Science.gov

Sample records for formation sites n44

  1. N44C nebula

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Resembling the hair in Botticelli's famous portrait of the birth of Venus, an image from NASA's Hubble Space Telescope has captured softly glowing filaments streaming from hot young stars in a nearby nebula.

    The image, presented by the Hubble Heritage Project, was taken in 1996 by Hubble's Wide Field and Planetary Camera 2, designed and built by NASA's Jet Propulsion Laboratory, Pasadena, Calif. The image is available online at

    http://heritage.stsci.edu , http://oposite.stsci.edu/pubinfo/pr/2002/12 orhttp://www.jpl.nasa.gov/images/wfpc .

    On the top right of the image is a source of its artistic likeness, a network of nebulous filaments surrounding the Wolf-Rayet star. This type of rare star is characterized by an exceptionally vigorous 'wind' of charged particles. The shock of the wind colliding with the surrounding gas causes the gas to glow.

    The Wolf-Rayet star is part of N44C, a nebula of glowing hydrogen gas surrounding young stars in the Large Magellanic Cloud. Visible from the Southern Hemisphere, the Large Magellanic Cloud is a small companion galaxy to the Milky Way.

    What makes N44C peculiar is the temperature of the star that illuminates it. The most massive stars -- those that are 10 to 50 times more massive than the Sun -- have maximum temperatures of 30,000 to 50,000 degrees Celsius (54,000 to 90,000 degrees Fahrenheit). The temperature of this star is about 75,000 degrees Celsius (135,000 degrees Fahrenheit). This unusually high temperature may be due to a neutron star or black hole that occasionally produces X-rays but is now inactive.

    N44C is part of a larger complex that includes young, hot, massive stars, nebulae, and a 'superbubble' blown out by multiple supernova explosions. Part of the superbubble is seen in red at the very bottom left of the Hubble image.

    The Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract with the Goddard

  2. A novel acidic matrix protein, PfN44, stabilizes magnesium calcite to inhibit the crystallization of aragonite.

    PubMed

    Pan, Cong; Fang, Dong; Xu, Guangrui; Liang, Jian; Zhang, Guiyou; Wang, Hongzhong; Xie, Liping; Zhang, Rongqing

    2014-01-31

    Magnesium is widely used to control calcium carbonate deposition in the shell of pearl oysters. Matrix proteins in the shell are responsible for nucleation and growth of calcium carbonate crystals. However, there is no direct evidence supporting a connection between matrix proteins and magnesium. Here, we identified a novel acidic matrix protein named PfN44 that affected aragonite formation in the shell of the pearl oyster Pinctada fucata. Using immunogold labeling assays, we found PfN44 in both the nacreous and prismatic layers. In shell repair, PfN44 was repressed, whereas other matrix proteins were up-regulated. Disturbing the function of PfN44 by RNAi led to the deposition of porous nacreous tablets with overgrowth of crystals in the nacreous layer. By in vitro circular dichroism spectra and fluorescence quenching, we found that PfN44 bound to both calcium and magnesium with a stronger affinity for magnesium. During in vitro calcium carbonate crystallization and calcification of amorphous calcium carbonate, PfN44 regulated the magnesium content of crystalline carbonate polymorphs and stabilized magnesium calcite to inhibit aragonite deposition. Taken together, our results suggested that by stabilizing magnesium calcite to inhibit aragonite deposition, PfN44 participated in P. fucata shell formation. These observations extend our understanding of the connections between matrix proteins and magnesium.

  3. A Novel Acidic Matrix Protein, PfN44, Stabilizes Magnesium Calcite to Inhibit the Crystallization of Aragonite*

    PubMed Central

    Pan, Cong; Fang, Dong; Xu, Guangrui; Liang, Jian; Zhang, Guiyou; Wang, Hongzhong; Xie, Liping; Zhang, Rongqing

    2014-01-01

    Magnesium is widely used to control calcium carbonate deposition in the shell of pearl oysters. Matrix proteins in the shell are responsible for nucleation and growth of calcium carbonate crystals. However, there is no direct evidence supporting a connection between matrix proteins and magnesium. Here, we identified a novel acidic matrix protein named PfN44 that affected aragonite formation in the shell of the pearl oyster Pinctada fucata. Using immunogold labeling assays, we found PfN44 in both the nacreous and prismatic layers. In shell repair, PfN44 was repressed, whereas other matrix proteins were up-regulated. Disturbing the function of PfN44 by RNAi led to the deposition of porous nacreous tablets with overgrowth of crystals in the nacreous layer. By in vitro circular dichroism spectra and fluorescence quenching, we found that PfN44 bound to both calcium and magnesium with a stronger affinity for magnesium. During in vitro calcium carbonate crystallization and calcification of amorphous calcium carbonate, PfN44 regulated the magnesium content of crystalline carbonate polymorphs and stabilized magnesium calcite to inhibit aragonite deposition. Taken together, our results suggested that by stabilizing magnesium calcite to inhibit aragonite deposition, PfN44 participated in P. fucata shell formation. These observations extend our understanding of the connections between matrix proteins and magnesium. PMID:24302723

  4. Site formation processes at Zhoukoudian, China.

    PubMed

    Goldberg, P; Weiner, S; Bar-Yosef, O; Xu, Q; Liu, J

    2001-11-01

    Zhoukoudian is often cited for its human remains and the early evidence of fire. Yet, since its first excavations over 70 years ago, detailed studies of processes responsible for the accumulation of anthropogenic and geogenic sediments in the site have been sparse. This paper provides some details of site formation processes mainly through field observations of the extant section at Locality 1, and the use of soil micromorphology and Fourier Transform Infrared Spectrometry (FTIR) analyses of the sediments. Samples from Layers 10 through 3 show extensive water deposition of fine silt-sized material (reworked loess), including fine-grained organic matter. The dark organic-rich unit in Layer 10--often cited as one of the earliest evidence of fire--is a water-laid accumulation. Much of the fine-grained sediment was derived from outside Locality 1, implying that the site was open to varying extents throughout most of its depositional history. The 4-6 m accumulation of "ashes" in Layer 4 represents subaerial water-laid silt deposits derived from the loess-covered hillslopes surrounding the site. They presumably accumulated in an open depression that formed after the collapse of the brecciated roof deposits represented by Layer 6. Diagenesis is present in many of the Layers, and is exemplified by calcite precipitation and dissolution, and localized apatite (dahllite) replacement of calcite. In Layer 4 diagenesis is more advanced, including calcite/dahllite precipitation, subaerial weathering of the loess and associated precipitation of hematite, alteration of clay and the neoformation of quartz. Many of our conclusions concur with those of Teilhard de Chardin & Young published over 70 years ago.

  5. Formation of RNA oligomers on montmorillonite: site of catalysis

    NASA Technical Reports Server (NTRS)

    Ertem, G.; Ferris, J. P.

    1998-01-01

    Certain montmorillonites catalyze the self condensation of the 5'-phosphorimidazolide of nucleosides in pH 8 aqueous electrolyte solutions at ambient temperatures leading to formation of RNA oligomers. In order to establish the nature of the sites on montmorillonite responsible for this catalytic activity, oligomerization reactions were run with montmorillonites which had been selectively modified (I) at the edges by (a) fluoride treatment, (b) silylation, (c) metaphosphate treatment of the anion exchange sites (II) in the interlayer by (a) saturation with quaternary alkylammonium ions of increasing size, (b) aluminum polyoxo cations. High pressure liquid chromatography, HPLC, analysis of condensation products for their chain lengths and yields indicated that modification at the edges did not affect the catalytic activity to a significant extent, while blocking the interlayer strongly inhibited product formation.

  6. Lamellipodial actin mechanically links myosin activity with adhesion site formation

    PubMed Central

    Giannone, Gregory; Dubin-Thaler, Benjamin; Rossier, Olivier; Cai, Yunfei; Chaga, Oleg; Jiang, Guoying; Beaver, William; Döbereiner, Hans-Günther; Freund, Yoav; Borisy, Gary; Sheetz, Michael P.

    2013-01-01

    Summary Cell motility proceeds by cycles of edge protrusion, adhesion and retraction. Whether these functions are coordinated by biochemical or biomechanical processes is unknown. We find that myosin II pulls the rear of the lamellipodial actin network, causing upward bending, edge retraction and initiation of new adhesion sites. The network then separates from the edge and condenses over the myosin. Protrusion resumes as lamellipodial actin regenerates from the front and extends rearward until it reaches newly assembled myosin, initiating the next cycle. Upward bending, observed by evanescence and electron microscopy, results in ruffle formation when adhesion strength is low. Correlative fluorescence and electron microscopy shows that the regenerating lamellipodium forms a cohesive, separable layer of actin above the lamellum. Thus, actin polymerization periodically builds a mechanical link, the lamellipodium, connecting myosin motors with the initiation of adhesion sites, suggesting that the major functions driving motility are coordinated by a biomechanical process. PMID:17289574

  7. Investigation of Gd3N@C2n (40 <= n <= 44) family by Raman and inelastic electron tunneling spectroscopy

    NASA Astrophysics Data System (ADS)

    Burke, Brian; Chan, Jack; Williams, Keith; Ge, Jiechao; Shu, Chunying; Fu, Wujun; Dorn, Harry; Kushmerick, James; Puretzky, Alexander; Geohegan, David

    2010-03-01

    The structure and vibrational spectrum of Gd3N@C80 is studied through Raman and inelastic electron tunneling spectroscopy (IETS) as well as density functional theory (DFT) and universal force field (UFF) calculations. Hindered rotations, shown by both theory and experiment, indicate the formation of a Gd3N-C80 bond which reduces the ideal icosahedral symmetry of the C80 cage. The vibrational modes involving the movement of the encapsulated species are a fingerprint of the interaction between the fullerene cage and the core complex. We present Raman data for the Gd3N@C2n (40 <= n <= 44) family as well as Y3N@C80, Lu3N@C80, and Y3N@C88 for comparison. Conductance measurements have been performed on Gd3N@C80 and reveal a Kondo effect similar to that observed in C60.

  8. On-site formation of emulsions by controlled air plugs.

    PubMed

    Huang, Xiaowen; Hui, Wenli; Hao, Chonglei; Yue, Wanqing; Yang, Mengsu; Cui, Yali; Wang, Zuankai

    2014-02-26

    Air plugs are usually undesirable in microfluidic systems because of their detrimental effect on the system's stability and integrity. By controlling the wetting properties as well as the topographical geometry of the microchannel, it is reported herein that air plugs can be generated in pre-defined locations to function as a unique valve, allowing for the on-site formation of various emulsions including single-component droplets, composite droplets with droplet-to-droplet concentration gradient, blood droplets, paired droplets, as well as bubble arrays without the need for precious flow control, a difficult task with conventional droplet microfluidics. Moreover, the self-generated air valve can be readily deactivated (turned off) by the introduction of an oil phase, allowing for the on-demand release of as-formed droplets for downstream applications. It is proposed that the simple, yet versatile nature of this technique can act as an important method for droplet microfluidics and, in particular, is ideal for the development of affordable lab-on-a-chip systems without suffering from scalability and manufacturing challenges that typically confound the conventional droplet microfluidics.

  9. Site Saturation Mutagenesis Applications on Candida methylica Formate Dehydrogenase

    PubMed Central

    Özgün, Gülşah P.; Ordu, Emel B.; Tütüncü, H. Esra; Yelboğa, Emrah; Sessions, Richard B.

    2016-01-01

    In NADH regeneration, Candida methylica formate dehydrogenase (cmFDH) is a highly significant enzyme in pharmaceutical industry. In this work, site saturation mutagenesis (SSM) which is a combination of both rational design and directed evolution approaches is applied to alter the coenzyme specificity of NAD+-dependent cmFDH from NAD+ to NADP+ and increase its thermostability. For this aim, two separate libraries are constructed for screening a change in coenzyme specificity and an increase in thermostability. To alter the coenzyme specificity, in the coenzyme binding domain, positions at 195, 196, and 197 are subjected to two rounds of SSM and screening which enabled the identification of two double mutants D195S/Q197T and D195S/Y196L. These mutants increase the overall catalytic efficiency of NAD+ to 5.6 × 104-fold and 5 × 104-fold value, respectively. To increase the thermostability of cmFDH, the conserved residue at position 1 in the catalytic domain of cmFDH is subjected to SSM. The thermodynamic and kinetic results suggest that 8 mutations on the first residue can be tolerated. Among all mutants, M1L has the best residual activity after incubation at 60°C with 17%. These studies emphasize that SSM is an efficient method for creating “smarter libraries” for improving the properties of cmFDH. PMID:27847673

  10. New particle formation events observed at a high altitude site Pico Espejo, Venezuela

    NASA Astrophysics Data System (ADS)

    Nieminen, Tuomo; Kontkanen, Jenni; Krejci, Radovan; Ström, Johan; Tunved, Peter; Hamburger, Thomas; Calderon, Silvia; Hoffman, Pedro

    2013-05-01

    Formation and growth events of nucleation mode particles (10-25 nm in diameter) were analyzed from 27 month period of particle size distribution measurements at the high altitude site Pico Espejo in Venezuela. Particle formation was observed both in air masses connected to boundary layer air and in free tropospheric conditions. The frequency and magnitude of particle formation at this high altitude site was comparable to many observations at lower altitude sites.

  11. Effects of Abasic Sites on Triple Helix Formation Characterized by Affinity Cleaving

    DTIC Science & Technology

    1991-06-01

    DNA . The influence of abasic sites in Watson - Crick double helical DNA has been characterized by spectroscopic and calorimetric techniques. (9-12) Two...alter- nate strands of duplex DNA by triple- helix formation (7). the detign ,-f rnmillm ra bases for completion of the triplet code, and the incorporation...prepared in order to compare the relative stabilities of triple helix formation 3 with 30-bp DNA duplexes containing the 15 base pair target sites d

  12. OceanSITES format and Ocean Observatory Output harmonisation: past, present and future

    NASA Astrophysics Data System (ADS)

    Pagnani, Maureen; Galbraith, Nan; Diggs, Stephen; Lankhorst, Matthias; Hidas, Marton; Lampitt, Richard

    2015-04-01

    The Global Ocean Observing System (GOOS) initiative was launched in 1991, and was the first step in creating a global view of ocean observations. In 1999 oceanographers at the OceanObs conference envisioned a 'global system of eulerian observatories' which evolved into the OceanSITES project. OceanSITES has been generously supported by individual oceanographic institutes and agencies across the globe, as well as by the WMO-IOC Joint Technical Commission for Oceanography and Marine Meteorology (under JCOMMOPS). The project is directed by the needs of research scientists, but has a strong data management component, with an international team developing content standards, metadata specifications, and NetCDF templates for many types of in situ oceanographic data. The OceanSITES NetCDF format specification is intended as a robust data exchange and archive format specifically for time-series observatory data from the deep ocean. First released in February 2006, it has evolved to build on and extend internationally recognised standards such as the Climate and Forecast (CF) standard, BODC vocabularies, ISO formats and vocabularies, and in version 1.3, released in 2014, ACDD (Attribute Convention for Dataset Discovery). The success of the OceanSITES format has inspired other observational groups, such as autonomous vehicles and ships of opportunity, to also use the format and today it is fulfilling the original concept of providing a coherent set of data from eurerian observatories. Data in the OceanSITES format is served by 2 Global Data Assembly Centres (GDACs), one at Coriolis, in France, at ftp://ftp.ifremer.fr/ifremer/oceansites/ and one at the US NDBC, at ftp://data.ndbc.noaa.gov/data/oceansites/. These two centres serve over 26,800 OceanSITES format data files from 93 moorings. The use of standardised and controlled features enables the files held at the OceanSITES GDACs to be electronically discoverable and ensures the widest access to the data. The OceanSITES

  13. Molecular Dynamics Simulations of Solvation and Kink Site Formation at the {001} Barite-Water Interface.

    SciTech Connect

    Stack, Andrew G

    2009-09-01

    Solvation and kink site formation on step edges are known to be controlling parameters in crystal growth and dissolution. However, links from classical crystal growth models to specific reactions at the mineral-water interface have remained elusive. Molecular dynamics is used here to examine the water structure on barium surface sites and kink site formation enthalpies for material adsorbed to and removed from the step parallel to the [120] direction on the {001} barite-water interface. The bariums at the interface are shown to be coordinatively unsaturated with respect to water, and it is suggested that this is due to a steric hindrance from the nature of the interface. Kink site detachment energies that include hydration energies are endothermic for barium and exothermic for sulfate. The implications and problems of using these parameters in a crystal growth model are discussed.

  14. DNA abasic site-directed formation of fluorescent silver nanoclusters for selective nucleobase recognition

    NASA Astrophysics Data System (ADS)

    Ma, Kun; Cui, Qinghua; Liu, Guiying; Wu, Fei; Xu, Shujuan; Shao, Yong

    2011-07-01

    DNA single-nucleotide polymorphism (SNP) detection has attracted much attention due to mutation related diseases. Various methods for SNP detection have been proposed and many are already in use. Here, we find that the abasic site (AP site) in the DNA duplex can be developed as a capping scaffold for the generation of fluorescent silver nanoclusters (Ag NCs). As a proof of concept, the DNA sequences from fragments near codon 177 of cancer supression gene p53 were used as a model for SNP detection by in situ formed Ag NCs. The formation of fluorescent Ag NCs in the AP site-containing DNA duplex is highly selective for cytosine facing the AP site and guanines flanking the site and can be employed in situ as readout for SNP detection. The fluorescent signal-on sensing for SNP based on this inorganic fluorophore is substantially advantageous over the previously reported signal-off responses using low-molecular-weight organic ligands. The strong dependence of fluorescent Ag NC formation on the sequences surrounding the AP site was successfully used to identify mutations in codon 177 of cancer supression gene p53. We anticipate that this approach will be employed to develop a practical SNP detection method by locating an AP site toward the midway cytosine in a target strand containing more than three consecutive cytosines.

  15. Hydraulic testing of Salado Formation evaporites at the Waste Isolation Pilot Plant site: Second interpretive report

    SciTech Connect

    Beauheim, R.L.; Roberts, R.M.; Dale, T.F.; Fort, M.D.; Stensrud, W.A.

    1993-12-01

    Pressure-pulse, constant-pressure flow, and pressure-buildup tests have been performed in bedded evaporites of the Salado Formation at the Waste Isolation Pilot Plant (WIPP) site to evaluate the hydraulic properties controlling brine flow through the Salado. Transmissivities have been interpreted from six sequences of tests conducted on five stratigraphic intervals within 15 m of the WIPP underground excavations.

  16. Insertion site and sealing technique affect residual hearing and tissue formation after cochlear implantation.

    PubMed

    Burghard, Alice; Lenarz, Thomas; Kral, Andrej; Paasche, Gerrit

    2014-06-01

    Tissue formation around the electrode array of a cochlear implant has been suggested to influence preservation of residual hearing as well as electrical hearing performance of implanted subjects. Further, inhomogeneity in the electrical properties of the scala tympani shape the electrical field and affect current spread. Intracochlear trauma due to electrode insertion and the insertion site itself are commonly seen as triggers for the tissue formation. The present study investigates whether the insertion site, round window membrane (RWM) vs. cochleostomy (CS), or the sealing material, no seal vs. muscle graft vs. carboxylate cement, have an influence on the amount of fibrous tissue and/or new bone formation after CI implantation in the guinea pig. Hearing thresholds were determined by auditory brainstem response (ABR) measurements prior to implantation and after 28 days. The amount of tissue formation was quantified by evaluation of microscopic images obtained by a grinding/polishing procedure to keep the CI in place during histological processing. An insertion via the round window membrane resulted after 28 days in less tissue formation in the no seal and muscle seal condition compared to the cochleostomy approach. Between these two sealing techniques there was no difference. Sealing the cochlea with carboxylate cement resulted always in a strong new bone formation and almost total loss of residual hearing. The amount of tissue formation and the hearing loss correlated at 1-8 kHz. Consequently, the use of carboxylate cement as a sealing material in cochlear implantation should be avoided even in animal studies, whereas sealing the insertion site with a muscle graft did not induce an additional tissue growth compared to omitting a seal. For hearing preservation the round window approach should be used.

  17. Authigenic Carbonate Formation on the Peru Margin; New Insights from IODP Site 1230

    NASA Astrophysics Data System (ADS)

    Abdullajintakam, S.; Naehr, T. H.

    2015-12-01

    Fluid seepage of reduced organic compounds such as methane impacts the geology and biology of the seabed by inducing complex, microbially mediated biogeochemical processes. Authigenic carbonates serve as one of the few permanent records of these of dynamic biogeochemical interactions that involve methanogenesis, methanotrophy, sulfate reduction and carbonate precipitation. Meister et al. (2007) investigated deep-sea dolomite formation at Sites 1227-1229 on the Peru margin, where dolomite precipitation occurs in association with organic carbon-rich continental margin sediments. Geochemical and petrographic studies indicated episodic dolomite precipitation at a dynamic sulfate methane transition zone (SMTZ). Variations in δ13C values of these dolomites between +15‰ and -15‰ were attributed to non-steady state conditions as a result of the upward and downward migration of the SMTZ. Our study aims to better understand the biogeochemical processes associated with authigenic carbonate precipitation in this dynamic deep-sea setting. We focused our efforts on IODP Site 1230, which is a gas-hydrate-bearing site that shows sulphate consumption within the uppermost 10 m below the seafloor as well as high methane production. Using a multi proxy approach, we combined X-ray diffraction, stable isotope geochemistry, and trace metal analysis of authigenic carbonates to elucidate conditions for authigenic carbonate formation. Results from Site 1230 are compared to Sites 1227 and 1229, which lacks gas hydrates and is characterized by high pore water sulfate and low methane concentrations. This study contributes to a more comprehensive understanding of authigenic carbonate formation and associated biogeochemical processes in continental margin sediments. Meister, P., Mckenzie, J. A., Vasconcelos, C., Bernasconi, S., Frank, M., Gutjhar, M. and SCHRAG, D. P. (2007), Dolomite formation in the dynamic deep biosphere: results from the Peru Margin. Sedimentology, 54: 1007-1032.

  18. Site formation and chronology of the new Paleolithic site Sima de Las Palomas de Teba, southern Spain

    NASA Astrophysics Data System (ADS)

    Kehl, Martin; Burow, Christoph; Cantalejo, Pedro; Domínguez-Bella, Salvador; Durán, Juan José; Henselowsky, Felix; Klasen, Nicole; Linstädter, Jörg; Medianero, Javier; Pastoors, Andreas; Ramos, José; Reicherter, Klaus; Schmidt, Christoph; Weniger, Gerd-Christian

    2016-03-01

    The newly identified Paleolithic site Sima de Las Palomas de Teba hosts an almost seven-m-thick sediment profile investigated here to elucidate the rock shelter's chronostratigraphy and formation processes. At its base, the sediment sequence contains rich archeological deposits recording intensive occupation by Neanderthals. Luminescence provides a terminus ante quem of 39.4 ± 2.6 ka or 44.9 ± 4.1 ka (OSL) and 51.4 ± 8.4 ka (TL). This occupation ended with a rockfall event followed by accumulation of archeologically sterile sediments. These were covered by sediments containing few Middle Paleolithic artifacts, which either indicate ephemeral occupation by Neanderthals or reworking as suggested by micromorphological features. Above this unit, scattered lithic artifacts of undiagnostic character may represent undefined Paleolithic occupations. Sediment burial ages between about 23.0 ± 1.5 ka (OSL) and 40.5 ± 3.4 ka (pIRIR) provide an Upper Paleolithic chronology for sediments deposited above the rockfall. Finally, a dung-bearing Holocene layer in the uppermost part of the sequence contains a fragment of a human mandible dated to 4032 ± 39 14C yr BP. Overall, the sequence represents an important new site for studying the end of Neanderthal occupation in southern Spain.

  19. Inhibition by alcohols of the localization of radioactive nitrosonornicotine in sites of tumor formation

    SciTech Connect

    Waddell, W.J.; Marlowe, C.

    1983-06-01

    Oral administration of ethanol, n-butanol, or t-butanol to mice 20 minutes before injection of carbon-14-labeled nitrosonornicotine inhibited the localization of radioactivity in bronchial and salivary duct epithelium and in the liver. Localization of radioactivity in the nasal epithelium and esophagus was not significantly reduced. These alcohols therefore may selectively inhibit tumor formation in three of the five sites where this carcinogen typically acts.

  20. Osterix regulates tooth root formation in a site-specific manner.

    PubMed

    Kim, T H; Bae, C H; Lee, J C; Kim, J E; Yang, X; de Crombrugghe, B; Cho, E S

    2015-03-01

    Bone and dentin share similar biochemical compositions and physiological properties. Dentin, a major tooth component, is formed by odontoblasts; in contrast, bone is produced by osteoblasts. Osterix (Osx), a zinc finger-containing transcription factor, has been identified as an essential regulator of osteoblast differentiation and bone formation. However, it has been difficult to establish whether Osx functions in odontoblast differentiation and dentin formation. To understand the role of Osx in dentin formation, we analyzed mice in which Osx was subjected to tissue-specific ablation under the control of either the Col1a1 or the OC promoter. Two independent Osx conditional knockout mice exhibited similar molar abnormalities. Although no phenotype was found in the crowns of these teeth, both mutant lines exhibited short molar roots due to impaired root elongation. Furthermore, the interradicular dentin in these mice showed severe hypoplastic features, which were likely caused by disruptions in odontoblast differentiation and dentin formation. These phenotypes were closely related to the temporospatial expression pattern of Osx during tooth development. These findings indicate that Osx is required for root formation by regulating odontoblast differentiation, maturation, and root elongation. Cumulatively, our data strongly indicate that Osx is a site-specific regulator in tooth root formation.

  1. Localized arteriole formation directly adjacent to the site of VEGF-induced angiogenesis in muscle.

    PubMed

    Springer, Matthew L; Ozawa, Clare R; Banfi, Andrea; Kraft, Peggy E; Ip, Tze-Kin; Brazelton, Timothy R; Blau, Helen M

    2003-04-01

    We have shown previously that implantation of myoblasts constitutively expressing the VEGF-A gene into nonischemic mouse skeletal muscle leads to overgrowth of capillary-like blood vessels and hemangioma formation. These aberrant effects occurred directly at the implantation site. We show here that these regions result from angiogenic capillary growth and involve a change in capillary growth pattern and that smooth muscle-coated vessels similar to arterioles form directly adjacent to the implantation site. Myoblasts genetically engineered to produce VEGF were implanted into mouse leg muscles. Implantation sites were surrounded by a zone of dense capillary-sized vessels, around which was a second zone of muscle containing larger, smooth-muscle-covered vessels but few capillaries, and an outer zone of muscle exhibiting normal capillary density. The lack of capillaries in the middle region suggests that the preexisting capillaries adjacent to the implantation site underwent enlargement and/or fusion and recruited a smooth muscle coat. Capillaries at the implantation site were frequently wrapped around VEGF-producing muscle fibers and were continuous with the circulation and were not observed to include bone-marrow-derived endothelial cells. In contrast with the distant arteriogenesis resulting from VEGF delivery described in previous studies, we report here that highly localized arterioles also form adjacent to the site of delivery.

  2. Vertical stratification of subsurface microbial community composition across geological formations at the Hanford Site

    SciTech Connect

    Lin, Xueju; Kennedy, David W.; Fredrickson, Jim K.; Bjornstad, Bruce N.; Konopka, Allan

    2011-11-29

    Microbial diversity in subsurface sediments at the Hanford Site 300 Area near Richland, Washington State (USA) was investigated by analyzing samples recovered from depths of 9 to 52 m. Approximately 8000 near full-length 16S rRNA gene sequences were analyzed across geological strata that include a natural redox transition zone. These strata included the oxic coarse-grained Hanford formation, fine-grained oxic and anoxic Ringold Formation sediments, and the weathered basalt group. We detected 1233 and 120 unique bacterial and archaeal OTUs (Operational Taxonomic Units at the 97% identity level), respectively. Microbial community structure and richness varied substantially across the different geological strata. Bacterial OTU richness (Chao1 estimator) was highest (>700) in the upper Hanford formation, and declined to about 120 at the bottom of the Hanford formation. Just above the Ringold oxic-anoxic interface, richness was about 325 and declined to less than 50 in the deeper reduced zones. The deeper Ringold strata were characterized by a preponderance (ca. 90%) of Proteobacteria. The Bacterial community in the oxic sediments contained not only members of 9 well-recognized phyla but also an unusually high proportion of 3 candidate divisions (GAL15, NC10, and SPAM). Additionally, novel phylogenetic orders were identified within the Delta-proteobacteria, a clade rich in microbes that carry out redox transformations of metals that are important contaminants on the Hanford Site.

  3. Temporal analysis of recruitment of mammalian ATG proteins to the autophagosome formation site.

    PubMed

    Koyama-Honda, Ikuko; Itakura, Eisuke; Fujiwara, Takahiro K; Mizushima, Noboru

    2013-10-01

    Autophagosome formation is governed by sequential functions of autophagy-related (ATG) proteins. Although their genetic hierarchy in terms of localization to the autophagosome formation site has been determined, their temporal relationships remain largely unknown. In this study, we comprehensively analyzed the recruitment of mammalian ATG proteins to the autophagosome formation site by live-cell imaging, and determined their temporal relationships. Although ULK1 and ATG5 are separated in the genetic hierarchy, they synchronously accumulate at pre-existing VMP1-positive punctate structures, followed by recruitment of ATG14, ZFYVE1, and WIPI1. Only a small number of ATG9 vesicles appear to be associated with these structures. Finally, LC3 and SQSTM1/p62 accumulate synchronously, while the other ATG proteins dissociate from the autophagic structures. These results suggest that autophagosome formation takes place on the VMP1-containing domain of the endoplasmic reticulum or a closely related structure, where ULK1 and ATG5 complexes are synchronously recruited.

  4. Secondary new particle formation in Northern Finland Pallas site between the years 2000 and 2010

    NASA Astrophysics Data System (ADS)

    Asmi, E.; Kivekäs, N.; Kerminen, V.-M.; Komppula, M.; Hyvärinen, A.-P.; Hatakka, J.; Viisanen, Y.; Lihavainen, H.

    2011-09-01

    Secondary new particle formation affects atmospheric aerosol and cloud droplet numbers and thereby, the aerosol effects on climate. In this paper, the frequency of nucleation events and the associated particle formation and growth rates, along with their seasonal variation, was analysed based on over ten years of aerosol measurements conducted at the Pallas GAW station in northern Finland. The long-term measurements also allowed a detailed examination of factors possibly favouring or suppressing particle formation. Effects of meteorological parameters and air mass properties as well as vapour sources and sinks for particle formation frequency and event parameters were inspected. In addition, the potential of secondary particle formation to increase the concentration of cloud condensation nuclei (CCN) sized particles was examined. Findings from these long-term measurements confirmed previous observations: event frequency peaked in spring and the highest growth rates were observed in summer, affiliated with increased biogenic activity. Events were almost exclusively observed in marine air masses on sunny cloud-free days. A low vapour sink by the background particle population as well as an elevated sulphuric acid concentration were found to favour particle formation. These were also conditions taking place most likely in marine air masses. Inter-annual trend showed a minimum in event frequency in 2003, when also the smallest annual median of growth rate was observed. This gives further evidence of the importance and sensitivity of particle formation for the condensing vapour concentrations at Pallas site. The particle formation was observed to increase CCN80 (>80 nm particle number) concentrations especially in summer and autumn seasons when the growth rates were the highest. When the growing mode exceeded the selected 80 nm limit, on average in those cases, 211 ± 114 % increase of CCN80 concentrations was observed.

  5. Secondary new particle formation in Northern Finland Pallas site between the years 2000 and 2010

    NASA Astrophysics Data System (ADS)

    Asmi, E.; Kivekäs, N.; Kerminen, V.-M.; Komppula, M.; Hyvärinen, A.-P.; Hatakka, J.; Viisanen, Y.; Lihavainen, H.

    2011-12-01

    Secondary new particle formation affects atmospheric aerosol and cloud droplet numbers and thereby, the aerosol effects on climate. In this paper, the frequency of nucleation events and the associated particle formation and growth rates, along with their seasonal variation, was analysed based on over ten years of aerosol measurements conducted at the Pallas GAW station in northern Finland. The long-term measurements also allowed a detailed examination of factors possibly favouring or suppressing particle formation. Effects of meteorological parameters and air mass properties as well as vapour sources and sinks for particle formation frequency and event parameters were inspected. In addition, the potential of secondary particle formation to increase the concentration of cloud condensation nuclei (CCN) sized particles was examined. Findings from these long-term measurements confirmed previous observations: event frequency peaked in spring and the highest growth rates were observed in summer, affiliated with increased biogenic activity. Events were almost exclusively observed in marine air masses on sunny cloud-free days. A low vapour sink by the background particle population as well as an elevated sulphuric acid concentration were found to favour particle formation. These were also conditions taking place most likely in marine air masses. Inter-annual trend showed a minimum in event frequency in 2003, when also the smallest annual median of growth rate was observed. This gives further evidence of the importance and sensitivity of particle formation for the condensing vapour concentrations at Pallas site. The particle formation was observed to increase CCN80 (>80 nm particle number) concentrations especially in summer and autumn seasons when the growth rates were the highest. When the growing mode exceeded the selected 80 nm limit, on average in those cases, 211 ± 114% increase of CCN80 concentrations was observed.

  6. Geoarchaeological investigation at Al-Khiday (central Sudan): late Quaternary palaeoenvironment and site formation

    NASA Astrophysics Data System (ADS)

    Zerboni, Andrea; Usai, Donatella; Salvatori, Sandro

    2010-05-01

    The micromorphological investigation on several pluristratified archaeological sites in central Sudan (Al-Khiday, left bank of the White Nile, Khartoum region, Sudan) permitted to elucidate depositional and post-depositional processes playing a role in the formation and preservation of the archaeological record. At Al-Khiday sites are located at the top of small mounds, representing the remains of Pleistocene sandy fluvial bars, and were attended since the beginning of the Holocene. The first occupation of the area corresponds to a pre-Mesolithic cemetery; than Mesolithic groups lived upon the mounds and their occupation is testified by several archaeological features: pits filled by ash and bones and living floors. Preserved Neolithic features are scarce and limited to few graves (V millennium BC). After this phase, a long gap in human attendance is registered, during which wind continued to dismantling the mounds and the sites; at ca. 2000 years BP Meroitic/Post-Meroitic groups built their tombs at the top of the archaeological sequences and altered most of the stratigraphic record. Thanks to micromorphology, it was possible to distinguish between archaeological strata still in situ and those disturbed by natural and anthropic processes; furthermore, this approach allowed to interpret the significance of several archaeological features (living floors, fireplaces, and garbage pits). In this case micromorphology of archaeological deposits was a key tool to reconstruct the depositional and post-depositional processes that contributed to the formation and preservation of the archaeological record.

  7. Tracing the sites of obscured star formation in the Antennae galaxies with Herschel-PACS

    NASA Astrophysics Data System (ADS)

    Klaas, U.; Nielbock, M.; Haas, M.; Krause, O.; Schreiber, J.

    2010-07-01

    Aims: FIR imaging of interacting galaxies allows locating even hidden sites of star formation and measuring of the relative strength of nuclear and extra-nuclear star formation. We want to resolve the star-forming sites in the nearby system of the Antennae. Methods: Thanks to the unprecedented sharpness and depth of the PACS camera onboard ESA's Herschel Space Observatory, it is possible for the first time to achieve a complete assessment of individual star-forming knots in the FIR with scan maps at 70, 100, and 160 μm. We used clump extraction photometry and SED diagnostics to derive the properties related to star-forming activity. Results: The PACS 70, 100, and 160 μm maps trace the knotty structure of the most recent star formation along an arc between the two nuclei in the overlap area. The resolution of the starburst knots and additional multi-wavelength data allow their individual star formation history and state to be analysed. In particular, the brightest knot in the mid-infrared (K1), east of the southern nucleus, exhibits the highest activity by far in terms of dust heating and star formation rate, efficiency, and density. With only 2 kpc in diameter, this area has a 10-1000 μm luminosity, which is as high as that of our Milky Way. It shows the highest deficiency in radio emission in the radio-to-FIR luminosity ratio and a lack of X-ray emission, classifying it as a very young complex. The brightest 100 and 160 μm emission region (K2), which is close to the collision front and consists of 3 knots, also shows a high star formation density and efficiency and lack of X-ray emission in its most obscured part, but an excess in the radio-to-FIR luminosity ratio. This suggests a young stage, too, but different conditions in its interstellar medium. Our results provide important checkpoints for numerical simulations of interacting galaxies when modelling the star formation and stellar feedback. Herschel is an ESA space observatory with science instruments

  8. VOC emissions, evolutions and contributions to SOA formation at a receptor site in eastern China

    NASA Astrophysics Data System (ADS)

    Yuan, B.; Hu, W. W.; Shao, M.; Wang, M.; Chen, W. T.; Lu, S. H.; Zeng, L. M.; Hu, M.

    2013-09-01

    Volatile organic compounds (VOCs) were measured by two online instruments (GC-FID/MS and PTR-MS) at a receptor site on Changdao Island (37.99° N, 120.70° E) in eastern China. Reaction with OH radical dominated chemical losses of most VOC species during the Changdao campaign. A photochemical-age-based parameterization method is used to calculate VOC emission ratios and to quantify the evolution of ambient VOCs. The calculated emission ratios of most hydrocarbons agree well with those obtained from emission inventory data, but determined emission ratios of oxygenated VOCs (OVOCs) are significantly higher than those from emission inventory data. The photochemical-age-based parameterization method is also used to investigate primary emissions and secondary formation of organic aerosol. The primary emission ratio of organic aerosol (OA) to CO is determined to be 14.9 μg m-3 ppm-1, and secondary organic aeorosols (SOA) are produced at an enhancement ratio of 18.8 μg m-3 ppm-1 to CO after 50 h of photochemical processing in the atmosphere. SOA formation is significantly higher than the level determined from VOC oxidation under both high-NOx (2.0 μg m-3 ppm-1 CO) and low-NOx conditions (6.5 μg m-3 ppm-1 CO). Polycyclic aromatic hydrocarbons (PAHs) and higher alkanes (> C10) account for as high as 17.4% of SOA formation, which suggests semi-volatile organic compounds (SVOCs) may be a large contributor to SOA formation during the Changdao campaign. The SOA formation potential of primary VOC emissions determined from field campaigns in Beijing and Pearl River Delta (PRD) is lower than the measured SOA levels reported in the two regions, indicating SOA formation is also beyond explainable by VOC oxidation in the two city clusters.

  9. Vertical stratification of subsurface microbial community composition across geological formations at the Hanford Site

    SciTech Connect

    Lin, Xueju; Kennedy, David W.; Fredrickson, Jim K.; Bjornstad, Bruce N.; Konopka, Allan

    2012-02-01

    The microbial diversity in subsurface sediments at the Hanford Site's 300 Area in southeastern Washington State was investigated by analyzing 21 samples recovered from depths that ranged from 9 to 52 m. Approximately 8000 non-chimeric Bacterial and Archaeal 16S rRNA gene sequences were analyzed across geological strata that contain a natural redox transition zone. These strata included the oxic coarse-grained Hanford formation, fine-grained oxic and anoxic Ringold Formation sediments, and the weathered basalt group. We detected 1233 and 120 unique bacterial and archaeal OTUs (Operational Taxonomic Units, defined at the 97% identity level). Microbial community structure and richness varied substantially across the different geological strata. Bacterial OTU richness (based upon Chao1 estimator) was highest (>700) in the upper Hanford formation, and declined to about 120 at the bottom of the Hanford formation. Just above the Ringold oxic-anoxic transition zone, richness was about 325 and declined to less than 50 in the deeper reduced zones. The Bacterial community in the oxic Hanford and Ringold Formations contained members of 9 major well-recognized phyla as well 30 as unusually high proportions of 3 candidate divisions (GAL15, NC10, and SPAM). The deeper Ringold strata were characterized by low OTU richness and a very high preponderance (ca. 90%) of Proteobacteria. The study has greatly expanded the intralineage phylogenetic diversity within some major divisions. These subsurface sediments have been shown to contain a large number of phylogenetically novel microbes, with substantial heterogeneities between sediment samples from the same geological formation.

  10. Hydraulic Testing of Salado Formation Evaporites at the Waste Isolation Pilot Plant Site: Final Report

    SciTech Connect

    Beauheim, Richard L.; Domski, Paul S.; Roberts, Randall M.

    1999-07-01

    This report presents interpretations of hydraulic tests conducted in bedded evaporates of the Salado Formation from May 1992 through May 1995 at the Waste Isolation Pilot Plant (WIPP) site in southeastern New Mexico. The WIPP is a US Department of Energy research and development facility designed to demonstrate safe disposal of transuranic wastes from the nation's defense programs. The WIPP disposal horizon is located in the lower portion of the Permian Salado Formation. The hydraulic tests discussed in this report were performed in the WIPP underground facility by INTERA inc. (now Duke Engineering and Services, Inc.), Austin, Texas, following the Field Operations Plan and Addendum prepared by Saulnier (1988, 1991 ) under the technical direction of Sandia National Laboratories, Albuquerque, New Mexico.

  11. Rapid On-Site Formation of a Free-Standing Flexible Optical Link for Sensing Applications

    PubMed Central

    Barrios, Carlos Angulo

    2016-01-01

    An optical link, based on a conventional Scotch tape waveguide, for sensing applications requiring rapid on-site assembly is proposed and demonstrated. The flexible waveguide contains an integrated aluminum one-dimensional grating coupler that, when stuck on the radiative surface of a light emitting device, allows light to be coupled in and transmitted through the tape, whose tip end is, in turn, adhered onto the photosensitive surface of a photodetector. The (de)coupling approaches exhibit high alignment tolerances that permit the formation of a free-standing flexible optical connection between surface-normal optoelectronic devices without the need of specialized equipment. As the first demonstration of a sensing application, the proposed optical link is easily configured as a cost-effective intensity-based refractometric sensor for liquid detection, which can be applicable to on-site quality and process control of, for example, beverages. PMID:27782049

  12. [Recruitment of osteogenic cells to bone formation sites during development and fracture repair - German Version].

    PubMed

    Böhm, A-M; Dirckx, N; Maes, C

    2016-04-01

    Recruitment of osteoblast lineage cells to their bone-forming locations is essential for skeletal development and fracture healing. In developing bones, osteoprogenitor cells invade the cartilage mold to establish the primary ossification center. Similarly, osteogenic cells infiltrate and populate the callus tissue that is formed following an injury. Proper bone development and successful fracture repair must, therefore, rely on controlled temporal and spatial navigation cues guiding the cells to the sites where new bone formation is needed. Some cellular mechanisms and molecular pathways involved have been elucidated.

  13. BOREAS TE-20 Soils Data Over the NSA-MSA and Tower Sites in Raster Format

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Veldhuis, Hugo; Knapp, David; Veldhuis, Hugo

    2000-01-01

    The BOREAS TE-20 team collected several data sets for use in developing and testing models of forest ecosystem dynamics. This data set was gridded from vector layers of soil maps that were received from Dr. Hugo Veldhuis, who did the original mapping in the field during 1994. The vector layers were gridded into raster files that cover the NSA-MSA and tower sites. The data are stored in binary, image format files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Center (DAAC).

  14. Assessment of the potential for karst in the Rustler Formation at the WIPP site.

    SciTech Connect

    Lorenz, John Clay

    2006-01-01

    This report is an independent assessment of the potential for karst dissolution in evaporitic strata of the Rustler Formation at the Waste Isolation Pilot Plant (WIPP) site. Review of the available data suggests that the Rustler strata thicken and thin across the area in depositional patterns related to lateral variations in sedimentary accommodation space and normal facies changes. Most of the evidence that has been offered for the presence of karst in the subsurface has been used out of context, and the different pieces are not mutually supporting. Outside of Nash Draw, definitive evidence for the development of karst in the Rustler Formation near the WIPP site is limited to the horizon of the Magenta Member in drillhole WIPP-33. Most of the other evidence cited by the proponents of karst is more easily interpreted as primary sedimentary structures and the localized dissolution of evaporitic strata adjacent to the Magenta and Culebra water-bearing units. Some of the cited evidence is invalid, an inherited baggage from studies made prior to the widespread knowledge of modern evaporite depositional environments and prior to the existence of definitive exposures of the Rustler Formation in the WIPP shafts. Some of the evidence is spurious, has been taken out of context, or is misquoted. Lateral lithologic variations from halite to mudstone within the Rustler Formation under the WIPP site have been taken as evidence for the dissolution of halite such as that seen in Nash Draw, but are more rationally explained as sedimentary facies changes. Extrapolation of the known karst features in Nash Draw eastward to the WIPP site, where conditions are and have been significantly different for half a million years, is unwarranted. The volumes of insoluble material that would remain after dissolution of halite would be significantly less than the observed bed thicknesses, thus dissolution is an unlikely explanation for the lateral variations from halite to mudstone and siltstone

  15. Isomer ratio measurements for the reaction 29Si( 18O, p2n) 44m, 44gSc

    NASA Astrophysics Data System (ADS)

    Groening, H.; Aleklett, K.; Moody, K. J.; McGaughey, P. L.; Loveland, W.; Seaborg, G. T.

    1982-11-01

    Isomer ratios for the reaction 29Si( 18O, p2n) 44gSc, 44gSc have been deduced from activity measurements for projectile energies between 30 and 99 MeV. Statistical model calculations show that the isomer ratio dependence on projectile energy up to about 80 MeV can be adequately described by assuming a fixed ratio of quadrupole to dipole γ-ray strengths. Such a ratio of E2/E1 strengths agrees with corresponding values deduced from the literature. The values of the γ-ray strength ratios needed to fit the experimental isomer ratios are extremely sensitive to the relative amounts of quadrupole γ-ray admixture and to the presence of discrete levels other than those which conform to the yrast line.

  16. Geology of the Hanna Formation, Hanna Underground Coal Gasification Site, Hanna, Wyoming

    SciTech Connect

    Oliver, R.L.; Youngberg, A.D.

    1984-01-01

    The Hanna Underground Coal Gasification (UCG) study area consists of the SW1/4 of Section 29 and the E1/2SE1/4 of Section 30 in Township 22 North, Range 81 West, Wyoming. Regionally, this is located in the coal-bearing Hanna Syncline of the Hanna Basin in southeast Wyoming. The structure of the site is characterized by beds dipping gently to the northeast. An east-west fault graben complex interrupts this basic trend in the center of the area. The target coal bed of the UCG experiments was the Hanna No. 1 coal in the Hanna Formation. Sedimentary rocks comprising the Hanna Formation consist of a sequence of nonmarine shales, sandstones, coals and conglomerates. The overburden of the Hanna No. 1 coal bed at the Hanna UCG site was divided into four broad local stratigraphic units. Analytical studies were made on overburden and coal samples taken from cores to determine their mineralogical composition. Textural and mineralogical characteristics of sandstones from local stratigraphic units A, B, and C were analyzed and compared. Petrographic analyses were done on the coal including oxides, forms of sulfur, pyrite types, maceral composition, and coal rank. Semi-quantitative spectrographic and analytic geochemical analyses were done on the overburden and coal and relative element concentrations were compared. Trends within each stratigraphic unit were also presented and related to depositional environments. The spectrographic analysis was also done by lithotype. 34 references, 60 figures, 18 tables.

  17. Site-specific function and regulation of Osterix in tooth root formation.

    PubMed

    He, Y D; Sui, B D; Li, M; Huang, J; Chen, S; Wu, L A

    2016-12-01

    Congenital diseases of tooth roots, in terms of developmental abnormalities of short and thin root phenotypes, can lead to loss of teeth. A more complete understanding of the genetic molecular pathways and biological processes controlling tooth root formation is required. Recent studies have revealed that Osterix (Osx), a key mesenchymal transcriptional factor participating in both the processes of osteogenesis and odontogenesis, plays a vital role underlying the mechanisms of developmental differences between root and crown. During tooth development, Osx expression has been identified from late embryonic to postnatal stages when the tooth root develops, particularly in odontoblasts and cementoblasts to promote their differentiation and mineralization. Furthermore, the site-specific function of Osx in tooth root formation has been confirmed, because odontoblastic Osx-conditional knockout mice demonstrate primarily short and thin root phenotypes with no apparent abnormalities in the crown (Journal of Bone and Mineral Research 30, 2014 and 742, Journal of Dental Research 94, 2015 and 430). These findings suggest that Osx functions to promote odontoblast and cementoblast differentiation and root elongation only in root, but not in crown formation. Mechanistic research shows regulatory networks of Osx expression, which can be controlled through manipulating the epithelial BMP signalling, mesenchymal Runx2 expression and cellular phosphorylation levels, indicating feasible routes of promoting Osx expression postnatally (Journal of Cellular Biochemistry 114, 2013 and 975). In this regard, a promising approach might be available to regenerate the congenitally diseased root and that regenerative therapy would be the best choice for patients with developmental tooth diseases.

  18. Site-specific function and regulation of Osterix in tooth root formation

    PubMed Central

    He, Y. D.; Sui, B. D.; Li, M.; Huang, J.; Chen, S.; Wu, L. A.

    2016-01-01

    Congenital diseases of tooth roots, in terms of developmental abnormalities of short and thin root phenotypes, can lead to loss of teeth. A more complete understanding of the genetic molecular pathways and biological processes controlling tooth root formation is required. Recent studies have revealed that Osterix (Osx), a key mesenchymal transcriptional factor participating in both the processes of osteogenesis and odontogenesis, plays a vital role underlying the mechanisms of developmental differences between root and crown. During tooth development, Osx expression has been identified from late embryonic to postnatal stages when the tooth root develops, particularly in odontoblasts and cementoblasts to promote their differentiation and mineralization. Furthermore, the site-specific function of Osx in tooth root formation has been confirmed, because odontoblastic Osx-conditional knockout mice demonstrate primarily short and thin root phenotypes with no apparent abnormalities in the crown (Journal of Bone and Mineral Research 30, 2014 and 742, Journal of Dental Research 94, 2015 and 430). These findings suggest that Osx functions to promote odontoblast and cementoblast differentiation and root elongation only in root, but not in crown formation. Mechanistic research shows regulatory networks of Osx expression, which can be controlled through manipulating the epithelial BMP signalling, mesenchymal Runx2 expression and cellular phosphorylation levels, indicating feasible routes of promoting Osx expression postnatally (Journal of Cellular Biochemistry 114, 2013 and 975). In this regard, a promising approach might be available to regenerate the congenitally diseased root and that regenerative therapy would be the best choice for patients with developmental tooth diseases. PMID:26599722

  19. Measurements of aerosol chemistry during new particle formation events at a remote rural mountain site.

    PubMed

    Creamean, Jessie M; Ault, Andrew P; Ten Hoeve, John E; Jacobson, Mark Z; Roberts, Gregory C; Prather, Kimberly A

    2011-10-01

    Determining the major sources of particles that act as cloud condensation nuclei (CCN) represents a critical step in the development of a more fundamental understanding of aerosol impacts on cloud formation and climate. Reported herein are direct measurements of the CCN activity of newly formed ambient particles, measured at a remote rural site in the Sierra Nevada Mountains of Northern California. Nucleation events in the winter of 2009 occurred during two pristine periods following precipitation, with higher gas-phase SO(2) concentrations during the second period, when faster particle growth occurred (7-8 nm/h). Amines, as opposed to ammonia, and sulfate were detected in the particle phase throughout new particle formation (NPF) events, increasing in number as the particles grew to larger sizes. Interestingly, long-range transport of SO(2) from Asia appeared to potentially play a role in NPF during faster particle growth. Understanding the propensity of newly formed particles to act as CCN is critical for predicting the effects of NPF on orographic cloud formation during winter storms along the Sierra Nevada Mountain range. The potential impact of newly formed particles in remote regions needs to be compared with that of transported urban aerosols when evaluating the impact of aerosols on clouds and climate.

  20. New Particle Formation Above a Loblolly Pine Forest at a New Tower Site in Central Virginia

    NASA Astrophysics Data System (ADS)

    Joerger, V.; O'Halloran, T. L.; Barr, J. G.

    2014-12-01

    We present initial results investigating the environmental controls on new particle formation events at a new research site in central Virginia. The Sweet Briar College Land-Atmosphere Research Station (SBC-LARS) became operational in July, 2014 and features a 37-meter tower within a ~30 year-old loblolly pine plantation that is surrounded by mixed deciduous forest at the eastern edge of the Blue Ridge Mountains. The tower supports meteorological instruments at three different heights (2, 26, and 37 meters) and two air sampling inlets located above the canopy. The inlets draw air samples into a climate-controlled shed where precursor gas concentrations (ozone, sulfur dioxide, and nitrogen oxides) are determined by gas analyzers. Aerosol size distributions between 10 and 470 nm are measured every 3 minutes by a Scanning Mobility Particle Sizer (SMPS). For this study, aerosol size distributions from July through November 2014 were analyzed along with HYSPLIT backwards trajectories, meteorological measurements, gas concentrations, and the condensational sink, to investigate controls on new particle formation. This station and corresponding dataset will contribute to a better understanding of the contribution of biogenic and anthropogenic emissions to aerosol formation in the southeastern United States.

  1. Role of Criegee Intermediates in Formation of Sulfuric Acid at BVOCs-rich Cape Corsica Site

    NASA Astrophysics Data System (ADS)

    Kukui, A.; Dusanter, S.; Sauvage, S.; Gros, V.; Bourrianne, T.; Sellegri, K.; Wang, J.; Colomb, A.; Pichon, J. M.; Chen, H.; Kalogridis, C.; Zannoni, N.; Bonsang, B.; Michoud, V.; Locoge, N.; Leonardis, T.

    2015-12-01

    Oxidation of SO2 in reactions with stabilised Criegee Intermediates (sCI) was suggested as an additional source of gaseous sulfuric acid (H2SO4) in the atmosphere, complementary to the conventional H2SO4 formation in reaction of SO2 with OH radicals. Evaluation of the importance of this additional source is complicated due to large uncertainty in the mechanism and rate constants for the reactions of different sCI with SO2, water vapor and other atmospheric species. Here we present an evaluation of the role of sCI in H2SO4 production at remote site on Cape Corsica near the North tip of Corsica Island (Ersa station, Western Mediterranean). In July 2013 comprehensive field observations including gas phase (OH and RO2 radicals, H2SO4, VOCs, NOx, SO2, others) and aerosol measurements were conducted at this site in the frame of ChArMEx project. During the field campaign the site was strongly influenced by local emissions of biogenic volatile compounds (BVOCs), including isoprene and terpenes, forming different sCI in reactions with ozone and, hence, presenting additional source of H2SO4 via sCI+SO2. However, this additional source of H2SO4 at the Ersa site was found to be insignificant. The observed concentrations of H2SO4 were found to be in good agreement with those estimated from the H2SO4 condensation sink and the production of H2SO4 only in the reaction of OH with SO2, without accounting for any additional H2SO4 source. Using the BVOCs observations we present estimation of the upper limit for the rate constants of H2SO4 production via reactions of different sCI with SO2.

  2. Cloning, localization and focus formation at DNA damage sites of canine Ku70

    PubMed Central

    KOIKE, Manabu; YUTOKU, Yasutomo; KOIKE, Aki

    2017-01-01

    Understanding the molecular mechanisms of DNA double-strand break (DSB) repair machinery, specifically non-homologous DNA-end joining (NHEJ), is crucial for developing next-generation radiotherapies and common chemotherapeutics for human and animal cancers. The localization, protein-protein interactions and post-translational modifications of core NHEJ factors, might play vital roles for regulation of NHEJ activity. The human Ku heterodimer (Ku70/Ku80) is a core NHEJ factor in the NHEJ pathway and is involved in sensing of DSBs. Companion animals, such as canines, have been proposed to be an excellent model for cancer research, including development of chemotherapeutics. However, the post-translational modifications, localization and complex formation of canine Ku70 have not been clarified. Here, we show that canine Ku70 localizes in the nuclei of interphase cells and that it is recruited quickly at laser-microirradiated DSB sites. Structurally, two DNA-PK phosphorylation sites (S6 and S51), an ubiquitination site (K114), two canonical sumoylation consensus motifs, a CDK phosphorylation motif, and a nuclear localization signal (NLS) in the human Ku70 are evolutionarily conserved in canine and mouse species, while the acetylation sites in human Ku70 are partially conserved. Intriguingly, the primary candidate nucleophile (K31) required for 5’dRP/AP lyase activity of human and mouse Ku70 is not conserved in canines, suggesting that canine Ku does not possess this activity. Our findings provide insights into the molecular mechanisms of Ku-dependent NHEJ in a canine model and form a platform for the development of next-generation common chemotherapeutics for human and animal cancers. PMID:28163277

  3. Cloning, localization and focus formation at DNA damage sites of canine Ku70.

    PubMed

    Koike, Manabu; Yutoku, Yasutomo; Koike, Aki

    2017-03-23

    Understanding the molecular mechanisms of DNA double-strand break (DSB) repair machinery, specifically non-homologous DNA-end joining (NHEJ), is crucial for developing next-generation radiotherapies and common chemotherapeutics for human and animal cancers. The localization, protein-protein interactions and post-translational modifications of core NHEJ factors, might play vital roles for regulation of NHEJ activity. The human Ku heterodimer (Ku70/Ku80) is a core NHEJ factor in the NHEJ pathway and is involved in sensing of DSBs. Companion animals, such as canines, have been proposed to be an excellent model for cancer research, including development of chemotherapeutics. However, the post-translational modifications, localization and complex formation of canine Ku70 have not been clarified. Here, we show that canine Ku70 localizes in the nuclei of interphase cells and that it is recruited quickly at laser-microirradiated DSB sites. Structurally, two DNA-PK phosphorylation sites (S6 and S51), an ubiquitination site (K114), two canonical sumoylation consensus motifs, a CDK phosphorylation motif, and a nuclear localization signal (NLS) in the human Ku70 are evolutionarily conserved in canine and mouse species, while the acetylation sites in human Ku70 are partially conserved. Intriguingly, the primary candidate nucleophile (K31) required for 5'dRP/AP lyase activity of human and mouse Ku70 is not conserved in canines, suggesting that canine Ku does not possess this activity. Our findings provide insights into the molecular mechanisms of Ku-dependent NHEJ in a canine model and form a platform for the development of next-generation common chemotherapeutics for human and animal cancers.

  4. Formation of target-specific binding sites in enzymes: solid-phase molecular imprinting of HRP

    NASA Astrophysics Data System (ADS)

    Czulak, J.; Guerreiro, A.; Metran, K.; Canfarotta, F.; Goddard, A.; Cowan, R. H.; Trochimczuk, A. W.; Piletsky, S.

    2016-05-01

    Here we introduce a new concept for synthesising molecularly imprinted nanoparticles by using proteins as macro-functional monomers. For a proof-of-concept, a model enzyme (HRP) was cross-linked using glutaraldehyde in the presence of glass beads (solid-phase) bearing immobilized templates such as vancomycin and ampicillin. The cross-linking process links together proteins and protein chains, which in the presence of templates leads to the formation of permanent target-specific recognition sites without adverse effects on the enzymatic activity. Unlike complex protein engineering approaches commonly employed to generate affinity proteins, the method proposed can be used to produce protein-based ligands in a short time period using native protein molecules. These affinity materials are potentially useful tools especially for assays since they combine the catalytic properties of enzymes (for signaling) and molecular recognition properties of antibodies. We demonstrate this concept in an ELISA-format assay where HRP imprinted with vancomycin and ampicillin replaced traditional enzyme-antibody conjugates for selective detection of templates at micromolar concentrations. This approach can potentially provide a fast alternative to raising antibodies for targets that do not require high assay sensitivities; it can also find uses as a biochemical research tool, as a possible replacement for immunoperoxidase-conjugates.Here we introduce a new concept for synthesising molecularly imprinted nanoparticles by using proteins as macro-functional monomers. For a proof-of-concept, a model enzyme (HRP) was cross-linked using glutaraldehyde in the presence of glass beads (solid-phase) bearing immobilized templates such as vancomycin and ampicillin. The cross-linking process links together proteins and protein chains, which in the presence of templates leads to the formation of permanent target-specific recognition sites without adverse effects on the enzymatic activity. Unlike

  5. Osterix/Sp7 limits cranial bone initiation sites and is required for formation of sutures.

    PubMed

    Kague, Erika; Roy, Paula; Asselin, Garrett; Hu, Gui; Simonet, Jacqueline; Stanley, Alexandra; Albertson, Craig; Fisher, Shannon

    2016-05-15

    During growth, individual skull bones overlap at sutures, where osteoblast differentiation and bone deposition occur. Mutations causing skull malformations have revealed some required genes, but many aspects of suture regulation remain poorly understood. We describe a zebrafish mutation in osterix/sp7, which causes a generalized delay in osteoblast maturation. While most of the skeleton is patterned normally, mutants have specific defects in the anterior skull and upper jaw, and the top of the skull comprises a random mosaic of bones derived from individual initiation sites. Osteoblasts at the edges of the bones are highly proliferative and fail to differentiate, consistent with global changes in gene expression. We propose that signals from the bone itself are required for orderly recruitment of precursor cells and growth along the edges. The delay in bone maturation caused by loss of Sp7 leads to unregulated bone formation, revealing a new mechanism for patterning the skull and sutures.

  6. Maryland power plant siting program radioecology database management system: format for coding radioecology data. Final report

    SciTech Connect

    Domotor, S.L.

    1986-01-01

    The Radioecology Laboratory of the State of Maryland Power Plant Siting Program (PPSP) conducts routine radiological monitoring programs designed to assess the environmental impact of radionuclides released by nuclear power plants affecting Maryland. The PPSP radioecology database management system was initiated to store existing and future monitoring data collected by PPSP and its subcontractors in a computer file format. From these files, SAS (Statistical Analysis System) datasets are created for qualitative and quantitative analysis of monitoring data, for modeling studies through incorporation of this data, or for predicting environmental impact. The system was designed to accommodate both gamma and beta radionuclide analyses from water, sediment, soil, air, foodstuff, and aquatic and terrestrial flora and fauna sample types. Plant releases of radionuclides and physical and chemical environmental parameters can also be stored.

  7. Location of femoral artery puncture site and the risk of postcatheterization pseudoaneurysm formation.

    PubMed

    Gabriel, Marcin; Pawlaczyk, Katarzyna; Waliszewski, Krzysztof; Krasiński, Zbigniew; Majewski, Wacław

    2007-08-21

    Iatrogenic causes constitute increasingly frequent sources of pseudoaneurysms due to endovascular interventions. However, till now, all analyses focused on evaluating different risk factors contributing to the development of pseudoaneurysm, overlooking the issue of localization of femoral puncture. The aim of this study was to assess the influence of position of femoral artery puncture on the risk of pseudoaneurysm formation. 116 patients were evaluated for the site of catheter insertion into femoral arteries. Another group of 273 patients, suspected of vascular complications after endovascular procedures, were diagnosed with pseudoaneurysms which were analyzed for the location of arterial wall disruption. Puncture sites of groin arteries, i.e. EIA (2.7%), CFA (77.5%), SFA and DFA (19.8%), correlated with pseudoaneurysm location reaching 7.6% (EIA), 54.3% (CFA) and 38.1% (SFA, DFA). Type of procedure influenced these values. Duplex ultrasound mapping of CFA before the endovascular intervention eliminated discrepancies between the incidence of pseudoaneurysm formation and the frequency of arterial puncture in the selected vascular segments. Pseudoaneurysms formed in 4.5% of patients undergoing traditional palpation-guided vessel cannulation and in 2.6% of patients after ultrasound-guided puncture of the femoral artery. Upon further analysis, we concluded that the likelihood of the development of pseudoaneurysm depends on the artery punctured in the groin. This risk increases dramatically for external iliac artery, superficial and deep femoral arteries. A simple means of prevention of this dangerous complication of femoral artery puncture is duplex ultrasound mapping of the groin arteries.

  8. Formation of target-specific binding sites in enzymes: solid-phase molecular imprinting of HRP.

    PubMed

    Czulak, J; Guerreiro, A; Metran, K; Canfarotta, F; Goddard, A; Cowan, R H; Trochimczuk, A W; Piletsky, S

    2016-06-07

    Here we introduce a new concept for synthesising molecularly imprinted nanoparticles by using proteins as macro-functional monomers. For a proof-of-concept, a model enzyme (HRP) was cross-linked using glutaraldehyde in the presence of glass beads (solid-phase) bearing immobilized templates such as vancomycin and ampicillin. The cross-linking process links together proteins and protein chains, which in the presence of templates leads to the formation of permanent target-specific recognition sites without adverse effects on the enzymatic activity. Unlike complex protein engineering approaches commonly employed to generate affinity proteins, the method proposed can be used to produce protein-based ligands in a short time period using native protein molecules. These affinity materials are potentially useful tools especially for assays since they combine the catalytic properties of enzymes (for signaling) and molecular recognition properties of antibodies. We demonstrate this concept in an ELISA-format assay where HRP imprinted with vancomycin and ampicillin replaced traditional enzyme-antibody conjugates for selective detection of templates at micromolar concentrations. This approach can potentially provide a fast alternative to raising antibodies for targets that do not require high assay sensitivities; it can also find uses as a biochemical research tool, as a possible replacement for immunoperoxidase-conjugates.

  9. A Randomized Trial Examining Housing First in Congregate and Scattered Site Formats

    PubMed Central

    Somers, Julian M.; Moniruzzaman, Akm; Patterson, Michelle; Currie, Lauren; Rezansoff, Stefanie N.; Palepu, Anita; Fryer, Karen

    2017-01-01

    Objective No previous experimental trials have investigated Housing First (HF) in both scattered site (SHF) and congregate (CHF) formats. We hypothesized that CHF and SHF would be associated with a greater percentage of time stably housed as well as superior health and psychosocial outcomes over 24 months compared to treatment as usual (TAU). Methods Inclusion criteria were homelessness, mental illness, and high need for support. Participants were randomised to SHF, CHF, or TAU. SHF consisted of market rental apartments with support provided by Assertive Community Treatment (ACT). CHF consisted of a single building with supports equivalent to ACT. TAU included existing services and supports. Results Of 800 people screened, 297 were randomly assigned to CHF (107), SHF (90), or TAU (100). The percentage of time in stable housing over 24 months was 26.3% in TAU (reference; 95% confidence interval (CI) = 20.5, 32.0), compared to 74.3% in CHF (95% CI = 69.3, 79.3, p<0.001) and 74.5% in SHF (95% CI = 69.2, 79.7, p<0.001). Secondary outcomes favoured CHF but not SHF compared to TAU. Conclusion HF in scattered and congregate formats is capable of achieving housing stability among people experiencing major mental illness and chronic homelessness. Only CHF was associated with improvement on select secondary outcomes. Registration Current Controlled Trials: ISRCTN57595077. PMID:28076358

  10. Ice Lens Formation and Frost Heave at the Phoenix Landing Site

    NASA Technical Reports Server (NTRS)

    Zent, A. P.; Sizemore, H. G.; Remple, A. W.

    2011-01-01

    Several lines of evidence indicate that the volume of shallow ground ice in the martian high latitudes exceeds the pore volume of the host regolith. Boynton et al. found an optimal fit to the Mars Odyssey Gamma Ray Spectrometer (GRS) data at the Phoenix landing site by modeling a buried layer of 50-75% ice by mass (up to 90% ice by volume). Thermal and optical observations of recent impact craters in the northern hemisphere have revealed nearly pure ice. Ice deposits containing only 1-2% soil by volume were excavated by Phoenix. The leading hypothesis for the origin of this excess ice is that it developed in situ by a mechanism analogous to the formation of terrestrial ice lenses and needle ice. Problematically, terrestrial soil-ice segregation is driven by freeze/thaw cycling and the movement of bulk water, neither of which are expected to have occurred in the geologically recent past on Mars. If however ice lens formation is possible at temperatures less than 273 K, there are possible implications for the habitability of Mars permafrost, since the same thin films of unfrozen water that lead to ice segregation are used by terrestrial psychrophiles to metabolize and grow down to temperatures of at least 258 K.

  11. Observing the formation of ice and organic crystals in active sites.

    PubMed

    Campbell, James M; Meldrum, Fiona C; Christenson, Hugo K

    2017-01-31

    Heterogeneous nucleation is vital to a wide range of areas as diverse as ice nucleation on atmospheric aerosols and the fabrication of high-performance thin films. There is excellent evidence that surface topography is a key factor in directing crystallization in real systems; however, the mechanisms by which nanoscale pits and pores promote nucleation remain unclear. Here, we use natural cleavage defects on Muscovite mica to investigate the activity of topographical features in the nucleation from vapor of ice and various organic crystals. Direct observation of crystallization within surface pockets using optical microscopy and also interferometry demonstrates that these sharply acute features provide extremely effective nucleation sites and allows us to determine the mechanism by which this occurs. A confined phase is first seen to form along the apex of the wedge and then grows out of the pocket opening to generate a bulk crystal after a threshold saturation has been achieved. Ice nucleation proceeds in a comparable manner, although our resolution is insufficient to directly observe a condensate before the growth of a bulk crystal. These results provide insight into the mechanism of crystal deposition from vapor on real surfaces, where this will ultimately enable us to use topography to control crystal deposition on surfaces. They are also particularly relevant to our understanding of processes such as cirrus cloud formation, where such topographical features are likely candidates for the "active sites" that make clay particles effective nucleants for ice in the atmosphere.

  12. Dynamic formation of single-atom catalytic active sites on ceria-supported gold nanoparticles

    DOE PAGES

    Wang, Yanggang; Mei, Donghai; Glezakou, Vassiliki Alexandra; ...

    2015-03-04

    Ab initio Molecular Dynamics simulations and static Density Functional Theory calculations have been performed to investigate the reaction mechanism of CO oxidation on Au/CeO2 catalyst. It is found that under reaction condition CO adsorption significantly labializes the surface atoms of the Au cluster and leads to the formation of isolated Au+-CO species that resides on the support in the vicinity of the Au particle. In this context, we identified a dynamic single-atom catalytic mechanism at the interfacial area for CO oxidation on Au/CeO2 catalyst, which is a lower energy pathway than that of CO oxidation at the interface with themore » metal particle. This results from the ability of the single atom site to strongly couple with the redox properties of the support in a synergistic manner thereby lowering the barrier for redox reactions. We find that the single Au+ ion, which only exists under reaction conditions, breaks away from the Au cluster to catalyze CO oxidation and returns to the Au cluster after the catalytic cycle is completed. Generally, our study highlights the importance of the dynamic creation of active sites under reaction conditions and their essential role in a catalytic process.« less

  13. Dynamic formation of single-atom catalytic active sites on ceria-supported gold nanoparticles

    SciTech Connect

    Wang, Yanggang; Mei, Donghai; Glezakou, Vassiliki Alexandra; Li, Jun; Rousseau, Roger J.

    2015-03-04

    Ab initio Molecular Dynamics simulations and static Density Functional Theory calculations have been performed to investigate the reaction mechanism of CO oxidation on Au/CeO2 catalyst. It is found that under reaction condition CO adsorption significantly labializes the surface atoms of the Au cluster and leads to the formation of isolated Au+-CO species that resides on the support in the vicinity of the Au particle. In this context, we identified a dynamic single-atom catalytic mechanism at the interfacial area for CO oxidation on Au/CeO2 catalyst, which is a lower energy pathway than that of CO oxidation at the interface with the metal particle. This results from the ability of the single atom site to strongly couple with the redox properties of the support in a synergistic manner thereby lowering the barrier for redox reactions. We find that the single Au+ ion, which only exists under reaction conditions, breaks away from the Au cluster to catalyze CO oxidation and returns to the Au cluster after the catalytic cycle is completed. Generally, our study highlights the importance of the dynamic creation of active sites under reaction conditions and their essential role in a catalytic process.

  14. Environmental significance of Upper Miocene phosphorites at hominid sites in the Lukeino Formation (Tugen Hills, Kenya)

    NASA Astrophysics Data System (ADS)

    Dericquebourg, Perrine; Person, Alain; Ségalen, Loïc; Pickford, Martin; Senut, Brigitte; Fagel, Nathalie

    2015-08-01

    The Lukeino Formation contains an important sedimentary and fossiliferous record of the late Miocene (6.09-5.68 Ma), which has in particular yielded the fossil remains of the oldest East African bipedal hominid called Orrorin tugenensis. This fluvio-lacustrine sedimentary succession crops out in the Kenyan part of the East African Rift. It is mainly composed of clay to sandy clay deposits intercalated with volcanic ash horizons, and localized layers of carbonates and diatomites. A detailed sedimentological and mineralogical study of the Lukeino Formation was conducted to throw light on the environmental conditions in which the hominids lived. Several centimetric, relatively continuous and indurated phosphatic horizons, of sedimentary origin, were identified at two sites (Sunbarua and Kapcheberek). Mineralogical (XRD) and geochemical analyses as well as observations by SEM, which was coupled with an energy dispersive spectroscopy (EDS) microprobe, indicate that the autochthonous phosphate layers are composed of a micritic matrix of francolite (38-93%), with incorporation of silicates in variable proportions from one layer to another. The phosphate matrix contains very well preserved and abundant diatom frustules in the basal phosphate layer. These diatoms are identified as Aulacoseira granulata, implying a pH of 7.8-8.2 for freshwaters of the Palaeolake Lukeino. Calcitic tubular structures, linked to a possible bacterial origin, are also observed locally. Phosphate layers occur abruptly within a thick clay-sandy series, associated with an intense runoff phase during the deposition of this interval of the Lukeino Formation. The massive and cyclic input of phosphorus to the lake promoted productivity to the stage where it caused a diatom bloom. The establishment of several phosphate horizons testifies to successive phases of eutrophication of Palaeolake Lukeino. The diatom cells provided some of the organic matter, which was decomposed by bacterial activity at the

  15. Formation of nanostructured Group IIA metal activated sensors: The transformation of Group IIA metal compound sites

    NASA Astrophysics Data System (ADS)

    Tune, Travis C.; Baker, Caitlin; Hardy, Neil; Lin, Arthur; Widing, Timothy J.; Gole, James L.

    2015-05-01

    Trends in the Group IIA metal oxides and hydroxides of magnesium, calcium, and barium are unique in the periodic table. In this study we find that they display novel trends as decorating nanostructures for extrinsic semiconductor interfaces. The Group IIA metal ions are strong Lewis acids. We form these M2+ ions in aqueous solution and bring these solutions in contact with a porous silicon interface to form interfaces for conductometric measurements. Observed responses are consistent with the formation of MgO whereas the heavier elements display behaviors which suggest the effect of their more basic nature. Mg(OH)2, when formed, represents a weak base whereas the heavier metal hydroxides of Ca, Sr, and Ba are strong bases. However, the hydroxides tend to give up hydrogen and act as Brönsted acids. For the latter elements, the reversible interaction response of nanostructures deposited to the porous silicon (PS) interface is modified, as the formation of more basic sites appears to compete with M2+ Lewis acidity and hydroxide Brönsted acidity. Mg2+ forms an interface whose response to the analytes NH3 and NO is consistent with MgO and well explained by the recently developing Inverse Hard/Soft Acid/Base model. The behavior of the Ca2+ and Ba2+ decorated interfaces as they interact with the hard base NH3 follows a reversal of the model, indicating a decrease in acidic character as the observed conductometric response suggests the interaction with hydroxyl groups. A change from oxide-like to hydroxide-like constituents is supported by XPS studies. The changes in conductometric response is easily monitored in contrast to changes associated with the Group IIA oxides and hydroxides observed in XPS, EDAX, IR, and NMR measurements.

  16. Deciphering site formation processes through soil micromorphology at Contrebandiers Cave, Morocco.

    PubMed

    Aldeias, Vera; Goldberg, Paul; Dibble, Harold L; El-Hajraoui, Mohamed

    2014-04-01

    Contrebandiers Cave preserves a Late Pleistocene sequence containing Middle Stone Age (MSA) so-called Maghrebian Mousterian and Aterian occupations, spanning from ∼126 to 95 ka (thousands of years ago), followed by spatially restricted Iberomaurusian industries. Micromorphological analyses, complemented by instrumental mineralogical identification and fabric orientation, allowed for the reconstruction of the main site formation processes at the site. Initial deposition is characterized by local reworking of marine shelly sands dating to Marine Isotopic Stage 5e (MIS5e). The subsequent stratification reveals sedimentary dynamics predominantly associated with gravity-driven inputs and contributions from weathering of the encasing bedrock, at the same time that anthropogenic sediments were being accumulated. The allochthonous components reflect soil degradation and vegetation changes around the cave during the last interglacial. Human occupations seems to be somewhat ephemeral in nature, with some stratigraphic units apparently lacking archaeological components, while in others the human-associated deposits (e.g., burned bones, charcoal, and ashes) can be substantial. Ephemeral breaks in sedimentation and/or erosion followed by stabilization are mainly discernible microscopically by the presence of phosphatic-rich laminae interpreted as short-lived surfaces, peaks of increased humidity and colonization by plants. More substantial erosion affects the uppermost Aterian layers, presumably due to localized reconfigurations of the cave's roof. The subsequent Iberomaurusian deposits are not in their primary position and are associated with well-sorted silts of aeolian origin. While the effects of chemical diagenesis are limited throughout the whole stratigraphic sequence, physical bioturbation (e.g., by wasps, rodents, and earthworms) is more pervasive and leads to localized movement of the original sedimentary particles.

  17. Assessment of potential radionuclide transport in site-specific geologic formations

    SciTech Connect

    Dosch, R.G.

    1980-08-01

    Associated with the development of deep, geologic repositories for nuclear waste isolation is a need for safety assessments of the potential for nuclide migration. Frequently used in estimating migration rates is a parameter generally known as a distribution coefficient, K/sub d/, which describes the distribution of a radionuclide between a solid (rock) and a liquid (groundwater) phase. This report is intended to emphasize that the use of K/sub d/ must be coupled with a knowledge of the geology and release scenarios applicable to a repository. Selected K/sub d/ values involving rock samples from groundwater/brine simulants typical of two potential repository sites, WIPP and NTS, are used to illustrate this concern. Experimental parameters used in K/sub d/ measurements including nuclide concentration, site sampling/rock composition, and liquid-to-solid ratios are discussed. The solubility of U(VI) in WIPP brine/groundwater was addressed in order to assess the potential contribution of this phenomena to K/sub d/ values. Understanding mehanisms of sorption of radionuclides on rocks would lead to a better predictive capability. Sorption is attributed to the presence of trace constituents (often unidentified) in rocks. An attempt was made to determine if this applied to WIPP dolomite rocks by comparing sorption behavior of the natural material with that of a synthetic dolomite prepared in the laboratory with reagent grade chemicals. The results were inconclusive. The results of a study of Tc sorption by an argillite sample from the Calico Hills formation at NTS under ambient laboratory conditions were more conclusive. The Tc sorption was found to be associated with elemental carbon. Available evidence points to a reduction mechanism leading to the apparent sorption of Tc on the solid phase.

  18. Micromorphology and site formation at Die Kelders Cave I, South Africa.

    PubMed

    Goldberg, P

    2000-01-01

    The deposits of Die Kelders I were previously described and studied by Tankard & Schweitzer (1974, 1976) from the standpoint of classical granulometric analysis of sand from a coastal cave in order to infer the geological history of the cave and its environs. This paper supplements these earlier works by taking a more holistic approach toward site formation processes by including investigation of the biogenic and anthropogenic influences on the cave deposits and history. The study employs the technique of soil micromorphology, which is the study of resin-impregnated, undisturbed blocks of sediment and petrographic thin sections, in which sediments from all areas of the cave were examined. The study showed that diagenesis of the deposits in the eastern areas of the excavation resulted in decalcification, which in turn brought about slumping and compaction. Equivalent stratigraphic layers exposed in the western and central areas were only mildly decalcified and consequently, these sediments contain limestone rock fall and relatively abundant marine and terrestrial mollusks, the latter not dissimilar to the Late Stone Age (LSA) midden which covers these deposits. Thus, in spite of lowered and more distant shorelines, marine resources were exploited during Middle Stone Age (MSA) times. Observations from these calcareous units also clearly demonstrates that previously recognized "occupational horizons" (e.g. Layers 6, 8 and 10) can be resolved micromorphologically into several ephemeral events, such as burning/fire, redistribution of ashes by wind and water, and non-deposition; the latter is shown by phosphatic alteration of sediments exposed on former surfaces and accumulation of guano, or the presence of millimeter-thick truncation surfaces below which aeolian dust infiltrated. Both field and microscopic observations illustrate that the deposits in caves are highly variable from wall to center, and that excavations should not be localized in just one microenvironment

  19. Eastern-Mediterranean ventilation variability during sapropel S1 formation, evaluated at two sites influenced by deep-water formation from Adriatic and Aegean Seas

    NASA Astrophysics Data System (ADS)

    Filippidi, A.; Triantaphyllou, M. V.; De Lange, G. J.

    2016-07-01

    Present-day bottom-water ventilation in the Eastern Mediterranean basin occurs through deep-water convection originating from the two marginal basins, i.e. Adriatic and Aegean Seas. In the paleo record, long periods of enhanced deep-water formation have been alternating with shorter periods of reduced deep-water formation. The latter is related mainly to low-latitude humid climate conditions and the enhanced deposition and preservation of organic-rich sediment units (sapropels). This study focuses on sedimentary archives of the most-recent sapropel S1, retrieved from two sites under the direct influence of the two deep-water formation areas. Restricted oxygen conditions have developed rapidly at the beginning of S1 deposition in the Adriatic site, but bottom-water conditions have not persistently remained anoxic during the full interval of sapropel deposition. In fact, the variability in intensity and persistence of sedimentary redox conditions at the two deep-water formation sites is shown to be related to brief episodes of climate cooling. In the Adriatic site, sapropel deposition appears to have been interrupted twice. The 8.2 ka event, only recovered at the Adria site, is characterized by gradually increasing suboxic to possibly intermittently oxic conditions and decreasing Corg fluxes, followed by an abrupt re-establishment of anoxic conditions. Another important event that disrupted sapropel S1 formation, has taken place at ca. 7.4 cal ka BP. The latter event has been recovered at both sites. In the Adriatic site it is followed by a period of sedimentary conditions that gradually change from suboxic to more permanently oxic, as deduced from the Mn/Al pattern. Using the same proxy for suboxic/oxic sedimentary redox conditions, we observe that conditions in the Aegean Sea site shift to more permanently oxic from the 7.4 ka event onwards. However, at both sites the accumulation and preservation of enhanced amounts of organic matter have continued under these

  20. U.S. Department of Energy's site screening, site selection, and initial characterization for storage of CO2 in deep geological formations

    USGS Publications Warehouse

    Rodosta, T.D.; Litynski, J.T.; Plasynski, S.I.; Hickman, S.; Frailey, S.; Myer, L.

    2011-01-01

    The U.S. Department of Energy (DOE) is the lead Federal agency for the development and deployment of carbon sequestration technologies. As part of its mission to facilitate technology transfer and develop guidelines from lessons learned, DOE is developing a series of best practice manuals (BPMs) for carbon capture and storage (CCS). The "Site Screening, Site Selection, and Initial Characterization for Storage of CO2 in Deep Geological Formations" BPM is a compilation of best practices and includes flowchart diagrams illustrating the general decision making process for Site Screening, Site Selection, and Initial Characterization. The BPM integrates the knowledge gained from various programmatic efforts, with particular emphasis on the Characterization Phase through pilot-scale CO2 injection testing of the Validation Phase of the Regional Carbon Sequestration Partnership (RCSP) Initiative. Key geologic and surface elements that suitable candidate storage sites should possess are identified, along with example Site Screening, Site Selection, and Initial Characterization protocols for large-scale geologic storage projects located across diverse geologic and regional settings. This manual has been written as a working document, establishing a framework and methodology for proper site selection for CO2 geologic storage. This will be useful for future CO2 emitters, transporters, and storage providers. It will also be of use in informing local, regional, state, and national governmental agencies of best practices in proper sequestration site selection. Furthermore, it will educate the inquisitive general public on options and processes for geologic CO2 storage. In addition to providing best practices, the manual presents a geologic storage resource and capacity classification system. The system provides a "standard" to communicate storage and capacity estimates, uncertainty and project development risk, data guidelines and analyses for adequate site characterization, and

  1. Effect of anthropogenic activity on formate and acetate levels in precipitation at four sites in Agra, India

    NASA Astrophysics Data System (ADS)

    Kumar, Nandini; Kulshreshta, U. C.; Saxena, A.; Kumari, K. M.; Srivastava, S. S.

    Twenty-four-hour precipitation samples from four sites: Dayalbagh (DB), Hari Parvat (HP), Taj Mahal (TM) and Udyog Kendra (UK) in Agra city, during the monsoon season (July-September) of 1991, were analysed for formate and acetate. Each site was representative of a different level of anthropogenic activity. The formate/acetate ratio observed appeared to be characteristic of the dominant activity at the site; the geometric means of the formate/acetate ratios calculated for individual samples were 0.99, 0.17, 0.83 and 0.21 for DB, HP, TM and UK, respectively. These corresponded to the level of pollution at the site. Direct acetate inputs from extensive combustion and automobile exhaust could contribute to elevated levels of the species at two of the four sites. Another possible indirect input could be from the alkaline hydrolysis of PAN, aided by relatively high pH values of rain water (volume-weighted averages = 6.79, 6.69, 7.22, 7.15) at the four sites.

  2. Site specific comparison of H2, CH4 and compressed air energy storage in porous formations

    NASA Astrophysics Data System (ADS)

    Tilmann Pfeiffer, Wolf; Wang, Bo; Bauer, Sebastian

    2016-04-01

    The supply of energy from renewable sources like wind or solar power is subject to fluctuations determined by the climatic and weather conditions, and shortage periods can be expected on the order of days to weeks. Energy storage is thus required if renewable energy dominates the total energy production and has to compensate the shortages. Porous formations in the subsurface could provide large storage capacities for various energy carriers, such as hydrogen (H2), synthetic methane (CH4) or compressed air (CAES). All three energy storage options have similar requirements regarding the storage site characteristics and consequently compete for suitable subsurface structures. The aim of this work is to compare the individual storage methods for an individual storage site regarding the storage capacity as well as the achievable delivery rates. This objective is pursued using numerical simulation of the individual storage operations. In a first step, a synthetic anticline with a radius of 4 km, a drop of 900 m and a formation thickness of 20 m is used to compare the individual storage methods. The storage operations are carried out using -depending on the energy carrier- 5 to 13 wells placed in the top of the structure. A homogeneous parameter distribution is assumed with permeability, porosity and residual water saturation being 500 mD, 0.35 and 0.2, respectively. N2 is used as a cushion gas in the H2 storage simulations. In case of compressed air energy storage, a high discharge rate of 400 kg/s equating to 28.8 mio. m³/d at surface conditions is required to produce 320 MW of power. Using 13 wells the storage is capable of supplying the specified gas flow rate for a period of 31 hours. Two cases using 5 and 9 wells were simulated for both the H2 and the CH4 storage operation. The target withdrawal rates of 1 mio. sm³/d are maintained for the whole extraction period of one week in all simulations. However, the power output differs with the 5 well scenario producing

  3. Quarries of Culture: An Ethnohistorical and Environmental Account of Sacred Sites and Rock Formations in Southern California's Mission Indian Country

    ERIC Educational Resources Information Center

    Karr, Steven M.

    2005-01-01

    Sacred sites and Rock Formations throughout Southern California's India Country are described by Indians as ancestral markers, origin and place-name locales, areas of deity habitation, and power sources. Early ethnographers were keen to record the traditional stories and meanings related to them by their Native collaborators. Rock formations…

  4. Site-specific dynamics of amyloid formation and fibrillar configuration of Aβ(1-23) using an unnatural amino acid.

    PubMed

    Liu, Haiyang; Lantz, Richard; Cosme, Patrick; Rivera, Nelson; Andino, Carlos; Gonzalez, Walter G; Terentis, Andrew C; Wojcikiewicz, Ewa P; Oyola, Rolando; Miksovska, Jaroslava; Du, Deguo

    2015-04-25

    We identify distinct site-specific dynamics over the time course of Aβ1-23 amyloid formation by using an unnatural amino acid, p-cyanophenylalanine, as a sensitive fluorescent and Raman probe. Our results also suggest the key role of an edge-to-face aromatic interaction in the conformational conversion to form and stabilize β-sheet structure.

  5. A Study of Geological Formation on Different Sites in Batu Pahat, Malaysia Based On HVSR Method Using Microtremor Measurement

    NASA Astrophysics Data System (ADS)

    Noor, M. A. M.; Madun, A.; Kamarudin, A. F.; Daud, M. E.

    2016-07-01

    Geological formation is a one of information need to know during site reconnaissance. Conventional method like borehole has been known is very accurate to identify the formation of geology of a site. However, the problem of this technique is very expensive and not economical for large area. In the last decade, microtremor measurement has been introduced as an alternative technique and widely used in the geological formation study. Therefore, the aim in this study is to determine the geological formation underneath of surface in Batu Pahat district using microtremor measurement. There are two parameters have been carried out from microtremor measurement in term of natural frequency and HVSR curves images. Microtremor measurements are done conducted at 15 sites surrounding of Batu Pahat. Horizontal to vertical spectral ratio (HVSR) method was used for analyzing microtermor measurement data, to determine the natural frequency and also HVSR curves image. In this study, values of natural frequencies are used to classify the soil types with range in the between 0.93 to 5.35 Hz, meanwhile the pattern of HVSR curve images has been shown exists a few groups of soil types surrounding Batu Pahat district. Hence, microtremor measurement indirectly can be used as a one technique to add value in the site reconnaissance in the future.

  6. Cooperativity between Al Sites Promotes Hydrogen Transfer and Carbon–Carbon Bond Formation upon Dimethyl Ether Activation on Alumina

    PubMed Central

    2015-01-01

    The methanol-to-olefin (MTO) process allows the conversion of methanol/dimethyl ether into olefins on acidic zeolites via the so-called hydrocarbon pool mechanism. However, the site and mechanism of formation of the first carbon–carbon bond are still a matter of debate. Here, we show that the Lewis acidic Al sites on the 110 facet of γ-Al2O3 can readily activate dimethyl ether to yield CH4, alkenes, and surface formate species according to spectroscopic studies combined with a computational approach. The carbon–carbon forming step as well as the formation of methane and surface formate involves a transient oxonium ion intermediate, generated by a hydrogen transfer between surface methoxy species and coordinated methanol on adjacent Al sites. These results indicate that extra framework Al centers in acidic zeolites, which are associated with alumina, can play a key role in the formation of the first carbon–carbon bond, the initiation step of the industrial MTO process. PMID:27162986

  7. Electroporation-induced formation of individual calcium entry sites in the cell body and processes of adherent cells.

    PubMed Central

    Teruel, M N; Meyer, T

    1997-01-01

    Electroporation is a widely used method for introducing macromolecules into cells. We developed an electroporation device that requires only 1 microl of sample to load adherent cells in a 10-mm2 surface area while retaining greater than 90% cell survivability. To better understand this device, field-induced permeabilization of adherent rat basophilic leukemia and neocortical neuroblastoma cells was investigated by using fluorescent calcium and voltage indicators. Rectangular field pulses led to the formation of only a few calcium entry sites, preferentially in the hyperpolarized parts of the cell body and processes. Individual entry sites were formed at the same locations when field pulses were repeated. Before calcium entry, a partial breakdown of the membrane potential was observed in both polar regions. Based on our results, a model is proposed for the formation and closure of macromolecule entry sites in adherent cells. First, the rapid formation of a large number of small pores leads to a partial membrane potential breakdown in both polar regions of the cell. Second, over tens of milliseconds, a few entry sites for macromolecules are formed, preferentially in the hyperpolarized part of cell body and processes, at locations defined by the local membrane structure. These entry sites reseal on a time scale of 50 ms to several seconds, with residual small pores remaining open for several minutes. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 8 FIGURE 9 PMID:9336174

  8. Ice Lens Formation and Frost Heave at the Phoenix Landing Site

    NASA Astrophysics Data System (ADS)

    Zent, A.; Sizemore, H. G.; Rempel, A. W.

    2010-12-01

    Several lines of evidence indicate that the volume of shallow ground ice in the Martian high latitudes exceeds the pore volume of the host regolith. Boynton et al. (2002) found an optimal fit to the Mars Odyssey Gamma Ray Spectrometer (GRS) data at the Phoenix landing site by modeling a buried layer of 50-75% ice by mass (up to 90% by volume). Thermal and optical observations of recent impact craters in the northern hemisphere have revealed nearly pure ice. Ice deposits containing only 1-2% soil by volume were excavated by Phoenix. The leading hypothesis for the origin of this excess, or segregated, ice is that it developed in situ by a mechanism analogous to the formation of terrestrial ice lenses and needle ice. Problematically, terrestrial soil-ice segregation is driven by freeze/thaw cycling and the movement of bulk water, which are not expected to have occurred in the geologically recent past on Mars. We have developed a numerical model that applies the physics of pre-melting to track phase partitioning in soil pore spaces and test for conditions under which ice lenses could initiate. Our results indicate that diurnal cycling in the ice-cemented regolith and resultant pressure gradients in thin films at grain-ice interfaces can cause interparticle forces to unload, initiating an ice lens at temperatures as low as 245 K. These results indicate that in situ ice segregation may have occurred on Mars in the recent past, and that geologically young ice lenses may account for much of observed excess ice.

  9. Sequence of apoptosis and inflammatory necrosis within the formative ovulatory site of sheep follicles.

    PubMed

    Murdoch, W J; Wilken, C; Young, D A

    1999-11-01

    The aim of this study was to define the temporal and spatial patterns of apoptosis, necrosis and inflammation within preovulatory ovine follicles. A gonadotrophin surge was induced in pro-oestrous ewes by GnRH, and isolated follicles were hemisected into apical and basal segments at 0, 10, 18 and 22 h (the time of ovulatory stigma development) after GnRH. Ovarian surface epithelial and granulosa cells were isolated and assessed by fluorescence microscopy for membrane phosphatidylserine translocation-annexin V (early-stage apoptosis), oligonucleosomal DNA nick endlabelling (advanced apoptosis), and nuclear propidium iodide incorporation (necrotic membrane disruption). Thecal shells were analysed for interstitial blood cells. Preovulatory follicles were also hemisected and subjected to electrophoretic DNA degradation analysis. Annexin V binding and in situ DNA fragmentation among ovarian surface epithelial and granulosa cells along the follicular apex were high 18 and 22 h after GnRH. Propidium iodide staining of apical ovarian surface and granulosa cells was apparent at 22 h. There was a coincident increase within the apical theca as the time of ovulation approached in extravasated leucocytes (18 and 22 h) and erythrocytes (22 h). Apoptotic DNA laddering and necrotic DNA smears within the follicular apex were evident on agarose gels at 18 and 22 h, respectively. In contrast, ovarian surface epithelium not associated with the ovulation site and the basal follicular wall were largely unafflicted. It is suggested that both modalities of cellular death, apoptosis and necrosis (with acute inflammation and vascular injury), contribute progressively to follicular stigma formation and ovarian rupture.

  10. Probing Enhanced Double-Strand Break Formation at Abasic Sites within Clustered Lesions in Nucleosome Core Particles.

    PubMed

    Banerjee, Samya; Chakraborty, Supratim; Jacinto, Marco Paolo; Paul, Michael D; Balster, Morgan V; Greenberg, Marc M

    2017-01-10

    DNA is rapidly cleaved under mild alkaline conditions at apyrimidinic/apurinic sites, but the half-life is several weeks in phosphate buffer (pH 7.5). However, abasic sites are ∼100-fold more reactive within nucleosome core particles (NCPs). Histone proteins catalyze the strand scission, and at superhelical location 1.5, the histone H4 tail is largely responsible for the accelerated cleavage. The rate constant for strand scission at an abasic site is enhanced further in a nucleosome core particle when it is part of a bistranded lesion containing a proximal strand break. Cleavage of this form results in a highly deleterious double-strand break. This acceleration is dependent upon the position of the abasic lesion in the NCP and its structure. The enhancement in cleavage rate at an apurinic/apyrimidinic site rapidly drops off as the distance between the strand break and abasic site increases and is negligible once the two forms of damage are separated by 7 bp. However, the enhancement of the rate of double-strand break formation increases when the size of the gap is increased from one to two nucleotides. In contrast, the cleavage rate enhancement at 2-deoxyribonolactone within bistranded lesions is more modest, and it is similar in free DNA and nucleosome core particles. We postulate that the enhanced rate of double-strand break formation at bistranded lesions containing apurinic/apyrimidinic sites within nucleosome core particles is a general phenomenon and is due to increased DNA flexibility.

  11. Site-specific glycoproteomics confirms that protein structure dictates formation of N-glycan type, core fucosylation and branching.

    PubMed

    Thaysen-Andersen, Morten; Packer, Nicolle H

    2012-11-01

    Growing evidence indicates that the individualized and highly reproducible N-glycan repertoires on each protein glycosylation site modulate function. Relationships between protein structures and the resulting N-glycoforms have previously been observed, but remain to be quantitatively confirmed and examined in detail to define the responsible mechanisms in the conserved mammalian glycosylation machinery. Here, we investigate this relationship by manually extracting and analyzing quantitative and qualitative site-specific glycoprofiling data from 117 research papers. Specifically, N-glycan structural motifs were correlated with the structure of the protein carriers, focusing on the solvent accessibility of the individual glycosylation sites and the physicochemical properties of the surrounding polypeptide chains. In total, 474 glycosylation sites from 169 mammalian N-glycoproteins originating from different tissues/body fluids were investigated. It was confirmed statistically that the N-glycan type, degree of core fucosylation and branching are strongly influenced by the glycosylation site accessibility. For these three N-glycan features, glycosylation sites carrying highly processed glycans were significantly more solvent-accessible than those carrying less processed counterparts. The glycosylation site accessibilities could be linked to molecular signatures at the primary and secondary protein levels, most notably to the glycoprotein size and the proportion of glycosylation sites located in accessible β-turns. In addition, the subcellular location of the glycoproteins influenced the formation of the N-glycan structures. These data confirm that protein structures dictate site-specific formation of several features of N-glycan structures by affecting the biosynthetic pathway. Mammals have, as such, evolved mechanisms enabling proteins to influence the N-glycans they present to the extracellular environment.

  12. Active Site Formation, Not Bond Kinetics, Limits Adhesion Rate between Human Neutrophils and Immobilized Vascular Cell Adhesion Molecule 1

    PubMed Central

    Waugh, Richard E.; Lomakina, Elena B.

    2009-01-01

    Abstract The formation of receptor ligand bonds at the interface between different cells and between cells and substrates is a widespread phenomenon in biological systems. Physical measurements of bond formation rates between cells and substrates have been exploited to increase our understanding of the biophysical mechanisms that regulate bond formation at interfaces. Heretofore, these measurements have been interpreted in terms of simple bimolecular reaction kinetics. Discrepancies between this simple framework and the behavior of neutrophils adhering to surfaces expressing vascular cell adhesion molecule 1 (VCAM-1) motivated the development of a new kinetic framework in which the explicit formation of active bond formation sites (reaction zones) are a prerequisite for bond formation to occur. Measurements of cells interacting with surfaces having a wide range of VCAM-1 concentrations, and for different durations of contact, enabled the determination of novel kinetic rate constants for the formation of reaction zones and for the intrinsic bond kinetics. Comparison of these rates with rates determined previously for other receptor-ligand pairs points to a predominant role of extrinsic factors such as surface topography and accessibility of active molecules to regions of close contact in determining forward rates of bond formation at cell interfaces. PMID:19134479

  13. Role of soil macrofauna in soil formation in post mining sites along climatic and litter quality gradients

    NASA Astrophysics Data System (ADS)

    Frouz, Jan

    2014-05-01

    Soil macrofauna can play important role in soil formation. Here we used thin soil sections to study this process in two environmental gradients, climatic gradient, and liter quality gradient. Climatic gradient consist from four chronosequences of post mining sites in the USA, covering hardwood forest (TN, IN), tallgrass prairie (IL), or shortgrass prairie (WY). Earthworms and other saprophages were absent in such shortgrass sites but were present in the wetter, eastern sites. Absence of saprophagous groups, and especially earthworms, resulted in the absence of bioturbation in shortgrass prairie sites while worm casts and other biogenic structures formed an important part of the soil profile in other chronosequences, in short grass prairie in turn physical processes, such as erosion may play important role in soil mixing. Litter quality gradient consists from set of 28 sites planted with six kind of tree stand (pine, larch, spruce, oak, lime and alder) and unreclaimed sites (covered by willow, birch, aspen dominated forest) on one large heap in Czech Republic. Earthworm density on these sites negatively correlate with CN ratio, the same relationships was shown for proportion of earthworm cast in soil volume. In sites with high earthworm density Oe layer was absent and A layer formed by worm casts was well developed, in the contrary when earthworm were absent Oe layer was thick and A layer absent. Development of A layer correlate with soil carbon storage.

  14. Dimerisation induced formation of the active site and the identification of three metal sites in EAL-phosphodiesterases

    PubMed Central

    Bellini, Dom; Horrell, Sam; Hutchin, Andrew; Phippen, Curtis W.; Strange, Richard W.; Cai, Yuming; Wagner, Armin; Webb, Jeremy S.; Tews, Ivo; Walsh, Martin A.

    2017-01-01

    The bacterial second messenger cyclic di-3′,5′-guanosine monophosphate (c-di-GMP) is a key regulator of bacterial motility and virulence. As high levels of c-di-GMP are associated with the biofilm lifestyle, c-di-GMP hydrolysing phosphodiesterases (PDEs) have been identified as key targets to aid development of novel strategies to treat chronic infection by exploiting biofilm dispersal. We have studied the EAL signature motif-containing phosphodiesterase domains from the Pseudomonas aeruginosa proteins PA3825 (PA3825EAL) and PA1727 (MucREAL). Different dimerisation interfaces allow us to identify interface independent principles of enzyme regulation. Unlike previously characterised two-metal binding EAL-phosphodiesterases, PA3825EAL in complex with pGpG provides a model for a third metal site. The third metal is positioned to stabilise the negative charge of the 5′-phosphate, and thus three metals could be required for catalysis in analogy to other nucleases. This newly uncovered variation in metal coordination may provide a further level of bacterial PDE regulation. PMID:28186120

  15. Dimerisation induced formation of the active site and the identification of three metal sites in EAL-phosphodiesterases.

    PubMed

    Bellini, Dom; Horrell, Sam; Hutchin, Andrew; Phippen, Curtis W; Strange, Richard W; Cai, Yuming; Wagner, Armin; Webb, Jeremy S; Tews, Ivo; Walsh, Martin A

    2017-02-10

    The bacterial second messenger cyclic di-3',5'-guanosine monophosphate (c-di-GMP) is a key regulator of bacterial motility and virulence. As high levels of c-di-GMP are associated with the biofilm lifestyle, c-di-GMP hydrolysing phosphodiesterases (PDEs) have been identified as key targets to aid development of novel strategies to treat chronic infection by exploiting biofilm dispersal. We have studied the EAL signature motif-containing phosphodiesterase domains from the Pseudomonas aeruginosa proteins PA3825 (PA3825(EAL)) and PA1727 (MucR(EAL)). Different dimerisation interfaces allow us to identify interface independent principles of enzyme regulation. Unlike previously characterised two-metal binding EAL-phosphodiesterases, PA3825(EAL) in complex with pGpG provides a model for a third metal site. The third metal is positioned to stabilise the negative charge of the 5'-phosphate, and thus three metals could be required for catalysis in analogy to other nucleases. This newly uncovered variation in metal coordination may provide a further level of bacterial PDE regulation.

  16. DDT Vertical Migration and Formation of Accumulation Layer in Pesticide-Producing Sites.

    PubMed

    Liu, Li; Bai, Liping; Man, Changgeng; Liang, Wuhong; Li, Fasheng; Meng, Xiaoguang

    2015-08-04

    Soil samples were collected at various depths (0.5-21.5 m) from ten boreholes that were drilled with a SH-30 Model Rig, four of which were at a dicofol production site while six were at a dichlorodiphenyltrichloroethane (DDT) production site. In industrial sites, the shallow soils at depths of 0-2 m were mostly backfill soils, which cannot represent the contamination situation of the sites. The contaminated levels in the deep original soil can represent the situation in contaminated sites. All the soil samples investigated at the DDT and dicofol production sites were found to be seriously polluted. The contents of both DDT (0.6-6071 mg/kg) and dicofol (0.5-1440 mg/kg) were much higher at the dicofol production site than at the DDT production site (DDTs, 0.01-664.6 mg/kg; dicofol, <0.1 mg/kg), even in the deep soil. DDTs had a different distribution in the soil of the pesticide production site from that in the soil outside the sites and that in agricultural soils. The results of the investigation revealed that DDTs were easily enriched in cohesive soil and in the bottom zone of aquifers, where the concentration was higher than in above the layers. DDTs were found to be hard to degrade, and their degradation speed was slower than their vertical migration, despite the fact that hydrophobic DDTs did not migrate easily in soils. In the dicofol production site, the value of DDE/DDD cannot indicate the degradation condition of DDTs, nor can the value of (DDE + DDD)/DDT identify how long DDTs have remained in the soil. It is debatable that the half-life of DDT inputted to soils is about 20-30 years, maybe longer than the generally recognized time.

  17. Radial Glial Cell-Neuron Interaction Directs Axon Formation at the Opposite Side of the Neuron from the Contact Site.

    PubMed

    Xu, Chundi; Funahashi, Yasuhiro; Watanabe, Takashi; Takano, Tetsuya; Nakamuta, Shinichi; Namba, Takashi; Kaibuchi, Kozo

    2015-10-28

    How extracellular cues direct axon-dendrite polarization in mouse developing neurons is not fully understood. Here, we report that the radial glial cell (RGC)-cortical neuron interaction directs axon formation at the opposite side of the neuron from the contact site. N-cadherin accumulates at the contact site between the RGC and cortical neuron. Inhibition of the N-cadherin-mediated adhesion decreases this oriented axon formation in vitro, and disrupts the axon-dendrite polarization in vivo. Furthermore, the RGC-neuron interaction induces the polarized distribution of active RhoA at the contacting neurite and active Rac1 at the opposite neurite. Inhibition of Rho-Rho-kinase signaling in a neuron impairs the oriented axon formation in vitro, and prevents axon-dendrite polarization in vivo. Collectively, these results suggest that the N-cadherin-mediated radial glia-neuron interaction determines the contacting neurite as the leading process for radial glia-guided neuronal migration and directs axon formation to the opposite side acting through the Rho family GTPases.

  18. Mechanism of site-specific psoralen photoadducts formation in triplex DNA directed by psoralen-conjugated oligonucleotides.

    PubMed

    Ping, Yueh-Hsin; Rana, Tariq M

    2005-02-22

    Triplex-formation oligonucleotides attached with a photoreactive psoralen molecule (psoTFO) can be used to induce site-specific DNA damage and to control gene expression. Inhibition of transcription by psoralen-cross-linked triplexes results in both arrest and termination of RNA Pol II transcriptional complexes during elongation. To understand the relationship between triplex psoralen cross-linking products and the fate of RNA Pol II elongation complexes, it is important to delineate the mechanism for creating site-specific psoralen photoadducts in a target duplex DNA. To investigate the mechanism of photoadduct-formation by psoralen photo-cross-linking, triplex structures were generated by targeting a DNA duplex with psoTFOs of different lengths. The psoralen photoadducts were then analyzed after UV irradiation, which initiates the psoralen cross-linking reaction. Our results demonstrated that UV irradiation of triplexes formed between a psoTFO and a DNA duplex generated two distinct groups of psoralen photoadducts: monoadducts and psoralen interstrand cross-link products. The formation of these psoralen photoadducts was also photoreversible through exposure to short wavelength UV irradiation. The length of a psoTFO was shown to establish the position at which psoralen was added to the target DNA duplex and determined which photoadducts products formed predominantly. Kinetic experiments that monitored the formation of the psoralen photoadducts also suggested that the length of the psoTFO influenced which photoadducts were preferentially formed at faster rates. Taken together, these studies provide new insight into the mechanism associated with the formation of psoralen photoadducts that are directed by psoTFO during triplex formation.

  19. Insights into site formation at Rose Cottage Cave, South Africa, based on the analysis of sediment peels

    NASA Astrophysics Data System (ADS)

    Kloos, Peter; Miller, Christopher E.; Kritikakis, Panagiotis; Wadley, Lyn

    2016-04-01

    Rose Cottage Cave (RCC), in South Africa, has been a key site for explaining the origins of modern human behaviour and movement of early modern humans out of Africa. Nine sediment peels were made previously from the profile sections, preserving original materials that provide a record of cultural and environmental change during the late Pleistocene and Holocene. Here, we present the preliminary results of the study of the RCC sediment peels which aims to investigate site formation processes and the implications for site interpretation. Methods used include micromorphology and Fourier Transform Infrared spectroscopy coupled with detailed observations of the peels. The predominance of geogenic processes is demonstrated by the abundance of silt- and sand-sized quartz grains, which entered the site primarily through a crevice at the back of the cave. RCC lacks rich anthropogenic deposits as noted at other Middle Stone Age sites in southern Africa, but anthropogenic input to the sediment is indicated by the presence of charcoal, burnt bone, lithic fragments, fat-derived char and ashes. Clay coating fragments and chaotic microstructures demonstrate that bioturbation and colluvial reworking homogenised much of the deposit and may explain the absence of preserved bedding and rarity of combustion features. Downward movement of water through the sequence, indicated by clay coatings, is the likely cause for poor bone preservation and near lack of ashes at the site, as well as fluctuations in dose rate that have complicated luminescence dating studies. Evidence for diagenesis at the site is in the form of secondary apatite and gypsum. Sedimentary structures such as channel lag deposits and (silt and sand) laminae observed in peels dating between 60 and 35 ka BP suggest a high-energy sedimentary environment, which experienced flooding events that eroded underlying deposits and deposited large volumes of sediment. This explains why some of the post-Howiesons Poort layers contain

  20. Impact of Internet Images: Impression-Formation Effects of University Web Site Images

    ERIC Educational Resources Information Center

    Ramasubramanian, Srividya; Gyure, James F.; Mursi, Nasreen M.

    2002-01-01

    Institutions of higher education are increasingly becoming dependent on Web-based marketing to reach out to their target audiences. The current empirical study examines the types of impressions formed by prospective students based on exposure to different university Web site images. A between-subjects experiment was conducted using four identical…

  1. Genetic alterations and cancer formation in a European flatfish at sites of different contaminant burdens.

    PubMed

    Lerebours, Adélaïde; Stentiford, Grant D; Lyons, Brett P; Bignell, John P; Derocles, Stéphane A P; Rotchell, Jeanette M

    2014-09-02

    Fish diseases are an indicator for marine ecosystem health since they provide a biological end-point of historical exposure to stressors. Liver cancer has been used to monitor the effects of exposure to anthropogenic pollution in flatfish for many years. The prevalence of liver cancer can exceed 20%. Despite the high prevalence and the opportunity of using flatfish to study environmentally induced cancer, the genetic and environmental factors driving tumor prevalence across sites are poorly understood. This study aims to define the link between genetic deterioration, liver disease progression, and anthropogenic contaminant exposures in the flatfish dab (Limanda limanda). We assessed genetic changes in a conserved cancer gene, Retinoblastoma (Rb), in association with histological diagnosis of normal, pretumor, and tumor pathologies in the livers of 165 fish from six sites in the North Sea and English Channel. The highest concentrations of metals (especially cadmium) and organic chemicals correlated with the presence of tumor pathology and with defined genetic profiles of the Rb gene, from these sites. Different Rb genetic profiles were found in liver tissue near each tumor phenotype, giving insight into the mechanistic molecular-level cause of the liver pathologies. Different Rb profiles were also found at sampling sites of differing contaminant burdens. Additionally, profiles indicated that histological "normal" fish from Dogger sampling locations possessed Rb profiles associated with pretumor disease. This study highlights an association between Rb and specific contaminants (especially cadmium) in the molecular etiology of dab liver tumorigenesis.

  2. Active site remodelling accompanies thioester bond formation in the SUMO E1

    SciTech Connect

    Olsen, Shaun K.; Capili, Allan D.; Lu, Xuequan; Tan, Derek S.; Lima, Christopher D.

    2010-03-30

    E1 enzymes activate ubiquitin (Ub) and ubiquitin-like (Ubl) proteins in two steps by carboxy-terminal adenylation and thioester bond formation to a conserved catalytic cysteine in the E1 Cys domain. The structural basis for these intermediates remains unknown. Here we report crystal structures for human SUMO E1 in complex with SUMO adenylate and tetrahedral intermediate analogues at 2.45 and 2.6 {angstrom}, respectively. These structures show that side chain contacts to ATP-Mg are released after adenylation to facilitate a 130 degree rotation of the Cys domain during thioester bond formation that is accompanied by remodelling of key structural elements including the helix that contains the E1 catalytic cysteine, the crossover and re-entry loops, and refolding of two helices that are required for adenylation. These changes displace side chains required for adenylation with side chains required for thioester bond formation. Mutational and biochemical analyses indicate these mechanisms are conserved in other E1s.

  3. Active site remodelling accompanies thioester bond formation in the SUMO E1.

    PubMed

    Olsen, Shaun K; Capili, Allan D; Lu, Xuequan; Tan, Derek S; Lima, Christopher D

    2010-02-18

    E1 enzymes activate ubiquitin (Ub) and ubiquitin-like (Ubl) proteins in two steps by carboxy-terminal adenylation and thioester bond formation to a conserved catalytic cysteine in the E1 Cys domain. The structural basis for these intermediates remains unknown. Here we report crystal structures for human SUMO E1 in complex with SUMO adenylate and tetrahedral intermediate analogues at 2.45 and 2.6 A, respectively. These structures show that side chain contacts to ATP.Mg are released after adenylation to facilitate a 130 degree rotation of the Cys domain during thioester bond formation that is accompanied by remodelling of key structural elements including the helix that contains the E1 catalytic cysteine, the crossover and re-entry loops, and refolding of two helices that are required for adenylation. These changes displace side chains required for adenylation with side chains required for thioester bond formation. Mutational and biochemical analyses indicate these mechanisms are conserved in other E1s.

  4. Barometric pressure transient testing applications at the Nevada Test Site: formation permeability analysis. Final report

    SciTech Connect

    Hanson, J.M.

    1984-12-01

    The report evaluates previous investigations of the gas permeability of the rock surrounding emplacement holes at the Nevada Test Site. The discussion sets the framework from which the present uncertainty in gas permeability can be overcome. The usefulness of the barometric pressure testing method has been established. Flow models were used to evaluate barometric pressure transients taken at NTS holes U2fe, U19ac and U20ai. 31 refs., 103 figs., 18 tabs. (ACR)

  5. Possibility of microscopic liquid water formation at landing sites on Mars and their observational potential

    NASA Astrophysics Data System (ADS)

    Pál, B.; Kereszturi, Á.

    2017-01-01

    Microscopic liquid brines, especially calcium-perchlorate could emerge by deliquescence on Mars during night time hours. Using climate model computations and orbital humidity observations, the ideal periods and their annual plus daily characteristics at various past, current and future landing sites were compared. Such results provide context for future analysis and targeting the related observations by the next missions for Mars. Based on the analysis, at most (but not all) past missions' landing sites, microscopic brine could emerge during night time for different durations. Analysing the conditions at ExoMars rover's primary landing site at Oxia Planum, the best annual period was found to be between Ls 115-225, and in Local Time 2-5, after midnight. In an ideal case, 4 h of continuous liquid phase can emerge there. Local conditions might cause values to differ from those estimated by the model. Thermal inertia could especially make such differences (low TI values favour fast cooling and H2O cold trapping at loose surfaces) and the concentration of calcium-perchlorate salt in the regolith also influences the process (it might occur preferentially at long-term exposed surfaces without recent loose dust coverage). These factors should be taken into account while targeting future liquid water observations on Mars.

  6. In site bioimaging of hydrogen sulfide uncovers its pivotal role in regulating nitric oxide-induced lateral root formation.

    PubMed

    Li, Yan-Jun; Chen, Jian; Xian, Ming; Zhou, Li-Gang; Han, Fengxiang X; Gan, Li-Jun; Shi, Zhi-Qi

    2014-01-01

    Hydrogen sulfide (H2S) is an important gasotransmitter in mammals. Despite physiological changes induced by exogenous H2S donor NaHS to plants, whether and how H2S works as a true cellular signal in plants need to be examined. A self-developed specific fluorescent probe (WSP-1) was applied to track endogenous H2S in tomato (Solanum lycopersicum) roots in site. Bioimaging combined with pharmacological and biochemical approaches were used to investigate the cross-talk among H2S, nitric oxide (NO), and Ca(2+) in regulating lateral root formation. Endogenous H2S accumulation was clearly associated with primordium initiation and lateral root emergence. NO donor SNP stimulated the generation of endogenous H2S and the expression of the gene coding for the enzyme responsible for endogenous H2S synthesis. Scavenging H2S or inhibiting H2S synthesis partially blocked SNP-induced lateral root formation and the expression of lateral root-related genes. The stimulatory effect of SNP on Ca(2+) accumulation and CaM1 (calmodulin 1) expression could be abolished by inhibiting H2S synthesis. Ca(2+) chelator or Ca(2+) channel blocker attenuated NaHS-induced lateral root formation. Our study confirmed the role of H2S as a cellular signal in plants being a mediator between NO and Ca(2+) in regulating lateral root formation.

  7. Radial Glial Cell–Neuron Interaction Directs Axon Formation at the Opposite Side of the Neuron from the Contact Site

    PubMed Central

    Xu, Chundi; Funahashi, Yasuhiro; Watanabe, Takashi; Takano, Tetsuya; Nakamuta, Shinichi; Namba, Takashi

    2015-01-01

    How extracellular cues direct axon–dendrite polarization in mouse developing neurons is not fully understood. Here, we report that the radial glial cell (RGC)–cortical neuron interaction directs axon formation at the opposite side of the neuron from the contact site. N-cadherin accumulates at the contact site between the RGC and cortical neuron. Inhibition of the N-cadherin-mediated adhesion decreases this oriented axon formation in vitro, and disrupts the axon–dendrite polarization in vivo. Furthermore, the RGC–neuron interaction induces the polarized distribution of active RhoA at the contacting neurite and active Rac1 at the opposite neurite. Inhibition of Rho–Rho-kinase signaling in a neuron impairs the oriented axon formation in vitro, and prevents axon–dendrite polarization in vivo. Collectively, these results suggest that the N-cadherin-mediated radial glia–neuron interaction determines the contacting neurite as the leading process for radial glia-guided neuronal migration and directs axon formation to the opposite side acting through the Rho family GTPases. SIGNIFICANCE STATEMENT Neurons are highly polarized cell lines typically with a single axon and multiple dendrites, which underlies the ability of integrating and transmitting the information in the brain. How is the axon–dendrite polarity of neurons established in the developing neocortex? Here we show that the N-cadherin-mediated radial glial cell–neuron interaction directs axon–dendrite polarization, the radial glial cell–neuron interaction induces polarized distribution of active RhoA and active Rac1 in neurons, and Rho–Rho-kinase signaling is required for axon–dendrite polarization. Our work advances the overall understanding of how extracellular cues direct axon–dendrite polarization in mouse developing neurons. PMID:26511243

  8. Mutations within potential glycosylation sites in the capsid protein of hepatitis E virus prevent the formation of infectious virus particles.

    PubMed

    Graff, Judith; Zhou, Yi-Hua; Torian, Udana; Nguyen, Hanh; St Claire, Marisa; Yu, Claro; Purcell, Robert H; Emerson, Suzanne U

    2008-02-01

    Hepatitis E virus is a nonenveloped RNA virus. However, the single capsid protein resembles a typical glycoprotein in that it contains a signal sequence and potential glycosylation sites that are utilized when recombinant capsid protein is overexpressed in cell culture. In order to determine whether these unexpected observations were biologically relevant or were artifacts of overexpression, we analyzed capsid protein produced during a normal viral replication cycle. In vitro transcripts from an infectious cDNA clone mutated to eliminate potential glycosylation sites were transfected into cultured Huh-7 cells and into the livers of rhesus macaques. The mutations did not detectably affect genome replication or capsid protein synthesis in cell culture. However, none of the mutants infected rhesus macaques. Velocity sedimentation analyses of transfected cell lysates revealed that mutation of the first two glycosylation sites prevented virion assembly, whereas mutation of the third site permitted particle formation and RNA encapsidation, but the particles were not infectious. However, conservative mutations that did not destroy glycosylation motifs also prevented infection. Overall, the data suggested that the mutations were lethal because they perturbed protein structure rather than because they eliminated glycosylation.

  9. BOREAS TE-1 Soils Data Over The SSA Tower Sites in Raster Format

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Anderson, Darwin; Knapp, David E.

    2000-01-01

    The BOREAS TE-1 team collected various data to characterize the soil-plant systems in the BOREAS SSA. This data set was gridded from vector layers of soil maps that were received from Dr. Darwin Anderson (TE-1), who did the original soil mapping in the field during 1994. The vector layers were gridded into raster files that cover approximately 1 square kilometer over each of the tower sites in the SSA. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  10. BOREAS TE-20 Soils Data Over the NSA-MSA and Tower Sites in Vector Format

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Veldhuis, Hugo; Knapp, David

    2000-01-01

    The BOREAS TE-20 team collected several data sets for use in developing and testing models of forest ecosystem dynamics. This data set contains vector layers of soil maps that were received from Dr. Hugo Veldhuis, who did the original mapping in the field during 1994. The vector layers were converted to ARCANFO EXPORT files. These data cover 1-kilometer diameters around each of the NSA tower sites, and another layer covers the NSA-MSA. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Center (DAAC).

  11. Stratigraphy of mid-Cretaceous formations at drilling sites in Weston and Johnson counties, northeastern Wyoming

    USGS Publications Warehouse

    Mereweather, E.A.

    1980-01-01

    The sedimentary rocks of early Late Cretaceous age in Weston County, Wyo., on the east flank of the Powder River Basin, are assigned, in ascending order, to the Belle Fourche Shale, Greenhorn Formation, and Carlile Shale. In Johnson County, on the west flank of the basin, the lower Upper Cretaceous strata are included in the Frontier Formation and the overlying Cody Shale. The Frontier Formation and some of the laterally equivalent strata in the Rocky Mountain region contain major resources of oil and gas. These rocks also include commercial deposits of bentonite. Outcrop sections, borehole logs, and core studies of the lower Upper Cretaceous rocks near Osage, in Weston County, and Kaycee, in Johnson County, supplement comparative studies of the fossils in the formations. Fossils of Cenomanian, Turonian, and Coniacian Age are abundant at these localities and form sequences of species which can be used for the zonation and correlation of strata throughout the region. The Belle Fourche Shale near Osage is about 115 m (meters) thick and consists mainly of noncalcareous shale, which was deposited in offshore-marine environments during Cenomanian time. These strata are overlain by calcareous shale and limestone of the Greenhorn Formation. In this area, the Greenhorn is about 85 m thick and accumulated in offshore, open-marine environments during the Cenomanian and early Turonian. The Carlile Shale overlies the Greenhorn and is composed of, from oldest to youngest, the Pool Creek Member, Turner Sandy Member, and Sage Breaks Member. In boreholes, the Pool Creek Member is about 23 m thick and consists largely of shale. The member was deposited in offshoremarine environments in Turonian time. These rocks are disconformably overlain by the Turner Sandy Member, a sequence about 50 m thick of interstratified shale, siltstone, and sandstone. The Turner accumulated during the Turonian in several shallow-marine environments. Conformably overlying the Turner is the slightly

  12. An evaluation of water quality in private drinking water wells near natural gas extraction sites in the Barnett Shale formation.

    PubMed

    Fontenot, Brian E; Hunt, Laura R; Hildenbrand, Zacariah L; Carlton, Doug D; Oka, Hyppolite; Walton, Jayme L; Hopkins, Dan; Osorio, Alexandra; Bjorndal, Bryan; Hu, Qinhong H; Schug, Kevin A

    2013-09-03

    Natural gas has become a leading source of alternative energy with the advent of techniques to economically extract gas reserves from deep shale formations. Here, we present an assessment of private well water quality in aquifers overlying the Barnett Shale formation of North Texas. We evaluated samples from 100 private drinking water wells using analytical chemistry techniques. Analyses revealed that arsenic, selenium, strontium and total dissolved solids (TDS) exceeded the Environmental Protection Agency's Drinking Water Maximum Contaminant Limit (MCL) in some samples from private water wells located within 3 km of active natural gas wells. Lower levels of arsenic, selenium, strontium, and barium were detected at reference sites outside the Barnett Shale region as well as sites within the Barnett Shale region located more than 3 km from active natural gas wells. Methanol and ethanol were also detected in 29% of samples. Samples exceeding MCL levels were randomly distributed within areas of active natural gas extraction, and the spatial patterns in our data suggest that elevated constituent levels could be due to a variety of factors including mobilization of natural constituents, hydrogeochemical changes from lowering of the water table, or industrial accidents such as faulty gas well casings.

  13. Spontaneous Isopeptide Bond Formation as a Powerful Tool for Engineering Site-Specific Antibody-Drug Conjugates

    PubMed Central

    Siegmund, Vanessa; Piater, Birgit; Zakeri, Bijan; Eichhorn, Thomas; Fischer, Frank; Deutsch, Carl; Becker, Stefan; Toleikis, Lars; Hock, Björn; Betz, Ulrich A. K.; Kolmar, Harald

    2016-01-01

    Spontaneous isopeptide bond formation, a stabilizing posttranslational modification that can be found in gram-positive bacterial cell surface proteins, has previously been used to develop a peptide-peptide ligation technology that enables the polymerization of tagged-proteins catalyzed by SpyLigase. Here we adapted this technology to establish a novel modular antibody labeling approach which is based on isopeptide bond formation between two recognition peptides, SpyTag and KTag. Our labeling strategy allows the attachment of a reporting cargo of interest to an antibody scaffold by fusing it chemically to KTag, available via semi-automated solid-phase peptide synthesis (SPPS), while equipping the antibody with SpyTag. This strategy was successfully used to engineer site-specific antibody-drug conjugates (ADCs) that exhibit cytotoxicities in the subnanomolar range. Our approach may lead to a new class of antibody conjugates based on peptide-tags that have minimal effects on protein structure and function, thus expanding the toolbox of site-specific antibody conjugation. PMID:27982100

  14. Ground-water flow model of the Boone formation at the Tar Creek superfund site, Oklahoma and Kansas

    USGS Publications Warehouse

    Reed, T.B.; Czarnecki, John B.

    2006-01-01

    Extensive mining activities conducted at the Tar Creek Superfund site, one of the largest Superfund sites in the United States, pose substantial health and safety risks. Mining activities removed a total of about 6,000,000 tons of lead and zinc by 1949. To evaluate the effect of this mining on the ground-water flow, a MODFLOW 2000 digital model has been developed to simulate ground-water flow in the carbonate formations of Mississippian age underlying the Tar Creek Superfund site. The model consists of three layers of variable thickness and a grid of 580 rows by 680 columns of cells 164 feet (50 meters) on a side. Model flux boundary conditions are specified for rivers and general head boundaries along the northern boundary of the Boone Formation. Selected cells in layer 1 are simulated as drain cells. Model calibration has been performed to minimize the difference between simulated and observed water levels in the Boone Formation. Hydraulic conductivity values specified during calibration range from 1.3 to 35 feet per day for the Boone Formation with the larger values occurring along the axis of the Miami Syncline where horizontal anisotropy is specified as 10 to 1. Hydraulic conductivity associated with the mine void is set at 50,000 feet per day and a specific yield of 1.0 is specified to represent that the mine void is filled completely with water. Residuals (the difference between measured and simulated ground-water altitudes) has a root-mean-squared value of 8.53 feet and an absolute mean value of 7.29 feet for 17 observed values of water levels in the Boone Formation. The utility of the model for simulating and evaluating the possible consequences of remediation activities has been demonstrated. The model was used to simulate the emplacement of chat (mine waste consisting of fines and fragments of chert) back into the mine. Scenarios using 1,800,000 and 6,500,000 tons of chat were run. Hydraulic conductivity was reduced from 50,000 feet per day to 35 feet

  15. Use of Modeling for Prevention of Solids Formation During Canyon Processing of Legacy Nuclear Materials at the Savannah River Site

    SciTech Connect

    Rhodes, W. D.; Crooks III, W. J.; Christian, J. D.

    2002-02-26

    The Savannah River Site (SRS) Environmental Management (EM) nuclear material stabilization program includes the dissolution and processing of legacy materials from various DOE sites. The SRS canyon facilities were designed to dissolve and process spent nuclear fuel and targets. As the processing of typical materials is completed, unusual and exotic nuclear materials are being targeted for stabilization. These unusual materials are often difficult to dissolve using historical flowsheet conditions and require more aggressive dissolver solutions. Solids must be prevented in the dissolver to avoid expensive delays associated with the build-up of insoluble material in downstream process equipment. Moreover, it is vital to prevent precipitation of all solids, especially plutonium-bearing solids, since their presence in dissolver solutions raises criticality safety issues. To prevent precipitation of undesirable solids in aqueous process solutions, the accuracy of computer models to predict precipitate formation requires incorporation of plant specific fundamental data. These data are incorporated into a previously developed thermodynamic computer program that applies the Pitzer correlation to derive activity coefficient parameters. This improved predictive model will reduce unwanted precipitation in process solutions at DOE sites working with EM nuclear materials in aqueous solutions.

  16. Site characterization of the highest-priority geologic formations for CO2 storage in Wyoming

    SciTech Connect

    Surdam, Ronald C.; Bentley, Ramsey; Campbell-Stone, Erin; Dahl, Shanna; Deiss, Allory; Ganshin, Yuri; Jiao, Zunsheng; Kaszuba, John; Mallick, Subhashis; McLaughlin, Fred; Myers, James; Quillinan, Scott

    2013-12-07

    This study, funded by U.S. Department of Energy National Energy Technology Laboratory award DE-FE0002142 along with the state of Wyoming, uses outcrop and core observations, a diverse electric log suite, a VSP survey, in-bore testing (DST, injection tests, and fluid sampling), a variety of rock/fluid analyses, and a wide range of seismic attributes derived from a 3-D seismic survey to thoroughly characterize the highest-potential storage reservoirs and confining layers at the premier CO2 geological storage site in Wyoming. An accurate site characterization was essential to assessing the following critical aspects of the storage site: (1) more accurately estimate the CO2 reservoir storage capacity (Madison Limestone and Weber Sandstone at the Rock Springs Uplift (RSU)), (2) evaluate the distribution, long-term integrity, and permanence of the confining layers, (3) manage CO2 injection pressures by removing formation fluids (brine production/treatment), and (4) evaluate potential utilization of the stored CO2

  17. Memo-RhoA-mDia1 signaling controls microtubules, the actin network, and adhesion site formation in migrating cells.

    PubMed

    Zaoui, Kossay; Honoré, Stéphane; Isnardon, Daniel; Braguer, Diane; Badache, Ali

    2008-11-03

    Actin assembly at the cell front drives membrane protrusion and initiates the cell migration cycle. Microtubules (MTs) extend within forward protrusions to sustain cell polarity and promote adhesion site turnover. Memo is an effector of the ErbB2 receptor tyrosine kinase involved in breast carcinoma cell migration. However, its mechanism of action remained unknown. We report in this study that Memo controls ErbB2-regulated MT dynamics by altering the transition frequency between MT growth and shortening phases. Moreover, although Memo-depleted cells can assemble the Rac1-dependent actin meshwork and form lamellipodia, they show defective localization of lamellipodial markers such as alpha-actinin-1 and a reduced number of short-lived adhesion sites underlying the advancing edge of migrating cells. Finally, we demonstrate that Memo is required for the localization of the RhoA guanosine triphosphatase and its effector mDia1 to the plasma membrane and that Memo-RhoA-mDia1 signaling coordinates the organization of the lamellipodial actin network, adhesion site formation, and MT outgrowth within the cell leading edge to sustain cell motility.

  18. The Link between Rare-Earth Peak Formation and the Astrophysical Site of the R Process

    NASA Astrophysics Data System (ADS)

    Mumpower, Matthew R.; McLaughlin, Gail C.; Surman, Rebecca; Steiner, Andrew W.

    2016-12-01

    The primary astrophysical source of the rare-earth elements is the rapid neutron capture process (r process). The rare-earth peak that is seen in the solar r-process residuals has been proposed to originate as a pile-up of nuclei during the end of the r process. We introduce a new method utilizing Monte Carlo studies of nuclear masses in the rare-earth region, that includes self-consistently adjusting β-decay rates and neutron capture rates, to find the mass surfaces necessary for the formation of the rare-earth peak. We demonstrate our method with two types of astrophysical scenario, one corresponding to conditions typical of hot winds from core-collapse supernovae and stellar-mass accretion disks, and one corresponding to conditions typical of the ejection of the material from the tidal tails of neutron star mergers. In each type of astrophysical condition, this method successfully locates a region of enhanced stability in the mass surface that is responsible for the rare-earth peak. For each scenario, we find that the change in the mass surface has qualitatively different features, thus future measurements can shed light on the type of environment in which the r process occurred.

  19. Evaluation of tritiated water diffusion through the Toarcian clayey formation of the Tournemire experimental site (France).

    PubMed

    Motellier, S; Devol-Brown, I; Savoye, S; Thoby, D; Alberto, J-C

    2007-10-30

    Through-diffusion experiments with tritiated water were performed on argillaceous samples from various zones of the Tournemire test site. It was intended to evaluate the homogeneity of the transport property of unfracturated samples and the influence of the orientation and the nature of the samples (presence of an opened fracture or a pre-existing tectonic fracture filled with calcite and pyrite). Homogeneous values of the tritiated water (HTO) effective diffusion coefficients were deduced from experiments carried out when diffusion occurred parallel to the stratigraphic bedding, with an apparent sensitivity to experimental conditions. Anisotropy was significant, De(HTO) perpendicular to the bedding being 1/3 lower than that parallel to the bedding. The observed fractures of the samples created by mechanical stress and partial dehydration during sawing and the presence of a pre-existing opened fracture did not affect the effective diffusion coefficients of tritiated water, which is probably due to the healing ability of the clayey medium during the re-saturation phases of the equilibrium steps performed prior to the diffusion experiments. On the contrary, a significant decrease of this transport parameter was induced by the occurrence of a pre-existing tectonic fracture, which was assigned to the dense structure of the filling phases.

  20. Climatology and Formation of Tropical Midlevel Clouds at the Darwin ARM Site

    SciTech Connect

    Riihimaki, Laura D.; McFarlane, Sally A.; Comstock, Jennifer M.

    2012-10-01

    A 4-yr climatology of midlevel clouds is presented from vertically pointing cloud lidar and radar measurements at the Atmospheric Radiation Measurement Program (ARM) site at Darwin, Australia. Few studies exist of tropical midlevel clouds using a dataset of this length. Seventy percent of clouds with top heights between 4 and 8 km are less than 2 km thick. These thin layer clouds have a peak in cloud-top temperature around the melting level (0°C) and also a second peak around -12.5°C. The diurnal frequency of thin clouds is highest during the night and reaches a minimum around noon, consistent with variation caused by solar heating. Using a 1.5-yr subset of the observations, the authors found that thin clouds have a high probability of containing supercooled liquid water at low temperatures: ~20% of clouds at -30°C, ~50% of clouds at -20°C, and ~65% of clouds at -10°C contain supercooled liquid water. The authors hypothesize that thin midlevel clouds formed at the melting level are formed differently during active and break monsoon periods and test this over three monsoon seasons. A greater frequency of thin midlevel clouds are likely formed by increased condensation following the latent cooling of melting during active monsoon periods when stratiform precipitation is most frequent. This is supported by the high percentage (65%) of midlevel clouds with preceding stratiform precipitation and the high frequency of stable layers slightly warmer than 0°C. In the break monsoon, a distinct peak in the frequency of stable layers at 0°C matches the peak in thin midlevel cloudiness, consistent with detrainment from convection.

  1. Dust Seds And Processing Near Sites Of High Mass Star Formation In The LMC

    NASA Astrophysics Data System (ADS)

    Hony, Sacha; Galliano, F.; Madden, S. M.; SAGE Consortium

    2010-01-01

    We present a study into the properties of the dust and complex molecules in and around selected HII regions in the Large Magellanic Cloud. The analysis is based on the Spitzer program SAGE (Surveying the Agents of a Galaxy's Evolution). Because of the lower metallicity environment, dust shielding is reduced and the effects of the ultraviolet radiation carry further than in the Milky way. Because of this these HII regions may better represent star forming regions in the more distant universe. We present the near- to far-IR spectral energy distributions (SEDs) as a function of radial distance to the center of the several clusters. The regions span a wide range in luminosities. We have developed a self consistent spherical clumpy dust radiative transfer model to interpret the observed trends. The model treats the detailed dust optical properties and transient grain heating as well as IR absorption and reprocession. This allows us to interpret the observed variations in SED in terms of the clumpiness, varying incident radiation-field and changing abundances of polycyclic aromatic hydrocarbons (PAHs), transiently heated very small grains (VSG) to submicron-sized grains in thermal equilibrium, i.e. in terms of the varying grain-size distribution. We find that the LMC massive star forming sites are typified by a several parsec sized void and clumpiness and PAH abundance which increases with distance from the central illuminating source. The inner void may be the result of massive star winds. The observed flat mid-IR SEDs require a grain-size distribution skewed to a higher fraction of smaller grains compared to the Milky Way dust.

  2. Phosphatidylglycerol of rat lung. Intracellular sites of formation de novo and acyl species pattern in mitochondria, microsomes and surfactant.

    PubMed Central

    Schlame, M; Rüstow, B; Kunze, D; Rabe, H; Reichmann, G

    1986-01-01

    The subcellular site of phosphatidylglycerol (PG) formation for lung surfactant has not been convincingly clarified. To approach this problem we analysed the acyl species pattern of lung PG in mitochondria, microsomes and surfactant by h.p.l.c. separation of its 1,2-diacyl-3-naphthylurethane derivatives. Both mitochondrial and microsomal PG proved identical with surfactant PG, containing the major species 1-palmitoyl-2-oleoyl-PG and 1,2-dipalmitoyl-PG. The fatty acid composition of mitochondrial PG differs markedly from that of diphosphatidylglycerol. This may be taken as an indication that mitochondrial PG is synthesized on purpose to form surfactant, rather than being only the precursor of diphosphatidylglycerol. In vitro, sn-[U-14C]glycerol 3-phosphate incorporation into PG of mitochondria or microsomes occurs in the presence of CTP, ATP and CoA but independently of the supply of exogenous lipoidic precursors. Although the rate in vitro of autonomous PG synthesis, and the endogenous PG content, are higher in mitochondria than in microsomes, it is assumed that both subcellular fractions are involved in PG formation for surfactant. PMID:3827844

  3. Fast Helix Formation in the B Domain of Protein A Revealed by Site-Specific Infrared Probes

    PubMed Central

    Davis, Caitlin M.; Cooper, A. Kat; Dyer, R. Brian

    2015-01-01

    Comparison of experimental and computational protein folding studies can be difficult because of differences in structural resolution. Isotope-edited infrared spectroscopy offers a direct measure of structural changes involved in protein folding at the single-residue level. Here we demonstrate the increased resolution of site-specific infrared probes to the peptide backbone in the B domain of staphylococcal protein A (BdpA). 13C=18O-labeled methionine was incorporated into each of the helices using recombinant protein expression. Laser-induced temperature jumps coupled with infrared spectroscopy were used to probe changes in the peptide backbone on the submillisecond time scale. The relaxation kinetics of the buried helices, solvated helices, and labeled positions were measured independently by probing the corresponding bands assigned in the amide I region. Using these wavelength-dependent measurements, we observe a fast nanosecond phase and slower microsecond phase at each position. We find at least partial formation of helices 1–3 in the fast intermediate state that precedes the transition state. These measurements provide direct, time-resolved experimental evidence of the early formation of partial helical structure in helices 1 and 3, supporting folding models proposed by computer simulations. PMID:25706439

  4. Fast helix formation in the B domain of protein A revealed by site-specific infrared probes.

    PubMed

    Davis, Caitlin M; Cooper, A Kat; Dyer, R Brian

    2015-03-10

    Comparison of experimental and computational protein folding studies can be difficult because of differences in structural resolution. Isotope-edited infrared spectroscopy offers a direct measure of structural changes involved in protein folding at the single-residue level. Here we demonstrate the increased resolution of site-specific infrared probes to the peptide backbone in the B domain of staphylococcal protein A (BdpA). (13)C═(18)O-labeled methionine was incorporated into each of the helices using recombinant protein expression. Laser-induced temperature jumps coupled with infrared spectroscopy were used to probe changes in the peptide backbone on the submillisecond time scale. The relaxation kinetics of the buried helices, solvated helices, and labeled positions were measured independently by probing the corresponding bands assigned in the amide I region. Using these wavelength-dependent measurements, we observe a fast nanosecond phase and slower microsecond phase at each position. We find at least partial formation of helices 1-3 in the fast intermediate state that precedes the transition state. These measurements provide direct, time-resolved experimental evidence of the early formation of partial helical structure in helices 1 and 3, supporting folding models proposed by computer simulations.

  5. Analysis of solutes in groundwaters from the Rustler Formation at and near the Waste Isolation Pilot Plant site

    SciTech Connect

    Robinson, K.L.

    1997-09-01

    Between 1976 and 1986, groundwater samples from more than 60 locations in the vicinity of the Waste Isolation Pilot Plant site were collected and analyzed for a variety of major, minor, and trace solutes. Most of the samples were from the Rustler Formation (the Culebra Dolomite, the Magenta Dolomite, or the zone at the contact between the Rustler and underlying Salado Formations) or the Dewey Lake Red Beds. The analytical data from the laboratories are presented here with accompanying discussions of sample collection methods, supporting field measurements, and laboratory analytical methods. A comparison of four data sets and a preliminary evaluation of the data for the major solutes (Cl{sup {minus}}, SO{sub 4}{sup {minus}2}, Na, K, Ca, and Mg) shows that the data for samples analyzed by UNC/Bendix for SNL seem to be the most reliable, but that at some locations, samples representative of the native, unperturbed groundwater have not been collected. At other locations, the water chemistry has apparently changed between sampling episodes.

  6. MECHANISMS OF PHASE FORMATION IN THE VITRIFICATION OF HIGH-FERROUS SAVANNAH RIVER SITE SB2 HLW SLUDGE SURROGATE - 9300

    SciTech Connect

    Marra, J

    2008-08-27

    Phase formation mechanisms associated with the vitrification of high-ferrous Savannah River Site (SRS) Sludge Batch 2 (SB2) high level waste surrogate were studied by infrared spectroscopy (IRS) and X-ray diffraction (XRD). Two mixtures at 50 wt% waste loading with commercially available Frit 320 (Li{sub 2}O - 8 wt %, B{sub 2}O{sub 3} - 8 wt %, Na{sub 2}O - 12 wt %, SiO{sub 2} - 72 wt %) and batch chemicals (LiOH {center_dot} H{sub 2}O, H{sub 3}BO{sub 3}, NaNO{sub 3}, SiO{sub 2}) to represent the frit formulation were prepared as slurries with a water content of {approx}50 wt%. The mixtures were air-dried at a temperature of 115 C and heat-treated at 500, 700, 900, 1000, 1100, 1200, and 1300 C for 1 hr at each temperature. Infrared spectra and XRD patterns of the products produced at each temperature were recorded. In both mixtures prepared using frit and batch chemicals to represent the frit, phase formation reactions were completed within the temperature range between 900 and 1000 C. However, residual quartz was still present in glass produced from the mixture with batch chemicals even at 1100 C. Although, the phase composition and structure of the glassy products obtained from both mixtures at temperatures over 1000 C were similar, the products obtained from the mixture using actual frit were more homogeneous than those from the mixture with batch chemicals. Thus, the use of frit rather than batch chemicals reduced the temperature range of phase formation and provided for production of higher quality glass.

  7. A FEEDBACK-DRIVEN BUBBLE G24.136+00.436: A POSSIBLE SITE OF TRIGGERED STAR FORMATION

    SciTech Connect

    Liu, Hong-Li; Li, JinZeng; Yuan, Jing-Hua; Wu, Yuefang; Dong, Xiaoyi; Liu, Tie E-mail: yfwu.pku@gmail.com

    2015-01-01

    We present a multi-wavelength study of the IR bubble G24.136+00.436. The J = 1-0 observations of {sup 12}CO, {sup 13}CO, and C{sup 18}O were carried out with the Purple Mountain Observatory 13.7 m telescope. Molecular gas with a velocity of 94.8 km s{sup –1} is found prominently in the southeast of the bubble, shaped as a shell with a total mass of ∼2 × 10{sup 4} M {sub ☉}. It was likely assembled during the expansion of the bubble. The expanding shell consists of six dense cores, whose dense (a few of 10{sup 3} cm{sup –3}) and massive (a few of 10{sup 3} M {sub ☉}) characteristics coupled with the broad linewidths (>2.5 km s{sup –1}) suggest that they are promising sites for forming high-mass stars or clusters. This could be further consolidated by the detection of compact H II regions in Cores A and E. We tentatively identified and classified 63 candidate young stellar objects (YSOs) based on the Spitzer and UKIDSS data. They are found to be dominantly distributed in regions with strong molecular gas emission, indicative of active star formation, especially in the shell. The H II region inside the bubble is mainly ionized by a ∼O8V star(s), of the dynamical age of ∼1.6 Myr. The enhanced number of candidate YSOs and secondary star formation in the shell as well as the timescales involved, indicate a possible scenario for triggering star formation, signified by the ''collect and collapse'' process.

  8. Identification of catalysis, substrate, and coenzyme binding sites and improvement catalytic efficiency of formate dehydrogenase from Candida boidinii.

    PubMed

    Jiang, Wei; Lin, Peng; Yang, Ruonan; Fang, Baishan

    2016-10-01

    Formate dehydrogenases (FDHs) are continually used for the cofactor regeneration in biocatalysis and biotransformation with hiring NAD(P)H-dependent oxidoreductases. Major weaknesses of most native FDHs are their low activity and operational stability in the catalytic reaction. In this work, the FDH from Candida boidinii (CboFDH) was engineered in order to gain an enzyme with high activity and better operational stability. Through comparing and analyzing its spatial structure with other FDHs, the catalysis, substrate, and coenzyme binding sites of the CboFDH were identified. To improve its performance, amino acids, which concentrated on the enzyme active site or in the conserved NAD(+) and substrate binding motif, were mutated. The mutant V120S had the highest catalytic efficiency (k cat/K m ) with COONH4 as it enhanced the catalytic velocity (k cat) and k cat/K m 3.48-fold and 1.60-fold, respectively, than that of the wild type. And, the double-mutant V120S-N187D had the highest k cat/K m with NAD(+) as it displayed an approximately 1.50-fold increase in k cat/K m . The mutants showed higher catalytic efficiency than other reported FDHs, suggesting that the mutation has achieved good results. The single and double mutants exhibited higher thermostability than the wild type. The structure-function relationship of single and double mutants was analyzed by homology models and site parsing. Asymmetric synthesis of L-tert-leucine was executed to evaluate the ability of cofactor regeneration of the mutants with about 100 % conversion rates. This work provides a helpful theoretical reference for the evolution of an enzyme in vitro and promotion of the industrial production of chiral compounds, e.g., amino acid and chiral amine.

  9. A parasitic nematode releases cytokinin that controls cell division and orchestrates feeding site formation in host plants.

    PubMed

    Siddique, Shahid; Radakovic, Zoran S; De La Torre, Carola M; Chronis, Demosthenis; Novák, Ondřej; Ramireddy, Eswarayya; Holbein, Julia; Matera, Christiane; Hütten, Marion; Gutbrod, Philipp; Anjam, Muhammad Shahzad; Rozanska, Elzbieta; Habash, Samer; Elashry, Abdelnaser; Sobczak, Miroslaw; Kakimoto, Tatsuo; Strnad, Miroslav; Schmülling, Thomas; Mitchum, Melissa G; Grundler, Florian M W

    2015-10-13

    Sedentary plant-parasitic cyst nematodes are biotrophs that cause significant losses in agriculture. Parasitism is based on modifications of host root cells that lead to the formation of a hypermetabolic feeding site (a syncytium) from which nematodes withdraw nutrients. The host cell cycle is activated in an initial cell selected by the nematode for feeding, followed by activation of neighboring cells and subsequent expansion of feeding site through fusion of hundreds of cells. It is generally assumed that nematodes manipulate production and signaling of the plant hormone cytokinin to activate cell division. In fact, nematodes have been shown to produce cytokinin in vitro; however, whether the hormone is secreted into host plants and plays a role in parasitism remained unknown. Here, we analyzed the spatiotemporal activation of cytokinin signaling during interaction between the cyst nematode, Heterodera schachtii, and Arabidopsis using cytokinin-responsive promoter:reporter lines. Our results showed that cytokinin signaling is activated not only in the syncytium but also in neighboring cells to be incorporated into syncytium. An analysis of nematode infection on mutants that are deficient in cytokinin or cytokinin signaling revealed a significant decrease in susceptibility of these plants to nematodes. Further, we identified a cytokinin-synthesizing isopentenyltransferase gene in H. schachtii and show that silencing of this gene in nematodes leads to a significant decrease in virulence due to a reduced expansion of feeding sites. Our findings demonstrate the ability of a plant-parasitic nematode to synthesize a functional plant hormone to manipulate the host system and establish a long-term parasitic interaction.

  10. The roles of vertical shear and topography on the eddy formation near the site of origin of the Brazil Current

    NASA Astrophysics Data System (ADS)

    Soutelino, R. G.; Gangopadhyay, A.; da Silveira, I. C. A.

    2013-11-01

    The site of origin of the Brazil Current (BC) is currently one of the less explored aspects of regional circulation and mesoscale activity in the west side of the South Atlantic Subtropical gyre. The few studies that are available, based either on in situ data or on numerical modeling, seems to agree that the region is characterized by relatively weak baroclinic flow, with substantial mesoscale activity, which is quite different from other western boundary current systems (e.g. Florida Current, in the North Atlantic). We present numerical simulations that show that the main realistic mesoscale features in the eddy-rich vicinities of the BC site of origin can be successfully modeled through the dynamical interaction between parameterized versions of two opposing mean western boundary currents (BC and North Brazil Undercurrent—NBUC) and local topography, with no influence of remote dynamics or atmospheric forcing. Large BC-related anticyclones observed in previous work were reproduced and recurrently formed during the model run. Two additional sensitivity experiments were performed. When NBUC is removed from the physical setting, the BC interaction with topography is not sufficient to generate eddies similar to observations. When an idealized flat-bottom and a physiographic configuration with no Abrolhos and Royal Charlotte Banks are considered, the BC-NBUC interaction is also not capable of developing realistic mesoscale structures. Our geophysical instability analyses suggest that BC-NBUC vertical shear is promoting baroclinic energy fluxes from the mean flow to the perturbations, resulting in eddy formation and growth in the region.

  11. Active site formation mechanism of carbon-based oxygen reduction catalysts derived from a hyperbranched iron phthalocyanine polymer

    NASA Astrophysics Data System (ADS)

    Hiraike, Yusuke; Saito, Makoto; Niwa, Hideharu; Kobayashi, Masaki; Harada, Yoshihisa; Oshima, Masaharu; Kim, Jaehong; Nabae, Yuta; Kakimoto, Masa-aki

    2015-04-01

    Carbon-based cathode catalysts derived from a hyperbranched iron phthalocyanine polymer (HB-FePc) were characterized, and their active-site formation mechanism was studied by synchrotron-based spectroscopy. The properties of the HB-FePc catalyst are compared with those of a catalyst with high oxygen reduction reaction (ORR) activity synthesized from a mixture of iron phthalocyanine and phenolic resin (FePc/PhRs). Electrochemical measurements demonstrate that the HB-FePc catalyst does not lose its ORR activity up to 900°C, whereas that of the FePc/PhRs catalyst decreases above 700°C. Hard X-ray photoemission spectra reveal that the HB-FePc catalysts retain more nitrogen components than the FePc/PhRs catalysts between pyrolysis temperatures of 600°C and 800°C. This is because the linked structure of the HB-FePc precursor has high thermostability against nitrogen desorption. Consequently, effective doping of active nitrogen species into the sp 2 carbon network of the HB-FePc catalysts may occur up to 900°C.

  12. A search for water on the moon at the Reiner Gamma Formation - A possible site of cometary coma impact

    NASA Technical Reports Server (NTRS)

    Roush, Ted L.; Lucey, Paul G.

    1988-01-01

    Earth-based telescopic measurements of the Reiner Gamma Formation in the 3-micron region were made to search for evidence of water at this proposed site of cometary interaction with the lunar surface. Comparison of the spectra of Reiner Gamma and laboratory measurements of a variety of minerals with adsorbed water or structural OH(-) show that there is no evidence for water at the locations measured. While these measurements rule out the presence of abundant bound H2O at these locations, they do not exclude the presence of OH(-) bearing minerals that have absorptions not detectable through the wet terrestrial atmosphere. The possible effects of high lunar temperatures on the reflectance spectra were examined, and it was concluded that these effects would not obscure a bound water absorption if it were present. Upper limits on the amount of water that could be present at the locations observed and remain undetected are 2.25 average wt pct for a mixture consisting of discrete patches of water-bearing and water-free minerals and 0.01 wt pct for an intimate mixture of these two materials.

  13. An intramembranous ossification model for the in silico analysis of bone tissue formation in tooth extraction sites.

    PubMed

    Corredor-Gómez, Jennifer Paola; Rueda-Ramírez, Andrés Mauricio; Gamboa-Márquez, Miguel Alejandro; Torres-Rodríguez, Carolina; Cortés-Rodríguez, Carlos Julio

    2016-07-21

    The accurate modeling of biological processes allows us to predict the spatiotemporal behavior of living tissues by computer-aided (in silico) testing, a useful tool for the development of medical strategies, avoiding the expenses and potential ethical implications of in vivo experimentation. A model for bone healing in mouth would be useful for selecting proper surgical techniques in dental procedures. In this paper, the formulation and implementation of a model for Intramembranous Ossification is presented aiming to describe the complex process of bone tissue formation in tooth extraction sites. The model consists in a mathematical description of the mechanisms in which different types of cells interact, synthesize and degrade extracellular matrices under the influence of biochemical factors. Special attention is given to angiogenesis, oxygen-dependent effects and growth factor-induced apoptosis of fibroblasts. Furthermore, considering the depth-dependent vascularization of mandibular bone and its influence on bone healing, a functional description of the cell distribution on the severed periodontal ligament (PDL) is proposed. The developed model was implemented using the finite element method (FEM) and successfully validated by simulating an animal in vivo experiment on dogs reported in the literature. A good fit between model outcome and experimental data was obtained with a mean absolute error of 3.04%. The mathematical framework presented here may represent an important tool for the design of future in vitro and in vivo tests, as well as a precedent for future in silico studies on osseointegration and mechanobiology.

  14. Submicron aerosols at thirteen diversified sites in China: size distribution, new particle formation and corresponding contribution to cloud condensation nuclei production

    NASA Astrophysics Data System (ADS)

    Peng, J. F.; Hu, M.; Wang, Z. B.; Huang, X. F.; Kumar, P.; Wu, Z. J.; Yue, D. L.; Guo, S.; Shang, D. J.; Zheng, Z.; He, L. Y.

    2014-06-01

    Understanding the particle number size distributions in diversified atmospheric environments is important in order to design mitigation strategies related to submicron particles and their effect on regional air quality, haze and human health. In this study, we conducted 15 different field measurement campaigns, each one-month long, between 2007 and 2011 at 13 individual sites in China. These were 5 urban sites, 4 regional sites, 3 coastal/background sites and one ship cruise measurement along eastern coastline of China. Size resolved particles were measured in the 15-600 nm size range. The median particle number concentrations (PNC) were found to vary in the range of 1.1-2.2 × 104 cm-3 at urban sites, 0.8-1.5 × 104 cm-3 at regional sites, 0.4-0.6 × 104 cm-3 at coastal/background sites, and 0.5 × 104 cm-3 during cruise measurements. Peak diameters at each of these sites varied greatly from 24 nm to 115 nm. Particles in the 15-25 nm (nucleation mode), 25-100 nm (Aitken mode) and 100-600 nm (accumulation mode) range showed different characteristics at each of the studied sites, indicating the features of primary emissions and secondary formation in these diversified atmospheric environments. Diurnal variations show a build-up of accumulation mode particles belt at regional sites, suggesting the contribution of regional secondary aerosol pollution. Frequencies of new particle formation (NPF) events were much higher at urban and regional sites than at coastal sites and cruise measurement. The average growth rates (GRs) of nucleation mode particles were 8.0-10.9 nm h-1 at urban sites, 7.4-13.6 nm h-1 at regional sites and 2.8-7.5 nm h-1 at both coastal and cruise measurement sites. The high gaseous precursors and strong oxidation at urban and regional sites not only favored the formation of particles, but also accelerated the growth rate of the nucleation mode particles. No significant difference in condensation sink (CS) during NPF days were observed among different

  15. Submicron aerosols at thirteen diversified sites in China: size distribution, new particle formation and corresponding contribution to cloud condensation nuclei production

    NASA Astrophysics Data System (ADS)

    Peng, J. F.; Hu, M.; Wang, Z. B.; Huang, X. F.; Kumar, P.; Wu, Z. J.; Guo, S.; Yue, D. L.; Shang, D. J.; Zheng, Z.; He, L. Y.

    2014-09-01

    Understanding the particle number size distributions in diversified atmospheric environments is important in order to design mitigation strategies related to submicron particles and their effects on regional air quality, haze and human health. In this study, we conducted 15 different field measurement campaigns between 2007 and 2011 at 13 individual sites in China, including five urban sites, four regional sites, three coastal/background sites and one ship cruise measurement along eastern coastline of China. Size resolved particles were measured in the 15-600 nm size range. The median particle number concentrations (PNCs) were found to vary in the range of 1.1-2.2 × 104 cm-3 at urban sites, 0.8-1.5 × 104 cm-3 at regional sites, 0.4-0.6 × 104 cm-3 at coastal/background sites, and 0.5 × 104 cm-3 during cruise measurement. Peak diameters at each of these sites varied greatly from 24 to 115 nm. Particles in the 15-25 nm (nucleation mode), 25-100 nm (Aitken mode) and 100-600 nm (accumulation mode) range showed different characteristics at each sites, indicating the features of primary emissions and secondary formation in these diversified atmospheric environments. Diurnal variations show a build-up of accumulation mode particles belt at regional sites, suggesting the contribution of regional secondary aerosol pollution. Frequencies of new particle formation (NPF) events were much higher at urban and regional sites than at coastal sites and during cruise measurement. The average growth rates (GRs) of nucleation mode particles were 8.0-10.9 nm h-1 at urban sites, 7.4-13.6 nm h-1 at regional sites and 2.8-7.5 nm h-1 at coastal sites and during cruise measurement. The high gaseous precursors and strong oxidation at urban and regional sites not only favored the formation of particles, but also accelerated the growth rate of the nucleation mode particles. No significant difference in condensation sink (CS) during NPF days were observed among different site types

  16. The Molybdenum Active Site of Formate Dehydrogenase Is Capable of Catalyzing C-H Bond Cleavage and Oxygen Atom Transfer Reactions.

    PubMed

    Hartmann, Tobias; Schrapers, Peer; Utesch, Tillmann; Nimtz, Manfred; Rippers, Yvonne; Dau, Holger; Mroginski, Maria Andrea; Haumann, Michael; Leimkühler, Silke

    2016-04-26

    Formate dehydrogenases (FDHs) are capable of performing the reversible oxidation of formate and are enzymes of great interest for fuel cell applications and for the production of reduced carbon compounds as energy sources from CO2. Metal-containing FDHs in general contain a highly conserved active site, comprising a molybdenum (or tungsten) center coordinated by two molybdopterin guanine dinucleotide molecules, a sulfido and a (seleno-)cysteine ligand, in addition to a histidine and arginine residue in the second coordination sphere. So far, the role of these amino acids in catalysis has not been studied in detail, because of the lack of suitable expression systems and the lability or oxygen sensitivity of the enzymes. Here, the roles of these active site residues is revealed using the Mo-containing FDH from Rhodobacter capsulatus. Our results show that the cysteine ligand at the Mo ion is displaced by the formate substrate during the reaction, the arginine has a direct role in substrate binding and stabilization, and the histidine elevates the pKa of the active site cysteine. We further found that in addition to reversible formate oxidation, the enzyme is further capable of reducing nitrate to nitrite. We propose a mechanistic scheme that combines both functionalities and provides important insights into the distinct mechanisms of C-H bond cleavage and oxygen atom transfer catalyzed by formate dehydrogenase.

  17. Bundle formation of smooth muscle desmin intermediate filaments by calponin and its binding site on the desmin molecule.

    PubMed

    Fujii, T; Takagi, H; Arimoto, M; Ootani, H; Ueeda, T

    2000-03-01

    Smooth muscle basic calponin, a major actin-, tropomyosin-, and calmodulin-binding protein, has been examined for its ability to interact with desmin intermediate filaments from smooth muscle cells using sedimentation analysis, turbidity changes, chemical cross-linking, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI TOF/MS), and electron microscopic observations. Calponin interacted with desmin intermediate filaments in a concentration-dependent manner in vitro. The binding of calponin to desmin produced dense aggregates at 30 degrees C. The dense aggregates were observed by electron microscopy to be composed of large anisotropic bundles of desmin filaments, indicating that calponin forms bundles of desmin filaments. The addition of calmodulin or S100 to the mixture of calponin and desmin caused the removal of calponin from the desmin filaments and inhibited bundle formation in the presence of Ca(2+), but not in the presence of EGTA. Calponin-related proteins including G-actin, tropomyosin, and SM22, had little effect on the binding of calponin to desmin filaments, whereas tubulin weakly inhibited the binding. Desmin had little influence on the calponin-actin and calponin-tubulin interactions using the zero-length cross-linker, EDC. Domain mapping with chymotryptic digestion showed that the binding site of calponin resides within the central a-helical rod domain of the desmin molecule. The chemical cross-linked products of calponin and synthetic peptides (TQ27, TNEKVELQELNDRFANYIEKVRFLEQQ; EE24, EEELRELRRQVDALTGQRARVEVE) derived from the rod domain were detected by MALDI TOF/MS. Furthermore, the calponin-desmin interaction was significantly inhibited by the addition of EE24, but only slightly by TQ27. These results suggest that calponin may act as a cross-linking protein between desmin filaments as well as among intermediate filaments, microfilaments and microtubules in smooth muscle cells.

  18. Evidence for sites of methylmercury formation in a flowing water system: impact of anthropogenic barriers and water management.

    PubMed

    Pizarro-Barraza, Claudia; Gustin, Mae Sexauer; Peacock, Mary; Miller, Matthieu

    2014-04-15

    The Truckee River, California-Nevada, USA is impacted by mercury (Hg) contamination associated with legacy gold mining. In this work, we investigated the potential for hot-spots of methylmercury (MeHg) formation in the river. Mercury concentrations in multiple media were also used to assess the impacts of anthropogenic barriers, restoration, and water management in this flowing water ecosystem. Water samples were collected on a seasonal time step over 3 years, and analyzed for total Hg (THg) and MeHg concentrations, along with a variety of other water quality parameters. In addition, we measured THg and MeHg in sediments, THg in macroinvertebrates, and THg and δ(15)N and δ(13)C concentrations in fish. Differences in stable isotopes and Hg concentrations in fish were applied to understand the mobility of fish in the river. Mercury concentrations of specific macroinvertebrate species were used to identify sites of MeHg production. In general, loads of Hg and nutrients in the river reach above the Reno-Sparks metropolitan area were similar to that reported for pristine systems, while within and below the city, water quality impacts were observed. Fish isotope data showed that in the city reach food resources were different than those upriver and downriver. Based on Hg and isotope data, mobility of the fish in the river is impacted by anthropogenic obstructions and water manipulation. Below the city, particle bound Hg, derived from the legacy mining, continues to be input to the Truckee River. This Hg is deposited in riparian habitats and areas of river restoration, where it is methylated and becomes available to biota. During spring, when flows were highest, MeHg produced and stored in the sediments is mobilized and transported downriver. Fish and macroinvertebrate concentrations increased downriver indicating passive uptake from water. The information presented here could be useful for those doing river restoration and water manipulation in mercury contaminated

  19. Interpretation of brine-permeability tests of the Salado Formation at the Waste Isolation Pilot Plant site: First interim report

    SciTech Connect

    Beauheim, R.L. ); Saulnier, G.J. Jr.; Avis, J.D. )

    1991-08-01

    Pressure-pulse tests have been performed in bedded evaporites of the Salado Formation at the Waste Isolation Pilot Plant (WIPP) site to evaluate the hydraulic properties controlling brine flow through the Salado. Hydraulic conductivities ranging from about 10{sup {minus}14} to 10{sup {minus}11} m/s (permeabilities of about 10{sup {minus}21} to 10{sup {minus}18} m{sup 2}) have been interpreted from nine tests conducted on five stratigraphic intervals within eleven meters of the WIPP underground excavations. Tests of a pure halite layer showed no measurable permeability. Pore pressures in the stratigraphic intervals range from about 0.5 to 9.3 MPa. An anhydrite interbed (Marker Bed 139) appears to be one or more orders of magnitude more permeable than the surrounding halite. Hydraulic conductivities appear to increase, and pore pressures decrease, with increasing proximity to the excavations. These effects are particularly evident within two to three meters of the excavations. Two tests indicated the presence of apparent zero-flow boundaries about two to three meters from the boreholes. The other tests revealed no apparent boundaries within the radii of influence of the tests, which were calculated to range from about four to thirty-five meters from the test holes. The data are insufficient to determine if brine flow through evaporites results from Darcy-like flow driven by pressure gradients within naturally interconnected porosity or from shear deformation around excavations connecting previously isolated pores, thereby providing pathways for fluids at or near lithostatic pressure to be driven towards the low-pressure excavations. Future testing will be performed at greater distances from the excavations to evaluate hydraulic properties and processes beyond the range of excavation effects.

  20. Evidence of formation of submicrometer water-soluble organic aerosols at a deciduous forest site in northern Japan in summer

    NASA Astrophysics Data System (ADS)

    Miyazaki, Yuzo; Jung, Jinsang; Fu, Pingqing; Mizoguchi, Yasuko; Yamanoi, Katsumi; Kawamura, Kimitaka

    2012-10-01

    Semicontinuous measurements of submicrometer water-soluble organic aerosols and particle size distributions were conducted at a deciduous forest site in northern Japan in August 2010. Increases in particle number concentration were frequently observed in daytime, accompanied by an increase in the concentrations of water-soluble organic carbon (WSOC). We found that daily averaged WSOC concentrations positively correlated with gross primary production of CO2 by the forest ecosystem (r2 = 0.63) and ambient temperature during daytime. These relations suggest that the formation of WSOC is closely linked to photosynthetic activity by the forest ecosystem, which depends on both temperature and solar radiation. Off-line chemical analysis of samples of particles with aerodynamic diameter smaller than 1 μm collected during a 2 day event of elevated WSOC levels suggests that photochemical aging of both α- andβ-pinene and isoprene oxidation products contributes to the particle growth and the WSOC mass. Organic tracers of primary biological aerosol particles (PBAPs) showed distinct diurnal variations with a maximum around noontime, also indicating that higher temperature and light intensity induce emissions of PBAPs. However, their contribution to the submicrometer WSOC mass was likely insignificant. During the day, the concentrations of 3-methyl-1,2,3-butanetricarboxylic acid (3-MBTCA) showed a strong dependence on temperature, and the ratios of WSOC to particle volume concentration increased with an increase in the concentration ratios of 3-MBTCA to pinonic acid (PA). This result supports a previous proposal that the 3-MBTCA/PA ratios in submicrometer particles can be a useful tracer for chemical aging of biogenic secondary organic aerosol from forest vegetation.

  1. Lung deposited surface area in Leicester urban background site/UK: Sources and contribution of new particle formation

    NASA Astrophysics Data System (ADS)

    Hama, Sarkawt M. L.; Ma, Nan; Cordell, Rebecca L.; Kos, Gerard P. A.; Wiedensohler, Alfred; Monks, Paul S.

    2017-02-01

    Lung Deposited Surface Area (LDSA) has been identified as a potential metric for the correlation of a physical aerosol particle properties with health outcomes. Currently, there is little urban LDSA data. As a case study, we investigated measurements of LDSA (alveolar) concentrations in a mid-size European city. LDSA and associated measurements were carried out over 1.5 years at an urban background site in Leicester, UK. Average LDSA concentrations in the cold (November-April) and warm (May-October) seasons of UK were 37 and 23 μm2 cm-3, respectively. LDSA correlates well (R2 = 0.65-0.7, r = 0.77-0.8) with traffic related pollutants, such as equivalent black carbon (eBC) and NOX. We also report for the first time in the UK the correlation between an empirically derived LDSA and eBC. Furthermore, the effect of wind speed and direction on the LDSA was explored. Higher LDSA concentrations are observed at low wind speeds (1-2 m s-1), owing to local traffic emissions. In addition, the diurnal variation of LDSA showed a second peak in the afternoon under warm and relatively clean atmospheric conditions, which can be attributed to photochemical new particle formation (NPF) and growth into the Aitken mode range. These NPF events increased the average background LDSA concentrations from 15.5 to 35.5 μm2 cm-3, although they might not be health-relevant. Overall, the results support the notion that local traffic emissions are a major contributor to observed LDSA concentrations with a clear seasonal pattern with higher values during winter.

  2. EphrinA4 mimetic peptide targeted to EphA binding site impairs the formation of long-term fear memory in lateral amygdala

    PubMed Central

    Dines, M; Lamprecht, R

    2014-01-01

    Fear conditioning leads to long-term fear memory formation and is a model for studying fear-related psychopathologies conditions such as phobias and posttraumatic stress disorder. Long-term fear memory formation is believed to involve alterations of synaptic efficacy mediated by changes in synaptic transmission and morphology in lateral amygdala (LA). EphrinA4 and its cognate Eph receptors are intimately involved in regulating neuronal morphogenesis, synaptic transmission and plasticity. To assess possible roles of ephrinA4 in fear memory formation we designed and used a specific inhibitory ephrinA4 mimetic peptide (pep-ephrinA4) targeted to EphA binding site. We show that this peptide, composed of the ephrinA4 binding domain, interacts with EphA4 and inhibits ephrinA4-induced phosphorylation of EphA4. Microinjection of the pep-ephrinA4 into rat LA 30 min before training impaired long- but not short-term fear conditioning memory. Microinjection of a control peptide derived from a nonbinding E helix site of ephrinA4, that does not interact with EphA, had no effect on fear memory formation. Microinjection of pep-ephrinA4 into areas adjacent to the amygdala had no effect on fear memory. Acute systemic administration of pep-ephrinA4 1 h after training also impaired long-term fear conditioning memory formation. These results demonstrate that ephrinA4 binding sites in LA are essential for long-term fear memory formation. Moreover, our research shows that ephrinA4 binding sites may serve as a target for pharmacological treatment of fear and anxiety disorders. PMID:25268254

  3. The strength of an Ig switch region is determined by its ability to drive R loop formation and its number of WGCW sites.

    PubMed

    Zhang, Zheng Z; Pannunzio, Nicholas R; Han, Li; Hsieh, Chih-Lin; Yu, Kefei; Lieber, Michael R

    2014-07-24

    R loops exist at the murine IgH switch regions and possibly other locations, but their functional importance is unclear. In biochemical systems, R loop initiation requires DNA sequence regions containing clusters of G nucleotides, but cellular studies have not been done. Here, we vary the G-clustering, total switch region length, and the number of target sites (WGCW sites for the activation-induced deaminase) at synthetic switch regions in a murine B cell line to determine the effect on class switch recombination (CSR). G-clusters increase CSR regardless of their immediate proximity to the WGCW sites. This increase is accompanied by an increase in R loop formation. CSR efficiency correlates better with the absolute number of WGCW sites in the switch region rather than the total switch region length or density of WGCW sites. Thus, the overall strength of the switch region depends on G-clusters, which initiate R loop formation, and on the number of WGCW sites.

  4. Size-resolved aerosol composition at an urban and a rural site in the Po Valley in summertime: implications for secondary aerosol formation

    NASA Astrophysics Data System (ADS)

    Sandrini, Silvia; van Pinxteren, Dominik; Giulianelli, Lara; Herrmann, Hartmut; Poulain, Laurent; Facchini, Maria Cristina; Gilardoni, Stefania; Rinaldi, Matteo; Paglione, Marco; Turpin, Barbara J.; Pollini, Francesca; Bucci, Silvia; Zanca, Nicola; Decesari, Stefano

    2016-09-01

    The aerosol size-segregated chemical composition was analyzed at an urban (Bologna) and a rural (San Pietro Capofiume) site in the Po Valley, Italy, during June and July 2012, by ion-chromatography (major water-soluble ions and organic acids) and evolved gas analysis (total and water-soluble carbon), to investigate sources and mechanisms of secondary aerosol formation during the summer. A significant enhancement of secondary organic and inorganic aerosol mass was observed under anticyclonic conditions with recirculation of planetary boundary layer air but with substantial differences between the urban and the rural site. The data analysis, including a principal component analysis (PCA) on the size-resolved dataset of chemical concentrations, indicated that the photochemical oxidation of inorganic and organic gaseous precursors was an important mechanism of secondary aerosol formation at both sites. In addition, at the rural site a second formation process, explaining the largest fraction (22 %) of the total variance, was active at nighttime, especially under stagnant conditions. Nocturnal chemistry in the rural Po Valley was associated with the formation of ammonium nitrate in large accumulation-mode (0.42-1.2 µm) aerosols favored by local thermodynamic conditions (higher relative humidity and lower temperature compared to the urban site). Nocturnal concentrations of fine nitrate were, in fact, on average 5 times higher at the rural site than in Bologna. The water uptake by this highly hygroscopic compound under high RH conditions provided the medium for increased nocturnal aerosol uptake of water-soluble organic gases and possibly also for aqueous chemistry, as revealed by the shifting of peak concentrations of secondary compounds (water-soluble organic carbon (WSOC) and sulfate) toward the large accumulation mode (0.42-1.2 µm). Contrarily, the diurnal production of WSOC (proxy for secondary organic aerosol) by photochemistry was similar at the two sites but

  5. Post burial alteration of the Permian Rustler Formation Evaporites, WIPP (Waste Isolation Pilot Plant) site, New Mexico: Textural, stratigraphic and chemical evidence

    SciTech Connect

    Lowenstein, T.K.

    1987-04-01

    The Rustler Formation is a Late Permian (Ochoan Series) evaporite found in the subsurface and in outcrop in New Mexico and west Texas. The main rock types of the Rustler Formation are anhydrite, gypsum, halite, dolostone and siliciclastic sandstone and mudstone. Across the WIPP site, located in southeastern New Mexico, some of the Rustler rock types and their thicknesses change dramatically over short lateral distances. These lateral variations have mainly been attributed to post-burial dissolution of evaporites. The aim of the present study is to distinguish syndepositional features from post burial alteration features in the Rustler Formation. Four borehole cores of the complete Rustler Formation were examined. Primary sedimentary structures, textures and fabrics were identified, based on comparison with modern evaporite deposits. Vertical and lateral patterns of primary sedimentary features were recorded. From this information, depositional settings have been assembled which best account for the observed types of primary features and their vertical and lateral distribution. With this framework, post-depositional diagenetic overprints were identified in the Rustler Formation. The question of whether subsurface diagenetic alteration is presently active at the WIPP site is addressed.

  6. Target-controlled formation of silver nanoclusters in abasic site-incorporated duplex DNA for label-free fluorescence detection of theophylline

    NASA Astrophysics Data System (ADS)

    Park, Ki Soo; Oh, Seung Soo; Soh, H. Tom; Park, Hyun Gyu

    2014-08-01

    A novel, label-free, fluorescence based sensor for theophylline has been developed. In the new sensor system, an abasic site-incorporated duplex DNA probe serves as both a pocket for recognition of theophylline and a template for the preparation of fluorescent silver nanoclusters. The strategy relies on theophylline-controlled formation of fluorescent silver nanoclusters from abasic site-incorporated duplex DNA. When theophylline is not present, silver ions interact with the cytosine groups opposite to the abasic site in duplex DNA. This interaction leads to efficient formation of intensely red fluorescent silver nanoclusters. In contrast, when theophylline is bound at the abasic site through pseudo base-pairing with appropriately positioned cytosines, silver ion binding to the cytosine nucleobase is prevented. Consequently, fluorescent silver nanoclusters are not formed causing a significant reduction of the fluorescence signal. By employing this new sensor, theophylline can be highly selectively detected at a concentration as low as 1.8 μM. Finally, the diagnostic capability and practical application of this sensor were demonstrated by its use in detecting theophylline in human blood serum.A novel, label-free, fluorescence based sensor for theophylline has been developed. In the new sensor system, an abasic site-incorporated duplex DNA probe serves as both a pocket for recognition of theophylline and a template for the preparation of fluorescent silver nanoclusters. The strategy relies on theophylline-controlled formation of fluorescent silver nanoclusters from abasic site-incorporated duplex DNA. When theophylline is not present, silver ions interact with the cytosine groups opposite to the abasic site in duplex DNA. This interaction leads to efficient formation of intensely red fluorescent silver nanoclusters. In contrast, when theophylline is bound at the abasic site through pseudo base-pairing with appropriately positioned cytosines, silver ion binding to

  7. [[superscript 3]H]-Flunitrazepam-Labeled Benzodiazepine Binding Sites in the Hippocampal Formation in Autism: A Multiple Concentration Autoradiographic Study

    ERIC Educational Resources Information Center

    Guptill, Jeffrey T.; Booker, Anne B.; Gibbs, Terrell T.; Kemper, Thomas L.; Bauman, Margaret L.; Blatt, Gene J.

    2007-01-01

    Increasing evidence indicates that the GABAergic system in cerebellar and limbic structures is affected in autism. We extended our previous study that found reduced [[superscript 3]H] flunitrazepam-labeled benzodiazepine sites in the autistic hippocampus to determine whether this reduction was due to a decrease in binding site number (B [subscript…

  8. Exploration of the 1891 Foerstner submarine vent site (Pantelleria, Italy): insights into the formation of basaltic balloons

    NASA Astrophysics Data System (ADS)

    Kelly, Joshua T.; Carey, Steven; Pistolesi, Marco; Rosi, Mauro; Croff-Bell, Katherine Lynn; Roman, Chris; Marani, Michael

    2014-07-01

    On October 17, 1891, a submarine eruption started at Foerstner volcano located within the Pantelleria Rift of the Strait of Sicily (Italy). Activity occurred for a period of 1 week from an eruptive vent located 4 km northwest of the island of Pantelleria at a water depth of 250 m. The eruption produced lava balloons that discharged gas at the surface and eventually sank to the seafloor. Remotely operated vehicle (ROV) video footage and high-resolution multi-beam mapping of the Foerstner vent site were used to create a geologic map of the AD 1891 deposits and conduct the first detailed study of the source area associated with this unusual type of submarine volcanism. The main Foerstner vent consists of two overlapping circular mounds with a total volume of 6.3 × 105 m3 and relief of 60 m. It is dominantly constructed of clastic scoriaceous deposits with some interbedded pillow lavas. Petrographic and geochemical analyses of Foerstner samples by X-ray fluorescence and inductively coupled plasma mass spectrometry reveal that the majority of the deposits are vesicular, hypocrystalline basanite scoria that display porphyritic, hyaloophitic, and vitrophyric textures. An intact lava balloon recovered from the seafloor consists of a large interior gas cavity surrounded by a thin lava shell comprising two distinct layers: a thin, oxidized, quenched crust surrounding the exterior of the balloon and a dark gray, tachylite layer lying beneath it. Ostwald ripening is proposed to be the dominant bubble growth mechanism of four representative Foerstner scoria samples as inferred by vesicle size distributions. Characterization of the diversity of deposit facies observed at Foerstner in conjunction with quantitative rock texture analysis indicates that submarine Strombolian-like activity is the most likely mechanism for the formation of lava balloons. The deposit facies observed at the main Foerstner vent are very similar to those produced by other known submarine Strombolian

  9. Geology, coal resources, and chemical analyses of coal from the Fruitland Formation, Kimbeto EMRIA study site, San Juan County, New Mexico

    USGS Publications Warehouse

    Schneider, Gary B.; Hildebrand, Rick T.; Affolter, Ronald H.

    1979-01-01

    The Kimbeto EMRIA study site, an area of about 20 square miles (52 km2), is located on the south margin of the San Juan Basin on the gently northward-dipping strata of the Upper Cretaceous Fruitland Formation and the Kirtland Shale. The coal beds are mainly in the lower 150 feet (45 m) of the Fruitland Format ion. Coal resources--measured, indicated, and inferred--with less than 400 feet (120 m) of overburden in the site are 69,085,000 short tons (62,660,100 metric tons), 369,078,000 short tons (334,754,000 metric tons), and 177,803,000 short tons (161,267,000 metric tons) respectively. About 68 percent of these resources are overlain by 200 feet (60 m) or less of overburden. The apparent rank of the coal ranges from subbituminous B to subbituminous A. The average Btu/lb value of 14 core samples from the site on the as-received basis is 8,240 (4580 Kcal/kg), average ash content is 23.4 percent, and average sulfur content is 0.5 percent. Analyses of coal from the Kimbeto EMRIA study site show significantly higher ash content and significantly lower contents of volatile matter, fixed carbon, carbon, and a significantly lower heat of combustion when compared with other coal analyses from the Rocky Mountain province.

  10. Correlation of the KHS Tuff of the Kibish Formation to volcanic ash layers at other sites, and the age of early Homo sapiens (Omo I and Omo II).

    PubMed

    Brown, Francis H; McDougall, Ian; Fleagle, John G

    2012-10-01

    Hominin specimens Omo I and Omo II from Member I of the Kibish Formation, Ethiopia are attributed to early Homo sapiens, and an age near 196 ka has been suggested for them. The KHS Tuff, within Member II of the Kibish Formation has not been directly dated at the site, but it is believed to have been deposited at or near the time of formation of sapropel S6 in the Mediterranean Sea. Electron microprobe analyses suggest that the KHS Tuff correlates with the WAVT (Waidedo Vitric Tuff) at Herto, Gona, and Konso (sample TA-55), and with Unit D at Kulkuletti in the Ethiopian Rift Valley. Konso sample TA-55 is older than 154 ka, and Unit D at Kulkuletti is dated at 183 ka. These correlations and ages provide strong support for the age originally suggested for the hominin remains Omo I and Omo II, and for correlation of times of deposition in the Kibish region with formation of sapropels in the Mediterranean Sea. The Aliyo Tuff in Member III of the Kibish Formation is dated at 104 ka, and correlates with Gademotta Unit 15 in the Ethiopian Rift Valley.

  11. Contribution of new particle formation to the total aerosol concentration at the high-altitude site Jungfraujoch (3580 m asl, Switzerland)

    NASA Astrophysics Data System (ADS)

    Tröstl, Jasmin; Herrmann, Erik; Frege, Carla; Bianchi, Federico; Molteni, Ugo; Bukowiecki, Nicolas; Hoyle, Christopher R.; Steinbacher, Martin; Weingartner, Ernest; Dommen, Josef; Gysel, Martin; Baltensperger, Urs

    2016-10-01

    Previous modeling studies hypothesized that a large fraction of cloud condensation nuclei (CCN) is attributed to new particle formation (NPF) in the free troposphere. Despite the potential importance of this process, only few long-term observations have been performed to date. Here we present the results of a 12 month campaign of NPF observations at the high-altitude site Jungfraujoch (JFJ, 3580 m above sea level (asl)). Our results show that NPF significantly adds to the total aerosol concentration at the JFJ and only occurs via previous precursor entrainment from the planetary boundary layer (PBL). Freshly nucleated particles do not directly grow to CCN size (90 nm) within observable time scales (maximum 48 h). The contribution of NPF to the CCN concentration is low within this time frame compared to other sources, such as PBL entrainment of larger particles. A multistep growth mechanism is proposed which allows previously formed Aitken mode particles to add to the CCN concentration. A parametrization is derived to explain formation rates at the JFJ, showing that precursor concentration, PBL influence, and global radiation are the key factors controlling new particle formation at the site.

  12. Regeneration of nigrostriatal dopaminergic axons after transplantation of olfactory ensheathing cells and fibroblasts prevents fibrotic scar formation at the lesion site.

    PubMed

    Teng, Xichuan; Nagata, Isao; Li, Hong-Peng; Kimura-Kuroda, Junko; Sango, Kazunori; Kawamura, Koki; Raisman, Geoffrey; Kawano, Hitoshi

    2008-11-01

    The fibrotic scar formed after central nervous system injury has been considered an obstacle to axonal regeneration. The present study was designed to examine whether cell transplantation into a damaged central nervous system can reduce fibrotic scar formation and promote axonal regeneration. Nigrostriatal dopaminergic axons were unilaterally transected in rats and cultures of olfactory-ensheathing cells (OECs), and olfactory nerve fibroblasts were transplanted into the lesion site. In the absence of transplants, few tyrosine hydroxylase-immunoreactive axons extended across the lesion 2 weeks after the transection. Reactive astrocytes increased around the lesion, and a fibrotic scar containing type IV collagen deposits developed in the lesion center. The immunoreactivity of chondroitin sulfate side chains and core protein of NG2 proteoglycan increased in and around the lesion. One and 2 weeks after transection and simultaneous transplantation, dopaminergic axons regenerated across the transplanted tissues, which consisted of p75-immunoreactive OECs and fibronectin-immunoreactive fibroblasts. Reactive astrocytes and chondroitin sulfate immunoreactivity increased around the transplants, whereas the deposition of type IV collagen and fibrotic scar formation were completely prevented at the lesion site. Transplantation of meningeal fibroblasts similarly prevented the formation of the fibrotic scar, although its effect on regeneration was less potent than transplantation of OECs and olfactory nerve fibroblasts. The present results suggest that elimination of the inhibitory fibrotic scar is important for neural regeneration.

  13. Co-doping of (Bi(0.5)Na(0.5))TiO(3): secondary phase formation and lattice site preference of Co.

    PubMed

    Schmitt, V; Staab, T E M

    2012-11-14

    Bismuth sodium titanate (Bi(0.5)Na(0.5))TiO(3) (BNT) is considered to be one of the most promising lead-free alternatives to piezoelectric lead zirconate titanate (PZT). However, the effect of dopants on the material has so far received little attention from an atomic point of view. In this study we investigated the effects of cobalt-doping on the formation of additional phases and determined the preferred lattice site of cobalt in BNT. The latter was achieved by comparing the measured x-ray absorption near-edge structure (XANES) spectra to numerically calculated spectra of cobalt on various lattice sites in BNT. (Bi(0.5)Na(0.5))TiO(3) + x mol% Co (x = 0.0, 0.5, 1.0, 2.6) was synthesized via solid state reaction. As revealed by SEM backscattering images, a secondary phase formed in all doped specimens. Using both XRD and SEM-EDX, it was identified as Co(2)TiO(4) for dopant levels >0.5 mol%. In addition, a certain amount of cobalt was incorporated into BNT, as shown by electron probe microanalysis. This amount increased with increasing dopant levels, suggesting that an equilibrium forms together with the secondary phase. The XANES experiments revealed that cobalt occupies the octahedral B-site in the BNT perovskite lattice, substituting Ti and promoting the formation of oxygen vacancies in the material.

  14. Venting formation fluids from deep-sea boreholes in a ridge flank setting: ODP Sites 1025 and 1026

    NASA Astrophysics Data System (ADS)

    Wheat, C. Geoffrey; Jannasch, Hans W.; Kastner, Miriam; Plant, Josh N.; Decarlo, Eric H.; Lebon, Geoff

    2004-08-01

    During ODP Leg 168, two of ten boreholes, ODP Holes 1025C and 1026B, were cased through the sediment section, penetrated basaltic crust that is overpressured, and sealed. In 1999 and 2000 the seals were removed, allowing crustal formation fluids to vent and be sampled. The composition of these fluids is compared to those of basal deep-sea pore waters, which have been the basis for estimating geochemical fluxes from low-temperature ridge flank hydrothermal systems. Estimates for the composition of the major ions in formation fluids based on basal pore waters are within 5% of the values measured in borehole fluids. Similar comparisons for minor and trace elements are not as good; some are reactive in the sediment section, resulting in large uncertainties in the pore water extrapolation, while others are influenced by a variety of contaminants, including steel, grease, drilling muds, and basal sediment. Evidence for contamination includes high dissolved and particulate concentrations of several metals (e.g., Fe, Cu, Co, Zn, and Pb) and measurable changes in concentration during the past four years in response to reaction with basal sediment. This new confidence in estimating the primary composition of formation fluids, coupled with advances in thermodynamic and kinetic models, reveals the possibility of anhydrite precipitation in ridge flank hydrothermal systems at temperatures of ˜70°C. Such new insights allow us to address the timing and conditions under which seawater-crustal reactions occur, leading to more accurate models of crustal evolution.

  15. An active site rearrangement within the Tetrahymena group I ribozyme releases nonproductive interactions and allows formation of catalytic interactions

    PubMed Central

    Sengupta, Raghuvir N.; Van Schie, Sabine N.S.; Giambaşu, George; Dai, Qing; Yesselman, Joseph D.; York, Darrin; Piccirilli, Joseph A.; Herschlag, Daniel

    2016-01-01

    Biological catalysis hinges on the precise structural integrity of an active site that binds and transforms its substrates and meeting this requirement presents a unique challenge for RNA enzymes. Functional RNAs, including ribozymes, fold into their active conformations within rugged energy landscapes that often contain misfolded conformers. Here we uncover and characterize one such “off-pathway” species within an active site after overall folding of the ribozyme is complete. The Tetrahymena group I ribozyme (E) catalyzes cleavage of an oligonucleotide substrate (S) by an exogenous guanosine (G) cofactor. We tested whether specific catalytic interactions with G are present in the preceding E•S•G and E•G ground-state complexes. We monitored interactions with G via the effects of 2′- and 3′-deoxy (–H) and −amino (–NH2) substitutions on G binding. These and prior results reveal that G is bound in an inactive configuration within E•G, with the nucleophilic 3′-OH making a nonproductive interaction with an active site metal ion termed MA and with the adjacent 2′-OH making no interaction. Upon S binding, a rearrangement occurs that allows both –OH groups to contact a different active site metal ion, termed MC, to make what are likely to be their catalytic interactions. The reactive phosphoryl group on S promotes this change, presumably by repositioning the metal ions with respect to G. This conformational transition demonstrates local rearrangements within an otherwise folded RNA, underscoring RNA's difficulty in specifying a unique conformation and highlighting Nature's potential to use local transitions of RNA in complex function. PMID:26567314

  16. Covalent Adduct Formation between the Antihypertensive Drug Hydralazine and Abasic Sites in Double- and Single-Stranded DNA

    PubMed Central

    2015-01-01

    Hydralazine (4) is an antihypertensive agent that displays both mutagenic and epigenetic properties. Here, gel electrophoretic, mass spectroscopic, and chemical kinetics methods were used to provide evidence that medicinally relevant concentrations of 4 rapidly form covalent adducts with abasic sites in double- and single-stranded DNA under physiological conditions. These findings raise the intriguing possibility that the genotoxic properties of this clinically used drug arise via reactions with an endogenous DNA lesion rather than with the canonical structure of DNA. PMID:25405892

  17. Pre-injection Comparison of Methods for Sampling Formation Water and Associated Gas from a Monitoring Well at a Carbon Dioxide Injection Site, Citronelle Oil Field, Alabama

    NASA Astrophysics Data System (ADS)

    Conaway, C.; Thordsen, J. J.; Manning, M. A.; Cook, P. J.; Abedini, A. A.; Trautz, R. C.; Thomas, B.; Kharaka, Y. K.

    2012-12-01

    The chemical composition of formation water and associated gases from the lower Cretaceous Paluxy Formation was determined using four different sampling methods at a well in the Citronelle Oil Field, Alabama, a site that will be used for a carbon dioxide injection experiment. Prior to each of the two sampling periods, the well was cleaned from the drilling fluids and KCl solutions by producing at least three pore volumes of formation water. Accurate measurements of the chemical composition of groundwater or formation water, including dissolved gasses, and gas samples is essential in understanding subsurface geochemical processes occurring as a result of geologic carbon dioxide injection, which is used for enhanced oil recovery (EOR) and has been proposed as a means of carbon sequestration. In this study, formation water and gas samples for geochemical analyses were obtained from well D-9-8 #2 at Citronelle using nitrogen lift, submersible pump, U-Tube, and a downhole (Kuster) sampler. Field chemical analyses included electrical conductivity, hydrogen sulfide, alkalinity, and pH, and laboratory analyses included major, minor and trace elements by mass spectrometry and ion chromatography, dissolved carbon, organic acid anions, free and dissolved gas species. The formation water obtained from this well is a Na-Ca-Cl brine with a salinity of 160,000 and 200,000 mg/L total dissolved solids (TDS). Differences were evident between sampling methodologies, particularly in pH, Fe and alkalinity measurements. The results of the comparison demonstrate the difficulty and importance of preserving volatile analytes in samples, with the downhole sampler and U-Tube system performing most favorably in this aspect.

  18. Structures of E. coli peptide deformylase bound to formate: insight into the preference for Fe2+ over Zn2+ as the active site metal.

    PubMed

    Jain, Rinku; Hao, Bing; Liu, Ren-Peng; Chan, Michael K

    2005-04-06

    E. coli peptide deformylase (PDF) catalyzes the deformylation of nascent polypeptides generated during protein synthesis. While PDF was originally thought to be a zinc enzyme, subsequent studies revealed that the active site metal is iron. In an attempt to understand this unusual metal preference, high-resolution structures of Fe-, Co-, and Zn-PDF were determined in complex with its deformylation product, formate. In all three structures, the formate ion binds the metal and forms hydrogen-bonding interactions with the backbone nitrogen of Leu91, the amide side chain of Gln50, and the carboxylate side chain of Glu133. One key difference, however, is how the formate binds the metal. In Fe-PDF and Co-PDF, formate binds in a bidentate fashion, while in Zn-PDF, it binds in a monodentate fashion. Importantly, these structural results provide the first clues into the origins of PDF's metal-dependent activity differences. On the basis of these structures, we propose that the basis for the higher activity of Fe-PDF stems from the better ability of iron to bind and activate the tetrahedral transition state required for cleavage of the N-terminal formyl group.

  19. Inhibition of translation initiation complex formation by GE81112 unravels a 16S rRNA structural switch involved in P-site decoding

    PubMed Central

    Fabbretti, Attilio; Schedlbauer, Andreas; Brandi, Letizia; Kaminishi, Tatsuya; Giuliodori, Anna Maria; Garofalo, Raffaella; Ochoa-Lizarralde, Borja; Takemoto, Chie; Yokoyama, Shigeyuki; Connell, Sean R.; Gualerzi, Claudio O.

    2016-01-01

    In prokaryotic systems, the initiation phase of protein synthesis is governed by the presence of initiation factors that guide the transition of the small ribosomal subunit (30S) from an unlocked preinitiation complex (30S preIC) to a locked initiation complex (30SIC) upon the formation of a correct codon–anticodon interaction in the peptidyl (P) site. Biochemical and structural characterization of GE81112, a translational inhibitor specific for the initiation phase, indicates that the main mechanism of action of this antibiotic is to prevent P-site decoding by stabilizing the anticodon stem loop of the initiator tRNA in a distorted conformation. This distortion stalls initiation in the unlocked 30S preIC state characterized by tighter IF3 binding and a reduced association rate for the 50S subunit. At the structural level we observe that in the presence of GE81112 the h44/h45/h24a interface, which is part of the IF3 binding site and forms ribosomal intersubunit bridges, preferentially adopts a disengaged conformation. Accordingly, the findings reveal that the dynamic equilibrium between the disengaged and engaged conformations of the h44/h45/h24a interface regulates the progression of protein synthesis, acting as a molecular switch that senses and couples the 30S P-site decoding step of translation initiation to the transition from an unlocked preIC to a locked 30SIC state. PMID:27071098

  20. Field-based description of rhyolite lava flows of the Calico Hills Formation, Nevada National Security Site, Nevada

    USGS Publications Warehouse

    Sweetkind, Donald S.; Bova, Shiera C.

    2015-01-01

    In the area south of the Rainier Mesa caldera, surface and subsurface geologic data are combined to interpret the overall thickness of the Calico Hills Formation and the proportion of lava flow lithology across the study area. The formation is at least 500 meters (m) thick and contains the greatest proportion of rhyolite lava flow to the northeast of Yucca Mountain in the lower part of Fortymile Canyon. The formation thins to the south and southwest where it is between 50 and 200 m thick beneath Yucca Mountain and contains no rhyolite lavas. Geologic mapping and field-based correlation of individual lava flows allow for the interpretation of the thickness and extent of specific flows and the location of their source areas. The most extensive flows have widths from 2 to 3 kilometers (km) and lengths of at least 5–6 km. Lava flow thickness varies from 150 to 250 m above interpreted source vents to between 30 and 80 m in more distal locations. Rhyolite lavas have length-to-height ratios of 10:1 or greater and, in one instance, a length-to-width ratio of 2:1 or greater, implying a tongue-shaped geometry instead of circular domes or tabular bodies. Although geologic mapping did not identify any physical feature that could be positively identified as a vent, lava flow thickness and the size of clasts in subjacent pyroclastic deposits suggest that primary vent areas for at least some of the flows in the study area are on the east side of Fortymile Canyon, to the northeast of Yucca Mountain.

  1. Rad54B Targeting to DNA Double-Strand Break Repair Sites Requires Complex Formation with S100A11

    PubMed Central

    Murzik, Ulrike; Hemmerich, Peter; Weidtkamp-Peters, Stefanie; Ulbricht, Tobias; Bussen, Wendy; Hentschel, Julia; von Eggeling, Ferdinand

    2008-01-01

    S100A11 is involved in a variety of intracellular activities such as growth regulation and differentiation. To gain more insight into the physiological role of endogenously expressed S100A11, we used a proteomic approach to detect and identify interacting proteins in vivo. Hereby, we were able to detect a specific interaction between S100A11 and Rad54B, which could be confirmed under in vivo conditions. Rad54B, a DNA-dependent ATPase, is described to be involved in recombinational repair of DNA damage, including DNA double-strand breaks (DSBs). Treatment with bleomycin, which induces DSBs, revealed an increase in the degree of colocalization between S100A11 and Rad54B. Furthermore, S100A11/Rad54B foci are spatially associated with sites of DNA DSB repair. Furthermore, while the expression of p21WAF1/CIP1 was increased in parallel with DNA damage, its protein level was drastically down-regulated in damaged cells after S100A11 knockdown. Down-regulation of S100A11 by RNA interference also abolished Rad54B targeting to DSBs. Additionally, S100A11 down-regulated HaCaT cells showed a restricted proliferation capacity and an increase of the apoptotic cell fraction. These observations suggest that S100A11 targets Rad54B to sites of DNA DSB repair sites and identify a novel function for S100A11 in p21-based regulation of cell cycle. PMID:18463164

  2. A dynamic flow simulation code benchmark study addressing the highly heterogeneous properties of the Stuttgart formation at the Ketzin pilot site

    NASA Astrophysics Data System (ADS)

    Kempka, Thomas; Class, Holger; Görke, Uwe-Jens; Norden, Ben; Kolditz, Olaf; Kühn, Michael; Walter, Lena; Wang, Wenqing; Zehner, Björn

    2013-04-01

    CO2 injection at the Ketzin pilot site located in Eastern Germany (Brandenburg) about 25 km west of Berlin is undertaken since June 2008 with a scheduled total amount of about 70,000 t CO2 to be injected into the saline aquifer represented by the Stuttgart Formation at a depth of 630 m to 650 m until the end of August 2013. The Stuttgart Formation is of fluvial origin determined by high-permeablity sandstone channels embedded in a floodplain facies of low permeability indicating a highly heterogeneous distribution of reservoir properties as facies distribution, porosity and permeability relevant for dynamic flow simulations. Following the dynamic modelling activities discussed by Kempka et al. (2010), a revised geological model allowed us to history match CO2 arrival times in the observation wells and reservoir pressure with a good agreement (Martens et al., 2012). Consequently, the validated reservoir model of the Stuttgart Formation at the Ketzin pilot site enabled us to predict the development of reservoir pressure and the CO2 plume migration in the storage formation by dynamic flow simulations. A benchmark study of industrial (ECLIPSE 100 as well as ECLIPSE 300 CO2STORE and GASWAT) and scientific dynamic flow simulations codes (TOUGH2-MP/ECO2N, OpenGeoSys and DuMuX) was initiated to address and compare the simulator capabilities considering a highly complex reservoir model. Hence, our dynamic flow simulations take into account different properties of the geological model such as significant variation of porosity and permeability in the Stuttgart Formation as well as structural geological features implemented in the geological model such as seven major faults located at the top of the Ketzin anticline. Integration of the geological model into reservoir models suitable for the different dynamic flow simulators applied demonstrated that a direct conversion of reservoir model discretization between Finite Volume and Finite Element flow simulators is not feasible

  3. Heterogeneity-enhanced gas phase formation in shallow aquifers during leakage of CO2-saturated water from geologic sequestration sites

    NASA Astrophysics Data System (ADS)

    Plampin, Michael R.; Lassen, Rune N.; Sakaki, Toshihiro; Porter, Mark L.; Pawar, Rajesh J.; Jensen, Karsten H.; Illangasekare, Tissa H.

    2014-12-01

    A primary concern for geologic carbon storage is the potential for leakage of stored carbon dioxide (CO2) into the shallow subsurface where it could degrade the quality of groundwater and surface water. In order to predict and mitigate the potentially negative impacts of CO2 leakage, it is important to understand the physical processes that CO2 will undergo as it moves through naturally heterogeneous porous media formations. Previous studies have shown that heterogeneity can enhance the evolution of gas phase CO2 in some cases, but the conditions under which this occurs have not yet been quantitatively defined, nor tested through laboratory experiments. This study quantitatively investigates the effects of geologic heterogeneity on the process of gas phase CO2 evolution in shallow aquifers through an extensive set of experiments conducted in a column that was packed with layers of various test sands. Soil moisture sensors were utilized to observe the formation of gas phase near the porous media interfaces. Results indicate that the conditions under which heterogeneity controls gas phase evolution can be successfully predicted through analysis of simple parameters, including the dissolved CO2 concentration in the flowing water, the distance between the heterogeneity and the leakage location, and some fundamental properties of the porous media. Results also show that interfaces where a less permeable material overlies a more permeable material affect gas phase evolution more significantly than interfaces with the opposite layering.

  4. A Threonine on the Active Site Loop Controls Transition State Formation in Escherichia Coli Respiratory Complex II

    SciTech Connect

    Tomasiak, T.M.; Maklashina, E.; Cecchini, G.; Iverson, T.M.

    2009-05-26

    In Escherichia coli, the complex II superfamily members succinate:ubiquinone oxidoreductase (SQR) and quinol:fumarate reductase (QFR) participate in aerobic and anaerobic respiration, respectively. Complex II enzymes catalyze succinate and fumarate interconversion at the interface of two domains of the soluble flavoprotein subunit, the FAD binding domain and the capping domain. An 11-amino acid loop in the capping domain (Thr-A234 to Thr-A244 in quinol:fumarate reductase) begins at the interdomain hinge and covers the active site. Amino acids of this loop interact with both the substrate and a proton shuttle, potentially coordinating substrate binding and the proton shuttle protonation state. To assess the loop's role in catalysis, two threonine residues were mutated to alanine: QFR Thr-A244 (act-T; Thr-A254 in SQR), which hydrogen-bonds to the substrate at the active site, and QFR Thr-A234 (hinge-T; Thr-A244 in SQR), which is located at the hinge and hydrogen-bonds the proton shuttle. Both mutations impair catalysis and decrease substrate binding. The crystal structure of the hinge-T mutation reveals a reorientation between the FAD-binding and capping domains that accompanies proton shuttle alteration. Taken together, hydrogen bonding from act-T to substrate may coordinate with interdomain motions to twist the double bond of fumarate and introduce the strain important for attaining the transition state.

  5. The Lindi Formation (upper Albian-Coniacian) and Tanzania Drilling Project Sites 36-40 (Lower Cretaceous to Paleogene): Lithostratigraphy, biostratigraphy and chemostratigraphy

    NASA Astrophysics Data System (ADS)

    Jiménez Berrocoso, Álvaro; Huber, Brian T.; MacLeod, Kenneth G.; Petrizzo, Maria Rose; Lees, Jacqueline A.; Wendler, Ines; Coxall, Helen; Mweneinda, Amina K.; Falzoni, Francesca; Birch, Heather; Haynes, Shannon J.; Bown, Paul R.; Robinson, Stuart A.; Singano, Joyce M.

    2015-01-01

    The 2009 Tanzania Drilling Project (TDP) expedition to southeastern Tanzania cored a total of 572.3 m of sediments at six new mid-Cretaceous to mid-Paleocene boreholes (TDP Sites 36, 37, 38, 39, 40A, 40B). Added to the sites drilled in 2007 and 2008, the new boreholes confirm the common excellent preservation of planktonic and benthic foraminifera and calcareous nannofossils from core samples that will be used for biostratigraphy, evolutionary studies, paleoceanography and climatic reconstructions from the Tanzanian margin, with implications elsewhere. The new sites verify the presence of a relatively expanded Upper Cretaceous succession in the region that has allowed a new stratigraphic unit, named here as the Lindi Formation (Fm), to be formally defined. The Lindi Fm (upper Albian to Coniacian), extending ∼120 km between Kilwa and Lindi, comprises a 335-m-thick, outer-shelf to upper-slope unit, consisting of dark gray claystone and siltstone interbeds, common finely-laminated intervals, minor cm-thick sandstones and up to 2.6% organic carbon in the Turonian. A subsurface, composite stratotype section is proposed for the Lindi Fm, with a gradational top boundary with the overlying Nangurukuru Fm (Santonian to Maastrichtian) and a sharp bottom contact with underlying upper Albian sandstones. The section cored at TDP Sites 36 and 38 belongs to the Lindi Fm and are of lower to middle Turonian age (planktonic foraminifera Whiteinella archaeocretacea to Helvetoglobotruncana helvetica Zones and nannofossils subzones UC6b ± UC7). The lower portion of TDP Site 39 (uppermost part of the Lindi Fm) is assigned to the lower to upper Coniacian (planktonic foraminifera Dicarinella concavata Zone and nannofossils zone UC 10), while the remaining part of this site is attributed to the Coniacian-Santonian transition and younger Santonian (planktonic foraminifera D. asymetrica Zone and upper part of nannofossils zone UC10). TDP Site 37 recovered relatively expanded (150 m thick

  6. Site specific isolated nanostructure array formation on a large area by broad ion beam without any mask and resist

    SciTech Connect

    Karmakar, Prasanta

    2014-06-09

    We report the formation of isolated nanostructure arrays on a large area via broad ion beam implantation without the aid of any mask or resist. Desired ions have been implanted at specific locations of the prefabricated silicon ripple or triangular structures by exploiting the variation of local ion impact angles. We have shown that the implantation of Fe ions on an O{sup +} ions induced pre fabricated triangular shaped patterned Si surface results in a self-organized periodic array of striped magnetic nanostructures having several micron length and about 50 nm width arranged with a spacial separation of ∼200 nm. The morphology, composition, crystalline structure, and magnetic property of these nanopatterns have been analyzed using high-resolution cross-sectional transmission electron microscopy and atomic force microscopy. A geometrical model has been proposed to explain the fundamental features of such ion-induced nanopattern structures.

  7. Site-directed mutagenesis reveals regions implicated in the stability and fiber formation of human λ3r light chains.

    PubMed

    Villalba, Miryam I; Canul-Tec, Juan C; Luna-Martínez, Oscar D; Sánchez-Alcalá, Rosalba; Olamendi-Portugal, Timoteo; Rudiño-Piñera, Enrique; Rojas, Sonia; Sánchez-López, Rosana; Fernández-Velasco, Daniel A; Becerril, Baltazar

    2015-01-30

    Light chain amyloidosis (AL) is a disease that affects vital organs by the fibrillar aggregation of monoclonal light chains. λ3r germ line is significantly implicated in this disease. In this work, we contrasted the thermodynamic stability and aggregation propensity of 3mJL2 (nonamyloidogenic) and 3rJL2 (amyloidogenic) λ3 germ lines. Because of an inherent limitation (extremely low expression), Cys at position 34 of the 3r germ line was replaced by Tyr reaching a good expression yield. A second substitution (W91A) was introduced in 3r to obtain a better template to incorporate additional mutations. Although the single mutant (C34Y) was not fibrillogenic, the second mutation located at CDR3 (W91A) induced fibrillogenesis. We propose, for the first time, that CDR3 (position 91) affects the stability and fiber formation of human λ3r light chains. Using the double mutant (3rJL2/YA) as template, other variants were constructed to evaluate the importance of those substitutions into the stability and aggregation propensity of λ3 light chains. A change in position 7 (P7D) boosted 3rJL2/YA fibrillogenic properties. Modification of position 48 (I48M) partially reverted 3rJL2/YA fibril aggregation. Finally, changes at positions 8 (P8S) or 40 (P40S) completely reverted fibril formation. These results confirm the influential roles of N-terminal region (positions 7 and 8) and the loop 40-60 (positions 40 and 48) on AL. X-ray crystallography revealed that the three-dimensional topology of the single and double λ3r mutants was not significantly altered. This mutagenic approach helped to identify key regions implicated in λ3 AL.

  8. Site-directed Mutagenesis Reveals Regions Implicated in the Stability and Fiber Formation of Human λ3r Light Chains

    SciTech Connect

    Villalba, Miryam I.; Canul-Tec, Juan C.; Luna-Martínez, Oscar D.; Sánchez-Alcalá, Rosalba; Olamendi-Portugal, Timoteo; Rudiño-Piñera, Enrique; Rojas, Sonia; Sánchez-López, Rosana; Fernández-Velasco, Daniel A.; Becerril, Baltazar

    2014-12-11

    Light chain amyloidosis (AL) is a disease that affects vital organs by the fibrillar aggregation of monoclonal light chains. λ3r germ line is significantly implicated in this disease. In this paper, we contrasted the thermodynamic stability and aggregation propensity of 3mJL2 (nonamyloidogenic) and 3rJL2 (amyloidogenic) λ3 germ lines. Because of an inherent limitation (extremely low expression), Cys at position 34 of the 3r germ line was replaced by Tyr reaching a good expression yield. A second substitution (W91A) was introduced in 3r to obtain a better template to incorporate additional mutations. Although the single mutant (C34Y) was not fibrillogenic, the second mutation located at CDR3 (W91A) induced fibrillogenesis. We propose, for the first time, that CDR3 (position 91) affects the stability and fiber formation of human λ3r light chains. Using the double mutant (3rJL2/YA) as template, other variants were constructed to evaluate the importance of those substitutions into the stability and aggregation propensity of λ3 light chains. A change in position 7 (P7D) boosted 3rJL2/YA fibrillogenic properties. Modification of position 48 (I48M) partially reverted 3rJL2/YA fibril aggregation. Finally, changes at positions 8 (P8S) or 40 (P40S) completely reverted fibril formation. These results confirm the influential roles of N-terminal region (positions 7 and 8) and the loop 40–60 (positions 40 and 48) on AL. X-ray crystallography revealed that the three-dimensional topology of the single and double λ3r mutants was not significantly altered. Finally, this mutagenic approach helped to identify key regions implicated in λ3 AL.

  9. Site-directed Mutagenesis Reveals Regions Implicated in the Stability and Fiber Formation of Human λ3r Light Chains

    DOE PAGES

    Villalba, Miryam I.; Canul-Tec, Juan C.; Luna-Martínez, Oscar D.; ...

    2014-12-11

    Light chain amyloidosis (AL) is a disease that affects vital organs by the fibrillar aggregation of monoclonal light chains. λ3r germ line is significantly implicated in this disease. In this paper, we contrasted the thermodynamic stability and aggregation propensity of 3mJL2 (nonamyloidogenic) and 3rJL2 (amyloidogenic) λ3 germ lines. Because of an inherent limitation (extremely low expression), Cys at position 34 of the 3r germ line was replaced by Tyr reaching a good expression yield. A second substitution (W91A) was introduced in 3r to obtain a better template to incorporate additional mutations. Although the single mutant (C34Y) was not fibrillogenic, themore » second mutation located at CDR3 (W91A) induced fibrillogenesis. We propose, for the first time, that CDR3 (position 91) affects the stability and fiber formation of human λ3r light chains. Using the double mutant (3rJL2/YA) as template, other variants were constructed to evaluate the importance of those substitutions into the stability and aggregation propensity of λ3 light chains. A change in position 7 (P7D) boosted 3rJL2/YA fibrillogenic properties. Modification of position 48 (I48M) partially reverted 3rJL2/YA fibril aggregation. Finally, changes at positions 8 (P8S) or 40 (P40S) completely reverted fibril formation. These results confirm the influential roles of N-terminal region (positions 7 and 8) and the loop 40–60 (positions 40 and 48) on AL. X-ray crystallography revealed that the three-dimensional topology of the single and double λ3r mutants was not significantly altered. Finally, this mutagenic approach helped to identify key regions implicated in λ3 AL.« less

  10. Site-directed Mutagenesis Reveals Regions Implicated in the Stability and Fiber Formation of Human λ3r Light Chains*

    PubMed Central

    Villalba, Miryam I.; Canul-Tec, Juan C.; Luna-Martínez, Oscar D.; Sánchez-Alcalá, Rosalba; Olamendi-Portugal, Timoteo; Rudiño-Piñera, Enrique; Rojas, Sonia; Sánchez-López, Rosana; Fernández-Velasco, Daniel A.; Becerril, Baltazar

    2015-01-01

    Light chain amyloidosis (AL) is a disease that affects vital organs by the fibrillar aggregation of monoclonal light chains. λ3r germ line is significantly implicated in this disease. In this work, we contrasted the thermodynamic stability and aggregation propensity of 3mJL2 (nonamyloidogenic) and 3rJL2 (amyloidogenic) λ3 germ lines. Because of an inherent limitation (extremely low expression), Cys at position 34 of the 3r germ line was replaced by Tyr reaching a good expression yield. A second substitution (W91A) was introduced in 3r to obtain a better template to incorporate additional mutations. Although the single mutant (C34Y) was not fibrillogenic, the second mutation located at CDR3 (W91A) induced fibrillogenesis. We propose, for the first time, that CDR3 (position 91) affects the stability and fiber formation of human λ3r light chains. Using the double mutant (3rJL2/YA) as template, other variants were constructed to evaluate the importance of those substitutions into the stability and aggregation propensity of λ3 light chains. A change in position 7 (P7D) boosted 3rJL2/YA fibrillogenic properties. Modification of position 48 (I48M) partially reverted 3rJL2/YA fibril aggregation. Finally, changes at positions 8 (P8S) or 40 (P40S) completely reverted fibril formation. These results confirm the influential roles of N-terminal region (positions 7 and 8) and the loop 40–60 (positions 40 and 48) on AL. X-ray crystallography revealed that the three-dimensional topology of the single and double λ3r mutants was not significantly altered. This mutagenic approach helped to identify key regions implicated in λ3 AL. PMID:25505244

  11. Site Formation Processes and Hunter-Gatherers Use of Space in a Tropical Environment: A Geo-Ethnoarchaeological Approach from South India

    PubMed Central

    Friesem, David E.; Lavi, Noa; Madella, Marco; Ajithprasad, P.; French, Charles

    2016-01-01

    Hunter-gatherer societies have distinct social perceptions and practices which are expressed in unique use of space and material deposition patterns. However, the identification of archaeological evidence associated with hunter-gatherer activity is often challenging, especially in tropical environments such as rainforests. We present an integrated study combining ethnoarchaeology and geoarchaeology in order to study archaeological site formation processes related to hunter-gatherers’ ways of living in tropical forests. Ethnographic data was collected from an habitation site of contemporary hunter-gatherers in the forests of South India, aimed at studying how everyday activities and way of living dictate patterns of material deposition. Ethnoarchaeological excavations of abandoned open-air sites and a rock-shelter of the same group located deep in the forests, involved field observations and sampling of sediments from the abandoned sites and the contemporary site. Laboratory analyses included geochemical analysis (i.e., FTIR, ICP-AES), phytolith concentration analysis and soil micromorphology. The results present a dynamic spatial deposition pattern of macroscopic, microscopic and chemical materials, which stem from the distinctive ways of living and use of space by hunter-gatherers. This study shows that post-depositional processes in tropical forests result in poor preservation of archaeological materials due to acidic conditions and intensive biological activity within the sediments. Yet, the multiple laboratory-based analyses were able to trace evidence for activity surfaces and their maintenance practices as well as localized concentrations of activity remains such as the use of plants, metals, hearths and construction materials. PMID:27783683

  12. Comparison of particle number size distributions and new particle formation between the urban and rural sites in the PRD region, China

    NASA Astrophysics Data System (ADS)

    Yue, D. L.; Hu, M.; Wang, Z. B.; Wen, M. T.; Guo, S.; Zhong, L. J.; Wiedensohler, A.; Zhang, Y. H.

    2013-09-01

    Particle number size distributions were simultaneously measured at the Guangzhou (GZ) urban site (23.13°N, 113.26°E) and the Back-garden (BG) rural site (23.5°N, 113.03°E) in the Pearl River Delta (PRD) region in July, 2006. It provided new findings into the evolution of particle number size distribution and new particle formation (NPF) in two different environments. Number concentration of particles (20 nm-10 μm diameter) at GZ was about 70% higher than at BG and significantly affected by traffic emission. However, number concentrations of the regional aerosols (100-660 nm) were (6 ± 3) × 103 cm-3 at both sites. At BG, the diurnal variation of particle number size distributions showed an obvious particle growth process beginning at about 9:00 (LT), probably caused by NPF. In contrast, particle number concentrations in the size rages of 20-45 nm, 45-100 nm, and 100-660 nm showed similar trends with two main peaks at about 12:00 (LT) and 19:00 (LT) at GZ. NPF events were observed at both sites, but the occurrence frequency at GZ was about 50% lower than at BG. Regional NPF events at both sites probably in the same air mass were simultaneously observed with similar growth rates, concentrations and production rates of the condensable vapors, and condensational sinks on July 6. On the whole, deceasing traffic emission will improve air quality efficiently in the aspect of particle number concentration and fine particulate pollution in the summer of PRD should be controlled in a regional scale, especially with stagnant air mass from South China Sea.

  13. Analysis of Dose at the Site of Second Tumor Formation After Radiotherapy to the Central Nervous System

    SciTech Connect

    Galloway, Thomas J.; Indelicato, Daniel J.; Amdur, Robert J.; Morris, Christopher G.; Swanson, Erika L.; Marcus, Robert B.

    2012-01-01

    Purpose: Second tumors are an uncommon complication of multimodality treatment of childhood cancer. The present analysis attempted to correlate the dose received as a component of primary treatment and the site of the eventual development of a second tumor. Methods and Materials: We retrospectively identified 16 patients who had received radiotherapy to sites in the craniospinal axis and subsequently developed a second tumor. We compared the historical fields and port films of the primary treatment with the modern imaging of the second tumor locations. We classified the location of the second tumors as follows: in the boost field; marginal to the boost field, but in a whole-brain field; in a whole-brain field; marginal to the whole brain/primary treatment field; and distant to the field. We divided the dose received into 3 broad categories: high dose (>45 Gy), moderate dose (20-36 Gy), and low dose (<20 Gy). Results: The most common location of the second tumor was in the whole brain field (57%) and in the moderate-dose range (81%). Conclusions: Our data contradict previous publications that suggested that most second tumors develop in tissues that receive a low radiation dose. Almost all the second tumors in our series occurred in tissue within a target volume in the cranium that had received a moderate dose (20-36 Gy). These findings suggest that a major decrease in the brain volume that receives a moderate radiation dose is the only way to substantially decrease the second tumor rate after central nervous system radiotherapy.

  14. Tianeptine: 5-HT uptake sites and 5-HT(1-7) receptors modulate memory formation in an autoshaping Pavlovian/instrumental task.

    PubMed

    Meneses, Alfredo

    2002-05-01

    Recent studies using invertebrate and mammal species have revealed that, endogenous serotonin (5-hydroxytryptamine, 5-HT) modulates cognitive processes, particularly learning and memory, though, at present, it is unclear the manner, where, and how long 5-HT systems are involved. Hence in this work, an attempt was made to study the effects of 5-HT endogenous on memory formation, using a 5-HT uptake facilitator (tianeptine) and, selective 5-HT(1-7) receptor antagonists to determine whether 5-HT uptake sites and which 5-HT receptors are involved, respectively. Results showed that post-training tianeptine injection enhanced memory consolidation in an autoshaping Pavlovian/instrumental learning task, which has been useful to detect changes on memory formation elicited by drugs or aging. On interaction experiments, ketanserin (5-HT(1D/2A/2C) antagonist) slightly enhanced tianeptine effects, while WAY 100635 (5-HT(1A) antagonist), SB-224289 (5-HT(1B) inverse agonist), SB-200646 (5-HT(2B/2C) antagonist), ondansetron (5-HT(3) antagonist), GR 127487 (5-HT(4) antagonist), Ro 04-6790 (5-HT(6) antagonist), DR 4004 (5-HT(7) antagonist), or fluoxetine (an inhibitor of 5-HT reuptake) blocked the facilitatory tianeptine effect. Notably, together tianeptine and Ro 04-6790 impaired learning consolidation. Moreover, 5-HT depletion completely reversed the tianeptine effect. Tianeptine also normalized an impaired memory elicited by scopolamine (an antimuscarinic) or dizocilpine (non-competitive glutamatergic antagonist), while partially reversed that induced by TFMPP (5-HT(1B/1D/2A-2C/7) agonist/antagonist). Finally, tianeptine-fluoxetine coadministration had no effect on learning consolidation; nevertheless, administration of an acetylcholinesterase inhibitor, phenserine, potentiated subeffective tianeptine or fluoxetine doses. Collectively, these data confirmed that endogenously 5-HT modulates, via uptake sites and 5-HT(1-7) receptors, memory consolidation, and are consistent with the

  15. Dislocation pile-ups as sites for formation of electromigration-induced transgranular slit-like voids in Al interconnects

    SciTech Connect

    Srikar, V.T.; Thompson, C.V.

    1999-12-17

    Electromigration-induced voiding in metal interconnects in Si integrated circuits is a serious reliability concern. The microstructure of narrow interconnects subject to post-pattern anneal is expected to be bamboo-like in character. These structures are best described as chains of single crystals, with grain boundaries perpendicular to the interconnect axis. In these microstructures, two distinct types of void morphologies have been reported in Al-alloy interconnects: large, wedge shaped erosion voids (E-voids), and narrow slit-like voids (S-voids). A summarized below, electromigration experiments conducted on single-crystal Al interconnects have clearly shown that the transition of erosion voids to slit-like voids is very strongly dependent on the crystallography of the interconnect, and also that there is some inhomogeneously distributed feature which triggers S-void formation, even in single-crystal interconnects. In summary, the authors feel that the strong crystallographic dependence of the S-voids, the possible effects of the enormous mechanical stresses (in excess of 1 GPa in some cases) which can exist in such interconnects, and the stochastic nature of the development of slit-like features, have not been adequately captured in the existing models. In what follows, the authors present a model for a role that dislocation pile-ups may play in reducing the energy of transition of E-voids to S-voids, and for controlling the location of this transition.

  16. Effects of CO2 on mechanical variability and constitutive behavior of the Lower Tuscaloosa formation, Cranfield Injection Site, USA

    DOE PAGES

    Rinehart, Alex J.; Dewers, Thomas A.; Broome, Scott T.; ...

    2016-08-25

    We characterize geomechanical constitutive behavior of reservoir sandstones at conditions simulating the “Cranfield” Southeast Regional Carbon Sequestration Partnership injection program. From two cores of Lower Tuscaloosa Formation, three sandstone lithofacies were identified for mechanical testing based on permeability and lithology. These include: chlorite-cemented conglomeratic sandstone (Facies A); quartz-cemented fine sandstone (Facies B); and quartz- and calcite-cemented very fine sandstone (Facies C). We performed a suite of compression tests for each lithofacies at 100 °C and pore pressure of 30 MPa, including hydrostatic compression and triaxial tests at several confining pressures. Plugs were saturated with supercritical CO2-saturated brine. Chemical environment affectedmore » the mechanical response of all three lithofacies, which experience initial plastic yielding at stresses far below estimated in situ stress. Measured elastic moduli degradation defines a secondary yield surface coinciding with in situ stress for Facies B and C. Facies A shows measurable volumetric creep strain and a failure envelope below estimates of in situ stress, linked to damage of chlorite cements by acidic pore solutions. Furthermore, the substantial weakening of a particular lithofacies by CO2 demonstrates a possible chemical-mechanical coupling during injection at Cranfield with implications for CO2 injection, reservoir permeability stimulation, and enhanced oil recovery.« less

  17. Formation and Persistence of Brine on Mars: Experimental Simulations throughout the Diurnal Cycle at the Phoenix Landing Site

    PubMed Central

    Martínez, G.M.; Rennó, N.O.

    2016-01-01

    Abstract In the last few years, water ice and salts capable of melting this ice and producing liquid saline water (brine) have been detected on Mars. Moreover, indirect evidence for brine has been found in multiple areas of the planet. Here, we simulate full diurnal cycles of temperature and atmospheric water vapor content at the Phoenix landing site for the first time and show experimentally that, in spite of the low Mars-like chamber temperature, brine forms minutes after the ground temperature exceeds the eutectic temperature of salts in contact with water ice. Moreover, we show that the brine stays liquid for most of the diurnal cycle when enough water ice is available to compensate for evaporation. This is predicted to occur seasonally in areas of the polar region where the temperature exceeds the eutectic value and frost or snow is deposited on saline soils, or where water ice and salts coexist in the shallow subsurface. This is important because the existence of liquid water is a key requirement for habitability. Key Words: Mars—Ice—Perchlorates—Brine—Water—Raman spectroscopy. Astrobiology 16, 937–948. PMID:27912028

  18. Site-1 protease-activated formation of lysosomal targeting motifs is independent of the lipogenic transcription control[S

    PubMed Central

    Klünder, Sarah; Heeren, Jörg; Markmann, Sandra; Santer, René; Braulke, Thomas; Pohl, Sandra

    2015-01-01

    Site-1 protease (S1P) cleaves membrane-bound lipogenic sterol regulatory element-binding proteins (SREBPs) and the α/β-subunit precursor protein of the N-acetylglucosamine-1-phosphotransferase forming mannose 6-phosphate (M6P) targeting markers on lysosomal enzymes. The translocation of SREBPs from the endoplasmic reticulum (ER) to the Golgi-resident S1P depends on the intracellular sterol content, but it is unknown whether the ER exit of the α/β-subunit precursor is regulated. Here, we investigated the effect of cholesterol depletion (atorvastatin treatment) and elevation (LDL overload) on ER-Golgi transport, S1P-mediated cleavage of the α/β-subunit precursor, and the subsequent targeting of lysosomal enzymes along the biosynthetic and endocytic pathway to lysosomes. The data showed that the proteolytic cleavage of the α/β-subunit precursor into mature and enzymatically active subunits does not depend on the cholesterol content. In either treatment, lysosomal enzymes are normally decorated with M6P residues, allowing the proper sorting to lysosomes. In addition, we found that, in fibroblasts of mucolipidosis type II mice and Niemann-Pick type C patients characterized by aberrant cholesterol accumulation, the proteolytic cleavage of the α/β-subunit precursor was not impaired. We conclude that S1P substrate-dependent regulatory mechanisms for lipid synthesis and biogenesis of lysosomes are different. PMID:26108224

  19. Adeno-associated virus (AAV) Rep proteins mediate complex formation between AAV DNA and its integration site in human DNA.

    PubMed Central

    Weitzman, M D; Kyöstiö, S R; Kotin, R M; Owens, R A

    1994-01-01

    AAV is unique among eukaryotic viruses in the ability of its DNA to integrate preferentially into a specific region of the human genome. Understanding AAV integration may aid in developing gene therapy systems with predictable integration sites. Using a gel mobility-shift assay, we have identified a DNA sequence within the AAV integration locus on human chromosome 19 which is specifically bound by the AAV Rep78 and Rep68 proteins. This Rep recognition sequence is a GCTC repeating motif very similar to sequences within the inverted terminal repeats of the AAV genome which are also bound by Rep78 and Rep68. Cloned oligonucleotides containing the recognition sequence can direct specific binding by Rep proteins. Binding assays with mutant Rep proteins show that the amino-terminal portion of Rep78 and Rep68 can direct binding to either the AAV terminal repeat hairpin DNA or chromosome 19. This human genomic DNA can be complexed with AAV DNA by Rep proteins as demonstrated by a dual-label (32P/biotin) assay. These results suggest a role for Rep in targeting viral integration. Images PMID:8016070

  20. Formation and Persistence of Brine on Mars: Experimental Simulations throughout the Diurnal Cycle at the Phoenix Landing Site.

    PubMed

    Fischer, E; Martínez, G M; Rennó, N O

    2016-12-01

    In the last few years, water ice and salts capable of melting this ice and producing liquid saline water (brine) have been detected on Mars. Moreover, indirect evidence for brine has been found in multiple areas of the planet. Here, we simulate full diurnal cycles of temperature and atmospheric water vapor content at the Phoenix landing site for the first time and show experimentally that, in spite of the low Mars-like chamber temperature, brine forms minutes after the ground temperature exceeds the eutectic temperature of salts in contact with water ice. Moreover, we show that the brine stays liquid for most of the diurnal cycle when enough water ice is available to compensate for evaporation. This is predicted to occur seasonally in areas of the polar region where the temperature exceeds the eutectic value and frost or snow is deposited on saline soils, or where water ice and salts coexist in the shallow subsurface. This is important because the existence of liquid water is a key requirement for habitability. Key Words: Mars-Ice-Perchlorates-Brine-Water-Raman spectroscopy. Astrobiology 16, 937-948.

  1. Formation and Persistence of Brine on Mars: Experimental Simulations throughout the Diurnal Cycle at the Phoenix Landing Site

    NASA Astrophysics Data System (ADS)

    Fischer, E.; Martínez, G. M.; Rennó, N. O.

    2016-12-01

    In the last few years, water ice and salts capable of melting this ice and producing liquid saline water (brine) have been detected on Mars. Moreover, indirect evidence for brine has been found in multiple areas of the planet. Here, we simulate full diurnal cycles of temperature and atmospheric water vapor content at the Phoenix landing site for the first time and show experimentally that, in spite of the low Mars-like chamber temperature, brine forms minutes after the ground temperature exceeds the eutectic temperature of salts in contact with water ice. Moreover, we show that the brine stays liquid for most of the diurnal cycle when enough water ice is available to compensate for evaporation. This is predicted to occur seasonally in areas of the polar region where the temperature exceeds the eutectic value and frost or snow is deposited on saline soils, or where water ice and salts coexist in the shallow subsurface. This is important because the existence of liquid water is a key requirement for habitability.

  2. The effect of animal health products on the formation of injection site lesions in subprimals of experimentally injected beef calves.

    PubMed Central

    Van Donkersgoed, J; Dubeski, P L; VanderKop, M; Aalhus, J L; Bygrove, S; Starr, W N

    2000-01-01

    Two hundred and twenty beef calves were used in an experimental study to determine the occurrence of injection site lesions at slaughter (15 to 18 months of age) following subcutaneous and intramuscular injection of various products into the top hip (top butt), thigh (round), and neck or rib of calves at birth, branding, or weaning. Products tested were: 2 different preparations of selenium; a 2-way, a 7-way, and an 8-way clostridial bacterin; 2 combination 7-way clostridial and Haemophilus somnus bacterins; 2 H. somnus bacterins; 2 different 4-way modified-live viral respiratory vaccines; a 4-way killed viral and H. somnus vaccine; and penicillin, florfenicol, ceftiofur, trimethoprim-sulfa, and tilmicosin. The occurrence of lesions, number of steaks affected with lesions, the trim weight of lesions, the histological class of lesions, and the estimated economic losses are described. Generally, products administered subcutaneously in the neck produced minimal tissue damage and economic losses. Images Figure 1. Figure 2. Figure 3. PMID:10945127

  3. Formation of nanostructured porous Cu-Au surfaces: the influence of cationic sites on (electro)-catalysis

    NASA Astrophysics Data System (ADS)

    Najdovski, Ilija; Selvakannan, Pr.; Bhargava, Suresh K.; O'Mullane, Anthony P.

    2012-09-01

    The fabrication of nanostructured bimetallic materials through electrochemical routes offers the ability to control the composition and shape of the final material that can then be effectively applied as (electro)-catalysts. In this work a clean and transitory hydrogen bubble templating method is employed to generate porous Cu-Au materials with a highly anisotropic nanostructured interior. Significantly, the co-electrodeposition of copper and gold promotes the formation of a mixed bimetallic oxide surface which does not occur at the individually electrodeposited materials. Interestingly, the surface is dominated by Au(i) oxide species incorporated within a Cu2O matrix which is extremely effective for the industrially important (electro)-catalytic reduction of 4-nitrophenol. It is proposed that an aurophilic type of interaction takes place between both oxidized gold and copper species which stabilizes the surface against further oxidation and facilitates the binding of 4-nitrophenol to the surface and increases the rate of reaction. An added benefit is that very low gold loadings are required typically less than 2 wt% for a significant enhancement in performance to be observed. Therefore the ability to create a partially oxidized Cu-Au surface through a facile electrochemical route that uses a clean template consisting of only hydrogen bubbles should be of benefit for many more important reactions.The fabrication of nanostructured bimetallic materials through electrochemical routes offers the ability to control the composition and shape of the final material that can then be effectively applied as (electro)-catalysts. In this work a clean and transitory hydrogen bubble templating method is employed to generate porous Cu-Au materials with a highly anisotropic nanostructured interior. Significantly, the co-electrodeposition of copper and gold promotes the formation of a mixed bimetallic oxide surface which does not occur at the individually electrodeposited materials

  4. Histone H1 plays a role in heterochromatin formation and VSG expression site silencing in Trypanosoma brucei.

    PubMed

    Povelones, Megan L; Gluenz, Eva; Dembek, Marcin; Gull, Keith; Rudenko, Gloria

    2012-01-01

    The African sleeping sickness parasite Trypanosoma brucei evades the host immune system through antigenic variation of its variant surface glycoprotein (VSG) coat. Although the T. brucei genome contains ∼1500 VSGs, only one VSG is expressed at a time from one of about 15 subtelomeric VSG expression sites (ESs). For antigenic variation to work, not only must the vast VSG repertoire be kept silent in a genome that is mainly constitutively transcribed, but the frequency of VSG switching must be strictly controlled. Recently it has become clear that chromatin plays a key role in silencing inactive ESs, thereby ensuring monoallelic expression of VSG. We investigated the role of the linker histone H1 in chromatin organization and ES regulation in T. brucei. T. brucei histone H1 proteins have a different domain structure to H1 proteins in higher eukaryotes. However, we show that they play a key role in the maintenance of higher order chromatin structure in bloodstream form T. brucei as visualised by electron microscopy. In addition, depletion of histone H1 results in chromatin becoming generally more accessible to endonucleases in bloodstream but not in insect form T. brucei. The effect on chromatin following H1 knock-down in bloodstream form T. brucei is particularly evident at transcriptionally silent ES promoters, leading to 6-8 fold derepression of these promoters. T. brucei histone H1 therefore appears to be important for the maintenance of repressed chromatin in bloodstream form T. brucei. In particular H1 plays a role in downregulating silent ESs, arguing that H1-mediated chromatin functions in antigenic variation in T. brucei.

  5. Importance of Highly Conserved Peptide Sites of Human Cytomegalovirus gO for Formation of the gH/gL/gO Complex.

    PubMed

    Stegmann, Cora; Abdellatif, Mohamed E A; Laib Sampaio, Kerstin; Walther, Paul; Sinzger, Christian

    2017-01-01

    The glycoprotein O (gO) is betaherpesvirus specific. Together with the viral glycoproteins H and L, gO forms a covalent trimeric complex that is part of the viral envelope. This trimer is crucial for cell-free infectivity of human cytomegalovirus (HCMV) but dispensable for cell-associated spread. We hypothesized that the amino acids that are conserved among gOs of different cytomegaloviruses are important for the formation of the trimeric complex and hence for efficient virus spread. In a mutational approach, nine peptide sites, containing all 13 highly conserved amino acids, were analyzed in the context of HCMV strain TB40-BAC4 with regard to infection efficiency and formation of the gH/gL/gO complex. Mutation of amino acids (aa) 181 to 186 or aa 193 to 198 resulted in the loss of the trimer and a complete small-plaque phenotype, whereas mutation of aa 108 or aa 249 to 254 caused an intermediate phenotype. While individual mutations of the five conserved cysteines had little impact, their relevance was revealed in a combined mutation, which abrogated both complex formation and cell-free infectivity. C343 was unique, as it was sufficient and necessary for covalent binding of gO to gH/gL. Remarkably, however, C218 together with C167 rescued infectivity in the absence of detectable covalent complex formation. We conclude that all highly conserved amino acids contribute to the function of gO to some extent but that aa 181 to 198 and cysteines 343, 218, and 167 are particularly relevant. Surprisingly, covalent binding of gO to gH/gL is required neither for its incorporation into virions nor for proper function in cell-free infection.

  6. Evaluation of Radionuclide Mobilization and Redistribution during Playa Lake Formation on the Frenchman Flat Playa, Nevada Nuclear Security Site

    NASA Astrophysics Data System (ADS)

    LeFebre, K.; Hershey, R. L.; Decker, D.

    2011-12-01

    An array of programs has been investigating the environmental impacts of nuclear testing at the Nevada National Security Site since 1973. Because of above-ground testing in the 1950s, ground surface contamination on surface soils and neutron activation of nearby soil and materials has occurred from atmospheric deposition. Other concerns include redistribution of surface-deposited radionuclides by runoff, infiltration, wind, and other mechanical means. The goal of this study is to identify the potential for radionuclide mobilization and redistribution by chemical reactions during sporadic flooding of the Frenchman Flat Playa. Radionuclide mobility is dependent on a number of factors and might occur when the playa becomes flooded. Several geochemical processes that could mobilize and redistribute radionuclides include dissolution of playa minerals, precipitation of new minerals in different locations, sorption of radionuclides onto suspended or colloidal materials, and infiltration of soluble radionuclides to the subsurface environment. Following the heavy winter precipitation that flooded the playa in 2010 and 2011, playa-lake water samples were collected from easily accessed locations and analyzed for major ions, TDS, hydrogen and oxygen isotopes and radionuclides; suspended/precipitated materials were characterized by XRD; and, water-soil geochemical reactions were modeled. The geochemical software PHREEQC was used to model the soil-water evolution of the playa-lake water over time. Inputs to model simulations include precipitation chemistry, major-ion chemistry from water samples, mineralogy from XRD analysis of sediments, and radionuclides from spectroscopic measurements or literature values. Model simulations were constructed in a series of steps so that important water-soil chemical reactions could be determined and the changes in the playa water chemistry quantified as a result of these reactions. As the sequence of steps is taken, the simulations become

  7. Self-expression and relationship formation in high relational mobility environments: A study of dual users of American and Japanese social networking sites.

    PubMed

    Takemura, Kosuke; Suzuki, Satoko

    2015-09-03

    This study proposes that self-expression motivation, an aspect of independent/individualistic psychological tendencies, aids in the formation of social relationships when social relationships are open and mobile. In societies characterised by high relational mobility (e.g., North America), which creates market-like competition in social relationships, individuals must express their uniqueness and worthiness to form new social relationships. Self-expression motivation has a relatively weak effect on relationship formation in low relational mobility societies (e.g., Japan), where social relationships are generally predetermined. This hypothesis was examined and supported through a study on dual users of two social networking sites-Facebook and Mixi (the "Facebook of Japan"). As expected, relational mobility was higher on Facebook than on Mixi. Moreover, the association between self-expression motivation and the number of new friends met on Facebook/Mixi was more positive for Facebook than it was for Mixi. The social functionality of independent tendencies is then discussed.

  8. Development of a magnetic method for reconstructing the paleoclimate of the rock formation time: A case study of the Paleolithic Kostenki-12 site section (the Voronezh region)

    NASA Astrophysics Data System (ADS)

    Pospelova, G. A.; Anikovich, M. V.; Hoffecker, J. F.; Kadzialko-Hofmokl, M.

    2007-12-01

    A magnetic method is proposed for reconstructing the paleoclimate existing at the formation time of rocks of the Paleolithic Kostenki-12 site section. Results obtained from an experimental study of scalar magnetic characteristics (SMCs) of the rocks (magnetic susceptibility, anhysteretic remanent magnetization, and saturation isothermal remanent magnetization) are presented. These results indicate complex along-section SMC behavior distinguished by alternating larger and smaller values of the parameters. The magnetic minerals of the section are mainly represented by pseudo-single-domain magnetite grains. The size of the magnetite grains in the pseudo-single-domain range varies along the section, increasing in its lower half. The SMCs values plotted on different scales for the upper and lower halves of the section clearly revealed 12 magnetic zones (MZs). Comparison of the MZs with palynological zones obtained in a parallel section showed, on the whole, a convergence of data: MZs with larger (smaller) SMC values correlate with thermomers (cryomers). Comparison of along-section SMC variations with the GRIP (Greenland Ice Core Project) curve of the time dependence of paleotemperatures confirmed or refined the ages of lithologic horizons. As a result, it is established that constraints on paleoclimatic changes in the rock formation time can be gained from SMC variations if the main carriers of magnetization in rocks are pseudo-single-domain magnetite grains even with magnetic grain size varying along the section.

  9. Formation of lipid bilayer membrane in a poly(dimethylsiloxane) microchip integrated with a stacked polycarbonate membrane support and an on-site nanoinjector.

    PubMed

    Teng, Wei; Ban, Changill; Hahn, Jong Hoon

    2015-03-01

    This paper describes a new and facile approach for the formation of pore-spanning bilayer lipid membranes (BLMs) within a poly(dimethylsiloxane) (PDMS) microfluidic device. Commercially, readily available polycarbonate (PC) membranes are employed for the support of BLMs. PC sheets with 5 μm, 2 μm, and 0.4 μm pore diameters, respectively, are thermally bonded into a multilayer-stack, reducing the pore density of 0.4 μm-pore PC by a factor of 200. The BLMs on this support are considerably stable (a mean lifetime: 17 h). This multilayer-stack PC (MSPC) membrane is integrated into the PDMS chip by an epoxy bonding method developed to secure durable bonding under the use of organic solvents. The microchip has a special channel for guiding a micropipette in the proximity of the MSPC support. With this on-site injection technique, tens to hundreds of nanoliters of solutions can be directly dispensed to the support. Incorporating gramicidin ion channels into BLMs on the MSPC support has confirmed the formation of single BLMs, which is based on the observation from current signals of 20 pS conductance that is typical to single channel opening. Based on the bilayer capacitance (1.4 pF), about 15% of through pores across the MSPC membrane are estimated to be covered with BLMs.

  10. Effect of Siloxane Ring Strain and Cation Charge Density on the Formation of Coordinately Unsaturated Metal Sites on Silica: Insights from DFT Studies

    SciTech Connect

    Das, Ujjal; Zhang, Guanghui; Hu, Bo; Hock, Adam S.; Redfern, Paul C.; Miller, Jeffrey T.; Curtiss, Larry A.

    2015-12-01

    Amorphous silica (SiO2) is commonly used as a support in heterogeneous catalysis. However, due to the structural disorder and temperature induced change of surface morphology, the structures of silica supported metal catalysts are difficult to determine. Most studies are primarily focused on understanding the interactions of different types of surface hydroxyl groups with metal ions. In comparison, the effect of siloxane ring size on the structure of silica supported metal catalysts and how it affects catalytic activity is poorly understood. Here, we have used density functional theory calculations to understand the effect of siloxane ring strain on structure and activity of different monomeric Lewis acid metal sites on silica. In particular, we have found that large siloxane rings favor strong dative bonding interaction between metal ion and surface hydroxyls, leading to the formation of high-coordinate metal sites. In comparison, metal-silanol interaction is weak in small siloxane rings, resulting in low-coordinate metal sites. The physical origin of this size dependence is associated with siloxane ring strain, and, a correlation between metal-silanol interaction energy and ring strain energy has been observed. In addition to ring strain, the strength of the metal-silanol interaction also depends on the positive charge density of the cations. In fact, a correlation also exists between metal-silanol interaction energy and charge density of several first-row transition and post-transition metals. The theoretical results are compared with the EXAFS data of monomeric Zn(II) and Ga(III) ions grafted on silica. The molecular level insights of how metal ion coordination on silica depends on siloxane ring strain and cation charge density will be useful in the synthesis of new catalysts.

  11. Heat-induced formation of a specific binding site for self-assembled Congo Red in the V domain of immunoglobulin L chain lambda.

    PubMed

    Piekarska, B; Konieczny, L; Rybarska, J; Stopa, B; Zemanek, G; Szneler, E; Król, M; Nowak, M; Roterman, I

    2001-11-01

    Moderate heating (40-50 degrees C) of immunoglobulins makes them accessible for binding with Congo Red and some related highly associated dyes. The binding is specific and involves supramolecular dye ligands presenting ribbon-like micellar bodies. The L chain lambda dimer, which upon heating disclosed the same binding requirement with respect to supramolecular dye ligands, was used in this work to identify the site of their attachment. Two clearly defined dye-protein (L lambda chain) complexes arise upon heating, here called complex I and complex II. The first is formed at low temperatures (up to 40-45 degrees C) and hence by a still native protein, while the formation of the second one is associated with domain melting above 55 degrees C. They contain 4 and 8 dye molecules bound per L chain monomer, respectively. Complex I also forms efficiently at high dye concentration even at ambient temperature. Complex I and its formation was the object of the present studies. Three structural events that could make the protein accessible to penetration by the large dye ligand were considered to occur in L chains upon heating: local polypeptide chain destabilization, VL-VL domain incoherence, and protein melting. Of these three possibilities, local low-energy structural alteration was found to correlate best with the formation of complex I. It was identified as decreased packing stability of the N-terminal polypeptide chain fragment, which as a result made the V domain accessible for dye penetration. The 19-amino acid N-terminal fragment becomes susceptible to proteolytic cleavage after being replaced by the dye at its packing locus. Its splitting from the dye-protein complex was proved by amino acid sequence analysis. The emptied packing locus, which becomes the site that holds the dye, is bordered by strands of amino acids numbered 74-80 and 105-110, as shown by model analysis. The character of the temperature-induced local polypeptide chain destabilization and its possible

  12. Repeated occurrences of methanogenic zones, diagenetic dolomite formation and linked silicate alteration in southern Bering Sea sediments (Bowers Ridge, IODP Exp. 323 Site U1341)

    NASA Astrophysics Data System (ADS)

    Wehrmann, L. M.; Ockert, C.; Mix, A. C.; Gussone, N.; Teichert, B. M. A.; Meister, P.

    2016-03-01

    porewater calcium was also influenced by ammonium-calcium exchange on clay minerals and carbonate recrystallization. Our study elucidates the response of porewater element concentrations and isotopic profiles interlinked with the formation of diagenetic carbonates to changes in the deposition of organic carbon in sediments of deeper water sites (>2000 m water depth) over prolonged timescales. It shows that variations in biogeochemical processes in response to changes in oceanographic conditions and a dynamic subseafloor biogeochemical zonation have to also be taken into account at these deep water sites for a global assessment of organic carbon burial fluxes and remineralization.

  13. The mechanism of formation of the seafloor massive sulfide ore body beneath the seafloor at HAKUREI Site in Izena Caldera, Middle Okinawa Trough

    NASA Astrophysics Data System (ADS)

    Yoshizumi, R.; Urabe, T.

    2012-12-01

    dominant at lower of the ore, relatively. The existence of "Black ore (sphalerite-galena ore)" at upper part and "Yellow ore (chalcopyrite-pyrite ore)" at lower part of the Lower ore indicate that the SMS ore beneath the seafloor has already the characteristic mineral assemblage of Kuroko ore deposit at the time of formation. Fe content in Sphalerite is over 6wt% in the Upper ore and under 1wt% in the Lower ore, respectively, which shows that the Lower ore is formed under high Sulfur and Oxygen fugacity than Upper ore if the temperature of formation is not very different each other. Barite occurs not only in the Upper ore, but also in the Lower ore and the crystal size becomes coarser downwards. These lines of evidence imply that the existence of the Lower ore indicates that the mineralization has been repeated in the HAKUREI site. This study is a part of "TAIGA" project funded by Grant-in-Aid program by Monbusho.t; t;

  14. The narrow active-site cleft of O-acetylserine sulfhydrylase from Leishmania donovani allows complex formation with serine acetyltransferases with a range of C-terminal sequences.

    PubMed

    Raj, Isha; Kumar, Sudhir; Gourinath, Samudrala

    2012-08-01

    Cysteine is a crucial substrate for the synthesis of glutathione and trypanothione, which in turn maintain intracellular redox homeostasis and defend against oxidative stress in the pathogen Leishmania donovani. Here, the identification, sequencing, characterization and crystal structure at 1.79 Å resolution of O-acetylserine sulfhydrylase (OASS), a cysteine-biosynthetic pathway enzyme from L. donovani (LdOASS), are reported. It shows binding to the serine acetyltransferase (SAT) C-terminal peptide, indicating that OASS and SAT interact with each other to form a cysteine synthase complex, further confirmed by the structure of LdOASS in complex with SAT C-terminal octapeptide at 1.68 Å resolution. Docking and fluorescence binding studies show that almost all SAT C-terminus mimicking tetrapeptides can bind to LdOASS. Some peptides had a higher binding affinity than the native peptide, indicating that SAT-OASS interactions are not sequence-specific. The structure of LdOASS with a designed peptide (DWSI) revealed that LdOASS makes more interactions with the designed peptide than with the native peptide. In almost all known SAT-OASS interactions the SAT C-terminal sequence was shown to contain amino acids with large side chains. Structural comparison with other OASSs revealed that LdOASS has a relatively less open active-site cleft, which may be responsible for its interaction with the smaller-amino-acid-containing C-terminal LdSAT peptide. Biochemical studies confirmed that LdOASS interacts with SATs from Entamoeba histolytica and Brucella abortus, further displaying its sequence-independent and versatile mode of interaction with SATs. This implicates a critical role of the size of the active-site cleft opening in OASS for SAT-OASS interaction and thus cysteine synthase complex formation.

  15. CO2–rock–brine interactions in Lower Tuscaloosa Formation at Cranfield CO2 sequestration site, Mississippi, U.S.A.

    USGS Publications Warehouse

    Lu, Jiemin; Kharaka, Yousif K.; Thordsen, James J.; Horita, Juske; Karamalidis, Athanasios; Griffith, Craig; Hakala, J. Alexandra; Ambats, Gil; Cole, David R.; Phelps, Tommy J.; Manning, Michael A.; Cook, Paul J.; Hovorka, Susan D.

    2012-01-01

    A highly integrated geochemical program was conducted at the Cranfield CO2-enhanced oil recovery (EOR) and sequestration site, Mississippi, U.S.A.. The program included extensive field geochemical monitoring, a detailed petrographic study, and an autoclave experiment under in situ reservoir conditions. Results show that mineral reactions in the Lower Tuscaloosa reservoir were minor during CO2 injection. Brine chemistry remained largely unchanged, which contrasts with significant changes observed in other field tests. Field fluid sampling and laboratory experiments show consistently slow reactions. Carbon isotopic composition and CO2 content in the gas phase reveal simple two-end-member mixing between injected and original formation gas. We conclude that the reservoir rock, which is composed mainly of minerals with low reactivity (average quartz 79.4%, chlorite 11.8%, kaolinite 3.1%, illite 1.3%, concretionary calcite and dolomite 1.5%, and feldspar 0.2%), is relatively unreactive to CO2. The significance of low reactivity is both positive, in that the reservoir is not impacted, and negative, in that mineral trapping is insignificant.

  16. Overburden characterization and post-burn study at the Hanna, Wyoming underground coal gasification site: stratigraphy, depositional environments and mineralogy, Hanna Formation

    SciTech Connect

    Craig, G.N. II; Burns, L.K.; Ethridge, F.G.; Laughter, T.; Youngberg, A.D.

    1982-03-01

    Several underground coal gasification (UCG) experiments have been conducted in the Hanna No. 1 coal seam. During the fall of 1980 the Laramie Energy Technology Center performed a post-burn field study of the Hanna II, Phases 2 and 3 experiment at the Hanna UCG site. The field work consisted of high resolution seismic, drilling, coring, and geophysical logging. The Department of Earth Resources, Colorado State University, contributed to the post-burn study by doing laboratory work on the cores and geophysical logs. The purpose of the laboratory work was to provide an estimate of the temperatures and chemical conditions reached during the conversion experiment by studying the mineralogical and textural characteristics of thermally altered and ulaltered overburden. In the vicinity of the burn cavity, overburden rocks have been subjected to high temperature pyrometamorphism during the Hanna II Phases 2 and 3 UCG experiments. Paralava rocks, buchites and paralava breccias containing glass and various high temperature minerals such as oligoclase, clinopyroxene, ferrocordierite, mullite, cristobalite, magnetite, and tridymite formed. Textures of some of these minerals suggest crystallization directly from a melt. Mineralogy and melting relations of the paralavas, ash fusion temperatures, and thermocouple measurements made during the experiment suggest that tempratures in excess of 1200/sup 0/C were attained. Rock color and the presence of reduced iron bearing minerals and blebs of native iron indicate that the experimental burn and the product gases in the area of paralava formation were reducing.

  17. The ER Stress Sensor PERK Coordinates ER-Plasma Membrane Contact Site Formation through Interaction with Filamin-A and F-Actin Remodeling.

    PubMed

    van Vliet, Alexander R; Giordano, Francesca; Gerlo, Sarah; Segura, Inmaculada; Van Eygen, Sofie; Molenberghs, Geert; Rocha, Susana; Houcine, Audrey; Derua, Rita; Verfaillie, Tom; Vangindertael, Jeroen; De Keersmaecker, Herlinde; Waelkens, Etienne; Tavernier, Jan; Hofkens, Johan; Annaert, Wim; Carmeliet, Peter; Samali, Afshin; Mizuno, Hideaki; Agostinis, Patrizia

    2017-03-02

    Loss of ER Ca(2+) homeostasis triggers endoplasmic reticulum (ER) stress and drives ER-PM contact sites formation in order to refill ER-luminal Ca(2+). Recent studies suggest that the ER stress sensor and mediator of the unfolded protein response (UPR) PERK regulates intracellular Ca(2+) fluxes, but the mechanisms remain elusive. Here, using proximity-dependent biotin identification (BioID), we identified the actin-binding protein Filamin A (FLNA) as a key PERK interactor. Cells lacking PERK accumulate F-actin at the cell edges and display reduced ER-PM contacts. Following ER-Ca(2+) store depletion, the PERK-FLNA interaction drives the expansion of ER-PM juxtapositions by regulating F-actin-assisted relocation of the ER-associated tethering proteins Stromal Interaction Molecule 1 (STIM1) and Extended Synaptotagmin-1 (E-Syt1) to the PM. Cytosolic Ca(2+) elevation elicits rapid and UPR-independent PERK dimerization, which enforces PERK-FLNA-mediated ER-PM juxtapositions. Collectively, our data unravel an unprecedented role of PERK in the regulation of ER-PM appositions through the modulation of the actin cytoskeleton.

  18. A Model for the Active-Site Formation Process in DMSO Reductase Family Molybdenum Enzymes Involving Oxido-Alcoholato and Oxido-Thiolato Molybdenum(VI) Core Structures.

    PubMed

    Sugimoto, Hideki; Sato, Masanori; Asano, Kaori; Suzuki, Takeyuki; Mieda, Kaoru; Ogura, Takashi; Matsumoto, Takashi; Giles, Logan J; Pokhrel, Amrit; Kirk, Martin L; Itoh, Shinobu

    2016-02-15

    New bis(ene-1,2-dithiolato)-oxido-alcoholato molybdenum(VI) and -oxido-thiolato molybdenum(VI) anionic complexes, denoted as [Mo(VI)O(ER)L2](-) (E = O, S; L = dimethoxycarboxylate-1,2-ethylenedithiolate), were obtained from the reaction of the corresponding dioxido-molybdenum(VI) precursor complex with either an alcohol or a thiol in the presence of an organic acid (e.g., 10-camphorsulfonic acid) at low temperature. The [Mo(VI)O(ER)L2](-) complexes were isolated and characterized, and the structure of [Mo(VI)O(OEt)L2](-) was determined by X-ray crystallography. The Mo(VI) center in [Mo(VI)O(OEt)L2](-) exhibits a distorted octahedral geometry with the two ene-1,2-dithiolate ligands being symmetry inequivalent. The computed structure of [Mo(VI)O(SR)L2](-) is essentially identical to that of [Mo(VI)O(OR)L2](-). The electronic structures of the resulting molybdenum(VI) complexes were evaluated using electronic absorption spectroscopy and bonding calculations. The nature of the distorted O(h) geometry in these [Mo(VI)O(EEt)L2](-) complexes results in a lowest unoccupied molecular orbital wave function that possesses strong π* interactions between the Mo(d(xy)) orbital and the cis S(p(z)) orbital localized on one sulfur donor from a single ene-1,2-dithiolate ligand. The presence of a covalent Mo-S(dithiolene) bonding interaction in these monooxido Mo(VI) compounds contributes to their low-energy ligand-to-metal charge transfer transitions. A second important d-p π bonding interaction derives from the ∼180° O(oxo)-Mo-E-C dihedral angle involving the alcoholate and thiolate donors, and this contributes to ancillary ligand contributions to the electronic structure of these species. The formation of [Mo(VI)O(OEt)L2](-) and [Mo(VI)O(SEt)L2](-) from the dioxidomolybdenum(VI) precursor may be regarded as a model for the active-site formation process that occurs in the dimethyl sulfoxide reductase family of pyranopterin molybdenum enzymes.

  19. Hydrothermal Alteration of Glass from Underground Nuclear Tests: Formation and Transport of Pu-clay Colloids at the Nevada National Security Site

    SciTech Connect

    Zavarin, M.; Zhao, P.; Joseph, C.; Begg, J.; Boggs, M.; Dai, Z.; Kersting, A. B.

    2015-05-27

    The testing of nuclear weapons at the Nevada National Security Site (NNSS), formerly the Nevada Test Site (NTS), has led to the deposition of substantial quantities of plutonium into the environment. Approximately 2.8 metric tons (3.1×104 TBq) of Pu were deposited in the NNSS subsurface as a result of underground nuclear testing. While 3H is the most abundant anthropogenic radionuclide deposited in the NNSS subsurface (4.7×106 TBq), plutonium is the most abundant from a molar standpoint. The only radioactive elements in greater molar abundance are the naturally occurring K, Th, and U isotopes. 239Pu and 240Pu represent the majority of alpha-emitting Pu isotopes. The extreme temperatures associated with underground nuclear tests and the refractory nature of Pu results in most of the Pu (98%) being sequestered in melted rock, referred to as nuclear melt glass (Iaea, 1998). As a result, Pu release to groundwater is controlled, in large part, by the leaching (or dissolution) of nuclear melt glass over time. The factors affecting glass dissolution rates have been studied extensively. The dissolution of Pu-containing borosilicate nuclear waste glasses at 90ºC has been shown to lead to the formation of dioctahedral smectite colloids. Colloid-facilitated transport of Pu at the NNSS has been observed. Recent groundwater samples collected from a number of contaminated wells have yielded a wide range of Pu concentrations from 0.00022 to 2.0 Bq/L. While Pu concentrations tend to fall below the Maximum Contaminant Level (MCL) established by the Environmental Protection Agency (EPA) for drinking water (0.56 Bq/L), we do not yet understand what factors limit the Pu concentration or its transport behavior. To quantify the upper limit of Pu concentrations produced as a result of melt glass dissolution and determine the nature of colloids and Pu associations, we performed a 3 year nuclear melt glass dissolution experiment

  20. Particulate matter (PM) episodes at a suburban site in Hong Kong: evolution of PM characteristics and role of photochemistry in secondary aerosol formation

    NASA Astrophysics Data System (ADS)

    Qin, Yi Ming; Jie Li, Yong; Wang, Hao; Lee, Berto Paul Yok Long; Huang, Dan Dan; Keung Chan, Chak

    2016-11-01

    Episodes with high concentrations of particulate matter (PM) across the seasons were investigated during four 1-month campaigns at a suburban site in Hong Kong. High-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) measurements revealed that both regional transport and secondary formation contributed to high PM levels during the episodes at this site. Based on distinct meteorological conditions, episodes were categorized into three types: liquid water content (LWC), solar irradiance (IR), and long-range transport (LRT). Despite the difference in meteorological conditions, all episodes were characterized by a high fraction of sulfate (45-56 %) and organics (23-34 %). However, aerosols in LWC episodes were less aged, consisting of the lowest fraction of secondary organic aerosol (SOA) and the highest fraction of small particles. Large particles mixed internally while freshly formed small particles mixed externally in LWC episodes. Aerosols in LRT episodes, by contrast, were the most aged and consisted of the highest proportion of low-volatility oxygenated organic aerosol (LVOOA) and the lowest proportion of small particles. Both small and large particles mixed externally in LRT episodes. The highest proportion of semi-volatile oxygenated organic aerosol (SVOOA) and a medium proportion of small particles were observed in IR episodes. Both small and large particles were likely externally mixed during IR episodes. Furthermore, aerosols experienced the most dramatic size increase and diurnal variation, with a time lag between SVOOA and LVOOA and a gradual increase in carbon oxidation state (OSc ≈ 2 × O : C - H : C). Five out of 10 episodes were of the IR type, further reflecting the importance of this type of episode. The evolution of aerosol components in one particular episode of the IR type, which exhibited a clear land-sea breeze pattern, was examined in detail. Sulfate and SOA due to photochemical aging

  1. Mapping the homotypic binding sites in CD31 and the role of CD31 adhesion in the formation of interendothelial cell contacts

    PubMed Central

    1995-01-01

    CD31 is a member of the immunoglobulin superfamily consisting of six Ig- related domains. It is constitutively expressed by platelets, monocytes, and some lymphocytes, but at tenfold higher levels on vascular endothelial cells. CD31 has both homotypic and heterotypic adhesive properties. We have mapped the homotypic binding sites using a deletion series of CD31-Fc chimeras and a panel of anti-CD31 monoclonal antibodies. An extensive surface of CD31 is involved in homotypic binding with domains 2 and 3 and domains 5 and 6 playing key roles. A model consistent with the experimental data is that CD31 on one cell binds to CD31 on an apposing cell in an antiparallel interdigitating mode requiring full alignment of the six domains of each molecule. In addition to establishing intercellular homotypic contacts. CD31 binding leads to augmented adhesion via beta 1 integrins. The positive cooperation between CD31 and beta 1 integrins can occur in heterologous primate cells (COS cells). The interaction is specific to both CD31 and beta 1 integrins. Neither intercellular adhesion molecule-1 (ICAM- 1)/leukocyte function-associated antigen-1 (LCAM-1) nor neural cell adhesion molecule (NCAM)/NCAM adhesion leads to recruitment of beta 1 integrin adhesion pathways. Establishment of CD31 contacts have effects on the growth and morphology of endothelial cells. CD31(D1-D6)Fc inhibits the growth of endothelial cells in culture. In addition, papain fragments of anti-CD31 antibodies (Fab fragments) disrupt interendothelial contact formation and monolayer integrity when intercellular contacts are being formed. The same reagents are without effect once these contacts have been established, suggesting that CD31- CD31 interactions are critically important only in the initial phases of intercellular adhesion. PMID:7534767

  2. Observation of new particle formation and measurement of sulfuric acid, ammonia, amines and highly oxidized organic molecules at a rural site in central Germany

    NASA Astrophysics Data System (ADS)

    Kürten, Andreas; Bergen, Anton; Heinritzi, Martin; Leiminger, Markus; Lorenz, Verena; Piel, Felix; Simon, Mario; Sitals, Robert; Wagner, Andrea C.; Curtius, Joachim

    2016-10-01

    The exact mechanisms for new particle formation (NPF) under different boundary layer conditions are not known yet. One important question is whether amines and sulfuric acid lead to efficient NPF in the atmosphere. Furthermore, it is not clear to what extent highly oxidized organic molecules (HOMs) are involved in NPF. We conducted field measurements at a rural site in central Germany in the proximity of three larger dairy farms to investigate whether there is a connection between NPF and the presence of amines and/or ammonia due to the local emissions from the farms. Comprehensive measurements using a nitrate chemical ionization-atmospheric pressure interface time-of-flight (CI-APi-TOF) mass spectrometer, a proton-transfer-reaction mass spectrometer (PTR-MS), particle counters and differential mobility analyzers (DMAs), as well as measurements of trace gases and meteorological parameters, were performed. We demonstrate here that the nitrate CI-APi-TOF is suitable for sensitive measurements of sulfuric acid, amines, a nitrosamine, ammonia, iodic acid and HOMs. NPF was found to correlate with sulfuric acid, while an anti-correlation with RH, amines and ammonia is observed. The anti-correlation between NPF and amines could be due to the efficient uptake of these compounds by nucleating clusters and small particles. Much higher HOM dimer (C19/C20 compounds) concentrations during the night than during the day indicate that these HOMs do not efficiently self-nucleate as no nighttime NPF is observed. Observed iodic acid probably originates from an iodine-containing reservoir substance, but the iodine signals are very likely too low to have a significant effect on NPF.

  3. Analysis of Site Formation and Assemblage Integrity Does Not Support Attribution of the Uluzzian to Modern Humans at Grotta del Cavallo.

    PubMed

    Zilhão, João; Banks, William E; d'Errico, Francesco; Gioia, Patrizia

    2015-01-01

    Based on the morphology of two deciduous molars and radiocarbon ages from layers D and E of the Grotta del Cavallo (Lecce, Italy), assigned to the Uluzzian, it has been proposed that modern humans were the makers of this Early Upper Paleolithic culture and that this finding considerably weakens the case for an independent emergence of symbolism among western European Neandertals. Reappraisal of the new dating evidence, of the finds curated in the Taranto Antiquities depot, and of coeval publications detailing the site's 1963-66 excavations shows that (a) Protoaurignacian, Aurignacian and Early Epigravettian lithics exist in the assemblages from layers D and E, (b) even though it contains both inherited and intrusive items, the formation of layer D began during Protoaurignacian times, and (c) the composition of the extant Cavallo assemblages is influenced in a non-negligible manner by the post-hoc assignment of items to stratigraphic units distinct from that of original discovery. In addition, a major disturbance feature affected the 1960s excavation trench down to Mousterian layer F, this feature went unrecognized until 1964, the human remains assigned to the Uluzzian were discovered that year and/or the previous year, and there are contradictions between field reports and the primary anthropological description of the remains as to their morphology and level of provenience. Given these major contextual uncertainties, the Cavallo teeth cannot be used to establish the authorship of the Uluzzian. Since this technocomplex's start date is ca. 45,000 calendar years ago, a number of Neandertal fossils are dated to this period, and the oldest diagnostic European modern human fossil is the <41,400 year-old Oase 1 mandible, Neandertal authorship of the Uluzzian remains the parsimonious reading of the evidence.

  4. Seasonal variation of atmospheric particle number concentrations, new particle formation and atmospheric oxidation capacity at the high Arctic site Villum Research Station, Station Nord

    NASA Astrophysics Data System (ADS)

    Nguyen, Quynh T.; Glasius, Marianne; Sørensen, Lise L.; Jensen, Bjarne; Skov, Henrik; Birmili, Wolfram; Wiedensohler, Alfred; Kristensson, Adam; Nøjgaard, Jacob K.; Massling, Andreas

    2016-09-01

    This work presents an analysis of the physical properties of sub-micrometer aerosol particles measured at the high Arctic site Villum Research Station, Station Nord (VRS), northeast Greenland, between July 2010 and February 2013. The study focuses on particle number concentrations, particle number size distributions and the occurrence of new particle formation (NPF) events and their seasonality in the high Arctic, where observations and characterization of such aerosol particle properties and corresponding events are rare and understanding of related processes is lacking.A clear accumulation mode was observed during the darker months from October until mid-May, which became considerably more pronounced during the prominent Arctic haze months from March to mid-May. In contrast, nucleation- and Aitken-mode particles were predominantly observed during the summer months. Analysis of wind direction and wind speed indicated possible contributions of marine sources from the easterly side of the station to the observed summertime particle number concentrations, while southwesterly to westerly winds dominated during the darker months. NPF events lasting from hours to days were mostly observed from June until August, with fewer events observed during the months with less sunlight, i.e., March, April, September and October. The results tend to indicate that ozone (O3) might be weakly anti-correlated with particle number concentrations of the nucleation-mode range (10-30 nm) in almost half of the NPF events, while no positive correlation was observed. Calculations of air mass back trajectories using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model for the NPF event days suggested that the onset or interruption of events could possibly be explained by changes in air mass origin. A map of event occurrence probability was computed, indicating that southerly air masses from over the Greenland Sea were more likely linked to those events.

  5. Unravelling the secrets of Cs controlled secondary ion formation: Evidence of the dominance of site specific surface chemistry, alloying and ionic bonding

    NASA Astrophysics Data System (ADS)

    Wittmaack, Klaus

    2013-03-01

    implantation can be evaluated as a function of Cs coverage. The summarised results imply that secondary ions are commonly not formed by charge transfer between an escaping atom and the electronic system of the sample but are already emitted as ions. The probability of ion formation appears to be controlled by the local ionic character of the alkali-target atom bonds, i.e., by the difference in electronegativity between the involved elements as well as by the electron affinity and the ionisation potential of the departing atom. This idea is supported by the finding that Si- yields exhibit the same very strong dependence on Cs coverage as Si+ and O- yields on the oxygen fraction in oxygen loaded Si. Most challenging to theoreticians is the finding that the ionisation probability is independent of the emission velocity of sputtered ions. This phenomenon cannot be rationalised along established routes of thinking. Different concepts need to be explored. An old, somewhat exotic idea takes account of the heavy perturbation created for a very short period of time at the site of ion emission (dynamic randomisation). Molecular dynamics simulations are desirable to clarify the issue. Ultimately it may be possible to describe all phenomena of enhanced or suppressed secondary ion formation, produced either by surface loading with alkali atoms or by enforced surface oxidation, on the basis of a single universal model. There is plenty of room for exciting new studies.

  6. Unravelling the secrets of Cs controlled secondary ion formation: Evidence of the dominance of site specific surface chemistry, alloying and ionic bonding

    NASA Astrophysics Data System (ADS)

    Wittmaack, Klaus

    2013-03-01

    implantation can be evaluated as a function of Cs coverage.The summarised results imply that secondary ions are commonly not formed by charge transfer between an escaping atom and the electronic system of the sample but are already emitted as ions. The probability of ion formation appears to be controlled by the local ionic character of the alkali-target atom bonds, i.e., by the difference in electronegativity between the involved elements as well as by the electron affinity and the ionisation potential of the departing atom. This idea is supported by the finding that Si- yields exhibit the same very strong dependence on Cs coverage as Si+ and O- yields on the oxygen fraction in oxygen loaded Si. Most challenging to theoreticians is the finding that the ionisation probability is independent of the emission velocity of sputtered ions. This phenomenon cannot be rationalised along established routes of thinking. Different concepts need to be explored. An old, somewhat exotic idea takes account of the heavy perturbation created for a very short period of time at the site of ion emission (dynamic randomisation). Molecular dynamics simulations are desirable to clarify the issue. Ultimately it may be possible to describe all phenomena of enhanced or suppressed secondary ion formation, produced either by surface loading with alkali atoms or by enforced surface oxidation, on the basis of a single universal model. There is plenty of room for exciting new studies.

  7. Natural heterogeneity and evolving geochemistry of Lower Tuscaloosa Formation brine in response to continuing CO2 injection at Cranfield EOR site, Mississippi, USA

    NASA Astrophysics Data System (ADS)

    Thordsen, J. J.; Kharaka, Y. K.; Thomas, B.; Abedini, A. A.; Conaway, C. H.; Manning, M. A.; Lu, J.

    2012-12-01

    Geochemical monitoring of Lower Tuscaloosa Formation (LTF) brine continues at the Cranfield CO2-enhanced oil recovery (EOR) and sequestration site to investigate the potential for the geologic storage of large volumes of CO2 in saline aquifers and depleted reservoirs. Cranfield oil field is a domal depleted oil and gas reservoir in the Mississippi Interior Salt Basin, with production in heterogeneous fluvial sandstones of the LTF (depth ~3000 m). CO2 flood began in July 2008. Brine samples were collected from selected production wells in March and December 2009, April 2010, and November 2011. Intensive sampling also was conducted for the first 18 days of a CO2 injection experiment below the oil-water contact (December 2009) at the Detailed Area of Study (DAS) 3-well array. The sampling objectives are to define the geochemical composition of the pre-injection brine, and to understand the geochemical changes resulting from interactions between the injected CO2, brine, and reservoir minerals. Results show that Tuscaloosa brine is Na-Ca-Cl type with total salinity ranging from ~140 to 160 g/L TDS (50 samples). Relatively large variations are observed in major divalent cations (Ca ~7,500-14,000 mg/L, Mg ~800-1,250 mg/L, Sr ~475-750 mg/L). Significant positive correlations are noted amongst Ca, Mg, Sr, Ba, and Br, whereas these solutes all trend negatively with Na and Cl. These results may be interpreted as possible binary mixing between two end-member waters: (1) high Na-Cl (51 and 97 g/L, respectively), low Ca, Mg, Sr, and Br (~7500, 800, 475, 280 mg/L, respectively); and (2) low Na-Cl (40 and 86 g/L), high Ca, Mg, Sr, and Br (~14,000, 1250, 750, 480 mg/L). This apparent binary mixing has no obvious correlation to CO2 injection, which suggests that observed variations are due to natural heterogeneities in LTF brine within the Cranfield dome. The variations may indicate vertical and/or lateral proximity to a halite source (i.e. salt dome), with the high Na-Cl, low Br

  8. Potential function of added minerals as nucleation sites and effect of humic substances on mineral formation by the nitrate-reducing Fe(II)-oxidizer Acidovorax sp. BoFeN1.

    PubMed

    Dippon, Urs; Pantke, Claudia; Porsch, Katharina; Larese-Casanova, Phil; Kappler, Andreas

    2012-06-19

    The mobility of toxic metals and the transformation of organic pollutants in the environment are influenced and in many cases even controlled by iron minerals. Therefore knowing the factors influencing iron mineral formation and transformation by Fe(II)-oxidizing and Fe(III)-reducing bacteria is crucial for understanding the fate of contaminants and for the development of remediation technologies. In this study we followed mineral formation by the nitrate-reducing Fe(II)-oxidizing strain Acidovorax sp. BoFeN1 in the presence of the crystalline Fe(III) (oxyhydr)oxides goethite, magnetite and hematite added as potential nucleation sites. Mössbauer spectroscopy analysis of minerals precipitated by BoFeN1 in (57)Fe(II)-spiked microbial growth medium showed that goethite was formed in the absence of mineral additions as well as in the presence of goethite or hematite. The presence of magnetite minerals during Fe(II) oxidation induced the formation of magnetite in addition to goethite, while the addition of humic substances along with magnetite also led to goethite but no magnetite. This study showed that mineral formation not only depends on the aqueous geochemical conditions but can also be affected by the presence of mineral nucleation sites that initiate precipitation of the same underlying mineral phases.

  9. Instrumentation used for hydraulic testing of potential water-bearing formations at the Waste Isolation Pilot Plant site in southeastern New Mexico

    USGS Publications Warehouse

    Basler, J.A.

    1983-01-01

    Requirements for testing hydrologic test wells at the proposed Waste Isolation Pilot Plant near Carlsbad, New Mexico, necessitated the use of inflatable formation packers and pressure transducers. Observations during drilling and initial development indicated small formation yields which would require considerable test times by conventional open-casing methods. A pressure-monitoring system was assembled for performance evaluation utilizing commercially available components. Formation pressures were monitored with a down-hole strain-gage transducer. An inflatable packer equipped with a 1/4-inch-diameter steel tube extending through the inflation element permitted sensing formation pressures in isolated test zones. Surface components of the monitoring system provided AC transducer excitation, signal conditioning for recording directly in engineering units, and both analog and digital recording. Continuous surface monitoring of formation pressures provided a means of determining test status and projecting completion times during any phase of testing. Maximum portability was afforded by battery operation with all surface components mounted in a small self-contained trailer. (USGS)

  10. The Drosophila GAGA factor is required for dosage compensation in males and for the formation of the male-specific-lethal complex chromatin entry site at 12DE.

    PubMed Central

    Greenberg, Anthony J; Yanowitz, Judith L; Schedl, Paul

    2004-01-01

    Drosophila melanogaster males have one X chromosome, while females have two. To compensate for the resulting disparity in X-linked gene expression between the two sexes, most genes from the male X chromosome are hyperactivated by a special dosage compensation system. Dosage compensation is achieved by a complex of at least six proteins and two noncoding RNAs that specifically associate with the male X. A central question is how the X chromosome is recognized. According to a current model, complexes initially assemble at approximately 35 chromatin entry sites on the X and then spread bidirectionally along the chromosome where they occupy hundreds of sites. Here, we report that mutations in Trithorax-like (Trl) lead to the loss of a single chromatin entry site on the X, male lethality, and mislocalization of dosage compensation complexes. PMID:15020425

  11. Structural characterization of human vimentin rod 1 and the sequencing of assembly steps in intermediate filament formation in vitro using site-directed spin labeling and electron paramagnetic resonance.

    PubMed

    Hess, John F; Budamagunta, Madhu S; Voss, John C; FitzGerald, Paul G

    2004-10-22

    We have previously established the utility of site-directed spin labeling and electron paramagnetic resonance to determine structural relationships among proteins in intact intermediate filaments. Using this same approach we have introduced spin labels at 21 residues between amino acids 169 and 193 in rod domain 1 of human vimentin. The electron paramagnetic resonance spectra provide direct evidence for the coiled coil nature of the vimentin dimer in this region. This finding is consistent with predictions but has never been demonstrated previously. In a previous study we identified residue 348 in the rod domain 2 as one point of overlap between adjacent dimers in intact filaments. In the present study we defined residue 191 in the rod domain 1 as a second point of overlap and established that the dimers are arranged in an anti-parallel and staggered orientation at this site. Finally, by isolating spin-labeled samples at successive stages during the dialysis that lead to filament assembly in vitro, we have been able to establish a sequence of interactions that occurs during in vitro assembly, starting with the alpha helix and loose coiled coil dimer formation, then the formation of tetrameric species centered on residue 191, followed by interactions centered on residue 348 suggestive of octamer or higher order multimer formation. A continuation of this strategy revealed that both 191-191 and 348-348 interactions are present in low ionic strength Tris buffers when vimentin is maintained at the "protofilament" stage of assembly.

  12. Preliminary Safety Analysis of the Gorleben Site: Thermo-mechanical Analysis of the Integrity of the Geological Barrier in the Gorleben Salt Formation - 13307

    SciTech Connect

    Eickemeier, R.; Heusermann, S.; Nipp, H.K.; Knauth, M.; Minkley, W.; Popp, T.

    2013-07-01

    Exploration work at the Gorleben salt dome has been carried out since 1977 to investigate the site regarding its suitability as a final repository for high-level radioactive wastes. In the framework of the 'Preliminary Safety Analysis of the Gorleben Site' a comprehensive assessment is being performed with focus on long-term safety. Because the integrity of the geological barrier is crucial for protection from damage caused by ionising radiation during the post-operational phase, 2D and 3D thermo-mechanical calculations for a reference section through the salt dome were carried out, all looking at two different waste emplacement concepts: emplacement in drifts and in boreholes. The calculated stresses are the basis for evaluating the barrier integrity on the basis of the dilatancy criterion and the fluid pressure criterion. (authors)

  13. Spp1, a member of the Set1 Complex, promotes meiotic DSB formation in promoters by tethering histone H3K4 methylation sites to chromosome axes.

    PubMed

    Sommermeyer, Vérane; Béneut, Claire; Chaplais, Emmanuel; Serrentino, Maria Elisabetta; Borde, Valérie

    2013-01-10

    Meiotic chromosomes are organized into arrays of loops that are anchored to the chromosome axis structure. Programmed DNA double-strand breaks (DSBs) that initiate meiotic recombination, catalyzed by Spo11 and accessory DSB proteins, form in loop sequences in promoters, whereas the DSB proteins are located on chromosome axes. Mechanisms bridging these two chromosomal regions for DSB formation have remained elusive. Here we show that Spp1, a conserved member of the histone H3K4 methyltransferase Set1 complex, is required for normal levels of DSB formation and is associated with chromosome axes during meiosis, where it physically interacts with the Mer2 DSB protein. The PHD finger module of Spp1, which reads H3K4 methylation close to promoters, promotes DSB formation by tethering these regions to chromosome axes and activating cleavage by the DSB proteins. This paper provides the molecular mechanism linking DSB sequences to chromosome axes and explains why H3K4 methylation is important for meiotic recombination.

  14. Bcl-xL overexpression blocks bax-mediated mitochondrial contact site formation and apoptosis in rod photoreceptors of lead-exposed mice

    NASA Astrophysics Data System (ADS)

    He, Lihua; Perkins, Guy A.; Poblenz, Ann T.; Harris, Jeffrey B.; Hung, Michael; Ellisman, Mark H.; Fox, Donald A.

    2003-02-01

    Photoreceptor apoptosis and resultant visual deficits occur in humans and animals with inherited and disease-, injury-, and chemical-induced retinal degeneration. A clinically relevant mouse model of progressive rod photoreceptor-selective apoptosis was produced by low-level developmental lead exposure and studied in combination with transgenic mice overexpressing Bcl-xL only in the photoreceptors. A multiparametric analysis of rod apoptosis and mitochondrial structure-function was performed. Mitochondrial cristae topography and connectivity, matrix volume, and contact sites were examined by using 3D electron tomography. Lead-induced rod-selective apoptosis was accompanied by rod Ca2+ overload, rhodopsin loss, translocation of Bax from the cytosol to the mitochondria, decreased rod mitochondrial respiration and membrane potential, mitochondrial cytochrome c release, caspase-3 activation, and an increase in the number of mitochondrial contact sites. These effects occurred without mitochondrial matrix swelling, outer membrane rupture, caspase-8 activation, or Bid cleavage. Bcl-xL overexpression completely blocked all apoptotic events, except Ca2+ overload, and maintained normal rod mitochondrial function throughout adulthood. This study presents images of mitochondrial contact sites in an in vivo apoptosis model and shows that Bcl-xL overexpression blocks increased contact sites and apoptosis. These findings extend our in vitro retinal studies with Pb2+ and Ca2+ and suggest that developmental lead exposure produced rod-selective apoptosis without mitochondrial swelling by translocating cytosolic Bax to the mitochondria, which likely sensitized the Pb2+ and Ca2+ overloaded rod mitochondria to release cytochrome c. These results have relevance for therapies in a wide variety of progressive retinal and neuronal degenerations where Ca2+ overload, lead exposure, and/or mitochondrial dysfunction occur.

  15. Programming for SITE.

    ERIC Educational Resources Information Center

    Mody, Bella

    1979-01-01

    Describes the Satellite Instructional Television Experiment (SITE) project in India during 1975-76, including programing patterns, formats, and audiences. Demonstrates that countries like India have the technical and managerial capability to design, operate, and maintain advanced communication technology. (JMF)

  16. Water-Level Reconstruction and its Implications for Late Pleistocene Paleontological Site Formation in Hoyo Negro, a Submerged Subterranean Pit in Quintana Roo, Mexico

    NASA Astrophysics Data System (ADS)

    Rissolo, D.; Reinhardt, E. G.; Collins, S.; Kovacs, S. E.; Beddows, P. A.; Chatters, J. C.; Nava Blank, A.; Luna Erreguerena, P.

    2014-12-01

    A massive pit deep within the now submerged cave system of Sac Actun, located along the central east coast of the Yucatan Peninsula, contains a diverse fossil assemblage of extinct megafauna as well as a nearly complete human skeleton. The inundated site of Hoyo Negro presents a unique and promising opportunity for interdisciplinary Paleoamerican and paleoenvironmental research in the region. Investigations have thus far revealed a range of associated features and deposits which make possible a multi-proxy approach to identifying and reconstructing the natural and cultural processes that have formed and transformed the site over millennia. Understanding water-level fluctuations (both related to, and independent from, eustatic sea level changes), with respect to cave morphology is central to understanding the movement of humans and animals into and through the cave system. Recent and ongoing studies involve absolute dating of human, faunal, macrobotanical, and geological samples; taphonomic analyses; and a characterization of site hydrogeology and sedimentological facies, including microfossil assemblages and calcite raft deposits.

  17. Identification of critical amino acid residues of Saccharomyces cerevisiae carbamoyl-phosphate synthetase: definition of the ATP site involved in carboxy-phosphate formation.

    PubMed

    Zheng, W; Lim, A L; Powers-Lee, S G

    1997-08-15

    Carbamoyl-phosphate synthetases (CPSases) utilize two molecules of ATP at two homologous domains, B and C, with ATP(B) used to form the enzyme-bound intermediate carboxy-phosphate and ATP(C) used to phosphorylate the carbamate intermediate. To further define the role of one CPSase peptide suggested by affinity labeling studies to be near the ATP(B) site, we have carried out site-directed mutagenic analysis of peptide 234-242 of the Saccharomyces cerevisiae arginine-specific CPSase. Mutants E234A, E234D, E236A, E236D and E238A were unable to complement the CPSase-deficient yeast strain LPL26 whereas mutants Y237A, E238D, R241K, R241E and R241P supported LPL26 growth as well as wild-type CPSase. Kinetic analysis of E234A and Y237A indicated impaired utilization of ATP(B) but not of ATP(C). D242A, a temperature-sensitive mutant, retained no detectable activity when assayed in vitro. These findings, together with the affinity labeling data and primary sequence analysis, strongly suggest that the yeast CPSase peptide 234-242 is located at the ATP(B) site and that some of its residues are important for functioning of the enzyme. D242 appears to occupy a critical structural position and E234, E236 and E238 appear to be critical for function, with the spatial arrangement of the carboxyl side chain also critical for E234 and E236.

  18. Stratigraphic correlation of the Awahab and Tafelberg Formations, Etendeka Group, Namibia, and location of an eruptive site for flood basalt volcanism

    NASA Astrophysics Data System (ADS)

    Marsh, J. S.; Milner, S. C.

    2007-08-01

    Detailed field and geochemical investigations in the vicinity of the type section of the Tafelberg Formation of the early Cretaceous Etendeka Group, NW Namibia, have revealed the existence of a large eruptive vent in the lower part of the regional volcanic sequence produced by Strombolian and Vulcanian eruptions. The vent is filled with the thick, differentiated, ponded Kudu-Run olivine-rich basaltic flow, which has a distinctive low Zr/Y geochemical signature as well as a Tafelberg-type tabular basalt and the Nil Desperandum latite. Field evidence indicates that the Kudu-Run basalt and the latite were erupted from fissures located within the vent. Associated with the vent is an extensive pyroclastic apron extending from the vent edge and which is interbedded with the regional stratigraphy. Blocks of Precambrain basement lithologies occur within this deposit and indicate that the vent was excavated to a depth of at least 350 m below the palaeosurface at that time. The original Tafelberg Formation type section described by Erlank et al. [Erlank, A.J., Marsh, J.S., Duncan, A.R., Miller, R.McG., Hawkesworth, C.H., Betton, P.J., Rex, D.C. 1984. Geochemistry and petrogenesis of the Etendeka volcanic rocks from SWA/Namibia, 195-247. In: Erlank, A.J. (Ed.), Petrogenesis of Volcanic Rocks of the Karoo province. Special Publication of the Geological Society of South Africa, vol. 13, 395 p.] the Tafelberg Gully section, crosses from the lower part of the regional sequence into the intra-vent sequence and returns to the regional sequence higher up. In doing so it includes some of the localized intra-vent flows and excludes a number of flows which are part of the regional sequence in its lower part, thus rendering it inappropriate as a type section. A revised type section for the Tafelberg Formation is described by combining the upper part of the Tafelberg Gully section with a new section of 14 flows at the base of the regional sequence in the Tafelberg North (TBN) section

  19. Contributions of Selected Biogenic and Aromatic Compounds to the Formation of Tropospheric Secondary Organic Aerosol over Several Sites in the United States

    NASA Astrophysics Data System (ADS)

    Jaoui, M.; Kleindienst, T. E.; Lewandowski, M.; Offenberg, J. H.; Corse, E. W.; Gerald, T.; Edney, E.

    2009-12-01

    The National Exposure Research Laboratory of the U.S. Environmental Protection Agency recently undertook an integrated laboratory and field research effort to better understand the contribution of biogenic and aromatic hydrocarbons to the formation of submicron ambient secondary organic aerosol (SOA). In the laboratory, isoprene, α-pinene, β-caryophyllene, 1,3-butadiene, 2-methyl-3-buten-2-ol, benzene, and toluene were individually irradiated under a wide range of conditions in a photochemical reaction chamber in the presence of nitrogen oxide (NOx). These hydrocarbons are thought to contribute to ambient SOA formation. In field studies conducted in Research Triangle Park, NC; Duke Forest in Chapel Hill, NC; Atlanta, GA; Pensacola, FL; Birmingham and Centerville, AL; Riverside, CA; Detroit, MI; Northbrook, East St. Louis and Bondville, IL; and Cincinnati, OH, ambient PM2.5 samples were collected for various periods between 2003 and 2006. The SOA collected from these laboratory experiments and the ambient PM2.5 samples were analyzed for organic carbon (OC) concentration and for organic tracer compounds by GC-MS using BSTFA derivatization for their identification and quantification. An organic tracer-based method was developed for estimating ambient SOA concentrations from individual SOA precursors to allow an assessment of SOA model predictions with ambient data. The results show that several major reaction products detected in SOA formed in the laboratory photooxidations were among the major compounds detected in field samples, effectively connecting laboratory and field results. Using the tracer-based method, the contributions of isoprene and monoterpenes to SOA formation show strong seasonal dependencies. However, no clear seasonal variations were observed for sesquiterpenes and aromatic hydrocarbons. The contribution of 2-methyl-3-buten-2-ol to ambient SOA was found to be not only season dependent but also higher in locations dominated by conifers, which are

  20. Phototriggered formation and repair of DNA containing a site-specific single strand break of the type produced by ionizing radiation or AP lyase activity.

    PubMed

    Zhang, K; Taylor, J S

    2001-01-09

    DNA strand breaks are produced by a variety of agents and processes such as ionizing radiation, xenobiotics, oxidative metabolism, and enzymatic processing of DNA base damage. One of the major types of strand breaks produced by these processes is a single nucleotide gap terminating in 5'- and 3'-phosphates. Previously, we had developed a method for sequence-specifically producing such phosphate-terminated strand breaks in an oligodeoxynucleotide by way of two photochemically activated (caged) building blocks placed in tandem. We now report the design and synthesis of a single caged building block consisting of 1,3-(2-nitrophenyl)-1,3-propanediol, for producing phosphate-terminated strand breaks, and its use producing such a break at a specific site in a double-stranded circular DNA vector. To produce the site-specific break in a duplex vector, a primer containing the caged single strand break was extended opposite the single strand form of a circular DNA vector followed by enzymatic ligation and purification. The single strand break could then be formed in quantitative yield by irradiation of the vector with 365 nm light. In contrast to a previous study, it was found that the strand break can be repaired by Escherichia coli DNA polymerase I and E. coli DNA ligase alone, though less efficiently than in the presence of the 3'-phosphate processing enzyme E. coli endonuclease IV. Repair in the absence of endonuclease IV could be attributed to hydrolysis of the 3'-phosphate in the presence of dNTP and to a lesser extent to exonucleolytic removal of the 3'-phosphate-bearing terminal nucleotide by way of the 3' --> 5' exonuclease activity of polymerase I. This work demonstrates that specialized 3'-end processing enzymes such as endonuclease IV or exonuclease III are not absolutely required for repair of phosphate-terminated gaps. In addition to preparing single strand breaks, the caged building block described should also be useful for preparing double strand breaks and

  1. Mauna Loa lava accumulation rates at the Hilo drill site: Formation of lava deltas during a period of declining overall volcanic growth

    USGS Publications Warehouse

    Lipman, P.W.; Moore, J.G.

    1996-01-01

    Accumulation rates for lava flows erupted from Mauna Loa, as sampled in the uppermost 280 m of the Hilo drill hole, vary widely for short time intervals (several thousand years), but overall are broadly similar to those documented elsewhere on this volcano since 100 ka. Thickness variations and accumulation rates for Mauna Loa lavas at the Hilo drill site have been strongly affected by local paleotopography, including funneling and ponding between Mauna Kea and Kilauea. In addition, gentle submerged slopes of Mauna Kea in Hilo Bay have permitted large shoreline displacements by Mauna Loa flows. Ages of eruptive intervals have been determined from published isotopic data and from eustatic sea level curves modified to include the isostatic subsidence of the island of Hawaii at 2.2-2.6 mm/yr. Prior to 10 ka, rates of Mauna Loa lava accumulation at the drill site varied from 0.6 to 4.3 mm/yr for dateable intervals, with an overall rate of 1.8 mm/yr. Major eruptive pulses at about 1.3 and 10 ka, each probably representing a single long-lived eruption based on lack of weathering between flow units, increase the overall accumulation rate to 2.4 mm/yr. The higher rate since 10 ka reflects construction of thick near-shoreline lava deltas as postglacial sea levels rose rapidly. Large lava deltas form only along coastal segments where initially subaerial slopes have been submerged by the combined effects of eustatic sea level rise, isostatic subsidence, or spreading of volcano flanks. Overall accumulation of 239 m of lava at the drill site since 100-120 ka closely balances submergence of the Hilo area, suggesting that processes of coastal lava deposition have been modulated by rise in sea level. The Hilo accumulation rate is slightly higher than average rates of 1-2 mm/yr determined elsewhere along the Mauna Loa coast, based on rates of shoreline coverage and dated sea cliff and fault scarp exposures. Low rates of coastal lava accumulation since 100 ka, near or below the rate

  2. Formation of HArF in solid Ar revisited: are mobile vacancies involved in the matrix-site conversion at 30 K?

    PubMed

    Khriachtchev, Leonid; Lignell, Antti; Rasanen, Markku

    2004-02-15

    The HArF molecule can occupy in solid Ar thermally unstable and stable configurations, and their microscopic structure is not understood at the moment. We present additional experimental results on the formation of two HArF configurations and analyze them with emphasis on possible reactions of the unstable configuration with matrix vacancies to form the stable configuration. We conclude that the existing computational scenarios do not describe fully the present experimental data. In order to explain qualitatively the experimental results, two tentative models are discussed. The first model is based on local mobility of matrix vacancies produced during photolysis and the second model considers isomerization of the HArF at Arn supermolecule. More importantly, the present results constitute the experimental basis for future theoretical studies.

  3. The structural basis for substrate anchoring, active site selectivity, and product formation by P450 PikC from Streptomyces venezuelae.

    PubMed

    Sherman, David H; Li, Shengying; Yermalitskaya, Liudmila V; Kim, Youngchang; Smith, Jarrod A; Waterman, Michael R; Podust, Larissa M

    2006-09-08

    The pikromycin (Pik)/methymycin biosynthetic pathway of Streptomyces venezuelae represents a valuable system for dissecting the fundamental mechanisms of modular polyketide biosynthesis, aminodeoxysugar assembly, glycosyltransfer, and hydroxylation leading to the production of a series of macrolide antibiotics, including the natural ketolides narbomycin and pikromycin. In this study, we describe four x-ray crystal structures and allied functional studies for PikC, the remarkable P450 monooxygenase responsible for production of a number of related macrolide products from the Pik pathway. The results provide important new insights into the structural basis for the C10/C12 and C12/C14 hydroxylation patterns for the 12-(YC-17) and 14-membered ring (narbomycin) macrolides, respectively. This includes two different ligand-free structures in an asymmetric unit (resolution 2.1 A) and two co-crystal structures with bound endogenous substrates YC-17 (resolution 2.35 A)or narbomycin (resolution 1.7 A). A central feature of the enzyme-substrate interaction involves anchoring of the desosamine residue in two alternative binding pockets based on a series of distinct amino acid residues that form a salt bridge and a hydrogen-bonding network with the deoxysugar C3' dimethylamino group. Functional significance of the salt bridge was corroborated by site-directed mutagenesis that revealed a key role for Glu-94 in YC-17 binding and Glu-85 for narbomycin binding. Taken together, the x-ray structure analysis, site-directed mutagenesis, and corresponding product distribution studies reveal that PikC substrate tolerance and product diversity result from a combination of alternative anchoring modes rather than an induced fit mechanism.

  4. Habitat change by the formation of alien Crassostrea-reefs in the Wadden Sea and its role as feeding sites for waterbirds

    NASA Astrophysics Data System (ADS)

    Markert, Alexandra; Esser, Wiebke; Frank, Dietrich; Wehrmann, Achim; Exo, Klaus-Michael

    2013-10-01

    Non-indigenous Pacific oysters (Crassostrea gigas) have been invading the central Wadden Sea since 1998, predominantly settling on intertidal blue mussel (Mytilus edulis) beds which are increasingly transformed into Crassostrea-reefs. Pacific oysters are strong ecosystem engineers and the habitat change is considered to be a threat for waterbirds losing important feeding sites in the intertidal of the Wadden Sea. This study has increased our understanding of the use of foraging habitats by birds according to changing food resources. During the spring and autumn migration period in 2007, we recorded bird densities at two reef types varying in Pacific oyster density and at the adjacent sand flat as a reference site. We also recorded feeding behaviour, choice of prey and assessed peck and intake rate of three target species: Eurasian oystercatcher Haematopus ostralegus, Eurasian curlew Numenius arquata and European herring gull Larus argentatus. To evaluate the use of the Crassostrea-reef in the central Wadden Sea, we compared bird densities of the target species at different intertidal feeding habitats in various regions and compared the biomass intake of Eurasian oystercatcher feeding on different prey species. We show that Eurasian oystercatcher and Eurasian curlew have adapted to the new situation and learned to exploit the food supply offered by Crassostrea-reefs. While foraging mainly on Pacific oysters, Eurasian oystercatchers attained sustainable intake rates even though food resource at dense reef during autumn was very poor due to a lack in harvestable oysters. Consolidation of reefs limits the accessibility of prey for Eurasian oystercatchers whereas a successful recruitment of Pacific oysters enhances the suitability of the habitat. Eurasian curlew was promoted by the engineering effects of the Pacific oyster while feeding extensively on shore crabs at the reefs. In contrast, European herring gulls appear hampered in foraging during low tide and hereby

  5. Part I. Cobalt thiolate complexes modeling the active site of cobalt nitrile hydratase. Part II. Formation of inorganic nanoparticles on protein scaffolding in Escherichia coli glutamine synthetase

    NASA Astrophysics Data System (ADS)

    Kung, Irene Yuk Man

    Part I. A series of novel cobalt dithiolate complexes with mixed imine/amine ligand systems is presented here as electronic and structural models for the active site in the bacterial enzyme class, nitrile hydratase (NHase). Pentadentate cobalt(II) complexes with S2N 3 ligand environments are first studied as precursors to the more relevant cobalt(III) complexes. Adjustment of the backbone length by removal of a methylene group increases the reactivity of the system; whereas reduction of the two backbone imine bonds to allow free rotation about those bonds may decrease reactivity. Reactivity change due to the replacement of the backbone amine proton with a more sterically challenging methyl group is not yet clear. Upon oxidation, the monocationic pentadentate cobalt(III) complex, 1b, shows promising reactivity similar to that of NHase. The metal's open coordination site allows reversible binding of the endogenous, monoanionic ligands, N 3- and NCS-. Oxygenation of the thiolate sulfur atoms by exposure to O2 and H2O 2 produces sulfenate and sulfinate ligands in complex 8, which resembles the crystal structure of "deactivated" Fe NHase. However, its lack of reactivity argues against the oxygenated enzyme structure as the active form. Six-coordinate cobalt(III) complexes with S2N4 amine/amine ligand systems are also presented as analogues of previously reported iron(III) compounds, which mimic the spectroscopic properties of Fe NHase. The cobalt complexes do not seem to similarly model Co NHase. However, the S = 0 cobalt(III) center can be spectroscopically silent and difficult to detect, making comparison with synthetic models using common techniques hard. Part II. Dodecameric Escherichia coli glutamine synthetase mutant, E165C, stacks along its six-fold axis to produce tubular nanostructures in the presence of some divalent metal ions, as does the wild type enzyme. The centrally located, engineered Cys-165 residues appear to bind to various species and may serve as

  6. Effects of CO2 on mechanical variability and constitutive behavior of the Lower Tuscaloosa formation, Cranfield Injection Site, USA

    SciTech Connect

    Rinehart, Alex J.; Dewers, Thomas A.; Broome, Scott T.; Eichhubl, Peter

    2016-08-25

    We characterize geomechanical constitutive behavior of reservoir sandstones at conditions simulating the “Cranfield” Southeast Regional Carbon Sequestration Partnership injection program. From two cores of Lower Tuscaloosa Formation, three sandstone lithofacies were identified for mechanical testing based on permeability and lithology. These include: chlorite-cemented conglomeratic sandstone (Facies A); quartz-cemented fine sandstone (Facies B); and quartz- and calcite-cemented very fine sandstone (Facies C). We performed a suite of compression tests for each lithofacies at 100 °C and pore pressure of 30 MPa, including hydrostatic compression and triaxial tests at several confining pressures. Plugs were saturated with supercritical CO2-saturated brine. Chemical environment affected the mechanical response of all three lithofacies, which experience initial plastic yielding at stresses far below estimated in situ stress. Measured elastic moduli degradation defines a secondary yield surface coinciding with in situ stress for Facies B and C. Facies A shows measurable volumetric creep strain and a failure envelope below estimates of in situ stress, linked to damage of chlorite cements by acidic pore solutions. Furthermore, the substantial weakening of a particular lithofacies by CO2 demonstrates a possible chemical-mechanical coupling during injection at Cranfield with implications for CO2 injection, reservoir permeability stimulation, and enhanced oil recovery.

  7. Chain Walking as a Strategy for Carbon-Carbon Bond Formation at Unreactive Sites in Organic Synthesis: Catalytic Cycloisomerization of Various 1,n-Dienes.

    PubMed

    Hamasaki, Taro; Aoyama, Yuka; Kawasaki, Junichi; Kakiuchi, Fumitoshi; Kochi, Takuya

    2015-12-30

    Carbon-carbon bond formation at unreactive sp(3)-carbons in small organic molecules via chain walking was achieved for the palladium-catalyzed cycloisomerization of 1,n-dienes. Various 1,n-dienes (n = 7-14) such as those containing cyclic alkenes, acyclic internal alkenes, and a trisubstituted alkene can be used for the chain-walking cycloisomerization/hydrogenation process, and five-membered ring compounds including simple cyclopentane and pyrrolidine derivatives can easily be prepared. Chain walking over a tertiary carbon was also found to be possible in the cycloisomerization. It is not necessary for the linker portion of the diene to contain a quaternary center, and diene substrates with two alkene moieties linked by a tertiary carbon or a nitrogen atom can also be used as substrates. Column chromatography using silica gel containing silver nitrate was found to be effective for isolating some of the cycloisomerization products without hydrogenation. Deuterium-labeling experiments provided direct evidence to show that the reaction proceeds via a chain-walking mechanism.

  8. Essential Role of the C-Terminal Helical Domain in Active Site Formation of Selenoprotein MsrA from Clostridium oremlandii

    PubMed Central

    Lee, Eun Hye; Lee, Kitaik; Hwang, Kwang Yeon; Kim, Hwa-Young

    2015-01-01

    We previously determined the crystal structures of 1-Cys type selenoprotein MsrA from Clostridium oremlandii (CoMsrA). The overall structure of CoMsrA is unusual, consisting of two domains, the N-terminal catalytic domain and the C-terminal distinct helical domain which is absent from other known MsrA structures. Deletion of the helical domain almost completely abolishes the catalytic activity of CoMsrA. In this study, we determined the crystal structure of the helical domain-deleted (ΔH-domain) form of CoMsrA at a resolution of 1.76 Å. The monomer structure is composed of the central rolled mixed β-sheet surrounded by α-helices. However, there are significant conformational changes in the N- and C-termini and loop regions of the ΔH-domain protein relative to the catalytic domain structure of full-length CoMsrA. The active site structure in the ΔH-domain protein completely collapses, thereby causing loss of catalytic activity of the protein. Interestingly, dimer structures are observed in the crystal formed by N-terminus swapping between two molecules. The ΔH-domain protein primarily exists as a dimer in solution, whereas the full-length CoMsrA exists as a monomer. Collectively, this study provides insight into the structural basis of the essential role of the helical domain of CoMsrA in its catalysis. PMID:25692691

  9. Analysis of Site Formation and Assemblage Integrity Does Not Support Attribution of the Uluzzian to Modern Humans at Grotta del Cavallo

    PubMed Central

    Zilhão, João; Banks, William E.; d’Errico, Francesco; Gioia, Patrizia

    2015-01-01

    Based on the morphology of two deciduous molars and radiocarbon ages from layers D and E of the Grotta del Cavallo (Lecce, Italy), assigned to the Uluzzian, it has been proposed that modern humans were the makers of this Early Upper Paleolithic culture and that this finding considerably weakens the case for an independent emergence of symbolism among western European Neandertals. Reappraisal of the new dating evidence, of the finds curated in the Taranto Antiquities depot, and of coeval publications detailing the site’s 1963–66 excavations shows that (a) Protoaurignacian, Aurignacian and Early Epigravettian lithics exist in the assemblages from layers D and E, (b) even though it contains both inherited and intrusive items, the formation of layer D began during Protoaurignacian times, and (c) the composition of the extant Cavallo assemblages is influenced in a non-negligible manner by the post-hoc assignment of items to stratigraphic units distinct from that of original discovery. In addition, a major disturbance feature affected the 1960s excavation trench down to Mousterian layer F, this feature went unrecognized until 1964, the human remains assigned to the Uluzzian were discovered that year and/or the previous year, and there are contradictions between field reports and the primary anthropological description of the remains as to their morphology and level of provenience. Given these major contextual uncertainties, the Cavallo teeth cannot be used to establish the authorship of the Uluzzian. Since this technocomplex’s start date is ca. 45,000 calendar years ago, a number of Neandertal fossils are dated to this period, and the oldest diagnostic European modern human fossil is the <41,400 year-old Oase 1 mandible, Neandertal authorship of the Uluzzian remains the parsimonious reading of the evidence. PMID:26154139

  10. Origin of the local structures at the Philae landing site and possible implications on the formation and evolution of 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Poulet, F.; Lucchetti, A.; Bibring, J.-P.; Carter, J.; Gondet, B.; Jorda, L.; Langevin, Y.; Pilorget, C.; Capanna, C.; Cremonese, G.

    2016-11-01

    In situ images of the 67P/Churyumov-Gerasimenko nucleus acquired by the CIVA cameras on-board PHILAE revealed a rough landscape dominated by consolidated materials. These data provide a unique view to constrain the past and present conditions prevailing at the surface of the comet. A quantitative analysis of microscopic structures (fractures and pebbles) is derived using a manual extraction from the images. Fractures/cracks are rather ubiquitous at various spatial scales with network and size (from sub-cm to 10 cm) well correlated to the texture of the landscape. The pebble size distributions are derived and compared to the size distribution of other cometary materials. The nature of the landscape is then discussed in relation to endogenic and exogenic processes of surface modification. The block seen in CIVA no. 1 is interpreted to be close-ups of fractured boulder/cliff belonging to the boulder field identified from the orbit near Abydos, this boulder field being itself the result of gravitational regressive erosion due to sublimation. The observed fractures are best explained by thermal insolation leading to thermal fatigue and/or to loss of volatile materials. This surficial fragmentation (up to >10 cm length) could generate macroscopic erosion that is also visible at larger scale from the orbit. There is at least an intriguing possibility that the pebbles are remnants of primordial accretion processes. We thus speculate that the Abydos landscape could be in favour of pebble accretion model instead of runaway coagulation model with a formation location in the outer region of the Solar system.

  11. Evidence for habitual use of fire at the end of the Lower Paleolithic: site-formation processes at Qesem Cave, Israel.

    PubMed

    Karkanas, Panagiotis; Shahack-Gross, Ruth; Ayalon, Avner; Bar-Matthews, Mira; Barkai, Ran; Frumkin, Amos; Gopher, Avi; Stiner, Mary C

    2007-08-01

    The Amudian (late Lower Paleolithic) site of Qesem Cave in Israel represents one of the earliest examples of habitual use of fire by middle Pleistocene hominids. The Paleolithic layers in this cave were studied using a suite of mineralogical and chemical techniques and a contextual sedimentological analysis (i.e., micromorphology). We show that the lower ca. 3m of the stratigraphic sequence are dominated by clastic sediments deposited within a closed karstic environment. The deposits were formed by small-scale, concentrated mud slurries (infiltrated terra rosa soil) and debris flows. A few intervening lenses of mostly in situ burnt remains were also identified. The main part of the upper ca. 4.5 m consists of anthropogenic sediment with only moderate amounts of clastic geogenic inputs. The deposits are strongly cemented with calcite that precipitated from dripping water. The anthropogenic component is characterized by completely combusted, mostly reworked wood ash with only rare remnants of charred material. Micromorphological and isotopic evidence indicates recrystallization of the wood ash. Large quantities of burnt bone, defined by a combination of microscopic and macroscopic criteria, and moderately heated soil lumps are closely associated with the wood-ash remains. The frequent presence of microscopic calcified rootlets indicates that the upper sequence formed in the vicinity of the former cave entrance. Burnt remains in the sediments are associated with systematic blade production and faunas that are dominated by the remains of fallow deer. Use-wear damage on blades and blade tools in conjunction with numerous cut marks on bones indicate an emphasis on butchering and prey-defleshing activities in the vicinity of fireplaces.

  12. Transport, biomass burning, and in-situ formation contribute to fine particle concentrations at a remote site near Grand Teton National Park

    NASA Astrophysics Data System (ADS)

    Schurman, M. I.; Lee, T.; Desyaterik, Y.; Schichtel, B. A.; Kreidenweis, S. M.; Collett, J. L.

    2015-07-01

    Ecosystem health and visibility degradation due to fine-mode atmospheric particles have been documented in remote areas and motivate particle characterization that can inform mitigation strategies. This study explores submicron (PM1) particle size, composition, and source apportionment at Grand Teton National Park using High-Resolution Time-of-Flight Aerosol Mass Spectrometer data with Positive Matrix Factorization and MODIS fire information. Particulate mass averages 2.08 μg/m3 (max = 21.91 μg/m3) of which 75.0% is organic; PMF-derived Low-Volatility Oxygenated Organic Aerosol (LV-OOA) averages 61.1% of PM1 (or 1.05 μg/m3), with sporadic but higher-concentration biomass burning (BBOA) events contributing another 13.9%. Sulfate (12.5%), ammonium (8.7%), and nitrate (3.8%) are generally low in mass. Ammonium and sulfate have correlated time-series and association with transport from northern Utah and the Snake River Valley. A regionally disperse and/or in situ photochemical LV-OOA source is suggested by 1) afternoon concentration enhancement not correlated with upslope winds, anthropogenic NOx, or ammonium sulfate, 2) smaller particle size, higher polydispersity, and lower levels of oxidation during the day and in comparison to a biomass burning plume inferred to have traveled ∼480 km, and 3) lower degree of oxidation than is usually observed in transported urban plumes and alpine sites with transported anthropogenic OA. CHN fragment spectra suggest organic nitrogen in the form of nitriles and/or pyridines during the day, with the addition of amine fragments at night. Fires near Boise, ID may be the source of a high-concentration biomass-burning event on August 15-16, 2011 associated with SW winds (upslope from the Snake River Valley) and increased sulfate, ammonium, nitrate, and CHN and CHON fragments (nominally, amines and organonitrates). Comparison to limited historical data suggests that the amounts and sources of organics and inorganics presented here

  13. Geomechanical characterization of an Upper Triassic reservoir rock (Stuttgart Formation) in the NE German Basin (pilot site for CO2 storage at Ketzin, Germany)

    NASA Astrophysics Data System (ADS)

    Klapperer, S.; Moeck, I.; Backers, T.

    2012-04-01

    behavior of rock are the angle of internal friction ψ and cohesion c, representing aspects determining failure occurrence that can be expressed and illustrated by the Mohr Coulomb failure criterion. As for the UCS there is also a wide range of values for ψ (4.06° to 36.98°) and c (10.45 MPa to 49.41 MPa) which differ distinctly within similar lithologies. With respect to these differences further geomechanical tests in combination with petrographic investigations will be in focus to evaluate the impact of lithologal as well as lithofacial characteristics on geomechanical properties. Thus the lithological and lithofacial heterogeneous characteristics of the Stuttgart formation could influence significantly the geomechanical behavior and transmission of stresses resulting from CO2 injection. Therefrom knowledge about these rock mechanical properties helps to provide a save and long term injection and prevent leakage scenarios.

  14. Assessing the impact of anthropogenic pollution on isoprene-derived secondary organic aerosol formation in PM2.5 collected from the Birmingham, Alabama, ground site during the 2013 Southern Oxidant and Aerosol Study

    NASA Astrophysics Data System (ADS)

    Rattanavaraha, Weruka; Chu, Kevin; Hapsari Budisulistiorini, Sri; Riva, Matthieu; Lin, Ying-Hsuan; Edgerton, Eric S.; Baumann, Karsten; Shaw, Stephanie L.; Guo, Hongyu; King, Laura; Weber, Rodney J.; Neff, Miranda E.; Stone, Elizabeth A.; Offenberg, John H.; Zhang, Zhenfa; Gold, Avram; Surratt, Jason D.

    2016-04-01

    In the southeastern US, substantial emissions of isoprene from deciduous trees undergo atmospheric oxidation to form secondary organic aerosol (SOA) that contributes to fine particulate matter (PM2.5). Laboratory studies have revealed that anthropogenic pollutants, such as sulfur dioxide (SO2), oxides of nitrogen (NOx), and aerosol acidity, can enhance SOA formation from the hydroxyl radical (OH)-initiated oxidation of isoprene; however, the mechanisms by which specific pollutants enhance isoprene SOA in ambient PM2.5 remain unclear. As one aspect of an investigation to examine how anthropogenic pollutants influence isoprene-derived SOA formation, high-volume PM2.5 filter samples were collected at the Birmingham, Alabama (BHM), ground site during the 2013 Southern Oxidant and Aerosol Study (SOAS). Sample extracts were analyzed by gas chromatography-electron ionization-mass spectrometry (GC/EI-MS) with prior trimethylsilylation and ultra performance liquid chromatography coupled to electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-QTOFMS) to identify known isoprene SOA tracers. Tracers quantified using both surrogate and authentic standards were compared with collocated gas- and particle-phase data as well as meteorological data provided by the Southeastern Aerosol Research and Characterization (SEARCH) network to assess the impact of anthropogenic pollution on isoprene-derived SOA formation. Results of this study reveal that isoprene-derived SOA tracers contribute a substantial mass fraction of organic matter (OM) ( ˜ 7 to ˜ 20 %). Isoprene-derived SOA tracers correlated with sulfate (SO42-) (r2 = 0.34, n = 117) but not with NOx. Moderate correlations between methacrylic acid epoxide and hydroxymethyl-methyl-α-lactone (together abbreviated MAE/HMML)-derived SOA tracers with nitrate radical production (P[NO3]) (r2 = 0.57, n = 40) were observed during nighttime, suggesting a potential role of the NO3 radical in

  15. Low-temperature formation and stabilization of rare allotropes of cyclooctasulfur (β-S8 and γ-S8) in the presence of organic carbon at a sulfur-rich glacial site in the Canadian High Arctic

    NASA Astrophysics Data System (ADS)

    Lau, Graham E.; Cosmidis, Julie; Grasby, Stephen E.; Trivedi, Christopher B.; Spear, John R.; Templeton, Alexis S.

    2017-03-01

    Large-scale deposits of elemental sulfur form annually on a glacier's surface at Borup Fiord Pass in the Canadian High Arctic. However, the mechanisms of mineralization and stabilization of elemental sulfur at this site are currently unknown. Here we show that X-ray diffraction (XRD) data for fresh sulfur precipitates collected from the surface of a melt pool over sulfide-rich ice reveal the presence of three sulfur allotropes, α-S8, β-S8, and γ-S8 (the three solid forms of cyclooctasulfur (S8)). The detection of the β-S8 allotrope of elemental sulfur is notable, since β-S8 typically only forms in high temperature environments (>96 °C). The γ-S8 allotrope is also rare in natural settings and has previously been implicated as a signature of microbial sulfur cycling. Using combustion and infrared spectroscopy approaches, organic carbon is also detected within the sample bearing the three allotropes of elemental sulfur. Electron microscopy and scanning transmission X-ray microscopy (STXM) at the C K-edge show that the sulfur precipitates are intimately associated with the organic carbon at the submicron scale. The occurrence of β-S8 and γ-S8 in this low-temperature setting indicates that there are unknown pathways for the formation and stabilization of these rare allotropes of elemental sulfur. In particular, we infer that the occurrence of these allotropes is related to their association with organic carbon. The formation of carbon-associated sulfur globules may not be a direct by-product of microbial activity; however, a potential role of direct or indirect microbial mediation in the formation and stabilization of β-S8 and γ-S8 remains to be assessed.

  16. Single site mutations in the hetero-oligomeric Mrp antiporter from alkaliphilic Bacillus pseudofirmus OF4 that affect Na+/H+ antiport activity, sodium exclusion, individual Mrp protein levels, or Mrp complex formation.

    PubMed

    Morino, Masato; Natsui, Shinsuke; Ono, Tomohiro; Swartz, Talia H; Krulwich, Terry A; Ito, Masahiro

    2010-10-01

    Mrp systems are widely distributed and structurally complex cation/proton antiporters. Antiport activity requires hetero-oligomeric complexes of all six or seven hydrophobic Mrp proteins (MrpA-MrpG). Here, a panel of site-directed mutants in conserved or proposed motif residues was made in the Mrp Na(+)(Li(+))/H(+) antiporter from an alkaliphilic Bacillus. The mutant operons were expressed in antiporter-deficient Escherichia coli KNabc and assessed for antiport properties, support of sodium resistance, membrane levels of each Mrp protein, and presence of monomeric and dimeric Mrp complexes. Antiport did not depend on a VFF motif or a conserved tyrosine pair, but a role for a conserved histidine in a potential quinone binding site of MrpA was supported. The importance of several acidic residues for antiport was confirmed, and the importance of additional residues was demonstrated (e.g. three lysine residues conserved across MrpA, MrpD, and membrane-bound respiratory Complex I subunits (NuoL/M/N)). The results extended indications that MrpE is required for normal membrane levels of other Mrp proteins and for complex formation. Moreover, mutations in several other Mrp proteins lead to greatly reduced membrane levels of MrpE. Thus, changes in either of the two Mrp modules, MrpA-MrpD and MrpE-MrpG, influence the other. Two mutants, MrpB-P37G and MrpC-Q70A, showed a normal phenotype but lacked the MrpA-MrpG monomeric complex while retaining the dimeric hetero-oligomeric complex. Finally, MrpG-P81A and MrpG-P81G mutants exhibited no antiport activity but supported sodium resistance and a low [Na(+)](in). Such mutants could be used to screen hypothesized but uncharacterized sodium efflux functions of Mrp apart from Na(+) (Li(+))/H(+) antiport.

  17. On the Formation and Properties of Interstrand DNA-DNA Cross-links Forged by Reaction of an Abasic Site With the Opposing Guanine Residue of 5′-CAp Sequences in Duplex DNA

    PubMed Central

    Johnson, Kevin M.; Price, Nathan E.; Wang, Jin; Fekry, Mostafa I.; Dutta, Sanjay; Seiner, Derrick R.; Wang, Yinsheng; Gates, Kent S.

    2014-01-01

    We recently reported that the aldehyde residue of an abasic (Ap) site in duplex DNA can generate an interstrand cross-link via reaction with a guanine residue on the opposing strand. This finding is intriguing because the highly deleterious nature of interstrand cross-links suggests that even small amounts of Ap-derived cross-links could make a significant contribution to the biological consequences stemming from the generation of Ap sites in cellular DNA. Incubation of 21-bp duplexes containing a central 5′-CAp sequence under conditions of reductive amination (NaCNBH3, pH 5.2) generated much higher yields of cross-linked DNA than reported previously. At pH 7, in the absence of reducing agents, these Ap-containing duplexes also produced cross-linked duplexes that were readily detected on denaturing polyacrylamide gels. Cross-link formation was not highly sensitive to reaction conditions and, once formed, the cross-link was stable to a variety of work-up conditions. Results of multiple experiments including MALDI-TOF mass spectrometry, gel mobility, methoxyamine capping of the Ap aldehyde, inosine-for-guanine replacement, hydroxyl radical footprinting, and LCMS/MS were consistent with a cross-linking mechanism involving reversible reaction of the Ap aldehyde residue with the N2-amino group of the opposing guanine residue in 5′-CAp sequences to generate hemiaminal, imine, or cyclic hemiaminal cross-links (7-10) that were irreversibly converted under conditions of reductive amination (NaCNBH3/pH 5.2) to a stable amine linkage. Further support for the importance of the exocyclic N2-amino group in this reaction was provided by an experiment showing that installation of a 2-aminopurine-thymine base pair at the cross-linking site produced high yields (15-30%) of a cross-linked duplex at neutral pH, in the absence of NaCNBH3. PMID:23215239

  18. Mutagenesis by peroxy radical is dominated by transversions at deoxyguanosine: evidence for the lack of involvement of 8-oxo-dG1 and/or abasic site formation.

    PubMed

    Valentine, M R; Rodriguez, H; Termini, J

    1998-05-12

    Oxidative damage of DNA by endogenously generated oxygen radicals contributes to the mutagenic process. Hydroxy, alkoxy, and peroxy radicals all have the potential to react with DNA, giving rise to strand breaks and potentially mutagenic oxidative base damage. Although reactions of the hydroxy radical with DNA have been well studied, far less is known about the reactivities of these other radicals with DNA and their mutation-inducing potential. Frequencies of DNA base modifications and strand break densities caused by peroxy radical (ROO*) oxidation were measured by glyoxal gel electrophoretic analysis. We report the spectrum of mutations induced in Escherichia coli upon transfection with peroxy radical treated DNA carrying the lacZ alpha gene as a reporter. Transfection of DNA exposed to micromolar amounts of peroxy radical resulted in a 30-fold increase in mutation frequency in non-SOS-inducible cells. Sequencing analysis of DNA isolated from mutants showed that among base substitution mutants 88% consisted of transversions at G, with a nearly equal number of G --> C and G --> T mutants. Transition mutations were rarely detected, in contrast to control experiments. Electrophoretic analysis of peroxy radical treated DNA exposed to NaOH, Nth, and Fpg proteins demonstrated that abasic sites are not formed to any detectable degree. The oxidative G lesions are sensitive to digestion by the Fpg protein. We were unable to detect the formation of 8-oxo-dG by HPLC/electrochemical analysis of peroxy radical oxidation of dG, suggesting that the G --> T transversions were not caused by this base lesion.

  19. Formation of a tight 1:1 complex of Clostridium pasteurianum Fe protein-Azotobacter vinelandii MoFe protein: evidence for long-range interactions between the Fe protein binding sites during catalytic hydrogen evolution.

    PubMed

    Clarke, T A; Maritano, S; Eady, R R

    2000-09-19

    It has been well documented that the combination of the MoFe protein of Azotobacter vinelandii nitrogenase (Av1) with the Fe protein (Cp2) from Clostridium pasteurianum nitrogenase produces an inactive, stable complex. However, we report that this heterologous nitrogenase has a low level of activity for H(2) evolution, with a specific activity of 12 nmol min(-)(1) mg(-)(1) of Av1. This activity does not arise from contaminating hydrogenase since it required the presence of both Cp2 and Av1 and showed saturation kinetics when increasing amounts of Cp2 were added to the assay. Incubation of the two proteins at a 4:1 Cp2:Av1 ratio in the absence of MgATP followed by analytical gel filtration showed, surprisingly, that the stoichiometry of the isolated complex was Av1.Cp2 instead of Av1.(Cp2)(2) as determined previously. The presence of MgATP in the elution buffer did not change the elution profile of the complex. The hydrodynamic radius of the isolated complex determined by dynamic light scattering was 5.93 +/- 0.14 nm, intermediate between Av1 and a stable 2:1 nitrogenase complex, consistent with a 1:1 assignment for the Av1.Cp2 complex. When assayed with Av2, the isolated Av1.Cp2 complex showed full half-site reactivity with a specific activity of 750 nmol of C(2)H(2) reduced min(-)(1) mg(-)(1) of Av1. The EPR spectrum of the isolated complex showed the Cp2 to be oxidized and the Av1 to retain the S = (3)/(2) signal characteristic of FeMoco. In the presence of MgATP, under turnover conditions at a 2:1 ratio of Cp2:Av1, the [4Fe-4S] center of Cp2 was protected from the chelator 2,2'-bipyridyl. This is consistent with the formation of a tight 2:1 complex of Av1.(Cp2)(2) which is more stable than the homologous Cp nitrogenase. Assuming that the Lowe-Thorneley model for nitrogenase applies and that a rate-limiting dissociation of the complex is required for H(2) evolution, then with a rate of 0.032 s(-)(1) the 1:1 complex is too stable to be involved in catalysis. The

  20. Site selection

    SciTech Connect

    Olsen, C.W.

    1983-07-01

    The conditions and criteria for selecting a site for a nuclear weapons test at the Nevada Test Site are summarized. Factors considered are: (1) scheduling of drill rigs, (2) scheduling of site preparation (dirt work, auger hole, surface casing, cementing), (3) schedule of event (when are drill hole data needed), (4) depth range of proposed W.P., (5) geologic structure (faults, Pz contact, etc.), (6) stratigraphy (alluvium, location of Grouse Canyon Tuff, etc.), (7) material properties (particularly montmorillonite and CO/sub 2/ content), (8) water table depth, (9) potential drilling problems (caving), (10) adjacent collapse craters and chimneys, (11) adjacent expended but uncollapsed sites, (12) adjacent post-shot or other small diameter holes, (13) adjacent stockpile emplacement holes, (14) adjacent planned events (including LANL), (15) projected needs of Test Program for various DOB's and operational separations, and (16) optimal use of NTS real estate.

  1. Diepoxybutane induces the formation of DNA-DNA rather than DNA-protein cross-links, and single-strand breaks and alkali-labile sites in human hepatocyte L02 cells.

    PubMed

    Wen, Ying; Zhang, Pan-Pan; An, Jing; Yu, Ying-Xin; Wu, Ming-Hong; Sheng, Guo-Ying; Fu, Jia-Mo; Zhang, Xin-Yu

    2011-11-01

    1,3-Butadiene (BD) is an air pollutant and a known carcinogen. 1,2,3,4-Diepoxybutane (DEB), one of the major in vivo metabolites of BD, is considered the ultimate culprit of BD mutagenicity/carcinogenicity. DEB is a bifunctional alkylating agent, being capable of inducing the formation of monoalkylated DNA adducts and DNA cross-links, including DNA-DNA and DNA-protein cross-links (DPC). In the present study, we investigated DEB-caused DNA cross-links and breaks in human hepatocyte L02 cells using comet assay. With alkaline comet assay, it was observed that DNA migration increased with the increase of DEB concentration at lower concentrations (10-200μM); however, at higher concentrations (200-1000μM), DNA migration decreased with the increase of DEB concentration. This result indicated the presence of cross-links at >200μM, which was confirmed by the co-treatment experiments using the second genotoxic agents, tert-butyl hydroperoxide and methyl methanesulfonate. At 200μM, which appeared as a threshold, the DNA migration-retarding effect of cross-links was just observable by the co-treatment experiments. At <200μM, the effect of cross-links was too weak to be detected. The DEB-induced cross-links were determined to be DNA-DNA ones rather than DPC through incubating the liberated DNA with proteinase K prior to unwinding and electrophoresis. However, at the highest DEB concentration tested (1000μM), a small proportion of DPC could be formed. In addition, the experiments using neutral and weakly alkaline comet assays showed that DEB did not cause double-strand breaks, but did induce single-strand breaks (SSB) and alkali-labile sites (ALS). Since SSB and ALS are repaired more rapidly than cross-links, the results suggested that DNA-DNA cross-links, rather than DPC, were probably responsible for mutagenicity/carcinogenicity of DEB.

  2. Evaluation of Cavity Collapse and Surface Crater Formation at the Norbo Underground Nuclear Test in U8c, Nevada Nuclear Security Site, and the Impact on Stability of the Ground Surface

    SciTech Connect

    Pawloski, G A

    2012-06-18

    Lawrence Livermore National Laboratory (LLNL) Containment Program performed a review of nuclear test-related data for the Norbo underground nuclear test in U8c to assist in evaluating this legacy site as a test bed for application technologies for use in On-Site Inspections (OSI) under the Comprehensive Nuclear Test Ban Treaty. This request is similar to one made for the Salut site in U8c (Pawloski, 2012b). Review of the Norbo site is complicated because the test first exhibited subsurface collapse, which was not unusual, but it then collapsed to the surface over one year later, which was unusual. Of particular interest is the stability of the ground surface above the Norbo detonation point. Proposed methods for on-site verification include radiological signatures, artifacts from nuclear testing activities, and imaging to identify alteration to the subsurface hydrogeology due to the nuclear detonation. Aviva Sussman from the Los Alamos National Laboratory (LANL) has also proposed work at this site. Both proposals require physical access at or near the ground surface of specific underground nuclear test locations at the Nevada Nuclear Security Site (NNSS), formerly the Nevada Test Site (NTS), and focus on possible activities such as visual observation, multispectral measurements, and shallow and deep geophysical surveys.

  3. Interpretation of single-well push-pull spikings conducted in deep crystalline formations (Soultz-s.-F. in the Upper Rhine Graben, and KTB-VB at the German site of ICDP)

    NASA Astrophysics Data System (ADS)

    Ghergut, J.; Sauter, M.; Behrens, H.; (Steffen) Fischer, S.; (Steffi) Fischer, S.; Licha, T.; Nottebohm, M.

    2009-04-01

    Two somewhat contrasting model approaches are presented, both aimed at interpreting long-term return signals from tracer push-pull tests conducted at single wells penetrating increased-permeability features in crystalline rock, about 4 km deep. The general idea is that single-well tracer push-pull tests, owing to the flow-field reversal, should provide privileged access to advection-independent parameters of solute transport, like the density of fluid-rock contact surface areas (Sauter et al., 2002). The latter is equivalent to the heat exchange area for a liquid-based geothermal system. At the geothermal site of Soultz-sous-Forêts in the Upper Rhine Graben, the French BRGM, in cooperation with EGI Utah and other partners, conducted a comprehensive tracer testing programme, whose results were presented in detail by Sanjuan et al. (2004, 2006), Rose et al. (2006). Of these results, we pick the tracer return signals detected during post-stimulation backflow periods at borehole GPK-2 between 2000 and 2002 (as published by Sanjuan et al., 2004) and attempt to interpret them in terms of a single-well injection-withdrawal sequence. Two chemically dissimilar organic tracers have been used by BRGM; however the difference between their return signals seems not significant enough to allow quantifying fluid-rock contact surfaces from this difference alone (additional / a priori information on coefficients of solute exchange across these surfaces would be required). Instead, the tracer return signals enable characterizing the nature of solute exchange processes within the spiked volume of the assumed fractured-porous formation (highly altered crystalline rock). At least one rapid-exchange (E-7 / d), slightly dispersive (Pe~12) component and one moderate-exchange (2E-8 / d), less dispersive (Pe~20) component appear to act within few hundred metres and, respectively, within at least 1 km radial distance from the borehole. - An alternative component of extremely fast exchange

  4. Photoluminescence and EPR studies on Fe³⁺ doped ZnAl₂O₄: an evidence for local site swapping of Fe³⁺ and formation of inverse and normal phase.

    PubMed

    Pathak, Nimai; Gupta, Santosh K; Sanyal, Kaushik; Kumar, Mithlesh; Kadam, R M; Natarajan, V

    2014-06-28

    Considering that ZnAl2O4 spinel has two different sites (octahedral and tetrahedral) and its properties change with dopant ion distribution among these two sites; ZnAl2O4 doped with varied concentrations of Fe(3+) was synthesized by a low temperature sol-gel combustion method. Phase purity and structural investigations were carried out using Rietveld refined X-ray diffraction which shows a decrease in the value of cell parameters at higher doping levels. Photoluminescence (PL) and electron paramagnetic resonance (EPR) studies have shown that on doping, Fe(3+) ions were distributed in both tetrahedral and octahedral sites. At octahedral sites, Fe(3+) exhibited a broad red emission around 745 nm while at tetrahedral sites it exhibited well-defined vibronic sidebands at 665, 674, 684 and 693 nm along with a broad blue band with a maxima at 445 nm at room temperature. EPR studies have shown a broad spectrum at g ≈ 2.2 which corresponds to the Fe(3+) in octahedral sites, while the broad signal at g ≈ 4.2 belongs to Fe(3+) in tetrahedral sites. It was also inferred from these studies that Fe(3+) prefers to occupy octahedral sites at higher concentrations and at higher annealing temperatures. The PL decay behavior of Fe(3+) in ZnAl2O4 has also shown that two different types of Fe(3+) ions were present in this matrix. The first type was a long lived species (τ ≈ 170 μs) present at octahedral sites and the other was a short lived species (τ ≈ 40 μs) present at the tetrahedral sites; the fraction of the long lived species predominate at higher concentrations. Thus the present work is mainly focused on understanding the tuning of local site occupancy of the dopant ion among those sites with varying concentration and annealing temperature, using the dopant ion itself as a spectroscopic probe, which further helps in understanding the phase (inverse and normal) of the spinel.

  5. Evaluation of Cavity Collapse and Surface Crater Formation at the Salut Underground Nuclear Test in U20ak, Nevada National Security Site, and the Impact of Stability of the Ground Surface

    SciTech Connect

    Pawloski, G A

    2012-04-25

    At the request of Jerry Sweeney, the LLNL Containment Program performed a review of nuclear test-related data for the Salut underground nuclear test in U20ak to assist in evaluating this legacy site as a test bed for application technologies for use in On-Site Inspections (OSI) under the Comprehensive Nuclear Test Ban Treaty. Review of the Salut site is complicated because the test experienced a subsurface, rather than surface, collapse. Of particular interest is the stability of the ground surface above the Salut detonation point. Proposed methods for on-site verification include radiological signatures, artifacts from nuclear testing activities, and imaging to identify alteration to the subsurface hydrogeologogy due to the nuclear detonation. Sweeney's proposal requires physical access at or near the ground surface of specific underground nuclear test locations at the Nevada Nuclear Test Site (NNSS, formerly the Nevada Test Site), and focuses on possible activities such as visual observation, multispectral measurements, and shallow, and deep geophysical surveys.

  6. Gaussian entanglement of formation

    SciTech Connect

    Wolf, M.M.; Giedke, G.; Krueger, O.; Werner, R. F.; Cirac, J.I.

    2004-05-01

    We introduce a Gaussian version of the entanglement of formation adapted to bipartite Gaussian states by considering decompositions into pure Gaussian states only. We show that this quantity is an entanglement monotone under Gaussian operations and provide a simplified computation for states of arbitrary many modes. For the case of one mode per site the remaining variational problem can be solved analytically. If the considered state is in addition symmetric with respect to interchanging the two modes, we prove additivity of the considered entanglement measure. Moreover, in this case and considering only a single copy, our entanglement measure coincides with the true entanglement of formation.

  7. 1994 Site Environmental Report

    SciTech Connect

    1995-05-01

    The 1994 Site Environmental Report summarizes environmental activities at Lawrence Berkeley Laboratory (LBL) for the calendar year (CY) 1994. The report strives to present environmental data in a manner that characterizes the performance and compliance status of the Laboratory`s environmental management programs when measured against regulatory standards and DOE requirements. The report also discusses significant highlight and planning efforts of these programs. The format and content of the report are consistent with the requirements of the US Department of Energy (DOE) Order 5400.1, General Environmental Protection Program.

  8. Motion Predicts Clinical Callus Formation

    PubMed Central

    Elkins, Jacob; Marsh, J. Lawrence; Lujan, Trevor; Peindl, Richard; Kellam, James; Anderson, Donald D.; Lack, William

    2016-01-01

    Background: Mechanotransduction is theorized to influence fracture-healing, but optimal fracture-site motion is poorly defined. We hypothesized that three-dimensional (3-D) fracture-site motion as estimated by finite element (FE) analysis would influence callus formation for a clinical series of supracondylar femoral fractures treated with locking-plate fixation. Methods: Construct-specific FE modeling simulated 3-D fracture-site motion for sixty-six supracondylar femoral fractures (OTA/AO classification of 33A or 33C) treated at a single institution. Construct stiffness and directional motion through the fracture were investigated to assess the validity of construct stiffness as a surrogate measure of 3-D motion at the fracture site. Callus formation was assessed radiographically for all patients at six, twelve, and twenty-four weeks postoperatively. Univariate and multivariate linear regression analyses examined the effects of longitudinal motion, shear (transverse motion), open fracture, smoking, and diabetes on callus formation. Construct types were compared to determine whether their 3-D motion profile was associated with callus formation. Results: Shear disproportionately increased relative to longitudinal motion with increasing bridge span, which was not predicted by our assessment of construct stiffness alone. Callus formation was not associated with open fracture, smoking, or diabetes at six, twelve, or twenty-four weeks. However, callus formation was associated with 3-D fracture-site motion at twelve and twenty-four weeks. Longitudinal motion promoted callus formation at twelve and twenty-four weeks (p = 0.017 for both). Shear inhibited callus formation at twelve and twenty-four weeks (p = 0.017 and p = 0.022, respectively). Titanium constructs with a short bridge span demonstrated greater longitudinal motion with less shear than did the other constructs, and this was associated with greater callus formation (p < 0.001). Conclusions: In this study of

  9. Characterization of Archaeological Sediments Using Fourier Transform Infrared (FT-IR) and Portable X-ray Fluorescence (pXRF): An Application to Formative Period Pyro-Industrial Sites in Pacific Coastal Southern Chiapas, Mexico.

    PubMed

    Neff, Hector; Bigney, Scott J; Sakai, Sachiko; Burger, Paul R; Garfin, Timothy; George, Richard G; Culleton, Brendan J; Kennett, Douglas J

    2016-01-01

    Archaeological sediments from mounds within the mangrove zone of far-southern Pacific coastal Chiapas, Mexico, are characterized in order to test the hypothesis that specialized pyro-technological activities of the region's prehistoric inhabitants (salt and ceramic production) created the accumulations visible today. Fourier transform infrared spectroscopy (FT-IR) is used to characterize sediment mineralogy, while portable X-ray fluorescence (pXRF) is used to determine elemental concentrations. Elemental characterization of natural sediments by both instrumental neutron activation analysis (INAA) and pXRF also contribute to understanding of processes that created the archaeological deposits. Radiocarbon dates combined with typological analysis of ceramics indicate that pyro-industrial activity in the mangrove zone peaked during the Late Formative and Terminal Formative periods, when population and monumental activity on the coastal plain and piedmont were also at their peaks.

  10. Galaxy formation

    SciTech Connect

    Silk, J.

    1984-11-01

    Implications of the isotropy of the cosmic microwave background on large and small angular scales for galaxy formation are reviewed. In primeval adiabatic fluctuations, a universe dominated by cold, weakly interacting nonbaryonic matter, e.g., the massive photino is postulated. A possible signature of photino annihilation in our galactic halo involves production of cosmic ray antiprotons. If the density is near its closure value, it is necessary to invoke a biasing mechanism for suppressing galaxy formation throughout most of the universe in order to reconcile the dark matter density with the lower astronomical determinations of the mean cosmological density. A mechanism utilizing the onset of primordial massive star formation to strip gaseous protogalaxies is described. Only the densest, early collapsing systems form luminous galaxies. (ESA)

  11. Transamidase subunit GAA1/GPAA1 is a M28 family metallo-peptide-synthetase that catalyzes the peptide bond formation between the substrate protein's omega-site and the GPI lipid anchor's phosphoethanolamine.

    PubMed

    Eisenhaber, Birgit; Eisenhaber, Stephan; Kwang, Toh Yew; Grüber, Gerhard; Eisenhaber, Frank

    2014-01-01

    The transamidase subunit GAA1/GPAA1 is predicted to be the enzyme that catalyzes the attachment of the glycosylphosphatidyl (GPI) lipid anchor to the carbonyl intermediate of the substrate protein at the ω-site. Its ~300-amino acid residue lumenal domain is a M28 family metallo-peptide-synthetase with an α/β hydrolase fold, including a central 8-strand β-sheet and a single metal (most likely zinc) ion coordinated by 3 conserved polar residues. Phosphoethanolamine is used as an adaptor to make the non-peptide GPI lipid anchor look chemically similar to the N terminus of a peptide.

  12. Comet formation

    NASA Astrophysics Data System (ADS)

    Blum, J.

    2014-07-01

    There has been vast progress in our understanding of planetesimal formation over the past decades, owing to a number of laboratory experiments as well as to refined models of dust and ice agglomeration in protoplanetary disks. Coagulation rapidly forms cm-sized ''pebbles'' by direct sticking in collisions at low velocities (Güttler et al. 2010; Zsom et al. 2010). For the further growth, two model approaches are currently being discussed: (1) Local concentration of pebbles in nebular instabilities until gravitational instability occurs (Johansen et al. 2007). (2) A competition between fragmentation and mass transfer in collisions among the dusty bodies, in which a few ''lucky winners'' make it to planetesimal sizes (Windmark et al. 2012a,b; Garaud et al. 2013). Predictions of the physical properties of the resulting bodies in both models allow a distinction of the two formation scenarios of planetesimals. In particular, the tensile strength (i.e, the inner cohesion) of the planetesimals differ widely between the two models (Skorov & Blum 2012; Blum et al. 2014). While model (1) predicts tensile strengths on the order of ˜ 1 Pa, model (2) results in rather compactified dusty bodies with tensile strengths in the kPa regime. If comets are km-sized survivors of the planetesimal-formation era, they should in principle hold the secret of their formation process. Water ice is the prime volatile responsible for the activity of comets. Thermophysical models of the heat and mass transport close to the comet-nucleus surface predict water-ice sublimation temperatures that relate to maximum sublimation pressures well below the kPa regime predicted for formation scenario (2). Model (1), however, is in agreement with the observed dust and gas activity of comets. Thus, a formation scenario for cometesimals involving gravitational instability is favored (Blum et al. 2014).

  13. Preshot Geophysical Properties of Palanquin Crater Site

    DTIC Science & Technology

    2007-11-02

    The rocks at the Palanquin site are of volcanic origin, and consist predominantly of trachyte porphyry of the Ribbon Cliff formation of Pliocene age...Pyroclastic volcanic tuff underlies the trachyte porphyry at a depth of 175 m and caps low hills adjacent to the site. The volcanic units have a

  14. Examining the effects of anthropogenic emissions on isoprene-derived secondary organic aerosol formation during the 2013 Southern Oxidant and Aerosol Study (SOAS) at the Look Rock, Tennessee ground site

    NASA Astrophysics Data System (ADS)

    Budisulistiorini, S. H.; Li, X.; Bairai, S. T.; Renfro, J.; Liu, Y.; Liu, Y. J.; McKinney, K. A.; Martin, S. T.; McNeill, V. F.; Pye, H. O. T.; Nenes, A.; Neff, M. E.; Stone, E. A.; Mueller, S.; Knote, C.; Shaw, S. L.; Zhang, Z.; Gold, A.; Surratt, J. D.

    2015-08-01

    A suite of offline and real-time gas- and particle-phase measurements was deployed at Look Rock, Tennessee (TN), during the 2013 Southern Oxidant and Aerosol Study (SOAS) to examine the effects of anthropogenic emissions on isoprene-derived secondary organic aerosol (SOA) formation. High- and low-time-resolution PM2.5 samples were collected for analysis of known tracer compounds in isoprene-derived SOA by gas chromatography/electron ionization-mass spectrometry (GC/EI-MS) and ultra performance liquid chromatography/diode array detection-electrospray ionization-high-resolution quadrupole time-of-flight mass spectrometry (UPLC/DAD-ESI-HR-QTOFMS). Source apportionment of the organic aerosol (OA) was determined by positive matrix factorization (PMF) analysis of mass spectrometric data acquired on an Aerodyne Aerosol Chemical Speciation Monitor (ACSM). Campaign average mass concentrations of the sum of quantified isoprene-derived SOA tracers contributed to ~ 9 % (up to 28 %) of the total OA mass, with isoprene-epoxydiol (IEPOX) chemistry accounting for ~ 97 % of the quantified tracers. PMF analysis resolved a factor with a profile similar to the IEPOX-OA factor resolved in an Atlanta study and was therefore designated IEPOX-OA. This factor was strongly correlated (r2 > 0.7) with 2-methyltetrols, C5-alkene triols, IEPOX-derived organosulfates, and dimers of organosulfates, confirming the role of IEPOX chemistry as the source. On average, IEPOX-derived SOA tracer mass was ~ 26 % (up to 49 %) of the IEPOX-OA factor mass, which accounted for 32 % of the total OA. A low-volatility oxygenated organic aerosol (LV-OOA) and an oxidized factor with a profile similar to 91Fac observed in areas where emissions are biogenic-dominated were also resolved by PMF analysis, whereas no primary organic aerosol (POA) sources could be resolved. These findings were consistent with low levels of primary pollutants, such as nitric oxide (NO ~ 0.03 ppb), carbon monoxide (CO ~ 116 ppb), and black

  15. Influence of Na+ on DNA reactions with aromatic epoxides and diol epoxides: evidence that DNA catalyzes the formation of benzo[a]pyrene and benz[a]anthracene adducts at intercalation sites.

    PubMed

    Fernando, H; Huang, C R; Milliman, A; Shu, L; LeBreton, P R

    1996-12-01

    Reactions of the benzo[a]pyrene (BP) and benz[a]anthracene (BA) metabolites, (+/-)-trans-7 8-dihydroxy-anti-9, 10-epoxy-7, 8, 9, 10-tetrahydro-BP (BPDE), (+/-)-trans-3, 4-dihydroxy-anti- 1,2-epoxy-1,2,3,4-tetrahydro-BA (BADE), (+/-)-BP-4,5-oxide (BPO), and (+/-)-BA-5, 6-oxide (BAO), were examined under pseudo-first-order conditions at varying Na+ (2.0-100 Mm) and native calf thymus DNA (ctDNA) concentrations. In 0.2 mM ctDNA and 2.0 mM Na+, at a pH of 7.3 most BPDE, BADE, BPO, and BAO (87-95%) undergo DNA catalyzed hydrolysis or rearrangement. For BPDE and BPO, overall, pseudo-first-order rate constants, k, in 2.0 mM Na+ and 0.2 mM ctDNA are 21-72 times larger than values obtained without DNA. For BADE and BAO, the rate constants are less strongly influenced by DNA; k values in 0.2 mM ctDNA are only 9-12 times larger than values obtained without DNA. Kinetic data for BPDE, BPO, BADE, and BAO and DNA intercalation association constants (KA) for BP and BA diols which are model compounds indicate that KA values for BPDE and BPO in 2.0 mM Na+ are 6.6-59 times larger than those of BADE and BAO. The greater DNA enhancement of rate constants for BPDE and BPO, versus BADE and BAO, correlates with the larger KA values of the BP metabolites. DNA adducts, which account for less than 10% of the yields, also form. For BPDE in 0.20 mM ctDNA, k decreases 5.1 times as the Na+ concentration increases from 2.0 to 100 mM. Nevertheless, the DNA adduct level remains constant over the range of Na+ concentrations examined. These results provide evidence that, for BPDE in 0.20 mM DNA and 2.0 mM Na+, ctDNA adduct formation follows a mechanism which is similar to that for DNA catalyzed hydrolysis. The pseudo-first-order rate constant for adduct formation, kAd, given approximately by kAd approximately equal to (kcat,AdKA[DNA])/(1 + KA[DNA]), where kcat,Ad is a catalytic rate constant. for BADE, BPO, and BAO, the influence of varying DNA and Na+ concentrations on k values is similar to that

  16. Cloud Formation

    NASA Astrophysics Data System (ADS)

    Graham, Mark Talmage

    2004-05-01

    Cloud formation is crucial to the heritage of modern physics, and there is a rich literature on this important topic. In 1927, Charles T.R. Wilson was awarded the Nobel Prize in physics for applications of the cloud chamber.2 Wilson was inspired to study cloud formation after working at a meteorological observatory on top of the highest mountain in Scotland, Ben Nevis, and testified near the end of his life, "The whole of my scientific work undoubtedly developed from the experiments I was led to make by what I saw during my fortnight on Ben Nevis in September 1894."3 To form clouds, Wilson used the sudden expansion of humid air.4 Any structure the cloud may have is spoiled by turbulence in the sudden expansion, but in 1912 Wilson got ion tracks to show up by using strobe photography of the chamber immediately upon expansion.5 In the interim, Millikan's study in 1909 of the formation of cloud droplets around individual ions was the first in which the electron charge was isolated. This study led to his famous oil drop experiment.6 To Millikan, as to Wilson, meteorology and physics were professionally indistinct. With his meteorological physics expertise, in WWI Millikan commanded perhaps the first meteorological observation and forecasting team essential to military operation in history.7 But even during peacetime meteorology is so much of a concern to everyone that a regular news segment is dedicated to it. Weather is the universal conversation topic, and life on land could not exist as we know it without clouds. One wonders then, why cloud formation is never covered in physics texts.

  17. 92-kD gelatinase is produced by eosinophils at the site of blister formation in bullous pemphigoid and cleaves the extracellular domain of recombinant 180-kD bullous pemphigoid autoantigen.

    PubMed Central

    Ståhle-Bäckdahl, M; Inoue, M; Guidice, G J; Parks, W C

    1994-01-01

    Eosinophils are prominent in bullous pemphigoid (BP), and proteases secreted from these and other inflammatory cells may induce disruption of the basement membrane. We used in situ hybridization and immunohistochemistry to localize the sites of 92-kD gelatinase expression in BP lesions. In all samples (20/20), a strong signal for gelatinase mRNA was detected only in eosinophils and was most pronounced where these cells accumulated at the floor of forming blisters. No other cells were positive for enzyme mRNA. Both eosinophils and neutrophils, however, contained immunoreactive 92-kD gelatinase indicating that active expression occurred only in eosinophils. Degranulated eosinophils were also seen near blisters, and as demonstrated by gelatin zymography, immunoblotting, and ELISA, 92-kD gelatinase protein was prominent in BP blister fluid. No other gelatinolytic activity was specifically detected in BP fluid, and only small amounts of 92-kD gelatinase were present in suction blister fluids. As demonstrated in vitro, 92-kD gelatinase cleaved the extracellular, collagenous domain of recombinant 180-kD BP autoantigen (BP180, BPAG2, HD4, type XVII collagen), a transmembrane molecule of the epidermal hemidesmosome. Our results suggest that production and release 92-kD gelatinase by eosinophils contributes significantly to tissue damage in BP. Images PMID:8182134

  18. Site-directed mutagenesis of azurin from Pseudomonas aeruginosa enhances the formation of an electron-transfer complex with a copper-containing nitrite reductase from Alcaligenes faecalis S-6.

    PubMed

    Kukimoto, M; Nishiyama, M; Tanokura, M; Murphy, M E; Adman, E T; Horinouchi, S

    1996-09-23

    Kinetic analysis of electron transfer between azurin from Pseudomonas aeruginosa and copper-containing nitrite reductase (NIR) from Akaligenes faecalis S-6 was carried out to investigate the specificity of electron transfer between copper-containing proteins. Apparent values of kcat and Km of NIR for azurin were 300-fold smaller and 172-fold larger than those for the physiological redox partner, pseudoazurin from A. faecalis S-6, respectively, suggesting that the electron transfer between azurin and NIR was less specific than that between pseudoazurin and NIR. One of the major differences in 3-D structure between these redox proteins, azurin and pseudoazurin, is the absence and presence of lysine residues near their type 1 copper sites, respectively. Three mutated azurins, D11K, P36K, and D11K/P36K, were constructed to evaluate the importance of lysine residues in the interaction with NIR. The redox potentials of D11K, P36K, and D11K/P36K azurins were higher than that of wild-type azurin by 48, 7, and 55 mV, respectively. As suggested by the increase in the redox potential, kinetic analysis of electron transfer revealed reduced ability of electron transfer in the mutated azurins. On the other hand, although each of the single mutations caused modest effects on the decrease in the Km value, the simultaneous mutations of D11K and P36K caused significant decrease in the Km value when compared to that for wild-type azurin. These results suggest that the introduction of two lysine residues into azurin facilitated docking to NIR.

  19. Solute Probes of Conformational Changes in Open Complex Formation by E. coli RNA Polymerase at the λPR Promoter: Evidence for Unmasking of the Active Site in the Isomerization Step and for Large-Scale Coupled Folding in the Subsequent Conversion to RPo†

    PubMed Central

    Kontur, Wayne S.; Saecker, Ruth M.; Davis, Caroline A.; Capp, Michael W.; Record, M. Thomas

    2008-01-01

    Transcription initiation is a multi-step process involving a series of requisite conformational changes in RNA polymerase (R) and promoter DNA (P) that create the open complex (RPo). Here we use the small solutes urea and glycine betaine (GB) to probe the extent and type of surface area changes in the formation of RPo between Eσ70 RNA polymerase and λPR promoter DNA. Effects of urea quantitatively reflect changes in amide surface and are particularly well suited to detect coupled protein folding events. GB provides a qualitative probe for the exposure or burial of anionic surface. Kinetics of formation and dissociation of RPo reveal strikingly large effects of the solutes on the final steps of RPo formation: urea dramatically increases the dissociation rate constant kd, whereas GB decreases the rate of dissociation. Formation of the first kinetically significant intermediate I1 is disfavored in urea, and moderately favored by GB. GB slows the rate-determining step that converts I1 to the second kinetically significant intermediate I2; urea has no effect on this step. The most direct interpretation of these data is that recognition of promoter DNA in I1 involves only limited conformational changes. Notably the data support the following hypotheses: 1) the negatively charged N-terminal domain of σ70 remains bound in the “jaws” of polymerase in I1; 2) the subsequent rate-determining isomerization step involves ejecting this domain from the jaws, thereby unmasking the active site; and 3) final conversion to RPo involves coupled folding of the mobile downstream clamp of polymerase. PMID:16475805

  20. Amphiplex Formation

    NASA Astrophysics Data System (ADS)

    Petersen, Shannon; Laaser, Jennifer; Lodge, Timothy

    2015-03-01

    Polymer-micelle complexes are currently under heavy investigation due to their potential applications in targeted drug delivery and gene therapy, yet the dynamics of the complex formation is still relatively unstudied. By varying the ratios of poly(styrene sulfonate) chains and cationic poly(dimethylaminoethyl methacrylate)-b-poly(styrene) micelles and the ionic strength of the system, we created a variety of complex configurations of different sizes and charges. The complexes were characterized dynamic light scattering and zeta potential measurements which provided information regarding the hydrodynamic radius, distribution of sizes, and effective charge.

  1. Late Pleistocene ice margin fluctuations in the Nahanni National Park-UNESCO World Heritage Site and their impact on glacial lake formation and architecture of drainage systems across the Yukon-NWT continental divide

    NASA Astrophysics Data System (ADS)

    Duk-Rodkin, A.; Barendregt, R. W.

    2009-12-01

    In the late Pleistocene the southern Mackenzie region was glaciated by ice masses from a Cordilleran and continental source (Laurentide). Stratigraphic and geomorphologic evidence indicate that the two glaciers occupied this region at different times during the Late Pleistocene. The continental ice sheet advanced over the foothills and up major valleys reaching its maximum extent, ca. 30 ka. B. P. This took place when Cordilleran glaciers were in their initial stages of development. The Laurentide Ice Sheet blocked the drainage of the South Nahanni River near Virginia Falls, forming a glacial lake which inundated an area of approximately 900 km2 at its maximum stand, and had an outlet to the southwest, across the continental divide into the Yukon Territory and eventually into the Pacific Ocean. Lacustrine sediments at various sites reach thicknesses ranging from 110 to 120 metres, at an elevation of around 700 m. Cordilleran glaciers advanced eastward and approximately 5000 years later blocked this southwestward drainage, rerouting it to the east and north along the Mackenzie Mountain front. The drainage was confined between the mountains and continental ice margin where it incised major canyons into the limestone bedrock, and produced a spectacular karst landscape, which today forms part of the Nahanni National Park. During the retreat of the Laurentide and advance of Cordilleran glaciers, glacial Lake Nahanni cut an outlet to the east at First Canyon. This outlet drained into a continuous northbound network of marginal meltwater channels joining the north-flowing drainage that eventually reached the Arctic Ocean, and during further retreat of the ice sheet established the Mackenzie River in its modern location. The presence of Laurentide ice in this region is evidenced by large granite boulders carried from the Canadian Shield. Erratics are found up to 100 km west of the mountain front. Neotectonic activity in the area is interpreted from exposures such as those

  2. Planet Formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Fonda, Mark (Technical Monitor)

    2002-01-01

    Modern theories of star and planet formation and of the orbital stability of planetary systems are described and used to discuss possible characteristics of undiscovered planetary systems. The most detailed models of planetary growth are based upon observations of planets and smaller bodies within our own Solar System and of young stars and their environments. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. These models predict that rocky planets should form in orbit about most single stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may dissipate before solid planetary cores can grow large enough to gravitationally trap substantial quantities of gas. A potential hazard to planetary systems is radial decay of planetary orbits resulting from interactions with material within the disk. Planets more massive than Earth have the potential to decay the fastest, and may be able to sweep up smaller planets in their path. The implications of the giant planets found in recent radial velocity searches for the abundances of habitable planets are discussed, and the methods that are being used and planned for detecting and characterizing extrasolar planets are reviewed.

  3. Implementation: Preparing the Site.

    ERIC Educational Resources Information Center

    Epstein, Susan Baerg

    1983-01-01

    Considers site requirements that should be specified by the library and the vendor for a library automated system located at a central site away from the library, including size of site, the environment, cleanliness, electrical power, security/safety (fire, restricted access), site certification, telecommunications, and terminal sites. (EJS)

  4. Habit formation

    PubMed Central

    Smith, Kyle S.; Graybiel, Ann M.

    2016-01-01

    Habits, both good ones and bad ones, are pervasive in animal behavior. Important frameworks have been developed to understand habits through psychological and neurobiological studies. This work has given us a rich understanding of brain networks that promote habits, and has also helped us to understand what constitutes a habitual behavior as opposed to a behavior that is more flexible and prospective. Mounting evidence from studies using neural recording methods suggests that habit formation is not a simple process. We review this evidence and take the position that habits could be sculpted from multiple dissociable changes in neural activity. These changes occur across multiple brain regions and even within single brain regions. This strategy of classifying components of a habit based on different brain signals provides a potentially useful new way to conceive of disorders that involve overly fixed behaviors as arising from different potential dysfunctions within the brain's habit network. PMID:27069378

  5. Habit formation.

    PubMed

    Smith, Kyle S; Graybiel, Ann M

    2016-03-01

    Habits, both good ones and bad ones, are pervasive in animal behavior. Important frameworks have been developed to understand habits through psychological and neurobiological studies. This work has given us a rich understanding of brain networks that promote habits, and has also helped us to understand what constitutes a habitual behavior as opposed to a behavior that is more flexible and prospective. Mounting evidence from studies using neural recording methods suggests that habit formation is not a simple process. We review this evidence and take the position that habits could be sculpted from multiple dissociable changes in neural activity. These changes occur across multiple brain regions and even within single brain regions. This strategy of classifying components of a habit based on different brain signals provides a potentially useful new way to conceive of disorders that involve overly fixed behaviors as arising from different potential dysfunctions within the brain's habit network.

  6. Ocean Disposal Site Monitoring

    EPA Pesticide Factsheets

    EPA is responsible for managing all designated ocean disposal sites. Surveys are conducted to identify appropriate locations for ocean disposal sites and to monitor the impacts of regulated dumping at the disposal sites.

  7. Hanford Site Development Plan

    SciTech Connect

    Rinne, C.A.; Curry, R.H.; Hagan, J.W.; Seiler, S.W.; Sommer, D.J. ); Yancey, E.F. )

    1990-01-01

    The Hanford Site Development Plan (Site Development Plan) is intended to guide the short- and long-range development and use of the Hanford Site. All acquisition, development, and permanent facility use at the Hanford Site will conform to the approved plan. The Site Development Plan also serves as the base document for all subsequent studies that involve use of facilities at the Site. This revision is an update of a previous plan. The executive summary presents the highlights of the five major topics covered in the Site Development Plan: general site information, existing conditions, planning analysis, Master Plan, and Five-Year Plan. 56 refs., 67 figs., 31 tabs.

  8. Barrier Formation

    PubMed Central

    Lyaruu, D.M.; Medina, J.F.; Sarvide, S.; Bervoets, T.J.M.; Everts, V.; DenBesten, P.; Smith, C.E.; Bronckers, A.L.J.J.

    2014-01-01

    Enamel fluorosis is an irreversible structural enamel defect following exposure to supraoptimal levels of fluoride during amelogenesis. We hypothesized that fluorosis is associated with excess release of protons during formation of hypermineralized lines in the mineralizing enamel matrix. We tested this concept by analyzing fluorotic enamel defects in wild-type mice and mice deficient in anion exchanger-2a,b (Ae2a,b), a transmembrane protein in maturation ameloblasts that exchanges extracellular Cl− for bicarbonate. Defects were more pronounced in fluorotic Ae2a,b−/− mice than in fluorotic heterozygous or wild-type mice. Phenotypes included a hypermineralized surface, extensive subsurface hypomineralization, and multiple hypermineralized lines in deeper enamel. Mineral content decreased in all fluoride-exposed and Ae2a,b−/− mice and was strongly correlated with Cl−. Exposure of enamel surfaces underlying maturation-stage ameloblasts to pH indicator dyes suggested the presence of diffusion barriers in fluorotic enamel. These results support the concept that fluoride stimulates hypermineralization at the mineralization front. This causes increased release of protons, which ameloblasts respond to by secreting more bicarbonates at the expense of Cl− levels in enamel. The fluoride-induced hypermineralized lines may form barriers that impede diffusion of proteins and mineral ions into the subsurface layers, thereby delaying biomineralization and causing retention of enamel matrix proteins. PMID:24170372

  9. Pattern Formation

    NASA Astrophysics Data System (ADS)

    Hoyle, Rebecca

    2006-03-01

    From the stripes of a zebra and the spots on a leopard's back to the ripples on a sandy beach or desert dune, regular patterns arise everywhere in nature. The appearance and evolution of these phenomena has been a focus of recent research activity across several disciplines. This book provides an introduction to the range of mathematical theory and methods used to analyse and explain these often intricate and beautiful patterns. Bringing together several different approaches, from group theoretic methods to envelope equations and theory of patterns in large-aspect ratio-systems, the book also provides insight behind the selection of one pattern over another. Suitable as an upper-undergraduate textbook for mathematics students or as a fascinating, engaging, and fully illustrated resource for readers in physics and biology, Rebecca Hoyle's book, using a non-partisan approach, unifies a range of techniques used by active researchers in this growing field. Accessible description of the mathematical theory behind fascinating pattern formation in areas such as biology, physics and materials science Collects recent research for the first time in an upper level textbook Features a number of exercises - with solutions online - and worked examples

  10. Radionuclide site survey report, Melbourne, Florida (RN-72). Final report

    SciTech Connect

    Walker, F.; Lucas, J.; Owen, M.; McKethan, E.M.; MacCartney, J.

    1998-11-16

    The format and content of this report are based on guidance provided by the Preparatory Commission for the CTBT Organization for conducting and documenting radionuclide site surveys (see GTBT/PC/IV/WGB/1) ``Requirements of Site Surveys for Radionuclide Stations``, (30 September 1997). The purpose of this report is to validate that the Melbourne site will fulfill the requirements for treaty compliance.

  11. Hanford Site Waste Management Units Report

    SciTech Connect

    Shearer, Jeffrey P.

    2013-02-13

    The Hanford Site Waste Management Units Report (HSWMUR) has been created to meet the requirements of the Tri-Party Agreement (TPA) Action Plan, Section 3.5, which states: “The Hanford Site Waste Management Units Report shall be generated, in a format agreed upon by the Parties, as a calendar year report and issued annually by the DOE by the end of February of each year, and posted electronically for regulator and public access. This report shall reflect all changes made in waste management unit status during the previous year.” This February 2013 version of the HSWMUR contains a comprehensive inventory of the 3427 sites and 564 subsites in the Waste Information Data System (WIDS). The information for each site contains a description of each unit and the waste it contains, where applicable. The WIDS database provides additional information concerning the sites contained in this report and is maintained with daily changes to these sites.

  12. Hanford Site Waste Management Units Report

    SciTech Connect

    Shearer, Jeffrey P.

    2012-02-29

    The Hanford Site Waste Management Units Report (HSWMUR) has been created to meet the requirements of the Tri-Party Agreement (TPA) Action Plan, Section 3.5, which states: “The Hanford Site Waste Management Units Report shall be generated, in a format agreed upon by the Parties, as a calendar year report and issued annually by the DOE by the end of February of each year, and posted electronically for regulator and public access. This report shall reflect all changes made in waste management unit status during the previous year.” This February 2012 version of the HSWMUR contains a comprehensive inventory of the 3389 sites and 540 subsites in the Waste Information Data System (WIDS). The information for each site contains a description of each unit and the waste it contains, where applicable. The WIDS database provides additional information concerning the sites contained in this report and is maintained with daily changes to these sites.

  13. Hanford Site Waste Management Units Report

    SciTech Connect

    Shearer, Jeffrey P.

    2014-02-19

    The Hanford Site Waste Management Units Report (HSWMUR) has been created to meet the requirements of the Tri-Party Agreement (TPA) Action Plan, Section 3.5, which states: “The Hanford Site Waste Management Units Report shall be generated, in a format agreed upon by the Parties, as a calendar year report and issued annually by the DOE by the end of February of each year, and posted electronically for regulator and public access. This report shall reflect all changes made in waste management unit status during the previous year.” This February 2013 version of the HSWMUR contains a comprehensive inventory of the 3438 sites and 569 subsites in the Waste Information Data System (WIDS). The information for each site contains a description of each unit and the waste it contains, where applicable. The WIDS database provides additional information concerning the sites contained in this report and is maintained with daily changes to these sites.

  14. Hanford Site Development Plan

    SciTech Connect

    Hathaway, H.B.; Daly, K.S.; Rinne, C.A.; Seiler, S.W.

    1993-05-01

    The Hanford Site Development Plan (HSDP) provides an overview of land use, infrastructure, and facility requirements to support US Department of Energy (DOE) programs at the Hanford Site. The HSDP`s primary purpose is to inform senior managers and interested parties of development activities and issues that require a commitment of resources to support the Hanford Site. The HSDP provides an existing and future land use plan for the Hanford Site. The HSDP is updated annually in accordance with DOE Order 4320.1B, Site Development Planning, to reflect the mission and overall site development process. Further details about Hanford Site development are defined in individual area development plans.

  15. Lawrence Berkeley Laboratory 1993 Site Environmental Report

    SciTech Connect

    Not Available

    1994-05-01

    This annual Site Environmental Report summarizes Lawrence Berkeley Laboratory`s (LBL`s) environmental activities in calendar year (CY) 1993. The purpose of this report is to characterize site environmental management performance, confirm compliance status with environmental standards and requirements, and highlight significant programs and efforts. Its format and content are consistent with the requirements of the US Department of Energy (DOE) Order 5400.1, General Environmental Protection Program.

  16. DUST FORMATION IN MACRONOVAE

    SciTech Connect

    Takami, Hajime; Ioka, Kunihito; Nozawa, Takaya E-mail: kunihito.ioka@kek.jp

    2014-07-01

    We examine dust formation in macronovae (as known as kilonovae), which are the bright ejecta of neutron star binary mergers and one of the leading sites of r-process nucleosynthesis. In light of information about the first macronova candidate associated with GRB 130603B, we find that dust grains of r-process elements have difficulty forming because of the low number density of the r-process atoms, while carbon or elements lighter than iron can condense into dust if they are abundant. Dust grains absorb emission from ejecta with an opacity even greater than that of the r-process elements, and re-emit photons at infrared wavelengths. Such dust emission can potentially account for macronovae without r-process nucleosynthesis as an alternative model. This dust scenario predicts a spectrum with fewer features than the r-process model and day-scale optical-to-ultraviolet emission.

  17. Site amplifications for generic rock sites

    USGS Publications Warehouse

    Boore, D.M.; Joyner, W.B.

    1997-01-01

    Seismic shear-wave velocity as a function of depth for generic rock sites has been estimated from borehole data and studies of crustal velocities, and these velocities have been used to compute frequency-dependent amplifications for zero attenuation for use in simulations of strong ground motion. We define a generic rock site as one whose velocity at shallow depths equals the average of those from the rock sites sampled by the borehole data. Most of the boreholes are in populated areas; for that reason, the rock sites sampled are of particular engineering significance. We consider two generic rock sites: rock, corresponding to the bulk of the borehole data, and very hard rock, such as is found in glaciated regions in large areas of eastern North America or in portions of western North America. The amplifications on rock sites can be in excess of 3.5 at high frequencies, in contrast to the amplifications of less than 1.2 on very hard rock sites. The consideration of unattenuated amplification alone is computationally convenient, but what matters for ground-motion estimation is the combined effect of amplification and attenuation. For reasonable values of the attenuation parameter K0, the combined effect of attenuation and amplification for rock sites peaks between about 2 and 5 Hz with a maximum level of less than 1.8. The combined effect is about a factor of 1.5 at 1 Hz and is less than unity for frequencies in the range of 10 to 20 Hz (depending on K0). Using these amplifications, we find provisional values of about ???? = 70 bars and K0 = 0.035 sec for rock sites in western North America by fitting our empirically determined response spectra for an M 6.5 event to simulated values. The borehole data yield shear velocities (V??30) of 618 and 306 m/sec for "rock" and "soil" sites, respectively, when averaged over the upper 30 m. From this, we recommend that V??30 equals 620 and 310 m/sec for applications requiring the average velocity for rock and soil sites in

  18. Remedial Action Plan and Site Design for stabilization of the inactive Uranium Mill Tailings sites at Slick Rock, Colorado: Appendix C to Attachment 3, Calculations. Final

    SciTech Connect

    1995-09-01

    This volume contains calculations for: Slick Rock processing sites background ground water quality; Slick Rock processing sites lysimeter water quality; Slick Rock processing sites on-site and downgradient ground water quality; Slick Rock disposal site background water quality; Burro Canyon disposal site, Slick Rock, Colorado, average hydraulic gradients and average liner ground water velocities in the upper, middle, and lower sandstone units of the Burro Canyon formation; Slick Rock--Burro Canyon disposal site, Burro Canyon pumping and slug tests--analyses; water balance and surface contours--Burro Canyon disposal cell; and analytical calculation of drawdown in a hypothetical well completed in the upper sandstone unit of the Burro Canyon formation.

  19. Superfund Site Assessment Process

    EPA Pesticide Factsheets

    Learn about the site assessment process used by the federal Superfund program to evaluate releases of hazardous substances that may pose a threat to human health or the environment and select an appropriate program for sites needing cleanup.

  20. Pesticide Use Site Index

    EPA Pesticide Factsheets

    The Pesticide Use Site Index will help a company (or other applicant) identify which data requirements are needed to register a pesticide product. It provides information on pesticide use sites and pesticide major use patterns.

  1. SMARTE'S SITE CHARACTERIZATION TOOL

    EPA Science Inventory

    Site Characterization involves collecting environmental data to evaluate the nature and extent of contamination. Environmental data could consist of chemical analyses of soil, sediment, water or air samples. Typically site characterization data are statistically evaluated for thr...

  2. Past Project Expo Sites

    EPA Pesticide Factsheets

    This page provides information for Project Expo sites that were featured at the LMOP Conferences in 2013 and 2014. Project Expo sites were featured as being interested in identifying project partners for the development of an LFG energy project.

  3. Yes! You Can Build a Web Site.

    ERIC Educational Resources Information Center

    Holzberg, Carol

    2001-01-01

    With specially formatted templates or simple Web page editors, teachers can lay out text and graphics in a work space resembling the interface of a word processor. Several options are presented to help teachers build Web sites. ree templates include Class Homepage Builder, AppliTools: HomePage, MySchoolOnline.com, and BigChalk.com. Web design…

  4. Educational Computing Course. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    Bump, Wren, Ed.

    This document contains the following papers on the educational computing course from the SITE (Society for Information Technology & Teacher Education) 2001 conference: "Using a Flexible Format To Create a Constructivist Learning Environment in the Educational Computing Course" (Wren M. Bump); "Technological Diversity: Managing…

  5. Site specific synthesis and polymerase bypass of oligonucleotides containing a 6-hydroxy-3,5,6,7-tetrahydro-9H-imidazo[1,2-a]purin-9-one base, an intermediate in the formation of 1,N2-etheno-2'-deoxyguanosine.

    PubMed

    Goodenough, Angela K; Kozekov, Ivan D; Zang, Hong; Choi, Jeong-Yun; Guengerich, F Peter; Harris, Thomas M; Rizzo, Carmelo J

    2005-11-01

    The reaction of DNA with certain bis-electrophiles such as chlorooxirane and chloroacetaldehyde produces etheno adducts. These lesions are highly miscoding, and some of the chemical agents that produce them have been shown to be carcinogenic in laboratory animals and in humans. An intermediate in the formation of 1,N2-ethenoguanine is 6-hydroxy-3,5,6,7-tetrahydro-9H-imidazo[1,2-a]purin-9-one (6-hydroxyethanoguanine), which undergoes conversion to the etheno adduct. The chemical properties and miscoding potential of the hydroxyethano adduct have not been previously studied. A synthesis of the hydroxyethano-adducted nucleoside was developed, and it was site specifically incorporated into oligonucleotides. This adduct had a half-life of between 24 and 48 h at neutral pH and 25 degrees C at the nucleoside and oligonucleotide levels. The miscoding potential of the hydroxyethano adduct was examined by primer extension reactions with the DNA polymerases Dpo4 and pol T7-, and the results were compared to the corresponding etheno-adducted oligonucleotide. Dpo4 preferentially incorporated dATP opposite the hydroxyethano adduct and dGTP opposite the etheno adduct; pol T7- preferentially incorporated dATP opposite the etheno adduct while dGTP and dATP were incorporated opposite the hydroxyethano adduct with nearly equal catalytic efficiencies. Collectively, these results indicate that the hydroxyethano adduct has a sufficient lifetime and miscoding properties to contribute to the mutagenic spectrum of chlorooxirane and related genotoxic species.

  6. The ASCD Healthy School Communities Project: Formative Evaluation Results

    ERIC Educational Resources Information Center

    Valois, Robert F.; Lewallen, Theresa C.; Slade, Sean; Tasco, Adriane N.

    2015-01-01

    Purpose: The purpose of this paper is to report the formative evaluation results from the Association for Supervision and Curriculum Development Healthy School Communities (HSC) pilot project. Design/methodology/approach: This study utilized 11 HSC pilot sites in the USA (eight sites) and Canada (three sites). The evaluation question was…

  7. Site Environmental Report, 1993

    SciTech Connect

    Not Available

    1994-06-01

    The Site Environmental Report (SER) is prepared annually in accordance with DOE Order 5400.1, ``General Environmental Protection Program.`` This 1993 SER provides the general public as well as scientists and engineers with the results from the site`s ongoing Environmental Monitoring Program. Also included in this report is information concerning the site`s progress toward achieving full compliance with requirements set forth by DOE, US Environmental Protection Agency (USEPA), and Ohio EPA (OEPA). For some readers, the highlights provided in the Executive Summary may provide sufficient information. Many readers, however, may wish to read more detailed descriptions of the information than those which are presented here.

  8. Site Development Planning Handbook

    SciTech Connect

    1981-01-01

    The Handbook provides facility managers and site planners at DOE organizations responsible for planning site developments and facilities utilization a step-by-step planning checklist to ensure that planners at each site are focusing on Department-wide goals and objectives. It begins with a brief discussion of a site development-by-objectives program design to promote, recognize, and implement opportunities for improvements in site utilization through planning. Additional information is included on: assembling existing data, plans, programs, and procedures; establishing realistic objectives; identifying site problems, opportunities; and development needs; determining priorities among development needs; developing short and long-range plans; choosing the right development solutions and meeting minimum legal site restrictions; presenting the plan; implementing elements of the plan; monitoring and reporting plan status; and modifying development program plans. (MCW)

  9. Bulk Site Reference Materials

    SciTech Connect

    Barich, J.J. III; Jones, R.R. Sr.

    1996-12-31

    The selection, manufacture and use of Bulk Site Reference Materials (BSRMs) at hazardous waste sites is discussed. BSRMs are useful in preparing stabilization/solidification (S/S) formulations for soils, ranking competing S/S processes, comparing S/S alternatives to other technologies, and in interpreting data from different test types. BSRMs are large volume samples that are representative of the physical and chemical characteristics of a site soil, and that contain contaminants at reasonably high levels. A successful BSRM is extremely homogeneous and well-characterized. While not representative of any point on the site, they contain the contaminants of the site in the matrices of the site. Design objectives for a BSRM are to produce a material that (1) maintains good fidelity to site matrices and contaminants, and (2) exhibits the lowest possible relative standard deviation.

  10. The Keystone Dame Site and other Archaic and Formative Sites in Northwest El Paso, Texas.

    DTIC Science & Technology

    1980-10-01

    specifically Apache plume, little-leaf sumac, acacia, sagebrush, was identified somewhat more often than tornilho. mesquite, and Mormon tea , or joint fir, which...Convolvulus - bindweed. Croton sp. - spurge. a Dithrvea wizlezenii - spectacle pod. SEhedra - mormon tea . Most of the Ephedra pollen in the samples...Lowell T. Bye, Robert A., Jr., Don Burgess, and Albino Mares Trias 1971 The Mammals of El Paso County, Texas. With 1975 Ethnobotany of the Western

  11. Rulison Site corrective action report

    SciTech Connect

    1996-09-01

    Project Rulison was a joint US Atomic Energy Commission (AEC) and Austral Oil Company (Austral) experiment, conducted under the AEC`s Plowshare Program, to evaluate the feasibility of using a nuclear device to stimulate natural gas production in low-permeability gas-producing geologic formations. The experiment was conducted on September 10, 1969, and consisted of detonating a 40-kiloton nuclear device at a depth of 2,568 m below ground surface (BGS). This Corrective Action Report describes the cleanup of petroleum hydrocarbon- and heavy-metal-contaminated sediments from an old drilling effluent pond and characterization of the mud pits used during drilling of the R-EX well at the Rulison Site. The Rulison Site is located approximately 65 kilometers (40 miles) northeast of Grand Junction, Colorado. The effluent pond was used for the storage of drilling mud during drilling of the emplacement hole for the 1969 gas stimulation test conducted by the AEC. This report also describes the activities performed to determine whether contamination is present in mud pits used during the drilling of well R-EX, the gas production well drilled at the site to evaluate the effectiveness of the detonation in stimulating gas production. The investigation activities described in this report were conducted during the autumn of 1995, concurrent with the cleanup of the drilling effluent pond. This report describes the activities performed during the soil investigation and provides the analytical results for the samples collected during that investigation.

  12. 40. December 20, 1933 View of portal site, tunnel no. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. December 20, 1933 View of portal site, tunnel no. 1, CWA men facing the portal. "Stripping the hillside grule sic formation between tunnels 1 and 2." - Scotts Bluff Summit Road, Gering, Scotts Bluff County, NE

  13. Cyclic Imide Dioxime: Formation and Hydrolytic Stability

    SciTech Connect

    Kang, S.O.; Vukovic, Sinisa; Custelcean, Radu; Hay, Benjamin

    2012-01-01

    Poly(acrylamidoximes) play an important role in the uranium extraction from seawater. The present work reports solution studies of simple analogs to address the formation and stability of two binding sites present in these polymers, open-chain amidoximes and cyclic imide dioximes, including: 1) conditions that maximize the formation of the cyclic form, 2) existence of a base-induced conversion from open-chain to cyclic form, and 3) degradation under acid and base conditions.

  14. TOPOGRAPHIC SITE RESPONSE AT HARD ROCK SITES

    NASA Astrophysics Data System (ADS)

    Yong, A. K.; Hough, S. E.

    2009-12-01

    Site (material impedance) and topographic (geometric form) effects are known to be key factors that influence seismic ground motions. To characterize site effects, Yong et al. (2009) developed a terrain-based Vs30 prediction model using an automated classification method (Iwahashi and Pike, 2007) that relied on taxonomic criteria (slope gradient, local convexity and surface texture) developed from geomorphometry to identify 16 terrain types from a 1-km spatial resolution (SRTM30 data) digital elevation model of California. On the basis that the underlying framework for this model contains parameters (esp., local convexity) which aptly describe the geometry (i.e., base to height ratio) of relief features that are known to also control the behavior of ground motions (Bouchon, 1973), we extend our investigation to study topographic effects. Focusing on sites that would generally be considered “hard rock,” the classification scheme distinguishes 7 separate terrain types ranging from “moderately eroded mountains” to “well dissected alpine summits.” Observed 1-Hz amplification factors at Southern California Seismographic Network sites reveal a weak but systematic correlation with these 7 terrain types. Significant scatter is also found within each terrain type; typical standard deviations of logarithmic amplification factors are 0.2-0.3. Considering stations that have high amplification factors, we find some that have apparently been misclassified due to data resolution limitations. Many of the remaining stations with higher than expected amplifications are located on or near topographic peaks or ridges. The unusually high amplification factors at hard-rock sites, typically factors of 1.5-2, can most plausibly be explained as a topographic effect.

  15. Viking landing sites

    NASA Technical Reports Server (NTRS)

    Panagakos, N.

    1973-01-01

    A valley near the mouth of the 20,000-foot-deep Martian Grand Canyon has been chosen by NASA as the site of its first automated landing on the planet Mars. The landing site for the second mission of the 1975-76 Viking spacecraft will probably be an area about 1,000 miles northeast of the first site, where the likelihood of water increases the chances of finding evidence of life.

  16. Site environmental report summary

    SciTech Connect

    Not Available

    1992-12-31

    In this summary of the Fernald 1992 Site Environmental Report the authors will describe the impact of the Fernald site on man and the environment and provide results from the ongoing Environmental Monitoring Program. Also included is a summary of the data obtained from sampling conducted to determine if the site complies with DOE, US Environmental Protection Agency (USEPA), and Ohio EPA (OEPA) requirements. These requirements are set to protect both man and the environment.

  17. Site environmental programs

    SciTech Connect

    Schmidt, J.W.; Hanf, R.W.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the site environmental programs. Effluent monitoring and environmental surveillance programs monitor for impacts from operations in several areas. The first area consists of the point of possible release into the environment. The second area consists of possible contamination adjacent to DOE facilities, and the third area is the general environment both on and off the site.

  18. 1994 Site environmental report

    SciTech Connect

    1995-07-01

    The Fernald site is a Department of Energy (DOE)-owned facility that produced high-quality uranium metals for military defense for nearly 40 years. DOE suspended production at the site in 1989 and formally ended production in 1991. Although production activities have ceased, the site continues to examine the air and liquid pathways as possible routes through which pollutants from past operations and current remedial activities may leave the site. The Site Environmental Report (SER) is prepared annually in accordance with DOE Order 5400.1, General Environmental Protection Program. This 1994 SER provides the general public as well as scientists and engineers with the results from the site`s ongoing Environmental Monitoring Program. Also included in this report is information concerning the site`s progress toward achieving full compliance with requirements set forth by DOE, U.S. Environmental Protection Agency (USEPA), and Ohio EPA (OEPA). For some readers, the highlights provided in this Executive Summary may provide sufficient information. Many readers, however, may wish to read more detailed descriptions of the information than those which are presented here. All information presented in this summary is discussed more fully in the main body of this report.

  19. Nevada Test Site Environmental Report 2003

    SciTech Connect

    Bechtel Nevada

    2004-10-01

    The Nevada Test Site Environmental Report 2003 was prepared by Bechtel Nevada to meet the requirements and guidelines of the U.S. Department of Energy and the information needs of the public. This report is meant to be useful to members of the public, public officials, regulators, and Nevada Test Site contractors. The Executive Summary strives to present in a concise format the purpose of the document, the NTS mission and major programs, a summary of radiological releases and doses to the public resulting from site operations, a summary of non-radiological releases, and an overview of the Nevada Test Site Environmental Management System. The Executive Summary, combined with the following Compliance Summary, are written to meet all the objectives of the report and to be stand-alone sections for those who choose not to read the entire document.

  20. Common File Formats.

    PubMed

    Mills, Lauren

    2014-03-21

    An overview of the many file formats commonly used in bioinformatics and genome sequence analysis is presented, including various data file formats, alignment file formats, and annotation file formats. Example workflows illustrate how some of the different file types are typically used.

  1. Catalysis of Dialanine Formation by Glycine in the Salt-Induced Peptide Formation Reaction.

    NASA Astrophysics Data System (ADS)

    Suwannachot, Yuttana; Rode, Bernd M.

    1998-02-01

    Mutual catalysis of amino acids in the salt-induced peptide formation (SIPF) reaction is demonstrated for the case of glycine/alanine. The presence of glycine enhances dialanine formation by a factor up to 50 and enables dialanine formation at much lower alanine concentrations. The actual amounts of glycine play an important role for this catalytic effect, the optimal glycine concentration is 1/8 of the alanine concentration. The mechanism appears to be based on the formation of the intermediate Gly-Ala-Ala tripeptide, connected to one coordination site of copper(II) ion, and subsequent hydrolysis to dialanine and glycine.

  2. Savannah River Site's Site Specific Plan

    SciTech Connect

    Not Available

    1991-08-01

    This Site Specific Plan (SSP) has been prepared by the Savannah River Site (SRS) in order to show the Environmental Restoration and Waste Management activities that were identified during the preparation of the Department of Energy-Headquarters (DOE-HQ) Environmental Restoration and Waste Management Five-Year Plan (FYP) for FY 1992--1996. The SSP has been prepared in accordance with guidance received from DOE-HQ. DOE-SR is accountable to DOE-HQ for the implementation of this plan. The purpose of the SSP is to develop a baseline for policy, budget, and schedules for the DOE Environmental Restoration and Waste Management activities. The plan explains accomplishments since the Fiscal Year (FY) 1990 plan, demonstrates how present and future activities are prioritized, identifies currently funded activities and activities that are planned to be funded in the upcoming fiscal year, and describes future activities that SRS is considering.

  3. Dispersal of smallmouth bass from a simulated tournament weigh-in site

    USGS Publications Warehouse

    Kaintz, Melissa A.; Bettoli, Phillip William

    2010-01-01

    Simulated smallmouth bass Micropterus dolomieu fishing tournaments were staged in Dale Hollow Lake, a 12,400-ha reservoir in Tennessee, between March 2004 and February 2005 to investigate posttournament dispersal. Smallmouth bass (n = 54) were captured with conventional hook-and-line tackle and artificial lures, placed in live wells, and subjected to a weigh-in procedure before being externally tagged with an ultrasonic transmitter and released. Water temperatures ranged from 7.4°C to 29.3°C (mean [SE] = 17.6°C [2.5]), fish ranged in total length from 330 to 572 mm (mean = 452 [8.3]), and no fish were dead at the weigh-ins. Smallmouth bass dispersed rapidly away from the release site, which was located at the head of a 68-ha embayment. After 3-5d, survivors (n = 44) traversed an average distance of 1,475 m [213]. Most (72%) fish swam uplake and out of the 385-ha study area after 6 d. The rapid dispersal of smallmouth bass may be relevant in systems that experience heavy tournament activity. The smallmouth bass caught and subjected to simulated tournament conditions on Dale Hollow Lake did not stockpile near the release site.

  4. Effect of venous injection site on accuracy of fast computed tomography (CT) estimation of myocardial perfusion

    SciTech Connect

    Bell, M.R.; Rumberger, J.A.; Lerman, L.O.; Behrenbeck, T.; Sheedy, P.F.; Ritman, E.L. )

    1990-02-26

    Measurement of myocardial perfusion with fast CT, using venous injections of contrast, underestimates high flow rates. Accounting for intramyocardial blood volume improves the accuracy of such measurements but the additional influence of different contrast injection sites is unknown. To examine this, eight closed chest anesthetized dogs (18-24 kg) underwent fast CT studies of regional myocardial perfusion which were compared to microspheres (M). Dilute iohexol (0.5 mL/kg) was injected over 2.5 seconds, via, in turn, the pulmonary artery (PA), proximal inferior vena cava (IVC) and femoral vein (FV) during CT scans performed at rest and after vasodilation with adenosine (M flow range: 52-399 mL/100 g/minute). Correlations made with M were not significantly different for PA vs IVC (n = 24), PA vs FV (n = 22) and IVC vs FV (n = 44). To determine the relative influence of injection site on accuracy of measurements above normal flow rates (> 150mL/100g/minute), CT flow (mL/100g/minute; mean {+-}SD) was compared to M. Thus, at normal flow, some CT overestimation of myocardial perfusion occurred with PA injections but FV or IVC injections provided for accurate measurements. At higher flow rates only PA and IVC injections enabled accurate CT measurements of perfusion. This may be related to differing transit kinetics of the input bolus of contrast.

  5. Preliminary Site Characterization Report, Rulsion Site, Colorado

    SciTech Connect

    1996-08-01

    This report is a summary of environmental information gathered during a review of the documents pertaining to Project Rulison and interviews with personnel who worked on the project. Project Rulison was part of Operation Plowshare (a program designed to explore peaceful uses for nuclear devices). The project consisted of detonating a 43-kiloton nuclear device on September 10, 1969, in western Colorado to stimulate natural gas production. Following the detonation, a reentry well was drilled and several gas production tests were conducted. The reentry well was shut-in after the last gas production test and was held in standby condition until the general cleanup was undertaken in 1972. A final cleanup was conducted after the emplacement and testing wells were plugged in 1976. However, some surface radiologic contamination resulted from decontamination of the drilling equipment and fallout from the gas flaring during drilling operations. With the exception of the drilling effluent pond, all surface contamination at the Rulison Site was removed during the cleanup operations. All mudpits and other excavations were backfilled, and both upper and lower drilling pads were leveled and dressed. This report provides information regarding known or suspected areas of contamination, previous cleanup activities, analytical results, a review of the regulatory status, the site`s physical environment, and future recommendations for Project Ruhson. Based on this research, several potential areas of contamination have been identified. These include the drilling effluent pond and mudpits used during drilling operations. In addition, contamination could migrate in the gas horizon.

  6. Formate Formation and Formate Conversion in Biological Fuels Production

    PubMed Central

    Crable, Bryan R.; Plugge, Caroline M.; McInerney, Michael J.; Stams, Alfons J. M.

    2011-01-01

    Biomethanation is a mature technology for fuel production. Fourth generation biofuels research will focus on sequestering CO2 and providing carbon-neutral or carbon-negative strategies to cope with dwindling fossil fuel supplies and environmental impact. Formate is an important intermediate in the methanogenic breakdown of complex organic material and serves as an important precursor for biological fuels production in the form of methane, hydrogen, and potentially methanol. Formate is produced by either CoA-dependent cleavage of pyruvate or enzymatic reduction of CO2 in an NADH- or ferredoxin-dependent manner. Formate is consumed through oxidation to CO2 and H2 or can be further reduced via the Wood-Ljungdahl pathway for carbon fixation or industrially for the production of methanol. Here, we review the enzymes involved in the interconversion of formate and discuss potential applications for biofuels production. PMID:21687599

  7. Site characterization handbook

    SciTech Connect

    Not Available

    1988-06-01

    This Handbook discusses both management and technical elements that should be considered in developing a comprehensive site characterization program. Management elements typical of any project of a comparable magnitude and complexity are combined with a discussion of strategies specific to site characterization. Information specific to the technical elements involved in site characterization is based on guidance published by the Nuclear Regulatory Commission (NRC) with respect to licensing requirements for LLW disposal facilities. The objective of this Handbook is to provide a reference for both NRC Agreement States and non-Agreement States for use in developing a comprehensive site characterization program that meets the specific objectives of the State and/or site developer/licensee. Each site characterization program will vary depending on the objectives, licensing requirements, schedules/budgets, physical characteristics of the site, proposed facility design, and the specific concerns raised by government agencies and the public. Therefore, the Handbook is not a prescriptive guide to site characterization. 18 refs., 6 figs.

  8. Tremont Field Site

    EPA Pesticide Factsheets

    Tremont Field Site is a 41.5-acre public park located northeast of the intersection of West 11th Street and Clark Avenue in Cleveland, Ohio. Through two deed transfers in 1948 and 1949, the City acquired the site from the United States Government.

  9. Plugged-in SITE.

    ERIC Educational Resources Information Center

    Phillips, Rhys

    2003-01-01

    Examines form, color, and technology at the University of Ottawa's School of Information Technology and Engineering (SITE) building, focusing on systems (e.g., SITE is a data wired building, but with no expensive raised floors or cheap dropped ceilings); assembly rather than construction (replacing standard notions of construction with the process…

  10. SAMPLING OF CONTAMINATED SITES

    EPA Science Inventory

    A critical aspect of characterization of the amount and species of contamination of a hazardous waste site is the sampling plan developed for that site. f the sampling plan is not thoroughly conceptualized before sampling takes place, then certain critical aspects of the limits o...

  11. Commercial Web Site Links.

    ERIC Educational Resources Information Center

    Thelwall, Mike

    2001-01-01

    Discusses business use of the Web and related search engine design issues as well as research on general and academic links before reporting on a survey of the links published by a collection of business Web sites. Results indicate around 66% of Web sites do carry external links, most of which are targeted at a specific purpose, but about 17%…

  12. The Iowa Validation Site

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Remote sensing can be used to observe the land surface hydrologic cycle, but the quantitative aspects of these observations are not well known. We present a small (1 km^2) experimental validation site, the Iowa Validation Site. Initially we have focused on validating remotely-sensed observations of ...

  13. Site Planning and Layout.

    ERIC Educational Resources Information Center

    Moore, Gary T.

    1998-01-01

    Examines five issues related to child care facility design: (1) siting the building, outdoor play, and service areas; (2) creating favorable microclimates; (3) developmentally appropriate play yards; (4) pedestrian access and site circulation; and (5) vehicular access and parking away from pedestrians and play. (KB)

  14. Sites of the Holocaust.

    ERIC Educational Resources Information Center

    McCleary, George F., Jr.

    1995-01-01

    Presents a map of Europe identifying the location of major concentration camps, extermination camps, and massacre sites during World War II. Maintains that only a few of the over 400 sites in the former Soviet Union where entire Jewish villages were exterminated are shown. (CFR)

  15. WWW: Neuroscience Web Sites

    ERIC Educational Resources Information Center

    Liu, Dennis

    2006-01-01

    The human brain contains an estimated 100 billion neurons, and browsing the Web, one might be led to believe that there's a Web site for every one of those cells. It's no surprise that there are lots of Web sites concerning the nervous system. After all, the human brain is toward the top of nearly everyone's list of favorite organs and of…

  16. Geologic 'Face on Mars' Formation

    NASA Technical Reports Server (NTRS)

    1976-01-01

    NASA's Viking 1 Orbiter spacecraft photographed this region in the northern latitudes of Mars on July 25, 1976 while searching for a landing site for the Viking 2 Lander. The speckled appearance of the image is due to missing data, called bit errors, caused by problems in transmission of the photographic data from Mars to Earth. Bit errors comprise part of one of the 'eyes' and 'nostrils' on the eroded rock that resembles a human face near the center of the image. Shadows in the rock formation give the illusion of a nose and mouth. Planetary geologists attribute the origin of the formation to purely natural processes. The feature is 1.5 kilometers (one mile) across, with the sun angle at approximately 20 degrees. The picture was taken from a range of 1,873 kilometers (1,162 miles).

  17. Site decommissioning management plan

    SciTech Connect

    Fauver, D.N.; Austin, J.H.; Johnson, T.C.; Weber, M.F.; Cardile, F.P.; Martin, D.E.; Caniano, R.J.; Kinneman, J.D.

    1993-10-01

    The Nuclear Regulatory Commission (NRC) staff has identified 48 sites contaminated with radioactive material that require special attention to ensure timely decommissioning. While none of these sites represent an immediate threat to public health and safety they have contamination that exceeds existing NRC criteria for unrestricted use. All of these sites require some degree of remediation, and several involve regulatory issues that must be addressed by the Commission before they can be released for unrestricted use and the applicable licenses terminated. This report contains the NRC staff`s strategy for addressing the technical, legal, and policy issues affecting the timely decommissioning of the 48 sites and describes the status of decommissioning activities at the sites.

  18. Site directed recombination

    DOEpatents

    Jurka, Jerzy W.

    1997-01-01

    Enhanced homologous recombination is obtained by employing a consensus sequence which has been found to be associated with integration of repeat sequences, such as Alu and ID. The consensus sequence or sequence having a single transition mutation determines one site of a double break which allows for high efficiency of integration at the site. By introducing single or double stranded DNA having the consensus sequence flanking region joined to a sequence of interest, one can reproducibly direct integration of the sequence of interest at one or a limited number of sites. In this way, specific sites can be identified and homologous recombination achieved at the site by employing a second flanking sequence associated with a sequence proximal to the 3'-nick.

  19. Patterns of oligonucleotide distribution within DNA and RNA functional sites

    SciTech Connect

    Kolchanov, N.A.; Kel, A.E.; Ponomarenko, M.P.; Romachenko, A.G.; Likchachev, J.; Milanesi, L.; Lim, H.

    1993-12-31

    Patterns of short oligonucleotide distribution within DNA and RNA functional sites have been analyzed using ``Site-Video`` computer system. The group of DNA functional sites involved nucleosome binding sites, gyrase cleavage sites, promoters of E. coli and men. The group of RNA functional sites involved donor and acceptor splice sites of men, translation initiation sites of E. coli and men and translation frame shift site sites. Analysis of these samples of nucleotide sequences have been carried out by the ``Site-Video`` computer system. For each type of site specific set of patterns of oligonucleotide distribution important for the functioning and recognition have been revealed. At the same time, the number of specific patterns revealed in RNA sites was significantly higher than those in DNA sites. On the base of the results obtained, the script of functional sites for evolutionary emergency have been prompted. According to it, two types of context feature selection took place: (1) positive selection targeted to the appearance of the definite types of context features in particular regions of functional sites;and (2) negative selection targeted to the elimination of definite types of context features in particular regions of functional sites. The authors suppose that evolutionary formation of any functional site is a multistep process realized via combination of positive and negative selections. Negative selection, via fixation of a specific pattern of mutations, eliminates false signals of regulatory proteins binding with the functional site. Positive selection leads to the appearance of local context features (signals) which provide for the specificity and efficiency of the site functioning.

  20. Lunar Polar Landing Sites

    NASA Astrophysics Data System (ADS)

    Kamps, Oscar; Foing, Bernard H.; Flahaut, Jessica

    2016-07-01

    An important step for a scientific mission is to assess on where the mission should be conducted. This study on landing site selection focuses on a mission to the poles of the Moon where an in-situ mission should be conducted to answer the questions with respect to volatiles and ices. The European interest for a mission to the poles of the Moon is presented in the mission concept called Heracles. This mission would be a tele-operated, sample return mission where astronauts will controlling a rover from an Orion capsule in cislunar orbit. The primary selection of landing sites was based on the scientific interest of areas near the poles. The maximum temperature map from Diviner was used to select sites where CO^2¬ should always be stable. This means that the maximum temperature is lower than 54K which is the sublimation temperature for CO^2¬ in lunar atmospheric pressure. Around these areas 14 potential regions of interest were selected. Further selection was based on the epoch of the surface in these regions of interest. It was thought that it would be of high scientific value if sites are sampled which have another epoch than already sampled by one of the Apollo or Luna missions. Only 6 sites on both North as South Pole could contain stable CO^2 ¬and were older than (Pre-)Necterian. Before a landing site and rover traverse was planned these six sites were compared on their accessibility of the areas which could contain stable CO^2. It was assumed that slope lower than 20^o is doable to rove. Eventually Amundsen and Rozhdestvenskiy West were selected as regions of interest. Assumptions for selecting landing sites was that area should have a slope lower than 5^o, a diameter of 1km, in partial illuminated area, and should not be isolated but inside an area which is in previous steps marked as accessible area to rove. By using multiple tools in ArcGIS it is possible to present the area's which were marked as potential landing sites. The closest potential landing

  1. The effect of conventional surgery and piezoelectric surgery bone harvesting techniques on the donor site morbidity of the mandibular ramus and symphysis.

    PubMed

    Altiparmak, N; Soydan, S S; Uckan, S

    2015-09-01

    The aim of this study was to evaluate the morbidity following bone harvesting at two different intraoral donor sites, mandibular symphysis and ramus, and to determine the effects of piezoelectric and conventional surgical graft harvesting techniques on donor site morbidity. Intraoral block bone grafts were harvested from the symphysis (n=44) and ramus (n=31). The two donor site groups were divided into two subgroups according to the surgical graft harvesting method used (conventional or piezoelectric surgery). Intraoperative and postoperative pain was assessed using a visual analogue scale (VAS). Donor site morbidity and the harvesting techniques were compared statistically. Of 290 teeth evaluated in the symphysis group, four needed root canal treatment after surgery. The incidence of transient paresthesia in the mucosa was significantly higher in the symphysis group than in the ramus group (P=0.004). In the symphysis group, the incidence of temporary skin and mucosa paresthesia was lower in the piezoelectric surgery subgroup than in the conventional surgery subgroup (P=0.006 and P=0.001, respectively). No permanent anaesthesia of any region of the skin was reported in either donor site group. VAS scores did not differ between the ramus and symphysis harvesting groups, or between the piezoelectric and conventional surgery subgroups. When the symphysis was chosen as the donor site, minor sensory disturbances of the mucosa and teeth were recorded. The use of piezoelectric surgery during intraoral harvesting of bone blocks, especially from the symphysis, can reduce these complications.

  2. Master Plans for Park Sites.

    ERIC Educational Resources Information Center

    Van Meter, Jerry R.

    This booklet is a general guide to park site planning. The four basic steps involved in developing a park site are a) determination of the uses of the site, b) analysis of the site potential for these uses, c) identification of the functional relationship among the uses, and d) coordination of the uses to the park sites. Uses of park sites are…

  3. The role of fanatics in consensus formation

    NASA Astrophysics Data System (ADS)

    Gündüç, Semra

    2015-08-01

    A model of opinion dynamics with two types of agents as social actors are presented, using the Ising thermodynamic model as the dynamics template. The agents are considered as opportunists which live at sites and interact with the neighbors, or fanatics/missionaries which move from site to site randomly in persuasion of converting agents of opposite opinion with the help of opportunists. Here, the moving agents act as an external influence on the opportunists to convert them to the opposite opinion. It is shown by numerical simulations that such dynamics of opinion formation may explain some details of consensus formation even when one of the opinions are held by a minority. Regardless the distribution of the opinion, different size societies exhibit different opinion formation behavior and time scales. In order to understand general behavior, the scaling relations obtained by comparing opinion formation processes observed in societies with varying population and number of randomly moving agents are studied. For the proposed model two types of scaling relations are observed. In fixed size societies, increasing the number of randomly moving agents give a scaling relation for the time scale of the opinion formation process. The second type of scaling relation is due to the size dependent information propagation in finite but large systems, namely finite-size scaling.

  4. Generalized trends in the formation energies of perovskite oxides.

    PubMed

    Zeng, ZhenHua; Calle-Vallejo, Federico; Mogensen, Mogens B; Rossmeisl, Jan

    2013-05-28

    Generalized trends in the formation energies of several families of perovskite oxides (ABO3) and plausible explanations to their existence are provided in this study through a combination of DFT calculations, solid-state physics analyses and simple physical/chemical descriptors. The studied elements at the A site of perovskites comprise rare-earth, alkaline-earth and alkaline metals, whereas 3d and 5d metals were studied at the B site. We also include ReO3-type compounds, which have the same crystal structure of cubic ABO3 perovskites except without A-site elements. From the observations we extract the following four conclusions for the perovskites studied in the present paper: for a given cation at the B site, (I) perovskites with cations of identical oxidation state at the A site possess close formation energies; and (II) perovskites with cations of different oxidation states at the A site usually have quite different but ordered formation energies. On the other hand, for a given A-site cation, (III) the formation energies of perovskites vary linearly with respect to the atomic number of the elements at the B site within the same period of the periodic table, and the slopes depend systematically on the oxidation state of the A-site cation; and (IV) the trends in formation energies of perovskites with elements from different periods at the B site depend on the oxidation state of A-site cations. Since the energetics of perovskites is shown to be the superposition of the individual contributions of their constituent oxides, the trends can be rationalized in terms of A-O and B-O interactions in the ionic crystal. These findings reveal the existence of general systematic trends in the formation energies of perovskites and provide further insight into the role of ion-ion interactions in the properties of ternary compounds.

  5. Retroviral integration: Site matters

    PubMed Central

    Demeulemeester, Jonas; De Rijck, Jan

    2015-01-01

    Here, we review genomic target site selection during retroviral integration as a multistep process in which specific biases are introduced at each level. The first asymmetries are introduced when the virus takes a specific route into the nucleus. Next, by co‐opting distinct host cofactors, the integration machinery is guided to particular chromatin contexts. As the viral integrase captures a local target nucleosome, specific contacts introduce fine‐grained biases in the integration site distribution. In vivo, the established population of proviruses is subject to both positive and negative selection, thereby continuously reshaping the integration site distribution. By affecting stochastic proviral expression as well as the mutagenic potential of the virus, integration site choice may be an inherent part of the evolutionary strategies used by different retroviruses to maximise reproductive success. PMID:26293289

  6. Siting Air Monitoring Stations

    ERIC Educational Resources Information Center

    Ludwig, F. L.

    1978-01-01

    Describes guidelines for consideration in selecting sites for air monitoring systems. Careful selection for spatial scale and specific sources assures that the collected data are accurately representing the situation. (Author/MA)

  7. Solar site test module

    NASA Technical Reports Server (NTRS)

    Kissel, R. R.; Scott, D. R.

    1980-01-01

    A solar site test module using the Rockwell AIM 65microcomputer is described. The module is designed to work at any site where an IBM site data acquisition system (SDAS) is installed and is intended primarily as a troubleshooting tool. It collects sensor information (temperatures, flow rates, etc.) and displays or prints it immediately in calibrated engineering units. It will read one sensor on demand, periodically read up to 10sensors or periodically read all sensors. Performance calculations can also be included with sensor data. Unattended operation is possible to, e.g., monitor a group of sensors once per hour. Work is underway to add a data acquisition system to the test module so that it can be used at sites which have no SDAS.

  8. Interplay between electron-phonon interaction and Hubbard repulsion: Bipolaron formation

    SciTech Connect

    Nath, S.; Mondal, N. S.; Ghosh, N. K.

    2015-06-24

    In the weak coupling limit, the 2D Hubbard model extended by on-site (local) and inter-site (long range) electron-phonon (EP) interaction has been investigated within Lanczos method of exact diagonalization (ED). On-site (S0) bipolaron formation has been favored by on-site EP interaction induced effective attraction between electrons. But, inter-site phonon mediated interaction between electrons helps to form both S0 and neighboring site (S1) bipolaron. It is further observed that both types of bipolaron formation are suppressed by on-site Hubbard repulsion.

  9. 48 CFR 302.7100 - HHS standard templates and formats.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... GENERAL DEFINITIONS OF WORDS AND TERMS HHS Standard Templates and Formats 302.7100 HHS standard templates..., may be accessed on the ASFR/OGAPA/DA Internet Web site. A complete listing of the standard...

  10. Star Formation in Galaxies

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Topics addressed include: star formation; galactic infrared emission; molecular clouds; OB star luminosity; dust grains; IRAS observations; galactic disks; stellar formation in Magellanic clouds; irregular galaxies; spiral galaxies; starbursts; morphology of galactic centers; and far-infrared observations.

  11. Simple Ontology Format (SOFT)

    SciTech Connect

    Sorokine, Alexandre

    2011-10-01

    Simple Ontology Format (SOFT) library and file format specification provides a set of simple tools for developing and maintaining ontologies. The library, implemented as a perl module, supports parsing and verification of the files in SOFt format, operations with ontologies (adding, removing, or filtering of entities), and converting of ontologies into other formats. SOFT allows users to quickly create ontologies using only a basic text editor, verify it, and portray it in a graph layout system using customized styles.

  12. Possible mechanisms of macrolayer formation

    SciTech Connect

    Sadasivan, P.; Chappidi, P.R.; Unal, C.; Nelson, R.A.

    1992-05-01

    The high heat flux nucleate boiling region, also called the vapor mushroom region, has been shown to have a thin liquid layer on the heater surface under the large mushroom-shaped vapor bubbles that grow from the heater surface. The name given to this liquid layer is the macrolayer to differentiate it from the microlayer that exists under the discrete bubbles found at lower heat fluxes in the nucleate boiling region. Typical thicknesses of this macrolayer range from 50 to 500 {mu}m for water on a flat horizontal boiling surface and depend upon the heat flux. Thus, the macrolayer is thicker than the wedge-shaped microlayers, found under discrete bubbles, which range in thickness from 1 to 10 {mu}m. Although the mechanism of microlayer formation and its evaporation is conceptually simple that of the macrolayer is still not understood. This paper critically compares the potential mechanisms proposed for macrolayer formation. These mechanisms include the Helmholtz instability applied to the vapor stem above active nucleation sites, liquid trapped by lateral coalescence of discrete bubbles that initially form during the mushroom bubble`s waiting period, and the limitation of liquid resupply at mushroom departure as a result of vapor flow from the active nucleation sites.

  13. Possible mechanisms of macrolayer formation

    SciTech Connect

    Sadasivan, P.; Chappidi, P.R.; Unal, C.; Nelson, R.A.

    1992-01-01

    The high heat flux nucleate boiling region, also called the vapor mushroom region, has been shown to have a thin liquid layer on the heater surface under the large mushroom-shaped vapor bubbles that grow from the heater surface. The name given to this liquid layer is the macrolayer to differentiate it from the microlayer that exists under the discrete bubbles found at lower heat fluxes in the nucleate boiling region. Typical thicknesses of this macrolayer range from 50 to 500 {mu}m for water on a flat horizontal boiling surface and depend upon the heat flux. Thus, the macrolayer is thicker than the wedge-shaped microlayers, found under discrete bubbles, which range in thickness from 1 to 10 {mu}m. Although the mechanism of microlayer formation and its evaporation is conceptually simple that of the macrolayer is still not understood. This paper critically compares the potential mechanisms proposed for macrolayer formation. These mechanisms include the Helmholtz instability applied to the vapor stem above active nucleation sites, liquid trapped by lateral coalescence of discrete bubbles that initially form during the mushroom bubble's waiting period, and the limitation of liquid resupply at mushroom departure as a result of vapor flow from the active nucleation sites.

  14. Beaver assisted river valley formation

    USGS Publications Warehouse

    Westbrook, C.J.; Cooper, D.J.; Baker, B.W.

    2011-01-01

    We examined how beaver dams affect key ecosystem processes, including pattern and process of sediment deposition, the composition and spatial pattern of vegetation, and nutrient loading and processing. We provide new evidence for the formation of heterogeneous beaver meadows on riverine system floodplains and terraces where dynamic flows are capable of breaching in-channel beaver dams. Our data show a 1.7-m high beaver dam triggered overbank flooding that drowned vegetation in areas deeply flooded, deposited nutrient-rich sediment in a spatially heterogeneous pattern on the floodplain and terrace, and scoured soils in other areas. The site quickly de-watered following the dam breach by high stream flows, protecting the deposited sediment from future re-mobilization by overbank floods. Bare sediment either exposed by scouring or deposited by the beaver flood was quickly colonized by a spatially heterogeneous plant community, forming a beaver meadow. Many willow and some aspen seedlings established in the more heavily disturbed areas, suggesting the site may succeed to a willow carr plant community suitable for future beaver re-occupation. We expand existing theory beyond the beaver pond to include terraces within valleys. This more fully explains how beavers can help drive the formation of alluvial valleys and their complex vegetation patterns as was first postulated by Ruedemann and Schoonmaker in 1938. ?? 2010 John Wiley & Sons, Ltd.

  15. Potential MER Landing Site in Melas Chasma

    NASA Technical Reports Server (NTRS)

    Weitz, C. M.; Parker, Timothy J.; Anderson, F. Scott

    2001-01-01

    We have selected one area in Valles Marineris as a potential landing site for the Mars Exploration Rover (MER) mission. After 30 years of analyses, the formation of the Valles Marineris system of troughs and its associated deposits still remains an enigma. Understanding all aspects of the Valles Marineris would significantly contribute to deciphering the internal and external history of Mars. A landing site within Melas Chasma could provide insight into both the formation of Valles Marineris and the composition and origin of the interior layered deposits (ILDs). The ILDs have been proposed as: (1) sedimentary deposits formed in lakes mass wasted material from the walls; (3) remnants of the wall rock; (4) carbonate deposits; (5) aeolian deposits; and (6) volcanic. More recently, Malin and Edgett suggest that the fine-scale, rhythmic layering seen in the interior deposits, as well as other layered deposits in craters, supports a sedimentary origin. Because an understanding of the formation of Valles Marineris and its interior deposits is so important to deciphering the history of Mars, we have proposed a landing site for the MER mission on an exposure of interior deposits in western Melas Chasma. Either MER-A and MER-B could land at this same location.

  16. Development of a Learning Progression for the Formation of the Solar System

    NASA Astrophysics Data System (ADS)

    Plummer, Julia D.; Palma, Christopher; Flarend, Alice; Rubin, KeriAnn; Shiou Ong, Yann; Botzer, Brandon; McDonald, Scott; Furman, Tanya

    2015-06-01

    This study describes the process of defining a hypothetical learning progression (LP) for astronomy around the big idea of Solar System formation. At the most sophisticated level, students can explain how the formation process led to the current Solar System by considering how the planets formed from the collapse of a rotating cloud of gas and dust. Development of this LP was conducted in 2 phases. First, we interviewed middle school, high school, and college students (N = 44), asking them to describe properties of the current Solar System and to explain how the Solar System was formed. Second, we interviewed 6th-grade students (N = 24) before and after a 15-week astronomy curriculum designed around the big idea. Our analysis provides evidence for potential levels of sophistication within the hypothetical LP, while also revealing common alternative conceptions or areas of limited understanding that could form barriers to progress if not addressed by instruction. For example, many students' understanding of Solar System phenomena was limited by either alternative ideas about gravity or limited application of momentum in their explanations. Few students approached a scientific-level explanation, but their responses revealed possible stepping stones that could be built upon with appropriate instruction.

  17. Estimating Absolute Site Effects

    SciTech Connect

    Malagnini, L; Mayeda, K M; Akinci, A; Bragato, P L

    2004-07-15

    The authors use previously determined direct-wave attenuation functions as well as stable, coda-derived source excitation spectra to isolate the absolute S-wave site effect for the horizontal and vertical components of weak ground motion. They used selected stations in the seismic network of the eastern Alps, and find the following: (1) all ''hard rock'' sites exhibited deamplification phenomena due to absorption at frequencies ranging between 0.5 and 12 Hz (the available bandwidth), on both the horizontal and vertical components; (2) ''hard rock'' site transfer functions showed large variability at high-frequency; (3) vertical-motion site transfer functions show strong frequency-dependence, and (4) H/V spectral ratios do not reproduce the characteristics of the true horizontal site transfer functions; (5) traditional, relative site terms obtained by using reference ''rock sites'' can be misleading in inferring the behaviors of true site transfer functions, since most rock sites have non-flat responses due to shallow heterogeneities resulting from varying degrees of weathering. They also use their stable source spectra to estimate total radiated seismic energy and compare against previous results. they find that the earthquakes in this region exhibit non-constant dynamic stress drop scaling which gives further support for a fundamental difference in rupture dynamics between small and large earthquakes. To correct the vertical and horizontal S-wave spectra for attenuation, they used detailed regional attenuation functions derived by Malagnini et al. (2002) who determined frequency-dependent geometrical spreading and Q for the region. These corrections account for the gross path effects (i.e., all distance-dependent effects), although the source and site effects are still present in the distance-corrected spectra. The main goal of this study is to isolate the absolute site effect (as a function of frequency) by removing the source spectrum (moment-rate spectrum) from

  18. Site clearance working group

    SciTech Connect

    1997-03-01

    The Gulf of Mexico and Louisiana continue to be areas with a high level of facility removal, and the pace of removal is projected to increase. Regulations were promulgated for the Gulf of Mexico and Louisiana requiring that abandoned sites be cleared of debris that could interfere with fishing and shrimping activities. The site clearance regulations also required verification that the sites were clear. Additionally, government programs were established to compensate fishermen for losses associated with snagging their equipment on oil and gas related objects that remained on the water bottoms in areas other than active producing sites and sites that had been verified as clear of obstructions and snags. The oil and gas industry funds the compensation programs. This paper reviews the regulations and evolving operating practices in the Gulf of Mexico and Louisiana where site clearance and fisherman`s gear compensation regulations have been in place for a number of years. Although regulations and guidelines may be in place elsewhere in the world, this paper focuses on the Gulf of Mexico and Louisiana. Workshop participants are encouraged to bring up international issues during the course of the workshop. Additionally, this paper raises questions and focuses on issues that are of concern to the various Gulf of Mexico and Louisiana water surface and water bottom stakeholders. This paper does not have answers to the questions or issues. During the workshop participants will debate the questions and issues in an attempt to develop consensus opinions and/or make suggestions that can be provided to the appropriate organizations, both private and government, for possible future research or policy adjustments. Site clearance and facility removal are different activities. Facility removal deals with removal of the structures used to produce oil and gas including platforms, wells, casing, piles, pipelines, well protection structures, etc.

  19. Design criteria for stabilization of inactive uranium mill tailings sites

    SciTech Connect

    1984-06-01

    The site-specific Remedial Action Plan (RAP), which includes the Site Conceputal Design (SCD); the Processing Site Characterization Report (PSCR); the Disposal Site Characterization Report (DSCR), (if required); and the project Site Design Criteria (SDC), as a set, have been prepared by the Technical Assistance Contractor (TAC) at the direction of the Department of Energy (DOE), and provide the Remedial Action Contractor (RAC) with sufficient information to complete the remedial action engineering designs. This Site Design Criteria (SDC) provides the basis or guidelines for the RAC to prepare the final design documentation for the Uranium Mill Tailings Remedial Action (UMTRA) Project sites. This document provides a set of operating procedures, formats for drawings, specifications, calculations, schedules and cost estimates, and minimum design constraints.

  20. Specification of sites for polarized growth in Saccharomyces cerevisiae and the influence of external factors on site selection.

    PubMed Central

    Madden, K; Snyder, M

    1992-01-01

    Many eucaryotic cell types exhibit polarized cell growth and polarized cell division at nonrandom sites. The sites of polarized growth were investigated in G1 arrested haploid Saccharomyces cerevisiae cells. When yeast cells are arrested during G1 either by treatment with alpha-factor or by shifting temperature-sensitive cdc28-1 cells to the restrictive temperature, the cells form a projection. Staining with Calcofluor reveals that in both cases the projection usually forms at axial sites (i.e., next to the previous bud scar); these are the same sites where bud formation is expected to occur. These results indicate that sites of polarized growth are specified before the end of G1. Sites of polarized growth can be influenced by external conditions. Cells grown to stationary phase and diluted into fresh medium preferentially select sites for polarized growth opposite the previous bud scar (i.e., distal sites). Incubation of cells in a mating mixture results in projection formation at nonaxial sites: presumably cells form projections toward their mating partner. These observations have important implications in understanding three aspects of cell polarity in yeast: 1) how yeast cell shape is influenced by growth conditions 2) how sites of polarized growth are chosen, and 3) the pathway by which polarity is affected and redirected during the mating process. Images PMID:1421575

  1. SLAC site design aesthetics

    SciTech Connect

    Hall, F.F.

    1985-10-01

    Stanford Linear Accelerator Center (SLAC) is a single mission laboratory dedicated to basic research in high energy particle physics. SLAC site also houses Stanford Synchrotron Radiation Laboratory (SSRL) which is a multi-mission laboratory for research using beams of ultraviolet light and low energy photons as emitted tangentially from SLAC colliding beam facilities. This paper discusses various aspects of SLAC site design aesthetics under the following headings: (1) imposed footprint of SLAC, (2) description of selected site, (3) use of earth cover for radiation and sight screens, (4) use of landscaping for cosmetic purposes, (5) use of exterior paint colors to soften SLAC impact on neighbors, (6) relocation of SLAC main entrance, (7) relocation of SLAC collider arcs and experimental hall, (8) parking lots and storage yards, and (9) land use zoning at SLAC.

  2. Site investigation for Magnus

    SciTech Connect

    Semple, R.M.; Rigden, W.J.

    1983-05-01

    In April 1982, BP's Magnus structure was installed about 150 km northeast of the Shetland Islands. The most northerly, deepest water platform in the North Sea, the steel tower is supported on groups of 2 m diameter piles that were driven, in good accordance with predictions, to an average penetration of 85 m in strong cohesive soils. The paper describes investigations performed at the platform site, and documents soil characteristics for conventional and state of the art pile analyses. Reference is made to several innovative techniques first used at the Magnus site that have since been incorporated into the larger North Sea investigations. Information is given about the geological history of the site. Test results are presented on soil strength and stiffness, including critical state soil mechanics parameters, on residual pore pressures after sampling, and on the effect of sample size on strength characteristics.

  3. Frequencies of restriction sites.

    PubMed Central

    Waterman, M S

    1983-01-01

    Restriction sites or other sequence patterns are usually assumed to occur according to a Poisson distribution with mean equal to the reciprocal of the probability of the given site or pattern. For situations where non-overlapping occurrences of patterns, such as restriction sites, are the objects of interest, this note shows that the Poisson assumption is frequently misleading. Both the case of base composition (independent bases) and of dinucleotide frequencies (Markov chains) are treated. Moreover, a new technique is presented which allows treatment of collections of patterns, where the departure from the Poisson assumption is even more striking. This later case includes double digests, and an example of a five enzyme digest is included. PMID:6324109

  4. Sand dollar sites orogenesis

    NASA Astrophysics Data System (ADS)

    Amos, Dee

    2013-04-01

    The determinology of the humble sand dollars habitat changing from inception to the drastic evolution of the zone to that of present day. Into the cauldron along the southern Californian 'ring of fire' lithosphere are evidence of geosynclinals areas, metasedimentary rock formations and hydrothermal activity. The explanation begins with 'Theia' and the Moon's formation, battles with cometary impacts, glacial ages, epochs with evolutionary bottlenecks and plate tectonics. Fully illustrated the lecture includes localised diagrams and figures with actual subject photographic examples of plutonic, granitic, jade and peridodite. Finally, the origins of the materials used in the lecture are revealed for prosecution by future students and the enjoyment of interested parties in general.

  5. Evidence for arrested bone formation during spaceflight

    NASA Technical Reports Server (NTRS)

    Turner, R. T.; Bobyn, J. D.; Duvall, P.; Morey, E. R.; Baylink, D. J.; Spector, M.

    1982-01-01

    Addressing the question of whether the bone formed in space is unusual, the morphology of bone made at the tibial diaphysis of rats before, during, and after spaceflight is studied. Evidence of arrest lines in the bone formed in space is reported suggesting that bone formation ceases along portions of the periosteum during spaceflight. Visualized by microradiography, the arrest lines are shown to be less mineralized than the surrounding bone matrix. When viewed by scanning electron microscopy, it is seen that bone fractures more readily at the site of an arrest line. These observations are seen as suggesting that arrest lines are a zone of weakness and that their formation may result in decreased bone strength in spite of normalization of bone formation after flight. The occurrence, location, and morphology of arrest lines are seen as suggesting that they are a visible result of the phenomenon of arrested bone formation.

  6. YUCCA MOUNTAIN SITE DESCRIPTION

    SciTech Connect

    A.M. Simmons

    2004-04-16

    The ''Yucca Mountain Site Description'' summarizes, in a single document, the current state of knowledge and understanding of the natural system at Yucca Mountain. It describes the geology; geochemistry; past, present, and projected future climate; regional hydrologic system; and flow and transport within the unsaturated and saturated zones at the site. In addition, it discusses factors affecting radionuclide transport, the effect of thermal loading on the natural system, and tectonic hazards. The ''Yucca Mountain Site Description'' is broad in nature. It summarizes investigations carried out as part of the Yucca Mountain Project since 1988, but it also includes work done at the site in earlier years, as well as studies performed by others. The document has been prepared under the Office of Civilian Radioactive Waste Management quality assurance program for the Yucca Mountain Project. Yucca Mountain is located in Nye County in southern Nevada. The site lies in the north-central part of the Basin and Range physiographic province, within the northernmost subprovince commonly referred to as the Great Basin. The basin and range physiography reflects the extensional tectonic regime that has affected the region during the middle and late Cenozoic Era. Yucca Mountain was initially selected for characterization, in part, because of its thick unsaturated zone, its arid to semiarid climate, and the existence of a rock type that would support excavation of stable openings. In 1987, the United States Congress directed that Yucca Mountain be the only site characterized to evaluate its suitability for development of a geologic repository for high-level radioactive waste and spent nuclear fuel.

  7. 5 CFR 2425.4 - Content and format of exceptions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... electronically through use of the eFiling system on the FLRA's Web site at www.flra.gov. Regardless of how you...Filing system on that Web site. Your failure to use, or properly fill out, an Authority-provided form... arbitrator. (d) Format. You may file your exception on an optional form that is available on the FLRA's...

  8. 5 CFR 2425.5 - Content and format of opposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... optional form that is available on the FLRA's Web site at www.flra.gov, or in any other format that is... use of the FLRA's eFiling system on that Web site. Your failure to use, or properly fill out,...

  9. Star Formation for Predictive Primordial Galaxy Formation

    NASA Astrophysics Data System (ADS)

    Milosavljević, Miloš; Safranek-Shrader, Chalence

    The elegance of inflationary cosmology and cosmological perturbation theory ends with the formation of the first stars and galaxies, the initial sources of light that launched the phenomenologically rich process of cosmic reionization. Here we review the current understanding of early star formation, emphasizing unsolved problems and technical challenges. We begin with the first generation of stars to form after the Big Bang and trace how they influenced subsequent star formation. The onset of chemical enrichment coincided with a sharp increase in the overall physical complexity of star forming systems. Ab-initio computational treatments are just now entering the domain of the predictive and are establishing contact with local observations of the relics of this ancient epoch.

  10. Waste Site Mapping

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Old aircraft considered not restorable are melted down in on-site furnaces to reclaim the aluminum in their airframes. The process produces aluminum ingots and leaves a residue known as "dross." Because dross contains contaminants like lead silver cadmium and copper, Pima County, the dross dumping site, wanted to locate areas where dross had been dumped. Dr. Larry Lepley and Sandra L. Perry used the Landsat Thematic Mapper to screen for dross. A special two-step procedure was developed to separate the dross dumps (typically no larger than 50 meters across) from the desert background. The project has opened the door for similar applications.

  11. statement of significance, location map, site plan, landscape plan, site ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    statement of significance, location map, site plan, landscape plan, site sections, evolution of cemetery landscape. - San Francisco National Cemetery, 1 Lincoln Boulevard, San Francisco, San Francisco County, CA

  12. List 9 - Active CERCLIS Sites:

    EPA Pesticide Factsheets

    The List 9 displays the sequence of activities undertaken at active CERCLIS sites. An active site is one at which site assessment, removal, remedial, enforcement, cost recovery, or oversight activities are being planned or conducted.

  13. The Chemistry of Planet Formation

    NASA Astrophysics Data System (ADS)

    Oberg, Karin I.

    2017-01-01

    Exo-planets are common, and they span a large range of compositions. The origins of the observed diversity of planetary compositions is largely unconstrained, but must be linked to the planet formation physics and chemistry. Among planets that are Earth-like, a second question is how often such planets form hospitable to life. A fraction of exo-planets are observed to be ‘physically habitable’, i.e. of the right temperature and bulk composition to sustain a water-based prebiotic chemistry, but this does not automatically imply that they are rich in the building blocks of life, in organic molecules of different sizes and kinds, i.e. that they are chemically habitable. In this talk I will argue that characterizing the chemistry of protoplanetary disks, the formation sites of planets, is key to address both the origins of planetary bulk compositions and the likelihood of finding organic matter on planets. The most direct path to constrain the chemistry in disks is to directly observe it. In the age of ALMA it is for the first time possible to image the chemistry of planet formation, to determine locations of disk snowlines, and to map the distributions of different organic molecules. Recent ALMA highlights include constraints on CO snowline locations, the discovery of spectacular chemical ring systems, and first detections of more complex organic molecules. Observations can only provide chemical snapshots, however, and even ALMA is blind to the majority of the chemistry that shapes planet formation. To interpret observations and address the full chemical complexity in disks requires models, both toy models and astrochemical simulations. These models in turn must be informed by laboratory experiments, some of which will be shown in this talk. It is thus only when we combine observational, theoretical and experimental constraints that we can hope to characterize the chemistry of disks, and further, the chemical compositions of nascent planets.

  14. Site study plan for intermediate hydrology clusters tests wells Deaf Smith County Site, Texas

    SciTech Connect

    Not Available

    1988-01-01

    To characterize the geologic, geochemical, and hydrologic characteristics of intermediate-depth formations at the proposed Deaf Smith County, Texas, repository site, wells called Intermediate Hydrology clusters will test the Dewey Lake, Alibates, Salado, Yates, Upper and Lower Seven Rivers, and Queen Grayburg Formations. Sixteen wells will be installed at six locations. One location will have four wills, two locations will have three wells, and three locations will have two wells for a total of 16 wells. Testing of the formations is to proceed from the bottom up, with 2-day pumping tests at the less permeable formations. Tracer tests and tests for verticall hydraulic properties will be designed and performed after other hydrologic tests are completed. After testing, selected wells are to be completed as single or possibly dual monitoring wells to observe water-level trends. To develop a hydrogeologic testing plan, the response of each formation to potential testing procedures was evaluated using design values and an assumend range for hydraulic parameters. These evaluations indicate that hydraulic properties of a sandy zone of the Dockum, the lower Sever Rivers, and possibly the Alibates and Queen/Grayburg can be determined by pumping tests. Standard of shut-in slug tests must be conducted in the remaining formations. Tests of very long duration would be required to determine the verticla properties of less permeable formations. Tracer tests would also require weeks or months. 61 figs., 34 refs., 4 tabs.

  15. Science. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    Roach, Linda E., Ed.

    This document contains the following papers on science from the SITE (Society for Information Technology & Teacher Education) 2001 conference: (1) "Using a Computer Simulation before Dissection To Help Students Learn Anatomy" (Joseph Paul Akpan and Thomas Andre); (2) "EARTH2CLASS: A Unique Workshop/On-Line/Distance-Learning…

  16. Savannah River Site Robotics

    SciTech Connect

    2010-01-01

    Meet Sandmantis and Frankie, two advanced robotic devices that are key to cleanup at Savannah River Site. Sandmantis cleans hard, residual waste off huge underground storage tanks. Frankie is equipped with unique satellite capabilities and sensing abilties that can determine what chemicals still reside in the tanks in a cost effective manner.

  17. SITE EMERGING TECHNOLOGY Program

    EPA Science Inventory

    This document is intended as a reference guide for EPA Regional decision makers and others interested in tchnologies in the SITE Demonstration and Technologies programs. The Technologies are described in technology profiles presented in alphabetical order by developer name and se...

  18. Savannah River Site Robotics

    ScienceCinema

    None

    2016-07-12

    Meet Sandmantis and Frankie, two advanced robotic devices that are key to cleanup at Savannah River Site. Sandmantis cleans hard, residual waste off huge underground storage tanks. Frankie is equipped with unique satellite capabilities and sensing abilties that can determine what chemicals still reside in the tanks in a cost effective manner.

  19. Mathematics. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    Connell, Michael L., Ed.; Lowery, Norene Vail, Ed.; Harnisch, Delwyn L., Ed.

    This document contains the following papers on mathematics from the SITE (Society for Information Technology & Teacher Education) 2001 conference: "Secondary Mathematics Methods Course with Technology Units: Encouraging Pre-Service Teachers To Use Technology" (Rajee Amarasinghe); "Competency Exams in College Mathematics"…

  20. Mathematics. [SITE 2002 Section].

    ERIC Educational Resources Information Center

    Connell, Michael L., Ed.; Lowery, Norene Vail, Ed.; Harnisch, Delwyn L., Ed.

    This document contains the following papers on mathematics from the SITE (Society for Information Technology & Teacher Education) 2002 conference: (1) "Teachers' Learning of Mathematics in the Presence of Technology: Participatory Cognitive Apprenticeship" (Mara Alagic); (2) "A Fractal Is a Pattern in Your Neighborhood" (Craig N. Bach); (3)…

  1. Proposed Drill Sites

    DOE Data Explorer

    Lane, Michael

    2013-06-28

    Proposed drill sites for intermediate depth temperature gradient holes and/or deep resource confirmation wells. Temperature gradient contours based on shallow TG program and faults interpreted from seismic reflection survey are shown, as are two faults interpreted by seismic contractor Optim but not by Oski Energy, LLC.

  2. Science. [SITE 2002 Section].

    ERIC Educational Resources Information Center

    Roach, Linda Easley, Ed.

    This document contains the following papers on science from the SITE (Society for Information Technology & Teacher Education) 2002 conference: (1) "Color & Light: Design and Evaluation of a Multimedia-Case for Elementary Teacher-Education" (Peter Blijleven and Ellen van den Berg); (2) "Standards-Based Design of Technology-Integrated Science…

  3. Research. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    McAlister, Kim, Ed.; Curtis, Reagan, Ed.

    This document contains the papers on research from the SITE (Society for Information Technology & Teacher Education) 2001 conference. Topics covered include: concerns of administrators and teachers in the diffusion of information technology; preservice elementary mathematics teachers' computer self efficacy, attitudes, and perceptions;…

  4. Theory. [SITE 2002 Section].

    ERIC Educational Resources Information Center

    Christensen, Paula, Ed.

    This document contains the following papers on theory from the SITE (Society for Information Technology & Teacher Education) 2002 conference: (1) "The Emerging Ecological Contribution of Online Resources and Tools to K-12 Classrooms" (Therese Laferriere, Robert Bracewell, Alain Breuleux); (2) "Pedagogical Ethnotechnography: A Bifocal Lens To…

  5. International. [SITE 2002 Section].

    ERIC Educational Resources Information Center

    Willis, Dee Anna, Ed.

    This document contains the following papers on international issues from the SITE (Society for Information Technology & Teacher Education) 2002 conference: (1) "The Management of Technological Change within Faculties in International American Schools" (Martine Audeoud); (2) "Going Global: Using a Website Development Project To…

  6. 2014 Site Environmental Report

    SciTech Connect

    Paquette, Douglas; Remien, Jason; Foley, Brian; Burke, John; Dorsch, William; Ratel, Karen; Howe, Robert; Welty, Tim; Williams, Jeffrey; Pohlpt, Peter; Lagattolla, Richard; Metz, Robert; Milligan, James; Lettieri, Lawrence

    2015-10-01

    BNL prepares an annual Site Environmental Report (SER) in accordance with DOE Order 231.1B, Environment, Safety and Health Reporting. The report is written to inform the public, regulators, employees, and other stakeholders of the Laboratory’s environmental performance during the calendar year in review.

  7. International. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    Willis, Dee Anna, Ed.

    This document contains the following papers on international issues from the SITE (Society for Information Technology & Teacher Education) 2001 conference: (1) "Attitudes of Malaysian Vocational Trainee Teachers towards the Integration of Computer in Teaching" (Ab. Rahim Bakar and Shamsiah Mohamed); (2) "Views from an Asian…

  8. Simulation. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    Seymour, Cathy R., Ed.

    This document contains three papers on simulation from the SITE (Society for Information Technology & Teacher Education) 2001 conference. "Simulations in the Learning Cycle: A Case Study Involving 'Exploring the Nardoo'" (William M. Dwyer and Valesca E. Lopez) presents a study of middle school students using a CD-based simulation…

  9. Elementary Classroom Web Sites

    ERIC Educational Resources Information Center

    Baker, Elizabeth A.

    2007-01-01

    The purpose of this study was to understand how elementary classroom Web sites support children's literacy. From a sociocultural perspective of literacy and a transformative stance toward the integration of literacy and technology, and building on explorations of new literacies, I discuss opportunities provided by the Internet that can support…

  10. Site study plan for exploratory shaft monitoring wells, Deaf Smith County Site, Texas: Preliminary Draft

    SciTech Connect

    Not Available

    1988-01-01

    As part of site characterization studies, two exploratory shafts will be constructed at the Deaf Smith County site, Texas. Twelve wells at five locations have been proposed to monitor potential impacts of shaft construction on water-bearing zones in the Ogallala Formation and the Dockum Group. In addition, tests have been proposed to determine the hydraulic properties of the water-bearing zones for use in design and construction of the shafts. Samples of the Blackwater Draw Formation, Ogallala Formation, and Dockum Group will be obtained during construction of these wells. Visual indentification, laboratory testing, and in situ testing will yield data necessary for Exploratory Shaft Facility design and construction. This activity provides the earliest data on the Blackwater Drew Formation, Ogallala Formation, and Dockum Group near the exploratory shaft locations. Drilling and hydrologic testing are scheduled prior to other subsurface activity at the Exploratory Shaft Facility to establish ground-water baseline conditions. The Technical Field Services Contractor is responsible for conducting the field program of drilling and testing. Samples and data will be handled and reported in accordance with established Salt Repository Project procedures. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that the appropriate documentation is maintained. 45 refs., 11 figs., 4 tabs.

  11. Tropical cyclone formation

    SciTech Connect

    Montgomery, M.T.; Farrell, B.F. )

    1993-01-15

    The physics of tropical cyclone formation is not well understood, and more is known about the mature hurricane than the formative mechanisms that produce it. It is believed part of the reason for this can be traced to insufficient upper-level atmospheric data. Recent observations suggest that tropical cyclones are initiated by asymmetric interactions associated with migratory upper-level potential vorticity disturbances and low-level disturbances. Favored theories of cyclones formation, however, focus on internal processes associated with cumulus convection and/or air-sea interaction. This work focuses on external mechanisms of cyclone formation and, using both a two- and three-dimensional moist geostrophic momentum model, investigates the role of upper-level potential vorticity disturbances on the formation process. A conceptual model of tropical cyclone formation is proposed, and implications of the theory are discussed. 71 refs., 5 figs., 1 tab.

  12. Small Wind Site Assessment Guidelines

    SciTech Connect

    Olsen, Tim; Preus, Robert

    2015-09-01

    Site assessment for small wind energy systems is one of the key factors in the successful installation, operation, and performance of a small wind turbine. A proper site assessment is a difficult process that includes wind resource assessment and the evaluation of site characteristics. These guidelines address many of the relevant parts of a site assessment with an emphasis on wind resource assessment, using methods other than on-site data collection and creating a small wind site assessment report.

  13. Closure Plan for the Area 5 Radioactive Waste Management Site at the Nevada Test Site

    SciTech Connect

    NSTec Environmental Management

    2008-09-01

    The Area 5 Radioactive Waste Management Site (RMWS) at the Nevada Test Site (NTS) is managed and operated by National Security Technologies, LLC (NSTec), for the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO). This document is the first update of the preliminary closure plan for the Area 5 RWMS at the NTS that was presented in the Integrated Closure and Monitoring Plan (DOE, 2005a). The major updates to the plan include a new closure schedule, updated closure inventory, updated site and facility characterization data, the Title II engineering cover design, and the closure process for the 92-Acre Area of the RWMS. The format and content of this site-specific plan follows the Format and Content Guide for U.S. Department of Energy Low-Level Waste Disposal Facility Closure Plans (DOE, 1999a). This interim closure plan meets closure and post-closure monitoring requirements of the order DOE O 435.1, manual DOE M 435.1-1, Title 40 Code of Federal Regulations (CFR) Part 191, 40 CFR 265, Nevada Administrative Code (NAC) 444.743, and Resource Conservation and Recovery Act (RCRA) requirements as incorporated into NAC 444.8632. The Area 5 RWMS accepts primarily packaged low-level waste (LLW), low-level mixed waste (LLMW), and asbestiform low-level waste (ALLW) for disposal in excavated disposal cells.

  14. SIRTF and star formation

    NASA Technical Reports Server (NTRS)

    Shu, Frank H.

    1988-01-01

    Four problems in the field of star formation that can be attacked to advantage with SIRTF are discussed: (1) the patterns of star formation in spiral galaxies, (2) the physical mechanism for bimodal star formation, (3) the nature of bipolar outflows from young stellar objects, and (4) the birth of brown dwarfs. In each case, SIRTF can provide the crucial combination of high angular resolution with great sensitivity over a broad range of wavelengths that is needed to address the relevant issues.

  15. Meiotic recombination cold spots in chromosomal cohesion sites.

    PubMed

    Ito, Masaru; Kugou, Kazuto; Fawcett, Jeffrey A; Mura, Sachiko; Ikeda, Sho; Innan, Hideki; Ohta, Kunihiro

    2014-05-01

    Meiotic chromosome architecture called 'axis-loop structures' and histone modifications have been shown to regulate the Spo11-dependent formation of DNA double-strand breaks (DSBs) that trigger meiotic recombination. Using genome-wide chromatin immunoprecipitation (ChIP) analyses followed by deep sequencing, we compared the genome-wide distribution of the axis protein Rec8 (the kleisin subunit of meiotic cohesin) with that of oligomeric DNA covalently bound to Spo11, indicative of DSB sites. The frequency of DSB sites is overall constant between Rec8 binding sites. However, DSB cold spots are observed in regions spanning ±0.8 kb around Rec8 binding sites. The axis-associated cold spots are not due to the exclusion of Spo11 localization from the axis, because ChIP experiments showed that substantial Spo11 persists at Rec8 binding sites during DSB formation. Spo11 fused with Gal4 DNA binding domain (Gal4BD-Spo11) tethered in close proximity (≤0.8 kb) to Rec8 binding sites hardly forms meiotic DSBs, in contrast with other regions. In addition, H3K4 trimethylation (H3K4me3) remarkably decreases at Rec8 binding sites. These results suggest that reduced histone H3K4me3 in combination with inactivation of Spo11 activity on the axis discourages DSB hot spot formation.

  16. Developing a perioperative educational video web site.

    PubMed

    O'Dowd Bell, Lynn

    2012-04-01

    Nurses frequently have to adjust to changes in technology, particularly in the OR, but cataloging the wealth of resources commonly used in the OR (eg, equipment, supplies, how to use them) has not kept pace. To address this, I worked with the information systems administrative coordinator at the University of Texas Medical Branch, Galveston, to design and implement a perioperative intranet site that includes videos and fact sheets about equipment and supplies and that can be accessed by all perioperative staff members. This required promoting the idea and getting stakeholder sign-on, soliciting videotapes and DVDs and screening all submissions for appropriateness, choosing and formatting applicable resources for use on the site, working with members of the information systems department to create a web site after the video library was assembled, and helping staff members use and accept the site as a valuable educational resource. This intranet web site has been available to staff members for two years, and data from a recent survey of staff members and from mandatory intranet inservice compliance programs show evidence of its effectiveness.

  17. Reservoir High's TE Site Wins Web Site of the Month

    ERIC Educational Resources Information Center

    Tech Directions, 2008

    2008-01-01

    This article features "Mr. Rhine's Technology Education Web Site," a winner of the Web Site of the Month. This Web site was designed by Luke Rhine, a teacher at the Reservoir High School in Fulton, Maryland. Rhine's Web site offers course descriptions and syllabuses, class calendars, lectures and presentations, design briefs and other course…

  18. 77 FR 75174 - Draft Guidance for Industry on Providing Submissions in Electronic Format-Summary Level Clinical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-19

    ... Electronic Format--Summary Level Clinical Site Data for Center for Drug Evaluation and Research's Inspection... ``Providing Submissions in Electronic Format--Summary Level Clinical Site Data for CDER's Inspection Planning... investigator sites for onsite inspection by FDA during the review of marketing applications. This...

  19. GLOBAL STAR FORMATION REVISITED

    SciTech Connect

    Silk, Joseph; Norman, Colin E-mail: norman@stsci.edu

    2009-07-20

    A general treatment of disk star formation is developed from a dissipative multiphase model, with the dominant dissipation due to cloud collisions. The Schmidt-Kennicutt (SK) law emerges naturally for star-forming disks and starbursts. We predict that there should be an inverse correlation between Tully-Fisher law and SK law residuals. The model is extended to include a multiphase treatment of supernova feedback that leads to a turbulent pressure-regulated generalization of the star formation law and is applicable to gas-rich starbursts. Enhanced pressure, as expected in merger-induced star formation, enhances star formation efficiency. An upper limit is derived for the disk star formation rate in starbursts that depends on the ratio of global ISM to cloud pressures. We extend these considerations to the case where the interstellar gas pressure in the inner galaxy is dominated by outflows from a central active galactic nucleus (AGN). During massive spheroid formation, AGN-driven winds trigger star formation, resulting in enhanced supernova feedback and outflows. The outflows are comparable to the AGN-boosted star formation rate and saturate in the super-Eddington limit. Downsizing of both SMBH and spheroids is a consequence of AGN-driven positive feedback. Bondi accretion feeds the central black hole with a specific accretion rate that is proportional to the black hole mass. AGN-enhanced star formation is mediated by turbulent pressure and relates spheroid star formation rate to black hole accretion rate. The relation between black hole mass and spheroid velocity dispersion has a coefficient (Salpeter time to gas consumption time ratio) that provides an arrow of time. Highly efficient, AGN-boosted star formation can occur at high redshift.

  20. Creation and Maintenance of a Syllabi Web Site: A Case Study.

    ERIC Educational Resources Information Center

    Kahn, Russell L.

    1997-01-01

    Describes the development and maintenance of the Association of Teachers of Technical Writing's (ATTW) Web site for course syllabi ranging from communication theory to Web design at Texas Tech University. Examines the rationale behind a central site; site design issues; updating method; and software used--Rich Text Format (RTF), RTFtoHTML, Fetch…

  1. [Surgical site infections].

    PubMed

    Sganga, Gabriele

    2014-01-01

    Surgical site infections (SSIs) are recognized as a common surgical complication, occurring in about 2-5% of all surgical procedures. SSIs represent the third most frequent nosocomial infection, accounting for 14-16% of all infections observed in hospitalized patients and up to 38% of those observed among surgical patients. Knowledge of incidence, epidemiology, classification, process of wound healing, and pathogenesis of surgical site infection is of great importance. Given the high economic burden that infections provoke, beyond the increased morbidity and mortality, it appears mandatory to improve our tools in order to reduce their incidence, as a reduction of only 0.1% can result in a considerable saving of economic resources to be allocated to other activities, such as screening and prevention programs.

  2. Formative Assessment Probes

    ERIC Educational Resources Information Center

    Eberle, Francis; Keeley, Page

    2008-01-01

    Formative assessment probes can be effective tools to help teachers build a bridge between students' initial ideas and scientific ones. In this article, the authors describe how using two formative assessment probes can help teachers determine the extent to which students make similar connections between developing a concept of matter and a…

  3. Ice Formation on Wings

    NASA Technical Reports Server (NTRS)

    Ritz, L

    1939-01-01

    This report makes use of the results obtained in the Gottingen ice tunnel in which the atmospheric conditions are simulated and the process of ice formation photographed. The effect of ice formation is threefold: 1) added weight to the airplane; 2) a change in the lift and drag forces; 3) a change in the stability characteristics.

  4. School Formative Feedback Systems

    ERIC Educational Resources Information Center

    Halverson, Richard

    2010-01-01

    Data-driven instructional improvement relies on developing coherent systems that allow school staff to generate, interpret, and act upon quality formative information on students and school programs. This article offers a formative feedback system model that captures how school leaders and teachers structure artifacts and practices to create…

  5. Understanding Alliance Formation Patterns

    DTIC Science & Technology

    2015-12-01

    most of the alliance formations throughout history. Using logistic regression models and statistical analysis for different historical periods from... historical periods, especially under conditions of war and peace and based on the polarity of the international system. The approach presented in the...alliance formation, historical periods, geographical proximity, trade exchange, regime type, national material capability, system-level conditions 15

  6. Formative Assessment in Context

    ERIC Educational Resources Information Center

    Oxenford-O'Brian, Julie

    2013-01-01

    This dissertation responds to critical gaps in current research on formative assessment practice which could limit successful implementation of this practice within the K-12 classroom context. The study applies a socio cultural perspective of learning to interpret a cross-case analysis of formative assessment practice occurring during one…

  7. Site environmental report: 1993

    SciTech Connect

    Not Available

    1994-10-01

    The Inhalation Toxicology Research Institute (ITRI) has in place an extensive radiological and nonradiological environmental monitoring program which monitors air emissions, groundwater, soil, and ambient air around the facility. ITRI is operated in a manner that minimizes any adverse impact to the environment. The ITRI facility is in compliance with air quality and hazardous waste regulations. However, due to the previous operations of its six on-site sewage lagoons, groundwater in the ITRI vicinity contains nitrate, total dissolved solids, and sulfate contamination that exceeds state groundwater standards. Also, due to an underground fuel system leak, a localized area of groundwater is contaminated with diesel fuel. In addition, a small quantity of mixed low-level waste generated in the process of laboratory research is presently stored on site while treatment and disposal options are determined. Based on present information, the contaminant plume originating from the sewage lagoons has not migrated off the ITRI site. In addition, a groundwater assessment is underway to determine the extent of groundwater contamination and options for remediation, if required. Diesel fuel leaks and spills have been characterized, and the extent of the contamination is currently being assessed with five new monitoring wells, MW-12 through {minus}15. All underground tanks and fuel lines have been removed, along with associated contaminated soil. A soil venting and volatilization remediation system continues to operate in the area of a fuel leak, where further remediation may be required to remove diesel oil in the groundwater.

  8. 1999 SITE ENVIRONMENTAL REPORT

    SciTech Connect

    ENGEL-COX,J.; ZIMMERMAN,E.; LEE,R.; WILLIAMS,J.; GREEN,T.; PAQUETTE,D.; HOODA,B.; SCARPITTA,S.; GENZER,P.; ET AL

    2000-09-01

    Throughout the scientific community, Brookhaven National Laboratory (BNL) is renowned for its leading-edge research in physics, medicine, chemistry, biology, materials, and the environment. BNL is committed to supporting its world-class scientific research with an internationally recognized environmental protection program. The 1999 Site Environmental Report (SER) summarizes the status of the Laboratory's environmental programs and performance, including the steady progress towards cleaning up the site and fully integrating environmental stewardship into all facets of the Laboratory's mission. BNL is located on 5,265 acres of pine barrens in Suffolk County in the center of Long Island, New York. The Laboratory is situated above a sole source aquifer at the headwaters of the Peconic River; therefore, protecting ground and surface water quality is a special concern. Approximately 3,600 acres of the site are undeveloped and serve as habitat for a wide variety of animals and plants, including one New York State endangered species, the tiger salamander, and two New York State threatened species, the banded sunfish and the stiff goldenrod. Monitoring, preserving, and restoring these ecological resources is a high priority for the Laboratory.

  9. Astronomy. Internet site

    NASA Astrophysics Data System (ADS)

    Maksimenko, Anatoly Vasilievich

    The Internet site covers a wide area of actual astronomical topics, including 1) Astronomical News 2) Didactics of Astronomy 3) Space Research (Cosmonautics) 4) That's interesting 5) A Handbook of an astronomer 6) The Solar system 7) A Photogalery 8) Works of Schoolars 9) History of Astronomy The most important of them is the section concerning Space Research (Cosmonautics). This section covers a wide range of topics, beginning with very complete Illustrated History of Soviet Space research , the building of Soviet Rockets, a complete list of Cosmonauts with biographies, a list of all the flies. The author of the site concerns much ineterest to recent and extraordinary astronomiucal phenomena, such as Hazardous asteroids, Comets, Solar and Moon Eclipses, Meteorites, as well as to correct from the scientifical point of view interpretation of the extraordinary astronomical phenomena. The section concerning the Solar system is richly illustrated and give detailed explanations to Solar System evolution and actual state, explains many phenomena in the Solar system. THe Internet site is designed for schoolars as well as to amateur and professional astronomers.

  10. International Symposium on Site Characterization for CO2Geological Storage

    SciTech Connect

    Tsang, Chin-Fu

    2006-02-23

    Several technological options have been proposed to stabilize atmospheric concentrations of CO{sub 2}. One proposed remedy is to separate and capture CO{sub 2} from fossil-fuel power plants and other stationary industrial sources and to inject the CO{sub 2} into deep subsurface formations for long-term storage and sequestration. Characterization of geologic formations for sequestration of large quantities of CO{sub 2} needs to be carefully considered to ensure that sites are suitable for long-term storage and that there will be no adverse impacts to human health or the environment. The Intergovernmental Panel on Climate Change (IPCC) Special Report on Carbon Dioxide Capture and Storage (Final Draft, October 2005) states that ''Site characterization, selection and performance prediction are crucial for successful geological storage. Before selecting a site, the geological setting must be characterized to determine if the overlying cap rock will provide an effective seal, if there is a sufficiently voluminous and permeable storage formation, and whether any abandoned or active wells will compromise the integrity of the seal. Moreover, the availability of good site characterization data is critical for the reliability of models''. This International Symposium on Site Characterization for CO{sub 2} Geological Storage (CO2SC) addresses the particular issue of site characterization and site selection related to the geologic storage of carbon dioxide. Presentations and discussions cover the various aspects associated with characterization and selection of potential CO{sub 2} storage sites, with emphasis on advances in process understanding, development of measurement methods, identification of key site features and parameters, site characterization strategies, and case studies.

  11. Biomineralization: mineral formation by organisms

    NASA Astrophysics Data System (ADS)

    Addadi, Lia; Weiner, Steve

    2014-09-01

    Organisms form many different types of minerals, with diverse shapes and sizes. These minerals fulfill a variety of functions. Inspired by the late H A Lowenstam, Steve Weiner and Lia Addadi have addressed many questions that relate to the mechanisms by which biological organisms produce these mineral phases and how their structures relate to their functions. Addadi and Weiner have explored the manner in which macromolecules extracted from mineralized tissues can interact with some crystal planes and not others, how these macromolecules can be occluded inside the forming crystals residing preferentially on specific crystal planes, and how they can induce one polymorph of calcium carbonate and not another to nucleate. Addadi and Weiner have also identified a novel strategy used by the sea urchin to form its smooth and convoluted mineralized skeletal elements. The strategy involves the initial production by cells of a highly disordered mineral precursor phase in vesicles, and then the export of this so-called amorphous phase to the site of skeletal formation, where it crystallizes. This strategy is now known to be used by many different invertebrate phyla, as well as by vertebrates to build bones and teeth. One of the major current research aims of the Weiner--Addadi group is to understand the biomineralization pathways whereby ions are extracted from the environment, are transported and deposited inside cells within vesicles, how these disordered phases are then transferred to the site of skeletal formation, and finally how the so-called amorphous phase crystallizes. Biology has clearly evolved unique strategies for forming crystalline minerals. Despite more than 300 years of research in this field, many challenging questions still remain unanswered.

  12. The Oak Ridge Reservation Annual Site Environmental Report Summary, 2007

    SciTech Connect

    None, None

    2009-02-28

    The Oak Ridge Reservation Annual Site Environmental Report is prepared and published each year to inform the public of the environmental activities that take place on the reservation and in the surrounding areas. It is written to comply with DOE Order 231.1A, Environment, Safety, and Health Reporting. This document has been prepared to present the highlights of the Oak Ridge Reservation Annual Site Environmental Report 2007 in an easy-to-read, summary format.

  13. Formation of Regulatory Modules by Local Sequence Duplication

    PubMed Central

    Nourmohammad, Armita; Lässig, Michael

    2011-01-01

    Turnover of regulatory sequence and function is an important part of molecular evolution. But what are the modes of sequence evolution leading to rapid formation and loss of regulatory sites? Here we show that a large fraction of neighboring transcription factor binding sites in the fly genome have formed from a common sequence origin by local duplications. This mode of evolution is found to produce regulatory information: duplications can seed new sites in the neighborhood of existing sites. Duplicate seeds evolve subsequently by point mutations, often towards binding a different factor than their ancestral neighbor sites. These results are based on a statistical analysis of 346 cis-regulatory modules in the Drosophila melanogaster genome, and a comparison set of intergenic regulatory sequence in Saccharomyces cerevisiae. In fly regulatory modules, pairs of binding sites show significantly enhanced sequence similarity up to distances of about 50 bp. We analyze these data in terms of an evolutionary model with two distinct modes of site formation: (i) evolution from independent sequence origin and (ii) divergent evolution following duplication of a common ancestor sequence. Our results suggest that pervasive formation of binding sites by local sequence duplications distinguishes the complex regulatory architecture of higher eukaryotes from the simpler architecture of unicellular organisms. PMID:21998564

  14. Probabilistic Modeling of Rosette Formation

    PubMed Central

    Long, Mian; Chen, Juan; Jiang, Ning; Selvaraj, Periasamy; McEver, Rodger P.; Zhu, Cheng

    2006-01-01

    Rosetting, or forming a cell aggregate between a single target nucleated cell and a number of red blood cells (RBCs), is a simple assay for cell adhesion mediated by specific receptor-ligand interaction. For example, rosette formation between sheep RBC and human lymphocytes has been used to differentiate T cells from B cells. Rosetting assay is commonly used to determine the interaction of Fc γ-receptors (FcγR) expressed on inflammatory cells and IgG coated on RBCs. Despite its wide use in measuring cell adhesion, the biophysical parameters of rosette formation have not been well characterized. Here we developed a probabilistic model to describe the distribution of rosette sizes, which is Poissonian. The average rosette size is predicted to be proportional to the apparent two-dimensional binding affinity of the interacting receptor-ligand pair and their site densities. The model has been supported by experiments of rosettes mediated by four molecular interactions: FcγRIII interacting with IgG, T cell receptor and coreceptor CD8 interacting with antigen peptide presented by major histocompatibility molecule, P-selectin interacting with P-selectin glycoprotein ligand 1 (PSGL-1), and L-selectin interacting with PSGL-1. The latter two are structurally similar and are different from the former two. Fitting the model to data enabled us to evaluate the apparent effective two-dimensional binding affinity of the interacting molecular pairs: 7.19 × 10−5 μm4 for FcγRIII-IgG interaction, 4.66 × 10−3 μm4 for P-selectin-PSGL-1 interaction, and 0.94 × 10−3 μm4 for L-selectin-PSGL-1 interaction. These results elucidate the biophysical mechanism of rosette formation and enable it to become a semiquantitative assay that relates the rosette size to the effective affinity for receptor-ligand binding. PMID:16603493

  15. Mechanisms of human kidney stone formation.

    PubMed

    Evan, Andrew P; Worcester, Elaine M; Coe, Fredric L; Williams, James; Lingeman, James E

    2015-01-01

    The precise mechanisms of kidney stone formation and growth are not completely known, even though human stone disease appears to be one of the oldest diseases known to medicine. With the advent of the new digital endoscope and detailed renal physiological studies performed on well phenotyped stone formers, substantial advances have been made in our knowledge of the pathogenesis of the most common type of stone former, the idiopathic calcium oxalate stone former as well as nine other stone forming groups. The observations from our group on human stone formers and those of others on model systems have suggested four entirely different pathways for kidney stone formation. Calcium oxalate stone growth over sites of Randall's plaque appear to be the primary mode of stone formation for those patients with hypercalciuria. Overgrowths off the ends of Bellini duct plugs have been noted in most stone phenotypes, do they result in a clinical stone? Micro-lith formation does occur within the lumens of dilated inner medullary collecting ducts of cystinuric stone formers and appear to be confined to this space. Lastly, cystinuric stone formers also have numerous small, oval, smooth yellow appearing calyceal stones suggestive of formation in free solution. The scientific basis for each of these four modes of stone formation are reviewed and used to explore novel research opportunities.

  16. Gasbuggy Site Assessment and Risk Evaluation

    SciTech Connect

    2011-03-01

    The Gasbuggy site is in northern New Mexico in the San Juan Basin, Rio Arriba County (Figure 1-1). The Gasbuggy experiment was designed to evaluate the use of a nuclear detonation to enhance natural gas production from the Pictured Cliffs Formation, a tight, gas-bearing sandstone formation. The 29-kiloton-yield nuclear device was placed in a 17.5-inch wellbore at 4,240 feet (ft) below ground surface (bgs), approximately 40 ft below the Pictured Cliffs/Lewis shale contact, in an attempt to force the cavity/chimney formed by the detonation up into the Pictured Cliffs Sandstone. The test was conducted below the southwest quarter of Section 36, Township 29 North, Range 4 West, New Mexico Principal Meridian. The device was detonated on December 10, 1967, creating a 335-ft-high chimney above the detonation point and a cavity 160 ft in diameter. The gas produced from GB-ER (the emplacement and reentry well) during the post-detonation production tests was radioactive and diluted, primarily by carbon dioxide. After 2 years, the energy content of the gas had recovered to 80 percent of the value of gas in conventionally developed wells in the area. There is currently no technology capable of remediating deep underground nuclear detonation cavities and chimneys. Consequently, the U.S. Department of Energy (DOE) must continue to manage the Gasbuggy site to ensure that no inadvertent intrusion into the residual contamination occurs. DOE has complete control over the 1/4 section (160 acres) containing the shot cavity, and no drilling is permitted on that property. However, oil and gas leases are on the surrounding land. Therefore, the most likely route of intrusion and potential exposure would be through contaminated natural gas or contaminated water migrating into a producing natural gas well outside the immediate vicinity of ground zero. The purpose of this report is to describe the current site conditions and evaluate the potential health risks posed by the most plausible

  17. Challenges in planet formation

    NASA Astrophysics Data System (ADS)

    Morbidelli, Alessandro; Raymond, Sean N.

    2016-10-01

    Over the past two decades, large strides have been made in the field of planet formation. Yet fundamental questions remain. Here we review our state of understanding of five fundamental bottlenecks in planet formation. These are the following: (1) the structure and evolution of protoplanetary disks; (2) the growth of the first planetesimals; (3) orbital migration driven by interactions between protoplanets and gaseous disk; (4) the origin of the Solar System's orbital architecture; and (5) the relationship between observed super-Earths and our own terrestrial planets. Given our lack of understanding of these issues, even the most successful formation models remain on shaky ground.

  18. Wood formation in Angiosperms.

    PubMed

    Déjardin, Annabelle; Laurans, Françoise; Arnaud, Dominique; Breton, Christian; Pilate, Gilles; Leplé, Jean-Charles

    2010-04-01

    Wood formation is a complex biological process, involving five major developmental steps, including (1) cell division from a secondary meristem called the vascular cambium, (2) cell expansion (cell elongation and radial enlargement), (3) secondary cell wall deposition, (4) programmed cell death, and (5) heartwood formation. Thanks to the development of genomic studies in woody species, as well as genetic engineering, recent progress has been made in the understanding of the molecular mechanisms underlying wood formation. In this review, we will focus on two different aspects, the lignification process and the control of microfibril angle in the cell wall of wood fibres, as they are both key features of wood material properties.

  19. Selective pacing sites.

    PubMed

    Coppola, G; La Greca, C; Corrado, E; Ajello, L; Nogara, A; Ciaramitaro, G; Augugliaro, S; Novo, G; Novo, S; Assennato, P

    2015-04-01

    he right ventricular apex (RVA) has always been the most used pacing site, because it is easily accessible and provides a stable lead position with a low dislodgment rate. However, it is well-known that long-term right ventricular apical pacing may have deleterious effects on left ventricular function by inducing a iatrogenic left bundle branch block, which can have strong influences on the left ventricle hemodynamic performances. More specifically, RVA pacing causes abnormal contraction patterns and the consequent dyssynchrony may cause myocardial perfusion defects, histopathological alterations, left ventricular dilation and both systolic and diastolic left ventricular dysfunction. All these long-term changes could account for the higher morbidity and mortality rates observe in patients with chronic RVA pacing compared with atrial pacing. This observation led to the reassessment of traditional approaches and to the research of alternative pacing sites, in order to get to more physiological pattern of ventricular activation and to avoid deleterious effects. Then, attempts were made with: right ventricular outflow tract (RVOT) pacing, direct His bundle pacing (DHBP), parahisian pacing (PHP) and bifocal (RVA + RVOT) pacing. For example, RVOT pacing, especially in its septal portion, is superior to the RVA pacing and it would determine a contraction pattern very similar to the spontaneous one, not only because the septal portions are the first parts to became depolarized, but also for the proximity to the normal conduction system. RVOT is preferable in terms of safety too. DHBP is an attractive alternative to RVA pacing because it leads to a synchronous depolarization of myocardial cells and, therefore, to an efficient ventricular contraction. So it would be the best technique, however the procedure requires longer average implant times and dedicated instruments and it cannot be carried out in patients affected by His bundle pathologies; furthermore, due to the His

  20. Site Enforcement Tracking System (SETS): National PRP listing by site

    SciTech Connect

    Not Available

    1992-07-01

    When expending Superfund monies at a CERCLA (Comprehensive Environmental Response, Compensation and Liability Act) site, EPA must conduct a search to identify parties with potential financial responsibility for remediation of uncontrolled hazardous waste sites. EPA regional Superfund Waste Management Staff issue a notice letter to the potentially responsible party (PRP). Data from the notice letter is used to form the Site Enforcement Tracking System (SETS). The data includes PRP name and address, a company contact person, the date the notice was issued, and the related CERCLA site name and identification number. SETS was created to track PRP identification at both NPL (National Priorities List) and non-NPL sites. SETS does not address the range of other administrative duties related to tracking the PRP. The listing by site name is organized in the following manner. Sites are sorted by state, as indicated in the site ID number. The first two characters of the site ID number constitute the state abbreviation of the site location. The listing by party name is arranged alphabetically by the name of the party and provides a company contact and address. Within each record, the sites associated with the PRP are listed. The first two characters of the site ID number constitute the state abbreviation of the site location.

  1. Lawrence Berkeley Laboratory 1994 site environmental report

    SciTech Connect

    1995-05-01

    The 1994 Site Environmental Report summarizes environmental activities at Lawrence Berkeley Laboratory (LBL) for the calendar year (CY) 1994. The report strives to present environmental data in a manner that characterizes the performance and compliance status of the Laboratory`s environmental management programs when measured against regulatory standards and DOE requirements. The report also discusses significant highlight and planning efforts of these programs. The format and content of the report are consistent with the requirements of the U.S. Department of Energy (DOE) Order 5400.1, General Environmental Protection Program.

  2. 1996 Site environmental report

    SciTech Connect

    1997-06-01

    The FEMP is a Department of Energy (DOE)-owned facility that produced high-quality uranium metals for military defense for nearly 40 years. DOE suspended production at the FEMP in 1989 and formally ended production in 1991. Although production activities have ceased, the site continues to examine the air and liquid pathways as possible routes through which pollutants from past operations and current remedial activities may leave the FEMP. The Site Environmental Report (SER) is prepared annually in accordance with DOE Order 5400.1, General Environmental Protection Program. This 1996 SER provides the general public as well as scientists and engineers with the results from the ongoing Environmental Monitoring Program. Also included in this report is information concerning the FEMP progress toward achieving full compliance with requirements set forth by DOE, U.S. Environmental Protection Agency (EPA), and Ohio EPA (OEPA). For some readers, the highlights provided in this Executive Summary may provide sufficient information. Many readers, however, may wish are presented here. All information presented in this summary is discussed more fully in the main body of this report.

  3. 2003 SITE ENVIRONMENTAL REPORT

    SciTech Connect

    ENVIRONMENT AND WASTE MANAGMENT SERVICES DIVISION; ET AL.

    2004-10-01

    Each year, Brookhaven National Laboratory (BNL), a multi-program national laboratory, prepares an annual Site Environmental Report (SER) in accordance with Order 231.1A, Environment, Safety and Health Reporting, of the U.S. Department of Energy (DOE). The SER is written to inform outside regulators, the public, and Laboratory employees of BNL's environmental performance during the calendar year in review, and to summarize BNL's on-site environmental data; environmental management performance; compliance with applicable DOE, Environmental Protection Agency (EPA), state, and local regulations; and environmental, restoration, and surveillance monitoring programs. BNL has prepared annual SERs since 1971 and has documented nearly all of its environmental history since the Laboratory's inception in 1947. This report is intended to be a technical document. It is available in print and as a downloadable file on the BNL web page at http://www.bnl.ser.htm. A summary of the SER is also prepared each year to provide a general overview, and is distributed with a CD version of the full-length SER. The summary supports BNL's educational and community outreach program.

  4. Spirit's Winter Work Site

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Annotated Version

    This portion of an image acquired by the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment camera shows the Spirit rover's winter campaign site. Spirit was parked on a slope tilted 11 degrees to the north to maximize sunlight during the southern winter season. 'Tyrone' is an area where the rover's wheels disturbed light-toned soils. Remote sensing and in-situ analyses found the light-toned soil at Tyrone to be sulfate rich and hydrated. The original picture is catalogued as PSP_001513_1655_red and was taken on Sept. 29, 2006.

    NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.

  5. Site Recommendation Subsurface Layout

    SciTech Connect

    C.L. Linden

    2000-06-28

    The purpose of this analysis is to develop a Subsurface Facility layout that is capable of accommodating the statutory capacity of 70,000 metric tons of uranium (MTU), as well as an option to expand the inventory capacity, if authorized, to 97,000 MTU. The layout configuration also requires a degree of flexibility to accommodate potential changes in site conditions or program requirements. The objective of this analysis is to provide a conceptual design of the Subsurface Facility sufficient to support the development of the Subsurface Facility System Description Document (CRWMS M&O 2000e) and the ''Emplacement Drift System Description Document'' (CRWMS M&O 2000i). As well, this analysis provides input to the Site Recommendation Consideration Report. The scope of this analysis includes: (1) Evaluation of the existing facilities and their integration into the Subsurface Facility design. (2) Identification and incorporation of factors influencing Subsurface Facility design, such as geological constraints, thermal loading, constructibility, subsurface ventilation, drainage control, radiological considerations, and the Test and Evaluation Facilities. (3) Development of a layout showing an available area in the primary area sufficient to support both the waste inventories and individual layouts showing the emplacement area required for 70,000 MTU and, if authorized, 97,000 MTU.

  6. AMF 1 Site Science

    SciTech Connect

    Miller, Mark Alan

    2016-08-18

    This report documents progress on DOE Grant# DE-FG02-08ER64531 funded by the Department of Energy’s Atmospheric Systems Research (ASR) program covering the period between its inception in 2008 and its conclusion in 2014. The Atmospheric Radiation Measurement (ARM) Program’s Mobile Facility #1 (AMF#1) is a collection of state-of-the art atmospheric sensing systems including remote and in situ instrumentation designed to characterize the atmospheric column above and in the immediate vicinity of the deployment location. The grant discussed in this report funded the activities of the AMF#1 Site Scientist Team. Broad responsibilities of this team included examining new deployment sites and recommending instrument deployment configurations; data quality control during the early stages of deployments and for certain instruments through the course of the deployment; scientific outreach in the host country or location (particularly international deployments); scientific research oriented toward basic questions about cloud physics and radiation transfer in the deployment region; and training of Ph.D. students to conduct future research relevant to the Atmospheric Systems Research (ASR) program.

  7. Site Plan & Site Section of Citrus Landscape (Showing Relationship ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Site Plan & Site Section of Citrus Landscape (Showing Relationship of Groves & Irrigation System to Grove Canal) - Arlington Heights Citrus Landscape, Southwestern portion of city of Riverside, Riverside, Riverside County, CA

  8. Site Plan & Site Section of Citrus Landscape (Showing Relationship ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Site Plan & Site Section of Citrus Landscape (Showing Relationship of Victoria Avenue to Citrus Groves) - Arlington Heights Citrus Landscape, Southwestern portion of city of Riverside, Riverside, Riverside County, CA

  9. Dust Devil Formation

    NASA Astrophysics Data System (ADS)

    Rafkin, S.; Jemmett-Smith, B.; Fenton, L.; Lorenz, R.; Takemi, T.; Ito, J.; Tyler, D.

    2016-11-01

    The essential dynamical characteristic of convective vortices, including dust devils, is a highly localized vorticity tube that extends into the vertical. This chapter is concerned with both the generation of vorticity and the subsequent focusing of that vorticity into a tight vortex, and with the environmental conditions that are conducive to the formation of convective vortices in general and dust devils in particular. A review of observations, theory, and modeling of dust devil formation is provided.

  10. Plant Formate Dehydrogenase

    SciTech Connect

    John Markwell

    2005-01-10

    The research in this study identified formate dehydrogenase, an enzyme that plays a metabolic role on the periphery of one-carbon metabolism, has an unusual localization in Arabidopsis thaliana and that the enzyme has an unusual kinetic plasticity. These properties make it possible that this enzyme could be engineered to attempt to engineer plants with an improved photosynthetic efficiency. We have produced transgenic Arabidopsis and tobacco plants with increased expression of the formate dehydrogenase enzyme to initiate further studies.

  11. Formation of Giant Planets

    NASA Technical Reports Server (NTRS)

    Lin, Douglas

    1999-01-01

    Under the support of NASA Origins grant, we studied the formation of gaps in protoplanetary disks due the tidal interaction between a fully grown protoplanet and protostellar disk. The result of this study is published in the Astrophysical Journal, (vol 514, 344-367, 1999) and in several conference proceedings. The main focus of this work is to analyze planet-disk interaction during the final stages of protoplanetary formation.

  12. Display formats manual

    NASA Technical Reports Server (NTRS)

    Runnels, R. L.

    1973-01-01

    The standards and procedures for the generation of operational display formats to be used in the Mission Control Center (MCC) display control system are presented. The required effort, forms, and fundamentals for the design, specifications, and production of display formats are identified. The principles of display design and system constraints controlling the creation of optimum operational displays for mission control are explained. The basic two types of MCC display systems for presenting information are described.

  13. ADASS XII Meeting Web Site

    NASA Astrophysics Data System (ADS)

    Liou, C.; Hulbert, S.

    We present the architecture, design, and implementation details of the ADASS XII web site. The web site was implemented in Zope, a high-performance application server, web server, and content management system rolled into one. Zope includes a robust, scalable object database, web services architecture, and powerful programming capabilities. The web site was built to conform to HTML, CSS, and accessibility standards as adopted by the W3C. This dynamic web site also taps into a back-end Sybase database while requiring a minimal amount of coding. We offer this site as a prototype web site suitable for reuse in supporting future ADASS meetings.

  14. Autonomous Formation Flight

    NASA Technical Reports Server (NTRS)

    Schkolnik, Gerard S.; Cobleigh, Brent

    2004-01-01

    NASA's Strategic Plan for the Aerospace Technology Enterprise includes ambitious objectives focused on affordable air travel, reduced emissions, and expanded aviation-system capacity. NASA Dryden Flight Research Center, in cooperation with NASA Ames Research Center, the Boeing Company, and the University of California, Los Angeles, has embarked on an autonomous-formation-flight project that promises to make significant strides towards these goals. For millions of years, birds have taken advantage of the aerodynamic benefit of flying in formation. The traditional "V" formation flown by many species of birds (including gulls, pelicans, and geese) enables each of the trailing birds to fly in the upwash flow field that exists just outboard of the bird immediately ahead in the formation. The result for each trailing bird is a decrease in induced drag and thus a reduction in the energy needed to maintain a given speed. Hence, for migratory birds, formation flight extends the range of the system of birds over the range of birds flying solo. The Autonomous Formation Flight (AFF) Project is seeking to extend this symbiotic relationship to aircraft.

  15. Preliminary siting characterization Salt Disposition Facility - Site B

    SciTech Connect

    Wyatt, D.

    2000-01-04

    A siting and reconnaissance geotechnical program has been completed in S-Area at the Savannah River Site in South Carolina. This program investigated the subsurface conditions for the area known as ``Salt Disposition Facility (SDF), Site B'' located northeast of H-Area and within the S-Area. Data acquired from the Site B investigation includes both field exploration and laboratory test data.

  16. Atomic-Scale Assembly of a Heterogeneous Catalytic Site

    SciTech Connect

    Han, Patrick; Axnanda, Stephanus; Lyubinetsky, Igor; Goodman, D. W.

    2007-11-21

    The (100) surface of a AuPd bulk alloy was imaged by scanning tunneling microscopy. Chemical-contrast revealed structures with short-range order involving surface Pd atoms at c(2x2) sites with respect to the surface lattice—a first time observation of a known active heterogeneous catalytic site with atomic resolution. Comparison of the Pd distribution in a AuPd(100) surface with that in a Au3Pd(100) surface shows the unique thermodynamic properties of the 50 : 50 alloy are decisive in controlling the formation of isolated Pd sites.

  17. Site Characterization Work Plan for the Gnome-Coach Site, New Mexico (Rev. 1, January 2002)

    SciTech Connect

    U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office

    2002-01-14

    Project Gnome was the first nuclear experiment conducted under the U.S. Atomic Energy Commission (AEC), predecessor to the U.S. Department of Energy (DOE), Plowshare Program. The Plowshare Program focused on developing nuclear devices exclusively for peaceful purposes. The intent of the Gnome experiment was to evaluate the effects of a nuclear detonation in a salt medium. Historically, Project Gnome consisted of a single detonation of a nuclear device on December 10, 1961 with the Salado Formation. Since the Gnome detonation, the AEC/DOE has conducted surface restoration, site reconnaissance, and decontamination and decommissioning activities at the site. In addition, annual groundwater sampling is performed under a long-term hydrological monitoring program begun in 1972. Coach, an experiment to be located near the Gnome project, was initially scheduled for 1963. Although construction and rehabilitation were completed for Coach, the experiment was canceled and never executed. Known collectively as Project Gnome-Coach, the site is located approximately 25 miles east of Carlsbad, New Mexico, in Eddy County, and is comprised of nearly 680 acres, of which approximately 60 acres are disturbed from the combined AEC/DOE operations. The scope of this work plan is to document the environmental objectives and the proposed technical site investigation strategies that will be utilized for the site characterization of the project. The subsurface at the Gnome-Coach site has two contaminant sources that are fundamentally different in terms of both their stratigraphic location and release mechanism. The goal of this characterization is to collect data of sufficient quantity and quality to establish current site conditions and to use the data to identify and evaluate if further action is required to protect human health and the environment and achieve permanent closure of the site. The results of these activities will be presented in a subsequent corrective action decision document.

  18. Site Characterization Work Plan for Gnome-Coach Site, New Mexico

    SciTech Connect

    DOE /NV

    2001-02-13

    Project Gnome was the first nuclear experiment conducted under the U.S. Atomic Energy Commission (AEC), predecessor to the U.S. Department of Energy (DOE), Plowshare Program. Gnome was part of a joint government-industry experiment focused on developing nuclear devices exclusively for peaceful purposes. The intent of the Gnome experiment was to evaluate the effects of a nuclear detonation in a salt medium. Historically, Project Gnome consisted of a single detonation of a nuclear device on December 10, 1961. Since the Gnome detonation, the AEC/DOE has conducted surface restoration, site reconnaissance, and decontamination and decommissioning activities at the site. In addition, annual groundwater sampling is performed under a long-term hydrological monitoring program begun in 1980. Coach, an experiment to be located near the Gnome project, was initially scheduled for 1963. Although construction and rehabilitation were completed for Coach, the experiment was canceled and never executed. Known collectively as Project Gnome-Coach, the site is situated within the Salado Formation approximately 25 miles east of Carlsbad, New Mexico, in Eddy County, and is comprised of nearly 680 acres, of which 60 acres are disturbed from the combined AEC/DOE operations. The scope of this work plan is to document the environmental objectives and the proposed technical site investigation strategies that will be utilized for the site characterization of the project. The subsurface at the Gnome-Coach site has two contaminant sources that are fundamentally different in terms of both their stratigraphic location and release mechanism. The goal of this characterization is to collect data of sufficient quantity and quality to establish current site conditions and to use the data to identify and evaluate if further action is required to protect human health and the environment and achieve permanent closure of the site. The results of these activities will be presented in a subsequent corrective

  19. Site-specific gene modification by PNAs conjugated to psoralen.

    PubMed

    Kim, Ki-Hyun; Nielsen, Peter E; Glazer, Peter M

    2006-01-10

    DNA-binding molecules, including triplex-forming oligonucleotides (TFOs) and peptide nucleic acids (PNAs), can be utilized to introduce site-specific mutations or to promote recombination at selected genomic sites. To further evaluate the utility of PNAs for site-specific gene modification, we tested dimeric bis-PNAs conjugated to psoralen. These PNAs are designed to form a triplex-invasion complex within the supF reporter gene in an episomal shuttle vector and to direct site-specific photoadduct formation by the conjugated psoralen. The psoralen-bis-PNA conjugate was found to direct photoadduct formation to the intended 5'-TpA base step next to the PNA-binding site, and the photoadduct formation efficiency displayed both concentration and UVA irradiation dependence. The effect of PNA-targeted photoadducts in a mammalian system was tested by SV40-based shuttle vector assay. After in vitro binding, we found that photoadducts directed by PNAs conjugated to psoralen-induced mutations at frequencies in the range of 0.46%, 6.5-fold above the background. In a protocol for intracellular gene targeting in the episomal shuttle vector, the psoralen-PNA-induced mutation frequency was 0.13%, 3.5-fold higher than the background. Most of the induced mutations were deletions and single-base-pair substitutions at or adjacent to the targeted PNA-binding and photoadduct-formation sites. When the results are taken together, they demonstrate the ability of bis-PNAs conjugated with psoralen to mediate site-specific gene modification, and they further support the development of PNAs as tools for gene-targeting applications.

  20. Potential Sites for Ice Nucleation on Aluminosilicate Clay Minerals and Related Materials.

    PubMed

    Freedman, Miriam Arak

    2015-10-01

    Few aerosol particles in clouds nucleate the formation of ice. The surface sites available for nucleus formation, which can include surface defects and functional groups, determine in part the activity of an aerosol particle toward ice formation. Although ice nucleation on particles has been widely studied, exploration of the specific sites at which the initial germ forms has been limited, but is important for predicting the microphysical properties of clouds, which impact climate. This Perspective focuses on what is currently known about surface sites for ice nucleation on aluminosilicate clay minerals, which are commonly found in ice residuals, as well as related materials.

  1. 2006 SITE ENVIRONMENTAL REPORT

    SciTech Connect

    BROOKHAVEN NATIONAL LABORATORY; RATEL,K.

    2007-10-01

    Each year, Brookhaven National Laboratory (BNL) prepares an annual Site Environmental Report (SER) in accordance with DOE Order 231.1A, Environment, Safety and Health Reporting of the U.S. Department of Energy. The report is written to inform the public, regulators, employees, and other stakeholders of BNL's environmental performance during the calendar year in review. The SER summarizes environmental data; environmental management performance; compliance with applicable DOE, federal, state, and local regulations; and compliance, restoration, and surveillance monitoring program performance. BNL has prepared annual SERs since 1971 and has documented nearly all of its environmental history since the Laboratory's inception in 1947. The report is available in print and as a downloadable file on the BNL web page at http://www.bnl.gov/ewms/ser/. A summary of the SER is also prepared each year to provide a general overview of the report, and is distributed with a CD of the full report.

  2. 2009 Site Environmental Report

    SciTech Connect

    Ratel, K.M.; Brookhaven National Laboratory

    2010-09-30

    Each year, Brookhaven National Laboratory (BNL) prepares an annual Site Environmental Report (SER) in accordance with DOE Order 231.1A, Environment, Safety and Health Reporting of the U.S. Department of Energy. The report is written to inform the public, regulators, employees, and other stakeholders of BNL's environmental performance during the calendar year in review. The SER summarizes environmental data; environmental management performance; compliance with applicable DOE, federal, state, and local regulations; and compliance, restoration, and surveillance monitoring program performance. BNL has prepared annual SERs since 1971 and has documented nearly all of its environmental history since the Laboratory's inception in 1947. The report is available in print and as a downloadable file on the BNL web page at http://www.bnl.gov/ewms/ser/. A summary of the SER is also prepared each year to provide a general overview of the report, and is distributed with a CD of the full report.

  3. 2002 SITE ENVIRONMENTAL REPORT.

    SciTech Connect

    BROOKHAVEN NATIONAL LABORATORY

    2003-10-01

    The 2002 Site Environmental Report (SER) is prepared in accordance with DOE Order 231.1, ''Environment, Safety and Health Reporting'', and summarizes the status of Brookhaven National Laboratory's (BNL) environmental programs and performance and restoration efforts, as well as any impacts, both past and present, that Laboratory operations have had on the environment. The document is intended to be technical in nature. A summary of the report is also prepared as a separate document to provide a general overview and includes a CD version of the full report. Operated by Brookhaven Science Associates (BSA) for the Department of Energy (DOE), BNL manages its world-class scientific research with particular sensitivity to environmental and community issues. BNL's motto, ''Exploring Life's Mysteries...Protecting its Future'', reflects BNL's management philosophy to fully integrate environmental stewardship into all facets of its missions, with a health balance between science and the environment.

  4. 2005 SITE ENVIRONMENTAL REPORT

    SciTech Connect

    BROOKHAVEN NATIONAL LABORATORY

    2006-08-29

    Each year, Brookhaven National Laboratory (BNL) prepares an annual Site Environmental Report (SER) in accordance with DOE Order 231.1A, Environment, Safety and Health Reporting of the U.S. Department of Energy (DOE). The report is written to inform the public, regulators, employees, and other stakeholders of BNL's environmental performance during the calendar year in review. The SER summarizes environmental data; environmental management performance; compliance with applicable DOE, federal, state, and local regulations; and compliance, restoration, and surveillance monitoring program performance. BNL has prepared annual SERs since 1971 and has documented nearly all of its environmental history since the Laboratory's inception in 1947. The report is available in print and as a downloadable file on the BNL web page at http://www.bnl.gov/ewms/ser/. A summary of the SER is also prepared each year to provide a general overview of the report, and is distributed with a CD of the full report.

  5. The site-2 protease.

    PubMed

    Rawson, Robert B

    2013-12-01

    The site-2 protease (S2P) is an unusually-hydrophobic integral membrane protease. It cleaves its substrates, which are membrane-bound transcription factors, within membrane-spanning helices. Although structural information for S2P from animals is lacking, the available data suggest that cleavage may occur at or within the lipid bilayer. In mammalian cells, S2P is essential owing to its activation of the sterol regulatory element binding proteins (SREBPs); in the absence of exogenous lipid, cells lacking S2P cannot survive. S2P is also important in the endoplasmic reticulum (ER) stress response, activating several different membrane-bound transcription factors. Human patients harboring reduction-of-function mutations in S2P exhibit an array of pathologies ranging from skin defects to neurological abnormalities. Surprisingly, Drosophila melanogaster lacking S2P are viable and fertile. This article is part of a Special Issue entitled: Intramembrane Proteases.

  6. Web Site Development Support

    NASA Technical Reports Server (NTRS)

    Abdul, Hameed

    2016-01-01

    This summer I assisted the RPT Program Office in developing a design plan to update their existing website to current NASA web standards. The finished website is intended for the general public, specifically potential customers interested in learning about NASA's chemical rocket test facility capabilities and test assignment process. The goal of the website is to give the public insight about the purpose and function of the RPT Program. Working on this project gave me the opportunity to learn skills necessary for effective project management. The RPT Program Office manages numerous facilities so they are required to travel often to other sites for meetings throughout the year. Maneuvering around the travel schedule of the office and the workload priority of the IT Department proved to be quite the challenge. I overcame the travel schedule of the office by frequently communicating and checking in with my mentor via email and telephone.

  7. Soil Characterization Database for the Area 5 Radioactive Waste Management Site, Nevada Test Site, Nye County, Nevada

    SciTech Connect

    Y. J. Lee; R. D. Van Remortel; K. E. Snyder

    2005-01-01

    Soils were characterized in an investigation at the Area 5 Radioactive Waste Management Site at the U.S. Department of Energy Nevada Test Site in Nye County, Nevada. Data from the investigation are presented in four parameter groups: sample and site characteristics, U.S. Department of Agriculture (USDA) particle size fractions, chemical parameters, and American Society for Testing Materials-Unified Soil Classification System (ASTM-USCS) particle size fractions. Spread-sheet workbooks based on these parameter groups are presented to evaluate data quality, conduct database updates,and set data structures and formats for later extraction and analysis. This document does not include analysis or interpretation of presented data.

  8. Soil Characterization Database for the Area 3 Radioactive Waste Management Site, Nevada Test Site, Nye County, Nevada

    SciTech Connect

    R. D. Van Remortel; Y. J. Lee; K. E. Snyder

    2005-01-01

    Soils were characterized in an investigation at the Area 3 Radioactive Waste Management Site at the U.S. Department of Energy Nevada Test Site in Nye County, Nevada. Data from the investigation are presented in four parameter groups: sample and site characteristics, U.S. Department of Agriculture (USDA) particle size fractions, chemical parameters, and American Society for Testing Materials-Unified Soil Classification System (ASTM-USCS) particle size fractions. Spread-sheet workbooks based on these parameter groups are presented to evaluate data quality, conduct database updates, and set data structures and formats for later extraction and analysis. This document does not include analysis or interpretation of presented data.

  9. Critical Path Web Site

    NASA Technical Reports Server (NTRS)

    Robinson, Judith L.; Charles, John B.; Rummel, John A. (Technical Monitor)

    2000-01-01

    Approximately three years ago, the Agency's lead center for the human elements of spaceflight (the Johnson Space Center), along with the National Biomedical Research Institute (NSBRI) (which has the lead role in developing countermeasures) initiated an activity to identify the most critical risks confronting extended human spaceflight. Two salient factors influenced this activity: first, what information is needed to enable a "go/no go" decision to embark on extended human spaceflight missions; and second, what knowledge and capabilities are needed to address known and potential health, safety and performance risks associated with such missions. A unique approach was used to first define and assess those risks, and then to prioritize them. This activity was called the Critical Path Roadmap (CPR) and it represents an opportunity to develop and implement a focused and evolving program of research and technology designed from a "risk reduction" perspective to prevent or minimize the risks to humans exposed to the space environment. The Critical Path Roadmap provides the foundation needed to ensure that human spaceflight, now and in the future, is as safe, productive and healthy as possible (within the constraints imposed on any particular mission) regardless of mission duration or destination. As a tool, the Critical Path Roadmap enables the decisionmaker to select from among the demonstrated or potential risks those that are to be mitigated, and the completeness of that mitigation. The primary audience for the CPR Web Site is the members of the scientific community who are interested in the research and technology efforts required for ensuring safe and productive human spaceflight. They may already be informed about the various space life sciences research programs or they may be newcomers. Providing the CPR content to potential investigators increases the probability of their delivering effective risk mitigations. Others who will use the CPR Web Site and its content

  10. Critical Path Web Site

    NASA Technical Reports Server (NTRS)

    Robinson, Judith L.; Charles, John B.; Rummel, John A. (Technical Monitor)

    2000-01-01

    Approximately three years ago, the Agency's lead center for the human elements of spaceflight (the Johnson Space Center), along with the National Biomedical Research Institute (NSBRI) (which has the lead role in developing countermeasures) initiated an activity to identify the most critical risks confronting extended human spaceflight. Two salient factors influenced this activity: first, what information is needed to enable a "go/no go" decision to embark on extended human spaceflight missions; and second, what knowledge and capabilities are needed to address known and potential health, safety and performance risks associated with such missions. A unique approach was used to first define and assess those risks, and then to prioritize them. This activity was called the Critical Path Roadmap (CPR) and it represents an opportunity to develop and implement a focused and evolving program of research and technology designed from a "risk reduction" perspective to prevent or minimize the risks to humans exposed to the space environment. The Critical Path Roadmap provides the foundation needed to ensure that human spaceflight, now and in the future, is as safe, productive and healthy as possible (within the constraints imposed on any particular mission) regardless of mission duration or destination. As a tool, the Critical Path Roadmap enables the decision maker to select from among the demonstrated or potential risks those that are to be mitigated, and the completeness of that mitigation. The primary audience for the CPR Web Site is the members of the scientific community who are interested in the research and technology efforts required for ensuring safe and productive human spaceflight. They may already be informed about the various space life sciences research programs or they may be newcomers. Providing the CPR content to potential investigators increases the probability of their delivering effective risk mitigations. Others who will use the CPR Web Site and its

  11. The Role of Fragile Sites in Sporadic Papillary Thyroid Carcinoma

    PubMed Central

    Dillon, Laura W.; Lehman, Christine E.; Wang, Yuh-Hwa

    2012-01-01

    The incidence of thyroid cancer is increasing, especially papillary thyroid carcinoma (PTC), making it currently the fastest-growing cancer among women. Reasons for this increase remain unclear, but several risk factors including radiation exposure and improved detection techniques have been suggested. Recently, the induction of chromosomal fragile site breakage was found to result in the formation of RET/PTC1 rearrangements, a common cause of PTC. Chromosomal fragile sites are regions of the genome with a high susceptibility to forming DNA breaks and are often associated with cancer. Exposure to a variety of external agents can induce fragile site breakage, which may account for some of the observed increase in PTC. This paper discusses the role of fragile site breakage in PTC development, external fragile site-inducing agents that may be potential risk factors for PTC, and how these factors are especially targeting women. PMID:22762011

  12. Controlled Orientation of Active Sites in a Nanostructured Multienzyme Complex

    PubMed Central

    Lim, Sung In; Yang, Byungseop; Jung, Younghan; Cha, Jaehyun; Cho, Jinhwan; Choi, Eun-Sil; Kim, Yong Hwan; Kwon, Inchan

    2016-01-01

    Multistep cascade reactions in nature maximize reaction efficiency by co-assembling related enzymes. Such organization facilitates the processing of intermediates by downstream enzymes. Previously, the studies on multienzyme nanocomplexes assembled on DNA scaffolds demonstrated that closer interenzyme distance enhances the overall reaction efficiency. However, it remains unknown how the active site orientation controlled at nanoscale can have an effect on multienzyme reaction. Here, we show that controlled alignment of active sites promotes the multienzyme reaction efficiency. By genetic incorporation of a non-natural amino acid and two compatible bioorthogonal chemistries, we conjugated mannitol dehydrogenase to formate dehydrogenase with the defined active site arrangement with the residue-level accuracy. The study revealed that the multienzyme complex with the active sites directed towards each other exhibits four-fold higher relative efficiency enhancement in the cascade reaction and produces 60% more D-mannitol than the other complex with active sites directed away from each other. PMID:28004799

  13. Site Environmental Report for 2001

    SciTech Connect

    Pauer, Ron

    2002-07-01

    The mission of Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) is to continue the long tradition of outstanding research that has made it a premier national and international multiprogram laboratory. In order to provide the highest degree of protection for the public and the environment, Berkeley Lab employs Integrated Safety Management (ISM). ISM is a comprehensive U.S. Department of Energy management system that involves five core functions (work planning, hazard and risk analysis, establishment of controls, work performance, and feedback and improvement). These five core functions are applied to all activities at Berkeley Lab. Laboratory activities are planned and conducted with full regard to protecting the public and the environment and complying with appropriate environmental laws and regulations. Both radiological and nonradiological activities are thoroughly monitored to assess their potential impact on public health and the environment. This annual Site Environmental Report covers activities for calendar year (CY) 2001. Volume I summarizes environmental protection performance and environmental monitoring activities. Volume II contains individual analytical data summarized in the first volume. Volume II is available on request. (For details, see the Preface.) Data are presented in the report using the International System of Units measuring system, more commonly referred to as the metric system. For the convenience of readers, both volumes of this report can be accessed on the Web from the Berkeley Lab Environmental Services home page, which is located at http://www.lbl.gov/ehs/esg. Readers are encouraged to comment on this report by completing either the survey card included with the distributed hard copy of the report or the survey form in the Web version of the report. The format and content of this report satisfy the requirements of United States Department of Energy (DOE) Order 231.1, Environment, Safety and Health Reporting,1 and

  14. RAPID DUST FORMATION IN NOVAE: THE SPEED CLASS—FORMATION TIMESCALE CORRELATION EXPLAINED

    SciTech Connect

    Williams, S. C.; Bode, M. F.; Darnley, M. J.; Evans, A.; Zubko, V.; Shafter, A. W.

    2013-11-10

    Observations show that the time of onset of dust formation in classical novae depends strongly on their speed class, with dust typically taking longer to form in slower novae. Using empirical relationships between speed class, luminosity and ejection velocity, it can be shown that dust formation timescale is expected to be essentially independent of speed class. However, following a nova outburst the spectrum of the central hot source evolves, with an increasing proportion of the radiation being emitted short-ward of the Lyman limit. The rate at which the spectrum evolves also depends on the speed class. We have therefore refined the simple model by assuming photons at energies higher than the Lyman limit are absorbed by neutral hydrogen gas internal to the dust formation sites, therefore preventing these photons reaching the nucleation sites. With this refinement the dust formation timescale is theoretically dependent on speed class and the results of our theoretical modification agree well with the observational data. We consider two types of carbon-based dust, graphite and amorphous carbon, with both types producing similar relationships. Our results can be used to predict when dust will form in a nova of a given speed class and hence when observations should optimally be taken to detect the onset of dust formation.

  15. Site selection for Mars exobiology.

    PubMed

    Farmer, J; Des Marais, D; Greeley, R; Landheim, R; Klein, H

    1995-03-01

    The selection of sites on Mars that have a high priority for exobiological research is fundamental for planning future exploration. The most immediate need is to identify targets for high resolution orbital imaging during the Mars Observer and Mars '94/'96 missions that can be used to refine site priorities for surface exploration. We present an objective approach to site selection whereby individual sites are selected and scored, based on the presence of key geological features which indicate high priority environments. Prime sites are those that show evidence for the prolonged activity of liquid water and which have sedimentary deposits that are likely to have accumulated in environments favorable for life. High priority areas include fluvio-lacustrine (stream-fed lake systems), springs, and periglacial environments. Sites where mineralization may have occurred in the presence of organisms (e.g. springs) are given high priority in the search for a fossil record on Mars. A systematic review of Viking data for 83 sites in the Mars Landing Site Catalog resulted in the selection of 13 as being of exobiological interest. The descriptions of these sites were expanded to address exobiological concerns. An additional five sites were identified for inclusion in the second edition of the MLSC. We plan to broaden our site selection activities to include a systematic global reconnaissance of Mars using Viking data, and will continue to refine site priorities for exobiological research based on data from future missions in order to define strategies for surface exploration.

  16. Deciding on Site Licensing Options.

    ERIC Educational Resources Information Center

    O'Brien, Dennis

    1990-01-01

    Explains site licensing, which grants certain microcomputer software rights to a school or district for a fee. Differences of rights among vendors are discussed, the impact of networking on-site licensing is described, and examples of the benefits of site licensing in public school districts are given. (LRW)

  17. DNAPL SITE EVALUATION - Project Summary

    EPA Science Inventory

    Dense nonaqueous-phase liquids (DNAPLs), especially chlorinated solvents, are among the most prevalent subsurface contaminants identified in ground-water supplies and at waste disposal sites. There are several site-characterization issues specific to DNAPL sites including (a) the...

  18. Abandoned Mine Lands: Site Information

    EPA Pesticide Factsheets

    A catalogue of mining sites proposed for and listed on the NPL as well as mining sites being cleaned up using the Superfund Alternative Approach. Also mine sites not on the NPL but that have had removal or emergency response cleanup actions.

  19. School Site Decisions and Dollars.

    ERIC Educational Resources Information Center

    Grube, Karl W.

    Three papers, each with an extensive bibliography, advance arguments concerning (1) the school site as a public land resource, (2) school board policy as related to economic alternatives for open space school site planning, and (3) the establishment of outdoor classrooms on school sites as public policy. In the first paper, the author contends…

  20. Site selection for Mars exobiology

    NASA Technical Reports Server (NTRS)

    Farmer, J.; Des Marais, D.; Greeley, R.; Landheim, R.; Klein, H.

    1995-01-01

    The selection of sites on Mars that have a high priority for exobiological research is fundamental for planning future exploration. The most immediate need is to identify targets for high resolution orbital imaging during the Mars Observer and Mars '94/'96 missions that can be used to refined site priorities for surface exploration. We present an objective approach to site selection whereby individual sites are selected and scored, based on the presence of key geological features which indicate high priority environments. Prime sites are those that show evidence for the prolonged activity of liquid water and which have sedimentary deposits that are likely to have accumulated in environments favorable for life. High priority areas include fluvio-lacustrine (stream-fed lake systems), springs, and periglacial environments. Sites where mineralization may have occurred in the presence of organisms (e.g. springs) are given high priority in the search for a fossil record on Mars. A systematic review of Viking data for 83 sites in the Mars Landing Site Catalog (MLSC) resulted in the selection of 13 as being of exobiological interest. The descriptions of these sites were expanded to address exobiological concerns. An additional five sites were identified for inclusion in the second edition of the MLSC. We plan to broaden our site selection activities to include a systematic global reconnaissance of Mars using Viking data, and will continue to refine site priorities for exobiological research based on data from future missions in order to define strategies for surface exploration.

  1. Positronium Formation in Muscle

    PubMed Central

    Gustafson, D. R.

    1970-01-01

    Positronium formation in muscle at +4°C and -4°C was examined by the measurement of the angular correlation of positron annihilation radiation. Since the positronium formation rate in ice is considerably higher than it is in water, there should be a comparable increase in the positronium formation rate in muscle tissue if recent speculation that cellular water is ordered in a semicrystalline icelike state is correct. Comparison of the angular correlation from muscle at +4°C with that from water at +4°C shows no enhancement of the positronium formation rate. Frozen muscle at -4°C shows an enhancement of the positronium formation rate of approximately half that found in ice at -4°C, indicating that most cellular water undergoes a normal water-ice transition when frozen. It is concluded therefore that cell water in muscle is not ordered in a hexagonal icelike structure. While the results are consistent with the hypothesis that cell water is in the liquid state, the hypothesis that cell water is ordered in an undetermined close packed structure which transforms to the hexagonal ice structure at or near 0°C cannot be ruled out. PMID:5436881

  2. Site descriptive modeling as a part of site characterization in Sweden - Concluding the surface based investigations

    SciTech Connect

    Andersson, Johan; Winberg, Anders; Skagius, Kristina; Stroem, Anders; Lindborg, Tobias

    2007-07-01

    The Swedish Nuclear Fuel and Waste Management Co., SKB, is currently finalizing its surface based site investigations for the final repository for spent nuclear fuel in the municipalities of Oestharmnar (the Forsmark area) and Oskarshamn (the Simpevar/Laxemar area). The investigation data are assessed into a Site Descriptive Model, constituting a synthesis of geology, rock mechanics, thermal properties, hydrogeology, hydro-geochemistry, transport properties and a surface system description. Site data constitute a wide range of different measurement results. These data both need to be checked for consistency and to be interpreted into a format more amenable for three-dimensional modeling. The three-dimensional modeling (i.e. estimating the distribution of parameter values in space) is made in a sequence where the geometrical framework is taken from the geological models and in turn used by the rock mechanics, thermal and hydrogeological modeling. These disciplines in turn are partly interrelated, and also provide feedback to the geological modeling, especially if the geological description appears unreasonable when assessed together with the other data. Procedures for assessing the uncertainties and the confidence in the modeling have been developed during the course of the site modeling. These assessments also provide key input to the completion of the site investigation program. (authors)

  3. Biological ice nucleation initiates hailstone formation

    NASA Astrophysics Data System (ADS)

    Michaud, Alexander B.; Dore, John E.; Leslie, Deborah; Lyons, W. Berry; Sands, David C.; Priscu, John C.

    2014-11-01

    Cloud condensation and ice nuclei in the troposphere are required precursors to cloud and precipitation formation, both of which influence the radiative balance of Earth. The initial stage of hailstone formation (i.e., the embryo) and the subsequent layered growth allow hail to be used as a model for the study of nucleation processes in precipitation. By virtue of the preserved particle and isotopic record captured by hailstones, they represent a unique form of precipitation that allows direct characterization of the particles present during atmospheric ice nucleation. Despite the ecological and economic consequences of hail storms, the dynamics of hailstone nucleation, and thus their formation, are not well understood. Our experiments show that hailstone embryos from three Rocky Mountain storms contained biological ice nuclei capable of freezing water at warm, subzero (°C) temperatures, indicating that biological particles can act as nucleation sites for hailstone formation. These results are corroborated by analysis of δD and δ18O from melted hailstone embryos, which show that the hailstones formed at similarly warm temperatures in situ. Low densities of ice nucleation active abiotic particles were also present in hailstone embryos, but their low concentration indicates they were not likely to have catalyzed ice formation at the warm temperatures determined from water stable isotope analysis. Our study provides new data on ice nucleation occurring at the bottom of clouds, an atmospheric region whose processes are critical to global climate models but which has challenged instrument-based measurements.

  4. CEO Sites Mission Management System (SMMS)

    NASA Technical Reports Server (NTRS)

    Trenchard, Mike

    2014-01-01

    uses the SMMS for three general functions - database queries of content and status, individual site creation and updates, and mission planning. The CEO administrator of the science site database is able to create or modify the content of sites and activate or deactivate them based on the requirements of the sponsors. The administrator supports and implements ISS mission planning by assembling, reporting, and activating mission-specific site selections for management; deactivating sites as requirements are met; and creating new sites, such as International Charter sites for disasters, as circumstances warrant. In addition to the above CEO internal uses, when site planning for a specific ISS mission is complete and approved, the SMMS can produce and export those essential site database elements for the mission into XML format for use by onboard Earth-location systems, such as Worldmap. The design, development, and implementation of the SMMS resulted in a superior database management system for CEO science sites by focusing on the functions and applications of the database alone instead of integrating the database with the multipurpose configuration of the AMPS. Unlike the AMPS, it can function and be modified within the existing Windows 7 environment. The functions and applications of the SMMS were expanded to accommodate more database elements, report products, and a streamlined interface for data entry and review. A particularly elegant enhancement in data entry was the integration of the Google Earth application for the visual display and definition of site coordinates for site areas defined by multiple coordinates. Transfer between the SMMS and Google Earth is accomplished with a Keyhole Markup Language (KML) expression of geographic data (see figures 3 and 4). Site coordinates may be entered into the SMMS panel directly for display in Google Earth, or the coordinates may be defined on the Google Earth display as a mouse-controlled polygonal definition and

  5. Hybridization Hotspots at Bat Swarming Sites

    PubMed Central

    Bogdanowicz, Wiesław; Piksa, Krzysztof; Tereba, Anna

    2012-01-01

    During late summer and early autumn in temperate zones of the Northern Hemisphere, thousands of bats gather at caves, mainly for the purpose of mating. We demonstrated that this swarming behavior most probably leads not only to breeding among bats of the same species but also interbreeding between different species. Using 14 nuclear microsatellites and three different methods (the Bayesian assignment approaches of STRUCTURE and NEWHYBRIDS and a principal coordinate analysis of pairwise genetic distances), we analyzed 375 individuals belonging to three species of whiskered bats (genus Myotis) at swarming sites across their sympatric range in southern Poland. The overall hybridization rate varied from 3.2 to 7.2%. At the species level, depending on the method used, these values ranged from 2.1–4.6% in M. mystacinus and 3.0–3.7% in M. brandtii to 6.5–30.4% in M. alcathoe. Hybrids occurred in about half of the caves we studied. In all three species, the sex ratio of hybrids was biased towards males but the observed differences did not differ statistically from those noted at the population level. In our opinion, factors leading to the formation of these admixed individuals and their relatively high frequency are: i) swarming behaviour at swarming sites, where high numbers of bats belonging to several species meet; ii) male-biased sex ratio during the swarming period; iii) the fact that all these bats are generally polygynous. The highly different population sizes of different species at swarming sites may also play some role. Swarming sites may represent unique hybrid hotspots, which, as there are at least 2,000 caves in the Polish Carpathians alone, may occur on a massive scale not previously observed for any group of mammal species in the wild. Evidently, these sites should be treated as focal points for the conservation of biodiversity and evolutionary processes. PMID:23300912

  6. Constraints on Exomoon Formation

    NASA Astrophysics Data System (ADS)

    Nakajima, Miki; Genda, Hidenori; Asphaug, Erik; Ida, Shigeru

    2014-11-01

    It has been widely accepted that the Earth’s moon formed by a giant impact during the late stage of the planetary formation process. The giant impact led to the formation of a debris disk around the Earth from which the Moon accreted. This type of satellite formation is considered to be common not only in the solar system (e.g., the Pluto-Charon system) but also in extrasolar systems (e.g. Ogihara & Ida 2009). However, no detailed research has been conducted on impact-induced exomoon formation. Wada et al. (2006) suggest that a vapor-rich disk is dynamically unstable and that it may not be suitable for moon formation. If this is the case, the mass and composition of a planet may affect the satellite formation process. Here, we show results from giant impact simulations of planets with various masses and compositions. We use the model suggested by Nakajima & Stevenson (2014) to estimate the vapor mass fractions of the disks. We find that the more massive and the more ice-rich the planet is, the higher the vapor mass fraction of the disk becomes. This indicates there is an upper limit of the planetary mass to form an impact-induced moon and the limit depends on the planetary composition. This upper limit is a few Earth masses for a rocky planet, and about an Earth mass for an icy planet. These results are consistent with the models that Earth’s and Pluto’s satellites formed by impacts. Although no exomoon has been detected yet, our model may be used to predict whether an observed terrestrial exoplanet could potentially have one or multiple impact-induced exomoons.

  7. Sensitivity Data File Formats

    SciTech Connect

    Rearden, Bradley T.

    2016-04-01

    The format of the TSUNAMI-A sensitivity data file produced by SAMS for cases with deterministic transport solutions is given in Table 6.3.A.1. The occurrence of each entry in the data file is followed by an identification of the data contained on each line of the file and the FORTRAN edit descriptor denoting the format of each line. A brief description of each line is also presented. A sample of the TSUNAMI-A data file for the Flattop-25 sample problem is provided in Figure 6.3.A.1. Here, only two profiles out of the 130 computed are shown.

  8. Formation of in situ oil shale retort in plural steps

    SciTech Connect

    Fernandes, R.J.

    1984-07-10

    A subterranean formation containing oil shale is prepared for in situ retorting by forming a fragmented permeable mass of formation particles containing oil shale in an in situ retort site. The retort is formed by excavating a lower level drift adjacent to a lower portion of the retort site and excavating an undercut within the retort site below a zone of unfragmented formation remaining within the retort site above the undercut. The bottom of the undercut slopes downwardly toward the lower level drift which opens into one side of the undercut, the slope being generally at the natural angle of slide of oil shale particles. The remaining zone of unfragmented formation is blasted downwardly toward the undercut in a series of lifts in sequence progressing upwardly in the retort site. The mass of formation particles formed during such blasting in lifts tends to slope downwardly toward the side of the retort adjacent the lower level drift. Formation particles are withdrawn from the fragmented mass between lifts through the lower level drift to provide void space toward which each lift is blasted. Such withdrawal of formation particles can create relatively higher permeability in the fragmented mass along the side above the lower level drift and relatively lower permeability in the fragmented mass along the opposite side of the retort. During retorting operations, to compensate for such permeability gradient, oxygen supplying gas is introduced into the upper low permeability region of the fragmented mass, and off gas is withdrawn through the lower level drift at the lower high permeability region for producing a generally diagonal gas flow pattern through the retort.

  9. JSC Toxicology Web Site

    NASA Technical Reports Server (NTRS)

    Garcia, Hector D.; Coleman, M.; James, J.; Lam, C.

    1999-01-01

    Data on chemical and biological materials to be flown in the pressurized volumes of habitable spacecraft, including the International Space Station (ISS), are needed by JSC toxicologists to assess the toxicity and assign hazard levels. This document defines submission schedules and establishes requirements for the types and format of these data. JSC 27472 Rev A is a major revision of JSC 25607, "Requirements for Submission of Test Sample-Materials Data for Shuttle Payload Safety Evaluations", dated October 1994, which was subsequently re-issued (September 1996) with a new document number, JSC 27472, but with the same title and date and no revisions. The revisions in the present document have been necessitated by the recent introduction of a two-step process (described in this document) for verification of data for flight materials and by the anticipated needs of the ISS. The requirements -for data submission apply to items which contain liquids, gases, gels, greases, powders/ particulates, radioisotopes, or biological materials and are located in the habitable pressurized volume of ISS or U.S. operated spacecraft. These include, but are not limited to, science payloads, government furnished equipment (GFE), risk mitigation experiments (RmEs), development test objectives (DTOs), detailed supplementary objectives (DSOs), life science experiments, and medical studies.

  10. Recover bromine on site

    SciTech Connect

    Schubert, P.; Mahajan, S.; Beatty, R.D.; Rostrup-Nielsen, T.; Schubert, D.W.; Lu, Phat Tan

    1993-04-01

    Chemists have long recognized the importance of recovering bromine from waste streams, and attempts to do so catalytically date back more than 50 years. Although the early interest in bromine recovery was driven primarily by economics, increased environmental pressures are providing additional incentives to recycle this element. As the acceptability of discharging wastes into the environment decreases, the cost of doing so increases, creating a need for alternative handling. The authors interest in waste bromine recovery was driven by both economic and environmental factors. In their evaluation of a research program that included a bromination step as part of a synthesis process, Catalytica researchers found that the process would be feasible commercially only if the waste HBr produced were recycled on site to bromine. A nonbromine route was eventually adopted for this particular research program, but the need for an economical and environmentally sound process for recycling HBr to bromine was recognized. The development of this process became a project in its own right. This process eliminates the need to form and ship aqueous sodium bromide offsite. It converts the waste HBr directly to bromine by catalytic oxidation.

  11. 2004 SITE ENVIRONMENTAL REPORT

    SciTech Connect

    BROOKHAVEN NATIONAL LABORATORY; SER TEAM; ENVIRONMENTAL INFORMATION MANAGEMENT SERVICES GROUP; ENVIROMENTAL AND WASTE MANAGEMENT SERVICES DIVISION FIELD SAMPLING TEAM

    2005-08-22

    Each year, Brookhaven National Laboratory (BNL) prepares an annual Site Environmental Report (SER) in accordance with DOE Order 231.1A, Environment, Safety and Health Reporting of the U.S. Department of Energy (DOE). The SER is written to inform the public, regulators, Laboratory employees, and other stakeholders of BNL's environmental performance during the calendar year in review. The report summarizes BNL's environmental data; environmental management performance; compliance with applicable DOE, federal, state, and local regulations; and restoration and surveillance monitoring programs. BNL has prepared annual SERs since 1971 and has documented nearly all of its environmental history since the Laboratory's inception in 1947. The SER is intended to be a technical document. It is available in print and as a downloadable file on the BNL web page at http://www.bnl.gov/esd/SER.htm. A summary of the SER is also prepared each year to provide a general overview of the report, and is distributed with a CD version of the full report. The summary supports BNL's educational and community outreach program.

  12. 2007 Site Environmental Report

    SciTech Connect

    Ratel,K.

    2008-10-01

    Brookhaven National Laboratory (BNL) prepares an annual Site Environmental Report (SER) in accordance with DOE Order 231.1A, Environment, Safety and Health Reporting of the U.S. Department of Energy. The report is written to inform the public, regulators, employees, and other stakeholders of the Laboratory's environmental performance during the calendar year in review. Volume I of the SER summarizes environmental data; environmental management performance; compliance with applicable DOE, federal, state, and local regulations; and performance in restoration and surveillance monitoring programs. BNL has prepared annual SERs since 1971 and has documented nearly all of its environmental history since the Laboratory's inception in 1947. Volume II of the SER, the Groundwater Status Report, also is prepared annually to report on the status of and evaluate the performance of groundwater treatment systems at the Laboratory. Volume II includes detailed technical summaries of groundwater data and its interpretation, and is intended for internal BNL users, regulators, and other technically oriented stakeholders. A brief summary of the information contained in Volume II is included in this volume in Chapter 7, Groundwater Protection. Both reports are available in print and as downloadable files on the BNL web page at http://www.bnl.gov/ewms/ser/. An electronic version on compact disc is distributed with each printed report. In addition, a summary of Volume I is prepared each year to provide a general overview of the report, and is distributed with a compact disc containing the-length report.

  13. Site Management Guide (Blue Book)

    SciTech Connect

    2014-03-01

    The U.S. Department of Energy (Department) Office of Legacy Management (LM), established in 2003, manages the Department’s postclosure responsibilities and ensures the future protection of human health and the environment. During World War II and the Cold War, the Federal government developed and operated a vast network of industrial facilities for the research, production, and testing of nuclear weapons, as well as other scientific and engineering research. These processes left a legacy of radioactive and chemical waste, environmental contamination, and hazardous facilities and materials at well over 100 sites. Since 1989, the Department has taken an aggressive accelerated cleanup approach to reduce risks and cut costs. At most Departmental sites undergoing cleanup, some residual hazards will remain at the time cleanup is completed due to financial and technical impracticality. However, the Department still has an obligation to protect human health and the environment after cleanup is completed. LM fulfills DOE’s postclosure obligation by providing long-term management of postcleanup sites which do not have continuing missions. LM is also responsible for sites under the Formerly Utilized Sites Remedial Action Program (FUSRAP). Currently, the U.S. Army Corps of Engineers (USACE) is responsible for site surveys and remediation at FUSRAP sites. Once remediation is completed, LM becomes responsible for long-term management. LM also has responsibility for uranium processing sites addressed by Title II of the Uranium Mill Tailings Radiation Control Act (UMTRCA). UMTRCA Title II sites are sites that were commercially owned and are regulated under a U.S. Nuclear Regulatory Commission (NRC) license. For license termination, the owner must conduct an NRC-approved cleanup of any on-site radioactive waste remaining from former uranium ore-processing operations. The site owner must also provide full funding for inspections and, if necessary, ongoing maintenance. Once site

  14. Time Dependent Models of Grain Formation Around Carbon Stars

    NASA Technical Reports Server (NTRS)

    Egan, M. P.; Shipman, R. F.

    1996-01-01

    Carbon-rich Asymptotic Giant Branch stars are sites of dust formation and undergo mass loss at rates ranging from 10(exp -7) to 10(exp -4) solar mass/yr. The state-of-the-art in modeling these processes is time-dependent models which simultaneously solve the grain formation and gas dynamics problem. We present results from such a model, which also includes an exact solution of the radiative transfer within the system.

  15. Formation in the Classroom

    ERIC Educational Resources Information Center

    Glennon, Fred; Jacobsen, Douglas; Jacobsen, Rhonda Hustedt; Thatamanil, John J.; Porterfield, Amanda; Moore, Mary Elizabeth

    2011-01-01

    What is the relationship between the academic knowledge of the guild and the formation of students in the classroom? This Forum gathers four essays originally presented at a Special Topics Session at the 2009 conference of the American Academy of Religion (Atlanta, Georgia), with a brief introductory essay by Fred Glennon explaining the genesis of…

  16. Endogenous Cooperation Network Formation

    NASA Astrophysics Data System (ADS)

    Angus, S.

    This paper employs insights from Complex Systems literature to develop a computational model of endogenous strategic network formation. Artificial Adaptive Agents (AAAs), implemented as finite state automata, play a modified two-player Iterated Prisoner's Dilemma game with an option to further develop the interaction space as part of their strategy. Several insights result from this relatively minor modification: first, I find that network formation is a necessary condition for cooperation to be sustainable but that both the frequency of interaction and the degree to which edge formation impacts agent mixing are both necessary conditions for cooperative networks. Second, within the FSA-modified IPD frame-work, a rich ecology of agents and network topologies is observed, with consequent payoff symmetry and network 'purity' seen to be further contributors to robust cooperative networks. Third, the dynamics of the strategic system under network formation show that initially simple dynamics with small interaction length between agents gives way to complex, a-periodic dynamics when interaction lengths are increased by a single step.

  17. Endogenous Cooperation Network Formation

    NASA Astrophysics Data System (ADS)

    Angus, S.

    This paper employs insights from Complex Systems literature to develop a computational model of endogenous strategic network formation. Artificial Adaptive Agents (AAAs), implemented as finite state automata, play a modified two-player Iterated Prisoner's Dilemma game with an option to further develop the interaction space as part of their strategy. Several insights result from this relatively minor modification: first, I find that network formation is a necessary condition for cooperation to be sustainable but that both the frequency of interaction and the degree to which edge formation impacts agent mixing are both necessary conditions for cooperative networks. Second, within the FSA-modified IPD frame-work, a rich ecology of agents and network topologies is observed, with consequent payoff symmetry and network `purity' seen to be further contributors to robust cooperative networks. Third, the dynamics of the strategic system under network formation show that initially simple dynamics with small interaction length between agents gives way to complex, a-periodic dynamics when interaction lengths are increased by a single step.

  18. Formation of planetesimals

    NASA Technical Reports Server (NTRS)

    Weidenschilling, Stuart J.

    1991-01-01

    Formation of planetesimals is discussed. The following subject areas are covered: (1) nebular structure; (2) aerodynamics of the solid bodies in the nebula; (3) problems with gravitational instability; (4) particle growth by coagulation; properties of fractal aggregates; and (5) coagulation and settling of fractal aggregates.

  19. Bacterial formate hydrogenlyase complex

    PubMed Central

    McDowall, Jennifer S.; Murphy, Bonnie J.; Haumann, Michael; Palmer, Tracy; Armstrong, Fraser A.; Sargent, Frank

    2014-01-01

    Under anaerobic conditions, Escherichia coli can carry out a mixed-acid fermentation that ultimately produces molecular hydrogen. The enzyme directly responsible for hydrogen production is the membrane-bound formate hydrogenlyase (FHL) complex, which links formate oxidation to proton reduction and has evolutionary links to Complex I, the NADH:quinone oxidoreductase. Although the genetics, maturation, and some biochemistry of FHL are understood, the protein complex has never been isolated in an intact form to allow biochemical analysis. In this work, genetic tools are reported that allow the facile isolation of FHL in a single chromatographic step. The core complex is shown to comprise HycE (a [NiFe] hydrogenase component termed Hyd-3), FdhF (the molybdenum-dependent formate dehydrogenase-H), and three iron-sulfur proteins: HycB, HycF, and HycG. A proportion of this core complex remains associated with HycC and HycD, which are polytopic integral membrane proteins believed to anchor the core complex to the cytoplasmic side of the membrane. As isolated, the FHL complex retains formate hydrogenlyase activity in vitro. Protein film electrochemistry experiments on Hyd-3 demonstrate that it has a unique ability among [NiFe] hydrogenases to catalyze production of H2 even at high partial pressures of H2. Understanding and harnessing the activity of the FHL complex is critical to advancing future biohydrogen research efforts. PMID:25157147

  20. 500+ Writing Formats.

    ERIC Educational Resources Information Center

    McIntosh, Margaret E.

    1997-01-01

    Suggests a multitude of ideas for students to communicate their ideas in writing using the language of mathematics. Includes a sampling of 500+ writing formats, 67 abbreviated writing assignments, and three complete assignments along with a sample student response to each. Sample assignments include advice column, biographical sketch, commercial,…

  1. The Formation of Trihalomethanes.

    ERIC Educational Resources Information Center

    Trussell, R. Rhodes; Umphres, Mark D.

    1978-01-01

    Reviewed are a number of factors important in the formation of trihalomethanes (THM) including the nature of aquatic humus and the influences of preozonation, bromide, pH, and chlorine. A brief investigation is also conducted into the kinetics of the THM reaction. Several major research needs are represented. (CS)

  2. Kepler Planet Formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2015-01-01

    Kepler has vastly increased our knowledge of planets and planetary systems located close to stars. The new data shows surprising results for planetary abundances, planetary spacings and the distribution of planets on a mass-radius diagram. The implications of these results for theories of planet formation will be discussed.

  3. Technobabble: File Formats.

    ERIC Educational Resources Information Center

    Wilson, Bradley

    1999-01-01

    Considers the confusion of over 20 different kinds of graphics programs. Briefly distinguishes between some of the more popular graphics formats (Photoshop, TIFF, JPEG, GIF, PICT, and EPS), and describes the benefits and disadvantages of each in the context of journalism education. (SC)

  4. S-nitrosothiol formation.

    PubMed

    Carver, Jeannean; Doctor, Allan; Zaman, Khalequz; Gaston, Benjamin

    2005-01-01

    Protein and peptide S-nitrosothiols (SNOs) are involved in guanylate cyclase-independent signaling associated with nitric oxide synthase (NOS) activation. As a general rule, SNO formation requires the presence of an electron acceptor such as Cu2+. Various proteins have been identified that catalyze SNO formation, including NOS itself, ceruloplasmin, and hemoglobin. Biochemical evidence suggests the existence of other SNO synthases and NOS-associated proteins involved in SNO formation following NOS activation. Indeed, both hydrophilic and hydrophobic consensus motifs have been identified that favor protein S-nitrosylation. Inorganic SNO formation appears also to occur in biological systems at low pH levels and/or in membranes. Once formed, SNOs localized to specific cellular compartments signal specific effects, ranging from gene regulation to ion channel gating. Indeed, the number of cellular and physiological functions appreciated to be regulated through SNO synthesis, localization, and catabolism is increasing. Although research into SNO biosynthesis is in its infancy, the importance of this field of biochemistry has been confirmed repeatedly by investigators from a broad spectrum of disciplines.

  5. Gasbuggy Site Assessment and Risk Evaluation

    SciTech Connect

    2011-03-01

    This report describes the geologic and hydrologic conditions and evaluates potential health risks to workers in the natural gas industry in the vicinity of the Gasbuggy, New Mexico, site, where the U.S. Atomic Energy Commission detonated an underground nuclear device in 1967. The 29-kiloton detonation took place 4,240 feet below ground surface and was designed to evaluate the use of a nuclear detonation to enhance natural gas production from the Pictured Cliffs Formation in the San Juan Basin, Rio Arriba County, New Mexico, on land administered by Carson National Forest. A site-specific conceptual model was developed based on current understanding of the hydrologic and geologic environment. This conceptual model was used for establishing plausible contaminant exposure scenarios, which were then evaluated for human health risk potential. The most mobile and, therefore, the most probable contaminant that could result in human exposure is tritium. Natural gas production wells were identified as having the greatest potential for bringing detonation-derived contaminants (tritium) to the ground surface in the form of tritiated produced water. Three exposure scenarios addressing potential contamination from gas wells were considered in the risk evaluation: a gas well worker during gas-well-drilling operations, a gas well worker performing routine maintenance, and a residential exposure. The residential exposure scenario was evaluated only for comparison; permanent residences on national forest lands at the Gasbuggy site are prohibited

  6. Site Characterization Progress Report Number 21

    SciTech Connect

    1999-09-30

    This is the 21 st progress report issued by the U.S. Department of Energy. This report provides a summary-level discussion of Yucca Mountain Site Characterization Project progress. Accomplishments this period are presented in a format that identifies important progress achieved and conveys how that progress supports the near-term objectives in the U.S. Department of Energy's schedule. Greater detail is documented in the cited references and in deliverables listed in Appendix A to this report. This document provides a discussion of recently completed and ongoing activities conducted by the Yucca Mountain Site Characterization Project during the six-month reporting period from April 1, 1999, through September 30, 1999. Some information presented herein is by necessity preliminary, because some deliverables and reports that support the discussions have not been finalized. Projected future deliverables and reports are listed in Appendix B and are noted in the text as works in progress. Appendix C lists the status of milestone reports referenced in previous progress reports commencing with Progress Report 17. A glossary of Yucca Mountain Site Characterization Project-specific terms used in this report is given in Appendix D.

  7. Formation of polarity convergences underlying shoot outgrowths

    PubMed Central

    Abley, Katie; Sauret-Güeto, Susanna; Marée, Athanasius FM; Coen, Enrico

    2016-01-01

    The development of outgrowths from plant shoots depends on formation of epidermal sites of cell polarity convergence with high intracellular auxin at their centre. A parsimonious model for generation of convergence sites is that cell polarity for the auxin transporter PIN1 orients up auxin gradients, as this spontaneously generates convergent alignments. Here we test predictions of this and other models for the patterns of auxin biosynthesis and import. Live imaging of outgrowths from kanadi1 kanadi2 Arabidopsis mutant leaves shows that they arise by formation of PIN1 convergence sites within a proximodistal polarity field. PIN1 polarities are oriented away from regions of high auxin biosynthesis enzyme expression, and towards regions of high auxin importer expression. Both expression patterns are required for normal outgrowth emergence, and may form part of a common module underlying shoot outgrowths. These findings are more consistent with models that spontaneously generate tandem rather than convergent alignments. DOI: http://dx.doi.org/10.7554/eLife.18165.001 PMID:27478985

  8. Surgical Site Infections

    PubMed Central

    Kleinman, Ken; Huang, Susan S.; Murphy, Michael V.; Yokoe, Deborah S.; Platt, Richard

    2017-01-01

    Background: Surgical site infection (SSI) rates are publicly reported as quality metrics and increasingly used to determine financial reimbursement. Objective: To evaluate the volume-outcome relationship as well as the year-to-year stability of performance rankings following coronary artery bypass graft (CABG) surgery and hip arthroplasty. Research Design: We performed a retrospective cohort study of Medicare beneficiaries who underwent CABG surgery or hip arthroplasty at US hospitals from 2005 to 2011, with outcomes analyzed through March 2012. Nationally validated claims-based surveillance methods were used to assess for SSI within 90 days of surgery. The relationship between procedure volume and SSI rate was assessed using logistic regression and generalized additive modeling. Year-to-year stability of SSI rates was evaluated using logistic regression to assess hospitals’ movement in and out of performance rankings linked to financial penalties. Results: Case-mix adjusted SSI risk based on claims was highest in hospitals performing <50 CABG/year and <200 hip arthroplasty/year compared with hospitals performing ≥200 procedures/year. At that same time, hospitals in the worst quartile in a given year based on claims had a low probability of remaining in that quartile the following year. This probability increased with volume, and when using 2 years’ experience, but the highest probabilities were only 0.59 for CABG (95% confidence interval, 0.52–0.66) and 0.48 for hip arthroplasty (95% confidence interval, 0.42–0.55). Conclusions: Aggregate SSI risk is highest in hospitals with low annual procedure volumes, yet these hospitals are currently excluded from quality reporting. Even for higher volume hospitals, year-to-year random variation makes past experience an unreliable estimator of current performance. PMID:27517331

  9. Characterization of Rous sarcoma virus polyadenylation site use in vitro

    SciTech Connect

    Maciolek, Nicole L.; McNally, Mark T.

    2008-05-10

    Polyadenylation of Rous sarcoma virus (RSV) RNA is inefficient, as approximately 15% of RSV RNAs represent read-through transcripts that use a downstream cellular polyadenylation site (poly(A) site). Read-through transcription has implications for the virus and the host since it is associated with oncogene capture and tumor induction. To explore the basis of inefficient RSV RNA 3'-end formation, we characterized RSV polyadenylation in vitro using HeLa cell nuclear extracts and HEK293 whole cell extracts. RSV polyadenylation substrates composed of the natural 3' end of viral RNA and various lengths of upstream sequence showed little or no polyadenylation, indicating that the RSV poly(A) site is suboptimal. Efficiently used poly(A) sites often have identifiable upstream and downstream elements (USEs and DSEs) in close proximity to the conserved AAUAAA signal. The sequences upstream and downstream of the RSV poly(A) site deviate from those found in efficiently used poly(A) sites, which may explain inefficient RSV polyadenylation. To assess the quality of the RSV USEs and DSEs, the well-characterized SV40 late USEs and/or DSEs were substituted for the RSV elements and vice versa, which showed that the USEs and DSEs from RSV are suboptimal but functional. CstF interacted poorly with the RSV polyadenylation substrate, and the inactivity of the RSV poly(A) site was at least in part due to poor CstF binding since tethering CstF to the RSV substrate activated polyadenylation. Our data are consistent with poor polyadenylation factor binding sites in both the USE and DSE as the basis for inefficient use of the RSV poly(A) site and point to the importance of additional elements within RSV RNA in promoting 3' end formation.

  10. Umatilla Satellite and Release Sites Project : Final Siting Report.

    SciTech Connect

    Montgomery, James M.

    1992-04-01

    This report presents the results of site analysis for the Umatilla Satellite and Release Sites Project. The purpose of this project is to provide engineering services for the siting and conceptual design of satellite and release facilities for the Umatilla Basin hatchery program. The Umatilla Basin hatchery program consists of artificial production facilities for salmon and steelhead to enhance production in the Umatilla River as defined in the Umatilla master plan approved in 1989 by the Northwest Power Planning Council. Facilities identified in the master plan include adult salmon broodstock holding and spawning facilities, facilities for recovery, acclimation, and/or extended rearing of salmon juveniles, and development of river sites for release of hatchery salmon and steelhead. The historic and current distribution of fall chinook, summer chinook, and coho salmon and steelhead trout was summarized for the Umatilla River basin. Current and future production and release objectives were reviewed. Twenty seven sites were evaluated for the potential and development of facilities. Engineering and environmental attributes of the sites were evaluated and compared to facility requirements for water and space. Site screening was conducted to identify the sites with the most potential for facility development. Alternative sites were selected for conceptual design of each facility type. A proposed program for adult holding facilities, final rearing/acclimation, and direct release facilities was developed.

  11. SitesIdentify: a protein functional site prediction tool

    PubMed Central

    2009-01-01

    Background The rate of protein structures being deposited in the Protein Data Bank surpasses the capacity to experimentally characterise them and therefore computational methods to analyse these structures have become increasingly important. Identifying the region of the protein most likely to be involved in function is useful in order to gain information about its potential role. There are many available approaches to predict functional site, but many are not made available via a publicly-accessible application. Results Here we present a functional site prediction tool (SitesIdentify), based on combining sequence conservation information with geometry-based cleft identification, that is freely available via a web-server. We have shown that SitesIdentify compares favourably to other functional site prediction tools in a comparison of seven methods on a non-redundant set of 237 enzymes with annotated active sites. Conclusion SitesIdentify is able to produce comparable accuracy in predicting functional sites to its closest available counterpart, but in addition achieves improved accuracy for proteins with few characterised homologues. SitesIdentify is available via a webserver at http://www.manchester.ac.uk/bioinformatics/sitesidentify/ PMID:19922660

  12. Nevada National Security Site Industrial Sites Project Closeout - 12498

    SciTech Connect

    Cabble, Kevin; Krauss, Mark; Matthews, Pat

    2012-07-01

    The U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office is responsible for environmental restoration (ER) at the Nevada National Security Site (NNSS). This includes remediation at Industrial Sites where past nuclear testing activities and activities that supported nuclear testing may have or are known to have resulted in the release of contaminants into the environment. Industrial Sites at the NNSS have included nuclear facilities that supported the nuclear rocket/missile development programs, gas stations, landfills, spill sites, ordnance sites, and numerous other waste disposal and release sites. The NNSS Industrial Sites activities neared completion at the end of fiscal year 2011 while other activities required under the Federal Facility Agreement and Consent Order (FFACO) and part of the same NNSS ER Project are forecasted to extend to 2027 or beyond. With the majority of Industrial Sites corrective action units (CAUs) completed (more than 250 CAUs and over 1,800 corrective action sites), it was determined that an activity closeout process should be implemented to ensure that the work completed over the past 15 years is well documented in a comprehensive and concise summary. While the process used to close each individual CAU is described in approved documents, no single document describes in summary fashion the work completed to close the many individual Industrial Sites. The activity closeout process will be used to develop an Industrial Sites closeout document that describes these years of work. This document will summarize the number of Industrial Sites closed under the FFACO and provide general descriptions of projects, contaminants removed, and sites closed in place with corresponding Use Restrictions. Other pertinent information related to Industrial Sites work such as the project history, closure decisions, historical declarations, remediation strategies, and final CAU status will be included in the closeout

  13. 2010 Site Environmental Report

    SciTech Connect

    Ratel, K.; Lee, R; Remien, J; Hooda, B; Green, T; Williams, J; Pohlot, P; Dorsch, W; Paquette, D; Burke, J

    2011-10-01

    Brookhaven National Laboratory (BNL) prepares an annual Site Environmental Report (SER) in accordance with DOE Order 231.1A, Environment, Safety and Health Reporting of the U.S. Department of Energy. The report is written to inform the public, regulators, employees, and other stakeholders of the Laboratory's environmental performance during the calendar year in review. Volume I of the SER summarizes environmental data; environmental management performance; compliance with applicable DOE, federal, state, and local regulations; and performance in restoration and surveillance monitoring programs. BNL has prepared annual SERs since 1971 and has documented nearly all of its environmental history since the Laboratory's inception in 1947. Volume II of the SER, the Groundwater Status Report, also is prepared annually to report on the status of and evaluate the performance of groundwater treatment systems at the Laboratory. Volume II includes detailed technical summaries of groundwater data and its interpretation, and is intended for internal BNL users, regulators, and other technically oriented stakeholders. A brief summary of the information contained in Volume II is included in Chapter 7, Groundwater Protection, of this volume. Both reports are available in print and as downloadable files on the BNL web page at http://www.bnl.gov/ewms/ser/. An electronic version on compact disc is distributed with each printed report. In addition, a summary of Volume I is prepared each year to provide a general overview of the report, and is distributed with a compact disc containing the full report. BNL is operated and managed for DOE's Office of Science by Brookhaven Science Associates (BSA), a partnership formed by Stony Brook University and Battelle Memorial Institute. For more than 60 years, the Laboratory has played a lead role in the DOE Science and Technology mission and continues to contribute to the DOE missions in energy resources, environmental quality, and national security

  14. Medusae Fossae Formation

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 10 April 2002) The Science This THEMIS visible image was acquired near 7o S, 172o W (188o E) and shows a remarkable martian geologic deposit known as the Medusae Fossae Formation. This Formation, seen here as the raised plateau in the upper two-thirds of the image, is a soft, easily eroded deposit that extends for nearly 1,000 km along the equator of Mars. In this region the deposit has been heavily eroded by the wind to produce a series of linear ridges called yardangs. These parallel ridges point in direction of the prevailing winds that carved them, and demonstrate the power of martian winds to sculpt the dry landscape of Mars. The Medusae Fossae Formation has been completely stripped from the surface in the lower third of the image, revealing a harder layer below that is more resistant to wind erosion. The easily eroded nature of the Medusae Fossae Formation suggests that it is composed of weakly cemented particles, and was most likely formed by the deposition of wind-blown dust or volcanic ash. Several ancient craters that were once completely buried by this deposit are being exposed, or exhumed, as the overlying Medusae Formation is removed. Very few impact craters are visible on this Formation, indicating that the surface seen today is relatively young, and that the processes of erosion are likely to be actively occurring. The Story Medusa of Greek mythology fame, the name-giver to this region, had snaky locks of hair that could turn a person to stone. Wild and unruly, this monster of the underworld could certainly wreak havoc on the world of the human imagination. As scary as she was, Medusa would have no advantage over the fierce, masterful winds blowing across Mars, which once carved the streaky, terrain at the top of this image. Wild and whipping, these winds have slowly eroded away the 'topsoil,' revealing ancient craters and other surface features they once covered. The loosely cemented particles of this 'topsoil' are likely made up of dust

  15. Completion of One Year Bioventing Tests, Site 388, Site 510.8, Site 1705, and Site 40002

    DTIC Science & Technology

    2007-11-02

    The Air Force Center for Environmental Excellence (AFCEE) one-year bioventing test and evaluation projects at your four sites have been completed...results from your sites and 121 other sites currently under operation, bioventing is cost-effectively remediating fuel contamination in a reasonable...Technical Protocol for a Field Treatability Test for Bioventing , May 1992, including Addendum One, February 1994. These are found in the "Tool Box" recently sent to your base.

  16. Site environmental report for 2002.

    SciTech Connect

    Larsen, Barbara L.

    2003-06-01

    Sandia National Laboratories, California (SNL/CA) is a government-owned/contractor-operated laboratory. Sandia Corporation, a Lockheed Martin Company, operates the laboratory for the Department of Energy's (DOE) National Nuclear Security Administration. The DOE, Sandia Site Office oversees operations at the site, using Sandia Corporation as a management and operating contractor. This Site Environmental Report for 2002 was prepared in accordance with DOE Order 231.1. The report provides a summary of environmental monitoring information and compliance activities that occurred at SNL/CA during calendar year 2002. General site and environmental program information is also included.

  17. Early Site Permit Demonstration Program: Siting Guide, Site selection and evaluation criteria for an early site permit application. Revision 1

    SciTech Connect

    Not Available

    1993-03-24

    In August 1991, the Joint Contractors came to agreement with Sandia National Laboratories (SNL) and the Department of Energy (DOE) on a workscope for the cost-shared Early Site Permit Demonstration Program. One task within the scope was the development of a guide for site selection criteria and procedures. A generic Siting Guide his been prepared that is a roadmap and tool for applicants to use developing detailed siting plans for their specific region of the country. The guide presents three fundamental principles that, if used, ensure a high degree of success for an ESP applicant. First, the site selection process should take into consideration environmentally diverse site locations within a given region of interest. Second, the process should contain appropriate opportunities for input from the public. Third, the process should be applied so that it is clearly reasonable to an impartial observer, based on appropriately selected criteria, including criteria which demonstrate that the site can host an advanced light water reactor (ALWR). The Siting Guide provides for a systematic, comprehensive site selection process in which three basic types of criteria (exclusionary, avoidance, and suitability) are presented via a four-step procedure. It provides a check list of the criteria for each one of these steps. Criteria are applied qualitatively, as well as presented numerically, within the guide. The applicant should use the generic guide as an exhaustive checklist, customizing the guide to his individual situation.

  18. Nevada Test Site Environmental Report 2005, Attachment A - Site Description

    SciTech Connect

    Cathy A. Wills

    2006-10-01

    This appendix to the ''Nevada Test Site Environmental Report 2005'', dated October 2006 (DOE/NV/11718--1214; DOE/NV/25946--007) expands on the general description of the Nevada Test Site (NTS) presented in the Introduction. Included are subsections that summarize the site?s geological, hydrological, climatological, and ecological setting. The cultural resources of the NTS are also presented. The subsections are meant to aid the reader in understanding the complex physical and biological environment of the NTS. An adequate knowledge of the site's environment is necessary to assess the environmental impacts of new projects, design and implement environmental monitoring activities for current site operations, and assess the impacts of site operations on the public residing in the vicinity of the NTS. The NTS environment contributes to several key features of the site which afford protection to the inhabitants of adjacent areas from potential exposure to radioactivity or other contaminants resulting from NTS operations. These key features include the general remote location of the NTS, restricted access, extended wind transport times, the great depths to slow-moving groundwater, little or no surface water, and low population density. This appendix complements the annual summary of monitoring program activities and dose assessments presented in the main body of this report.

  19. Site Enforcement Tracking System (SETS): National PRP listing by site

    SciTech Connect

    Not Available

    1992-04-01

    When expending Superfund monies at a CERCLA (Comprehensive Environmental Response, Compensation and Liability Act) site, EPA must conduct a search to identify parties with potential financial responsibility for remediation of uncontrolled hazardous waste sites. EPA regional Superfund Waste Management Staff issue a notice letter to the potentially responsible party (PRP). Data from the notice letter are used to form the Site Enforcement Tracking System (SETS). The data include PRP name and address, a company contact person, the date the notice was issued, and the related CERCLA site name and identification number. SETS was created to track PRP identification at both NPL (National Priorities List) and non-NPL sites. SETS does not address the range of other administrative duties related to tracking the PRP. These lists (updated quarterly) represent EPA's preliminary findings on the identities of potentially responsible parties. The site report is designed to provide PRP information linked by the associated site, which appears according to the state where the site is located.

  20. 1884, 1889 & 1893 Site Maps Brookland Site Development ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1884, 1889 & 1893 Site Maps - Brookland Site Development Study, Brookland, bounded by B&O Railroad Tracks, Rhode Island & Brentwood Avenues on the south, 18th Street & South Dakota Avenue on the east, and Michigan Avenue on the North, Washington, District of Columbia, DC

  1. 1863, 1880 & 1884 Site Maps Brookland Site Development ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1863, 1880 & 1884 Site Maps - Brookland Site Development Study, Brookland, bounded by B&O Railroad Tracks, Rhode Island & Brentwood Avenues on the south, 18th Street & South Dakota Avenue on the east, and Michigan Avenue on the North, Washington, District of Columbia, DC

  2. Thioredoxin binding site of phosphoribulokinase overlaps the catalytic site. [R

    SciTech Connect

    Porter, M.A.; Hartman, F.C.

    1986-01-01

    The ATP-regulatory binding site of phosphoribulokinase was studied using bromoacetylethanolamine phosphate (BrAcNHEtOP). BrAcNHEtOP binds to the active-regulatory binding site of the protein. Following trypsin degradation of the labeled protein, fragments were separated by HPLC and sequenced. (DT)

  3. Site locality identification study: Hanford Site. Volume II. Data cataloging

    SciTech Connect

    Not Available

    1980-07-01

    Data compilation and cataloging for the candidate site locality identification study were conducted in order to provide a retrievable data cataloging system for the present siting study and future site evaluation and licensng processes. This task occurred concurrently with and also independently of other tasks of the candidate site locality identification study. Work in this task provided the data utilized primarily in the development and application of screening and ranking processes to identify candidate site localities on the Hanford Site. The overall approach included two steps: (1) data acquisition and screening; and (2) data compilation and cataloging. Data acquisition and screening formed the basis for preliminary review of data sources with respect to their probable utilization in the candidate site locality identification study and review with respect to the level of completeness and detail of the data. The important working assumption was that the data to be used in the study be based on existing and available published and unpublished literature. The data compilation and cataloging provided the basic product of the Task; a retrievable data cataloging system in the form of an annotated reference list and key word index and an index of compiled data. The annotated reference list and key word index are cross referenced and can be used to trace and retrieve the data sources utilized in the candidate site locality identification study.

  4. 11. VIEW OF A SITE RETURN WEAPONS COMPONENT. SITE RETURNS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. VIEW OF A SITE RETURN WEAPONS COMPONENT. SITE RETURNS WERE NUCLEAR WEAPONS SHIPPED TO THE ROCKY FLATS PLANT FROM THE NUCLEAR WEAPON STOCKPILE FOR RETIREMENT, TESTING, OR UPGRADING. FISSILE MATERIALS (PLUTONIUM, URANIUM, ETC.) AND RARE MATERIALS (BERYLLIUM) WERE RECOVERED FOR REUSE, AND THE REMAINDER WAS DISPOSED. (8/7/62) - Rocky Flats Plant, Plutonium Fabrication, Central section of Plant, Golden, Jefferson County, CO

  5. Site Plan, Brief History, Site Elevation, Main Gate Detail, Southern ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Site Plan, Brief History, Site Elevation, Main Gate Detail, Southern Live Oak (Quercus Virginiana) Information - Main Gate and Auburn Oaks at Toomer's Corner, Entrance to Auburn University's Campus, Intersection of West Magnolia Avenue and South College Street, Auburn, Lee County, AL

  6. Structural determinants for the formation of sulfhemeprotein complexes

    PubMed Central

    Román-Morales, Elddie; Pietri, Ruth; Ramos-Santana, Brenda; Vinogradov, Serge N.; Lewis-Ballester, Ariel; López-Garriga, Juan

    2010-01-01

    Several hemoglobins were explored by UV-Vis and resonance Raman spectroscopy to define sulfheme complex formation. Evaluation of these proteins upon the reaction with H2O2 or O2 in the presence of H2S suggest: (a) the formation of the sulfheme derivate requires a HisE7 residue in the heme distal site with an adequate orientation to form an active ternary complex; (b) that the ternary complex intermediate involves the HisE7, the peroxo or ferryl species, and the H2S molecule. This moiety precedes and triggers the sulfheme formation. PMID:20732304

  7. Cosmological structure formation

    NASA Technical Reports Server (NTRS)

    Schramm, David N.

    1991-01-01

    A summary of the current forefront problem of physical cosmology, the formation of structures (galaxies, clusters, great walls, etc.) in the universe is presented. Solutions require two key ingredients: (1) matter; and (2) seeds. Regarding the matter, it now seems clear that both baryonic and non-baryonic matter are required. Whether the non-baryonic matter is hot or cold depends on the choice of seeds. Regarding the seeds, both density fluctuations and topological defects are discussed. The combination of isotropy of the microwave background and the recent observations indicating more power on large scales have severly constrained, if not eliminated, Gaussian fluctuations with equal power on all scales, regardless of the eventual resolution of both the matter and seed questions. It is important to note that all current structure formation ideas require new physics beyond SU(3) x SU(2) x U(1).

  8. Cosmic structure formation

    NASA Technical Reports Server (NTRS)

    Bertschinger, Edumund

    1994-01-01

    This article reviews the prevailing paradigm for how galaxies and larger structures formed in the universe: gravitational instability. Basic observational facts are summarized to motivate the standard cosmological framework underlying most detailed investigations of structure formation. The observed univers approaches spatial uniformity on scales larger than about 10(exp 26) cm. On these scales gravitational dynamics is almost linear and therefore relatively easy to relate to observations of large-scale structure. On smaller scales cosmic structure is complicated not only by nonlinear gravitational clustering but also by nonlinear nongravitational gas dynamical processes. The complexity of these phenomena makes galaxy formation one of the grand challenge problems of the physical sciences. No fully satisfactory theory can presently account in detail for the observed cosmic structure. However, as this article summarizes, significant progress has been made during the last few years.

  9. Formation of bacterial nanocells

    NASA Astrophysics Data System (ADS)

    Vainshtein, Mikhail; Kudryashova, Ekaterina; Suzina, Natalia; Ariskina, Elena; Voronkov, Vadim

    1998-07-01

    Existence of nanobacteria received increasing attention both in environmental microbiology/geomicro-biology and in medical microbiology. In order to study a production of nanoforms by typical bacterial cells. Effects of different physical factors were investigated. Treatment of bacterial cultures with microwave radiation, or culturing in field of electric current resulted in formation a few types of nanocells. The number and type of nanoforms were determined with type and dose of the treatment. The produced nanoforms were: i) globules, ii) clusters of the globules--probably produced by liaison, iii) nanocells coated with membrane. The viability of the globules is an object opened for doubts. The nanocells discovered multiplication and growth on solidified nutrient media. The authors suggest that formation of nanocells is a common response of bacteria to stress-actions produced by different agents.

  10. Prominence Formation Processes

    NASA Astrophysics Data System (ADS)

    Welsch, B. T.; DeVore, C. R.; Antiochos, S. K.

    2005-01-01

    Martens and Zwaan (ApJ v. 558 872) have proposed a prominence/ filament formation model in which differential rotation drives reconnection between two initially unconnected active regions to form helical field lines that support mass and are held down by overlying field. Using an MHD solver with adaptive refinement we simulated this process by imposing a shear flow meant to mimic differential rotation on two bipolar flux distributions meant to mimic distinct active regions. In some runs the flux systems are initially potential while in others they have been twisted by footpoint rotation to inject helicity prior to imposing the shear flow. The resulting structures are studied to understand the role of helicity in the formation of prominence-like structures.

  11. Format-Preserving Encryption

    NASA Astrophysics Data System (ADS)

    Bellare, Mihir; Ristenpart, Thomas; Rogaway, Phillip; Stegers, Till

    Format-preserving encryption (FPE) encrypts a plaintext of some specified format into a ciphertext of identical format—for example, encrypting a valid credit-card number into a valid credit-card number. The problem has been known for some time, but it has lacked a fully general and rigorous treatment. We provide one, starting off by formally defining FPE and security goals for it. We investigate the natural approach for achieving FPE on complex domains, the “rank-then-encipher” approach, and explore what it can and cannot do. We describe two flavors of unbalanced Feistel networks that can be used for achieving FPE, and we prove new security results for each. We revisit the cycle-walking approach for enciphering on a non-sparse subset of an encipherable domain, showing that the timing information that may be divulged by cycle walking is not a damaging thing to leak.

  12. Dust Formation and Destruction

    NASA Astrophysics Data System (ADS)

    Wiebe, Dmitry

    Recent infrared and sub-millimeter observations have opened up a new window in dust evolution studies. High angular resolution of Spitzer and Herschel space telescopes from near to far-infrared wavelengths allows observing dust emission in galactic and extragalactic star-forming complexes, covering a broad range of metallicities, radiation field properties, etc. A wide-scale picture of dust evolution starts to arise from these observations. In my contribution I will try to cover major recent advances in studies of dust formation and destruction, including such topics as a diverse role of supernovae in dust evolution, possibility of dust formation and/or growth in molecular clouds, and VSG and PAH evolution in HII regions and complexes.

  13. Tetrahedron Formation Control

    NASA Technical Reports Server (NTRS)

    Petruzzo, Charles; Guzman, Jose

    2004-01-01

    This paper considers the preliminary development of a general optimization procedure for tetrahedron formation control. The maneuvers are assumed to be impulsive and a multi-stage optimization method is employed. The stages include (1) targeting to a fixed tetrahedron location and orientation, and (2) rotating and translating the tetrahedron. The number of impulsive maneuvers can also be varied. As the impulse locations and times change, new arcs are computed using a differential corrections scheme that varies the impulse magnitudes and directions. The result is a continuous trajectory with velocity discontinuities. The velocity discontinuities are then used to formulate the cost function. Direct optimization techniques are employed. The procedure is applied to the NASA Goddard Magnetospheric Multi-Scale (MMS) mission to compute preliminary formation control fuel requirements.

  14. Site Cleanup Report for Sites PBF-33 and PBF-34

    SciTech Connect

    W. L. Jolley

    2007-01-16

    This document summaries the actions taken to remove asbestos-reinforced-concrete (transite) pipe and miscellaneous debris from Power Purst Facility (PBF)-33 and PBF-34 sites. Removal of pipe and debris were performed in November 2006 in accordance with the requirements discussed in notice of soil disturbance NSD-PBF-07-01. Debris at these two sites were classified as industrial waste that could be disposed at the Central Facilities Area (CFA) landfill at the Idaho National Laboratory. Asbestos removal was performed as Class IV asbestos cleanup work. All transite pipe was double bagged and dispositioned in the INL Landfill Complex at CFA. The remaining miscellaneous debris was loaded into dump trucks and taken to the INL Landfill Complex at CFA for final disposition. Cleanup actions are complete for both sites, and no debris or hazardous constituents remain. Therefore, both sites will be classified as No action sites.

  15. Formate-assisted pyrolysis

    DOEpatents

    DeSisto, William Joseph; Wheeler, Marshall Clayton; van Heiningen, Adriaan R. P.

    2015-03-17

    The present invention provides, among other thing, methods for creating significantly deoxygenated bio-oils form biomass including the steps of providing a feedstock, associating the feedstock with an alkali formate to form a treated feedstock, dewatering the treated feedstock, heating the dewatered treated feedstock to form a vapor product, and condensing the vapor product to form a pyrolysis oil, wherein the pyrolysis oil contains less than 30% oxygen by weight.

  16. Formation of Transient Lamellipodia

    PubMed Central

    Zimmermann, Juliane; Falcke, Martin

    2014-01-01

    Cell motility driven by actin polymerization is pivotal to the development and survival of organisms and individual cells. Motile cells plated on flat substrates form membrane protrusions called lamellipodia. The protrusions repeatedly appear and retract in all directions. If a lamellipodium is stabilized and lasts for some time, it can take over the lead and determine the direction of cell motion. Protrusions traveling along the cell perimeter have also been observed. Their initiation is in some situations the effect of the dynamics of the pathway linking plasma membrane receptors to actin filament nucleation, e.g. in chemotaxis. However, lamellipodia are also formed in many cells incessantly during motion with a constant state of the signaling pathways upstream from nucleation promoting factors (NPFs), or spontaneously in resting cells. These observations strongly suggest protrusion formation can also be a consequence of the dynamics downstream from NPFs, with signaling setting the dynamic regime but not initiating the formation of individual protrusions. A quantitative mechanism for this kind of lamellipodium dynamics has not been suggested yet. Here, we present a model exhibiting excitable actin network dynamics. Individual lamellipodia form due to random supercritical filament nucleation events amplified by autocatalytic branching. They last for about 30 seconds to many minutes and are terminated by filament bundling, severing and capping. We show the relevance of the model mechanism for experimentally observed protrusion dynamics by reproducing in very good approximation the repetitive protrusion formation measured by Burnette et al. with respect to the velocities of leading edge protrusion and retrograde flow, oscillation amplitudes, periods and shape, as well as the phase relation between protrusion and retrograde flow. Our modeling results agree with the mechanism of actin bundle formation during lamellipodium retraction suggested by Burnette et al. and

  17. A design method for an intuitive web site

    SciTech Connect

    Quinniey, M.L.; Diegert, K.V.; Baca, B.G.; Forsythe, J.C.; Grose, E.

    1999-11-03

    The paper describes a methodology for designing a web site for human factor engineers that is applicable for designing a web site for a group of people. Many web pages on the World Wide Web are not organized in a format that allows a user to efficiently find information. Often the information and hypertext links on web pages are not organized into intuitive groups. Intuition implies that a person is able to use their knowledge of a paradigm to solve a problem. Intuitive groups are categories that allow web page users to find information by using their intuition or mental models of categories. In order to improve the human factors engineers efficiency for finding information on the World Wide Web, research was performed to develop a web site that serves as a tool for finding information effectively. The paper describes a methodology for designing a web site for a group of people who perform similar task in an organization.

  18. Catalysts of DNA Strand Cleavage at Apurinic/Apyrimidinic Sites

    PubMed Central

    Minko, Irina G.; Jacobs, Aaron C.; de Leon, Arnie R.; Gruppi, Francesca; Donley, Nathan; Harris, Thomas M.; Rizzo, Carmelo J.; McCullough, Amanda K.; Lloyd, R. Stephen

    2016-01-01

    Apurinic/apyrimidinic (AP) sites are constantly formed in cellular DNA due to instability of the glycosidic bond, particularly at purines and various oxidized, alkylated, or otherwise damaged nucleobases. AP sites are also generated by DNA glycosylases that initiate DNA base excision repair. These lesions represent a significant block to DNA replication and are extremely mutagenic. Some DNA glycosylases possess AP lyase activities that nick the DNA strand at the deoxyribose moiety via a β- or β,δ-elimination reaction. Various amines can incise AP sites via a similar mechanism, but this non-enzymatic cleavage typically requires high reagent concentrations. Herein, we describe a new class of small molecules that function at low micromolar concentrations as both β- and β,δ-elimination catalysts at AP sites. Structure-activity relationships have established several characteristics that appear to be necessary for the formation of an iminium ion intermediate that self-catalyzes the elimination at the deoxyribose ring. PMID:27363485

  19. Quasar induced galaxy formation: a new paradigm?

    NASA Astrophysics Data System (ADS)

    Elbaz, D.; Jahnke, K.; Pantin, E.; Le Borgne, D.; Letawe, G.

    2009-12-01

    Aims: We discuss observational evidence that quasars play a key role in the formation of galaxies, starting from the detailed study of the quasar HE0450-2958 and extending the discussion to a series of converging evidence that radio jets may trigger galaxy formation. Methods: We use mid infrared imaging with VISIR at the ESO-VLT to model the mid to far infrared energy distribution of the system and the stellar population of the companion galaxy using optical VLT-FORS spectroscopy. The results are combined with optical, CO, radio continuum imaging from ancillary data. Results: The direct detection with VISIR of the 7 kpc distant companion galaxy of HE0450-2958 allows us to spatially separate the sites of quasar and star formation activity in this composite system made of two ultra-luminous infrared galaxies (ULIRGs), where the quasar generates the bulk of the mid infrared light and the companion galaxy powered by star formation dominates in the far infrared. No host galaxy has yet been detected for this quasar, but the companion galaxy stellar mass would bring HE0450-2958 in the local M{BH} - Mstar^bulge relation if it were to merge with the QSO. This is bound to happen because of their close distance (7 kpc) and low relative velocity ( 60-200 km s-1). We conclude that we may be witnessing the building of the M{BH} - Mstar^bulge relation, or at least of a major event in that process. The star formation rate ( 340 M⊙ yr-1), age (40-200 Myr) and stellar mass ( [5-6]×1010 M⊙) are consistent with jet-induced formation of the companion galaxy. We suggest that HE0450-2958 may be fueled by fresh material from cold gas accretion from intergalactic filaments. We map the projected galaxy density surrounding the QSO as a potential tracer of intergalactic filaments and discuss a putative detection. Comparison to other systems suggest that an inside-out formation of quasar host galaxies and jet-induced galaxy formation may be a common process. Two tests are proposed for

  20. Terrestrial planet formation

    PubMed Central

    Righter, K.; O’Brien, D. P.

    2011-01-01

    Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (∼106 y), followed by planetesimals to embryos (lunar to Mars-sized objects; few × 106 y), and finally embryos to planets (107–108 y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids. PMID:21709256

  1. Tetrahedron Formation Control

    NASA Technical Reports Server (NTRS)

    Guzman, Jose J.

    2003-01-01

    Spacecraft flying in tetrahedron formations are excellent instrument platforms for electromagnetic and plasma studies. A minimum of four spacecraft - to establish a volume - is required to study some of the key regions of a planetary magnetic field. The usefulness of the measurements recorded is strongly affected by the tetrahedron orbital evolution. This paper considers the preliminary development of a general optimization procedure for tetrahedron formation control. The maneuvers are assumed to be impulsive and a multi-stage optimization method is employed. The stages include targeting to a fixed tetrahedron orientation, rotating and translating the tetrahedron and/or varying the initial and final times. The number of impulsive maneuvers citn also be varied. As the impulse locations and times change, new arcs are computed using a differential corrections scheme that varies the impulse magnitudes and directions. The result is a continuous trajectory with velocity discontinuities. The velocity discontinuities are then used to formulate the cost function. Direct optimization techniques are employed. The procedure is applied to the Magnetospheric Multiscale Mission (MMS) to compute preliminary formation control fuel requirements.

  2. Primordial Planet Formation

    NASA Astrophysics Data System (ADS)

    Schild, Rudolph E.; Gibson, Carl H.

    Recent spacecraft observations exploring solar system properties impact standard paradigms of the formation of stars, planets and comets. We stress the unexpected cloud of microscopic dust resulting from the DEEP IMPACT mission, and the existence of molten nodules in STARDUST samples. And the theory of star formation does not explain the common occurrence of binary and multiple star systems in the standard gas fragmentation scenario. No current theory of planet formation can explain the iron core of the earth, under oceans of water. These difficulties are avoided in a scenario where the planet mass objects form primordially and are today the baryonic dark matter. They have been detected in quasar microlensing and anomalous quasar radio brightening bursts. The primordial planets often concentrate together to form a star, with residual matter seen in pre-stellar accretion discs around the youngest stars. These primordial planet mass bodies were formed of hydrogen-helium, aggregated in dense clumps of a trillion at the time of plasma neutralization 380,000 years after the big bang. Most have been frozen and invisible, but are now manifesting themselves in numerous ways as sensitive modern space telescopes become operational. Their key detection signature is their thermal emission spectrum, pegged at the 13.8 degrees Kelvin triple point of hydrogen, the baryonic dark matter (Staplefeldt et al. 1999).

  3. Stabilizing clayey formations

    SciTech Connect

    Lipowski, S. A.; Miskel Jr., J. J.; Schick, M. J.

    1985-03-19

    Process for treating a clayey geological formation to prevent, inhibit or reduce swelling or migrating of clay particles in a formation by treating the formation with an effective amount of a quaternized oligomer which is the reaction product of a polyamine having a primary amino group and a tertiary amino group with a difunctional reactant to form a precondensate monomer which is then chain extended and quaternized by reaction with a dihalogenated hydrocarbon ether. A preferred oligomer is a product of: (I) about 1.0 mole of a precondensate which is the reaction product of (A) from about 2.0 to about 3.0 mole of a polyamine having a primary amino group and a tertiary amino group, the polyamine having a non-cyclic backbone containing between 1 and 6 carbon atoms, with (B) about 1.0 mole of a difunctional reactant which is a diester of a mixture of dicarboxylic acids such as adipic, glutaric and succinic acid, with (II) from about 1.0 to about 1.2 mole of a chain extender such as dichloroethylether. Process is useful in oil producing operations.

  4. Mars brine formation experiment

    NASA Technical Reports Server (NTRS)

    Moore, Jeffrey M.; Bullock, Mark A.; Stoker, Carol R.

    1992-01-01

    Evaporites, particularly carbonates, nitrates, and sulfates, may be major sinks of volatiles scavenged from the martian atmosphere. Mars is thought to have once had a denser, warmer atmosphere that permitted the presence of liquid surface water. The conversion of atmospheric CO2 into carbonate is hypothesized to have degraded the martian climate to its present state of a generally subfreezing, desiccated desert. The rate for such a conversion under martian conditions is poorly known, so the time scale of climate degradation by this process cannot be easily evaluated. If some models are correct, carbonate formation may have been fast at geological time scales. The experiments of Booth and Kieffer also imply fast (10(exp 6) - 10(exp 7) yr) removal of the missing CO2 inventory, estimated to be 1 - 5 bar, by means of carbonate formation. The timing of formation of many of the fluvial features observed on Mars is, in large part, dependent on when and how fast the atmosphere changed. A knowledge of the rate at which carbonates and nitrates formed is also essential for assessing the probability that life, or its chemical precursors, could have developed on Mars. No previous experiments have quantitatively evaluated the rate of solution for a suite of mobile anions and cations from unaltered minerals and atmospheric gases into liquid water under Mars-like conditions. Such experiments are the focus of this task.

  5. [The formative causation].

    PubMed

    Bonilla, Ernesto

    2012-12-01

    The hypothesis of formative causation proposed by Rupert Sheldrake in 1981, affirms that morphogenetic fields play a causal role in the development and maintenance of the forms of systems at all levels of complexity and that nature is governed by habits. All animals and plants draw upon and contribute to the collective memory of their species. The author suggested that memory is inherent in nature and it is transmitted by a process called morphic resonance and works through fields called morphic fields. The hypothesis of formative causation accounts for the repetition of forms but does not explain how the first example of any given form originally came into being. Despite the advances in molecular biology, morphogenesis continues to elude a molecular explanation and seems to depend on morphogenetic fields. The hypothesis of formative causation interprets many physical and biological phenomena in a way radically different than those proposed by existing theories. According to this hypothesis the conscious self can be thought of as interacting with morphic fields in order to be connected with the external environment and with the state of the body in consciously controlled activity.

  6. Terrestrial planet formation.

    PubMed

    Righter, K; O'Brien, D P

    2011-11-29

    Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (~10(6) y), followed by planetesimals to embryos (lunar to Mars-sized objects; few 10(6) y), and finally embryos to planets (10(7)-10(8) y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids.

  7. Histopathology Predicts the Mechanism of Stone Formation

    NASA Astrophysics Data System (ADS)

    Evan, Andrew P.

    2007-04-01

    About 5% of American women and 12% of men will develop a kidney stone at some time in their life and these numbers appear to be on the rise. Despite years of scientific research into the mechanisms of stone formation and growth, limited advances have been made until recently. Randall's original observations and thoughts on the mechanisms for kidney stone formation have been validated for idiopathic calcium oxalate stone formers (ICSF) but not for most other stone forming groups. Our current studies on selected groups of human stone formers using intraoperative papillary biopsies has shown overwhelming evidence for the presence of Randall's plaque in ICSF and that stone formation and growth are exclusively linked to its availability to urinary ions and proteins. Intense investigation of the plaque-stone junction is needed if we are to understand the factors leading to the overgrowth process on exposed regions of plaque. Such information should allow the development of treatment strategies to block stone formation in ICSF patients. Patients who form brushite stones, or who form apatite stones because of distal renal tubular acidosis (dRTA), or patients with calcium oxalate stones due to obesity bypass procedures, or patients with cystinuria, get plugged inner medullary collecting ducts (IMCD) which leads to total destruction of the lining cells and focal sites of interstitial fibrosis. These stone formers have plaque but at levels equal to or below non-stone formers, which would suggest that they form stones by a different mechanism than do ICSF patients.

  8. Effect of spaceflight on periosteal bone formation in rats

    NASA Technical Reports Server (NTRS)

    Wronski, T. J.; Morey, E. R.

    1983-01-01

    Male Wistar rats were placed in orbit for 18.5 days aboard the Soviet COSMOS 1129 biological satellite. Tetracycline was administered before and after spaceflight to label areas of bone formation. An inhibition of periosteal bone formation occurred during spaceflight in the tibial and humeral diaphyses, but this defect was corrected during the postflight period. The increased extent of arrest lines at these skeletal sites suggested that periosteal bone formation may have even ceased during spaceflight. The rib exhibited a small but nonsignificant decrease in periosteal bone formation. Endosteal bone resorption was not affected markedly by spaceflight conditions. The observed inhibition of periosteal bone formation may be a result of mechanical unloading, but endocrine factors cannot be ruled out.

  9. Intraosseous Infusion Rates under High Pressure: A Cadaveric Comparison of Anatomic Sites

    DTIC Science & Technology

    2014-01-01

    myeloproliferative malignancy, fracture of targeted bone, previous orthopedic procedures near insertion site, recent IO placement, prosthetic limb or...not evaluate the sternal IO access site. Complications from IO placement have been documented to include iatrogenic bone fracture , osteomyelitis...compartment syndrome, growth plate disruption, hematoma formation, fat embolization, and tissue necrosis [34-37]. These complications can not only be

  10. Privacy and Social Networking Sites

    ERIC Educational Resources Information Center

    Timm, Dianne M.; Duven, Carolyn J.

    2008-01-01

    College students are relying on the Internet to make connections with other people every day. As the Internet has developed and grown, so have the capabilities for interaction. Social networking sites, a group of Web sites that provide people with the opportunity to create an online profile and to share that profile with others, are a part of…

  11. Site Environmental Report summary, 1993

    SciTech Connect

    Not Available

    1994-06-01

    This report describes the Fernald site mission, exposure pathways, and environmental standards and guidelines. Environmental monitoring activities measure and estimate the amount of radioactive and nonradioactive materials that may leave the site and enter the surrounding environment. This presents an overall view of the impact these activities have on the local environment and public health.

  12. Educational Leadership. [SITE 2002 Section].

    ERIC Educational Resources Information Center

    2002

    This document contains the following papers on educational leadership from the SITE (Society for Information Technology & Teacher Education) 2002 conference: (1) "Personality Assessment of Educational Leaders via Technology" (Pamela T. Barber Freeman and Michael L. McFrazier); (2) "Contributions and Concerns of SITE Participants: A Survey of…

  13. SITE: INNOVATION ON THE MOVE

    EPA Science Inventory

    A recent review of the SITE Program indicated that operational shifts are necessary to maintain the program's position as a progressive, "state-of-the-art" leader in the environmental field. The SITE Program will shift from a technology-driven focus to a more integrated approach ...

  14. Hanford Site technical baseline database

    SciTech Connect

    Porter, P.E., Westinghouse Hanford

    1996-05-10

    This document includes a cassette tape that contains the Hanford specific files that make up the Hanford Site Technical Baseline Database as of May 10, 1996. The cassette tape also includes the delta files that delineate the differences between this revision and revision 3 (April 10, 1996) of the Hanford Site Technical Baseline Database.

  15. Hanford site sodium management plan

    SciTech Connect

    Guttenberg, S.

    1995-09-25

    The Hanford Site Sodium Management Plan, Revision 1, provides changes to the major elements and management strategy to ensure an integrated and coordinated approach for disposition of the more than 350,000 gallons of sodium and related sodium facilities located at the DOE`s Hanford Site

  16. Criteria for School Site Selection.

    ERIC Educational Resources Information Center

    Stanford Univ., CA.

    An outline of the factors and conditions affecting the desirability of a specific building site. The primary factor headings are--(1) availability, (2) location, (3) environment, (4) accessibility, (5) size, (6) shape, (7) topography, (8) acquisition, (9) cost of land, (10) soil condition, (11) sub-surface condition, (12) site preparation, (13)…

  17. Site Environmental Report for 2013

    SciTech Connect

    Pauer, Ron; Baskin, David; Borglin, Ned; Fox, Robert; Harvey, Zachary; Jelinski, John; Thorson, Patrick; Wahl, Linnea; Wehle, Petra; Xu, Suying

    2014-09-01

    This report, prepared by LBNL for the U.S. Department of Energy, Berkeley Site Office provides a comprehensive summary of the environmental program activities at LBNL for calendar year 2013 SERS are prepared annually for all DOE sites with significant environmental activities, and distributed to relevant external regulatory agencies and other interested organizations or individual.

  18. Site environmental report for 1996

    SciTech Connect

    Holland, R.C.

    1997-08-01

    To help verify effective protection of public safety and preservation of the environment, Sandia National Laboratories (SNL)/California maintains an extensive, ongoing environmental monitoring program. This program monitors all significant airborne and liquid effluents and the environment at the SNL/California site perimeter. Lawrence Livermore National Laboratory (LLNL) performs off-site environmental monitoring for both sites. These monitoring efforts ensure that emission controls are effective in preventing contamination of the environment. As part of SNL/California`s Environmental Monitoring Program, an environmental surveillance system measures the possible presence of radioactive and hazardous materials in ambient air, surface water, groundwater, sewage, soil, vegetation, and locally produced food-stuffs. The program also includes an extensive environmental dosimetry program, which measures external radiation levels around the Livermore site and nearby vicinity. Each year, the results of the Environmental Monitoring Program are published in this report, the Site Environmental Report. This executive summary focuses on impacts to the environment and estimated radiation doses to the public from site emissions. Chapter 3, {open_quotes}Compliance Summary,{close_quotes} reviews the site`s various environmental protection activities and compliance status, with applicable environmental regulations. The effluent monitoring and environmental surveillance results for 1996 show that SNL/California operations had no harmful effects on the environment or the public. 37 figs., 12 tabs.

  19. JPL's parabolic dish test site

    NASA Technical Reports Server (NTRS)

    Hagen, T. L.

    1980-01-01

    A parabolic dish test site (PDTS) was established in the California Mojave Desert to carry out work in testing solar point focusing concentrator systems and related hardware. The site was chosen because of its high solar insolation level and year around clear sky conditions. The various facilities and equipment at the PDTS, and the concentrator experiments being performed are described.

  20. Nevada Test Site Environmental Report 2007 Attachment A: Site Description

    SciTech Connect

    Cathy Wills

    2008-09-01

    This appendix expands on the general description of the Nevada Test Site (NTS) presented in the Introduction to the Nevada Test Site Environmental Report 2007 (U.S. Department of Energy [DOE], 2008). Included are subsections that summarize the site's geological, hydrological, climatological, and ecological setting. The cultural resources of the NTS are also presented. The subsections are meant to aid the reader in understanding the complex physical and biological environment of the NTS. An adequate knowledge of the site's environment is necessary to assess the environmental impacts of new projects, design and implement environmental monitoring activities for current site operations, and assess the impacts of site operations on the public residing in the vicinity of the NTS. The NTS environment contributes to several key features of the site which afford protection to the inhabitants of adjacent areas from potential exposure to radioactivity or other contaminants resulting from NTS operations. These key features include the general remote location of the NTS, restricted access, extended wind transport times, the great depths to slow-moving groundwater, little or no surface water, and low population density. This attachment complements the annual summary of monitoring program activities and dose assessments presented in the main body of this report.