts) and applied in California's San Joaquin Valley, in-well heating of NAPLs trapped at the water table using the VEG technology has proven as effective as electrical resistivity heating (ERH) in changing the viscosity of and mobilizing NAPLs in groundwater in support of recovery, but has achieved these results while minimizing the remedial carbon footprint by 90%, reducing energy use by 99%, and reducing remedial costs by more than 95%. NAPL recovery using VEG has also allowed for completion of source removal historically

  20. Cost studies of thermally enhanced in situ soil remediation technologies

    SciTech Connect

    Bremser, J.; Booth, S.R.

    1996-05-01

    This report describes five thermally enhanced technologies that may be used to remediate contaminated soil and water resources. The standard methods of treating these contaminated areas are Soil Vapor Extraction (SVE), Excavate & Treat (E&T), and Pump & Treat (P&T). Depending on the conditions at a given site, one or more of these conventional alternatives may be employed; however, several new thermally enhanced technologies for soil decontamination are emerging. These technologies are still in demonstration programs which generally are showing great success at achieving the expected remediation results. The cost savings reported in this work assume that the technologies will ultimately perform as anticipated by their developers in a normal environmental restoration work environment. The five technologies analyzed in this report are Low Frequency Heating (LF or Ohmic, both 3 and 6 phase AC), Dynamic Underground Stripping (DUS), Radio Frequency Heating (RF), Radio Frequency Heating using Dipole Antennae (RFD), and Thermally Enhanced Vapor Extraction System (TEVES). In all of these technologies the introduction of heat to the formation raises vapor pressures accelerating contaminant evaporation rates and increases soil permeability raising diffusion rates of contaminants. The physical process enhancements resulting from temperature elevations permit a greater percentage of volatile organic compound (VOC) or semi- volatile organic compound (SVOC) contaminants to be driven out of the soils for treatment or capture in a much shorter time period. This report presents the results of cost-comparative studies between these new thermally enhanced technologies and the conventional technologies, as applied to five specific scenarios.

  1. Acoustically enhanced remediation of contaminated soil and ground water

    SciTech Connect

    Iovenitti, J.L.; Rynne, T.M.; Spencer, J.W. Jr.

    1994-12-31

    This program systematically evaluates the use of acoustic excitation fields (AEFs) to increase fluid and contaminant extraction rates from a wide range of unconsolidated soils. Successful completion of this program will result in a commercially-viable, advanced in-situ remediation technology that will significantly reduce clean-up times and costs. This technology should have wide applicability since it is envisioned to augment existing remediation technologies, such as traditional pump and treat and soil vapor extraction, not replace them. The overall program has three phases: Phase 1--laboratory scale parametric investigation; Phase 2--technology scaling study; Phase 3--field demonstration. Phase 1 of the program, corresponding to this period of performance, has as its primary objectives to provide a laboratory-scale proof of concept, and to fully characterize the effects of AEFs on fluid and contaminant extraction rates in a wide variety of soil types. The laboratory measurements of the soil transport properties and process parameters will be used in a computer model of the enhanced remediation process. A Technology Merit and Trade Study will complete Phase 1.

  2. Enhancement of in situ microbial remediation of aquifers

    DOEpatents

    Fredrickson, James K.; Brockman, Fred J.; Streile, Gary P.; Cary, John W.; McBride, John F.

    1993-01-01

    Methods are provided for remediating subsurface areas contaminated by toxic organic compounds. An innocuous oil, such as vegetable oil, mineral oil, or other immiscible organic liquid, is introduced into the contaminated area and permitted to move therethrough. The oil concentrates or strips the organic contaminants, such that the concentration of the contaminants is reduced and such contaminants are available to be either pumped out of the subsurface area or metabolized by microorganisms. Microorganisms may be introduced into the contaminated area to effect bioremediation of the contamination. The methods may be adapted to deliver microorganisms, enzymes, nutrients and electron donors to subsurface zones contaminated by nitrate in order to stimulate or enhance denitrification.

  3. [Anolyte enhanced electrokinetic remediation of fluorine-contaminated soils].

    PubMed

    Zhu, Shu-Fa; Yan, Chun-Li; Dong, Tie-You; Tang, Hong-Yan

    2009-07-15

    An experimental study was carried out in order to determine the characteristics of migration and its influencing factor of soil fluorine in the electrokinetic process under different applied voltage and concentration of anolyte. The feasibility of anolyte enhanced on electrokinetic remediation of fluorine-contaminated soil was analyzed. The results show that when deionized water is used as anolyte with the 1.0 V/cm voltage gradient, the cumulative mass of fluorine in catholyte and anolyte are 8.2 mg and 47.7 mg respectively and the removal rate of fluorine is only 8.8%. Anolyte enhanced electrokinetic process can promote effectively the migration of fluoride in soil. When 0.02 mol/L NaOH solutionis employed as the anolyte, the removal rates are 25.9%, 31.2% and 47.3% with 1.0, 1.5 and 2.0 V/cm voltage gradient respectively. As the concentration of anolyte increased to 0.1 mol/L, the removal rates are 55.4%, 61.1% and 73.0%. The electromigration is the main transport mechanism and the electroosmotic flow has an effect on the migration of fluorine in soil. The voltage gradient and the concentration of anolyte are the main factors influencing the removal rate of fluorine in soil. Appropriate anolyte enhanced electrokinetic method can be applied to remediate fluorine from contaminated soil.

  4. Surfactant-enhanced remediation of organic contaminated soil and water.

    PubMed

    Paria, Santanu

    2008-04-21

    Surfactant based remediation technologies for organic contaminated soil and water (groundwater or surface water) is of increasing importance recently. Surfactants are used to dramatically expedite the process, which in turn, may reduce the treatment time of a site compared to use of water alone. In fact, among the various available remediation technologies for organic contaminated sites, surfactant based process is one of the most innovative technologies. To enhance the application of surfactant based technologies for remediation of organic contaminated sites, it is very important to have a better understanding of the mechanisms involved in this process. This paper will provide an overview of the recent developments in the area of surfactant enhanced soil and groundwater remediation processes, focusing on (i) surfactant adsorption on soil, (ii) micellar solubilization of organic hydrocarbons, (iii) supersolubilization, (iv) density modified displacement, (v) degradation of organic hydrocarbon in presence surfactants, (vi) partitioning of surfactants onto soil and liquid organic phase, (vii) partitioning of contaminants onto soil, and (viii) removal of organics from soil in presence of surfactants. Surfactant adsorption on soil and/or sediment is an important step in this process as it results in surfactant loss reduced the availability of the surfactants for solubilization. At the same time, adsorbed surfactants will retained in the soil matrix, and may create other environmental problem. The biosurfactants are become promising in this application due to their environmentally friendly nature, nontoxic, low adsorption on to soil, and good solubilization efficiency. Effects of different parameters like the effect of electrolyte, pH, soil mineral and organic content, soil composition etc. on surfactant adsorption are discussed here. Micellar solubilization is also an important step for removal of organic contaminants from the soil matrix, especially for low aqueous

  5. Hydraulic characterization for steam enhanced remediation conducted in fractured rock.

    PubMed

    Stephenson, Kyle M; Novakowski, Kent; Davis, Eva; Heron, Gorm

    2006-01-10

    To explore the viability of Steam Enhanced Remediation (SER) in fractured rock a small-scale steam injection and water/vapour extraction pilot study was conducted at the former Loring Air Force Base in northern Maine, USA. A detailed well testing program was undertaken to assist in the design of the injection and extraction well array, and to assess the possibility of off-site heat and contaminant migration. A structurally complex limestone having low matrix porosity and a sparse distribution of fractures underlies the study site. To characterize the groundwater and steam flow pathways, single-well slug tests and more than 100 pulse interference tests were conducted. The results of the well testing indicate that the study site is dominated by steeply dipping bedding plane fractures that are interconnected only between some wells in the injection/extraction array. The SER system was designed to take advantage of interconnected fractures located at depth in the eastern end of the site. An array of 29 wells located in an area of 60 by 40 m was used for steam injection and water/vapour extraction. The migration of heat was monitored in several wells using thermistor arrays having a 1.5 m vertical spacing. Temperature measurements obtained during and after the 3 month steam injection period showed that heat migration generally occurred along those fracture features identified by the pulse interference testing. Based on these results, it is concluded that the pulse interference tests were valuable in assisting with the design of the injection/extraction well geometry and in predicting the migration pathways of the hot water associated with the steam injection. The pulse interference test method should also prove useful in support of any other remedial method dependant on the fracture network for delivery of remedial fluid or extraction of contaminants.

  6. Multi objective optimization of the setup of a surfactant-enhanced DNAPL remediation.

    PubMed

    Schaerlaekens, Jan; Carmeliet, Jan; Feyen, Jan

    2005-04-01

    Surfactant-enhanced aquifer remediation (SEAR) is widely considered a promising technique to remediate dense nonaqueous phase liquid (DNAPL) contaminations in-situ. The costs of a SEAR remediation are important and depend mostly on the setup of the remediation. Costs can be associated with the installation of injection and extraction wells, the required time of the remediation (and thus labor costs, lease of installations, and energy), the extracted water volume (the purification of the extracted water), and the injected surfactant amount. A cost-effective design of the remediation setup allows an optimal use of resources. In this work, a SEAR remediation was simulated for a hypothetical typical DNAPL contamination. A constrained multi-objective optimization of the model was applied to obtain a Pareto set of optimal remediation strategies with different weights for the two objectives of the remediation: (i) the maximal removal of DNAPL mass (ii) with a minimal total cost. A relatively sharp Pareto front was found, showing a considerable tradeoff between DNAPL removal and total remediation costs. These Pareto curves can help decision makers select an optimal remediation strategy in terms of cost and remediation efficiency depending on external constraints such as the available budget and obligatory remediation goals.

  7. Enhancement of in situ microbial remediation of aquifers

    DOEpatents

    Fredrickson, J.K.; Brockman, F.J.; Streile, G.P.; Cary, J.W.; McBride, J.F.

    1993-11-30

    Methods are provided for remediating subsurface areas contaminated by toxic organic compounds. An innocuous oil, such as vegetable oil, mineral oil, or other immiscible organic liquid, is introduced into the contaminated area and permitted to move therethrough. The oil concentrates or strips the organic contaminants, such that the concentration of the contaminants is reduced and such contaminants are available to be either pumped out of the subsurface area or metabolized by microorganisms. Microorganisms may be introduced into the contaminated area to effect bioremediation of the contamination. The methods may be adapted to deliver microorganisms, enzymes, nutrients and electron donors to subsurface zones contaminated by nitrate in order to stimulate or enhance denitrification. 4 figures.

  8. Gas Dynamics during Thermal Remediation: Visualization, Quantification and Enhancement

    NASA Astrophysics Data System (ADS)

    Mumford, K. G.; Hegele, P. R.

    2014-12-01

    In situ thermal treatment (ISTT) technologies, such as electrical resistance heating (ERH) and thermal conductive heating (TCH), rely on the in situ production of a gas phase composed of steam and vaporized volatile organic compounds (VOCs). This gas phase must be captured, extracted, and processed in an aboveground treatment system to meet remediation objectives. When used to treat volatile non-aqueous phase liquids (NAPLs), gases can be created at temperatures below the boiling points of both the groundwater and the NAPL, in a process commonly referred to as co-boiling, and vaporized VOCs can condense if gases are transported to colder regions or are not captured before thermal treatment has stopped. As such, an understanding of gas formation, connection, and flow is important for the design and operation of ISTT technologies. A recent series of laboratory experiments focused on the visualization and quantification of gas dynamics during water boiling and NAPL-water co-boiling, and the investigation of potential NAPL redistribution. Experiments were conducted in a sand-packed glass-walled chamber (40 cm tall × 20 cm wide × 1 cm thick) heated by electrical resistance. Temperatures and electric currents were measured, and digital images were captured throughout the experiments to quantify gas saturations using light transmission techniques. Additional experiments also investigated the exsolution of dissolved gas as a technique to enhance gas production at lower temperatures. Results showed the development of disconnected and connected gas flow regimes, with disconnected flow occurring at early times and during co-boiling. Results also showed the potential for NAPL redistribution due to displacement by gas formed within pools, and due to condensation in colder regions. These results highlight the need to carefully consider gases in the design of ISTT heating and gas extraction systems to ensure remediation performance.

  9. A multi-objective optimization framework for surfactant-enhanced remediation of DNAPL contaminations

    NASA Astrophysics Data System (ADS)

    Schaerlaekens, Jan; Mertens, Jan; Van Linden, Jan; Vermeiren, Gert; Carmeliet, Jan; Feyen, Jan

    2006-08-01

    The occurrence of Dense Non-Aqueous Phase Liquid (DNAPL) contaminations in the subsurface is a threat for drinkwater resources in the western world. Surfactant-Enhanced Aquifer Remediation (SEAR) is widely considered as one of the most promising techniques to remediate DNAPL contaminations in-situ, be it with considerable additional costs compared to classical pump-and-treat remediations. A cost-effective design of the remediation set-up is therefore essential. In this work, a pilot SEAR test is executed at a DNAPL contaminated site in Belgium in order to collect data for the calibration of a multi-phase multi-component model. The calibrated model is used to assess a series of scenario-analyses for the full-scale remediation of the site. The remediation variables that were varied were the injection and extraction rate, the injection and extraction duration, and the surfactant injection concentrations. A constrained multi-objective optimization of the model was applied to obtain a Pareto set of optimal remediation strategies with different weights for the two objectives of the remediation: (i) the maximal removal of DNAPL and (ii) a total minimal cost. These Pareto curves can help decision makers to select an optimal remediation strategy in terms of cost and remediation efficiency. The Pareto front shows a considerable trade-off between the total remediation cost and the removed DNAPL mass.

  10. Enhancing the diversity of the pediatrician workforce.

    PubMed

    Friedman, Aaron L

    2007-04-01

    This policy statement describes the key issues related to diversity within the pediatrician and health care workforce to identify barriers to enhancing diversity and offer policy recommendations to overcome these barriers in the future. The statement addresses topics such as health disparities, affirmative action, recent policy developments and reports on workforce diversity, and research on patient and provider diversity. It also broadens the discussion of diversity beyond the traditional realms of race and ethnicity to include cultural attributes that may have an effect on the quality of health care. Although workforce diversity is related to the provision of culturally effective pediatric care, it is a discrete issue that merits separate discussion and policy formulation. At the heart of this policy-driven action are multiorganizational and multispecialty collaborations designed to address substantive educational, financial, organizational, and other barriers to improved workforce diversity.

  11. Sand amendment enhances bioelectrochemical remediation of petroleum hydrocarbon contaminated soil.

    PubMed

    Li, Xiaojing; Wang, Xin; Ren, Zhiyong Jason; Zhang, Yueyong; Li, Nan; Zhou, Qixing

    2015-12-01

    Bioelectrochemical system is an emerging technology for the remediation of soils contaminated by petroleum hydrocarbons. However, performance of such systems can be limited by the inefficient mass transport in soil. Here we report a new method of sand amendment, which significantly increases both oxygen and proton transports, resulting to increased soil porosity (from 44.5% to 51.3%), decreased Ohmic resistance (by 46%), and increased charge output (from 2.5 to 3.5Cg(-1)soil). The degradation rates of petroleum hydrocarbons increased by up to 268% in 135d. The degradation of n-alkanes and polycyclic aromatic hydrocarbons with high molecular weight was accelerated, and denaturing gradient gel electrophoresis showed that the microbial community close to the air-cathode was substantially stimulated by the induced current, especially the hydrocarbon degrading bacteria Alcanivorax. The bioelectrochemical stimulation imposed a selective pressure on the microbial community of anodes, including that far from the cathode. These results suggested that sand amendment can be an effective approach for soil conditioning that will enhances the bioelectrochemical removal of hydrocarbons in contaminated soils. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. The Use of Enhanced Bioremediation at the Savannah River Site to Remediate Pesticides and PCBs

    SciTech Connect

    Beul, R.

    2003-09-30

    Enhanced bioremediation is quickly developing into an economical and viable technology for the remediation of contaminated soils. Until recently, chlorinated organic compounds have proven difficult to bioremediate. This article reviews the ongoing remediation occurring at the Chemicals, Metals, and Pesticides (CMP) Pits using windrow turners to facilitate microbial degradation of certain pesticides and PCBs.

  13. From "Remedial English" to "English Enhancement" (So, What Else Is New?).

    ERIC Educational Resources Information Center

    Allison, Desmond

    1992-01-01

    The case against a "remedial" view of English as a Second Language (ESL) is presented, and an alternative approach is offered: an "enhancement" account of programs that aim to improve students' command of English in the course of an English-medium college or university education. The transition from "remedial" to…

  14. Enhanced Remedial Amendment Delivery through Fluid Viscosity Modifications: Experiments and numerical simulations

    SciTech Connect

    Zhong, Lirong; Oostrom, Martinus; Wietsma, Thomas W.; Covert, Matthew A.

    2008-07-29

    Abstract Heterogeneity is often encountered in subsurface contamination characterization and remediation. Low-permeability zones are typically bypassed when remedial fluids are injected into subsurface heterogeneous aquifer systems. Therefore, contaminants in the bypassed areas may not be contacted by the amendments in the remedial fluid, which may significantly prolong the remediation operations. Laboratory experiments and numerical studies have been conducted to develop the Mobility-Controlled Flood (MCF) technology for subsurface remediation and to demonstrate the capability of this technology in enhancing the remedial amendments delivery to the lower permeability zones in heterogeneous systems. Xanthan gum, a bio-polymer, was used to modify the viscosity of the amendment-containing remedial solutions. Sodium mono-phosphate and surfactant were the remedial amendment used in this work. The enhanced delivery of the amendments was demonstrated in two-dimensional (2-D) flow cell experiments, packed with heterogeneous systems. The impact of polymer concentration, fluid injection rate, and permeability contract in the heterogeneous systems has been studied. The Subsurface Transport over Multiple Phases (STOMP) simulator was modified to include polymer-induced shear thinning effects. Shear rates of polymer solutions were computed from pore-water velocities using a relationship proposed in the literature. Viscosity data were subsequently obtained from empirical viscosity-shear rate relationships derived from laboratory data. The experimental and simulation results clearly show that the MCF technology is capable of enhancing the delivery of remedial amendments to subsurface lower permeability zones. The enhanced delivery significantly improved the NAPL removal from these zones and the sweeping efficiency on a heterogeneous system was remarkably increased when a polymer fluid was applied. MCF technology is also able to stabilize the fluid displacing front when there is a

  15. Surfactant enhanced remediation of an alluvial aquifer contaminated with DNAPL

    SciTech Connect

    Londergan, J.T.; Meinardus, H.W.; Pope, G.A.; Brown, C.L.

    1997-12-31

    During 1996, a successful demonstration of surfactant-enhanced-aquifer-remediation (SEAR) and the use of partitioning interwell tracer tests (PITTs) was conducted beneath the former waste disposal trenches at Operable Unit 2 at Hill AFB, Utah. The trenches had received large volumes of chlorinated solvents from degreasing operations. The solvents drained downward, pooling in an alluvial sand aquifer confined in a buried paleochannel eroded into thick clay deposits. The hydraulic conductivity of the alluvium is in the range of 10{sup -3} to 10{sup -2} cm/sec. The well array installed for the demonstration consisted of a line of three injection wells, a line of three extraction wells, a central observation well, and a single hydraulic control well. The distance between injectors and extractors was 20 feet; the distance between individual injectors and extractors in line was 10 feet. The water table was 25 feet below ground surface with a saturated zone approximately 19 feet thick. There was a 4 foot thick zone of DNAPL 42-46 feet below ground surface. The injectors and extractors were completed in this DNAPL zone. The demonstration was conducted in two phases. The first of these consisted of an initial partitioning interwell tracer test (PITT) followed by a pilot scale surfactant flood. The PITT indicated that a total of approximately 346 gallons of DNAPL was present in, the demonstration area. The pilot scale surfactant flood demonstrated the efficacy of the surfactant, showed there was no degradation of hydraulic conductivity due to the introduction of a surfactant solution, and demonstrated that the effluent could be efficiently treated by the on-site steam stripper. Approximately 185 gallons of DNAPL were removed from the aquifer by the pilot scale surfactant flood. The second phase consisted of a pre-flood PITT, a line drive surfactant flood, and a post-flood PITT.

  16. Environmental Footprint Analysis of Steam Enhanced Extraction Remedy: Former Williams Air Force Base, Site ST012 Mesa, AZ

    EPA Pesticide Factsheets

    This green remediation (GR) study quantifies environmental footprint for an In-Situ Thermal Treatment (ISTT) remedy using Steam Enhanced Extraction (SEE) for Site ST012 located on the Former Williams Air Force Base (AFB) in Mesa, Arizona.

  17. Integrating Diverse Datasets Improves Developmental Enhancer Prediction

    PubMed Central

    Erwin, Genevieve D.; Oksenberg, Nir; Truty, Rebecca M.; Kostka, Dennis; Murphy, Karl K.; Ahituv, Nadav; Pollard, Katherine S.; Capra, John A.

    2014-01-01

    Gene-regulatory enhancers have been identified using various approaches, including evolutionary conservation, regulatory protein binding, chromatin modifications, and DNA sequence motifs. To integrate these different approaches, we developed EnhancerFinder, a two-step method for distinguishing developmental enhancers from the genomic background and then predicting their tissue specificity. EnhancerFinder uses a multiple kernel learning approach to integrate DNA sequence motifs, evolutionary patterns, and diverse functional genomics datasets from a variety of cell types. In contrast with prediction approaches that define enhancers based on histone marks or p300 sites from a single cell line, we trained EnhancerFinder on hundreds of experimentally verified human developmental enhancers from the VISTA Enhancer Browser. We comprehensively evaluated EnhancerFinder using cross validation and found that our integrative method improves the identification of enhancers over approaches that consider a single type of data, such as sequence motifs, evolutionary conservation, or the binding of enhancer-associated proteins. We find that VISTA enhancers active in embryonic heart are easier to identify than enhancers active in several other embryonic tissues, likely due to their uniquely high GC content. We applied EnhancerFinder to the entire human genome and predicted 84,301 developmental enhancers and their tissue specificity. These predictions provide specific functional annotations for large amounts of human non-coding DNA, and are significantly enriched near genes with annotated roles in their predicted tissues and lead SNPs from genome-wide association studies. We demonstrate the utility of EnhancerFinder predictions through in vivo validation of novel embryonic gene regulatory enhancers from three developmental transcription factor loci. Our genome-wide developmental enhancer predictions are freely available as a UCSC Genome Browser track, which we hope will enable

  18. Integrating diverse datasets improves developmental enhancer prediction.

    PubMed

    Erwin, Genevieve D; Oksenberg, Nir; Truty, Rebecca M; Kostka, Dennis; Murphy, Karl K; Ahituv, Nadav; Pollard, Katherine S; Capra, John A

    2014-06-01

    Gene-regulatory enhancers have been identified using various approaches, including evolutionary conservation, regulatory protein binding, chromatin modifications, and DNA sequence motifs. To integrate these different approaches, we developed EnhancerFinder, a two-step method for distinguishing developmental enhancers from the genomic background and then predicting their tissue specificity. EnhancerFinder uses a multiple kernel learning approach to integrate DNA sequence motifs, evolutionary patterns, and diverse functional genomics datasets from a variety of cell types. In contrast with prediction approaches that define enhancers based on histone marks or p300 sites from a single cell line, we trained EnhancerFinder on hundreds of experimentally verified human developmental enhancers from the VISTA Enhancer Browser. We comprehensively evaluated EnhancerFinder using cross validation and found that our integrative method improves the identification of enhancers over approaches that consider a single type of data, such as sequence motifs, evolutionary conservation, or the binding of enhancer-associated proteins. We find that VISTA enhancers active in embryonic heart are easier to identify than enhancers active in several other embryonic tissues, likely due to their uniquely high GC content. We applied EnhancerFinder to the entire human genome and predicted 84,301 developmental enhancers and their tissue specificity. These predictions provide specific functional annotations for large amounts of human non-coding DNA, and are significantly enriched near genes with annotated roles in their predicted tissues and lead SNPs from genome-wide association studies. We demonstrate the utility of EnhancerFinder predictions through in vivo validation of novel embryonic gene regulatory enhancers from three developmental transcription factor loci. Our genome-wide developmental enhancer predictions are freely available as a UCSC Genome Browser track, which we hope will enable

  19. CHEMICAL ENHANCEMENTS TO PUMP-AND-TREAT REMEDIATION

    EPA Science Inventory

    Conventional pump-and-treat technologies are among the most widely used systems for the remediation of contaminated ground-water. ithin recent years it has become recognized that these systems can require protracted periods of time to make significant reductions in the quantity o...

  20. HYDRAULIC CHARACTERIZATION FOR STEAM ENHANCED REMEDIATION CONDUCTED IN FRACTURED ROCK

    EPA Science Inventory

    Remediation of fractured rock sites contaminated by non-aqueous phase liquids has long been recognized as the most difficult undertaking of any site clean-up. This is primarily the result of the complexity of the fracture framework, which governs the groundwater flow pathways and...

  1. HYDRAULIC CHARACTERIZATION FOR STEAM ENHANCED REMEDIATION CONDUCTED IN FRACTURED ROCK

    EPA Science Inventory

    Remediation of fractured rock sites contaminated by non-aqueous phase liquids has long been recognized as the most difficult undertaking of any site clean-up. This is primarily the result of the complexity of the fracture framework, which governs the groundwater flow pathways and...

  2. CHEMICAL ENHANCEMENTS TO PUMP-AND-TREAT REMEDIATION

    EPA Science Inventory

    Conventional pump-and-treat technologies are among the most widely used systems for the remediation of contaminated ground-water. ithin recent years it has become recognized that these systems can require protracted periods of time to make significant reductions in the quantity o...

  3. Geoscience Diversity Enhancement Project: Student Responses.

    ERIC Educational Resources Information Center

    Rodrigue, Christine M.; Wechsler, Suzanne P.; Whitney, David J.; Ambos, Elizabeth L.; Ramirez-Herrera, Maria Teresa; Behl, Richard; Francis, Robert D.; Larson, Daniel O.; Hazen, Crisanne

    This paper describes an interdisciplinary project at California State University (Long Beach) designed to increase the attractiveness of the geosciences to underrepresented groups. The project is called the Geoscience Diversity Enhancement Project (GDEP). It is a 3-year program which began in the fall of 2001 with funding from the National Science…

  4. Streamline simulation of surfactant enhanced aquifer remediation. Master`s thesis

    SciTech Connect

    Tunison, D.I.

    1996-12-01

    Nonaqueous Phase Liquids (NAPLs) are a recognized source of groundwater contamination. Surfactant Enhanced Aquifer Remediation (SEAR) shows promise in increasing the efficiency and effectiveness over traditional `pump and treat` NAPL remediation processes. Laboratory results are not always consistent with the effects observed in field applications because of the complex interactions that occur in the subsurface. Mathematical modeling is required to enable accurate prediction and understanding of SEAR.

  5. Engineered Injection and Extraction for Enhanced In-situ Remediation of Sorbing Solutes in Groundwater

    NASA Astrophysics Data System (ADS)

    Webber, B. D.; Neupauer, R. M.; Piscopo, A. N.; Mays, D. C.

    2012-12-01

    Groundwater remediation is becoming increasingly more important as the world's population grows and the necessity of access to clean drinking water persists. The majority of current groundwater treatment methods involve pumping the contaminated groundwater out of the soil and treating it above ground. Sorbed contaminants are difficult to remediate using this conventional pump-and-treat method, and often produce poor treatment results because sorbed contaminants are difficult to extract from the aquifer; therefore in-situ remediation research is of particular importance. One type of in-situ groundwater remediation involves a treatment solution of varying composition being injected into the polluted aquifer to react with the contaminant and degrade it to an acceptable byproduct. Increasing the amount of spreading between the contaminant and the treatment solution promotes an increase in contact area and more desired reactions. It has been previously determined that sequential injection and extraction using four wells for in-situ remediation can enhance the spreading of an aqueous contaminant and treatment solution and increase degradation through more reactions. In this work, we focus on sorbing contaminants and investigate the effectiveness of the injection and extraction methods on varying degrees of contaminant sorption. Tests were conducted in homogeneous and heterogeneous soil media, and with instantaneous and kinetic reaction. It was determined that engineered injection and extraction methods previously developed for aqueous contaminants also enhance in-situ remediation of sorbing solutes.

  6. Using visual processing training to enhance standard cognitive remediation outcomes in schizophrenia: A pilot study.

    PubMed

    Contreras, Natalia A; Tan, Eric J; Lee, Stuart J; Castle, David J; Rossell, Susan L

    2017-09-14

    Approaches to cognitive remediation (CR) that address sensory perceptual skills before higher cognitive skills, have been found to be effective in enhancing cognitive performance in schizophrenia. To date, however, most of the conducted trials have concentrated on auditory processing. The aim of this study was to explore whether the addition of visual processing training could enhance standard cognitive remediation outcomes in a schizophrenia population. Twenty participants were randomised to either receive 20h of computer-assisted cognitive remediation alone or 20h of visual processing training modules and cognitive remediation training. All participants were assessed at baseline and at the end of cognitive remediation training on cognitive and psychosocial (i.e. self-esteem, quality of life) measures. At the end of the study participants across both groups improved significantly in overall cognition and psychosocial functioning. No significant differences were observed between groups on any of the measures. Of potential interest, however, was that the Cohen's d assessing the between group difference in the rates of change were moderate/large for a greater improvement in Visual Learning, Working Memory and Social Cognition for the visual training plus cognitive remediation group. On the basis of our effect sizes on three domains of cognition, we recommend replicating this intervention with a larger sample. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Diverse and participative learning methodologies: a remedial teaching intervention for low marks dental students in Chile.

    PubMed

    Alcota, Marcela; Muñoz, Andrea; González, Fermín E

    2011-10-01

    The purpose of this educational intervention was to diagnose the learning style of a group of low marks (i.e., grades) dental students in Chile and improve their academic achievement by means of remedial teaching. The intervention group was composed of ten students in endodontics and eleven in pedodontics with low marks. These two groups were mutually exclusive. The Kolb test of learning styles was applied to the low mark students group and to the rest of the class (n=72). Diverse methodologies were applied to the low marks students, such as seminars, case-based learning and problem-based learning, directed study, plenary discussions and debate, integration and questions, and web-based learning in an effort to cover all learning styles. Students' perceptions of the educational intervention were assessed by means of a questionnaire. The learning styles of the low marks group were mainly divergent (52.4 percent) and convergent (19 percent). Accommodators and assimilators were 14.3 percent each. The rest of the class showed a very distinct frequencies distribution: divergent 18 percent, convergent 20 percent, accommodators 28 percent, and assimilators 34 percent. After the educational intervention, the mean of the scores obtained by the intervention group in formal evaluations was higher than the average scores obtained before the intervention for both courses. Students' perceptions of the activities were that they were effective for their learning process (76 percent) and that the teaching methodologies were useful mainly to clarify concepts and contents from both courses (82 percent). We can conclude that the use of diverse and participative teaching methodologies in a remedial teaching intervention, to cover all the different learning styles of the students, contributes to improve their marks in formal evaluations.

  8. Evolution of transcriptional enhancers and animal diversity.

    PubMed

    Rubinstein, Marcelo; de Souza, Flávio S J

    2013-12-19

    Deciphering the genetic bases that drive animal diversity is one of the major challenges of modern biology. Although four decades ago it was proposed that animal evolution was mainly driven by changes in cis-regulatory DNA elements controlling gene expression rather than in protein-coding sequences, only now are powerful bioinformatics and experimental approaches available to accelerate studies into how the evolution of transcriptional enhancers contributes to novel forms and functions. In the introduction to this Theme Issue, we start by defining the general properties of transcriptional enhancers, such as modularity and the coexistence of tight sequence conservation with transcription factor-binding site shuffling as different mechanisms that maintain the enhancer grammar over evolutionary time. We discuss past and current methods used to identify cell-type-specific enhancers and provide examples of how enhancers originate de novo, change and are lost in particular lineages. We then focus in the central part of this Theme Issue on analysing examples of how the molecular evolution of enhancers may change form and function. Throughout this introduction, we present the main findings of the articles, reviews and perspectives contributed to this Theme Issue that together illustrate some of the great advances and current frontiers in the field.

  9. Evolution of transcriptional enhancers and animal diversity

    PubMed Central

    Rubinstein, Marcelo; de Souza, Flávio S. J.

    2013-01-01

    Deciphering the genetic bases that drive animal diversity is one of the major challenges of modern biology. Although four decades ago it was proposed that animal evolution was mainly driven by changes in cis-regulatory DNA elements controlling gene expression rather than in protein-coding sequences, only now are powerful bioinformatics and experimental approaches available to accelerate studies into how the evolution of transcriptional enhancers contributes to novel forms and functions. In the introduction to this Theme Issue, we start by defining the general properties of transcriptional enhancers, such as modularity and the coexistence of tight sequence conservation with transcription factor-binding site shuffling as different mechanisms that maintain the enhancer grammar over evolutionary time. We discuss past and current methods used to identify cell-type-specific enhancers and provide examples of how enhancers originate de novo, change and are lost in particular lineages. We then focus in the central part of this Theme Issue on analysing examples of how the molecular evolution of enhancers may change form and function. Throughout this introduction, we present the main findings of the articles, reviews and perspectives contributed to this Theme Issue that together illustrate some of the great advances and current frontiers in the field. PMID:24218630

  10. Welcoming Linguistic Diversity and Saying Adios to Remediation: Stretch and Studio Composition at a Hispanic-Serving Institution

    ERIC Educational Resources Information Center

    Davila, Bethany A.; Elder, Cristyn L.

    2017-01-01

    In this program profile, we describe the stretch/studio program recently implemented at the University of New Mexico. This program responds both to an institutional move away from remediation and to the large number of linguistically and racially diverse students at our institution. In this profile, we describe the new program's curriculum, which…

  11. STEAM ENHANCED REMEDIATION RESEARCH FOR DNAPL IN FRACTURED ROCK, LORING AIR FORCE BASE, LIMESTONE, MAINE

    EPA Science Inventory

    This report details a research project on Steam Enhanced Remediation (SER) for the recovery of volatile organic compounds from fractured limestone that was carried out at the Quarry at the former Loring Air Force Base in Limestone, Maine. This project was carried out by USEPA, Ma...

  12. STEAM ENHANCED REMEDIATION RESEARCH FOR DNAPL IN FRACTURED ROCK, LORING AIR FORCE BASE, LIMESTONE, MAINE

    EPA Science Inventory

    This report details a research project on Steam Enhanced Remediation (SER) for the recovery of volatile organic compounds from fractured limestone that was carried out at the Quarry at the former Loring Air Force Base in Limestone, Maine. This project was carried out by USEPA, Ma...

  13. Treating impaired cognition in schizophrenia: the case for combining cognitive-enhancing drugs with cognitive remediation.

    PubMed

    Michalopoulou, Panayiota G; Lewis, Shôn W; Wykes, Til; Jaeger, Judith; Kapur, Shitij

    2013-08-01

    Cognitive impairment is a well-documented feature of schizophrenia and represents a major impediment to the functional recovery of patients. The therapeutic strategies to improve cognition in schizophrenia have either used medications (collectively referred to as 'cognitive-enhancing drugs' in this article) or non-pharmacological training approaches ('cognitive remediation'). Cognitive-enhancing drugs have not as yet been successful and cognitive remediation has shown modest success. Therefore, we may need to explore new therapeutic paradigms to improve cognition in schizophrenia. The optimal approach may require a combination of cognitive-enhancing drugs with cognitive remediation. We review the available data from animal and human studies that provide the conceptual basis, proof-of-concept and illustrations of success of such combination strategies in experimental and clinical paradigms in other conditions. We address the major design issues relevant to the choice of the cognitive-enhancing drugs and cognitive remediation, as well as the timing and the duration of the intervention as will be relevant for schizophrenia. Finally, we address the practical realities of the development and testing of such combined approaches in the real-world clinical situation and conclude that while scientifically attractive, there are several practical difficulties to be overcome for this approach to be clinically feasible. Copyright © 2013 Elsevier B.V. and ECNP. All rights reserved.

  14. Competitive substrate biodegradation during surfactant-enhanced remediation

    SciTech Connect

    Goudar, C.; Strevett, K.; Grego, J.

    1999-12-01

    The impact of synthetic surfactants on the aqueous phase biodegradation of benzene, toluene, and p-xylene (BTpX) was studied using two anionic surfactants, sodium dodecyl sulfate (SDS) and sodium dodecyl benzene sulfonate (SDBS), and two nonionic surfactants, POE(20) sorbitan monooleate (T-maz-80) and octyl-phenolpoly(ethyleneoxy) ethanol (CA-620). Batch biodegradation experiments were performed to evaluate surfactant biodegradability using two different microbial cultures. Of the four surfactants used in this study, SDS and T-maz-80 were readily degraded by a microbial consortium obtained from an activated sludge treatment system, whereas only SDS was degraded by a microbial culture that was acclimated to BTpX. Biodegradation kinetic parameters associated with SDS and T-maz-80 degradation by the activated sludge consortium were estimated using respirometric data in conjunction with a nonlinear parameter estimation technique as {mu}{sub max} = 0.93 h{sup {minus}1}, K{sub s}= 96.18 mg/L and {mu}{sub max} = 0.41 h{sup {minus}1}, K{sub s} = 31.92 mg/L, respectively. When both BTpX and surfactant were present in the reactor along with BTpX-acclimated microorganisms, two distinct biodegradation patterns were seen. SDS was preferentially utilized inhibiting hydrocarbon biodegradation, whereas, the other three surfactants had no impact on BTpX biodegradation. None of the four surfactants were toxic to the microbial cultures used in this study. Readily biodegradable surfactants are not very effective for subsurface remediation applications as they are rapidly consumed, and also because of their potential inhibitory effects on intrinsic hydrocarbon biodegradation. This greatly increases treatment costs as surfactant recovery and reuse are adversely affected.

  15. Cyclodextrin-enhanced solubilization of organic contaminants with implications for aquifer remediation

    SciTech Connect

    McCray, J.E.; Boving, T.B.; Brusseau, M.L.

    2000-12-31

    Reagents that enhance the aqueous solubility of nonaqueous phase organic liquid (NAPL) contaminants are under investigation for use in enhanced subsurface remediation technologies. Cyclodextrin, a glucose-based molecule, is such a reagent. In this paper, laboratory experiments and numerical model simulations are used to evaluate and understand the potential remediation performance of cyclodextrin. Physical properties of cyclodextrin solutions such as density, viscosity, and NAPL-aqueous interfacial tension are measured. Their analysis indicates that no serious obstacles exist related to fluid properties that would prevent the use of cyclodextrin solutions for subsurface NAPL remediation. Cyclodextrin-enhanced solubilization for a large suite of typical ground water contaminants is measured in the laboratory, and the results are related to the physiochemical properties of the organic compounds. The most-hydrophobic contaminants experience a larger relative solubility enhancement than the less-hydrophobic contaminants but have lower aqueous-phase apparent solubilities. Numerical model simulations of enhanced-solubilization flushing of NAPL-contaminated soil demonstrate that the more-hydrophilic compounds exhibit the greatest mass-removal relates due to their greater apparent solubilities, and thus are initially more effectively removed from soil by enhanced-solubilization-flushing reagents. However, the relatively more hydrophobic contaminants exhibit a greater improvement in contaminant mass-removal (compared with water flushing) than that exhibited for the relatively hydrophilic contaminants.

  16. Acoustically enhanced remediation of contaminated soils and ground water. Volume 1

    SciTech Connect

    1995-10-01

    The Phase 1 laboratory bench-scale investigation results have shown that acoustically enhanced remediation (AER) technology can significantly accelerate the ground water remediation of non-aqueous phase liquids (NAPLs) in unconsolidated soils. The testing also determined some of the acoustic parameters which maximize fluid and contaminant extraction rates. A technology merit and trade analysis identified the conditions under which AER could be successfully deployed in the field, and an analysis of existing acoustical sources and varying methods for their deployment found that AER technology can be successfully deployed in-situ. Current estimates of deployability indicate that a NAPL plume 150 ft in diameter can be readily remediated. This program focused on unconsolidated soils because of the large number of remediation sites located in this type of hydrogeologic setting throughout the nation. It also focused on NAPLs and low permeability soil because of the inherent difficult in the remediation of NAPLs and the significant time and cost impact caused by contaminated low permeability soils. This overall program is recommended for Phase 2 which will address the technology scaling requirements for a field scale test.

  17. POTENTIAL ENHANCEMENTS TO NATURAL ATTENUATION: LINES OF INQUIRY SUPPORTING ENHANCED PASSIVE REMEDIATION OF CHLORINATED SOLVENTS

    SciTech Connect

    Vangelas, K; Tom Early, T; Michael Heitkamp, M; Brian02 Looney, B; David Major, D; Brian Riha, B; Jody Waugh, J; Gary Wein, G

    2004-06-18

    The Department of Energy (DOE) is sponsoring an initiative to facilitate efficient, effective and responsible use of Monitored Natural Attenuation (MNA) and Enhanced Passive Remediation (EPR) for chlorinated solvents. This Office of Environmental Management (EM) ''Alternative Project,'' focuses on providing scientific and policy support for MNA/EPR. A broadly representative working group of scientists supports the project along with partnerships with regulatory organizations such as the Interstate Technology and Regulatory Council and the U.S. Environmental Protection Agency (EPA). The initial product of the technical working group was a summary report that articulated the conceptual approach and central scientific tenants of the project, and that identified a prioritized listing of technical targets for field research. This report documented the process in which: (1) scientific ground rules were developed, (2) lines of inquiry were identified and then critically evaluated, (3) promising applied research topics were highlighted in the various lines of inquiry, and (4) these were discussed and prioritized. The summary report will serve as a resource to guide management and decision-making throughout the period of the subject MNA/EPR Alternative Project. To support and more fully document the information presented in the summary report, we are publishing a series of supplemental documents that present the full texts from the technical analyses within the various lines of inquiry (see listing). The following report - documenting our evaluation of the state of the science of the characterization and monitoring process and tools-- is one of those supplemental documents.

  18. Diverse pollinator communities enhance plant reproductive success

    PubMed Central

    Albrecht, Matthias; Schmid, Bernhard; Hautier, Yann; Müller, Christine B.

    2012-01-01

    Understanding the functional consequences of biodiversity loss is a major goal of ecology. Animal-mediated pollination is an essential ecosystem function and service provided to mankind. However, little is known how pollinator diversity could affect pollination services. Using a substitutive design, we experimentally manipulated functional group (FG) and species richness of pollinator communities to investigate their consequences on the reproductive success of an obligate out-crossing model plant species, Raphanus sativus. Both fruit and seed set increased with pollinator FG richness. Furthermore, seed set increased with species richness in pollinator communities composed of a single FG. However, in multiple-FG communities, highest species richness resulted in slightly reduced pollination services compared with intermediate species richness. Our analysis indicates that the presence of social bees, which showed roughly four times higher visitation rates than solitary bees or hoverflies, was an important factor contributing to the positive pollinator diversity–pollination service relationship, in particular, for fruit set. Visitation rate at different daytimes, and less so among flower heights, varied among social bees, solitary bees and hoverflies, indicating a niche complementarity among these pollinator groups. Our study demonstrates enhanced pollination services of diverse pollinator communities at the plant population level and suggests that both the niche complementarity and the presence of specific taxa in a pollinator community drive this positive relationship. PMID:23034701

  19. Electrokinetic-enhanced permanganate delivery and remediation of contaminated low permeability porous media.

    PubMed

    Chowdhury, Ahmed I A; Gerhard, Jason I; Reynolds, David; Sleep, Brent E; O'Carroll, Denis M

    2017-04-15

    Back diffusion of contaminants from low permeability strata has inhibited site remediation and closure due to an inability to deliver remediants into these strata. This study demonstrates the potential of electrokinetics (EK) to significantly reduce back diffusion of chlorinated compounds from low permeability porous media. Experiments were conducted in a two-dimensional sandbox packed with vertical layers of coarse sand and silt contaminated with aqueous trichloroethene (TCE). Three experiments, each approximately 41 days in duration, compared EK-enhanced in situ chemical oxidation (EK-ISCO) to EK or ISCO alone. EK-ISCO successfully delivered the oxidant (permanganate, PM) throughout the silt cross-section while ISCO without EK resulted only in PM delivery to the edges of the silt layer fringes. EK-ISCO resulted in a 4.4-fold reduction in TCE concentrations in the coarse sand compared to a 3.5-fold reduction from ISCO alone. EK-ISCO with a 25 mA current was found to be more effective than with 300 mA current. Overall, this study suggests that electrokinetics coupled with an appropriate in situ remediation technique, such as ISCO, can enhance remediation of lower permeability strata and limit the extent of contaminant back diffusion.

  20. [Microwave thermal remediation of soil contaminated with crude oil enhanced by granular activated carbon].

    PubMed

    Li, Da-Wei; Zhang, Yao-Bin; Quan, Xie; Zhao, Ya-Zhi

    2009-02-15

    The advantage of rapid, selective and simultaneous heating of microwave heating technology was taken to remediate the crude oil-contaminated soil rapidly and to recover the oil contaminant efficiently. The contaminated soil was processed in the microwave field with addition of granular activated carbon (GAC), which was used as strong microwave absorber to enhance microwave heating of the soil mixture to remove the oil contaminant and recover it by a condensation system. The influences of some process parameters on the removal of the oil contaminant and the oil recovery in the remediation process were investigated. The results revealed that, under the condition of 10.0% GAC, 800 W microwave power, 0.08 MPa absolute pressure and 150 mL x min(-1) carrier gas (N2) flow-rate, more than 99% oil removal could be obtained within 15 min using this microwave thermal remediation enhanced by GAC; at the same time, about 91% of the oil contaminant could be recovered without significant changes in chemical composition. In addition, the experiment results showed that GAC can be reused in enhancing microwave heating of soil without changing its enhancement efficiency obviously.

  1. Emerging Opportunities for School Psychologists to Enhance our Remediation Procedure Evidence Base as We Apply Response to Intervention

    ERIC Educational Resources Information Center

    Skinner, Christopher H.; McCleary, Daniel F.; Skolits, Gary L.; Poncy, Brian C.; Cates, Gary L.

    2013-01-01

    The success of Response-to-Intervention (RTI) and similar models of service delivery is dependent on educators being able to apply effective and efficient remedial procedures. In the process of implementing problem-solving RTI models, school psychologists have an opportunity to contribute to and enhance the quality of our remedial-procedure…

  2. Analysis of the Effects of the Computer Enhanced Classroom on the Achievement of Remedial High School Math Students.

    ERIC Educational Resources Information Center

    Lang, William Steve; And Others

    The effects of the use of computer-enhanced instruction with remedial students were assessed, using 4,293 ninth through twelfth graders--3,308 Black, 957 White, and 28 Other--involved in the Governor's Remediation Initiative (GRI) in Georgia. Data sources included the Comprehensive Tests of Basic Skills (CTBS), a data collection form developed for…

  3. Cosolvent-enhanced electrokinetic remediation of soils contaminated with phenanthrene

    SciTech Connect

    Li, A.; Cheung, K.A.; Reddy, K.R.

    2000-06-01

    This research was carried out to evaluate feasibility of using an electrokinetic technique to remove hydrophobic organic pollutants from soils, with the assistance of a cosolvent (n-butylamine, tetrahydrofuran, or acetone) added to the conducting fluid. The experiments were carried out on glacial till clay with phenanthrene as the test compound. Desorption equilibrium was investigated by batch tests. The electrokinetic experiments were conducted using a 19.1 cm long x 6.2 cm inside diameter column under controlled voltage. Water or 20% (volume) cosolvent solution was constantly supplied at the anode. The concentration of phenanthrene in the effluent collected at the cathode was monitored. Each experiment lasted for 100 to 145 days. Results showed that the presence of n-butylamine significantly enhanced the desorption and electrokinetic transport of phenanthrene; about 43% of the phenanthrene was removed after 127 days or 9 pore volumes. The effect of acetone was not as significant as butylamine. The effluent flow in the tetrahydrofuran experiments was minimal, and phenanthrene was not detected in the effluent. The use of water as the conducting solution did not cause observable phenanthrene migration.

  4. Optimal Well Placement for Enhanced Degradation during In Situ Groundwater Remediation

    NASA Astrophysics Data System (ADS)

    Greene, J. A.; Neupauer, R.; Piscopo, A. N.; Kasprzyk, J. R.

    2015-12-01

    Active spreading strategies have been developed to enhance contaminant degradation during in situ remediation by increasing contact of the injected treatment chemical with the contaminant plume. The contact between these reactants is increased by strategically injecting and extracting water at wells surrounding the plume to reconfigure the treatment chemical and contaminant plume in the aquifer, which leads to enhanced contaminant degradation. The distance and orientation of the wells relative to the contaminant plume affects the ability of active spreading strategies to efficiently degrade contaminant. In this study, we use a multi-objective evolutionary algorithm to optimize the distance and orientation of wells for both circular and elliptical contaminant plumes with uniform and Gaussian initial concentration distributions. The optimization yields results that maximize the amount of degradation achieved during in situ remediation while minimizing any extraction of treatment chemical.

  5. Microwave thermal remediation of crude oil contaminated soil enhanced by carbon fiber.

    PubMed

    Li, Dawei; Zhang, Yaobin; Quan, Xie; Zhao, Yazhi

    2009-01-01

    Thermal remediation of the soil contaminated with crude oil using microwave heating enhanced by carbon fiber (CF) was explored. The contaminated soil was treated with 2.45 GHz microwave, and CF was added to improve the conversion of microwave energy into thermal energy to heat the soil. During microwave heating, the oil contaminant was removed from the soil matrix and recovered by a condensation system of ice-salt bath. The experimental results indicated that CF could efficiently enhance the microwave heating of soil even with relatively low-dose. With 0.1 wt.% CF, the soil could be heated to approximately 700 degrees C within 4 min using 800 W of microwave irradiation. Correspondingly, the contaminated soil could be highly cleaned up in a short time. Investigation of oil recovery showed that, during the remediation process, oil contaminant in the soil could be efficiently recovered without causing significant secondary pollution.

  6. Mobility Controlled Flooding (MCF) Technology for Enhanced Sweeping and NAPL Remediation in Heterogeneous Systems

    NASA Astrophysics Data System (ADS)

    Zhong, L.; Oostrom, M.; Wietsma, T.

    2005-12-01

    Heterogeneity is often encountered in subsurface contamination characterization and remediation. Low-permeability zones are bypassed when remedial fluid is injected into heterogeneous systems. The contaminant in the bypassed areas is therefore untouched by the remedial fluid, which can prolong the remediation operations significantly. Methods of forcing fluids into low-permeability flow paths have been developed and widely implemented to solve the heterogeneity-induced bypassing problem encountered during oil recovery in the petroleum industry over the past 40 years. Since the intent of the petroleum reservoir engineers is to control the mobility of the injected fluid in the high-permeable zones so that the fluid can be pushed through the low-permeable zones to contact and mobilize the remaining oil in these zones, this method are referred as mobility controlled flooding (MCF) technology in the petroleum engineering literature. Two methods of mobility control have been developed. One method is to use a water-soluble polymer to increase the viscosity of the injectate so that the in situ pore pressure is raised, and cross-flow between layers with different permeability occurs. The other method is to use surfactant-foam flood to generate foam in high permeable zones in situ; therefore, the injected fluid is forced into the low-permeable areas. A water-soluble polymer, xanthan gum, and surfactant MA-80 was used to formulate MCF remedial fluids to remediate nonaqueous phase liquid (NAPL) contaminated heterogonous systems in two-dimensional (2-D) flow-cell (40 by 50 by 5 cm) experiments. It was demonstrated that the MCF technology is capable of sweeping the low-permeability flow paths. The bypassing of low-permeable zones was significantly reduced. The removal of NAPL trapped in the low-perm zones was remarkable enhanced attributed to more efficient NAPL mobilization. The results also indicate that the MCF technology is able to manage the fluid density effects. The

  7. Development, Discouragement, or Diversion? New Evidence on the Effects of College Remediation Policy

    ERIC Educational Resources Information Center

    Scott-Clayton, Judith; Rodriguez, Olga

    2015-01-01

    Half of all college students will enroll in remedial coursework but evidence of its effectiveness is mixed. Using a regression-discontinuity design with data from a large urban community college system, we make three contributions. First, we articulate three alternative hypotheses regarding the potential impacts of remediation. Second, in addition…

  8. Development, Discouragement, or Diversion? New Evidence on the Effects of College Remediation Policy

    ERIC Educational Resources Information Center

    Scott-Clayton, Judith; Rodriguez, Olga

    2015-01-01

    Half of all college students will enroll in remedial coursework but evidence of its effectiveness is mixed. Using a regression-discontinuity design with data from a large urban community college system, we make three contributions. First, we articulate three alternative hypotheses regarding the potential impacts of remediation. Second, in addition…

  9. Prediction and minimization of vertical migration of DNAPLS using surfactant enhanced aquifer remediation at neutral buoyancy

    NASA Astrophysics Data System (ADS)

    Shook, G. Michael; Pope, Gary A.; Kostarelos, K.

    1998-11-01

    Surfactant enhanced aquifer remediation (SEAR) had previously been thought to require a capillary barrier below the contaminated zone to prevent the vertical migration of a microemulsion containing solubilized DNAPL. This paper shows the vertical migration of the dense microemulsion is described and predicted by the value of three dimensionless scaling groups. Embedded within these scaling groups are four design parameters. The value of these parameters can be manipulated in order to reduce the amount of vertical migration anticipated for a given remediation design. Plots have been constructed that illustrate the relationship between vertical migration and the value of the scaling groups; such plots can be used to predict vertical migration and to determine appropriate screen intervals of extraction wells to ensure full capture of the contaminants. This predictive capability has been verified in laboratory experiments. Predicted migration of the microemulsion agreed within about 2% of that observed. Development of the scaling groups is presented, remediation design implications are discussed, and laboratory verification is shown. Additional discussion of the laboratory work is given in a companion paper [Kostarelos, K., Pope, G.A., Rouse, B.A., Shook, G.M., 1998. A new concept: the use of neutrally-buoyant microemulsions for DNAPL remediation, J. Contam. Hydro., this edition].

  10. A Review of Multidimensional, Multifluid Intermediate-scale Experiments: Nonaqueous Phase Liquid Dissolution and Enhanced Remediation

    SciTech Connect

    Oostrom, Mart; Dane, Jacob H.; Wietsma, Thomas W.

    2006-05-01

    A review is presented of original multidimensional, intermediate-scale experiments involving nonaqueous phase liquids. The experimental approach at this scale can be viewed as an important intermediary between column studies and field trials. The primary advantage of intermediate-scale flow cell experiments is that field-scale processes can be simulated under controlled conditions. The experiments are frequently conducted to provide data sets to test and verify numerical and analytical flow and transport models. The controlled setting and laboratory instrumentation reduces the uncertainty in parameter estimation, allowing comparisons between simulation and experimental results to focus on flow and transport processes. A total of about 120 original contributions were identified and reviewed. Depending on the main topic of NAPL experimental research, the papers were divided into the following sections: (1) Dissolution, (2) Enhanced Remediation, (3) Flow behavior, (4) Quantification, and, (5) Imaging. In this paper, the categories Dissolution and Enhanced Remediation are discussed and suggestions for future research are provided. In a companion paper, experimental work related to the other three categories is reviewed. The Dissolution category includes experiments in which NAPL removal occurs due to water flushing. The Enhanced Remediation section contains experimental contributions investigating surfactant flushing, alcohol flushing, surfactant/alcohol combinations, dense brine barrier strategies, oil recovery through pumping, soil vapor extraction, air sparging, steam injection, bioremediation, and other techniques.

  11. 77 FR 593 - Enhanced Prudential Standards and Early Remediation Requirements for Covered Companies

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-05

    ...The Board is requesting comment on proposed rules that would implement the enhanced Prudential standards required to be established under section 165 of the Dodd-Frank Wall Street Reform and Consumer Protection Act (Dodd-Frank Act or Act) and the early remediation requirements established under section 166 of the Act. The enhanced standards include risk-based capital and leverage requirements, liquidity standards, requirements for overall risk management (including establishing a risk committee), single-counterparty credit limits, stress test requirements, and a debt-to-equity limit for companies that the Financial Stability Oversight Council has determined pose a grave threat to financial stability.

  12. Enhancing Student Compositional Diversity in the Sociology Classroom

    ERIC Educational Resources Information Center

    Lyon, Katherine A.; Guppy, Neil

    2016-01-01

    It is well documented that interaction between diverse students encourages positive learning outcomes. Given this, we examine how to enhance the quantity and quality of student diversity in university classrooms. Drawing on sociological theory linking life experiences with ways of knowing, we investigate how to increase classroom diversity by…

  13. Enhancing Student Compositional Diversity in the Sociology Classroom

    ERIC Educational Resources Information Center

    Lyon, Katherine A.; Guppy, Neil

    2016-01-01

    It is well documented that interaction between diverse students encourages positive learning outcomes. Given this, we examine how to enhance the quantity and quality of student diversity in university classrooms. Drawing on sociological theory linking life experiences with ways of knowing, we investigate how to increase classroom diversity by…

  14. Soil moisture could enhance electrokinetic remediation of arsenic-contaminated soil.

    PubMed

    Shin, Su-Yeon; Park, Sang-Min; Baek, Kitae

    2017-04-01

    Electrokinetic remediation (EKR) is the most efficient technique for remediation of fine-grained soil. The primary removal mechanisms of heavy metal in EKR are the electromigration and electroosmosis flow under appropriate electric gradients. Most EKR studies have researched the variation according to the electrolyte and electric voltage. Also, EKR could be influenced by the migration velocity of ions, while few studies have investigated the effect of moisture content. In this study, soil moisture was controlled by using tap water and NaOH as electrolytes to enhance electromigration and electroosmosis flow. In both electrolytes, the higher moisture content led to the more As removal efficiency, but there were no differences between tap water and NaOH. Therefore, tap water was the most cost-effective electrolyte to remove As from fine-grained soil.

  15. Effect of heterogeneity on enhanced reductive dechlorination: Analysis of remediation efficiency and groundwater acidification

    NASA Astrophysics Data System (ADS)

    Brovelli, A.; Lacroix, E.; Robinson, C. E.; Gerhard, J.; Holliger, C.; Barry, D. A.

    2011-12-01

    Enhanced reductive dehalogenation is an attractive in situ treatment technology for chlorinated contaminants. The process includes two acid-forming microbial reactions: fermentation of an organic substrate resulting in short-chain fatty acids, and dehalogenation resulting in hydrochloric acid. The accumulation of acids and the resulting drop of groundwater pH are controlled by the mass and distribution of chlorinated solvents in the source zone, type of electron donor, alternative terminal electron acceptors available and presence of soil mineral phases able to buffer the pH (such as carbonates). Groundwater acidification may reduce or halt microbial activity, and thus dehalogenation, significantly increasing the time and costs required to remediate the aquifer. In previous work a detailed geochemical and groundwater flow simulator able to model the fermentation-dechlorination reactions and associated pH change was developed. The model accounts for the main processes influencing microbial activity and groundwater pH, including the groundwater composition, the electron donor used and soil mineral phase interactions. In this study, the model was applied to investigate how spatial variability occurring at the field scale affects dechlorination rates, groundwater pH and ultimately the remediation efficiency. Numerical simulations were conducted to examine the influence of heterogeneous hydraulic conductivity on the distribution of the injected, fermentable substrate and on the accumulation/dilution of the acidic products of reductive dehalogenation. The influence of the geometry of the DNAPL source zone was studied, as well as the spatial distribution of soil minerals. The results of this study showed that the heterogeneous distribution of the soil properties have a potentially large effect on the remediation efficiency. For examples, zones of high hydraulic conductivity can prevent the accumulation of acids and alleviate the problem of groundwater acidification. The

  16. Celebrating Diversity: Enhancing Harmony on Campus.

    ERIC Educational Resources Information Center

    McGlynn, Angela Provitera

    The purpose of this booklet is to help teachers prepare students to live and work harmoniously in a society where diversity is the norm. Following background information on the development of the booklet, strategies are described for increasing harmony and learning in the classroom, such as creating diverse collaborative learning groups to bind…

  17. Cosolubilization synergism occurrence in codesorption of PAH mixtures during surfactant-enhanced remediation of contaminated soil.

    PubMed

    Liang, Xujun; Guo, Chuling; Wei, Yanfu; Lin, Weijia; Yi, Xiaoyun; Lu, Guining; Dang, Zhi

    2016-02-01

    Surfactant-enhanced remediation (SER) has been widely applied in decontaminating PAH-polluted soil. Most researches focus on evaluating washing efficiency without considering pollutants' mutual interaction. This study aims to investigate cosolubilization effect between phenanthrene (Phe) and pyrene (Pyr) in nonionic surfactant Triton X-100 (TX100) solution on their codesorption performance from soil. Cosolubilization experiment showed that, when cosolubilized, solubility of Phe and Pyr in TX100 increased by 15.38% and 18.19%, respectively, as quantified by the deviation ratio of molar solubilization ratio in single and binary solute solubilization systems. The synergism may be due to the enlarged micelle volume caused by PAHs solubilized in the shell region of the micelle. The cosolubilization effect was further observed in the soil washing process. The strengthened TX100 solubilization capacity towards Phe and Pyr could increase the two PAHs' codesorption efficiency from soil, accompanied by synergistic extent of 6-15%. However, synergism in codesorption was weaker than that observed in the cosolubilization system, which may be related to surfactant loss to soil and PAH partition into soil organic matter and the sorbed surfactants. The improved remediation performance during codesorption of mixed PAHs implies the significance of combining PAHs' mutual interaction into evaluating SER, which may reduce the surfactant washing concentration and save remediation cost.

  18. Vacuum enhanced air sparging data results of a pilot test of a remediation trench

    SciTech Connect

    Forster, K.; Brenneke, S.; King, P.L.

    1995-09-01

    Air sparging (AS) and soil vapor extraction (SVE) are two methods used to recover hydrocarbons from vadose zone and ground water. Air sparging and soil vapor extraction also introduce oxygen to the ground water and the vadose zone which may enhance the biodegradation of hydrocarbons in the subsurface. The basic AS/SVE trench system design at the subject site consists of a horizontal section of air sparging pipe within the remediation trench. Compressed air is forced into the remediation trench through a 1-inch slotted PVC pipe. The air passes through the ground water, effectively stripping volatile organic hydrocarbons from the water. The volatile organics are removed and discharged to the atmosphere utilizing vapor extraction wells placed adjacent to or within the remediation trench. Because the behavior of the contaminants and the soil characteristics can change from site to site, it is common to perform a pilot test using equipment to simulate the actual conditions which will be encountered. The pilot test results are used to predict the equipment requirements and performance specifications.

  19. An enhanced adaptive management approach for remediation of legacy mercury in the South River.

    PubMed

    Foran, Christy M; Baker, Kelsie M; Grosso, Nancy R; Linkov, Igor

    2015-01-01

    Uncertainties about future conditions and the effects of chosen actions, as well as increasing resource scarcity, have been driving forces in the utilization of adaptive management strategies. However, many applications of adaptive management have been criticized for a number of shortcomings, including a limited ability to learn from actions and a lack of consideration of stakeholder objectives. To address these criticisms, we supplement existing adaptive management approaches with a decision-analytical approach that first informs the initial selection of management alternatives and then allows for periodic re-evaluation or phased implementation of management alternatives based on monitoring information and incorporation of stakeholder values. We describe the application of this enhanced adaptive management (EAM) framework to compare remedial alternatives for mercury in the South River, based on an understanding of the loading and behavior of mercury in the South River near Waynesboro, VA. The outcomes show that the ranking of remedial alternatives is influenced by uncertainty in the mercury loading model, by the relative importance placed on different criteria, and by cost estimates. The process itself demonstrates that a decision model can link project performance criteria, decision-maker preferences, environmental models, and short- and long-term monitoring information with management choices to help shape a remediation approach that provides useful information for adaptive, incremental implementation.

  20. An Enhanced Adaptive Management Approach for Remediation of Legacy Mercury in the South River

    PubMed Central

    Foran, Christy M.; Baker, Kelsie M.; Grosso, Nancy R.; Linkov, Igor

    2015-01-01

    Uncertainties about future conditions and the effects of chosen actions, as well as increasing resource scarcity, have been driving forces in the utilization of adaptive management strategies. However, many applications of adaptive management have been criticized for a number of shortcomings, including a limited ability to learn from actions and a lack of consideration of stakeholder objectives. To address these criticisms, we supplement existing adaptive management approaches with a decision-analytical approach that first informs the initial selection of management alternatives and then allows for periodic re-evaluation or phased implementation of management alternatives based on monitoring information and incorporation of stakeholder values. We describe the application of this enhanced adaptive management (EAM) framework to compare remedial alternatives for mercury in the South River, based on an understanding of the loading and behavior of mercury in the South River near Waynesboro, VA. The outcomes show that the ranking of remedial alternatives is influenced by uncertainty in the mercury loading model, by the relative importance placed on different criteria, and by cost estimates. The process itself demonstrates that a decision model can link project performance criteria, decision-maker preferences, environmental models, and short- and long-term monitoring information with management choices to help shape a remediation approach that provides useful information for adaptive, incremental implementation. PMID:25665032

  1. Field-scale evaluation of enhanced aquifer remediation using in-situ alcohol flushing

    SciTech Connect

    Rao, P.S.C.; Annable, M.D.; Hatfield, K.H.; Graham, W.D.; Wood, A.L.; Enfield, C.

    1995-09-01

    In-situ flushing of soils and aquifers contaminated with a variety of fuels and oils (e.g., gasoline, diesel, jet fuels, solvents, degreasers, coal tar, creosote, etc.) is based on enhanced mobilization and/or solubilization of the entrapped residual oils. The former technique involves immiscible displacement of oil macroemulsions, ganglia, blobs, and banks, whereas the latter technique is based on enhanced solubilization of the oil constituents and their miscible displacement. Results from lab-scale and field-scale evaluations of in-situ flushing with water-alcohol mixtures for enhanced solubilization of residual oils will be discussed. Emphasis of the presentation will be on the data collected during a recently completed field test of the in-situ cosolvent flushing technology, which was conducted at the Hill Air Force Base, utah, to remediate a shallow, unconfined aquifer contaminated with jet fuel and chlorinated solvents. As a part of this field test, studies were also conducted to evaluate the use of partitioning tracers (methyl alcohols) for quantifying the residual oils present at the site prior to and after cosolvent flushing. Criteria for performance assessment as well as the technological, regulatory, and economic factors governing full-scale applications for aquifer remediation will be discussed.

  2. Assessment of the effectiveness of onsite exsitu remediation by enhanced natural attenuation in the Niger Delta region, Nigeria.

    PubMed

    Okparanma, Reuben N; Azuazu, Ikeabiama; Ayotamuno, Josiah M

    2017-09-09

    This study was conducted to quantify and rank the effectiveness of onsite exsitu remediation by enhanced natural attenuation using soil quality index. The investigation was conducted at three oil spill sites in the Niger Delta (5.317°N, 6.467°E), Nigeria with a predominance of Oxisols. Baseline assessment and a two-step post-remediation monitoring of the sites were conducted. Target contaminants including total petroleum hydrocarbon (TPH) and BTEX (benzene, toluene, ethylbenzene, and xylene) were analyzed by gas chromatography-mass spectrometry. Results of the baseline assessment showed that TPH concentrations across the study sites averaged between 5113 and 7640 mg/kg at 0- to 1-m depth, which was higher than the local regulatory value of 5000 mg/kg. The soil quality index across the sites ranged between 68 and 45, suggesting medium to high potential ecological health risks with medium to high priority for remediation. BTEX concentrations followed a similar trend. However, after remediation TPH degraded rapidly initially and then slowly but asymptotically during the post-remediation monitoring period. Then, soil quality index across the study sites ranged between 100 and 58, indicating very low to medium potential ecological health risks. This demonstrates the effectiveness of onsite exsitu remediation by enhanced natural attenuation as a remediation strategy for petroleum-contaminated soils, which holds great promise for the Niger Delta province. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Intermediate intrinsic diversity enhances neural population coding.

    PubMed

    Tripathy, Shreejoy J; Padmanabhan, Krishnan; Gerkin, Richard C; Urban, Nathaniel N

    2013-05-14

    Cell-to-cell variability in molecular, genetic, and physiological features is increasingly recognized as a critical feature of complex biological systems, including the brain. Although such variability has potential advantages in robustness and reliability, how and why biological circuits assemble heterogeneous cells into functional groups is poorly understood. Here, we develop analytic approaches toward answering how neuron-level variation in intrinsic biophysical properties of olfactory bulb mitral cells influences population coding of fluctuating stimuli. We capture the intrinsic diversity of recorded populations of neurons through a statistical approach based on generalized linear models. These models are flexible enough to predict the diverse responses of individual neurons yet provide a common reference frame for comparing one neuron to the next. We then use Bayesian stimulus decoding to ask how effectively different populations of mitral cells, varying in their diversity, encode a common stimulus. We show that a key advantage provided by physiological levels of intrinsic diversity is more efficient and more robust encoding of stimuli by the population as a whole. However, we find that the populations that best encode stimulus features are not simply the most heterogeneous, but those that balance diversity with the benefits of neural similarity.

  4. Intermediate intrinsic diversity enhances neural population coding

    PubMed Central

    Tripathy, Shreejoy J.; Padmanabhan, Krishnan; Gerkin, Richard C.; Urban, Nathaniel N.

    2013-01-01

    Cell-to-cell variability in molecular, genetic, and physiological features is increasingly recognized as a critical feature of complex biological systems, including the brain. Although such variability has potential advantages in robustness and reliability, how and why biological circuits assemble heterogeneous cells into functional groups is poorly understood. Here, we develop analytic approaches toward answering how neuron-level variation in intrinsic biophysical properties of olfactory bulb mitral cells influences population coding of fluctuating stimuli. We capture the intrinsic diversity of recorded populations of neurons through a statistical approach based on generalized linear models. These models are flexible enough to predict the diverse responses of individual neurons yet provide a common reference frame for comparing one neuron to the next. We then use Bayesian stimulus decoding to ask how effectively different populations of mitral cells, varying in their diversity, encode a common stimulus. We show that a key advantage provided by physiological levels of intrinsic diversity is more efficient and more robust encoding of stimuli by the population as a whole. However, we find that the populations that best encode stimulus features are not simply the most heterogeneous, but those that balance diversity with the benefits of neural similarity. PMID:23630284

  5. Enhancing Diversity in Biomedical Data Science.

    PubMed

    Canner, Judith E; McEligot, Archana J; Pérez, María-Eglée; Qian, Lei; Zhang, Xinzhi

    2017-01-01

    The gap in educational attainment separating underrepresented minorities from Whites and Asians remains wide. Such a gap has significant impact on workforce diversity and inclusion among cross-cutting Biomedical Data Science (BDS) research, which presents great opportunities as well as major challenges for addressing health disparities. This article provides a brief description of the newly established National Institutes of Health Big Data to Knowledge (BD2K) diversity initiatives at four universities: California State University, Monterey Bay; Fisk University; University of Puerto Rico, Río Piedras Campus; and California State University, Fullerton. We emphasize three main barriers to BDS careers (ie, preparation, exposure, and access to resources) experienced among those pioneer programs and recommendations for possible solutions (ie, early and proactive mentoring, enriched research experience, and data science curriculum development). The diversity disparities in BDS demonstrate the need for educators, researchers, and funding agencies to support evidence-based practices that will lead to the diversification of the BDS workforce.

  6. A compositional simulator for modeling surfactant enhanced aquifer remediation, 1 formulation

    NASA Astrophysics Data System (ADS)

    Delshad, M.; Pope, G. A.; Sepehrnoori, K.

    1996-08-01

    We describe a three-dimensional, multicomponent, multiphase compositional finite-difference simulator for application to the analysis of contaminant transport and surfactant enhanced aquifer remediation (SEAR) of non aqueous- phase liquid (NAPL) pollutants. Mixtures of surfactant, water and NAPL can form many types of micellar and microemulsion phases with a complex and important dependence on many variables of which the dilute aqueous solution typically assumed in SEAR models is just one example. The phase behavior model is central to our approach and allows for the full range of the commonly observed micellar and microemulsion behavior pertinent to SEAR. The other surfactant related properties such as adsorption, interfacial tension, capillary pressure, capillary number and microemulsion viscosity are all dependent on an accurate phase behavior model. This has proven to be a highly successful approach for surfactant enhanced oil recovery modeling, so it was adapted to SEAR modeling. However, there are many significant differences between petroleum and environmental applications of surfactants, so many new features have been added to model contaminant transport and remediation and these are described and illustrated for the first time here.

  7. Remediation of Nitrobenzene Contaminated Soil by Combining Surfactant Enhanced Soil Washing and Effluent Oxidation with Persulfate

    PubMed Central

    Yan, Jingchun; Gao, Weiguo; Qian, Linbo; Han, Lu; Chen, Yun; Chen, Mengfang

    2015-01-01

    The combination of surfactant enhanced soil washing and degradation of nitrobenzene (NB) in effluent with persulfate was investigated to remediate NB contaminated soil. Aqueous solution of sodium dodecylbenzenesulfonate (SDBS, 24.0 mmol L-1) was used at a given mass ratio of solution to soil (20:1) to extract NB contaminated soil (47.3 mg kg-1), resulting in NB desorption removal efficient of 76.8%. The washing effluent was treated in Fe2+/persulfate and Fe2+/H2O2 systems successively. The degradation removal of NB was 97.9%, being much higher than that of SDBS (51.6%) with addition of 40.0 mmol L-1 Fe2+ and 40.0 mmol L-1 persulfate after 15 min reaction. The preferential degradation was related to the lone pair electron of generated SO4•−, which preferably removes electrons from aromatic parts of NB over long alkyl chains of SDBS through hydrogen abstraction reactions. No preferential degradation was observed in •OH based oxidation because of its hydrogen abstraction or addition mechanism. The sustained SDBS could be reused for washing the contaminated soil. The combination of the effective surfactant-enhanced washing and the preferential degradation of NB with Fe2+/persulfate provide a useful option to remediate NB contaminated soil. PMID:26266532

  8. Remediation of nitrobenzene contaminated soil by combining surfactant enhanced soil washing and effluent oxidation with persulfate.

    PubMed

    Yan, Jingchun; Gao, Weiguo; Qian, Linbo; Han, Lu; Chen, Yun; Chen, Mengfang

    2015-01-01

    The combination of surfactant enhanced soil washing and degradation of nitrobenzene (NB) in effluent with persulfate was investigated to remediate NB contaminated soil. Aqueous solution of sodium dodecylbenzenesulfonate (SDBS, 24.0 mmol L-1) was used at a given mass ratio of solution to soil (20:1) to extract NB contaminated soil (47.3 mg kg-1), resulting in NB desorption removal efficient of 76.8%. The washing effluent was treated in Fe2+/persulfate and Fe2+/H2O2 systems successively. The degradation removal of NB was 97.9%, being much higher than that of SDBS (51.6%) with addition of 40.0 mmol L-1 Fe2+ and 40.0 mmol L-1 persulfate after 15 min reaction. The preferential degradation was related to the lone pair electron of generated SO4•-, which preferably removes electrons from aromatic parts of NB over long alkyl chains of SDBS through hydrogen abstraction reactions. No preferential degradation was observed in •OH based oxidation because of its hydrogen abstraction or addition mechanism. The sustained SDBS could be reused for washing the contaminated soil. The combination of the effective surfactant-enhanced washing and the preferential degradation of NB with Fe2+/persulfate provide a useful option to remediate NB contaminated soil.

  9. Remediation of Cd(II)-contaminated soil via humin-enhanced electrokinetic technology.

    PubMed

    Ding, Ling; Lv, Wenying; Yao, Kun; Li, Liming; Wang, Mengmeng; Liu, Guoguang

    2017-02-01

    Humin is the component of humic substances that is recalcitrant to extraction by either strong bases or strong acids, which contains a variety of functional groups that may combine with heavy metal ions. The present study employed humin as an adsorbent to investigate the efficacy of a remediation strategy under the effects of humin-enhanced electrokinetics. Because the cations gravitate toward cathode and anions are transferred to anode, humin was placed in close proximity to the cathode in the form of a package. The humin was taken out after the experiments to determine whether a target pollutant (cadmium) might be completely removed from soil. Acetic acid-sodium acetate was selected as the electrolyte for these experiments, which was circulated between the two electrode chambers via a peristaltic pump, in order to control the pH of the soil. The results indicated that when the remediation duration was extended to 240 h, the removal of acid extractable Cd(II) could be up to 43.86% efficiency, and the adsorption of the heavy metal within the humin was 86.15 mg/kg. Further, the recycling of the electrolyte exhibited a good control of the pH of the soil. When comparing the pH of the soil with the circulating electrolyte during remediation, in contrast to when it was not being recycled, the pH of the soil at the anode increased from 3.89 to 5.63, whereas the soil at the cathode decreased from 8.06 to 7.10. This indicated that the electrolyte recycling had the capacity to stabilize the pH of the soil.

  10. Enhanced removal of petroleum hydrocarbons using a bioelectrochemical remediation system with pre-cultured anodes.

    PubMed

    Venkidusamy, Krishnaveni; Megharaj, Mallavarapu; Marzorati, Massimo; Lockington, Robin; Naidu, Ravi

    2016-01-01

    Bioelectrochemical remediation (BER) systems such as microbial fuel cells (MFCs) have recently emerged as a green technology for the effective remediation of petroleum hydrocarbon contaminants (PH) coupled with simultaneous energy recovery. Recent research has shown that biofilms previously enriched for substrate degrading bacteria resulted in excellent performance in terms of substrate removal and electricity generation but the effects on hydrocarbon contaminant degradation were not examined. Here we investigate the differences between enriched biofilm anodes and freshly inoculated new anodes in diesel fed single chamber mediatorless microbial fuel cells (DMFC) using various techniques for the enhancement of PH contaminant remediation with concomitant electricity generation. An anodophilic microbial consortium previously selected for over a year through continuous culturing with a diesel concentration of about 800mgl(-1) and which now showed complete removal of this concentration of diesel within 30days was compared to that of a freshly inoculated new anode MFC (showing 83.4% removal of diesel) with a simultaneous power generation of 90.81mW/m(2) and 15.04mW/m(2) respectively. The behaviour of pre-cultured anodes at a higher concentration of PH (8000mgl(-1)) was also investigated. Scanning electron microscopy observation revealed a thick biofilm covering the pre-cultured anodic electrode but not the anode from the freshly inoculated MFC. High resolution imaging showed the presence of thin 60nm diametre pilus-like projections emanating from the cells. Anodic microbial community profiling confirmed that the selection for diesel degrading exoelectrogenic bacteria had occurred. Identification of a biodegradative gene (alkB) provided strong evidence of the catabolic pathway used for diesel degradation in the DMFCs.

  11. Future HIV Mentoring Programs to Enhance Diversity.

    PubMed

    Stoff, David M; Cargill, Victoria A

    2016-09-01

    This paper proposes a general template to guide future mentoring program development addressing: (i) considerations to ensure an adequate research workforce; (ii) key guidelines and principles of mentoring; and (iii) use of a logic model to develop program milestones, outcomes and evaluation. We focus on these areas to guide and inform the most effective mentoring program components, which we find to be more helpful than identifying specific features and ingredients. Although the focus is on the development of a new generation of investigators from diverse backgrounds, this template may also apply to mentoring programs for other investigators and for disciplines beyond HIV.

  12. Induced metal redistribution and bioavailability enhancement in contaminated river sediment during in situ biogeochemical remediation.

    PubMed

    Liu, Tongzhou; Zhang, Zhen; Mao, Yanqing; Yan, Dickson Y S

    2016-04-01

    In situ sediment remediation using Ca(NO3)2 or CaO2 for odor mitigation and acid volatile sulfide (AVS) and organic pollutant (such as TPH and PAHs) removal was reported in many studies and fieldwork. Yet, the associated effects on metal mobilization and potential distortion in bioavailability were not well documented. In this study, contaminated river sediment was treated by Ca(NO3)2 and CaO2 in bench studies. Through the investigation of AVS removal, organic matter removal, the changes in sediment oxidation-reduction potential (ORP), microbial activity, and other indigenous parameters, the effects on metal bioavailability, bioaccessibility, and fraction redistribution in sediment were evaluated. The major mechanisms for sediment treated by Ca(NO3)2 and CaO2 are biostimulation with indigenous denitrifying bacteria and chemical oxidation, respectively. After applying Ca(NO3)2 and CaO2, the decreases of metal concentrations in the treated sediment were insignificant within a 35-day incubation period. However, the [SEMtot-AVS]/f OC increased near to the effective boundary of toxicity (100 μmol g(-1) organic carbon (OC)), indicating that both bioavailability and bioaccessibility of metals (Cu, Zn, and Ni) to benthic organisms are enhanced after remediation. Metals were found redistributed from relatively stable fractions (oxidizable and residual fractions) to weakly bound fractions (exchangeable and reducible fractions), and the results are in line with the enhanced metal bioavailability. Compared with Ca(NO3)2, CaO2 led to higher enhancement in metal bioavailability and bioaccessibility, and more significant metal redistribution, probably due to its stronger chemical reactive capacity to AVS and sediment organic matter. The reactions in CaO2-treated sediment would probably shift from physicochemical to biochemical heterotrophic oxidation for sediment organic matter degradation. Therefore, further investigation on the long-term metal redistribution and associated

  13. A remediation performance model for enhanced metabolic reductive dechlorination of chloroethenes in fractured clay till.

    PubMed

    Manoli, Gabriele; Chambon, Julie C; Bjerg, Poul L; Scheutz, Charlotte; Binning, Philip J; Broholm, Mette M

    2012-04-01

    A numerical model of metabolic reductive dechlorination is used to describe the performance of enhanced bioremediation in fractured clay till. The model is developed to simulate field observations of a full scale bioremediation scheme in a fractured clay till and thereby to assess remediation efficiency and timeframe. A relatively simple approach is used to link the fermentation of the electron donor soybean oil to the sequential dechlorination of trichloroethene (TCE) while considering redox conditions and the heterogeneous clay till system (clay till matrix, fractures and sand stringers). The model is tested on lab batch experiments and applied to describe sediment core samples from a TCE-contaminated site. Model simulations compare favorably to field observations and demonstrate that dechlorination may be limited to narrow bioactive zones in the clay matrix around fractures and sand stringers. Field scale simulations show that the injected donor is expected to be depleted after 5 years, and that without donor re-injection contaminant rebound will occur in the high permeability zones and the mass removal will stall at 18%. Long remediation timeframes, if dechlorination is limited to narrow bioactive zones, and the need for additional donor injections to maintain dechlorination activity may limit the efficiency of ERD in low-permeability media. Future work should address the dynamics of the bioactive zones, which is essential to understand for predictions of long term mass removal.

  14. How Heat Can Enhance In-Situ Soil and Aquifer Remediation

    EPA Pesticide Factsheets

    The purpose of this Issue Paper and the three companion Issue Papers (Davis, 1997a, b, c) is to provide to those involved in assessing remediation technologies some basic information on the thermal remediation techniques.

  15. Enhanced Amendment Delivery to Subsurface Using Shear Thinning Fluid and Aqueous Foam for Metal, Radionuclide, and NAPL Remediation

    NASA Astrophysics Data System (ADS)

    Zhong, L.; Szecsody, J.; Li, X.; Oostrom, M.; Truex, M.

    2010-12-01

    In many contamination sites, removal of contaminants by any active remediation efforts is not practical due to the high cost and technological limitations. Alternatively, in situ remediation is expected to be the most important remediation strategy. Delivery of reactive amendment to the contamination zone is essential for the reactions between the contaminants and remedial amendments to proceed in situ. It is a challenge to effectively deliver remedial amendment to the subsurface contamination source areas in both aquifer and vadose zone. In aquifer, heterogeneity induces fluid bypassing the low-permeability zones, resulting in certain contaminated areas inaccessible to the remedial amendment delivered by water injection, thus inhibiting the success of remedial operations. In vadose zone in situ remediation, conventional solution injection and infiltration for amendment delivery have difficulties to achieve successful lateral spreading and uniform distribution of the reactive media. These approaches also tend to displace highly mobile metal and radionuclide contaminants such as hexavalent chromium [Cr(VI)] and technetium (Tc-99), causing spreading of contaminations. Shear thinning fluid and aqueous foam can be applied to enhance the amendment delivery and improve in situ subsurface remediation efficiency under aquifer and vadose zone conditions, respectively. Column and 2-D flow cell experiments were conducted to demonstrate the enhanced delivery and improved remediation achieved by the application of shear thinning fluid and foam injection at the laboratory scale. Solutions of biopolymer xanthan gum were used as the shear thinning delivering fluids. Surfactant sodium lauryl ether sulfate (STEOL CS-330) was the foaming agent. The shear thinning fluid delivery (STFD) considerably improved the sweeping efficiency over a heterogeneous system and enhanced the non-aqueous liquid phase (NAPL) removal. The delivery of amendment into low-perm zones (LPZs) by STFD also

  16. Genetic diversity enhances restoration success by augmenting ecosystem services.

    PubMed

    Reynolds, Laura K; McGlathery, Karen J; Waycott, Michelle

    2012-01-01

    Disturbance and habitat destruction due to human activities is a pervasive problem in near-shore marine ecosystems, and restoration is often used to mitigate losses. A common metric used to evaluate the success of restoration is the return of ecosystem services. Previous research has shown that biodiversity, including genetic diversity, is positively associated with the provision of ecosystem services. We conducted a restoration experiment using sources, techniques, and sites similar to actual large-scale seagrass restoration projects and demonstrated that a small increase in genetic diversity enhanced ecosystem services (invertebrate habitat, increased primary productivity, and nutrient retention). In our experiment, plots with elevated genetic diversity had plants that survived longer, increased in density more quickly, and provided more ecosystem services (invertebrate habitat, increased primary productivity, and nutrient retention). We used the number of alleles per locus as a measure of genetic diversity, which, unlike clonal diversity used in earlier research, can be applied to any organism. Additionally, unlike previous studies where positive impacts of diversity occurred only after a large disturbance, this study assessed the importance of diversity in response to potential environmental stresses (high temperature, low light) along a water-depth gradient. We found a positive impact of diversity along the entire depth gradient. Taken together, these results suggest that ecosystem restoration will significantly benefit from obtaining sources (transplants or seeds) with high genetic diversity and from restoration techniques that can maintain that genetic diversity.

  17. Hydraulic fracturing to enhance the remediation of DNAPL in low permeability soils

    SciTech Connect

    Murdoch, L.; Slack, B.

    1996-08-01

    Meager rates of fluid flow are a major obstacle to in situ remediation of low permeability soils. This paper describes methods designed to avoid that obstacle by creating fractures and filling them with sand to increase well discharge and change paths of fluid flow in soil. Gently dipping fractures 10 m in maximum dimension and 1 to 2 cm thick can be created in some contaminated soils at depths of a few in or greater. Hydraulic fractures can also be used to create electrically conductive layers or to deliver granules of chemically or biologically active compounds that will degrade contaminants in place. Benefits of applying hydraulic fractures to DNAPL recovery include rates of fluid recovery, enhancing upward gradients to improve hydrodynamic stabilization, forming flat-lying reactive curtains to intersect compounds moving downward, or improving the performance of electrokinetics intended to recover compounds dissolved in water. 30 refs., 7 figs., 1 tab.

  18. Modeling surfactant-enhanced nonaqueous-phase liquid remediation of porous media

    SciTech Connect

    White, M.D.; Oostrom, M.

    1998-12-01

    A mathematical model is developed to investigate the main processes associated with surfactant-enhanced nonaqueous-phase liquid (NAPL) remediation of porous media. The model couples four nonlinear mass balance conservation equations (i.e., water, NAPL-phase organic, aqueous-phase organic, and aqueous-phase surfactant) that incorporate aqueous- and NAPL-phase migration and transport of aqueous-phase dissolved surfactant and organics. Rate-limited solubilization of the organic into the aqueous phase is represented by a linear driving force expression and is dependent on the surfactant-enhanced equilibrium concentration. Surfactant-enhanced mobilization of the NAPL phase is incorporated using surfactant concentration-dependent interfacial tension lowering, scaled relative permeability-saturation-capillary pressure relations, and trapping number-dependent effective residual saturations for the nonwetting liquid. Sorption of surfactant is assumed to conform to a Langmuir isotherm model, whereas organic sorption is modeled using a linear isotherm with a surfactant and soil-organic content-dependent retardation coefficient. The model is used to simulate experiments described by Pennel et al. (1996) in which the NAPL perchloroethylene was flushed from sand columns using different surfactant solutions.

  19. Diversity Enhances NPP, N Retention, and Soil Microbial Diversity in Experimental Urban Grassland Assemblages

    PubMed Central

    Thompson, Grant L.; Kao-Kniffin, Jenny

    2016-01-01

    Urban grasslands, landscapes dominated by turfgrasses for aesthetic or recreational groundcovers, are rapidly expanding in the United States and globally. These managed ecosystems are often less diverse than the natural or agricultural lands they replace, leading to potential losses in ecosystem functioning. Research in non-urban systems has provided evidence for increases in multiple ecosystem functions associated with greater plant diversity. To test if biodiversity-ecosystem function findings are applicable to urban grasslands, we examined the effect of plant species and genotypic diversity on three ecosystem functions, using grassland assemblages of increasing diversity that were grown within a controlled environment facility. We found positive effects of plant diversity on reduced nitrate leaching and plant productivity. Soil microbial diversity (Mean Shannon Diversity, H’) of bacteria and fungi were also enhanced in multi-species plantings, suggesting that moderate increments in plant diversity influence the composition of soil biota. The results from this study indicate that plant diversity impacts multiple functions that are important in urban ecosystems; therefore, further tests of urban grassland biodiversity should be examined in situ to determine the feasibility of manipulating plant diversity as an explicit landscape design and function trait. PMID:27243768

  20. Diversity Enhances NPP, N Retention, and Soil Microbial Diversity in Experimental Urban Grassland Assemblages.

    PubMed

    Thompson, Grant L; Kao-Kniffin, Jenny

    2016-01-01

    Urban grasslands, landscapes dominated by turfgrasses for aesthetic or recreational groundcovers, are rapidly expanding in the United States and globally. These managed ecosystems are often less diverse than the natural or agricultural lands they replace, leading to potential losses in ecosystem functioning. Research in non-urban systems has provided evidence for increases in multiple ecosystem functions associated with greater plant diversity. To test if biodiversity-ecosystem function findings are applicable to urban grasslands, we examined the effect of plant species and genotypic diversity on three ecosystem functions, using grassland assemblages of increasing diversity that were grown within a controlled environment facility. We found positive effects of plant diversity on reduced nitrate leaching and plant productivity. Soil microbial diversity (Mean Shannon Diversity, H') of bacteria and fungi were also enhanced in multi-species plantings, suggesting that moderate increments in plant diversity influence the composition of soil biota. The results from this study indicate that plant diversity impacts multiple functions that are important in urban ecosystems; therefore, further tests of urban grassland biodiversity should be examined in situ to determine the feasibility of manipulating plant diversity as an explicit landscape design and function trait.

  1. Probiotic Diversity Enhances Rhizosphere Microbiome Function and Plant Disease Suppression

    PubMed Central

    Hu, Jie; Friman, Ville-Petri; Gu, Shao-hua; Wang, Xiao-fang; Eisenhauer, Nico; Yang, Tian-jie; Ma, Jing; Shen, Qi-rong; Jousset, Alexandre

    2016-01-01

    ABSTRACT Bacterial communities associated with plant roots play an important role in the suppression of soil-borne pathogens, and multispecies probiotic consortia may enhance disease suppression efficacy. Here we introduced defined Pseudomonas species consortia into naturally complex microbial communities and measured the importance of Pseudomonas community diversity for their survival and the suppression of the bacterial plant pathogen Ralstonia solanacearum in the tomato rhizosphere microbiome. The survival of introduced Pseudomonas consortia increased with increasing diversity. Further, high Pseudomonas diversity reduced pathogen density in the rhizosphere and decreased the disease incidence due to both intensified resource competition and interference with the pathogen. These results provide novel mechanistic insights into elevated pathogen suppression by diverse probiotic consortia in naturally diverse plant rhizospheres. Ecologically based community assembly rules could thus play a key role in engineering functionally reliable microbiome applications. PMID:27965449

  2. Diversity and Relatedness Enhance Survival in Colour Polymorphic Grasshoppers

    PubMed Central

    Caesar, Sofia; Karlsson, Magnus; Forsman, Anders

    2010-01-01

    Evolutionary theory predicts that different resource utilization and behaviour by alternative phenotypes may reduce competition and enhance productivity and individual performance in polymorphic, as compared with monomorphic, groups of individuals. However, firm evidence that members of more heterogeneous groups benefit from enhanced survival has been scarce or lacking. Furthermore, benefits associated with phenotypic diversity may be counterbalanced by costs mediated by reduced relatedness, since closely related individuals typically are more similar. Pygmy grasshoppers (Tetrix subulata) are characterized by extensive polymorphism in colour pattern, morphology, behaviour and physiology. We studied experimental groups founded by different numbers of mothers and found that survival was higher in low than in high density, that survival peaked at intermediate colour morph diversity in high density, and that survival was independent of diversity in low density where competition was less intense. We further demonstrate that survival was enhanced by relatedness, as expected if antagonistic and competitive interactions are discriminately directed towards non-siblings. We therefore also performed behavioural observations and staged encounters which confirmed that individuals recognized and responded differently to siblings than to non-siblings. We conclude that negative effects associated with competition are less manifest in diverse groups, that there is conflicting selection for and against genetic diversity occurring simultaneously, and that diversity and relatedness may facilitate the productivity and ecological success of groups of interacting individuals. PMID:20526364

  3. Diversity and relatedness enhance survival in colour polymorphic grasshoppers.

    PubMed

    Caesar, Sofia; Karlsson, Magnus; Forsman, Anders

    2010-05-28

    Evolutionary theory predicts that different resource utilization and behaviour by alternative phenotypes may reduce competition and enhance productivity and individual performance in polymorphic, as compared with monomorphic, groups of individuals. However, firm evidence that members of more heterogeneous groups benefit from enhanced survival has been scarce or lacking. Furthermore, benefits associated with phenotypic diversity may be counterbalanced by costs mediated by reduced relatedness, since closely related individuals typically are more similar. Pygmy grasshoppers (Tetrix subulata) are characterized by extensive polymorphism in colour pattern, morphology, behaviour and physiology. We studied experimental groups founded by different numbers of mothers and found that survival was higher in low than in high density, that survival peaked at intermediate colour morph diversity in high density, and that survival was independent of diversity in low density where competition was less intense. We further demonstrate that survival was enhanced by relatedness, as expected if antagonistic and competitive interactions are discriminately directed towards non-siblings. We therefore also performed behavioural observations and staged encounters which confirmed that individuals recognized and responded differently to siblings than to non-siblings. We conclude that negative effects associated with competition are less manifest in diverse groups, that there is conflicting selection for and against genetic diversity occurring simultaneously, and that diversity and relatedness may facilitate the productivity and ecological success of groups of interacting individuals.

  4. Documenting clinical performance problems among medical students: feedback for learner remediation and curriculum enhancement.

    PubMed

    Mavis, Brian E; Wagner, Dianne P; Henry, Rebecca C; Carravallah, Laura; Gold, Jon; Maurer, Joel; Mohmand, Asad; Osuch, Janet; Roskos, Steven; Saxe, Andrew; Sousa, Aron; Prins, Vince Winkler

    2013-01-01

    Introduction We operationalized the taxonomy developed by Hauer and colleagues describing common clinical performance problems. Faculty raters pilot tested the resulting worksheet by observing recordings of problematic simulated clinical encounters involving third-year medical students. This approach provided a framework for structured feedback to guide learner improvement and curricular enhancement. Methods Eighty-two problematic clinical encounters from M3 students who failed their clinical competency examination were independently rated by paired clinical faculty members to identify common problems related to the medical interview, physical examination, and professionalism. Results Eleven out of 26 target performance problems were present in 25% or more encounters. Overall, 37% had unsatisfactory medical interviews, with 'inadequate history to rule out other diagnoses' most prevalent (60%). Seventy percent failed because of physical examination deficiencies, with missing elements (69%) and inadequate data gathering (69%) most common. One-third of the students did not introduce themselves to their patients. Among students failing based on standardized patient (SP) ratings, 93% also failed to demonstrate competency based on the faculty ratings. Conclusions Our review form allowed clinical faculty to validate pass/fail decisions based on standardized patient ratings. Detailed information about performance problems contributes to learner feedback and curricular enhancement to guide remediation planning and faculty development.

  5. Ecosystem recovery after climatic extremes enhanced by genotypic diversity

    PubMed Central

    Reusch, Thorsten B. H.; Ehlers, Anneli; Hämmerli, August; Worm, Boris

    2005-01-01

    Contemporary climate change is characterized both by increasing mean temperature and increasing climate variability such as heat waves, storms, and floods. How populations and communities cope with such climatic extremes is a question central to contemporary ecology and biodiversity conservation. Previous work has shown that species diversity can affect ecosystem functioning and resilience. Here, we show that genotypic diversity can replace the role of species diversity in a species-poor coastal ecosystem, and it may buffer against extreme climatic events. In a manipulative field experiment, increasing the genotypic diversity of the cosmopolitan seagrass Zostera marina enhanced biomass production, plant density, and faunal abundance, despite near-lethal water temperatures due to extreme warming across Europe. Net biodiversity effects were explained by genotypic complementarity rather than by selection of particularly robust genotypes. Positive effects on invertebrate fauna suggest that genetic diversity has second-order effects reaching higher trophic levels. Our results highlight the importance of maintaining genetic as well as species diversity to enhance ecosystem resilience in a world of increasing uncertainty. PMID:15710890

  6. From Remediation to Acceleration: Recruiting, Retaining, and Graduating Future Culturally and Linguistically Diverse (CLD) Educators

    ERIC Educational Resources Information Center

    Herrera, Socorro G.; Morales, Amanda R.; Holmes, Melissa A.; Terry, Dawn Herrera

    2012-01-01

    This ethnographic case study explores one mid-western state university's response to the challenge of culturally and linguistically diverse (CLD), especially Latino/a, student recruitment and retention. BESITOS (Bilingual/Bicultural Education Students Interacting To Obtain Success) is an integrated teacher preparation program implemented at a…

  7. Teaching Strategies for Enhancing Peer Interaction among Diverse Learners

    ERIC Educational Resources Information Center

    Sit, Helena Hing Wa

    2012-01-01

    Hong Kong's universities have been attracting non-local students to diversify the overall student mix and enhance internationalism in higher education. Mainland Chinese students have become the largest non-local student source in this Western-style higher education sector. The diversity of student body together with the promotion of multicultural…

  8. Perchlorate and nitrate remediation efficiency and microbial diversity in a containerized wetland bioreactor.

    PubMed

    Krauter, Paula; Daily, Bill; Dibley, Valerie; Pinkart, Holly; Legler, Tina

    2005-01-01

    We have developed a method to remove perchlorate (14-27 microg/L) and nitrate (48 mg/L) from contaminated groundwater using a wetland bioreactor. The bioreactor has operated continuously in a remote field location for more than 2 yr with a stable ecosystem of indigenous organisms. This study assesses the bioreactorfor long-term perchlorate and nitrate remediation by evaluating influent and effluent groundwater for oxidation-reduction conditions and nitrate and perchlorate concentrations. Total community DNA was extracted and purified from 10-g sediment samples retrieved from vertical coring of the bioreactor during winter. Analysis by denaturing gradient gel electrophoresis of short, 16S rDNA, polymerase-chainreaction products was used to identify dominant microorganisms. Bacteria genera identified were closely affiliated with bacteria widely distributed in soils, mud layers, and fresh water. Of the 17 dominant bands sequenced, most were gram negative and capable of aerobic or anaerobic respiration with nitrate as the terminal electron acceptor (Pseudomonas, Acinetobacter, Halomonas, and Nitrospira). Several identified genera (Rhizobium, Acinetobactor, and Xanthomonas) are capable of fixing atmospheric nitrogen into a combined form (ammonia) usable by host plants. Isolates were identified from the Proteobacteria class, known for the ability to reduce perchlorate. Initial bacterial assessments of sediments confirm the prevalence of facultative anaerobic bacteria capable of reducing perchlorate and nitrate in situ.

  9. Perchlorate and Nitrate Remediation Efficiency and Microbial Diversity in a Containerized Wetland Bioreactor

    SciTech Connect

    Jr., B D; Dibley, V; Pinkart, H; Legler, T

    2004-06-09

    We have developed a method to remove perchlorate (14 to 27 {micro}g/L) and nitrate (48 mg/L) from contaminated groundwater using a wetland bioreactor. The bioreactor has operated continuously in a remote field location for more than two years with a stable ecosystem of indigenous organisms. This study assesses the bioreactor for long-term perchlorate and nitrate remediation by evaluating influent and effluent groundwater for reduction-oxidation conditions and nitrate and perchlorate concentrations. Total community DNA was extracted and purified from 10-g sediment samples retrieved from vertical coring of the bioreactor during winter. Analysis by denaturing gradient gel electrophoresis of short, 16S rDNA, polymerase-chain-reaction products was used to identify dominant microorganisms. Bacteria genera identified were closely affiliated with bacteria widely distributed in soils, mud layers, and fresh water. Of the 17 dominant bands sequenced, most were gram negative and capable of aerobic or anaerobic respiration with nitrate as the terminal electron acceptor (Pseudomonas, Acinetobacter, Halomonas, and Nitrospira). Several identified genera (Rhizobium, Acinetobactor, and Xanthomonas) are capable of fixing atmospheric nitrogen into a combined form (ammonia) usable by host plants. Isolates were identified from the Proteobacteria class, known for the ability to reduce perchlorate. Initial bacterial assessments of sediments confirm the prevalence of facultative anaerobic bacteria capable of reducing perchlorate and nitrate in situ.

  10. SETTING DATA QUALITY OBJECTIVES FOR THERMALLY ENHANCED, IN SITU REMEDIATION PROJECTS

    EPA Science Inventory

    The design and implementation of an in-situ technology requires an up-front and clear understanding of the remedial objectives of the technology application and the data that will be collected to track the progress of remediation and to assess the ultimate success of in-sit...

  11. SETTING DATA QUALITY OBJECTIVES FOR THERMALLY ENHANCED, IN SITU REMEDIATION PROJECTS

    EPA Science Inventory

    The design and implementation of an in-situ technology requires an up-front and clear understanding of the remedial objectives of the technology application and the data that will be collected to track the progress of remediation and to assess the ultimate success of in-sit...

  12. Enhanced remediation of chlorpyrifos by ryegrass (Lolium multiflorum) and a chlorpyrifos degrading bacterial endophyte Mezorhizobium sp. HN3.

    PubMed

    Jabeen, Hina; Iqbal, Samina; Ahmad, Fiaz; Afzal, Muhammad; Firdous, Sadiqa

    2016-01-01

    For effective remediation of contaminants, plant-endophyte partnership is a promising field to be explored. Generally endophytic bacteria assist their host plant by withstanding the stress induced by the contaminants. The objective of this study was to explore the suitability of plant-bacterial partnership for chlorpyrifos (CP) remediation using ryegrass and a CP degrading endophyte, Mesorhizobium sp. HN3 which belongs to plant growth promoting rhizobia. The inoculated yfp-tagged Mesorhizobium sp. HN3 efficiently colonized in the rhizosphere, enhanced plant growth and degradation of CP and its metabolite 3,5,6 trichloro-2-pyridinol (TCP). Significantly lower CP residues were observed in the roots and shoots of plants vegetated in inoculated soil which might be attributed to the efficient root colonization of HN3yfp. These results suggest the involvement of Mesorhizobium sp. HN3yfp in CP degradation inside the roots and rhizosphere of plants and further emphasize on the effectiveness of endophytic bacteria in stimulating the remediation of pesticide contaminants. This is the first report which demonstrates the efficacy of bacterial endophyte for degradation of CP residues taken up by the plant and enhanced remediation of chlorpyrifos contaminated soil.

  13. Removal of heavy metals from contaminated soil by electrodialytic remediation enhanced with organic acids.

    PubMed

    Merdoud, Ouarda; Cameselle, Claudio; Boulakradeche, Mohamed Oualid; Akretche, Djamal Eddine

    2016-11-09

    The soil from an industrial area in Algeria was contaminated with Cr (8370 mg kg(-1)), Ni (1135 mg kg(-1)) and zinc (1200 mg kg(-1)). The electrodialytic remediation of this soil was studied using citric acid and EDTA as facilitating agents. 0.1 M citric acid or EDTA was added directly to the soil before it was introduced in an electrodialytic cell in an attempt to enhance the heavy metal solubility in the interstitial fluid. The more acidic pH in the soil when citric acid was used as the facilitating agent was not enough to mobilize and remove the metals from the soil. Only 7.2% of Ni and 6.7% of Zn were removed from the soil in the test with citric acid. The best results were found with EDTA, which was able to solubilize and complex Zn and Ni forming negatively charged complexes that were transported and accumulated in the anolyte. Complete removal was observed for Ni and Zn in the electrodialytic treatment with EDTA. Minor amounts of Cr were removed with both EDTA and citric acid.

  14. Electrokinetic-enhanced bioaugmentation for remediation of chlorinated solvents contaminated clay

    PubMed Central

    Mao, Xuhui; Wang, James; Ciblak, Ali; Cox, Evan E.; Riis, Charlotte; Terkelsen, Mads; Gent, David B.; Alshawabkeh, Akram N.

    2012-01-01

    Successful bioremediation of contaminated soils is controlled by the ability to deliver bioremediation additives, such as bacteria and/or nutrients, to the contaminated zone. Because hydraulic advection is not practical for delivery in clays, electrokinetic (EK) injection is an alternative for efficient and uniform delivery of bioremediation additive into low-permeability soil and heterogeneous deposits. EK–enhanced bioaugmentation for remediation of clays contaminated with chlorinated solvents is evaluated. Dehalococcoides (Dhc) bacterial strain and lactate ions are uniformly injected in contaminated clay and complete dechlorination of chlorinated ethene is observed in laboratory experiments. The injected bacteria can survive, grow, and promote effective dechlorination under EK conditions and after EK application. The distribution of Dhc within the clay suggests that electrokinetic transport of Dhc is primarily driven by electroosmosis. In addition to biodegradation due to bioaugmentation of Dhc, an EK-driven transport of chlorinated ethenes is observed in the clay, which accelerates cleanup of chlorinated ethenes from the anode side. Compared with conventional advection-based delivery, EK injection is significantly more effective forestablis hingmicrobial reductive dechlorination capacity in low-permeability soils. PMID:22365139

  15. Potential enhancements to addressing programmatic risk in the tank waste remediation system (TWRS) program

    SciTech Connect

    Brothers, A.; Fassbender, L.; Bilyard, G.; Levine, L.

    1996-04-01

    Pacific Northwest National Laboratory (PNNL) conducted a Tank Waste Remediation System (TWRS) Risk Management methodology development task. The objective of this task was to develop risk management methodology focused on (1) the use of programmatic risk information in making TWRS architecture selection decisions and (2) the identification/evaluation/selection of TWRS risk-handling actions. Methods for incorporating programmatic risk/uncertainty estimates into trade studies are provided for engineers/analysts. Methods for identifying, evaluating, and selecting risk-handling actions are provided for managers. The guidance provided in this report is designed to help decision-makers make difficult judgments. Current approaches to architecture selection decisions and identification/evaluation/selection of risk-handling actions are summarized. Three categories of sources of programmatic risk (parametric, external, and organizational) are examined. Multiple analytical approaches are presented to enhance the current alternative generation and analysis (AGA) and risk-handling procedures. Appendix A describes some commercially available risk management software tools and Appendix B provides a brief introduction to quantification of risk attitudes. The report provides three levels of analysis for enhancing the AGA Procedure: (1) qualitative discussion coupled with estimated uncertainty ranges for scores in the alternatives-by-criteria matrix; (2) formal elicitation of probability distributions for the alternative scores; and (3) a formal, more structured, comprehensive risk analysis. A framework is also presented for using the AGA programmatic risk analysis results in making better decisions. The report also presents two levels of analysis for evaluation and selection of risk-handling actions: (1) qualitative analysis and judgmental rankings of alternative actions, and (2) Simple Multi-Attribute Rating Technique (SMART).

  16. Developmental, Remedial, and Basic Skills: Diverse Programs and Approaches at Community Colleges

    ERIC Educational Resources Information Center

    Hagedorn, Linda Serra; Kuznetsova, Inna

    2016-01-01

    Community colleges have been challenged to increase their graduation, transfer, and general success rates. Because they serve the largest proportion of nontraditional students and students of color, their participation in programs to enhance the number of college graduates contributes to social equity and justice. One of the biggest obstacles has…

  17. Electrokinetic-Enhanced Remediation of Phenanthrene-Contaminated Soil Combined with Sphingomonas sp. GY2B and Biosurfactant.

    PubMed

    Lin, Weijia; Guo, Chuling; Zhang, Hui; Liang, Xujun; Wei, Yanfu; Lu, Guining; Dang, Zhi

    2016-04-01

    Electrokinetic-microbial remediation (EMR) has emerged as a promising option for the removal of polycyclic aromatic hydrocarbons (PAHs) from contaminated soils. The aim of this study was to enhance degradation of phenanthrene (Phe)-contaminated soils using EMR combined with biosurfactants. The electrokinetic (EK) remediation, combined with Phe-degrading Sphingomonas sp. GY2B, and biosurfactant obtained by fermentation of Pseudomonas sp. MZ01, degraded Phe in the soil with an efficiency of up to 65.1 % at the anode, 49.9 % at the cathode after 5 days of the treatment. The presence of biosurfactants, electricity, and a neutral electrolyte stimulated the growth of the degrading bacteria as shown by a rapid increase in microbial biomass with time. The electrical conductivity and pH changed little during the course of the treatment, which benefitted the growth of microorganisms and the remediation of Phe-contaminated soil. The EMR system with the addition of biosurfactant had the highest Phe removal, demonstrating the biosurfactant may enhance the bioavailability of Phe and the interaction with the microorganism. This study suggests that the EMR combined with biosurfactants can be used to enhance in situ bioremediation of PAH-contaminated soils.

  18. Fermented liquid feed enhances bacterial diversity in piglet intestine.

    PubMed

    Tajima, Kiyoshi; Ohmori, Hideyuki; Aminov, Rustam I; Kobashi, Yuri; Kawashima, Tomoyuki

    2010-02-01

    Because of limitations imposed on the antibiotic use in animal industry, there is a need for alternatives to maintain the efficiency of production. One of them may be the use of fermented liquid feed (FLF) but how it affects gut ecology is poorly understood. We investigated the effect of three diets, standard dry feed (control), dry feed supplemented with antibiotics, and fermented liquid feed (FLF, fermented with Lactobacillus plantarum), on gut bacterial diversity in piglets. The structure of the ileal and caecal communities was estimated by sequencing the SSU rRNA gene libraries. Antibiotic-supplemented feed slightly increased bacterial diversity in the ileum but reduced it in the caecum while in FLF-fed animals bacterial diversity was elevated. The majority of bacterial sequences in the ileum of all three groups belonged to lactobacilli (92-98%). In the caecum the lactobacilli were still dominant in control and antibiotic-fed animals (59% and 64% of total bacterial sequences, respectively) but in FLF-fed animals they fell to 31% with the concomitant increase in the Firmicutes diversity represented by the Dorea, Coprococcus, Roseburia and Faecalibacterium genera. Thus FLF affects the gut ecology in a different way than antibiotics and contributes to the enhanced bacterial diversity in the gastrointestinal tract.

  19. Addition of allochthonous fungi to a historically contaminated soil affects both remediation efficiency and bacterial diversity.

    PubMed

    Federici, Ermanno; Leonardi, Vanessa; Giubilei, Maria A; Quaratino, Daniele; Spaccapelo, Roberta; D'Annibale, Alessandro; Petruccioli, Maurizio

    2007-11-01

    Botryosphaeria rhodina DABAC P82 and Pleurotus pulmonarius CBS 664.97 were tested for their ability to grow and to degrade aromatic hydrocarbons in an aged contaminated soil. To evaluate the impact of indigenous microflora on the overall process, incubations were performed on both fumigated and nonfumigated soils. Fungal colonization by B. rhodina was unexpectedly lower in the fumigated than in the nonfumigated soil while the growth of P. pulmonarius showed an opposite response. Degradation performances and detoxification by both fungi in the nonfumigated soil were markedly higher than those observed in the fumigated one. Heterotrophic bacterial counts in nonfumigated soil augmented with either B. rhodina or P. pulmonarius were significantly higher than those of the corresponding incubation control (6.7 +/- 0.3 x 10(8) and 8.35 +/- 0.6 x 10(8), respectively, vs 9.2 +/- 0.3 x 10(7)). Bacterial communities of both incubation controls and fungal-augmented soil were compared by numerical analysis of denaturing gradient gel electrophoresis profiles of polymerase chain reaction (PCR)-amplified 16S ribosomal RNA (rRNA) genes and cloning and sequencing of PCR-amplified 16S rRNA genes. Besides increasing overall diversity, fungal augmentation led to considerable qualitative differences with respect to the pristine soil.

  20. [Continuous remediation of heavy metal contaminated soil by co-cropping system enhanced with chelator].

    PubMed

    Wei, Ze-Bin; Guo, Xiao-Fang; Wu, Qi-Tang; Long, Xin-Xian

    2014-11-01

    In order to elucidate the continuous effectiveness of co-cropping system coupling with chelator enhancement in remediating heavy metal contaminated soils and its environmental risk towards underground water, soil lysimeter (0.9 m x 0.9 m x 0.9 m) experiments were conducted using a paddy soil affected by Pb and Zn mining in Lechang district of Guangdong Province, 7 successive crops were conducted for about 2.5 years. The treatments included mono-crop of Sedum alfredii Hance (Zn and Cd hyperaccumulator), mono-crop of corn (Zea mays, cv. Yunshi-5, a low-accumulating cultivar), co-crop of S. alfredii and corn, and co-crop + MC (Mixture of Chelators, comprised of citric acid, monosodium glutamate waste liquid, EDTA and KCI with molar ratio of 10: 1:2:3 at the concentration of 5 mmol x kg(-1) soil). The changes of heavy metal concentrations in plants, soil and underground water were monitored. Results showed that the co-cropping system was suitable only in spring-summer seasons and significantly increased Zn and Cd phytoextraction. In autumn-winter seasons, the growth of S. alfredii and its phytoextraction of Zn and Cd were reduced by co-cropping and MC application. In total, the mono-crops of S. alfredii recorded a highest phytoextraction of Zn and Cd. However, the greatest reduction of soil Zn, Cd and Pb was observed with the co-crop + MC treatment, the reduction rates were 28%, 50%, and 22%, respectively, relative to the initial soil metal content. The reduction of this treatment was mainly attributed to the downwards leaching of metals to the subsoil caused by MC application. The continuous monitoring of leachates during 2. 5 year's experiment also revealed that the addition of MC increased heavy metal concentrations in the leaching water, but they did not significantly exceed the III grade limits of the underground water standard of China.

  1. Green remediation: enhanced reductive dechlorination using recycled rinse water as bioremediation substrate

    SciTech Connect

    Dawson, Gaynor; McKeon, Tom

    2007-07-01

    Enhanced reductive dechlorination (ERD) has rapidly become a remedy of choice for use on chlorinated solvent contamination when site conditions allow. With this approach, solutions of an organic substrate are injected into the affected aquifer to stimulate biological growth and the resultant production of reducing conditions in the target zone. Under the reducing conditions, hydrogen is produced and ultimately replaces chlorine atoms on the contaminant molecule causing sequential dechlorination. Under suitable conditions the process continues until the parent hydrocarbon precursor is produced, such as the complete dechlorination of trichloroethylene (TCE) to ethene. The process is optimized by use of a substrate that maximizes hydrogen production per unit cost. When natural biota are not present to promote the desired degradation, inoculates can be added with the substrate. The in-situ method both reduces cost and accelerates cleanup. Successful applications have been extended from the most common chlorinated compounds perchloroethylene (PCE) and TCE and related products of degradation, to perchlorate, and even explosives such as RDX and trinitrotoluene on which nitrates are attacked in lieu of chloride. In recent work, the process has been further improved through use of beverage industry wastewaters that are available at little or no cost. With material cost removed from the equation, applications can maximize the substrate loading without significantly increasing total cost. The extra substrate loading both accelerates reaction rates and extends the period of time over which reducing conditions are maintained. In some cases, the presence of other organic matter in addition to simple sugars provides for longer performance times of individual injections, thereby working in a fashion similar to emulsified vegetable oil. The paper discusses results of applications at three different sites contaminated with chlorinated ethylenes. The applications have included

  2. DEMONSTRATION OF PILOT-SCALE PERVAPORATION SYSTEMS FOR VOLATILE ORGANIC COMPOUND REMOVAL FROM A SURFACTANT ENHANCED AQUIFER REMEDIATION FLUID. II. HOLLOW FIBER MEMBRANE MODULES

    EPA Science Inventory

    Pilot-scale demonstration of pervaporation-based removal of volatile organic compounds from a surfactant enhanced aquifer remediation (SEAR) fluid has been conducted at USEPA's Test & Evaluation Facility using hollow fiber membrane modules. The membranes consisted of microporous...

  3. The Effectiveness of Creative Drama as an Instructional Strategy to Enhance the Reading Comprehension Skills of Fifth-Grade Remedial Readers.

    ERIC Educational Resources Information Center

    DuPont, Sherry

    1992-01-01

    Finds that fifth grade remedial reading students' comprehension skill, as measured by standardized and criterion-referenced tests, are enhanced through a reading program that utilizes the strategy of creative drama integrated with children's literature reading material. (SR)

  4. DEMONSTRATION OF PILOT-SCALE PERVAPORATION SYSTEMS FOR VOLATILE ORGANIC COMPOUND REMOVAL FROM A SURFACTANT ENHANCED AQUIFER REMEDIATION FLUID. II. HOLLOW FIBER MEMBRANE MODULES

    EPA Science Inventory

    Pilot-scale demonstration of pervaporation-based removal of volatile organic compounds from a surfactant enhanced aquifer remediation (SEAR) fluid has been conducted at USEPA's Test & Evaluation Facility using hollow fiber membrane modules. The membranes consisted of microporous...

  5. Development, Discouragement, or Diversion? New Evidence on the Effects of College Remediation. NBER Working Paper No. 18328

    ERIC Educational Resources Information Center

    Scott-Clayton, Judith; Rodriguez, Olga

    2012-01-01

    Half of all college students take at least one remedial course as part of their postsecondary experience, despite mixed evidence on the effectiveness of this intervention. Using a regression-discontinuity design with data from a large urban community college system, we extend the research on remediation in three ways. First, we articulate three…

  6. Soil invertebrate fauna enhances grassland succession and diversity.

    PubMed

    De Deyn, Gerlinde B; Raaijmakers, Ciska E; Zoomer, H Rik; Berg, Matty P; de Ruiter, Peter C; Verhoef, Herman A; Bezemer, T Martijn; van der Putten, Wim H

    2003-04-17

    One of the most important areas in ecology is to elucidate the factors that drive succession in ecosystems and thus influence the diversity of species in natural vegetation. Significant mechanisms in this process are known to be resource limitation and the effects of aboveground vertebrate herbivores. More recently, symbiotic and pathogenic soil microbes have been shown to exert a profound effect on the composition of vegetation and changes therein. However, the influence of invertebrate soil fauna on succession has so far received little attention. Here we report that invertebrate soil fauna might enhance both secondary succession and local plant species diversity. Soil fauna from a series of secondary grassland succession stages selectively suppress early successional dominant plant species, thereby enhancing the relative abundance of subordinate species and also that of species from later succession stages. Soil fauna from the mid-succession stage had the strongest effect. Our results clearly show that soil fauna strongly affects the composition of natural vegetation and we suggest that this knowledge might improve the restoration and conservation of plant species diversity.

  7. Enhancing (crop) plant photosynthesis by introducing novel genetic diversity.

    PubMed

    Dann, Marcel; Leister, Dario

    2017-09-26

    Although some elements of the photosynthetic light reactions might appear to be ideal, the overall efficiency of light conversion to biomass has not been optimized during evolution. Because crop plants are depleted of genetic diversity for photosynthesis, efforts to enhance its efficiency with respect to light conversion to yield must generate new variation. In principle, three sources of natural variation are available: (i) rare diversity within extant higher plant species, (ii) photosynthetic variants from algae, and (iii) reconstruction of no longer extant types of plant photosynthesis. Here, we argue for a novel approach that outsources crop photosynthesis to a cyanobacterium that is amenable to adaptive evolution. This system offers numerous advantages, including a short generation time, virtually unlimited population sizes and high mutation rates, together with a versatile toolbox for genetic manipulation. On such a synthetic bacterial platform, 10 000 years of (crop) plant evolution can be recapitulated within weeks. Limitations of this system arise from its unicellular nature, which cannot reproduce all aspects of crop photosynthesis. But successful establishment of such a bacterial host for crop photosynthesis promises not only to enhance the performance of eukaryotic photosynthesis but will also reveal novel facets of the molecular basis of photosynthetic flexibility.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'. © 2017 The Author(s).

  8. Low-concentration tailing and subsequent quicklime-enhanced remediation of volatile chlorinated hydrocarbon-contaminated soils by mechanical soil aeration.

    PubMed

    Ma, Yan; Du, Xiaoming; Shi, Yi; Xu, Zhu; Fang, Jidun; Li, Zheng; Li, Fasheng

    2015-02-01

    Mechanical soil aeration has long been regarded as an effective ex-situ remediation technique and as suitable for remediation of large-scale sites contaminated by volatile organic compounds (VOCs) at low cost. However, it has been reported that the removal efficiency of VOCs from soil is relatively low in the late stages of remediation, in association with tailing. Tailing may extend the remediation time required; moreover, it typically results in the presence of contaminants residues at levels far exceeding regulations. In this context, the present study aimed to discuss the tailing that occurs during the process of remediation of soils contaminated artificially with volatile chlorinated hydrocarbons (VCHs) and to assess possible quicklime-enhanced removal mechanisms. The results revealed the following conclusions. First, temperature and aeration rate can be important controls on both the timing of appearance of tailing and the levels of residual contaminants. Furthermore, the addition of quicklime to soil during tailing can reduce the residual concentrations rapidly to below the remedial target values required for site remediation. Finally, mechanical soil aeration can be enhanced using quicklime, which can improve the volatilization of VCHs via increasing soil temperature, reducing soil moisture, and enhancing soil permeability. Our findings give a basic understanding to the elimination of the tailing in the application of mechanical soil aeration, particularly for VOCs-contaminated soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. 78 FR 13294 - Enhanced Prudential Standards and Early Remediation Requirements for Foreign Banking...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-27

    ... Foreign Banking Organizations and Foreign Nonbank Financial Companies AGENCY: Board of Governors of the... and the early remediation requirements established under section 166 of the Act for foreign banking... Requirements for Foreign Banking Organizations and Foreign Nonbank Financial Companies, 77 FR 76628 (December...

  10. Arsenic Remediation Enhancement Through Chemical Additions to Pump and Treat Operations

    NASA Astrophysics Data System (ADS)

    Wovkulich, K.; Mailloux, B. J.; Stute, M.; Simpson, H. J.; Keimowitz, A. R.; Powell, A.; Lacko, A.; Chillrud, S. N.

    2008-12-01

    Arsenic is a contaminant found at more than 500 US Superfund sites. Since pump and treat technologies are widely used for remediation of contaminated groundwater, increasing the efficiency of contaminant removal at such sites should allow limited financial resources to clean up more sites. The Vineland Chemical Company Superfund site is extensively contaminated with arsenic after waste arsenic salts were stored and disposed of improperly for much of the company's 44 year manufacturing lifetime. Despite approximately eight years of pump and treat remediation, arsenic concentrations in the recovery wells can still be greater than 1000 ppb. The arsenic concentrations in the groundwater remain high because of slow desorption of arsenic from contaminated aquifer solids. Extrapolation of laboratory column experiments suggest that continuing the current groundwater remediation practice based on flushing ambient groundwater through the system may require on the order of hundreds of years to clean the site. However, chemical additions of phosphate or oxalic acid into the aquifer could decrease the remediation time scale substantially. Laboratory results from a soil column experiment using input of 10 mM oxalic acid suggest that site clean up of groundwater could be decreased to as little as four years. Pilot scale forced gradient field experiments will help establish whether chemical additions can be effective for increasing arsenic mobilization from aquifer solids and thus substantially decrease pump and treat clean up time.

  11. Part 2: A field study of enhanced remediation of Toluene in the vadose zone using a nutrient solution

    USGS Publications Warehouse

    Tindall, J.A.; Weeks, E.P.; Friedel, M.

    2005-01-01

    The objective of this study was to test the effectiveness of a nitrate-rich nutrient solution and hydrogen peroxide (H2O2) to enhance in-situ microbial remediation of toluene in the unsaturated zone. Three sand-filled plots were tested in three phases (each phase lasting approximately 2 weeks). During the control phase, toluene was applied uniformly via sprinkler irrigation. Passive remediation was allowed to occur during this phase. A modified Hoagland nutrient solution, concentrated in 150 L of water, was tested during the second phase. The final phase involved addition of 230 moles of H2O2 in 150 L of water to increase the available oxygen needed for aerobic biodegradation. During the first phase, measured toluene concentrations in soil gas were reduced from 120 ppm to 25 ppm in 14 days. After the addition of nutrients during the second phase, concentrations were reduced from 90 ppm to about 8 ppm within 14 days, and for the third phase (H 2O2), toluene concentrations were about 1 ppm after only 5 days. Initial results suggest that this method could be an effective means of remediating a contaminated site, directly after a BTEX spill, without the intrusiveness and high cost of other abatement technologies such as bioventing or soil-vapor extraction. However, further tests need to be completed to determine the effect of each of the BTEX components. ?? Springer 2005.

  12. Enhanced Remediation of Toluene in the Vadose Zone via a Nitrate-Rich Nutrient Solution: Field Study

    NASA Astrophysics Data System (ADS)

    Tindall, J. A.; Friedel, M. J.

    2003-12-01

    The objective of this study was to test the effectiveness of nitrate-rich nutrient solutions and hydrogen peroxide (H202) to enhance in-situ microbial remediation of toluene. Three sand filled plots (2 m2 surface area and 1.5 meters deep) were tested in three phases (each phase lasting approximately 2 weeks). During each phase, toluene (21.6 mol as an emulsion in 50L of water) was applied uniformly via sprinkler irrigation. Passive remediation was allowed to occur during the first (control) phase. A nutrient solution (modified Hoagland), concentrated in 40L of water, was tested during the second phase. The final phase involved addition of 230 moles of H202 in 50L of water to increase the available oxygen needed for aerobic biodegradation. During the first phase, toluene concentrations in soil gas were reduced from 120 ppm to 25 ppm in 14 days. After the addition of nutrients during the second phase, concentrations were reduced from 90 ppm to about 8 ppm within 14 days, and for the third phase (H202), toluene concentrations were about 1 ppm after only five days. Initial results suggest that this method could be an effective means of remediating a contaminated site, directly after a BTEX spill, without the intrusiveness and high cost of other abatement technologies such as bioventing and soil vapor extraction. However, further tests need to be completed to determine the effect of each of the BTEX components.

  13. Microbial metabolism and community structure in response to bioelectrochemically enhanced remediation of petroleum hydrocarbon-contaminated soil.

    PubMed

    Lu, Lu; Huggins, Tyler; Jin, Song; Zuo, Yi; Ren, Zhiyong Jason

    2014-04-01

    This study demonstrates that electrodes in a bioelectrochemical system (BES) can potentially serve as a nonexhaustible electron acceptor for in situ bioremediation of hydrocarbon contaminated soil. The deployment of BES not only eliminates aeration or supplement of electron acceptors as in contemporary bioremediation but also significantly shortens the remediation period and produces sustainable electricity. More interestingly, the study reveals that microbial metabolism and community structure distinctively respond to the bioelectrochemically enhanced remediation. Tubular BESs with carbon cloth anode (CCA) or biochar anode (BCA) were inserted into raw water saturated soils containing petroleum hydrocarbons for enhancing in situ remediation. Results show that total petroleum hydrocarbon (TPH) removal rate almost doubled in soils close to the anode (63.5-78.7%) than that in the open circuit positive controls (37.6-43.4%) during a period of 64 days. The maximum current density from the BESs ranged from 73 to 86 mA/m(2). Comprehensive microbial and chemical characterizations and statistical analyses show that the residual TPH has a strongly positive correlation with hydrocarbon-degrading microorganisms (HDM) numbers, dehydrogenase activity, and lipase activity and a negative correlation with soil pH, conductivity, and catalase activity. Distinctive microbial communities were identified at the anode, in soil with electrodes, and soil without electrodes. Uncommon electrochemically active bacteria capable of hydrocarbon degradation such as Comamonas testosteroni, Pseudomonas putida, and Ochrobactrum anthropi were selectively enriched on the anode, while hydrocarbon oxidizing bacteria were dominant in soil samples. Results from genus or phylum level characterizations well agree with the data from cluster analysis. Data from this study suggests that a unique constitution of microbial communities may play a key role in BES enhancement of petroleum hydrocarbons

  14. Field Test of Enhanced Remedial Amendment Delivery Using a Shear-Thinning Fluid

    SciTech Connect

    Truex, Michael J.; Vermeul, Vincent R.; Adamson, David; Oostrom, Martinus; Zhong, Lirong; Mackley, Rob D.; Fritz, Brad G.; Horner, Jacob A.; Johnson, Timothy C.; Thomle, Jonathan N.; Newcomer, Darrell R.; Johnson, Christian D.; Rysz, Michal; Wietsma, Thomas W.; Newell, Charles J.

    2015-03-01

    Heterogeneity of hydraulic properties in aquifers may lead to contaminants residing in lower-permeability zones where it is difficult to deliver remediation amendments using conventional injection processes. The focus of this effort is to examine use of a shear-thinning fluid (STF) to improve the uniformity of remedial amendment distribution within a heterogeneous aquifer. Previous studies have demonstrated the significant potential of STFs for improving remedial amendment delivery in heterogeneous aquifers, but quantitative evaluation of these improvements from field applications are lacking. A field-scale test was conducted that compares data from successive injection of a tracer in water followed by injection of a tracer in a STF to evaluate the impact of the STF on tracer distribution uniformity in the presence of permeability contrasts within the targeted injection zone. Data from tracer breakthrough at multiple depth-discrete monitoring intervals and electrical resistivity tomography showed that inclusion of STF in the injection solution slowed movement in high-permeability pathways, improved delivery of amendment to low-permeability materials, and resulted in better uniformity in injected fluid distribution within the targeted treatment zone.

  15. Geotechnical behaviour of low-permeability soils in surfactant-enhanced electrokinetic remediation.

    PubMed

    López-Vizcaíno, Rubén; Navarro, Vicente; Alonso, Juan; Yustres, Ángel; Cañizares, Pablo; Rodrigo, Manuel A; Sáez, Cristina

    2016-01-01

    Electrokinetic processes provide the basis of a range of very interesting techniques for the remediation of polluted soils. These techniques consist of the application of a current field in the soil that develops different transport mechanisms capable of mobilizing several types of pollutants. However, the use of these techniques could generate nondesirable effects related to the geomechanical behavior of the soil, reducing the effectiveness of the processes. In the case of the remediation of polluted soils with plasticity index higher than 35, an excessive shrinkage can be observed in remediation test. For this reason, the continued evaporation that takes place in the sample top can lead to the development of cracks, distorting the electrokinetic transport regime, and consequently, the development of the operation. On the other hand, when analyzing silty soils, in the surroundings of injection surfactant wells, high seepages can be generated that give rise to the development of piping processes. In this article methods are described to allow a reduction, or to even eliminate, both problems.

  16. Garlic, from Remedy to Stimulant: Evaluation of Antifungal Potential Reveals Diversity in Phytoalexin Allicin Content among Garlic Cultivars; Allicin Containing Aqueous Garlic Extracts Trigger Antioxidants in Cucumber

    PubMed Central

    Hayat, Sikandar; Cheng, Zhihui; Ahmad, Husain; Ali, Muhammad; Chen, Xuejin; Wang, Mengyi

    2016-01-01

    Garlic has the charisma of a potent remedy and holds its repute of a therapeutic panacea since the dawn of civilization. An integrated approach was adopted to evaluate the genetic diversity among Chinese garlic cultivars for their antifungal potency as well as allicin content distribution and, furthermore; a bioassay was performed to study the bio-stimulation mechanism of aqueous garlic extracts (AGE) in the growth and physiology of cucumber (Cucumis sativus). Initially, 28 garlic cultivars were evaluated against four kinds of phytopathogenic fungi; Fusarium oxysporum, Botrytis cinerea, Verticillium dahliae and Phytophthora capsici, respectively. A capricious antifungal potential among the selected garlic cultivars was observed. HPLC fingerprinting and quantification confirmed diversity in allicin abundance among the selected cultivars. Cultivar G025, G064, and G074 had the highest allicin content of 3.98, 3.7, and 3.66 mg g-1, respectively, whereas G110 was found to have lowest allicin content of 0.66 mg g-1. Cluster analysis revealed three groups on the basis of antifungal activity and allicin content among the garlic cultivars. Cultivar G025, G2011-4, and G110 were further evaluated to authenticate the findings through different solvents and shelf life duration and G025 had the strongest antifungal activity in all conditions. minimum inhibitory concentration and minimum fungicidal concentration of Allicin aqueous standard (AAS) and AGE showed significant role of allicin as primary antifungal substance of AGE. Leaf disk bioassay against P. capsici and V. dahliae to comparatively study direct action of AGE and AAS during infection process employing eggplant and pepper leaves showed a significant reduction in infection percentage. To study the bioactivity of AGE, a bioassay was performed using cucumber seedlings and results revealed that AGE is biologically active inside cucumber seedlings and alters the defense mechanism of the plant probably activating reactive

  17. Garlic, from Remedy to Stimulant: Evaluation of Antifungal Potential Reveals Diversity in Phytoalexin Allicin Content among Garlic Cultivars; Allicin Containing Aqueous Garlic Extracts Trigger Antioxidants in Cucumber.

    PubMed

    Hayat, Sikandar; Cheng, Zhihui; Ahmad, Husain; Ali, Muhammad; Chen, Xuejin; Wang, Mengyi

    2016-01-01

    Garlic has the charisma of a potent remedy and holds its repute of a therapeutic panacea since the dawn of civilization. An integrated approach was adopted to evaluate the genetic diversity among Chinese garlic cultivars for their antifungal potency as well as allicin content distribution and, furthermore; a bioassay was performed to study the bio-stimulation mechanism of aqueous garlic extracts (AGE) in the growth and physiology of cucumber (Cucumis sativus). Initially, 28 garlic cultivars were evaluated against four kinds of phytopathogenic fungi; Fusarium oxysporum, Botrytis cinerea, Verticillium dahliae and Phytophthora capsici, respectively. A capricious antifungal potential among the selected garlic cultivars was observed. HPLC fingerprinting and quantification confirmed diversity in allicin abundance among the selected cultivars. Cultivar G025, G064, and G074 had the highest allicin content of 3.98, 3.7, and 3.66 mg g(-1), respectively, whereas G110 was found to have lowest allicin content of 0.66 mg g(-1). Cluster analysis revealed three groups on the basis of antifungal activity and allicin content among the garlic cultivars. Cultivar G025, G2011-4, and G110 were further evaluated to authenticate the findings through different solvents and shelf life duration and G025 had the strongest antifungal activity in all conditions. minimum inhibitory concentration and minimum fungicidal concentration of Allicin aqueous standard (AAS) and AGE showed significant role of allicin as primary antifungal substance of AGE. Leaf disk bioassay against P. capsici and V. dahliae to comparatively study direct action of AGE and AAS during infection process employing eggplant and pepper leaves showed a significant reduction in infection percentage. To study the bioactivity of AGE, a bioassay was performed using cucumber seedlings and results revealed that AGE is biologically active inside cucumber seedlings and alters the defense mechanism of the plant probably activating

  18. Laboratory {open_quotes}proof of principle{close_quotes} investigation for the acoustically enhanced remediation technology

    SciTech Connect

    Iovenitti, J.L.; Spencer, J.W. Jr.; Hill, D.G.

    1995-10-01

    Weiss Associates is conducting a three phase program investigating the systematics of using acoustic excitation fields (AEFs) to enhance the in-situ remediation of contaminated soil and ground water under both saturated and unsaturated conditions: Phase I - Laboratory Scale Parametric Investigation; Phase II - Technology Scaling Study; and Phase III - Large Scale Field Tests. Phase I, the subject of this paper, consisted primarily of a laboratory proof of principle investigation. The field deployment and engineering viability of acoustically enhanced remediation (AER) technology was also examined. Phase II is a technology scaling study addressing the scale up between laboratory size samples on the order of inches, and the data required for field scale testing, on the order of hundreds of feet. Phase III will consist of field scale testing at an non-industrialized, non-contaminated site and at a contaminated site to validate the technology. Summarized herein are the results of the Phase I {open_quotes}proof-of-principle{close_quotes} investigation, and recommendations for Phase H. A general overview of AER technology along with the plan for the Phase I investigation was presented.

  19. Amphetamine enhances retrieval following diverse sources of forgetting.

    PubMed

    Quartermain, D; Judge, M E; Jung, H

    1988-01-01

    The generality of amphetamine-induced retrieval enhancement was investigated by determining whether pretest administration could alleviate different types of forgetting. Thirsty mice were punished for licking a water tube following a period of free drinking. Forgetting of the conditioned drink suppression was induced in different groups of animals by; protein synthesis inhibition, cholinergic receptor blockade, inhibition of norepinephrine synthesis, stimulation of serotonin receptors, electroconvulsive shock, a 2.5 month training to test interval and the use of senescent animals with an endogenous memory defect. Thirty min prior to testing mice were injected with either saline or with 2 mg/kg d-amphetamine sulphate. Results showed that amphetamine produced a highly significant improvement in remembering in all of the forgetting treatment groups. It is concluded that amphetamine can alleviate forgetting caused by widely diverse etiologies probably by activating a nonspecific general retrieval system.

  20. Meaningful Engagement to Enhance Diversity: Broadened Impact Actualized

    NASA Astrophysics Data System (ADS)

    Whitney, V. W.; Pyrtle, A. J.

    2008-12-01

    The MS PHD'S Professional Development Program was established by and for UR/US populations to facilitate increased and sustained participation within the Earth system science community. MS PHD'S is jointly funded by NSF and NASA. Fourteen (14) minority Earth system scientists served as Program mentors and one- hundred fifteen (115) minority and non-minority scientists served as Meeting Mentors to student participants. Representatives from fifty-six (56) agencies and institutions provided support and exposure to MS PHD'S student participants. Two hundred fifty-eight (258) highly qualified UR/US students completed on-line applications to participate in the MS PHD'S Professional Development Program. Because of funding limitations, slightly fewer than 50% of the applicants were selected to participate. One-hundred twenty-six (126) undergraduate and graduate students from 26 states and Puerto Rico participated in the MS PHD'S program. Sixty-eight (68) MS PHD'S student participants self-identified as African American; thirty-four (34) as Puerto Rican; nine (9) as Hispanic/Mexican American, ten (10) as Native American and one (1) each as African, Asian, Pacific Islander, Hispanic and Multi-Ethnic. During the five year span of MS PHD'S programming, sixteen (16) student participants completed BS degrees, twelve (12) completed MS degrees and ten (10) completed the Doctoral degrees. How did MS PHD'S establish meaningful engagement to enhance diversity within the Earth system science community? This case study reveals replicable processes and constructs to enhance the quality of meaningful collaboration and engagement. In addition, the study addresses frequently asked questions (FAQ's) on outreach, recruitment, engagement, retention and success of students from underrepresented populations within diversity-focused programs.

  1. Surfactant-enhanced solubilization of tetrachloroethylene and degradation products in pump-and-treat remediation. Book chapter

    SciTech Connect

    West, C.C.

    1992-01-01

    Experiments were conducted to investigate the enhanced solubilization of tetrachloroethylene (PCE), trichloroethylene (TCE), and 1,2-dichloroethylene (DCE) in nonionic surfactant solutions of Triton X-100, Brij-30, Igepal CA-720, and Tergitol NP-10 (alkylpolyoxyethylenes). Surfactant solubilization is being considered as a means to enhance mobile phase solubilities of ground-water contaminants for the purpose of improving the efficiency of pump and treat remediation. The primary objectives of the study were to observe the solubilization of relatively hydrophilic organic solutes at system temperatures similar to ground-water conditions and to determine if solubilization can be linearly correlated to the octanol/water partition coefficient, as has been observed by others for hydrophobic organic solutes. The results of the study show that surfactant solubilization of hydrophilic solutes is highly correlated with their octanol/water partition coefficient when corrected for temperature effects. It was also observed that there appears to be little difference in solubilizing efficiency between the four surfactants.

  2. Stand structural diversity rather than species diversity enhances aboveground carbon storage in secondary subtropical forests in Eastern China

    NASA Astrophysics Data System (ADS)

    Ali, Arshad; Yan, En-Rong; Chen, Han Y. H.; Chang, Scott X.; Zhao, Yan-Tao; Yang, Xiao-Dong; Xu, Ming-Shan

    2016-08-01

    height diversity through silvicultural operations might constitute an effective approach for enhancing aboveground C storage in these forests.

  3. Exercise Induced Neuroplasticity to Enhance Therapeutic Outcomes of Cognitive Remediation in Schizophrenia: Analyzing the Role of Brain-Derived Neurotrophic Factor.

    PubMed

    Campos, Carlos; Rocha, Nuno Bf; Nardi, Antonio E; Lattari, Eduardo; Machado, Sergio

    2016-12-23

    Cognitive impairment is a major manifestation of schizophrenia and a crucial treatment target as these deficits are closely related to patients' functional outcomes. Cognitive remediation is the gold-standard practice to address cognitive deficits in schizophrenia. There is clear evidence stating that cognitive remediation improves cognitive function and promotes structural neuroplastic changes in patients with schizophrenia, with brain-derived neurotrophic factor (BDNF) expression emerging as a potential biomarker for its efficacy. This is particularly important as there is clear evidence relating atypical BDNF expression to cognitive impairment in patients with schizophrenia. Despite the valuable role of cognitive remediation in the management of schizophrenia, there is still a need to develop methods that allow to maximize its efficacy. In this review, we present a hypothesis arguing that cognitive remediation efficacy for patients with schizophrenia can be enhanced by aerobic exercise-induced BDNF upregulation. There have been a few trials reporting where combining aerobic exercise with cognitive training was superior to cognitive training alone to improve cognitive functioning in patients with schizophrenia. Furthermore, there is preliminary evidence suggesting that combined aerobic and cognitive training can increase peripheral BDNF levels. Thereby, engaging in aerobic exercise in close temporal proximity to cognitive remediation may allow to achieve a state of neuroplastic readiness in the brain, facilitating cognitive functioning enhancement. Although this hypothesis still lacks evidence, future clinical trials using cognitive remediation for schizophrenia should explore strategies to maximize neuroplasticity and achieve optimal cognitive improvements.

  4. Electrokinetic remediation of a Cu contaminated red soil by conditioning catholyte pH with different enhancing chemical reagents.

    PubMed

    Zhou, Dong-Mei; Deng, Chang-Fen; Cang, Long

    2004-07-01

    The effect of enhancement reagents on the efficiency of electrokinetic remediation of Cu contaminated red soil is evaluated. The enhancement agents were a mix of organic acids, including lactic acid+NaOH, HAc-NaAc and HAc-NaAc+EDTA. The soil was prepared to an initial Cu concentration of 438 mgkg(-1) by incubating the soil with CuSO4 solution in a flooded condition for 1 month. Sequential extraction showed that Cu was partitioned in the soil as follows: 195 mgkg(-1) as water soluble and exchangeable, 71 mgkg(-1) as carbonate bound and 105 mgkg(-1) as Fe and Mn oxides. The results indicate that neutralizing the catholyte pH maintains a lower soil pH compared to that without electrokinetic treatment. The electric currents varied depending upon the conditioning solutions and increased with an increasing applied voltage potential. The electroosmotic flow rate changed significantly when different conditioning enhancing reagents were used. It was observed that lactic acid+NaOH treatments resulted in higher soil electric conductivities than HAc-NaAc and HAc-NaAc+EDTA treatments. Ultimately, enhancement by lactic acid+NaOH resulted in highest removal efficiency (81% Cu removal) from the red soil. The presence of EDTA did not enhance Cu removal efficiencies from the red soil, because EDTA complexed with Cu to form negatively charge complexes, which slowly migrated toward the anode chamber retarding Cu2+ transport towards the cathode.

  5. Stochastical analysis of surfactant-enhanced remediation of denser-than-water nonaqueous phase liquid (DNAPL)-contaminated soils.

    PubMed

    Zhang, Renduo; Wood, A Lynn; Enfield, Carl G; Jeong, Seung-Woo

    2003-01-01

    Stochastical analysis was performed to assess the effect of soil spatial variability and heterogeneity on the recovery of denser-than-water nonaqueous phase liquids (DNAPL) during the process of surfactant-enhanced remediation. UTCHEM, a three-dimensional, multicomponent, multiphase, compositional model, was used to simulate water flow and chemical transport processes in heterogeneous soils. Soil spatial variability and heterogeneity were accounted for by considering the soil permeability as a spatial random variable and a geostatistical method was used to generate random distributions of the permeability. The randomly generated permeability fields were incorporated into UTCHEM to simulate DNAPL transport in heterogeneous media and stochastical analysis was conducted based on the simulated results. From the analysis, an exponential relationship between average DNAPL recovery and soil heterogeneity (defined as the standard deviation of log of permeability) was established with a coefficient of determination (r2) of 0.991, which indicated that DNAPL recovery decreased exponentially with increasing soil heterogeneity. Temporal and spatial distributions of relative saturations in the water phase, DNAPL, and microemulsion in heterogeneous soils were compared with those in homogeneous soils and related to soil heterogeneity. Cleanup time and uncertainty to determine DNAPL distributions in heterogeneous soils were also quantified. The study would provide useful information to design strategies for the characterization and remediation of nonaqueous phase liquid-contaminated soils with spatial variability and heterogeneity.

  6. Humic Acids Enhanced U(VI) Attenuation in Acidic Waste Plumes: An In-situ Remediation Approach

    NASA Astrophysics Data System (ADS)

    Wan, J.; Dong, W.; Tokunaga, T. K.

    2010-12-01

    and HA by groundwater leaching are non-detectable over a long period of time (200 days and > 100 PV without further addition of HA). As a natural reactive agent for in-situ remediation, HAs are cost-effective (enormous reservoir in nature), nontoxic, resistant to biodegradation, soluble, and easily introducible to the subsurface. This method has high potential to efficiently and sustainably enhance natural attenuation of U within acidic waste plumes.

  7. Analytical solutions for surfactant-enhanced remediation of nonaqueous phase liquids

    NASA Astrophysics Data System (ADS)

    Laforce, Tara; Johns, Russell T.

    2005-10-01

    Benchmark compositional solutions are presented for the remediation of aquifers contaminated with nonaqueous phase liquids (NAPLs) by injection of surfactant-water mixtures. The method of characteristics (MOC) is used to find one-dimensional analytical solutions to the Riemann problem where three partially miscible phases are flowing in a Winsor type III microemulsion. In partially miscible flow, two or three phases form when the components (constituents) are mixed in some but not all proportions. Three relative permeability models are examined, and MOC solutions are found. Fine-grid numerical simulations match the MOC results. The composition routes and contaminant recoveries can differ significantly depending on the relative permeability model used. The results for each model are optimized to determine the minimum surfactant volume required for complete contaminant recovery. Unlike two-phase partially miscible flow, the presence of three flowing phases makes it impossible to reach miscibility between the injected and resident fluids, regardless of surfactant concentration.

  8. Development of Enhanced Remedial Techniques for Petroleum Fuel and Related Contaminants in Soil and Groundwater

    SciTech Connect

    Paul Fallgren

    2009-02-10

    Western Research Institute (WRI) in conjunction with Earth Tech and the U.S. Department of Energy (DOE) was to identify proper sites with soils and/or groundwater contaminated by petroleum constituents and MTBE. Biodegradation rates would have been quantitatively assessed in both laboratory and field tests to achieve the optimal destruction of contaminants of concern. WRI and Earth Tech identified a site contaminated with high concentrations of methanol associated with petroleum hydrocarbons. The site was assessed and a remediation project plan was prepared; however, the site was soon acquired by a new company. An agreement between Earth Tech, WRI, and the new site owners could not be reached; therefore, a work was performed to identify a new project site. Task 33 was terminated and the available funding was redeployed to other Tasks after receiving approval from the U.S. DOE task manager.

  9. Surfactant-enhanced aquifer remediation at the Portsmouth Gaseous Diffusion Plant

    SciTech Connect

    Jackson, R.E.; Londergan, J.T.; Pickens, J.F.

    1995-10-01

    Many DOE facilities are situated in areas of sand and gravel which have become polluted with dense, non-aqueous phase liquids or DNAPLs, such as chlorinated solvents, from the various industrial operations at these facilities. The presence of such DNAPLs in sand and gravel aquifers is now recognized as the principal factor in the failure of standard ground-water remediation methods. The principal objective of this study, as stated in the Statement of Work of the contract (DE-AC21-92MC29111), is to demonstrate that multi-component DNAPLs can be readily solubilized in sand and gravel aquifers by dilute surfactant solutions. The specific objectives of the contract are: to identify dilute surfactants or blends of surfactants in the laboratory that will efficiently extract multi-component DNAPLs from sand and gravel aquifers by micellar solubilization (Phase 1); 2. to test the efficacy of the identified surfactants or blends of surfactants to solubilize in situ perchloroethylene (PCE) and trichloroethylene (TCE) DNAPLs by the injection and the subsequent extraction through an existing well or wells at a government-owned contaminated site (Phase 1); and 3. to demonstrate the full-scale operation of this remedial technology at a government-owned contaminated site (Phase 2). Specific objective number 1 has been completed and reported to DOE. However, the results of the test referred to in specific objective number 2, conducted at Paducah Gaseous Diffusion Plant in 1994, were inconclusive. Following this first test, it was decided by DOE and INTERA to move the test site elsewhere due to difficulties with obtaining core samples of the sand and gravel aquifer containing the DNAPL and with ascertaining the location of the DNAPL relative to the injection well. The solubilization test at the Portsmouth Gaseous Diffusion Plant (PORTS) will constitute the second test of Phase 1 of this contract.

  10. Remediation of metal polluted hotspot areas through enhanced soil washing--evaluation of leaching methods.

    PubMed

    Fedje, Karin Karlfeldt; Yillin, Li; Strömvall, Ann-Margret

    2013-10-15

    Soil washing offers a permanent remediation alternative for metal polluted sites. In addition, the washed out metals can be recovered from the leachate and re-introduced into the social material cycle instead of landfilled. In this paper, soil, bark and bark-ash washing was tested on four different metal polluted soil and bark samples from hotspots at former industrial sites. Six different leaching agents; HCl, NH4Cl, lactic acid, EDDS and two acidic process waters from solid waste incineration, were tested, discussed and evaluated. For the soil washing processes, the final pH in the leachate strongly influences the metal leachability. The results show that a pH < 2 is needed to achieve a high leaching yield, while <50 w% of most metals were leached when the pH was higher than 2 or below 10. The acidic process waste waters were generally the most efficient at leaching metals from all the samples studied, and as much as 90-100 w% of the Cu was released from some samples. Initial experiments show that from one of these un-purified leachates, Cu metal (>99% purity) could be recovered. After a single leaching step, the metal contents of the soil residues still exceed the maximum limits according to the Swedish guidelines. An additional washing step is needed to reduce the contents of easy soluble metal compounds in the soil residues. The overall results from this study show that soil and bark-ash washing followed by metal recovery is a promising on-site permanent alternative to remediate metal polluted soils and to utilize non-used metal resources. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Enhanced-electrokinetic remediation of copper-pyrene co-contaminated soil with different oxidants and pH control.

    PubMed

    Cang, Long; Fan, Guang-Ping; Zhou, Dong-Mei; Wang, Quan-Ying

    2013-02-01

    Electrokinetic (EK) remediation has potential to simultaneously remove heavy metals and organic compounds from soil, but the removal percent of these pollutants is very low in general if no enhancing treatment is applied. This study developed a new enhanced-EK remediation technology to decontaminate a heavy metal-organic compound co-contaminated soil by applying different oxidants and pH control. A red soil was used as a model clayed soil, and was spiked with pyrene and Cu at about 500 mg kg(-1) for both to simulate real situation. Bench-scale EK experiments were performed using four oxidants (H(2)O(2), NaClO, KMnO(4), and Na(2)S(2)O(8)) and controlling electrolyte pH at 3.5 or 10. After the treatments with 1.0 V cm(-1) of voltage gradient for 335 h, soil pH, electrical conductivity, and the concentrations and chemical fractionations of soil pyrene and Cu were analyzed. The results showed that there was significant migration of pyrene and Cu from the soil, and the removal percent of soil pyrene and Cu varied in the range of 30-52% and 8-94%, respectively. Low pH favoured the migration of soil Cu, while KMnO(4) was the best one for the degradation of pyrene among the tested oxidants, although it unfortunately prevented the migration of soil Cu by forming Cu oxide. Application of Na(2)S(2)O(8) and to control the catholyte pH at 3.5 were found to be the best operation conditions for decontaminating the Cu-pyrene co-contaminated soil.

  12. Application of iron electrode corrosion enhanced electrokinetic-Fenton oxidation to remediate diesel contaminated soils: A laboratory feasibility study

    NASA Astrophysics Data System (ADS)

    Tsai, Tzai-Tang; Sah, Jygau; Kao, Chih-Ming

    2010-01-01

    SummaryDiesel soil contamination on gas stations or refinery plants is a worldwide environmental problem. The main objectives of this study were to (1) evaluate the efficiency of electrokinetic (EK) by using different electrode materials (graphite and iron rods) and electrolytes (tap water, 0.01 M NaCl, and 0.1 M NaCl) on the remediation of diesel contaminated soils, and (2) evaluate the feasibility of total petroleum hydrocarbon-diesel (TPH-D) reducing in soils via EK-Fenton oxidation enhanced by corroded iron electrode. The EK and EK-Fenton experiments were conducted in batch and sand box experiments, respectively. Batch experiments reveal that the most appropriate electrolyte was 0.1 M NaCl when iron electrode was used in the EK system. Sand box experiments indicate that the TPH-D concentration dropped from 10,000 to 300 mg kg -1 when amorphous iron/total iron (Fe o/Fe t) ratio increased from 0.1 to 0.33, with the addition of 8% of H 2O 2 and 0.1 M NaCl after 60 days of EK-Fenton operation. Electrokinetically enhanced oxidation with the presence of both H 2O 2 and Fe 3O 4 (iron electrode corrosion) resulted in higher TPH-D removal efficiency (97%) compared to the efficiencies observed from EK (55%) or Fenton oxidation (27%) alone. This demonstrates that EK-Fenton oxidation catalyzed by iron electrode corrosion is a valuable direction to efficiently and effectively remediate diesel contaminated soils.

  13. Acellular Gelatinous Material of Human Umbilical Cord Enhances Wound Healing: A Candidate Remedy for Deficient Wound Healing

    PubMed Central

    Bakhtyar, Nazihah; Jeschke, Marc G.; Mainville, Laurence; Herer, Elaine; Amini-Nik, Saeid

    2017-01-01

    Impaired wound healing is a severe clinical challenge and research into finding effective wound healing strategies is underway as there is no ideal treatment. Gelatinous material from the umbilical cord called Wharton's jelly is a valuable source of mesenchymal stem cells which have been shown to aid wound healing. While the cellular component of Wharton's jelly has been the subject of extensive research during the last few years, little is known about the de-cellularized jelly material of the umbilical cord. This is important as they are native niche of stem cells. We have isolated Wharton's jelly from umbilical cords and then fractionated acellular gelatinous Wharton's jelly (AGWJ). Here, we show for the first time that AGWJ enhances wound healing in vitro as well as in vivo for wounds in a murine model. In vivo staining of the wounds revealed a smaller wound length in the AGWJ treated wounds in comparison to control treatment by enhancing cell migration and differentiation. AGWJ significantly enhanced fibroblast cell migration in vitro. Aside from cell migration, AGWJ changed the cell morphology of fibroblasts to a more elongated phenotype, characteristic of myofibroblasts, confirmed by upregulation of alpha smooth muscle actin using immunoblotting. AGWJ treatment of wounds led to accelerated differentiation of cells into myofibroblasts, shortening the proliferation phase of wound healing. This data provides support for a novel wound healing remedy using AGWJ. AGWJ being native biological, cost effective and abundantly available globally, makes it a highly promising treatment option for wound dressing and skin regeneration. PMID:28421003

  14. DEMONSTRATION OF PILOT-SCALE PREVAPORATION SYSTEMS FOR VOLATILE ORGANIC COMPOUND REMOVAL FROM A SURFACTANT ENHANCED AQUIFER REMEDIATION FLUID. I. SPIRAL WOUND MEMBRANE MODULES

    EPA Science Inventory

    During the summer of 1996, a pilot-scale demonstration of a surfactant enhanced aquifer remediation (SEAR) process for removal of dense non-aqueous phase liquids (DNAPLs) from soils was conducted at Hill Air Force Base in Layton, Utah. Five thousand gallons of the extracted DNAP...

  15. DEMONSTRATION OF PILOT-SCALE PREVAPORATION SYSTEMS FOR VOLATILE ORGANIC COMPOUND REMOVAL FROM A SURFACTANT ENHANCED AQUIFER REMEDIATION FLUID. I. SPIRAL WOUND MEMBRANE MODULES

    EPA Science Inventory

    During the summer of 1996, a pilot-scale demonstration of a surfactant enhanced aquifer remediation (SEAR) process for removal of dense non-aqueous phase liquids (DNAPLs) from soils was conducted at Hill Air Force Base in Layton, Utah. Five thousand gallons of the extracted DNAP...

  16. Shift in microbial group during remediation by enhanced natural attenuation (RENA) of a crude oil-impacted soil: a case study of Ikarama Community, Bayelsa, Nigeria.

    PubMed

    Chikere, Chioma Blaise; Azubuike, Christopher Chibueze; Fubara, Evan Miebaka

    2017-06-01

    Acute and chronic pollution of environments with crude oil does not bode well for biota living within the vicinity of polluted environments. This is due to environmental and public health concerns on the negative impact of crude oil pollution on living organisms. Enhancing microbial activities by adding nutrients and other amendments had proved effective in pollutant removal during bioremediation. This study was carried out to determine how microbial group respond during remediation by enhanced natural attenuation (RENA) during a field-scale bioremediation. Crude oil-polluted soil samples were collected (before, during, and after remediation) from a site undergoing remediation by enhanced natural attenuation (RENA) at Ikarama Community, Bayelsa State, Nigeria, and were analyzed for total petroleum hydrocarbon (TPH), polyaromatic hydrocarbon (PAH), and a shift in microbial community. The gas chromatography-flame ionization detector (GC-FID) results showed that the pollutant concentrations (TPH and PAH) reduced by 98 and 85%, respectively, after the remediation. Culturable hydrocarbon utilizing bacteria (CHUB) was highest (8.3 × 10(4) cfu/g) for sample collected during the remediation studies, whilst sample collected after remediation had low CHUB (6.1 × 10(4) cfu/g) compared to that collected before remediation (7.7 × 10(4) cfu/g). Analysis of 16S rRNA of the isolated CHUB showed they belonged to eight bacterial genera namely: Achromobacter, Alcaligenes, Azospirillus, Bacillus, Lysinibacillus, Ochrobactrum, Proteus, and Pusillimonas, with Alcaligenes as the dominant genus. In this study, it was observed that the bacterial community shifted from mixed group (Gram-positive and -negative) before and during the remediation, to only the latter group after the remediation studies. The betaproteobacteria groups were the dominant isolated bacterial phylotype. This study showed that RENA is an effective method of reducing pollutant concentration in crude oil

  17. Experimental canopy removal enhances diversity of vernal pond amphibians.

    PubMed

    Skelly, David K; Bolden, Susan R; Freidenburg, L Kealoha

    2014-03-01

    Vernal ponds are often treated as protected environments receiving special regulation and management. Within the landscapes where they are found, forest vegetation frequently dominates surrounding uplands and can grow to overtop and shade pond basins. Two bodies of research offer differing views of the role of forest canopy for vernal pond systems. Studies of landscape conversion suggest that removing forest overstory within uplands can cause local extinctions of amphibians by altering terrestrial habitat or hindering movement. Studies of canopy above pond basins imply an opposite relationship; encroachment of overstory vegetation can be associated with local extinctions potentially via changes in light, thermal, and food resource environments. Unresolved uncertainties about the role of forest canopy reveal significant gaps in our understanding of wetland species distributions and dynamics. Any misunderstanding of canopy influences is simultaneously important to managers because current practices emphasize promoting or conserving vegetation growth particularly within buffers immediately adjacent to ponds. We evaluated this apparent contradiction by conducting a landscape-scale, long-term experiment using 14 natural vernal ponds. Tree felling at six manipulated ponds was limited in spatial scope but was nevertheless effective in increasing water temperature. Compared with eight control ponds, manipulated ponds maintained more amphibian species during five years post-manipulation. There was little evidence that any species was negatively influenced, and the reproductive effort of species for which we estimated egg inputs maintained pretreatment population densities in manipulated compared with control ponds. Overall, our experiment shows that a carefully circumscribed reduction of overhead forest canopy can enhance the capacity of vernal ponds to support wildlife diversity and suggests a scale dependence of canopy influences on amphibians. These findings have

  18. Enhancement of acoustic tomography using spatial and frequency diversities

    NASA Astrophysics Data System (ADS)

    Mansour, Ali

    2012-12-01

    This article introduces several contributions to enhance an important application such as acoustic tomography (AT), using mainly the spatial and spectral diversities of underwater acoustic signals. Due to their inherited properties, (i.e. spareness, non-stationarity or cyclostationarity, wide-band frequency range, wide range of power, etc.), the process of underwater acoustic signals becomes a real challenge for many scientists and engineers who are involved in studies related to the ocean. For various applications, these studies require huge and daily information. AT techniques remain fast and cheap ways to obtain such data. Nowadays, active acoustic tomography (AAT), is communally used to generate powerful and repetitive acoustic sources. Recently, researchers have been attracted by an alternative way, called passive acoustic tomography (PAT), which uses acoustic opportune signals of their environment. PAT techniques are mainly used for ecological, economical and other reasons such as military applications. With PAT, no signal is emitted; therefore, problems become more challenging. The number and positions of existent sources are unknown, and sensors measure mixtures of available sources. Algorithms based on time or frequency domains are widely deployed to classify, identify, and study received signals in AAT applications. For PAT, researchers employ multiple sensors in order to add an extra dimension, (such as space). This article focuses on approaches used in space along with time or frequency to extract information, improve performances, and simplify the overall architecture. This article explains the use of signal processing and statistical approaches to solve problems raised using PAT and discusses the experimental results. The review of the literature offers a big variety of algorithms to deal with classic AAT problems. Therefore, only problems related to PAT have been considered herein.

  19. Intraspecific functional diversity of common species enhances community stability.

    PubMed

    Wood, Connor M; McKinney, Shawn T; Loftin, Cynthia S

    2017-03-01

    Common species are fundamental to the structure and function of their communities and may enhance community stability through intraspecific functional diversity (iFD). We measured among-habitat and within-habitat iFD (i.e., among- and within-plant community types) of two common small mammal species using stable isotopes and functional trait dendrograms, determined whether iFD was related to short-term population stability and small mammal community stability, and tested whether spatially explicit trait filters helped explain observed patterns of iFD. Southern red-backed voles (Myodes gapperi) had greater iFD than deer mice (Peromyscus maniculatus), both among habitats, and within the plant community in which they were most abundant (their "primary habitat"). Peromyscus maniculatus populations across habitats differed significantly between years and declined 78% in deciduous forests, their primary habitat, as did the overall deciduous forest small mammal community. Myodes gapperi populations were stable across habitats and within coniferous forest, their primary habitat, as was the coniferous forest small mammal community. Generalized linear models representing internal trait filters (e.g., competition), which increase within-habitat type iFD, best explained variation in M. gapperi diet, while models representing internal filters and external filters (e.g., climate), which suppress within-habitat iFD, best explained P. maniculatus diet. This supports the finding that M. gapperi had higher iFD than P. maniculatus and is consistent with the theory that internal trait filters are associated with higher iFD than external filters. Common species with high iFD can impart a stabilizing influence on their communities, information that can be important for conserving biodiversity under environmental change.

  20. PILOT-SCALE EVALUATION OF THE IRON-ENHANCED DECHLORINATION TECHNOLOGY FOR REMEDIATION OF CONTAMINATED GROUNDWATER

    EPA Science Inventory

    An iron-enhanced dechlorination technology was evaluated, under the U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation (SITE) program, at a contaminated printed circuit board manufacturing site in New Jersey. This paper describes the feasibility...

  1. PILOT-SCALE EVALUATION OF THE IRON-ENHANCED DECHLORINATION TECHNOLOGY FOR REMEDIATION OF CONTAMINATED GROUNDWATER

    EPA Science Inventory

    An iron-enhanced dechlorination technology was evaluated, under the U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation (SITE) program, at a contaminated printed circuit board manufacturing site in New Jersey. This paper describes the feasibility...

  2. Influence of humic substances on enhanced remediation of soil polluted by a copper-nickel smelter

    NASA Astrophysics Data System (ADS)

    Tregubova, Polina; Turbaevskaya, Valeria; Korneecheva, Mariya; Kupriyanova, Yuliya; Koptsik, Galina

    2017-04-01

    The problem of technogenic contamination through the anthropogenic activity is quite urgent nowadays. Long-term air pollution with sulphur dioxide and heavy metals (HM) by injuring vegetation and inhibition of plant and soil microorganisms growth and activity causes appearance of the barren areas - highly damaged eroded ecosystems requiring remediation. There are a lot of remediation ways, but an appropriate restoration method, which does not expensive, does not demand special technical support and corresponds to the natural conditions of soil development is still open to question. We suggest application of exogenous humic substances as the possible environmentally friendly solution of HM toxicity problem and soil health restoration. Using of humates can result in the improvement of soil properties, localization of contamination by decreasing of HM mobility and bioavailability through binding them in relatively immobile complexes, and in stabilization of organic pool. But practice of scientific society as well as our previous investigations demonstrates ambiguous influence of exogenic humic substances on the behavior of HM depending on origin, doses, molecular weight of organic matter and state of microorganisms. In this research we have provided series of short-term (45 days) experiments dedicated to the evaluation of suitable doses of humates of different origin - coal and peat - inoculated by nitrogen fixers and mycorhizae-forming fungi in comparison with lime and NPK-fertilizer on the properties of contaminated soil and mobility of HM. The object of investigation was Al-Fe-humus abrazems from the vicinity of mining-and-metallurgical integrated work located in the Kola Peninsula, Russia. This soil is characterized by the absence of vegetation, complete loss of the organic horizon in result of the erosion processes, low pH (pH H2O 4.1-5.0), low exchangeable acidity (0.8-1.6 cmolc/kg), and depletion of organic mater (content of total carbon is 0.3-0.5%). The main

  3. Column tests to enhance sulphide precipitation with liquid organic electron donators to remediate AMD-influenced groundwater

    NASA Astrophysics Data System (ADS)

    Bilek, Felix

    2006-03-01

    Dump groundwaters in the former East-German lignite-mining district are characterized by high amounts of ferrous iron and sulphate. Both the pyrite weathering products endanger the surface water quality when discharged into lakes. Only the precipitation of both contaminants in the subsurface can prevent the further contamination of surface waters. The two-step process of microbial catalyzed sulphate reduction and iron sulphide precipitation is limited by the low availability of natural organic substances as electron donators. Therefore, a new remediation technique is developed based on the injection of a liquid organic electron donator (methanol) into the contaminated aquifer. The saturated aquifer is used as a bioreactor, where iron monosulphides are precipitated in the groundwater-filled pore space. Column experiments were performed under natural pressure and temperature conditions with natural anoxic groundwater and original sediments to test the remediation technology. The test showed that a complete iron removal (4 mmol/l), even under rather acid conditions (pH 3.8), is possible after having established an active sulphate reducer population. The turnover of the added organic substance with sulphate is complete and the amount of the resulting sulphide controls the effluent pH. In addition, intensified microbial activity triggers the turnover of natural organic substances. Also, natural Fe(III) hydroxides react with the sulphide produced. Considering the long natural retention times (decades), artificially enhanced FeS precipitation is spontaneous, although it shows kinetic behaviour in the range of days. In light of the promising results, the development of a field scale application of this technique is considered to be necessary. It will have to focus on the improved precipitation control of the FeS in the subsurface.

  4. Enhancing Diversity in Vocational Education. Information Series No. 351.

    ERIC Educational Resources Information Center

    Bowen, Blannie E.; Jackson, Gary B.

    Vocational education can play a significant role in achieving the ideals of a diverse society. Although workplace changes and global economics make vocational education essential, an increasingly diverse population includes groups that have not traditionally participated extensively in vocational education. Philosophical and attitudinal changes…

  5. Is biotic resistance enhanced by natural variation in diversity?

    USGS Publications Warehouse

    Grace, James B.; Harrison, Susan P.; Cornell, Howard

    2017-01-01

    Theories linking diversity to ecosystem function have been challenged by the widespread observation of more exotic species in more diverse native communities. Few studies have addressed the underlying processes by dissecting how biotic resistance to new invaders may be shaped by the same environmental influences that determine diversity and other community properties.In grasslands with heterogeneous soils, we added invaders and removed competitors to analyze the causes of invasion resistance. Abiotic resistance was measured using invader success in the absence of the resident community. Biotic resistance was measured as the reduction in invader success in the presence of the resident community.Invaders were most successful where biotic resistance was lowest and abiotic resistance was highest, confirming the dominant role of biotic resistance. Contrary to theory, though, biotic resistance was highest where both species richness and functional diversity were lowest. In the multivariate framework of a structural equation model, biotic resistance was independent of community diversity, and was highest where fertile soils led to high community biomass.Seed predation slightly augmented biotic resistance without qualitatively changing the results. Soil-related genotypic variation in the invader also did not affect the results.We conclude that in natural systems, diversity may be correlated with invasibility and yet have little effect on biotic resistance to invasion. More generally, the environmental causes of variation in diversity should be considered when examining the potential functional consequences of diversity.

  6. MOVING BEYOND PUMP AND TREAT TOWARD ENHANCED ATTENUATION AND COMBINED REMEDIES T-AREA, SAVANNAH RIVER SITE

    SciTech Connect

    Looney, B; Brian Riha, B; Warren Hyde, W; Jay Noonkester, J; Gerald Blount, G

    2008-04-03

    Groundwater beneath T-Area, a former laboratory and semiworks operation at the Department of Energy (DOE) Savannah River Site, is contaminated by chlorinated solvents (cVOCs). Since the contamination was detected in the 1980s, the cVOCs at T-Area have been treated by a combination of soil vapor extraction and groundwater pump and treat. The site has received approval to discontinue the active treatments and implement a full scale test of enhanced attenuation--an engineering and regulatory strategy that has recently been developed by DOE and the Interstate Technology and Regulatory Council. Enhanced attenuation uses active engineering solutions to alter the target site in such a way that the contaminant plume will passively stabilize and shrink and to document that the action will be effective, timely, and sustainable. The paradigm recognizes that attenuation remedies are fundamentally based on a mass balance. Thus, long-term plume dynamics can be altered either by reducing the contaminant loading from the source or by increasing the rate of natural attenuation processes within all, or part of, the plume volume. The combination of technologies that emerged for T-Area included: (1) neat (pure) vegetable oil deployment in the deep vadose zone in the former source area, (2) emulsified vegetable oil deployment within the footprint of the groundwater plume, and (3) identification of attenuation mechanisms and rates for the distal portion of the plume. In the first part, neat oil spreads laterally forming a thin layer on the water table to intercept and reduce future cVOC loading (via partitioning) and reduce oxygen inputs (via biostimulation). In the second and third parts, emulsified oil forms active bioremediation reactor zones within the plume footprint to degrade existing groundwater contamination (via reductive dechlorination) and stimulates long-term attenuation capacity in the distal plume (via cometabolism). For T-Area, the enhanced attenuation development

  7. Minimal increase in genetic diversity enhances predation resistance.

    PubMed

    Koh, Kai S; Matz, Carsten; Tan, Chuan H; LE, Hoang L; Rice, Scott A; Marshall, Dustin J; Steinberg, Peter D; Kjelleberg, Staffan

    2012-04-01

    The importance of species diversity to emergent, ecological properties of communities is increasingly appreciated, but the importance of within-species genetic diversity for analogous emergent properties of populations is only just becoming apparent. Here, the properties and effects of genetic variation on predation resistance in populations were assessed and the molecular mechanism underlying these emergent effects was investigated. Using biofilms of the ubiquitous bacterium Serratia marcescens, we tested the importance of genetic diversity in defending biofilms against protozoan grazing, a main source of mortality for bacteria in all natural ecosystems. S. marcescens biofilms established from wild-type cells produce heritable, stable variants, which when experimentally combined, persist as a diverse assemblage and are significantly more resistant to grazing than either wild type or variant biofilms grown in monoculture. This diversity effect is biofilm-specific, a result of either facilitation or resource partitioning among variants, with equivalent experiments using planktonic cultures and grazers resulting in dominance by a single resistant strain. The variants studied are all the result of single nucleotide polymorphisms in one regulatory gene suggesting that the benefits of genetic diversity in clonal biofilms can occur through remarkably minimal genetic change. The findings presented here provide a new insight on the integration of genetics and population ecology, in which diversity arising through minimal changes in genotype can have major ecological implications for natural populations. © 2011 Blackwell Publishing Ltd.

  8. Plant functional diversity enhances associations of soil fungal diversity with vegetation and soil in the restoration of semiarid sandy grassland.

    PubMed

    Zuo, Xiaoan; Wang, Shaokun; Lv, Peng; Zhou, Xin; Zhao, Xueyong; Zhang, Tonghui; Zhang, Jing

    2016-01-01

    The trait-based approach shows that plant functional diversity strongly affects ecosystem properties. However, few empirical studies show the relationship between soil fungal diversity and plant functional diversity in natural ecosystems. We investigated soil fungal diversity along a restoration gradient of sandy grassland (mobile dune, semifixed dune, fixed dune, and grassland) in Horqin Sand Land, northern China, using the denaturing gradient gel electrophoresis of 18S rRNA and gene sequencing. We also examined associations of soil fungal diversity with plant functional diversity reflected by the dominant species' traits in community (community-weighted mean, CWM) and the dispersion of functional trait values (FD is). We further used the structure equation model (SEM) to evaluate how plant richness, biomass, functional diversity, and soil properties affect soil fungal diversity in sandy grassland restoration. Soil fungal richness in mobile dune and semifixed dune was markedly lower than those of fixed dune and grassland (P < 0.05). Soil fungal richness was positively associated with plant richness, biomass, CWM plant height, and soil gradient aggregated from the principal component analysis, but SEM results showed that plant richness and CWM plant height determined by soil properties were the main factors exerting direct effects. Soil gradient increased fungal richness through indirect effect on vegetation rather than direct effect. The negative indirect effect of FDis on soil fungal richness was through its effect on plant biomass. Our final SEM model based on plant functional diversity explained nearly 70% variances of soil fungal richness. Strong association of soil fungal richness with the dominant species in the community supported the mass ratio hypothesis. Our results clearly highlight the role of plant functional diversity in enhancing associations of soil fungal diversity with community structure and soil properties in sandy grassland ecosystems.

  9. Genetic diversity in honey bee colonies enhances productivity and fitness.

    PubMed

    Mattila, Heather R; Seeley, Thomas D

    2007-07-20

    Honey bee queens mate with many males, creating numerous patrilines within colonies that are genetically distinct. The effects of genetic diversity on colony productivity and long-term fitness are unknown. We show that swarms from genetically diverse colonies (15 patrilines per colony) founded new colonies faster than swarms from genetically uniform colonies (1 patriline per colony). Accumulated differences in foraging rates, food storage, and population growth led to impressive boosts in the fitness (i.e., drone production and winter survival) of genetically diverse colonies. These results further our understanding of the origins of polyandry in honey bees and its benefits for colony performance.

  10. Correlation between DNAPL distribution area and dissolved concentration in surfactant enhanced aquifer remediation effluent: a two-dimensional flow cell study

    SciTech Connect

    Wu, Bin; Li, Huiying; Du, Xiaoming; Zhong, Lirong; Yang, Bin; Du, Ping; Gu, Qingbao; Li, Fasheng

    2016-02-01

    During the process of surfactant enhanced aquifer remediation (SEAR), free phase dense non-aqueous phase liquid (DNAPL) may be mobilized and spread. The understanding of the impact of DNAPL spreading on the SEAR remediation is not sufficient with its positive effect infrequently mentioned. To evaluate the correlation between DNAPL spreading and remediation efficiency, a two-dimensional sandbox apparatus was used to simulate the migration and dissolution process of 1,2-DCA (1,2-dichloroethane) DNAPL in SEAR. Distribution area of DNAPL in the sandbox was determined by digital image analysis and correlated with effluent DNAPL concentration. The results showed that the effluent DNAPL concentration has significant positive linear correlation with the DNAPL distribution area, indicating the mobilization of DNAPL could improve remediation efficiency by enlarging total NAPL-water interfacial area for mass transfer. Meanwhile, the vertical migration of 1,2-DCA was limited within the boundary of aquifer in all experiments, implying that by manipulating injection parameters in SEAR, optimal remediation efficiency can be reached while the risk of DNAPL vertical migration is minimized. This study provides a convenient visible and quantitative method for the optimization of parameters for SEAR project, and an approach of rapid predicting the extent of DNAPL contaminant distribution based on the dissolved DNAPL concentration in the extraction well.

  11. Impacts of Enhanced Reductive Bioremediation on Post-Remediation Groundwater Quality

    DTIC Science & Technology

    2015-11-15

    carbon, and naturally occurring hazardous compounds (e.g., arsenic ). Fortunately, this ‘plume’ of impacted groundwater is usually confined within the...SUBJECT TERMS secondary water quality impacts; anaerobic bioremediation; enhanced reductive dechlorination; methane; iron; manganese; arsenic 16...Cumulative frequency distributions for change in SWQI concentrations at 47 ERB sites ............ 20 3.3 Arsenic versus iron concentrations for

  12. Diversity Shrinkage: Cross-Validating Pareto-Optimal Weights to Enhance Diversity via Hiring Practices.

    PubMed

    Song, Q Chelsea; Wee, Serena; Newman, Daniel A

    2017-07-27

    To reduce adverse impact potential and improve diversity outcomes from personnel selection, one promising technique is De Corte, Lievens, and Sackett's (2007) Pareto-optimal weighting strategy. De Corte et al.'s strategy has been demonstrated on (a) a composite of cognitive and noncognitive (e.g., personality) tests (De Corte, Lievens, & Sackett, 2008) and (b) a composite of specific cognitive ability subtests (Wee, Newman, & Joseph, 2014). Both studies illustrated how Pareto-weighting (in contrast to unit weighting) could lead to substantial improvement in diversity outcomes (i.e., diversity improvement), sometimes more than doubling the number of job offers for minority applicants. The current work addresses a key limitation of the technique-the possibility of shrinkage, especially diversity shrinkage, in the Pareto-optimal solutions. Using Monte Carlo simulations, sample size and predictor combinations were varied and cross-validated Pareto-optimal solutions were obtained. Although diversity shrinkage was sizable for a composite of cognitive and noncognitive predictors when sample size was at or below 500, diversity shrinkage was typically negligible for a composite of specific cognitive subtest predictors when sample size was at least 100. Diversity shrinkage was larger when the Pareto-optimal solution suggested substantial diversity improvement. When sample size was at least 100, cross-validated Pareto-optimal weights typically outperformed unit weights-suggesting that diversity improvement is often possible, despite diversity shrinkage. Implications for Pareto-optimal weighting, adverse impact, sample size of validation studies, and optimizing the diversity-job performance tradeoff are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  13. Enhancing institutions and research through human diversity: reflections on diversity, inclusion, and the future of plant and natural resource sciences

    Treesearch

    Michael J. Dockry

    2015-01-01

    Many research institutions and professional societies are looking to enhance the diversity of their members, employees, and scientists. To do this, their efforts often focus on recruitment and retention of minority employees and employees from protected classes (e.g., race, religion, sex, age); however, recruitment and retention efforts can prove difficult and do not...

  14. Cultivating Diversity and Competency in STEM: Challenges and Remedies for Removing Virtual Barriers to Constructing Diverse Higher Education Communities of Success.

    PubMed

    Whittaker, Joseph A; Montgomery, Beronda L

    2012-01-01

    The need to increase the number of college graduates in Science, Technology, Engineering, and Mathematics (STEM) disciplines is a national issue. As the demographics of the United States' population grow increasingly more diverse, the recognition that students of color are disproportionately under-represented among those individuals successful at completing STEM degrees requires exigent and sustained intervention. Although a range of efforts and funding have been committed to increasing the success of under-represented minority (URM) students at primarily white, or majority, institutions, widespread progress has been slow. Simultaneously, Historically Black Colleges and Universities and Minority Serving Institutions have demonstrated disproportionate successes in graduating URM students with STEM degrees and those that proceed to completing graduate-level degrees in the sciences. The differential successes of particular institutions with promoting the achievement of diverse individuals in obtaining academic STEM degrees suggest that with committed and strategic leadership, advancements in creating academic communities that promote the success of a diverse range of students in STEM can be achieved in part through assessing and mitigating environmental barriers that impede success at majority institutions. In this paper, we address issues related to the engagement of URM students in majority settings and describe some efforts that have shown success for promoting diversity in STEM and highlight continuing issues and factors associated with cultivating diversity in academic STEM disciplines at majority institutions. Recommended efforts include addressing academic assistance, professional and cultural socialization issues and institutional environmental factors that are associated with success or lack thereof for URMs in STEM.

  15. Enhanced remediation of black liquor by activated sludge bioaugmented with a novel exogenous microorganism culture.

    PubMed

    Zheng, Yu; Chai, Li-Yuan; Yang, Zhi-Hui; Tang, Chong-Jian; Chen, Yue-Hui; Shi, Yan

    2013-07-01

    Black liquor (BL) is a notoriously difficult wastewater to treat due to the economic and efficiency limitations of physiochemical methods and intrinsic difficulties with bioremediation strategies caused by the high pH (10-13) and lignin content. This study investigated the feasibility of a novel bioaugmentation strategy for BL treatment, which uses a mixed microorganism culture of lignocellulose-degrading microorganisms isolated from degraded bamboo slips. Black liquor treatment was assessed in terms of chemical oxygen demand (COD) and color removal with a sequencing batch reactor organic loading rate of 9 kg COD/L·day under highly alkaline conditions (pH 10). Results revealed that bioaugmented activated sludge treatment of BL with special mixed microorganisms significantly enhanced the removal efficiency of COD, color, and lignin from the wastewater up to 64.8, 50.5, and 53.2 %, respectively. Gel permeation chromatography profiles showed that the bioaugmentation system could successfully degrade high molecular lignin fragments in black liquor. This work confirms bioaugmentation as a feasible alternative strategy for enhanced biological treatment of wastewater with high lignin content and high organic load rate under strongly alkaline conditions.

  16. THERMAL REMEDIATION

    EPA Science Inventory

    Thermal remediation is being proposed by Region I for remediation of the overburden soil and groundwater at the Solvent Recovery Services New England Superfund site. This presentation at the public meeting will acquaint area residents with thermal remediation. The two types of ...

  17. THERMAL REMEDIATION

    EPA Science Inventory

    Thermal remediation is being proposed by Region I for remediation of the overburden soil and groundwater at the Solvent Recovery Services New England Superfund site. This presentation at the public meeting will acquaint area residents with thermal remediation. The two types of ...

  18. Biodegradation of aged diesel in diverse soil matrixes: impact of environmental conditions and bioavailability on microbial remediation capacity.

    PubMed

    Sutton, Nora B; van Gaans, Pauline; Langenhoff, Alette A M; Maphosa, Farai; Smidt, Hauke; Grotenhuis, Tim; Rijnaarts, Huub H M

    2013-07-01

    While bioremediation of total petroleum hydrocarbons (TPH) is in general a robust technique, heterogeneity in terms of contaminant and environmental characteristics can impact the extent of biodegradation. The current study investigates the implications of different soil matrix types (anthropogenic fill layer, peat, clay, and sand) and bioavailability on bioremediation of an aged diesel contamination from a heterogeneous site. In addition to an uncontaminated sample for each soil type, samples representing two levels of contamination (high and low) were also used; initial TPH concentrations varied between 1.6 and 26.6 g TPH/kg and bioavailability between 36 and 100 %. While significant biodegradation occurred during 100 days of incubation under biostimulating conditions (64.4-100 % remediation efficiency), low bioavailability restricted full biodegradation, yielding a residual TPH concentration. Respiration levels, as well as the abundance of alkB, encoding mono-oxygenases pivotal for hydrocarbon metabolism, were positively correlated with TPH degradation, demonstrating their usefulness as a proxy for hydrocarbon biodegradation. However, absolute respiration and alkB presence were dependent on soil matrix type, indicating the sensitivity of results to initial environmental conditions. Through investigating biodegradation potential across a heterogeneous site, this research illuminates the interplay between soil matrix type, bioavailability, and bioremediation and the implications of these parameters for the effectiveness of an in situ treatment.

  19. Cultivating Diversity and Competency in STEM: Challenges and Remedies for Removing Virtual Barriers to Constructing Diverse Higher Education Communities of Success

    PubMed Central

    Whittaker, Joseph A.; Montgomery, Beronda L.

    2012-01-01

    The need to increase the number of college graduates in Science, Technology, Engineering, and Mathematics (STEM) disciplines is a national issue. As the demographics of the United States’ population grow increasingly more diverse, the recognition that students of color are disproportionately under-represented among those individuals successful at completing STEM degrees requires exigent and sustained intervention. Although a range of efforts and funding have been committed to increasing the success of under-represented minority (URM) students at primarily white, or majority, institutions, widespread progress has been slow. Simultaneously, Historically Black Colleges and Universities and Minority Serving Institutions have demonstrated disproportionate successes in graduating URM students with STEM degrees and those that proceed to completing graduate-level degrees in the sciences. The differential successes of particular institutions with promoting the achievement of diverse individuals in obtaining academic STEM degrees suggest that with committed and strategic leadership, advancements in creating academic communities that promote the success of a diverse range of students in STEM can be achieved in part through assessing and mitigating environmental barriers that impede success at majority institutions. In this paper, we address issues related to the engagement of URM students in majority settings and describe some efforts that have shown success for promoting diversity in STEM and highlight continuing issues and factors associated with cultivating diversity in academic STEM disciplines at majority institutions. Recommended efforts include addressing academic assistance, professional and cultural socialization issues and institutional environmental factors that are associated with success or lack thereof for URMs in STEM. PMID:23493445

  20. Professional Development Strategies to Enhance Diversity in the Geosciences

    ERIC Educational Resources Information Center

    Sherman-Morris, Kathleen; Rodgers, John C., III; McNeal, Karen S.; Brown, Michael E.; Dyer, Jamie L.

    2012-01-01

    Because of the historically low numbers of minorities in geoscience careers and college majors, an area of growing attention is how teacher professional development may be utilized to increase diversity in the geosciences (Pecore et al., 2007; Sedlock & Metzger, 2007). This paper examines teacher preferences for the timing, location and…

  1. Study Abroad: Enhanced Learning Experience in Cultural Diversity

    ERIC Educational Resources Information Center

    Jaoko, Japheth

    2010-01-01

    This paper examines how a study abroad experiential learning course in diversity provided a cultural immersion experience for a group of social work students from a small private university in central Kentucky. The students participated in a three-week international education experience in Kenya and reported this experience helped them become more…

  2. Professional Development Strategies to Enhance Diversity in the Geosciences

    ERIC Educational Resources Information Center

    Sherman-Morris, Kathleen; Rodgers, John C., III; McNeal, Karen S.; Brown, Michael E.; Dyer, Jamie L.

    2012-01-01

    Because of the historically low numbers of minorities in geoscience careers and college majors, an area of growing attention is how teacher professional development may be utilized to increase diversity in the geosciences (Pecore et al., 2007; Sedlock & Metzger, 2007). This paper examines teacher preferences for the timing, location and…

  3. Increasing Academic Excellence and Enhancing Diversity Are Compatible Goals

    ERIC Educational Resources Information Center

    Sternberg, Robert Jeffrey

    2008-01-01

    It is possible to simultaneously increase academic excellence and diversity. This article describes how the theory of successful intelligence can be used to accomplish both of these goals. The theory postulates that intelligence comprises creative skills in generating novel ideas, analytical skills in discerning whether they are good ideas, and…

  4. Increasing Academic Excellence and Enhancing Diversity Are Compatible Goals

    ERIC Educational Resources Information Center

    Sternberg, Robert Jeffrey

    2008-01-01

    It is possible to simultaneously increase academic excellence and diversity. This article describes how the theory of successful intelligence can be used to accomplish both of these goals. The theory postulates that intelligence comprises creative skills in generating novel ideas, analytical skills in discerning whether they are good ideas, and…

  5. Effects of source zone heterogeneity on surfactant-enhanced NAPL dissolution and resulting remediation end-points.

    PubMed

    Saenton, S; Illangasekare, T H; Soga, K; Saba, T A

    2002-11-01

    The effectiveness of removal of nonaqueous phase liquids (NAPLs) from the entrapment source zone of the subsurface has been limited by soil heterogeneity and the inability to locate all entrapped sources. The goal of this study was to demonstrate the uncertainty of degree of source removal associated with aquifer heterogeneity. In this demonstration, source zone NAPL removal using surfactant-enhanced dissolution was considered. Model components that simulate the processes of natural dissolution in aqueous phase and surfactant-enhanced dissolution were incorporated into an existing code of contaminant transport. The dissolution modules of the simulator used previously developed Gilland-Sherwood type phenomenological models of NAPL dissolution to estimate mass transfer coefficients that are upscaleable to multidimensional flow conditions found at field sites. The model was used to simulate the mass removal from 10 NAPL entrapment zone configurations based on previously conducted two-dimensional tank experiments. These entrapment zones represent the NAPL distribution in spatially correlated random fields of aquifer hydraulic conductivity. The numerical simulations representing two-dimensional conditions show that effectiveness of mass removal depends on the aquifer heterogeneity that controls the NAPL entrapment and delivery of the surfactant to the locations of entrapped NAPLs. Flow bypassing resulting from heterogeneity and the reduction of relative permeability due to NAPL entrapment reduces the delivery efficiency of the surfactant, thus prolonging the remediation time to achieve desired end-point NAPL saturations and downstream dissolved concentrations. In some extreme cases, the injected surfactant completely bypassed the NAPL source zones. It was also found that mass depletion rates for different NAPL source configurations vary significantly. The study shows that heterogeneity result in uncertainties in the mass removal and achievable end-points that are

  6. [Remediation of Cu/phenanthrene and combined contaminated loess soil by chemical-enhanced washing].

    PubMed

    Zhong, Jin-Kui; Zhao, Bao-Wei; Zhu, Kun; Ma, Feng-Feng; Yang, Xing-Chun; Ran, Jing-Yuan

    2011-10-01

    The chemical-enhanced washing of Cu2+ or/and phenanthrene (PHE) single or combined contaminated loess soil in Gansu Province was investigated with disodium ethylene diamine tetraacetate (EDTA) or/and sodium dodecyl sulfate (SDS) by the batch equilibrium experiments. The experimental results showed that EDTA or/and SDS could remove efficiently Cu2+ and/or PHE in single-contaminated or combined contaminated loess soils. The Cu2+ removal was significantly promoted by coexisting PHE with low concentration of EDTA (EDTA < 0.1 mol/L), however, the removal was slightly hindered with high concentration of EDTA (EDTA > 0.1 mol/L). As for the PHE removal by EDTA, it was founded that coexisting Cu2+ could enhance the PHE removal in the investigated ranges of the concentrations of EDTA. When concentration of EDTA was 0.01 mol/L, the removal of combined PHE was 20.94% higher than that of single PHE. The experimental results of the removal of contaminations by SDS showed that coexisting Cu2+ could suppress slightly the removal of PHE at a concentration of less than 4 000 mg/L SDS, but could assist the removal of PHE in 5 000 mg/L or higher SDS concentration. On the contrary, the influence of coexisting PHE for the removal of Cu2+ by SDS was that it facilitated Cu2+ extraction by low concentrations of SDS, however, it inhibited the removal of Cu2+ at high concentrations of SDS. The removal efficiencies of PHE and Cu2+ were improved greatly as using combined EDTA-SDS. Beside, there are some differences in the removal efficiency of the oth contaminants with the different sequence of EDTA and SDS added in the washing solution. In EDTA washing followed by SDS, SDS washing followed by EDTA and mixture of SDS-EDTA washing concurrently, the removal of Cu2+ is 91.40%, 95.10% and 96.50%, respectively, which is 28.46%, 32.16%, 33.56% higher than that of combined, 62.94%, by single EDTA. For PHE, the removal is 68.30%, 85.40%, 84.95%, respectively, which is 16.14%, 33.24%, 32. 79% higher

  7. Effect of OSE(II)-Enhanced Soil Washing(OESW) for TPH -Contaminated Soil Remediation

    NASA Astrophysics Data System (ADS)

    Hwang, J. H.; Lee, D. H.; Woo, N. C.

    2015-12-01

    The objectives of this study were to perform potentially suitable active agent that solubilize total petroleum hydrocarbon (TPH) present as contaminants and to evaluate the optimal range of process parameters that can increase the removal efficiency in OSE(II)-enhanced soil washing (OESW) pilot tests. Used experimental method for solubilisation of TPH by using OSE(II) was batch experiments. The active agent solution parameters for OESW pilot tests were solution concentration, solution pH in the OESW pilot tests. Based on the batch experiments, OSE(II) was proved as a suitable active agent that solubilizes TPH present as contaminants. The highest recovery (92-95 %) of the contaminants was obtained using a OSE(II) in the batch experiments. The pilot test results revealed that the optimum conditions were achieved with a OSE(II) surfactant solution concentration of 10 % (v/v), a OSE(II) surfactant solution pH of 6.5-7.5 of OSE(II) active agent solution. The maximum removal of contaminants (88 %) was obtained when optimum conditions were simultaneously met in pilot-scale OESW operations. These results confirm the viability of OESW for treating TPH-contaminated soil.

  8. Horizontal arrangement of anodes of microbial fuel cells enhances remediation of petroleum hydrocarbon-contaminated soil.

    PubMed

    Zhang, Yueyong; Wang, Xin; Li, Xiaojing; Cheng, Lijuan; Wan, Lili; Zhou, Qixing

    2015-02-01

    With the aim of in situ bioremediation of soil contaminated by hydrocarbons, anodes arranged with two different ways (horizontal or vertical) were compared in microbial fuel cells (MFCs). Charge outputs as high as 833 and 762C were achieved in reactors with anodes horizontally arranged (HA) and vertically arranged (VA). Up to 12.5 % of the total petroleum hydrocarbon (TPH) was removed in HA after 135 days, which was 50.6 % higher than that in VA (8.3 %) and 95.3 % higher than that in the disconnected control (6.4 %). Hydrocarbon fingerprint analysis showed that the degradation rates of both alkanes and polycyclic aromatic hydrocarbons (PAHs) in HA were higher than those in VA. Lower mass transport resistance in the HA than that of the VA seems to result in more power and more TPH degradation. Soil pH was increased from 8.26 to 9.12 in HA and from 8.26 to 8.64 in VA, whereas the conductivity was decreased from 1.99 to 1.54 mS/cm in HA and from 1.99 to 1.46 mS/cm in VA accompanied with the removal of TPH. Considering both enhanced biodegradation of hydrocarbon and generation of charge in HA, the MFC with anodes horizontally arranged is a promising configuration for future applications.

  9. Remediation of hexachlorobenzene contaminated soils by rhamnolipid enhanced soil washing coupled with activated carbon selective adsorption.

    PubMed

    Wan, Jinzhong; Chai, Lina; Lu, Xiaohua; Lin, Yusuo; Zhang, Shengtian

    2011-05-15

    The present study investigates the selective adsorption of hexachlorobenzene (HCB) from rhamnolipid solution by a powdered activated carbon (PAC). A combined soil washing-PAC adsorption technique is further evaluated on the removal of HCB from two soils, a spiked kaolin and a contaminated real soil. PAC at a dosage of 10 g L(-1) could achieve a HCB removal of 80-99% with initial HCB and rhamnolipid concentrations of 1 mg L(-1) and 3.3-25 g L(-1), respectively. The corresponding adsorptive loss of rhamnolipid was 8-19%. Successive soil washing-PAC adsorption tests (new soil sample was subjected to washing for each cycle) showed encouraging leaching and adsorption performances for HCB. When 25 g L(-1) rhamnolipid solution was applied, HCB leaching from soils was 55-71% for three cycles of washing, and HCB removal by PAC was nearly 90%. An overall 86% and 88% removal of HCB were obtained for kaolin and real soil, respectively, by using the combined process to wash one soil sample for twice. Our investigation suggests that coupling AC adsorption with biosurfactant-enhanced soil washing is a promising alternative to remove hydrophobic organic compounds from soils. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Remediation: Real Students, Real Standards.

    ERIC Educational Resources Information Center

    Culross, Rita

    1996-01-01

    Addressing the diverse educational needs of the adult student population can be achieved without dumbing down the college curriculum, using costly remedial programs, or sending the wrong message to America's youth. Possible solutions include college-public school partnerships providing remediation, community college programs, distance learning,…

  11. Resource waves: phenological diversity enhances foraging opportunities for mobile consumers

    USGS Publications Warehouse

    Armstrong, Jonathan B.; Takimoto, Gaku; Schindler, Daniel E.; Hayes, Matthew M.; Kauffman, Matthew J.

    2016-01-01

    Time can be a limiting constraint for consumers, particularly when resource phenology mediates foraging opportunity. Though a large body of research has explored how resource phenology influences trophic interactions, this work has focused on the topics of trophic mismatch or predator swamping, which typically occur over short periods, at small spatial extents or coarse resolutions. In contrast many consumers integrate across landscape heterogeneity in resource phenology, moving to track ephemeral food sources that propagate across space as resource waves. Here we provide a conceptual framework to advance the study of phenological diversity and resource waves. We define resource waves, review evidence of their importance in recent case studies, and demonstrate their broader ecological significance with a simulation model. We found that consumers ranging from fig wasps (Chalcidoidea) to grizzly bears (Ursus arctos) exploit resource waves, integrating across phenological diversity to make resource aggregates available for much longer than their component parts. In model simulations, phenological diversity was often more important to consumer energy gain than resource abundance per se. Current ecosystem-based management assumes that species abundance mediates the strength of trophic interactions. Our results challenge this assumption and highlight new opportunities for conservation and management. Resource waves are an emergent property of consumer–resource interactions and are broadly significant in ecology and conservation.

  12. Genetic diversity enhances the resistance of a seagrass ecosystem to disturbance.

    PubMed

    Hughes, A Randall; Stachowicz, John J

    2004-06-15

    Motivated by recent global reductions in biodiversity, empirical and theoretical research suggests that more species-rich systems exhibit enhanced productivity, nutrient cycling, or resistance to disturbance or invasion relative to systems with fewer species. In contrast, few data are available to assess the potential ecosystem-level importance of genetic diversity within species known to play a major functional role. Using a manipulative field experiment, we show that increasing genotypic diversity in a habitat-forming species (the seagrass Zostera marina) enhances community resistance to disturbance by grazing geese. The time required for recovery to near predisturbance densities also decreases with increasing eelgrass genotypic diversity. However, there is no effect of diversity on resilience, measured as the rate of shoot recovery after the disturbance, suggesting that more rapid recovery in diverse plots is due solely to differences in disturbance resistance. Genotypic diversity did not affect ecosystem processes in the absence of disturbance. Thus, our results suggest that genetic diversity, like species diversity, may be most important for enhancing the consistency and reliability of ecosystems by providing biological insurance against environmental change.

  13. Enhanced carcinogenicity by coexposure to arsenic and iron and a novel remediation system for the elements in well drinking water.

    PubMed

    Kumasaka, Mayuko Y; Yamanoshita, Osamu; Shimizu, Shingo; Ohnuma, Shoko; Furuta, Akio; Yajima, Ichiro; Nizam, Saika; Khalequzzaman, Md; Shekhar, Hossain U; Nakajima, Tamie; Kato, Masashi

    2013-03-01

    Various carcinomas including skin cancer are explosively increasing in arsenicosis patients who drink arsenic-polluted well water, especially in Bangladesh. Although well drinking water in the cancer-prone areas contains various elements, very little is known about the effects of elements except arsenic on carcinogenicity. In order to clarify the carcinogenic effects of coexposure to arsenic and iron, anchorage-independent growth and invasion in human untransformed HaCaT and transformed A431 keratinocytes were examined. Since the mean ratio of arsenic and iron in well water was 1:10 in cancer-prone areas of Bangladesh, effects of 1 μM arsenic and 10 μM iron were investigated. Iron synergistically promoted arsenic-mediated anchorage-independent growth in untransformed and transformed keratinocytes. Iron additionally increased invasion in both types of keratinocytes. Activities of c-SRC and ERK that regulate anchorage-independent growth and invasion were synergistically enhanced in both types of keratinocytes. Our results suggest that iron promotes arsenic-mediated transformation of untransformed keratinocytes and progression of transformed keratinocytes. We then developed a low-cost and high-performance adsorbent composed of a hydrotalcite-like compound for arsenic and iron. The adsorbent rapidly reduced concentrations of both elements from well drinking water in cancer-prone areas of Bangladesh to levels less than those in WHO health-based guidelines for drinking water. Thus, we not only demonstrated for the first time increased carcinogenicity by coexposure to arsenic and iron but also proposed a novel remediation system for well drinking water.

  14. Laboratory investigation of flux reduction from dense non-aqueous phase liquid (DNAPL) partial source zone remediation by enhanced dissolution

    NASA Astrophysics Data System (ADS)

    Kaye, Andrew J.; Cho, Jaehyun; Basu, Nandita B.; Chen, Xiaosong; Annable, Michael D.; Jawitz, James W.

    2008-11-01

    This study investigated the benefits of partial removal of dense nonaqueous phase liquid (DNAPL) source zones using enhanced dissolution in eight laboratory scale experiments. The benefits were assessed by characterizing the relationship between reductions in DNAPL mass and the corresponding reduction in contaminant mass flux. Four flushing agents were evaluated in eight controlled laboratory experiments to examine the effects of displacement fluid property contrasts and associated override and underride on contaminant flux reduction ( Rj) vs. mass reduction ( Rm) relationships ( Rj( Rm)): 1) 50% ethanol/50% water (less dense than water), 2) 40% ethyl-lactate/60% water (more dense than water), 3) 18% ethanol/26% ethyl-lactate/56% water (neutrally buoyant), and 4) 2% Tween-80 surfactant (also neutrally buoyant). For each DNAPL architecture evaluated, replicate experiments were conducted where source zone dissolution was conducted with a single flushing event to remove most of the DNAPL from the system, and with multiple shorter-duration floods to determine the path of the Rj( Rm) relationship. All of the single-flushing experiments exhibited similar Rj( Rm) relationships indicating that override and underride effects associated with cosolvents did not significantly affect the remediation performance of the agents. The Rj( Rm) relationship of the multiple injection experiments for the cosolvents with a density contrast with water tended to be less desirable in the sense that there was less Rj for a given Rm. UTCHEM simulations supported the observations from the laboratory experiments and demonstrated the capability of this model to predict Rj( Rm) relationships for non-uniformly distributed NAPL sources.

  15. Plant diversity enhances moth diversity in an intensive forest management experiment.

    PubMed

    Root, Heather T; Verschuyl, Jake; Stokely, Thomas; Hammond, Paul; Scherr, Melissa A; Betts, Matthew G

    2017-01-01

    Intensive forest management (IFM) promises to help satisfy increasing global demand for wood but may come at the cost of local reductions to forest biodiversity. IFM often reduces early seral plant diversity as a result of efforts to eliminate plant competition with crop trees. If diversity is a function of bottom-up drivers, theory predicts that specialists at lower trophic levels (e.g., insect herbivores) should be particularly sensitive to reductions in plant diversity. We conducted a stand-level experiment to test bottom-up controls on moth community structure, as mediated by degrees of forest management intensity. Using a dataset of 12,003 moths representing 316 moth species, moth richness decreased only slightly, if at all, as herbicide intensity increased (P = 0.062); the moderate treatment, which is most commonly applied in the northwestern USA, was estimated to have 4.72 (±2.14 SE, P = 0.039) fewer species than the control. Structural equation modeling revealed strong support for an effect of herbicide on plant abundance, which influenced plant species richness and subsequently moth species richness. Moth species richness was associated with plant species richness and followed a power law function (z = 0.42, P = 0.006), which is surprisingly consistent with a recent large-scale experiment in agricultural systems, and provides support for bottom-up drivers of moth community structure. Moth abundance was not influenced by the direct effects of silvicultural herbicide treatments. Site-level effects and variation in pre-harvest vegetation communities resulted in residual broadleaf and herbaceous vegetation in even the most intensive treatment. Even at low densities, these residual deciduous and herbaceous plants supported higher than expected moth abundance and richness. We conclude that forest management practices that retain early seral vegetation diversity are the most likely to conserve moth communities. © 2016 by the Ecological Society of

  16. The Enhancement Seminar Model as a Strategy to Promote Diversity and Student Success in MSW Programs

    ERIC Educational Resources Information Center

    Watson, Larry D.; Rycraft, Joan R.

    2010-01-01

    This study evaluates the effectiveness of an enhancement program by examining a cohort of 57 students admitted on probationary status to an MSW program in 2002 and required to participate in the enhancement program. The demographics for students admitted on probation demonstrate that the program is effective in increasing the diversity of the…

  17. Bird functional diversity decreases with time since disturbance: Does patchy prescribed fire enhance ecosystem function?.

    PubMed

    Sitters, Holly; Di Stefano, Julian; Christie, Fiona; Swan, Matthew; York, Alan

    2016-01-01

    Animal species diversity is often associated with time since disturbance, but the effects of disturbances such as fire on functional diversity are unknown. Functional diversity measures the range, abundance, and distribution of trait values in a community, and links changes in species composition with the consequences for ecosystem function. Improved understanding of the relationship between time since fire (TSF) and functional diversity is critical given that the frequency of both prescribed fire and wildfire is expected to increase. To address this knowledge gap, we examined responses of avian functional diversity to TSF and two direct measures of environmental heterogeneity, plant diversity, and structural heterogeneity. We surveyed birds across a 70-year chronosequence spanning four vegetation types in southeast Australia. Six bird functional traits were used to derive four functional diversity indices (richness, evenness, divergence, and dispersion) and the effects of TSF, plant diversity and structural heterogeneity on species richness and the functional diversity indices were examined using mixed models. We used a regression tree method to identify traits associated with species more common in young vegetation. Functional richness and dispersion were negatively associated with TSF in all vegetation types, suggesting that recent prescribed fire generates heterogeneous vegetation and provides greater opportunities for resource partitioning. Species richness was not significantly associated with TSF, and is probably an unreliable surrogate for functional diversity in fire-prone systems. A positive, relationship between functional evenness and structural heterogeneity was comnon to all vegetation types, suggesting that fine-scale (tens of meters) structural variation can enhance ecosystem function. Species more common in young vegetation were primarily linked by their specialist diets, indicating that ecosystem services such as seed dispersal and insect control

  18. [Enhancement of GA3 and EDTA on Lolium perenne to remediate Pb contaminated soil and its detoxification mechanism].

    PubMed

    Wu, Qiu-Ling; Wang, Wen-Chu; He, Shan-Ying

    2014-10-01

    A pot experiment was conducted to study the effects of plant growth regulator GA3 and metal chelate EDTA on enhancing the remediation of Pb contaminated soil, and the detoxification mechanism of Lolium perenne grown on Pb contaminated soil at 250 and 500 mg · kg(-1). The results showed that cell wall deposition and vacuolar compartmentalization played important roles in the detoxification of Pb in L. perenne shoot. The addition of EDTA alone increased Pb concentration in plants and Pb proportions in soluble fraction and organelles fraction, and enhanced the toxicity of Pb to plant, leading to the significant reduction of the plant biomass (P < 0.05). Foliar spray of lower concentration of GA3 (1 μmol · L(-1) or 10 μmol · L(-1)) alone significantly increased Pb accumulation by L. perenne (P < 0.05), but Pb proportions in soluble and organelles fraction were decreased, which alleviated the adverse effects of Pb on plant, thus improving the growth of plants (P < 0.05), with 1 μmol · L(-1) GA3 being the most effective. In contract, the addition of 100 μmol · L(-1) GA3 decreased Pb concentration in L. perenne, but increased the proportions of Pb in soluble fraction and organelles fraction, resulting in the reduction of plant biomass. Lower concen- tration of GA3 might alleviate the adverse effects of Pb and/or EDTA on plant, since the biomass amounts in the different treatments were in order of GA3 alone of lower concentration > GA3 of lower concentration + EDTA > EDTA alone. The combination application of low concentration of GA3 and EDTA showed a synergistic effect on the Pb accumulation in L. perenne (P < 0.05). Especially, Pb concentration in shoot and Pb extraction efficiency reached 1250.6 mg · kg(-1) and 1.1%, respec- tively, under the treatment of EDTA + 1 μmol L(-1) GA3 on the Pb 500 mg · kg(-1) soil. Therefore, the application of 1 μmol · L(-1) GA3 along with EDTA appeared to be a potential approach for phytoremediation of Pb contaminated soil.

  19. Enhanced Chemical Incident Response Plan (ECIRP). Appendix F, remediation analysis with Decision Support Tools (DSTs) for wide-area chemical hazards.

    SciTech Connect

    Hassig, Nancy L.; Pulsipher, Brent A.; Foltz, Greg W.; Hoette, Trisha Marie

    2011-07-01

    The Defense Threat Reduction Agency (DTRA) commissioned an assessment of the Consequence Management (CM) plans in place on military bases for response to a chemical attack. The effectiveness of the CM plans for recovering from chemical incidents was modeled using a multiple Decision Support Tools (DSTs). First, a scenario was developed based on an aerial dispersion of a chemical agent over a wide-area of land. The extent of contamination was modeled with the Hazard Prediction and Assessment Capability (HPAC) tool. Subsequently, the Analyzer for Wide Area Restoration Effectiveness (AWARE) tool was used to estimate the cost and time demands for remediation based on input of contamination maps, sampling and decontamination resources, strategies, rates and costs. The sampling strategies incorporated in the calculation were designed using the Visual Sample Plan (VSP) tool. Based on a gaps assessment and the DST remediation analysis, an Enhanced Chemical Incident Response Plan (ECIRP) was developed.

  20. DNAPL Surface Chemistry: Its Impact on DNAPL Distribution in the Vadose Zone and its Manipulation to Enhance Remediation

    SciTech Connect

    Suan Power; Stefan Grimberg; Miles Denham

    2003-06-16

    The remediation of DNAPLs in subsurface environments is often limited by the heterogeneous distribution of the organic fluid. The fraction of DNAPL that is in the high conductivity regions of the subsurface can often be recovered relatively easily, although DNAPL in lower conductivity regions is much more difficult to extract, either through direct pumping or remediation measures based on interface mass transfer. The distribution of DNAPL within the vadose zone is affected by a complex interplay of heterogeneities in the porous matrix and the interfacial properties defining the interactions among all fluid and solid phases. Decreasing the interfacial tension between a DNAPL and water in the vadose zone could change the spreading of the DNAPL, thereby increase the surface area for mass transfer and the effectiveness of soil vapor extraction remediation.

  1. Parallel Exploitation of Diverse Host Nutrients Enhances Salmonella Virulence

    PubMed Central

    Steeb, Benjamin; Claudi, Beatrice; Burton, Neil A.; Tienz, Petra; Schmidt, Alexander; Farhan, Hesso; Mazé, Alain; Bumann, Dirk

    2013-01-01

    Pathogen access to host nutrients in infected tissues is fundamental for pathogen growth and virulence, disease progression, and infection control. However, our understanding of this crucial process is still rather limited because of experimental and conceptual challenges. Here, we used proteomics, microbial genetics, competitive infections, and computational approaches to obtain a comprehensive overview of Salmonella nutrition and growth in a mouse typhoid fever model. The data revealed that Salmonella accessed an unexpectedly diverse set of at least 31 different host nutrients in infected tissues but the individual nutrients were available in only scarce amounts. Salmonella adapted to this situation by expressing versatile catabolic pathways to simultaneously exploit multiple host nutrients. A genome-scale computational model of Salmonella in vivo metabolism based on these data was fully consistent with independent large-scale experimental data on Salmonella enzyme quantities, and correctly predicted 92% of 738 reported experimental mutant virulence phenotypes, suggesting that our analysis provided a comprehensive overview of host nutrient supply, Salmonella metabolism, and Salmonella growth during infection. Comparison of metabolic networks of other pathogens suggested that complex host/pathogen nutritional interfaces are a common feature underlying many infectious diseases. PMID:23633950

  2. Drivers and applications of integrated clean-up technologies for surfactant-enhanced remediation of environments contaminated with polycyclic aromatic hydrocarbons (PAHs).

    PubMed

    Liang, Xujun; Guo, Chuling; Liao, Changjun; Liu, Shasha; Wick, Lukas Y; Peng, Dan; Yi, Xiaoyun; Lu, Guining; Yin, Hua; Lin, Zhang; Dang, Zhi

    2017-06-01

    Surfactant-enhanced remediation (SER) is considered as a promising and efficient remediation approach. This review summarizes and discusses main drivers on the application of SER in removing polycyclic aromatic hydrocarbons (PAHs) from contaminated soil and water. The effect of PAH-PAH interactions on SER efficiency is, for the first time, illustrated in an SER review. Interactions between mixed PAHs could enhance, decrease, or have no impact on surfactants' solubilization power towards PAHs, thus affecting the optimal usage of surfactants for SER. Although SER can transfer PAHs from soil/non-aqueous phase liquids to the aqueous phase, the harmful impact of PAHs still exists. To decrease the level of PAHs in SER solutions, a series of SER-based integrated cleanup technologies have been developed including surfactant-enhanced bioremediation (SEBR), surfactant-enhanced phytoremediation (SEPR) and SER-advanced oxidation processes (SER-AOPs). In this review, the general considerations and corresponding applications of the integrated cleanup technologies are summarized and discussed. Compared with SER-AOPs, SEBR and SEPR need less operation cost, yet require more treatment time. To successfully achieve the field application of surfactant-based technologies, massive production of the cost-effective green surfactants (i.e. biosurfactants) and comprehensive evaluation of the drivers and the global cost of SER-based cleanup technologies need to be performed in the future. Copyright © 2017. Published by Elsevier Ltd.

  3. Enhancement of stability of various nZVI suspensions used in groundwater remediation with environmentally friendly organic stabilizers

    NASA Astrophysics Data System (ADS)

    Schmid, Doris; Wagner, Stephan; Velimirović, Milica; Laumann, Susanne; Micić, Vesna; Hofmann, Thilo

    2014-05-01

    The use of nanoscale zero-valent iron (nZVI) particles for in situ remediation of polluted soil and groundwater has been shown as one of the most promising techniques [1]. The success of this technology depends on the mobility, reactivity, and longevity of nZVI particles. The mobility of nZVI particles depends on the properties of the single particles, stability of the particle suspension, and the aquifer material [1,2]. In order to enhance the mobility of nZVI, the mobility-decisive properties of the nZVI particles in suspension such as concentration, size distribution, surface charge, and sedimentation rate have to be investigated and optimized. Previous studies showed that pristine nZVI particles aggregate rapidly in water, reducing the particles radius of influence after injection [3]. In order to prevent aggregation and sedimentation of the nZVI particles, and consequently improve the stability of nZVI suspension and therefore the mobility of the nZVI particles, surface stabilizers can be used to provide electrostatic repulsion and steric or electrosteric stabilization [3,4]. The objective of this lab-scale study is to investigate the potential for enhancing the stability of different nZVI suspensions by means of environmentally friendly organic stabilizers, including carboxymethyl cellulose, pectin, alginate, xanthan, and guar gum. The different nZVI particles used included pristine and polyacrylic acid-coated nZVI particles provided in suspension (Nanofer 25 and Nanofer 25S, respectively, NANOIRON s.r.o., Czech Republic), air-stable nZVI particles (Nanofer Star, (NANOIRON s.r.o., Czech Republic), and milled iron flakes (UVR-FIA, Germany). In order to study the enhancement of nZVI stability (1 g L-1 total iron) different concentrations of organic stabilizers (1-20 wt.%) were applied in these nZVI suspensions. Each nZVI suspension was freshly prepared and treated for 10 minutes with Ultra-Turrax (15 000 rpm) and 10 minutes ultrasonic bath prior to

  4. Diversity climate enhances work outcomes through trust and openness in workgroup communication.

    PubMed

    Hofhuis, Joep; van der Rijt, Pernill G A; Vlug, Martijn

    2016-01-01

    Diversity climate, defined as an organizational climate characterized by openness towards and appreciation of individual differences, has been shown to enhance outcomes in culturally diverse teams. To date, it remains unclear which processes are responsible for these findings. This paper presents two quantitative studies (n = 91; 246) that identify trust and openness in workgroup communication as possible mediators. We replicate earlier findings that perceived diversity climate positively relates to job satisfaction, sense of inclusion, work group identification and knowledge sharing in teams. In study 1, trust is shown to mediate the effects of perceived diversity climate on team members' sense of inclusion. In study 2, trust mediates the relationship between perceived diversity climate and workgroup identification and openness mediates its relationship with knowledge sharing.

  5. SIMPLE ANALYTICAL MODEL FOR HEAT FLOW IN FRACTURES-APPLICATION TO STEAM ENHANCED REMEDIATION CONDUCTED IN FRACTURED ROCK

    EPA Science Inventory

    Remediation of fractured rock sites contaminated by non-aqueous phase liquids has long been recognized as the most difficult undertaking of any site clean-up. Recent pilot studies conducted at the Edwards Air Force Base in California and the former Loring Air Force Base in Maine ...

  6. SIMPLE ANALYTICAL MODEL FOR HEAT FLOW IN FRACTURES - APPLICATION TO STEAM ENHANCED REMEDIATION CONDUCTED IN FRACTURED ROCK

    EPA Science Inventory

    Remediation of fractured rock sites contaminated by non-aqueous phase liquids has long been recognized as the most difficult undertaking of any site clean-up. Recent pilot studies conducted at the Edwards Air Force Base in California and the former Loring Air Force Base in Maine ...

  7. The development of alum rates to enhance the remediation of phosphorus in fluvial systems following manure spills

    USDA-ARS?s Scientific Manuscript database

    Following the remediation of animal manure spills that reach surface waters, contaminated streambed sediments are often left in place and become a source for internal P loading within the stream in subsequent flow. The objective of this study was to develop treatment rates and combinations of alum a...

  8. SIMPLE ANALYTICAL MODEL FOR HEAT FLOW IN FRACTURES-APPLICATION TO STEAM ENHANCED REMEDIATION CONDUCTED IN FRACTURED ROCK

    EPA Science Inventory

    Remediation of fractured rock sites contaminated by non-aqueous phase liquids has long been recognized as the most difficult undertaking of any site clean-up. Recent pilot studies conducted at the Edwards Air Force Base in California and the former Loring Air Force Base in Maine ...

  9. SIMPLE ANALYTICAL MODEL FOR HEAT FLOW IN FRACTURES - APPLICATION TO STEAM ENHANCED REMEDIATION CONDUCTED IN FRACTURED ROCK

    EPA Science Inventory

    Remediation of fractured rock sites contaminated by non-aqueous phase liquids has long been recognized as the most difficult undertaking of any site clean-up. Recent pilot studies conducted at the Edwards Air Force Base in California and the former Loring Air Force Base in Maine ...

  10. Quicklime-induced changes of soil properties: Implications for enhanced remediation of volatile chlorinated hydrocarbon contaminated soils via mechanical soil aeration.

    PubMed

    Ma, Yan; Dong, Binbin; He, Xiaosong; Shi, Yi; Xu, Mingyue; He, Xuwen; Du, Xiaoming; Li, Fasheng

    2017-04-01

    Mechanical soil aeration is used for soil remediation at sites contaminated by volatile organic compounds. However, the effectiveness of the method is limited by low soil temperature, high soil moisture, and high soil viscosity. Combined with mechanical soil aeration, quicklime has a practical application value related to reinforcement remediation and to its action in the remediation of soil contaminated with volatile organic compounds. In this study, the target pollutant was trichloroethylene, which is a volatile chlorinated hydrocarbon pollutant commonly found in contaminated soils. A restoration experiment was carried out, using a set of mechanical soil-aeration simulation tests, by adding quicklime (mass ratios of 3, 10, and 20%) to the contaminated soil. The results clearly indicate that quicklime changed the physical properties of the soil, which affected the environmental behaviour of trichloroethylene in the soil. The addition of CaO increased soil temperature and reduced soil moisture to improve the mass transfer of trichloroethylene. In addition, it improved the macroporous cumulative pore volume and average pore size, which increased soil permeability. As soil pH increased, the clay mineral content in the soils decreased, the cation exchange capacity and the redox potential decreased, and the removal of trichloroethylene from the soil was enhanced to a certain extent. After the addition of quicklime, the functional group COO of soil organic matter could interact with calcium ions, which increased soil polarity and promoted the removal of trichloroethylene. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. [Interactive effect of spent mushroom compost and rhamnolipids to enhance the efficiency of alfalfa remediation of aged PAHs contaminated soil].

    PubMed

    Zhang, Jing; Lin, Xian-Gui; Li, Xuan-Zhen; Yin, Rui

    2010-10-01

    Polycyclic aromatic hydrocarbons (PAHs) are a group of the most widespread organic pollutants, which distributed widely in soil and sediment. Pot experiment was conducted to improve efficiency of phytoremediation using alfalfa (Medicago sativa L.) in aged PAHs contaminated soil by introducing spent mushroom compost and rhamnolipids. Plant biomass, PAHs concentrations, number of soil microorganism, soil enzyme activity and soil microbial functional diversity were determined after 60 days of alfalfa growth. The results showed that within 60 days, removal ratio of PAHs in treatment of alfalfa alone (AL) reached to 14.43%, while removal ratio of PAHs in treatments of "GZ + RH0.5, + AL" and "GZ + RH1.0 + AL" reached to 32.64% and 36.95%, which were 115.45% and 156.06% higher than that of phytoremediation. Contrasted to the control, the treatment of "GZ + RH1.0 + AL" had more plant biomass than others, shoot and root dry weight were 1.05 g/pot and 0.20 g/pot, respectively. During the process of phytoremediation, the number of soil bacteria and fungi were greatly increased by "GZ + RH1.0 + AL" and reached to 31.37 x 10(6) CFU x g(-1) and 5.86 x 10(6) CFU x g(-1), especially the number of PAHs-degrading bacteria reached to 39.57 x 10(5) MPN x g(-1), which were 29 times more than control treatment and 4 times more than treatment of alfalfa alone (AL). Moreover, soil dehydrogenase activity and the functional diversity of soil microbial community were increased significantly by the treatment of "GZ + RH1.0 + AL", respectively. Therefore, interaction of spent mushroom compost and rhamnolipids to enhance the phytoremediation efficiency had satisfied results in removal aged PAHs from an agricultural soil, the feasibility of this method needed to be further proved by large-area scale field experiment.

  12. Tropical Tree Trait Diversity Enhances Forest Biomass Resilience in a Dynamic Global Vegetation Model

    NASA Astrophysics Data System (ADS)

    Sakschewski, B.; Kirsten, T.; von Bloh, W.; Poorter, L.; Pena-Claros, M.; Boit, A.

    2016-12-01

    Functional diversity of ecosystems has been found to increase ecosystem functions and therefore enhance ecosystem resilience against environmental stressors. However, global carbon-cycle and biosphere models still classify the global vegetation into a relatively small number of distinct plant functional types (PFT) with constant features over space and time. Therefore, those models might underestimate the resilience and adaptive capacity of natural vegetation under climate change by ignoring positive effects that functional diversity might bring about. We diversified a set a of selected tree traits in a dynamic global vegetation model (LPJmL). In the new subversion, called LPJmL-FIT, Amazon region biomass stocks and forest structure appear significantly more resilient against climate change. Enhanced tree trait diversity enables the simulated rainforests to adjust to new environmental conditions via ecological sorting. These results may stimulate a new debate on the value of biodiversity for climate change mitigation.

  13. Enhancing the Curriculum through the Addition of Rich and Diverse Language Development Activities.

    ERIC Educational Resources Information Center

    Anen, Judith

    The primary goal of this practicum was to provide opportunities for rich and diverse language activities designed to enhance the kindergarten curriculum. New instructional guidelines were designed that encouraged daily classroom time devoted to language development activities. These activities replaced all formal isolated skill instruction.…

  14. Assessing the Crossdisciplinarity of Technology-Enhanced Learning with Science Overlay Maps and Diversity Measures

    ERIC Educational Resources Information Center

    Kalz, Marco; Specht, Marcus

    2014-01-01

    This paper deals with the assessment of the crossdisciplinarity of technology-enhanced learning (TEL). Based on a general discussion of the concept interdisciplinarity and a summary of the discussion in the field, two empirical methods from scientometrics are introduced and applied. Science overlay maps and the Rao-Stirling diversity index are…

  15. Evolution of increased phenotypic diversity enhances population performance by reducing sexual harassment in damselflies.

    PubMed

    Takahashi, Yuma; Kagawa, Kotaro; Svensson, Erik I; Kawata, Masakado

    2014-07-18

    The effect of evolutionary changes in traits and phenotypic/genetic diversity on ecological dynamics has received much theoretical attention; however, the mechanisms and ecological consequences are usually unknown. Female-limited colour polymorphism in damselflies is a counter-adaptation to male mating harassment, and thus, is expected to alter population dynamics through relaxing sexual conflict. Here we show the side effect of the evolution of female morph diversity on population performance (for example, population productivity and sustainability) in damselflies. Our theoretical model incorporating key features of the sexual interaction predicts that the evolution of increased phenotypic diversity will reduce overall fitness costs to females from sexual conflict, which in turn will increase productivity, density and stability of a population. Field data and mesocosm experiments support these model predictions. Our study suggests that increased phenotypic diversity can enhance population performance that can potentially reduce extinction rates and thereby influence macroevolutionary processes.

  16. Modest enhancements to conventional grassland diversity improve the provision of pollination services.

    PubMed

    Orford, Katherine A; Murray, Phil J; Vaughan, Ian P; Memmott, Jane

    2016-06-01

    Grassland for livestock production is a major form of land use throughout Europe and its intensive management threatens biodiversity and ecosystem functioning in agricultural landscapes. Modest increases to conventional grassland biodiversity could have considerable positive impacts on the provision of ecosystem services, such as pollination, to surrounding habitats.Using a field-scale experiment in which grassland seed mixes and sward management were manipulated, complemented by surveys on working farms and phytometer experiments, the impact of conventional grassland diversity and management on the functional diversity and ecosystem service provision of pollinator communities were investigated.Increasing plant richness, by the addition of both legumes and forbs, was associated with significant enhancements in the functional diversity of grassland pollinator communities. This was associated with increased temporal stability of flower-visitor interactions at the community level. Visitation networks revealed pasture species Taraxacum sp. (Wigg.) (dandelion) and Cirsium arvense (Scop.) (creeping thistle) to have the highest pollinator visitation frequency and richness. Cichorium intybus (L.) (chichory) was highlighted as an important species having both high pollinator visitation and desirable agronomic properties.Increased sward richness was associated with an increase in the pollination of two phytometer species; Fragaria × ananassa (strawberry) and Silene dioica (red campion), but not Vicia faba (broad bean). Enhanced functional diversity, richness and abundance of the pollinator communities associated with more diverse neighbouring pastures were found to be potential mechanisms for improved pollination. Synthesis and applications. A modest increase in conventional grassland plant diversity with legumes and forbs, achievable with the expertise and resources available to most grassland farmers, could enhance pollinator functional diversity, richness and abundance

  17. Restoration and management for plant diversity enhances the rate of belowground ecosystem recovery.

    PubMed

    Klopf, Ryan P; Baer, Sara G; Bach, Elizabeth M; Six, Johan

    2017-03-01

    The positive relationship between plant diversity and ecosystem functioning has been criticized for its applicability at large scales and in less controlled environments that are relevant to land management. To inform this gap between ecological theory and application, we compared recovery rates of belowground properties using two chronosequences consisting of continuously cultivated and independently restored fields with contrasting diversity management strategies: grasslands restored with high plant richness and managed for diversity with frequent burning (n = 20) and grasslands restored with fewer species that were infrequently burned (n = 15). Restoration and management for plant diversity resulted in 250% higher plant richness. Greater recovery of roots and more predictable recovery of the active microbial biomass across the high diversity management strategy chronosequence corresponded with faster recovery of soil structure. The high diversity grasslands also had greater nutrient conservation indicated by lower available inorganic nitrogen. Thus, mesic grasslands restored with more species and managed for high plant diversity with frequent burning enhances the rate of belowground ecosystem recovery from long-term disturbance at a scale relevant to conservation practices on the landscape. © 2017 by the Ecological Society of America.

  18. Remediation of polycyclic aromatic hydrocarbon and metal-contaminated soil by successive methyl-β-cyclodextrin-enhanced soil washing-microbial augmentation: a laboratory evaluation.

    PubMed

    Sun, Mingming; Luo, Yongming; Teng, Ying; Jia, Zhongjun; Li, Zhengao; Deng, Shiping

    2013-02-01

    Polycyclic aromatic hydrocarbon (PAH) and metal-polluted sites caused by abandoned coking plants are receiving wide attention. To address the associated environmental concerns, innovative remediation technologies are urgently needed. This study was initiated to investigate the feasibility of a cleanup strategy that employed an initial phase, using methyl-β-cyclodextrin (MCD) solution to enhance ex situ soil washing for extracting PAHs and metals simultaneously, followed by the addition of PAH-degrading bacteria (Paracoccus sp. strain HPD-2) and supplemental nutrients to treat the residual soil-bound PAHs. Elevated temperature (50 °C) in combination with ultrasonication (35 kHz, 30 min) at 100 g MCD L(-1) was effective in extracting PAHs and metals to assist soil washing; 93 % of total PAHs, 72 % of Cd, 78 % of Ni, 93 % of Zn, 84 % of Cr, and 68 % of Pb were removed from soil after three successive washing cycles. Treating the residual soil-bound PAHs for 20 weeks led to maximum biodegradation rates of 34, 45, 36, and 32 % of the remaining total PAHs, 3-ring PAHs, 4-ring PAHs, and 5(+6)-ring PAHs after washing procedure, respectively. Based on BIOLOG Ecoplate assay, the combined treatment at least partially restored microbiological functions in the contaminated soil. The ex situ cleanup strategy through MCD-enhanced soil washing followed by microbial augmentation can be effective in remediating PAH and metal-contaminated soil.

  19. Remediation of organochlorine pesticides (OCPs) contaminated site by successive methyl-β-cyclodextrin (MCD) and sunflower oil enhanced soil washing - Portulaca oleracea L. cultivation.

    PubMed

    Ye, Mao; Sun, Mingming; Hu, Feng; Kengara, Fredrick Orori; Jiang, Xin; Luo, Yongming; Yang, Xinlun

    2014-06-01

    An innovative ex situ soil washing technology was developed in this study to remediate organochlorine pesticides (OCPs)-contaminated site. Elevated temperature (50 °C) combined with ultrasonication (35 kHz, 30 min) at 25 g L(-1) methyl-β-cyclodextrin and 100 mL L(-1) sunflower oil were effective in extracting OCPs from the soil. After four successive washing cycles, the removal efficiency for total OCPs, DDTs, endosulfans, 1,2,3,4,5,6-hexachlorocyclohexanes, heptachlors, and chlordanes were all about 99%. The 4th washed soil with 3 months cultivation of Portulaca oleracea L. and nutrient addition significantly increase (p<0.05) the number, biomass carbon, nitrogen, and functioning diversity of soil microorganisms. This implied that the microbiological functioning of the soil was at least partially restored. This combined cleanup strategy proved to be effective and environmental friendly. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. CT urography of urinary diversions with enhanced CT digital radiography: preliminary experience.

    PubMed

    Sudakoff, Gary S; Guralnick, Michael; Langenstroer, Peter; Foley, W Dennis; Cihlar, Krista L; Shakespear, Jonathan S; See, William A

    2005-01-01

    The purpose of this study was to determine if 3D-rendered CT urography (CTU) depicts both normal and abnormal findings in patients with urinary diversions and if the addition of contrast-enhanced CT digital radiography (CTDR) improves opacification of the urinary collecting system. Thirty CTU and contrast-enhanced CTDR examinations were performed in 24 patients who underwent cystectomy for bladder cancer. Indications for evaluation included hematuria, tumor surveillance, or suspected diversion malfunction. All examinations were evaluated without knowledge of the stage or grade of a patient's tumor and were compared with the clinical records. Opacification of the urinary collecting system was evaluated with 3D CTU alone, contrast-enhanced CTDR alone, and combined CTU and CTDR. Nine abnormalities were identified including distal ureteral strictures (n = 4), vascular compression of the mid left ureter (n = 1), scarring of the mid right pole infundibulum (n = 1), bilateral hydronephrosis and hydroureter (n = 1), urinary reservoir calculus (n = 1), and tumor recurrence invading the afferent limb of the neobladder (n = 1). Eight of the nine detected abnormalities were surgically or pathologically confirmed. All abnormalities were identified on all three imaging techniques but were best seen on 3D CTU and enhanced CTDR images. Incomplete opacification of the urinary collecting system occurred in 17 patients with CTU alone, 12 patients with contrast-enhanced CTDR alone, and nine patients with combined CTU and contrast-enhanced CTDR. Compared with CTU alone, the combined technique of 3D CTU and contrast-enhanced CTDR improved opacification by a statistically significant difference (p = 0.037). CTU with 3D rendering can accurately depict both normal and abnormal postoperative findings in patients with urinary diversions. Adding enhanced CTDR can improve visualization of the urinary collecting system.

  1. Initial genetic diversity enhances population establishment and alters genetic structuring of a newly established Daphnia metapopulation.

    PubMed

    Holmes, Christopher J; Pantel, Jelena H; Schulz, Kimberly L; Cáceres, Carla E

    2016-07-01

    When newly created habitats are initially colonized by genotypes with rapid population growth rates, later arriving colonists may be prevented from establishing. Although these priority effects have been documented in multiple systems, their duration may be influenced by the diversity of the founding population. We conducted a large-scale field manipulation to investigate how initial clonal diversity influences temporal and landscape patterns of genetic structure in a developing metapopulation. Six genotypes of obligately asexual Daphnia pulex were stocked alone (no clonal diversity) or in combination ('high' clonal diversity) into newly created experimental woodland ponds. We also measured the population growth rate of all clones in the laboratory when raised on higher-quality and lower-quality resources. Our predictions were that in the 3 years following stocking, clonally diverse populations would be more likely to persist than nonclonally diverse populations and exhibit evidence for persistent founder effects. We expected that faster growing clones would be found in more pools and comprise a greater proportion of individuals genotyped from the landscape. Genetic composition, both locally and regionally, changed significantly following stocking. Six of 27 populations exhibited evidence for persistent founder effects, and populations stocked with 'high' clonal diversity were more likely to exhibit these effects than nonclonally diverse populations. Performance in the laboratory was not predictive of clonal persistence or overall dominance in the field. Hence, we conclude that although laboratory estimates of fitness did not fully explain metapopulation genetic structure, initial clonal diversity did enhance D. pulex population establishment and persistence in this system. © 2016 John Wiley & Sons Ltd.

  2. Genetic diversity enhanced by ancient introgression and secondary contact in East Pacific black mangroves.

    PubMed

    Nettel, Alejandro; Dodd, Richard S; Afzal-Rafii, Zara; Tovilla-Hernández, Cristian

    2008-06-01

    Regional distribution of genetic diversity in widespread species may be influenced by hybridization with locally restricted, closely related species. Previous studies have shown that Central American East Pacific populations of the wide-ranged Avicennia germinans, the black mangrove, harbour higher genetic diversity than the rest of its range. Genetic diversity in this region might be enhanced by introgression with the locally restricted Avicennia bicolor. We tested the hypotheses of ancient hybridization using phylogenetic analysis of the internal transcribed spacer region (ITS) of the nuclear ribosomal DNA and intergenic chloroplast DNA; we also tested for current hybridization by population level analysis of nuclear microsatellites. Our results unveiled ancient ITS introgression between a northern Pacific Central American A. germinans lineage and A. bicolor. However, microsatellite data revealed contemporary isolation between the two species. Polymorphic ITS sequences from Costa Rica and Panama are consistent with a zone of admixture between the introgressant ITS A. germinans lineage and a southern Central American lineage of A. germinans. Interspecific introgression influenced lineage diversity and divergence at the nuclear ribosomal DNA; intraspecific population differentiation and secondary contact are more likely to have enhanced regional genetic diversity in Pacific Central American populations of the widespread A. germinans.

  3. The complicated substrates enhance the microbial diversity and zinc leaching efficiency in sphalerite bioleaching system.

    PubMed

    Xiao, Yunhua; Xu, YongDong; Dong, Weiling; Liang, Yili; Fan, Fenliang; Zhang, Xiaoxia; Zhang, Xian; Niu, Jiaojiao; Ma, Liyuan; She, Siyuan; He, Zhili; Liu, Xueduan; Yin, Huaqun

    2015-12-01

    This study used an artificial enrichment microbial consortium to examine the effects of different substrate conditions on microbial diversity, composition, and function (e.g., zinc leaching efficiency) through adding pyrite (SP group), chalcopyrite (SC group), or both (SPC group) in sphalerite bioleaching systems. 16S rRNA gene sequencing analysis showed that microbial community structures and compositions dramatically changed with additions of pyrite or chalcopyrite during the sphalerite bioleaching process. Shannon diversity index showed a significantly increase in the SP (1.460), SC (1.476), and SPC (1.341) groups compared with control (sphalerite group, 0.624) on day 30, meanwhile, zinc leaching efficiencies were enhanced by about 13.4, 2.9, and 13.2%, respectively. Also, additions of pyrite or chalcopyrite could increase electric potential (ORP) and the concentrations of Fe3+ and H+, which were the main factors shaping microbial community structures by Mantel test analysis. Linear regression analysis showed that ORP, Fe3+ concentration, and pH were significantly correlated to zinc leaching efficiency and microbial diversity. In addition, we found that leaching efficiency showed a positive and significant relationship with microbial diversity. In conclusion, our results showed that the complicated substrates could significantly enhance microbial diversity and activity of function.

  4. DNAPL Surface Chemistry: Its Impact on DNAPL Distribution in the Vadose Zone and its Manipulation to Enhance Remediation

    SciTech Connect

    Powers, Susan E.; Grimberg, Stefan; Denham, Miles E.; Borkovec, Michal

    2001-06-01

    The primary hypothesis of this work is that surface-active chemicals and/or microorganisms present in the unsaturated zone can significantly alter interfacial phenomena governing the migration of DNAPLs, thereby affecting the accessibility of a DNAPL during remediation efforts. The surface-active materials are present in complex NAPL mixtures and are produced through microbial metabolic processes. The overall goal of this proposed research is to understand the role of and changes in interfacial phenomena on the accessibility of DNAPL in the vadose zone.

  5. DNAPL Surface Chemistry: Its Impact on DNAPL Distribution in the Vadose Zone and its Manipulation to Enhance Remediation

    SciTech Connect

    Powers, Susan E.; Grimberg, Stefan; Denham, Miles E.; Borkovec, Michal

    2002-06-01

    The primary hypothesis of this work is that surface-active chemicals and/or microorganisms present in the unsaturated zone can significantly alter interfacial phenomena governing the migration of DNAPLs, thereby affecting the accessibility of a DNAPL during remediation efforts. The surface-active materials are present in complex NAPL mixtures and are produced through microbial metabolic processes. The overall goal of this proposed research is to understand the role of and changes in interfacial phenomena on the accessibility of DNAPL in the vadose zone.

  6. Sampling and Selection Factors that Enhance the Diversity of Microbial Collections: Application to Biopesticide Development

    PubMed Central

    Park, Jun-Kyung; Lee, Seung-Hwan; Lee, Jang-Hoon; Han, Songhee; Kang, Hunseung; Kim, Jin-Cheol; Kim, Young Cheol; Gardener, Brian McSpadden

    2013-01-01

    Diverse bacteria are known to colonize plants. However, only a small fraction of that diversity has been evaluated for their biopesticide potential. To date, the criteria for sampling and selection in such bioprospecting endeavors have not been systematically evaluated in terms of the relative amount of diversity they provide for analysis. The present study aimed to enhance the success of bio-prospecting efforts by increasing the diversity while removing the genotypic redundancy often present in large collections of bacteria. We developed a multivariate sampling and marker-based selection strategy that significantly increase the diversity of bacteria recovered from plants. In doing so, we quantified the effects of varying sampling intensity, media composition, incubation conditions, plant species, and soil source on the diversity of recovered isolates. Subsequent sequencing and high-throughput phenotypic analyses of a small fraction of the collected isolates revealed that this approach led to the recovery of over a dozen rare and, to date, poorly characterized genera of plant-associated bacteria with significant biopesticide activities. Overall, the sampling and selection approach described led to an approximately 5-fold improvement in efficiency and the recovery of several novel strains of bacteria with significant biopesticide potential. PMID:25288941

  7. X-231A demonstration of in-situ remediation of DNAPL compounds in low permeability media by soil fracturing with thermally enhanced mass recovery or reactive barrier destruction

    SciTech Connect

    Siegrist, R.L. |; Lowe, K.S.; Murdoch, L.D. |; Slack, W.W.; Houk, T.C.

    1998-03-01

    The overall goal of the program of activities is to demonstrate robust and cost-effective technologies for in situ remediation of DNAPL compounds in low permeability media (LPM), including adaptations and enhancements of conventional technologies to achieve improved performance for DNAPLs in LPM. The technologies sought should be potential for application at simple, small sites (e.g., gasoline underground storage tanks) as well as at complex, larger sites (e.g., DOE land treatment units). The technologies involved in the X-231A demonstration at Portsmouth Gaseous Diffusion Plant (PORTS) utilized subsurface manipulation of the LPM through soil fracturing with thermally enhanced mass recovery or horizontal barrier in place destruction. To enable field evaluation of these approaches, a set of four test cells was established at the X-231A land treatment unit at the DOE PORTS plant in August 1996 and a series of demonstration field activities occurred through December 1997. The principal objectives of the PORTS X-231A demonstration were to: determine and compare the operational features of hydraulic fractures as an enabling technology for steam and hot air enhanced soil vapor extraction and mass recovery, in situ interception and reductive destruction by zero valent iron, and in situ interception and oxidative destruction by potassium permanganate; determine the interaction of the delivered agents with the LPM matrix adjacent to the fracture and within the fractured zone and assess the beneficial modifications to the transport and/or reaction properties of the LPM deposit; and determine the remediation efficiency achieved by each of the technology strategies.

  8. GROUND WATER ISSUE: HOW HEAT CAN ENHANCE IN-SITU SOIL AND AQUIFER REMEDIATION: IMPORTANT CHEMICAL PROPERTIES & GUIDANCE ON CHOOSING THE APPROPRIATE TECHNIQUE

    EPA Science Inventory

    The purpose of this Issue Paper and the three companion Issue Papers (Davis, 1997a, b, c) is to provide to those involved in assessing remediation technologies some basic information on the thermal remediation techniques.

  9. Toxic remediation

    DOEpatents

    Matthews, Stephen M.; Schonberg, Russell G.; Fadness, David R.

    1994-01-01

    What is disclosed is a novel toxic waste remediation system designed to provide on-site destruction of a wide variety of hazardous organic volatile hydrocarbons, including but not limited to halogenated and aromatic hydrocarbons in the vapor phase. This invention utilizes a detoxification plenum and radiation treatment which transforms hazardous organic compounds into non-hazardous substances.

  10. Reimagining Remediation

    ERIC Educational Resources Information Center

    Handel, Stephen J.; Williams, Ronald A.

    2011-01-01

    In 2007, the College Board's Community College Advisory Panel--a group of college presidents that advises the organization's membership on community college issues--asked these authors to write a paper describing effective remedial education programs. They never wrote the paper. The problem was not the lack of dedicated faculty and staff working…

  11. A demonstration of the applicability of implementing the enhanced Remedial Action Priority System (RAPS) for environmental releases

    SciTech Connect

    Whelan, G.; Droppo, J.G. Jr.; Strenge, D.L.; Walter, M.B.; Buck, J.W.

    1989-12-01

    The Remedial Action Priority System (RAPS) and the Multimedia Environmental Pollutant Assessment System (MEPAS) were developed to prioritize problems associated with potential releases of hazardous chemical and radioactive materials in a scientific and objective manner based on limited site information. This report documents the model testing efforts of the RAPS/MEPAS methodology for the atmospheric, surface water, groundwater, and exposure components. Comparisons are given of model outputs with measured data at three sites: the US Department of Energy's Mound facility in Ohio and Hanford facility in Washington, and a chromium-cadmium plating site in New York. The results show that the simulated magnitudes, spacial and temporal trends, and distributions of contaminants corresponded well with the measured data. 25 refs., 86 figs., 26 tabs.

  12. Functional diversity enhances the resistance of ecosystem multifunctionality to aridity in Mediterranean drylands

    PubMed Central

    Valencia-Gómez, Enrique; Maestre, Fernando T.; Le Bagousse-Pinguet, Yoann; Quero, José Luis; Tamme, Riin; Börger, Luca; García-Gómez, Miguel; Gross, Nicolas

    2015-01-01

    SUMMARY We used a functional trait-based approach to assess the impacts of aridity and shrub encroachment on the functional structure of Mediterranean dryland communities (functional diversity and community-weighted mean trait values [CWM]), and to evaluate how these functional attributes ultimately affect multifunctionality (i.e., the provision of several ecosystem functions simultaneously). Shrub encroachment (the increase in the abundance/cover of shrubs) is a major land cover change that is taking place in grasslands worldwide. Studies conducted on drylands have reported positive or negative impacts of shrub encroachment depending on the functions and the traits of the sprouting or non-sprouting shrub species considered. Functional diversity and CWM were equally important as drivers of multifunctionality responses to both aridity and shrub encroachment. Size traits (e.g., vegetative height or lateral spread) and leaf traits (e.g., specific leaf area and leaf dry matter content) captured the effect of shrub encroachment on multifunctionality with a relative high accuracy (r2=0.63). Functional diversity also improved the resistance of multifunctionality along the aridity gradient studied. Maintaining and enhancing functional diversity in plant communities may help to buffer negative effects of ongoing global environmental change on dryland multifunctionality. PMID:25615801

  13. Therapeutic effects of remediating autophagy failure in a mouse model of Alzheimer disease by enhancing lysosomal proteolysis.

    PubMed

    Yang, Dun-Sheng; Stavrides, Philip; Mohan, Panaiyur S; Kaushik, Susmita; Kumar, Asok; Ohno, Masuo; Schmidt, Stephen D; Wesson, Daniel W; Bandyopadhyay, Urmi; Jiang, Ying; Pawlik, Monika; Peterhoff, Corrinne M; Yang, Austin J; Wilson, Donald A; St George-Hyslop, Peter; Westaway, David; Mathews, Paul M; Levy, Efrat; Cuervo, Ana M; Nixon, Ralph A

    2011-07-01

    The extensive autophagic-lysosomal pathology in Alzheimer disease (AD) brain has revealed a major defect: in the proteolytic clearance of autophagy substrates. Autophagy failure contributes on several levels to AD pathogenesis and has become an important therapeutic target for AD and other neurodegenerative diseases. We recently observed broad therapeutic effects of stimulating autophagic-lysosomal proteolysis in the TgCRND8 mouse model of AD that exhibits defective proteolytic clearance of autophagic substrates, robust intralysosomal amyloid-β peptide (Aβ) accumulation, extracellular β-amyloid deposition and cognitive deficits. By genetically deleting the lysosomal cysteine protease inhibitor, cystatin B (CstB), to selectively restore depressed cathepsin activities, we substantially cleared Aβ, ubiquitinated proteins and other autophagic substrates from autolysosomes/lysosomes and rescued autophagic-lysosomal pathology, as well as reduced total Aβ40/42 levels and extracellular amyloid deposition, highlighting the underappreciated importance of the lysosomal system for Aβ clearance. Most importantly, lysosomal remediation prevented the marked learning and memory deficits in TgCRND8 mice. Our findings underscore the pathogenic significance of autophagic-lysosomal dysfunction in AD and demonstrate the value of reversing this dysfunction as an innovative therapeautic strategy for AD.

  14. Can mangrove plantation enhance the functional diversity of macrobenthic community in polluted mangroves?

    PubMed

    Leung, Jonathan Y S; Cheung, Napo K M

    2017-03-15

    Mangrove plantation is widely applied to re-establish the plant community in degraded mangroves, but its effectiveness to restore the ecological functions of macrobenthic community remains poorly known, especially when pollution may overwhelm its potential positive effect. Here, we tested the effect of mangrove plantation on the ecological functions of macrobenthic community in a polluted mangrove by analyzing biological traits of macrobenthos and calculating functional diversity. Mangrove plantation was shown to enhance the functional diversity and restore the ecological functions of macrobenthic community, depending on seasonality. Given the polluted sediment, however, typical traits of opportunistic species (e.g. small and short-lived) prevailed in all habitats and sampling times. We conclude that mangrove plantation can help diversify the ecological functions of macrobenthic community, but its effectiveness is likely reduced by pollution. From the management perspective, therefore, pollution sources must be stringently regulated and mangrove plantation should be conducted to fully recover degraded mangroves.

  15. Science inquiry and student diversity: Enhanced abilities and continuing difficulties after an instructional intervention

    NASA Astrophysics Data System (ADS)

    Lee, Okhee; Buxton, Cory; Lewis, Scott; Leroy, Kathryn

    2006-09-01

    This study examines elementary students' abilities to conduct science inquiry through their participation in an instructional intervention over a school year. The study involved 25 third and fourth grade students from six elementary schools representing diverse linguistic and cultural groups. Prior to and at the completion of the intervention, the students participated in elicitation sessions as they conducted a semistructured inquiry task on evaporation. The results indicate that students demonstrated enhanced abilities with some aspects of the inquiry task, but continued to have difficulties with other aspects of the task even after instruction. Although students from all demographic subgroups showed substantial gains, students from non-mainstream and less privileged backgrounds in science showed greater gains in inquiry abilities than their more privileged counterparts. The results contribute to the emerging literature on designing learning environments that foster science inquiry of elementary students from diverse backgrounds.

  16. Enhancing the Performance of Medical Implant Communication Systems through Cooperative Diversity.

    PubMed

    Hegyi, Barnabás; Levendovszky, János

    2010-01-01

    Battery-operated medical implants-such as pacemakers or cardioverter-defibrillators-have already been widely used in practical telemedicine and telecare applications. However, no solution has yet been found to mitigate the effect of the fading that the in-body to off-body communication channel is subject to. In this paper, we reveal and assess the potential of cooperative diversity to combat fading-hence to improve system performance-in medical implant communication systems. In the particular cooperative communication scenario we consider, multiple cooperating receiver units are installed across the room accommodating the patient with a medical implant inside his/her body. Our investigations have shown that the application of cooperative diversity is a promising approach to enhance the performance of medical implant communication systems in various aspects such as implant lifetime and communication link reliability.

  17. Strategies for enhancing research in aging health disparities by mentoring diverse investigators

    PubMed Central

    Harawa, Nina T.; Manson, Spero M.; Mangione, Carol M.; Penner, Louis A.; Norris, Keith C.; DeCarli, Charles; Scarinci, Isabel C.; Zissimopoulos, Julie; Buchwald, Dedra S.; Hinton, Ladson; Pérez-Stable, Eliseo J.

    2017-01-01

    Introduction The Resource Centers for Minority Aging Research (RCMAR) program was launched in 1997. Its goal is to build infrastructure to improve the well-being of older racial/ethnic minorities by identifying mechanisms to reduce health disparities. Methods Its primary objectives are to mentor faculty in research addressing the health of minority elders and to enhance the diversity of the workforce that conducts elder health research by prioritizing the mentorship of underrepresented diverse scholars. Results Through 2015, 12 centers received RCMAR awards and provided pilot research funding and mentorship to 361 scholars, 70% of whom were from underrepresented racial/ethnic groups. A large majority (85%) of RCMAR scholars from longstanding centers continue in academic research. Another 5% address aging and other health disparities through nonacademic research and leadership roles in public health agencies. Conclusions Longitudinal, team-based mentoring, cross-center scholar engagement, and community involvement in scholar development are important contributors to RCMAR’s success. PMID:28856013

  18. Adolescent Literacy: More than Remediation

    ERIC Educational Resources Information Center

    Biancarosa, Gina

    2012-01-01

    The challenge of adolescent literacy involves more than providing remediation for students who have not mastered basic reading skills. To become successful learners, adolescents must master complex texts, understand the diverse literacy demands of the different content areas, and navigate digital texts. In this article, Biancarosa reviews what the…

  19. Ensemble of Surrogates-based Optimization for Identifying an Optimal Surfactant-enhanced Aquifer Remediation Strategy at Heterogeneous DNAPL-contaminated Sites

    NASA Astrophysics Data System (ADS)

    Lu, W., Sr.; Xin, X.; Luo, J.; Jiang, X.; Zhang, Y.; Zhao, Y.; Chen, M.; Hou, Z.; Ouyang, Q.

    2015-12-01

    The purpose of this study was to identify an optimal surfactant-enhanced aquifer remediation (SEAR) strategy for aquifers contaminated by dense non-aqueous phase liquid (DNAPL) based on an ensemble of surrogates-based optimization technique. A saturated heterogeneous medium contaminated by nitrobenzene was selected as case study. A new kind of surrogate-based SEAR optimization employing an ensemble surrogate (ES) model together with a genetic algorithm (GA) is presented. Four methods, namely radial basis function artificial neural network (RBFANN), kriging (KRG), support vector regression (SVR), and kernel extreme learning machines (KELM), were used to create four individual surrogate models, which were then compared. The comparison enabled us to select the two most accurate models (KELM and KRG) to establish an ES model of the SEAR simulation model, and the developed ES model as well as these four stand-alone surrogate models was compared. The results showed that the average relative error of the average nitrobenzene removal rates between the ES model and the simulation model for 20 test samples was 0.8%, which is a high approximation accuracy, and which indicates that the ES model provides more accurate predictions than the stand-alone surrogate models. Then, a nonlinear optimization model was formulated for the minimum cost, and the developed ES model was embedded into this optimization model as a constrained condition. Besides, GA was used to solve the optimization model to provide the optimal SEAR strategy. The developed ensemble surrogate-optimization approach was effective in seeking a cost-effective SEAR strategy for heterogeneous DNAPL-contaminated sites. This research is expected to enrich and develop the theoretical and technical implications for the analysis of remediation strategy optimization of DNAPL-contaminated aquifers.

  20. Ensemble of surrogates-based optimization for identifying an optimal surfactant-enhanced aquifer remediation strategy at heterogeneous DNAPL-contaminated sites

    NASA Astrophysics Data System (ADS)

    Jiang, Xue; Lu, Wenxi; Hou, Zeyu; Zhao, Haiqing; Na, Jin

    2015-11-01

    The purpose of this study was to identify an optimal surfactant-enhanced aquifer remediation (SEAR) strategy for aquifers contaminated by dense non-aqueous phase liquid (DNAPL) based on an ensemble of surrogates-based optimization technique. A saturated heterogeneous medium contaminated by nitrobenzene was selected as case study. A new kind of surrogate-based SEAR optimization employing an ensemble surrogate (ES) model together with a genetic algorithm (GA) is presented. Four methods, namely radial basis function artificial neural network (RBFANN), kriging (KRG), support vector regression (SVR), and kernel extreme learning machines (KELM), were used to create four individual surrogate models, which were then compared. The comparison enabled us to select the two most accurate models (KELM and KRG) to establish an ES model of the SEAR simulation model, and the developed ES model as well as these four stand-alone surrogate models was compared. The results showed that the average relative error of the average nitrobenzene removal rates between the ES model and the simulation model for 20 test samples was 0.8%, which is a high approximation accuracy, and which indicates that the ES model provides more accurate predictions than the stand-alone surrogate models. Then, a nonlinear optimization model was formulated for the minimum cost, and the developed ES model was embedded into this optimization model as a constrained condition. Besides, GA was used to solve the optimization model to provide the optimal SEAR strategy. The developed ensemble surrogate-optimization approach was effective in seeking a cost-effective SEAR strategy for heterogeneous DNAPL-contaminated sites. This research is expected to enrich and develop the theoretical and technical implications for the analysis of remediation strategy optimization of DNAPL-contaminated aquifers.

  1. Evaluation of the Eological Management and Enhancement Alernative for Remediation of the K1007-P1 Pond

    SciTech Connect

    Peterson, M.J.

    2005-10-31

    An evaluation of the human and ecological risks associated with the P1 Pond and surrounding environs was conducted as part of the ETTP Site-Wide Remedial Investigation. The RI provides the basis for the focus on PCBs as the most important unacceptable risk to human and ecological health in the pond. Other P1 contaminants, media, or pathways of risk to receptors are identified in the RI, but are not addressed as a major risk reduction goal for the ETTP Site-Wide Feasibility Study. Therefore, the goal of the Ecological Management alternative is to reduce unacceptable risks associated with PCBs in fish. Many of the actions proposed for this alternative, however, are likely to reduce risks associated with other contaminants and their pathways. The high PCB concentrations in fish from the P1 Pond are most certainly due in part to the current ecological condition of the pond that maximizes PCB biomagnification. This basic assumption and the factors contributing to it were evaluated by conducting an intensive field study of the P1 Pond in the summer of 2004 (for a thorough presentation of current P1 Pond biological conditions, see Peterson et al. 2005). Major hypotheses regarding the P1 Pond's current fish community, PCB fate and transport processes, pond vegetation, and limnological conditions that contribute to the high PCB levels in fish were validated by the study (Appendix A), The results of the 2004 ecological assessment, in concert with long-term datasets obtained as part of the ETTP Biological Monitoring and Abatement Program (BMAP) and recent abiotic sampling for the RI, provide the basis for the assessment of current conditions.

  2. Phyto-enhanced remediation of soil co-contaminated with lead and diesel fuel using biowaste and Dracaena reflexa: A laboratory study.

    PubMed

    Dadrasnia, Arezoo; Pariatamby, Agamuthu

    2016-03-01

    In phytoremediation of co-contaminated soil, the simultaneous and efficient remediation of multiple pollutants is a major challenge rather than the removal of pollutants. A laboratory-scale experiment was conducted to investigate the effect of 5% addition of each of three different organic waste amendments (tea leaves, soy cake, and potato skin) to enhance the phytoaccumulation of lead (60 mg kg(-1)) and diesel fuel (25,000 mg kg(-1)) in co-contaminated soil by Dracaena reflexa Lam for a period of 180 day. The highest rate of oil degradation was recorded in co-contaminated soil planted with D. reflexa and amended with soy cake (75%), followed by potato skin (52.8%) and tea leaves (50.6%). Although plants did not accumulate hydrocarbon from the contaminated soil, significant bioaccumulation of lead in the roots and stems of D. reflexa was observed. At the end of 180 days, 16.7 and 9.8 mg kg(-1) of lead in the stems and roots of D. reflexa were recorded, respectively, for the treatment with tea leaves. These findings demonstrate the potential of organic waste amendments in enhancing phytoremediation of oil and bioaccumulation of lead. © The Author(s) 2015.

  3. Cognitive remediation therapy (CRT) as a treatment enhancer of eating disorders and obsessive compulsive disorders: study protocol for a randomized controlled trial.

    PubMed

    van Passel, Boris; Danner, Unna; Dingemans, Alexandra; van Furth, Eric; Sternheim, Lot; van Elburg, Annemarie; van Minnen, Agnes; van den Hout, Marcel; Hendriks, Gert-Jan; Cath, Daniëlle

    2016-11-10

    Anorexia nervosa (AN) and Obsessive Compulsive Disorder (OCD) are among the most incapacitating and costly of mental disorders. Cognitive Behaviour Therapy (CBT), medication, and combination regimens, to which in AN personalised guidance on weight control is added, are moderately successful, leaving room for more effective treatment algorithms. An underlying deficit which the two disorders share is cognitive inflexibility, a trait that is likely to impede treatment engagement and reduce patients' ability to benefit from treatment. Cognitive remediation therapy (CRT) is an easy-to-use intervention aimed at reducing cognitive inflexibility and thereby enhancing treatment outcome, which we aim to test in a controled study. In a randomized-controlled multicenter clinical trial 64 adult patients with AN and 64 with OCD are randomized to 10 bi-weekly sessions with either CRT or a control condition, after which Treatment As Usual (TAU) is started. All patients are evaluated during single-blind assessments at baseline, post-CRT/control intervention, and after 6 months. Indices of treatment effect are disorder-specific symptom severity, quality of life, and cost-effectivity. Also, moderators and mediators of treatment effects will be studied. To our knowledge, this is the first randomized controlled trial using an control condition evaluating the efficacy and effectiveness of CRT as a treatment enhancer preceding TAU for AN, and the first study to investigate CRT in OCD, moreover taking cost-effectiveness of CRT in AN and OCD into account. The Netherlands Trial Register NTR3865 . Registered 20 february 2013.

  4. Can Diversity in the Undergraduate Engineering Population BE Enhanced Through Curricular Change?

    NASA Astrophysics Data System (ADS)

    Busch-Vishniac, Ilene J.; Jarosz, Jeffrey P.

    The lack of diversity in the engineering workforce is a persistent problem, with no signs of pending improvement. The situation continues despite a serious technical workforce shortage in the United States. Efforts to promote diversity in the student body in U.S. engineering schools, such as industrial partnerships, academic services, and the establishment of social networks, have produced modest gains. The authors intend to pursue a distinctly different approach to the problem of encouraging a diverse engineering student population, one that focuses on the curriculum. This study reviews curricular innovations attempted to date as a basis for rebuilding the undergraduate engineering curriculum from the ground up. The goal is to produce a curriculum that retains the salient technical material but enhances the link between fundamentals and applications, reduces critical path lengths in the course sequence, introduces team experiences into all courses, and creates an atmosphere of inclusion rather than exclusion. The new curriculum will require trial, assessment, and revision before it is ready for adoption.

  5. Limiting resources in sessile systems: food enhances diversity and growth of suspension feeders despite available space.

    PubMed

    Svensson, Robin J; Marshall, Dustin J

    2015-03-01

    Much of our understanding of competition comes trom onservations in sessue systems, such as rainforests and marine invertebrate communities. In terrestrial systems, sessile species often compete for multiple limiting resources (i.e., space, light, and nutrients), but in marine systems, space is viewed as the primary or sole limiting resource. Competition theory, on the other hand, suggests that competition for a single limiting resource is unlikely to maintain high species diversity, but manipulative tests of competition for other resources in marine benthic systems are exceedingly rare. Here, we manipulate the availability of food for a classic system, marine sessile invertebrate communities, and investigate the effects on species diversity, abundance, and composition during early succession as well as on the growth of bryozoan populations in the field. We found the number of species to be greater, available space to be lower, and the community composition to be different in assemblages subjected to increased food availability compared to controls. Similarly, laboratory-settled bryozoans deployed into the field grew more in the presence of enhanced food. Our results suggest that food can act as a limiting resource, affecting both diversity and abundance, even when bare space is still available in hard-substratum communities. Consequently, broadening the view of resource limitation beyond solely space may increase our understanding and predictability of marine sessile systems.

  6. Partnership to Enhance Diversity in Marine Geosciences: Holocene Climate and Anthropogenic Changes from Long Island Sound, NY

    NASA Astrophysics Data System (ADS)

    McHugh, C. M.; Zheng, Y.; Kohfeld, K. E.; Marchese, P.; Cormier, M.; Warkentine, B.

    2005-12-01

    This project, sponsored by the National Science Foundation, Opportunities to Enhance Diversity in the Geosciences Division, will develop a program based on multidisciplinary investigations of Long Island Sound, as a vehicle to enhance diversity in geosciences. The program includes a curriculum centered on geosciences with a substantial field and laboratory component. Students will participate in a one-week oceanographic expedition to Long Island Sound aboard the R/V Cape Henlopen and in day trips using SUNY Maritime College's R/V Alexanderson. The goal is to illustrate the dominant physical processes in an urban coastal area by using a variety of oceanographic mapping techniques, such as multibeam bathymetric mapping, sediment and water sampling, and current profiling. The working hypothesis is that New York City students will be attracted to geosciences through an integrated field and research experience which familiarizes them with their own environment. Furthermore, they will be introduced to solving geoscience problems in a hands-on manner while receiving one-on-one mentoring in a supportive environment. Strong support exists from the City University of New York (CUNY) at the graduate level through MAGNET fellowships. At the undergraduate level, the geoscience curriculum fulfills a science requirement for completion of a BA in geosciences. Support also exists from the "Alliance for Minority Participation" (AMP), a program supported by the National Science Foundation and in which Queens College (QC) and CUNY participate, and the "Search for Education, Elevation, and Knowledge" (SEEK), a QC program designed to provide educational opportunities for academically motivated students who need substantial financial assistance to attend college. The main scientific objectives are 1) to evaluate the impact of anthropogenic activities through studies of the waters, plankton, and sediments and to propose measures for their remediation, and 2) to begin to assess long

  7. The potential for solubilizing agents to enhance the remediation of hydrophobic organic solutes in soil-water suspensions. [Quarterly report

    SciTech Connect

    Laha, S.; Liu, Z.; Edwards, D.; Luthy, R.G.

    1991-02-01

    This paper discusses the feasibility for use of surfactant solubilizing agents to enhance the solubility and the rate of microbial degradation of hydrophobic organic solutes in soil-water suspensions. Hydrophobic organic contaminants are strongly sorbed to soil or sediment material, and as a consequence the rate of microbial degradation may depend greatly on the desorption of the sorbed-phase contaminant and the accessibility of the contaminant to soil microorganisms. Chemical solubilizing agents may enhance the rate of hydrophobic organic solute degradation by increasing the rate of solute desorption from soil and the extent of solute partitioning to the aqueous phase. The presentation will review on-going research on: surfactant solubilization of polycyclic aromatic hydrocarbon (PAH) compounds in clean water, and in soil-water suspensions; and experiments to assess if the addition of surfactant to soil-water suspension results in faster rate of mineralization of PAH compounds in soil.

  8. The potential for solubilizing agents to enhance the remediation of hydrophobic organic solutes in soil-water suspensions

    SciTech Connect

    Laha, S.; Liu, Z.; Edwards, D.; Luthy, R.G.

    1991-02-01

    This paper discusses the feasibility for use of surfactant solubilizing agents to enhance the solubility and the rate of microbial degradation of hydrophobic organic solutes in soil-water suspensions. Hydrophobic organic contaminants are strongly sorbed to soil or sediment material, and as a consequence the rate of microbial degradation may depend greatly on the desorption of the sorbed-phase contaminant and the accessibility of the contaminant to soil microorganisms. Chemical solubilizing agents may enhance the rate of hydrophobic organic solute degradation by increasing the rate of solute desorption from soil and the extent of solute partitioning to the aqueous phase. The presentation will review on-going research on: surfactant solubilization of polycyclic aromatic hydrocarbon (PAH) compounds in clean water, and in soil-water suspensions; and experiments to assess if the addition of surfactant to soil-water suspension results in faster rate of mineralization of PAH compounds in soil.

  9. Plant-based remedies for wolf bites and rituals against wolves in the Iberian Peninsula: Therapeutic opportunities and cultural values for the conservation of biocultural diversity.

    PubMed

    González, José A; Carvalho, Ana Maria; Vallejo, José Ramón; Amich, Francisco

    2017-09-14

    Combined approaches to local knowledge and folk plant use improve awareness and promote effective strategies for the conservation of significant biocultural patrimony. Moreover, the information reported might be the basis for further appropriate phytochemical and pharmacological research. Therefore we provide an insight into traditional herbal remedies and practices for healing bite injuries in humans and domestic animals caused by the Iberian wolf. Wolf bites are associated with inflammatory processes and rabies is a potential complication AIMS: This paper describes and summarises the medicinal-veterinary empirical and ritual uses of the Iberian flora for wolf injuries and reviews the ethnopharmacological data of specific plants that are already published. The Iberian wolf is a critically endangered subspecies of the grey wolf. Livestock attacks attributed to wolves are increasingly frequent in the Iberian Peninsula, resulting in serious social problems. Interesting strategies for Iberian wolf conservation might be related to traditional grazing practices that are deeply linked with empirical knowledge and local practices passed on by oral tradition, which are also vulnerable now. Based on documentary sources from the beginning of the twentieth century to the present, we systematically searched old monographs, regional documents, technical papers, project reports, as well as the international and national databases and the available scientific literature, without restrictions regarding the language of the publications consulted. A total of 39 remedies for healing wolf bite injuries in humans and domestic animals was reported, highlighting the medicinal use of 33 species of vascular plants, mostly wild herbs, belonging to 18 botanical families. The use of wood ashes was also reported. The number of use-reports found represents a very high number considering similar European studies. Leaves were the predominant plant part mentioned. Boiling plant materials in water

  10. A context based approach using Green Chemistry/Bio-remediation principles to enhance interest and learning of organic chemistry in a high school AP chemistry classroom

    NASA Astrophysics Data System (ADS)

    Miller, Tricia

    The ability of our planet to sustain life and heal itself is not as predictable as it used to be. Our need for educated future scientists who know what our planet needs, and can passionately apply that knowledge to find solutions should be at the heart of science education today. This study of learning organic chemistry through the lens of the environmental problem "What should be done with our food scraps?" explores student interest, and mastery of certain concepts in organic chemistry. This Green Chemistry/ Bio-remediation context-based teaching approach utilizes the Nature MillRTM, which is an indoor food waste composting machine, to learn about organic chemistry, and how this relates to landfill reduction possibilities, and resource production. During this unit students collected food waste from their cafeteria, and used the Nature MillRTM to convert food waste into compost. The use of these hands on activities, and group discussions in a context-based environment enhanced their interest in organic chemistry, and paper chromatography. According to a one-tailed paired T-test, the result show that this context-based approach is a significant way to increase both student interest and mastery of the content.

  11. Reliability enhancement of APR + diverse protection system regarding common cause failures

    SciTech Connect

    Oh, Y. G.; Kim, Y. M.; Yim, H. S.; Lee, S. J.

    2012-07-01

    The Advanced Power Reactor Plus (APR +) nuclear power plant design has been developed on the basis of the APR1400 (Advanced Power Reactor 1400 MWe) to further enhance safety and economics. For the mitigation of Anticipated Transients Without Scram (ATWS) as well as Common Cause Failures (CCF) within the Plant Protection System (PPS) and the Emergency Safety Feature - Component Control System (ESF-CCS), several design improvement features have been implemented for the Diverse Protection System (DPS) of the APR + plant. As compared to the APR1400 DPS design, the APR + DPS has been designed to provide the Safety Injection Actuation Signal (SIAS) considering a large break LOCA accident concurrent with the CCF. Additionally several design improvement features, such as channel structure with redundant processing modules, and changes of system communication methods and auto-system test methods, are introduced to enhance the functional reliability of the DPS. Therefore, it is expected that the APR + DPS can provide an enhanced safety and reliability regarding possible CCF in the safety-grade I and C systems as well as the DPS itself. (authors)

  12. Diversity of a mesophilic lignocellulolytic microbial consortium which is useful for enhancement of biogas production.

    PubMed

    Yan, Lei; Gao, Yamei; Wang, Yanjie; Liu, Quan; Sun, Zhiyuan; Fu, Borui; Wen, Xue; Cui, Zongjun; Wang, Weidong

    2012-05-01

    A mesophilic lignocellulolytic microbial consortium BYND-5, established by successive subcultivation, was applied to enhance the biogas production. The degradation efficiency of BYND-5 for rice straw was more than 49.0 ± 1.8% after 7 days of cultivation at 30°C. Various organic compounds, including acetic acid, propionic acid, butyric acid and glycerin were detected during biodegradation. The diversity analysis of BYND-5 was conducted by ARDRA (Amplified ribosomal DNA restriction analysis) of the 16S rDNA clone library. Results indicated that bacterial groups represented in the clone library were the Firmicutes (5.96%), the Bacteroidetes (40.0%), Deferribacteres (8.94%), Proteobacteria (16.17%), Lentisphaerae (2.13%), Fibrobacteraceae (1.7%), and uncultured bacterium (25.1%). Additionally, the enhancement of biogas yield and methane content was directly related to the pretreatment with BYND-5. The microbial community identified herein is potential candidate consortium for the degradation of waste lignocellulose and enhancement of biogas production under the mesophilic temperature conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Increasing zooplankton size diversity enhances the strength of top-down control on phytoplankton through diet niche partitioning.

    PubMed

    Ye, Lin; Chang, Chun-Yi; García-Comas, Carmen; Gong, Gwo-Ching; Hsieh, Chih-Hao

    2013-09-01

    1. The biodiversity-ecosystem functioning debate is a central topic in ecology. Recently, there has been a growing interest in size diversity because body size is sensitive to environmental changes and is one of the fundamental characteristics of organisms linking many ecosystem properties. However, how size diversity affects ecosystem functioning is an important yet unclear issue. 2. To fill the gap, with large-scale field data from the East China Sea, we tested the novel hypothesis that increasing zooplankton size diversity enhances top-down control on phytoplankton (H1) and compared it with five conventional hypotheses explaining the top-down control: flatter zooplankton size spectrum enhances the strength of top-down control (H2); nutrient enrichment lessens the strength of top-down control (H3); increasing zooplankton taxonomic diversity enhances the strength of top-down control (H4); increasing fish predation decreases the strength of top-down control of zooplankton on phytoplankton through trophic cascade (H5); increasing temperature intensifies the strength of top-down control (H6). 3. The results of univariate analyses support the hypotheses based on zooplankton size diversity (H1), zooplankton size spectrum (H2), nutrient (H3) and zooplankton taxonomic diversity (H4), but not the hypotheses based on fish predation (H5) and temperature (H6). More in-depth analyses indicate that zooplankton size diversity is the most important factor in determining the strength of top-down control on phytoplankton in the East China Sea. 4. Our results suggest a new potential mechanism that increasing predator size diversity enhances the strength of top-down control on prey through diet niche partitioning. This mechanism can be explained by the optimal predator-prey body-mass ratio concept. Suppose each size group of zooplankton predators has its own optimal phytoplankton prey size, increasing size diversity of zooplankton would promote diet niche partitioning of predators

  14. Herbivory and drought interact to enhance spatial patterning and diversity in a savanna understory.

    PubMed

    Porensky, Lauren M; Wittman, Sarah E; Riginos, Corinna; Young, Truman P

    2013-10-01

    The combination of abiotic stress and consumer stress can have complex impacts on plant community structure. Effective conservation and management of semi-arid ecosystems requires an understanding of how different stresses interact to structure plant communities. We explored the separate and combined impacts of episodic drought, livestock grazing, and wild ungulate herbivory on species co-occurrence and diversity patterns in a relatively productive, semi-arid Acacia savanna. Specifically, we analyzed 9 years of biannual plant community data from the Kenya long-term exclosure experiment, a broad-scale manipulative experiment that has excluded different combinations of large mammalian herbivores from 18 4-ha plots since 1995. During droughts, we observed low species diversity and random species co-occurrence patterns. However, when rain followed a major drought, areas exposed to moderate cattle grazing displayed high species diversity and evidence of significant species aggregation. These patterns were not apparent in the absence of cattle, even if other large herbivores were present. To explore possible mechanisms, we examined patterns separately for common and rare species. We found that aggregation patterns were likely driven by rare species responding similarly to the availability of open micro-sites. Our results indicate that in a productive, fire-suppressed savanna, the combination of periodic drought and moderate cattle grazing can enhance plant biodiversity and fine-scale spatial heterogeneity by opening up space for species that are otherwise rare or cryptic. Our findings also emphasize that domestic herbivores can have significantly stronger impacts on plant community dynamics than wild herbivores, even in an ecosystem with a long history of grazing.

  15. Bee Species Diversity Enhances Productivity and Stability in a Perennial Crop

    PubMed Central

    Rogers, Shelley R.; Tarpy, David R.; Burrack, Hannah J.

    2014-01-01

    Wild bees provide important pollination services to agroecoystems, but the mechanisms which underlie their contribution to ecosystem functioning—and, therefore, their importance in maintaining and enhancing these services—remain unclear. We evaluated several mechanisms through which wild bees contribute to crop productivity, the stability of pollinator visitation, and the efficiency of individual pollinators in a highly bee-pollination dependent plant, highbush blueberry. We surveyed the bee community (through transect sampling and pan trapping) and measured pollination of both open- and singly-visited flowers. We found that the abundance of managed honey bees, Apis mellifera, and wild-bee richness were equally important in describing resulting open pollination. Wild-bee richness was a better predictor of pollination than wild-bee abundance. We also found evidence suggesting pollinator visitation (and subsequent pollination) are stabilized through the differential response of bee taxa to weather (i.e., response diversity). Variation in the individual visit efficiency of A. mellifera and the southeastern blueberry bee, Habropoda laboriosa, a wild specialist, was not associated with changes in the pollinator community. Our findings add to a growing literature that diverse pollinator communities provide more stable and productive ecosystem services. PMID:24817218

  16. Co-Cultivation—A Powerful Emerging Tool for Enhancing the Chemical Diversity of Microorganisms

    PubMed Central

    Marmann, Andreas; Aly, Amal H.; Lin, Wenhan; Wang, Bingui; Proksch, Peter

    2014-01-01

    Marine-derived bacteria and fungi are promising sources of novel bioactive compounds that are important for drug discovery programs. However, as encountered in terrestrial microorganisms there is a high rate of redundancy that results in the frequent re-discovery of known compounds. Apparently only a part of the biosynthetic genes that are harbored by fungi and bacteria are transcribed under routine laboratory conditions which involve cultivation of axenic microbial strains. Many biosynthetic genes remain silent and are not expressed in vitro thereby seriously limiting the chemical diversity of microbial compounds that can be obtained through fermentation. In contrast to this, co-cultivation (also called mixed fermentation) of two or more different microorganisms tries to mimic the ecological situation where microorganisms always co-exist within complex microbial communities. The competition or antagonism experienced during co-cultivation is shown to lead to a significantly enhanced production of constitutively present compounds and/or to an accumulation of cryptic compounds that are not detected in axenic cultures of the producing strain. This review highlights the power of co-cultivation for increasing the chemical diversity of bacteria and fungi drawing on published studies from the marine and from the terrestrial habitat alike. PMID:24549204

  17. Organic amendments enhance microbial diversity and abundance of functional genes in Australian Soils

    NASA Astrophysics Data System (ADS)

    Aldorri, Sind; McMillan, Mary; Pereg, Lily

    2016-04-01

    Food and cash crops play important roles in Australia's economy with black, grey and red clay soil, widely use for growing cotton, wheat, corn and other crops in rotation. While the majority of cotton growers use nitrogen and phosphate fertilizers only in the form of agrochemicals, a few experiment with the addition of manure or composted plant material before planting. We hypothesized that the use of such organic amendments would enhance the soil microbial function through increased microbial diversity and abundance, thus contribute to improved soil sustainability. To test the hypothesis we collected soil samples from two cotton-growing farms in close geographical proximity and with mostly similar production practices other than one grower has been using composted plants as organic amendment and the second farmer uses only agrochemicals. We applied the Biolog Ecoplate system to study the metabolic signature of microbial communities and used qPCR to estimate the abundance of functional genes in the soil. The soil treated with organic amendments clearly showed higher metabolic activity of a more diverse range of carbon sources as well as higher abundance of genes involved in the nitrogen and phosphorous cycles. Since microbes undertake a large number of soil functions, the use of organic amendments can contribute to the sustainability of agricultural soils.

  18. Cognitive Remediation Strategies

    PubMed Central

    WEINSTEIN, CHERYL S.

    1994-01-01

    Evidence continues to emerge that childhood symptoms of attention-deficit hyperactivity disorder (ADHD) persist into adulthood. These symptoms include motoric hyperactivity, restlessness, attention deficits, poor organizational skills, impulsivity, and memory impairment. Poor academic and work performance, frustration, humiliation, and shame are also components of adult ADHD. Psychotherapists are challenged to understand the meaning of the disorder and its ramifications in all aspects of life. An active multimodal approach, including somatic treatment and psychotherapy, is needed. In addition, cognitive remediation strategies to enhance attention, organization, memory, and problem-solving skills are an important adjunct to treatment. These strategies serve as psychological tools to circumvent deficits. PMID:22700173

  19. Application of biosurfactants and periodic voltage gradient for enhanced electrokinetic remediation of metals and PAHs in dredged marine sediments.

    PubMed

    Ammami, M T; Portet-Koltalo, F; Benamar, A; Duclairoir-Poc, C; Wang, H; Le Derf, F

    2015-04-01

    Dredged harbor sediment co-contaminated by heavy metals and polycyclic aromatic hydrocarbons (PAHs) was subjected to enhanced electrokinetic treatments, using a mixture of a chelating agent (citric acid CA) and a surfactant as additives in the processing fluids. We tested various operating conditions (at 1 V cm(-1)): different CA concentrations, applying a periodic voltage gradient, pre-conditioning the sediment with the additives, and replacing the synthetic surfactant Tween 20 (TW20) by biosurfactants. Increasing the CA concentration was favorable for both metal and PAH removal. Applying a periodic voltage gradient associated to a low concentration of CA and TW20 provided the best results for Zn, Cd and Pb removal and also for removal of the 16 priority PAHs. Promising results were obtained with solutions containing rhamnolipids (0.028%) and a viscosin-like biosurfactant produced by Pseudomonas fluorescens Pfa7B (0.025%), associated to a periodic voltage gradient. Although the rhamnolipid and the viscosin-like compounds involved a higher electrical current than TW20, metals were less removed from the sediment. The electroosmotic flow was lower when we used biosurfactants, hence a less effective effect on PAH removal.

  20. Enhanced Solubilisation of Six PAHs by Three Synthetic Cyclodextrins for Remediation Applications: Molecular Modelling of the Inclusion Complexes

    PubMed Central

    Morillo, Esmeralda; Sánchez-Trujillo, María Antonia; Moyano, José Ramón; Villaverde, Jaime; Gómez-Pantoja, María Eulalia; Pérez-Martínez, José Ignacio

    2012-01-01

    Solubilisation of six polycyclic aromatic hydrocarbons (PAHs) (acenaphthene, anthracene, fluoranthene, fluorene, phenanthrene and pyrene) by three synthetic cyclodextrins (CDs) (2-hydroxypropyl-β-CD, hydroxypropyl-γ-CD and ramdomly methylated-β-CD) was investigated in order to select the CD which presents the greatest increase in solubility and better complexation parameters for its use in contaminated scenarios. The presence of the three cyclodextrins greatly enhanced the apparent water solubility of all the PAHs through the formation of inclusion complexes of 1∶1 stoichiometry. Anthracene, fluoranthene, fluorene and phenanthrene clearly presented a higher solubility when β-CD derivatives were used, and especially the complexes with the ramdomly methylated-β-CD were favoured. On the contrary, pyrene presented its best solubility results when using 2-hydroxypropyl-γ-CD, but for acenaphthene the use of any of the three CDs gave the same results. Complementary to experimental phase-solubility studies, a more in-depth estimation of the inclusion process for the different complexes was carried out using molecular modelling in order to find a correlation between the degree of solubilisation and the fit of PAH molecules within the cavity of the different CDs and to know the predominant driving forces of the complexation. PMID:23028493

  1. [Ex-situ remediation of PAHs contaminated site by successive methyl-beta-cyclodextrin enhanced soil washing].

    PubMed

    Sun, Ming-Ming; Teng, Ying; Luo, Yong-Ming; Li, Zhen-Gao; Jia, Zhong-Jun; Zhang, Man-Yun

    2013-06-01

    Polycyclic aromatic hydrocarbon (PAH) polluted sites caused by abandoned coking plants have attracted great attentions. This study investigated the feasibility of using methyl-beta-cyclodextrin (MCD) solution to enhance ex situ soil washing for extracting PAHs. Treatment with elevated temperature (50 degrees C) in combination with ultrasonication (35 kHz, 30 min) at 100 g x L(-1) was effective. It was found that 96.7% +/- 2.4% of 3-ring PAH, 89.7% +/- 3.2% of 4-ring PAH, 76.3% +/- 2.2% of 5 (+6)-ring PAH and 91.3% +/- 3.1% of total PAHs were removed from soil after five successive washing cycles. The desorption kinetics of PAHs from contaminated soil was determined before and after successive washings. The 400 h Tenax extraction of PAHs from soil was decreasing gradually with increasing washing times. Furthermore, the F(r), F(sl), k(r), k(sl) and k(vl) were significantly lower than those of CK (P < 0.01). Therefore, considering the removal efficiency and potential environmental risk after soil )ashing, successive washing three times was selected as a reasonable parameter. These results have practical implications for site risk assessment and cleanup strategies.

  2. Teaching Communication Ethics and Diversity: Using Technology and Community Engagement to Enhance Learning

    ERIC Educational Resources Information Center

    Swenson-Lepper, Tammy

    2012-01-01

    The workforce in the United States is becoming more diverse. To help students prepare to work and live in a diverse society, the author developed a lower-division course called "Communication Ethics and Diversity." After this course, students should be able to: (1) define diversity and communication ethics; (2) understand a variety of…

  3. Teaching Communication Ethics and Diversity: Using Technology and Community Engagement to Enhance Learning

    ERIC Educational Resources Information Center

    Swenson-Lepper, Tammy

    2012-01-01

    The workforce in the United States is becoming more diverse. To help students prepare to work and live in a diverse society, the author developed a lower-division course called "Communication Ethics and Diversity." After this course, students should be able to: (1) define diversity and communication ethics; (2) understand a variety of…

  4. REPORT ON THE GEOELECTRICAL DETECTION OF SURFACTANT ENHANCED AQUIFER REMEDIATION OF PCE: PROPERTY CHANGES IN AQUEOUS SOLUTIONS DUE TO SURFACTANT TREATMENT OF PERCHLOROETHYLENE: IMPLICATIONS TO GEOPHYSICAL MEASUREMENTS

    EPA Science Inventory

    Select physicochemical properties of nine surfactants which are conventionally used in the remediation of perchloroethylene (PCE, a.k.a. tetrachloroethene) were evaluated with varying concentrations of PCE and indicator dyes in aqueous solutions using a response surface quadrati...

  5. REPORT ON THE GEOELECTRICAL DETECTION OF SURFACTANT ENHANCED AQUIFER REMEDIATION OF PCE: PROPERTY CHANGES IN AQUEOUS SOLUTIONS DUE TO SURFACTANT TREATMENT OF PERCHLOROETHYLENE: IMPLICATIONS TO GEOPHYSICAL MEASUREMENTS

    EPA Science Inventory

    Select physicochemical properties of nine surfactants which are conventionally used in the remediation of perchloroethylene (PCE, a.k.a. tetrachloroethene) were evaluated with varying concentrations of PCE and indicator dyes in aqueous solutions using a response surface quadrati...

  6. Long-term no-tillage and organic input management enhanced the diversity and stability of soil microbial community.

    PubMed

    Wang, Yi; Li, Chunyue; Tu, Cong; Hoyt, Greg D; DeForest, Jared L; Hu, Shuijin

    2017-12-31

    Intensive tillage and high inputs of chemicals are frequently used in conventional agriculture management, which critically depresses soil properties and causes soil erosion and nonpoint source pollution. Conservation practices, such as no-tillage and organic farming, have potential to enhance soil health. However, the long-term impact of no-tillage and organic practices on soil microbial diversity and community structure has not been fully understood, particularly in humid, warm climate regions such as the southeast USA. We hypothesized that organic inputs will lead to greater microbial diversity and a more stable microbial community, and that the combination of no-tillage and organic inputs will maximize soil microbial diversity. We conducted a long-term experiment in the southern Appalachian mountains of North Carolina, USA to test these hypotheses. The results showed that soil microbial diversity and community structure diverged under different management regimes after long term continuous treatments. Organic input dominated the effect of management practices on soil microbial properties, although no-tillage practice also exerted significant impacts. Both no-tillage and organic inputs significantly promoted soil microbial diversity and community stability. The combination of no-tillage and organic management increased soil microbial diversity over the conventional tillage and led to a microbial community structure more similar to the one in an adjacent grassland. These results indicate that effective management through reducing tillage and increasing organic C inputs can enhance soil microbial diversity and community stability. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Enhancing majority members' pro-diversity beliefs in small teams: the facilitating effect of self-anchoring.

    PubMed

    van Veelen, Ruth; Otten, Sabine; Hansen, Nina

    2014-01-01

    Majority members often react negatively to efforts to stimulate diversity. An important reason for this is that in diverse groups, majority members' own group bond is typically based on perceived prototypicality, which serves to disregard those who are different. In the present research we investigate how majority members' pro-diversity beliefs may be enhanced, by experimentally manipulating how the self is cognitively defined in relation to a diverse group. Specifically, we hypothesize that majority members' focus on the personal self (i.e., self-anchoring) rather than the social self (i.e., self-stereotyping) when creating a group bond may facilitate their pro-diversity beliefs and positive attitudes toward minority members. In two experiments we manipulated self-anchoring and self-stereotyping via mindset priming among ethnic majority members in diverse teams. As expected, results showed that relative to self-stereotyping, majority members' self-anchoring enhanced pro-diversity beliefs and positive attitudes toward minority members.

  8. The Role of Minority Serving Institutions and REU Programs for Enhancing Diversity in Astronomy

    NASA Astrophysics Data System (ADS)

    Stassun, K. G.

    2002-12-01

    In this Special Session we will highlight the important role of Minority Serving Institutions in preparing future minority astronomers. Minority Serving Institutions include Historically Black Colleges and Universities (HBCUs), Hispanic Serving Institutions (HSIs), and Tribal Colleges and Universities (TCUs). We will also stress the role that REU (Research Experiences for Undergraduates) programs can have in enhancing diversity in astronomy. The session will feature a panel of invited speakers from Minority Serving Institutions and REU programs who will present viewpoints, strategies, and discussion on processes that encourage and mentor individuals who elect to pursue science-related careers including astronomy and astrophysics. Specific objectives for the Session include: Report to the AAS membership on the important role played by Minority Serving Institutions, where these institutions are, the populations they serve; Introduce the AAS membership to representatives from various Minority Serving Institutions, including an HBCU, an HSI, a TCU, and a community college, and to representatives from REU programs; Provide an opportunity for representatives from these institutions to describe their role in preparing minority undergraduates in the sciences, how their programs bridge to PhD-granting programs in astronomy, and ways they suggest for the AAS to help enhance these bridges; Provide an opportunity for AAS members to dialogue with these representatives, hopefully resulting in specific ``action items" that will serve to strengthen partnerships with Minority Serving Institutions.

  9. Enhancing Diversity in Science: Is Teaching Science Process Skills the Answer?

    PubMed Central

    Cunningham, Matthew

    2006-01-01

    The Biology Fellows Program at the University of Washington aims to enhance diversity in science by helping students succeed in the rigorous introductory biology classes and motivating them to engage in undergraduate research. The composite Scholastic Achievement Test scores and high school grade point averages of the Biology Fellows are comparable to those of students who are not in the program; however, they earn, on average, higher grades in introductory biology classes than non-Biology Fellows. Underrepresented minorities and disadvantaged students in the program also earn higher grades in the introductory biology classes than do their non-Biology Fellows counterparts. Analysis of the performance of Biology Fellows shows that the program assists students who are not proficient in certain science process skills and that students who lack these skills are at risk for failing introductory biology. This evaluation provides insight for designing programs that aim to enhance the performance of beginning students of biology, particularly for underrepresented minorities, who want to obtain a life science degree. PMID:17012213

  10. Enhancing diversity in science: is teaching science process skills the answer?

    PubMed

    Dirks, Clarissa; Cunningham, Matthew

    2006-01-01

    The Biology Fellows Program at the University of Washington aims to enhance diversity in science by helping students succeed in the rigorous introductory biology classes and motivating them to engage in undergraduate research. The composite Scholastic Achievement Test scores and high school grade point averages of the Biology Fellows are comparable to those of students who are not in the program; however, they earn, on average, higher grades in introductory biology classes than non-Biology Fellows. Underrepresented minorities and disadvantaged students in the program also earn higher grades in the introductory biology classes than do their non-Biology Fellows counterparts. Analysis of the performance of Biology Fellows shows that the program assists students who are not proficient in certain science process skills and that students who lack these skills are at risk for failing introductory biology. This evaluation provides insight for designing programs that aim to enhance the performance of beginning students of biology, particularly for underrepresented minorities, who want to obtain a life science degree.

  11. Application of a crustacean bioassay to evaluate a multi-contaminated (metal, PAH, PCB) harbor sediment before and after electrokinetic remediation using eco-friendly enhancing agents.

    PubMed

    Tian, Y; Boulangé-Lecomte, C; Benamar, A; Giusti-Petrucciani, N; Duflot, A; Olivier, S; Frederick, C; Forget-Leray, J; Portet-Koltalo, F

    2017-12-31

    Electrokinetic (EK) remediation can be a suitable technology for treating contaminated dredged harbor sediment, stored on terrestrial disposal sites. Citric acid (CA) and biosurfactants (rhamnolipids and saponin) were chosen as enhancing agents for simultaneous metal (Cd, Cr, Cu, Pb, Zn) and PAH/PCB removal by EK because of their potential low toxicity with a view to site restoration. Three EK runs were performed using a periodic voltage (1Vcm(-1)) and various concentrations of agents. The best combination of CA (0.2molL(-1)) and saponin (0.85gL(-1)) did not remove high amounts of metals (4.4-15.8%) and provided only slightly better results for PAH and PCB removal (29.2% and 38.2%, respectively). The harbor sediment was highly resistant to metal and organics mobilization and transport because of an aged contamination, a high buffering capacity, a very low hydraulic permeability and a high organic matter content. The efficiency of the EK process was also assessed by measuring the acute toxicity of the EK-treated sediment on E. affinis copepods exposed to sediment elutriates. Fortunately, the use of CA and biosurfactants did not significantly impact on sediment toxicity. Some treated sediment sections, particularly those near the anode compartment, were statistically more toxic than the raw sediment. More particularly, E. affinis copepods were significantly sensitive to low pH values and oxidative conditions, to Cu, and to a lesser extent to Pb amounts. The speciation of these metals probably changed in these pH and redox conditions so that they became more easily leachable and bioavailable. In contrast, toxicity was negatively correlated to PAH and PCB amounts after EK treatment, probably due to the production of oxidized metabolites of PAHs and PCBs. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Cattle Manure Enhances Methanogens Diversity and Methane Emissions Compared to Swine Manure under Rice Paddy.

    PubMed

    Kim, Sang Yoon; Pramanik, Prabhat; Bodelier, Paul L E; Kim, Pil Joo

    2014-01-01

    Livestock manures are broadly used in agriculture to improve soil quality. However, manure application can increase the availability of organic carbon, thereby facilitating methane (CH4) production. Cattle and swine manures are expected to have different CH4 emission characteristics in rice paddy soil due to the inherent differences in composition as a result of contrasting diets and digestive physiology between the two livestock types. To compare the effect of ruminant and non-ruminant animal manure applications on CH4 emissions and methanogenic archaeal diversity during rice cultivation (June to September, 2009), fresh cattle and swine manures were applied into experimental pots at 0, 20 and 40 Mg fresh weight (FW) ha-1 in a greenhouse. Applications of manures significantly enhanced total CH4 emissions as compared to chemical fertilization, with cattle manure leading to higher emissions than swine manure. Total organic C contents in cattle (466 g kg-1) and swine (460 g kg-1) manures were of comparable results. Soil organic C (SOC) contents were also similar between the two manure treatments, but dissolved organic C (DOC) was significantly higher in cattle than swine manure. The mcrA gene copy numbers were significantly higher in cattle than swine manure. Diverse groups of methanogens which belong to Methanomicrobiaceae were detected only in cattle-manured but not in swine-manured soil. Methanogens were transferred from cattle manure to rice paddy soils through fresh excrement. In conclusion, cattle manure application can significantly increase CH4 emissions in rice paddy soil during cultivation, and its pretreatment to suppress methanogenic activity without decreasing rice productivity should be considered.

  13. Cattle Manure Enhances Methanogens Diversity and Methane Emissions Compared to Swine Manure under Rice Paddy

    PubMed Central

    Kim, Sang Yoon; Pramanik, Prabhat; Bodelier, Paul L. E.; Kim, Pil Joo

    2014-01-01

    Livestock manures are broadly used in agriculture to improve soil quality. However, manure application can increase the availability of organic carbon, thereby facilitating methane (CH4) production. Cattle and swine manures are expected to have different CH4 emission characteristics in rice paddy soil due to the inherent differences in composition as a result of contrasting diets and digestive physiology between the two livestock types. To compare the effect of ruminant and non-ruminant animal manure applications on CH4 emissions and methanogenic archaeal diversity during rice cultivation (June to September, 2009), fresh cattle and swine manures were applied into experimental pots at 0, 20 and 40 Mg fresh weight (FW) ha−1 in a greenhouse. Applications of manures significantly enhanced total CH4 emissions as compared to chemical fertilization, with cattle manure leading to higher emissions than swine manure. Total organic C contents in cattle (466 g kg−1) and swine (460 g kg−1) manures were of comparable results. Soil organic C (SOC) contents were also similar between the two manure treatments, but dissolved organic C (DOC) was significantly higher in cattle than swine manure. The mcrA gene copy numbers were significantly higher in cattle than swine manure. Diverse groups of methanogens which belong to Methanomicrobiaceae were detected only in cattle-manured but not in swine-manured soil. Methanogens were transferred from cattle manure to rice paddy soils through fresh excrement. In conclusion, cattle manure application can significantly increase CH4 emissions in rice paddy soil during cultivation, and its pretreatment to suppress methanogenic activity without decreasing rice productivity should be considered. PMID:25494364

  14. Molecular diversity management strategies for building and enhancement of diverse and focused lead discovery compound screening collections.

    PubMed

    Schuffenhauer, A; Popov, M; Schopfer, U; Acklin, P; Stanek, J; Jacoby, E

    2004-12-01

    This publication describes processes for the selection of chemical compounds for the building of a high-throughput screening (HTS) collection for drug discovery, using the currently implemented process in the Discovery Technologies Unit of the Novartis Institute for Biomedical Research, Basel Switzerland as reference. More generally, the currently existing compound acquisition models and practices are discussed. Our informatics, chemistry and biology-driven compound selection consists of two steps: 1) The individual compounds are filtered and grouped into three priority classes on the basis of their individual structural properties. Substructure filters are used to eliminate or penalize compounds based on unwanted structural properties. The similarity of the structures to reference ligands of the main proven druggable target families is computed, and drug-similar compounds are prioritized for the following diversity analysis. 2) The compounds are compared to the archive compounds and a diversity analysis is performed. This is done separately for the prioritized, regular and penalized compounds with increasingly stringent dissimilarity criterion. The process includes collecting vendor catalogues and monitoring the availability of samples together with the selection and purchase decision points. The development of a corporate vendor catalogue database is described. In addition to the selection methods on a per single molecule basis, selection criteria for scaffold and combinatorial chemistry projects in collaboration with compound vendors are discussed.

  15. Extensive genetic diversity and low linkage disequilibrium within the COMT locus in Germplasm Enhancement of Maize populations

    USDA-ARS?s Scientific Manuscript database

    The Caffeic acid 3-O-methytransferase (COMT) gene is a prime candidate for cell wall digestibility improvement based on the characterization of brown midrib-3 mutants. We compared the genetic diversity and linkage disequilibrium at COMT locus between populations sampled within the Germplasm Enhance...

  16. Utilizing genetic diversity in the desert watermelon citrullus colocynthis for enhancing watermelon cultivars for resistance to biotic and abiotic stress

    USDA-ARS?s Scientific Manuscript database

    Wide genetic diversity exists among the desert watermelon Citrullus colocynthis (L.) Schrad. (CC) accessions collected in the deserts of northern Africa, the Middle East, and Asia. Because of their resistance to biotic and abiotic stresses, there can be a viable source of genes used for enhancing wa...

  17. Input Subject Diversity Enhances Early Grammatical Growth: Evidence from a Parent-Implemented Intervention

    ERIC Educational Resources Information Center

    Hadley, Pamela A.; Rispoli, Matthew; Holt, Janet K.; Papastratakos, Theodora; Hsu, Ning; Kubalanza, Mary; McKenna, Megan M.

    2017-01-01

    Purpose: The current study used an intervention design to test the hypothesis that parent input sentences with diverse lexical noun phrase (NP) subjects would accelerate growth in children's sentence diversity. Method: Child growth in third person sentence diversity was modeled from 21-30 months (n = 38) in conversational language samples obtained…

  18. Nine proposed action areas to enhance diversity and inclusion in the American Fisheries Society

    Treesearch

    Brooke E. Penaluna; Ivan Arismendi; Christine M. Moffitt; Zachary L. Penney

    2017-01-01

    Increasing diversity in the fisheries profession, including diversity of members of the American Fisheries Society (AFS), is vital to ensuring the future relevance of fish and their habitats, fisheries, and fisheries professionals in the broader context of society. Any well-informed natural resource professional understands the value of a diverse ecosystem, and savvy...

  19. Input Subject Diversity Enhances Early Grammatical Growth: Evidence from a Parent-Implemented Intervention

    ERIC Educational Resources Information Center

    Hadley, Pamela A.; Rispoli, Matthew; Holt, Janet K.; Papastratakos, Theodora; Hsu, Ning; Kubalanza, Mary; McKenna, Megan M.

    2017-01-01

    Purpose: The current study used an intervention design to test the hypothesis that parent input sentences with diverse lexical noun phrase (NP) subjects would accelerate growth in children's sentence diversity. Method: Child growth in third person sentence diversity was modeled from 21-30 months (n = 38) in conversational language samples obtained…

  20. Use of Borehole-Radar Methods to Monitor a Steam-Enhanced Remediation Pilot Study at a Quarry at the Former Loring Air Force Base, Maine

    USGS Publications Warehouse

    Gregoire, Colette; Joesten, Peter K.; Lane, Jr., John W.

    2007-01-01

    Single-hole radar reflection and crosshole radar tomography surveys were used in conjunction with conventional borehole-geophysical methods to evaluate the effectiveness of borehole-radar methods for monitoring the movement of steam and heat through fractured bedrock. The U.S. Geological Survey, in cooperation with U.S. Environmental Protection Agency (USEPA), conducted surveys in an abandoned limestone quarry at the former Loring Air Force Base during a field-scale, steam-enhanced remediation (SER) pilot project conducted by the USEPA, the U.S. Air Force, and the Maine Department of Environmental Protection to study the viability of SER to remediate non-aqueous phase liquid contamination in fractured bedrock. Numerical modeling and field experiments indicate that borehole-radar methods have the potential to monitor the presence of steam and to measure large temperature changes in the limestone matrix during SER operations. Based on modeling results, the replacement of water by steam in fractures should produce a decrease in radar reflectivity (amplitude of the reflected wave) by a factor of 10 and a change in reflection polarity. In addition, heating the limestone matrix should increase the bulk electrical conductivity and decrease the bulk dielectric permittivity. These changes result in an increase in radar attenuation and an increase in radar-wave propagation velocity, respectively. Single-hole radar reflection and crosshole radar tomography data were collected in two boreholes using 100-megahertz antennas before the start of steam injection, about 10 days after the steam injection began, and 2 months later, near the end of the injection. Fluid temperature logs show that the temperature of the fluid in the boreholes increased by 10?C (degrees Celsius) in one borehole and 40?C in the other; maximum temperatures were measured near the bottom of the boreholes. The results of the numerical modeling were used to interpret the borehole-radar data. Analyses of the

  1. Functional diversity enhances the resistance of ecosystem multifunctionality to aridity in Mediterranean drylands.

    PubMed

    Valencia, Enrique; Maestre, Fernando T; Le Bagousse-Pinguet, Yoann; Quero, José Luis; Tamme, Riin; Börger, Luca; García-Gómez, Miguel; Gross, Nicolas

    2015-04-01

    We used a functional trait-based approach to assess the impacts of aridity and shrub encroachment on the functional structure of Mediterranean dryland communities (functional diversity (FD) and community-weighted mean trait values (CWM)), and to evaluate how these functional attributes ultimately affect multifunctionality (i.e. the provision of several ecosystem functions simultaneously). Shrub encroachment (the increase in the abundance/cover of shrubs) is a major land cover change that is taking place in grasslands worldwide. Studies conducted on drylands have reported positive or negative impacts of shrub encroachment depending on the functions and the traits of the sprouting or nonsprouting shrub species considered. FD and CWM were equally important as drivers of multifunctionality responses to both aridity and shrub encroachment. Size traits (e.g. vegetative height or lateral spread) and leaf traits (e.g. specific leaf area and leaf dry matter content) captured the effect of shrub encroachment on multifunctionality with a relative high accuracy (r(2)  = 0.63). FD also improved the resistance of multifunctionality along the aridity gradient studied. Maintaining and enhancing FD in plant communities may help to buffer negative effects of ongoing global environmental change on dryland multifunctionality.

  2. Microbial functional diversity enhances predictive models linking environmental parameters to ecosystem properties.

    PubMed

    Powell, Jeff R; Welsh, Allana; Hallin, Sara

    2015-07-01

    Microorganisms drive biogeochemical processes, but linking these processes to real changes in microbial communities under field conditions is not trivial. Here, we present a model-based approach to estimate independent contributions of microbial community shifts to ecosystem properties. The approach was tested empirically, using denitrification potential as our model process, in a spatial survey of arable land encompassing a range of edaphic conditions and two agricultural production systems. Soil nitrate was the most important single predictor of denitrification potential (the change in Akaike's information criterion, corrected for sample size, ΔAIC(c) = 20.29); however, the inclusion of biotic variables (particularly the evenness and size of denitrifier communities [ΔAIC(c) = 12.02], and the abundance of one denitrifier genotype [ΔAIC(c) = 18.04]) had a substantial effect on model precision, comparable to the inclusion of abiotic variables (biotic R2 = 0.28, abiotic R2 = 0.50, biotic + abiotic R2 = 0.76). This approach provides a valuable tool for explicitly linking microbial communities to ecosystem functioning. By making this link, we have demonstrated that including aspects of microbial community structure and diversity in biogeochemical models can improve predictions of nutrient cycling in ecosystems and enhance our understanding of ecosystem functionality.

  3. Crop rotational diversity enhances belowground communities and functions in an agroecosystem.

    PubMed

    Tiemann, L K; Grandy, A S; Atkinson, E E; Marin-Spiotta, E; McDaniel, M D

    2015-08-01

    Biodiversity loss, an important consequence of agricultural intensification, can lead to reductions in agroecosystem functions and services. Increasing crop diversity through rotation may alleviate these negative consequences by restoring positive aboveground-belowground interactions. Positive impacts of aboveground biodiversity on belowground communities and processes have primarily been observed in natural systems. Here, we test for the effects of increased diversity in an agroecosystem, where plant diversity is increased over time through crop rotation. As crop diversity increased from one to five species, distinct soil microbial communities were related to increases in soil aggregation, organic carbon, total nitrogen, microbial activity and decreases in the carbon-to-nitrogen acquiring enzyme activity ratio. This study indicates positive biodiversity-function relationships in agroecosystems, driven by interactions between rotational and microbial diversity. By increasing the quantity, quality and chemical diversity of residues, high diversity rotations can sustain soil biological communities, with positive effects on soil organic matter and soil fertility.

  4. Use of borehole radar reflection logging to monitor steam-enhanced remediation in fractured limestone-results of numerical modelling and a field experiment

    USGS Publications Warehouse

    Gregoire, C.; Joesten, P.K.; Lane, J.W.

    2006-01-01

    Ground penetrating radar is an efficient geophysical method for the detection and location of fractures and fracture zones in electrically resistive rocks. In this study, the use of down-hole (borehole) radar reflection logs to monitor the injection of steam in fractured rocks was tested as part of a field-scale, steam-enhanced remediation pilot study conducted at a fractured limestone quarry contaminated with chlorinated hydrocarbons at the former Loring Air Force Base, Limestone, Maine, USA. In support of the pilot study, borehole radar reflection logs were collected three times (before, during, and near the end of steam injection) using broadband 100 MHz electric dipole antennas. Numerical modelling was performed to predict the effect of heating on radar-frequency electromagnetic (EM) wave velocity, attenuation, and fracture reflectivity. The modelling results indicate that EM wave velocity and attenuation change substantially if heating increases the electrical conductivity of the limestone matrix. Furthermore, the net effect of heat-induced variations in fracture-fluid dielectric properties on average medium velocity is insignificant because the expected total fracture porosity is low. In contrast, changes in fracture fluid electrical conductivity can have a significant effect on EM wave attenuation and fracture reflectivity. Total replacement of water by steam in a fracture decreases fracture reflectivity of a factor of 10 and induces a change in reflected wave polarity. Based on the numerical modelling results, a reflection amplitude analysis method was developed to delineate fractures where steam has displaced water. Radar reflection logs collected during the three acquisition periods were analysed in the frequency domain to determine if steam had replaced water in the fractures (after normalizing the logs to compensate for differences in antenna performance between logging runs). Analysis of the radar reflection logs from a borehole where the temperature

  5. Enhancing Orthographic Competencies and Reducing Domain-Specific Test Anxiety: The Systematic Use of Algorithmic and Self-Instructional Task Formats in Remedial Spelling Training

    ERIC Educational Resources Information Center

    Faber, Gunter

    2010-01-01

    In this study the effects of a remedial spelling training approach were evaluated, which systematically combines certain visualization and verbalization methods to foster students' spelling knowledge and strategy use. Several achievement and test anxiety data from three measurement times were analyzed. All students displayed severe spelling…

  6. Reinventing Remedial Education

    ERIC Educational Resources Information Center

    Stuart, Reginald

    2009-01-01

    Remedial education, although widely used and disguised with other names, was rarely talked about for it could tarnish a school's reputation if widely discussed. Today, more and more colleges and universities are ditching the old stigma associated with remedial education, reinventing their remedial education and retention programs and, in the…

  7. Multiple diversity-stability mechanisms enhance population and community stability in aquatic food webs.

    PubMed

    Downing, Amy L; Brown, Bryan L; Leibold, Mathew A

    2014-01-01

    Biodiversity has been shown to increase the temporal stability of community and ecosystem attributes through multiple mechanisms, but these same mechanisms make less consistent predictions about the effects of richness on population stability. The overall effects of biodiversity on population and community stability will therefore depend on the dominant mechanisms that are likely to vary with the nature of biodiversity loss and the degree of environmental variability. We conducted a mesocosm experiment in which we generated a gradient in zooplankton species richness by directly manipulating dominant species and by allowing/preventing immigration from a metacommunity. The mesocosms were maintained under either constant or variable nutrient environments. Population, community, and ecosystem data were collected for five months. We found that zooplankton population and community stability is enhanced in species-rich communities in both constant and variable environments. Species richness increased primarily through the addition of species with low abundance. The communities that were connected to a metacommunity via immigration were the most diverse and the most stable, indicating the importance of both metacommunity dynamics and rare species for stability. We found little evidence for selection effects or overyielding as stabilizing forces. We did find support for asynchronous dynamics and statistical averaging, both of which predict destabilizing effects at the population level. We also found support for weak interactions, which predicts that both populations and communities will become more stable as richness increases. In order to understand the effects of biodiversity loss on stability, we will need to understand when different stabilizing mechanisms tend to operate but also how multiple mechanisms interact.

  8. DDE remediation and degradation.

    PubMed

    Thomas, John E; Ou, Li-Tse; All-Agely, Abid

    2008-01-01

    breakdown of DDE by the extracellular lignolytic enzymes produced by white rot fungi. The addition of adjutants such as sodium ion, surfactants, and cellulose increased the rate of DDT aerobic or anaerobic degradation but did little to enhance the rate of DDE disappearance under anaerobic conditions. Only in the past decade has it been demonstrated that DDE can undergo reductive dechlorination under methanogenic and sulfidogenic conditions to form the degradation product DDMU, 1-chloro-2,2'-bis-(4'-chlorophenyl)ethane. The only pure culture reported to degrade DDE under anaerobic conditions was the denitrifier Alcaligens denitrificans. The degradation of DDE by this bacterium was enhanced by glucose, whereas biphenyl fumes had no effect. Abiotic remediation by DDE volatilization was enhanced by flooding and irrigation and deepplowing inhibited the volatilization. The use of zero-valent iron and surfactants in flooded soils enhanced DDT degradation but did not significantly alter the rate of DDE removal. Other catalysts (palladized magnesium, palladium on carbon, and nickel/aluminum alloys) degraded DDT and its metabolites, including DDE. However, these systems are often biphasic or involve explosive gases or both. Safer abiotic alternatives use UV light with titanium oxide or visible light with methylene green to degrade DDT, DDD, and DDE in aqueous or mixed solvent systems. Remediation and degradation of DDE in soil and water by phytoextraction, aerobic and anaerobic microorganisms, or abiotic methods can be accomplished. However, success has been limited, and great care must be taken that the method does not transfer the contaminants to another locale (by volatilization, deep plowing, erosion, or runoff) or to another species (by ingestion of accumulating plants or contaminated water). Although the remediation of DDT-, DDD-, and DDE-contaminated soil and water is beset with myriad problems, there remain many open avenues of research.

  9. Exotic species enhance response diversity to land-use change but modify functional composition.

    PubMed

    Stavert, Jamie R; Pattemore, David E; Gaskett, Anne C; Beggs, Jacqueline R; Bartomeus, Ignasi

    2017-08-16

    Two main mechanisms may buffer ecosystem functions despite biodiversity loss. First, multiple species could share similar ecological roles, thus providing functional redundancy. Second, species may respond differently to environmental change (response diversity). However, ecosystem function would be best protected when functionally redundant species also show response diversity. This linkage has not been studied directly, so we investigated whether native and exotic pollinator species with similar traits (functional redundancy) differed in abundance (response diversity) across an agricultural intensification gradient. Exotic pollinator species contributed most positive responses, which partially stabilized overall abundance of the pollinator community. However, although some functionally redundant species exhibited response diversity, this was not consistent across functional groups and aggregate abundances within each functional group were rarely stabilized. This shows functional redundancy and response diversity do not always operate in concert. Hence, despite exotic species becoming increasingly dominant in human-modified systems, they cannot replace the functional composition of native species. © 2017 The Author(s).

  10. Recent breeding programs enhanced genetic diversity in both desi and kabuli varieties of chickpea (Cicer arietinum L.)

    PubMed Central

    Thudi, Mahendar; Chitikineni, Annapurna; Liu, Xin; He, Weiming; Roorkiwal, Manish; Yang, Wei; Jian, Jianbo; Doddamani, Dadakhalandar; Gaur, Pooran M.; Rathore, Abhishek; Samineni, Srinivasan; Saxena, Rachit K.; Xu, Dawen; Singh, Narendra P.; Chaturvedi, Sushil K.; Zhang, Gengyun; Wang, Jun; Datta, Swapan K.; Xu, Xun; Varshney, Rajeev K.

    2016-01-01

    In order to understand the impact of breeding on genetic diversity and gain insights into temporal trends in diversity in chickpea, a set of 100 chickpea varieties released in 14 countries between 1948 and 2012 were re-sequenced. For analysis, the re-sequencing data for 29 varieties available from an earlier study was also included. Copy number variations and presence absence variations identified in the present study have potential to drive phenotypic variations for trait improvement. Re-sequencing of a large number of varieties has provided opportunities to inspect the genetic and genomic changes reflecting the history of breeding, which we consider as breeding signatures and the selected loci may provide targets for crop improvement. Our study also reports enhanced diversity in both desi and kabuli varieties as a result of recent chickpea breeding efforts. The current study will aid the explicit efforts to breed for local adaptation in the context of anticipated climate changes. PMID:27982107

  11. Recent breeding programs enhanced genetic diversity in both desi and kabuli varieties of chickpea (Cicer arietinum L.).

    PubMed

    Thudi, Mahendar; Chitikineni, Annapurna; Liu, Xin; He, Weiming; Roorkiwal, Manish; Yang, Wei; Jian, Jianbo; Doddamani, Dadakhalandar; Gaur, Pooran M; Rathore, Abhishek; Samineni, Srinivasan; Saxena, Rachit K; Xu, Dawen; Singh, Narendra P; Chaturvedi, Sushil K; Zhang, Gengyun; Wang, Jun; Datta, Swapan K; Xu, Xun; Varshney, Rajeev K

    2016-12-16

    In order to understand the impact of breeding on genetic diversity and gain insights into temporal trends in diversity in chickpea, a set of 100 chickpea varieties released in 14 countries between 1948 and 2012 were re-sequenced. For analysis, the re-sequencing data for 29 varieties available from an earlier study was also included. Copy number variations and presence absence variations identified in the present study have potential to drive phenotypic variations for trait improvement. Re-sequencing of a large number of varieties has provided opportunities to inspect the genetic and genomic changes reflecting the history of breeding, which we consider as breeding signatures and the selected loci may provide targets for crop improvement. Our study also reports enhanced diversity in both desi and kabuli varieties as a result of recent chickpea breeding efforts. The current study will aid the explicit efforts to breed for local adaptation in the context of anticipated climate changes.

  12. GC fractionation enhances microbial community diversity assessment and detection of minority populations of bacteria by denaturing gradient gel electrophoresis.

    PubMed

    Holben, William E; Feris, Kevin P; Kettunen, Anu; Apajalahti, Juha H A

    2004-04-01

    Effectively and accurately assessing total microbial community diversity is one of the primary challenges in modern microbial ecology. This is particularly true with regard to the detection and characterization of unculturable populations and those present only in low abundance. We report a novel strategy, GC fractionation combined with denaturing gradient gel electrophoresis (GC-DGGE), which combines mechanistically different community analysis approaches to enhance assessment of microbial community diversity and detection of minority populations of microbes. This approach employs GC fractionation as an initial step to reduce the complexity of the community in each fraction. This reduced complexity facilitates subsequent detection of diversity in individual fractions. DGGE analysis of individual fractions revealed bands that were undetected or only poorly represented when total bacterial community DNA was analyzed. Also, directed cloning and sequencing of individual bands from DGGE lanes corresponding to individual G+C fractions allowed detection of numerous phylotypes that were not recovered using a traditional random cloning and sequencing approach.

  13. Increasing zooplankton size diversity enhances the strength of top-down control on phytoplankton in the East China Sea

    NASA Astrophysics Data System (ADS)

    Ye, L.; Chang, C.; García-Comas, C.; Gong, G.; Hsieh, C.

    2012-12-01

    Body size is one of the fundamental characteristics of organisms linking many ecosystem properties and functions. Recent studies suggest that environmental changes alter the size structure of pelagic food webs; however, ecosystem consequences of such changes remain unclear. Here we tested our main hypothesis that increasing zooplankton size diversity enhances top-down control on phytoplankton in the East China Sea (H1), as well as five conventional hypotheses explaining the top-down control: shallower zooplankton size spectrum enhances the strength of top-down control (H2); nutrient enrichment lessens the strength of top-down control (H3); increasing zooplankton taxonomic diversity enhances the strength of top-down control (H4); increasing fish predation is linked to decreasing the strength of top-down control of zooplankton on phytoplankton (H5); increasing temperature intensifies the strength of top-down control (H6). While the results of our univariate analyses support H1, H2, H3, and H4, more in depth analyses indicate that zooplankton size diversity is the most important factor in determining the strength of top-down control on phytoplankton in East China Sea. Our results suggest a new potential mechanism that increasing predator size diversity enhances the strength of top-down control on prey through diet niche partitioning. This mechanism can be explained by the concept of optimal predator-prey body-mass ratio concept. Suppose each size group of zooplankton predators has its own optimal phytoplankton prey size, increasing size diversity of zooplankton would promote diet niche partitioning of predators and thus elevates the top-down control.Fig. 1 Scatter plots the relationship between zooplankton/phytoplankton biomass ratio versus (A) zooplankton size diversity, (B) slope of zooplankton size spectrum, (C) Zoolankton Shannon diversity, (D) NO3, (E) PO4, (F) SiO3, (G) water temperature, and (H) fish larvae density in the East China Sea. Table 1. Results of the

  14. Duct Remediation Program: Remediation operations and implementation

    SciTech Connect

    Beckman, T.d.; Davis, M.M.; Karas, T.M.

    1992-11-01

    Plutonium holdup material has accumulated in the process ventilation duct systems at Rocky Flats. Non-Destructive Assay (NDA) measurements identified ducts containing this material. The Defense Nuclear Facility Safety Board and the Department of Energy established the criteria for remediation of these ducts. A remediation team was assembled and a program plan created. This program plan included activities such as fissile material accumulation identification, criticality safety assessments, radiation dose determinations, facility safety evaluations, prevention of future accumulation, and removal of holdup material. Several operational considerations had to be evaluated in determining completion of remediation.

  15. Scientist Spotlight Homework Assignments Shift Students’ Stereotypes of Scientists and Enhance Science Identity in a Diverse Introductory Science Class

    PubMed Central

    Schinske, Jeffrey N.; Perkins, Heather; Snyder, Amanda; Wyer, Mary

    2016-01-01

    Research into science identity, stereotype threat, and possible selves suggests a lack of diverse representations of scientists could impede traditionally underserved students from persisting and succeeding in science. We evaluated a series of metacognitive homework assignments (“Scientist Spotlights”) that featured counterstereotypical examples of scientists in an introductory biology class at a diverse community college. Scientist Spotlights additionally served as tools for content coverage, as scientists were selected to match topics covered each week. We analyzed beginning- and end-of-course essays completed by students during each of five courses with Scientist Spotlights and two courses with equivalent homework assignments that lacked connections to the stories of diverse scientists. Students completing Scientist Spotlights shifted toward counterstereotypical descriptions of scientists and conveyed an enhanced ability to personally relate to scientists following the intervention. Longitudinal data suggested these shifts were maintained 6 months after the completion of the course. Analyses further uncovered correlations between these shifts, interest in science, and course grades. As Scientist Spotlights require very little class time and complement existing curricula, they represent a promising tool for enhancing science identity, shifting stereotypes, and connecting content to issues of equity and diversity in a broad range of STEM classrooms. PMID:27587856

  16. Scientist Spotlight Homework Assignments Shift Students' Stereotypes of Scientists and Enhance Science Identity in a Diverse Introductory Science Class.

    PubMed

    Schinske, Jeffrey N; Perkins, Heather; Snyder, Amanda; Wyer, Mary

    2016-01-01

    Research into science identity, stereotype threat, and possible selves suggests a lack of diverse representations of scientists could impede traditionally underserved students from persisting and succeeding in science. We evaluated a series of metacognitive homework assignments ("Scientist Spotlights") that featured counterstereotypical examples of scientists in an introductory biology class at a diverse community college. Scientist Spotlights additionally served as tools for content coverage, as scientists were selected to match topics covered each week. We analyzed beginning- and end-of-course essays completed by students during each of five courses with Scientist Spotlights and two courses with equivalent homework assignments that lacked connections to the stories of diverse scientists. Students completing Scientist Spotlights shifted toward counterstereotypical descriptions of scientists and conveyed an enhanced ability to personally relate to scientists following the intervention. Longitudinal data suggested these shifts were maintained 6 months after the completion of the course. Analyses further uncovered correlations between these shifts, interest in science, and course grades. As Scientist Spotlights require very little class time and complement existing curricula, they represent a promising tool for enhancing science identity, shifting stereotypes, and connecting content to issues of equity and diversity in a broad range of STEM classrooms.

  17. Earth Science Pipeline: Enhancing Diversity in the Geosciences Through Outreach and Research

    NASA Astrophysics Data System (ADS)

    McGill, S. F.; Fryxell, J. E.; Smith, A. L.; Leatham, W. B.; Brunkhorst, B. J.

    2004-12-01

    (GPS) to monitor elastic strain accumulation across the San Andreas and San Jacinto faults along a 70-km-long transect near our campus. To date 80 participants have been involved in the GPS project, including 23 undergraduate students from under-represented ethnic groups and 23 teachers. Several participants have remained involved in the project, helping to process and model the GPS data, leading to presentations at SCEC and AGU meetings. In addition, all of our data has been submitted to the Southern California Earthquake Center's Data Center and is available for use by other scientists. Of the participants in the GPS project, 100% would recommend the program to other students or teachers, 93% regarded the experience as very worthwhile, and 81% said that the project had greatly increased their interest in the Earth Sciences. It is still too early to measure the long-term fruit of our work with middle and early high school students. However, our work with undergraduate students is already beginning to show some promise. During the four years prior to the start of our efforts, the average number of geology majors from under-represented groups in our department was 5 (22.7% of the total number of geology majors). During the three years of focused effort, the average was 8.3 students from under-represented groups (28.4% of the total). This work was funded by a grant from the National Science Foundation's program Opportunities for Enhancing Diversity in the Geosciences.

  18. Stabilisation of nanoscale zero-valent iron with biochar for enhanced transport and in-situ remediation of hexavalent chromium in soil.

    PubMed

    Su, Huijie; Fang, Zhanqiang; Tsang, Pokeung Eric; Fang, Jianzhang; Zhao, Dongye

    2016-07-01

    In this study, a biochar-supported nanoscale zero-valent iron (nZVI@BC) material was used for in situ remediation of hexavalent chromium-contaminated soil. Sedimentation tests and column experiments were used to compare the stability and mobility of nZVI@BC and bare-nZVI. The immobilisation efficiency of chromium, toxic effect of chromium and the content of iron were assessed through leaching tests and pot experiments. Sedimentation tests and transport experiments indicated that nZVI@BC with nZVI to BC mass ratio of 1:1 exhibited better stability and mobility than that of bare-nZVI. The immobilisation efficiency of Cr(VI) and Crtotal was 100% and 92.9%, respectively, when the soil was treated with 8 g/kg of nZVI@BC for 15 days. Moreover, such remediation effectively reduced the leachability of Fe caused by bare-nZVI. In addition, pot experiments showed that such remediation reduced the phytotoxicity of Cr and the leachable Fe and was favourable for plant growth.

  19. Enhancing Diversity in Computational Geoscience: An Essential Component of Our Response to a Changing Planet

    NASA Astrophysics Data System (ADS)

    Loft, R.

    2014-12-01

    Many of the best jobs and innovations in the 21st century will come from the information technology sector, and one of the greatest challenges and opportunities for humanity will be using this technology to better understand our environment and our impact on it. Yet in an increasingly diverse America, many elements of our society go missing in this critical intersection of opportunity and societal benefit. In this talk I will give an overview of our attempts to bring about a transformation of the Computational and Information System Laboratory (CISL) at the National Center for Atmospheric Research (NCAR) into a more inclusive and diverse organization, and to bring students from diverse backgrounds into contact with the grand change of understanding and living with a changing planet. In this context, the integration of specific programs like research internships, visitor support and diversity outreach will be discussed.

  20. Managing diversity and enhancing team outcomes: the promise of transformational leadership.

    PubMed

    Kearney, Eric; Gebert, Diether

    2009-01-01

    In a sample of 62 research and development (R&D) teams, the authors examined transformational leadership as a moderator of the relationship of age, nationality, and educational background diversity with team outcomes. When levels of transformational leadership were high, nationality and educational diversity were positively related to team leaders' longitudinal ratings of team performance. These relationships were nonsignificant when transformational leadership was low. Age diversity was not related to team performance when transformational leadership was high, and it was negatively related to team performance when transformational leadership was low. Two mediated moderation effects help explain these findings. Transformational leadership moderated the relationship of the 3 examined diversity dimensions with the elaboration of task-relevant information, which in turn was positively associated with team performance. Moreover, transformational leadership moderated the relationship of the 3 diversity types with collective team identification, which in turn was positively related to the elaboration of task-relevant information. The authors discuss the theoretical and practical implications of these results. Overall, this study suggests that transformational leadership can foster the utilization of the potential, but frequently untapped, benefits entailed by both demographic and informational/cognitive team diversity. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

  1. Surface Conductive Graphene-Wrapped Micromotors Exhibiting Enhanced Motion.

    PubMed

    Ma, Xing; Katuri, Jaideep; Zeng, Yongfei; Zhao, Yanli; Sanchez, Samuel

    2015-10-01

    Surface-conductive Janus spherical motors are fabricated by wrapping silica particles with reduced graphene oxide capped with a thin Pt layer. These motors exhibit a 100% enhanced velocity as compared to standard SiO2 -Pt motors. Furthermore, the versatility of graphene may open up possibilities for a diverse range of applications from active drug delivery systems to water remediation.

  2. Natural Remediation at Savannah River Site

    SciTech Connect

    Lewis, C. M.; Van Pelt, R.

    2002-02-25

    Natural remediation is a general term that includes any technology or strategy that takes advantage of natural processes to remediate a contaminated media to a condition that is protective of human health and the environment. Natural remediation techniques are often passive and minimally disruptive to the environment. They are generally implemented in conjunction with traditional remedial solutions for source control (i.e., capping, stabilization, removal, soil vapor extraction, etc.). Natural remediation techniques being employed at Savannah River Site (SRS) include enhanced bio-remediation, monitored natural attenuation, and phytoremediation. Enhanced bio-remediation involves making nutrients available and conditions favorable for microbial growth. With proper precautions and feeding, the naturally existing microbes flourish and consume the contaminants. Case studies of enhanced bio-remediation include surface soils contaminated with PCBs and pesticides, and Volatile Organic Compound (VOC) contamination in both the vadose zone and groundwater. Monitored natural attenuation (MNA) has been selected as the preferred alternative for groundwater clean up at several SRS waste units. Successful implementation of MNA has been based on demonstration that sources have been controlled, groundwater modeling that indicates that plumes will not expand or reach surface water discharge points at levels that exceed regulatory limits, and continued monitoring. Phytoremediation is being successfully utilized at several SRS waste units. Phytoremediation involves using plants and vegetation to uptake, break down, or manage contaminants in groundwater or soils. Case studies at SRS include managing groundwater plumes of tritium and VOCs with pine trees that are native to the area. Significant decreases in tritium discharge to a site stream have been realized in one phytoremediation project. Studies of other vegetation types, methods of application, and other target contaminants are

  3. Seaweed diversity enhances nitrogen uptake via complementary use of nitrate and ammonium.

    PubMed

    Bracken, Matthew E S; Stachowicz, John J

    2006-09-01

    The consequences of declining biodiversity remain controversial, in part because many studies focus on a single metric of ecosystem functioning and fail to consider diversity's integrated effects on multiple ecosystem functions. We used tide pool microcosms as a model system to show that different conclusions about the potential effects of producer diversity on ecosystem functioning may result when ecosystem functions are measured separately vs. together. Specifically, we found that in diverse seaweed assemblages, uptake of either nitrate or ammonium alone was equal to the average of the component monocultures. However, when nitrate and ammonium were available simultaneously, uptake by diverse assemblages was 22% greater than the monoculture average because different species were complementary in their use of different nitrogen forms. Our results suggest that when individual species have dominant effects on particular ecosystem processes (i.e., the sampling effect), multivariate complementarity can arise if different species dominate different processes. Further, these results suggest that similar mechanisms (complementary nutrient uptake) may underlie diversity-functioning relationships in both algal and vascular-plant-based systems.

  4. Assessing and Exploiting Functional Diversity in Germplasm Pools to Enhance Abiotic Stress Adaptation and Yield in Cereals and Food Legumes

    PubMed Central

    Dwivedi, Sangam L.; Scheben, Armin; Edwards, David; Spillane, Charles; Ortiz, Rodomiro

    2017-01-01

    There is a need to accelerate crop improvement by introducing alleles conferring host plant resistance, abiotic stress adaptation, and high yield potential. Elite cultivars, landraces and wild relatives harbor useful genetic variation that needs to be more easily utilized in plant breeding. We review genome-wide approaches for assessing and identifying alleles associated with desirable agronomic traits in diverse germplasm pools of cereals and legumes. Major quantitative trait loci and single nucleotide polymorphisms (SNPs) associated with desirable agronomic traits have been deployed to enhance crop productivity and resilience. These include alleles associated with variation conferring enhanced photoperiod and flowering traits. Genetic variants in the florigen pathway can provide both environmental flexibility and improved yields. SNPs associated with length of growing season and tolerance to abiotic stresses (precipitation, high temperature) are valuable resources for accelerating breeding for drought-prone environments. Both genomic selection and genome editing can also harness allelic diversity and increase productivity by improving multiple traits, including phenology, plant architecture, yield potential and adaptation to abiotic stresses. Discovering rare alleles and useful haplotypes also provides opportunities to enhance abiotic stress adaptation, while epigenetic variation has potential to enhance abiotic stress adaptation and productivity in crops. By reviewing current knowledge on specific traits and their genetic basis, we highlight recent developments in the understanding of crop functional diversity and identify potential candidate genes for future use. The storage and integration of genetic, genomic and phenotypic information will play an important role in ensuring broad and rapid application of novel genetic discoveries by the plant breeding community. Exploiting alleles for yield-related traits would allow improvement of selection efficiency and

  5. Assessing and Exploiting Functional Diversity in Germplasm Pools to Enhance Abiotic Stress Adaptation and Yield in Cereals and Food Legumes.

    PubMed

    Dwivedi, Sangam L; Scheben, Armin; Edwards, David; Spillane, Charles; Ortiz, Rodomiro

    2017-01-01

    There is a need to accelerate crop improvement by introducing alleles conferring host plant resistance, abiotic stress adaptation, and high yield potential. Elite cultivars, landraces and wild relatives harbor useful genetic variation that needs to be more easily utilized in plant breeding. We review genome-wide approaches for assessing and identifying alleles associated with desirable agronomic traits in diverse germplasm pools of cereals and legumes. Major quantitative trait loci and single nucleotide polymorphisms (SNPs) associated with desirable agronomic traits have been deployed to enhance crop productivity and resilience. These include alleles associated with variation conferring enhanced photoperiod and flowering traits. Genetic variants in the florigen pathway can provide both environmental flexibility and improved yields. SNPs associated with length of growing season and tolerance to abiotic stresses (precipitation, high temperature) are valuable resources for accelerating breeding for drought-prone environments. Both genomic selection and genome editing can also harness allelic diversity and increase productivity by improving multiple traits, including phenology, plant architecture, yield potential and adaptation to abiotic stresses. Discovering rare alleles and useful haplotypes also provides opportunities to enhance abiotic stress adaptation, while epigenetic variation has potential to enhance abiotic stress adaptation and productivity in crops. By reviewing current knowledge on specific traits and their genetic basis, we highlight recent developments in the understanding of crop functional diversity and identify potential candidate genes for future use. The storage and integration of genetic, genomic and phenotypic information will play an important role in ensuring broad and rapid application of novel genetic discoveries by the plant breeding community. Exploiting alleles for yield-related traits would allow improvement of selection efficiency and

  6. Enhanced interannual precipitation variability increases plant functional diversity that in turn ameliorates negative impact on productivity.

    PubMed

    Gherardi, Laureano A; Sala, Osvaldo E

    2015-12-01

    Although precipitation interannual variability is projected to increase due to climate change, effects of changes in precipitation variance have received considerable less attention than effects of changes in the mean state of climate. Interannual precipitation variability effects on functional diversity and its consequences for ecosystem functioning are assessed here using a 6-year rainfall manipulation experiment. Five precipitation treatments were switched annually resulting in increased levels of precipitation variability while maintaining average precipitation constant. Functional diversity showed a positive response to increased variability due to increased evenness. Dominant grasses decreased and rare plant functional types increased in abundance because grasses showed a hump-shaped response to precipitation with a maximum around modal precipitation, whereas rare species peaked at high precipitation values. Increased functional diversity ameliorated negative effects of precipitation variability on primary production. Rare species buffered the effect of precipitation variability on the variability in total productivity because their variance decreases with increasing precipitation variance.

  7. Tree Diversity Enhances Stand Carbon Storage but Not Leaf Area in a Subtropical Forest.

    PubMed

    Castro-Izaguirre, Nadia; Chi, Xiulian; Baruffol, Martin; Tang, Zhiyao; Ma, Keping; Schmid, Bernhard; Niklaus, Pascal A

    2016-01-01

    Research about biodiversity-productivity relationships has focused on herbaceous ecosystems, with results from tree field studies only recently beginning to emerge. Also, the latter are concentrated largely in the temperate zone. Tree species diversity generally is much higher in subtropical and tropical than in temperate or boreal forests, with reasons not fully understood. Niche overlap and thus complementarity in the use of resources that support productivity may be lower in forests than in herbaceous ecosystems, suggesting weaker productivity responses to diversity change in forests. We studied stand basal area, vertical structure, leaf area, and their relationship with tree species richness in a subtropical forest in south-east China. Permanent forest plots of 30 x 30 m were selected to span largely independent gradients in tree species richness and secondary successional age. Plots with higher tree species richness had a higher stand basal area. Also, stand basal area increases over a 4-year census interval were larger at high than at low diversity. These effects translated into increased carbon stocks in aboveground phytomass (estimated using allometric equations). A higher variability in tree height in more diverse plots suggested that these effects were facilitated by denser canopy packing due to architectural complementarity between species. In contrast, leaf area was not or even negatively affected by tree diversity, indicating a decoupling of carbon accumulation from leaf area. Alternatively, the same community leaf area might have assimilated more C per time interval in more than in less diverse plots because of differences in leaf turnover and productivity or because of differences in the display of leaves in vertical and horizontal space. Overall, our study suggests that in species-rich forests niche-based processes support a positive diversity-productivity relationship and that this translates into increased carbon storage in long-lived woody

  8. Genome-wide screens for in vivo Tinman binding sites identify cardiac enhancers with diverse functional architectures.

    PubMed

    Jin, Hong; Stojnic, Robert; Adryan, Boris; Ozdemir, Anil; Stathopoulos, Angelike; Frasch, Manfred

    2013-01-01

    The NK homeodomain factor Tinman is a crucial regulator of early mesoderm patterning and, together with the GATA factor Pannier and the Dorsocross T-box factors, serves as one of the key cardiogenic factors during specification and differentiation of heart cells. Although the basic framework of regulatory interactions driving heart development has been worked out, only about a dozen genes involved in heart development have been designated as direct Tinman target genes to date, and detailed information about the functional architectures of their cardiac enhancers is lacking. We have used immunoprecipitation of chromatin (ChIP) from embryos at two different stages of early cardiogenesis to obtain a global overview of the sequences bound by Tinman in vivo and their linked genes. Our data from the analysis of ~50 sequences with high Tinman occupancy show that the majority of such sequences act as enhancers in various mesodermal tissues in which Tinman is active. All of the dorsal mesodermal and cardiac enhancers, but not some of the others, require tinman function. The cardiac enhancers feature diverse arrangements of binding motifs for Tinman, Pannier, and Dorsocross. By employing these cardiac and non-cardiac enhancers in machine learning approaches, we identify a novel motif, termed CEE, as a classifier for cardiac enhancers. In vivo assays for the requirement of the binding motifs of Tinman, Pannier, and Dorsocross, as well as the CEE motifs in a set of cardiac enhancers, show that the Tinman sites are essential in all but one of the tested enhancers; although on occasion they can be functionally redundant with Dorsocross sites. The enhancers differ widely with respect to their requirement for Pannier, Dorsocross, and CEE sites, which we ascribe to their different position in the regulatory circuitry, their distinct temporal and spatial activities during cardiogenesis, and functional redundancies among different factor binding sites.

  9. Genome-Wide Screens for In Vivo Tinman Binding Sites Identify Cardiac Enhancers with Diverse Functional Architectures

    PubMed Central

    Jin, Hong; Stojnic, Robert; Adryan, Boris; Ozdemir, Anil; Stathopoulos, Angelike; Frasch, Manfred

    2013-01-01

    The NK homeodomain factor Tinman is a crucial regulator of early mesoderm patterning and, together with the GATA factor Pannier and the Dorsocross T-box factors, serves as one of the key cardiogenic factors during specification and differentiation of heart cells. Although the basic framework of regulatory interactions driving heart development has been worked out, only about a dozen genes involved in heart development have been designated as direct Tinman target genes to date, and detailed information about the functional architectures of their cardiac enhancers is lacking. We have used immunoprecipitation of chromatin (ChIP) from embryos at two different stages of early cardiogenesis to obtain a global overview of the sequences bound by Tinman in vivo and their linked genes. Our data from the analysis of ∼50 sequences with high Tinman occupancy show that the majority of such sequences act as enhancers in various mesodermal tissues in which Tinman is active. All of the dorsal mesodermal and cardiac enhancers, but not some of the others, require tinman function. The cardiac enhancers feature diverse arrangements of binding motifs for Tinman, Pannier, and Dorsocross. By employing these cardiac and non-cardiac enhancers in machine learning approaches, we identify a novel motif, termed CEE, as a classifier for cardiac enhancers. In vivo assays for the requirement of the binding motifs of Tinman, Pannier, and Dorsocross, as well as the CEE motifs in a set of cardiac enhancers, show that the Tinman sites are essential in all but one of the tested enhancers; although on occasion they can be functionally redundant with Dorsocross sites. The enhancers differ widely with respect to their requirement for Pannier, Dorsocross, and CEE sites, which we ascribe to their different position in the regulatory circuitry, their distinct temporal and spatial activities during cardiogenesis, and functional redundancies among different factor binding sites. PMID:23326246

  10. India Basin 900 Innes Remediation

    EPA Pesticide Factsheets

    Lower Walnut Creek Restoration Project will restore and enhance coastal wetlands along southern shoreline of Suisun Bay from Suisun Bay upstream along Walnut Creek, improving habitat quality, diversity, and connectivity along three miles of creek channel.

  11. Assessing the trend in sustainable remediation: A questionnaire survey of remediation professionals in various countries.

    PubMed

    Hou, Deyi; Guthrie, Peter; Rigby, Mark

    2016-12-15

    Over the past decade, sustainable remediation has grown from an emerging concept into a widely accepted new institutional norm. Scholar literature increased exponentially from nearly none in late 1990s to over 400 publications per year in 2014. The present study used a questionnaire survey conducted in 2012 and 2014 to assess the global trend in the awareness and practice of sustainable remediation. A total of 373 responses were received from survey participants located in 22 countries. The survey found that the US and the UK similarly had the highest level of awareness and adoption rate of sustainable remediation. Asia and other developing countries had much lower awareness levels and/or adoption rates. For all regions, the adoption rates were significantly lower than awareness levels, indicating a large gap between awareness and practice. One specific example is regarding minimizing greenhouse gas emission, which is a focal point in sustainable remediation literature, but with very low adoption rate according to this survey. This study also found that the adoption rates of a few sustainable remediation considerations, such as "minimizing local scale secondary impact", "minimizing national to global scale secondary impact", and "bringing prosperity to disadvantaged community", had decreased between 2012 and 2014. On the other hand, the survey also suggests the remediation community has rendered more expertise, training, and resources in sustainable remediation between 2012 and 2014. The mixed results suggest that in order to enhance sustainable remediation adoption, it is imperative to employ continued effort to enhance the understanding of sustainable remediation by practitioners and to link self-interest and public interest with sustainable remediation considerations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. No Child Misunderstood: Enhancing Early Childhood Teachers' Multicultural Responsiveness to the Social Competence of Diverse Children

    ERIC Educational Resources Information Center

    Han, Heejeong Sophia; Thomas, M. Shelley

    2010-01-01

    As a result of rapid demographic changes in our society, more children from diverse racial/cultural backgrounds join our early childhood classrooms. The majority of early childhood teachers, on the other hand, are middle-class and of European-decent. This paper provides early childhood teachers with both theoretical and practical understandings…

  13. Problems and Recommendations: Enhancing Communication with Culturally and Linguistically Diverse Students.

    ERIC Educational Resources Information Center

    Kader, Shereen Abdel; Yawkey, Thomas D.

    2002-01-01

    Notes that communication between teachers and culturally and linguistically diverse (CLD) students need serious consideration especially in recognizing potential sources of miscommunication and misinterpretation. Considers sources of miscommunication within verbal and nonverbal communication. Discusses each element and offers examples in CLD…

  14. Science Inquiry and Student Diversity: Enhanced Abilities and Continuing Difficulties after an Instructional Intervention

    ERIC Educational Resources Information Center

    Lee, Okhee; Buxton, Cory; Lewis, Scott; LeRoy, Kathryn

    2006-01-01

    This study examines elementary students' abilities to conduct science inquiry through their participation in an instructional intervention over a school year. The study involved 25 third and fourth grade students from six elementary schools representing diverse linguistic and cultural groups. Prior to and at the completion of the intervention, the…

  15. Science Inquiry and Student Diversity: Enhanced Abilities and Continuing Difficulties after an Instructional Intervention

    ERIC Educational Resources Information Center

    Lee, Okhee; Buxton, Cory; Lewis, Scott; LeRoy, Kathryn

    2006-01-01

    This study examines elementary students' abilities to conduct science inquiry through their participation in an instructional intervention over a school year. The study involved 25 third and fourth grade students from six elementary schools representing diverse linguistic and cultural groups. Prior to and at the completion of the intervention, the…

  16. Enhancing Practice with Infants and Toddlers from Diverse Language and Cultural Backgrounds

    ERIC Educational Resources Information Center

    Nemeth, Karen N.; Erdosi, Valeria

    2012-01-01

    As infant/toddler programs encounter growing diversity, they need to reenvision the impact they have on children and families in all areas of practice, from recruiting new enrollees to stocking classrooms to changing the ways adults interact with children and families with different languages and from different cultures. What happens on the first…

  17. State Strategies To Address Diversity and Enhance Equity in Higher Education.

    ERIC Educational Resources Information Center

    Ratliff, Charles A.; Rawlings, Howard P.; Ards, Sheila; Sherman, Jane

    The three case studies in this report describe state-level efforts to address diversity and equity in postsecondary institutions in California, Maryland, and Washington. A preface provides some background on affirmative action programs, litigation history, and the roles of state coordinating agencies and institutional governing boards. The…

  18. Enhancing Practice with Infants and Toddlers from Diverse Language and Cultural Backgrounds

    ERIC Educational Resources Information Center

    Nemeth, Karen N.; Erdosi, Valeria

    2012-01-01

    As infant/toddler programs encounter growing diversity, they need to reenvision the impact they have on children and families in all areas of practice, from recruiting new enrollees to stocking classrooms to changing the ways adults interact with children and families with different languages and from different cultures. What happens on the first…

  19. Tree Diversity Enhances Stand Carbon Storage but Not Leaf Area in a Subtropical Forest

    PubMed Central

    Castro-Izaguirre, Nadia; Chi, Xiulian; Baruffol, Martin; Tang, Zhiyao; Ma, Keping; Schmid, Bernhard

    2016-01-01

    Research about biodiversity–productivity relationships has focused on herbaceous ecosystems, with results from tree field studies only recently beginning to emerge. Also, the latter are concentrated largely in the temperate zone. Tree species diversity generally is much higher in subtropical and tropical than in temperate or boreal forests, with reasons not fully understood. Niche overlap and thus complementarity in the use of resources that support productivity may be lower in forests than in herbaceous ecosystems, suggesting weaker productivity responses to diversity change in forests. We studied stand basal area, vertical structure, leaf area, and their relationship with tree species richness in a subtropical forest in south-east China. Permanent forest plots of 30 x 30 m were selected to span largely independent gradients in tree species richness and secondary successional age. Plots with higher tree species richness had a higher stand basal area. Also, stand basal area increases over a 4-year census interval were larger at high than at low diversity. These effects translated into increased carbon stocks in aboveground phytomass (estimated using allometric equations). A higher variability in tree height in more diverse plots suggested that these effects were facilitated by denser canopy packing due to architectural complementarity between species. In contrast, leaf area was not or even negatively affected by tree diversity, indicating a decoupling of carbon accumulation from leaf area. Alternatively, the same community leaf area might have assimilated more C per time interval in more than in less diverse plots because of differences in leaf turnover and productivity or because of differences in the display of leaves in vertical and horizontal space. Overall, our study suggests that in species-rich forests niche-based processes support a positive diversity–productivity relationship and that this translates into increased carbon storage in long-lived woody

  20. Development and Implementation of a Workshop to Enhance the Effectiveness of Mentors Working with Diverse Mentees in HIV Research

    PubMed Central

    Fernandez, Alicia; Stoff, David M.; Narahari, Swathi; Blank, Michael; Fuchs, Jonathan; Evans, Clyde H.; Kahn, James S.; Johnson, Mallory O.

    2014-01-01

    Abstract A growing body of evidence highlights the importance of competent mentoring in academic research in the field of HIV, particularly for early stage investigators from diverse, underrepresented backgrounds. We describe the development and implementation of a 2-day intensive workshop to train mid-level and senior-level investigators conducting HIV-related clinical and translational research across multiple academic institutions on more effective mentoring, with an emphasis on techniques to foster mentees of diversity. The workshop was focused on training mentors in techniques designed to improve the effectiveness of the mentor–mentee relationship, and included didactic presentations, interactive discussions, and small-group problem-based learning activities. Mid-level or senior-level faculty involved or planning to be involved in significant mentorship activities related to HIV research were eligible. Surveys and formal actions plans allowed for workshop evaluation and laid the groundwork for subsequent workshops. Twenty-six faculty from 16 U.S.-based institutions participated, with good representation across discipline, gender, and race/ethnicity. The sessions were highly rated and discussions and evaluations revealed important barriers and facilitators to mentoring, challenges and solutions related to mentoring mentees from diverse backgrounds, and specific tools to enhance mentoring effectiveness. The Mentoring the Mentors training program for HIV researchers focusing on early career investigators of diversity was the first of its kind and was well attended, was rated highly, and provided guidance for improving the program in the future. This training program fills an important gap in the HIV researcher community and offers guidance for training mentors interested in diversity issues in settings outside of HIV. PMID:24735004

  1. Designing Clinical Remediation Programs.

    ERIC Educational Resources Information Center

    Oleszewski, Susan C.

    1989-01-01

    Elements and considerations in the provision of effective remediation for optometry students not achieving in clinical competence are discussed. Remediation of technical, cognitive, and noncognitive skills are included. A course in professional communication offered by the Pennsylvania College of Optometry is described. (MSE)

  2. An enhanced calibration of a recently released megatree for the analysis of phylogenetic diversity.

    PubMed

    Gastauer, M; Meira-Neto, J A A

    2016-04-19

    Dated or calibrated phylogenetic trees, in which branch lengths correspond to evolutionary divergence times between nodes, are important requirements for computing measures of phylogenetic diversity or phylogenetic community structure. The increasing knowledge about the diversification and evolutionary divergence times of vascular plants requires a revision of the age estimates used for the calibration of phylogenetic trees by the bladj algorithm of the Phylocom 4.2 package. Comparing the recently released megatree R20120829.new with two calibrated vascular plant phylogenies provided in the literature, we found 242 corresponding nodes. We modified the megatree (R20120829mod.new), inserting names for all corresponding nodes. Furthermore, we provide files containing age estimates from both sources for the updated calibration of R20120829mod.new. Applying these files consistently in analyses of phylogenetic community structure or diversity serves to avoid erroneous measures and ecological misinterpretation.

  3. Plant diversity affects behavior of generalist root herbivores, reduces crop damage, and enhances crop yield.

    PubMed

    Staudacher, Karin; Schallhart, Nikolaus; Thalinger, Bettina; Wallinger, Corinna; Juen, Anita; Traugott, Michael

    2013-07-01

    Soil-dwelling pests inflict considerable economic damage in agriculture but are hard to control. A promising strategy to reduce pest pressure on crops is to increase the plant diversity in agroecosystems. This approach, however, demands a sound understanding of species' interactions, which is widely lacking for subterranean herbivore-plant systems. Here, we examine the effects of plant diversification on wireworms, the soil-dwelling larvae of click beetles that threaten crops worldwide. We conducted a field experiment employing plant diversification by adding either wheat or a mix of six associated plants (grasses, legumes, and forbs) between rows of maize to protect it from Agriotes wireworms. Wireworm feeding behavior, dispersal between crop and associated plants, as well as maize damage and yield were examined. The former was assessed combining molecular gut content and stable isotope analysis. The pests were strongly attracted by the associated plants in August, when the crop was most vulnerable, whereas in September, shortly before harvest, this effect occurred only in the plant mix. In maize monoculture, the larvae stayed in the principal crop throughout the season. Larval delta13C signatures revealed that maize feeding was reduced up to sevenfold in wireworms of the vegetationally diversified treatments compared to those of the maize monoculture. These findings were confirmed by molecular analysis, which additionally showed a dietary preference of wireworms for specific plants in the associated plant mix. Compared to the monoculture, maize damage was reduced by 38% and 55% in the wheat and plant mix treatment, which translated into a yield increase of 30% and 38%, respectively. The present findings demonstrate that increasing the plant diversity in agroecosystems provides an effective insurance against soil pests. The underlying mechanisms are the diversion of the pest from the principle crop and a changed feeding behavior. The deployment of diverse mixes of

  4. The Many Faces of Mentoring to Enhance Diversity in the Geosciences

    NASA Astrophysics Data System (ADS)

    Ricciardi, L.; Johnson, A.; Williamson Whitney, V.

    2009-12-01

    The establishment of the AGU Diversity Plan in 2002 recommends a policy of education, engagement, outreach, facilitation, partnership and collaboration in order to increase the diversity and representation of minorities in Earth system science (ESS). Such increased representation will provide the global scientific community with an expanded means of communicating the science behind ecological and economic practices that affect natural resources. However, conventional educational tracts for degrees in ESS often do not fully prepare underrepresented groups for academic and professional success. The Minorities Striving and Pursuing Higher Degrees of Success in Earth System Science Professional Development Program (MS PHD’S PDP) provides professional development experiences to facilitate the advancement of minorities committed to achieving outstanding Earth system science careers. The MS PHD’S PDP expands upon traditional preparation by providing a diversified mentoring program that engages distinguished academicians, scientific organizations, industry partners, alumni, peers, and representatives of non-science disciplines in the support, increase, and retention of underrepresented groups in ESS programs. MS PHD’S PDP student benefits from mentoring experiences include completion of academic programs and establishment of successful careers. Afterward, as MS PHD’S PDP alumni, they provide similar mentoring experiences to subsequent generations of underrepresented ESS students thereby ensuring continuity and growth of diversity in ESS.

  5. Wild Herbivore Grazing Enhances Insect Diversity over Livestock Grazing in an African Grassland System

    PubMed Central

    Roets, Francois; Samways, Michael J.

    2016-01-01

    Southern Africa’s grassland biodiversity is threatened by habitat transformation such as commercial forestry. Ecological networks (ENs) have been instigated to alleviate the pressure of habitat transformation on local biodiversity. ENs are large scale webs of corridors and patches of natural vegetation criss-crossing production landscapes that can simulate conditions in protected areas (PAs). Many ENs have lost many native large mammal species, which have been replaced by domestic livestock to retain natural grazing dynamics, which could have an impact on the long-term value of ENs for insects. Here we compared dung beetle, butterfly and grasshopper diversity in ENs across a landscape mosaic of timber plantations, where 1) wild megaherbivores were maintained, 2) in ENs where these herbivores were replaced by livestock and, 3) in a nearby World Heritage PA which retained its natural complement of megaherbivores. Sites in the PA far from any plantation were similar in composition to those in the wild grazed EN. Presence of the wild grazers improved the alpha- and beta-diversity of all focal insect taxa when compared to domestic grazing. Furthermore, species composition shows significant differences between the two grazing systems indicating that an assemblage of native large mammals facilitates insect diversity conservation. We support the maintenance or introduction of large native mammals in ENs or similar conservation areas in production landscapes to simulate the ecological conditions and natural heterogeneity in nearby PAs. PMID:27783685

  6. Enhancing the diversity of a corporate database using chemical database clustering and analysis

    NASA Astrophysics Data System (ADS)

    Shemetulskis, Norah E.; Dunbar, James B., Jr.; Dunbar, Bonnie W.; Moreland, David W.; Humblet, Christine

    1995-10-01

    The contribution that the Chemical Abstracts structural database (CAST-3D) and the Maybridge database (MAY) would make to diversifying the structural information and property space spanned by our corporate database (CBI) is assessed. A subset of the CAST-3D database has been selected to augment the structural diversity of various electronic databases used in computer-assisted drug design projects. The analysis of the MAY database directly offers the potential to expand the CBI compound library, but also provides a source for structural diversity in a format suitable for computer-assisted database searching and molecular design. The analysis performed is twofold. First, a nonhierarchical clustering technique available in the Daylight clustering package is applied to evaluate the structural differences between databases. The comparison is then extended to analyze various structure-derived property spaces calculated from molecular descriptors such as the logarithm of the octanol-water partition coefficient (CLOGP), the molar refractivity (CMR) and the electronic dipole moment (CDM). The diversity contribution of each database to these property spaces is quantified in relation to our corporate database.

  7. Pectin enhances the effect of fecal microbiota transplantation in ulcerative colitis by delaying the loss of diversity of gut flora.

    PubMed

    Wei, Yao; Gong, Jianfeng; Zhu, Weiming; Tian, Hongliang; Ding, Chao; Gu, Lili; Li, Ning; Li, Jieshou

    2016-11-03

    Fecal microbiota transplantation (FMT) induces remission in ulcerative colitis (UC). However, the treatment effect of FMT diminishes over time. Maintaining the diversity of the gut flora for long periods may improve the effects of FMT in UC. Pectin, which can be fermented by gut microbiota into short-chain fatty acids, is postulated to shape the composition and maintain the balance of gut microbiota following transplantation. This study investigated whether pectin could enhance the effects of FMT in UC patients. Three FMT patients and four FMTP patients achieved the primary outcome. The Mayo scores of the FMTP group were lower than those of the FMT group at weeks 4 and 12 (P = 0.042 and P = 0.042, respectively). There were no differences in the diversity of the gut flora between the two groups at weeks 4 and 12; however, the composition of the gut flora of the FMTP group was more similar than the FMT group to that of the donor at all-time points post-treatment. Pectin decreased the Mayo score by preserving the diversity of the gut flora following FMT for UC. Current Controlled Trial NCT02016469 . Registered 10 November 2013.

  8. Bacterial community diversity in a low-permeability oil reservoir and its potential for enhancing oil recovery.

    PubMed

    Xiao, Meng; Zhang, Zhong-Zhi; Wang, Jing-Xiu; Zhang, Guang-Qing; Luo, Yi-Jing; Song, Zhao-Zheng; Zhang, Ji-Yuan

    2013-11-01

    The diversity of indigenous bacterial community and the functional species in the water samples from three production wells of a low permeability oil reservoir was investigated by high-throughput sequencing technology. The potential of application of indigenous bacteria for enhancing oil recovery was evaluated by examination of the effect of bacterial stimulation on the formation water-oil-rock surface interactions and micromodel test. The results showed that production well 88-122 had the most diverse bacterial community and functional species. The broth of indigenous bacteria stimulated by an organic nutrient activator at aerobic condition changed the wettability of the rock surface from oil-wet to water-wet. Micromodel test results showed that flooding using stimulated indigenous bacteria following water flooding improved oil recovery by 6.9% and 7.7% in fractured and unfractured micromodels, respectively. Therefore, the zone of low permeability reservoir has a great potential for indigenous microbial enhanced oil recovery. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. MF59 Adjuvant Enhances Diversity and Affinity of Antibody-Mediated Immune Response to Pandemic Influenza Vaccines

    PubMed Central

    Khurana, Surender; Verma, Nitin; Yewdell, Jonathan W.; Hilbert, Anne Katrin; Castellino, Flora; Lattanzi, Maria; Del Giudice, Giuseppe; Rappuoli, Rino; Golding, Hana

    2012-01-01

    Oil-in-water adjuvants have been shown to improve immune responses against pandemic influenza vaccines as well as reduce the effective vaccine dose, increasing the number of doses available to meet global vaccine demand. Here, we use genome fragment phage display libraries and surface plasmon resonance to elucidate the effects of MF59 on the quantity, diversity, specificity, and affinity maturation of human antibody responses to the swine-origin H1N1 vaccine in different age groups. In adults and children, MF59 selectively enhanced antibody responses to the hemagglutinin 1 (HA1) globular head relative to the more conserved HA2 domain in terms of increased antibody titers as well as a more diverse antibody epitope repertoire. Antibody affinity, as inferred by greatly diminished (≥10-fold) off-rate constants, was significantly increased in toddlers and children who received the MF59-adjuvanted vaccine. Moreover, MF59 also improved antibody affinity maturation after each sequential vaccination against avian H5N1 in adults. For both pandemic influenza vaccines, there was a close correlation between serum antibody affinity and virus-neutralizing capacity. Thus, MF59 quantitatively and qualitatively enhances functional antibody responses to HA-based vaccines by improving both epitope breadth and binding affinity, demonstrating the added value of such adjuvants for influenza vaccines. PMID:21632986

  10. MF59 adjuvant enhances diversity and affinity of antibody-mediated immune response to pandemic influenza vaccines.

    PubMed

    Khurana, Surender; Verma, Nitin; Yewdell, Jonathan W; Hilbert, Anne Katrin; Castellino, Flora; Lattanzi, Maria; Del Giudice, Giuseppe; Rappuoli, Rino; Golding, Hana

    2011-06-01

    Oil-in-water adjuvants have been shown to improve immune responses against pandemic influenza vaccines as well as reduce the effective vaccine dose, increasing the number of doses available to meet global vaccine demand. Here, we use genome fragment phage display libraries and surface plasmon resonance to elucidate the effects of MF59 on the quantity, diversity, specificity, and affinity maturation of human antibody responses to the swine-origin H1N1 vaccine in different age groups. In adults and children, MF59 selectively enhanced antibody responses to the hemagglutinin 1 (HA1) globular head relative to the more conserved HA2 domain in terms of increased antibody titers as well as a more diverse antibody epitope repertoire. Antibody affinity, as inferred by greatly diminished (≥10-fold) off-rate constants, was significantly increased in toddlers and children who received the MF59-adjuvanted vaccine. Moreover, MF59 also improved antibody affinity maturation after each sequential vaccination against avian H5N1 in adults. For both pandemic influenza vaccines, there was a close correlation between serum antibody affinity and virus-neutralizing capacity. Thus, MF59 quantitatively and qualitatively enhances functional antibody responses to HA-based vaccines by improving both epitope breadth and binding affinity, demonstrating the added value of such adjuvants for influenza vaccines.

  11. Soil fertility and plant diversity enhance microbial performance in metal-polluted soils.

    PubMed

    Stefanowicz, Anna M; Kapusta, Paweł; Szarek-Łukaszewska, Grażyna; Grodzińska, Krystyna; Niklińska, Maria; Vogt, Rolf D

    2012-11-15

    This study examined the effects of soil physicochemical properties (including heavy metal pollution) and vegetation parameters on soil basal respiration, microbial biomass, and the activity and functional richness of culturable soil bacteria and fungi. In a zinc and lead mining area (S Poland), 49 sites were selected to represent all common plant communities and comprise the area's diverse soil types. Numerous variables describing habitat properties were reduced by PCA to 7 independent factors, mainly representing subsoil type (metal-rich mining waste vs. sand), soil fertility (exchangeable Ca, Mg and K, total C and N, organic C), plant species richness, phosphorus content, water-soluble heavy metals (Zn, Cd and Pb), clay content and plant functional diversity (based on graminoids, legumes and non-leguminous forbs). Multiple regression analysis including these factors explained much of the variation in most microbial parameters; in the case of microbial respiration and biomass, it was 86% and 71%, respectively. The activity of soil microbes was positively affected mainly by soil fertility and, apparently, by the presence of mining waste in the subsoil. The mining waste contained vast amounts of trace metals (total Zn, Cd and Pb), but it promoted microbial performance due to its inherently high content of macronutrients (total Ca, Mg, K and C). Plant species richness had a relatively strong positive effect on all microbial parameters, except for the fungal component. In contrast, plant functional diversity was practically negligible in its effect on microbes. Other explanatory variables had only a minor positive effect (clay content) or no significant influence (phosphorus content) on microbial communities. The main conclusion from this study is that high nutrient availability and plant species richness positively affected the soil microbes and that this apparently counteracted the toxic effects of metal contamination. Copyright © 2012 Elsevier B.V. All rights

  12. 45 CFR 77.5 - Remedial action procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Remedial action procedures. 77.5 Section 77.5 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION REMEDIAL ACTIONS APPLICABLE... judgment of the official designated to make a final decision, it would materially enhance his ability to...

  13. Enhanced soil washing process for the remediation of PBDEs/Pb/Cd-contaminated electronic waste site with carboxymethyl chitosan in a sunflower oil-water solvent system and microbial augmentation.

    PubMed

    Ye, Mao; Sun, Mingming; Wan, Jinzhong; Fang, Guodong; Li, Huixin; Hu, Feng; Jiang, Xin; Kengara, Fredrick Orori

    2015-02-01

    An innovative ex situ soil washing technology was developed to remediate polybrominated diphenyl ethers (PBDEs) and heavy metals in an electronic waste site. Elevated temperature (50 °C) in combination with ultrasonication (40 kHz, 20 min) at 5.0 mL L(-1) sunflower oil and 2.5 g L(-1) carboxymethyl chitosan were found to be effective in extracting mixed pollutants from soil. After two successive washing cycles, the removal efficiency rates for total PBDEs, BDE28, BDE47, BDE209, Pb, and Cd were approximately 94.1, 93.4, 94.3, 99.1, 89.3, and 92.7 %, respectively. Treating the second washed soil with PBDE-degrading bacteria (Rhodococcus sp. strain RHA1) inoculation and nutrient addition for 3 months led to maximum biodegradation rates of 37.3, 52.6, 23.9, and 1.3 % of the remaining total PBDEs, BDE28, BDE47, BDE209, respectively. After the combined treatment, the microbiological functions of washed soil was partially restored, as indicated by a significant increase in the counts, biomass C, N, and functioning diversity of soil microorganisms (p < 0.05), and the residual PBDEs and heavy metals mainly existed as very slow desorbing fractions and residual fractions, as evaluated by Tenax extraction combined with a first-three-compartment model and sequential extraction with metal stability indices (I R and U ts). Additionally, the secondary environmental risk of mixed contaminants in the remediated soil was limited. Therefore, the proposed combined cleanup strategy is an environment-friendly technology that is important for risk assessment and management in mixed-contaminated sites.

  14. Bioremediation of contaminated marine sediments can enhance metal mobility due to changes of bacterial diversity.

    PubMed

    Fonti, Viviana; Beolchini, Francesca; Rocchetti, Laura; Dell'Anno, Antonio

    2015-01-01

    Bioremediation strategies applied to contaminated marine sediments can induce important changes in the mobility and bioavailability of metals with potential detrimental consequences on ecosystem health. In this study we investigated changes of bacterial abundance and diversity (by a combination of molecular fingerprinting and next generation sequencing analyses) during biostimulation experiments carried out on anoxic marine sediments characterized by high metal content. We provide evidence that the addition of organic (lactose and/or acetate) and/or inorganic compounds to contaminated sediments determines a significant increase of bacterial growth coupled with changes in bacterial diversity and assemblage composition. Experimental systems supplied only with organic substrates were characterized by an increase of the relative importance of sulfate reducing bacteria belonging to the families Desulfobacteraceae and Desulfobulbaceae with a concomitant decrease of taxa affiliated with Flavobacteriaceae. An opposite effect was observed in the experimental treatments supplied also with inorganic nutrients. The increase of bacterial metabolism coupled with the increase of bacterial taxa affiliated with Flavobacteriaceae were reflected in a significant decrease of Cd and Zn associated with sedimentary organic matter and Pb and As associated with the residual fraction of the sediment. However, independently from the experimental conditions investigated no dissolution of metals occurred, suggesting a role of bacterial assemblages in controlling metal solubilization processes. Overall results of this study have allowed to identify key biogeochemical interactions influencing the metal behavior and provide new insights for a better understanding of the potential consequences of bio-treatments on the metal fate in contaminated marine sediments.

  15. Implementing sponge physiological and genomic information to enhance the diversity of its culturable associated bacteria.

    PubMed

    Lavy, Adi; Keren, Ray; Haber, Markus; Schwartz, Inbar; Ilan, Micha

    2014-02-01

    In recent years new approaches have emerged for culturing marine environmental bacteria. They include the use of novel culture media, sometimes with very low-nutrient content, and a variety of growth conditions such as temperature, oxygen levels, and different atmospheric pressures. These approaches have largely been neglected when it came to the cultivation of sponge-associated bacteria. Here, we used physiological and environmental conditions to reflect the environment of sponge-associated bacteria along with genomic data of the prominent sponge symbiont Candidatus Poribacteria sp. WGA-4E, to cultivate bacteria from the Red Sea sponge Theonella swinhoei. Designing culturing conditions to fit the metabolic needs of major bacterial taxa present in the sponge, through a combined use of diverse culture media compositions with aerobic and microaerophilic states, and addition of antibiotics, yielded higher diversity of the cultured bacteria and led to the isolation of novel sponge-associated and sponge-specific bacteria. In this work, 59 OTUs of six phyla were isolated. Of these, 22 have no close type strains at the species level (< 97% similarity of 16S rRNA gene sequence), representing novel bacteria species, and some are probably new genera and even families.

  16. Ethyl lactate-EDTA composite system enhances the remediation of the cadmium-contaminated soil by autochthonous willow (Salix x aureo-pendula CL 'J1011') in the lower reaches of the Yangtze River.

    PubMed

    Li, Jiahua; Sun, Yuanyuan; Yin, Ying; Ji, Rong; Wu, Jichun; Wang, Xiaorong; Guo, Hongyan

    2010-09-15

    In order to explore a practical approach to the remediation of the cadmium (Cd)-contaminated soil in the lower reaches of the Yangtze River, we evaluated the effects of a local willow (Salix x aureo-pendula CL 'J1011') of absorbing, accumulating, and translocating Cd; and assessed the potential of chelator ethylenediaminetetraacetic acid (EDTA) in combination with ethyl lactate for enhancing the efficiency of the willow in removing Cd in two water-culture growth chamber trials and a field one. The willow showed a high tolerance to Cd in growth chamber trial 1 where the Cd concentration in the medium reached up to 25 mg L(-1) medium, and the bioaccumulation factors (BAFs) of the shoots for Cd rose from 3.8 to 7.4 as the Cd concentration in the medium was elevated from 5 to 25 mg L(-1) medium. In growth chamber trial 2, the average Cd removal rates in two treatments with EDTA and ethyl lactate (molar ratios of EDTA to ethyl lactate=68/39 and 53.5/53.5, respectively) reached 0.71 mg d(-1) pot(-1) for the duration of Day 5-8 and 0.59 mg d(-1) pot(-1) for that of Day 8-11, which were 5- and 4-fold of their counterparts in the control, respectively. In the field trial, for the remediational duration of 45 days, three treatments-willow alone, willow combined with EDTA, and willow combined with EDTA and ethyl lactate-led to decreases in the Cd concentration in soil by 5%, 20%, and 29%, respectively; increases in that in the leaves by 14.6%, 56.7%, and 146.5%, respectively; and increases in that in the stems by 15.6%, 41.2%, and 87.4%, respectively, compared to their counterparts on Day 0. These results indicate that EDTA combined with ethyl lactate significantly enhanced the efficiency of willow in removing Cd from the soil. Therefore, a phytoextration system consisting of the autochthonous willow, EDTA, and ethyl lactate has high potential for the remediation of the Cd-polluted soil in the lower reaches of the Yangtze River.

  17. Unconventional cancer remedies.

    PubMed Central

    Danielson, K J; Stewart, D E; Lippert, G P

    1988-01-01

    Unproven and disproven remedies continue to abound for illnesses for which conventional treatment is only partially effective. This is particularly true with cancer, for which up to 50% of patients may be receiving unorthodox therapy. This article examines unconventional cancer remedies, their adverse effects, their common factors and the basis for their appeal, as well as what motivates and characterizes patients who choose these treatments. Also discussed is an approach that may be used by the conventional physician for patients who are likely to seek unorthodox treatment. This approach will help patients make the best decision about their treatment and protect them from the hazards of unconventional remedies. PMID:3285984

  18. Enhancing our understanding of anatomical diversity in Tomentella ectomycorrhizas: characterization of six new morphotypes.

    PubMed

    Jakucs, Erzsébet; Erős-Honti, Zsolt; Seress, Diána; Kovács, Gábor M

    2015-08-01

    Ectomycorrhizas (ECM) formed by Tomentella species (Thelephorales, Basidiomycota) were collected in beech forests of Hungary and studied using anatomical and molecular phylogenetic methods. The mycobionts were identified by analysing the sequences of nuclear ribosomal DNA (nrDNA) internal transcribed spacer (ITS) regions together with sequences obtained from public databases. At the sampling plots, we found the occurrence of 11 Tomentella morphotypes. Among these, six morphotypes (four identified, Tomentella atroarenicolor, Tomentella bryophila, Tomentella lapida, Tomentella subclavigera, and two unidentified) were morpho-anatomically characterized for the first time. Although the six morphotypes differed anatomically from each other and from Tomentella ectomycorrhizas described previously, they shared anatomical features common to tomentelloid ectomycorrhizas fungi. These results expand our understanding of the diversity of this widely distributed ectomycorrhizal genus.

  19. Enhancing the Educational Environment for Diverse Nursing Students Through Mentoring and Shared Governance.

    PubMed

    Latham, Christine L; Singh, Harsimran; Ringl, Karen K

    2016-11-01

    A structured peer-mentoring program for diverse nursing students culminated in shared governance meetings between mentors and program coordinators to address mentees' concerns and issues. After informed consent, mentees reviewed mentor profiles online and selected mentors. Baseline data were collected on ethnic identity, lifestyle, social support, and academic habits. Outcome data included mentors' self-reflective journal themes and student satisfaction surveys and focus group evaluation of the program. Students reported weak scores in the areas of wellness, exercise, and stress management. Journaling revealed valuable information about challenges faced by mentees that could impair their success. Mentors' proactive suggestions to handle major mentee journal themes were shared with nursing school administrators using a shared governance approach. The mentoring program supported students and culminated in a shared governance process to discuss ways to address mentee challenges that might improve the educational environment for future students. [J Nurs Educ. 2016;55(11):605-614.]. Copyright 2016, SLACK Incorporated.

  20. Sex Differences in Workplace Satisfaction and Engagement of Academic Pathologists: Opportunities to Enhance Faculty Diversity.

    PubMed

    Howell, Lydia Pleotis; Lyons, Mary Lipscomb; Thor, Ann; Dandar, Valerie

    2015-07-01

    There is attrition of women across professorial ranks in academic pathology. Women are underrepresented as leaders; 15.4% of academic pathology departments are chaired by women, according to the Association of American Medical Colleges (AAMC). To identify areas for targeted interventions that can advance academic and leadership development of women faculty by examining (1) sex differences in career satisfaction in US medical school pathology departments participating in the AAMC's Faculty Forward Engagement Survey, and (2) findings from a survey of the Association of Pathology Chairs (APC). The AAMC Faculty Forward Engagement Survey data are from 14 US medical schools participating in the 2011-2012 survey. Pathologists' response rate was 66% (461 of 697). To investigate sex differences, t tests and χ(2) analyses were used. The APC survey, administered to academic department chairs, had a 55% response rate (104 of 189). According to the Faculty Forward Engagement Survey, women report more time in patient care and less time in research. Women consider formal mentorship, feedback, and career advancement more important than men do and are less satisfied with communication and governance. The APC survey shows that 20% to 40% of nonchair department leaders are women. More than half of chairs report satisfaction with the sex diversity of their departmental leaders. Opportunities exist for department chairs and professional organizations to create targeted interventions to support career satisfaction, recruitment, retention, and career and leadership development for women in academic pathology. Although chairs report satisfaction with diversity within department leadership, responses of women faculty indicate there is work to be done to grow more women leaders.

  1. Coupled enhancer and coding sequence evolution of a homeobox gene shaped leaf diversity

    PubMed Central

    Vuolo, Francesco; Mentink, Remco A.; Hajheidari, Mohsen; Bailey, C. Donovan; Filatov, Dmitry A.; Tsiantis, Miltos

    2016-01-01

    Here we investigate mechanisms underlying the diversification of biological forms using crucifer leaf shape as an example. We show that evolution of an enhancer element in the homeobox gene REDUCED COMPLEXITY (RCO) altered leaf shape by changing gene expression from the distal leaf blade to its base. A single amino acid substitution evolved together with this regulatory change, which reduced RCO protein stability, preventing pleiotropic effects caused by its altered gene expression. We detected hallmarks of positive selection in these evolved regulatory and coding sequence variants and showed that modulating RCO activity can improve plant physiological performance. Therefore, interplay between enhancer and coding sequence evolution created a potentially adaptive path for morphological evolution. PMID:27852629

  2. Neurophysiological Evidence for Remediation of Reward Processing Deficits in Chronic Pain and Opioid Misuse Following Treatment with Mindfulness-Oriented Recovery Enhancement: Exploratory ERP Findings from a Pilot RCT

    PubMed Central

    Garland, Eric L.; Froeliger, Brett; Howard, Matthew O.

    2014-01-01

    Dysregulated processing of natural rewards may be a central pathogenic process in the etiology and maintenance of prescription opioid misuse and addiction among chronic pain patients. This study examined whether a Mindfulness-Oriented Recovery Enhancement (MORE) intervention could enhance natural reward processing through training in savoring as indicated by event-related brain potentials (ERPs). Participants were chronic pain patients at risk for opioid misuse who were randomized to eight weeks of MORE (n=11) or a support group control condition (n=18). ERPs to images representing naturally rewarding stimuli (e.g., beautiful landscapes, intimate couples) and neutral images were measured before and after 8 weeks of treatment. Analyses focused on the late positive potential (LPP) - an ERP response in the 400 – 1000 ms time window thought to index allocation of attention to emotional information. Treatment with MORE was associated with significant increases in LPP response to natural reward stimuli relative to neutral stimuli which were correlated with enhanced positive affective cue-responses and reductions in opioid craving from pre- to post-treatment. Findings suggest that cognitive training regimens centered on strengthening attention to natural rewards may remediate reward processing deficits underpinning addictive behavior. PMID:25385024

  3. Superfund Green Remediation

    EPA Pesticide Factsheets

    Green remediation is the practice of considering all environmental effects of site cleanup and incorporating options – like the use of renewable energy resources – to maximize the environmental benefits of cleanups.

  4. Superfund Green Remediation

    EPA Pesticide Factsheets

    Green remediation is the practice of considering all environmental effects of site cleanup and incorporating options – like the use of renewable energy resources – to maximize the environmental benefits of cleanups.

  5. Remediating Common Math Errors.

    ERIC Educational Resources Information Center

    Wagner, Rudolph F.

    1981-01-01

    Explanations and remediation suggestions for five types of mathematics errors due either to perceptual or cognitive difficulties are given. Error types include directionality problems, mirror writing, visually misperceived signs, diagnosed directionality problems, and mixed process errors. (CL)

  6. Other Remedy Options Evaluated

    EPA Pesticide Factsheets

    EPA considered several remedy options for reducing emissions from electric generating units (EGUs) that contribute significantly to nonattainment or interfere with maintenance of the air quality standards by downwind states.

  7. REMEDIATION OF CONTAMINATED SOILS BY SOLVENT FLUSHING

    EPA Science Inventory

    Solvent flushing is a potential technique for remediating a waste disposal/spill site contaminated with organic chemicals. This technique involves the injection of a solvent mixture (e.g., water plus alcohols) that enhances contaminant solubility, reduces the retardation factor, ...

  8. REMEDIATION OF CONTAMINATED SOILS BY SOLVENT FLUSHING

    EPA Science Inventory

    Solvent flushing is a potential technique for remediating a waste disposal/spill site contaminated with organic chemicals. This technique involves the injection of a solvent mixture (e.g., water plus alcohols) that enhances contaminant solubility, reduces the retardation factor, ...

  9. Sustainable multistage process for enhanced productivity of bioplastics from waste remediation through aerobic dynamic feeding strategy: Process integration for up-scaling.

    PubMed

    Amulya, K; Jukuri, Srinivas; Venkata Mohan, S

    2015-01-01

    Polyhydroxyalkanoates (PHA) production was evaluated in a multistage operation using food waste as a renewable feedstock. The first step involved the production of bio-hydrogen (bio-H2) via acidogenic fermentation. Volatile fatty acid (VFA) rich effluent from bio-H2 reactor was subsequently used for PHA production, which was carried out in two stages, Stage II (culture enrichment) and Stage III (PHA production). PHA-storing microorganisms were enriched in a sequencing batch reactor (SBR), operated at two different cycle lengths (CL-24; CL-12). Higher polymer recovery as well as VFA removal was achieved in CL-12 operation both in Stage II (16.3% dry cell weight (DCW); VFA removal, 84%) and Stage III (23.7% DCW; VFA removal, 88%). The PHA obtained was a co-polymer [P(3HB-co-3HV)] of PHB and PHV. The results obtained indicate that this integrated multistage process offers new opportunities to further leverage large scale PHA production with simultaneous waste remediation in the framework of biorefinery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. A Ten-Year Retrospective Look at the NSF/GEO Opportunities for Enhancing Diversity in the Geosciences (OEDG) Program

    NASA Astrophysics Data System (ADS)

    Karsten, J. L.

    2013-12-01

    The Opportunities for Enhancing Diversity in the Geosciences (OEDG) program - established in 2002 by the National Science Foundation's Directorate for Geosciences (GEO) - has been a mainstay in GEO's efforts to broaden participation of traditionally underrepresented minorities in the geosciences. The primary goal of the OEDG program has been to engage a diverse population of students in learning about - and pursuing advanced degrees and careers in - the geosciences. Raising public awareness of the importance and relevance of the geosciences among diverse audiences has been a secondary goal. During the past decade, the OEDG program has supported a variety of planning grants, proof-of-concept projects, and larger full-scale implementation efforts across the U.S. These projects have contributed a rich array of culturally-tailored resources for learning about geoscience career pathways and opportunities to participate in geoscience research experiences. OEDG has also developed networking and mentoring programs tailored for diverse student audiences, as well as the educators who work with them, and has helped to build capacity in the geosciences at minority-serving institutions. Perhaps the most important legacy of the OEDG program has been the establishment of an enthusiastic and effective community of educators, administrators, students and organizations dedicated to increasing diversity in the geosciences. Evaluation data collected for individual OEDG projects has helped to improve the impact of specific projects and increase our understanding of which approaches are more successful in achieving OEDG program goals. In addition, GEO has supported a decade-long, program-wide evaluation of the OEDG portfolio through a contract to the American Institutes for Research (AIR). Synthesis of results from both the project- and program-level evaluation activities has identified evidence-based 'best practices' that are essential for achieving success in broadening participation

  11. A Call for Training the Trainers: Focus on Mentoring to Enhance Diversity in Mental Health Research

    PubMed Central

    Twamley, Elizabeth W.; Cardenas, Veronica; Lebowitz, Barry; Reynolds, Charles F.

    2009-01-01

    There is a widening disparity between the proportion of ethnic minority Americans in the population and the number of researchers from these minority groups. One major obstacle in this arena relates to a dearth of mentors for such trainees. The present academic settings are not optimal for development and sustenance of research mentors, especially for mentees from underrepresented minority ethnic groups. Mentoring skills can and should be evaluated and enhanced. Universities, medical schools, and funding agencies need to join hands and implement national- and local-level programs to help develop and reward mentors of junior scientists from ethnic minority groups. PMID:19246662

  12. Environmental Remediation Data Management Tools

    SciTech Connect

    Wierowski, J. V.; Henry, L. G.; Dooley, D. A.

    2002-02-26

    Computer software tools for data management can improve site characterization, planning and execution of remediation projects. This paper discusses the use of two such products that have primarily been used within the nuclear power industry to enhance the capabilities of radiation protection department operations. Advances in digital imaging, web application development and programming technologies have made development of these tools possible. The Interactive Visual Tour System (IVTS) allows the user to easily create and maintain a comprehensive catalog containing digital pictures of the remediation site. Pictures can be cataloged in groups (termed ''tours'') that can be organized either chronologically or spatially. Spatial organization enables the user to ''walk around'' the site and view desired areas or components instantly. Each photo is linked to a map (floor plan, topographical map, elevation drawing, etc.) with graphics displaying the location on the map and any available tour/component links. Chronological organization enables the user to view the physical results of the remediation efforts over time. Local and remote management teams can view these pictures at any time and from any location. The Visual Survey Data System (VSDS) allows users to record survey and sample data directly on photos and/or maps of areas and/or components. As survey information is collected for each area, survey data trends can be reviewed for any repetitively measured location or component. All data is stored in a Quality Assurance (Q/A) records database with reference to its physical sampling point on the site as well as other information to support the final closeout report for the site. The ease of use of these web-based products has allowed nuclear power plant clients to plan outage work from their desktop and realize significant savings with respect to dose and cost. These same tools are invaluable for remediation and decommissioning planning of any scale and for recording

  13. Experience matters: prior exposure to plant toxins enhances diversity of gut microbes in herbivores.

    PubMed

    Kohl, Kevin D; Dearing, M D

    2012-09-01

    For decades, ecologists have hypothesised that exposure to plant secondary compounds (PSCs) modifies herbivore-associated microbial community composition. This notion has not been critically evaluated in wild mammalian herbivores on evolutionary timescales. We investigated responses of the microbial communities of two woodrat species (Neotoma bryanti and N. lepida). For each species, we compared experienced populations that independently converged to feed on the same toxic plant (creosote bush, Larrea tridentata) to naïve populations with no exposure to creosote toxins. The addition of dietary PSCs significantly altered gut microbial community structure, and the response was dependent on previous experience. Microbial diversity and relative abundances of several dominant phyla increased in experienced woodrats in response to PSCs; however, opposite effects were observed in naïve woodrats. These differential responses were convergent in experienced populations of both species. We hypothesise that adaptation of the foregut microbiota to creosote PSCs in experienced woodrats drives this differential response. © 2012 Blackwell Publishing Ltd/CNRS.

  14. Enhancing attachment security in the infants of women in a jail-diversion program.

    PubMed

    Cassidy, Jude; Ziv, Yair; Stupica, Brandi; Sherman, Laura J; Butler, Heidi; Karfgin, Andrea; Cooper, Glen; Hoffman, Kent T; Powell, Bert

    2010-07-01

    Pregnant female offenders face multiple adversities that make successful parenting difficult. As a result, their children are at risk of developing insecure attachment and attachment disorganization, both of which are associated with an increased likelihood of poor developmental outcomes. We evaluated the outcomes of participants in Tamar's Children, a 15-month jail-diversion intervention for pregnant, nonviolent offenders with a history of substance abuse. All women received extensive wrap-around social services as well as the Circle of Security Perinatal Protocol (Cooper, Hoffman, & Powell, 2003). We present data on 20 women and their infants who completed the full dosage of treatment (a residential-living phase from pregnancy until infant age six months and community-living phase until 12 months). Results indicated that (1) program infants had rates of attachment security and attachment disorganization comparable to rates typically found in low-risk samples (and more favorable than those typically found in high-risk samples); (2) program mothers had levels of maternal sensitivity comparable to mothers in an existing community comparison group; and (3) improvement over time emerged for maternal depressive symptomatology, but not other aspects of maternal functioning. Given the lack of a randomized control group, results are discussed in terms of the exploratory, program-development nature of the study.

  15. A gonogenic stimulated transition of mouse embryonic stem cells with enhanced control of diverse differentiation pathways

    PubMed Central

    Moshfegh, Cameron; Aires, Lina; Kisielow, Malgorzata; Vogel, Viola

    2016-01-01

    Embryonic stem (ES) cells share markers with undifferentiated primordial germ cells (PGCs). Here, we discovered that a cellular state with some molecular markers of male gonocyte induction, including a G1/S phase arrest and upregulation of specific genes such as Nanos2, Tdrd1, Ddx4, Zbtb16 and Plk1s1, can be chemically induced in male mouse ES cells in vitro, which we termed gonogenic stimulated transition (GoST). After longer culture of the resulting GoST cells without chemical stimulation, several molecular markers typical for early gonocytes were detected including the early gonocyte marker Tex101. Motivated by previous studies that found multipotency in cell lines derived from neonatal male germ cells in vitro, we then compared the differentiation potential of GoST cells to that of ES cells in vitro. Interestingly, GoST cells showed equal neurogenic, but enhanced cardiogenic and hepatogenic differentiation compared to ES cells in vitro. This work shows for the first time that some important molecular markers of the first developmental sexual differentiation program can be induced in male mouse ES cells in vitro and defines a novel concept to generate cells with enhanced multipotency. PMID:27157261

  16. Pyrosequencing reveals highly diverse microbial communities in microbial electrolysis cells involved in enhanced H2 production from waste activated sludge.

    PubMed

    Lu, Lu; Xing, Defeng; Ren, Nanqi

    2012-05-01

    Renewable H(2) production from a plentiful biomass, waste activated sludge (WAS), can be achieved by fermentation, but the yields are low. The use of a microbial electrolysis cell (MEC) can increase the H(2) production yields to several times that of fermentation. We have proved that the enhancement of H(2) production was due to the ability of MECs to use a wider range of organic matter in WAS than in fermentation. To support this result strongly, we here investigated the microbial community structures of WAS and anode biofilms in WAS-fed MECs. A pyrosequencing analysis based on the bacterial 16S rRNA gene showed that dominant populations in MECs were more diverse than those in WAS (inoculum and substrate) after enrichment, and there was a clear distinction between MECs and WAS in microbial community structure. Diverse acid-producing bacteria and exoelectrogens (predominance of Geobacter) were detected in MECs but they were only rarely found in WAS. It has been reported that these acid-producing bacteria can ferment various sugars and amines with acetate, propionate, and butyrate as their major by-products. This was consistent with our chemical analyses. Detected exoelectrogens are known to use these organic acids (mainly acetate) and certain sugars to directly produce current for H(2) generation at the cathodes in the MECs. Using quantitative real-time PCR, we demonstrated that a consistent feed of alkaline-pretreated WAS containing large amounts of acetate led to a predominance of acetoclastic methanogens, while hydrogenotrophic methanogens were abundant in MECs fed both raw and alkaline-pretreated WAS. Syntrophic interactions between phylogenetically diverse microbial populations in anodophilic biofilms were found to drive the efficient cascade utilization of organic matter in WAS.

  17. Green Remediation Best Management Practices: Implementing In Situ Thermal Technologies

    EPA Pesticide Factsheets

    Over recent years, the use of in situ thermal technologies such as electrical resistance heating, thermal conductive heating, and steam enhanced extraction to remediate contaminated sites has notably increased.

  18. Queerin' the PGD clinic : human enhancement and the future of bodily diversity.

    PubMed

    Sparrow, Robert

    2013-06-01

    Disability activists influenced by queer theory and advocates of "human enhancement" have each disputed the idea that what is "normal" is normatively significant, which currently plays a key role in the regulation of pre-implantation genetic diagnosis (PGD). Previously, I have argued that the only way to avoid the implication that parents have strong reasons to select children of one sex (most plausibly, female) over the other is to affirm the moral significance of sexually dimorphic human biological norms. After outlining the logic that generates this conclusion, I investigate the extent to which it might also facilitate an alternative, progressive, opening up of the notion of the normal and of the criteria against which we should evaluate the relative merits of different forms of embodiment. This paper therefore investigates the implications of ideas derived from queer theory for the future of PGD and of PGD for the future of queerness.

  19. Hanford Groundwater Remediation

    SciTech Connect

    Charboneau, B.; Thompson, K. M.; Wilde, R.; Ford, B.; Gerber, M.

    2006-07-01

    By 1990 nearly 50 years of producing plutonium put approximately 1.70 E+12 liters (450 billion gallons) of liquid wastes into the soil of the 1,518-square kilometer (586-square mile) Hanford Site in southeast Washington State. The liquid releases consisted of chemicals used in laboratory experiments, manufacturing and rinsing uranium fuel, dissolving that fuel after irradiation in Hanford's nuclear reactors, and in liquefying plutonium scraps needed to feed other plutonium-processing operations. Chemicals were also added to the water used to cool Hanford's reactors to prevent corrosion in the reactor tubes. In addition, water and acid rinses were used to clean plutonium deposits from piping in Hanford's large radiochemical facilities. All of these chemicals became contaminated with radionuclides. As Hanford raced to help win World War II, and then raced to produce materials for the Cold War, these radioactive liquid wastes were released to the Site's sandy soils. Early scientific experiments seemed to show that the most highly radioactive components of these liquids would bind to the soil just below the surface of the land, thus posing no threat to groundwater. Other experiments predicted that the water containing most radionuclides would take hundreds of years to seep into groundwater, decaying (or losing) most of its radioactivity before reaching the groundwater or subsequently flowing into the Columbia River, although it was known that some contaminants like tritium would move quickly. Evidence today, however, shows that many contaminants have reached the Site's groundwater and the Columbia River, with more on its way. Over 259 square kilometers (100 square miles) of groundwater at Hanford have contaminant levels above drinking-water standards. Also key to successfully cleaning up the Site is providing information resources and public-involvement opportunities to Hanford's stakeholders. This large, passionate, diverse, and geographically dispersed community is

  20. HANFORD GROUNDWATER REMEDIATION

    SciTech Connect

    CHARBONEAU, B; THOMPSON, M; WILDE, R.; FORD, B.; GERBER, M.S.

    2006-02-01

    By 1990 nearly 50 years of producing plutonium put approximately 1.70E + 12 liters (450 billion gallons) of liquid wastes into the soil of the 1,518-square kilometer (586-square mile) Hanford Site in southeast Washington State. The liquid releases consisted of chemicals used in laboratory experiments, manufacturing and rinsing uranium fuel, dissolving that fuel after irradiation in Hanford's nuclear reactors, and in liquefying plutonium scraps needed to feed other plutonium-processing operations. Chemicals were also added to the water used to cool Hanford's reactors to prevent corrosion in the reactor tubes. In addition, water and acid rinses were used to clean plutonium deposits from piping in Hanford's large radiochemical facilities. All of these chemicals became contaminated with radionuclides. As Hanford raced to help win World War II, and then raced to produce materials for the Cold War, these radioactive liquid wastes were released to the Site's sandy soils. Early scientific experiments seemed to show that the most highly radioactive components of these liquids would bind to the soil just below the surface of the land, thus posing no threat to groundwater. Other experiments predicted that the water containing most radionuclides would take hundreds of years to seep into groundwater, decaying (or losing) most of its radioactivity before reaching the groundwater or subsequently flowing into the Columbia River, although it was known that some contaminants like tritium would move quickly. Evidence today, however, shows that many contaminants have reached the Site's groundwater and the Columbia River, with more on its way. Over 259 square kilometers (100 square miles) of groundwater at Hanford have contaminant levels above drinking-water standards. Also key to successfully cleaning up the Site is providing information resources and public-involvement opportunities to Hanford's stakeholders. This large, passionate, diverse, and geographically dispersed community is

  1. Neurophysiological evidence for remediation of reward processing deficits in chronic pain and opioid misuse following treatment with Mindfulness-Oriented Recovery Enhancement: exploratory ERP findings from a pilot RCT.

    PubMed

    Garland, Eric L; Froeliger, Brett; Howard, Matthew O

    2015-04-01

    Dysregulated processing of natural rewards may be a central pathogenic process in the etiology and maintenance of prescription opioid misuse and addiction among chronic pain patients. This study examined whether a Mindfulness-Oriented Recovery Enhancement (MORE) intervention could augment natural reward processing through training in savoring as indicated by event-related brain potentials (ERPs). Participants were chronic pain patients at risk for opioid misuse who were randomized to 8 weeks of MORE (n = 11) or a support group control condition (n = 18). ERPs to images representing naturally rewarding stimuli (e.g., beautiful landscapes, intimate couples) and neutral images were measured before and after 8 weeks of treatment. Analyses focused on the late positive potential (LPP)--an ERP response in the 400-1,000 ms time window thought to index allocation of attention to emotional information. Treatment with MORE was associated with significant increases in LPP response to natural reward stimuli relative to neutral stimuli which were correlated with enhanced positive affective cue-responses and reductions in opioid craving from pre- to post-treatment. Findings suggest that cognitive training regimens centered on strengthening attention to natural rewards may remediate reward processing deficits underpinning addictive behavior.

  2. Uneven-aged silviculture can enhance within stand heterogeneity and beetle diversity.

    PubMed

    Joelsson, Klara; Hjältén, Joakim; Work, Timothy

    2017-09-26

    more diverse assemblages at the stand level than would otherwise be seen in less heterogeneous stand types. This suggests that uneven-aged silviculture may provide added conservation benefits for both open habitat and old-growth specialists than silvicultural approaches that reduce stand heterogeneity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Evolution of Newcastle Disease Virus Quasispecies Diversity and Enhanced Virulence after Passage through Chicken Air Sacs

    PubMed Central

    Meng, Chunchun; Qiu, Xusheng; Yu, Shengqing; Li, Chuanfeng; Sun, Yingjie; Chen, Zongyan; Liu, Kaichun; Zhang, Xiangle; Tan, Lei; Song, Cuiping; Liu, Guangqing

    2015-01-01

    ABSTRACT It has been reported that lentogenic Newcastle disease virus (NDV) isolates have the potential to become velogenic after their transmission and circulation in chickens, but the underlying mechanism is unclear. In this study, a highly velogenic NDV variant, JS10-A10, was generated from the duck-origin lentogenic isolate JS10 through 10 consecutive passages in chicken air sacs. The velogenic properties of this selected variant were determined using mean death time (MDT) assays, intracerebral pathogenicity index (ICPI), the intravenous pathogenicity index (IVPI), histopathology, and the analysis of host tissue tropism. In contrast, JS10 remained lentogenic after 20 serial passages in chicken eggs (JS10-E20). The JS10, JS10-A10, and JS10-E20 genomes were sequenced and found to be nearly identical, suggesting that both JS10-A10 and JS10-E20 were directly generated from JS10. To investigate the mechanism for virulence enhancement, the partial genome covering the F0 cleavage site of JS10 and its variants were analyzed using ultradeep pyrosequencing (UDPS) and the proportions of virulence-related genomes in the quasispecies were calculated. Velogenic NDV genomes accumulated as a function of JS10 passaging through chicken air sacs. Our data suggest that lentogenic NDV strains circulating among poultry might be a risk factor to future potential velogenic NDV outbreaks in chickens. IMPORTANCE An avirulent isolate, JS10, was passaged through chicken air sacs and embryos, and the pathogenicity of the variants was assessed. A virulent variant, JS10-A10, was generated from consecutive passage in air sacs. We developed a deep-sequencing approach to detect low-frequency viral variants across the NDV genome. We observed that virulence enhancement of JS10 was due to the selective accumulation of velogenic quasispecies and the concomitant disappearance of lentogenic quasispecies. Our results suggest that because it is difficult to avoid contact between natural waterfowl

  4. Effect of electrokinetic remediation on indigenous microbial activity and community within diesel contaminated soil.

    PubMed

    Kim, Seong-Hye; Han, Hyo-Yeol; Lee, You-Jin; Kim, Chul Woong; Yang, Ji-Won

    2010-07-15

    Electrokinetic remediation has been successfully used to remove organic contaminants and heavy metals within soil. The electrokinetic process changes basic soil properties, but little is known about the impact of this remediation technology on indigenous soil microbial activities. This study reports on the effects of electrokinetic remediation on indigenous microbial activity and community within diesel contaminated soil. The main removal mechanism of diesel was electroosmosis and most of the bacteria were transported by electroosmosis. After 25 days of electrokinetic remediation (0.63 mA cm(-2)), soil pH developed from pH 3.5 near the anode to pH 10.8 near the cathode. The soil pH change by electrokinetics reduced microbial cell number and microbial diversity. Especially the number of culturable bacteria decreased significantly and only Bacillus and strains in Bacillales were found as culturable bacteria. The use of EDTA as an electrolyte seemed to have detrimental effects on the soil microbial activity, particularly in the soil near the cathode. On the other hand, the soil dehydrogenase activity was enhanced close to the anode and the analysis of microbial community structure showed the increase of several microbial populations after electrokinetics. It is thought that the main causes of changes in microbial activities were soil pH and direct electric current. The results described here suggest that the application of electrokinetics can be a promising soil remediation technology if soil parameters, electric current, and electrolyte are suitably controlled based on the understanding of interaction between electrokinetics, contaminants, and indigenous microbial community.

  5. Functional organization of an Mbp enhancer exposes striking transcriptional regulatory diversity within myelinating glia.

    PubMed

    Dionne, Nancy; Dib, Samar; Finsen, Bente; Denarier, Eric; Kuhlmann, Tanja; Drouin, Régen; Kokoeva, Maia; Hudson, Thomas J; Siminovitch, Kathy; Friedman, Hana C; Peterson, Alan C

    2016-01-01

    In mammals, large caliber axons are ensheathed by myelin, a glial specialization supporting axon integrity and conferring accelerated and energy-efficient action potential conduction. Myelin basic protein (MBP) is required for normal myelin elaboration with maximal mbp transcription in oligodendrocytes requiring the upstream M3 enhancer. To further characterize the mechanism regulating mbp transcription, we defined M3 structure/function relationships by evaluating its evolutionary conservation, DNA footprints and the developmental programing conferred in mice by M3 derivatives. Multiple M3 regulatory element combinations were found to drive expression in oligodendrocytes and Schwann cells with a minimal 129 bp sequence conferring expression in oligodendrocytes throughout myelin elaboration, maintenance and repair. Unexpectedly, M3 derivatives conferred markedly different spatial and temporal expression programs thus illuminating striking transcriptional heterogeneity within post-mitotic oligodendrocytes. Finally, one M3 derivative engaged only during primary myelination, not during adult remyelination, demonstrating that transcriptional regulation in the two states is not equivalent. © 2015 Wiley Periodicals, Inc.

  6. Enhancement of microbial diversity and methane yield by bacterial bioaugmentation through the anaerobic digestion of Haematococcus pluvialis.

    PubMed

    Aydin, Sevcan

    2016-06-01

    Microalgae has recalcitrant cell walls that may limit digestibility and, therefore, reduce bioenergy production. In light of the fact that cellulose can increase the cell wall recalcitrance of the Haematococcus pluvialis species of microalgae, the objective of this research was to examine how bioaugmentation with the Clostridium thermocellum at various inoculum ratios represents a viable method by which the CH4 production of microalgae can be enhanced. The results of the investigation revealed that bioaugmentation with C. thermocellum increased the degradation of H. pluvialis biomass and resulted in a 18-38 % increase in methane production as a result of increased cell disruption. In addition, the use of Illumina Miseq sequencing highlighted that the bacterial and archaeal diversity and quantities in the genus were enhanced as a result of the addition of C. thermocellum and this, in itself, improved the efficiency of the biodegradation. Bioaugmentation with C. thermocellum (%15) was also determined to represent the most energy-efficiency method of producing methane.

  7. Integration of biotechnology in remediation and pollution prevention activities

    SciTech Connect

    Strong-Gunderson, J.M.

    1996-02-01

    The North American Free Trade Agreement/North American Agreement on Environmental Cooperation provides a mechanism for an international collaboration between the US, Canada, and Mexico to jointly develop, modify, or refine technologies that remediate or protect the environment. These countries have a vested interest in this type of collaboration because contaminants do not respect the boundaries of a manufacturing site, region, city, state, or country. The Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) consists of a diverse group of individuals who address a variety of environmental issues. ESD is involved in basic and applied research on the fate, transport, and remediation of contaminants; environmental assessment; environmental engineering; and demonstrations of advanced remediation technologies. The remediation and protection of the environment includes water, air, and soils for organic, inorganic, and radioactive contaminants. In addition to remediating contaminated sites, research also focuses on life-cycle analyses of industrial processes and the production of green technologies. The author focuses this discussion on subsurface remediation and pollution prevention; however, the research activities encompass water, soil and air and many of the technologies are applicable to all environments. The discussion focuses on the integration of biotechnology with remediation activities and subsequently linking these biological processes to other remediation technologies.

  8. Remediation; An overview

    SciTech Connect

    Bishop, J.

    1988-09-01

    The U.SD. government began committing the nation legally and financially in the last decade to the ultimate remediation of virtually all of the hazardous wastes that were produced in the past and remain to threaten human health and the environment, all that continue to be generated, and all that will be created in the future. Whether engendered by acts of God or human industry, the laws and regulations mandate, hazardous wastes and the threats they pose will be removed or rendered harmless. As mobilization for tackling the monumental task implied by those commitments has progressed, key concepts have changed in meaning. The remedy of remediation once literally meant burying our hazardous waste problems in landfills, for example, a solution now officially defined as the least desirable-although still commonly chosen - course of action. The process of identifying hazardous substances and determining in what quantities they constitute health and environmental hazards continues apace. As measurement technologies become increasingly precise and capable to detecting more 9s to the right of the decimal point, acceptable levels of emissions into the air and concentrations in the ground or water are reduced. This article is intended as a sketch of where the national commitment of remediation currently stands, with examples of implications for both generators of hazardous wastes and those who have entered-or seek to enter-the rapidly growing business of remediation.

  9. Does agricultural crop diversity enhance soil microbial biomass and organic matter dynamics? A meta-analysis.

    PubMed

    McDaniel, M D; Tiemann, L K; Grandy, A S

    2014-04-01

    Our increasing dependence on a small number of agricultural crops, such as corn, is leading to reductions in agricultural biodiversity. Reductions in the number of crops in rotation or the replacement of rotations by monocultures are responsible for this loss of biodiversity. The belowground implications of simplifying agricultural plant communities remain unresolved; however, agroecosystem sustainability will be severely compromised if reductions in biodiversity reduce soil C and N concentrations, alter microbial communities, and degrade soil ecosystem functions as reported in natural communities. We conducted a meta-analysis of 122 studies to examine crop rotation effects on total soil C and N concentrations, and the faster cycling microbial biomass C and N pools that play key roles in soil nutrient cycling and physical processes such as aggregate formation. We specifically examined how rotation crop type and management practices influence C and N dynamics in different climates and soil types. We found that adding one or more crops in rotation to a monoculture increased total soil C by 3.6% and total N by 5.3%, but when rotations included a cover crop (i.e., crops that are not harvested but produced to enrich the soil and capture inorganic N), total C increased by 8.5% and total N 12.8%. Rotations substantially increased the soil microbial biomass C (20.7%) and N (26.1%) pools, and these overwhelming effects on microbial biomass were not moderated by crop type or management practices. Crop rotations, especially those that include cover crops, sustain soil quality and productivity by enhancing soil C, N, and microbial biomass, making them a cornerstone for sustainable agroecosystems.

  10. Enhanced summer warming reduces fungal decomposer diversity and litter mass loss more strongly in dry than in wet tundra.

    PubMed

    Christiansen, Casper T; Haugwitz, Merian S; Priemé, Anders; Nielsen, Cecilie S; Elberling, Bo; Michelsen, Anders; Grogan, Paul; Blok, Daan

    2017-01-01

    Many Arctic regions are currently experiencing substantial summer and winter climate changes. Litter decomposition is a fundamental component of ecosystem carbon and nutrient cycles, with fungi being among the primary decomposers. To assess the impacts of seasonal climatic changes on litter fungal communities and their functioning, Betula glandulosa leaf litter was surface-incubated in two adjacent low Arctic sites with contrasting soil moisture regimes: dry shrub heath and wet sedge tundra at Disko Island, Greenland. At both sites, we investigated the impacts of factorial combinations of enhanced summer warming (using open-top chambers; OTCs) and deepened snow (using snow fences) on surface litter mass loss, chemistry and fungal decomposer communities after approximately 1 year. Enhanced summer warming significantly restricted litter mass loss by 32% in the dry and 17% in the wet site. Litter moisture content was significantly reduced by summer warming in the dry, but not in the wet site. Likewise, fungal total abundance and diversity were reduced by OTC warming at the dry site, while comparatively modest warming effects were observed in the wet site. These results suggest that increased evapotranspiration in the OTC plots lowered litter moisture content to the point where fungal decomposition activities became inhibited. In contrast, snow addition enhanced fungal abundance in both sites but did not significantly affect litter mass loss rates. Across sites, control plots only shared 15% of their fungal phylotypes, suggesting strong local controls on fungal decomposer community composition. Nevertheless, fungal community functioning (litter decomposition) was negatively affected by warming in both sites. We conclude that although buried soil organic matter decomposition is widely expected to increase with future summer warming, surface litter decay and nutrient turnover rates in both xeric and relatively moist tundra are likely to be significantly restricted by

  11. Enhancing Ocean Literacy and Expertise of Diverse Populations via Graduate School Fellowship Opportunities

    NASA Astrophysics Data System (ADS)

    Mayo, M.; Ithier-Guzman, W.; Pyrtle, A. J.; Betzer, P.; Batson, B.; Bhansali, S.; Greene, B.; Turner, R.

    2007-05-01

    In 2004, the University of South Florida (USF) was granted by the National Science Foundation a Louis Stokes Alliance for Minority Participation (LSAMP) Bridge to the Doctorate (BD) site award (HRD# 0217675). As part of the Florida-Georgia Louis Stokes Alliance for Minority Participation (FGLSAMP), USF is one of thirteen institutions in an alliance that is dedicated to significantly increasing the number of underrepresented minority students who obtain undergraduate and graduate STEM degrees. The BD program at USF incorporates the goals of FGLSAMP and facilitates the recruitment of underrepresented minorities pursuing careers in the STEM fields at the graduate level. The thematic focus of the FGLSAMP USF BD program is focused on the development and application of biogeochemical sensors for marine, aquatic, environmental, remote sensing and biomedical applications. After recruitment, BD graduate fellowship recipients are provided with NSF-funded financial support for two years, and opportunities to participate in professional development workshops, seminars and short courses, as well as additional financial support to pursue and complete their doctoral studies (beyond the initial two years of NSF BD funding), in a variety of forms, including, but not limited to, Alfred P. Sloan Minority Scholarships, Florida Education Fund's McKnight Doctoral Fellowships, USF College of Graduate Studies Fellowships, USF CMS endowed fellowships, USF CMS research assistantships, and USF CMS teaching assistantships. Collectively, 3 LSAMP BD grants have been awarded at USF to support 56 underrepresented minority fellowship recipients, of which 14 are currently graduate students at the USF College of Marine Science (CMS). Since the arrival of the BD Fellowship program, the graduate community has diversified, showing an increase of over 40% in underrepresented minorities at CMS. The BD program has enhanced the research and learning environment for all CMS students, as well as fostered a

  12. Solutions Remediate Contaminated Groundwater

    NASA Technical Reports Server (NTRS)

    2010-01-01

    During the Apollo Program, NASA workers used chlorinated solvents to clean rocket engine components at launch sites. These solvents, known as dense non-aqueous phase liquids, had contaminated launch facilities to the point of near-irreparability. Dr. Jacqueline Quinn and Dr. Kathleen Brooks Loftin of Kennedy Space Center partnered with researchers from the University of Central Florida's chemistry and engineering programs to develop technology capable of remediating the area without great cost or further environmental damage. They called the new invention Emulsified Zero-Valent Iron (EZVI). The groundwater remediation compound is cleaning up polluted areas all around the world and is, to date, NASA's most licensed technology.

  13. Diversity of LTR-retrotransposons and Enhancer/Suppressor Mutator-like transposons in cassava (Manihot esculenta Crantz).

    PubMed

    Gbadegesin, Michael A; Wills, Matthew A; Beeching, John R

    2008-10-01

    Cassava (Manihot esculenta Crantz), though a major world crop with enormous potential, is very under studied. Little is known about its genome structure and organisation. Transposable elements have a key role in the evolution of genome structure, and can be used as important tools in applied genetics. This paper sets out to survey the diversity of members of three major classes of transposable element within the cassava genome and in relation to similar elements in other plants. Members of two classes of LTR-retrotransposons, Ty1/copia-like and Ty3/gypsy-like, and of Enhancer/Suppressor Mutator (En/Spm)-like transposons were isolated and characterised. Analyses revealed 59 families of Ty1/copia, 26 families of Ty3/gypsy retrotransposons, and 40 families of En/Spm in the cassava genome. In the comparative analyses, the predicted amino acid sequences for these transposon classes were compared with those of related elements from other plant species. These revealed that there were multiple lineages of Ty1/copia-like retrotransposons in the genome of cassava and suggested that vertical and horizontal transmission as the source of cassava Mecops may not be mutually exclusive. For the Ty3/gypsy elements network, two groups of cassava Megyps were evident including the Arabidopsis Athila lineage. However, cassava En/Spm-like elements (Meens) constituted a single group within a network of plant En/Spm-like elements. Hybridisation analysis supported the presence of transposons in the genome of cassava in medium (Ty3/gypsy and En/Spm) to high (Ty1/copia) copy numbers. Thus the cassava genome was shown to contain diverse members of three major classes of transposable element; however, the different classes exhibited contrasting evolutionary histories.

  14. 13 CFR 108.1810 - Events of default and SBA's remedies for NMVC Company's noncompliance with terms of Debentures.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... substantive regulation promulgated under the Act. (9) Failure to maintain diversity. You fail to maintain diversity between management and ownership as required by § 108.150. (g) SBA remedies for events of default...

  15. Efficacy of CERCLA remedies in light of five-year reviews.

    SciTech Connect

    Hocking, E. K.; Martino, L.; Environmental Assessment

    2003-01-01

    Reviews of several remedies selected and implemented under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended, revealed deficiencies in remedy protectiveness although the remedy had only been in place for five years. Many of these deficiencies should have been foreseeable, and therefore preventable, at the time the remedy was selected. Analysis of successes and deficiencies noted in the CERCLA five-year reviews highlights the pivotal role that monitoring plans and land use controls have in ensuring remedy protectiveness. The analysis demonstrated that remedy protectiveness assessments and remedy modification justifications depend on robust site and remedy monitoring plans as well as on adequately developed conceptual site models. Comprehensive understanding and inferences regarding past, present, and future land and resource use at the remedy selection stage can enhance remedy protectiveness because stakeholders can determine if land use controls are necessary and if they can be implemented and enforced. The findings from this analysis of five-year reviews of remedy protectiveness are applicable to initial remedy selection decisions and subsequent enhancements of their effectiveness through time.

  16. COST OF MTBE REMEDIATION

    EPA Science Inventory

    Widespread contamination of methyl tert-butyl ether (MTBE) in ground water has raised concerns about the increased cost of remediation of MTBE releases compared to BTEX-only sites. To evaluate these cost, cost information for 311 sites was furnished by U.S. EPA Office of Undergr...

  17. Trade Remedies: A Primer

    DTIC Science & Technology

    2005-05-02

    ornamental fish, tilapia , monkfish).36 The European Union proposes to establish an additional 15% tariff on imports of certain women’s apparel, office...which reversed (continued...) ruling.39 Supporters of trade remedies, including many in Congress and domestic industry representatives, believe that

  18. COST OF MTBE REMEDIATION

    EPA Science Inventory

    Widespread contamination of methyl tert-butyl ether (MTBE) in ground water has raised concerns about the increased cost of remediation of MTBE releases compared to BTEX-only sites. To evaluate these cost, cost information for 311 sites was furnished by U.S. EPA Office of Undergr...

  19. Reading Diagnosis and Remediation.

    ERIC Educational Resources Information Center

    Strang, Ruth

    This monograph includes an extensive review and evaluation of the research literature and offers teachers and clinicians background for understanding reading diagnosis, the correlates and causes of reading disabilities, diagnostic techniques, and remediation. The following topics are discussed: (1) the nature and levels of diagnosis, (2) the…

  20. Lau Remedies Outlined.

    ERIC Educational Resources Information Center

    Cardenas, Jose A.

    The understanding of two principles is important if school districts are to develop comprehensive plans responsive to the Lau v. Nichols remedies specified by the Department of Health, Education, and Welfare (HEW) in ways that both adhere to the spirit of the Lau decision and allow the school district to develop coherent educational programs for…

  1. Modularizing Remedial Mathematics

    ERIC Educational Resources Information Center

    Wong, Aaron

    2013-01-01

    As remedial mathematics education has become an increasingly important topic of conversation in higher education. Mathematics departments have been put under increased pressure to change their programs to increase the student success rate. A number of models have been introduced over the last decade that represent a wide range of new ideas and…

  2. 2014 Ohio Remediation Report

    ERIC Educational Resources Information Center

    Ohio Board of Regents, 2014

    2014-01-01

    In fulfillment of Ohio Revised Code 3333.041 (A) (1) the Chancellor has published a listing by school district of the number of the 2013 high school graduates who attended a state institution of higher education in academic year 2013-2014 and the percentage of each district's graduates required by the institution to enroll in a remedial course in…

  3. Delivering Health Care to Refugees: Cross-Cultural Training To Enhance the Delivery of Quality Health Care to Culturally Diverse Persons.

    ERIC Educational Resources Information Center

    Dunn, David, Ed.

    This manual was written for both health care professionals and community leaders wishing to work together to enhance the availability of culturally appropriate health care services for refugees. The material is also relevant to people who wish to develop the sensitivity and skill needed to serve any culturally diverse clientele. The booklet…

  4. The Use of Ecological Restoration Principles To Achieve Remedy Protection At the Fernald Preserve and Weldon Spring Sites

    SciTech Connect

    Powell, J.; Johnston, F.; Homer, J.; Deyo, Y.

    2008-07-01

    At both the Fernald Preserve and the Weldon Spring Site, the development of ecological restoration goals and objectives was used to complement and even enhance achievement of selected remedies. Warm-season native grasses and forbs were used for revegetation of remediated areas. The hardiness and ability to establish in low-nutrient conditions make native grasses ideal candidates for reestablishment of vegetation in excavated areas. At the Fernald Preserve, native grasses were used for vegetative cover on an on-site disposal facility as well. Also at the Fernald Preserve, excavation footprints were optimized to increase the quantity and quality of created wetlands. Drainage features in a couple instances provide passive groundwater recharge, potentially accelerating groundwater remediation efforts. In addition, a number of clean materials and structures were beneficially reused as part of ecological restoration designs, including wood-chip mulch and woody debris, clean concrete, and a rail trestle. At the Weldon Spring Site, several methods were used to control erosion for three years after the initial seeding of native species. A field evaluation of soil conditions and general species diversity was performed in 2007 and it was determined that erosion at the site was typical and repairing naturally. These approaches resulted in 'win-win' strategies needed to successfully remediate and restore complex projects such as the Fernald Preserve and Weldon Spring. (authors)

  5. A review of cognitive remediation approaches for schizophrenia: from top-down to bottom-up, brain training to psychotherapy.

    PubMed

    Best, Michael W; Bowie, Christopher R

    2017-07-01

    Individuals with psychotic disorders experience profound impairment in neurocognition, which is consistently found to be the best predictor of independent community functioning. Several diverse behavioural treatments designed to enhance neurocognitive abilities have been developed, with subtle to stark differences among them. Various approaches, to varying degrees, have demonstrated success across diffuse outcomes: improved brain structure and function, performance on neuropsychological tests, and community activities associated with daily living. Areas covered: This paper reviews the different approaches to cognitive remediation and the differential effects these approaches have on neurophysiological function, neurocognitive abilities, and real-world community functioning. Cognitive remediation approaches can be broadly classified along two dimensions: 1) treatment target, and 2) treatment modality. Some approaches target more basic perceptual skills, some target higher level executive processes, while some are non-targeted and seek to improve general cognitive ability. With regard to modality, approaches might have little/no therapist involvement and rely exclusively on computerized practice or they may include intensive therapist involvment to generalize neurocognitive change to community functioning. Expert commentary: Compared to other widely implemented treatments for schizophrenia, cognitive remediation produces better effects on outcome measures. It is time for cognitive remediation to be adopted as a best practice in the treatment of schizophrenia.

  6. Optimization of silver nanoparticles for surface enhanced Raman spectroscopy of structurally diverse analytes using visible and near-infrared excitation.

    PubMed

    Meyer, Matthew W; Smith, Emily A

    2011-09-07

    Several experimental parameters affecting surface enhanced Raman (SER) signals using 488, 785 and 1064 nm excitation for eight diverse analytes are reported. Citrate reduced silver colloids having average diameters ranging from 40 ± 10 to 100 ± 20 nm were synthesized. The nanoparticles were characterized by transmission electron microscopy, dynamic light scattering and absorbance spectrophotometry before and after inducing nanoparticle aggregation with 0.99% v/v 0.5 M magnesium chloride. The nanoparticle aggregates and SERS signal were stable between 30 and 90 minutes after inducing aggregation. For the analytes 4-mercaptopyridine, 4-methylthiobenzoic acid and the dipeptide phenylalanine-cysteine using all three excitation wavelengths, the highest surface area adjusted SER signal was obtained using 70 ± 20 nm nanoparticles, which generated 290 ± 40 nm aggregates with the addition of magnesium chloride. The decrease in the SER signal using non-optimum colloids was 12 to 42% using 488 nm excitation and larger decreases in signal, up to 92%, were observed using near infrared excitation wavelengths. In contrast, pyridine, benzoic acid, and phenylalanine required 220 ± 30 nm aggregates for the highest SER signal with 785 or 1064 nm excitation, but larger aggregates (290 ± 40 nm) were required with 488 nm excitation. The optimum experimental conditions measured with the small molecule analytes held for a 10 amino acid peptide and hemoglobin. Reproducible SERS measurements with 2 to 9% RSD have been obtained by considering nanoparticle size, aggregation conditions, excitation wavelength and the nature of the analyte-silver interaction.

  7. Seed retention by pioneer trees enhances plant diversity resilience on gravel bars: Observations from the river Allier, France

    NASA Astrophysics Data System (ADS)

    Corenblit, Dov; Vidal, Vincent; Cabanis, Manon; Steiger, Johannes; Garófano-Gómez, Virginia; Garreau, Alexandre; Hortobágyi, Borbála; Otto, Thierry; Roussel, Erwan; Voldoire, Olivier

    2016-07-01

    Pioneer riparian trees which establish in river active tracts on gravel bars enhance fine sediment retention during high flows within their stands and in their lee side, forming obstacle marks. Fine sediment retention can be accompanied by deposition of seeds transported by water dispersal, i.e. by hydrochory. We tested the hypothesis that pioneer riparian trees significantly control seed deposition on gravel bars by forming sediment obstacle marks. We described the seed bank structure and compared samples collected from obstacle marks and bare coarse-grained bar surfaces. At the surface (at 2 cm depth), seed abundance (N) and richness (S) (expressed as mean ± sd) were significantly higher in areas directly affected by riparian trees, i.e. obstacle marks, (N: 693 ± 391; S: 17 ± 3) than in bare surfaces (N: 334 ± 371; S: 13 ± 5). Surface and sub-surface (at 20 cm depth) samples were also significantly different, with the sub-surface samples almost devoid of seeds (respectively N: 514 ± 413; S: 15 ± 5 and N: 3 ± 6; S: 1 ± 2). These results suggest a biogeomorphic feedback between sediment and associated seed retention mediated by hydrochory, vegetation growth and local seed dispersal mediated by barochory. Such feedback may improve plant diversity resilience on gravel alluvial bars of high-energy rivers.

  8. AMS Online Weather Studies: The National Dissemination of a Distance Learning Course for Enhancing Diversity in the Geosciences

    NASA Astrophysics Data System (ADS)

    Weinbeck, R. S.; Geer, I. W.; Mills, E. W.; Porter, W. A.; Moran, J. M.

    2004-12-01

    Our nation faces a serious challenge in attracting young people to science and science-related careers (including teaching). This is particularly true for members of groups underrepresented in science, mathematics, engineering, and technology and is especially acute in the number of minority college students majoring in the geosciences. A formidable obstacle in attracting undergraduates to the geosciences is lack of access, that is, no opportunity to enroll in geoscience courses simply because none is offered at their college or university. Often college-level introductory courses are a student's first exposure to the geosciences. To help alleviate this problem of access, the American Meteorological Society (AMS) has developed and implemented nationally an introductory weather and climate course, Online Weather Studies, which can be added to an institution's menu of general education course offerings. This highly successful course has been licensed by over 230 colleges and universities nationwide, among them 72 minority-serving institutions which have joined via the AMS Online Weather Studies Geosciences Diversity Program since 2002. This program designed to reach institutions serving large numbers of minority students has been made possible through support from the National Science Foundation (NSF) Opportunities for Enhancing Diversity in the Geosciences (OEDG) and Course, Curriculum and Laboratory Improvement-National Dissemination (CCLI-ND) programs. Online Weather Studies is an innovative, 12- to 15-week introductory college-level, online distance-learning course on the fundamentals of atmospheric science. Learner-formatted current weather data are delivered via the Internet and coordinated with investigations keyed to the day's weather. The principal innovation of Online Weather Studies is that students learn about weather as it happens in near real-time - a highly motivational learning experience. The AMS Education Program designed and services this course

  9. Enhancing Diversity in the Geosciences through National Dissemination of the AMS Online Weather Studies Distance Learning Course

    NASA Astrophysics Data System (ADS)

    Weinbeck, R. S.; Geer, I. W.; Mills, E. W.; Porter, W. A.; Moran, J. M.

    2002-12-01

    Our nation faces a serious challenge in attracting young people to science and science-related careers (including teaching). This is particularly true for members of groups underrepresented in science, mathematics, engineering, and technology and is especially acute in the number of minority college students majoring in the geosciences. A formidable obstacle in attracting undergraduates to the geosciences is lack of access, that is, no opportunity to enroll in an introductory geoscience course simply because none is offered at their college or university. Often introductory or survey courses are a student's first exposure to the geosciences. To help alleviate this problem, the American Meteorological Society (AMS) through its Education Program developed and implemented nationally an introductory weather and climate course, Online Weather Studies, which can be added to an institution's menu of general education course offerings. This highly successful course will be offered at 130 colleges and universities nationwide, including 30 minority-serving institutions, 20 of which have joined the AMS Online Weather Studies Diversity Program during 2002. The AMS encourages course adoption by more institutions serving large numbers of minority students through support from the National Science Foundation (NSF) Opportunities for Enhancing Diversity in the Geosciences (OEDG) and Course, Curriculum and Laboratory Improvement-National Dissemination (CCLI-ND) programs. Online Weather Studies is an innovative, 12- to 15-week introductory college-level, online distance-learning course on the fundamentals of atmospheric science. Learner-formatted current weather data are delivered via the Internet and coordinated with investigations keyed to the day's weather. The principal innovation of Online Weather Studies is that students learn about weather as it happens in near real-time-a highly motivational learning experience. The AMS Education Program designed and services this course and

  10. Effects of gentle remediation technologies on soil biological and biochemical activities - a review.

    NASA Astrophysics Data System (ADS)

    Marschner, B.; Haag, R.; Renella, G.

    2009-04-01

    Remediation technologies for contaminated sites are generally designed to reduce risks for human health, groundwater or plant quality. While some drastic remediation measures such as soil excavation, thermal treatment or soil washing eliminate or strongly reduce soil life, in-situ treatments involving plants or immobilizing additives may also restore soil functionality by establishing or promoting a well structured and active community of soil organisms. Biological parameters that are sensitive to contaminants and other pedo-environmental conditions and which contribute to biogeochemical nutrient cycles, can be used as synthetic indicators of the progress and also the efficiency of given remediation approaches. Data from long-term studies on re-vegetated mine spoils show that biological and biochemical activity is enhanced with increasing plant density and diversity. Among the soil amendments, most measures that introduce organic matter or alkalinity to the contaminated soils also improve microbial or faunal parameters. Only few amendments, such as phosphates and chelators have deleterious effects on soil biota. In this review, soil microbial biomass and the activity of the enzymes phosphatase and arylsulphatase are identified as suitable and sensitive biological indicators for soil health. The results and future research needs are are summarized.

  11. Innovative vitrification for soil remediation

    SciTech Connect

    Jetta, N.W.; Patten, J.S.; Hart, J.G.

    1995-12-01

    The objective of this DOE demonstration program is to validate the performance and operation of the Vortec Cyclone Melting System (CMS{trademark}) for the processing of LLW contaminated soils found at DOE sites. This DOE vitrification demonstration project has successfully progressed through the first two phases. Phase 1 consisted of pilot scale testing with surrogate wastes and the conceptual design of a process plant operating at a generic DOE site. The objective of Phase 2, which is scheduled to be completed the end of FY 95, is to develop a definitive process plant design for the treatment of wastes at a specific DOE facility. During Phase 2, a site specific design was developed for the processing of LLW soils and muds containing TSCA organics and RCRA metal contaminants. Phase 3 will consist of a full scale demonstration at the DOE gaseous diffusion plant located in Paducah, KY. Several DOE sites were evaluated for potential application of the technology. Paducah was selected for the demonstration program because of their urgent waste remediation needs as well as their strong management and cost sharing financial support for the project. During Phase 2, the basic nitrification process design was modified to meet the specific needs of the new waste streams available at Paducah. The system design developed for Paducah has significantly enhanced the processing capabilities of the Vortec vitrification process. The overall system design now includes the capability to shred entire drums and drum packs containing mud, concrete, plastics and PCB`s as well as bulk waste materials. This enhanced processing capability will substantially expand the total DOE waste remediation applications of the technology.

  12. Effects of remediation amendments on vadose zone microorganisms

    SciTech Connect

    Miller, Hannah M.; Tilton, Fred A.

    2012-08-10

    Surfactant-based foam delivery technology has been studied to remediate Hanford 200 area deep vadose zone sediment. However, the surfactants and remediation amendments have an unknown effect on indigenous subsurface microorganisms. Microbial populations are important factors to consider in remediation efforts due to their potential to alter soil geochemistry. This project focuses on measuring microbial metabolic responses to remediation amendments in batch and column studies using Deep Vadose Zone Sediments. Initial studies of the microbes from Hanford 200 area deep vadose zone sediment showed surfactants sodium dodecyl sulfate (SDS) and cocamidopropyl betaine (CAPB) and remediation amendment calcium polysulfide (CPS) had no affect on microbial growth using BiologTM Ecoplates. To move towards a more realistic field analog, soil columns were packed with Hanford 200 Area sediment. Once microbial growth in the column was verified by observing growth of the effluent solution on tryptic soy agar plates, remedial surfactants were injected into the columns, and the resulting metabolic diversity was measured. Results suggest surfactant sodium dodecyl sulfate (SDS) stimulates microbial growth. The soil columns were also visualized using X-ray microtomography to inspect soil packing and possibly probe for evidence of biofilms. Overall, BiologTM Ecoplates provide a rapid assay to predict effects of remediation amendments on Hanford 200 area deep vadose zone microorganisms.

  13. Remediation technologies for contaminated sediments

    SciTech Connect

    Swanson, L.M.

    1995-09-01

    Although soil and groundwater remediation has been conducted for many years, sediment remediation is still in its infancy. Regulatory agencies are now beginning to identify areas where contaminated sediments exist and evaluate their environmental impact. As these evaluations are completed, the projects must shift focus to how these sediments can be remediated. Also as the criteria for aquatic disposal of dredged sediments become more stringent, remediation technologies must be developed to address contaminated sediments generated by maintenance dredging.This report describes the various issues and possible technologies for sediment remediation.

  14. Restructuring reward processing with Mindfulness-Oriented Recovery Enhancement: novel therapeutic mechanisms to remediate hedonic dysregulation in addiction, stress, and pain.

    PubMed

    Garland, Eric L

    2016-06-01

    Though valuation processes are fundamental to survival of the human species, hedonic dysregulation is at the root of an array of maladies, including addiction, stress, and chronic pain, as evidenced by the allostatic shift in the relative salience of natural reward to drug reward observed among persons with severe substance use disorders. To address this crucial problem, novel interventions are needed to restore hedonic regulatory processes gone awry in persons exhibiting addictive behaviors. This article describes a theoretical rationale and empirical evidence for the effects of one such new intervention, Mindfulness-Oriented Recovery Enhancement (MORE), on top-down and bottom-up mechanisms implicated in cognitive control and hedonic regulation. MORE is innovative and distinct from extant mindfulness-based interventions in that it unites traditional mindfulness meditation with reappraisal and savoring strategies designed to reverse the downward shift in salience of natural reward relative to drug reward, representing a crucial tipping point to disrupt the progression of addiction-a mechanistic target that no other behavioral intervention has been designed to address. Though additional studies are needed, clinical and biobehavioral data from several completed and ongoing trials suggest that MORE may exert salutary effects on addictive behaviors and the neurobiological processes that underpin them.

  15. Enhanced tolerance and remediation to mixed contaminates of PCBs and 2,4-DCP by transgenic alfalfa plants expressing the 2,3-dihydroxybiphenyl-1,2-dioxygenase.

    PubMed

    Wang, Yan; Ren, Hejun; Pan, Hongyu; Liu, Jinliang; Zhang, Lanying

    2015-04-09

    Polychlorinated biphenyls (PCBs) and 2,4-dichlorophenol (2,4-DCP) generally led to mixed contamination of soils as a result of commercial and agricultural activities. Their accumulation in the environment poses great risks to human and animal health. Therefore, the effective strategies for disposal of these pollutants are urgently needed. In this study, genetic engineering to enhance PCBs/2,4-DCP phytoremediation is a focus. We cloned the 2,3-dihydroxybiphenyl-1,2-dioxygenase (BphC.B) from a soil metagenomic library, which is the key enzyme of aerobic catabolism of a variety of aromatic compounds, and then it was expressed in alfalfa driven by CaMV 35S promoter using Agrobacterium-mediated transformation. Transgenic line BB11 was selected out through PCR, Western blot analysis and enzyme activity assays. Its disposal and tolerance to both PCBs and 2,4-DCP were examined. The tolerance capability of transgenic line BB11 towards complex contaminants of PCBs/2,4-DCP significantly increased compared with non-transgenic plants. Strong dissipation of PCBs and high removal efficiency of 2,4-DCP were exhibited in a short time. It was confirmed expressing BphC.B would be a feasible strategy to help achieving phytoremediation in mixed contaminated soils with PCBs and 2,4-DCP.

  16. Enhanced proliferation of fibroblasts and endothelial cells treated with an extract of the leaves of Chromolaena odorata (Eupolin), an herbal remedy for treating wounds.

    PubMed

    Phan, T T; Hughes, M A; Cherry, G W

    1998-03-01

    Burns are a major problem in many developing countries. Eupolin ointment is a topical agent used in the treatment of soft-tissue wounds and burns in Vietnam and is made from an aqueous extract of the leaves of Chromolaena odorata (formerly Eupatorium odoratum). Clinical studies using this extract have shown antimicrobial and anticoagulation effects as well as the promotion of tissue remodeling in the wound healing process. However, the mechanism by which this agent affects cells involved in the wound healing process is unknown. In our research, fibroblasts and endothelial cells, two cell types that play a crucial role in wound healing, were used to investigate some of the effects of Eupolin extract in vitro. Cell growth was estimated by a colorimetric assay at different time intervals. Enhanced growth of fibroblasts and endothelial cells was found at concentrations of 10 microg/ml and 100 microg/ml of Eupolin extract. This was particularly evident in medium supplemented with only 0.5% fetal calf serum where the cells were quiescent. Toxicity of the extract to fibroblasts was observed at 250 microg/ml in Dulbecco's modified Eagle's medium/0.5% fetal calf serum, but there was no significant damage at this dose to the endothelial cells. The results of the study demonstrated that Eupolin extract increased fibroblast and endothelial cell growth, and this could explain in part the beneficial clinical effects that have been observed.

  17. APS Education and Diversity Efforts

    NASA Astrophysics Data System (ADS)

    Prestridge, Katherine; Hodapp, Theodore

    2015-11-01

    American Physical Society (APS) has a wide range of education and diversity programs and activities, including programs that improve physics education, increase diversity, provide outreach to the public, and impact public policy. We present the latest programs spearheaded by the Committee on the Status of Women in Physics (CSWP), with highlights from other diversity and education efforts. The CSWP is working to increase the fraction of women in physics, understand and implement solutions for gender-specific issues, enhance professional development opportunities for women in physics, and remedy issues that impact gender inequality in physics. The Conferences for Undergraduate Women in Physics, Professional Skills Development Workshops, and our new Professional Skills program for students and postdocs are all working towards meeting these goals. The CSWP also has site visit and conversation visit programs, where department chairs request that the APS assess the climate for women in their departments or facilitate climate discussions. APS also has two significant programs to increase participation by underrepresented minorities (URM). The newest program, the APS National Mentoring Community, is working to provide mentoring to URM undergraduates, and the APS Bridge Program is an established effort that is dramatically increasing the number of URM PhDs in physics.

  18. Monitoring and remediating groundwater

    SciTech Connect

    Vedder, M.

    1995-03-01

    Choosing the optimum groundwater remediation process is a site-specific task. A variety of factors--including soil type, water type, water flow, water table levels and contaminant type--influence sampling and treatment techniques. Because underground contaminant plumes must first be characterized and mapped, initial sampling often is a hit or miss proposition. Historical geophysical data can be obtained from many local water boards to supplement the process. Equipment used in sampling includes drilling rigs, depth probes, bailers, sample tubing and well pumps. Once samples are collected, they are preserved with ice and transported to an environmental laboratory for analysis. Common groundwater contaminants include hydrocarbons, solvents, metals and volatile organic compounds. Typical lab analysis methods include gas chromatography and spectrometry. Remediation options include air stripping, carbon adsorption, the use of bacterial cultures, chemical precipitation, ion exchange, reverse osmosis and ultrafiltration.

  19. DESIGN OF A SURFACTANT REMEDIATION FIELD DEMONSTRATION BASED ON LABORATORY AND MODELINE STUDIES

    EPA Science Inventory

    Surfactant-enhanced subsurface remediation is being evaluated as an innovative technology for expediting ground-water remediation. This paper reports on laboratory and modeling studies conducted in preparation for a pilot-scale field test of surfactant-enhanced subsurface remedia...

  20. DESIGN OF A SURFACTANT REMEDIATION FIELD DEMONSTRATION BASED ON LABORATORY AND MODELINE STUDIES

    EPA Science Inventory

    Surfactant-enhanced subsurface remediation is being evaluated as an innovative technology for expediting ground-water remediation. This paper reports on laboratory and modeling studies conducted in preparation for a pilot-scale field test of surfactant-enhanced subsurface remedia...

  1. Remediation Technology Collaboration Development

    NASA Technical Reports Server (NTRS)

    Mahoney, John; Olsen, Wade

    2010-01-01

    This slide presentation reviews programs at NASA aimed at development at Remediation Technology development for removal of environmental pollutants from NASA sites. This is challenging because there are many sites with different environments, and various jurisdictions and regulations. There are also multiple contaminants. There must be different approaches based on location and type of contamination. There are other challenges: such as costs, increased need for resources and the amount of resources available, and a regulatory environment that is increasing.

  2. Trade Remedies: A Primer

    DTIC Science & Technology

    2008-07-30

    Developing nations, such as India and South Africa , had begun using trade remedy actions more frequently, whereas they were tools used almost exclusively...CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING...group of products are minerals and metals (such as brass sheet and strip; gray portland cement and clinker ; magnesium). The fourth largest group

  3. Remediating munitions contaminated soils

    SciTech Connect

    Shea, P.J.; Comfort, S.D.

    1995-10-01

    The former Nebraska Ordnance Plant (NOP) at Mead, NE was a military loading, assembling, and packing facility that produced bombs, boosters and shells during World War II and the Korean War (1942-1945, 1950-1956). Ordnances were loaded with 2,4,6-trinitrotoluene (TNT), amatol (TNT and NH{sub 4}NO{sub 3}), tritonal (TNT and Al) and Composition B (hexahydro-1,3,5-trinitro-1,3,5-triazine [RDX] and TNT). Process waste waters were discharged into wash pits and drainage ditches. Soils within and surrounding these areas are contaminated with TNT, RDX and related compounds. A continuous core to 300 cm depth obtained from an NOP drainage ditch revealed high concentrations of TNT in the soil profile and substantial amounts of monoamino reduction products, 4-amino-2,6-dinitrotoluene (4ADNT) and 2-amino-4,6-dinitrotoluene (2ADNT). Surface soil contained TNT in excess of 5000 mg kg{sup -1} and is believed to contain solid phase TNT. This is supported by measuring soil solution concentrations at various soil to solution ratios (1:2 to 1:9) and obtaining similar TNT concentrations (43 and 80 mg L{sup -1}). Remediating munitions-contaminated soil at the NOP and elsewhere is of vital interest since many of the contaminants are carcinogenic, mutagenic or otherwise toxic to humans and the environment. Incineration, the most demonstrated remediation technology for munitions-containing soils, is costly and often unacceptable to the public. Chemical and biological remediation offer potentially cost-effective and more environmentally acceptable alternatives. Our research objectives are to: (a) characterize the processes affecting the transport and fate of munitions in highly contaminated soil; (b) identify effective chemical and biological treatments to degrade and detoxify residues; and (c) integrate these approaches for effective and practical remediation of soil contaminated with TNT, RDX, and other munitions residues.

  4. Trade Remedies: A Primer

    DTIC Science & Technology

    2006-06-14

    Agricultural products are the second largest category, including asparagus , mushrooms, shrimp, honey, roses, and cut flowers. It appears, generally, that a...on the manufacture, production , or export of the merchandise, and the ITC determines injury. U.S. safeguard laws (19 U.S.C. 2251 et seq.) authorize...Remedy Laws . . . . . . . . . . . . . . . . . . . . . . . 29 List of Figures Figure 1. AD and CVD Orders in Place by Product Group

  5. CENTRAL PLATEAU REMEDIATION

    SciTech Connect

    ROMINE, L.D.

    2006-02-01

    A systematic approach to closure planning is being implemented at the Hanford Site's Central Plateau to help achieve the goal of closure by the year 2035. The overall objective of Central Plateau remediation is to protect human health and the environment from the significant quantity of contaminated material that resulted from decades of plutonium production in support of the nation's defense. This goal will be achieved either by removing contaminants or placing the residual contaminated materials in a secure configuration that minimizes further migration to the groundwater and reduces the potential for inadvertent intrusion into contaminated sites. The approach to Central Plateau cleanup used three key concepts--closure zones, closure elements, and closure process steps--to create an organized picture of actions required to complete remediation. These actions were merged with logic ties, constraints, and required resources to produce an integrated time-phased schedule and cost profile for Central Plateau closure. Programmatic risks associated with implementation of Central Plateau closure were identified and analyzed. Actions to mitigate the most significant risks are underway while high priority remediation projects continue to make progress.

  6. Environmental impacts of remediation of a trichloroethene-contaminated site: life cycle assessment of remediation alternatives.

    PubMed

    Lemming, Gitte; Hauschild, Michael Z; Chambon, Julie; Binning, Philip J; Bulle, Cécile; Margni, Manuele; Bjerg, Poul L

    2010-12-01

    The environmental impacts of remediation of a chloroethene-contaminated site were evaluated using life cycle assessment (LCA). The compared remediation options are (i) in situ bioremediation by enhanced reductive dechlorination (ERD), (ii) in situ thermal desorption (ISTD), and (iii) excavation of the contaminated soil followed by off-site treatment and disposal. The results showed that choosing the ERD option will reduce the life-cycle impacts of remediation remarkably compared to choosing either ISTD or excavation, which are more energy-demanding. In addition to the secondary impacts of remediation, this study includes assessment of local toxic impacts (the primary impact) related to the on-site contaminant leaching to groundwater and subsequent human exposure via drinking water. The primary human toxic impacts were high for ERD due to the formation and leaching of chlorinated degradation products, especially vinyl chloride during remediation. However, the secondary human toxic impacts of ISTD and excavation are likely to be even higher, particularly due to upstream impacts from steel production. The newly launched model, USEtox, was applied for characterization of primary and secondary toxic impacts and combined with a site-dependent fate model of the leaching of chlorinated ethenes from the fractured clay till site.

  7. 10 CFR 1040.88 - Remedial and affirmative action by recipients.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... remedial action as the Director, Office of Civil Rights and Diversity, considers necessary to overcome the... benefits to the elderly or to children, the provision of those benefits shall be presumed to be voluntary...

  8. Enhancing the Efficacy of Lecturers in Educating Student Cohorts Consisting of Culturally Diverse Groups in a Medical University

    ERIC Educational Resources Information Center

    Chakravarthi, Srikumar; Haleagrahara, Nagaraja; Judson, John Paul

    2010-01-01

    Lecturers exert a potent influence over the achievement of all students, low-income culturally diverse students in particular. Although recent research has confirmed that lecturer involvement is critical for promoting academic engagement of low-income and ethnically diverse students in America and other countries, other literature suggests that…

  9. Vaporization or Chemical Reaction: Which controls the fate of contaminants treated by in situ thermal remediation?

    EPA Science Inventory

    Thermal remediation technologies, which includes steam enhanced extraction, electrical resistance heating, and thermal conductive heating, have been developed based on technologies employed by the enhanced oil recovery industry. Although mobilization and/or volatilization of con...

  10. Vaporization or Chemical Reaction: Which controls the fate of contaminants treated by in situ thermal remediation?

    EPA Science Inventory

    Thermal remediation technologies, which includes steam enhanced extraction, electrical resistance heating, and thermal conductive heating, have been developed based on technologies employed by the enhanced oil recovery industry. Although mobilization and/or volatilization of con...

  11. Novel sorbents for environmental remediation

    NASA Astrophysics Data System (ADS)

    Manariotis, Ioannis D.; Karapanagioti, Hrissi K.; Werner, David

    2014-05-01

    Nowadays, one of the major environmental problems is the pollution of aquatic systems and soil by persistent pollutants. Persistent pollutants have been found widespread in sediments, surface waters, and drinking water supplies. The removal of pollutants can be accomplished prior to their discharge to receiving bodies or by immobilizing them onto soil. Sorption is the most commonly applied process, and activated carbons have been widely used. Rapid progress in nanotechnology and a new focus on biomass-based instead of non-renewable starting materials have produced a wide range of novel engineered sorbents including biosorbents, biochars, carbon-based nanoparticles, bio-nano hybrid materials, and iron-impregnated activated carbons. Sorbent materials have been used in environmental remediation processes and especially in agricultural soil, sediments and contaminated soil, water treatment, and industrial wastewater treatment. Furthermore, sorbents may enhance the synergistic action of other processes, such as volatilization and biodegradation. Novel sorbents have been employed for the removal or immobilization of persistent pollutants such as and include heavy metals (As, Cr, Cu, Pb, Cd, and Hg), halogenated organic compounds, endocrine disrupting chemicals, metalloids and non-metallic elements, and other organic pollutants. The development and evaluation of novel sorbents requires a multidisciplinary approach encompassing environmental, nanotechnology, physical, analytical, and surface chemistry. The necessary evaluations encompass not only the efficiency of these materials to remove pollutants from surface waters and groundwater, industrial wastewater, polluted soils and sediments, etc., but also the potential side-effects of their environmental applications. The aim of this work is to present the results of the use of biochar and impregnated carbon sorbents for the removal of organic pollutants and metals. Furthermore, the new findings from the forthcoming session

  12. Remediation of Uranium Impacted Sediments in a Watercourse - 12486

    SciTech Connect

    Shephard, E.; Walter, N.; Downey, H.; Collopy, P.; Conant, J.

    2012-07-01

    In 2009, remediation was initiated for a non-operational fuel cycle facility previously used for government contract work. Between 2009 and the spring of 2011, remediation efforts were focused on demolition of contaminated buildings and removal of contaminated soil. In the late spring of 2011, the last phase of remediation commenced involving the removal of contaminated sediments from portions of a 1,200 meter long gaining stream. Planning and preparation for remediation of the stream began in 2009 with submittal of permit applications to undertake construction activities in a wetland area. The permitting process was lengthy and involved securing permits from multiple agencies. However, early and frequent communication with stakeholders played an integral role in efficiently obtaining the permit approvals. Frequent communication with stakeholders throughout the planning and remediation process also proved to be a key factor in timely completion of the project. The remediation of the stream involved the use of temporary bladder berms to divert surface water flow, water diversion piping, a sediment vacuum removal system, excavation of sediments using small front-end loaders, sediment dewatering, and waste packaging, transportation and disposal. Many safeguards were employed to protect several species of concern in the work area, water management during project activities, challenges encountered during the project, methods of Final Status Survey, and stream restoration. The planning and permitting effort for the Site Brook remediation began in May 2009 and permits were approved and in place by February 2011. The remediation and restoration of the Site Brook began in April 2011 and was completed in November 2011. The remediation of the Site Brook involved the use of temporary bladder berms to divert surface water flow, water diversion piping, a sediment vacuum removal system, excavation of sediments using small front-end loaders, sediment dewatering, and waste

  13. IN-SITU THERMAL REMEDIATION: MECHANISMS, PRINCIPLES, AND CASE STUDIES

    EPA Science Inventory

    Since the early 1990's, thermal methods of enhanced oil recovery have been adapted for the remediation of soils and groundwater. Steam injection and electrical resistance heating have proven to be robust and aggressive techniques for the enhanced recovery of volatile and semivol...

  14. IN-SITU THERMAL REMEDIATION: MECHANISMS, PRINCIPLES, AND CASE STUDIES

    EPA Science Inventory

    Since the early 1990's, thermal methods of enhanced oil recovery have been adapted for the remediation of soils and groundwater. Steam injection and electrical resistance heating have proven to be robust and aggressive techniques for the enhanced recovery of volatile and semivol...

  15. Integrated in-situ remediation

    SciTech Connect

    Fustos, V.; Lieberman, P.

    1996-01-01

    This article presents an integrated approach to ex-situ and in-situ remediation. A sequence of processes, used successfully in their own right, but used synergistically in this approach, have achieved short-term, economic remediation. In addition the range of contaminants that can be treated is extended. The Process uses ozone, compressed oxygen, water vapor, heat, bioaugmentation and vapor extraction to remediate lower molecular weight hydrocarbons and higher molecular weight hydrocarbons. 3 figs.

  16. [Cognitive remediation and nursing care].

    PubMed

    Schenin-King, Palmyre; Thomas, Fanny; Braha-Zeitoun, Sonia; Bouaziz, Noomane; Januel, Dominique

    2016-01-01

    Therapies based on cognitive remediation integrate psychiatric care. Cognitive remediation helps to ease cognitive disorders and enable patients to improve their day-to-day lives. It is essential to complete nurses' training in this field. This article presents the example of a patient with schizophrenia who followed the Cognitive Remediation Therapy programme, enabling him to access mainstream employment. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  17. Electrokinetic remediation prefield test methods

    NASA Technical Reports Server (NTRS)

    Hodko, Dalibor (Inventor)

    2000-01-01

    Methods for determining the parameters critical in designing an electrokinetic soil remediation process including electrode well spacing, operating current/voltage, electroosmotic flow rate, electrode well wall design, and amount of buffering or neutralizing solution needed in the electrode wells at operating conditions are disclosed These methods are preferably performed prior to initiating a full scale electrokinetic remediation process in order to obtain efficient remediation of the contaminants.

  18. CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY

    SciTech Connect

    BERGMAN, T. B.; STEFANSKI, L. D.; SEELEY, P. N.; ZINSLI, L. C.; CUSACK, L. J.

    2012-09-19

    THE CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY WAS CONDUCTED TO DEVELOP AN OPTIMAL SEQUENCE OF REMEDIATION ACTIVITIES IMPLEMENTING THE CERCLA DECISION ON THE CENTRAL PLATEAU. THE STUDY DEFINES A SEQUENCE OF ACTIVITIES THAT RESULT IN AN EFFECTIVE USE OF RESOURCES FROM A STRATEGIC PERSPECTIVE WHEN CONSIDERING EQUIPMENT PROCUREMENT AND STAGING, WORKFORCE MOBILIZATION/DEMOBILIZATION, WORKFORCE LEVELING, WORKFORCE SKILL-MIX, AND OTHER REMEDIATION/DISPOSITION PROJECT EXECUTION PARAMETERS.

  19. Saxton soil remediation project

    SciTech Connect

    Holmes, R.D.

    1995-12-31

    The Saxton Nuclear Experimental Facility (SNEF) consists of a 23-MW(thermal) pressurized light water thermal reactor located in south central Pennsylvania. The Saxton Nuclear Experimental Corporation (SNEC), a wholly owned subsidiary of the General Public Utilities (GPU) Corporation, is the licensee for the SNEF. Maintenance and decommissioning activities at the site are conducted by GPU Nuclear, also a GPU subsidiary and operator of the Three Mile Island and Oyster Creek nuclear facilities. The remediation and radioactive waste management of contaminated soils is described.

  20. Nanomaterials for Environmental Remediation

    SciTech Connect

    Fryxell, Glen E.; Mattigod, Shas V.

    2006-01-30

    Over the last 10-15 years, there has been an explosion of activity in the design and synthesis of nanomaterials built around a wide variety of basic architectures. In more recent years, a portion of this effort has focused on the environmental impacts and environmental applications of these nanomaterials. Why all this interest in nanomaterials? What advantages might these tiny structures provide to environmental remediation efforts? This chapter is intended to provide an overview of research in this area, as well as outline some of the advantages that these materials provide to environmental clean-up efforts.

  1. 43 CFR 20.602 - Remedial action.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Remedial action. 20.602 Section 20.602... Disciplinary and Remedial Actions § 20.602 Remedial action. (a)(1) Remedial action should normally be.... (2) If the bureau Ethics Counselor decides that remedial action is required, such action shall be...

  2. Remediating Remediation: From Basic Writing to Writing across the Curriculum

    ERIC Educational Resources Information Center

    Faulkner, Melissa

    2013-01-01

    This article challenges faculty members and administrators to rethink current definitions of remediation. First year college students are increasingly placed into basic writing courses due to a perceived inability to use English grammar correctly, but it must be acknowledged that all students will encounter the need for remediation as they attempt…

  3. Home Assessment and Remediation.

    PubMed

    Barnes, Charles S; Horner, W Elliott; Kennedy, Kevin; Grimes, Carl; Miller, J David

    2016-01-01

    Awareness of the relationship of fungi to asthma in indoor air is very old and well documented. There is substantial evidence that mold and dampness exacerbate asthma in sensitized individuals. Many governmental and nongovernmental organizations around the world have issued guidelines to the effect that the elimination of moisture intrusion and the removal of moldy items from living space can improve respiratory health. The process of home assessment for moisture and mold presence is discussed along with factors that can be used to guide fungal exposure reduction efforts. An approach to the assessment process itself is outlined, and common causes of moisture and mold damage are described. Points that should be included in a report resulting from a home assessment and rudimentary elements of report interpretation are discussed. Emphasis is that interpretation of sampling for moisture and fungal presence should be provided by the person performing the assessment. We conclude that multifaceted remediation contributes to fungal allergen avoidance. The use of an indoor environmental professional to generate evaluation reports and remediation activities can be a valuable contribution to an overall allergen avoidance strategy.

  4. Managing soil remediation problems.

    PubMed

    Okx, J P; Hordijk, L; Stein, A

    1996-12-01

    Soil remediation has only a short history but the problem addressed is a significant one. Cost estimates for the clean-up of contaminated sites in the European Union and the United States are in the order of magnitude of 1,400 billion ECU. Such an enormous operation deserves the best management it can get. Reliable cost estimations per contaminated site are an important prerequisite. This paper addresses the problems related to site-wise estimations.When solving soil remediation problems, we have to deal with a large number of scientific disciplines. Too often solutions are presented from the viewpoint of only one discipline. In order to benefit from the combined disciplinary knowledge and experience, we think that it is necessary to describe the interrelations between these disciplines. This can be realized by developing an adequate model of the desired process which enables to consider and evaluate the essential factors as interdependent components of the total system.The resulting model provides a binding paradigm to the contributing disciplines which will result in improved efficiency and effectivity of the decision and the cost estimation process. In the near future, we will release the "Biosparging and Bioventing Expert Support System", an expert support system for problem owners, consultants and authorities dealing with the design and operation of a biosparging and/or a bioventing system.

  5. Remediation of Deep Vadose Zone Radionuclide and Metal Contamination: Status and Issues

    SciTech Connect

    Dresel, P. Evan; Truex, Michael J.; Cantrell, Keri

    2008-12-30

    This report documents the results of a PNNL literature review to report on the state of maturity of deep vadose zone remediation technologies for metal contaminants including some radionuclides. Its recommendations feed into decisionmakers need for scientific information and cost-effective in situ remediation technlogies needed under DOE's Environmental Management initiative Enhanced Remediation Methods: Scientific & Technical Basis for In Stu Treatment Systems for Metals and Radionuclides.

  6. Innovative Technologies for Chlorinated Solvent Remediation

    NASA Astrophysics Data System (ADS)

    Pennell, Kurt D.; Cápiro, Natalie L.

    2014-07-01

    The following sections are included: * INTRODUCTION * TRADITIONAL REMEDIATION TECHNOLOGIES (1980s) * RESEARCH AND DEVELOPMENT OF INNOVATIVE REMEDIATION TECHNOLOGIES (1990s-2000s) * CURRENT TRENDS IN CHLORINATED SOLVENT REMEDIATION (2010s) * CLOSING THOUGHTS * REFERENCES

  7. Remedial Education: A Position Paper.

    ERIC Educational Resources Information Center

    Chausow, Hymen M.

    Extensive commitment to the remedial "tracking approach" over many years by the City Colleges of Chicago has not produced the desired outcomes. The results of several studies indicate that: student achievement in remedial courses has not resulted in improved performance in regular college courses; student and institutional retention is…

  8. Interpersonal Needs of Remedial Readers.

    ERIC Educational Resources Information Center

    Cochran, Judith

    A study sought to determine the effects of reading deficiency on the interpersonal relationship needs of regular and remedial readers as composite groups and on elementary and secondary school remedial and regular readers as age groups. Elementary and secondary school students were randomly selected and tested on the Gates-MacGinitie Reading Tests…

  9. Error Analysis and Remedial Teaching.

    ERIC Educational Resources Information Center

    Corder, S. Pit

    The purpose of this paper is to analyze the role of error analysis in specifying and planning remedial treatment in second language learning. Part 1 discusses situations that demand remedial action. This is a quantitative assessment that requires measurement of the varying degrees of disparity between the learner's knowledge and the demands of the…

  10. Remedial Education: A Position Paper.

    ERIC Educational Resources Information Center

    Chausow, Hymen M.

    Extensive commitment to the remedial "tracking approach" over many years by the City Colleges of Chicago has not produced the desired outcomes. The results of several studies indicate that: student achievement in remedial courses has not resulted in improved performance in regular college courses; student and institutional retention is…

  11. Thematic Teaching in Remedial Mathematics.

    ERIC Educational Resources Information Center

    Pace, John P.

    For many students the present remedial mathematics curriculum is a collection of loosely related, very difficult to understand topics, and many, in consequence, lack the motivation to persist in remedial math courses. Most alternative instructional methods used in these courses fail to convey a sense of the underlying purpose of mathematics and…

  12. Enhancing pediatric workforce diversity and providing culturally effective pediatric care: implications for practice, education, and policy making.

    PubMed

    2013-10-01

    This policy statement serves to combine and update 2 previously independent but overlapping statements from the American Academy of Pediatrics (AAP) on culturally effective health care (CEHC) and workforce diversity. The AAP has long recognized that with the ever-increasing diversity of the pediatric population in the United States, the health of all children depends on the ability of all pediatricians to practice culturally effective care. CEHC can be defined as the delivery of care within the context of appropriate physician knowledge, understanding, and appreciation of all cultural distinctions, leading to optimal health outcomes. The AAP believes that CEHC is a critical social value and that the knowledge and skills necessary for providing CEHC can be taught and acquired through focused curricula across the spectrum of lifelong learning. This statement also addresses workforce diversity, health disparities, and affirmative action. The discussion of diversity is broadened to include not only race, ethnicity, and language but also cultural attributes such as gender, religious beliefs, sexual orientation, and disability, which may affect the quality of health care. The AAP believes that efforts must be supported through health policy and advocacy initiatives to promote the delivery of CEHC and to overcome educational, organizational, and other barriers to improving workforce diversity.

  13. Biofilm formation and microbial community analysis of the simulated river bioreactor for contaminated source water remediation.

    PubMed

    Xu, Xiang-Yang; Feng, Li-Juan; Zhu, Liang; Xu, Jing; Ding, Wei; Qi, Han-Ying

    2012-06-01

    The start-up pattern of biofilm remediation system affects the biofilm characteristics and operating performances. The objective of this study was to evaluate the performances of the contaminated source water remediation systems with different start-up patterns in view of the pollutants removal performances and microbial community succession. The operating performances of four lab-scale simulated river biofilm reactors were examined which employed different start-up methods (natural enrichment and artificial enhancement via discharging sediment with influent velocity gradient increase) and different bio-fillers (Elastic filler and AquaMats® ecobase). At the same time, the microbial communities of the bioreactors in different phases were analyzed by polymerase chain reaction, denaturing gradient gel electrophoresis, and sequencing. The pollutants removal performances became stable in the four reactors after 2 months' operation, with ammonia nitrogen and permanganate index (COD(Mn)) removal efficiencies of 84.41-94.21% and 69.66-76.60%, respectively. The biomass of mature biofilm was higher in the bioreactors by artificial enhancement than that by natural enrichment. Microbial community analysis indicated that elastic filler could enrich mature biofilm faster than AquaMats®. The heterotrophic bacteria diversity of biofilm decreased by artificial enhancement, which favored the ammonia-oxidizing bacteria (AOB) developing on the bio-fillers. Furthermore, Nitrosomonas- and Nitrosospira-like AOB coexisted in the biofilm, and Pseudomonas sp., Sphaerotilus sp., Janthinobacterium sp., Corynebacterium aurimucosum were dominant in the oligotrophic niche. Artificial enhancement via the combination of sediment discharging and influent velocity gradient increasing could enhance the biofilm formation and autotrophic AOB enrichment in oligotrophic niche.

  14. National Heart, Lung, and Blood Institute Workshop Summary: Enhancing Opportunities for Training and Retention of a Diverse Biomedical Workforce.

    PubMed

    Duncan, Gregg A; Lockett, Angelia; Villegas, Leah R; Almodovar, Sharilyn; Gomez, Jose L; Flores, Sonia C; Wilkes, David S; Tigno, Xenia T

    2016-04-01

    Committed to its mission of conducting and supporting research that addresses the health needs of all sectors of the nation's population, the Division of Lung Diseases, National Heart, Lung, and Blood Institute of the National Institutes of Health (NHLBI/NIH) seeks to identify issues that impact the training and retention of underrepresented individuals in the biomedical research workforce. Early-stage investigators who received grant support through the NIH Research Supplements to Promote Diversity in Health Related Research Program were invited to a workshop held in Bethesda, Maryland in June, 2015, in order to (1) assess the effectiveness of the current NHLBI diversity program, (2) improve its strategies towards achieving its goal, and (3) provide guidance to assist the transition of diversity supplement recipients to independent NIH grant support. Workshop participants participated in five independent focus groups to discuss specific topics affecting underrepresented individuals in the biomedical sciences: (1) Socioeconomic barriers to success for diverse research scientists; (2) role of the academic research community in promoting diversity; (3) life beyond a research project grant: non-primary investigator career paths in research; (4) facilitating career development of diverse independent research scientists through NHLBI diversity programs; and (5) effectiveness of current NHLBI programs for promoting diversity of the biomedical workforce. Several key issues experienced by young, underrepresented biomedical scientists were identified, and solutions were proposed to improve on training and career development for diverse students, from the high school to postdoctoral trainee level, and address limitations of currently available diversity programs. Although some of the challenges mentioned, such as cost of living, limited parental leave, and insecure extramural funding, are also likely faced by nonminority scientists, these issues are magnified among diversity

  15. National Heart, Lung, and Blood Institute Workshop Summary: Enhancing Opportunities for Training and Retention of a Diverse Biomedical Workforce

    PubMed Central

    Duncan, Gregg A.; Lockett, Angelia; Villegas, Leah R.; Almodovar, Sharilyn; Gomez, Jose L.; Flores, Sonia C.; Tigno, Xenia T.

    2016-01-01

    Rationale: Committed to its mission of conducting and supporting research that addresses the health needs of all sectors of the nation's population, the Division of Lung Diseases, National Heart, Lung, and Blood Institute of the National Institutes of Health (NHLBI/NIH) seeks to identify issues that impact the training and retention of underrepresented individuals in the biomedical research workforce. Objectives: Early-stage investigators who received grant support through the NIH Research Supplements to Promote Diversity in Health Related Research Program were invited to a workshop held in Bethesda, Maryland in June, 2015, in order to (1) assess the effectiveness of the current NHLBI diversity program, (2) improve its strategies towards achieving its goal, and (3) provide guidance to assist the transition of diversity supplement recipients to independent NIH grant support. Methods: Workshop participants participated in five independent focus groups to discuss specific topics affecting underrepresented individuals in the biomedical sciences: (1) Socioeconomic barriers to success for diverse research scientists; (2) role of the academic research community in promoting diversity; (3) life beyond a research project grant: non–primary investigator career paths in research; (4) facilitating career development of diverse independent research scientists through NHLBI diversity programs; and (5) effectiveness of current NHLBI programs for promoting diversity of the biomedical workforce. Measurements and Main Results: Several key issues experienced by young, underrepresented biomedical scientists were identified, and solutions were proposed to improve on training and career development for diverse students, from the high school to postdoctoral trainee level, and address limitations of currently available diversity programs. Although some of the challenges mentioned, such as cost of living, limited parental leave, and insecure extramural funding, are also likely faced by

  16. Electrodialytic remediation of suspended mine tailings.

    PubMed

    Hansen, Henrik K; Rojo, Adrian; Pino, Denisse; Ottosen, Lisbeth M; Ribeiro, Alexandra B

    2008-07-01

    This work shows the laboratory results of nine electrodialytic remediation experiments on copper mine tailings. A newly designed remediation cell, where the solids were kept in suspension by airflow, was tested. The results show that electric current could remove copper from suspended tailings applying 40 mA during 7 days. The liquid-to-solid ratios used were 3, 6 and 9 mL g(- 1). With addition of sulfuric acid, the process was enhanced because the pH decreased to either 2 or 4, and copper was therefore dissolved. The maximum copper removal was 80% with addition of sulfuric acid in 7-day experiment at 40 mA, with approximately 137.5 g mine tailings on dry basis. The removal for a static (baseline) experiment only amounted 15% when passing approximately the same amount of charge through 130 g of mine tailings. The use of air bubbling to keep the tailings suspended increased the removal efficiency from 1% to 80% compared to experiments with no stirring but with the same operational conditions. This showed the crucial importance of having the solids in suspension and not settled during the remediation.

  17. Scientist Spotlight Homework Assignments Shift Students' Stereotypes of Scientists and Enhance Science Identity in a Diverse Introductory Science Class

    ERIC Educational Resources Information Center

    Schinske, Jeffrey N.; Perkins, Heather; Snyder, Amanda; Wyer, Mary

    2016-01-01

    Research into science identity, stereotype threat, and possible selves suggests a lack of diverse representations of scientists could impede traditionally underserved students from persisting and succeeding in science. We evaluated a series of metacognitive homework assignments ("Scientist Spotlights") that featured counterstereotypical…

  18. Baby leaf lettuce germplasm enhancement: developing diverse populations with resistance to bacterial leaf spot caused by Xanthomonas campestris pv. vitians

    USDA-ARS?s Scientific Manuscript database

    Baby leaf lettuce cultivars with resistance to bacterial leaf spot (BLS) caused by Xanthomonas campestris pv. vitians (Xcv) are needed to reduce crop losses. The objectives of this research were to assess the genetic diversity for BLS resistance in baby leaf lettuce cultivars and to select early gen...

  19. Qualitative Comparative Analysis, Necessary Conditions, and Limited Diversity: Some Problematic Consequences of Schneider and Wagemann's Enhanced Standard Analysis

    ERIC Educational Resources Information Center

    Cooper, Barry; Glaesser, Judith

    2016-01-01

    We discuss a recent development in the set theoretic analysis of data sets characterized by limited diversity. Ragin, in developing his Qualitative Comparative Analysis (QCA), developed a standard analysis that produces parsimonious, intermediate, and complex Boolean solutions of truth tables. Schneider and Wagemann argue this standard analysis…

  20. Two-age silviculture: an innovative tool for enhancing species diversity and vertical structure in Appalachian hardwoods

    Treesearch

    Gary W. Miller; Petra B. Wood; Jeffrey V. Nichols; Jeffrey V. Nichols

    1995-01-01

    Silvicultural practices that promote a two-age stand structure provide an opportunity to maintain diversity of woody species and vertical structure for extended periods of time in Appalachian hardwoods. Data from four two-age stands initiated by deferment cutting in West Virginia are summarized for the first 10 to 15 years after treatment. Results indicated that 15...

  1. Scientist Spotlight Homework Assignments Shift Students' Stereotypes of Scientists and Enhance Science Identity in a Diverse Introductory Science Class

    ERIC Educational Resources Information Center

    Schinske, Jeffrey N.; Perkins, Heather; Snyder, Amanda; Wyer, Mary

    2016-01-01

    Research into science identity, stereotype threat, and possible selves suggests a lack of diverse representations of scientists could impede traditionally underserved students from persisting and succeeding in science. We evaluated a series of metacognitive homework assignments ("Scientist Spotlights") that featured counterstereotypical…

  2. Demonstrate the Model and Evaluation of Geoscience Research At Storm Peak (GRASP), a Field Research Experience Designed to Enhance Diversity in the Geosciences

    NASA Astrophysics Data System (ADS)

    Hallar, A. G.; Mccubbin, I. B.; Lynds, S. E.; Dodson, C.

    2012-12-01

    Geoscience Research at Storm Peak (GRASP) has created an exceptional field-research experience, with both remote and urban settings, for a diverse group of undergraduate students. GRASP is supported by the National Science Foundation's Opportunity for Enhancing Diversity in Geoscience (OEDG) Program. In 2011, GRASP accepted a third cohort. To date, twenty-two students have participated in GRASP. The program exposed GRASP participants to potential careers in the geosciences and provided them with an authentic research experience at Storm Peak Laboratory. Storm Peak Laboratory, a high elevation atmospheric science research facility, is located in Steamboat Springs, Colorado. The GRASP participants were selected based on academic excellence with their scientific disciplines and interest in careers pursing research. They are an interdisciplinary group including majors in engineering, chemistry, geology, and meteorology. Multiple evaluation methods were employed using both qualitative and quantitative techniques in order to examine the impacts and effects of GRASP on participants. Results will be presented.

  3. Applications of Ecological Engineering Remedies for Uranium Processing Sites, USA

    SciTech Connect

    Waugh, William

    2016-05-23

    The U.S. Department of Energy (USDOE) is responsible for remediation of environmental contamination and long-term stewardship of sites associated with the legacy of nuclear weapons production during the Cold War in the United States. Protection of human health and the environment will be required for hundreds or even thousands of years at many legacy sites. USDOE continually evaluates and applies advances in science and technology to improve the effectiveness and sustainability of surface and groundwater remedies (USDOE 2011). This paper is a synopsis of ecological engineering applications that USDOE is evaluating to assess the effectiveness of remedies at former uranium processing sites in the southwestern United States. Ecological engineering remedies are predicated on the concept that natural ecological processes at legacy sites, once understood, can be beneficially enhanced or manipulated. Advances in tools for characterizing key processes and for monitoring remedy performance are demonstrating potential. We present test cases for four ecological engineering remedies that may be candidates for international applications.

  4. Computer-Assisted Remedial Reading Intervention for School Beginners at Risk for Reading Disability

    ERIC Educational Resources Information Center

    Saine, Nina L.; Lerkkanen, Marja-Kristiina; Ahonen, Timo; Tolvanen, Asko; Lyytinen, Heikki

    2011-01-01

    The aim of the longitudinal study was to investigate whether a computer application designed for remedial reading training can enhance letter knowledge, reading accuracy, fluency, and spelling of at-risk children. The participants, 7-year-old Finnish school beginners (N = 166), were assigned to 1 of 3 groups: (a) regular remedial reading…

  5. Source control strategy accelerates remediation

    SciTech Connect

    Garland, S.B. II; Hammond, R.

    1993-06-01

    Shallow land burial of ion-level radioactive wastes at ORNL has resulted in the release of contaminants into surrounding soil, groundwater, and surface water. Multiple contaminated areas occurring in close proximity make it difficult to relate contaminant releases to a specific site. To address this issue, similar and contiguous contaminated sites within the same drainage area have been combined into Waste Area Groupings. These Waste Area Groupings were prioritized and became the focus of the Comprehensive Environmental Response, Compensation, and Liability Act remediation process. Since the majority of the groupings are in the White Oak Creek drainage basin, the remediation strategy is to control contaminant releases from these source areas first, followed by remediation of White Oak Creek. In planning the remediation program, it became clear that until the issues of ultimate land use and institutional control, waste treatment technologies, and waste disposal facilities are resolved, final remediation objectives cannot be defined and remedial alternatives cannot be evaluated. Consequently, instead of postponing remedial actions until these issues are resolved, a strategy to control the sources of contaminant release with a serie s of interim actions was developed. In the near term, this strategy reduces off-site risk by eliminating contaminant releases and controls on-site risk through institutional control. Source control will allow time to achieve consensus on long-term institutional control and land use issues to develop appropriate treatment technologies, and to construct the necessary disposal facilities without further environmental degradation.

  6. Electrokinetic remediation of fluorine-contaminated soil: conditioning of anolyte.

    PubMed

    Kim, Do-Hyung; Jeon, Chil-Sung; Baek, Kitae; Ko, Sung-Hwan; Yang, Jung-Seok

    2009-01-15

    The feasibility of anolyte conditioning on electrokinetic remediation of fluorine-contaminated soil was investigated with a field soil. The initial concentration of fluorine, pH and water content in the soil were 414mg/kg, 8.91 and 15%, respectively. Because the extraction of fluorine generally increased with the soil pH, the pH of the anode compartment was controlled by circulating strong alkaline solution to enhance the extraction of fluorine during electrokinetic remediation. The removal of fluorine increased with the concentration of the alkaline solution and applied current density and fluorine removed up to 75.6% within 14 days. Additionally, anolyte conditioning sharply increased the electro-osmotic flow, which enhanced the removal of fluorine in this study. In many respects, anolyte conditioning in electrokinetic remediation of fluorine-contaminated soil will be a promising technology.

  7. Remediating Computational Deficits at Third Grade: A Randomized Field Trial

    PubMed Central

    Fuchs, Lynn S.; Powell, Sarah R.; Hamlett, Carol L.; Fuchs, Douglas; Cirino, Paul T.; Fletcher, Jack M.

    2011-01-01

    The major purposes of this study were to assess the efficacy of tutoring to remediate 3rd-grade computational deficits and to explore whether remediation is differentially efficacious depending on whether students experience mathematics difficulty alone or concomitantly with reading difficulty. At 2 sites, 127 students were stratified on mathematics difficulty status and randomly assigned to 4 conditions: word recognition (control) tutoring or 1 of 3 computation tutoring conditions: fact retrieval, procedural computation and computational estimation, and combined (fact retrieval + procedural computation and computational estimation). Results revealed that fact retrieval tutoring enhanced fact retrieval skill, and procedural computation and computational estimation tutoring (whether in isolation or combined with fact retrieval tutoring) enhanced computational estimation skill. Remediation was not differentially efficacious as a function of students’ mathematics difficulty status. PMID:21709759

  8. Monitoring engineered remediation with borehole radar

    USGS Publications Warehouse

    Lane, J.W.; Day-Lewis, F. D.; Joesten, P.K.

    2007-01-01

    The success of engineered remediation is predicated on correct emplacement of either amendments (e.g., vegetable-oil emulsion, lactate, molasses, etc.) or permeable reactive barriers (e.g., vegetable oil, zero-valent iron, etc.) to enhance microbial or geochemical breakdown of contaminants and treat contaminants. Currently, site managers have limited tools to provide information about the distribution of injected materials; the existence of gaps or holes in barriers; and breakdown or transformation of injected materials over time. ?? 2007 Society of Exploration Geophysicists.

  9. Applications of microwave radiation environmental remediation technologies

    SciTech Connect

    Krause, T.R.; Helt, J.E.

    1993-05-01

    A growing number of environmental remediation technologies (e.g., drying, melting, or sintering) utilize microwave radiation as an integral part of the process. An increasing number of novel applications, such as sustaining low-temperature plasmas or enhancing chemical reactivity, are also being developed. An overview of such technologies being developed by the Department of Energy is presented. A specific example being developed at Argonne National Laboratory, microwave-induced plasma reactors for the destruction of volatile organic compounds, is discussed in more detail.

  10. Applications of microwave radiation environmental remediation technologies

    SciTech Connect

    Krause, T.R.; Helt, J.E.

    1993-01-01

    A growing number of environmental remediation technologies (e.g., drying, melting, or sintering) utilize microwave radiation as an integral part of the process. An increasing number of novel applications, such as sustaining low-temperature plasmas or enhancing chemical reactivity, are also being developed. An overview of such technologies being developed by the Department of Energy is presented. A specific example being developed at Argonne National Laboratory, microwave-induced plasma reactors for the destruction of volatile organic compounds, is discussed in more detail.

  11. Radio Frequency Heating for Soil Remediation.

    PubMed

    Price, Stephen L; Kasevich, Raymond S; Johnson, Mark A; Wiberg, Dan; Marley, Michael C

    1999-02-01

    Radio frequency heating (RFH) is a technology that increases the cost-effectiveness of a variety of site remediation technologies by accelerating the rate of contaminant removal. Heating makes the physical, chemical, and biological properties of materials such as contaminants, soil, and groundwater more amenable to remediation. RFH brings controlled heating to the subsurface, enhancing the removal of contaminants by soil vapor extraction (SVE), groundwater aeration (air sparging), bioremediation, and product recovery. The results presented are from a bench-scale study and a field demonstration that both used RFH to enhance the performance of SVE. The bench-scale study performed on PCE-contaminated soil revealed an increase, by a factor of 8, in the removal rate when RFH was used to heat soil to 90 °C. The application of RFH for a three-week period at a former gasoline station near St. Paul, MN, resulted in raising the ambient soil temperature from 8 °C to 100 °C in the immediate vicinity of the RFH applicator and to 40 °C 1.5 m (5 ft) away. Most significantly, the use of an integrated RFH/SVE system achieved an overall 50% reduction in gasoline range organics (GRO) in soil over a two- to three-month period. The discussion includes applications of RFH for enhancing bioremediation and product recovery.

  12. Polarization-diverse light absorption enhancement in organic photovoltaic structures with one-dimensional, long-pitch metallic gratings: Design and experiment

    NASA Astrophysics Data System (ADS)

    Liu, Yifen; Dhakal, Rabin; Dalal, Vikram; Kim, Jaeyoun

    2012-12-01

    We report the design and experimental realization of an organic photovoltaic device structure that can trap incident light in all polarization states without relying on two-dimensional, short-pitch (<400 nm) gratings. Instead, we utilized easily patternable one-dimensional, long-pitch (>1000 nm) gratings and achieved the polarization diversity through balanced allocation of the plasmonic and guided mode-based light trapping routes to different polarization states. The experimental results showed strong enhancements in light absorption in all polarization states that would translate into a 15%-25% increase in the power conversion efficiency.

  13. An Antifungal Combination Matrix Identifies a Rich Pool of Adjuvant Molecules that Enhance Drug Activity Against Diverse Fungal Pathogens

    PubMed Central

    Robbins, Nicole; Spitzer, Michaela; Yu, Tennison; Cerone, Robert P.; Averette, Anna K.; Bahn, Yong-Sun; Heitman, Joseph; Sheppard, Donald C.; Tyers, Mike; Wright, Gerard D.

    2015-01-01

    SUMMARY There is an urgent need to identify new treatments for fungal infections. By combining sub-lethal concentrations of the known antifungals fluconazole, caspofungin, amphotericin B, terbinafine, benomyl and cyprodinil with ~3600 compounds in diverse fungal species, we generated a deep reservoir of chemical-chemical interactions termed the Antifungal Combinations Matrix (ACM). Follow-up susceptibility testing against a fluconazole resistant isolate of C. albicans unveiled ACM combinations capable of potentiating fluconazole in this clinical strain. We used chemical genetics to elucidate the mode-of-action of the antimycobacterial drug clofazimine, a compound with unreported antifungal activity that synergized with several antifungals. Clofazimine induces a cell membrane stress for which the Pkc1 signaling pathway is required for tolerance. Further tests against additional fungal pathogens, including Aspergillus fumigatus, highlighted that clofazimine exhibits efficacy as a combination agent against multiple fungi. Thus, the ACM is a rich reservoir of chemical combinations with therapeutic potential against diverse fungal pathogens. PMID:26549450

  14. Ecosystem engineering by invasive exotic beavers reduces in-stream diversity and enhances ecosystem function in Cape Horn, Chile.

    PubMed

    Anderson, Christopher B; Rosemond, Amy D

    2007-11-01

    Species invasions are of global significance, but predicting their impacts can be difficult. Introduced ecosystem engineers, however, provide an opportunity to test the underlying mechanisms that may be common to all invasive engineers and link relationships between changes in diversity and ecosystem function, thereby providing explanatory power for observed ecological patterns. Here we test specific predictions for an invasive ecosystem engineer by quantifying the impacts of habitat and resource modifications caused by North American beavers (Castor canadensis) on aquatic macroinvertebrate community structure and stream ecosystem function in the Cape Horn Biosphere Reserve, Chile. We compared responses to beavers in three habitat types: (1) forested (unimpacted) stream reaches, (2) beaver ponds, and (3) sites immediately downstream of beaver dams in four streams. We found that beaver engineering in ponds created taxonomically simplified, but more productive, benthic macroinvertebrate assemblages. Specifically, macroinvertebrate richness, diversity and number of functional feeding groups were reduced by half, while abundance, biomass and secondary production increased three- to fivefold in beaver ponds compared to forested sites. Reaches downstream of beaver ponds were very similar to natural forested sections. Beaver invasion effects on both community and ecosystem parameters occurred predominantly via increased retention of fine particulate organic matter, which was associated with reduced macroinvertebrate richness and diversity (via homogenization of benthic microhabitat) and increased macroinvertebrate biomass and production (via greater food availability). Beaver modifications to macroinvertebrate community structure were largely confined to ponds, but increased benthic production in beaver-modified habitats adds to energy retention and flow for the entire stream ecosystem. Furthermore, the effects of beavers on taxa richness (negative) and measures of

  15. Mosaic vaccines elicit CD8+ T lymphocyte responses that confer enhanced immune coverage of diverse HIV strains in monkeys.

    PubMed

    Santra, Sampa; Liao, Hua-Xin; Zhang, Ruijin; Muldoon, Mark; Watson, Sydeaka; Fischer, Will; Theiler, James; Szinger, James; Balachandran, Harikrishnan; Buzby, Adam; Quinn, David; Parks, Robert J; Tsao, Chun-Yen; Carville, Angela; Mansfield, Keith G; Pavlakis, George N; Felber, Barbara K; Haynes, Barton F; Korber, Bette T; Letvin, Norman L

    2010-03-01

    An effective HIV vaccine must elicit immune responses that recognize genetically diverse viruses. It must generate CD8+ T lymphocytes that control HIV replication and CD4+ T lymphocytes that provide help for the generation and maintenance of both cellular and humoral immune responses against the virus. Creating immunogens that can elicit cellular immune responses against the genetically varied circulating isolates of HIV presents a key challenge for creating an HIV vaccine. Polyvalent mosaic immunogens derived by in silico recombination of natural strains of HIV are designed to induce cellular immune responses that recognize genetically diverse circulating virus isolates. Here we immunized rhesus monkeys by plasmid DNA prime and recombinant vaccinia virus boost with vaccine constructs expressing either consensus or polyvalent mosaic proteins. As compared to consensus immunogens, the mosaic immunogens elicited CD8+ T lymphocyte responses to more epitopes of each viral protein than did the consensus immunogens and to more variant sequences of CD8+ T lymphocyte epitopes. This increased breadth and depth of epitope recognition may contribute both to protection against infection by genetically diverse viruses and to the control of variant viruses that emerge as they mutate away from recognition by cytotoxic T lymphocytes.

  16. A Framework for Remediating Number Combination Deficits

    ERIC Educational Resources Information Center

    Fuchs, Lynn S.; Powell, Sarah R.; Seethaler, Pamela M.; Fuchs, Douglas; Hamlett, Carol L.; Cirino, Paul T.; Fletcher, Jack M.

    2010-01-01

    This article introduces a framework for the remediation of number combination (NC) deficits. Research on the remediation of NC deficits is summarized, and research program studies are used to illustrate the 3 approaches to remediation. The Framework comprises a 2-stage system of remediation. The less intensive stage implementing 1 of 3…

  17. Honey: An Effective Cough Remedy?

    MedlinePlus

    ... cough remedy? Is it true that honey calms coughs better than cough medicine does? Answers from James M. Steckelberg, M. ... throat. But honey alone may be an effective cough suppressant, too. In one study, children age 2 ...

  18. ICDF Complex Remedial Action Report

    SciTech Connect

    W. M. Heileson

    2007-09-26

    This Idaho CERCLA Disposal Facility (ICDF) Remedial Action Report has been prepared in accordance with the requirements of Section 6.2 of the INEEL CERCLA Disposal Facility Remedial Action Work Plan. The agency prefinal inspection of the ICDF Staging, Storage, Sizing, and Treatment Facility (SSSTF) was completed in June of 2005. Accordingly, this report has been developed to describe the construction activities completed at the ICDF along with a description of any modifications to the design originally approved for the facility. In addition, this report provides a summary of the major documents prepared for the design and construction of the ICDF, a discussion of relevant requirements and remedial action objectives, the total costs associated with the development and operation of the facility to date, and identification of necessary changes to the Agency-approved INEEL CERCLA Disposal Facility Remedial Action Work Plan and the ICDF Complex Operations and Maintenance Plan.

  19. Dandruff: Lifestyle and Home Remedies

    MedlinePlus

    ... management By Mayo Clinic Staff Lifestyle and home remedies In addition to regular shampooing, you can take ... your skin and increases your risk of skin cancer, don't sunbathe. Instead, just spend a little ...

  20. Remediation of contaminated soils

    SciTech Connect

    Radhakrishnan, R.; Ariza, C.H.

    1997-07-01

    At least three types of zones of contamination exist whenever there is a chemical release. The impact of Non-Aqueous-Phase Liquids (NAPL) on soils and groundwater, together with the ultimate transport and migration of constituent chemicals in their dissolved or sorbed states, had led environmentalists to develop several techniques for cleaning a contaminated soil. Zone 1 represents the unsaturated zone which could be contaminated to retention capacity by both Dense Non-Aqueous-Phase Liquids (DNAPL) and Light Non-Aqueous-Phase Liquids (LNAPL). Zone 2 represents residual DNAPL or LNAPL contamination found below the groundwater table in the saturated zone. Zone 3 is represented by either the presence of NAPL dissolved in the aqueous phase, volatilized in the unsaturated zone or sorbed to either saturated or unsaturated soils. Cleanup of petroleum contaminated soils is presented in this paper. Among several techniques developed for this purpose, in-situ biological remediation is discussed in detail as a technique that does not involve excavation, thus, the costs and disruption of excavating soil are eliminated.

  1. Covert Operant Reinforcement of Remedial Reading Learning Tasks.

    ERIC Educational Resources Information Center

    Schmickley, Verne G.

    The effects of covert operant reinforcement upon remedial reading learning tasks were investigated. Forty junior high school students were taught to imagine either neutral scenes (control) or positive scenes (treatment) upon cue while reading. It was hypothesized that positive covert reinforcement would enhance performance on several measures of…

  2. [Composition of NOM in raw water of Danjiangkou Reservoir of South-to-North Water Diversion Project and comparison of efficacy of enhanced coagulation].

    PubMed

    Cheng, Tuo; Xu, Bin; Zhu, He-Zhen; Xia, Sheng-Ji; Chu, Wen-Hai; Hu, Guang-Xin

    2015-03-01

    The best enhanced coagulation conditions for the raw water of Danjiangkou Reservoir of South-to-North Water Diversion Project and the molecular weights as well as hydrophobicity composition of Natural organic matter (NOM) in the water were investigated in this study. The results showed that the NOM in the raw water of Danjiangkou Reservoir of South-to-North Water Diversion Project was mainly composed of the fraction with a molecular weight of < 1 000 and transphilic components. Dissolved organic carbon (DOC, 39.98%) and UV254 (39.10%) were the major components. And the fraction with a molecular weight of < 1 000 had the highest contents of THMFP and N-DBPFP. In the raw water of Danjiangkou Reservoir, the sum of transphilic and hydrophobic fractions was up to 80%, and the hydrophobic fraction was the minimum contributor of the NOM, but the THMFP of the hydrophobic fraction had the highest percentage. And when the raw water of Danjiangkou Reservoir was treated using polymeric ferric sulfate (PFS, 4 mg x L(-1)) and poly-acrylamide (PAM, 0.4 mg x L(-1)) , the optimal removal rates of turbidity, DOC, UV254 and THMFP were 76.33%, 25.57%, 37.78% and 23.16%, respectively. The results of this paper can provide theoretical and technological basis for upgrading of the process and operation optimization of original drinking water treatment plants in the intake area of South-to-North Water Diversion Project.

  3. Microbial Repopulation Following In Situ STAR Remediation

    NASA Astrophysics Data System (ADS)

    Gerhard, J.; Overbeeke, G.; Edwards, E.; Lomheim, L.; Grant, G.

    2016-12-01

    STAR (Self-sustaining Treatment for Active Remediation) is an emerging remediation technology that employs a self-sustaining smouldering reaction to destroy nonaqueous phase liquids (NAPLs) in the subsurface. The reaction front travels outwards from an ignition well at approximately 0.5 per day and subjects the soil to temperatures of 400°C-1000°C. The objectives of this work were to monitor re-saturation of the soil over time and quantify the microbial repopulation of the treated zone. STAR is currently being applied as a full scale, in situ remedy for coal tar beneath a former creosol manufacturing facility in New Jersey, USA. This study analyzed soil cores taken at regular intervals following STAR treatment, allowing time for groundwater to re-infiltrate and for microbial populations to potentially reestablish. Soil and groundwater were analyzed for total number of microorganisms via quantitative Polymerase Chain Reaction (qPCR), as well as microbial diversity via amplicon sequencing. Results demonstrate that microbes rapidly repopulated over a 2 month period to 106 gene copies/g of soil. However, concentrations in the treated zone did not rise above this concentration over 6 months post-STAR, indicating a low carrying capacity of the treated soil. To examine the system in more detail and consider the effects of bio-stimulation, a bench top column study using site soil and artificial groundwater explored the rate at which STAR-treated soil is repopulated with naturally occurring microorganisms in the presence and absence of lactate and a terminal electron acceptor. Results demonstrated that biostimulation did not increase the carrying capacity of the STAR treated sol, but rather shifted the microbial community to reflect the TEA provided, in this case, promoting sulfate reducers. Overall, the work illustrates that microbial populations in STAR treated soil do recover via groundwater infiltration but robust communities will take time to naturally establish.

  4. Recombination enhances HIV-1 envelope diversity by facilitating the survival of latent genomic fragments in the plasma virus population

    SciTech Connect

    Immonen, Taina T.; Conway, Jessica M.; Romero-Severson, Ethan O.; Perelson, Alan S.; Leitner, Thomas; Kouyos, Roger Dimitri

    2015-12-22

    HIV-1 is subject to immune pressure exerted by the host, giving variants that escape the immune response an advantage. Virus released from activated latent cells competes against variants that have continually evolved and adapted to host immune pressure. Nevertheless, there is increasing evidence that virus displaying a signal of latency survives in patient plasma despite having reduced fitness due to long-term immune memory. We investigated the survival of virus with latent envelope genomic fragments by simulating within-host HIV-1 sequence evolution and the cycling of viral lineages in and out of the latent reservoir. Our model incorporates a detailed mutation process including nucleotide substitution, recombination, latent reservoir dynamics, diversifying selection pressure driven by the immune response, and purifying selection pressure asserted by deleterious mutations. We evaluated the ability of our model to capture sequence evolution in vivo by comparing our simulated sequences to HIV-1 envelope sequence data from 16 HIV-infected untreated patients. Empirical sequence divergence and diversity measures were qualitatively and quantitatively similar to those of our simulated HIV-1 populations, suggesting that our model invokes realistic trends of HIV-1 genetic evolution. Moreover, reconstructed phylogenies of simulated and patient HIV-1 populations showed similar topological structures. Our simulation results suggest that recombination is a key mechanism facilitating the persistence of virus with latent envelope genomic fragments in the productively infected cell population. Recombination increased the survival probability of latent virus forms approximately 13-fold. Prevalence of virus with latent fragments in productively infected cells was observed in only 2% of simulations when we ignored recombination, while the proportion increased to 27% of simulations when we allowed recombination. We also found that the selection pressures exerted by different fitness

  5. Recombination Enhances HIV-1 Envelope Diversity by Facilitating the Survival of Latent Genomic Fragments in the Plasma Virus Population

    PubMed Central

    Immonen, Taina T.; Conway, Jessica M.; Romero-Severson, Ethan O.; Perelson, Alan S.; Leitner, Thomas

    2015-01-01

    HIV-1 is subject to immune pressure exerted by the host, giving variants that escape the immune response an advantage. Virus released from activated latent cells competes against variants that have continually evolved and adapted to host immune pressure. Nevertheless, there is increasing evidence that virus displaying a signal of latency survives in patient plasma despite having reduced fitness due to long-term immune memory. We investigated the survival of virus with latent envelope genomic fragments by simulating within-host HIV-1 sequence evolution and the cycling of viral lineages in and out of the latent reservoir. Our model incorporates a detailed mutation process including nucleotide substitution, recombination, latent reservoir dynamics, diversifying selection pressure driven by the immune response, and purifying selection pressure asserted by deleterious mutations. We evaluated the ability of our model to capture sequence evolution in vivo by comparing our simulated sequences to HIV-1 envelope sequence data from 16 HIV-infected untreated patients. Empirical sequence divergence and diversity measures were qualitatively and quantitatively similar to those of our simulated HIV-1 populations, suggesting that our model invokes realistic trends of HIV-1 genetic evolution. Moreover, reconstructed phylogenies of simulated and patient HIV-1 populations showed similar topological structures. Our simulation results suggest that recombination is a key mechanism facilitating the persistence of virus with latent envelope genomic fragments in the productively infected cell population. Recombination increased the survival probability of latent virus forms approximately 13-fold. Prevalence of virus with latent fragments in productively infected cells was observed in only 2% of simulations when we ignored recombination, while the proportion increased to 27% of simulations when we allowed recombination. We also found that the selection pressures exerted by different fitness

  6. Metabolite induction via microorganism co-culture: a potential way to enhance chemical diversity for drug discovery.

    PubMed

    Bertrand, Samuel; Bohni, Nadine; Schnee, Sylvain; Schumpp, Olivier; Gindro, Katia; Wolfender, Jean-Luc

    2014-11-01

    Microorganisms have a long track record as important sources of novel bioactive natural products, particularly in the field of drug discovery. While microbes have been shown to biosynthesize a wide array of molecules, recent advances in genome sequencing have revealed that such organisms have the potential to yield even more structurally diverse secondary metabolites. Thus, many microbial gene clusters may be silent under standard laboratory growth conditions. In the last ten years, several methods have been developed to aid in the activation of these cryptic biosynthetic pathways. In addition to the techniques that demand prior knowledge of the genome sequences of the studied microorganisms, several genome sequence-independent tools have been developed. One of these approaches is microorganism co-culture, involving the cultivation of two or more microorganisms in the same confined environment. Microorganism co-culture is inspired by the natural microbe communities that are omnipresent in nature. Within these communities, microbes interact through signaling or defense molecules. Such compounds, produced dynamically, are of potential interest as new leads for drug discovery. Microorganism co-culture can be achieved in either solid or liquid media and has recently been used increasingly extensively to study natural interactions and discover new bioactive metabolites. Because of the complexity of microbial extracts, advanced analytical methods (e.g., mass spectrometry methods and metabolomics) are key for the successful detection and identification of co-culture-induced metabolites. This review focuses on co-culture studies that aim to increase the diversity of metabolites obtained from microbes. The various strategies are summarized with a special emphasis on the multiple methods of performing co-culture experiments. The analytical approaches for studying these interaction phenomena are discussed, and the chemical diversity and biological activity observed among the

  7. Recombination Enhances HIV-1 Envelope Diversity by Facilitating the Survival of Latent Genomic Fragments in the Plasma Virus Population.

    PubMed

    Immonen, Taina T; Conway, Jessica M; Romero-Severson, Ethan O; Perelson, Alan S; Leitner, Thomas

    2015-12-01

    HIV-1 is subject to immune pressure exerted by the host, giving variants that escape the immune response an advantage. Virus released from activated latent cells competes against variants that have continually evolved and adapted to host immune pressure. Nevertheless, there is increasing evidence that virus displaying a signal of latency survives in patient plasma despite having reduced fitness due to long-term immune memory. We investigated the survival of virus with latent envelope genomic fragments by simulating within-host HIV-1 sequence evolution and the cycling of viral lineages in and out of the latent reservoir. Our model incorporates a detailed mutation process including nucleotide substitution, recombination, latent reservoir dynamics, diversifying selection pressure driven by the immune response, and purifying selection pressure asserted by deleterious mutations. We evaluated the ability of our model to capture sequence evolution in vivo by comparing our simulated sequences to HIV-1 envelope sequence data from 16 HIV-infected untreated patients. Empirical sequence divergence and diversity measures were qualitatively and quantitatively similar to those of our simulated HIV-1 populations, suggesting that our model invokes realistic trends of HIV-1 genetic evolution. Moreover, reconstructed phylogenies of simulated and patient HIV-1 populations showed similar topological structures. Our simulation results suggest that recombination is a key mechanism facilitating the persistence of virus with latent envelope genomic fragments in the productively infected cell population. Recombination increased the survival probability of latent virus forms approximately 13-fold. Prevalence of virus with latent fragments in productively infected cells was observed in only 2% of simulations when we ignored recombination, while the proportion increased to 27% of simulations when we allowed recombination. We also found that the selection pressures exerted by different fitness

  8. Enhancing Diversity In The Geosciences; Intensive Field Experience In USA And Mexico For Middle And High School Teachers Serving Large Hispanic Populations.

    NASA Astrophysics Data System (ADS)

    Leal-Bautista, R. M.; Kitts, K. B.; Velazquez Oliman, G.; Perry, E. C.

    2008-12-01

    To encourage Hispanic participation and enrolment in the geosciences and ultimately enhance diversity within the discipline, we recruited ten middle and high school science teachers serving large Hispanic populations (60-97%) for a paid three-week field experience supported by an NSF Opportunities for Enhancing Diversity in the Geosciences grant. In 2006, the field experiences focused on volcanic events and the water problems of the Central part of Mexico. In 2008, the field experiences focused on karstic and hydrogeological conditions of the Yucatan Peninsula. In addition to the geological aspects of the fieldwork experience, the trip to Mexico exposed the teachers to a social environment outside of their community where they interacted with a diverse group of scientists from the Universidad National Autonoma de Mexico (UNAM), Centro de Investigacion Cientifica de Yucatan (CICY) and Centro Nacional de Desastres (CENAPRED). A key part of this project was the encounter between American and Mexican teachers that included a day of presentations, panel discussion and some class-room activities. Direct interaction between the cooperating teachers and the American and Mexican geoscientists provided actual scientific research experiences to educate and to help dispel misconceptions the teachers themselves may have had about who geoscientists really are and what they do. Teachers of the 2006 group produced educational materials from their field experiences and presented these materials at professional conferences. We measured the efficacy of these activities quantitatively via pre- and post-tests assessing confidence levels, preconceptions and biases, NIU staff observations of participants in their home institutions, and evaluations of participants' field books and pedagogical materials. We present these data here and identify specific activities that are both effective and efficient in changing teacher behaviours and attitudes enabling them to better connect with their

  9. Stock enhancement or sea ranching? Insights from monitoring the genetic diversity, relatedness and effective population size in a seeded great scallop population (Pecten maximus).

    PubMed

    Morvezen, R; Boudry, P; Laroche, J; Charrier, G

    2016-09-01

    The mass release of hatchery-propagated stocks raises numerous questions concerning its efficiency in terms of local recruitment and effect on the genetic diversity of wild populations. A seeding program, consisting of mass release of hatchery-produced juveniles in the local naturally occurring population of great scallops (Pecten maximus L.), was initiated in the early 1980s in the Bay of Brest (France). The present study aims at evaluating whether this seeding program leads to actual population enhancement, with detectable effects on genetic diversity and effective population size, or consists of sea ranching with limited genetic consequences on the wild stock. To address this question, microsatellite-based genetic monitoring of three hatchery-born and naturally recruited populations was conducted over a 5-year period. Results showed a limited reduction in allelic richness but a strong alteration of allelic frequencies in hatchery populations, while genetic diversity appeared very stable over time in the wild populations. A temporal increase in relatedness was observed in both cultured stock and wild populations. Effective population size (Ne) estimates were low and variable in the wild population. Moreover, the application of the Ryman-Laikre model suggested a high contribution of hatchery-born scallops to the reproductive output of the wild population. Overall, the data suggest that the main objective of the seeding program, which is stock enhancement, is fulfilled. Moreover, gene flow from surrounding populations and/or the reproductive input of undetected sub-populations within the bay may buffer the Ryman-Laikre effect and ensure the retention of the local genetic variability.

  10. “URM Candidates Are Encouraged to Apply”: A National Study to Identify Effective Strategies to Enhance Racial and Ethnic Faculty Diversity in Academic Departments of Medicine

    PubMed Central

    Peek, Monica E.; Kim, Karen E.; Johnson, Julie K.; Vela, Monica B.

    2016-01-01

    Purpose There is little evidence regarding which factors and strategies are associated with high proportions of underrepresented minority (URM) faculty in academic medicine. The authors conducted a national study of U.S. academic medicine departments to better understand the challenges, successful strategies, and predictive factors for enhancing racial and ethnic diversity among faculty (i.e., physicians with an academic position or rank). Method This was a mixed-methods study using quantitative and qualitative methods. The authors conducted a cross-sectional study of eligible departments of medicine in 125 accredited U.S. medical schools, dichotomized into low-URM (bottom 50%) versus high-URM rank (top 50%). They used t tests and chi-squared tests to compare departments by geographic region, academic school rank, city type, and composite measures of “diversity best practices.” The authors also conducted semistructured in-depth interviews with a subsample from the highest-and lowest-quartile medical schools in terms of URM rank. Results Eighty-two medical schools responded (66%). Geographic region and academic rank were statistically associated with URM rank, but not city type or composite measures of diversity best practices. Key themes emerged from interviews regarding successful strategies for URM faculty recruitment and retention including institutional leadership, the use of human capital and social relationships and strategic deployment of institutional resources. Conclusions Departments of medicine with high proportions of URM faculty employ a number of successful strategies and programs for recruitment and retention. More research is warranted to identify new successful strategies and to determine the impact of specific strategies on establishing and maintaining workforce diversity. PMID:23348090

  11. "URM candidates are encouraged to apply": a national study to identify effective strategies to enhance racial and ethnic faculty diversity in academic departments of medicine.

    PubMed

    Peek, Monica E; Kim, Karen E; Johnson, Julie K; Vela, Monica B

    2013-03-01

    There is little evidence regarding which factors and strategies are associated with high proportions of underrepresented minority (URM) faculty in academic medicine. The authors conducted a national study of U.S. academic medicine departments to better understand the challenges, successful strategies, and predictive factors for enhancing racial and ethnic diversity among faculty (i.e., physicians with an academic position or rank). This was a mixed-methods study using quantitative and qualitative methods. The authors conducted a cross-sectional study of eligible departments of medicine in 125 accredited U.S. medical schools, dichotomized into low-URM (bottom 50%) versus high-URM rank (top 50%). They used t tests and chi-squared tests to compare departments by geographic region, academic school rank, city type, and composite measures of "diversity best practices." The authors also conducted semistructured in-depth interviews with a subsample from the highest- and lowest-quartile medical schools in terms of URM rank. Eighty-two medical schools responded (66%). Geographic region and academic rank were statistically associated with URM rank, but not city type or composite measures of diversity best practices. Key themes emerged from interviews regarding successful strategies for URM faculty recruitment and retention, including institutional leadership, the use of human capital and social relationships, and strategic deployment of institutional resources. Departments of medicine with high proportions of URM faculty employ a number of successful strategies and programs for recruitment and retention. More research is warranted to identify new successful strategies and to determine the impact of specific strategies on establishing and maintaining workforce diversity.

  12. Understanding and enhancing the learning experiences of culturally and linguistically diverse nursing students in an Australian bachelor of nursing program.

    PubMed

    Jeong, Sarah Yeun-Sim; Hickey, Noelene; Levett-Jones, Tracy; Pitt, Victoria; Hoffman, Kerry; Norton, Carol Anne; Ohr, Se Ok

    2011-04-01

    The growth in numbers of culturally and linguistically diverse students entering nursing programs in Australia presents challenges for academic and clinical staff, and most importantly the students themselves. In this paper we present the findings from a pilot study designed to explore these issues and to develop strategies to address them. This study used a qualitative explorative approach to gain rich in-depth data. Eleven culturally and linguistically diverse students, three clinical facilitators, and four academic staff participated in focus group interviews. Four major themes emerged: level of English language competence, feelings of isolation, limited opportunities for learning, and inadequate university support. The issues we identified led to a meaningful discussion of the political, financial, social and intercultural context that they are entrapped in. This paper provides educators, clinicians, policy makers and researchers with an insight where and how they commence to break the trap and highlights, the need for further research into the perspectives of Australian students' who study and socialise with their international peers. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Rhizosphere competent Pantoea agglomerans enhances maize (Zea mays) and chickpea (Cicer arietinum L.) growth, without altering the rhizosphere functional diversity.

    PubMed

    Mishra, Aradhana; Chauhan, Puneet Singh; Chaudhry, Vasvi; Tripathi, Manisha; Nautiyal, Chandra Shekhar

    2011-10-01

    Plant growth promoting Pantoea agglomerans NBRISRM (NBRISRM) was able to produce 60.4 μg/ml indole acetic acid and solubilize 77.5 μg/ml tri-calcium phosphate under in vitro conditions. Addition of 2% NaCl (w/v) in the media induced the IAA production and phosphate solubilization by 11% and 7%, respectively. For evaluating the plant growth promotory effect of NBRISRM inoculation a micro plot trial was conducted using maize and chickpea as host plants. The results revealed significant increase in all growth parameters tested in NBRISRM inoculated maize and chickpea plants, which were further confirmed by higher macronutrients (N, P and K) accumulation as compared to un-inoculated controls. Throughout the growing season of maize and chickpea, rhizosphere population of NBRISRM were in the range 10(7)-10(8) CFU/g soil and competing with 10(7)-10(9) CFU/g soil with heterogeneous bacterial population. Functional richness, diversity, and evenness were found significantly higher in maize rhizosphere as compared to chickpea, whereas NBRISRM inoculation were not able to change it, in both crops as compared to their un-inoculated control. To the best of our knowledge this is first report where we demonstrated the effect of P. agglomerans strain for improving maize and chickpea growth without altering the functional diversity.

  14. Effectiveness of a redesigned water diversion using rock vortex weirs to enhance longitudinal connectivity for small Salmonids

    USGS Publications Warehouse

    Martens, Kyle D.; Connolly, Patrick J.

    2010-01-01

    For nearly 100 years, water diversions have affected fish passage in Beaver Creek, a tributary of the lower Methow River in north-central Washington State. From 2000 to 2004, four dam-style water diversions were replaced with a series of rock vortex weirs (RVWs). The weirs were designed to allow fish passage while maintaining the ability to divert water into irrigation canals. We observed the new appearance of three species (juvenile Chinook salmon Oncorhynchus tshawytscha, juvenile coho salmon O. kisutch, and mountain whitefish Prosopium williamsoni) upstream of the RVWs, indicating successful restoration of longitudinal connectivity. We used passive integrated transponder (PIT) tags and instream PIT tag interrogation systems during 2004–2007 to evaluate upstream passage of small salmonids (<240 mm fork length) through one series of RVWs. We documented 109 upstream passage events by small salmonids through the series of RVWs; most of the events (81%) involved passage of rainbow trout O. mykiss or juvenile steelhead (anadromous rainbow trout). Small rainbow trout or steelhead ranging from 86 to 238 mm (adjusted fork length) were able to pass upstream through the RVWs, although a delay in fish passage at discharges below 0.32 m3/s was detected in comparison with nearby control sections.

  15. The Germplasm Enhancement of Maize (GEM) project: A Public-Private Partnership (PPP) to increase genetic diversity in US maize

    USDA-ARS?s Scientific Manuscript database

    The Germplasm Enhancement of Maize (GEM) Project is a mission-oriented, cooperative research effort of the United States Department of Agriculture – Agricultural Research Service (USDA-ARS), land grant universities, private industry, and international agricultural research centers to broaden the ger...

  16. WATER AS A REAGENT FOR SOIL REMEDIATION

    SciTech Connect

    Indira S. Jayaweera; Jordi Diaz-Ferraro

    2000-02-28

    SRI International is conducting experiments to develop and evaluate hydrothermal extraction technology for remediating petroleum-contaminated soils. Most current remediation practices generally fail (or are cost prohibitive) to remove the polycyclic aromatic hydrocarbons (PAHs) found in petroleum-contaminated sites or they require the use of organic solvents to achieve removal, at the expense of additional contamination and with the added cost of recycling solvents. Hydrothermal extraction offers the promise of efficiently extracting PAHs and other kinds of organics from contaminated soils at moderate temperatures and pressures, using only water and inorganic salts such as carbonate. Initial work is being conducted at SRI to measure the solubility and rate of solubilization of selected PAHs (anthracene, fluoranthene, pyrene, and chrysene) in water, using SRI's hydrothermal optical cell with the addition of varying amounts of sodium carbonate to evaluate the efficiency of the technology for removing PAHs from the soil. Preliminary results with pyrene and fluoranthene in water clearly indicate a significant enhancement of solubility with increase in temperature. During this quarter, we conducted experiments with pyrene in the temperature range 200 to 300 C and observed a great enhancement in solubility with an increase in temperature. We also started experiments with real-world soil samples purchased from the subcontractor.

  17. Surfactants and cosolvents for NAPL remediation. A technologies practices manual

    SciTech Connect

    Lowe, D.F.; Oubre, C.L.; Ward, C.H.

    1999-11-01

    This book gives you tools to provide assistance in the application of surfactant- and cosolvent-based flushing technologies to subsurface remediation. Written for the field practitioners, the book covers important aspects--from design to operation--of this unique remediation technique. Topics of discussion include the following: technology description and current status; geology and contaminant distribution; surfactant/cosolvent enhanced recovery of NAPL; produced fluids and management and surfactant/cosolvent flushing; cost considerations; field project case studies; literature summary database; cost worksheets/design worksheets; surfactant cost estimates; and future research.

  18. Recombination enhances HIV-1 envelope diversity by facilitating the survival of latent genomic fragments in the plasma virus population

    DOE PAGES

    Immonen, Taina T.; Conway, Jessica M.; Romero-Severson, Ethan O.; ...

    2015-12-22

    HIV-1 is subject to immune pressure exerted by the host, giving variants that escape the immune response an advantage. Virus released from activated latent cells competes against variants that have continually evolved and adapted to host immune pressure. Nevertheless, there is increasing evidence that virus displaying a signal of latency survives in patient plasma despite having reduced fitness due to long-term immune memory. We investigated the survival of virus with latent envelope genomic fragments by simulating within-host HIV-1 sequence evolution and the cycling of viral lineages in and out of the latent reservoir. Our model incorporates a detailed mutation processmore » including nucleotide substitution, recombination, latent reservoir dynamics, diversifying selection pressure driven by the immune response, and purifying selection pressure asserted by deleterious mutations. We evaluated the ability of our model to capture sequence evolution in vivo by comparing our simulated sequences to HIV-1 envelope sequence data from 16 HIV-infected untreated patients. Empirical sequence divergence and diversity measures were qualitatively and quantitatively similar to those of our simulated HIV-1 populations, suggesting that our model invokes realistic trends of HIV-1 genetic evolution. Moreover, reconstructed phylogenies of simulated and patient HIV-1 populations showed similar topological structures. Our simulation results suggest that recombination is a key mechanism facilitating the persistence of virus with latent envelope genomic fragments in the productively infected cell population. Recombination increased the survival probability of latent virus forms approximately 13-fold. Prevalence of virus with latent fragments in productively infected cells was observed in only 2% of simulations when we ignored recombination, while the proportion increased to 27% of simulations when we allowed recombination. We also found that the selection pressures exerted by different

  19. Overcoming Antigenic Diversity by Enhancing the Immunogenicity of Conserved Epitopes on the Malaria Vaccine Candidate Apical Membrane Antigen-1

    PubMed Central

    Dutta, Sheetij; Dlugosz, Lisa S.; Drew, Damien R.; Ge, Xiopeng; Ababacar, Diouf; Rovira, Yazmin I.; Moch, J. Kathleen; Shi, Meng; Long, Carole A.; Foley, Michael; Beeson, James G.; Anders, Robin F.; Miura, Kazutoyo; Haynes, J. David; Batchelor, Adrian H.

    2013-01-01

    Malaria vaccine candidate Apical Membrane Antigen-1 (AMA1) induces protection, but only against parasite strains that are closely related to the vaccine. Overcoming the AMA1 diversity problem will require an understanding of the structural basis of cross-strain invasion inhibition. A vaccine containing four diverse allelic proteins 3D7, FVO, HB3 and W2mef (AMA1 Quadvax or QV) elicited polyclonal rabbit antibodies that similarly inhibited the invasion of four vaccine and 22 non-vaccine strains of P. falciparum. Comparing polyclonal anti-QV with antibodies against a strain-specific, monovalent, 3D7 AMA1 vaccine revealed that QV induced higher levels of broadly inhibitory antibodies which were associated with increased conserved face and domain-3 responses and reduced domain-2 response. Inhibitory monoclonal antibodies (mAb) raised against the QV reacted with a novel cross-reactive epitope at the rim of the hydrophobic trough on domain-1; this epitope mapped to the conserved face of AMA1 and it encompassed the 1e-loop. MAbs binding to the 1e-loop region (1B10, 4E8 and 4E11) were ∼10-fold more potent than previously characterized AMA1-inhibitory mAbs and a mode of action of these 1e-loop mAbs was the inhibition of AMA1 binding to its ligand RON2. Unlike the epitope of a previously characterized 3D7-specific mAb, 1F9, the 1e-loop inhibitory epitope was partially conserved across strains. Another novel mAb, 1E10, which bound to domain-3, was broadly inhibitory and it blocked the proteolytic processing of AMA1. By itself mAb 1E10 was weakly inhibitory but it synergized with a previously characterized, strain-transcending mAb, 4G2, which binds close to the hydrophobic trough on the conserved face and inhibits RON2 binding to AMA1. Novel inhibition susceptible regions and epitopes, identified here, can form the basis for improving the antigenic breadth and inhibitory response of AMA1 vaccines. Vaccination with a few diverse antigenic proteins could provide universal

  20. Strategies for Monitoring the Performance of DNAPL Source Zone Remedies. Technical/Regulatory Guidelines

    DTIC Science & Technology

    2004-08-01

    Environmental Geotechnology, Balkema AA, Rotterdam, The Netherlands, pp. 311–20. Davis, E.L. 1997. “How Heat Can Enhance In-Situ Soil and Aquifer...Area A remediation. The remediation design used a combination of steam- enhanced extraction (SEE) and electrical resistance heating (ERH) of soil and...TCE is biodegraded via reductive dechlorination, greater than 99% of the TCE is transformed to cis-DCE rather than trans-DCE. Thus, it is unlikely

  1. Spectral induced polarization for monitoring electrokinetic remediation processes

    NASA Astrophysics Data System (ADS)

    Masi, Matteo; Losito, Gabriella

    2015-12-01

    Electrokinetic remediation is an emerging technology for extracting heavy metals from contaminated soils and sediments. This method uses a direct or alternating electric field to induce the transport of contaminants toward the electrodes. The electric field also produces pH variations, sorption/desorption and precipitation/dissolution of species in the porous medium during remediation. Since heavy metal mobility is pH-dependent, the accurate control of pH inside the material is required in order to enhance the removal efficiency. The common approach for monitoring the remediation process both in laboratory and in the field is the chemical analysis of samples collected from discrete locations. The purpose of this study is the evaluation of Spectral Induced Polarization as an alternative method for monitoring geochemical changes in the contaminated mass during remediation. The advantage of this technique applied to field-scale is to offer higher resolution mapping of the remediation site and lower cost compared to the conventional sampling procedure. We carried out laboratory-scale electrokinetic remediation experiments on fine-grained marine sediments contaminated by heavy metal and we made Spectral Induced Polarization measurements before and after each treatment. Measurements were done in the frequency range 10- 3-103 Hz. By the deconvolution of the spectra using the Debye Decomposition method we obtained the mean relaxation time and total chargeability. The main finding of this work is that a linear relationship exists between the local total chargeability and pH, with good agreement. The observed behaviour of chargeability is interpreted as a direct consequence of the alteration of the zeta potential of the sediment particles due to pH changes. Such relationship has a significant value for the interpretation of induced polarization data, allowing the use of this technique for monitoring electrokinetic remediation at field-scale.

  2. Mathematical Modelling of Bacterial Populations in Bio-remediation Processes

    NASA Astrophysics Data System (ADS)

    Vasiliadou, Ioanna A.; Vayenas, Dimitris V.; Chrysikopoulos, Constantinos V.

    2011-09-01

    An understanding of bacterial behaviour concerns many field applications, such as the enhancement of water, wastewater and subsurface bio-remediation, the prevention of environmental pollution and the protection of human health. Numerous microorganisms have been identified to be able to degrade chemical pollutants, thus, a variety of bacteria are known that can be used in bio-remediation processes. In this study the development of mathematical models capable of describing bacterial behaviour considered in bio-augmentation plans, such as bacterial growth, consumption of nutrients, removal of pollutants, bacterial transport and attachment in porous media, is presented. The mathematical models may be used as a guide in designing and assessing the conditions under which areas contaminated with pollutants can be better remediated.

  3. The norms, rules and motivational values driving sustainable remediation of contaminated environments: A study of implementation.

    PubMed

    Prior, Jason

    2016-02-15

    Efforts to achieve sustainability are transforming the norms, rules and values that affect the remediation of contaminated environments. This is altering the ways in which remediation impacts on the total environment. Despite this transformation, few studies have provided systematic insights into the diverse norms and rules that drive the implementation of sustainable remediation at contaminated sites, and no studies have investigated how values motivate compliance with these norms and rules. This study is a systematic analysis of the rules, norms and motivational values embedded in sustainable remediation processes at three sites across Australia, using in-depth interviews conducted with 18 participants between 2011 and 2014, through the application of Crawford and Ostrom's Institutional Grammar and Schwartz's value framework. These approaches offered methods for identifying the rules, norms, and motivational values that guided participants' actions within remediation processes at these sites. The findings identify a core set of 16 norms and 18 rules (sanctions) used by participants to implement sustainable remediation at the sites. These norms and rules: define the position of participants within the process, provide means for incorporating sustainability into established remediation practices, and define the scope of outcomes that constitute sustainable remediation. The findings revealed that motivational values focused on public interest and self-interest influenced participants' compliance with norms and rules. The findings also found strong interdependence between the norms and rules (sanctions) within the remediation processes and the normative principles operating within the broader domain of environmental management and planning. The paper concludes with a discussion of: the system of norms operating within sustainable remediation (which far exceed those associated with ESD); their link, through rules (sanctions) to contemporary styles of regulatory

  4. The arsenic resistance listeria genomic island LGI2 exhibits sequence and integration site diversity and propensity for three Listeria monocytogenes clones with enhanced virulence.

    PubMed

    Lee, Sangmi; Ward, Todd J; Jima, Dereje D; Parsons, Cameron; Kathariou, Sophia

    2017-08-25

    In the foodborne pathogen Listeria monocytogenes, arsenic resistance is primarily encountered in serotype 4b clones considered to have enhanced virulence, and is associated with an arsenic resistance gene cluster within a 35 kb chromosomal region, Listeria genomic island 2 (LGI2). LGI2 was first identified in strain Scott A and includes genes putatively involved in arsenic and cadmium resistance, DNA integration, conjugation and pathogenicity. However, genomic localization and sequence content of LGI2 remain poorly characterized. Here we investigated 85 arsenic-resistant L. monocytogenes strains, mostly of serotype 4b. All but one of the 70 serotype 4b strains belonged to clonal complexes CC1, CC2 and CC4, three major clones associated with enhanced virulence. PCR analysis suggested that 53 strains (62.4%) harbored an island highly similar to LGI2 of Scott A, frequently (42/53) in the same location as Scott A (LMOf2365_2257 homolog). Random-primed PCR and whole genome sequencing revealed seven novel insertion sites, mostly internal to chromosomal coding sequences, among strains harboring LGI2 outside the LMOf2365_2257 homolog. Interestingly, many CC1 strains harbored a noticeably diversified LGI2 (LGI2-1) in a unique location (LMOf2365_0902 homolog), and with a novel additional gene. With few exceptions, the tested LGI2 genes were not detected in arsenic-resistant strains of serogroup 1/2, which instead often harbored a Tn554-associated arsenic resistance determinant not encountered in serotype 4b. These findings indicate that in L. monocytogenes LGI2 has a propensity for certain serotype 4b clones, exhibits content diversity and is highly promiscuous, suggesting ability to mobilize various accessory genes into diverse chromosomal loci.IMPORTANCEListeria monocytogenes is widely distributed in the environment and causes listeriosis, a foodborne disease with high mortality and morbidity. Arsenic and other heavy metals can powerfully shape the populations of human

  5. Remediation of uranium impacted sediments in a watercourse

    SciTech Connect

    Shephard, Eugene; Walter, Nelson; Downey, Heath; Collopy, Peter; Conant, John

    2013-07-01

    In 2009, remediation was initiated for a non-operational fuel cycle facility previously used for government contract work located in Windsor, Connecticut, USA. Radiological contaminants consisted primarily of high enriched uranium (HEU). Other radionuclides encountered in relatively minor amounts in certain areas of the clean-up included Co-60, Cs- 137, Ra-226, Th-232 and low enriched uranium (LEU).Between 2009 and the spring of 2011, remediation efforts were focused on demolition of contaminated buildings and removal of contaminated soil. In the late spring of 2011, the last phase of remediation commenced involving the removal of contaminated sediments from portions of a 1,200 meter long gaining stream. Planning and preparation for remediation of the stream began in 2009 with submittal of permit applications to undertake construction activities in a wetland area. The permitting process was lengthy and involved securing permits from multiple agencies. However, early and frequent communication with stakeholders played an integral role in efficiently obtaining the permit approvals. Frequent communication with stakeholders throughout the planning and remediation process also proved to be a key factor in timely completion of the project. The remediation of the stream involved the use of temporary bladder berms to divert surface water flow, water diversion piping, a sediment vacuum removal system, excavation of sediments using small front-end loaders, sediment dewatering, and waste packaging, transportation and disposal. Many safeguards were employed to protect several species of concern in the work area, water management during project activities, challenges encountered during the project, methods of Final Status Survey, and stream restoration. (authors)

  6. Natural attenuation software (NAS): Assessing remedial strategies and estimating timeframes

    USGS Publications Warehouse

    Mendez, E.; Widdowson, M.; Chapelle, F.; Casey, C.

    2005-01-01

    Natural Attenuation Software (NAS) is a screening tool to estimate remediation timeframes for monitored natural attenuation (MNA) and to assist in decision-making on the level of source zone treatment in conjunction with MNA using site-specific remediation objectives. Natural attenuation processes that NAS models include are advection, dispersion, sorption, non-aqueous phase liquid (NAPL) dissolution, and biodegradation of either petroleum hydrocarbons or chlorinated ethylenes. Newly-implemented enhancements to NAS designed to maximize the utility of NAS for site managers were observed. NAS has expanded source contaminant specification options to include chlorinated ethanes and chlorinated methanes, and to allow for the analysis of any other user-defined contaminants that may be subject to microbially-mediated transformations (heavy metals, radioisotopes, etc.). Included is the capability to model co-mingled plumes, with constituents from multiple contaminant categories. To enable comparison of remediation timeframe estimates between MNA and specific engineered remedial actions , NAS was modified to incorporate an estimation technique for timeframes associated with pump-and-treat remediation technology for comparison to MNA. This is an abstract of a paper presented at the 8th International In Situ and On-Site Bioremediation Symposium (Baltimore, MD 6/6-9/2005).

  7. Polyphosphate Remediation Technology for In-Situ Stabilization of Uranium

    SciTech Connect

    Wellman, Dawn M.; Pierce, Eric M.; Bacon, Diana H.; Fruchter, Jonathan S.; Vermeul, Vincent R.; Webb, Samuel M.

    2009-03-01

    A labortory testing program has been conducted to optimize polyphosphate remediation technology for implementation through a field-scale technology infiltration demonstration to stabilize soluble, uranium-bearing source phases in the vadose zone and capillary fringe. Source treatment in the deep vadose zone will accelerate the natural attenuation of uranium to more thermodynamically stable uranium-phosphate minerals, enhancing the performance of the proposed polyphosphate remediation within the 300 Area aquifer. The objective of this investigation was to develop polyphosphate remediation technology to treat uranium contamination contained within the deep vadose zone and capillary fringe. This paper presents the results of an investigation that evaluated the rate and extent of reaction between polyphosphate and the uranium mineral phases present within the 300 Area vadose zone and capillary fringe and autunite formation as a function of polyphosphate formulation and concentration. This information is critical for identifying the optimum implementation approach and controlling the flux of uranium from the vadose zone and capillary fringe to the underlying aquifer during remediation. Results from this investigation will be used to design a full-scale remediation of uranium at the 300 Area of the Hanford Site.

  8. Combined remediation technologies: results from field trials at chlorinated solvent impacted sites

    NASA Astrophysics Data System (ADS)

    O'Carroll, D. M.; Chowdhury, A. I.; Lomheim, L.; Boparai, H. K.; Weber, K.; Austrins, L. M.; Edwards, E.; Sleep, B.; de Boer, C. V.; Garcia, A. N.

    2015-12-01

    Non-aqueous phase liquids (NAPLs) are one class of waste liquids often generated from waste mixtures in industrial processes containing surfactants, chlorinated hydrocarbons and other compounds. Chlorinated solvents, a particularly persistent NAPL contaminant, frequently contaminate water sources for decades and are one of the more common contaminants at brownfield and industrialized sites. Although considerable advances in our understanding of the phenomena governing NAPL remediation have been made, and a number of innovative remediation technologies have been developed, existing technologies are rarely able to achieve clean up goals in contaminated aquifers at the completion of remedial activities. The development and pilot scale testing of new and innovative remediation technologies is, therefore, crucial to achieve clean up goals at contaminated sites. Our research group is currently investigating a number of innovative remediation technologies, either individually or as combined remedies. This includes the applicability of nanometals and ISCO (e.g., persulfate) for contaminated site remediation. These technologies can be combined with technologies to enhance amendment delivery (e.g., electrokinetics) or create conditions favorable for enhanced biotic contaminant degradation. This presentation will discuss outcomes from a number of field trials conducted at chlorinated solvent impacted sites by our group with a particular focus on combined remediation technologies.

  9. SURFACTANTS AND SUBSURFACE REMEDIATION

    EPA Science Inventory

    Because of the limitations of pump-and-trat technology, attention is now focused on the feasibility of surfactant use to increase its efficiency. Surfactants have been studied for use in soil washing and enhanced oil recovery. Although similarities exist between the application...

  10. SURFACTANTS AND SUBSURFACE REMEDIATION

    EPA Science Inventory

    Because of the limitations of pump-and-trat technology, attention is now focused on the feasibility of surfactant use to increase its efficiency. Surfactants have been studied for use in soil washing and enhanced oil recovery. Although similarities exist between the application...

  11. The Geoscience Diversity Enhancement Program (GDEP): A Model for Faculty and Student Engagement in Urban Geoscience Research

    NASA Astrophysics Data System (ADS)

    Ambos, E. L.; Lee, C.; Behl, R.; Francis, R. D.; Holk, G.; Larson, D.; Rodrigue, C.; Wechsler, S.; Whitney, D.

    2004-12-01

    For the past three years (2002-2004) faculty in the departments of geological sciences, geography, and anthropology at California State University, Long Beach have joined to offer an NSF-funded (GEO-0119891) eight-week summer research experience to faculty and students at Long Beach area high schools and community colleges. GDEP's goal is to increase the numbers of students from underrepresented groups (African-American, Hispanic, American Indian, Pacific Islander, and disabled) enrolling in baccalaureate degree programs in the geosciences. The major strategies to achieve this goal all tie to the concept of research-centered experiences, which might also be termed inquiry-based instruction. More than fifteen (15) separate and diverse geoscience research studies have been conducted. These include such disparate topics as geochemical studies of fault veins, GPS/GIS surveys of vegetation patterns for fire hazard assessment, and seismic studies of offshore fault systems. As the program has matured, research projects have become more interdisciplinary, and faculty research teams have expanded. Whereas the first year, each CSULB faculty member tended to lead her/his project as a separate endeavor, by the third summer, faculty were collaborating in research teams. Several projects have involved community-based research, at sites within an hour's drive from the urban Long Beach campus. For example, last summer, four faculty linked together to conduct a comprehensive geography and geology study of an Orange County wilderness area, resulting in creation of maps, brochures, and websites for use by the general public. Another faculty group conducted geophysical surveys at an historic archaeological site in downtown Los Angeles, producing maps of underground features that will be incorporated into a cultural center and museum. Over the past three summers, the program has grown to involve more than 25 high school and community college students, and more than 30 CSULB, high

  12. Diverse Thinking about Diversity

    ERIC Educational Resources Information Center

    Kaplan, Sandra N.

    2013-01-01

    This article focuses on the concept of diversity in educational decision making. It is noted that the differences that distinguish the needs, interests and abilities are identified by educators. It lists misconceptions resulting from not attending to within-group diversity, and states that a "loss of self" for individual members of…

  13. Diverse Thinking about Diversity

    ERIC Educational Resources Information Center

    Kaplan, Sandra N.

    2013-01-01

    This article focuses on the concept of diversity in educational decision making. It is noted that the differences that distinguish the needs, interests and abilities are identified by educators. It lists misconceptions resulting from not attending to within-group diversity, and states that a "loss of self" for individual members of…

  14. Enhancing diversity in the public health research workforce: the research and mentorship program for future HIV vaccine scientists.

    PubMed

    Sopher, Carrie J; Adamson, Blythe Jane S; Andrasik, Michele P; Flood, Danna M; Wakefield, Steven F; Stoff, David M; Cook, Ryan S; Kublin, James G; Fuchs, Jonathan D

    2015-04-01

    We developed and evaluated a novel National Institutes of Health-sponsored Research and Mentorship Program for African American and Hispanic medical students embedded within the international, multisite HIV Vaccine Trials Network, and explored its impact on scientific knowledge, acquired skills, and future career plans. Scholars conducted social, behavioral, clinical, or laboratory-based research projects with HIV Vaccine Trials Network investigators over 8 to 16 weeks (track 1) or 9 to 12 months (track 2). We conducted an in-depth, mixed-methods evaluation of the first 2 cohorts (2011-2013) to identify program strengths, areas for improvement, and influence on professional development. A pre-post program assessment demonstrated increases in self-reported knowledge, professional skills, and interest in future HIV vaccine research. During in-depth interviews, scholars reported that a supportive, centrally administered program; available funding; and highly involved mentors and staff were keys to the program's early success. A multicomponent, mentored research experience that engages medical students from underrepresented communities and is organized within a clinical trials network may expand the pool of diverse public health scientists. Efforts to sustain scholar interest over time and track career trajectories are warranted.

  15. Enhancing Diversity in the Public Health Research Workforce: The Research and Mentorship Program for Future HIV Vaccine Scientists

    PubMed Central

    Adamson, Blythe Jane S.; Andrasik, Michele P.; Flood, Danna M.; Wakefield, Steven F.; Stoff, David M.; Cook, Ryan S.; Kublin, James G.; Fuchs, Jonathan D.

    2015-01-01

    Objectives. We developed and evaluated a novel National Institutes of Health–sponsored Research and Mentorship Program for African American and Hispanic medical students embedded within the international, multisite HIV Vaccine Trials Network, and explored its impact on scientific knowledge, acquired skills, and future career plans. Methods. Scholars conducted social, behavioral, clinical, or laboratory-based research projects with HIV Vaccine Trials Network investigators over 8 to 16 weeks (track 1) or 9 to 12 months (track 2). We conducted an in-depth, mixed-methods evaluation of the first 2 cohorts (2011–2013) to identify program strengths, areas for improvement, and influence on professional development. Results. A pre–post program assessment demonstrated increases in self-reported knowledge, professional skills, and interest in future HIV vaccine research. During in-depth interviews, scholars reported that a supportive, centrally administered program; available funding; and highly involved mentors and staff were keys to the program’s early success. Conclusions. A multicomponent, mentored research experience that engages medical students from underrepresented communities and is organized within a clinical trials network may expand the pool of diverse public health scientists. Efforts to sustain scholar interest over time and track career trajectories are warranted. PMID:25122028

  16. Remedial Action Contacts Directory - 1997

    SciTech Connect

    1997-05-01

    This document, which was prepared for the US Department of Energy (DOE) Office of Environmental Restoration (ER), is a directory of 2628 individuals interested or involved in environmental restoration and/or remedial actions at radioactively contaminated sites. This directory contains a list of mailing addresses and phone numbers of DOE operations, area, site, project, and contractor offices; an index of DOE operations, area, site, project, and contractor office sorted by state; a list of individuals, presented by last name, facsimile number, and e-mail address; an index of affiliations presented alphabetically, with individual contacts appearing below each affiliation name; and an index of foreign contacta sorted by country and affiliation. This document was generated from the Remedial Action Contacts Database, which is maintained by the Remedial Action Program Information Center (RAPIC).

  17. Perceptions of Risk of Developing Skin Cancer for Diverse Audiences: Enhancing Relevance of Sun Protection to Reduce the Risk.

    PubMed

    Robinson, June K; Friedewald, John; Gordon, Elisa J

    2016-03-01

    Sixty-five percent of kidney transplant recipients (KTRs) develop squamous cell carcinoma (SCC). Perceptions of risk of developing skin cancer, amelioration of this risk with sun protection, and having choices among sun protection strategies may enhance sun protection use by KTRS, who are at greater risk than the general population. Thirty KTRs stratified among non-Hispanic Whites, non-Hispanic Blacks, and Hispanic/Latinos evaluated three versions of the interactive, web-based, electronic sun protection program and suggested refinements. The sequence of content presentation prepared the participant to accept the credibility, accuracy, and relevance of the message. Beginning with informing participants that using sun protection reduces the chance of developing skin cancer made the information credible to KTRs. Showing skin cancer on all skin types and patient testimonials enhanced participants' awareness of their susceptibility to develop skin cancer and primed patients to receive their personal risk of developing skin cancer. Coupling presentation of knowledge about the benefits of sun protection in reducing the risk of developing skin cancer with the personal risk of getting the disease was essential to KTRs believing that they could influence their health outcome.

  18. Perceptions of Risk of Developing Skin Cancer for Diverse Audiences: Enhancing Relevance of Sun Protection to Reduce the Risk

    PubMed Central

    Friedewald, John; Gordon, Elisa J.

    2016-01-01

    Sixty-five percent of kidney transplant recipients (KTRs) develop squamous cell carcinoma (SCC). Perceptions of risk of developing skin cancer, amelioration of this risk with sun protection, and having choices among sun protection strategies may enhance sun protection use by KTRS, who are at greater risk than the general population. Thirty KTRs stratified among non-Hispanic Whites, non-Hispanic Blacks, and Hispanic/Latinos evaluated three versions of the interactive, web-based, electronic sun protection program and suggested refinements. The sequence of content presentation prepared the participant to accept the credibility, accuracy, and relevance of the message. Beginning with informing participants that using sun protection reduces the chance of developing skin cancer made the information credible to KTRs. Showing skin cancer on all skin types and patient testimonials enhanced participants' awareness of their susceptibility to develop skin cancer and primed patients to receive their personal risk of developing skin cancer. Coupling presentation of knowledge about the benefits of sun protection in reducing the risk of developing skin cancer with the personal risk of getting the disease was essential to KTRs believing that they could influence their health outcome. PMID:26209181

  19. Harnessing Diversity in Wheat to Enhance Grain Yield, Climate Resilience, Disease and Insect Pest Resistance and Nutrition Through Conventional and Modern Breeding Approaches

    PubMed Central

    Mondal, Suchismita; Rutkoski, Jessica E.; Velu, Govindan; Singh, Pawan K.; Crespo-Herrera, Leonardo A.; Guzmán, Carlos; Bhavani, Sridhar; Lan, Caixia; He, Xinyao; Singh, Ravi P.

    2016-01-01

    Current trends in population growth and consumption patterns continue to increase the demand for wheat, a key cereal for global food security. Further, multiple abiotic challenges due to climate change and evolving pathogen and pests pose a major concern for increasing wheat production globally. Triticeae species comprising of primary, secondary, and tertiary gene pools represent a rich source of genetic diversity in wheat. The conventional breeding strategies of direct hybridization, backcrossing and selection have successfully introgressed a number of desirable traits associated with grain yield, adaptation to abiotic stresses, disease resistance, and bio-fortification of wheat varieties. However, it is time consuming to incorporate genes conferring tolerance/resistance to multiple stresses in a single wheat variety by conventional approaches due to limitations in screening methods and the lower probabilities of combining desirable alleles. Efforts on developing innovative breeding strategies, novel tools and utilizing genetic diversity for new genes/alleles are essential to improve productivity, reduce vulnerability to diseases and pests and enhance nutritional quality. New technologies of high-throughput phenotyping, genome sequencing and genomic selection are promising approaches to maximize progeny screening and selection to accelerate the genetic gains in breeding more productive varieties. Use of cisgenic techniques to transfer beneficial alleles and their combinations within related species also offer great promise especially to achieve durable rust resistance. PMID:27458472

  20. Harnessing Diversity in Wheat to Enhance Grain Yield, Climate Resilience, Disease and Insect Pest Resistance and Nutrition Through Conventional and Modern Breeding Approaches.

    PubMed

    Mondal, Suchismita; Rutkoski, Jessica E; Velu, Govindan; Singh, Pawan K; Crespo-Herrera, Leonardo A; Guzmán, Carlos; Bhavani, Sridhar; Lan, Caixia; He, Xinyao; Singh, Ravi P

    2016-01-01

    Current trends in population growth and consumption patterns continue to increase the demand for wheat, a key cereal for global food security. Further, multiple abiotic challenges due to climate change and evolving pathogen and pests pose a major concern for increasing wheat production globally. Triticeae species comprising of primary, secondary, and tertiary gene pools represent a rich source of genetic diversity in wheat. The conventional breeding strategies of direct hybridization, backcrossing and selection have successfully introgressed a number of desirable traits associated with grain yield, adaptation to abiotic stresses, disease resistance, and bio-fortification of wheat varieties. However, it is time consuming to incorporate genes conferring tolerance/resistance to multiple stresses in a single wheat variety by conventional approaches due to limitations in screening methods and the lower probabilities of combining desirable alleles. Efforts on developing innovative breeding strategies, novel tools and utilizing genetic diversity for new genes/alleles are essential to improve productivity, reduce vulnerability to diseases and pests and enhance nutritional quality. New technologies of high-throughput phenotyping, genome sequencing and genomic selection are promising approaches to maximize progeny screening and selection to accelerate the genetic gains in breeding more productive varieties. Use of cisgenic techniques to transfer beneficial alleles and their combinations within related species also offer great promise especially to achieve durable rust resistance.