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Articles 4861 - 4890 of 11222

Full-Text Articles in Engineering

Determining Individual Mineral Contributions To U(Vi) Adsorption In A Contaminated Aquifer Sediment: A Fluorescence Spectroscopy Study, Zheming Wang, John M. Zachara, Jean-Francois Boily, Yuanxian Xia, Tom C. Resch, Dean A. Moore, Chongxuan Liu Jan 2011

Determining Individual Mineral Contributions To U(Vi) Adsorption In A Contaminated Aquifer Sediment: A Fluorescence Spectroscopy Study, Zheming Wang, John M. Zachara, Jean-Francois Boily, Yuanxian Xia, Tom C. Resch, Dean A. Moore, Chongxuan Liu

United States Department of Energy: Publications

The adsorption and speciation of U(VI) was investigated on contaminated, fine grained sediment materials from the Hanford 300 area (SPP1 GWF) in simulated groundwater using cryogenic laser-induced U(VI) fluorescence spectroscopy combined with chemometric analysis. A series of reference minerals (montmorillonite, illite, Michigan chlorite, North Carolina chlorite, California clinochlore, quartz and synthetic 6-line ferrihydrite) was used for comparison that represents the mineralogical constituents of SPP1 GWF. Surface area-normalized Kd values were measured at U(VI) concentrations of 5 X 10−7 and 5 X 10−6 mol L−1 that displayed the following affinity series: 6-line-ferrihydrite > North Carolina chlorite ≈ California clinochlore …

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The Mineralogic Transformation Of Ferrihydrite Induced By Heterogeneous Reaction With Bioreduced Anthraquinone Disulfonate (Aqds) And The Role Of Phosphate, John M. Zachara, Ravi K. Kukkadapu, Tanya Peretyazhko, Mark Bowden, Chongmin Wang, David Kennedy, Dean Moore, Bruce Arey Jan 2011

The Mineralogic Transformation Of Ferrihydrite Induced By Heterogeneous Reaction With Bioreduced Anthraquinone Disulfonate (Aqds) And The Role Of Phosphate, John M. Zachara, Ravi K. Kukkadapu, Tanya Peretyazhko, Mark Bowden, Chongmin Wang, David Kennedy, Dean Moore, Bruce Arey

United States Department of Energy: Publications

Bioreduced anthraquinone-2,6-disulfonate (AH2DS; dihydro-anthraquinone) was reacted with a 2-line, Si-substituted ferrihydrite under anoxic conditions at neutral pH in PIPES buffer. Phosphate (P) and bicarbonate (C); common adsorptive oxyanions and media/buffer components known to effect ferrihydrite mineralization; and Fe(II)aq (as a catalytic mineralization agent) were used in comparative experiments. Heterogeneous AH2DS oxidation coupled with Fe(III) reduction occurred within 0.13–1 day, with mineralogic transformation occurring thereafter. The product suite included lepidocrocite, goethite, and/or magnetite, with proportions varing with reductant:oxidant ratio (r:o) and the presence of P or C. Lepidocrocite was the primary product at low r:o in the absence of P …

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Interfacial Reactivity Of Radionuclides: Emerging Paradigms From Molecular-Level Observations, A.R. Felmy, E.S. Ilton, K.M. Rosso, John M. Zachara Jan 2011

Interfacial Reactivity Of Radionuclides: Emerging Paradigms From Molecular-Level Observations, A.R. Felmy, E.S. Ilton, K.M. Rosso, John M. Zachara

United States Department of Energy: Publications

Over the past few decades an increasing array of molecular-level analytical probes has provided new detailed insight into mineral and radionuclide interfacial reactivity in subsurface environments. This capability has not only helped change the way mineral surface reactivity is studied but also how field scale contaminant migration problems are addressed and ultimately resolved. Here we review relatively new interfacial reactivity paradigms and assess their implications for future research directions. Specific examples include understanding the following: the role of site-to-site electron conduction at mineral surfaces and through bulk mineral phases and the effects of local chemical environment on the stability of …

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Structure Of A Bacterial Cell Surface Decaheme Electron Conduit, Thomas A. Clarke, Marcus Edwards, Andrew J. Gates, Andrea Hall, Gaye F. White, Justin Bradley, Catherine L. Reardon, Liang Shi, Alexander Beliaev, Matthew Marshall, Zheming Wang, Nicholas Watmough, James K. Fredrickson, John M. Zachara, Julea Butt, David J. Richardson Jan 2011

Structure Of A Bacterial Cell Surface Decaheme Electron Conduit, Thomas A. Clarke, Marcus Edwards, Andrew J. Gates, Andrea Hall, Gaye F. White, Justin Bradley, Catherine L. Reardon, Liang Shi, Alexander Beliaev, Matthew Marshall, Zheming Wang, Nicholas Watmough, James K. Fredrickson, John M. Zachara, Julea Butt, David J. Richardson

United States Department of Energy: Publications

Some bacterial species are able to utilize extracellular mineral forms of iron and manganese as respiratory electron acceptors. In Shewanella oneidensis this involves decaheme cytochromes that are located on the bacterial cell surface at the termini of transouter- membrane electron transfer conduits. The cell surface cytochromes can potentially play multiple roles in mediating electron transfer directly to insoluble electron sinks, catalyzing electron exchange with flavin electron shuttles or participating in extracellular intercytochrome electron exchange along “nanowire” appendages. We present a 3.2-Å crystal structure of one of these decaheme cytochromes, MtrF, that allows the spatial organization of the 10 hemes to …

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Sop For Pathway Inference In Integrated Microbial Genomes (Img), Iain Anderson, Amy Chen, Victor Markowitz, Nikos Kyrpides, Natalia Ivanova Jan 2011

Sop For Pathway Inference In Integrated Microbial Genomes (Img), Iain Anderson, Amy Chen, Victor Markowitz, Nikos Kyrpides, Natalia Ivanova

United States Department of Energy: Publications

One of the most important aspects of genomic analysis is the prediction of which pathways, both metabolic and non-metabolic, are present in an organism. In IMG, this is carried out by the assignment of IMG terms, which are organized into IMG pathways. Based on manual and automatic assignment of IMG terms, the presence or absence of IMG pathways is automatically inferred. The three categories of pathway assertion are asserted (likely present), not asserted (likely absent), and unknown. In the unknown category, at least one term necessary for the pathway is missing, but an ortholog in another organism has the corresponding …

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Complete Genome Sequence Of The Cellulolytic Thermophile Clostridium Thermocellum Dsm1313, Lawrence Feinberg, Justine Foden, Trisha Barrett, Karen Walston Davenport, David Bruce, Chris Detter, Roxanne Tapia, Cliff Han, Alla Lapidus, Susan Lucas, Jan-Fang Cheng, Samuel Pitluck, Tanja Woyke, Natalia Ivanova, Natalia Mikhailova, Miriam Land, Loren Hauser, D. Aaron Argyros, Lynne Goodwin, David Hogsett, Nicky Caiazza Jan 2011

Complete Genome Sequence Of The Cellulolytic Thermophile Clostridium Thermocellum Dsm1313, Lawrence Feinberg, Justine Foden, Trisha Barrett, Karen Walston Davenport, David Bruce, Chris Detter, Roxanne Tapia, Cliff Han, Alla Lapidus, Susan Lucas, Jan-Fang Cheng, Samuel Pitluck, Tanja Woyke, Natalia Ivanova, Natalia Mikhailova, Miriam Land, Loren Hauser, D. Aaron Argyros, Lynne Goodwin, David Hogsett, Nicky Caiazza

United States Department of Energy: Publications

Clostridium thermocellum DSM1313 is a thermophilic, anaerobic bacterium with some of the highest rates of cellulose hydrolysis reported. The complete genome sequence reveals a suite of carbohydrate-active enzymes and demonstrates a level of diversity at the species level distinguishing it from the type strain ATCC 27405.

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Img/M: The Integrated Metagenome Data Management And Comparative Analysis System, Victor M. Markowitz, I-Min A. Chen, Ken Chu, Ernest Szeto, Krishna Palaniappan, Yuri Grechkin, Anna Ratner, Biju Jacob, Amrita Pati, Marcel Huntemann, Konstantinos Liolios, Ioanna Pagani, Iain Anderson, Konstantinos Mavromatis, Natalia N. Ivanova, Nikos C. Kyrpides Jan 2011

Img/M: The Integrated Metagenome Data Management And Comparative Analysis System, Victor M. Markowitz, I-Min A. Chen, Ken Chu, Ernest Szeto, Krishna Palaniappan, Yuri Grechkin, Anna Ratner, Biju Jacob, Amrita Pati, Marcel Huntemann, Konstantinos Liolios, Ioanna Pagani, Iain Anderson, Konstantinos Mavromatis, Natalia N. Ivanova, Nikos C. Kyrpides

United States Department of Energy: Publications

The integrated microbial genomes and metagenomes (IMG/M) system provides support for comparative analysis of microbial community aggregate genomes (metagenomes) in a comprehensive integrated context. IMG/M integrates metagenome data sets with isolate microbial genomes from the IMG system. IMG/M’s data content and analytical capabilities have been extended through regular updates since its first release in 2007. IMG/M is available at http://img.jgi.doe.gov/m. A companion IMG/M systems provide support for annotation and expert review of unpublished metagenomic data sets (IMG/M ER: http://img.jgi.doe.gov/mer).

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Complete Genome Sequence Of Lactobacillus Buchneri Nrrl B-30929, A Novel Strain From A Commercial Ethanol Plant, Siqing Liu, Timothy D. Leathers, Alex Copeland, Olga Chertkov, Lynne Goodwin, David A. Mills Jan 2011

Complete Genome Sequence Of Lactobacillus Buchneri Nrrl B-30929, A Novel Strain From A Commercial Ethanol Plant, Siqing Liu, Timothy D. Leathers, Alex Copeland, Olga Chertkov, Lynne Goodwin, David A. Mills

United States Department of Energy: Publications

Lactobacillus buchneri strain NRRL B-30929 was a contaminant obtained from a commercial ethanol fermentation. This facultative anaerobe is unique because of its rapid growth on xylose and simultaneous fermentation of xylose and glucose. The strain utilizes a broad range of carbohydrate substrates and possesses a high tolerance to ethanol and other stresses, making it an attractive candidate for bioconversion of biomass substrates to various bioproducts. The genome sequence of NRRL B-30929 will provide insight into the unique properties of this lactic acid bacterium.

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Vista Region Viewer (Rviewer)—A Computational System For Prioritizing Genomic Intervals For Biomedical Studies, Igor Lukashin, Pavel Novichkov, Dario Boffelli, Alex R. Paciorkowski, Simon Minovitsky, Song Yang, Inna Dubchak Jan 2011

Vista Region Viewer (Rviewer)—A Computational System For Prioritizing Genomic Intervals For Biomedical Studies, Igor Lukashin, Pavel Novichkov, Dario Boffelli, Alex R. Paciorkowski, Simon Minovitsky, Song Yang, Inna Dubchak

United States Department of Energy: Publications

Summary:
Current genome browsers are designed for linear browsing of individual genomic regions, but the high-throughput nature of experiments aiming to elucidate the genetic component of human disease makes it very important to develop user-friendly tools for comparing several genomic regions in parallel and prioritizing them based on their functional content. We introduce VISTA Region Viewer (RViewer), an interactive online tool that allows for efficient screening and prioritization of regions of the human genome for follow-up studies. The tool takes as input genetic variation data from different biomedical studies, determines a number of various functional parameters for both coding …

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Complete Genome Sequence Of The Plant Growth-Promoting Endophyte Burkholderia Phytofirmans Strain Psjn, Alexandra Weilharter, Birgit Mitter, Maria V. Shin, Patrick S. G. Chain, Jerzy Nowak, Angela Sessitsch Jan 2011

Complete Genome Sequence Of The Plant Growth-Promoting Endophyte Burkholderia Phytofirmans Strain Psjn, Alexandra Weilharter, Birgit Mitter, Maria V. Shin, Patrick S. G. Chain, Jerzy Nowak, Angela Sessitsch

United States Department of Energy: Publications

Burkholderia phytofirmans PsJNT is able to efficiently colonize the rhizosphere, root, and above-ground plant tissues of a wide variety of genetically unrelated plants, such as potatoes, canola, maize, and grapevines. Strain PsJN shows strong plant growth-promoting effects and was reported to enhance plant vigor and resistance to biotic and abiotic stresses. Here, we report the genome sequence of this strain, which indicates the presence of multiple traits relevant for endophytic colonization and plant growth promotion.

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Characterization Of The Intragranular Water Regime Within Subsurface Sediments: Pore Volume, Surface Area, And Mass Transfer Limitations, Michael B. Hay, Deborah L. Stoliker, James A. Davis, John M. Zachara Jan 2011

Characterization Of The Intragranular Water Regime Within Subsurface Sediments: Pore Volume, Surface Area, And Mass Transfer Limitations, Michael B. Hay, Deborah L. Stoliker, James A. Davis, John M. Zachara

United States Department of Energy: Publications

Although ‘‘intragranular’’ pore space within grain aggregates, grain fractures, and mineral surface coatings may contain a relatively small fraction of the total porosity within a porous medium, it often contains a significant fraction of the reactive surface area, and can thus strongly affect the transport of sorbing solutes. In this work, we demonstrate a batch experiment procedure using tritiated water as a high-resolution diffusive tracer to characterize the intragranular pore space. The method was tested using uranium contaminated sediments from the vadose and capillary fringe zones beneath the former 300A process ponds at the Hanford site (Washington). Sediments were contacted …

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Multispecies Diffusion Models: A Study Of Uranyl Species Diffusion, Chongxuan Liu, Jianying Shang, John M. Zachara Jan 2011

Multispecies Diffusion Models: A Study Of Uranyl Species Diffusion, Chongxuan Liu, Jianying Shang, John M. Zachara

United States Department of Energy: Publications

Rigorous numerical description of multispecies diffusion requires coupling of species, charge, and aqueous and surface complexation reactions that collectively affect diffusive fluxes. The applicability of a fully coupled diffusion model is, however, often constrained by the availability of species self-diffusion coefficients, as well as by computational complication in imposing charge conservation. In this study, several diffusion models with variable complexity in charge and species coupling were formulated and compared to describe reactive multispecies diffusion in groundwater. Diffusion of uranyl [U(VI)] species was used as an example in demonstrating the effectiveness of the models in describing multispecies diffusion. Numerical simulations found …

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Transient Groundwater Chemistry Near A River: Effects On U(Vi) Transport In Laboratory Column Experiments, Jun Yin, Roy Haggerty, Deborah L. Stoliker, Douglas B. Kent, Jonathan D. Istok, Janek Greskowiak, John M. Zachara Jan 2011

Transient Groundwater Chemistry Near A River: Effects On U(Vi) Transport In Laboratory Column Experiments, Jun Yin, Roy Haggerty, Deborah L. Stoliker, Douglas B. Kent, Jonathan D. Istok, Janek Greskowiak, John M. Zachara

United States Department of Energy: Publications

In the 300 Area of a U(VI)-contaminated aquifer at Hanford, Washington, USA, inorganic carbon and major cations, which have large impacts on U(VI) transport, change on an hourly and seasonal basis near the Columbia River. Batch and column experiments were conducted to investigate the factors controlling U(VI) adsorption/desorption by changing chemical conditions over time. Low alkalinity and low Ca concentrations (Columbia River water) enhanced adsorption and reduced aqueous concentrations. Conversely, high alkalinity and high Ca concentrations (Hanford groundwater) reduced adsorption and increased aqueous concentrations of U(VI). An equilibrium surface complexation model calibrated using laboratory batch experiments accounted for the decrease …

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Simulating Adsorption Of U(Vi) Under Transient Groundwater Flow And Hydrochemistry: Physical Versus Chemical Nonequilibrium Model, Janek Greskowiak, Michael Hay, Henning Prommer, Chongxuan Liu, Vincent Post, Rui Ma, James Davis, Chunmiao Zheng, John M. Zachara Jan 2011

Simulating Adsorption Of U(Vi) Under Transient Groundwater Flow And Hydrochemistry: Physical Versus Chemical Nonequilibrium Model, Janek Greskowiak, Michael Hay, Henning Prommer, Chongxuan Liu, Vincent Post, Rui Ma, James Davis, Chunmiao Zheng, John M. Zachara

United States Department of Energy: Publications

Coupled intragrain diffusional mass transfer and nonlinear surface complexation processes play an important role in the transport behavior of U(VI) in contaminated aquifers. Two alternative model approaches for simulating these coupled processes were analyzed and compared: (1) the physical nonequilibrium approach that explicitly accounts for aqueous speciation and instantaneous surface complexation reactions in the intragrain regions and approximates the diffusive mass exchange between the immobile intragrain pore water and the advective pore water as multirate first-order mass transfer and (2) the chemical nonequilibrium approach that approximates the diffusion-limited intragrain surface complexation reactions by a set of multiple first-order surface complexation …

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Transition Of Cellulose Crystalline Structure And Surface Morphology Of Biomass As A Function Of Ionic Liquid Pretreatment And Its Relation To Enzymatic Hydrolysis, Gang Cheng, Patanjali Varanasi, Chenlin Li, Hanbin Liu, Yuri B. Melnichenko, Blake A. Simmons, Michael S. Kent, Seema Singh Jan 2011

Transition Of Cellulose Crystalline Structure And Surface Morphology Of Biomass As A Function Of Ionic Liquid Pretreatment And Its Relation To Enzymatic Hydrolysis, Gang Cheng, Patanjali Varanasi, Chenlin Li, Hanbin Liu, Yuri B. Melnichenko, Blake A. Simmons, Michael S. Kent, Seema Singh

United States Department of Energy: Publications

Cellulose is inherently resistant to breakdown, and the native crystalline structure (cellulose I) of cellulose is considered to be one of themajor factors limiting its potential in terms of cost-competitive lignocellulosic biofuel production. Here we report the impact of ionic liquid pretreatment on the cellulose crystalline structure in different feedstocks, including microcrystalline cellulose (Avicel), switchgrass (Panicum virgatum), pine (Pinus radiata), and eucalyptus (Eucalyptus globulus), and its influence on cellulose hydrolysis kinetics of the resultant biomass. These feedstocks were pretreated using 1-ethyl-3-methyl imidazolium acetate ([C2mim][OAc]) at 120 and 160°C for 1, 3, 6, and 12 …

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Absolute High-Resolution Se+ Photoionization Cross-Section Measurements With Rydberg-Series Analysis, D. A. Esteves, R. C. Bilodeau, N. C. Sterling, R. A. Phaneuf, A. L. D. Kilcoyne, E. C. Red, A. Aguilar Jan 2011

Absolute High-Resolution Se+ Photoionization Cross-Section Measurements With Rydberg-Series Analysis, D. A. Esteves, R. C. Bilodeau, N. C. Sterling, R. A. Phaneuf, A. L. D. Kilcoyne, E. C. Red, A. Aguilar

United States Department of Energy: Publications

Absolute single photoionization cross-section measurements for Se+ ions were performed at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory using the photo-ion merged-beams technique. Measurements were made at a photon energy resolution of 5.5 meV from 17.75 to 21.85 eV spanning the 4s24p34So3/2 ground-state ionization threshold and the 2Po3/2,2Po1/2,2Do5/2, and2Do3/2 metastable state thresholds. Extensive analysis of the complex resonant structure in this region identified numerous Rydberg series of resonances and …

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Photoionization Measurements For The Iron Isonuclear Sequence Fe3+, Fe5+, And Fe7+, M. F. Gharaibeh, A. Aguilar, A. M. Covington, E. D. Emmons, S. W. J. Scully, R. A. Phaneuf, A. Muller, J. D. Bozek, A. L. D. Kilcoyne, A. S. Schlachter, I. Alvarez, C. Cisneros, G. Hinojosa Jan 2011

Photoionization Measurements For The Iron Isonuclear Sequence Fe3+, Fe5+, And Fe7+, M. F. Gharaibeh, A. Aguilar, A. M. Covington, E. D. Emmons, S. W. J. Scully, R. A. Phaneuf, A. Muller, J. D. Bozek, A. L. D. Kilcoyne, A. S. Schlachter, I. Alvarez, C. Cisneros, G. Hinojosa

United States Department of Energy: Publications

Cross sections for single photoionization of Fe3+, Fe5+, and Fe7+ ions were measured at spectral resolutions of 0.04, 0.15, and 0.13 eV, respectively, by merging mass- and charge-selected ion beams with a beam of monochromatized synchrotron undulator radiation. The measurements span photon energy ranges beginning at the ionization thresholds and extending several tens of electron volts to include the most important resonant contributions due to 3p–nd transitions to autoionizing states. The photoion yield spectra are characterized by narrow resonances and also broad features in Fe3+ and Fe5+ that are believed to result …

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An Approach To Crystallizing Proteins By Metal-Mediated Synthetic Symmetrization, Arthur Laganowsky, Minglei Zhao, Angela B. Soriaga, Michael R. Sawaya, Duilio Cascio, Todd O. Yeates Jan 2011

An Approach To Crystallizing Proteins By Metal-Mediated Synthetic Symmetrization, Arthur Laganowsky, Minglei Zhao, Angela B. Soriaga, Michael R. Sawaya, Duilio Cascio, Todd O. Yeates

United States Department of Energy: Publications

Combining the concepts of synthetic symmetrization with the approach of engineering metal-binding sites, we have developed a new crystallization methodology termed metal-mediated synthetic symmetrization. In this method, pairs of histidine or cysteine mutations are introduced on the surface of target proteins, generating crystal lattice contacts or oligomeric assemblies upon coordination with metal. Metal-mediated synthetic symmetrization greatly expands the packing and oligomeric assembly possibilities of target proteins, thereby increasing the chances of growing diffraction-quality crystals. To demonstrate this method, we designed various T4 lysozyme (T4L) and maltose-binding protein (MBP) mutants and cocrystallized them with one of three metal ions: copper (Cu …

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Modification Of Native Grasses For Biofuel Production May Increase Virus Susceptibility, Abbie C. Schrotenboer, Michael S. Allen, Carolyn M. Malmstrom Jan 2011

Modification Of Native Grasses For Biofuel Production May Increase Virus Susceptibility, Abbie C. Schrotenboer, Michael S. Allen, Carolyn M. Malmstrom

United States Department of Energy: Publications

Bioenergy production is driving modifications to native plant species for use as novel biofuel crops. Key aims are to increase crop growth rates and to enhance conversion efficiency by reducing biomass recalcitrance to digestion. However, selection for these biofuel-valuable traits has potential to compromise plant defenses and alter interactions with pests and pathogens. Insect-vectored plant viruses are of particular concern because perennial crops have potential to serve as virus reservoirs that influence regional disease dynamics. In this study, we examined relationships between growth rates and biomass recalcitrance in five switchgrass (Panicum virgatum) populations, ranging from near wild type …

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Ecosystem Services Altered By Human Changes In The Nitrogen Cycle: A New Perspective For Us Decision Making, Jana E. Compton, John A. Harrison, Robin L. Dennis, Tara L. Greaver, Brian H. Hill, Stephen J. Jordan, Henry Walker, Holly V. Campbell Jan 2011

Ecosystem Services Altered By Human Changes In The Nitrogen Cycle: A New Perspective For Us Decision Making, Jana E. Compton, John A. Harrison, Robin L. Dennis, Tara L. Greaver, Brian H. Hill, Stephen J. Jordan, Henry Walker, Holly V. Campbell

United States Environmental Protection Agency: Publications

Human alteration of the nitrogen (N) cycle has produced benefits for health and well-being, but excess N has altered many ecosystems and degraded air and water quality. US regulations mandate protection of the environment in terms that directly connect to ecosystem services. Here, we review the science quantifying effects of N on key ecosystem services, and compare the costs of N-related impacts or mitigation using the metric of cost per unit of N. Damage costs to the provision of clean air, reflected by impaired human respiratory health, are well characterized and fairly high (e.g. costs of ozone and particulate damages …

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Toxicity And Recovery In The Pregnant Mouse After Gestational Exposure To The Cyanobacterial Toxin, Cylindrospermopsin, N. Chernoff, E. H. Rogers, R. D. Zehr, M. I. Gage, D. E. Malarkey, C. A. Bradfield, Y. Liu, J. E. Schmid, R. H. Jaskot, J. H. Richards, C. R. Wood, M. B. Rosen Jan 2011

Toxicity And Recovery In The Pregnant Mouse After Gestational Exposure To The Cyanobacterial Toxin, Cylindrospermopsin, N. Chernoff, E. H. Rogers, R. D. Zehr, M. I. Gage, D. E. Malarkey, C. A. Bradfield, Y. Liu, J. E. Schmid, R. H. Jaskot, J. H. Richards, C. R. Wood, M. B. Rosen

United States Environmental Protection Agency: Publications

Cylindrospermopsin (CYN) is a tricyclic alkaloid toxin produced by fresh water cyanobacterial species worldwide. CYN has been responsible for both livestock and human poisoning after oral exposure. This study investigated the toxicity of CYN to pregnant mice exposed during different segments of gestation. The course of recovery and individual responses to the toxin were evaluated. Adverse effects of CYN were monitored up to 7 weeks post-dosing by clinical examination, histopathology, biochemistry and gene expression. Exposure on gestational days (GD) 8–12 induced significantly more lethality than GD13–17 exposure. Periorbital, gastrointestinal and distal tail hemorrhages were seen in both groups. Serum markers …

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Maternal Influences On Epigenetic Programming Of The Developing Hypothalamic-Pituitary-Adrenal Axis, Curtis E. Grace, Sung-Je Kim, John M. Rogers Jan 2011

Maternal Influences On Epigenetic Programming Of The Developing Hypothalamic-Pituitary-Adrenal Axis, Curtis E. Grace, Sung-Je Kim, John M. Rogers

United States Environmental Protection Agency: Publications

Parental and environmental factors during the prenatal and postnatal periods permanently affect the physiology and metabolism of offspring, potentially increasing disease risk later in life. Underlying mechanisms are being elucidated, and effects on a number of organs and metabolic pathways are likely involved. In this review, we consider effects on the developing hypothalamic-pituitary-adrenal (HPA) axis, which may represent a common pathway for developmental programming. The focus is on prenatal and early postnatal development, during which the HPA axis may be programmed in a manner that affects health for a lifetime. Programming of the HPA axis involves, at least in part, …

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Current And Future Needs For Developmental Toxicity Testing, Susan L. Makris, James H. Kim, Amy Ellis, Willem Faber, Wafa Harrouk, Joseph M. Lewis, Merle G. Paule, Jennifer Seed, Melissa Tassinari, Rochelle Tyl Jan 2011

Current And Future Needs For Developmental Toxicity Testing, Susan L. Makris, James H. Kim, Amy Ellis, Willem Faber, Wafa Harrouk, Joseph M. Lewis, Merle G. Paule, Jennifer Seed, Melissa Tassinari, Rochelle Tyl

United States Environmental Protection Agency: Publications

A review is presented of the use of developmental toxicity testing in the United States and international regulatory assessment of human health risks associated with exposures to pharmaceuticals (human and veterinary), chemicals (agricultural, industrial, and environmental), food additives, cosmetics, and consumer products. Developmental toxicology data are used for prioritization and screening of pharmaceuticals and chemicals, for evaluating and labeling of pharmaceuticals, and for characterizing hazards and risk of exposures to industrial and environmental chemicals. The in vivo study designs utilized in hazard characterization and dose-response assessment for developmental outcomes have not changed substantially over the past 30 years and have …

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Aryl Hydrocarbon Receptor Activation During Pregnancy, And In Adult Nulliparous Mice, Delays The Subsequent Development Of Dmba-Induced Mammary Tumors, Tao Wang, Heather M. Gavin, Volker M. Arlt, B. Paige Lawrence, Suzanne E. Fenton, Daniel Medina, Beth A. Vorderstrasse Jan 2011

Aryl Hydrocarbon Receptor Activation During Pregnancy, And In Adult Nulliparous Mice, Delays The Subsequent Development Of Dmba-Induced Mammary Tumors, Tao Wang, Heather M. Gavin, Volker M. Arlt, B. Paige Lawrence, Suzanne E. Fenton, Daniel Medina, Beth A. Vorderstrasse

United States Environmental Protection Agency: Publications

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), the prototypic ligand for the aryl hydrocarbon receptor (AhR), promotes tumor formation in some model systems. However, with regard to breast cancer, epidemiological and animal studies are inconclusive as to whether exposure increases tumor incidence or may instead be protective. We have previously reported that mice exposed to TCDD during pregnancy have impaired differentiation of mammary tissue, including decreased branching and poor development of lobuloalveolar structures. Because normal pregnancy-induced mammary differentiation may protect against subsequent neoplastic transformation, we hypothesized that TCDD-treated mice would be more susceptible to chemical carcinogenesis after parturition. To test this, mice were …

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Emergy As A Life Cycle Impact Assessment Indicator A Gold Mining Case Study, Wesley W. Ingwesen Jan 2011

Emergy As A Life Cycle Impact Assessment Indicator A Gold Mining Case Study, Wesley W. Ingwesen

United States Environmental Protection Agency: Publications

Founded in thermodynamics and systems ecology, emergy evaluation is a method to associate a product with its dependencies on all upstream environmental and resource flows using a common unit of energy. Emergy is thus proposed as an indicator of aggregate resource use for life cycle assessment (LCA). An LCA of gold mining, based on an original life cycle inventory of a large gold mine in Peru, is used to demonstrate how emergy can be incorporated as an impact indicator into a process-based LCA model. The results demonstrate the usefulness of emergy in the LCA context. The adaptation of emergy evaluation, …

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Evolution Of Natural History Information In The 21st Century – Developing An Integrated Framework For Biological And Geographical Data, Deborah A. Reusser, Henry Lee Ii Jan 2011

Evolution Of Natural History Information In The 21st Century – Developing An Integrated Framework For Biological And Geographical Data, Deborah A. Reusser, Henry Lee Ii

United States Environmental Protection Agency: Publications

Threats to marine and estuarine species operate over many spatial scales, from nutrient enrichment at the watershed/estuarine scale to invasive species and climate change at regional and global scales. To help address research questions across these scales, we provide here a standardized framework for a biogeographical information system containing queriable biological data that allows extraction of information on multiple species, across a variety of spatial scales based on species distributions, natural history attributes and habitat requirements. As scientists shift from research on localized impacts on individual species to regional and global scale threats, macroecological approaches of studying multiple species over …

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Effects Of Biologically-Active Chemical Mixtures On Fish In A Wastewater-Impacted Urban Stream, Larry B. Barber, Gregory K. Brown, Todd G. Nettesheim, Elizabeth W. Murphy, Stephen E. Bartell, Heiko L. Schoenfuss Jan 2011

Effects Of Biologically-Active Chemical Mixtures On Fish In A Wastewater-Impacted Urban Stream, Larry B. Barber, Gregory K. Brown, Todd G. Nettesheim, Elizabeth W. Murphy, Stephen E. Bartell, Heiko L. Schoenfuss

United States Environmental Protection Agency: Publications

Stream flow in urban aquatic ecosystems often is maintained by water-reclamation plant (WRP) effluents that contain mixtures of natural and anthropogenic chemicals that persist through the treatment processes. In effluent-impacted streams, aquatic organisms such as fish are continuously exposed to biologically-active chemicals throughout their life cycles. The North Shore Channel of the Chicago River (Chicago, Illinois) is part of an urban ecosystem in which >80% of the annual flow consists of effluent from the North Side WRP. In this study, multiple samplings of the effluent and stream water were conducted and fish (largemouth bass and carp) were collected on 2 …

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Test 1999: John Deere 8335rt, Nebraska Tractor Test Lab Jan 2011

Test 1999: John Deere 8335rt, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

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Investigating Rfid For Linear Asset Management, Judy A. Perkins Ph.D., P.E., Erick C. Jones Ph.D., P.E., Cssbb, Judith L. Mwakalonge Ph.D., E.I.T Jan 2011

Investigating Rfid For Linear Asset Management, Judy A. Perkins Ph.D., P.E., Erick C. Jones Ph.D., P.E., Cssbb, Judith L. Mwakalonge Ph.D., E.I.T

Mid-America Transportation Center: Final Reports and Technical Briefs

A linear asset is defined as an asset whose length plays a critical role in its maintenance. Examples of such assets include roads, pipelines, and railroad tracks. Major features of a roadway asset include traffic lights, number of lanes, speed limits, guardrails, and highway billboards. Linear assets, along with their features, are hard to physically access; therefore, previously captured inventory information files may be inaccurate. To address this problem, some of the transportation agencies are investigating technologies that will assist in solving this asset inventory problem. Radio Frequency Identification (RFID) is a technology that uses communication via radio waves to …

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Improving The Freight Transportation Roadway System During Snow Events: A Performance Evaluation Of Deicing Chemicals, Christopher Y. Tuan, Barbara M. Gerbino-Bevins Jan 2011

Improving The Freight Transportation Roadway System During Snow Events: A Performance Evaluation Of Deicing Chemicals, Christopher Y. Tuan, Barbara M. Gerbino-Bevins

Mid-America Transportation Center: Final Reports and Technical Briefs

The ability of state DOTs to adequately clear roadways during winter weather conditions is critical for a safe and effective freight transportation system. Variables affecting winter maintenance operations include the type of precipitation, air and pavement temperature, traffic, wind, time of day, day of week, and maintenance equipment. The main objective of this study is to identify the best practices for normal deicing operations, based on the performance rating of deicing chemicals. Optimum deicer/brine ratios and the associated application rates will be determined for various weather conditions. The best practices will ensure effective deicing operation and economical use of deicing …

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